Search

Over recent decades, Chinese giant salamanders Andrias spp. have declined dramatically across much of their range. Overexploitation and habitat degradation have been widely cited as the cause of these declines. To investigate the relative contribution of each of these factors in driving the declines, we carried out standardized ecological and questionnaire surveys at 98 sites across the range of giant salamanders in China. We did not find any statistically significant differences between water parameters (temperature, dissolved oxygen, ammonia, nitrite, nitrate, salinity, alkalinity, hardness and flow rate) recorded at sites where giant salamanders were detected by survey teams and/or had been recently seen by local respondents, and sites where they were not detected and/or from which they had recently been extirpated. Additionally, we found direct and indirect evidence that the extraction of giant salamanders from the wild is ongoing, including within protected areas. Our results support the hypothesis that the decline of giant salamanders across China has been primarily driven by overexploitation. Data on water parameters may be informative for the establishment of conservation breeding programmes, an initiative recommended for the conservation of these species.

The CuO–La2O3/ZrO2 catalysts calcined at different temperatures from 500 to 800 °C were studied for the hydrogenation of oxalates to ethylene glycol (EG). Along with the increase of calcination temperatures, the BET surface area, pore volume, and Cu dispersion decreased, whereas the crystallite sizes of Cu species increased. Interestingly, the superior performance such as a 98% selectivity of EG in dimethyl oxalate hydrogenation or a 96.5% selectivity of EG in diethyl oxalate hydrogenation was obtained over the catalyst calcined at 700 °C. Essentially, the surface synergism between Cu species and monoclinic ZrO2 was enhanced by the higher calcination temperature, resulting in the remarkable surface adsorption and activation of H2. Besides, the increase of calcination temperature significantly reduced the surface acidity and basicity, which could effectively suppress the byproduct formation.

Right here, flower-like FeMoO

Objectives: Swamp eel is one model species for sexual reversion and an aquaculture fish in China. One local strain with deep yellow and big spots of Monopterus albus has been selected for consecutive selective breeding. The objectives of this study were characterizing the Simple Sequence Repeats (SSRs) of M. albus in the assembled genome obtained recently, and developing polymorphic SSRs for future breeding programs. Methods: The genome wide SSRs were mined by using MISA software, and their types and genomic distribution patterns were investigated. Based on the available flanking sequences, primer pairs were batched developed, and Polymorphic SSRs were identified by using Polymorphic SSR Retrieval tool. The obtained polymorphic SSRs were validated by using e-PCR and capillary electrophoresis, then they were used to investigate genetic diversity of one breeding population. Results: A total of 364,802 SSRs were identified in assembled M. albus genome. The total length, density and frequency of SSRs were 8,204,641 bp, 10,259 bp/Mb, and 456.16 loci/Mb, respectively. Mononucleotide repeats were predominant among SSRs (33.33%), and AC and AAT repeats were the most abundant di- and tri-nucleotide repeats motifs. A total of 287,189 primer pairs were designed, and a high-density physical map was constructed (359.11 markers per Mb). A total of 871 polymorphic SSRs were identified, and 38 SSRs of 101 randomly selected ones were validated by using e-PCR and capillary electrophoresis. Using these 38 polymorphic SSRs, 201 alleles were detected and genetic diversity level (Na, PIC, HO, and He) was evaluated. Conclusions: The genome-wide SSRs and newly developed SSR markers will provide a useful tool for genetic mapping, diversity analysis studies in swamp eel in the future. The high level of genetic diversity (Na = 5.29, PIC = 0.5068, HO = 0.4665, He = 0.5525) but excess of homozygotes ( FIS = 0.155) in one breeding population provide baseline information for future breeding program.

In this study, a new fluorinated methacrylamide (MACF) was synthesized and evaluated as an adsorbent in the dispersive solid-phase extraction for the effective determination and extraction of 20 organophosphorus pesticides (OPPs) from ginseng samples using the QuEChERS (quick, easy, cheap, effective, rugged, safe) method coupled with GC-MS/MS. The properties of MACF were characterized using Fourier-transform infrared spectroscopy, elemental analysis, and high-resolution 19 F NMR. MACF, chitosan, primary and secondary amine, octadecylsilane, graphitized carbon black, Z-Sep, Z-Sep+ , and EMR-Lipid were compared in terms of extraction efficiency. The best results were obtained when MACF was used. Matrix-matched calibration was employed for quantification. All the OPPs exhibited good linearity (r2 > 0.9969) with the concentration at their respective concentration ranges. The limits of detection were 1.5-3.0 μg/kg, and the limits of quantification were 5.0-10.0 μg/kg. The trueness of the 20 pesticides at four spiked levels ranged from 86.1 to 111.1%, and the relative standard deviation was less than 11.3%. The modified QuEChERS method using MACF as the adsorbent was sensitive, reliable, and cost-effective and could be used for the determination of 20 OPP residues in ginseng.

