Search Results (36)

Skin aging is accelerated by inflammation processes generated by oxidative stress and external factors such as UV radiation. Plants belonging to the genus Kalanchoe that are rich sources of antioxidants could potentially strengthen the skin barrier if used as ingredients in cosmetic formulations. However, their use is limited due to the contents of bufadienolides, known cardiotoxins. This study aimed to establish a semi-quantitative profile of bufadienolides in the juices of K. blossfeldiana, K. daigremontiana, and K. pinnata using UHPLC combined with charged aerosol detection (CAD) and high-resolution mass spectrometry (HR-MS). Additionally, the study determined the ability of bufadienolides to penetrate the skin barrier using the Bronaugh Diffusion Cell Apparatus and Strat-M membrane. The study also assessed the ferric and molybdenum-reducing powers, as well as the radical scavenging capabilities of these plants juices using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) methods. The in vitro antihyaluronidase and antityrosinase activities and sun protection factor (SPF) were evaluated spectrophotometrically, indicating moderate capability to inhibit the skin enzymes, but low SPF protection for all analyzed juices. The semi-qualitative analysis demonstrated the presence of bufadienolides occurring in two juices from K. daigremontiana and K. pinnata, with the highest contents of 1,3,5-bersaldegenin-orthoacetate, bryophyllin-A/bryotoxin-C, bersaldegenin-acetate/bryophyllin-C, and diagremontianin. After passing through the skin model, no bufadienolide compounds were present in the subcutaneous filtrate. Antiradical and reduction assays revealed the antioxidant potential of K. blossfeldiana and K. pinnata. These results indicate that Kalanchoe juices have antiaging potential and appear safe for dermal applications. Full article

Microplastics are plastic particles ranging in size from 1 μm to 5 mm, emitted at the source or resulting from the degradation of larger objects. Today, their global distribution is one of the major environmental problems recognized by the United Nations Sustainable Development Goals, polluting aquatic, terrestrial and atmospheric systems and requiring avant-garde solutions. Solid–liquid filtration is widely used in both industrial and biological systems, where some aquatic species are examined using very specialized filter-feeding apparatus, and when applied to industrial processes, microparticles can be separated from the water while minimizing maintenance costs, as they require less backwashing or additional energy consumption. The REMOURE project uses the Mediterranean species Mobula mobular (Bonnaterre, 1788) as a reference for the testing and optimization of low-cost microplastic filters applied to wastewater. For this purpose, a hydrodynamic test rig was designed and constructed by considering the hydraulic feeding conditions of the marine species, with a scale factor of 6. This paper presents the design conditions and the evaluation of the test results for the combination of three different variables: (1) flap disposition (two different models were considered); (2) inclination with respect to the flow direction; and (3) flow velocity. The models were printed in polyamide and videos were recorded to evaluate the behaviour of dye injection through the lobes. The videos were processed, and the results were statistically treated and used to calibrate a CFD model to optimize the filter design to be studied in a prototype wastewater treatment plant. Full article

Sediment barriers are used on construction sites to protect downstream waterbodies from the impacts of sediment-laden stormwater runoff. Although ubiquitous on construction sites, many sediment barrier practices lack performance-based testing to determine effectiveness and treatment mechanisms, with previous evaluations being limited to conditions local to the Southeastern U.S., with conditions in other regions remaining untested. Testing was conducted to determine the effectiveness of woven silt fence barriers and provide structural improvements to common installation methods. Testing was conducted using a large-scale sediment barrier testing apparatus at the Auburn University—Stormwater Research Facility. The results from testing indicate that Nebraska DOT standard silt fence installations can be improved to reduce the risk of structural failures such as undermining, complete installation failure, slow dewatering, and overtopping. To improve structural performance, four modifications (a 15.2 cm [6 in.] offset trench, wooden posts, a dewatering board with an overflow weir, and a dewatering board with an overflow weir with adjusted post spacing) were tested. On average, 83% of introduced sediment was retained behind the tested barriers. The water quality results across the testing of standard and modified installations indicated that stormwater treatment was due to sedimentation within the impoundment formed by silt fence installations and not filtration through geotextile fabric. Full article

