Glass Microfiber Research Articles

Fluorescent sensor based on pyrroloquinoline quinone (PQQ)-glucose dehydrogenase for glucose detection with smartphone-adapted signal analysis.

A new nano-structured platform for fluorescent analysis using PQQ-dependent glucose dehydrogenase (PQQ-GDH) was developed, particularly using a smartphone for transduction and quantification of optical signals. The PQQ-GDH enzyme was immobilized on SiO2 nanoparticles deposited on glass microfiber filter paper, providing a high load of the biocatalytic enzyme. The platform was tested and optimized for glucose determination using a wild type of the PQQ-GDH enzyme. The analysis was based on the fluorescence generated by the reduced form of phenazine methosulfate produced stoichiometrically to the glucose concentration. The fluorescent signals were generated at separate analytical spots on the paper support under wavelength (365nm) UV excitation. The images of the analytical spots, dependent on the glucose concentration, were obtained using a photo camera of a standard smartphone. Then, the images were processed and quantified using software installed in a smartphone. The developed biocatalytic platform is the first step to assembling a large variety of biosensors using the same platform functionalized with artificial allosteric chimeric PQQ-dependent glucose dehydrogenase activated with different analytes. The future combination of the artificial enzymes, the presently developed analytical platform, and signal processing with a smartphone will lead to novel point-of-care and end-user biosensors applicableto virtually all possible analytes.

Well water sources simultaneous contamination with Cryptosporidium and Acanthamoeba in East-Southeast Asia and Acanthamoeba spp. in biofilms in the Philippines.

Cryptosporidium is the leading agent of waterborne parasitic protozoan outbreaks and is the second leading cause of infant mortality due to diarrhoea worldwide. Acanthamoeba spp. causes Acanthamoeba keratitis (AK) and a life-threatening condition known as granulomatous amoebic encephalitis (GAE). The present study aimed to assess the water quality of an indigenous and a rural community for waterborne parasitic protozoan contamination. Aquatic samples (n = 22) were processed by filtration of 500 mL portion through a 1.2 μm pore size glass microfiber filter and eluted for light microscopy, culture in non-nutrient agar, and PCR analysis. Overall, 36% (8/22) of the investigated aquatic samples were positive for either Cryptosporidium spp. oocysts (13%; 3/22) or Acanthamoeba spp., (36%; 8/22) or both (13%; 3/22). Cryptosporidium spp. oocysts were detected in 27% (3/11) of wet season samples only while Acanthamoeba spp. were detected in 18% (2/11) and 55% (6/11) of wet and dry season samples, respectively. Subsequently, molecular detection for Acanthamoeba species identified A. lenticulata and A. hatchetti with 98-99% BLAST similarity. This is the first report on the simultaneous contamination of Cryptosporidium and Acanthamoeba in well water sources in East-Southeast Asia, the first detection of Acanthamoeba spp. in biofilms in the Philippines, and the longest viability demonstrated for A. lenticulata in two-year-old water samples stored at room temperature.

Dendrite suppression with zirconium (IV) based metal–organic frameworks modified glass microfiber separator for ultralong-life rechargeable zinc-ion batteries

Metal–organic frameworks (MOFs) are increasingly employed in designing an active material for various battery systems due to the variety of structures, morphology, and controllable composition at a molecular level. Moreover, their high porosity enables a facile electrolyte penetration and ion transportation. In this work, we focus on the performance and life cycle of aqueous rechargeable zinc-ion batteries (ZIBs) using zirconium (IV) based MOFs, including UiO-66 and MOF-808 modified glass microfiber separators. The results demonstrated that the symmetrical cell using MOF-808 modified separator extended a relatively stable voltage plateau of symmetric Zn battery over 350 h owing to improved uniformity of Zn ion flux during striping/plating processes. For the capacity retention at the current density of 1.0 A g −1 , the ZIBs using UiO-66@GFC and MOF-808@GFC exhibited higher specific capacities than that using the pristine separator. In addition, the ZIBs with MOF-808 modified separators could prolong the cycle life to as high as 8000 cycles because the modified separators could inhibit non-uniform dendritic zinc growth on a zinc anode surface according to scanning electron micrographs. Hence, the UiO-66 and MOF-808 modified glass microfibers as separators are promising materials for high-performance aqueous zinc-ion batteries with long-life cycles. • No short-circuit of Zn|MnO 2 is achieved for over 8000 cycles at 1 A g −1 . • MOFs modified separators exhibit uniform Zn flux on striping/plating processes after cycling for 1000 cycles. • The percentage of capacitive retention of MOFs modified separators retain 50% after 3000 cycles. • MOFs modified separators were successfully by the one-step dip-coating process.

