Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Article Types

Countries / Regions

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Search Results (1,019)

Search Parameters:
Keywords = volume modifications

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
15 pages, 3562 KiB  
Article
Synergistic Control of Shrinkage and Mechanical Properties in Expansive Soil Slurry via Coupled Cement–Fiber Reinforcement
by Dongxing Zhang, Yuchen Wang, Zhaohong Zhang, Zhenping Sun, Chengzhi Wang and Shuang Zou
Buildings 2025, 15(14), 2550; https://doi.org/10.3390/buildings15142550 - 19 Jul 2025
Viewed by 183
Abstract
This study elucidates the synergistic effects of polypropylene fiber and cement (physical–chemical) on stabilized expansive soil slurry. A comparative analysis was conducted on the fluidity, 28-day mechanical strength, and shrinkage properties (autogenous and drying) of slurries with different modifications. The underlying mechanisms were [...] Read more.
This study elucidates the synergistic effects of polypropylene fiber and cement (physical–chemical) on stabilized expansive soil slurry. A comparative analysis was conducted on the fluidity, 28-day mechanical strength, and shrinkage properties (autogenous and drying) of slurries with different modifications. The underlying mechanisms were further investigated through Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analysis. Results demonstrate that the cement addition substantially enhanced fluidity, mechanical strength, and early-age volume stability through hydration. However, it was insufficient to mitigate long-term drying shrinkage at low dosages. Conversely, incorporating 0.5% polypropylene fiber reduced slurry fluidity but markedly improved flexural strength. Crucially, a pronounced synergistic effect was observed in the co-modified slurry; the specimen with 20% cement and 0.5% fiber exhibited a 28-day drying shrinkage of only 0.57%, a performance comparable to the specimen with 60% cement and no fibers. Microstructural analysis revealed that cement hydration products created a robust fiber-matrix interfacial transition zone, evidenced by C-S-H gel enrichment. This enhanced interface enabled the fibers to effectively bridge microcracks and restrain both autogenous and drying shrinkage. This research validates that the combined cement–fiber approach is a highly effective strategy for improving expansive soil slurry, yielding critical enhancements in flexural performance and long-term dimensional stability while allowing for a significant reduction in cement content. Full article
(This article belongs to the Special Issue Trends and Prospects in Cementitious Material)
Show Figures

Figure 1

14 pages, 1681 KiB  
Article
Potential of Bioinspired Artificial Vaginas to Improve Semen Quality in Dolphins
by Jacquline Rich, Guillermo J. Sánchez-Contreras, Jonathan R. Cowart and Dara N. Orbach
J. Mar. Sci. Eng. 2025, 13(7), 1376; https://doi.org/10.3390/jmse13071376 - 19 Jul 2025
Viewed by 423
Abstract
Semen collection is an important component of conservation and animal husbandry. Semen quality is generally improved using voluntary collection methods, particularly artificial vaginas (AVs). Most commercially available AVs are tube-shaped with few species-specific design augmentations. As genitalia are highly variable across taxa, incorporating [...] Read more.
Semen collection is an important component of conservation and animal husbandry. Semen quality is generally improved using voluntary collection methods, particularly artificial vaginas (AVs). Most commercially available AVs are tube-shaped with few species-specific design augmentations. As genitalia are highly variable across taxa, incorporating species-specific genital morphologies into AV designs may enhance collected semen quality. We compared dolphin semen quality using: (1) silicone bioinspired artificial vaginas (BAVs) that reflect the internal shape of dolphin vaginas, and (2) manual stimulation. Sperm motility and kinematic parameters of five bottlenose dolphins (Tursiops sp.) were assessed using computer-aided sperm analysis (CASA). Sperm collected using BAVs showed non-significant increases in median progressive and rapid motility, and increases in median and mean linear motility, supporting a sexual selection functional hypothesis for the biodiverse vaginal folds unique to whales, dolphins, and porpoises. Sperm concentration decreased with BAV collection, while no consistent trends were detected in volume, pH, velocity, or plasma membrane integrity. Modifications to AVs for other species that incorporate genital morphologies may also optimize collected semen quality for application to artificial insemination. Full article
(This article belongs to the Section Marine Biology)
Show Figures

