Purifying chylous plasma by precluding triglyceride via carboxylated polyethersulfone microfiltration membrane

Precluding the excessive lipoproteins from plasma rapidly and effectively is highly needed for biomedical detection and reducing plasma product scrap in blood donation stations.The current centrifugation procedure is high-cost and time-consuming.Herein,we fabricated an anionic microfiltration polyethersulfone(PES)membrane modified by interface swelling and implanting of acrylic acid(AA)for screening out large particle lipoprotein chylomicron(CM)and adsorbing cationic very low-density lipoproteins(VLDL).To improve the separation efficiency,a two-stage filtration through carboxylated polyethersulfone microfiltration membranes with the mean pore size of 0.45 and 0.22μm respectively were conducted.Attenuated total reflection Fourier transform infrared technique(ATR-FTIR),water contact angle(WCA),Zeta potential and scanning electron microscope(SEM)were employed to characterize the modified membrane.To test the effectiveness of this membrane,plasma flux and concentration variation of plasma components were examined to study the purification effectiveness.Furthermore,the hemocompatibility of modified membranes was tested to confirm its practicability on bloodcontacting materials.The carboxylated polyethersulfone microfiltration membrane shows its promising potential application to purify chylous plasma.

Dispersive Ability of Carboxylated Cellulose Nanofibrils for Aqueous Monolayer Montmorillonite Dispersion:Influence of Na^(+) and Ca^(2+) Concentrations

Carboxylated cellulose nanofibrils(CNFs)have emerged as effective green dispersants for monolayer montmorillonite(MMT)dispersions.However,their dispersion capability is sensitive to the metal ion concentration in aqueous solutions.Hence,this study investigated the effects of Na^(+) and Ca^(2+) concentrations on the dispersive ability of carboxylated CNFs for monolayer MMTs in water.Quartz crystal microbalance with dissipation monitoring(QCM-D)and atomic force microscopy(AFM)were utilized to explore the interfacial interactions between the carboxylated CNFs and monolayer MMTs under different Na^(+) and Ca^(2+) concentrations.When the concentration of Na^(+) reached 0.1 mmol/L,the adhesion mass of carboxylated CNFs on MMT-coated wafer peaked at 24.47 mg/m^(2),higher than control sample(carboxylated CNF-dispersed monolayer MMT dispersion without metal ions,16.03 mg/m^(2)).Moreover,the electrostatic shielding effect promoted a better dispersion of monolayer MMTs by carboxylated CNF dispersant.With a further increase in the Na^(+) concentration,the surface charge of CNFs and MMTs would be reversed resulting from the improved electrostatic shielding effect,which weaken the dispersive ability of carboxylated CNFs.The addition of Ca^(2+) reduced the dispersive ability of carboxylated CNFs for monolayer MMTs,because Ca^(2+) required a lower concentration for the onset of charge reversal compared to Na^(+).This study provides interfacial scale insights into the influence of metal ion concentration on carboxylated CNF-dispersed monolayer MMT dispersions.It also provides a strategy to enhance the dispersive ability of carboxylated CNFs for monolayer MMTs.

Simultaneous Extraction of Carboxylated Celulose Nanocrystals and Nanofibrils via Citric Acid Hydrolysis--A Sustainable Route

In this study, cellulose nanocrystals(CNC) with surface carboxylic groups were prepared from bleached softwood pulp by hydrolysis with concentrated citric acid at concentrations of 60 wt%~80 wt%. The solid residues from acid hydrolysis were collected for producing cellulose nanofibrils(CNF) via post high-pressure homogenization. Citric acid could be easily recovered after hydrolysis reactions through crystallization due to its low water solubility or through precipitation as a calcium salt followed by acidification. Several important properties of CNC and CNF, such as dimension, crystallinity, surface chemistry, thermal stability, were evaluated. Results showed that the obtained CNC and CNF surfaces contained carboxylic acid groups that facilitated functionalization and dispersion in aqueous processing. The recyclability of citric acid and the carboxylated CNC/CNF give the renewable cellulose nanomaterial huge potential for a wide range of industrial applications. Furthermore, the resultant CNC and CNF were used as reinforcing agents to make sodium carboxymethyl cellulose(CMC) films. Both CNC and CNF showed reinforcing effects in CMC composite films. The tensile strength of CMC films increased by 54.3% and 85.7% with 10 wt% inclusion of CNC and CNF, respectively. This study provides detailed information on carboxylated nanocellulose prepared by critic acid hydrolysis; a sustainable approach for the preparation of CNC/CNF is of significant importance for their various uses.