Concepts for millimeter wave-based detection of African trypanosomes in field-compatible liquid systems

Abstract Human African Trypanosomiasis (HAT) is caused by the African trypanosome, a single-cell parasite that proliferates in the blood and cerebrospinal fluid of infected patients. Diagnostic measures for this pathogen are currently not sufficiently robust and reliable enough to permit effective disease control procedures. As a consequence, we suggested the development of a new sensor type, combining the selectivity of parasite-specific nucleic acid aptamers with the sensitivity of resonant electromagnetic devices to capture and detect the disease-causing organism. While we accomplished the detection of parasite cells in dehydrated specimens, here we summarize our recent progress toward electromagnetic sensors capable of uncovering parasites in liquid patient samples. We present a technique for the removal of blood cells from blood specimens and the deposition of trypanosome cells on glass microfiber membranes for dielectric spectrometry. Liquid suspensions of trypanosomes are characterized to determine the actual dielectric properties of single parasites and lastly, we present two sensor concepts optimized for the detection in liquids, along with a fabrication technique for the integration of microfluidic sample confinements.

Synergy of copper Selenide/MXenes composite with enhanced solar-driven water evaporation and seawater desalination

Despite significant of solar energy to power water evaporation in seawater desalination, the commercial application of this technology is limited by the poor light absorption and low photothermal conversion of existing photothermal materials. Herein, we report a simple method for solar-driven water evaporation using a device comprising Cu2-xSe/Nb2CTx nanocomposites supported by a glass microfiber membrane, which utilizes cotton thread as water transport pathway. The proposed device demonstrates excellent light absorption, water transportation, and thermal management. Benefiting from the strong synergetic photothermal effect of Cu2-xSe and Nb2CTx, the Cu2-xSe/Nb2CTx nanocomposites function as an efficient solar absorber with excellent photothermal conversion efficiency. The rough surface, low thermal conductivity and good hydrophilicity of glass microfiber membrane could maximize light capture, limit heat loss, and timely replenish water during the water evaporation process. When evaluated as a water evaporation system for outdoor seawater desalination, the system achieved a water evaporation of 12.60 kg·m−2 within 6 h. High fresh water generation rate is an important embodiment of high photothermal conversion efficiency. This study demonstrates a new route for designing solar desalination devices with high photothermal conversion properties.

NeuroTorp, a lateral flow test based on toxin-receptor affinity for in-situ early detection of cyclic imine toxins

The emergent cyclic imine toxins produced by marine dinoflagellates are potent antagonists of nicotinic acetylcholine receptors. Shellfish accumulate cyclic imine toxins following filter-feeding on toxic dinoflagellates vectoring them to humans. Herein is presented a lateral flow test for the detection of cyclic imine toxins based on three new concepts for test strips: i) the immobilization of lipoprotein vesicles in the test-line, ii) the high affinity of neurotoxins for their receptor targets and iii) the use of high porosity glass fiber filter membranes as support for the fabrication of the lateral flow test NeuroTorp (WO2017108115). Purified electrocyte membrane vesicles from Torpedo marmorata were used as a source of receptor and were immobilized in the test-line. Biotin-α-bungarotoxin was used as toxin tracer for the NeuroTorp LFT given its high affinity for nicotinic acetylcholine receptors while neutravidin nanogold particle conjugates enable its visual detection. Herein is reported for the first time the use of GF/C glass fiber membranes as the stationary phase for a lateral flow test. The GF/C filter ensures both: the immobilization of a complex lipoprotein in the test-line and the capillary migration of the mobile phase. Scanning electron microscopy studies shed light into the mechanism by which Torpedo-electrocyte membranes vesicles are immobilized in the GF/C glass microfiber. The electrocyte membrane vesicles anchor in neighboring microfibers randomly disposed in the same plane of the GF/C filter forming stable microfilm structures ensuring the functionality of nicotinic acetylcholine receptors. NeuroTorp is a ready-to-use low-cost early warning device for rapid detection of cyclic imine toxins in shellfish by end-users.

