Search

We present a hollow-core fiber (HCF) based transient absorption experiment, with capabilities beyond common titanium:sapphire based setups. By spectral filtering of the HCF spectrum, we provide pump pulses centered at 425 nm with several hundred nJ of pulse energy at the sample position. By employing the red edge of the HCF output for seeding CaF2, we obtain smooth probing spectra in the range between 320 and 900 nm. We demonstrate the capabilities of our experiment by following the ultrafast relaxation dynamics of a radical cationic photocatalyst to prove its pre-association with an arene substrate, a phenomenon that was not detectable previously by steady-state spectroscopic techniques. The detected preassembly rationalizes the successful participation of radical ionic photocatalysts in single electron transfer reactions, a notion that has been subject to controversy in recent years. [ABSTRACT FROM AUTHOR]

The ceramic membrane is widely used in the field of domestic sewage treatment due to its high flexural strength, acid and alkali corrosion resistance, easy cleaning, and other advantages. This article uses coal gangue and loess as the main raw material (coal gangue:loess = 8:2), calcium carbonate as the pore‐forming agent, and carboxymethyl cellulose as the binder. The ceramic membrane was prepared by extrusion molding method and solid particle sintering method. The effects of pore‐forming agent content and sintering temperature on the physical and chemical properties of the ceramic membrane, such as flexural strength, microstructure, pure water flux, and acid‐base corrosion rate, were investigated. The results show that when the sintering temperature is 1000°C and the pore‐forming agent content is 10wt%, the pure water flux exceeds 1434L/h m2 MPa, the flexural strength exceeds 25.4 MPa, the porosity exceeds 46.9%, and the acid‐alkali corrosion rate of the ceramic membrane below 1.6%/0.15%. At this time, the treatment efficiency of domestic sewage is excellent, the removal rate of COD, suspended solids and ammonia nitrogen exceeds 27.66%, 99.9%, and 26.77%, respectively. This work has trend‐setting significance for the fabrication and application of low‐cost ceramic membranes. [ABSTRACT FROM AUTHOR]

DNA topoisomerases are attractive targets for anticancer agents. Dual topoisomerase I/II inhibitors are particularly appealing due to their reduced rates of resistance. A number of therapeutically relevant topoisomerase inhibitors are bacterial natural products. Mining the untapped chemical diversity encoded by soil microbiomes presents an opportunity to identify additional natural topoisomerase inhibitors. Here we couple metagenome mining, bioinformatic structure prediction algorithms, and chemical synthesis to produce the dual topoisomerase inhibitor tapcin. Tapcin is a mixed p‐aminobenzoic acid (PABA)‐thiazole with a rare tri‐thiazole substructure and picomolar antiproliferative activity. Tapcin reduced colorectal adenocarcinoma HT‐29 cell proliferation and tumor volume in mouse hollow fiber and xenograft models, respectively. In both studies it showed similar activity to the clinically used topoisomerase I inhibitor irinotecan. The study suggests that the interrogation of soil microbiomes using synthetic bioinformatic natural product methods has the potential to be a rewarding strategy for identifying potent, biomedically relevant, antiproliferative agents. [ABSTRACT FROM AUTHOR]

Photo‐thermo‐electric (PTE) technology is a simple but sustainable method that directly converts solar energy into electricity. However, the manufacturing of flexible and breathable PTE generators for practical applications, such as intelligent wearable and self‐powered sensors, poses significant challenges due to the rigid thermoelectric materials and unbreathable substrates. Here, a highly‐flexible and breathable photo‐thermal‐electric membrane (FB‐PTEM) is developed by magnetron sputtering (MS) on a photo‐thermal nanofiber membrane. A single unit of FB‐PTEM produced an open‐circuit voltage of 0.52 V under 1 sun (100 mW cm−2) and 0.2 V under LED illumination, making it suitable for all‐weather use. The photo‐thermal nanofiber membrane exhibited high photo‐thermal conversion capacity of reaching 70 °C within 50 s under 1 sun irradiation. The FB‐PTEM with a thickness of 0.35 mm achieved a self‐temperature difference of 20.6 °C under 1 sun with the low thermal conductivity of the nanofiber membrane. Furthermore, it has a vapor permeability of 14.6 kg m−2 d−1 due to the inherent high porosity of the nanofiber membranes. The FB‐PTEM demonstrates great potential for the development of highly flexible thermoelectric materials, as it encompasses various advantageous features such as self‐temperature difference, lightweight design, high breathability, and all‐weather suitability. [ABSTRACT FROM AUTHOR]

Micro-tubular protonic ceramic fuel cells (MT-PCFCs) offer significant advantages in energy utilization and storage, including high stability/durability and intermediate working temperature. Inefficient intraluminal current collection and costly fabrication processes are challenges for high-performance MT-PCFCs. Herein, hierarchically structured Ni/Ni–BaCe 0.7 Zr 0.1 Y 0.2 O 3-δ dual-layer hollow fibers (DLHFs) have been fabricated by the phase-inversion assisted co-spinning/co-sintering technique. By adjusting the viscosity of anode suspension, the DLHFs' microstructure is tailored and optimized for porosity, pore size, and thickness of collector layer and spongy region. After assembling MT-PCFCs, effects of DLHFs' microstructure on fuel cell performance are investigated, revealing that a thinner spongy region reduces gas transfer resistance, lowers polarization impedance, and enhances fuel cell performance. A maximum power density of 687.1 mWcm−2 for the optimum MT-PCFC is reached at 700 °C. The innovative DLHF design enhances current collecting efficiency for MT-PCFCs and exhibits potential in other micro-tubular applications, such as hydrogen pumps and electrochemical reactors. [Display omitted] • Hierarchical structure anodic collector/anode DLHFs were fabricated in single-step. • A mesh-like current collector is integrated inside the anode microtubule. • Adjusting PVP content altered the porosity, pore size, and morphology of the DLHFs. • Thinner spongy region reduced polarization impedance and enhanced cell performance. • MT-PCFC with 0.7 wt% PVP content offered an MPD of 687.1 mW/cm2 at 700 °C. [ABSTRACT FROM AUTHOR]

In various applications, a polymeric hollow fiber heat exchanger (PHFHE) is a competitive alternative to a conventional heat exchanger (HE). Standard empirical models for predicting the crossflow tube HE characteristics are defined for devices with rigid tubes with relatively large diameters compared to the polymeric hollow fibers with an outer diameter of around 1 mm. This study examines the impact of tension force on airside heat transfer rate and pressure drop in a crossflow PHFHE. The tension force influences the stiffness of the flexible polymeric fibers and their response to applied airflow. Two liquid–gas PHFHEs were designed and manufactured to ensure uniformity of the fibers' arrangement (inline and staggered). An experimental stand enabling the application of defined tension force in the range of 0–9000 N was designed, manufactured and placed into the calorimetric tunnel, where heat transfer rate and pressure drop measurement were performed with varying air velocity between 2 and 8 ms−1 (corresponding to Reynolds number of 240–970). Among our key findings was that the elongation of the fibers due to thermal expansion or stress relaxation has a considerable impact on the fibers' arrangement and resulting fluid flow. Moreover, the application of tension force yielded no substantial change in air pressure drop; however, it led to a notable enhancement in heat transfer rate. Specifically, under a maximal tension force of 9000 N, the heat transfer rate increased by around 11% compared to the unloaded state. [ABSTRACT FROM AUTHOR]

