http://www.mdpi.com/section/material_sciences http://www.mdpi.com/1422-0067/11/3/1103/ Dye sensitized solar cell (DSSC) is the only solar cell that can offer both the flexibility and transparency. Its efficiency is comparable to amorphous silicon solar cells but with a much lower cost. This review not only covers the fundamentals of DSSC but also the related cutting-edge research and its development for industrial applications. Most recent research topics on DSSC, for example, applications of nanostructured TiO2, ZnO electrodes, ionic liquid electrolytes, carbon nanotubes, graphene and solid state DSSC have all been included and discussed. http://www.mdpi.com/1422-0067/11/3/1103/ Tue, 16 Mar 2010 00:00:00 CET International Journal of Molecular Sciences 2010-03-16 11 3 Review 1103 1113 1422-0067 Dye Sensitized Solar Cells 2010-03-16 doi: 10.3390/ijms11031103 Wei http://www.mdpi.com/1422-0067/11/3/1070/ Advances in stem cell research have provided important understanding of the cell biology and offered great promise for developing new strategies for tissue regeneration. The beneficial effects of stem cell therapy depend also by the development of new approachs for the track of stem cells in living subjects over time after transplantation. Recent developments in the use of nanotechnologies have contributed to advance of the high-resolution in vivo imaging methods, including positron emission tomography (PET), single-photon emission tomography (SPECT), magnetic resonance (MR) imaging, and X-Ray computed microtomography (microCT). This review examines the use of nanotechnologies for stem cell tracking. http://www.mdpi.com/1422-0067/11/3/1070/ Fri, 12 Mar 2010 00:00:00 CET International Journal of Molecular Sciences 2010-03-12 11 3 Review 1070 1081 1422-0067 Stem Cell Tracking by Nanotechnologies 2010-03-12 doi: 10.3390/ijms11031070 Villa Erratico Razini Fiori Rustichelli Torrente Belicchi http://www.mdpi.com/1422-0067/11/3/967/ Magnetic nanoparticles (MNPs) are important contrast agents used to monitor a range of neuropathological processes; microglial cells significantly contribute to MNP uptake in sites of pathology. Microglial activation occurs following most CNS pathologies but it is not known if such activation alters MNP uptake, intracellular processing and toxicity. We assessed these parameters in microglial cultures with and without experimental ‘activation’. Microglia showed rapid and extensive MNP uptake under basal conditions with no changes found following activation; significant microglial toxicity was observed at higher particle concentrations. Based on our findings, we suggest that avid MNP uptake by endogenous CNS microglia could significantly limit uptake by other cellular subtypes in mixed neural cell populations. http://www.mdpi.com/1422-0067/11/3/967/ Mon, 08 Mar 2010 00:00:00 CET International Journal of Molecular Sciences 2010-03-08 11 3 Communication 967 981 1422-0067 Robust Uptake of Magnetic Nanoparticles (MNPs) by Central Nervous System (CNS) Microglia: Implications for Particle Uptake in Mixed Neural Cell Populations 2010-03-08 doi: 10.3390/ijms11030967 Mark R. Pickard Divya M. Chari http://www.mdpi.com/1422-0067/11/3/943/ The stacking of discotic molecules (hexakis(alkoxy)diquinoxalino[2,3-a:2’,3’-c]phenazines) in the columnar phase sandwiched between two flat glass substrates has been studied. The surface free energy of the substrates, measured by means of sessile drop technique, is found to have significant influence on the way that the discotic molecules anchor on the surface, and a steady thermal state of the system is crucial for a homogenous orientation of the discotic columns. On a surface of high free energy, the discotic molecules anchor with their disc-face toward the surface. A decrease in the surface free energy of the substrate causes the discotic columns to tilt away from the normal of the substrate. http://www.mdpi.com/1422-0067/11/3/943/ Mon, 08 Mar 2010 00:00:00 CET International Journal of Molecular Sciences 2010-03-08 11 3 Article 943 955 1422-0067 Orientational Packing of a Confined Discotic Mesogen in the Columnar Phase 2010-03-08 doi: 10.3390/ijms11030943 Wenjun Zheng Ya-Ting Hu Cheng-Yan Chiang Chi Wi Ong http://www.mdpi.com/1422-0067/11/3/789/ Interleukin 12 (termed IL-12p70 and commonly designated IL-12) is an important immunoregulatory cytokine that is produced mainly by antigen-presenting cells. The expression of IL-12 during infection regulates innate responses and determines the type of adaptive immune responses. IL-12 induces interferon-γ (IFN-γ) production and triggers CD4+ T cells to differentiate into type 1 T helper (Th1) cells. Studies have suggested that IL-12 could play a vital role in treating many diseases, such as viral and bacterial infections and cancers. The unique heterodimeric structure, which IL-12 shares with its family members including IL-23, IL-27, and IL-35, has recently brought more attention to understanding the mechanisms that regulate the functions of IL-12. This article describes the structure and biological activities of IL-12 in both the innate and adaptive arms of the immune system, and discusses the applications of IL-12 in treating and preventing infections. http://www.mdpi.com/1422-0067/11/3/789/ Fri, 26 Feb 2010 00:00:00 CET International Journal of Molecular Sciences 2010-02-26 11 3 Review 789 806 1422-0067 Interleukin 12 a Key Immunoregulatory Cytokine in Infection Applications 2010-02-26 doi: 10.3390/ijms11030789 Therwa Hamza John B. Barnett Bingyun Li http://www.mdpi.com/1422-0067/11/2/704/ If we could realize an autonomous polymer system driven under biological conditions by a tailor-made molecular design, human beings could create unprecedented biomimetic functions and materials such as heartbeats, autonomous peristaltic pumps, etc. In order to achieve this objective, we have investigated the molecular design of such a polymer system. As a result, we were the first to demonstrate a self-oscillating polymer system driven in a solution where only malonic acid existed, which could convert the chemical energy of the Belousov-Zhabotinsky (BZ) reaction into a change in the conformation of the polymer chain. To cause the self-oscillation in solution, we have attempted to construct a built-in system where the required BZ system substrates other than the organic acid are incorporated into the polymer itself. That is, the novel polymer chain incorporated the metal catalyst of the BZ reaction, a pH-control site and an oxidant supply site at the same time. As a result of introducing the pH control and oxidant supply sites into the conventional-type self-oscillating polymer chain, the novel polymer chain caused aggregation-disaggregation self-oscillations in the solution. We clarified that the period of the self-oscillation of the novel self-oscillating polymer chain was proportional to the concentration of the malonic acid. Therefore, the concentration of the malonic acid can be determined by measuring the period of the novel self-oscillating polymer solution. In this review, we introduce the detailed molecular design of the novel self-oscillating polymer chain and its self-oscillating behavior. Moreover, we report an autonomous self-oscillating polymer gel actuator that causes a bending-stretching motion under the constant conditions. http://www.mdpi.com/1422-0067/11/2/704/ Wed, 10 Feb 2010 00:00:00 CET International Journal of Molecular Sciences 2010-02-10 11 2 Review 704 718 1422-0067 Molecular Design and Functional Control of Novel Self-Oscillating Polymers 2010-02-10 doi: 10.3390/ijms11020704 Yusuke Hara Shingo Maeda Shuji Hashimoto Ryo Yoshida http://www.mdpi.com/1422-0067/11/2/532/ The amorphous polymer film swelling in a liquid solvent below the glass transition temperature was characterized by a few kinetic parameters (especially the mutual diffusion coefficient