Electrospinning Chitosan/Fe-Mn Nanofibrous Composite for Efficient and Rapid Removal of Arsenite from Water.

Efficient removal of extremely mobile and toxic As(III) from water is a challenging but critical task. Herein, we developed a functionalized sorbent of chitosan nanofiber with iron-manganese (Fe-Mn@CS NF) using a one-step hybrid electrospinning approach to remove trace As(III) from water. Batch adsorption studies were performed to determine the adsorption efficiency under a variety of conditions, including contact time, starting concentration of As(III), ionic strength, and the presence of competing anions. The experimental results demonstrated that the concentration of As(III) dropped from 550 to less than 1.2 µg/L when using 0.5 g/L Fe-Mn@CS NF. This demonstrates the exceptional adsorption efficiency (99.8%) of Fe-Mn@CS NF for removing As(III) at pH 6.5. The kinetic tests revealed that the adsorption equilibrium was reached in 2.6 h, indicating a quick uptake of As(III). The ionic strength effect analysis showed that the adsorbed As(III) formed inner-sphere surface complexes with Fe-Mn@CS NF. The presence of SO42- or F- had a negligible impact on As(III) uptake, while the presence of PO43- impeded As(III) absorption by competing for adsorption sites. The exhausted sorbent could be effectively regenerated with a dilute NaOH solution. Even after 10 cycles of regenerating Fe-Mn@CS NF, the adsorption efficiency of As(III) in natural groundwater was maintained over 65%. XPS and FTIR analyses show that the presence of M-OH and C-O groups on the sorbent surface is essential for removing As(III) from water. Overall, our study highlights the significant potential of Fe-Mn@CS NF for the efficient and quick elimination of As(III) from water.

Coraliomargarita parva sp. nov., isolated from mangrove sediment and genome-based analysis of the class Opitutae revealed five novel families: Coraliomargaritaceae fam. nov., Pelagicoccaceae fam. nov., Cerasicoccaeae fam. nov., Oceanipulchritudinaceae fam. nov., and Alterococcaeae fam. nov.

Members of the class Opitutae are widely distributed in various environments such as rice paddy soil, freshwater lakes, seawater, marine sediment, and invertebrate digestive tracts. The class currently consists of two orders, Opitutales and Puniceicoccales, represented by the families Opitutaceae and Puniceicoccaceae, respectively, which are primarily delineated on the basis of 16S rRNA gene sequences and limited phenotypic characterizations of a few type strains. The scarcity of 16S rRNA gene and genome sequences generated from the type strains of the class Opitutae constrained our understanding of the ecological distribution and adequate resolution of its taxonomy. Here, an Opitutae strain designated WMMB3T, isolated from a mangrove sediment, was subjected to taxonomic characterization. The 16S rRNA gene of strain WMMB3T shared high sequence similarities with Coraliomargarita akajimensis DSM 45221T and C. sinensis WN38T of 96.1 and 95.9%, respectively. Phylogenetic analysis suggested that strain WMMB3T formed a monophyletic branch affiliated to the genus Coraliomargarita. The average nucleotide identity (ANI) values, digital DNA-DNA hybridization (dDDH) values and average amino acid identity (AAI) values of strain WMMB3T compared between Coraliomargarita members were 71.8-72.5, 20.7, and 68.2-68.7%, respectively, indicating that strain WMMB3T represented a novel species of Coraliomargarita. The genome of strain WMMB3T was 4.5 Mbp with a DNA G + C content of 56.0%. The respiratory quinone was menaquinone-7. The major fatty acids were iso-C14:0, and C18:1ω9c. Based on genomic, phenotypic, and chemotaxonomic characterizations, strain WMMB3T represents a novel species, and Coraliomargarita parva sp. nov. is proposed. Additionally, the phylogenomic analysis of more than 500 genomes of the class Opitutae, encompassing a majority of uncultivated bacteria and a few type strains, was performed using the Genome Taxonomic Database toolkit (GTDB-Tk) to present adequate resolution of the taxonomy. Combined with 16S rRNA gene sequence phylogeny and genomic relatedness, five novel families retrieved mainly from marine habitats were proposed: Coraliomargaritaceae fam. nov., Pelagicoccaceae fam. nov., Cerasicoccaeae fam. nov., Oceanipulchritudinaceae fam. nov., and Alterococcaeae fam. nov. AAI values of 58-60% could be considered as the boundary to delineate families of the class Opitutae. This study provided a new taxonomic framework of the class Opitutae based on the genomic data.