The optimal performance of composites enriched with hollow spheres has been reported in contemporary literature, whereas their thermal properties have received less attention. In this regard, a finite element method (FEM)-based micromechanical model has been developed systematically to investigate the role of intra-matrix embedding of hollow spheres on the thermal conductivity and coefficient of thermal expansion (CTE) of unidirectional fiber-reinforced hybrid composites. In so doing, the concept of representative volume element (RVE) considers microstructures comprising an epoxy matrix, E-glass fiber, and E-glass hollow spheres, assuming perfect bonding (ideal interface) between the components and modified approximate periodic boundary conditions. By computing the longitudinal and transverse temperature gradients generated due to the application of uniform heat flux as well as the geometrical variation in RVE owing to temperature enhancement, thermal conductivity and CTE have been respectively determined. Comprehensive evaluations have been conducted to examine the effects of microstructural-level features, including fiber volume content and orientation, plus volume content and thickness of hollow spheres, on the effective thermal conductivity and CTE of pseudo-porous ternary E-glass/epoxy composites. [ABSTRACT FROM AUTHOR]

This study examined essential factors in the use of hollow fiber membranes that affect CO2 removal efficiency. In the simulation, a finite element model for a membrane with ten fibers was used. Each fiber is 175 mm long with inner radius of 0.75 mm and outer radius of 1.5 mm. Liquid and gas flow rates were set at 100–800 mL min−1, and adsorbent concentration was adjusted in the range of 200–1500 mol m−3 for monoethanolamine, piperazine (PZ), and ethylenediamine absorbents. Increasing the liquid flow rate, gas flow rate, and absorbent concentration leads to an increase, decrease, and increase in efficiency, respectively. Thus, using PZ as absorbent with a concentration of 1080 mol m−3 liquid and gas flow rates of 400 and 180 mL min−1, respectively, showed a CO2 removal efficiency of > 95 % for a membrane effective length of 0.3 m. [ABSTRACT FROM AUTHOR]

Adeno-associated viruses (AAV) are currently predominant viral transfer tools for gene therapy, and efforts are being made to design faster and more efficient methods and technologies for their manufacturing. The early selection of high-performing filters is essential for developing an ultrafiltration and diafiltration (UF/DF) process, especially when feed material is scarce, and timelines are short. However, few methods and technologies exist to enable process optimization with multiple variations in a single run. In this study, we explored the potential of Ambr® Crossflow for high-throughput, automated screening of different membrane materials, pore sizes and different process conditions for the UF/DF step of AAV8. The best overall performance was obtained with a 100 kDa PES flat sheet cassette. The UF/DF process was further transferred to a larger scale to the Sartoflow® Smart Tangential Flow Filtration (TFF) system using a 100 kDa PES Sartocon® Slice 200 cassette and compared to a 100 kDa PES hollow fiber. Virus recovery, permeate flux and total protein removal values of the flat sheet cassette were similar to those achieved in small-scale devices, and higher than those of the hollow fiber, thus demonstrating similar performance at a larger process scale. The high-throughput, automated method described herein allowed to screen multiple materials and process parameters of a UF/DF process in a time- and resource-efficient way, making it a useful tool to accelerate early-stage downstream process development of AAV. [ABSTRACT FROM AUTHOR]

Aligned with the recent trend and imperative to reduce separation layer thickness in gas separation membranes to the nanometer scale in order to raise permeance to levels that can render them competitive with respect to other gas separation technologies, a novel approach and device for fabricating defect-free composite hollow fiber (HF) membranes by dip-coating is described. The presented method avoids the fundamental drawbacks of state-of-the-art techniques for applying a thin gas separation layer onto a porous HF substrate, providing a safe but, at the same time, easily up-scalable way of producing HF membranes at a relatively high production rate. As a basic concept, hanging HF substrates are coated by allowing the coating solution to flow and drip along their external surface. The adaptability of this method, stemming from the array of available coating solutions (a plethora of dispersed nanofillers) and the multitude of substrate options, holds great promise for the fabrication of highly selective and defect-free composite HF membranes. [ABSTRACT FROM AUTHOR]

To address the issues of insufficient strength and poor precision in polystyrene forming parts during the selective laser sintering process, a ternary composite of polystyrene/glass fiber/hollow glass microbeads was prepared through co-modification by incorporating glass fiber and hollow glass microbeads into polystyrene using a mechanical mixing method. The bending strength and dimensional accuracy of the sintered composites were investigated by conducting an orthogonal test and analysis of variance to study the effects of laser power, scanning speed, scanning spacing, and delamination thickness. The process parameters were optimized and selected to determine the optimal combination. The results demonstrated that when considering bending strength and Z-dimensional accuracy as evaluation criteria for terpolymer sintered parts, the optimum process parameters are as follows: laser power of 24 W, scanning speed of 1600 mm/s, scanning spacing of 0.24 mm, and delamination thickness of 0.22 mm. Under these optimal process parameters, the bending strength of sintered parts reaches 6.12 MPa with a relative error in the Z-dimension of only 0.87%. The bending strength of pure polystyrene sintered parts is enhanced by 15.69% under the same conditions, while the relative error in the Z-dimension is reduced by 63.45%. It improves the forming strength and precision of polystyrene in the selective laser sintering process and achieves the effect of enhancement and modification, which provides a reference and a new direction for exploring polystyrene-based high-performance composites and expands the application scope of selective laser sintering technology. [ABSTRACT FROM AUTHOR]

In the present manuscript, an automated three‐phase hollow fiber liquid‐phase microextraction followed by high‐performance liquid chromatography‐diode array detection is applied for the extraction and determination of three pyrethroids, deltamethrin, fenpropathrin, and permethrin in water and fruit samples. N‐dodecane was selected as a supported liquid membrane (SLM) and its polarity was adjusted by trioctylphosphine oxide one‐variable‐at‐a‐time method was used in order to achieve optimal hollow fiber liquid‐phase microextraction parameters such as type of organic acceptor phase, the composition of SLM, ionic strength of sample solution, extraction time, length of hollow fibers and stirring speed. Under the optimal conditions, the calibration curves for the three pyrethroids were plotted, and figures of merit of the proposed method were calculated. The linear dynamic ranges were in the range of 0.9–200, 0.75–200, and 1.5–200 μg/L for deltamethrin, fenpropathrin, and permethrin, with the coefficient of determination better than 0.998. The limits of detection were in the range of 0.3, 0.25, and 0.5 and the limits of quantification were in the range of 0.9, 0.75, and 1.5 μg/L for deltamethrin, fenpropathrin, and permethrin, respectively. The precision of the method was evaluated in terms of relative standard deviation at two different concentration levels 10 and 50 μg/L. The results of real sample analysis in cucumber exhibited high sensitivity, excellent sample clean‐up, favorable repeatability, and suitable accuracy. [ABSTRACT FROM AUTHOR]

Nanofibers are the center of researcher’s attention due to their applications in industrial, technological, and scientific fields. Nanofibers are fabricated via a famous technique known as electrospinning. But through single-nozzle electrospinning, we cannot use all the precursor solutions, and the desired geometry of fibers is also prevented. To overcome the limitations of single-nozzle electrospinning, an advanced version of electrospinning has been introduced which is termed as co-axial electrospinning. This review will describe the processes as well as advancements made to co-axial electrospinning which empower the formation of uniform fibers with enhanced characteristics. This technique can be used to fabricate functional and hollow fibers from non-spinnable precursors. One common drawback that is observed in the single-nozzle electrospinning is the degradability of drugs which can be avoided by co-axial electrospinning. The comparison of co-axial electrospinning with single-nozzle conventional electrospinning has been established and supported with up-to-date literature. The services of co-axial electrospinning in several fields have been summarized but with more emphasis on the biomedical field. Their major applications in wound dressing, periodontal regeneration, nerve tissue engineering, bone tissue engineering, double drug delivery, and cancer treatment have been reported. Future recommendations are established for the potential researchers to design a more effective and sustainable methodology for the development of functional core-sheath nanofibers.

