The KDM5A/RBP2 histone demethylase represses NOTCH signaling to sustain neuroendocrine differentiation and promote small cell lung cancer tumorigenesis.

More than 90% of small cell lung cancers (SCLCs) harbor loss-of-function mutations in the tumor suppressor gene RB1 The canonical function of the RB1 gene product, pRB, is to repress the E2F transcription factor family, but pRB also functions to regulate cellular differentiation in part through its binding to the histone demethylase KDM5A (also known as RBP2 or JARID1A). We show that KDM5A promotes SCLC proliferation and SCLC's neuroendocrine differentiation phenotype in part by sustaining expression of the neuroendocrine transcription factor ASCL1. Mechanistically, we found that KDM5A sustains ASCL1 levels and neuroendocrine differentiation by repressing NOTCH2 and NOTCH target genes. To test the role of KDM5A in SCLC tumorigenesis in vivo, we developed a CRISPR/Cas9-based mouse model of SCLC by delivering an adenovirus (or an adeno-associated virus [AAV]) that expresses Cre recombinase and sgRNAs targeting Rb1, Tp53, and Rbl2 into the lungs of Lox-Stop-Lox Cas9 mice. Coinclusion of a KDM5A sgRNA decreased SCLC tumorigenesis and metastasis, and the SCLCs that formed despite the absence of KDM5A had higher NOTCH activity compared to KDM5A+/+ SCLCs. This work establishes a role for KDM5A in SCLC tumorigenesis and suggests that KDM5 inhibitors should be explored as treatments for SCLC.

Final epidemic size and critical times for susceptible-infectious-recovered models with a generalized contact rate.

During the spread of an infectious disease, the contact rate or the incidence rate may affect disease characteristics. For simplicity, most disease models assume standard incidence or mass action rates to calculate the basic reproduction number, final epidemic size, and peak time of an epidemic. For standard incidence, the contact rate remains constant resulting in the incidence rate is inversely proportional to the population size, while for the mass action rate, this contact rate is proportional to the total population size resulting in the incidence rate is independent of the population size. In this paper, we consider susceptible-infectious-recovered epidemic models with a generalized contact rate C(N) and a nonlinear incidence rate in view of the behavioral change from susceptible or infectious individuals when an infectious disease appears. The basic reproduction number and the final size equation are derived. The impact of different types of contact rates on them is studied. Moreover, two critical times (peak time and epidemic duration) of an epidemic are considered. Explicit formulas for the peak time and epidemic duration are obtained. These formulas are helpful not only for taking early effective epidemic precautions but also for understanding how the epidemic duration can be changed by acting on the model parameters, especially when the epidemic model is used to make public health policy.

Characteristics of Dialdehyde Cellulose Nanofibrils Derived from Cotton Linter Fibers and Wood Fibers.

Two types of cellulose nanofibrils (CNFs) were isolated from cotton linter fibers and hardwood fibers through mechanical fibrillation methods. The dialdehyde cellulose nanofibrils (DACNFs) were prepared through the periodate oxidation method, and their morphological and structural properties were investigated. The characteristics of the DACNFs during the concentration process were also explored. The AFM analysis results showed that the mean diameters of wood fiber-based CNFs and cotton fiber-based CNFs were about 52.03 nm and 69.51 nm, respectively. However, the periodate oxidation treatment process obviously reduced the nanofibril size and destroyed the crystalline region of the nanofibrils. Due to the high crystallinity of cotton fibers, the cotton fiber-based DACNFs exhibited a lower aldehyde content and suspension stability compared to the wood fiber-based DACNFs. For the concentration process of the DACNF suspension, the bound water content of the concentrated cotton fiber-based DACNFs was lowered to 0.41 g/g, which indicated that the cotton fiber-based DACNFs could have good redispersibility. Both the wood fiber-based and cotton fiber-based DACNF films showed relatively good transmittance and mechanical strength. In addition, to the cotton fiber-based DACNF films had a very low swelling ratio, and the barrier water vapor and oxygen properties of the redispersed cotton fiber-based DACNF films decreased by very little. In sum, this study has demonstrated that cotton fibers could serve as an effective alternative to wood fibers for preparing CNFs, and that cotton fiber-based DACNFs have huge application prospects in the field of packaging film materials due to their stable properties during the concentration process.

