Construction of cellulose-based hybrid hydrogel beads containing carbon dots and their high performance in the adsorption and detection of mercury ions in water.

Cellulose-based adsorbents have been extensively developed in heavy metal capture and wastewater treatment. However, most of the reported powder adsorbents suffer from the difficulties in recycling due to their small sizes and limitations in detecting the targets for the lack of sensitive sensor moieties in the structure. Accordingly, carbon dots (CDs) were proposed to be encapsulated in cellulosic hydrogel beads to realize the simultaneous detection and adsorption of Hg (II) in water due to their excellent fluorescence sensing performance. Besides, the molding of cellulose was beneficial to its recycling and further reduced the potential environmental risk generated by secondary pollution caused by adsorbent decomposition. In addition, the detection limit of the hydrogel beads towards Hg (II) reached as low as 8.8 × 10-8 M, which was below the mercury effluent standard declared by WHO, exhibiting excellent practicability in Hg (II) detection and water treatment. The maximum adsorption capacity of CB-50 % for Hg (II) was 290.70 mg/g. Moreover, the adsorbent materials also had preeminent stability that the hydrogel beads could maintain sensitive and selective sensing performance towards Hg (II) after 2 months of storage. Additionally, only 3.3% of the CDs leaked out after 2 weeks of immersion in water, ensuring the accuracy of Hg (II) evaluation. Notably, the adsorbent retained over 80% of its original adsorption capacity after five consecutive regeneration cycles, underscoring its robustness and potential for sustainable environmental applications.

Dansyl-labelled cellulose as dual-functional adsorbents for elimination and detection of mercury in aqueous solution via aggregation-induced emission.

Dansyl chloride fluorophore exhibits typical aggregation induced fluorescence emission behavior in acetone/water solution. To realize the integration of detective and adsorptive functions, dansyl chloride is covalently immobilized on cellulose substrate to fabricate an efficient adsorbent for mercury ions in water. The as-prepared material exhibits excellent fluorescence sensing performance exclusively for Hg (II) with the presence of other metal ions. A sensitive and selective fluorescence quenching across the concentration range of 0.1-8.0 mg/L is observed with a detection limit of 8.33 × 10-9 M as a result of the inhibition of aggregation induced emission caused by the coordination between adsorbent and Hg (II). Besides, the adsorption properties for Hg (II) including the influence of initial concentration and contact time are investigated. Langmuir model and pseudo-second-order kinetics are demonstrated to fit well with the adsorption experiment for the uptake of Hg (II) by the functionalized adsorbent, also, intraparticle diffusion kinetic model is proved to aptly describe the Hg (II) removal in aqueous solution. In addition, the recognition mechanism is considered to originate from the Hg (II) triggered structural reversals of naphthalene ring units which are verified by the X-ray photoelectron spectroscopy and density functional theory calculation. Moreover, the synthesis method used in this work also provides a strategy for the sensing application of organic sensor molecules with AIE properties in which the aggregated behavior could be appropriately realized.

Enhanced human enterovirus 71 infection by endocytosis inhibitors reveals multiple entry pathways by enterovirus causing hand-foot-and-mouth diseases.

BACKGROUND: Human enterovirus 71 (EV71) was previously known to enter cells through clathrin or caveolar mediated endocytic pathways. However, we observed chlorpromazine (CPZ) or dynasore (DNS), which inhibit clathrin and dynamin mediated endocytosis, did not suppress EV71 cell entry in particular cell types. So the current knowledge of entry mechanisms by EV71 is not complete. METHODS: Viral infection was examined by flow cytometry or end-point dilution assays. Viral entry was monitored by immunofluorescence or pseudoviral infections. Various inhibitors were utilized for manipulating endocytic pathways. Cellular proteins were knockdown by siRNA. RESULTS: CPZ and DNS did not inhibit but rather enhance viral infection in A549 cells, while they inhibited infections in other cells tested. We further found CPZ did not affect EV71 binding to target cells and failed to affect viral translation and replication, but enhanced viral entry in A549 cells. Immunofluorescence microscopy further confirmed this increased entry. Using siRNA experiment, we found that the enhancement of EV71 infection by CPZ did not require the components of clathrin mediated endocytosis. Finally, CPZ also enhanced infection by Coxackivirus A16 in A549 cells. CONCLUSIONS: CPZ and DNS, previously reported as EV71 entry inhibitors, may rather lead to increased viral infection in particular cell types. CPZ and DNS increased viral entry and not other steps of viral life cycles. Therefore, our study indicated an unknown dynamin-independent entry pathway utilized by enteroviruses that cause Hand-Foot-and-Mouth Diseases.