Graphical abstract

26 pages, 11154 KiB  
Article
The Pore Structure and Fractal Characteristics of Upper Paleozoic Coal-Bearing Shale Reservoirs in the Yangquan Block, Qinshui Basin
by Jinqing Zhang, Xianqing Li, Xueqing Zhang, Xiaoyan Zou, Yunfeng Yang and Shujuan Kang
Fractal Fract. 2025, 9(7), 467; https://doi.org/10.3390/fractalfract9070467 - 18 Jul 2025
Viewed by 214
Abstract
The investigation of the pore structure and fractal characteristics of coal-bearing shale is critical for unraveling reservoir heterogeneity, storage-seepage capacity, and gas occurrence mechanisms. In this study, 12 representative Upper Paleozoic coal-bearing shale samples from the Yangquan Block of the Qinshui Basin were [...] Read more.
The investigation of the pore structure and fractal characteristics of coal-bearing shale is critical for unraveling reservoir heterogeneity, storage-seepage capacity, and gas occurrence mechanisms. In this study, 12 representative Upper Paleozoic coal-bearing shale samples from the Yangquan Block of the Qinshui Basin were systematically analyzed through field emission scanning electron microscopy (FE-SEM), high-pressure mercury intrusion, and gas adsorption experiments to characterize pore structures and calculate multi-scale fractal dimensions (D1D5). Key findings reveal that reservoir pores are predominantly composed of macropores generated by brittle fracturing and interlayer pores within clay minerals, with residual organic pores exhibiting low proportions. Macropores dominate the total pore volume, while mesopores primarily contribute to the specific surface area. Fractal dimension D1 shows a significant positive correlation with clay mineral content, highlighting the role of diagenetic modification in enhancing the complexity of interlayer pores. D2 is strongly correlated with the quartz content, indicating that brittle fracturing serves as a key driver of macropore network complexity. Fractal dimensions D3D5 further unveil the synergistic control of tectonic activity and dissolution on the spatial distribution of pore-fracture systems. Notably, during the overmature stage, the collapse of organic pores suppresses mesopore complexity, whereas inorganic diagenetic processes (e.g., quartz cementation and tectonic fracturing) significantly amplify the heterogeneity of macropores and fractures. These findings provide multi-scale fractal theoretical insights for evaluating coal-bearing shale gas reservoirs and offer actionable recommendations for optimizing the exploration and development of Upper Paleozoic coal-bearing shale gas resources in the Yangquan Block of the Qinshui Basin. Full article
Show Figures

Figure 1

26 pages, 3044 KiB  
Article
Optimization of YF17D-Vectored Zika Vaccine Production by Employing Small-Molecule Viral Sensitizers to Enhance Yields
by Sven Göbel, Tilia Zinnecker, Ingo Jordan, Volker Sandig, Andrea Vervoort, Jondavid de Jong, Jean-Simon Diallo, Peter Satzer, Manfred Satzer, Kai Dallmeier, Udo Reichl and Yvonne Genzel
Vaccines 2025, 13(7), 757; https://doi.org/10.3390/vaccines13070757 - 16 Jul 2025
Viewed by 524
Abstract
Background: Modern viral vector production needs to consider process intensification for higher yields from smaller production volumes. However, innate antiviral immunity triggered in the producer cell may limit virus replication. While commonly used cell lines (e.g., Vero or E1A-immortalised cells) are already compromised [...] Read more.
Background: Modern viral vector production needs to consider process intensification for higher yields from smaller production volumes. However, innate antiviral immunity triggered in the producer cell may limit virus replication. While commonly used cell lines (e.g., Vero or E1A-immortalised cells) are already compromised in antiviral pathways, the redundancy of innate signaling complicates host cell optimization by genetic engineering. Small molecules that are hypothesized to target antiviral pathways (Viral Sensitizers, VSEs) added to the culture media offer a versatile alternative to genetic modifications to increase permissiveness and, thus, viral yields across multiple cell lines. Methods: To explore how the yield for a chimeric Zika vaccine candidate (YF-ZIK) could be further be increased in an intensified bioprocess, we used spin tubes or an Ambr15 high-throughput microbioreactor system as scale-down models to optimize the dosing for eight VSEs in three host cell lines (AGE1.CR.pIX, BHK-21, and HEK293-F) based on their tolerability. Results: Addition of VSEs to an already optimized infection process significantly increased infectious titers by up to sevenfold for all three cell lines tested. The development of multi-component VSE formulations using a design of experiments approach allowed further synergistic titer increases in AGE1.CR.pIX cells. Scale-up to 1 L stirred-tank bioreactors and 3D-printed mimics of 200 or 2000 L reactors resulted in up to threefold and eightfold increases, respectively. Conclusions: Addition of single VSEs or combinations thereof allowed a further increase in YF-ZIK titers beyond the yield of an already optimized, highly intensified process. The described approach validates the use of VSEs and can be instructive for optimizing other virus production processes. Full article
Show Figures