of swelling and its mean value) obtained by interference of monochromatic light in the wedge arrangement. This interferometric method allows one to determine the concentration field in the swollen surface layer and consequently to compute the concentration-dependent diffusion coefficient. A software system developed at the Department of Physics and Material Engineering at TBU in Zlin has been used for the evaluation of the main kinetic parameters of the swelling process. The software can be used for the on-line analyses of interferograms during the swelling process. The main application outputs are the computation of the concentration profile, the concentration gradient, the mutual diffusion coefficient of the swelling by the solvent and its mean value. http://www.mdpi.com/1422-0067/11/2/532/ Wed, 03 Feb 2010 00:00:00 CET International Journal of Molecular Sciences 2010-02-03 11 2 Article 532 543 1422-0067 The Measurement of Polymer Swelling Processes by an Interferometric Method and Evaluation of Diffusion Coefficients 2010-02-03 doi: 10.3390/ijms11020532 Aleš Mráček http://www.mdpi.com/1422-0067/11/1/354/ Bone adaptation or integration of an implant is characterized by a series of biological reactions that start with bone turnover at the interface (a process of localized necrosis), followed by rapid repair. The wound healing response is guided by a complex activation of macrophages leading to tissue turnover and new osteoblast differentiation on the implant surface. The complex role of implant surface topography and impact on healing response plays a role in biological criteria that can guide the design and development of future tissue-implant surface interfaces. http://www.mdpi.com/1422-0067/11/1/354/ Mon, 25 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-25 11 1 Review 354 369 1422-0067 Surface Modification of Biomedical and Dental Implants and the Processes of Inflammation, Wound Healing and Bone Formation 2010-01-25 doi: 10.3390/ijms11010354 Clark M. Stanford http://www.mdpi.com/1422-0067/11/1/329/ New organic dyes comprising carbazole, iminodibenzyl, or phenothiazine moieties, respectively, as the electron donors, and cyanoacetic acid or acrylic acid moieties as the electron acceptors/anchoring groups were synthesized and characterized. The influence of heteroatoms on carbazole, iminodibenzyl and phenothiazine donors, and cyano-substitution on the acid acceptor is evidenced by spectral, electrochemical, photovoltaic experiments, and density functional theory calculations. The phenothiazine dyes show solar-energy-to-electricity conversion efficiency (η) of 3.46–5.53%, whereas carbazole andiminodibenzyl dyesshow η of 2.43% and 3.49%, respectively. http://www.mdpi.com/1422-0067/11/1/329/ Fri, 22 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-22 11 1 Article 329 353 1422-0067 Synthesis and Characterization of Organic Dyes Containing Various Donors and Acceptors 2010-01-22 doi: 10.3390/ijms11010329 Tzi-Yi Wu Ming-Hsiu Tsao Fu-Lin Chen Shyh-Gang Su Cheng-Wen Chang Hong-Paul Wang Yuan-Chung Lin Wen-Chung Ou-Yang I-Wen Sun http://www.mdpi.com/1422-0067/11/1/254/ Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO2 films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm2) and a high IPCE value (65% at λ = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm2, corresponding to a solar to electrical power conversion of 1.26%. http://www.mdpi.com/1422-0067/11/1/254/ Wed, 20 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-20 11 1 Article 254 267 1422-0067 Efficient Dye-Sensitized Solar Cells Using Red Turnip and Purple Wild Sicilian Prickly Pear Fruits 2010-01-20 doi: 10.3390/ijms11010254 Giuseppe Calogero Gaetano Di Marco Silvia Cazzanti Stefano Caramori Roberto Argazzi Aldo Di Carlo Carlo Alberto Bignozzi http://www.mdpi.com/1422-0067/11/1/189/ Aqueous solutions of ethoxylated alcohols which form lyotropic liquid crystals at high concentrations (40–80%) were selected as model lubricating substances. Microscopic studies under polarized light and viscosity measurements were carried out in order to confirm the presence of liquid crystalline structures in the case of alcohol solutions with ethoxylation degrees of 3, 5, 7 and 10. Microscopic images and viscosity coefficient values characteristic of various mesophases were obtained. As expected, the viscosity of LLCs decreases considerably with an increase in shearing rate which is characteristic of liquid crystals being non-Newtonian liquids. Antiseizure properties were determined by means of a four-ball machine (T-02 Tester) and characterized by scuffing load (Pt), seizure load (Poz) and limiting pressure of seizure (poz). Alcohol ethoxylates forming mesophases in aqueous solutions have the strongest effect on the Pt values which are several times higher than those measured in the presence of water. Ethoxylates with higher degrees of ethoxylation exhibit higher values of scuffing load. Those changes have been interpreted as a result of higher cloud points at which those compounds lose their amphiphilic properties. In general, the presence of mesophases in the bulk phase and particularly in the surface phase may lead to the formation of a lubricant film which separates the frictionally cooperating elements of a friction pair. The antiseizure efficiency of alcohol solutions is highest up to the load value which does not exceed the scuffing load value. http://www.mdpi.com/1422-0067/11/1/189/ Tue, 12 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-12 11 1 Article 189 205 1422-0067 The Effect of Liquid Crystalline Structures on Antiseizure Properties of Aqueous Solutions of Ethoxylated Alcohols 2010-01-12 doi: 10.3390/ijms11010189 Marian Wlodzimierz Sulek Anna Bak http://www.mdpi.com/1422-0067/11/1/154/ Imagine devices or particles so small that they are invisible to the naked eye. Imagine that such entities could be used to patrol our bodies and autonomously augment endogenous defense and repair mechanisms. Imagine the defeat of illness at a fraction of the current costs. Bionanotechnology is the field of science that deals with just that: the development of imaging, tracking, targeting, sensing, diagnostic, and eventually therapeutic capabilities based on particles in the nanometer range, i.e., “nanoparticles”. Within the extensive group of nanoparticles, semiconducting quantum dots play a central and prominent role. Quantum dots excel at a myriad of physical properties, most notably their fluorescent properties, such as high quantum yield, photo-stability, broad absorption spectra, and their remarkable size-dependent emission-tunability. http://www.mdpi.com/1422-0067/11/1/154/ Tue, 12 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-12 11 1 Editorial 154 163 1422-0067 Quantum Dots—From Synthesis to Applications in Biomedicine and Life Sciences 2010-01-12 doi: 10.3390/ijms11010154 Gregor P.C. Drummen http://www.mdpi.com/1422-0067/11/1/52/ Many kinds of stimuli-responsive polymer and gels have been developed and applied to biomimetic actuators or artificial muscles. Electroactive polymers that change shape when stimulated electrically seem to be particularly promising. In all cases, however, the mechanical motion is driven by external stimuli, for example, reversing the direction of electric field. On the other hand, many living organisms can generate an autonomous motion without external driving stimuli like self-beating of heart muscles. Here we show a novel biomimetic gel actuator that can walk spontaneously with a wormlike motion without switching of external stimuli. The self-oscillating motion is produced by dissipating chemical energy of oscillating reaction. Although the gel is completely composed of synthetic polymer, it shows autonomous motion as if it were alive. http://www.mdpi.com/1422-0067/11/1/52/ Tue, 05 Jan 2010 00:00:00 CET International Journal of