The aim of this research was to measure the filtration properties of waste coal ash under the influence of hydrostatic pressure generated in a three-axial compression apparatus. The scope of work included determining the compactibility parameters, maximum bulk density and optimal moisture content. Permeability tests were performed for a sample with an average grain composition at three compaction indices $I_S$: 0.964, 0.98 and 1.00. The hydrostatic pressure ranging from 0.5 to 1.8 bar corresponded to the layer depths from 2.17 to 7.83 m. Gradually increasing the pressure during the first loading cycle caused irreversible changes in the structure of the sample by local material agglomeration or grain interlocking. The water permeability coefficient was higher in the second loading cycle than in the first cycle. It was shown that waste coal ash cannot be used as a construction material on its own. To obtain constant filtration properties, the waste coal ash material should be doped, or an optimal compactionshould be used ($I_S$ = 1.00). The results presented in this study are important for assessing the use of waste coal ash for construction engineering purposes. Full article

The elimination and retrieval of slag produced during the hot-dip galvanizing process are crucial in reducing plating defects and enhancing economic efficiency. Hot-dip galvanizing slag can be separated and purified efficiently by using graphite carbon felt filtration in a supergravity field. The effects of the gravity coefficient (G), separation temperature (T), and separation time (t) on the separation efficiency were investigated. Under the optimal conditions as G = 300, T = 460 °C, and t = 120 s, these conditions yielded filtered zinc with 0.022 wt% Fe and 1.097 wt% Al. The separation efficiencies achieved were 87% for the acquisition ratio of filtered zinc (A_Zn), 93.67% for the recovery ratio of zinc (R_Zn), and 96.01% for the loss ratio of iron (L_Fe). Based on these laboratory findings, an amplified centrifugal separation apparatus was conceptually designed for future online separation and recycle of zinc slag on an engineering scale. The filtered zinc obtained from this apparatus contained 0.027 wt% Fe and 1.844 wt% Al, while the recovery ratio of zinc (R_Zn) and the loss ratio of iron (L_Fe) achieved 85.97% and 95.47%, respectively. Full article

Small-scale continuous apparatuses for solid product manufacturing are receiving increasing interest due to the demand for the fast market availability of specialty chemical products manufactured in integrated and modular processing plants. Relevant unit operations span from crystallization over solid–liquid separation and filter cake washing to drying. For this purpose, the quasi-continuous filter belt crystallizer (QCFBC) was developed and is presented here. The newly integrated unit operations with positive pressure filtration ($\Delta p_{\max }$ = 0.8 bar), filter cake washing (${\dot{V}}_{\mathrm{wash}}$ = 55 mL·min⁻¹), and convection drying ($T_{\mathrm{dry}}$ = 60 °C) have been individually characterized and integrated into the filter apparatus that has been modified for continuous operation. They were synchronized with the flexible cooling crystallization, enabling for a seamless production process. Sucrose in water was used as model substance system. Long-term operations of up to 14 h were successfully performed with dry product filter cakes (22.64 g ± 1.64 g·h⁻¹) of constant quality attributes ($x_{50,3}$ = 216.095 ± 14.766, $span$ = 0.347 ± 0.109, $Y_{\mathrm{rel}.}$ = 69.9% ± 5%, $X_{\mathrm{RM}}$ = 1.64 mg·g⁻¹ ± 1.38 mg·g⁻¹). Full article

Nano-water-based drilling fluids (NWBDFs) are prepared using nano-copper oxide (CuO) and multiwalled carbon nanotubes (MWCNTs) as modification materials. The effects of the temperature and concentration of the nanoparticles (NPs) on the rheological properties are studied using a rotational rheometer and viscometer. Also, the influence of two NPs on the filtration properties is studied using a low-pressure and low-temperature filtration apparatus, as well as a scanning electron microscope (SEM). It is found that MWCNTs with a concentration of $0.05 w/v\%$ have the most obvious influence on the NWBDFs, which improve the stability of the gel structure against temperature and also decrease the filtration rate. Finally, a theoretical model predicating the yield point ($\mathrm{YP}$) and the plastic viscosity (PV) as a function of the temperature considering the influence of the NPs is developed based on DLVO theory. Full article