Aging properties of polyethylene and polylactic acid microplastics and their adsorption behavior of Cd(II) and Cr(VI) in aquatic environments.

In this study, we examined the aging characteristics of polyethylene (PE) and polylactic acid (PLA) microplastics (MPs), examining the adsorption behaviors and mechanisms concerning Cd(II) and Cr(VI) under both single and binary systems. The results revealed that aging treatment changed the physicochemical properties of MPs. The aging mechanisms of PLA and PE MPs were shown to be similar by the 2D-FTIR-COS study. These mechanisms involve the formation of oxygen-containing functional groups through the combination of carbon chain breakdown and oxygen. Aged MPs had a greater ability to adsorb metal ions than pristine MPs, with PLA MPs outperforming PE MPs. After 30 days of aging, Cd(II) adsorption increased by 40.61 % and 25.49 % for PE and PLA MPs, respectively, while Cr(VI) adsorption increased by 37.50 % and 69.29 %, respectively. The adsorption ability of PE and PLA MPs with Cd(II) or Cr(VI) under binary systems was less than that under single systems, with Cd(II) exhibiting more adsorption competitiveness than Cr(VI). Humic acid (HA), ionic species and strength, solution pH, and adsorption of Cd(II) and Cr(VI) were found to be significantly correlated. Further investigation into the adsorption mechanisms of Cd(II) and Cr(VI) on PE and PLA MPs revealed that pore-filling, electrostatic interactions, complexation, and hydrogen bonding play important roles in the adsorption process. The study's conclusions are crucial for assessing the risk associated with concurrent contamination by metal ions and microplastics.

Cellulose-based adsorbent using in mercury detection and removal from water via an efficient grafting strategy of fluorometric sensors by click reaction.

Mercury pollution in waters attracts lots of attention due to its serious toxicity and high bioenrichment and many efforts have been devoted in the development of adsorbents for mercury detection and removal. Herein, a cellulose-based adsorbent Cell-TriA-HQ is functionalized with quinoline fluorophore by covalent immobilization through "Click reaction" with high yield. In addition to the admirable adsorptive performance, the prepared adsorbent exhibits excellent selectivity and sensitivity towards Hg (II) in water that the detection limit for Hg (II) is determined to be as low as 1.92 × 10-7 M. The sensitive fluorescence enhancement response is considered to be resulted from the inhibition of photo-induced electron transfer between triazole and quinoline groups and the reinforcement of structural rigidity. The easy manipulation along with excellent performance of adsorption capacity, detective ability and reusability for the multifunctional adsorbent makes it potential in mercury monitoring and removal from aqueous solutions in the field of water treatment.

Response characteristics of indigenous microbial community in polycyclic aromatic hydrocarbons (PAHs) contaminated aquifers under polyethylene microplastics stress: A microcosmic experimental study.

To understand the response characteristics of indigenous microbial community in PAH-contaminated aquifers to the coexistence of microplastics. In this paper, we constructed a groundwater microecosystem using lithologic media collected from the field and subjected it to the stress of a polyethylene microplastics (PE-MPs) concentration gradient. By conducting adsorption experiments and 16S rRNA sequencing, we revealed the growth, structure, metabolism, and resistance mechanisms of the indigenous microbial community in the aquifer lithologic media exposed to varying levels of co-stress from PE-MPs and phenanthrene. Our findings suggest that the adsorption capacity of aquifer lithologic media for phenanthrene is significantly weaker than that of PE-MPs. Additionally, our observations indicated that small particle lithologic media had a greater adsorption capacity for phenanthrene than large particle lithologic media. The presence of PE-MPs was found to increase both the abundance and diversity of microbial communities, although the relationship was not linear with the content of PE-MPs. When exposed to the combined stress of PE-MPs and phenanthrene, the relative abundance of Proteobacteria decreased while that of Bacteroidetes increased. Several genera belonging to Proteobacteria (Aeromonas, Desulfovibrio, Klebsiella, Pantoea, and Microvirgula) and Bacteroidetes (Macellibacteroides and Bacteroides) occupied a central position in the microbial community interaction network and showed significant correlations with other genera. Furthermore, an increase in the proportion of genera capable of degrading various refractory organics was observed. The presence of PE-MPs increased the phenanthrene content in the aquifer lithologic media, thereby intensifying the inhibitory effect on indigenous microbial community in this environment. Despite an increase in the phenanthrene content of aquifer lithologic media due to the presence of PE-MPs, indigenous microbial community in this environment exhibited resistance to the combined inhibition of PE-MPs and phenanthrene through a series of resistance mechanisms. These mechanisms included strengthening the N-cycle process, enhancing metabolic capacity for phenanthrene, improving perception, response, and adaptation to changes in the external environment or intracellular state, modifying the transmembrane transport of the cell membrane to the substrate, and regulating life processes.