The uncertainty analysis of moisture measurements in the hollow fiber membrane was conducted in this study to ensure the reliability of a design for membrane humidifiers. As moisture is pivotal for proton exchange membrane fuel cell durability and performance, it is necessary to humidify the reactant gases. In vehicular fuel cells, membrane humidifiers have been implemented to regulate the water content levels of cathode air, thereby avoiding fuel cell operation limitations, particularly in high-temperature environments. Minimized error in measurements of water exchange is required to improve the effectiveness of shelltube membrane humidifier design. The uncertainty analysis was conducted through parametric experiments under isothermal conditions with varying conditional parameters, including temperature, pressure, and inlet relative humidity. The transport metric is represented by the vapor transfer rate from wet to dry air through the membrane, which is affected by the sensitivity of the corresponding operating parameters and sensor reliability. Therefore, the error of each conditional (input) parameter and the overall error of the measured result (water transfer rate) were determined to evaluate the quality of measurements. From the analysis, the most sensitive factor was discovered to be the inlet relative humidity, with error increasing as temperature increased. The uncertainty of water transport measurements was highest at 90℃, amounting to 3.97%. Consequently, it can be concluded that the measurement of water transport in the membrane humidifier meets good reliability for further design and investigation. [ABSTRACT FROM AUTHOR]

In order to obtain a fibrous biofilm carrier material with a good water purification effect, the biofilm carrier of PAN and PAN-PEO (mass ratio 9:1) was prepared by the electrospinning process, and the performance differences between the fabric biofilm carriers of PAN, PAN-PEO (mass ratio 9:1), and blank non-woven fabric, including the structure of biofilm carriers (surface morphology, specific surface area, and porosity), surface wettability (water contact angle and water absorbance) and membrane hanging ratio, were tested through various characterization methods. The experimental results show that the nanofiber membrane of PAN and PAN-PEO (mass ratio 9:1) prepared by the electrospinning process has a diameter of 75–375 nm, a specific surface area of 19.2 m2/g, and a porosity of 80%. The fiber diameter of non-woven fabric is in the micrometer range, with a specific surface area of 0.3659 m2/g and a porosity of 60%. This indicates that the nanofiber biofilm of PAN and PAN-PEO (mass ratio 9:1) prepared by electrospinning belongs to the carrier with a small diameter, high specific surface area, and high porosity, which can provide more attachment sites and pores for micro-organisms and is more conducive to their attachment in wastewater treatment. At the same time, the water contact angles of PAN and PAN-PEO (mass ratio 9:1) are 27.97° and 18°, respectively, and the water absorption of both reached 300%. The water contact angle of non-woven fabric is 93.32°, and the water absorption rate is only 75%. This shows that the nanofiber biofilms of PAN and PAN-PEO (mass ratio 9:1) prepared by electrospinning effectively improve the infiltration of the carrier in sewage. Finally, under the same conditions, bacterial growth and biofilm growth experiments were conducted on the nanofiber biofilm carriers of PAN and PAN-PEO (mass ratio 9:1) and the biofilm carriers of non-woven fabric. It was found that the effectiveness of the PAN and PAN-PEO (mass ratio 9:1) nanofiber biofilm carrier was significantly higher than that of non-woven fabric in treating wastewater. After 3 days of bacterial cultivation, the membrane hanging ratio of the PAN nanofiber biofilm carrier was 90.36%, the membrane hanging ratio of the PAN-PEO (mass ratio 9:1) nanofiber biofilm carrier was 82.04%, and the membrane hanging ratio of the non-woven fabric biofilm carrier was only 27.32%. After 15 days of bacterial cultivation, the membrane hanging ratio of the PAN nanofiber biofilm carrier was 147.52%, the membrane hanging ratio of the PAN-PEO (mass ratio 9:1) nanofiber biofilm carrier was 147.52%, and the membrane hanging ratio of the non-woven fabric biofilm carrier was 110.53%. [ABSTRACT FROM AUTHOR]

The detonation properties of mixtures of gelled nitromethane (NM) with hollow glass microballoons (GMBs), the concentration of which varied from 16 to 30 wt. %, have been studied using an optical technique with high temporal and spatial resolution. It is shown that the addition of GMBs up to 30 wt. % does not qualitatively change the reaction zone structure of NM, which is in accordance with the classical detonation theory. However, the detonation parameters of the mixture decrease significantly with increasing GMB concentration—the pressure at the Chapman–Jouguet point drops by more than an order of magnitude at a porosity of 75%. The non-monotonic nature of the change in critical detonation diameter with decreasing mixture density is noted. The dependence of the critical diameter on the porosity of U-shape with the formation of two local minima at 8 and 18 wt. % GMB in the mixture and a local maximum at 13 wt. % GMB is obtained. At a concentration above 20 wt. % GMB, the critical detonation diameter increases dramatically, and at 30 wt. % GMB, the critical diameter becomes comparable to that of gelled NM. [ABSTRACT FROM AUTHOR]

A novel strategy based on gradient porous hollow fiber membrane (GPF) is proposed for the modular assembly of enzyme-nanozyme cascade systems. The porous structure of GPF provided sufficient specific surface area, while the gradient structure effectively minimized the leaching of enzymes and nanozymes. To enhance stability, we prepared and immobilized metal–organic framework (MOF) nanozymes, resulting in the fabrication of GPF-MOF with excellent stability and reusability for colorimetric H2O2 detection. To improve specificity and expand the detection range, micro-crosslinked natural enzymes were modularly assembled, using glucose oxidase as the model enzyme. The assembled system, GPF-mGOx@MOF, achieved a low detection limit of 0.009 mM and a linear range of 0.2 to 11 mM. The sensor retained 87.2% and 80.7% of initial activity after being stored for 49 days and 9 recycles, respectively. Additionally, the reliability of the biosensor was validated through glucose determination of human blood and urine samples, yielding comparable results to a commercial glucose meter. [ABSTRACT FROM AUTHOR]

The use of a liquid desiccant air dehumidifier is an energy-efficient technology that can improve both indoor air temperature and humidity. However, the risk of concentrated liquid desiccant leakage into the air conditioning system during dehumidification can corrode the system, negatively impact indoor air quality, and potentially harm residents. To address this issue, this study investigates the effectiveness of osmotic distillation (OD) and direct contact membrane distillation (DCMD) for dehumidification and regeneration, respectively. The study analyzes the impact of inlet operating parameters, including liquid desiccant concentration, temperature, and flow rate, and air flow rate on the dehumidification performance and stability of the OD process. Calcium chloride was utilized as the liquid desiccant in this study. The results indicated that the dehumidification performance of the OD process improved with a higher desiccant concentration and lower desiccant temperature. However, the desiccant flow rate did not have a significant impact on dehumidification performance. Furthermore, the dehumidification performance decreased with a higher inlet air flow rate, but the moisture removal rate increased. The OD process demonstrated stable operation during the dehumidification process. DCMD was effective for desiccant regeneration, and no scaling occurred due to the deposition of calcium chloride crystals. However, the permeation flux of DCMD decreased as the feed concentration increased due to a decline in the feed vapour pressure and an increase in concentration polarization effect. In conclusion, the experimental results indicated that OD can effectively dehumidify humid air, while DCMD is a viable option for desiccant regeneration. • Osmotic distillation (OD) was used for air dehumidification. • Direct contact membrane distillation (DCMD) was used for desiccant regeneration. • PVDF HF membrane was applied to OD and DCMD systems. • Operating parameters of the OD system were studied for air dehumidification. • Regeneration performance of calcium chloride liquid desiccant was examined. [ABSTRACT FROM AUTHOR]