Enhancing Mechanical and Antimicrobial Properties of Dialdehyde Cellulose-Silver Nanoparticle Composites through Ammoniated Nanocellulose Modification.

Given the widespread prevalence of viruses, there is an escalating demand for antimicrobial composites. Although the composite of dialdehyde cellulose and silver nanoparticles (DAC@Ag1) exhibits excellent antibacterial properties, its weak mechanical characteristics hinder its practical applicability. To address this limitation, cellulose nanofibers (CNFs) were initially ammoniated to yield N-CNF, which was subsequently incorporated into DAC@Ag1 as an enhancer, forming DAC@Ag1/N-CNF. We systematically investigated the optimal amount of N-CNF and characterized the DAC@Ag1/N-CNF using FT-IR, XPS, and XRD analyses to evaluate its additional properties. Notably, the optimal mass ratio of N-CNF to DAC@Ag1 was found to be 5:5, resulting in a substantial enhancement in mechanical properties, with a 139.8% increase in tensile elongation and a 33.1% increase in strength, reaching 10% and 125.24 MPa, respectively, compared to DAC@Ag1 alone. Furthermore, the inhibition zones against Escherichia coli and Staphylococcus aureus were significantly expanded to 7.9 mm and 15.9 mm, respectively, surpassing those of DAC@Ag1 alone by 154.8% and 467.9%, indicating remarkable improvements in antimicrobial efficacy. Mechanism analysis highlighted synergistic effects from chemical covalent bonding and hydrogen bonding in the DAC@Ag1/N-CNF, enhancing the mechanical and antimicrobial properties significantly. The addition of N-CNF markedly augmented the properties of the composite film, thereby facilitating its broader application in the antimicrobial field.

Sustainable and Scalable Synthesis of 2D Ultrathin Hierarchical Porous Carbon Nanosheets for High-Performance Supercapacitor.

2D carbon nanomaterials such as graphene, carbon nanosheets, and their derivatives, representing the emerging class of advanced multifunctional materials, have gained great research interest because of their extensive applications ranging from electrochemistry to catalysis. However, sustainable and scalable synthesis of 2D carbon nanosheets (CNs) with hierarchical architecture and irregular structure via a green and low-cost strategy remains a great challenge. Herein, prehydrolysis liquor (PHL), an industrial byproduct of the pulping industry, is first employed to synthesize CNs via a simple hydrothermal carbonization technique. After mild activation with NH4 Cl and FeCl3 , the as-prepared activated CNs (A-CN@NFe) display an ultrathin structure (≈3 nm) and a desirable specific surface area (1021 m2 g-1 ) with hierarchical porous structure, which enables it to be both electroactive materials and structural support materials in nanofibrillated cellulose/A-CN@NFe/polypyrrole (NCP) nanocomposite, and thus endowing nanocomposite with impressive capacitance properties of 2546.3 mF cm-2 at 1 mA cm-2 . Furthermore, the resultant all-solid-state symmetric supercapacitor delivers a satisfactory energy storage ability of 90.1 µWh cm-2 at 250.0 µW cm-2 . Thus, this work not only opens a new window for sustainable and scalable synthesis of CNs, but also offers a double profits strategy for energy storage and biorefinery industry.

Regulatory Mechanism of Opposite Charges on Chiral Self-Assembly of Cellulose Nanocrystals.

The charge plays an important role in cellulose nanocrystal (CNC) self-assembly to form liquid crystal structures, which has rarely been systematically explored. In this work, a novel technique combining atomic force microscopy force and atomistic molecular dynamics simulations was addressed for the first time to systematically investigate the differences in the CNC self-assembly caused by external positive and negative charges at the microscopic level, wherein sodium polyacrylate (PAAS) and chitosan oligosaccharides (COS) were used as external positive and negative charge additives, respectively. The results show that although the two additives both make the color of CNC films shift blue and eventually disappear, their regulatory mechanisms are, respectively, related to the extrusion of CNC particles by PAAS and the reduction in CNC surface charge by COS. The two effects both decreased the spacing between CNC particles and further increased the cross angle of CNC stacking arrangement, which finally led to the color variations. Moreover, the disappearance of color was proved to be due to the kinetic arrest of CNC suspensions before forming chiral nematic structure with the addition of PAAS and COS. This work provides an updated theoretical basis for the detailed disclosure of the CNC self-assembly mechanism.