Mechanistic insights into the lignin dissolution behavior in amino acid based deep eutectic solvents.

Deep eutectic solvents (DESs) composed by amino acids (L-arginine, L-proline, L-alanine) as the hydrogen bond acceptors (HBAs) and carboxylic acids (formic acid, acetic acid, lactic acid, levulinic acid) as hydrogen bond donors (HBDs) were prepared and used for the dissolution of dealkaline lignin (DAL). The mechanism of lignin dissolution in DESs was explored at molecular level by combining the analysis of Kamlet-Taft (K-T) solvatochromic parameters, FTIR spectrum and density functional theory (DFT) calculations of DESs. Firstly, it was found that the formation of new hydrogen bonds between lignin and DESs mainly drove the dissolution of lignin, which were accompanied by the erosion of hydrogen bond networks in both lignin and DESs. The nature of hydrogen bond network within DESs was fundamentally determined by the type and number of functional groups in both HBA and HBD, which affected its ability to form hydrogen bond with lignin. One hydroxyl group and carboxyl group in HBDs provided active protons, which facilitated proton-catalyzed cleavage of ß-O-4, thus enhancing the dissolution of DESs. The superfluous functional group resulted in more extensive and stronger hydrogen bond network in the DESs, thus decreasing the lignin dissolving ability. Moreover, it was found that lignin solubility had a closed positive correlation with the subtraction value of α and ß (net hydrogen donating ability) of DESs. Among all the investigated DESs, L-alanine/formic acid (1:3) with the strong hydrogen-bond donating ability (acidity), weak hydrogen-bond accepting ability (basicity) and small steric-hindrance effect showed the best lignin dissolving ability (23.99 wt%, 60 °C). On top of that, the value of α and ß of L-proline/carboxylic acids DESs showed some positive correlation with the global electrostatic potential (ESP) maxima and minima of the corresponding DESs respectively, indicating the analysis of ESP quantitative distributions of DESs could be an effective tool for DESs screening and design for lignin dissolution as well as other applications.

HIF-1α-mediated autophagy and canonical Wnt/ß-catenin signalling activation are involved in fluoride-induced osteosclerosis in rats.

Fluoride (F) exposure can cause osteosclerosis, which is characterised by a high bone mass, but its mechanism is not fully illustrated. Here, we aimed to evaluate the effects of excessive F exposure on the bone lesion by treating female Sprague-Dawley rats with different concentrations of sodium fluoride (NaF) (0, 55, 110 and 221 mg/L) for 90 days and the corresponding concentrations of fluorine ion (0, 25, 50 and 100 mg/L, respectively). Histopathological results showed that excessive F exposure caused the enlargement of trabeculae and their integration into one large piece, growth plate thickening, articular cartilage impairment and bone collagen abnormality. Meanwhile, F promoted calcium deposition and bone mineralisation, and induced abnormal osteogenesis increased. The results of micro-computed tomography also confirmed that excessive F destroyed the bone microstructure and induced a high-bone-mass phenotype, consistent with the results of pathomorphology. Mechanistically, excessive amounts of F led to angiogenesis inhibition and HIF-1α signalling enhancement. Subsequently, F induced autophagy and canonical Wnt/ß-catenin signalling pathway activation. Collectively, these results manifested that F enhanced the hypoxia inducible factor-1α signalling, which in turn triggered autophagy and canonical Wnt/ß-catenin signalling activation, ultimately leading to osteosclerosis in the rats.

Behavior Strategy Analysis Based on the Multi-Stakeholder Game under the Plastic Straw Ban in China.

Since 1 January 2021, China has banned nondegradable disposable straws in the catering industry. To promote the enforcement of the ban of plastic straws and improve the relationship between economic development and environmental protection, based on the evolutionary game method, this paper constructs the game model from the supply side and the demand side, respectively. Subsequently, through the dynamic equation, stable system evolution strategy is obtained. Furthermore, simulation is conducted to test the influence of the main parameters in the model on the evolution of system strategy. The results show that (1) the change of the government strategy mainly depends on its regulation costs and revenue, while the production strategy of a company is affected by the government and consumer strategies. (2) From the perspective of enterprise supply, government subsidies can promote technological innovation and develop new plastic straw substitutes. However, government penalties have little effect on violating enterprises. In addition, from the perspective of enterprise demand, with the collaboration of enterprises and consumers, it is easier for enterprises to carry out technological innovation. (3) Consumer acceptance of the substitutes for disposable plastic straws as well as online comments have a decisive influence on the enterprises' selections for research and development (R&D) strategies.