Filter paper-based colorimetric analysis: An instrument-free strategy for semiquantitative naked-eye detection of food colorants

A filter paper-based colorimetric strategy for instrument-independent visual detection of artificial food colorants (FCs) was developed in this study. Indicator papers were prepared via the one-step polycondensation of silane coupling agents onto glass microfiber filter papers, and colorimetric cards with a fine one-to-one correspondence between their colors and FCs concentrations were straightforward obtained by the extraction of FCs with indicator papers by virtue of electrostatic interaction and hydrophobic effect. Filter papers post-modified via such a simple way were proved to be of improved binding class selectivity and colorimetric sensitivity, allowing for in-situ colorimetric assay of FCs in an unprecedently wide range of applicable pH (1.0–12.0) with high reliability and fine versatility. Finally, the semiquantitative naked-eye determination of FCs (Allura red, brilliant blue and sunset yellow) in real-world drink samples was experimentally confirmed to be feasible by comparison with the findings of UV–vis absorption spectra, HPLC and mass spectra.

Anomalous matrix and interlayer pore structure of 3D-printed fiber-reinforced cementitious composites

Ordinary 3D-printed neat cement paste generally possesses a porous interface between two neighbored filaments. Our work demonstrates that the addition of glass microfibers into cementitious slurries may lead to an anomalous pore structure, i.e., the increased porosity of the inner and outer matrices in filaments and the densified interlayer between filaments in fiber-reinforced cementitious composites (FRCC). Limited glass microfiber addition (0.6%) has no benefits to the bending strength of FRCC beams, the compressive strength of filament matrix, and the bonding behaviors between filaments. The coupled mechanisms of lubrication layer and pressurized bleeding on the surface of filaments, and air-void entrapments in the matrix of filaments were proposed to account for the formation of the anomalous pore structure and strengths. Our findings would deepen the understanding of matrix-interlayer structures in 3D-printed FRCC towards better tuning and design of 3D printing-based additive manufacturing.

RPA/CRISPR/Cas12a-Based On-Site and Rapid Nucleic Acid Detection of Toxoplasma gondii in the Environment.

Toxoplasma gondii is an opportunistic pathogen widely distributed within the world, poses a huge threat to human health, and causes significant economic losses to the livestock industry. Herein, we developed a portable one-pot detection of T.gondii by combining recombinase polymerase amplification (RPA) and a clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system. A glass microfiber filter device used for the first step can efficiently extract T.gondii from low-concentration samples. The lyophilized RPA reagents and Cas12a/crRNA reagents are prestored in one Eppendorf tube, and both reactions can be performed on a low-cost thermal controller (∼37 °C), avoiding the drawbacks of the step-by-step addition of components. The developed RPA/CRISPR/Cas12a system exhibits a high selectivity toward the B1 gene amplicon of T.gondii over other parasites with a limit of detection of 3.3 copies/μL. The visual signal readout can be easily realized by a fluorometer or lateral-flow strip. A portable suitcase containing the minimum equipment and lyophilized reagents was adopted for the rapid determination of T.gondii in heavily polluted landfill leachate. This system presents rapidness, robustness and on-site features for the detection of nucleic acids of the parasite, making it a promising tool for field applications in remote areas.

Viscosity Simulation of Glass Microfiber and an Unusual Air Filter with High-Efficiency Antibacterial Functionality Enabled by ZnO/Graphene-Modified Glass Microfiber.

The current global pandemic of new coronary pneumonia clearly reveals the importance of developing highly efficient filtration and fast germicidal performance of multifunctional air filters. In this study, a novel air filter with a controllable morphology based on the rod-like to flower-like zinc oxide/graphene-based photocatalytic composite particles loaded on glass microfiber was prepared by one-step microwave rapid synthesis. The multifunctional air filter shows the following special functions: the 10 mg·L–1 organic pollutant solution RhB was completely degraded within 2 h under a 500 W xenon lamp, and also 99% of Escherichia coli and Staphylococcus aureus were inactivated under a 60 W light-emitting diode lamp. Furthermore, after introducing the controllable morphology zinc oxide/graphene-based photocatalytic composite particles, the filtration efficiency of the multifunctional air filter was also kept at the same level (99.8%) as the one without any addition, indicating no loss of high-efficiency filtration while obtaining the rapid bactericidal function. The rapid antibacterial principle of the multifunctional air filter has also been proposed through the UV–vis spectroscopies, photoluminescence, and electron-spin resonance spectrum. The zinc oxide/graphene-based photocatalytic composite particles tightly coated on the glass microfiber surface could increase the active sites by changing the morphology of zinc oxide and, in the meantime, promote the separation of zinc oxide photo-generated electron–hole pairs to improve the rapid sterilization ability of the multifunctional air filters. In addition, an empirical formula to evaluate the relationship between the composition, viscosity, and viscosity modulus of glass microfiber was proposed by testing the viscosity of glass microfiber composed of 14 different compositions at 1300 and 1400 °C, which can be used as a criterion to evaluate the production technology of glass microfiber filters.