A hollow fiber supported liquid membrane (HFSLM) was used to extract and eliminate glufosinate ammonium from aqueous solution using TOA (tri-n-octylamine) in hexane and sodium hydroxide (NaOH) as carrier and stripping phase, respectively. Maximum extraction (∼76%) and stripping (∼75%) were achieved by feed solution at pH 1.0, temperature 60 °C, TOA concentration 6% (v/v) and NaOH concentration 1.0 M. The developed mathematical model exhibited high precision when predicting the concentration of glufosinate ammonium in raffinate solution and extraction percentage under different feed flow rates, with correlation coefficient (R²) 0.9863. [ABSTRACT FROM AUTHOR]

TiO2−CeO2−Pt hollow nanospheres (1 wt‐% Pt) are realized using a liquid‐phase strategy using NaCl as a template. The NaCl template is first coated with TiO2 and thereafter with CeO2 via the hydrolyzation of TiCl(OiPr)3 and Ce(OiPr)4 as suitable alkoxides. Finally, the NaCl template is removed by washing with water. The resulting @TiO2−CeO2 hollow nanospheres (□: inner cavity) exhibit an outer diameter of 140–180 nm, a wall thickness of 30–40 nm, an inner cavity of 80–100 nm, a specific surface area of 210 m2/g, a pore volume and area of 0.08 cm3/g and 191 m2/g, mainly with micropores ≥5 Å and ≤14 Å. The hollow nanosphere support is impregnated with Pt nanoparticles, using two different methods – a wet‐chemical deposition (Pt(ac)2, acetone, 25 °C) and a supercritical fluid reactive deposition (SFRD) process ([Pt(COD)Me2], supercritical CO2, 80 °C, 15.6 MPa) resulting in an uniform size distribution with Pt nanoparticles 2.5±0.1 nm (TiO2−CeO2−PtWCD) and 2.3±0.1 nm (TiO2−CeO2−PtSFRD) in size. The catalytic properties of the TiO2−CeO2−Pt hollow nanospheres are evaluated for CO oxidation between 50 and 500 °C. A promising catalytic activity and stable light‐out/light‐off temperatures are observed especially for the TiO2−CeO2−PtSFRD sample, indicating the suitability of hollow nanospheres as high‐porosity catalyst material. [ABSTRACT FROM AUTHOR]

The photocatalysis for environment purification and clean energy production has attracted widespread attention, however, traditional powder-form photocatalysts cannot meet the practical application due to their poor recyclability, especially in slurry system. Here, polypyrrole/cadmium sulfide/nickel (PPy/CdS/Ni) multi-layer hollow fibrous photocatalyst with favorable photocatalytic activity for pollutants removal and hydrogen (H 2) evolution was successfully fabricated, which possesses a narrow band gap of ∼1.87 eV and enhanced visible-light photocatalytic activity. The removal efficiency of methylene blue (MB) and tetracycline can reach up to ∼94.76% and ∼76.1%, respectively. Simultaneously, the TOC removal efficiency with regard to MB can reach up to 78.1% and Cd2+ leakage is extremely low (<3 mg⋅L−1). More interestingly, H 2 evolution rate of PPy/CdS/Ni hollow fiber is up to as high as 665.7 μmol⋅g−1⋅h−1, which is about 1.43 and 1.86 folds higher than the PPy/CdS/Ni/PET fiber (466.3 μmol⋅g−1⋅h−1) and CdS/Ni/PET fiber (357.1 μmol⋅g−1⋅h−1), respectively. As a fiber-form intrinsic photocatalyst, our catalytic fiber shows great promise for pollutants removal and hydrogen energy production due to its easy-handling and recyclement. [Display omitted] • A novel PPy/CdS/Ni hollow fiber with photocatalytic activity was synthesized. • Pollutant removal efficiency and H 2 evolution rate are appreciable. • Possible photocatalytic mechanism was proposed. • PPy/CdS/Ni hollow fiber shows good photocatalytic stability and recyclability. [ABSTRACT FROM AUTHOR]

Hollow-structured ceramic fibers with multiple components are ideal as lightweight insulation materials. In this study, tetraethyl orthosilicate, boric acid, and zirconia octahydrate were used as raw materials for fabricating SiZrBOC hollow ceramic fibers through coaxial electrospinning. These ceramic fibers exhibit a low thermal conductivity and an excellent temperature resistance. The electrospun SiZrBOC hollow ceramic fibers display a clean and compact morphology with internal folds. Fourier-transform infrared spectroscopy and thermogravimetric analysis (TGA) were used to assess the transformation process and thermal behavior of the hollow ceramic fibers. The results suggest that the incorporation of B promotes the formation of Si–O–B bonds within the system, leading to a maximum yield of 75.49 wt% for the production of the SiZrBOC hollow ceramic fibers. The phase composition and microstructure of the SiZrBOC hollow ceramic fibers were analyzed via X-ray diffraction (XRD) measurements. The pyrolysis at 1000 °C resulted in the appearance of diffraction peaks corresponding to SiO 2 and SiC in the XRD patterns of the SiZrBOC hollow ceramic fibers. Laser thermal conductivity measurements reveal that the SiZrBOC hollow ceramic fibers exhibit a thermal conductivity of only 0.06 W‧m−1K−1 at 25 °C and 0.124 W‧m−1K−1 at 500 °C, indicating a significantly superior thermal insulation performance compared with conventional solid SiZrBOC ceramic fibers. [ABSTRACT FROM AUTHOR]

Multi-leaf hollow-profiled fiber is a complex-shaped fiber with a hollow structure with at least three leaves arranged outside. In this work, spinning processes for the preparation of multi-leaf hollow-profiled fiber with complex cross-section patterns were proposed. Initially, the characteristics and preparation methods of multi-leaf hollow-profiled fibers were analyzed, and the key technologies for their preparation were studied. Further, micro-hole spinnerets were designed, and the numerical simulations of melt flow in the spinning channel were performed. Then, the preparation of six-leaf hollow profiled fibers was carried out to study the formation of the cross-sections. Finally, as an extension and application, an experimental verification of the melt spinning parameters' effects on eight-leaf hollow fiber preparation was conducted. From the results of the spinning experiments, it was found that when the volume flow rate of a single hole increased from 2.33 × 10−8 m3/s to 3.33 × 10−8 m3/s, the profile degree of the spun fiber increased from 30.93% to a maximum value of 40.99%. Furthermore, when the cooling speed increased from 0.6 m/s to 1 m/s, the profile degree increased from 29.56% to 41.63%. When the initial blowing height increased from 80 mm to 140 mm, the profile degree decreased from 40.99% to 27.13%. When the spinning temperature increased from 285 °C to 290 °C, the profile degree decreased from 40.99% to 38.56%. However, the winding speed had an insignificant effect on the cross-sectional shape of the spun fibers. Moreover, the spun fibers showed good performance and a natural three-dimensional crimp function. [ABSTRACT FROM AUTHOR]

As the prevalence of electromagnetic interference (EMI) continues to rise, there is a growing demand for shielding materials, which play a crucial role in electronic devices, communication systems, health protection, etc. However, conventional EMI shielding materials encounter difficulties in effectively addressing the escalating intricacies of electromagnetic environments and diverse shielding scenarios, wherein foldability, flexibility, and lightweight are desired. In this work, a novel EMI shielding material, silver‐hollow‐fiber (AgHF), is developed by combining blow‐spinning, UV radiation, and temperature‐controlled annealing technologies. During the fabrication process, UV radiation is used to selectively reduce silver ions on the outer surface of precursor fiber, and temperature‐controlled annealing is further employed to remove the inside polymer, forming a hollow fiber structure. The AgHF exhibits superior flexibility, lightweight, remarkable mechanical stability, and excellent EMI shielding efficiency (SE). Particular, the AgHF with a thickness of 163 µm demonstrates an EMI SE of 101.65 dB, and with minimal degradation of less than 10% even after undergoing 2000 bending cycles. The remarkable EMI shielding performance, combined with the lightweight, flexibility, and mechanical stability of AgHF, positions it as a highly promising material for a wide range of EMI shielding applications in the future. [ABSTRACT FROM AUTHOR]