Electrogenerated chemiluminescence biosensing method based on 5-hydroxymethylcytosine antibody and PDDA-CNTs nanocomposites for the determination of 5-hydroxymethylcytosine double-stranded DNA.

A highly sensitive electrogenerated chemiluminescence (ECL) method was developed for trace analysis of 5-hydroxymethylcytosine double-stranded DNA (5-hmC-dsDNA). The poly-(dimethyldiallyl ammonium chloride)/multiwalled carbon nanotubes composite was assembled on a bare glassy carbon electrode (GCE) to provide high specific surface area on which the loadable capacity of 5-hmC-dsDNA and 5-hmC antibody can be greatly increased. The derivative of ruthenium (II) bibyridine, Ru (bpy)2 (dcbpy)NHS, coupled with 5-hmC antibody to activate an ECL reaction when the applied potential was biased at 1.4 V vs. Ag/AgCl. The loading ratio of substrates were optimized to enhance the detection sensitivity of 5-hmC-dsDNA. It was found that the ECL intensity was a piecewise linear function of the concentration of 5-hmC-dsDNA over the range of 1.0 × 10-11-2.0 × 10-9 M. A linear relationship of I = 6850.3 C(nM) + 863.8 (R = 0.9954) was obtained from 0.01 to 0.2 nM, while the fitting equation of I = 3840.0 C(nM) + 1392.4 (R = 0.9974) is for the concentration range of 0.2 - 2.0 nM. The detectable low limit can reach to 2.3 × 10-12 M. Formation of the antigen-antibody immunocomplex in highly concentrated solutions should undertake most of the responsibility for a decrease in slope. Furthermore, reliability, reproducibility and practicability of the ECL method have been proved to perform well, even in real bio-tissues, suggesting promising prospect in early diagnosis of cancer.

The Establishment of Infectious Clone and Single Round Infectious Particles for Coxsackievirus A10.

Coxsackievirus A10 (CVA10) is one of the major etiological agents of hand, foot, and mouth disease. There are no vaccine and antiviral drugs for controlling CVA10 infection. Reverse genetic tools for CVA10 will benefit its mechanistic study and development of vaccines and antivirals. Here, two infectious clones for the prototype and a Myc-tagged CVA10 were constructed. Viable CVA10 viruses were harvested by transfecting the viral mRNA into human rhabdomyosarcoma (RD) cells. Rescued CVA10 was further confirmed by next generation sequencing and characterized experimentally. We also constructed the vectors for CVA10 subgenomic replicon with luciferase reporter and viral capsid with EGFP reporter, respectively. Co-transfection of the viral replicon RNA and capsid expresser in human embryonic kidney 293T (HEK293T) cells led to the production of single round infectious particles (SRIPs). Based on CVA10 replicon RNA, SRIPs with either the enterovirus A71 (EVA71) capsid or the CVA10 capsid were generated. Infection by EVA71 SRIPs required SCARB2, while CVA10 SRIPs did not. Finally, we showed great improvement of the replicon activity and SRIPs production by insertion of a cis-active hammerhead ribozyme (HHRib) before the 5'-untranslated region (UTR). In summary, reverse genetic tools for prototype strain of CVA10, including both the infectious clone and the SRIPs system, were successfully established. These tools will facilitate the basic and translational study of CVA10.

Fluorescence-sensitive adsorbent based on cellulose using for mercury detection and removal from aqueous solution with selective "on-off" response.

A new fluorogenic bio-adsorbent was successfully synthesized for detection and adsorption of mercury ions in aqueous solution. It showed high sensitivity in removing Hg (II) at low concentration with a detection limit of 84 ppb which was below the maximum discharge standard in enterprise drain off water in China, besides, the adsorbent had good selectivity towards Hg (II) among numerous kinds of cations in water that it showed fluorescent quenching properties for Hg (II) ions due to photo-induced electron transfer. In addition, batch adsorption experiments were investigated to study the influence of initial concentration of metal ions, contact time, pH of the solution on the adsorption capacity. Equilibrium adsorption isotherms demonstrated the Hg (II) removing process fitted well with Langmuir isotherm model, and the maximum adsorption capacity for mercury was measured to be 143.88 mg/g. Furthermore, the adsorption kinetics was found to follow pseudo-second-order model. FTIR spectra and SEM-elemental mapping clearly confirmed the adsorbed heavy metal ions.