Waste eggshell-supported CuO used as heterogeneous catalyst for reactive blue 19 degradation through peroxymonosulfate activation (CuO/eggshell catalysts activate PMS to degrade reactive blue 19).

Advanced oxidation processes play an important role in the removal of organic pollutants from wastewater, in which it is essential to develop an eco-friendly, effective, stable, and inexpensive catalyst. Herein, waste eggshell-supported copper oxide (CuO/eggshell) was synthesized via a facile method and employed as peroxymonosulfate (PMS) activator for the elimination of reactive blue 19 (RB19). CuO/eggshell exhibited high degradation efficiency of RB19 (approximately 100%) by activation of PMS under the optimum conditions of 20 mg/L RB19, 0.2 g/L CuO/eggshell, 0.36 mM PMS, and initial pH 7.12 within 20 min. In addition, the effects of catalyst dosage, PMS concentration, initial pH, inorganic ions, and humic acid on RB19 degradation were investigated. Scavenging experiments and electron paramagnetic resonance revealed that multiple reactive oxygen species, including sulfate radicals (SO4·-), hydroxyl radicals (·OH), superoxide radicals (O2·-), and singlet oxygen (1O2), contributed to RB19 degradation, and 1O2 played a dominant role. Finally, a possible PMS activation mechanism was proposed. This study suggests that loading catalytically active components onto waste eggshell is eco-friendly and effective for enhancing the degradation of dyes from wastewater.

Gut microbiota health closely associates with PCB153-derived risk of host diseases.

Although the production and use of PCB153 have been banned globally, PCB153 pollution remains because of its persistence and long half-life in the environment. There is ongoing evidence that exposure to PCB153 may influence gut microbiota health and increase the risk of host health. It is needed to illuminate whether there are associations between gut microbiota dysregulation and PCB153-induced host diseases. Importantly, it is urgently needed to find specific strains as biomarkers to monitor PCB153 pollution and associated disorders. The work aims to investigate the change of gut microbiota composition, structure and diversity and various host physiological indexes, to ravel the chain causality of PCB153, gut microbiota health and host health, and to find potential gut microbiota markers for PCB153 pollution. Here, adult female mice were administrated with PCB153. Obtained results indicated that PCB153 led to gut microbiota health deterioration. PCB153 exposure also induced obesity, hepatic lipid accumulation, abdominal adipose tissue depots and dyslipidemia in mice. Furthermore, specific gut microbiota significantly correlated with the host health indexes. This work provides support for the relationship between gut microbiota aberrance derived from PCB153 and risk of host health, and offers some indications of possible indicative functions of gut microbiota on PCB153 pollution.

Bioinspired liquid gating membrane-based catheter with anticoagulation and positionally drug release properties.

Catheters are indispensable medical devices that are extensively used in daily medical treatment. However, existing catheter materials continue to encounter many problems, such as thrombosis, single functionality, and inadaptability to environmental changes. Inspired by blood vessels, we develop a self-adaptive liquid gating membrane-based catheter with anticoagulation and positionally drug release properties. Our multifunctional liquid gating membrane-based catheter significantly attenuates blood clot formation and can be used as a general catheter design strategy to offer various drugs positionally releasing applications to comprehensively enhance the safety, functionality, and performance of medical catheters' materials.

Inner Surface Design of Functional Microchannels for Microscale Flow Control.

Fluidic flow behaviors in microfluidics are dominated by the interfaces created between the fluids and the inner surface walls of microchannels. Microchannel inner surface designs, including the surface chemical modification, and the construction of micro-/nanostructures, are good examples of manipulating those interfaces between liquids and surfaces through tuning the chemical and physical properties of the inner walls of the microchannel. Therefore, the microchannel inner surface design plays critical roles in regulating microflows to enhance the capabilities of microfluidic systems for various applications. Most recently, the rapid progresses in micro-/nanofabrication technologies and fundamental materials have also made it possible to integrate increasingly complex chemical and physical surface modification strategies with the preparation of microchannels in microfluidics. Besides, a wave of researches focusing on the ideas of using liquids as dynamic surface materials is identified, and the unique characteristics endowed with liquid-liquid interfaces have revealed that the interesting phenomena can extend the scope of interfacial interactions determining microflow behaviors. This review extensively discusses the microchannel inner surface designs for microflow control, especially evaluates them from the perspectives of the interfaces resulting from the inner surface designs. In addition, prospective opportunities for the development of surface designs of microchannels, and their applications are provided with the potential to attract scientific interest in areas related to the rapid development and applications of various microchannel systems.