Graphical abstract

16 pages, 2025 KiB  
Article
Coating Performance of Heat-Treated Wood: An Investigation in Populus, Quercus, and Pinus at Varying Temperatures
by Andromachi Mitani, Paschalina Terzopoulou, Konstantinos Ninikas, Dimitrios Koutsianitis and Georgios Ntalos
Forests 2025, 16(7), 1159; https://doi.org/10.3390/f16071159 - 14 Jul 2025
Viewed by 156
Abstract
Thermal modification applies to a technique for the enhancement of biological durability, stability, and appearance of wood. Much is known about its effects on the chemical and physical attributes of wood. However, there is a knowledge gap concerning the effects of heat treatment [...] Read more.
Thermal modification applies to a technique for the enhancement of biological durability, stability, and appearance of wood. Much is known about its effects on the chemical and physical attributes of wood. However, there is a knowledge gap concerning the effects of heat treatment on surface coating performance of different wood species. The focus of this research is heat treatment regulation of 160 °C, 180 °C, and 200 °C for three commercially important wood species which are Populus (poplar), Quercus (oak), and Pinus (pine). These treatments were evaluated in relation to coating performance indicators adhesion, integrity, and visual stability during and after natural and artificial weathering. It was revealed that specific responses among species differences exist. Populus behaved differently and exhibited a steady loss in mass and volume. Quercus demonstrated gradual degradation alongside enhanced lignin stability. Pinus exhibited maintenance of volume and mass until 180 °C after which accelerated degradation was observed. Coating durability and adhesion exhibited dependence on thermal condition, wood species, porosity, surface chemistry and microstructural variations that occurred. The research results can be used to streamline finishing processes for thermally modified wood while underscoring the critical nature of precise treatment parameter adjustments guided by species-specific responses to ensure long-term stability. Full article
(This article belongs to the Section Wood Science and Forest Products)
Show Figures

Figure 1

19 pages, 3181 KiB  
Article
Overexpression of BDNF and uPA Combined with the Suppression of Von Hippel–Lindau Tumor Suppressor Enhances the Neuroprotective Activity of the Secretome of Human Mesenchymal Stromal Cells in the Model of Intracerebral Hemorrhage
by Stalik S. Dzhauari, Alexandra L. Primak, Nataliya A. Basalova, Natalia I. Kalinina, Anna O. Monakova, Kirill D. Bozov, Arkadiy Ya. Velichko, Maria E. Illarionova, Olga A. Grigorieva, Zhanna A. Akopyan, Vladimir S. Popov, Pavel G. Malkov, Anastasia Yu. Efimenko, Vsevolod A. Tkachuk and Maxim N. Karagyaur
Int. J. Mol. Sci. 2025, 26(14), 6697; https://doi.org/10.3390/ijms26146697 - 12 Jul 2025
Viewed by 261
Abstract
Nerve tissue damage is an unsolved problem in modern neurology and neurosurgery, which prompts the need to search for approaches to stimulate neuroprotection and regeneration of neural tissue. Earlier we have shown that the secretome of human mesenchymal stromal cells (MSCs) stimulates rat [...] Read more.
Nerve tissue damage is an unsolved problem in modern neurology and neurosurgery, which prompts the need to search for approaches to stimulate neuroprotection and regeneration of neural tissue. Earlier we have shown that the secretome of human mesenchymal stromal cells (MSCs) stimulates rat survival, reduces the severity of neurological deficits, and decreases the volume of brain damage in a hemorrhagic stroke model. A significant disadvantage of using the MSC secretome is the need to concentrate it (at least 5–10 fold) to achieve appreciable pharmacological activity. This increases the cost of obtaining clinically applicable amounts of secretome and slows down the clinical translation of this technology. Here, we created a number of genetically modified human MSC cultures, including immortalized MSCs and those with hyperexpression of brain-derived neurotrophic factor (BDNF) and urokinase-type plasminogen activator (uPA) and with suppressed expression of Von Hippel–Lindau tumor suppressor (VHL), and we evaluated the pharmacological activity of their secretomes in a model of intracerebral hemorrhage (ICH) in rats. The secretome of MSCs immortalized by hyperexpression of the catalytic subunit of human telomerase (hTERT) revealed neuroprotective activity indistinguishable from that of primary MSC cultures, yet it still required 10-fold concentration to achieve neuroprotective efficacy. The secretome of MSC culture with combined hyperexpression of BDNF and uPA and suppressed expression of Von Hippel–Lindau tumor suppressor even without additional concentration reduced the severity of neurological disorders and decreased brain lesion volume in the ICH model. The secretomes of MSCs with separate overexpression of BDNF and uPA or suppression of VHL had no such effect or, on the contrary, revealed a toxic effect in the ICH model. Presumably, this may be due to an imbalance in the representation of individual growth factors in the secretome of genetically modified MSCs, which individually may lead to undesirable effects in damaged nervous tissue, such as increased permeability of the blood–brain barrier (under the influence of pro-angiogenic factors) or neural cell apoptosis (due to an excess of neurotrophic factors). The obtained data show that genetic modification of MSC cultures can enhance or alter the therapeutic activity of their secretomes, which can be used in the creation of promising sources of biopharmaceutical substances. Full article
Show Figures