Experimental and Numerical Investigation of Single Fiber Pull-Out Tests of Steel Macro-Fiber and Glass Micro-Fiber in a Cementitious Matrix

Abstract This paper presents a modeling-based relationship between fiber diameter and frictional bond strength for steel macro-fiber (0.8-mm diameter) and glass micro-fiber (5–24-μm diameter) embedded in a cementitious matrix. A combined approach of experimental stress-displacement results obtained through single fiber pull-out tests and finite element modeling (FEM)–based stress-displacement results yielded the friction coefficient for the two types of fibers used. Further analysis relating to the pressure exerted on the fiber caused by the surrounding concrete reveals that a smaller fiber diameter would improve the bond strength. The improvements in frictional bond strength due to reduced diameter are based on FEM analysis. Validation of the experimental results is done through numerical approaches. The results showed that in the case of the same diameter, the pressure of the surrounding concrete decreases throughout the fiber sliding. The results also showed that the smaller diameter of fiber improves the properties of fiber-reinforced concrete interfaces.

Investigation of Jute and Glass Fibre Reinforced Hybrid Composites Manufactured through Compression Molding Process

Expensive and non-biodegradable synthetic fibres are commonly utilized as reinforcement in composites for better mechanical properties. The eco-friendly and low-cost properties of natural fibres are promising alternative reinforcement for composites. In this study epoxy-based glass and jute fibres reinforced hybrid composites are fabricated varying fibre stacking sequences, 1jute-1glass alternatively (j-g-j-) and 4glass-9jute-4glass (4g-9j-4g). Hybridization of jute and glass fibre results better tensile, flexural and water absorption properties than only jute fibre reinforced composites but inferior to only glass fibre reinforced composites. The 4g-9j-4g stacking sequence resulted in better mechanical and water absorption properties than j-g-j-- stacking sequence. The effect of chemical treatment and glass microfiber infusion are also investigated. Chemically treated jute fibre and 2 wt.% microfiber infused hybrid composite shows about 42% improvements in flexural strength as compared to untreated and without microfiber infused composites. However, fibre chemical treatment and microfiber do not have a positive impact on tensile strength.

Dielectric heating of highly corrosive and oxidizing reagents on a hybrid glass microfiber-polymer centrifugal microfluidic device.

Many assays necessitate the use of highly concentrated acids, powerful oxidizing agents, or a combination of the two. Although microfluidic devices offer vast potential for rapid analytical interrogation at the point-of-need (PON), they cannot escape the fundamental requirement for reagent compatibility. Worse, many innovative protocols have been developed that would represent a significant improvement to current field-forward practices within their respective disciplines, but adoption falters due to chemical incompatibility with challenging reagents. Polymeric centrifugal microfluidic devices meet many of the needs for accommodating complex chemical or biochemical protocols in a multiplexed and automatable format. Yet, they also struggle to accommodate highly reactive chemical components long term. In this work, we report on a simple and inexpensive reagent storage strategy that bypasses the typical complexity involved with integration of liquid reagents on microfluidic devices. Moreover, we demonstrate microdevice compatibility and operation after six months of corrosive reagent storage as well as post dielectric heating. This new strategy allows for storage of multiple highly corrosive and oxidative reagents simultaneously, enhancing the possibilities for multistep assay integration at the PON for a diverse array of applications. Successful detection after one week of corrosive reagent storage of an illicit drug and neurotransmitter metabolite, for forensic and clinical applications, is demonstrated. Furthermore, environmental sample preparation via microwave-assisted wet acid digestion is performed on-disc and integrated with downstream detection. Quantitative detection of a heavy metal in soil is achieved by way of on-disc calibration and found to be accurate within 2.4% compared to a gold standard reference (ICP-OES).