Using ethylene glycol as solvent and PVP as structure-directing agent, CuFe2O4 nanospheres were successfully prepared by solvothermal method. The crystal structure, morphology, magnetic properties, and pore-size distribution of samples were characterized by using X-ray diffraction, scanning electron microscope, transmission electron microscope, VSM, and BET, respectively. The effects of various preparation factors on the crystal form and morphology of the obtained samples were systematically discussed. The result exhibited that the self-assembled hollow nanospheres with good crystal form and morphology are obtained under the conditions of 0.50 g PVP, 9 mmol NaAc, reaction temperature of 180 °C, and reaction time of 24 h. The catalytic activity of CuFe2O4 hollow nanospheres was evaluated by the degradation of methylene blue (MB) and the possible degradation mechanism and pathway of MB in the CuFe2O4/H2O2 photo-Fenton-like system were proposed. In addition, the properties of CuFe2O4 particles prepared by different methods were compared and analyzed. The sample synthesized by solvothermal method has a large specific surface area and excellent magnetic properties. Furthermore, the increase in the photoelectric response and the conductivity are beneficial to the improvement of catalytic performance.

Currently, we lack a clear understanding of how climate influences the responses of soil organic carbon (OC) and nitrogen (N) to land-use changes in semiarid regions. Thus, to clarify the mechanism...

Andrias davidianus is one of most farmed amphibians owing to its palatability and nutritional value. In this transitional group between aquatic and terrestrial animals the effects of temperature and sex hormones on sex ratio and growth are not fully understood. Here, we quantified the sex dimorphism of A. davidianus growth with adult males approximately 30% larger than females, and for the first time determined the time of initiation of sex differentiation to be ~98 days post-hatching (dph). Mortality increased significantly with increased temperature, from 9.4% at 20°C to 40.6% at 28°C. At temperatures ≥30°C we observed 100% mortality. The proportion of males was 66.1% at 28°C, significantly higher than in the control group (p < 0.05). 17α-estradiol induced larval feminization and produced female bias of 81-100% at concentrations from 25 µg l-1 to 1000 µg l-1. However, sex bias was not observed in larvae exposed to 17α-methyltestosterone at concentrations of 50 µg l-1 and 100 µg l-1. Additionally, growth characteristics at different temperatures showed that 28°C inhibited growth and 24°C promoted growth, reflecting the expression profile of growth-related genes (GH, GHR, and IGF-1). Sex steroids including 17β-estradiol and 17α-methyltestosterone significantly inhibited growth (p < 0.05). The results suggest that water temperature and sex steroids play a vital role in gonad differentiation and growth of A. davidianus.

Homogeneous hollow CuO–ZnO–Al2O3 microspheres, which were synthesised, used carbonaceous saccharide as a template by the hydrothermal treatment at 180°C. The hollow microspheres structure of composite metal oxides was characterised by the methods of X-ray powder diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy and N2 adsorption–desorption isothermal. In the evaluation of the hydrogenation of carbon dioxide, the synthesised hollow CuO/ZnO/Al2O3 composite microspheres exhibited higher selectivity and yield of methanol than CuO/ZnO/Al2O3 prepared by a co-precipitation method. An optimum yield of methanol of 15.3% with the 24.7% CO2 per pass conversion was obtained under the reaction conditions of pressure at 3.0 MPa, space velocity at 1800 ml gcat −1 h−1, the volume ratio of CO2/H2 at 1:3 and temperature at 262°C.

