Search

The analysis and numerical simulation of the heating mode of a metal plate scanning beam of laser radiation was carried out. In the transverse-one-dimensional approximation, the estimates are obtained of the main dependences of the characteristics of the steady temperature profile on the parameters of the pr-oblem. [ABSTRACT FROM AUTHOR]

Osteoporosis is a significant global health concern that can be difficult to detect early due to a lack of symptoms. At present, the examination of osteoporosis depends mainly on methods containing dual-energy X-ray, quantitative CT, etc., which are high costs in terms of equipment and human time. Therefore, a more efficient and economical method is urgently needed for diagnosing osteoporosis. With the development of deep learning, automatic diagnosis models for various diseases have been proposed. However, the establishment of these models generally requires images with only lesion areas, and annotating the lesion areas is time-consuming. To address this challenge, we propose a joint learning framework for osteoporosis diagnosis that combines localization, segmentation, and classification to enhance diagnostic accuracy. Our method includes a boundary heat map regression branch for thinning segmentation and a gated convolution module for adjusting context features in the classification module. We also integrate segmentation and classification features and propose a feature fusion module to adjust the weight of different levels of vertebrae. We trained our model on a self-built dataset and achieved an overall accuracy rate of 93.3% for the three label categories (normal, osteopenia, and osteoporosis) in the testing datasets. The area under the curve for the normal category is 0.973; for the osteopenia category, it is 0.965; and for the osteoporosis category, it is 0.985. Our method provides a promising alternative for the diagnosis of osteoporosis at present. [ABSTRACT FROM AUTHOR]

• LDO/BC was successfully prepared via coprecipitation and co-pyrolysis. • LDO/BC had an outstanding performance for Cu2+ and Cd2+ adsorption. • Ca was beneficial to the formation of more regular layered and flake structure. • LDO/BC exhibited an excellent remediation for heavy metals in contaminated soil. The combined pollution of heavy metals is ubiquitous worldwide. Mn/Al-layered double oxide-loaded crab shells biochar (LDO/BC) was prepared, so as to remediate the combined pollution of Cd and Cu in soil and water. The pristine and used LDO/BC were characterized and the results revealed that the layered double oxide was successfully loaded on crab shells biochar (BC) and metal element Ca in crab shells was beneficial to the formation of more regular layered and flake structure. The maximal adsorption capacity (Q m) of LDO/BC for aqueous Cu2+ and Cd2+ was 66.23 and 73.47 mg/g, respectively. LDO/BC and BC were used to remediate e-waste-contaminated soil for the first time and exhibited highly efficient performance. The extraction amount of Cu and Cd in the contaminated soil by diethylene triamine penta-acetic acid (DTPA) after treating with 5% LDO/BC was significantly reduced from 819.84 to 205.95 mg/kg (with passivation rate 74.8%) and 8.46 to 4.16 mg/kg (with passivation rate 50.8%), respectively, inferring that the bioavailability of heavy metals declined remarkably. The experimental result also suggested that after remediation by LDO/BC the exchangeable and weak acid soluble Cu and Cd in soil translated to reducible, residual and oxidizable fraction which are more stable state. Precipitation, complexation and ion exchange were proposed as the possible mechanisms for Cd and Cu removal. In general, these experiment results indicate that LDO/BC can be a potentially effective reagent for remediation of heavy metal contaminated water and soil. [Display omitted] [ABSTRACT FROM AUTHOR]

The present research offers novel understandings of the reproductive biology of Pseudecheneis sulcatus (McClelland, 1842) found in the Yarlung Zangbo Grand Canyon, a biodiversity hotspot. Reproductive characteristics of Pseudecheneis sulcatus, including their maturation age, fertility, spawning season, and maximum body size, constitute important aspects of its life-history traits. We collected a total of 310 specimens from the Yarlung Zangbo River's Motuo reach between March and November 2016 and found the male-to-female ratio to be 0.73:1, markedly different from the anticipated 1:1. The total length of individuals ranged from 72 to 207 mm, while overall weight ranged from 2.5 to 65.0 g. Their length at first maturity was estimated as 131 mm in males and 132 mm in females. Based on the adult proportion and fluctuation in the monthly gonadosomatic index (GSI) and size distribution of oocytes, spawning was determined to occur from March to June. The absolute fecundity ranged between 247 and 2886 eggs, while the fluctuation in average relative fertility ranged between 16.8 and 77.1 eggs/g of fish. The fecundity of P. sulcatus was linearly correlated to the overall weight and length of the fish along with the ovarian weight. In conclusion, P. sulcatus spawned synchronously in spring and early summer, exhibiting low fecundity and large oocytes. Our results provided basic information in understanding how this species adapted well to the unique canyon environment, which may be useful for developing a sustainable conservation plan for P. sulcatus at the lower reach of the Yarlung Zangbo River. [ABSTRACT FROM AUTHOR]

The problem of heat dissipation has become a key to maintain the operation state and extending the service time of electronic components. Developing effective thermal management materials and technologies is of great significance to solve this problem. Previously, passive cooling using phase change materials (PCMs) has been proposed as a thermal management method for electronic devices. In this work, a hybrid thermal management system coupling the heat storage of PCMs and the thermal conduction of high conductivity materials is designed toward thermal management of electronic devices. Specifically, ternary composite gels consisting of eicosane, styrene-ethylene-butylene-styrene (SEBS) and boron nitride (BN) are fabricated by liquid-phase blending and sol–gel transition toward the highly efficient thermal management of electronic devices. The van der Waals force between SEBS and eicosane and the π–π interaction between SEBS and BN enable the excellent form-stability of the ternary composite gels. Taking advantage of the merits of the functional components, the proposed ternary composite gels demonstrate a high thermal energy storage capacity of 157.5 Jg−1 and high thermal conductivity of 1.08 Wm−1 K−1. The ternary composite gels are applied in the thermal management of CPU and chip to reduce their working temperature via the synergistic effect of heat dissipation and heat storage. It is anticipated that the ternary composite gels create a state of the art alternative for the next-generation flexible and multifunctional thermal management devices. [ABSTRACT FROM AUTHOR]

Present efforts to support the essential industrial‐scale electrolytic production of copper‐based metal powders urgently require approaches to the real‐time predicting of corrosion of copper cathodes employed in electrolytic production processes. However, current approaches are extremely limited owing to the difficulty of accurately modeling the complex cathode corrosion process. In this study, the corrosion process under different parameters was analyzed by a self‐designed continuous electrolytic corrosion experimental device, clarify the influence mechanism of current density on the corrosion of the solid–liquid–gas interface area, and addresses this issue by applying a random forest machine learning approach based on three process parameters, including the electrolyte temperature, liquid‐level fluctuation cycle period, and current density. The dataset employed in the model is obtained using a novel experimental corrosion test method based on electrode arrays. The experimental results include the corrosion rates of copper cathode plates at different positions relative to the liquid electrolyte level during the electrolysis process. The resulting stochastic model is demonstrated to obtain a high prediction accuracy of 97% for the various regions of copper cathode plates defined according to liquid electrolyte level. [ABSTRACT FROM AUTHOR]

Background: To evaluate the diagnostic value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) in immunocompromised patients for the diagnosis of suspected pneumonia in comparison with that of conventional microbiological tests (CMTs).Methods: Sixty-nine immunocompromised patients with suspected pneumonia received both CMTs and mNGS of BALF were analyzed retrospectively. The diagnostic value was compared between CMTs and mNGS, using the clinical composite diagnosis as the reference standard.Results: Sixty patients were diagnosed of pneumonia including fifty-two patients with identified pathogens and eight patients with probable pathogens. Taking the composite reference standard as a gold standard, 42 pathogens were identified by CMTs including nine bacteria, 17 fungi, 8 virus, 6 Mycobacterium Tuberculosis, and two Legionella and 19(45%) of which were detected by BALF culture. As for mNGS, it identified 76 pathogens including 20 bacteria, 31 fungi, 14 virus, 5 Mycobacterium Tuberculosis, four Legionella and two Chlamydia psittaci. The overall detection rate of mNGS for pathogens were higher than that of CMTs. However, a comparable diagnostic accuracy of mNGS and CMTs were found for bacterial and viral infections. mNGS exhibited a higher diagnostic accuracy for fungal detection than CMTs (78% vs. 57%, P < 0.05), which mainly because of the high sensitivity of mNGS in patients with Pneumocystis jirovecii pneumonia (PJP) (100% vs. 28%, P < 0.05). Nineteen patients were identified as pulmonary co-infection, mNGS test showed a higher detection rate and broader spectrum for pathogen detection than that of CMTs in co-infection. Moreover, Pneumocystis jirovecii was the most common pathogen in co-infection and mNGS have identified much more co-pathogens of PJP than CMTs.Conclusions: mNGS of BALF improved the microbial detection rate of pathogens and exhibited remarkable advantages in detecting PJP and identifying co-infection in immunocompromised patients. [ABSTRACT FROM AUTHOR]