Figure 1

27 pages, 9385 KiB  
Article
Comparative Analysis of Studies of Geological Conditions at the Planning and Construction Stage of Dam Reservoirs: A Case Study of New Facilities in South-Western Poland
by Maksymilian Połomski, Mirosław Wiatkowski and Gabriela Ługowska
Appl. Sci. 2025, 15(14), 7811; https://doi.org/10.3390/app15147811 - 11 Jul 2025
Viewed by 179
Abstract
Geological surveys have vital importance at the planning stage of dammed reservoir construction projects. The results of these surveys determine the majority of the technical solutions adopted in the construction design to ensure the proper safety and stability parameters of the structure during [...] Read more.
Geological surveys have vital importance at the planning stage of dammed reservoir construction projects. The results of these surveys determine the majority of the technical solutions adopted in the construction design to ensure the proper safety and stability parameters of the structure during water damming. Where the ground type is found to be different from what is expected, the construction project may be delayed or even cancelled. This study analyses issues and design modifications caused by the identification of different soil conditions during the construction of four new flood control reservoirs in the Nysa Kłodzka River basin in south-western Poland. The key findings are as follows: (1) a higher density of exploratory boreholes in areas with potentially fractured rock mass is essential for selecting the appropriate anti-filtration protection; (2) when deciding to apply deep piles, it is reasonable to verify, at the planning stage, whether they can be installed using the given technology directly at the planned site; (3) inaccurate identification of foundation soils under the dam body can lead to significant design modifications—in contrast, a denser borehole grid helps to determine the precise elevation of the base layer, which is essential for reliably estimating the volume of material required for the embankment; (4) in order to correctly assess the soil deposits located, for instance, in the reservoir basin area, it is more effective to use test excavations rather than relying solely on borehole-based investigations—as a last resort, test excavations can be used to supplement the latter. Full article
Show Figures

Figure 1

39 pages, 3629 KiB  
Review
Radiative Heat Transfer Properties of Fiber–Aerogel Composites for Thermal Insulation
by Mohanapriya Venkataraman, Sebnem Sözcü and Jiří Militký
Gels 2025, 11(7), 538; https://doi.org/10.3390/gels11070538 - 11 Jul 2025
Viewed by 355
Abstract
Fiber–aerogel composites have gained significant attention as high-performance thermal insulation materials due to their unique microstructure, which suppresses conductive, convective, and radiative heat transfer. At room temperature, silica aerogels in particular exhibit ultralow thermal conductivity (<0.02 W/m·K), which is two to three times [...] Read more.
Fiber–aerogel composites have gained significant attention as high-performance thermal insulation materials due to their unique microstructure, which suppresses conductive, convective, and radiative heat transfer. At room temperature, silica aerogels in particular exhibit ultralow thermal conductivity (<0.02 W/m·K), which is two to three times lower than that of still air (0.026 W/m·K). Their brittle skeleton and high infrared transparency, however, restrict how well they insulate, particularly at high temperatures (>300 °C). Incorporating microscale fibers into the aerogel matrix enhances mechanical strength and reduces radiative heat transfer by increasing scattering and absorption. For instance, it has been demonstrated that adding glass fibers reduces radiative heat transmission by around 40% because of increased infrared scattering. This review explores the fundamental mechanisms governing radiative heat transfer in fiber–aerogel composites, emphasizing absorption, scattering, and extinction coefficients. We discuss recent advancements in fiber-reinforced aerogels, focusing on material selection, structural modifications, and predictive heat transfer models. Recent studies indicate that incorporating fiber volume fractions as low as 10% can reduce the thermal conductivity of composites by up to 30%, without compromising their mechanical integrity. Key analytical and experimental methods for determining radiative properties, including Fourier transform infrared (FTIR) spectroscopy and numerical modeling approaches, are examined. The emissivity and transmittance of fiber–aerogel composites have been successfully measured using FTIR spectroscopy; tests show that fiber reinforcement at high temperatures reduces emissivity by about 15%. We conclude by outlining the present issues and potential avenues for future research to optimize fiber–aerogel composites for high-temperature applications, including energy-efficient buildings (where long-term thermal stability is necessary), electronics thermal management systems, and aerospace (where temperatures may surpass 1000 °C), with a focus on improving the materials’ affordability and scalability for industrial applications. Full article
(This article belongs to the Special Issue Synthesis and Application of Aerogel (2nd Edition))
Show Figures