Background Chinese giant salamander Andrias davidianus is an endangered species. The success of artificial breeding provides a useful way to protect this species. However, the method to identify the sex and mechanism of sex determination were unclear which hinder the improvement of the artificial breeding. Detection of a sex specific marker provides an effective approach to identify genetic sex and investigate the sex determination mechanism. Results We used restriction-site-associated DNA (RAD) sequencing to isolate a sex-specific genetic marker in A. davidianus to expand knowledge of the sex determination mechanism. Four male and four female specimens were subjected to RAD sequencing, which generated 934,072,989 reads containing approximately 134.4 Gb of sequences. The first round of comparison of the assembled sequence against the opposite sex raw reads revealed 19,097 female and 17,994 male unmatched sequences. Subsequently, 19,097 female sequences were subjected to a BLAST search against male genomic data, which revealed 308 sequences unmapped to the male genome. One hundred of these were randomly selected and validated by PCR in five male and five female specimens, and four putative sex-specific sequences were produced. Further validation was performed by PCR in another 24 females and 24 males, and all female individuals exhibited the expected specific bands, while the males did not. To apply the sex-specific marker, three specimens reversed from genetic female to physiological male were found in a group exposed to elevated temperature, and 13 individuals reversed from genetic male to physiological female were obtained in a 17β-estradiol exposed group. Conclusion This is the first report of a sex-specific marker in A. davidianus and may have potential for elucidation of its sex determination mechanism and, hence, its conservation. Electronic supplementary material The online version of this article (10.1186/s12864-019-5771-5) contains supplementary material, which is available to authorized users.

Oily wastewater treatment has attracted the attention of many researchers. The development of high efficiency and green emulsified oil/water separation materials is urgent. In this paper, inspired by nature, the wood slice with superhydrophobic/superoleophilic property was prepared successfully via a simple vacuum impregnation and surface modification process. The superhydrophobic wood slice possesses outstanding separation capability with separation efficiency higher than 98.0% for a series of water-in-oil emulsions. More importantly, the separation efficiency of the superhydrophobic wood slice was still greater than 98.0% after 6 cycles, indicating that the superhydrophobic wood slice had excellent recyclability. In addition, wood is an abundant, low-cost, readily processed, biodegradable and environmentally friendly materials. Therefore, we believe that such a simple, low-cost, high-efficiency, and large-scale preparation method has great potential for solve the pollution problems caused by oily industrial wastewater in the practical application.

Wt1 and StAR are two multifunctional genes that play an important role in sexual differentiation, especially in development of testicles and spermatogenesis, but the studies of amphibians are rare. In this study, we have cloned and characterized the complete cDNA of Wt1 and StAR in Andrias davidianus. The Wt1 has two isoforms, encoding 416 aa or 419 aa protein with a conserved zinc finger structure region. The StAR encodes 287 aa protein with a conserved domain containing putative lipid binding sites. The two genes showed high homology among amphibians by phylogenetic analysis. Molecular evolution analysis indicated that Wt1 gene underwent positive selection, while StAR gene showed no positive selection. Tissue expression patterns revealed that Wt1 expression was higher in liver, moderate in testis and kidney, low in the rest of the tissues, while StAR expression was higher in testis, moderate in kidney and brain, low in the rest of the tissues. Moreover, compared to female and reversal-female, Wt1 and StAR both showed higher expression level in male and reversal-male. Our results suggest the important role of Wt1 and StAR in sexual development of Andrias davidianus, and also provide information for functional study of amphibian Wt1 and StAR.

Background: Chinese giant salamander Andrias davidianus is called “baby fish” in China. Due to its palatability and nutritional value, it was widely cultured in China. The current study was to evaluate the genetic diversity of the farmed A. davidianus. Methods: 30 salamanders were collected from farm and DNA was extracted. Thirty contigs potentially containing SNPs were selected from the previously developed RAD-seq library. The primer was designed and PCR was performed, than the products was sequenced from different direction. At last the sequences were analyzed using the vector NTI 10.Result: 5824bp high-quality sequences embodied in 16 contigs were sequenced and eighty SNP loci were identified which each SNP locus exhibited bi-alleles. The effective allele number from 1.03 to 2.00 and the minor allele frequency was 0.017 to 0.500. The expected heterozygosity was from 0.0333 to 0.5091 and the observed heterozygosity was 0.0333 to 1.0000. Sixty-six of the 80 loci significantly deviated from the Hardy-Weinberg equilibrium (P less than 0.05). The results provide useful genomic resources to evaluate the genetic diversity of A. davidianus for conservation and aquaculture.