The air-dried aerial part of Epilobium angustifolium is a very popular recreational tea in the Eastern edge of Europe. Studies have found that the extract of E. angustifolium has strong anti-inflammatory effects, and the oenothein B contained therein is speculated the main anti-inflammatory component. In this study, a fraction without oenothein B from the ethanol extract of E. angustifolium exhibited a much stronger anti-inflammatory activity than that of the oenothein B. Guided by rapid characterization of the chemical compositions based on UPLC–Orbitrap–MS/MS, a total of 39 compounds, including 20 flavonoids and 19 other phenolic acids were identified in the active fraction, based on the accurate mass within 3 ppm error. Further investigation resulted in the isolation and identification of 10 compounds, one of which was a new compound, and four known compounds were identified in E. angustifolium for the first time. All isolated compounds exhibited significant inhibitory activity on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW 264.7 cells. This study indicated that the anti-inflammatory active ingredients in E. angustifolium were mainly concentrated in the 30% ethanol eluted fraction obtained over macroporous adsorption resin. In addition to the oenothein B, there are a large number of other more effective anti-inflammatory components in E. angustifolium. [ABSTRACT FROM AUTHOR]

The spatial–temporal patterns of fish assemblages in lotic systems can provide useful information in developing effective conservation measures. This study aimed to explore the spatial and seasonal changes in fish assemblages and their association with environmental factors in mountain streams of the Ren River, southwest China. Field investigations were conducted at 18 sites during the rainy and dry seasons in 2017. A total of 1,330 individuals, belonging to three orders, eight families, 19 genera, and 21 species, were collected. Analysis of similarities (ANOSIM) showed that the structure of fish assemblages varied significantly at the spatial scale, but not at the seasonal scale. In low‐order sites, fish assemblages were mainly dominated by cold‐water and rheophilic species (e.g., Rhynchocypris oxycephalus, Scaphesthes macrolepis, Metahomaloptera omeiensis, and Gnathopogon herzensteini), while those in high‐order sites were predominated by warm‐water and eurytopic or stagnophilic species (e.g., Squalidus argentatus, Hemiculter leucisculus, and Zacco platypus). Canonical correspondence analysis (CCA) showed that the fish assemblages were structured by a combination of large‐scale landscape factors (e.g., altitude and C‐link) and small‐scale habitat features (e.g., channel width, water temperature, and depth). Among these factors, landscape had the greatest influence on fish assemblages, while local habitat variables were less important or were only significant in certain seasons. [ABSTRACT FROM AUTHOR]

Psilorhynchus homaloptera mainly inhabits turbulent waters in the lower reach of the Yarlung Zangbo River, Tibet, China, and it is the only species of Psilorhynchus in China. However, many important aspects of its biology remain poorly documented, which hinders the conservation efforts. Therefore, we studied its reproduction using 801 specimens from the Motuo sector of the lower Yarlung Zangbo River from December 2015 to November 2016. The sex ratio was 0.68:1 (male:female) for the overall population. Females reached a larger total length and weight (134 mm and 18.6 g) than males did (113 mm and 12.2 g). Lengths at maturity were estimated 80.0 mm for males and 93.1 mm for females. Our analyses of gonad development and the size distribution of oocytes suggest that P. homaloptera is a single spawner with the peak spawning period between September and October. Furthermore, the estimated mean absolute fecundity was 557±204 eggs per fish, and mean relative fecundity was 50.9±10.9 eggs per g of female weight. The fecundity of P. homaloptera increased linearly with increasing total length, total weight, ovary weight, and age. This study on the reproductive biology of P. homaloptera demonstrates that the fish was in a vulnerable state due to the increasing anthropogenic activities in the lower Yarlung Zangbo River. [ABSTRACT FROM AUTHOR]

Stimulus‐responsive multimodal optical materials demonstrating tunable optical behaviors possess significant application in optoelectronic materials and devices. Introducing fluorescent elements into liquid crystal structures is a common strategy. The design of hybrid optical structure at molecular level is seldom reported. Herein, novel Janus oligomers (JOs) combining the chiral nematic liquid crystalline (CNLC) units and the photoluminescent (PL) units on organosilicon oligomers by molecular grafting are proposed. The as‐prepared JOs display brilliant visible light reflection originating from the chiral arrangement of the CNLC segments. The discrete pyrene chromogenic segments in the CNLC matrix enable the quantum yield and PL lifetime of JOs to be up to 38.58% and 68.45 ns. Furthermore, the JOs present dual‐mode thermochromic performances, the blue‐shift reflection across the full‐spectrum visible light region, and the highly sensitive PL evolution. The JOs can be manufactured into dynamic anti‐counterfeiting patterns with fast and reversible response by screen printing. The Janus optical structure enabled by chemically coupling different optical elements at the molecular level provides a templated strategy to create the next generation of intelligent hybrid optical materials. [ABSTRACT FROM AUTHOR]

Reservoirs are important artificial ecosystems that modify the hydrological and ecological characteristics of a river. Knowledge of the basic characteristics of fish assemblages in reservoirs is a first step toward the development of effective conservation policies. We used the information collected over a 10-year period (2006–2015) to assess the structure of the fish assemblages in the Three Gorge Reservoir (TGR) in a river-dam gradient. Three fish zones were detected in TGR. Species richness was the highest in the upper zone and lowest in the lower zone. The riverine zones were dominated by rheophilic species Coreius guichenoti and Pelteobagrus vachelli. The transitional zones were dominated by Coreius heterodon and Rhinogobio cylindricus. The lacustrine zones were dominated by eurytopic species Hypophthalmichthys molitrix, Aristichthys nobilis, Hemiculter bleekeri and Cyprinus carpio. For the functional characteristics, fish assemblages in riverine and transitional zones were dominated by insectivorous species, equilibrium strategists and rheophilic species (e.g., Coreius heterodon and Coreius guichenoti). In lacustrine zones, the fish assemblage was dominated by habitat generalists common to lakes and reservoirs (e.g., Hemiculter bleekeri, Hypophthalmichthys molitrix, Aristichthys nobilis). Moreover, 18 exotic species (e.g., Protosalanx hyalocranius, Ictalurus punctatus, Megalobrama amblycephala, Tilapia) were collected in TGR, most of which only existed in the lacustrine zone. The results highlight the importance of freely flowing riverine reaches for conserving native fish in the upper Changjiang River and adaptive management strategies for fisheries in TGR. [ABSTRACT FROM AUTHOR]

Four new limonoids, 7,12-dihydroxyvilasinone (1), vilasindione (2), 4-dehydroxynimbandiol (3) and azadiramide B (4), were isolated from extracts of Bacillus subtilis -fermented neem seeds. Their planar structures and relative configurations were elucidated by spectroscopic methods including UV, IR, MS and NMR, and the absolute stereochemistry was determined by comparing their experimental and calculated CD spectra. 4 is a rare salannin-class limonoid alkaloid. In cytotoxic assays, 3 showed inhibitory activity against MDA-MB-231, A375 and Hela cell lines with IC 50 values of 21.45 ± 5.41, 17.67 ± 3.96 and 28.13 ± 9.12 μM, respectively, while 4 selectively inhibited growth of MDA-MB-231 cell line with an IC 50 value of 15.73 ± 6.07 μM. Unlabelled Image [ABSTRACT FROM AUTHOR]