Controllable Liquid-Liquid Printing with Defect-free, Corrosion-Resistance, Unrestricted Wetting Condition.

Conventional printing is worth revisiting because of its established procedures in meeting the surging demand of manufacturing printed electronics, 3D products, etc. However, one goal in penetrating printing into these is to control pattern transfer with no limitation of wettability. Here we introduce a miscible liquid-liquid transfer printing mechanism that can synchronize material preparation and material patterning with desirable properties including limitless selection of raw materials, corrosion resistance, no wetting constraint, and ability to prepare large-area defect-free materials for multi-function applications. Theoretical modeling and experiments demonstrate that donor liquid could be used to make patterns within the bulk of a receiver material, allowing the obtained intrinsically patterned functional materials to be resistant to harsh conditions. Different from current liquid printing technologies, this printing approach enables stable and defect-free material preparation and is expected to prove useful in flexible display, soft electronics, 4D printing, and beyond.

Enhanced adsorption of arsenite from aqueous solution by an iron-doped electrospun chitosan nanofiber mat: Preparation, characterization and performance.

A novel iron-doped chitosan electrospun nanofiber mat (Fe@CTS ENM) was synthesized, which was proven to be effective for the removal of arsenite (As(III)) from water at neutral pH condition. The physiochemical properties and adsorption mechanism were explored by SEM-EDS and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments were carried out to evaluate the As(III) adsorption performance of the Fe@CTS ENM with various process parameters, such as adsorbent dose, solution pH, initial As(III) concentration, contact time, ionic strength, coexisting anions, and natural organic matter. The experimental results indicated that the maximum adsorption capacity was up to 36.1 mg g-1. Especially, when the adsorbent dosage was higher than 0.3 g L-1, the As(III) concentration was reduced from 100 µg L-1 to less than 10 µg L-1, which indicated the Fe@CTS ENM could effectively remove trace As(III) from water over a wide pH range (from 3.3 to 7.5). Kinetics study demonstrated that the adsorption equilibrium was achieved within 2.0 h, corresponding to a fast uptake of As(III). The presence of common co-ions and humic acid had little effect on the As(III) adsorption. XPS analysis suggested that the FeO, COH, COC and CN groups on the adsorbent surface play dominant roles in the adsorption of As(III). Adsorption-desorption regeneration test further demonstrated that no appreciable loss in the adsorption capacities was observed, which confirmed that the Fe@CTS ENM maintained a desirable life cycle that was free of complex synthesis processes, expensive and toxic materials, qualifying it as an efficient and low-cost As(III) adsorbent.

Liquid gating elastomeric porous system with dynamically controllable gas/liquid transport.

The development of membrane technology is central to fields ranging from resource harvesting to medicine, but the existing designs are unable to handle the complex sorting of multiphase substances required for many systems. Especially, the dynamic multiphase transport and separation under a steady-state applied pressure have great benefits for membrane science, but have not been realized at present. Moreover, the incorporation of precisely dynamic control with avoidance of contamination of membranes remains elusive. We show a versatile strategy for creating elastomeric microporous membrane-based systems that can finely control and dynamically modulate the sorting of a wide range of gases and liquids under a steady-state applied pressure, nearly eliminate fouling, and can be easily applied over many size scales, pressures, and environments. Experiments and theoretical calculation demonstrate the stability of our system and the tunability of the critical pressure. Dynamic transport of gas and liquid can be achieved through our gating interfacial design and the controllable pores' deformation without changing the applied pressure. Therefore, we believe that this system will bring new opportunities for many applications, such as gas-involved chemical reactions, fuel cells, multiphase separation, multiphase flow, multiphase microreactors, colloidal particle synthesis, and sizing nano/microparticles.

Dynamic air/liquid pockets for guiding microscale flow.