Molecular Sciences 2010-01-05 11 1 Review 52 66 1422-0067 Active Polymer Gel Actuators 2010-01-05 doi: 10.3390/ijms11010052 Shingo Maeda Yusuke Hara Ryo Yoshida Shuji Hashimoto http://www.mdpi.com/1422-0067/10/12/5411/ Microfabricated systems provide an excellent platform for the culture of cells, and are an extremely useful tool for the investigation of cellular responses to various stimuli. Advantages offered over traditional methods include cost-effectiveness, controllability, low volume, high resolution, and sensitivity. Both biocompatible and bioincompatible materials have been developed for use in these applications. Biocompatible materials such as PMMA or PLGA can be used directly for cell culture. However, for bioincompatible materials such as silicon or PDMS, additional steps need to be taken to render these materials more suitable for cell adhesion and maintenance. This review describes multiple surface modification strategies to improve the biocompatibility of MEMS materials. Basic concepts of cell-biomaterial interactions, such as protein adsorption and cell adhesion are covered. Finally, the applications of these MEMS materials in Tissue Engineering are presented. http://www.mdpi.com/1422-0067/10/12/5411/ Fri, 18 Dec 2009 00:00:00 CET International Journal of Molecular Sciences 2009-12-18 10 12 Review 5411 5441 1422-0067 Cell Culture on MEMS Platforms: A Review 2009-12-18 doi: 10.3390/ijms10125411 Ming Ni Wen Hao Tong Deepak Choudhury Nur Aida Abdul Rahim Ciprian Iliescu Hanry Yu http://www.mdpi.com/1422-0067/10/12/5257/ This review covers recent advances and work on the microstructure features, mechanical properties and cracking processes of conducting polymer film/coatingsubstrate structures under different testing conditions. An attempt is made to characterize and quantify the relationships between mechanical properties and microstructure features. In addition, the film cracking mechanism on the micro scale and some influencing factors that play a significant role in the service of the film-substrate structure are presented. These investigations cover the conducting polymer film/coating nucleation process, microstructure-fracture characterization, translation of brittle-ductile fractures, and cracking processes near the largest inherent macromolecule defects under thermal-mechanical loadings, and were carried out using in situ scanning electron microscopy (SEM) observations, as a novel method for evaluation of interface strength and critical failure stress. http://www.mdpi.com/1422-0067/10/12/5257/ Tue, 08 Dec 2009 00:00:00 CET International Journal of Molecular Sciences 2009-12-08 10 12 Review 5257 5284 1422-0067 Investigations on the Mechanical Properties of Conducting Polymer Coating-Substrate Structures and Their Influencing Factors 2009-12-08 doi: 10.3390/ijms10125257 Xi-Shu Wang Hua-Ping Tang Xu-Dong Li Xin Hua http://www.mdpi.com/1422-0067/10/12/5115/ This paper deals with the effect of interface structures on the mechanical properties of fiber reinforced composite materials. First, the background of research, development and applications on hybrid composite materials is introduced. Second, metal/polymer composite bonded structures are discussed. Then, the rationale is given for nanostructuring the interface in composite materials and structures by introducing nanoscale features such as nanopores and nanofibers. The effects of modifying matrices and nano-architecturing interfaces on the mechanical properties of nanocomposite materials are examined. A nonlinear damage model for characterizing the deformation behavior of polymeric nanocomposites is presented and the application of this model to carbon nanotube-reinforced and reactive graphite nanotube-reinforced epoxy composite materials is shown. http://www.mdpi.com/1422-0067/10/12/5115/ Wed, 25 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-25 10 12 Review 5115 5134 1422-0067 Effect of Interface Structure on Mechanical Properties of Advanced Composite Materials 2009-11-25 doi: 10.3390/ijms10125115 Yong X. Gan http://www.mdpi.com/1422-0067/10/11/5031/ Polyimides having dendritic side chains were investigated. The terphenylene diamine monomer having a first-generation monodendron, 3,4,5-tris(n-dodecyloxy)-benzoate and the monomer having a second-generation monodendron, 3,4,5-tris[-3’,4’,5’-tri(n-dodecyloxy)benzyloxy]benzoate were successfully synthesized and the corresponding soluble dendritic polyimides were obtained by polycondensation with conventional tetracarboxylic dianhydride monomers such as benzophenone tertracarboxylic dianhydride (BTDA). The two-step polymerizations in NMP that is a general method for the synthesis of soluble polyimides is difficult; however, the expected dendritic polyimides can be obtained in aromatic polar solvents such as m-cresol and pyridine. The solubility of these dendoronized polyimides is characteristic; soluble in common organic solvents such as dichloromethane, chloroform, toluene and THF. These dendronized polyimides exhibited high glass transition temperatures and good thermal stability in both air and under nitrogen. Their application as alignment layers for LCDs was investigated, and it was found that these polyimides having dendritic side chains were applicable for the vertically aligned nematic liquid crystal displays (VAN-LCDs). http://www.mdpi.com/1422-0067/10/11/5031/ Thu, 19 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-19 10 11 Article 5031 5053 1422-0067 Dendronized Polyimides Bearing Long-Chain Alkyl Groups and Their Application for Vertically Aligned Nematic Liquid Crystal Displays 2009-11-19 doi: 10.3390/ijms10115031 Yusuke Tsuda Jae Min OH Renpei Kuwahara http://www.mdpi.com/1422-0067/10/11/4977/ Modification of different zirconium propoxide precursors with H2dea was investigated by characterization of the isolated modified species. Upon modification of zirconium n-propoxide and [Zr(OnPr)(OiPr)3(iPrOH)]2 with ½ a mol equivalent of H2dea the complexes [Zr2(OnPr)6(OCH2CH2)2NH]2 (1) and [Zr2(OnPr)2(OiPr)4(OCH2CH2)2NH]2 (2) were obtained. However, 1H-NMR studies of these tetranuclear compounds showed that these are not time-stable either in solution or solid form. The effect of this time instability on material properties is demonstrated by light scattering and TEM experiments. Modification of zirconium isopropoxide with either ½ or 1 equivalent mol of H2dea results in formation of the trinuclear complex, Zr{η3μ2-NH(C2H4O)2}3[Zr(OiPr)3]2(iPrOH)2 (3) countering a unique nona-coordinated central zirconium atom. This complex 3 is one of the first modified zirconium propoxide precursors shown to be stable in solution for long periods of time. The particle size and morphology of the products of sol-gel synthesis are strongly dependent on the time factor and eventual heat treatment of the precursor solution. Reproducible sol-gel synthesis requires the use of solution stable precursors. http://www.mdpi.com/1422-0067/10/11/4977/ Fri, 13 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-13 10 11 Article 4977 4989 1422-0067 Modification of Different Zirconium Propoxide Precursors by Diethanolamine. Is There a Shelf Stability Issue for Sol-Gel Applications? 