Highlights • Chemical composition of essential oil of Artemisia dracunculus var. qinghaiensis was reported from the Qinghai-Tibet Plateau. • Sabinene is the major constituent of the essential oil in this taxon from the Qinghai-Tibet Plateau. • The essential oil of A. dracunculus var. qinghaiensis shows moderate inhibitory effects against pathogenic microorganisms. Abstract Many plant species that occur at the high-altitudes such as Qinghai-Tibet Plateau (QTP) under extreme climate conditions have potential medicinal functions. To explore the potential use of such plants, we extracted the essential oil from Artemisia dracunculus var. qinghaiensis Y. R. Ling collected from QTP at the flower-buds stage (0.67% v / w) by the hydro-distillation method. The chemical compositions and antimicrobial activity of the essential oil were determined using the gas chromatography/mass spectrometry (GC/MS) and agar disk-diffusion methods, respectively. Thirty-seven compounds accounting for 60.88% of the total detected components, with a high proportion of monoterpenes (42.12%) were identified in the essential oil. Of these, sabinene (19.19%), β-terpinene (8.94%), terpinen-4-ol (3.83%), and α-pinene (3.08%) were identified as the major compounds. The essential oil showed inhibitory activity against seven microbial strains (Staphylococcus aureus , Micrococcus luteus , Bacillus subtilis , Klebsiella pneumoniae , Pseudomonas aeruginosa , Salmonella paratyphi , and Saccharomyces cerevisiae) at the minimum concentrations (MICs) of 1.25–5.0 μl/ml. Our results suggest that the essential oil of the QTP A. dracunculus var. qinghaiensis can be used as a potential biomedical resource. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Rare earth complex/chiral liquid crystal composites are firstly realized. • A brand new concept of dual-mode optical modulation has been established. • The optical modulation can be operated at low voltages (within 10 V) and ultrashort response time. Abstract Due to the superior optical properties and tremendous application prospects in the field of optical devices, both rare earth complex (REC) and chiral nematic liquid crystal (CNLC) have attracted widespread attention in the fields of theoretical research and engineering applications. Among the research on the optical behaviors of CNLC or REC, the controllable modulation of selective reflection of CNLCs and emitted fluorescence of RECs is of great significance to fabricated tunable optical materials. In this study, europium (III) complexes are dissolved and assembled in the chiral matrix of CNLCs to form binary CNLC-REC composites due to excellent compatibility between RECs and CNLCs. The selective reflection combined with the photoluminescence of binary fluorescent CNLCs are investigated, an electrically-controlled microscopic structure model is established to elaborate the dual-mode optical modulation based on the stable CNLC-REC composites. The reflectance of CNLCs can be tuned in the process from planar state with brilliant Bragg reflection to focal conic state with chaotic scattering, the intensity of fluorescence emitted by RECs can be modulated due to the increased scattering of incident UV light on the surface of CNLC-REC composite films. Furthermore, the dual-mode optical modulation can be operated at low voltages and the response time is within 3 ms. This facile and ultrafast methodology can be used to develop state-of-the-art tunable optical devices in the fields of LC display, fluorescent display and optical sensors. [ABSTRACT FROM AUTHOR]

In order to construct reduced graphene oxide (RGO) contained 3D ordered chiral architecture and exploit the anisotropic properties of RGO to develop functional soft matter, a brand new nanosurfactant which is two-dimensional charged zirconium phosphate (CZ) nanoplatelet is firstly designed and applied to disperse RGO in liquid phase and ordered soft matter. The rheological behavior analysis shows the RGO suspensions can change from unhomogeneous non-newtonian nanofluids to homogeneous newtonian nanofluids after being exfoliated by CZ nanoplatelets. Absorption spectra indicate that the dispersion stability of RGO in liquid phase can be gradually improved with the increase of CZ content. RGO is effectively dispersed in a type of ordered soft matter (chiral nematic liquid crystals, CNLCs) when the mass ratio between CZ and RGO reaches 8. X-ray diffraction results prove that the interlayer spacing of CNLCs has been reduced with the increase of RGO content. Raman spectra confirm the characteristic bands of CZ-RGO-CNLC composites and the physical coupling among CZ, RGO and CNLC. The ternary CZ-RGO-CNLC composites possess chiral helical configuration and Bragg selective reflection characteristic. The driving electric intensity and the saturated electric intensity of the ternary CZ-RGO-CNLC composites with 0.1 wt% RGO addition can be significantly reduced compared with single-component CNLCs. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A rare spiro-type limonoid spirodione (1) was isolated from neem seeds. • The absolute stereochemistry of this skeleton is firstly elucidated by ECD method. • A plausible biosynthetic pathway for this skeleton was proposed. Abstract A rare spiro-type limonoid spirodione (1) was isolated from the seeds of Azadirachta indica A. Juss. Its structure was elucidated through analysis of the spectroscopic data including HRESIMS, NMR, etc., and the absolute configurations were assigned by comparison of experimental and TDDFT-calculated ECD spectra. 1 showed moderate activities against Staphylococcus aureus ATCC 25922 and S. epidermidis ATCC 12228 with MICs of 16 and 64 μg/mL, respectively. [ABSTRACT FROM AUTHOR]

Chinese sturgeon ( Acipenser sinensis) is the flagship species of the Changjiang River. The migration route of this species is blocked by the first dam, the Gezhou Dam, and its reproduction is affected by the Three Gorges Dam (TGD), one of the largest dams in the world. We studied the impact of the impoundment of the Three Gorges Reservoir (TGR) since 2003 on the spawning stock and the natural reproduction of the Chinese sturgeon by using our monitoring data from 1997 to 2013. Results indicate that TGR impoundment has delayed the first spawning dates of the fish from middle-late October to late November, decreased the amount of spawning activities from twice to only once each year, and significantly reduced egg production. In particular, the fish did not demonstrate any spawning activities in 2013. Therefore, TGR impoundment significantly affects the natural reproduction of the fish downstream of the TGD. The spawning stock size of the fish is also predicted to further decrease in the future, which will lead to a risk of population extinction. Ecological regulations must be imposed on decreasing the water temperature to 20°C before mid-October and increasing water discharge downstream of the TGD in October to induce spawning of the Chinese sturgeon. [ABSTRACT FROM AUTHOR]

An effective and promising approach for dispersion and alignment of carbon nanotubes (CNTs) with the help of fluorinated liquid crystalline surfactants (FLCSs), which possess excellent affinity with CNTs and liquid crystals (LCs), is presented here. A binary mode is designed to express the dispersion of CNTs with CNTs joining the nematic matrix of FLCSs. Ultraviolet-visible spectrum and fourier transform infrared (FTIR) spectrum are recorded to figure out the concentration of effectively dispersed CNTs by FLCSs, the concentration in chloroform reaches a maximum 1.481 mg mL. The miscibility between FLCSs and CNTs is analyzed by FTIR imaging system with P7 giving rise to the best miscibility. The homogeneously dispersed CNTs decrease the glass transition temperature of FLCSs by increasing the degree of freedom of the segment on FLCS to move, and enhance the thermal stability of FLCSs by increasing the decomposition temperature and the activation energy for thermal decomposition. The optical textures show that P7 increases the compatibility between LC host and CNTs. The chiral stability and electro-optical property of LC host are both optimized by CNT doping. [ABSTRACT FROM AUTHOR]

Focusing on the phenomenon of the crack on the autoclave flange, a three-dimensional model of the autoclave was established based on the Ansys Workbench platform. A new finite element analysis flow for optimizing the design of autoclave teeth was established using the Fluent, Static Structure, and Direct Optimization modules. The paper analyzed and discussed the maximum stress and minimum fatigue life at the corresponding position. The variation trend of stress and fatigue life at the corresponding position after fillet optimization was also discussed. The results showed that the equivalent stress of autoclave teeth without fillet optimization reached the maximum under different fillet sizes. The equivalent stress and fatigue life of the autoclave tooth were the same as the rounded corner size obtained by the optimization design. The optimal global solution could be obtained through the optimization design process. [ABSTRACT FROM AUTHOR]

Due to the limitation of huge forming load, inhomogeneity of plastic deformation, and small volume of deformation region, it is difficult to prepare bulk ultra-fine grains material (UFGM) with industry size by the existing severe plastic deformation (SPD) methods. In this study, a novel SPD method, namely 3D-SPD, was proposed. By establishing finite element model, the distribution of material flow, restraining to Mannesmann effect, and comparison of load were discussed. Based on the self-developed rolling mill, the corresponding experiments were conducted. The experimental results reveal that the buck ultra-fine grains material of 45 steel was obtained under the condition of feed angle 21°, cross angle 15°, cone angle 5°, reduction rate 50%, and roll speed 30 rpm. The average grain size was refined from 46 to 0.8–4 μm. The tensile test results indicate that the yield strength and tensile strength of the rolled bar were significantly improved. [ABSTRACT FROM AUTHOR]