Molecularly imprinted sensor based on carboxylated carbon nanotubes/Keggin-type polyoxometalates nanocomposite for the detection of furazolidone

Due to its properties of mutagenic,teratogenic,and carcinogenic,the detection of furazolidone(FZD)in aquaculture is of great importance for food safety and human health.In this study,molecularly imprinted fi lms modifi ed with carboxylated multi-walled carbon nanotube-phosphomolybdic acid composite were used to fabricate an electrochemical sensor for the determination of FZD.The nanocomposites were characterized using infrared spectroscopy,scanning electron microscopy,energy-dispersive X-ray spectroscopy,and X-ray diff raction.The electrochemical characteristics of the modifi ed electrodes were examined using electrochemical impedance spectroscopy,cyclic voltammetry,and diff erential pulse voltammetry.The sensor exhibited exceptional catalytic performance.The calibration curves were acquired in the concentration range of 6 nmol·L^(−1)to 0.6μmol·L^(−1),with a limit of detection of 3.38 nmol·L^(−1).Additionally,the sensor proved successful in recognizing FZD in shrimp samples with satisfactory recoveries and precision.The method provides a strategy to construct a molecularly imprinted electrochemical sensing platform using nanomaterials,which has great promise in the field of food safety.

Enabling heterogeneous catalysis to achieve carbon neutrality: Directional catalytic conversion of CO_(2) into carboxylic acids

The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.

Effective and selective adsorption of uranyl ions by porous polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal composite

Composite materials have elicited much interest because of their superior performance in the removal of toxic and radioactive uranyl ions from aqueous solutions.With polyethyleneimine as a functional group,carboxylated chitosan as a matrix,and oxidizing activated carbon as a nanofiller,this study synthesized a novel environment-friendly polyethylenimine-functionalized carboxylated chitosan/oxidized activated charcoal(PCO)biocomposite with a unique three-dimensional porous structure.PCO was synthesized through an easy chemical cross-linking method.Detailed characterization certified the formation of the unique three-dimensional porous structure.The obtained PCO was used to remove uranyl ions from an aqueous solution,demonstrating the maximum adsorption capacity of 450 mg·g^(−1).The adsorption capacity of PCO decreased by less than 7.51%after five adsorption-desorption cycles.PCO exhibited good adsorption selectivity(K_(d)=3.45×10^(4) mL·g^(−1))for uranyl ions.The adsorption mechanism of PCO was also discussed.The material showed good potential for application in the treatment of wastewater containing uranyl ions.

Immobilization of nano-zero-valent irons by carboxylated cellulose nanocrystals for wastewater remediation

Nano-zero-valent irons(nZVI)have shown great potential to function as universal a nd low-cost magnetic adsorbents.Yet,the rapid agglomeration and easy surface corrosion of nZVI in solution greatly hinders their overall applicability.Here,carboxylated cellulose nanocrystals(CCNC),widely available from renewable biomass resources,wer e prepared and applied for the immobilization of nZVI.In doing so,carboxylated cellulose nanocrystals supporting nano-zero-valent irons(CCNC-nZVI)were obtained via an in-situ growth method.The CCNC-nZVI were characterized and then evaluated for their performances in wastewater treatment.The results obtained show that nZVI nanoparticles could attach to the carboxyl and hydroxyl groups of CCNC,and well disperse on the CCNC surface with a size of〜10nm.With the CCNC acting as corrosion inhibitors improving the reaction activity of nZVI,CCNC-nZVI exhibited an improved dispersion stability and electron utilization efficacy.The Pb(II)adsorption capacity of CCNC-nZVI reached 509.3 mg·g^-1(298.15 K,pH=4.0),significantly higher than that of CCNC.The adsorption was a spontaneous exothermic process and could be perfectly fitted by the pseudo-second-order kinetics model.This study may provide a novel and green method for immobilizing magnetic nanomaterials by using biomassbased resources to develop effective bio-adsorbents for wastewater decontamination.

Amine-functionalized metal organic framework@graphene oxide as filler in PAEK-containing carboxyl group membrane for ultrafiltration with ultra-high permeability and strong fouling resistance

Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.