TRIBOLOGICAL ASPECT OF ASSESSMENT OF EFFICIENCY OF FILTRATION USING MULTI-LAYER MATERIALS

This study presents the results of testing for the efficiency and effectiveness of filtration using multi-layer filter materials, and briefly presents a new technology for manufacturing filter media using these materials. The first part of the article describes the causes of the formation of impurities in operating fluids and the tribological effects of their impact. The second part is dedicated to testing for filtration efficiency and effectiveness for different filter materials. The third part of the article briefly describes the technology for manufacturing filter media using efficient but difficult-to-form materials. The testing results showed significant differences in filtering efficiency and effectiveness between the cellulose samples and the samples of filter materials based on glass microfibre layers. All of the tested multi-layer materials allow filtration effectiveness of over 90% to be achieved over the entire range of impurity sizes included in the experiment. The results of a comparative test for pressure change during filtration also indicate that glass microfibre materials have a considerably longer operating life than cellulose materials. The time after which a sharp increase in pressure occurs (due to the filter layer being filled with impurities) is nearly four times longer for multi-layer materials than for cellulose materials. The methods for cutting, forming, and joining filter materials have been developed by the author of this article and implemented at the EXMOT company.

A Structured Hybrid Catalyst to Improve ORR Activity and Phosphoric Acid in the High-Temperature Exchange Membrane Fuel Cell

The high-temperature proton exchange membrane fuel cell (HT-PEMFC) based on a phosphoric acid (PA)-doped polybenzimidazole (PBI) membrane electrolyte has been attracted attention because of its higher kinetics of oxygen reduction reaction, no flooding issues and excellent carbon monoxide tolerance [1, 2]. However, PA leaching from PBI membrane to electrode is one of the biggest problems as the loss of phosphoric acid causing worse proton conductivity of PBI membrane and preventing gas transfer in the electrode [3]. Furthermore, HT-PEMFC requires higher amount of platinum (Pt) (normally between 0.7 and 1.2 mg cm-2) to provide high electrochemical surface area, which accounts for a higher proportion in the cost of a total fuel cell stack [4]. Therefore, the reduction of phosphoric acid permeation and catalyst dosage are two challenges in HT-PEMFC.Many studies and technologies have been conducted to prevent the permeation of PA. Currently, the modification of PBI membrane structure is the main method by introducing materials with more -NH2 functional groups to form stable chemical bonds with phosphoric acid molecules and prevent their movement [5-7]. However, the composite membrane materials are not uniform and the intercalation of materials (SiO2, Graphene et al) will cause crossover issues to influence the durability of HT-PEMFC [7].Based on our previous research, platinum supported on nitrogen doped reduced electrochemically exfoliated graphene oxide/carbon black hybrid catalysts (Pt/NrEGOx-CBy) have higher oxygen reduction reaction (ORR) activity. This work aims to optimize the ratio of NrEGO and CB in HT-PEMFC and explore the effect of NrEGO flakes on PA permeation to improve the durability of HT-PEMFC. The preliminary results showed that Pt/NrEGO2-CB3 catalyst in a membrane electrode assembly (MEA) had the mass power density of 1.652 W mgPt -1 with a decay rate of 0.01 mV h-1 within 100 hours, which is much lower than that of 1.125 mV h-1 in the commercial Pt/C as shown in Figure 1.Reference[1] J. Lobato, H. Zamora, J. Plaza, P. Cañizares, M.A. Rodrigo. Enhancement of high temperature PEMFC stability using catalysts based on Pt supported on SiC based materials. Applied Catalysis B: Environmental. 2016. 198: 516-524.[2] Y. Hu, Y. Jiang, J.O. Jensen, L.N. Cleemann, Q. Li. Catalyst Evaluation for Oxygen Reduction Reaction in Concentrated Phosphoric Acid at Elevated Temperatures. Journal of Power Sources. 2018. 375: 77-78.[3] G. Liu, H. Zhang, J. Hu, Y. Zhai, D. Xu, Z.-g. Shao. Studies of performance degradation of a high temperature PEMFC based on H3PO4-doped PBI. Journal of Power Sources. 2006. 162 (1): 547-552.[4] H. Su, T.-C. Jao, O. Barron, B.G. Pollet, S. Pasupathi. Low platinum loading for high temperature proton exchange membrane fuel cell developed by ultrasonic spray coating technique. Journal of Power Sources. 2014. 267: 155-159.[5] F. Liu, S. Wang, J. Li, X. Tian, X. Wang, H. Chen, Z. Wang. Polybenzimidazole/ionic-liquid-functional silica composite membranes with improved proton conductivity for high temperature proton exchange membrane fuel cells. Journal of Membrane Science. 2017. 541: 492-499.[6] K.-J. Peng, J.-Y. Lai, Y.-L. Liu. Nanohybrids of graphene oxide chemically-bonded with Nafion: Preparation and application for proton exchange membrane fuel cells, Journal of Membrane Science. 2016. 514: 86-94.[7] C.-L. Lu, C.-P. Chang, Y.-H. Guo, T.-K. Yeh, Y.-C. Su, P.-C. Wang, K.-L. Hsueh, F.-G. Tseng. High-performance and low-leakage phosphoric acid fuel cell with synergic composite membrane stacking of micro glass microfiber and nano PTFE. Renewable Energy. 2019. 134: 982-988. Figure 1