Switchable Circularly Polarized Signals with High Asymmetric Factor Triggered by Dual Photonic Bandgap Structure.

Currently, the smart photonic materials that can switch circularly polarized signals in real-time have attracted extensive attention due to numerous potential applications in information storage and photonics displays. However, the dynamically reversible switching of circularly polarized signals requires precise structural reconfiguration, which is rarely achieved in traditional biomaterials. Herein, a dual photonic bandgap (PBG) structure is constructed based on the optical propagation principle of cellulose-based photonic crystals, enabling the flexible switching of the intensity, wavelength, and direction of circularly polarized luminescence (CPL). By adjusting the fluorescence intensity and the matching degree of chiral structure, the asymmetric factor value of dual PBG structure is up to -1.47, far exceeding other cellulose-based materials. Importantly, it is demonstrated that dual CPL emission can be efficiently induced by two different PBGs, opening a new approach for on-demand switching of single and dual CPL emission. In addition, the dual PBG structure exhibits dual circularly polarized reflected signals under the circular polarizer, which perfectly embodies the applicability of multiple encryptions in QR codes. This work provides new insights into the real-time manipulation of circularly polarized signals by chiral photonic materials.

On-target efficacy of a HIF-2α antagonist in preclinical kidney cancer models.

Clear cell renal cell carcinoma, the most common form of kidney cancer, is usually linked to inactivation of the pVHL tumour suppressor protein and consequent accumulation of the HIF-2α transcription factor (also known as EPAS1). Here we show that a small molecule (PT2399) that directly inhibits HIF-2α causes tumour regression in preclinical mouse models of primary and metastatic pVHL-defective clear cell renal cell carcinoma in an on-target fashion. pVHL-defective clear cell renal cell carcinoma cell lines display unexpectedly variable sensitivity to PT2399, however, suggesting the need for predictive biomarkers to be developed to use this approach optimally in the clinic.

Sensitive photoelectrochemical detection of colitoxin DNA based on NCDs@CuO/ZnO heterostructured nanocomposites with efficient separation capacity of photo-induced carriers.

A metal-organic framework (MOF) of Cu-TPA (terephthalic acid) microsphere was prepared, followed by calcinating the MOF precursor of Cu-TPA/ZIF-8 mixture to obtain the CuO/ZnO. N-doped carbon dots (NCDs) were employed to combine the CuO/ZnO composite to form a tripartite heterostructured architecture of NCDs@CuO/ZnO, which led to a fierce enlargement of the photocurrent response. This  was ascribed to the thinner-shell structure of the CuO microsphere and the fact that hollow ZnO particles could sharply promote the incidence intensity of visible light. The more porous defectiveness exposed on CuO/ZnO surface was in favor of rapidly infiltrating electrolyte ions. The p-n type CuO/ZnO composite with more contact interface could abridge the transfer distance of photo-induced electron (e-1)/hole (h+) pairs and repress their recombination availably. NCDs not only could boost electron transfer rate on the electrode interface but also successfully sensitized the CuO/ZnO composite, which resulted in high conversion efficiency of photon-to-electron. The probe DNA (S1) was firmly assembled on the modified ITO electrode surface (S1/NCDs@CuO/ZnO) through an amidation reaction. Under optimal conditions, the prepared DNA biosensor displayed a wide linear range of 1.0 × 10-6 ~ 7.5 × 10-1 nM and a low limit of detection (LOD) of 1.81 × 10-7 nM for colitoxin DNA (S2) measure, which exhibited a better photoelectrochemistry (PEC) analysis performance than that obtained by differential pulse voltammetry techniques. The relative standard deviation (RSD) of the sensing platform for target DNA detection of 5.0 × 10-2 nM was 6.3%. This proposed DNA biosensor also showed good selectivity, stability, and reproducibility, demonstrating that the well-designed and synthesized photoactive materials of NCDs@CuO/ZnO are promising candidates for PEC analysis.

Chiral Photonic Liquid Crystal Films Derived from Cellulose Nanocrystals.