Length‐length (LLRs) and length‐weight relationships (LWRs) were described for ten fish species inhabiting the Yichang reach in middle Yangtze River below Gezhouba Dam, China. Fish were sampled using drifting gillnets (30–40 m long ×1.0–1.5 m high, mesh size: 20, 40 and 60 mm) and stationary gillnets (40–60 m long ×1.8–2.0 m high, mesh size: 20, 40, 60, 80, 100 and 140 mm) from October to next January each year between October 2016 and January 2021. All fishes were measured in the field immediately after collection for total length (TL) and standard length (SL) to the nearest 0.1 cm and for body weight (BW) to the nearest 0.1 g. There was strong correlation between length and weight of all ten species (r2 > 0.95). The values of parameter b in LWRs ranged from 2.871 to 3.480. The results provided new data for FishBase and for establishing conservation measures of fish resources after fishing closure in the Yangtze River. [ABSTRACT FROM AUTHOR]

Two-dimensional transition-metal carbides/carbonitrides (MXenes) have demonstrated wide application prospect in energy conversion and storage, mostly in the form of electrochemical energy storage. Compared with the conversion between chemical energy and electrical energy, an energy conversion process initiated by solar energy and driven by the physical change of energy materials will be a sustainable and environmentally friendly strategy. Therefore, a high-performance MXene aerogel-based phase change material for solar energy conversion and thermal energy storage is constructed. MXene nanosheets with an extinction coefficient of 25.67 L/(g.cm) at 808 nm demonstrate excellent light absorption performance, which can spontaneously convert the solar energy into thermal energy. The polyethylene glycol (PEG) possessing high affinity with MXene acts the medium for thermal energy storage and release in the process of fusion and solidification. The MXene@PEG aerogels are lightweight, with a density about 30 mg/cm3. The MXene skeleton is introduced as supporting materials to keep the shape of MXene@PEG aerogel stable during the phase change process. The MXene nanosheets improve the thermal stability of PEG, the thermal decomposition temperatures can be increased by 40 °C. The actual fusion and solidification enthalpies of MXene@PEG aerogels can reach 167.72 and 141.51 J/g, respectively. The photothermal storage efficiency of MXene@PEG aerogels reaches a relatively high value of 92.5%. This work provides a new type of scaffold for lightweight and shape-stable photothermal carrier and paves the way for the application of non-graphene 2D materials toward solar energy utilization. Image 1 • A brand new concept of MXene aerogel-based phase change materials for solar energy conversion has been established. • The MXene aerogel-based phase change materials are lightweight and shape-stable. • The photothermal storage efficiency of Mxene@PEG aerogels reaches 92.5%. [ABSTRACT FROM AUTHOR]

The medium temperature phase change material gels (PCMGs) have a thermal storage capacity to meet the body's needs for thermal comfort in cold environments. However, traditional PCMGs are prone to leakage and break in solid-liquid phase change process towards personal thermal management (PTM) application. This study develops an innovative approach that uses covalent and ionic crosslinking to simultaneously maintain the form-stability and self-healing capabilities of sodium acetate trihydrate (SAT) PCMGs. The self-healing performance of SAT PCMGs is contributed to the dynamic interaction of ionic bonds and hydrogen bonds in sodium polyacrylate (PAAS) and calcium alginate (CA). The interaction between SAT and dual network (PAAS and CA) provides form-stability to SAT. To remove SAT's supercooling degree, sodium dihydrogen phosphate dihydrate is chosen as the nucleating agent. The proposed SAT PCMGs demonstrate high shape stability, high self-healing properties, high thermal conductivity (0.58 W m−1 K−1) and high thermal energy storage capacity (170.30 Jg-1). Germanium (Ge) membrane prepared by combining Ge powder with chitosan presents high solar absorption. A device consisting of Ge membrane and SAT PCMG is applied in static and dynamic PTM to produce thermal comfort by solar-thermal conversion, thermal energy storage and thermal energy utilization. With this effort, an advanced substitute for the upcoming solar-thermal PTM devices is created. • Novel phase change material gels confining sodium acetate trihydrate in double cross-linked network are proposed. • Sodium acetate trihydrate gels possess high thermal energy storage capacity of 155.11 Jg−1. • Sodium acetate trihydrate gels present excellent form-stability and high self-healing performance. • Sodium acetate trihydrate gels combined with Ge membrane realize the solar harvesting and personal thermal management. [ABSTRACT FROM AUTHOR]

Due to the excellent optical properties and great application prospects in the optical field, both pyrene compounds (PCs) and chiral liquid crystal have attracted extensive attention in theoretical research and practical applications. Fluorescent chiral liquid-crystalline networks (FCLCN) with good liquid-crystalline properties and tunable fluorescence properties as a response to temperature were prepared using Poly(methylhydrogeno)siloxane (PMHS), chiral liquid-crystalline monomer (M1), chiral crosslinker (M2) and organic fluorescent pyrene compounds (M3). The as-prepared FCLCN display reversible chiral Grandjean texture during the heating and cooling process from the intrinsic chiral arrangement of FCLCN. The discrete pyrene chromogenic segments in FCLCN matrix endowed the networks with excellent fluorescence properties when irradiating with ultraviolet light and the fluorescence can be precisely adjusted by temperature, furthermore, the FCLCN presents highly sensitive fluorescence evolution with a high response sensitivity of 3.4% K−1. The FCLCN can be manufactured into temperature-driven dynamic fluorescence patterns with a fast and reversible response. [ABSTRACT FROM AUTHOR]

As one of the important biodiversity conservation areas in China, the ecosystem in the lower reaches of the Yarlung Zangbo River is fragile, and is particularly sensitive to global changes. To reveal the diversity pattern of phytoplankton, the metabarcode sequencing was employed in the Medog section of the lower reaches of the Yarlung Zangbo River during autumn 2019 in present study. The phytoplankton assemblies can be significantly divided into the main stem and the tributaries; there are significant differences in the phytoplankton biomass, alpha and beta diversity between the main stem and the tributaries. While both the main stem and the tributaries are affected by dispersal limitation, the phytoplankton assemblages in the entire lower reaches are primarily influenced by heterogeneous selection. Community dissimilarity and assembly process were significantly correlated with turbidity, electrical conductivity, and nitrogen nutrition. The tributaries were the main source of the increase in phytoplankton diversity in the lower reaches of the Yarlung Zangbo River. Such diversity pattern of phytoplankton in the lower reach may be caused by the special habitat in Medog, that is, the excessive flow velocity, and the significant spatial heterogeneity in physical and chemical factors between stem and tributaries. Based on the results and conclusions obtained in present study, continuous long-term monitoring is essential to assess and quantify the impact of global changes on phytoplankton. [ABSTRACT FROM AUTHOR]

Aim: Understanding the patterns and drivers of biodiversity across space and time is commonly based on species diversity, which may ignore species' functional role and evolutionary history and result in an incomplete understanding of community assembly. It is suggested that integrating species, functional, and phylogenetic diversity could provide a more holistic assessment of community assembly in natural ecosystems. This study aimed to explore the elevational patterns and environmental drivers of multiple facets of fish diversity and community structure in a subtropical river during the wet and dry seasons. Location: The Chishui River basin, China. Methods: We investigated the responses of fish species richness, functional richness, and phylogenetic diversity to elevation in different seasons. Moreover, we compared functional dispersion and mean pairwise distance with those obtained from null models to infer assembly mechanisms shaping community structure. Additionally, we examined the environmental drivers (e.g. water chemistry, temperature, and river size) of fish diversity and community structure. Results: Fish species richness, functional richness, and phylogenetic diversity showed a negative relationship with elevation in the Chishui River basin. Fish communities tended to be on average functionally random but phylogenetically clustered. Furthermore, phylogenetic structure exhibited a decreasing pattern along the elevational gradient. Despite no significant seasonal changes for fish diversity (except for phylogenetic diversity), fish communities became more phylogenetically overdispersed and clustered at low and high elevations in the dry season. Additionally, the responses of fish diversity and community structure to environmental variables were not synchronous. Conclusions: At the basin scale, environmental filtering was prevalent in shaping fish phylogenetic structure, whereas stochasticity was likely more important for functional structure. Moreover, the ecological mechanisms shaping individual fish communities switched from limiting similarity to environmental filtering as elevation increased, and the underlying forces at two ends of the elevational gradient became more prominent in the dry season. [ABSTRACT FROM AUTHOR]