To understand the relationship between the catalytic performance, crystallite size, and acidity of SAPO-34 zeolites better, a series of SAPO-34 zeolites were prepared by hydrothermal crystallization using palygorskite as silicon and partial aluminum source, and selecting two kinds of triethylamine, morpholine and tetraethylammonium hydroxide as dual templates. The obtained SAPO-34 zeolites were characterized via the methods of XRD, SEM, N2-adsorption–desorption, NH3-TPD, FTIR, XRF, 29Si MAS NMR, 27Al MAS NMR and TG. The properties of the templates affected the crystal growth rate that triethylamine and morpholine can cause a larger crystallite size while tetraethylammonium hydroxide can form small crystallite size particles. The number of acid sites of SAPO-34 zeolites first decreased and then increased with the increase of morpholine. The formation of Si islands can enhance the number of acid sites of SAPO-34 zeolites. The catalytic performance of SAPO-34 zeolites in methanol-to-olefins (MTO) reaction was investigated in a fixed bed reactor. Under reaction conditions, when the reaction temperature was 400 °C, the feed WHSV was 2.0 h−1, the mass of the catalyst was 0.5 g, at atmospheric pressure, the sample with an amount of acid sites of 0.85 mmol g−1 and crystallite size of 0.84 μm exhibited the optimum catalytic performance with methanol conversion at 100%, light olefin selectivity at 97.15% and catalytic lifetime at more than 1050 min.

Company with global educational reform brought by digital governance and the challenge of COVID-19 pandemic in the year 2020, it is quite necessary to explore learners’ recognition behaviors for on-line learning in the context of locked environment. By investigating on-line learning practices in China eastern provincial regions, the study attempts to disclose the undergraduate students’ perceptions on the issues pertaining to on-line learning and the innate critical factors for individual intention through the selected region of relatively-developed eastern China. A survey design was used for the study, and a close- ended questionnaire with the six point Likert scale was developed regarding the issues over on-line learning practices. The findings indicate that instructor characteristics and teaching resources are the predictors of the perceived usefulness of on-line learning, and perceived usefulness coupled with the joyfulness are the predictors of on-line learning recognition. While statistically significant, perceived adaptability was shown to own the weakest effect for on-line learning recognition among the predictors. All these results are consistent with previous studies in other China regions, proving the universal trait of learners’ perception and individual behavior towards on-line learning. Implications and future research are discussed eventually.

In fish, sperm motility activation is one of the most essential procedures for fertilization. Previous studies have mainly focused on the external environmental effects and intracellular signals in sperm activation; however, little is known about the metabolic process of sperm motility activation in fish. In the present study, using ricefield eel (Monopterus albus) sperm as a model, metabonomics was used to analyze the metabolic mechanism of the sperm motility activation in fish. Firstly, 529 metabolites were identified in the sperm of ricefield eel, which were clustered into the organic acids, amino acids, nucleotides, benzene, and carbohydrates, respectively. Among them, the most abundant metabolites in sperm were L-phenylalanine, DL-leucine, L-leucine, lysolecithin choline 18:0, L-tryptophan, adenine, hypoxanthine, 7-Methylguanine, shikimic acid, and L-tyrosine. Secondly, compared to pre-activated sperm, the level of S-sulfo-L-cysteine and L-asparagine were both increased in the post-activated sperm. Ninety-two metabolites were decreased in the post-activated sperm, including quinic acid, acetylsalicylic acid, 7,8-dihydro L-biopterin, citric acid, glycylphenylalanine, and dihydrotachysterol (DHT). Finally, basing on the pathway analysis, we found that the changed metabolites in sperm motility activation were mainly clustered into energy metabolism and anti-oxidative stress. Fish sperm motility activation would be accompanied by the release of a large amount of energy, which might damage the genetic material of sperm. Thus, the anti-oxidative stress function is a critical process to maintain the normal physiological function of sperm.

In fish, sperm motility activation is one of the most essential procedures for fertilization. Previous studies have mainly focused on the external environmental effects and intracellular signals in sperm activation, however, little is known about the metabolic process of sperm motility activation in fish. In the present study, using ricefield eel (Monopterus albus) sperm as a model, metabonomics was used to analyze the metabolic mechanism of the sperm motility activation in fish. Firstly, 529 metabolites were identified in the sperm of ricefield eel, which were clustered into the organic acids, amino acids, nucleotides, benzene, and carbohydrates, respectively. Among them, the most abundant metabolites in sperm were L-phenylalanine, DL-leucine, L-leucine, lysolecithin choline 18:0, L-tryptophan, adenine, hypoxanthine, 7-Methylguanine, shikimic acid, and L-tyrosine. Secondly, compared to pre-activated sperm, the level of S-sulfo-L-cysteine and L-asparagine were both increased in the post-activated sperm. Ninety-two metabolites were decreased in the post-activated sperm, including quinic acid, acetylsalicylic acid, 7,8-dihydro L-biopterin, citric acid, glycylphenylalanine, and dihydrotachysterol (DHT). Finally, basing on the pathway analysis, we found that the changed metabolites in sperm motility activation were mainly clustered into energy metabolism and anti-oxidative stress. Fish sperm motility activation would be accompanied by the release of a large amount of energy, which might damage the genetic material of sperm. Thus, the anti-oxidative stress function is a critical process to maintain the normal physiological function of sperm.