Development of two-dimensional qualitative visualization method for isoflavones secreted from soybean roots using sheets with immobilized bovine serum albumin

A visualization method for the qualitative evaluation of soybean isoflavones secreted from soybean roots by transferring them onto a sheet with immobilized bovine serum albumin (BSA) was developed. BSA was chemically bonded onto a glass microfiber filter. The fluorescence quenching resulting from the interaction of BSA with soybean isoflavones such as daidzein and daidzin was utilized. Fluorescence images before and after soybean roots were placed in contact with the sheets with immobilized BSA were taken with an electron-multiplying charge-coupled device camera. The fluorescence quenching in the images was visualized and analyzed. Soybean isoflavones were extracted from the sheets for quantitative analysis, and the correlation coefficient between the quenched fluorescence intensity per sheet and the total amount of soybean isoflavones was 0.78 (p < 0.01), indicating a high correlation. The quenched fluorescence intensity was lower in pumpkin roots, which do not secrete soybean isoflavone. It was found from analyzed images that soybean isoflavone is secreted in larger amounts from the basal region of the taproot and the tips of the lateral roots of soybean.

A multi-centre, single-blinded randomised controlled clinical trial evaluating the effect of resorbable glass fibre matrix in the treatment of diabetic foot ulcers.

Diabetic foot ulcers (DFUs) are at risk for detrimental complications even with current, standard of care (SOC) treatments. The primary objective of this randomised controlled trial was to compare a unique resorbable glass microfiber matrix (Mirragen; Advanced Wound Matrix [BBGFM]; ETS Wound Care, Rolla, Missouri) compared with a standard of care group (SOC, collagen alginate dressing) at 12 weeks. Both groups received standard diabetic foot care including glucose monitoring, weekly debridements when needed and an offloading device. The primary endpoint was proportion of full‐thickness, non‐infected, non‐ischaemic wounds healed at 12 weeks, with secondary endpoints including percent area reduction (PAR) and changes in Semmes‐Weinstein monofilament testing. The result illustrated in the intent‐to‐treat analysis at 12 weeks showed that 70% (14/20) of the BBGFM‐treated DFUs healed compared with 25% (5/20) treated with SOC alone (adjusted P = .006). Mean PAR at 12 weeks was 79% in the BBGFM group compared with 37% in the SOC group (adjusted P = .027). Mean change in neuropathic score between baseline and up to 12 weeks of treatment was 2.0 in the BBGFM group compared with −0.6 in the SOC group where positive improvement in scores are better (adjusted P = .008). The mean number of BBGFM applications was 6.0. In conclusion, adding BBGFM to SOC significantly improved wound healing with no adverse events related to treatment compared with SOC alone.

A Recommendation for a Pre-Standardized Marine Microalgal Dry Weight Determination Protocol for Laboratory Scale Culture Using Ammonium Formate as a Washing Agent.