Disentangling the factors governing community structure across various spatial and temporal scales is a core task in community ecology and biogeography, because it could provide valuable insights into biodiversity conservation and management. The relative role of environmental (a proxy for niche‐based mechanism) and spatial (a proxy for dispersal) effects in shaping ecological communities depends on diversity facets, network positions, seasonality and biological characteristics of the focal organisms. However, such patterns are not well understood for fish communities in large river systems, especially if all of these patterns are examined simultaneously.We investigated fish taxonomic, functional and phylogenetic total β‐diversity (and their turnover and nestedness phenomena) at different spatial scales (basin vs. section scales) and seasons (wet vs. dry seasons) in a subtropical river system (the Chishui River basin, China). We also quantified the relative importance of environmental variables and spatial factors in shaping fish β‐diversity by using generalised dissimilarity modelling.At the basin scale, fish taxonomic and phylogenetic β‐diversity across seasons mainly reflected turnover, yet turnover and nestedness contributed likewise to total functional β‐diversity. Taxonomic and phylogenetic β‐diversity were strongly correlated (r from 0.39 to 0.87), whereas functional and both taxonomic and phylogenetic facets were relatively weakly correlated (r from 0.27 to 0.65). Generalised dissimilarity modelling suggested that phylogenetic β‐diversity phenomena were consistently more influenced by environmental variables (wet 16.1%, dry 22.4%) than by spatial factors (wet 6.7%, dry 4.8%). However, for both taxonomic and functional facets, environmental variables (turnover 13.8%, nestedness 6.4%) and spatial factors (turnover 4.3%, nestedness 9.4%) accounted for a greater proportion of variations in turnover and nestedness, respectively.At the section scale, only phylogenetic total β‐diversity and nestedness, as well as taxonomic nestedness significantly differed between the headwater and downstream sections. Furthermore, headwater communities were primarily explained by spatial (15.7%) and environmental (12.7%) variables in the wet season, while environmental factors (25.9%; spatial 7.7%) dominated in the dry season. By contrast, downstream communities were more influenced by environmental factors (17.9%; spatial 8.3%) in the wet season, whereas environmental (11.0%) and spatial variables (11.5%) contributed likewise to β‐diversity in the dry season.Our results highlight that, compared with taxonomic β‐diversity, accounting for turnover and nestedness of functional and phylogenetic β‐diversity helps to reveal distinct biodiversity patterns, and potential environmental and spatial controls. Given that community–environment relationships and the relative contribution of environmental and spatial factors varied between seasons and between the basin and section scales, our study underlines the importance of long‐term dynamics and spatial scales in metacommunity studies. Our findings also suggest that maintaining environmental heterogeneity and adequate hydrological connectivity would be essential for the conservation of fish diversity. Overall, our study advances current knowledge of fish biodiversity patterns and their maintenance mechanisms by adding insights from multi‐faceted diversity and seasonality, which has rarely been done in large subtropical rivers. [ABSTRACT FROM AUTHOR]

All inorganic perovskite nanocrystals (AIPNCs) have attracted tremendous research interest due to their fascinating properties in the field of photoelectron. Conventional synthesis of AIPNCs is usually conducted by using batch reactions under gas protection at high temperatures. Herein, an automated microreactor platform consisting of flow-focusing microfluidics is firstly applied to synthesize AIPNCs without gas protection at room temperature. The nucleation and growth is based on the ultrafast mixing and phase separation in low-toxicity solvent. The AIPNCs formed in the microreactor have good crystallinity and narrow size distribution. Meanwhile, the flow-focusing microfluidics also can be used to encapsulate AIPNCs into templated microspheres to improve their stability against temperature, light and water. Furthermore, the as-constructed AIPNC spheres exhibiting linear temperature response represent their promising microthermometer application. It is envisioned that the microfluidic technique provides another alternative to synthesize Ni2+-doped, Ce3+-doped, Yb3+-doped, Bi3+-substituted AIPNCs or organic-inorganic hybrid perovskite nanocrystals and to fabricate templated AIPNC materials and devices. [ABSTRACT FROM AUTHOR]

In the present study, we investigated the age, growth, and reproductive characteristics of Euchiloglanis davidi, a species of Sisoridae fishes, from the Yalong River, China. Fish samples were collected from the tributaries of the middle and lower Yalong River in May 2013 and December 2015. Their standard length ranged from 67 to 190 mm, and the total weight ranged from 3.42 to 75.06 g. The age and growth pattern of E. davidi were determined using the vertebra. Furthermore, the sampled fish were categorized into 10 age groups (1–10 years old): the maximum age was 10 years and 9 years for male and female fish, respectively. The relationship between the standard length and weight was expressed as W = 6.744 × 10−5 L2.653, and the t-test showed allometric growth. The growth of E. davidi was defined by the von Bertalanffy growth function, described as Lt = 260.8(1−e−0.104(t+1.942)), Wt = 173.5(1−e−0.104(t+1.942))2.653, respectively. The growth inflection point was observed at 7.44 years, with corresponding length and weight values of 162.50 mm and 49.46 g. The fecundity ranged from 105 to 352 eggs, with an average of 205 eggs. The relative fecundity of weight (FW) ranged from 2.90 to 8.98 eggs/g, and the relative fecundity of length (FL) ranged from 0.71 to 2.11 eggs/mm. Altogether, these characteristics of slow growth and low fecundity demonstrated the vulnerability of E. davidi to exploitation in the middle and lower reaches of the Yalong River. [ABSTRACT FROM AUTHOR]

Shortjaw tapertail anchovy, Coilia brachygnathus, is one of the anchovy species that exclusively lives in freshwaters, which is the dominant species in Dongting Lake. In order to explain its success as a dominant species in Dongting Lake, the basic biological knowledge of this species was studied from July 2013 to July 2015 in the channel connecting Dongting Lake and the Yangtze River. A total of 11 064 samples of C. brachygnathus were collected, and their standard length ranged between 6.8 and 35.4 cm. The length-weight relationship was W= 0.0026 L3.057, and von Bertalanffy growth curve was Lt = 36.41(1-e-0.28(tþ0.8)). The exploitation rate (E) of 0.49, indicated no overfishing on this species. Its movement patterns were highly significantly and positively correlated with the rate of variation in water level, discharge and water temperature. When water level (discharge and temperatures) were rising (mainly March to July), C. brachygnathus migrated into Dongting Lake, peaking in May. When the water level (discharge and temperatures) were falling (mainly October to December), the migratory behaviour changed to exiting Dongting Lake, peaking in October. The present study suggests, fast generation time, low exploitation rate and the river-lake movements (migrations) are the possible reasons that made C. brachygnathus a dominant species in this area. [ABSTRACT FROM AUTHOR]

Over 70 % of the earth's surface is water, though people are facing a shortage of clean water. Desalination and purification plants have been utilizing inexhaustible saline and dirty water for decades, but here we present a portable solar-powered device that works during the journey. The independent steam generator is based on a novel wooden material coated with carbonized carbon dots (CCD). A facile hydrothermal treatment is applied to the balsa wood to produce a superhydrophilic, salt-resisting, and self-insulated wooden sponge. The CCD microspheres show broad absorption over the solar spectrum while the wooden sponge provides a rapid water supply and heat localization. The floating CCD@wooden sponge evaporator generates steam at the rate of 2.24 kg m−2 h−1 and has an energy efficiency of 85.0 % under 1 sun irradiation. With a unique design of portable water purifier, a traveler could easily obtain clean water after collecting and purifying undrinkable water such as seawater and wastewater on the move as long as the sun shines. [Display omitted] • Massively synthesized carbon dots were calcined to produce porous carbon spheres with broadband absorption. • Facile hydrothermal treatment was applied to the wood for superhydrophilic and self-thermal-insulation properties. • The evaporator based on carbon spheres and wood has an evaporation at 2.24 kg m-2 h-1 and an energy efficiency of 85 %. • A portable purifier is capable of both seawater desalination and wastewater purification without static conditions. [ABSTRACT FROM AUTHOR]