2009-11-13 doi: 10.3390/ijms10114977 Gerald I. Spijksma Dave H. A. Blank Henny J. M. Bouwmeester Vadim G. Kessler http://www.mdpi.com/1422-0067/10/11/4963/ The aim of this study was to determine the optimal heat treatment conditions for enhancement of pressed silk-mediated 3D-like proliferation of normal human dermal fibroblasts, as well as to determine the responses to heat shock of cells and intracellular signaling pathways. The beginning of 3D-like pattern formation of cells was observed in the second week after the start of the experiment. The mean rates of beginning of 3D-like pattern formation by cells heat-treated at 40 ºC and 43 ºC for 10 min were significantly higher (3.2- and 8.6-fold, respectively) than that of untreated cells. We found that apoptosis had occurred in 7.5% and 50.0% of the cells at one week after heat treatment for 10 min at 43 ºC and 45 ºC, respectively. Western blot analysis demonstrated that phosphorylation of p38 MAPK and that of Hsp27 were markedly increased by heat treatment at 43 ºC for 10 min. The results of an experiment using a p38 MAPK inhibitor and Hsp27 inhibitor suggest that activation of p38 MAPK by heat shock is associated with 3D-like cell proliferation and that Hsp27 contributes to the inhibition of apoptosis. The results of this study should be useful for further studies aimed at elucidation of the physiologic mechanisms underlying thermotherapy. http://www.mdpi.com/1422-0067/10/11/4963/ Thu, 12 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-12 10 11 Article 4963 4976 1422-0067 Heat Shock-Induced Three-Dimensional-Like Proliferation of Normal Human Fibroblasts Mediated by Pressed Silk 2009-11-12 doi: 10.3390/ijms10114963 Fukumi Hiragami Hirotoshi Motoda Toshiaki Takezawa Chiyuki Takabayashi Shigeki Inoue Yuji Wakatake Yoshio Kano http://www.mdpi.com/1422-0067/10/11/4954/ Wt% of aragonite, a CaCO3 polymorph, increased with higher hydraulic activity (°C) of limestone in precipitated calcium carbonate (PCC) from the lime-soda process (Ca(OH)2-NaOH-Na2CO3). Only calcite, the most stable polymorph, was crystallized at hydraulic activity under 10 °C, whereas aragonite also started to crystallize over 10 °C. The crystallization of PCC is more dependent on the hydraulic activity of limestone than CaO content, a factor commonly used to classify limestone ores according to quality. The results could be effectively applied to the determination of polymorphs in synthetic PCC for eco-friendly paper manufacture. http://www.mdpi.com/1422-0067/10/11/4954/ Wed, 11 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-11 10 11 Article 4954 4962 1422-0067 Effect of Hydraulic Activity on Crystallization of Precipitated Calcium Carbonate (PCC) for Eco-Friendly Paper 2009-11-11 doi: 10.3390/ijms10114954 Jung-Ah Kim Gi-Chun Han Mihee Lim Kwang-Suk You Miyoung Ryu Ji-Whan Ahn Toyohisa Fujita Hwan Kim http://www.mdpi.com/1422-0067/10/11/4772/ Several divinylic mesogenic monomers were synthesized based on coupling the monomer 4-(4-pentenyloxy)benzoic acid with chlorohydroquinone, 2,5-dihydroxyacetophenone, methylhydroquinone or 2-methoxyhydroquinone. This resulted in novel mesogens of phenylene esters with different lateral substituent groups. The effect of the lateral substituent group on the thermotropic phase behavior for these liquid crystalline compounds was investigated using DSC and optical polarized microscopy. All the mesogens proved to have a wide nematic liquid crystalline range. Only the phenylene ester, which has a methoxy lateral substituent, exhibited both nematic and smectic phases. Structural confirmation of all new derivatives was accomplished by 1H- and 13C-NMR spectroscopic analysis, along with CH elemental analysis. http://www.mdpi.com/1422-0067/10/11/4772/ Wed, 04 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-04 10 11 Article 4772 4788 1422-0067 Synthesis, Characterization and Texture Observations of Calamitic Liquid Crystalline Compounds 2009-11-04 doi: 10.3390/ijms10114772 Maher A. Qaddoura Kevin D. Belfield http://www.mdpi.com/1422-0067/10/11/4754/ Home-based soft X-ray time-resolved scattering experiments with nanosecond time resolution (10 ns) and nanometer spatial resolution were carried out at a table top soft X-ray plasma source (2.2–5.2 nm). The investigated system was the lyotropic liquid crystal C16E7/paraffin/glycerol/formamide/IR 5. Usually, major changes in physical, chemical, and/or optical properties of the sample occur as a result of structural changes and shrinking morphology. Here, these effects occur as a consequence of the energy absorption in the sample upon optical laser excitation in the IR regime. The liquid crystal shows changes in the structural response within few hundred nanoseconds showing a time decay of 182 ns. A decrease of the Bragg peak diffracted intensity of 30% and a coherent macroscopic movement of the Bragg reflection are found as a response to the optical pump. The Bragg reflection movement is established to be isotropic and diffusion controlled (1 μs). Structural processes are analyzed in the Patterson analysis framework of the time-varying diffraction peaks revealing that the inter-lamellar distance increases by 2.7 Å resulting in an elongation of the coherently expanding lamella crystallite. The present studies emphasize the possibility of applying TR-SXRD techniques for studying the mechanical dynamics of nanosystems. http://www.mdpi.com/1422-0067/10/11/4754/ Wed, 04 Nov 2009 00:00:00 CET International Journal of Molecular Sciences 2009-11-04 10 11 Article 4754 4771 1422-0067 Time-Resolved Soft X-ray Diffraction Reveals Transient Structural Distortions of Ternary Liquid Crystals 2009-11-04 doi: 10.3390/ijms10114754 Wilson Quevedo Christian Peth Gerhard Busse Mirko Scholz Klaus Mann Simone Techert http://www.mdpi.com/1422-0067/10/11/4707/ Silver nanoparticles doped on titanium oxide (TiO2) were produced by laser-liquid interaction of silver nitrate (AgNO3) in isopropanol. Characteristics of Ag/TiO2 (Ag doped TiO2) nanoparticles produced by the methods presented in this article were investigated by XRD, TEM, SEM, EDX, and UV-Vis. From the UV-Vis measurements, the absorption of visible light of the Ag/TiO2 photocatalysts was improved (additional absorption at longer wavelength in visible light region) obviously. The photocatalytic efficiency of Ag/TiO2 was tested by the degradation of methylene blue (MB) in aqueous solution. A maximum of 82.3% MB degradation is achieved by 2.0 wt% Ag/TiO2 photocatalyst under 2 h illumination with a halogen lamp. http://www.mdpi.com/1422-0067/10/11/4707/ Thu, 29 Oct 2009 00:00:00 CET International Journal of Molecular Sciences 2009-10-29 10 11 Article 4707 4718 1422-0067 Laser-Induced Silver Nanoparticles on Titanium Oxide for Photocatalytic Degradation of Methylene Blue 2009-10-29 doi: 10.3390/ijms10114707 Thou-Jen Whang Hsien-Yu Huang Mu-Tao Hsieh Jyun-Jen Chen http://www.mdpi.com/1422-0067/10/11/4638/ This review is focused on molecular momentum transport at fluid-solid interfaces mainly related to microfluidics and nanofluidics in micro-/nano-electro-mechanical systems (MEMS/NEMS). This broad subject covers molecular dynamics behaviors, boundary conditions, molecular momentum accommodations, theoretical and phenomenological models in terms of gas-solid and liquid-solid interfaces affected by various physical factors, such as fluid and solid species, surface roughness, surface patterns, wettability, temperature, pressure, fluid viscosity and polarity. This review offers an overview of the major achievements, including experiments, theories and molecular dynamics simulations, in the field with particular emphasis on the effects on microfluidics and nanofluidics in nanoscience and nanotechnology. In Section 1 we present a brief introduction on the backgrounds, history and concepts. Sections 2 and 3 are focused on molecular momentum transport at gas-solid and liquid-solid interfaces, respectively. Summary and conclusions are finally presented in Section 4. http://www.mdpi.com/1422-0067/10/11/4638/ Thu, 29 Oct 2009 00:00:00 CET International Journal of Molecular Sciences 2009-10-29 10 11 Review 4638 4706 1422-0067 Molecular Momentum Transport at Fluid-Solid Interfaces in MEMS/NEMS: A Review 2009-10-29 doi: 10.3390/ijms10114638 Bing-Yang Cao Jun Sun Min Chen Zeng-Yuan Guo http://www.mdpi.com/1422-0067/10/11/4575/ Attempts have been made to develop dye-sensitized solar cells based on the principles and materials of photosynthesis: We first tested photosynthetic pigments, carotenoids (Cars), chlorophylls (Chls) and their derivatives, to find sensitizers showing reasonable performance (photocurrent and conversion efficiency). We then tried to introduce the principles of photosynthesis, including electron transfer and energy transfer from Car to Phe a. Also, we tried co-sensitization using the pheophorbide (Phe) a and Chl c2 pair which further enhanced the performance of the component sensitizers as follows: Jsc = 9.0 + 13.8 → 14.0 mA cm–2 and η = 3.4 + 4.6 → 5.4%. http://www.mdpi.com/1422-0067/10/11/4575/ Tue, 27 Oct 2009 00:00:00 CET International Journal of Molecular Sciences 2009-10-27 10 11 Review 4575 4622 1422-0067 Dye-Sensitized Solar Cells Based on the Principles and Materials of Photosynthesis: Mechanisms of Suppression and Enhancement of Photocurrent and Conversion Efficiency 2009-10-27 doi: 10.3390/ijms10114575 Yasushi Koyama Takeshi Miki Xiao-Feng Wang Hiroyoshi Nagae http://www.mdpi.com/1422-0067/10/10/4559/ The Δ- and Λ-isomerism of octahedral metal complexes is employed as a source of chirality for inducing chiral nematic phases. By applying a wide range of chiral metal complexes as a dopant, it has been found that tris(β-diketonato)metal(III) complexes exhibit an extremely high value of helical twisting power. The mechanism of induction of the chiral nematic phase is postulated on the basis of a surface chirality model. The strategy for designing an efficient dopant is described, together with the results using a number of examples of Co(III), Cr(III) and Ru(III) complexes with C2 symmetry. The development of photo-responsive dopants to achieve the photo-induced structural change of liquid crystal by use of photo-isomerization of chiral metal complexes is also described. http://www.mdpi.com/1422-0067/10/10/4559/ Fri, 23 Oct 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-10-23 10 10 Review 4559 4574 1422-0067 Application of Δ- and Λ-Isomerism of Octahedral Metal Complexes for Inducing Chiral Nematic Phases 2009-10-23 doi: 10.3390/ijms10104559 Hisako Sato Akihiko Yamagishi http://www.mdpi.com/1422-0067/10/10/4498/ Defect inspection plays a critical role in thin film transistor liquid crystal display (TFT-LCD) manufacture, and has received much attention in the field of automatic optical inspection (AOI). Previously, most focus was put on the problems of macro-scale Mura-defect detection in cell process, but it has recently been found that the defects which substantially influence the yield rate of LCD panels are actually those in the TFT array process, which is the first process in TFT-LCD manufacturing. Defect inspection in TFT array process is therefore considered a difficult task. This paper presents a novel inspection scheme based on kernel principal component analysis (KPCA) algorithm, which is a nonlinear version of the well-known PCA algorithm. The inspection scheme can not only detect the defects from the images captured from the surface of LCD panels, but also recognize the types of the detected defects automatically. Results, based on real images provided by a LCD manufacturer in Taiwan, indicate that the KPCA-based defect inspection scheme is able to achieve a defect detection rate of over 99% and a high defect classification rate of over 96% when the imbalanced support vector machine (ISVM) with 2-norm soft margin is employed as the classifier. More importantly, the inspection time is less than 1 s per input image. http://www.mdpi.com/1422-0067/10/10/4498/ Thu, 22 Oct 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-10-22 10 10 Article 4498 4514 1422-0067 In-TFT-Array-Process Micro Defect Inspection Using Nonlinear Principal Component Analysis 2009-10-22 doi: 10.3390/ijms10104498 Yi-Hung Liu Chi-Kai Wang Yung Ting Wei-Zhi Lin Zhi-Hao Kang Ching-Shun Chen Jih-Shang Hwang http://www.mdpi.com/1422-0067/10/10/4375/ The in vivo healing process of vascular grafts involves the interaction of many contributing factors. The ability of vascular grafts to provide an environment which allows successful accomplishment of this process is extremely difficult. Poor endothelisation, inflammation, infection, occlusion, thrombosis, hyperplasia and pseudoaneurysms are common issues with synthetic grafts in vivo. Advanced materials composed of decellularised extracellular matrices (ECM) have been shown to promote the healing process via modulation of the host immune response, resistance to bacterial infections, allowing re-innervation and reestablishing homeostasis in the healing region. The physiological balance within the newly developed vascular tissue is maintained via the recreation of correct biorheology and mechanotransduction factors including host immune response, infection control, homing and the attraction of progenitor cells and infiltration by host tissue. Here, we review the progress in this tissue engineering approach, the enhancement potential of ECM materials and future prospects to reach the clinical environment. http://www.mdpi.com/1422-0067/10/10/4375/ Mon, 12 Oct 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-10-12 10 10 Review 4375 4417 1422-0067 ECM-Based Materials in Cardiovascular Applications: Inherent Healing Potential and Augmentation of Native Regenerative Processes 2009-10-12 doi: 10.3390/ijms10104375 Anna V. Piterina Aidan J. Cloonan Claire L. Meaney Laura M. Davis Anthony Callanan Michael T. Walsh Tim M. McGloughlin http://www.mdpi.com/1422-0067/10/10/4352/ High-density polyethylene (PE) foils were modified by an Ar+ plasma discharge and subsequent grafting with biomolecules, namely glycine (Gly), polyethylene glycol (PEG), bovine serum albumin (BSA), colloidal carbon particles (C) or BSA and C (BSA + C). As revealed by atomic force microscopy (AFM), goniometry and Rutherford Backscattering Spectroscopy (RBS), the surface chemical structure and surface morphology of PE changed dramatically after plasma treatment. The contact angle decreased for the samples treated by plasma, mainly in relation to the formation of oxygen structures during plasma irradiation. A further decrease in the contact angle was obvious after glycine and PEG grafting. The increase in oxygen concentration after glycine and PEG grafting proved that the two molecules were chemically linked to the plasma-activated surface. Plasma treatment led to ablation of the PE surface layer, thus the surface morphology was changed and the surface roughness was increased. The materials were then seeded with vascular smooth muscle cells (VSMC) derived from rat aorta and incubated in a DMEM medium with fetal bovine serum. Generally, the cells adhered and grew better on modified rather than on unmodified PE samples. Immunofluorescence showed that focal adhesion plaques containing talin, vinculin and paxillin were most apparent in cells on PE grafted with PEG or BSA + C, and the fibres containing α-actin, β-actin or SM1 and SM2 myosins were thicker, more numerous and more brightly stained in the cells on all modified PE samples than on pristine PE. An enzyme-linked immunosorbent assay (ELISA) revealed increased concentrations of focal adhesion proteins talin and vinculin and also a cytoskeletal protein β-actin in cells on PE modified with BSA + C. A contractile protein α-actin was increased in cells on PE grafted with PEG or Gly. These results showed that PE activated with plasma and subsequently grafted with bioactive molecules and colloidal C particles, especially with PEG and BSA + C, promotes the adhesion, proliferation and phenotypic maturation of VSMC. http://www.mdpi.com/1422-0067/10/10/4352/ Mon, 12 Oct 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-10-12 10 10 Article 4352 4374 1422-0067 Improved Adhesion, Growth and Maturation of Vascular Smooth Muscle Cells on Polyethylene Grafted with Bioactive Molecules and Carbon Particles 2009-10-12 doi: 10.3390/ijms10104352 Martin Parizek Nikola Kasalkova Lucie