Garlic and winter wheat are major economic and grain crops in China, and their boundaries have increased substantially in recent decades. Updated and accurate garlic and winter wheat maps are critical for assessing their impacts on society and the environment. Remote sensing imagery can be used to monitor spatial and temporal changes in croplands such as winter wheat and maize. However, to our knowledge, few studies are focusing on garlic area mapping. Here, we proposed a method for coupling active and passive satellite imagery for the identification of both garlic and winter wheat in Northern China. First, we used passive satellite imagery (Sentinel-2 and Landsat-8 images) to extract winter crops (garlic and winter wheat) with high accuracy. Second, we applied active satellite imagery (Sentinel-1 images) to distinguish garlic from winter wheat. Third, we generated a map of the garlic and winter wheat by coupling the above two classification results. For the evaluation of classification, the overall accuracy was 95.97%, with a kappa coefficient of 0.94 by eighteen validation quadrats (3 km by 3 km). The user’s and producer’s accuracies of garlic are 95.83% and 95.85%, respectively; and for the winter wheat, these two accuracies are 97.20% and 97.45%, respectively. This study provides a practical exploration of targeted crop identification in mixed planting areas using multisource remote sensing data.

Graphene oxide–supported β-cyclodextrin was prepared with graphene oxide and β-cyclodextrin as raw materials and epichlorohydrin as crosslinking agent, respectively. It was characterized by the methods of Raman spectroscopy, FT-IR, and SEM. The graphene oxide–supported β-cyclodextrin showed excellent adsorption performance for p-nitrophenol, and the absorption equilibrium can be achieved within 2 h. The adsorptive capacity is 117.28 mg/g at adsorption temperature of 313 K and pH at 8.0. Adsorption isotherms showed that the adsorption capacity increases with the increases of temperature and adsorption process could be better fitted by Langmuir isotherm (R2 > 0.995). Thermodynamic functions (ΔG, ΔH, and ΔS) investigation showed that the adsorption is spontaneous, endothermic, and random. The adsorption kinetics of p-nitrophenol over graphene oxide–supported β-cyclodextrin is conformed to a pseudo-second-order process. This study has suggested that the graphene oxide–supported β-cyclodextrin could play an efficient and beneficial source of the adsorbent for the purpose of eliminating p-nitrophenol from aqueous solution.

The swamp eel (Monopterus albus) is one economically important fish in China and South-Eastern Asia and a good model species to study sex inversion. There are different genetic lineages and multiple local strains of swamp eel in China, and one local strain of M. albus with deep yellow and big spots has been selected for consecutive selective breeding due to superiority in growth rate and fecundity. A high-quality reference genome of the swamp eel would be a very useful resource for future selective breeding program. In the present study, we applied PacBio single-molecule sequencing technique (SMRT) and the high-throughput chromosome conformation capture (Hi-C) technologies to assemble the M. albus genome. A 799 Mb genome was obtained with the contig N50 length of 2.4 Mb and scaffold N50 length of 67.24 Mb, indicating 110-fold and ∼31.87-fold improvement compared to the earlier released assembly (∼22.24 Kb and 2.11 Mb, respectively). Aided with Hi-C data, a total of 750 contigs were reliably assembled into 12 chromosomes. Using 22,373 protein-coding genes annotated here, the phylogenetic relationships of the swamp eel with other teleosts showed that swamp eel separated from the common ancestor of Zig-zag eel ∼49.9 million years ago, and 769 gene families were found expanded, which are mainly enriched in the immune system, sensory system, and transport and catabolism. This highly accurate, chromosome-level reference genome of M. albus obtained in this work will be used for the development of genome-scale selective breeding.