Emerging peroxidase (POD)-like nanozymes have been exploited to construct biosensors towards biomolecular detection. However, the enzymatic activity, sensing mechanism and detection method of the biosensors towards ascorbic acid (AA) analysis are still challenging research topics. Herein, a novel scandium-MOF (Sc-MOF) nanozyme is synthesized via a wet-chemical method. An efficient AA biosensor is developed owing to the POD-like characteristics of the Sc-MOF. The Sc-MOF nanozyme can convert hydrogen peroxide into hydroxyl radicals. Afterwards, colorless 3,3′,5,5′-tetramethylbenzidine (TMB) is converted into blue oxidized TMB by hydroxyl radicals. The Michaelis–Menten constants of the Sc-MOF nanozyme (Km = 0.013 mM for TMB and 0.246 mM for H2O2) are obviously superior to those of horseradish peroxidase. The AA concentration can be determined by putting forward a colorimetric method and an absorbance turn-off mechanism. The linear range of the Sc-MOF based colorimetric method is 0.2–20 μM. The limit of detection is 0.174 μM. The AA detection also demonstrates superior specificity and anti-interference features. Furthermore, the Sc-MOF-based biosensors are applied to qualitative and quantitative AA detection in human serum. The Sc-MOF nanozyme can inspire researchers to develop novel transition metal based biological enzymes and expand their applications in enzymatic biochemical reactions. [ABSTRACT FROM AUTHOR]

Nanozymes have been emerging as substitutes for natural enzymes to construct biosensors towards biomolecular detection. However, the detection of glutathione (GSH) by nanozyme-based biosensors still remains a great challenge for research on catalytic activity enhancement and the detection mechanism. In this work, Sb-doped iron oxychloride (Sb-FeOCl) with a well-defined nanorod-like structure is prepared by high-temperature calcination. Sb-FeOCl nanorods have high peroxidase-like activity, which can catalyze the decomposition of H2O2 into ·OH and then oxidize 3,3′,5,5′-tetramethylbenzidine (TMB). In view of these intriguing observations, a reliable colorimetric method with a simple mixing and detection strategy is developed for the detection of GSH. The linear range of GSH detection is 1–36 μM. The detection limit of GSH reaches a low level of 0.495 μM (3σ/slope). The GSH sensing system also exhibits excellent specificity and anti-interference. Taking advantage of the advantages of the Sb-FeOCl nanorod-based biosensor, it can be used to quantitatively detect GSH levels in human serum. It can be anticipated that the Sb-FeOCl nanorods have broad prospects in the field of enzymatic biochemical reactions. [ABSTRACT FROM AUTHOR]

Phase change cold storage, as an emerging cold chain method of maintaining a low-temperature environment and effectively ensuring the quality of biochemical reagents, is extensively utilized because of its benefits of high energy density, low cost, energy conservation and environmentally friendly mode. However, the low thermal conductivity of working medium affects its cold charging/discharging rate and operating efficiency. Meanwhile, the high leakage characteristic in the phase change process leads to a decrease of cold storage capacity and contamination of items. This work proposes the efficient utilization of cold energy enabled by leakage-free phase change cold storage brine gels with extraordinary high thermal conductivity towards biochemical reagent cold chain. Phase change thermal storage gel is prepared by confining brine in the sodium polyacrylate‑calcium alginate network and porous adsorption of expanded graphite. The prepared materials present leak free characteristics and almost 100% mass retention rate. Expanded graphite addition enables the thermal conductivity increase from 0.542 W m−1 K−1 to an extremely high value of 2.766 W m−1 K−1 (an increase of 510%). The enthalpy value of the cold storage brine gel is as high as 144 Jg−1, stably releasing cold at around −24 °C. By regulating the distribution of cold storage working medium, the minimum temperature difference inside the apparatus can be reduced from 6.7 °C to about 1 °C. Finally, performance-enhancing phase change cold storage materials and apparatus in the cold chain of biological reagents is fruitful, effectively providing a long-lasting and uniform low-temperature environment. • Porous medium adsorption and chemical crosslinking are used to fabricate phase change cold storage brine gels. • The brine gels possess a high thermal conductivity of 2.766Wm-1K-1 and a high latent heat of 144 Jg-1. • A novel method for achieving temperature uniformity in the cold storage equipment is proposed. • The assembled cold storage equipment is successfully applied in the biochemical reagents cold chain to ensure the quality. [ABSTRACT FROM AUTHOR]

The deterioration of climate exacerbates the freshwater crisis. Solar-thermal interfacial evaporation, using sunlight as a driving energy source, is a promising approach to provide an effective solution to freshwater shortages. However, the low energy conversion efficiency and expensive evaporator manufacturing are still to be resolved. Herein, a strategy of clean water harvesting by solar-absorbing germanium@k-carrageenan (Ge@CA) evaporator demonstrating superior energy conversion is proposed. The Ge nanoparticles exhibit a significant solar absorption of 92.33% to achieve efficient solar-thermal conversion. The CA hydrogel provides three-dimensional water transmission channels to the evaporating surface. Meanwhile, the Ge nanoparticles can be fabricated by a facile ball-milling method. The CA as a cheap biomass can be easily interacted with KCl to obtain the porous hydrogel. Taking the advantages of Ge nanoparticles and CA hydrogel, the Janus-type Ge@CA hydrogel evaporator can achieve an evaporation rate of 2.88 kg m−2·h−1 and a solar-vapor conversion efficiency of 82.65% under 1 sun irradiation. Furthermore, the evaporator can produce thermoelectricity with the output voltage of 140.95 mV and the short-circuit current of 13.32 mA, yielding a power of 1.17 W m−2. This reported solar device has huge potential for cutting-edge solar harvesting and usage. Solar-absorbing Ge nanoparticles@K-carrageenan hydrogel demonstrating superior solar absorbance and high solar energy efficiency are applied in robust solar-thermal water harvesting and power generation. [Display omitted] • Ge nanoparticles with excellent solar absorption capacity are synthetized by ball milling. • A novel solar evaporator is constructed by coating Ge nanoparticles on a biomass hydrogel. • The Janus type solar evaporator can effectively produce clean water and reject the salts. [ABSTRACT FROM AUTHOR]

In the past decades, it has been debated whether ecological niche should be conserved among closely related species (phylogenetic niche conservatism, PNC) or largely divergent (traditional ecological niche theory and ecological speciation) and whether niche specialist and generalist might remain in equilibrium or niche generalist could not appear. In this study, we employed morphological traits to describe ecological niche and test whether different niche dimensions exhibit disparate evolutionary patterns. We conducted our analysis on three Rhinogobio fish species ( R. typus, R. cylindricus, and R. ventralis) from the upper Yangtze River, China. Among the 32 measured morphological traits except body length, PCA extracted the first four principal components with their loading scores >1.000. To find the PNC among species, Mantel tests were conducted with the Euclidean distances calculated from the four principal components (representing different niche dimensions) against the pairwise distances calculated from mitochondrial cytochrome b sequence variations. The results showed that the second and the third niche dimension, both related to swimming ability and behavior, exhibited phylogenetic conservatism. Further comparison on niche breadth among these three species revealed that the fourth dimension of R. typus showed the greatest width, indicating that this dimension exhibited niche generalism. In conclusion, our results suggested that different niche dimensions could show different evolutionary dynamic patterns: they may exhibit PNC or not, and some dimensions may evolve generalism. [ABSTRACT FROM AUTHOR]

A reliable chromatographic strategy is crucial for the extraction of target compounds from natural sources as it is related to the preparation efficiency, as well as the purity of the compounds. In this study, medium-pressure normal-phase liquid chromatography and high-pressure reverse-phase liquid chromatography were combined to prepare and purify ergosterol from Tulasnellaceae sp. of Gymnadenia orchidis. First, Tulasnellaceae sp. was extracted three times (2.0 L and 2 h each time) with ethyl acetate, and the 6.0 L of extract solution was concentrated under reduced pressure to yield 2.2 g of crude sample. Then, the crude sample was pretreated utilizing silica gel medium-pressure liquid chromatography to enrich the target ingredient (586.0 mg). Finally, high-pressure reversed-phase liquid chromatography was used to purify the target compound, and the compound was characterized as ergosterol (purity > 95%) using spectral data. Overall, the simple and reproducible integrated chromatographic strategy developed in this study has the potential for the large-scale purification of steroids for laboratory and even industrial research. To the best of our knowledge, this is also the first report of ergosterol in Tulasnellaceae sp. [ABSTRACT FROM AUTHOR]