Bacakova Petr Slepicka Vera Lisa Martina Blazkova Vaclav Svorcik http://www.mdpi.com/1422-0067/10/10/4267/ The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 °C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled “Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions—Method by analysis of evolved carbon dioxide—Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test”. The evolved CO2 was trapped by an additional aqueous Ba(OH)2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the 14C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO2 (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30% lower than those based on the ISO method. These differences between the ISO and AMS methods are caused by the fact that part of the carbons from PBS are changed into metabolites by the microorganisms in the compost, and not changed into CO2. http://www.mdpi.com/1422-0067/10/10/4267/ Wed, 30 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-30 10 10 Article 4267 4283 1422-0067 Biodegradation of Poly(butylene succinate) Powder in a Controlled Compost at 58 °C Evaluated by Naturally-Occurring Carbon 14 Amounts in Evolved CO2 Based on the ISO 14855-2 Method 2009-09-30 doi: 10.3390/ijms10104267 Masao Kunioka Fumi Ninomiya Masahiro Funabashi http://www.mdpi.com/1422-0067/10/10/4223/ This article reviews the degradability of chemically synthesized bioelastomers, mainly designed for soft tissue repair. These bioelastomers involve biodegradable polyurethanes, polyphosphazenes, linear and crosslinked poly(ether/ester)s, poly(ε-caprolactone) copolymers, poly(1,3-trimethylene carbonate) and their copolymers, poly(polyol sebacate)s, poly(diol-citrates) and poly(ester amide)s. The in vitro and in vivo degradation mechanisms and impact factors influencing degradation behaviors are discussed. In addition, the molecular designs, synthesis methods, structure properties, mechanical properties, biocompatibility and potential applications of these bioelastomers were also presented. http://www.mdpi.com/1422-0067/10/10/4223/ Tue, 29 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-29 10 10 Review 4223 4256 1422-0067 Recent Advances in Synthetic Bioelastomers 2009-09-29 doi: 10.3390/ijms10104223 Rui Shi Dafu Chen Quanyong Liu Yan Wu Xiaochuan Xu Liqun Zhang Wei Tian http://www.mdpi.com/1422-0067/10/9/4178/ This study presents a new nanotechnology application involving an ITO thin-film removal reuse process using an eccentric-form negative electrode, offering a fast removal rate from the surface of liquid crystal displays (LCDs). For the precision removal process, a small amount of eccentricity of the negative electrode or a higher rotational speed of the negative electrode corresponds to a higher etching rate for the ITO. A higher flow velocity of the electrolyte and a higher working temperature also correspond to a higher removal rate. The average effect of the eccentricity is better than the effects of a pulsed current, while the current rating need not be prolonged by the off-time. http://www.mdpi.com/1422-0067/10/9/4178/ Thu, 24 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-24 10 9 Article 4178 4186 1422-0067 Implementation of a Reuse Process for Liquid Crystal Displays Using an Eccentric-Form Tool 2009-09-24 doi: 10.3390/ijms10094178 Pai-Shan Pa http://www.mdpi.com/1422-0067/10/9/4102/ Two decades ago, the literature dealing with the possible applications of low molar mass liquid crystals, also called monomer liquid crystals (MLCs), only included about 50 references. Today, thousands of papers, conference reports, books or book chapters and patents refer to the study and applications of MLCs as lubricants and lubricant additives and efforts are made to develop new commercial applications. The development of more efficient lubricants is of paramount technological and economic relevance as it is estimated that half the energy consumption is dissipated as friction. MLCs have shown their ability to form ordered boundary layers with good load-carrying capacity and to lower the friction coefficients, wear rates and contact temperature of sliding surfaces, thus contributing to increase the components service life and to save energy. This review includes the use of MLCs in lubrication, and dispersions of MLCs in conventional polymers (PDMLCs). Finally, new lubricating system composed of MLC blends with surfactants, ionic liquids or nanophases are considered. http://www.mdpi.com/1422-0067/10/9/4102/ Fri, 18 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-18 10 9 Review 4102 4115 1422-0067 Liquid Crystals in Tribology 2009-09-18 doi: 10.3390/ijms10094102 Francisco-José Carrión Ginés Martínez-Nicolás Patricia Iglesias José Sanes María-Dolores Bermúdez http://www.mdpi.com/1422-0067/10/9/4088/ Transparent BaTiO3:Eu3+ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO3:Eu3+ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu3+ doped BaTiO3. http://www.mdpi.com/1422-0067/10/9/4088/ Thu, 17 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-17 10 9 Article 4088 4101 1422-0067 Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive 2009-09-17 doi: 10.3390/ijms10094088 Margarita García-Hernández Antonieta García-Murillo Felipe de J. Carrillo-Romo David Jaramillo-Vigueras Geneviève Chadeyron Elder De la Rosa Damien Boyer http://www.mdpi.com/1422-0067/10/9/4033/ Many key components of implantable medical devices are made from polymeric materials. The functions of these materials include structural support, electrical insulation, protection of other materials from the environment of the body, and biocompatibility, as well as other things such as delivery of a therapeutic drug. In such roles, the stability and integrity of the polymer, over what can be a very long period of time, is very important. For most of these functions, stability over time is desired, but in other cases, the opposite–the degradation and disappearance of the polymer over time is required. In either case, it is important to understand both the chemistry that can lead to the degradation of polymers as well as the kinetics that controls these reactions. Hydrolysis and oxidation are the two classes of reactions that lead to the breaking down of polymers. Both are discussed in detail in the context of the environmental factors that impact the utility of various polymers for medical device applications. Understanding the chemistry and kinetics allows prediction of stability as well as explanations for observations such as porosity and the unexpected behavior of polymeric composite materials in some situations. In the last part, physical degradation such interfacial delamination in composites is discussed. http://www.mdpi.com/1422-0067/10/9/4033/ Fri, 11 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-11 10 9 Review 4033 4065 1422-0067 Degradability of Polymers for Implantable Biomedical Devices 2009-09-11 doi: 10.3390/ijms10094033 SuPing Lyu Darrel Untereker http://www.mdpi.com/1422-0067/10/9/4009/ Quantitative understanding of the mechanical behavior of biological liquid crystals such as proteins is essential for gaining insight into their biological functions, since some proteins perform notable mechanical functions. Recently, single-molecule experiments have allowed not only the quantitative characterization of the mechanical behavior of proteins such as protein unfolding mechanics, but also the exploration of the free energy landscape for protein folding. In this work, we have reviewed the current state-of-art in single-molecule bioassays that enable quantitative studies on protein unfolding mechanics and/or various molecular interactions. Specifically, single-molecule pulling experiments based on atomic force microscopy (AFM) have been overviewed. In addition, the computational simulations on single-molecule pulling experiments have been reviewed. We have also reviewed