AAV mediated carboxyl terminus of Hsp70 interacting protein overexpression mitigates the cognitive and pathological phenotypes of APP/PS1 mice

The E3 ubiquitin ligase,carboxyl terminus of heat shock protein 70(Hsp70)interacting protein(CHIP),also functions as a co-chaperone and plays a crucial role in the protein quality control system.In this study,we aimed to investigate the neuroprotective effect of overexpressed CHIP on Alzheimer’s disease.We used an adeno-associated virus vector that can cross the blood-brain barrier to mediate CHIP overexpression in APP/PS1 mouse brain.CHIP overexpression significantly ameliorated the performance of APP/PS1 mice in the Morris water maze and nest building tests,reduced amyloid-βplaques,and decreased the expression of both amyloid-βand phosphorylated tau.CHIP also alleviated the concentration of microglia and astrocytes around plaques.In APP/PS1 mice of a younger age,CHIP overexpression promoted an increase in ADAM10 expression and inhibitedβ-site APP cleaving enzyme 1,insulin degrading enzyme,and neprilysin expression.Levels of HSP70 and HSP40,which have functional relevance to CHIP,were also increased.Single nuclei transcriptome sequencing in the hippocampus of CHIP overexpressed mice showed that the lysosomal pathway and oligodendrocyte-related biological processes were up-regulated,which may also reflect a potential mechanism for the neuroprotective effect of CHIP.Our research shows that CHIP effectively reduces the behavior and pathological manifestations of APP/PS1 mice.Indeed,overexpression of CHIP could be a beneficial approach for the treatment of Alzheimer’s disease.

Uncinatic acids A-C,three new carboxylated flavonoids from Selaginella uncinata

Three new carboxylated flavonoids, uncinatic acids A-C（1–3）, were isolated from the whole herb of Selaginella uncinata. Their structures were established on the basis of extensive NMR analysis including1 D, 2D NMR experiments and HR-ESIMS techniques. All of them share the carboxylation structural characteristic. Compounds 1 and 2 belong to novel naturally occuring furanoflavonoids which is firstly reported in genus Selaginella. Such furanoflavonoids with dicarboxylic acid structrure have never been discovered before. In addition, the isolates were tested for their cytotoxicity against A549 and BGC-823 cell lines in vitro.

Electrochemical Reaction Mechanism of Phenacetin at a Carboxylated Multiwall Carbon Nanotube Modified Electrode and Its Analytical Applications

A novel type of carboxylated multiwalled carbon nanotube modified electrode（c-MWCNTs/GCE） was constructed and the electrochemical properties of phenacetin（PHE） at it were studied. In a buffer solution of 0.1 mol/L HAc-NaAc（pH=5.3）, PHE exhibited a couple of quasi-reversible redox peaks and an anodic peak in the poten- tial range of 0.2--1.2 V at c-MWCNTs/GCE. The peak current was proportional to the concentration of PHE in the range of 4.0× 10^-6_ 1.0 × 10^-4 mol/L with a detection limit of 1.0× 10^-6 mol/L（S/N=3）. The c-MWCNTs/GCE showed excellent repeatability and stability and the electrochemical reaction mechanism of PHE was proposed. This method was used to determine the content of PHE in medical tablets and the recovery was determined to be 96.5%--104.2% by means of a standard addition method.

Fabrication of nanocomposite electrochemical sensors with poly(3,4-ethylenedioxythiophene)conductive polymer and Au nanoparticles adsorbed on carboxylated nanocrystalline cellulose

Au nanoparticles(AuNPs)were prepared by reducing HAuCl4 with NaBH4,and then adsorbed uniformly on the surface of carboxylated nanocrystalline cellulose(CNCC).The obtained AuNPs/CNCC particles were doped into a conductive polymer of poly(3,4-ethylenedioxythiophene)(PEDOT)to yield a highly conductive nanocomposite,which was deposited onto a glassy carbon electrode(GCE)by an electrochemical method.The PEDOT/AuNPs/CNCC nanocomposite showed low electrochemical impedance and good electrocatalytic activity toward ascorbic acid.Based on this novel nanocomposite material,an amperometric sensor was developed for the detection of ascorbic acid with a detection limit as low as 0.29μM.When operated at-0.15 V,the sensor detected ascorbic acid in the range of 0.88μM to 15000μM.