• A ternary PCMGs consisting of octadecanol, SEBS and hydroxylated carbon nanotubes are proposed. • PCMGs present excellent flexibility, improved form-stability and high biocompatibility. • PCMGs possess high thermal energy storage capacity, high solar absorbance and high cost-effectiveness. • PCMGs are utilized for thermoelectric power generation and personal thermal management. The utilization of renewable biomass and the conversion of renewable energy are promising strategies for providing clean energy and meeting energy needs. In this work, a ternary phase change material gels (PCMGs) composed of octadecanol (OD), styrene-ethylene-butylene-styrene (SEBS) and hydroxylated carbon nanotubes (HCNTs) are proposed to realize the biomass utilization and solar energy harvesting. As a kind of biomass, OD possesses the characteristics of high phase change latent heat, low cost, renewability, environmental friendliness and biosafety. SEBS provides the crosslinked network to load the OD and introduce the free-standing feature. The HCNTs can realize the highly-efficient solar harvesting through the solar-thermal conversion. The Van der Waals force between SEBS and OD, the π-π interaction between SEBS and HCNTs and the hydrogen bond between OD and HCNTs enable the excellent form-stability. Taking advantages of the synergistic effect of the functional components, the proposed biomass-based PCMGs demonstrate high thermal energy storage capacity of 183.04 Jg−1, high solar absorbance of 95.68%, high cost-effectiveness of 3.92 × 10-5$J−1 and high cell viability of 117.9%. The biomass-based PCMGs are effectively applied in the thermoelectric power generation and personal thermal management. This work creates a state-of-the-art alternative for the next-generation solar-thermal materials devices. [ABSTRACT FROM AUTHOR]

Ascorbic acid (AA) is a powerful antioxidant in food safety and disease treatment. It is of great significance to develop a low-cost, high-stability, and easy-to-operate colorimetric method for quantitative detection of AA in food or human body. Although various nanozymes have been developed for the colorimetric detection of AA, the size regulation of the catalytic center of nanozymes remains a challenge. In this work, we propose a combined strategy of flow chemistry synthesis and pyrolysis to realize the controllable adjustment of the catalytic center size of nanozymes. Zinc-cobalt zeolitic imidazole frameworks (ZnCo-ZIFs) with different sizes are synthesized by flow chemistry. Nitrogen-doped carbon materials with different Co catalytic centers (80 nm–10 nm) are then obtained by pyrolysis of ZnCo-ZIFs precursors. Among them, cobalt quantum dot embedded nitrogen-doped carbon (Co QDs/N-C) exhibits excellent oxidase activity, with V max and K m of 4.19 × 10−7 M s−1 and 0.12 mM. Therefore, a simple, low-cost, and stable colorimetric method for the detection of AA is established with a good linear relationship (3–500 μM) and low detection limit (0.40 μM). This work has certain guiding significance for the size regulation of catalytic center of nanozyme, and the detection method has broad application prospects in biochemical sensing field. • This work proposes a synthesis strategy that combines flow chemistry and pyrolysis. • The Co QDs/N-C with excellent oxidase activity is synthesized by above strategy. • The Michaelis-Menten constant of Co QDs/N-C for TMB is as low as 0.12 mM. • A sensing platform based on Co QDs/N-C nanozyme is developed for the detection of AA, with a LOD 0.40 μM. [ABSTRACT FROM AUTHOR]

The existence of pesticide residues in the hydrosphere, biosphere, and anthroposphere can cause acute or chronic diseases and deteriorate the environment. Therefore, efficient detection of pesticide residues is of great significance to prevent food poisoning, control food pollution, and protect human lives by recognizing their distribution and concentration. Herein, a novel smartphone-coupled three-layered paper-based microfluidic chip is proposed as a facile platform to detect the pesticides. The stereoscopic capillary-driven fluid transport is enabled by the three-layered microfluidic chip configuration. The detection mechanism is based on the enzyme inhibition reaction and the chromatic reaction. The detection results are obtained by a smartphone and figured out by colorimetric quantitative analysis. Taking advantages of the above merits, we demonstrate the utilization of this smartphone-coupled three-layered paper-based microfluidic chip for the effective analysis of typical pesticides (profenofo and methomyl). The linear ranges of profenofo and methomyl are 0.27–2.1 μmol L−1 and 0.14–1.85 μmol L−1, respectively. The corresponding limits of detection in the chips are 55 nM and 34 nM, respectively. The paper-based chips are also highly cost-effective with a total cost of 0.082 ¥ per piece. It can be anticipated that this technique will open new avenues for the mass fabrication of paper-based microfluidic chips and provide state-of-the-art methods in the field of analytical chemistry. [ABSTRACT FROM AUTHOR]

Thermal conductive composite materials (TCCMs) applied in the thermal management are of ever-rising significance with the rapid development of a variety of thermal-related industrial products. Previously, the demand for TCCMs with differential thermal conductivity is generally met by using two strategies, tuning the material composition and designing the composite microstructure. However, the miscibility between different components is usually poor, resulting in the uniformity of thermal conductivity of TCCMs. In this work, the flexible reduced graphene oxide@calcium alginate (RGO@CA) composite fibers are fabricated by wet spinning of the lyotropic graphene oxide composite liquid crystals and wet chemical reduction. The resulted RGO@CA composite fibers exhibit high tensile strength of about 200 MPa. The graded utilization of the waste heat can be realized by using RGO@CA composite fibers with different compositions. The displayed utilizations of the waste heat include thermal energy storage, optical sensor, thermal source for chemical reaction. The proposed liquid crystal spinning demonstrates a novel strategy for developing advanced materials toward the thermal management and waste heat recovery of electronic devices and systems. [ABSTRACT FROM AUTHOR]

• 4 locomotor groups and 4 trophic groups were classified in the Anning River. • Environmental variables, taxonomic and functional groups exhibited significant changes with respect to the DFH. • Spatial changes in taxonomic and functional groups along the river were primarily due to turnover processes. • The influence of landscape features on functional organizations was more significant compared to local habitat variables. To investigate the longitudinal gradient patterns and the factors influencing fish taxonomic and functional groups, a survey involving 28 sampling sites was conducted in the Anning River in November 2020 and April 2021. A total of 60 fish species were collected, and these species were classified into 4 locomotor groups and 4 trophic groups, resulting in 11 combined functional groups based on locomotor and trophic characteristics. The results of two-way cross similarity analysis (ANOSIM) revealed significant changes in both the fish taxonomic and functional groups along the longitudinal gradient, while no significant seasonal variation was observed in either group. Spatial changes in taxonomic and functional groups along the river were primarily due to turnover processes, as indicated by the similarity percentage analysis. Variance partitioning analysis demonstrated that local habitat conditions and land use/cover explained 37.56% and 41.33% of the spatial variation in taxonomic and functional organizations, respectively. Notably, the influence of landscape features on taxonomic organization was less significant than that of local habitat variables. Nevertheless, landscape conditions played a more important role than local environmental factors in explaining variations associated with functional organization. Our study helps in understanding the spatial patterns and formation mechanisms of taxonomic and functional groups driven by multiple-scale environmental factors in mountain rivers. In addition, our results showed that the response of functional groups to different scale environmental factors differ from taxonomic groups. [ABSTRACT FROM AUTHOR]

Microencapsulated phase change materials (MEPCMs) have been widely used in many fields as thermal energy storage materials. This study reported a novel MEPCM with the functions of thermal energy storage, photothermal conversion, ultraviolet (UV) shielding, and superhydrophobicity, which was particularly suitable for intelligent textiles. The microcapsules based on an n-eicosane core and a CuO-doped polyurea shell with hierarchical structure were fabricated through a one-step interfacial polymerization. The morphology of the capsules and the hierarchical shell structure were identified through scanning and transmission electron microscopy. Thermal analysis indicated that the microcapsules had a high latent heat of 162.3 J/g and demonstrated a high thermal reliability. These microcapsules achieved a good photothermal conversion capability and can reduce UV radiation by approximately 30%. The water contact angle of the MEPCM was over 148° and showed a good superhydrophobic property. Cotton fabric coated with the prepared MEPCM was investigated. Results showed that it achieved a high phase change enthalpy of 36.8 J/g, an effective thermoregulation capability, and a large contact angle of 141.6°. [ABSTRACT FROM AUTHOR]