the AFM cantilever-based bioassay that provides insight into various molecular interactions. Our review highlights the AFM-based single-molecule bioassay for quantitative characterization of biological liquid crystals such as proteins. http://www.mdpi.com/1422-0067/10/9/4009/ Thu, 10 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-10 10 9 Review 4009 4032 1422-0067 Experimental and Computational Characterization of Biological Liquid Crystals: A Review of Single-Molecule Bioassays 2009-09-10 doi: 10.3390/ijms10094009 Kilho Eom Jaemoon Yang Jinsung Park Gwonchan Yoon Young Soo Sohn Shinsuk Park Dae Sung Yoon Sungsoo Na Taeyun Kwon http://www.mdpi.com/1422-0067/10/9/3971/ We review the theoretical research on the influence of disorder on structure and phase behavior of condensed matter system exhibiting continuous symmetry breaking focusing on liquid crystal phase transitions. We discuss the main properties of liquid crystals as adequate systems in which several open questions with respect to the impact of disorder on universal phase and structural behavior could be explored. Main advantages of liquid crystalline materials and different experimental realizations of random field-type disorder imposed on liquid crystal phases are described. http://www.mdpi.com/1422-0067/10/9/3971/ Thu, 10 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-10 10 9 Review 3971 4008 1422-0067 The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior 2009-09-10 doi: 10.3390/ijms10093971 Vlad Popa-Nita Ivan Gerlič Samo Kralj http://www.mdpi.com/1422-0067/10/9/3861/ Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites’ molecular toxicology and to give implications for possible improvements concerning their biocompatibility. http://www.mdpi.com/1422-0067/10/9/3861/ Fri, 04 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-04 10 9 Review 3861 3899 1422-0067 Molecular Toxicology of Substances Released from Resin–Based Dental Restorative Materials 2009-09-04 doi: 10.3390/ijms10093861 Athina Bakopoulou Triantafillos Papadopoulos Pavlos Garefis http://www.mdpi.com/1422-0067/10/9/3824/ Anaerobic biodegradation tests of poly(lactic acid) (PLA) powder were done at the thermophilic (55 °C) and mesophilic temperature (35 °C) under aquatic conditions [total solid concentrations of the used sludge were 2.07% (at 55 °C) and 2.24% (at 35 °C)] using a newly developed evaluation system. With this system, the evolved biogas is collected in a gas sampling bag at atmospheric pressure. This method is more convenient than using a pressure transducer or inverted graduated cylinder submerged in water. PLA was degraded about 60% in 30 days, about 80% in 40 days and about 90% in 60 days at 55 °C. On the other hand, the PLA degradation started in 55 days at 35 °C and degradation rate was much slower than at 55 °C. http://www.mdpi.com/1422-0067/10/9/3824/ Wed, 02 Sep 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-09-02 10 9 Article 3824 3835 1422-0067 Anaerobic Biodegradation Tests of Poly(lactic acid) under Mesophilic and Thermophilic Conditions Using a New Evaluation System for Methane Fermentation in Anaerobic Sludge 2009-09-02 doi: 10.3390/ijms10093824 Hisaaki Yagi Fumi Ninomiya Masahiro Funabashi Masao Kunioka http://www.mdpi.com/1422-0067/10/9/3776/ Medical applications of nanoparticular systems have attracted considerable attention because of their potential use in therapeutic targeting of disease tissues and their lower level of toxicity against healthy tissue, relative to traditional pharmaceutical drugs. The use of nanoparticular systems has been shown to overcome the limitations of most anticancer drugs in clinical applications. In particular, the improved performance of smarted nanoparticular system for solving the drug resistance problems that typically interrupt tumor treatment has provided a promising strategy for successful tumor chemotherapy. This review highlights recent studies that have examined the therapeutic effect of nanoparticular systems on drug-resistant tumors and presents insight on how they work. http://www.mdpi.com/1422-0067/10/9/3776/ Mon, 31 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-31 10 9 Review 3776 3792 1422-0067 The Reversal of Drug-Resistance in Tumors Using a Drug-Carrying Nanoparticular System 2009-08-31 doi: 10.3390/ijms10093776 Kyung Taek Oh Hye Jung Baik A Hyeong Lee Young Taik Oh Yu Seok Youn Eun Seong Lee http://www.mdpi.com/1422-0067/10/9/3722/ Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. http://www.mdpi.com/1422-0067/10/9/3722/ Wed, 26 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-26 10 9 Review 3722 3742 1422-0067 Biodegradability of Plastics 2009-08-26 doi: 10.3390/ijms10093722 Yutaka Tokiwa Buenaventurada P. Calabia Charles U. Ugwu Seiichi Aiba http://www.mdpi.com/1422-0067/10/8/3635/ Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradability were studied. Reproducibility of biodegradation test of ISO 14855-2 by MODA was confirmed. Validity of sample preparation method for polymer pellets, polymer film, and polymer products of ISO/DIS 10210 for ISO 14855-2 was confirmed. http://www.mdpi.com/1422-0067/10/8/3635/ Tue, 18 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-18 10 8 Review 3635 3654 1422-0067 Biodegradability Evaluation of Polymers by ISO 14855-2 2009-08-18 doi: 10.3390/ijms10083635 Masahiro Funabashi Fumi Ninomiya Masao Kunioka http://www.mdpi.com/1422-0067/10/8/3599/ We have developed a mulch sheet made by inflation molding of PLA, Ecoflex® and modified starch, which all have different biodegradabilities. A field test of use as an agricultural mulch sheet for mandarin oranges was carried out over two years. The mechanical properties of the mulch sheet were weakened with time during the field test, but the quality of the mandarin oranges increased, a result of the controlled degradation of the sheet. The most degradable modified starch degraded first, allowing control of the moisture on the soil. Accelerator mass spectroscopy was used for evaluation of the biomass carbon ratio. The biomass carbon ratio decreased by degradation of the biobased materials, PLA and modified starch in the mulch sheet. http://www.mdpi.com/1422-0067/10/8/3599/ Mon, 17 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-17 10 8 Article 3599 3615 1422-0067 Utilization of a Biodegradable Mulch Sheet Produced from Poly(Lactic Acid)/Ecoflex®/Modified Starch in Mandarin Orange Groves 2009-08-17 doi: 10.3390/ijms10083599 Yuya Tachibana Takuya Maeda Osamu Ito Yasukatsu Maeda Masao Kunioka http://www.mdpi.com/1422-0067/10/8/3442/ Biocompatible materials are of considerable interest in the development of cell/drug delivery carriers for therapeutic applications. This paper investigates the effects of the Bloom index of gelatin on its interaction with retinal pigment epithelial (RPE) cells. Following two days of culture of ARPE-19 cells with gelatin samples G75-100, G175, and G300, the in vitro biocompatibility was determined by cell proliferation and viability assays, and glutamate uptake measurements, as well as cytokine expression analyses. The mitochondrial dehydrogenase activity in the G300 groups was significantly lower than that of G75-100 and G175 groups. The Live/Dead assays also showed that the gelatin samples G300 induced mild cytotoxicity. In comparison with the treatment of gelatins with low Bloom index, the exposure to high Bloom strength gelatins markedly reduced the glutamate uptake capacity of ARPE-19 cells. One possible explanation for these observations is that the presence of gelatin samples G300 with high viscosity in the medium may affect the nutrient availability to cultured cells. The analyses of pro-inflammatory cytokine IL-6 expression at both mRNA and protein levels showed that the gelatins with low Bloom index caused less cellular inflammatory reaction and had more acceptable