As a nanoscale renewable resource derived from lignocellulosic materials, cellulose nanocrystals (CNCs) have the features of high purity, high crystallinity, high aspect ratio, high Young's modulus, and large specific surface area. The most interesting trait is that they can form the entire films with bright structural colors through the evaporation-induced self-assembly (EISA) process under certain conditions. Structural color originates from micro-nano structure of CNCs matrixes via the interaction of nanoparticles with light, rather than the absorption and reflection of light from the pigment. CNCs are the new generation of photonic liquid crystal materials of choice due to their simple and convenient preparation processes, environmentally friendly fabrication approaches, and intrinsic chiral nematic structure. Therefore, understanding the forming mechanism of CNCs in nanoarchitectonics is crucial to multiple fields of physics, chemistry, materials science, and engineering application. Herein, a timely summary of the chiral photonic liquid crystal films derived from CNCs is systematically presented. The relationship of CNC, structural color, chiral nematic structure, film performance, and applications of chiral photonic liquid crystal films is discussed. The review article also summarizes the most recent achievements in the field of CNCs-based photonic functional materials along with the faced challenges.

Mechanisms of acquired resistance to rapalogs in metastatic renal cell carcinoma.

The mechanistic target of rapamycin (mTOR) is an established therapeutic target in renal cell carcinoma (RCC). Mechanisms of secondary resistance to rapalog therapy in RCC have not been studied previously. We identified six patients with metastatic RCC who initially responded to mTOR inhibitor therapy and then progressed, and had pre-treatment and post-treatment tumor samples available for analysis. We performed deep whole exome sequencing on the paired tumor samples and a blood sample. Sequence data was analyzed using Mutect, CapSeg, Absolute, and Phylogic to identify mutations, copy number changes, and their changes over time. We also performed in vitro functional assays on PBRM1 in RCC cell lines. Five patients had clear cell and one had chromophobe RCC. 434 somatic mutations in 416 genes were identified in the 12 tumor samples. 201 (46%) of mutations were clonal in both samples while 129 (30%) were acquired in the post-treatment samples. Tumor heterogeneity or sampling issues are likely to account for some mutations that were acquired in the post-treatment samples. Three samples had mutations in TSC1; one in PTEN; and none in MTOR. PBRM1 was the only gene in which mutations were acquired in more than one post-treatment sample. We examined the effect of PBRM1 loss in multiple RCC cell lines, and could not identify any effect on rapalog sensitivity in in vitro culture assays. We conclude that mTOR pathway gene mutations did not contribute to rapalog resistance development in these six patients with advanced RCC. Furthermore, mechanisms of resistance to rapalogs in RCC remain unclear and our results suggest that PBRM1 loss may contribute to sensitivity through complex transcriptional effects.

An enhanced photoelectrochemical biosensor for colitoxin DNA based on HKUST-1/TiO2 and derived HKUST-CuO/TiO2 heterogeneous composites.

HKUST-1 MOFs and its derivative HKUST-CuO were coupled with TiO2 nanoparticles to form the heterogeneous composites of HKUST-1/TiO2 and HKUST-CuO/TiO2 based on their well-suitable bandgap energies (Eg). Compared with mono-component HKUST-1 or HKUST-CuO, the prepared composites displayed photoelectrochemical (PEC) response due to the synergistic effect from their heterogeneous structure. Higher photocurrent response was obtained on HKUST-CuO/TiO2-modified ITO electrode (HKUST-CuO/TiO2/ITO), which could be attributed to the hollow structure with a thin shell of HKUST-CuO greatly enhancing visible spectra harvesting. The CuO component in HKUST-CuO not only could accelerate electron transfer on the heterojunction interface but also effectively separate the photo-generated charge carriers (e-1/h+). Based on the excellent PEC performance of prepared photoactive composite material, under visible-light excitation (λ ≥ 420 nm) and with a working potential of 0 V (vs. Ag/AgCl), the S1 (probe DNA)/HKUST-CuO/TiO2/ITO PEC platform was successfully fabricated for colitoxin DNA detection without using ascorbic acid (AA) as an electron donor. Compared with the analysis results on S1/HKUST-1/TiO2/ITO electrode, S1/HKUST-CuO/TiO2/ITO displayed a wider linear response range from 1.0 × 10-6 to 4.0 × 10-1 nM with a lower detection limit of 3.73 × 10-7 nM (S/N = 3), the linear regression equation was ΔI (10-6 A) =0.5549-0.1858 log (CS2/M), which confirmed the HKUST-CuO could improve sensitivity because of its prominent PEC property. The relative standard deviation (RSD) of the PEC sensor for target DNA detection of 2.0 × 10-4 nM was 7.4%. The proposed DNA biosensor also possessed good specificity and stability. Hence, this reported work was a promising strategy for molecular diagnosis in the bio-analysis field. (A) Schematic illustration of the preparation process of the proposed PEC biosensors for colitoxin DNA detection. (B) The preparation process of HKUST-1 and HKUST-CuO.