The detection and quantification of micro(nano)plastics in the marine environment are essential requirements to understand the full impacts of plastic pollution on the ecosystem and human health. Here, static light scattering (SLS) and dynamic (DLS) light scattering techniques are assessed for their capacity to detect colloidal particles with diameters between d = 0.1 and 0.8 µm at very low concentrations in seawater. The detection limit of the apparatus was determined using model monodisperse spherical polystyrene latex particles with diameters of 0.2 µm and 0.5 µm. It is shown that the concentration and size of colloids can be determined down to about 10⁻⁶ g/L. Light scattering measurements on seawater obtained from different locations in Western Europe show that colloidal particles were detected with DLS in seawater filtered through 0.8 µm pore size filters. The concentration of these particles was not higher than 1 µg/L, with an average diameter of about 0.6 µm. We stress that these particles are not necessarily plastic. No particles were detected after filtration through 0.45 µm pore size filters. Full article

The present work sheds light on the potentiality of proteins extracted from oak (Quercus robur) leaves to treat both drinking water and industrial oily wastewater. The work was structured in three steps: firstly, oak leaves in powder form were analyzed by FTIR, XRD and SEM, thus showing the presence of proteins acting as bio-coagulants; secondly, an experimental design was conducted. According to the design of experiences based on fractional design (2⁸⁻⁴), the highest protein concentration (4.895 mg/g) was obtained for the following operating parameters: no filtration, pH of 12, temperature of 20 °C, stirring speed of 300 rpm, stirring time of 60 min, maceration time of 4 h, centrifugation speed of 400 rpm, centrifugation time of 10 min. Finally, a jar test apparatus was used to study the effects of proteins from oak leaves on the characteristics of both drinking water and industrial oily wastewater. In drinking water, the turbidity was reduced from 15.7 to 4.82 NTU when 0.098 mg/L of oak leaves protein was added, thus satisfying the requirements of the national drinking water standards; whereas, in industrial oily wastewater turbidity, total suspended solids, chemical oxygen demand and organic matter were reduced by 96.87, 89.86, 96.39 and 46.28%, respectively, when 0.538 mg/L of oak leaves protein was added. This study opens new perspectives related to the research and development of organic coagulants applicable to industrial wastewater treatment. Full article

Increasing plastic fragments (PFs) in the environment have attracted considerable social and academic attention. Several methods have been proposed to mitigate plastic pollution, such as filtration and degradation. This study focuses on the removal of plastic fragments from a water flow. A field collection survey of beached PFs was conducted at Kurihama Beach (Yokosuka, Kanagawa, Japan) to identify their polymer types and quantify different PFs. An anchored-buoy-type filter was designed to capture surface and submerged PFs from the water flow. A small-scale experimental apparatus was developed with the incorporation of these filters. Four types of filters (steel wire frame, plankton net, reverse osmosis filter, and carbon-block filter) were used as PF removers based on their size. The PF capture experiment was conducted at various PF concentrations, water densities, and flow speeds. The number of captured PFs was calculated using particle counting and mass measurement. The average efficiency of the designed filter was 81.53%, with the efficiency reaching 94.5%. The designed filter was reported to work well in both seawater and freshwater. Full article

Human tissues and disease models require well-defined biomimetic microenvironments. During the past decade, innovative developments in materials science, microfabrication, and polymer science have provided us with the ability to manipulate cellular microenvironments for regenerative medicine and tissue engineering applications. Solution blow spinning is a facile fiber fabricating method that requires a simple apparatus, a concentrated polymer solution within a volatile solvent, and a high-pressure gas source. Commercially available airbrushes, typically used for painting and cosmetic makeup, have successfully generated a range of nanofibers and films. Applications under investigation are similar to electrospinning and include enzyme immobilization, drug delivery, filtration, infection protection, tissue engineering, and wound healing. This review will discuss fiber fabrication methods before a more detailed discussion of the potential of blow-spinning in biomedical applications. Full article