Microscale flows of fluids are mainly guided either by solid matrices or by liquid-liquid interfaces. However, the solid matrices are plagued with persistent fouling problems, while liquid-liquid interfaces are limited to low-pressure applications. Here we report a dynamic liquid/solid/gas material containing both air and liquid pockets, which are formed by partially infiltrating a porous matrix with a functional liquid. Using detailed theoretical and experimental data, we show that the distribution of the air- and liquid-filled pores is responsive to pressure and enables the formation and instantaneous recovery of stable liquid-liquid interfaces that sustain a wide range of pressures and prevent channel contamination. This adaptive design is demonstrated for polymeric materials and extended to metal-based systems that can achieve unmatched mechanical and thermal stability. Our platform with its unique adaptive pressure and antifouling capabilities may offer potential solutions to flow control in microfluidics, medical devices, microscale synthesis, and biological assays.

Bioinspired Universal Flexible Elastomer-Based Microchannels.

Flexible and stretchable microscale fluidic devices have a broad range of potential applications, ranging from electronic wearable devices for convenient digital lifestyle to biomedical devices. However, simple ways to achieve stable flexible and stretchable fluidic microchannels with dynamic liquid transport have been challenging because every application for elastomeric microchannels is restricted by their complex fabrication process and limited material selection. Here, a universal strategy for building microfluidic devices that possess exceptionally stable and stretching properties is shown. The devices exhibit superior mechanical deformability, including high strain (967%) and recovery ability, where applications as both strain sensor and pressure-flow regulating device are demonstrated. Various microchannels are combined with organic, inorganic, and metallic materials as stable composite microfluidics. Furthermore, with surface chemical modification these stretchable microfluidic devices can also obtain antifouling property to suit for a broad range of industrial and biomedical applications.

Functionalized chitosan electrospun nanofiber for effective removal of trace arsenate from water.

An environment-friendly iron functionalized chitosan elctrospun nanofiber (ICS-ENF) was synthesized for trace arsenate removal from water. The ICS-ENF was fabricated by electrospinning a mixture of chitosan, PEO and Fe(3+) followed by crosslinking with ammonia vapor. The physicochemical properties of ICS-ENF were characterized by FESEM, TEM-EDX and XRD. The ICS-ENF was found to be highly effective for As(V) adsorption at neutral pH. The As(V) adsorption occurred rapidly and achieved equilibrium within 100 min, which was well fitted by pseudo-second-order kinetics model. The As(V) adsorption decreased with increased ionic strength, suggesting an outer-sphere complexation of As(V) on ICS-ENF. Freundlich model well described the adsorption isotherm, and the maximum adsorption capacity was up to 11.2 mg/g at pH 7.2. Coexisting anions of chloride and sulfate showed negligible influence on As(V) removal, but phosphate and silicate significantly reduced As(V) adsorption by competing for adsorption sites. FTIR and XPS analysis demonstrated -NH, -OH and C-O were responsible for As(V) uptake. ICS-ENF was easily regenerated using 0.003 M NaOH, and the removal rate remained above 98% after ten successively adsorption-desorption recycles. This study extends the potential applicability of electrospun nanofibers for water purification and provides a promising approach for As(V) removal from water.

The combined effects of DEHP and PCBs on phospholipase in the livers of mice.

Di(2-ethylhexyl) phthalate (DEHP) and polychlorinated biphenyls (PCBs) are two widely distributed pollutants that are of great concern due to their adverse health effects. However, few studies have investigated the combined effects of DEHP and PCBs. In this study, adult mice were continuously exposed to mixtures of DEHP (15 mg/kg bodyweight/day) and Aroclor 1254 (7.5 mg/kg bodyweight/day) for 12 days to investigate the combined effects of these compounds. The results showed that the ratio of the liver weight to the body weight was higher in the treated group than that in the control group. The effects of combined exposure on three important receptors, the proliferator-activated receptor (PPAR), estrogen receptor (ER), and aryl hydrocarbon receptor (AHR), were investigated. The mRNA level of PPARγ was significantly up-regulated after exposure. The expression level of ERα was decreased in the male treated group. In contrast, the expression levels of AHR and related genes (cyp1a1 and cyp1b1) were not markedly affected. The expression level of phospholipase A (PLA) was significantly down-regulated at both the mRNA and protein levels in male mice after combined treatment. In all, our study demonstrated the combined effects of DEHP and PCBs on the expression levels of key receptors in mice. The combined exposure led to a decrease in phospholipase in male mice.