Inactivation of the PBRM1 tumor suppressor gene amplifies the HIF-response in VHL-/- clear cell renal carcinoma.

Most clear cell renal carcinomas (ccRCCs) are initiated by somatic inactivation of the VHL tumor suppressor gene. The VHL gene product, pVHL, is the substrate recognition unit of an ubiquitin ligase that targets the HIF transcription factor for proteasomal degradation; inappropriate expression of HIF target genes drives renal carcinogenesis. Loss of pVHL is not sufficient, however, to cause ccRCC. Additional cooperating genetic events, including intragenic mutations and copy number alterations, are required. Common examples of the former are loss-of-function mutations of the PBRM1 and BAP1 tumor suppressor genes, which occur in a mutually exclusive manner in ccRCC and define biologically distinct subsets of ccRCC. PBRM1 encodes the Polybromo- and BRG1-associated factors-containing complex (PBAF) chromatin remodeling complex component BRG1-associated factor 180 (BAF180). Here we identified ccRCC lines whose ability to proliferate in vitro and in vivo is sensitive to wild-type BAF180, but not a tumor-associated BAF180 mutant. Biochemical and functional studies linked growth suppression by BAF180 to its ability to form a canonical PBAF complex containing BRG1 that dampens the HIF transcriptional signature.

Reconstruction of Finger Pulp Defects With an Innervated Distally-Based Neurovascular Flap.

PURPOSE: Finger pulp resurfacing is a challenging reconstructive problem. This article introduces sensory reconstruction of finger pulp defects using an innervated distally-based neurovascular flap raised from the dorsum of the thumb. METHODS: From May 2015 to May 2017, the innervated distally-based neurovascular flap was used in 36 patients. The mean age at surgery was 37 years (range, 18-61 years). All patients were assessed using the total active motion (TAM) scoring system of the American Society for Surgery of the Hand. The sensitivity of the flap was tested using static 2-point discrimination. RESULTS: Full flap survival was achieved in 35 cases. Partial necrosis at the distal margin of the flap was observed in 1 case. At the final follow-up (mean, 20 months; range, 18-23 months), the mean TAM of the thumb was 206° (range, 188°-238°), including 8 excellent and 28 good results. The mean TAM of fingers was 266° (range, 251°-282°), including 4 excellent and 32 good results. The mean value of static 2-point discrimination was 5 mm (range, 4-7 mm) in the flap, including 31 excellent and 5 good results. CONCLUSIONS: The innervated distally-based neurovascular flap raised from the dorsum of the thumb is a reliable alternative for sensory reconstruction of finger pulp defects. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

A photoelectrochemical aptasensor for thrombin based on the use of carbon quantum dot-sensitized TiO2 and visible-light photoelectrochemical activity.

A photoelectrochemical (PEC) aptasensor for the highly sensitive and specific detection of thrombin is described. This aptasensor is based on an indium tin oxide (ITO) support that is covered with carbon quantum dot (CQD)-sensitized TiO2 and acts as a photoactive matrix. The ITO/TiO2/CQD electrode was prepared by impregnation assembly. It displays an enhanced and steady photocurrent response under irradiation by visible light. A carboxyl-functionalized thrombin-binding aptamer was covalently immobilized on the modified ITO to obtain a PEC aptasensor whose photocurrent decreases with increasing concentration of thrombin. Under 420 nm irradiation at a bias voltage of 0 V, the aptasensor has a linear response in the 1.0 to 250 pM thrombin concentration range, with a 0.83 pM detection limit. Conceivably, this approach can be extended to numerous other PEC aptasensors for the detection of targets for which appropriate aptamers are available. Graphical abstract Schematic of a PEC aptasensor for thrombin. It is based on the use of CQD as the sensitizer, TiO2/CQDs as the photoactive matrix, and the thrombin aptamer as the recognition element.