A novel, cost-effective, simple and environmentally friendly method was developed for separating, preconcentrating and quantifying volatile analytes. That approach utilised switchable hydrophilicity solvent-based hollow fiber liquid-liquid microextraction in combination with headspace gas chromatography. The extraction was carried out from 1 l of water solution. 100 µl of nonanoic acid, immobilised within a polypropylene capillary, was selected as an extraction solvent. After the extraction, the capillary with the extract was transferred to a headspace vial, and headspace gas chromatographic analysis was performed. To facilitate the transition of volatile analytes to the headspace for subsequent analysis, nonanoic acid was converted to hydrophilic nonanoate by adding a sodium hydroxide solution. The effectiveness of the suggested strategy was demonstrated in the determination of benzene and its derivatives in water samples. Various parameters affecting the extraction and headspace gas chromatographic determination were investigated and optimised. Under the optimal conditions, the analytical characteristics of the proposed technique were determined. Using this approach, the limits of quantification for all analytes were found to be below the maximum acceptable concentration. [ABSTRACT FROM AUTHOR]

A parallel dual‐cavity fiber‐optic Fabry‐Perot (F‐P) salinity sensor based on hollow core fiber and a ceramic ferrule is proposed. The sensor is comprised of a F‐P reference cavity and a F‐P sensing cavity in parallel. The reference cavity is a closed cavity that is fusion spliced with a segment of single‐mode optical fiber (SMF) and a small piece of silica tube (ST). The sensing cavity is an open liquid cavity that is connected by a ferrule after inserting two single‐mode fibers into a ceramic core, facilitating the replacement of salt water. Variations in the salinity of salt water will affect the change in refractive index of optical path, and then change the output spectral structure. By precisely controlling the length of two cavities, the free spectral range (FSR) of the sensing cavity is approximately equal to the FSR of the reference cavity, resulting in the generation of the Vernier effect, which improves the sensitivity of the sensor to salinity greatly. From the experimental results, it can be seen that the sensor sensitivity to salinity reaches −0.78 nm/‰ (−3809.68 nm/RIU) in the salinity range from 35‰ to 20‰ at room temperature of 25°C, which is 10.8 times higher than the sensitivity of a single sensing cavity. The enhancement factor is generally consistent with theoretical analysis results. [ABSTRACT FROM AUTHOR]

Tellurium and selenium isotopes have wide applications in nuclear medicine. In this study, extraction of these elements from copper anode slime is carried out by using the hollow fiber renewal liquid membrane technique (HFRLM). At first batch experiments were carried out by using different concentrations of extractants (TBP, DEHPA, Alamin 336, Cyanex 272), and out of four, TBP 30%(v/v) in 4 M HCl provided the best results. Moreover, more recovery of tellurium ions than selenium is achieved by using HFRLM technology, which reveals the potential of using this method for selective extraction of tellurium with a separation factor higher than 15. [ABSTRACT FROM AUTHOR]

To address the issue of low mechanical strength in self-supported hollow fiber membranes, a research study was conducted to fabricate polysulfone braid-reinforced hollow fiber (PSF BRHF) membranes for natural gas purification. In this study, polyethylene (PET) was used as a braid support. PSF BRHF membranes were fabricated by employing dip coating and drying technique. The BRHF membranes underwent comprehensive analysis, including the manipulation of polymer (PSF) concentration (15 wt%, 18 wt%, and 21 wt%) and the number of coating layers (1–4). Characterization of the fabricated membrane samples involved scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gas separation performance testing, and mechanical strength testing. The results indicated that membranes fabricated with higher polymer concentrations exhibited a denser structure with a thicker separation layer. An increase in the separation layer thickness was also observed with an increasing number of coating layers. Importantly, all fabricated membrane samples demonstrated remarkable thermal stability. To assess the performance, gas separation tests were conducted using pure gases at 3 bar. Notably, the membrane sample with 21 wt% PSF and the 3rd coating layer (21_3 PSF) exhibited the most promising gas separation performance among all the samples selected to carry out the separation performance test, achieving a CO2/CH4 selectivity of 1.83. Mechanical strength testing revealed that 21_3 PSF BRHF (68.2 MPa) fabricated in this study outperformed conventional self-supported PSF hollow fiber membranes (9.44 MPa), as reported in the literature. These findings underscore the potential of BRHF membranes for natural gas purification, although further improvements are still possible. [ABSTRACT FROM AUTHOR]

A large number of non-degradable materials have severely damaged the ecological environment. Now, people are increasingly pursuing the use of environmentally friendly materials to replace traditional chemical materials. Polyhydroxyalkonates (PHAs) are receiving increasing attention because of the unique biodegradability and biocompatibility they offer. However, the applications of PHAs are still limited due to high production costs and insufficient study. This project examines the optimal electrospinning parameters for the production of PHA-based fibrous membranes for air filtration. A common biodegradable polyester, Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), was electrospun into a nanofibrous membrane with a well-controlled surface microstructure. In order to produce smooth, bead-free fibers with micron-scale diameters, the effect of the process parameters (applied electric field, solution flow rate, inner diameter of hollow needle, and polymer concentration) on the electrospun fiber microstructure was optimized. The well-defined fibrous structure was optimized at an applied electric field of 20 kV, flow rate of 0.5 mL/h, solution concentration of 12 wt.%, and needle inner diameter of 0.21 mm. The morphology of the electrospun PHBV fibrous membrane was observed by scanning electron microscopy (SEM). Fourier transform infrared (FTIR) and Raman spectroscopy were used to explore the chemical signatures and phases of the electrospun PHBV nanofiber. The ball burst strength (BBS) was measured to assess the mechanical strength of the membrane. The small pore size of the nanofiber membranes ensured they had good application prospects in the field of air filtration. The particle filtration efficiency (PFE) of the optimized electrospun PHBV fibrous membrane was above 98% at standard atmospheric pressure. [ABSTRACT FROM AUTHOR]

Determining trace chromium in complex samples usually requires a sample preparation technique to isolate and extract the analytes from matrices and enrich them for trace analysis. Several methods have been reported for chromium extraction; among them are membrane-based microextraction techniques due to their unique features, such as high level of clean-up, high enrichment factors, facile automation, and compliance with green chemistry principles. In the current review, the latest developments in hollow fibre membrane liquid-phase microextraction (HF-LPME), electromembrane extraction (EME), gel electromembrane microextraction (G-EME) systems for the detection of chromium in environmental samples are summarised. Furthermore, the fabrications of selected systems are briefly described and discussed. Finally, the systems' performance regarding their precision and accuracy, detection limits, and advantages and disadvantages are critically reviewed and evaluated. [ABSTRACT FROM AUTHOR]

Porous or hollow crystals have attracted considerable interest due to their unique properties and outstanding performance in various applications. In this study, hollow Pb1−xSrxF2 crystals have been successfully fabricated via controlled precipitation–dissolution at the liquid–gas interface. As a result of the reaction on the surface of a solution mixture of Pb(CH3COO)2 and Sr(CH3COO)2 under the action of gaseous HF, a film of Pb1−xSrxF2 crystals with a fluorite-type structure was formed. Placing the film on the water surface resulted in selective dissolution and formation of hollow crystals, associated with a relative increase in the overall Sr content in the Pb1−xSrxF2 solid solution. By adjusting the crystallization conditions and the dissolution time it was possible to obtain hollow crystals with a wall thickness of 20–40 nm, membrane films with ordered through holes, or microstructures with flower-like morphology. The Gas–Solution Interface Technique used in this work can potentially be utilized to synthesize other metal fluorides with tunable porous morphology. [ABSTRACT FROM AUTHOR]