A simple structure copolymer donor based on carboxylated benzodithiophene for polymer solar cells

The design and development of low-cost and efficient photovoltaic materials remain a major challenge for the research and application of polymer solar cells(PSCs).Therefore,developing efficient photovoltaic polymers with simple structure and easy preparation has become an important research topic.Here we report a facilely synthesized electron-donating polymer X1 with a simple chemical structure,which is composed of carboxylated benzo[1,2-b:4,5-b′]dithiophene(BDT)and thiophene unit.The carboxylate substituents on the BDT unit endowed the polymer with appropriate solubility,low-lying highest occupied molecular orbital(HOMO)energy level,and superior absorption.The PSCs based on X1 as the donor showed a high power conversion efficiency of 16.6%,with a remarkable short-circuit current density of 27.07 m A cm^(-2).These results demonstrated that X1 is a highly promising candidate for low-cost and efficient PSCs.Furthermore,this study revealed the potential of carboxylated BDT as an effective building block in the research and development of high-performance photovoltaic materials.

Carboxylated carbon nanotubes with high electrocatalytic activity for oxygen evolution in acidic conditions

Since most electrocatalysts for oxygen evolution reaction(OER),except for precious metal oxides RuO_(2) and IrO_(2),are unstable in harsh acidic solutions,it is highly desirable to develop high-performance OER electrocatalysts for acidic media,though it is still a big challenge.Herein,we report a simple strategy to produce carboxyl-enriched multiwalled carbon nanotubes(COOH-MWNTs)that exhibit stable and high electrocatalytic activities for OER in acidic solutions,showing an overpotential at a current density of 10 mA cm^(–2) and a Tafel slope as low as of 265 mV and 82 mV dec^(–1),respectively.As far as we are aware,these results represent the best OER performance for metal-free electrocatalysts,even comparable to those of RuO_(2) and IrO_(2).We have further revealed the catalytic mechanism,which involves one electron lose from the COOH-MWNTs catalyst at the beginning of the OER process to trigger H_(2)O molecule oxidation by forming peralcohol,followed by the recapture of one electron from water molecule to oxidize water and to recover the initial state for the COOH-MWNTs catalyst.The unravel of this new OER mechanism is important as it provides new insights into the crucial role of organic functional groups in electrocatalytic processes.Also,the mechanistic understanding can be used to guide the design and development of novel metalfree catalysts for acidic OER electrocatalysis and beyond.

基于Auto Dock Vina软件的药物化学虚拟仿真实验构建与应用

目前药物化学实验偏有机合成技能的培养,忽视了药物化学课程的主要内容。因此我们尝试在药物化学实验课程中构建Oseltamivir carboxylate与神经氨酸酶的分子对接虚拟仿真实验,帮助学生理解药物与靶蛋白的作用方式,提高学习兴趣。本研究通过提前发布学习视频、靶蛋白的下载与预处理、靶分子的结构获取与预处理、AutoDock vina参数设置与对接、Py MOL软件分析结果与图片制作以及学生PPT汇报结果等实验内容。该实验的实施将帮助学生掌握分子对接的基本技能,深入理解立体化学结构对药物与靶蛋白相互作用的影响,提高学生学习药物化学的兴趣,为AutoDock vina软件在药物化学教学中的应用提供参考。

Electrocarboxylation of CO_(2) with Organic Substrates:Toward Cathodic Reaction

Electrocarboxylation of carbon dioxide(CO_(2))using organic substrates has emerged as a promising method for the sustainable synthesis of value-added carboxylic acids due to its renewable energy source and mild reaction conditions.The reactivity and product selectivity of electrocarboxylation are highly dependent on the cathodic behavior,involving a sequence of electron transfers and chemical reactions.Hence,it is necessary to understand the cathodic reaction mechanisms for optimizing reaction performance and product distribution.In this work,a review of recent advancements in the electrocarboxylation of CO_(2)with organic substrates based on different cathodic reaction pathways is presented to provide a reference for the development of novel methodologies of CO_(2)electrocarboxylation.Herein,cathodic reactions are particularly classified into two categories based on the initial electron carriers(i.e.,CO_(2)radical anion and substrate radical anion).Furthermore,three cathodic pathways(ENE(N),ENED,and EDEN)of substrate radical anion-induced electrocarboxylation are discussed,which differ in their electron transfer sequence,substrate dissociation,and nucleophilic reaction,to highlight their implications on reactivity and product selectivity.