A novel reverse fluorescent immunoassay approach for sensing human chorionic gonadotropin based on silver-gold nano-alloy and magnetic nanoparticles.

A novel and environmentally friendly reverse fluorescent immunoassay approach was proposed and utilized for sensing human chorionic gonadotropin (HCG) in human serum by coupling a newly prepared and highly fluorescent glutathione-stabilized silver-gold nano-alloy (GSH-AgAuNAs) with magnetic nanoparticles (MNPs). To construct such a reverse system, fluorescent GSH-AgAuNAs and MNPs were first prepared and bio-functionalized with monoclonal antibodies (Mab-I and Mab-II) toward HCG antigen, respectively. Then, the GSH-AgAuNAs functionalized with Mab-I were incubated with HCG, followed by the addition of MNPs attached to Mab-II. Thereafter, a sandwich-type immunoassay could be constructed for determination of HCG owing to the antibody-antigen recognition between the functionalized GSH-AgAuNAs and MNPs. Afterwards, a magnetic collection was employed. Hence, the amount of GSH-AgAuNAs would be reduced through an immuno-magnetic separation, thus weakening the fluorescent intensity. Different from conventional immunoassay, our work determined the quantitative signal by measuring the decreasing gradient fluorescent intensity. Under optimal conditions, the developed reverse method exhibited a wide linear range of 0.5-600 ng mL(-1) toward HCG with a detection limit of 0.25 ng mL(-1). Additionally, the proposed immunoassay was validated using spiked samples, illustrating a satisfactory result in practical application.

An efficient signal-on aptamer-based biosensor for adenosine triphosphate detection using graphene oxide both as an electrochemical and electrochemiluminescence signal indicator.

An efficient aptasensor was developed in which graphene oxide (GO) was employed as an indicator for both electrochemical impedance spectroscopy and electrochemiluminescence (ECL) signal generation. The aptasensor was fabricated by self-assembling the ECL probe of a thiolated adenosine triphosphate binding aptamer (ABA) tagged with a Ru complex (Ru(bpy)3(2+) derivatives) onto the surface of gold nanoparticle (AuNP) modified glassy carbon electrode (GCE). ABA immobilized onto AuNP modified GCE could strongly adsorb GO due to the strong π-π interaction between ABA and graphene oxide; ECL quenching of the Ru complex then takes place because of energy transfer and electron transfer, and a large increase of the electron transfer resistance (Ret) of the electrode. While in the presence of target adenosine triphosphate (ATP), the ABA prefers to form ABA-ATP bioaffinity complexes, which have weak affinity to graphene oxide and keep the graphene oxide away from the electrode surface, thus allowing the ECL signal enhancement, and in conjunction with the decrease of the Ret. Because of the high ECL quenching efficiency, unique structure, and electronic properties of graphene oxide, the Ret and ECL intensity versus the logarithm of ATP concentration was linear in the wide range from 10 pM to 10 nM with an ultra-low detection limit of 6.7 pM to 4.8 pM, respectively. The proposed aptasensor exhibited excellent reproducibility, stability, and outstanding selectivity, and ATP could be effectively distinguished from its analogues. More significantly, this efficient ECL aptasensor strategy based on GO acting both as an electrochemical and ECL signal indicator is general and can be easily extended to other biological binding events.

Development of high-barrier composite films for sustainable reduction of non-biodegradable materials in food packaging application.

Widely employed petroleum-based food packaging materials have inflicted irreparable harm on ecosystems, primarily stemming from their non-biodegradable attributes and recycling complexities. Inspired by natural nacre with a layered aragonite platelet/nanofiber/protein multi-structure, we prepared high-barrier composite films by self-assembly of cellulose nanofibrils (CNF), cellulose nanocrystals (CNC), montmorillonite (MMT), polyvinyl alcohol (PVA) and alkyl ketene dimer (AKD). The composite films demonstrated outstanding barrier properties with oxygen vapor transmission of 0.193 g·mm·m-2·day-1 and water vapor transmission rates of 0.062 cm3·mm·m-2·day-1·0.1 MPa-1, which were significantly lower than those of most biomass-degradable packaging materials. Additionally, the impacts of mixing nanocellulose with various aspect ratios on the tensile strength and folding cycles of the films were examined. The exceptional resistance of the composite films to oil and water provides a novel and sustainable approach to reduce non-biodegradable plastic packaging.