Harvesting sunlight into cost-effective electricity presents an enticing prospect for self-powered wearable applications. The photothermal materials with an extensive absorption are fundamental to achieve optical and thermal concentration of the sunlight for efficiency output electricity of wearable solar thermoelectric generators (STEGs). Here, we synthesize an organic charge-transfer (CT) cocrystal with a flat absorption from ultraviolet to second near-infrared region (200 to 1950 nanometers) and a high photothermal conversion efficiency (PCE) of 80.5%, which is introduced into polyurethane toward large-area nanofiber membrane by electrospinning technology. These corresponding membranes demonstrate a high PCE of 73.7% under the strain more than 80%. Sandwiched with carbon nanotube-based thermoelectric fibers, the membranes as stretchable solar absorbers of STEGs could supply a notably increase temperature gradient, processing a maximum output voltage density of 23.4 volts per square meter at 1:00 p.m. under sunlight. This strategy presents an important insight in heat management for wearable STEGs with a desired electricity output. [ABSTRACT FROM AUTHOR]

[Display omitted] Photocatalytic water splitting has been regarded as one of the most promising technologies to generate hydrogen as an ideal energy carrier in the future. However, most of the experience for such process are derived from the researches based on the suspension powder photocatalysts under a stirring condition and a practical scaling application is urgently calling for the high-efficient panel reactors based on the membrane photocatalysts. Herein, we develop a new series of flexible and ultrastable membrane photocatalysts through a controllable growth of covalent organic framework (COF) photocatalysts on the polyacrylonitrile (PAN) electrospun fiber membrane. Multiple characterization techniques verify the successful anchoring of the COF-photocatalysts on the PAN fibers, forming a three-dimensional porous PAN/COF membrane photocatalyst with excellent light absorption ability, high specific surface area, and good hydrophily. As a result, the optimized PAN/COF membrane photocatalyst exhibits excellent hydrogen evolution rate up to 1.25 mmol g−1h−1 under visible-light irradiation without stirring, which is even higher than that of the corresponding suspension COF-powder photocatalyst with stirring. In particular, the PAN/COF membrane photocatalyst demonstrates a much more superior hydrogen evolution stability and also a much better recyclability. This study gives some experience for the practical scaling application of solar-driven water splitting. [ABSTRACT FROM AUTHOR]

A Type I porous liquid based on the mixed-linker zeolitic imidazolate framework, ZIF-8/90-PL, has been prepared by a one-step imine condensation reaction and characterized by X-ray diffraction, FT-IR spectroscopy, TGA and rheology analysis. This facile preparation strategy of a porous liquid has enormous industrial production and application potential, with over one kilogram of ZIF-8/90-PL being successfully prepared. ZIF-8/90-PL can be directly used as a liquid absorbent or be co-processed with alumina hollow fibers to form a composite membrane with improved selectivity in the context of CO2 separation from CH4 or N2. This simple synthesis method is expected to be extended to other metal–organic frameworks. [ABSTRACT FROM AUTHOR]

Previous research indicated that free-living sporangial filament keep hollow morph under high-culture density and form bipartite cells under low-culture density, while the following conchospore release was inhibited by high light. Here, we further explored the molecular bases of these affects caused by light and culture density using a transcriptome analysis. Many differentially expressed genes (DEGs) related to carbon dioxide concentration and fixation, photosynthesis, chlorophyll synthesis and nitrogen absorption were upregulated under high-light conditions compared with low-light conditions, indicating the molecular basis of rapid vegetative growth under the former. The stress response- and ion transport-related DEGs, as well as the gene encoding the vacuole formation-brefeldin A-inhibited guanine nucleotide exchange protein (BIG, py05721), were highly expressed under high-density conditions, indicating the molecular basis of the hollow morph of free-living sporangial filaments under high-culture density conditions. Additionally, the brefeldin A treatment indicated that the hollow morph was directly influenced by vacuole formation-related vesicle traffic. Others DEGs related to cell wall components, zinc-finger proteins, ASPO1527, cell cycle and cytoskeleton were highly expressed in the low density with low-light group, which might be related to the formation and release of conchospores. These results provide a deeper understanding of sporangial filaments in Neopyropia yezoensis and related species. [ABSTRACT FROM AUTHOR]

Experiments of bubbly flows in a column with submerged hollow fiber membranes are carried out to discuss the relation between bubbly flow characteristics and fouling control. Two kinds of liquids, water and xanthan gum-water solution (XG-W), are used as the liquid phases. The relaxation rates of membranes are set at 0.0 or 0.5%. The number of small bubbles with ellipsoidal shapes in water are larger than that in XG-W, while large bubbles with spherical cap shapes are remarkably observed in XG-W in spite of the presence of membranes. The rate of large bubbles is enhanced in XG-W due to bubble coalescence. The gas holdup in water is higher than that in XG-W. The gas holdup becomes higher due to the presence of membranes and membrane relaxation in both water and XG-W. For discussion on fouling control due to bubbly flows, experiments are carried out to remove pseudo sludge attached to hollow fiber membranes. The relaxation of membranes enhances the removal rate of pseudo sludge. The mean removal rate, which is the mean value of the removal rate of each membrane, increases with increasing the gas holdup. This relation is well expressed by a linear regression in the present experimental range regardless of the liquid property and membrane relaxation, that is, the gas holdup has a prospect of an indicator for estimating fouling probability. • Bubbly flows in a column with submerged hollow fiber membranes are dealt with. • The viscous property of liquids and membrane relaxation affect bubbly flows. • The removal rates of pseudo sludge on membranes relate to the flow characteristics. [ABSTRACT FROM AUTHOR]

This study reports the synthesis of 2D leaf-like ZIF-L and its modification using [BMIM][BF4] ionic liquid (IL). The nanosheet was then embedded up to 5 wt% into the polyethersulfone (PES) to form mixed matrix hollow fiber membrane (MMHFM) to separate CO2/N2 gases. IL altered the surface charge of the ZIF-L which results in a more uniform dispersion of ZIF-L in the polymer matrix and minimizes the ZIF-L agglomeration on the lumen side. The filler–polymer interaction was improved as suggested by the TGA data. An evaluation of the performance of the MMHFM indicated that the synergistic effect between the filler modification and its loading is crucial in improving the performance of the membrane. The incorporation of unmodified ZIF-L resulted in a significant loss of selectivity at low loading (≥ 1 wt%). Meanwhile, permeance and selectivity trade-off are absent up until 2.5 wt% IL@ZIF-L. Besides, better ZIF-L dispersion and enhanced interaction between the filler and polymer are the factors that improved the separation performance of the MMHFM, hence highlighting the vital role of IL in the system. At the feed pressure of 2 bar, PES/IL@Z0.5 improved the CO2 permeance and ideal CO2/N2 selectivity by 106% and 86%, respectively, relative to the pristine. [ABSTRACT FROM AUTHOR]

The release of algal toxins in algae-containing water sources poses a serious threat to drinking water safety and human health. The conventional water treatment processes of water plants have a limited ability to remove algae and algal toxins, especially algal toxins with a molecular weight (MW) of less than 1000 Da. To eliminate algal pollution from a water source, a two-stage ultrafiltration (UF) process with a large polysulfone hollow fiber membrane with a MW cut-off of 200 kDa and a small aromatic polyamide roll membrane with a MW cut-off of 1 kDa were applied after a traditional sand filter in a water treatment plant. UF operation conditions, including the operating time, pressure, and membrane flux, were investigated. With an operating pressure of 0.05–0.08 MPa, the polysulfone hollow fiber membrane removed algae effectively, as the influent algal cell concentration ranged from 1–30 cells/mL but exhibited a limited removal of algal toxins. With an operating pressure of 0.3–0.4 MPa, the elimination of microcystins (MCs) reached 96.3% with the aromatic polyamide roll membrane. The operating pressure, membrane flux, and operating time were selected as the experimental factors, and the effects on the UF efficiency to remove algal toxins and biodegradable dissolved organic carbon were investigated by the response surface methodology. The model showed that the order of influence on the membrane operating efficiency was operating pressure > membrane flux > running time. The optimal UF operating conditions were an operating pressure of 0.3 MPa, a membrane flux of 17.5 L/(m2·h), and a running time of 80 min. [ABSTRACT FROM AUTHOR]