Figure 1

15 pages, 452 KiB  
Systematic Review
The Efficacy of Neoantigen-Loaded Dendritic Cell Vaccine Immunotherapy in Non-Metastatic Gastric Cancer
by Menelaos Papakonstantinou, Paraskevi Chatzikomnitsa, Areti Danai Gkaitatzi, Athanasia Myriskou, Alexandros Giakoustidis, Dimitrios Giakoustidis and Vasileios N. Papadopoulos
Med. Sci. 2025, 13(3), 90; https://doi.org/10.3390/medsci13030090 - 11 Jul 2025
Viewed by 698
Abstract
Introduction: Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Even though surgery and chemotherapy are the mainstay of treatment, immunotherapy, and more specifically anti-tumor vaccination, has gained popularity over the past years due to the lower related toxicity and [...] Read more.
Introduction: Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. Even though surgery and chemotherapy are the mainstay of treatment, immunotherapy, and more specifically anti-tumor vaccination, has gained popularity over the past years due to the lower related toxicity and fewer long-term side effects. Dendritic cell (DC) vaccines have been shown to induce tumor specific cytotoxic T-cell (CTL) responses both in vitro and in vivo; however, due to the nature of the disease, resistance to immunotherapy is often developed. Various modifications, such as the implementation of viral vectors, tumor RNA, or even tumor-specific peptides (neoantigens), have been studied as a means to avoid resistance and enhance the effectiveness of the vaccines. In this review, we aim to assess the effects of neoantigen-loaded DC vaccines (naDCVs) on the immune response against gastric cancer cells. Materials and methods: A thorough literature search was conducted on PubMed and clinicaltrials.gov for studies assessing the efficacy of naDCVs against gastric cancer both in vivo and in vitro. The studies were assessed for eligibility by two independent reviewers based on predetermined inclusion and exclusion criteria. The search was completed following the PRISMA guidelines. Results: Eleven studies were included in our systematic review. In five of the studies, the effects of the naDCVs were tested in vitro; in two and in four they were examined both in vitro and in vivo. The in vitro studies showed that the naDCVs resulted in a more robust immune response against the cancer cells in the study groups compared to the control groups. The in vivo studies conducted on mice showed that tumor volume was reduced in the groups treated with the naDCV compared to the untreated groups. What is more, the cytotoxic effect of CTLs against tumor cells was also increased in the vaccine groups. One of the studies was conducted on humans as a phase I study. The results show increased CTL proliferation and cytokine production in the vaccinated group compared to the control, but no difference regarding the tumor size was observed. Conclusions: Neoantigen-loaded DC vaccines can stimulate a strong immune response against specific gastric cancer cell peptides and enhance tumor cell lysis, therefore hindering or even reversing disease progression, offering great potential for the treatment of patients with gastric cancer. Full article
(This article belongs to the Special Issue Feature Papers in Section Cancer and Cancer-Related Diseases)
Show Figures

Figure 1

18 pages, 2162 KiB  
Article
Simultaneous Decontamination for Ammonia Nitrogen and Phosphate Efficiently by Crystal Morphology MgO-Coated Functional Biochar Derived from Sludge and Sunflower Stalk
by Zhiwei Li, Jingxin Huang, Weizhen Zhang, Hao Yu and Yin Wang
Toxics 2025, 13(7), 577; https://doi.org/10.3390/toxics13070577 - 9 Jul 2025
Viewed by 303
Abstract
Eutrophication driven by nitrogen and phosphorus discharge remains a critical global environmental challenge. This study developed a sustainable strategy for synergistic nutrient removal and recovery by fabricating MgO-coated biochar (Mg-MBC600) through co-pyrolysis of municipal sludge and sunflower stalk (300–700 °C). Systematic investigations revealed [...] Read more.
Eutrophication driven by nitrogen and phosphorus discharge remains a critical global environmental challenge. This study developed a sustainable strategy for synergistic nutrient removal and recovery by fabricating MgO-coated biochar (Mg-MBC600) through co-pyrolysis of municipal sludge and sunflower stalk (300–700 °C). Systematic investigations revealed temperature-dependent adsorption performance, with optimal nutrient removal achieved at 600 °C pyrolysis. The Mg-MBC600 composite exhibited enhanced physicochemical properties, including a specific surface area of 156.08 m2/g and pore volume of 0.1829 cm3/g, attributable to magnesium-induced structural modifications. Advanced characterization confirmed the homogeneous dispersion of MgO nanoparticles (~50 nm) across carbon matrices, forming active sites for chemisorption via electron-sharing interactions. The maximum adsorption capacities of Mg-MBC600 for nitrogen and phosphorus reached 84.92 mg/L and 182.27 mg/L, respectively. Adsorption kinetics adhered to the pseudo-second-order model, indicating rate-limiting chemical bonding mechanisms. Equilibrium studies demonstrated hybrid monolayer–multilayer adsorption. Solution pH exerted dual-phase control: acidic conditions (pH 3–5) favored phosphate removal through Mg3(PO4)2 precipitation, while neutral–alkaline conditions (pH 7–8) promoted NH4+ adsorption via MgNH4PO4 crystallization. XPS analysis verified that MgO-mediated chemical precipitation and surface complexation dominated nutrient immobilization. This approach establishes a circular economy framework by converting waste biomass into multifunctional adsorbents, simultaneously addressing sludge management challenges and enabling eco-friendly wastewater remediation. Full article
(This article belongs to the Special Issue Environmental Study of Waste Management: Life Cycle Assessment)
Show Figures