Accurately quantifying spatiotemporal changes in surface water is essential for water resources management, nevertheless, the dynamics of Poyang Lake surface water areas with high spatiotemporal resolution, as well as its responses to climate change, still face considerable uncertainties. Using the time series of Sentinel-1 images with 6- or 12-day intervals, the Sentinel-1 water index (SWI), and SWI-based water extraction model (SWIM) from 2015 to 2020 were used to document and study the short-term characteristics of southwest Poyang Lake surface water. The results showed that the overall accuracy of surface water area was satisfactory with an average of 91.92%, and the surface water area ranged from 129.06 km2 on 2 March 2017 to 1042.57 km2 on 17 July 2016, with significant intra- and inter-month variability. Within the 6-day interval, the maximum change of lake area was 233.42 km2 (i.e., increasing from 474.70 km2 up to 708.12 km2). We found that the correlation coefficient between the water area and the 45-day accumulated precipitation reached to 0.75 (p &lt, 0.001). Moreover, a prediction model was built to predict the water area based on climate records. These results highlight the significance of high spatiotemporal resolution mapping for surface water in the erratic southwest Poyang Lake under a changing climate. The automated water extraction algorithm proposed in this study has potential applications in delineating surface water dynamics at broad geographic scales.

Waste residue of Chinese prickly ash seeds were simply treated with aqueous ZnCl2 to prepared the high-performed activated carbon. It was characterized by the methods of XRD, SEM, EDX, FT-IR, BET a...

Early season crop identification is of great importance for monitoring crop growth and predicting yield for decision-makers and private sectors. As one of the largest producers of winter wheat worldwide, China outputs more than 18% of the global production of winter wheat. However, there are no distribution maps of winter wheat over a large spatial extent with high spatial resolution. In this study, we applied a phenology-based approach to distinguish winter wheat from other crops by comparing the similarity of the seasonal changes of satellite-based vegetation index over all croplands with a standard seasonal change derived from known winter wheat fields. Especially, this study examined the potential of early season large-area mapping of winter wheat and developed accurate winter wheat maps with 30 m spatial resolution for three years (2016–2018) over eleven provinces, which produce more than 98 % of the winter wheat in China. A comprehensive assessment based on survey samples revealed producer' and user' accuracies higher than 89.30 % and 90.59 %, respectively. The winter wheat map exhibited good correspondence with the agricultural census area data at the municipal and county levels. In addition, the earliest identifiable time of the geographical location of winter wheat was achieved by the end of March, giving a lead time of approximately three months before harvest, and the optimal identifiable time of winter wheat was at the end of April with an overall accuracy of 89.88 %. These results are expected to aid in the timely monitoring of crop conditions. The 30 m winter wheat maps in China are available via an open-data repository (DOI: http://doi.org/10.6084/m9.figshare.12003990, Dong et al., 2020).

In view of the large proportion of thin and poor layers in the weak-alkali ternary flooding block, the statistical analysis method is used to optimize the division of well groups with injection capacity, establish a strategy chart for different types of groups to maintain injection and tap potential, and optimize the well groups of different sand body connectivity types. The fracturing method strengthens the whole process of fracturing in the well area with poor injection capacity. The effective thickness water absorption ratio is over 80%, the maximum water cut reduction in the stage is 9.65%, the low water cut stable period is 16 months, and the recovery factor is increased by 8.77 percentage points. development effect.

Separation of emulsified oil/water mixtures has become an increasingly important topic worldwide. Superwetting materials offer a good platform for emulsified oil/water separation, whereas these materials can generally separate one type of emulsion. For controllable oil/water separation, switchable wetting materials have been adopted. However, the use of these materials is generally restricted by a variety of factors, such as stimuli-responsive molecules and continuous external stimuli. Herein, we reported an intelligent membrane for the controllable separation of oil/water emulsions, which exhibited high efficiency as a single-unit and did not require any continuous external stimuli. Combining nanoscale pores and the switchable wettability between underwater superoleophobicity and underoil (super)hydrophobicity, the controllable separation of oil­in­water and water­in­oil emulsions could be easily implemented by alternatively washing the membrane with ethanol and drying it. In addition, the as-obtained membrane still presented excellent separation efficiencies, above 99.0% after six cycles. Moreover, the as-prepared membrane exhibited outstanding mechanical properties and stability under various harsh conditions. The reported method could be used to prepare such membranes on a large-scale and could open up new prospects for manufacturing novel oil/water emulsions separating materials.