Simple SummaryMicroalgae are increasingly recognized as a source of valuable biomass with numerous health benefits. Cleaning of marine microalgal biomass is very crucial for microalgal studies as the salt on the microalgae cells will lead to overestimation of biomass determination. Incomplete washing of salt from microalgae could also interfere with the nutritional analyses. The biomass, especially dry weight, has been utilized for nutritional or compositional evaluation. Although standard methods of marine microalgal dry weight determination are available, these methods did not provide comprehensive details, and the parameters vary among themselves. Without a standard method, a comparison of results among previous studies can be misleading and unreliable. Therefore, the current study aimed to investigate and determine the ideal setting of several parameters in the marine microalgal dry weight determination for laboratory-scale culture. The present findings could assist in developing a standardized protocol to ensure a high quality of biomass for microalgal studies. Microalgal biomass is one of the crucial criteria in microalgal studies. Many reported methods, even the well-established protocol on microalgal dry weight (DW) determination, vary greatly, and reliable comparative assessment amongst published results could be problematic. This study aimed to determine the best condition of critical parameters in marine microalgal DW determination for laboratory-scale culture using four different marine microalgal species. These parameters included the washing process, grades of glass microfiber filter (GMF), GMF pretreatment conditions, washing agent (ammonium formate) concentrations, culture: washing agent ratios (v:v) and washing cycles. GMF grade GF/A with precombustion at 450 °C provided the most satisfactory DW and the highest ash-free dry weight (AFDW)/DW ratio. Furthermore, 0.05 M ammonium formate with 1:2 culture: washing agent ratio and a minimum of two washing cycles appeared to be the best settings of microalgal DW determination. The present treatment increased the AFDW/DW ratio of the four respective microalgae by a minimum of 19%. The findings of this study could serve as a pivotal reference in developing a standardized protocol of marine microalgal DW determination to obtain veracious and reliable marine microalgal DW.

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Separator is a crucial component for flexible lithium‐ion batteries. In article number eom2.12126, Haipeng Yu and co‐workers realize a green and scalable modification for glass microfiber separators without any complex operations. Based on the gradient entropy diffusion effect of fluidic cellulose macromolecules, they successfully prepared a cellulose/glass microfiber composite film with high surface density, adjustable pore structure, good flexibility, strong mechanical properties, and anti‐disintegration performance. These properties promote the rapid ion transmission and inhibit the lithium dendrite growth. image

Spinning and Fully Integrated Microdevice for Rapid Screening of Vancomycin-Resistant Enterococcus.

This study introduces a spinning and fully integrated paper-based microdevice that can perform multiple functions, including DNA extraction, amplification, and colorimetric detection, for monitoring two major vancomycin-resistant Enterococci (VREs), which carry the vanA and vanB genes. The spinning microdevice is composed of a stationary part and a spinning part. The square-shaped stationary part has two zones: the lysis and reaction zones. The spinning part, which has a spin wheel-like shape, was inserted perpendicularly into the stationary part so that its two semicircles remained on the upper and lower parts. Sodium hydroxide-treated glass microfiber filter discs, inserted in the upper semicircle, were soaked in the lysis chambers by folding them toward the lysis zone to capture DNA in the lysis chambers. The captured DNA was transferred to the reaction chambers by folding the discs toward the reaction chambers. Water was added to the sodium hydroxide-treated glass microfiber filter discs to elute purified DNA into the reaction chambers. The upper semicircle was then unfolded, and the reaction chambers were sealed for subsequent loop-mediated isothermal amplification (LAMP) for 45 min. After the reaction, the spinning part was spun in the lysis zone direction to bring the lower semicircle, inserted with phenolphthalein-treated glass microfiber filter discs, toward the upper part of the stationary part. By folding it toward the reaction chambers, the lower semicircle came into contact with them and the phenolphthalein-treated glass microfiber filter discs were soaked in the reaction chambers and expressed color after 30 s. Based on the pH change during the LAMP reaction, the phenolphthalein-treated discs remained pink in the absence of target DNA, while those in contact with the positive samples turned colorless. A sensitive detection with a VRE limit of detection of 102 CFU/mL for tap water spiked with VRE carrying the vanA gene was achieved using this microdevice. Both VREs, carrying vanA and vanB genes, were successfully identified from tap water and contaminated equipment surfaces within 75 min. The introduced microdevice demonstrated a rapid, accurate, and sensitive performance for the environmental assessment of VRE contamination in resource-limited regions.