α-zirconium phosphate (α-ZrP) nanocrystals with surface active groups and layered structure have been widely used in radionuclide removal, proton conductors, chemical sensors, flame retardant and corrosion-resistant materials. The previous synthesis of α-ZrP nanocrystals is time-consuming and lack of controllability. Herein, a multifactor-regulated fast synthesis strategy in a microwave reactor is proposed to realize the fast and controllable production of the high-quality α-ZrP nanocrystals. Compared with the conventional hydrothermal synthesis, the reaction time has been reduced from 24 h to 15 min. The degree of crystallinity, the morphology, the lateral size and the thickness can be controlled by adjusting the reaction parameters. Results demonstrate that the obtained α-ZrP nanocrystals possess good crystallinity, disk morphology, abundant active functional groups, superior thermal stability and strippable layered structure. Furthermore, the α-ZrP nanocrystals synthesized by the microwave-assisted multifactor-regulated method as environmentally friendly carriers possess better pesticide adsorption efficiency than those synthesized by the conventional hydrothermal synthesis as the result of the smaller size and more exposed adsorption sites. It is envisioned that the multifactor-regulated synthesis in a microwave reactor provides a more efficient and energy-saving alternative to synthesize high-quality nanocrystals and broaden their application in chemical engineering. [ABSTRACT FROM AUTHOR]

• A method was developed for preparing D-mannitol@silica/graphene oxide nanocapsules. • Graphene oxide incorporation had little effect on latent heat of the nanocapsules. • The thermal stability of the nanocapsules was enhanced. • The thermal reliability index was 96.1% after repeated thermal cycling. • The thermal conductivity was increased to 129% through nanoencapsulation. Sugar alcohols have considerable potential for usage in medium-temperature thermal energy storage applications; however, they suffer from poor thermal reliability and low thermal conductivity. Nanoencapsulation is an effective approach to improve the thermal energy storage performance of the phase-change materials. Until now, nanoencapsulation of sugar alcohols with a high phase-change performance has been rarely reported. The objective of this study is to develop a method for the nanoencapsulation of sugar alcohols with an enhanced phase-change performance. D-mannitol nanocapsules with a silica–graphene oxide composite shell were synthesized and investigated to demonstrate the validity of this novel method. The morphology, size distribution, and core–shell microstructure of the nanocapsules were observed using a scanning electron microscope, particle size and zeta potential analyzer, and transmission electron microscope. In addition, the phase-change performance of the nanocapsules was studied using a differential scanning calorimeter, a thermogravimetric analyzer, and weight loss and appearance investigation. The results demonstrate that the melting and solidifying latent heat of the nanocapsules are 216.7 and 174.4 kJ/kg, respectively. The energy storage efficiency of the nanocapsules was 75.8% and its 96.1% was maintained after repeated thermal cycling. Compared with pure D-mannitol, the thermal conductivity of the nanocapsules was observed to increase by up to 128.6%. The novel nanocapsules exhibited good medium-temperature thermal energy storage prospects. [ABSTRACT FROM AUTHOR]

Sugar alcohols with high latent heat have great potential for medium temperature thermal energy storage. Micro/nano-encapsulation can effectively improve the performance of phase change materials (PCMs), such as avoiding leakage and enhancing thermophysical properties. However, only a few work have been reported on the microencapsulation of sugar alcohol, and the reported methods showed some drawbacks such as requiring strictly controlled reactions or resulting in disability for the capsules to solidify. This paper reports for the first time the synthesis and properties of nanocapsules of a sugar alcohol D-mannitol (DM) by a facile sol-gel method. The nanoencapsulation was confirmed by various characterization using Fourier transformation infrared spectroscope (FT-IR), X-ray diffractometer (XRD), and transmission electron microscope (TEM). Uniform size distribution of the nanoencapsulated DM (NEDM) in 100–200 nm was observed by scanning electron microscope (SEM). The phase change performance of the NEDMs were investigated by differential scanning calorimeter (DSC). The results show that the NEDMs with a melting temperature of 166.2 °C, a melting enthalpy of 220.3 J/g, and an encapsulation ratio of 76.5% were obtained. The thermal reliability of the NEDMs was demonstrated by thermal cycling experiments. The thermal stability of the NEDMs was enhanced compared to DM as investigated by thermogravimetric analyzer (TGA). The NEDMs exhibited great potential for applications in medium temperature thermal energy storage and transfer. • A facile method for nanoencapsulation of D-mannitol was developed. • Nanocapsules with uniform size distribution in 100–200 nm were obtained. • Melting enthalpy of the nanocapsules was up to 220.3 kJ/kg. • The nanocapsules exhibited improved phase change performance and thermal stability. [ABSTRACT FROM AUTHOR]

Silymarin extracted from milk thistle seeds, is used for treating hepatic diseases. Silybin and isosilybin are its main components, and synthesized from coupling of taxifolin and coniferyl alcohol. Here, the biosynthetic pathways of taxifolin and coniferyl alcohol were reconstructed in Saccharomyces cerevisiae for the first time. To alleviate substantial burden caused by a great deal of genetic manipulation, expression of the enzymes (e.g. ZWF1, TYR1 and ARO8) playing multiple roles in the relevant biosynthetic pathways was selectively optimized. The strain YT1035 overexpressing seven heterologous enzymes and five native enzymes and the strain YC1053 overexpressing seven heterologous enzymes and four native enzymes, respectively produce 336.8 mg/L taxifolin and 201.1 mg/L coniferyl alcohol. Silybin and isosilybin are synthesized from taxifolin and coniferyl alcohol under catalysis of APX1t (the truncated milk thistle peroxidase), with a yield of 62.5%. This study demonstrates an approach for producing silybin and isosilybin from glucose for the first time. • Yeast was engineered for producing taxifolin and coniferyl alcohol, respectively. • A total of 21 exogenous genes were tested in yeast. • Overexpression of the native genes with dual roles dramatically enhanced the titers. • Taxifolin and coniferyl alcohol were rapidly purified by a green process. • Silybin and isosilybin were synthesized by enzymatic catalysis. [ABSTRACT FROM AUTHOR]

• Fusion of ERG20 and its mutant mERG20 significantly boosted diterpenoid production. • The yeasts were achieved for producing nor -, syn - and ent -copalyl diphosphate. • A yeast-based platform was built for characterizing all types of diterpene synthases. Yeast has been widely used for large-scale production of terpenoids. In yeast, modifications of terpenoid biosynthetic pathways have been intensively studied. tHMG1 (encoding the catalytic domain of 3-hydroxy-3-methylglutaryl coenzyme A reductase of yeast) and UPC2-1 (the G888D mutant of UPC2 encoding a transcription factor) were integrated into yeast chromosome, and ERG9 (the squalene synthase gene of yeast) was knocked down to yield the chassis strain DH02. A F96C mutation in ERG20 (farnesyl diphosphate synthase of yeast) was conducted to obtain mERG20 which can function as a geranylgeranyl diphosphate synthase (GGPS). Then, three fused genes, including BTS1 (the yeast innate GGPS) -ERG20 , ERG20-mERG20 and mERG20-ERG20 , were constructed, and expressed either by the pESC-based plasmids in DH02, or by being integrated into DH02 chromosome. The highest geranylgeraniol (GGOH) content was observed in the extracts of DH12 integrated with ERG20-mERG20 , corresponding to 3.2 and 2.3 folds of those of the strains integrated with BTS1 and mERG20 , respectively. Finally, three genes encoding nor -copalyl diphosphate synthase (nor -CPS), ent -CPS and syn -CPS were integrated into the chromosome of DH12, respectively, to construct yeasts for producing corresponding copalyl diphosphates (CPPs). Thus, a yeast-based platform was built for characterizing all types of diterpene synthases using GGPP or various CPPs as their substrates. [ABSTRACT FROM AUTHOR]

We established a two‐dimensional strong cation exchange/reversed‐phase liquid chromatography protocol to isolate and purify isoquinoline alkaloids from Corydalis impatiens. Isoquinoline alkaloids were first enriched from a C. impatiens extract in which liposoluble components were removed using a medium‐pressure chromatographic tower containing middle chromatogram isolated gel. A strong cation exchange column was employed to separate and obtain 30 fractions. We chose fractions 22–29 for reversed‐phase liquid chromatography purification using characteristic isoquinoline alkaloid ultraviolet absorption spectra. Several isoquinoline alkaloid fractions (22–29) were further separated, and those of low resolution were isolated via two‐dimensional liquid chromatography in the orthogonal plane. A total of eight novel isoquinoline alkaloids with characteristic ultraviolet spectra were obtained from C. impatiens. We thus demonstrate the benefits of off‐line two‐dimensional strong cation exchange/reversed‐phase liquid chromatography to isolate isoquinoline alkaloids from C. impatiens. [ABSTRACT FROM AUTHOR]