In this work, a novel approach is suggested to grow bilayer fibers by combining electrospinning and atomic layer deposition (ALD). Polyvinyl alcohol (PVA) fibers are obtained by electrospinning and subsequently covered with thin Al2O3 deposited at a low temperature by ALD. To burn the PVA core, the fibrous structures are subjected to high-temperature annealing. Differential scanning calorimetry (DSC) analysis of the PVA mat is performed to establish the proper annealing regime for burning off the PVA core and obtaining hollow fibers. The hollow fibers thus formed are covered with a ZnO layer deposited by ALD at a higher temperature within the ALD window of ZnO. This procedure allows us to prepare ZnO films with better crystallinity and stoichiometry. Different characterization methods—SEM, ellipsometry, XRD, and XPS—are performed at each step to investigate the processes in detail. [ABSTRACT FROM AUTHOR]

A negative curvature hollow core fiber (NCHCF) refractive index (RI) sensor based on localized surface plasmon resonance (LSPR) is proposed. The gold nanowires are deposited in four cladding tubes in the y-direction, with the core region serving as the analyte channel. The full vector finite element method (FEM) is used to analyze the influence of various structural parameters on this sensor, and the structural parameters are optimized and selected. Ultimately, an average sensitivity of 9356.59 nm/RIU is accomplished within a spacious refractive index detection scope of RI = 1.28–1.43. The sensor attained a maximum sensitivity of 10,220 nm/RIU at RI = 1.36. In the bargain, there is an excellent linear correlation between the resonance wavelength and the refractive index of the analyte, with a value of 0.99901 and a factor of merit (FOM) range of 119.9563–155.9432 RIU−1, achieving a resolution of 10−6 RIU. The sensor has potential applications in various fields such as environmental protection, food safety, and medical diagnostics due to its high sensitivity, spacious detection scope, and positive linear response. [ABSTRACT FROM AUTHOR]

Chirality is a critical issue in pharmaceutics, forensic chemistry, therapeutic drug monitoring, doping control, toxicology, or environmental investigations as enantiomers of a chiral compound can exhibit different activities, i.e., one enantiomer can have the desired effect while the other one can be inactive or even toxic. To monitor enantioselective metabolism or toxicokinetic/toxicodynamic mechanisms in extremely low content in biological or environmental matrices, sample preparation is vital. The present review describes current status of development of liquid-phase microextraction approaches such as hollow fiber liquid-phase microextraction (HF-LPME), electromembrane extraction (EME), dispersive liquid-liquid microextraction (DLLME), and supramolecular solvent-based microextraction (SSME), used for sample preparation of enantiomers/chiral compounds. The advantages and limitations of the above techniques are discussed. Attention is also focused on chiral separation approaches commonly applied to study the stereo-selective metabolism or toxicokinetic/toxicodynamic mechanisms of enantiomers in the biological and environmental samples. [ABSTRACT FROM AUTHOR]

This review systematically summarizes the repair mechanisms and applications of self‐healing polyurethane (SHPU) materials aiming at energy conservation and safety under different repair methods. As of now, the repair methods that have emerged can be divided into two categories: substance landfill and bond repair. In terms of the repair mechanisms for both, the former involves the release of healing agents from micro‐carriers (microcapsules, hollow fibers, and microvascular) to fill the damaged area upon external impact. In contrast, bond repair combines physical and chemical changes triggered by light, heat, and other factors. To achieve efficient self‐healing in this mode, both the reorganization of broken chemical bonds and the high mobility of chain segments are crucial. Reversible covalent bonds and supramolecular interactions, as two branches of aforementioned reversible chemical bonds, share the responsibility for maintaining efficient self‐healing despite infinite cycling. Additionally, multiple synergistic crosslinked networks, special nanomaterials, and microphase separation are often used to solve the problem of incompatible healing efficiency and mechanical strength in bond repair. When the perspective is focused on the application, this gradually improved SHPU with strong potential and comprehensive performance has provided raw materials for many fields related to human development, such as road, architecture, healthcare, and electronic. [ABSTRACT FROM AUTHOR]

The high‐temperature industrial waste oil treatment has put forward new requirements for membrane materials. Poly (tetrafluoroethylene) (PTFE) is regarded as the excellent membrane material for membrane process, due to its excellent properties. Herein, the reinforced PTFE hollow fiber membrane (PTFE‐HFM) was prepared by the combination of wrapping and heat setting technology. The objection of this study was focusing on the outstanding chemical and thermal resistance of PTEF‐HFM for overcoming harsh waste oil treatment. PTFE‐HFM exhibited better chemical resistance in the experiment of acid and alkali compared to PVDF‐HFM, which the surface of PVDF‐HFM corroded obviously and none of PTFE‐HFM. The pore size and porosity were precisely adjusted by heat setting technology. Firstly, the morphologies of PTFE‐HFM was investigated by scanning electron microscopy, which exhibited favorable interfacial bonding state between PTFE separation layer and supporting layer. Subsequently, the prepared membranes exhibited high‐temperature waste oil permeability of 195 L m−2 h−1 bar−1with only 3% attenuation in long‐term operation. Besides, the rejection of lubricants contained activated carbon also reached to 99%. Overall, the facile preparation and excellent performance of robust reinforced PTFE‐HFM highlights its great potential in treating high‐temperature waste oil. [ABSTRACT FROM AUTHOR]

The main causes of mortality in horses are the gastrointestinal pathologies associated with septic shock. Stem cells have shown, through systemic injection, a capacity to decrease inflammation and to regenerate injured tissue faster. Nevertheless, to achieve this rapid and total regeneration, systemic injections of 1 to 2 million cells per kilogram of body weight must be considered. Here, we demonstrate for the first time the feasibility and expansion capacity of equine muscle-derived mesenchymal stromal cells (mdMSCs) in a functionally closed, automated, perfusion-based, hollow-fiber bioreactor (HFBR) called the Quantum™ Cell Expansion System (Terumo Blood and Cell Technologies). This feature greatly increases the number of generated cells with a surface area of 1.7 m2. The expansion of mdMSCs is very efficient in this bioreactor. The maximum expansion generated twenty times more cells than the initial seeding in nine days. The best returns were observed with an optimal seeding between 10 and 25 million mdMSCs, using the Bull's eye loading method and with a run duration between 7 and 10 days. Moreover, all the generated cells kept their stem properties: the ability to adhere to plastic and to differentiate into chondroblasts, osteoblasts and adipocytes. They also showed the expression of CD-44 and CD-90 markers, with a positive rate above 93%, while CD-45 and MHCII were non-expressed, with a positive rate below 0.5%. By capitalizing on the scalability, automation and 3D culture capabilities of the Quantum™, it is possible to generate large quantities of high-quality equine mdMSCs for gastrointestinal disorders and other clinical applications. [ABSTRACT FROM AUTHOR]