A sensitive signal-off electrogenerated chemiluminescence biosensing method for the discrimination of DNA hydroxymethylation based on glycosylation modification and signal quenching from ferroceneboronic acid.

In this study, a new and sensitive signal-off electrogenerated chemiluminescence (ECL) biosensing method for the quantification of 5-hydroxymethylcytosine in DNA (5-hmC-DNA) was developed. The method achieved simple and sensitive detection of 5-hmC-DNA based on the glycosylation of 5-hmC, combining both the amplification function of gold nanoparticles (AuNPs) and the high quenching efficiency of the tris(2, 2'-ripyridine) dichlororuthenium(II) (Ru(bpy)32+)-ferrocene (Fc) system. First, the electrode modified with a mixture of Nafion and AuNPs was utilized as the platform for electrostatically adsorbing Ru(bpy)32+(an ECL-emitting species) and assembling 5-hmC-DNA. The 5-hmC-DNA was glycosylated by T4 ß-glucosyltransferase, yielding ß-glucosyl-5-hydroxymethyl-cytosine in DNA (5-ghmC-DNA). Finally, quencher-FcBA was further covalently bound to 5-ghmC-DNA through formation of boronate ester covalent bonds between boronic acid and cis-diols of 5-ghmC, resulting in a decrease in ECL intensity. The results indicated that the decreased ECL intensity was directly linear to the concentration of 5-hmC-DNA in the range from 1.0×10-8 to 5.0×10-11M with a low detection limit of 1.63×10-11M. In addition, this ECL method was demonstrated to be useful for the quantification of 5-hmC in clinical serum samples. Moreover, the method allowed good discrimination among cytosine (5-C), 5-methylcytosine (5-mC), and 5-hmC in DNA.

[Association of variants in chromosome 9p21.3 and chronic periodontitis in the Han Chinese population].

PURPOSE: To investigate the association of the single nucleotide polymorphism (SNP) in chromosome 9p21.3 and chronic periodontitis in the Han Chinese population. METHODS: rs2891168,rs1333048 and rs1333042 genotypes of randomly grouped 172 healthy control subjects and 221 patients with chronic periodontitis(CP) were genotyped by TaqMan probe real-time fluorescent quantitative PCR. Statistical analysis of Chi-square test was performed using SPSS16.0 software package. RESULTS: Rs2891168 was closely associated with chronic periodontitis(P=0.003), and the frequency of G allele was higher in the patients compared with the control(48.36% vs 40.00%, OR=1.209, 95% CI: 1.001-1.461, P=0.045). Rs1333048 and rs1333042 were not associated with chronic periodontitis. CONCLUSIONS: There is SNP correlated with chronic periodontitis in chromosome 9p21.3, which indicates that the 9p21.3 locus may be the susceptible region. However, the mechanism remains unclear.

COL1A2 gene polymorphisms (Pvu II and Rsa I), serum calciotropic hormone levels, and dental fluorosis.

OBJECTIVES: To investigate the relationship between dental fluorosis, polymorphisms in the COL1A2 gene, and serum calciotropic hormone levels. METHODS: We conducted a case-control study among children between 8 and 12 years of age with (n = 75) and without (n = 165) dental fluorosis in two counties in Henan Province, China. The PvuII and RsaI polymorphisms in the COL1A2 gene were genotyped using the PCR-RFLP procedure. Calcitonin and osteocalcin levels in the serum were measured using radioimmunassays. RESULTS: Children carrying the homozygous genotype PP of COL1A2 PvuII had a significantly increased risk of dental fluorosis (OR =4.85, 95% CI: 1.22-19.32) compared to children carrying the homozygous genotype pp in an endemic fluorosis village (EFV). However, the risk (OR = 1.07, 95% CI: 0.45-2.52) was not elevated when the control population was recruited from a non-endemic fluorosis village. Additionally, fluoride levels in urine and osteocalcin levels in serum were found to be significantly lower in controls from non-endemic villages compared to cases. However, the differences in fluoride and osteocalcin levels were not observed when cases were compared to a control population from endemic fluorosis villages. CONCLUSIONS: This study provides the first evidence of an association between polymorphisms in the COL1A2 gene with dental fluorosis in high fluoride exposed populations. Future studies are needed to confirm the association.