Figure 1

12 pages, 1742 KiB  
Article
Studies on Molecular Dynamics Simulation and Reaction Mechanism for Methane Adsorption in Long-Flame Coal Modified by Cyclical Microwave Treatment
by Guofei Zhao, Yongbo Cai, Tianbai Zhou, Guangtong Yang, Long Wang, Liankun Zhang, Yuefang Wang and Xiaoyu Zhang
Processes 2025, 13(7), 2134; https://doi.org/10.3390/pr13072134 - 4 Jul 2025
Viewed by 303
Abstract
A quantitative characterization of the change in coal molecular structures with different cyclical microwave modification parameters and a better understanding of the reaction mechanism of the modification are of great significance for the commercial extraction of coal bed methane (CBM). Therefore, long-flame coal [...] Read more.
A quantitative characterization of the change in coal molecular structures with different cyclical microwave modification parameters and a better understanding of the reaction mechanism of the modification are of great significance for the commercial extraction of coal bed methane (CBM). Therefore, long-flame coal samples obtained from the Ordos Basin, China, were modified by microwave radiation with different times, and the long-flame coal molecular structure parameters were determined by solid-state 13C nuclear magnetic resonance (ss13C NMR), Fourier transform infrared (FTIR) spectrometry, and X-ray photoelectron spectrometry (XPS). Atomistic representations of the raw long-flame coal molecular model and modified long-flame coal molecular models were established. The temperature rise, pore volume increase, mineral removal, and functional group changes after the modification have a negative effect on methane adsorption. After the modification, the decrease in surface area of the micropores reduced the adsorption site of methane in coal. As a result, the methane adsorption amount decreased linearly with the decreasing surface area. The CH4 adsorption isotherms of the long-flame models were dynamically simulated and analyzed. The results of this study can prove that after multiple cycles of microwave modifications, the functional groups in long-flame coal were fractured, and the number of micropores was reduced, which effectively decreased the methane adsorption performance in long-flame coal seams, thereby promoting methane extraction. Microwave modification is a promising method for enhancing CBM recovery. Full article
Show Figures

Figure 1

19 pages, 5973 KiB  
Article
Chitosan-Modified SBA-15 as a Support for Transition Metal Catalysts in Cyclohexane Oxidation and Photocatalytic Hydrogen Evolution
by Assemgul S. Auyezkhanova, Alima K. Zharmagambetova, Eldar T. Talgatov, Aigul I. Jumekeyeva, Sandugash N. Akhmetova, Zhannur K. Myltykbayeva, Imge Kalkan, Atıf Koca, Akzhol A. Naizabayev and Aigul T. Zamanbekova
Catalysts 2025, 15(7), 650; https://doi.org/10.3390/catal15070650 - 3 Jul 2025
Viewed by 475
Abstract
This work aims to study the catalytic properties of Fe, Cr, and Cu catalysts deposited on chitosan–silica (SBA-15) composites in liquid phase oxidation of cyclohexane (CH) with H2O2 and photocatalytic hydrogen evolution reaction. The catalysts were obtained by consecutive adsorption [...] Read more.
This work aims to study the catalytic properties of Fe, Cr, and Cu catalysts deposited on chitosan–silica (SBA-15) composites in liquid phase oxidation of cyclohexane (CH) with H2O2 and photocatalytic hydrogen evolution reaction. The catalysts were obtained by consecutive adsorption of chitosan (CS) and metal ions (Fe3+, Cr3+, Cu2+) on SBA-15 at ambient conditions. Characterization of the catalysts by XRD, IR spectroscopy, XPS, TEM, SEM, etc., showed the CS and metal ion adsorption on the solid support. Modification with CS provided better immobilization of the metal ions on SBA-15. The synthesized catalysts demonstrated different performance in liquid phase oxidation of cyclohexane with H2O2 under mild conditions at 40 °C and atmospheric pressure. Cyclohexane conversion on Fe–CS/SBA-15 (18.5%) and Cr–CS/SBA-15 (21.6%) was higher than on Cu–CS/SBA-15 (9.3%). The influence of different conditions of the reaction such as time, temperature, catalyst dosage, substrate and oxidant ratio on cyclohexane conversion in the presence of the most efficient Cr–CS/SBA-15 catalyst was also studied. The optimal reaction conditions were found to be the following: duration of reaction—4 h, temperature of reaction—50 °C, mcat—0.03 g, a substrate/H2O2 ratio of 1:3. In addition, Cr–CS/SBA-15 and Fe–CS/SBA-15 catalysts were studied in a photocatalytic H2 evolution reaction. The Fe-containing catalyst demonstrated superior efficiency in photocatalytic H2 evolution. The total volume of hydrogen produced within 3 h was 103 mL/g. Thus, this study demonstrates that chitosan possesses promising potential in the design of the supported catalysts for cyclohexane oxidation and photocatalytic hydrogen evolution reactions. Full article
(This article belongs to the Special Issue Homogeneous and Heterogeneous Catalytic Oxidation and Reduction)
Show Figures