Composition, distribution, and risk assessment of heavy metals in large-scale river water on the Tibetan Plateau.

Heavy metals present in aquatic ecosystems constitute a significant threat to both the environment and human health. In this study, we analyzed various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb and Sb) using extensive surface water samples collected from the Tibetan Plateau in 2021 and 2023. Results showed that downstream water samples exhibited higher content (mean 12.6 µg/L) of heavy metals compared to those from the glacier basins. It is noteworthy that heavy metal content varied significantly both in the glacier basin and downstream (4.6-29.1 µg/L and 7.8-55.2 µg/L, respectively). However, elevated concentrations at certain sites (e.g., Saga County and Dangque Zangbu River) were primarily attributed to the disproportionate contribution of individual heavy metals, possibly stemming from specific human activities or natural conditions. In the glacier basin, only Cr exhibited a decreasing trend in enrich factors (EF) with increasing Sc concentration, whereas, in the downstream areas, most elements displayed a declining trend. Furthermore, apart from a few sampling sites, heavy metal concentrations in the glacier basin remained relatively balanced, suggesting that these metals predominantly originate from natural sources. The values of potential ecological risk for an individual element (Eri) and potential ecological risk index (PER) indicate that the ecological and human risks associated with almost heavy metals (except As) in the aquatic ecosystem are minimal. ENVIRONMENTAL IMPLICATION: Heavy metals in aquatic ecosystems pose a significant threat to ecological and human health. Due to delicate ecological balance of the Tibetan Plateau and its critical role as a water resource, we analyzed various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb and Sb) concentrations and EF in land surface river water, to find out the pollution levels and possible sources of heavy metals in the aquatic ecosystems. The results of risk assessment showed that the prevention and management of arsenic in Tibetan Plateau needs attention, but most heavy metals pose no threaten to ecological and human health.

Distribution and source of heavy metals in Tibetan Plateau topsoil: New insight into the influence of long-range transported sources to the surrounding glaciers.

Heavy metals present a substantial threat to both the environment and human health. Considering the delicate ecological equilibrium of the Tibetan Plateau (TP) and its heightened susceptibility to anthropogenic impacts, scholarly attention has progressively turned toward the examination of heavy metal pollution within the plateau's environment. In this study, we conducted a comprehensive analysis of various heavy metals (As, Cr, Co, Ni, Cu, Mo, Cd, Pb, and Sb), utilizing topsoil samples collected from the TP during the period of 2018-2021. Additionally, snow and cryoconite samples obtained from TP glaciers during the same timeframe were also subjected to analysis. The results indicate elevated concentrations of total heavy metals in the eastern and western TP (328.7 µg/g), as opposed to the central and southern TP (145.7 µg/g). Most heavy metals exhibit a consistent spatial distribution pattern. High Enrichment Factors (EFs) and Geoaccumulation Index (Igeo) values for As and Cd suggest their enrichment in TP topsoil. Receptor modeling identified three primary sources of heavy metals within the topsoil: industrial sources (42.3%), inherent natural sources within the surface soil (20.6%), and vehicular emissions (14.2%). Substantial differences in heavy metal concentrations and spatial distribution were observed between the topsoil and the glacial snow-cryoconite matrix. The prominent presence of Sb in the snow-cryoconite matrix, in contrast to its low abundance in the topsoil, indicates distinct source influences of long-range transported materials between the two environments. Our inference suggests that the influence of heavy metals from distant pollutants undergo mixing and dilution in the topsoil due to the presence of local indigenous heavy metals, although such influence is notably observed on the glacier surface of the TP. Consequently, this underscores the significant impact of long-range transported sources on heavy metals, surpassing the influence of local TP soils, to the alpine glaciers and even other atmospheric sediments in Tibetan Plateau.