Volatile Compounds Fingerprints for White Duck down and White Goose down Determined by Gas Chromatography-Ion Mobility Spectrometry

This work first describes a simple approach for the untargeted profiling of volatile compounds for distinguishing between white duck down (WDD) and white goose down (WGD) based on resolution-optimized GC-IMS combined with optimized chemometric techniques, namely PCA. The detection method for down samples was established by using GC-IMS. Meanwhile, the reason of unpleasant odors caused by WDD was explained on the basis of the characteristic volatile compounds identification. GC-IMS fingerprinting can be considered a revolutionary approach for a truly fully automatable, cost-efficient, and in particular highly sensitive method. A total of 22 compounds were successfully separated and identified through GC-IMS method, and the significant differences in volatile compounds were observed in three parts of WDD and WGD samples. The most characteristic volatile compounds of WGD belong to aldehydes, whereas carboxylic acids from WDD were detected generated by autoxidation reaction. Meanwhile, the main reason of unpleasant odor generation was possibly attributed to the high concentration of volatile carboxylic acids of WDD. Therefore, the constructed model presents a simple and efficient method of analysis and serves as a basis for down processing and quality control.

Synthesis of Al2S3/MoS2 Nanocomposite by Electrochemical Method: Correlation for Photodegradation of Trichloroacetic Acid, Chloroacetic Acid, Acetic Acid and Study of Antibacterial Efficiency

Al2S3/MoS2 nanocomposite has been synthesized through electrochemical method and characterized by UV-Visible spectroscopy, XRD, SEM and EDAX data. UV-Visible spectroscopy measurements reveal that the Al2S3/MoS2 nanocomposite has maximum absorption at 353.04 nm and this peak position reflects the band gap of particles and it is found to be 2.51 eV which was calculated using Tauc plot. X-Ray diffraction (XRD) reveals crystaline size to be 49.85 nm which was calculated using Williamson-Hall (W-H) plot method. Photocatalytic degradation of acetic acid, chloroacetic acid and trichloroacetic acid has been studied by volumetric method using NaOH solution. Photocatalytic degradation of chloroacetic acid and acetic acid follows first order kinetics. The photodegradation efficiency for Al2S3/MoS2 nanocomposite was found to be ≈97.8%. A Taft linear free energy relationship is noted for the catalysed reaction with ρ* = 0.233 and indicating electron withdrawing groups enhance the rate. An isokinetic relation is observed with β = 358 K indicating that enthalpy factor controls the reaction rate. The result of this paper suggests the possibility of degradation of organic compounds, industrial effluants and toxic organic compounds by photodegradation process by ecofriendly Al2S3/ MoS2. The antibacterial activity of Al2S3/MoS2 nanocomposite was investigated. These particles were shown to have an effective bactericide.

直接电导检测离子排斥色谱法测定C_1～C_6脂肪族有机酸

建立了直接电导检测离子排斥色谱分离测定C1-C6脂肪族有机酸（甲酸、乙酸、丙酸、丁酸、戊酸、己酸）的方法。以Shim-pack SCR-102H色谱柱为分离柱,选用p-甲苯磺酸水溶液为流动相,考察了流动相中p-甲苯磺酸的浓度、流速、pH、色谱柱温度对分离和测定脂肪族有机酸的影响,确定了最佳的色谱条件为：0.2mmol/Lp-甲苯磺酸水溶液作为流动相,流速1.2mL/min,柱温45℃。所测有机酸的检测限为0.03-0.99mg/L,相对标准偏差在2.3%以下（n=5）,回收率为91.2%-105.6%,整个分析过程在28min内完成。该法用于白酒样品的分析,结果令人满意。

Positively charged nanofiltration membrane fabricated by poly(acid–base) complexing effect induced phase inversion method for heavy metal removal

Poly(arylene ether ketone)s with carboxylic groups(PAEK-COOH)is a good membrane fabrication material,a kind of polyacids,while polyethylenimine(PEI)is a weak organic base,a kind of polybases.Those polyacids and polybases would form ionic complexation at the interface of two liquid phases.In this paper,PAEK-COOH/N-methyl pyrrolidone(NMP)/1,4-dioxane(DO)mixture,employed as polymer casting solution and aqueous solution of PEI,used as coagulation bath,respectively.Then ion complexation induced phase inversion process is applied to prepare positively charged nanofiltration membrane with thinner but denser separation skin layer.The complexing reaction at the interface of two liquid phases has great influence on the kinetic aspects of phase inversion process,which in accordance would affect the morphology and performance of the membrane.The obtained membrane,fabricated via the ion complexation induced phase inversion method,is positively charged,has high water permeability,and possesses high rejection towards divalent cations,such as Mg^(2+),Ca^(2+),Pb^(2+)etc.,which could be used for removal of heavy metals from polluted water.At the optimal condition,the pure water flux of the PAEK-COOH-PEI nanofiltration membrane is 24.3 L·m^(-2)·h^(-1),with MgCl_2rejection of 92.2%.