Graphical abstract

19 pages, 2575 KiB  
Article
Formulation-Dependent Extrudability of Highly Filled Alginate System for Vaginal Drug Delivery
by Arianna Chiappa, Alice Fusari, Marco Uboldi, Fabiana Cavarzan, Paola Petrini, Lucia Zema, Alice Melocchi and Francesco Briatico Vangosa
Gels 2025, 11(7), 510; https://doi.org/10.3390/gels11070510 - 1 Jul 2025
Viewed by 271
Abstract
The incorporation of solid particles as a filler to a hydrogel is a strategy to modulate its properties for specific applications, or even to introduce new functionalities to the hydrogel itself. The efficacy of such a modification depends on the filler content and [...] Read more.
The incorporation of solid particles as a filler to a hydrogel is a strategy to modulate its properties for specific applications, or even to introduce new functionalities to the hydrogel itself. The efficacy of such a modification depends on the filler content and its interaction with the hydrogel matrix. In drug delivery applications, solid particles can be added to hydrogels to improve drug loading capacity, enable the inclusion of poorly soluble drugs, and modulate release kinetics. This work focuses on the case of alginate (ALG)-based hydrogels, obtained following an internal gelation procedure using CaCO3 as the Ca2+ source and containing a high solid volume fraction (up to 50%) of metronidazole (MTZ), a drug with low water solubility, as a potential extrusion-based drug delivery system. The impact of the hydrogel precursor composition (ALG and MTZ content) on the rheological behavior of the filled hydrogel and precursor suspension were investigated, as well as the hydrogel stability and MTZ dissolution. In the absence of solid MTZ, the precursor solutions showed a slightly shear thinning behavior, more accentuated with the increase in ALG concentration. The addition of drugs exceeding the saturation concentration in the precursor suspension resulted in a substantial increase (about one order of magnitude) in the low-shear viscosity and, for the highest MTZ loadings, a yield stress. Despite the significant changes, precursor formulations retained their extrudability, as confirmed by both numerical estimates and experimental validation. MTZ particles did not affect the crosslinking of the precursors to form the hydrogel, but they did control its viscoelastic behavior. In unfilled hydrogels, the ALG concentration controls stability (from 70 h for the lowest concentration to 650 h for the highest) upon immersion in acetate buffer at pH 4.5, determining the MTZ release/hydrogel dissolution behavior. The correlations between composition and material properties offer a basis for building predictive models for fine-tuning their composition of highly filled hydrogel systems. Full article
(This article belongs to the Special Issue Recent Research on Alginate Hydrogels in Bioengineering Applications)
Show Figures