The Chinese giant salamander Andrias davidianus is a protected amphibian with high nutritional and economic value. Understanding its sex determination mechanism is important for improving culture techniques and sex control in breeding. However, little information on the characterization of critical genes involved in sex is available. Herein, sequencing of ovary and test produced 40,783,222 and 46,128,902 raw reads, respectively, which were jointly assembled into 80,497 unigenes. Of these, 36,609 unigenes were annotated, of which 8907 were female-biased and 10,385 were male-biased. Several sex-related pathways were observed, including the Wnt signaling pathway. After elevated temperature and estrogen exposure, neomale and neofemale specimens were identified by a female-specific marker for the first time. RT-qPCR analysis showed the expression profile of ten selected sex-biased genes to be exhibited consistently in male and neomale and in female and neofemale, with the exception of the Amh and TfIIIa genes. Results suggested that these genes may play important roles in A. davidianus sex determination and gonad development. This provides a basis for further investigation of the molecular mechanisms of sex determination in amphibians.

Lassa fever (LF) is a viral hemorrhagic fever that causes high morbidity and severe mortality annually. The disease is endemic to two geographically separate areas within tropical West Africa, one in Nigeria and the second predominantly in Sierra Leone-Guinea-Liberia-Mali. Lassa virus (LASV), the causative agent of the disease, exhibits clear delineation of phylogeography between the endemic areas. In order to characterize the genetic nature of Nigerian-non-Nigerian epidemic split, we performed molecular epidemiological analyses on non-Nigerian isolates (lineage IV as well as lineage V) and their sister group from north-central Nigeria (lineage III). The results showed that adaptive genetic diversification has occurred between these currently circulating clusters in the spread process, and a number of replacement divergences have been fixed between these clusters on the viral RNA-dependent RNA polymerase (L protein). This study highlights the viral L protein could be a determinant factor for the epidemic split.

The water adhesion is important for superhydrophobic materials. Compared with considerable research on metal corrosion protection using superhydrophobic coatings, research involving the different water adhesion of superhydrophobic coating on its anti-corrosive behavior is neglected. Herein, superhydrophobic coatings with controllable water adhesion were successfully fabricated by spraying different percentages of hydrophobic SiO 2 nanoparticles (NPs) on the Al substrate, and then the influence of water adhesion of superhydrophobic surfaces on their anti-corrosive behaviour was studied. The electrochemical test was carried out on the superhydrophobic surface with different water adhesion to reveal the influence of water adhesion on anti-corrosion capability. The results showed that the anti-corrosion was markedly influenced by the water adhesion of the superhydrophobic coating, and their corrosion resistance was varied in the order of low-adhesion > medium-adhesion > high-adhesion. Moreover, the superhydrophobic coating with the percentage of OTS-SiO 2 = 100 possesses unexpected corrosion protection property with lower corrosion rate (CR) and higher polarization resistance (R p ). The corrosive current reduced and impedance modulus (R ct ) increased with the decrease of adhesion. In addition, the anti-corrosion mechanism of superhydrophobic coatings with different adhesion was elaborated.

Due to the unique micro/nanoscale rough surface structures and water-repellency, the superhydrophobic surfaces hold great potential of anti-corrosive protection. This study reported a facile and controllable electrospinning technology to fabricate polyvinylidenefluoride (PVDF)/stearic acid (SA) nanofibers onto metal substrates for long-time anti-corrosive protection. Moreover, the anti-corrosion performances of the superhydrophobic nanofibers coated metal substrates were characterized by the Tafel polarization curve and electrochemical impedance spectroscopy (EIS). In addition, the electrochemical corrosion test results demonstrated the superhydrophobic PVDF/SA nanofibrous coatings possessed superior anti-corrosion performances for long-term metal substrates preservation, even after being immersed in a 3.5 wt% NaCl aqueous solutions up to 30 days. Therefore, we deeply believe the superhydrophobic PVDF/SA nanofibrous coatings could present a superior application prospect in anti-corrosive protection.

To search the evidence of molecular evolution mechanism for aquatic and cave habitat in Andrias davidianus, the evolution analysis was carried out among several species transcriptome data. The transcriptome data of Notophthalmus viridescens, Xenopus tropicalis, Cynops pyrrhogaster, Hynobius chinensis and A. davidianus were obtained from the Genbank and reassembled except Xenopus tropicalis. The BLAST search of transcriptome data obtained 1244 single-copy orthologous genes among five species. A phylogenetic tree showed A. davidianus to have the closest relationship to H. chinensis. Fourteen positively selected genes were detected in A. davidianus and N. vridescens group and fifteen in A. davidianus and H. chinensis group. Five genes were shared in the both groups which involved in the immune system, suggesting that A. davidianus adaptation to an aquatic and cave environment required rapid evolution of the immune system compared to N. viridescens and H. chinensis. Electronic supplementary material The online version of this article (10.1186/s41065-018-0056-6) contains supplementary material, which is available to authorized users.