biocompatibility than their high Bloom strength counterparts. These findings suggest that the Bloom index gives influence on cellular responses to gelatin materials. http://www.mdpi.com/1422-0067/10/8/3442/ Mon, 03 Aug 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-08-03 10 8 Article 3442 3456 1422-0067 The Role of Bloom Index of Gelatin on the Interaction with Retinal Pigment Epithelial Cells 2009-08-03 doi: 10.3390/ijms10083442 Jui Yang Lai http://www.mdpi.com/1422-0067/10/7/3224/ Synthetic polymers belonging to the aliphatic polyester group have become highly promising biomaterials for reconstructive medicine. The purpose of the present work is a biological evaluation of lactide-glycolide co-polymer (PLGA) and its composites with carbon fibers (PLGA+CF) or hydroxyapatite (PLGA+HA). The cytotoxicity of the evaluated materials towards hFOB 1.19 human osteoblast-like cells was assessed. Moreover, during the one-year contact of the assessed materials with living osseous tissue, the progress of bone formation was analyzed and the accompanying process of the materials’ degradation was evaluated. The materials under evaluation proved to be biocompatible. http://www.mdpi.com/1422-0067/10/7/3224/ Wed, 15 Jul 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-07-15 10 7 Article 3224 3234 1422-0067 The Evaluation of the Possibilities of Using PLGA Co-Polymer and Its Composites with Carbon Fibers or Hydroxyapatite in the Bone Tissue Regeneration Process – in Vitro and in Vivo Examinations 2009-07-15 doi: 10.3390/ijms10073224 Magdalena Cieślik Anna Mertas Anna Morawska-Chochół Daniel Sabat Rajmund Orlicki Aleksander Owczarek Wojciech Król Tadeusz Cieślik http://www.mdpi.com/1422-0067/10/7/2972/ Tissue engineering is a multidisciplinary field focused on in vitro reconstruction of mammalian tissues. In order to allow a similar three-dimensional organization of in vitro cultured cells, biocompatible scaffolds are needed. This need has provided immense momentum for research on “smart scaffolds” for use in cell culture. One of the most promising materials for tissue engineering and regenerative medicine is a hyaluronan derivative: a benzyl ester of hyaluronan (HYAFF®). HYAFF® can be processed to obtain several types of devices such as tubes, membranes, non-woven fabrics, gauzes, and sponges. All these scaffolds are highly biocompatible. In the human body they do not elicit any adverse reactions and are resorbed by the host tissues. Human hepatocytes, dermal fibroblasts and keratinocytes, chondrocytes, Schwann cells, bone marrow derived mesenchymal stem cells and adipose tissue derived mesenchymal stem cells have been successfully cultured in these meshes. The same scaffolds, in tube meshes, has been applied for vascular tissue engineering that has emerged as a promising technology for the design of an ideal, responsive, living conduit with properties similar to that of native tissue. http://www.mdpi.com/1422-0067/10/7/2972/ Fri, 03 Jul 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-07-03 10 7 Review 2972 2985 1422-0067 Hyaluronan Benzyl Ester as a Scaffold for Tissue Engineering 2009-07-03 doi: 10.3390/ijms10072972 Vincenzo Vindigni Roberta Cortivo Laura Iacobellis Giovanni Abatangelo Barbara Zavan http://www.mdpi.com/1422-0067/10/6/2798/ Volumetric strain can be divided into two parts: strain due to bond distance change and strain due to vacancy sources and sinks. In this paper, efforts are focused on studying the atomic lattice strain due to a vacancy in an FCC metal lattice with molecular dynamics simulation (MDS). The result has been compared with that from a continuum mechanics method. It is shown that using a continuum mechanics approach yields constitutive results similar to the ones obtained based purely on molecular dynamics considerations. http://www.mdpi.com/1422-0067/10/6/2798/ Fri, 19 Jun 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-06-19 10 6 Article 2798 2808 1422-0067 Lattice Strain Due to an Atomic Vacancy 2009-06-19 doi: 10.3390/ijms10062798 Shidong Li Michael S. Sellers Cemal Basaran Andrew J. Schultz David A. Kofke http://www.mdpi.com/1422-0067/10/6/2789/ In this study, the effects of various boron compounds on the termite resistance of MDF panels were evaluated. Either borax (BX), boric acid (BA), zinc borate (ZB), or sodium perborate tetrahydrate (SPT) were added to urea-formaldehyde (UF) resin at target contents of 1%, 1.5%, 2% and 2.5% based on dry fiber weight. The panels were then manufactured using 12% urea-formaldehyde resin and 1% NH4Cl. MDF samples from the panels were tested against the subterranean termites, Coptotermes formosanus Shiraki. Laboratory termite resistance tests showed that all samples containing boron compounds had greater resistance against termite attack compared to untreated MDF samples. At the second and third weeks of exposure, nearly 100% termite mortalities were recorded in all boron compound treated samples. The highest termite mortalities were determined in the samples with either BA or BX. Also, it was found that SPT showed notable performance on the termite mortality. As chemical loadings increased, termite mortalities increased, and at the same time the weight losses of the samples decreased. http://www.mdpi.com/1422-0067/10/6/2789/ Fri, 19 Jun 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-06-19 10 6 Article 2789 2797 1422-0067 Termite Resistance of MDF Panels Treated with Various Boron Compounds 2009-06-19 doi: 10.3390/ijms10062789 Mustafa Usta Derya Ustaomer Saip Nami Kartal Sedat Ondaral http://www.mdpi.com/1422-0067/10/5/2122/ Quantum dots (QDs) are useful novel luminescent markers, but their embryonic toxicity is yet to be fully established, particularly in oocyte maturation and sperm fertilization. Earlier experiments by our group show that CdSe-core QDs have cytotoxic effects on mouse blastocysts and are associated with defects in subsequent development. Here, we further investigate the influence of CdSe-core QDs on oocyte maturation, fertilization, and subsequent pre- and postimplantation development. CdSe-core QDs induced a significant reduction in the rates of oocyte maturation, fertilization, and in vitro embryo development, but not ZnS-coated CdSe QDs. Treatment of oocytes with 500 nM CdSe-core QDs during in vitro maturation (IVM) led to increased resorption of postimplantation embryos and decreased placental and fetal weights. To our knowledge, this is the first study to report the negative impact of CdSe-core QDs on mouse oocyte development. Moreover, surface modification of CdSe-core QDs with ZnS effectively prevented this cytotoxicity. http://www.mdpi.com/1422-0067/10/5/2122/ Thu, 14 May 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-05-14 10 5 Article 2122 2135 1422-0067 Cytotoxic Effects of CdSe Quantum Dots on Maturation of Mouse Oocytes, Fertilization, and Fetal Development 2009-05-14 doi: 10.3390/ijms10052122 Ming-Shu Hsieh Nion-Heng Shiao Wen-Hsiung Chan http://www.mdpi.com/1422-0067/10/5/1942/ Fluoroaromatic compounds are used as agrochemicals and released into environment as pollutants. Glycosylation of 2-, 3-, and 4-fluorophenols using plant cell cultures of Nicotiana tabacum was investigated to elucidate their potential to metabolize these compounds. Cultured N. tabacum cells converted 2-fluorophenol into its β-glucoside (60%) and β-gentiobioside (10%). 4-Fluorophenol was also glycosylated to its β-glucoside (32%) and β-gentiobioside (6%) by N. tabacum cells. On the other hand, N. tabacum glycosylated 3-fluorophenol to β-glucoside (17%). http://www.mdpi.com/1422-0067/10/5/1942/ Mon, 27 Apr 2009 00:00:00 CEST International Journal of Molecular Sciences 2009-04-27 10 5 Article 1942 1949 1422-0067 Glycosylation of Fluorophenols by Plant Cell Cultures 2009-04-27 doi: 10.3390/ijms10051942 Kei Shimoda Naoji Kubota Yoko Kondo Daisuke Sato Hiroki Hamada