Figure 1

18 pages, 2325 KiB  
Article
Ultrasound Improves Gallbladder Contraction Function: A Non-Invasive Experimental Validation Using Small Animals
by Run Guo, Tian Chen, Fan Ding, Li-Ping Liu, Fang Chen, Gang Zhao and Bo Zhang
Bioengineering 2025, 12(7), 716; https://doi.org/10.3390/bioengineering12070716 - 30 Jun 2025
Viewed by 333
Abstract
Background: Gallbladder hypomotility is a key pathogenic factor in cholelithiasis. Non-invasive interventions to enhance gallbladder contractility remain limited. Ultrasound therapy has shown promise in various muscular disorders, but its effects on gallbladder function are unexplored. Methods: This study employed low-intensity pulsed ultrasound (LIPUS) [...] Read more.
Background: Gallbladder hypomotility is a key pathogenic factor in cholelithiasis. Non-invasive interventions to enhance gallbladder contractility remain limited. Ultrasound therapy has shown promise in various muscular disorders, but its effects on gallbladder function are unexplored. Methods: This study employed low-intensity pulsed ultrasound (LIPUS) at a 3 MHz frequency and 0.8 W/cm2 intensity with a 20% duty cycle to irradiate the gallbladder region of fasting guinea pigs. Gallbladder contractile function was evaluated through multiple complementary approaches: in vivo assessment via two-dimensional/three-dimensional ultrasound imaging to monitor volumetric changes; quantitative functional evaluation using nuclear medicine scintigraphy (99mTc-HIDA); and ex vivo experiments including isolated gallbladder muscle strip tension measurements, histopathological analysis, α-smooth muscle actin (α-SMA) immunohistochemistry, and intracellular calcium fluorescence imaging. Results: Ultrasound significantly enhanced gallbladder emptying, evidenced by the volume reduction and increased ejection fraction. Scintigraphy confirmed accelerated bile transport in treated animals. Ex vivo analyses demonstrated augmented contractile force, amplitude, and frequency in ultrasound-treated smooth muscle. Histological examination revealed smooth muscle hypertrophy, α-SMA upregulation, and elevated intracellular calcium levels. Extended ultrasound exposure produced sustained functional improvements without tissue damage. Conclusions: Ultrasound effectively enhances gallbladder contractile function through mechanisms involving smooth muscle structural modification and calcium signaling modulation. These findings establish the experimental foundation for ultrasound as a promising non-invasive therapeutic approach to improve gallbladder motility and potentially prevent gallstone formation. Full article
Show Figures

Figure 1

20 pages, 4351 KiB  
Article
Preparation and Enhanced Oil Recovery Mechanisms of Janus-SiO2-Reinforced Polymer Gel Microspheres
by Fei Gao, Baolei Liu, Yuelong Liu, Lei Xing and Yan Zhang
Gels 2025, 11(7), 506; https://doi.org/10.3390/gels11070506 - 30 Jun 2025
Cited by 1 | Viewed by 315
Abstract
In order to improve oil recovery efficiency in low-permeability reservoirs, this study developed amphiphilic Janus-SiO2 nanoparticles to prepare polymer gel microspheres for enhanced oil recovery (EOR). Firstly, Janus-SiO2 nanoparticles were synthesized via surface modification using (3-aminopropyl)triethoxysilane and α-bromoisobutyryl bromide. Fourier-transform infrared [...] Read more.
In order to improve oil recovery efficiency in low-permeability reservoirs, this study developed amphiphilic Janus-SiO2 nanoparticles to prepare polymer gel microspheres for enhanced oil recovery (EOR). Firstly, Janus-SiO2 nanoparticles were synthesized via surface modification using (3-aminopropyl)triethoxysilane and α-bromoisobutyryl bromide. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) characterization confirmed the successful grafting of amino and styrene chains, with the particle size increasing from 23.8 nm to 32.9 nm while maintaining good dispersion stability. The Janus nanoparticles exhibited high interfacial activity, reducing the oil–water interfacial tension to 0.095 mN/m and converting the rock surface wettability from oil-wet (15.4°) to strongly water-wet (120.6°), thereby significantly enhancing the oil stripping efficiency. Then, polymer gel microspheres were prepared by reversed-phase emulsion polymerization using Janus-SiO2 nanoparticles as emulsifiers. When the concentration range of nanoparticles was 0.1–0.5 wt%, the particle size range of polymer gel microspheres was 316.4–562.7 nm. Polymer gel microspheres prepared with a high concentration of Janus-SiO2 nanoparticles can ensure the moderate swelling capacity of the particles under high-temperature and high-salinity conditions. At the same time, it can also improve the mechanical strength and shear resistance of the microspheres. Core displacement experiments confirmed the dual synergistic effect of this system. Polymer gel microspheres can effectively plug high-permeability zones and improve sweep volume, while Janus-SiO2 nanoparticles enhance oil displacement efficiency. Ultimately, this system achieved an incremental oil recovery of 19.72%, exceeding that of conventional polymer microsphere systems by more than 5.96%. The proposed method provides a promising strategy for improving oil recovery in low-permeability heterogeneous reservoir development. Full article
(This article belongs to the Special Issue Gels for Oil and Gas Industry Applications (3rd Edition))
Show Figures

Graphical abstract

Back to TopTop