The permeability of the glomerular filtration barrier (GFB) is mainly regulated by podocytes and their foot processes. Protein kinase G type Iα (PKGIα) and adenosine monophosphate-dependent kinase (AMPK) affect the contractile apparatus of podocytes and influence the permeability of the GFB. Therefore, we studied the interplay between PKGIα and AMPK in cultured rat podocytes. The glomerular permeability to albumin and transmembrane FITC-albumin flux decreased in the presence of AMPK activators and increased in the presence of PKG activators. The knockdown of PKGIα or AMPK with small-interfering RNA (siRNA) revealed a mutual interaction between PKGIα and AMPK and influenced podocyte permeability to albumin. Moreover, PKGIα siRNA activated the AMPK-dependent signaling pathway. AMPKα2 siRNA increased basal levels of phosphorylated myosin phosphate target subunit 1 and decreased the phosphorylation of myosin light chain 2. Podocytes that were treated with AMPK or PKG activators were characterized by the different organization of actin filaments within the cell. Our findings suggest that mutual interactions between PKGIα and AMPKα2 regulate the contractile apparatus and permeability of the podocyte monolayer to albumin. Understanding this newly identified molecular mechanism in podocytes provides further insights into the pathogenesis of glomerular disease and novel therapeutic targets for glomerulopathies. Full article

Kidney disease management and treatment are currently causing a substantial global burden. The kidneys are the most important organs in the human urinary system, selectively filtering blood and metabolic waste into urine via the renal glomerulus. Based on charge and/or molecule size, the glomerular filtration apparatus acts as a barrier to therapeutic substances. Therefore, drug distribution to the kidneys is challenging, resulting in therapy failure in a variety of renal illnesses. Hence, different approaches to improve drug delivery across the glomerulus filtration barrier are being investigated. Nanotechnology in medicine has the potential to have a significant impact on human health, from illness prevention to diagnosis and treatment. Nanomaterials with various physicochemical properties, including size, charge, surface and shape, with unique biological attributes, such as low cytotoxicity, high cellular internalization and controllable biodistribution and pharmacokinetics, have demonstrated promising potential in renal therapy. Different types of nanosystems have been employed to deliver drugs to the kidneys. This review highlights the features of the nanomaterials, including the nanoparticles and corresponding hydrogels, in overcoming various barriers of drug delivery to the kidneys. The most common delivery sites and strategies of kidney-targeted drug delivery systems are also discussed. Full article

An improvement of the pulse decay method of rock permeability measurement is presented. The technique is based on fitting experimental data to analytical and numerical solutions of the filtration equations derived with regard to the variation of flowing gas properties with temperature and pressure. A special apparatus and software for the implementation of this method were developed. A single experiment in which gas is used as a flowing medium enables determining both the permeability of a sample to water and the Klinkenberg constant. The permeability measurements on the samples of different types of rock with various reservoir properties were carried out and demonstrated satisfactory accuracy and efficiency of the method. An effective method for anisotropic permeability measurement is proposed as a development of this technique. Full article

Advances in urban infrastructure, a flourishing polymer sector, and more traffic have all contributed to a rise in micro(nano)plastics in the environment. Researchers are exploring the production, fate, toxicity threshold, and severity of micro(nano)plastic exposure. Albeit, understanding sampling protocols, preservation of samples, and characterization of micro(nano)plastics obtained from the different mediums (e.g., soil, water, air, and living bodies) is still challenging. Particularly identification of micro(nano)plastics, on the other hand, is restricted and limited to the typical generic definition of contaminating sources. In addition, before micro(nano)plastics degrade naturally, many challenges must be overcome, enhancing the need for research on assisted degradation. Thus, a systematic review is presented, which begins by discussing micro(nano)plastic identification, sampling, and handling; then showcases the environmental and health consequences and how to control them; finally, it discusses environmental micro(nano)plastics management options. According to studies, biological and chemical methods to break down micro(nano)plastics have risen in popularity. However, these methods often only cover one type of plastic. Furthermore, these solutions can transform polymers into micro(nano)plastics and may also produce byproducts, increasing environmental contamination risk. Therefore, control, prevention, and management strategies are all investigated to generate more realistic and long-term solutions. The literature suggests a combination of different microorganisms (e.g., different bacterial species) and different approaches (e.g., filtration with degradation) could be more effective in the treatment of micro(nano)plastics. Furthermore, according to the literature, relevant health risks associated with micro(nano)plastics to humans from various exposure routes are currently unclear. Likewise, standardization of methods supported with sophisticated state-of-the-art apparatus for detecting micro(nano)plastics is required. Overall, precision in micro(nano)plastic identification and treatment strategy selection is critical, and their usage should be regulated if their environmental behavior is not properly addressed. Full article