Nano-doped hollow fiber is currently receiving extensive attention due to its multifunctionality and booming development. However, the microfluidic fabrication of nano-doped hollow fiber in a simple, smooth, stable, continuous, well-controlled manner without system blockage remains challenging. In this study, we employ a microfluidic method to fabricate nano-doped hollow fiber, which not only makes the preparation process continuous, controllable, and efficient, but also improves the dispersion uniformity of nanoparticles. Hydrogel hollow fiber doped with carbon nanotubes is fabricated and exhibits superior electrical conductivity (15.8 S m−1), strong flexibility (342.9%), and versatility as wearable sensors for monitoring human motions and collecting physiological electrical signals. Furthermore, we incorporate iron tetroxide nanoparticles into fibers to create magnetic-driven micromotors, which provide trajectory-controlled motion and the ability to move through narrow channels due to their small size. In addition, manganese dioxide nanoparticles are embedded into the fiber walls to create self-propelled micromotors. When placed in a hydrogen peroxide environment, the micromotors can reach a top speed of 615 μm s−1 and navigate hard-to-reach areas. Our nano-doped hollow fiber offers a broad range of applications in wearable electronics and self-propelled machines and creates promising opportunities for sensors and actuators. [ABSTRACT FROM AUTHOR]

Membrane contactors have good prospects in the field of CO2 capture. In this study, the effects of operation conditions (gas velocity, liquid flow, CO2 pressure, amine concentration, and CO2 loading) on CO2 absorption flux (JCO2) for CO2 absorption into N‐methyl‐4‐piperidinol (MPDL) solution in membrane contactors were investigated through experiments and simulations. A three‐dimensional (3D) model was developed using COMSOL Multiphysics software to study the comprehensive CO2 mass transfer process in the multifiber membrane contactor and the effect of the number of fibers on the flow and CO2 concentration distribution without simplifying the geometry compared with those of traditional one‐dimensional (1D) and two‐dimensional (2D) models. Non‐ideal effects occurring in hollow fiber membrane contactors can be explained using a 3D modeling. By comparing the simulated JCO2 with the experimental JCO2, the effectiveness of the model was determined. The simulation results emphasize that the spatial concentration distribution has a great correlation with the corresponding velocity distribution. Additionally, reducing the uneven velocity distribution of gas and liquid is a very important factor to improve the mass transfer performance of CO2. Increasing the number of fibers with a constant total volumetric flux can reduce the thickness of the boundary layer and promote the mass transfer. [ABSTRACT FROM AUTHOR]

Developing optimized regimens for combination antibiotic therapy is challenging and often performed empirically over many clinical studies. Novel implementation of a hybrid machine‐learning pharmacokinetic/pharmacodynamic/toxicodynamic (ML‐PK/PD/TD) approach optimizes combination therapy using human PK/TD data along with in vitro PD data. This study utilized human population PK (PopPK) of aztreonam, ceftazidime/avibactam, and polymyxin B along with in vitro PDs from the Hollow Fiber Infection Model (HFIM) to derive optimal multi‐drug regimens de novo through implementation of a genetic algorithm (GA). The mechanism‐based PD model was constructed based on 7‐day HFIM experiments across 4 clinical, extensively drug resistant Klebsiella pneumoniae isolates. GA‐led optimization was performed using 13 different fitness functions to compare the effects of different efficacy (60%, 70%, 80%, or 90% of simulated subjects achieving bacterial counts of 102 CFU/mL) and toxicity (66% of simulated subjects having a target polymyxin B area under the concentration‐time curve [AUC] of 100 mg·h/L and aztreonam AUC of 1,332 mg·h/L) on the optimized regimen. All regimens, except those most heavily weighted for toxicity prevention, were able to achieve the target efficacy threshold (102 CFU/mL). Overall, GA‐based regimen optimization using preclinical data from animal‐sparing in vitro studies and human PopPK produced clinically relevant dosage regimens similar to those developed empirically over many years for all three antibiotics. Taken together, these data provide significant insight into new therapeutic approaches incorporating ML to regimen design and treatment of resistant bacterial infections. [ABSTRACT FROM AUTHOR]

Desert rose seed (DRS) fibers are derived from seed pods of Adenium obesum plants, which belong to the Apocynaceae family. DRS fibers are primarily indigenous to southern Africa and greater Arabia but can also be found in various regions spanning China, Thailand, and India. Despite numerous studies that have focused on the characterization and utilization of various parts of Adenium obesum plants, the physical characterization and absorption behavior of desert rose seed fibers have not yet been explored. Thus, the objective of this study was to comprehensively evaluate the morphology, chemical composition, structural dimensions, fiber surface absorption characteristics, and tensile strength properties of these fibers. Desert rose seed fibers are inherently exceptional fibers resembling a "cross flower" cross-sectional structure that exhibits a unique hollow formation with thin fiber walls and a spacious lumen of fiber samples. The results demonstrate that the density of the fibers obtained from desert rose seed is comparatively low (0.48 g/cm3), while the moisture content was noted as 10.3%. Furthermore, the fiber length distribution of the samples was noted as relatively concentrated. Cellulose I was identified as the primary constituent of DRS fibers, accounting for approximately 54.2 ± 2% of their total structure. Moreover, the exceptional surface characteristics of desert rose seed fibers make them extremely hydrophobic and promote a strong affinity for oil. Thus, this study also introduces a novel source of superwetting materials obtained from the naturally available biodegradable material from Adenium obesum plants. These materials possess intrinsic lyophilic and hydrophobic properties and are chemically stable, light weight, and structurally robust. Our findings demonstrate that superlyophilic fiber networks in DRS fibers can serve as efficient oil absorbents, exhibiting outstanding absorption capacity and tremendous reusability. These naturally derived biological fibers demonstrated the ability to perform a continuous oil–water separation process across various organic solvents (chloroform (CF), soybean oil (SO), cyclohexane (CH), dichloromethane (DCM), paraffin liquid (PL), and ethanol (EL)) that coexist with water. [ABSTRACT FROM AUTHOR]

This study focuses on the optimization of polyethersulfone (PES) hollow fiber membranes fabricated with the phase inversion method. A Box–Behnken experimental design was employed with three different PES concentration ratios (11, 14, 17 wt.%), three polyvinylpyrrolidone (PVP) molecular weight ratios (K30/K90 ratios of 6:0, 3:3, 0:6 wt.%), three different bore fluid (BF) composition ratios (water/alcohol ratios of 20:80, 60:40, 100:0), and three different air gap values (24, 37, and 50 cm). The results were analyzed in terms of pure water permeability (PWP) and porosity as optimization parameters using response surface methodology and the classification and regression tree (CART) model. ANOVA results revealed significant effects of PES concentration, PVP molecular weight, and BF composition on the outcomes. After optimization, the maximum PWP and the maximum porosity were obtained as 360.15 L/m2 h bar, 60.57%, respectively. The CART model achieved sufficient accuracy in classifying samples. [ABSTRACT FROM AUTHOR]

Blood oxygenators are used to saturate oxygen levels and remove carbon dioxide from the body during cardiopulmonary bypass. Although the natural lung is hydrophilic, commercially used oxygenator materials are hydrophobic. Surface hydrophobicity weakens blood compatibility, as long‐term contact with the blood environment may lead to different degrees of blood activity. Polysulfone may be considered an alternative hydrophilic material in the design of oxygenators. Therefore, it may be directed toward developing hydrophilic membranes. This study aims to investigate the feasibility of achieving blood gas transfer with a polysulfone‐based microporous hollow fiber membrane and compare it with the commercially available polypropylene membranes. Structural differences in the membrane morphology, surface hydrophilicity, tortuosity, mass transfer rate, and material properties under different operation conditions of temperature and flow rates are reported. The polysulfone membrane has a water contact angle of 81.3°, whereas a commercial polypropylene membrane is 94.5°. The mass transfer resistances (s/m) for the polysulfone and polypropylene membranes are calculated to be 4.8 × 104 and 1.5 × 104 at 25°C, respectively. The module made of polysulfone was placed in the cardiopulmonary bypass circuit in parallel with the commercial oxygenator, and pH, pO2, pCO2 levels, and metabolic activity were measured in blood samples. [ABSTRACT FROM AUTHOR]