Separation of emulsified oil/water mixtures is urgently desired and worldwide challenge. Herein, a facile electrospinning technology was utilized to prepare polyvinylidenefluoride (PVDF)/stearic acid (SA) nanofibrous membranes onto mesh substrates for efficient separation of emulsified water-in-oil mixtures. Furthermore, the as-prepared PVDF/SA nanofibrous membranes showed robust superhydrophobicity with water contact angle above 154° even after immersion in oils and corrosive solutions. More importantly, the as-fabricated nanofibrous membranes could effectively separate tiny water droplets from both surfactant-stabilized and surfactant-free water-in-oil emulsions with separation efficiency larger than 99.9%. All of these characteristics would make the superhydrophobic PVDF/SA nanofibrous membranes a great promise of realizing oil recovery in real word.

Efficient and rapid separation of emulsified oil/water mixtures is urgently needed and still remains a worldwide challenge. Even though traditional superhydrophobic/superoleophilic filtration membranes have demonstrated to be effective for separation of water-in-oil emulsions, they still suffer from complicated fabrication procedures and lower flux, resulting from their nanoscale pore size. Herein, green desert sands (50 μm to 1 mm) with under-oil superhydrophilicity were introduced, for the first time, to develop into a layer for efficient gravity-directed separation of various water-in-oil emulsions, which could avoid not only sophisticated filtration membranes fabrication process but also the use of expensive low energy materials of fluorosilane involved in traditional superhydrophobic materials. It is worth mentioning that the sand layer could serve as an adsorbent material with under-oil superhydrophilicity, achieving ultrafast gravity-driven separation of tiny water droplets from various water-in-oil emulsions with flux as high as 2342 L m−2 h even though the interspacing between the sand particles is greater than the size of emulsified droplets. Moreover, the sand can be abundantly obtained from deserts, which is another advantage that the current filtrate materials do not possess. In summary, this study provides a general avenue to design under-oil superhydrophilic materials for rapid separation of water-in-oil emulsions. Such an approach can provide some new perspectives for fabrication of novel emulsion-separating materials.

Antimicrobial peptides (AMPs) as part of host defense systems has been widely recognized in most organisms. Cathelicidin is an important family of AMPs acting as multifunctional effector molecules in innate immunity and exists in organisms with cathelicidin-like precursor. Andrias davidianus (A. davidianus) is a unique species in China and the biggest amphibians in the world. With the rapid growth of A. davidianus aquaculture, pathogens of bacteria, virus and fungus were reported, however little is known about antimicrobial peptides derived from A. davidianus. To investigate antimicrobial peptides of cathelicidin-like in A. davidianus, cathelicidin-like precursor gene cloning and bioinformatic analysis was carried out. The results showed that 1106 bp full-length cDNA of cathelicidin-like precursor was obtained, which was including a 35 bp 5' terminal UTR, a 546 bp open reading frame (ORF) and a 525 bp 5' terminal UTR. The cathelicidin-like precursor amino acid (AA) sequence of A. davidianus comprised N-terminal signal peptide (21 AA), highly conserved cathelin domain and C-terminal mature peptide. The cathelicidin-like precursor gene nucleotide sequence showed low identify with other cathelicidin-like sequences, while AA sequence displayed relatively higher similarity with cathelicidin-like isolated from other species. Phylogenetic tree indicated cathelicidinlike precursor of A. davidianus was firstly clade with Tylototrition verrucosus, which also belonged to Caudata, Amphibian. The precursor gene expression was detected by RT-qPCR. The result displayed this gene was abundant expression in A. davidianus skin. According the specificity proteases cleavage and characteristic of cathelicidin, five putative mature cathelicidin were predicted. This study confirms the presence of cathelicidin in A. davidianus. Their results not only reveal innate immune system of A. davidianus but also enlarge the AMP knowledge of urodele amphibians.

The separation of oil/water mixtures under acidic, alkaline and salty conditions remains a great challenge. Facile, low-cost and easily scale-up processes for the fabrication functional materials to effective oil/water separation under harsh environment are urgently desired. Herein, a superhydrophobic diatomite coating was successfully fabricated by a facile one-step spray-coating process for the gravity driven separation of oil/water mixtures in strong acidic, alkaline and salty environments. In addition, the as-prepared superhydrophobic diatomite-coated meshes can separate a series of oil/ water mixtures with separation efficiency up to 99.8%. Moreover, the as-prepared coated mesh still maintained a separation efficiency exceeding 99.5% and stable recyclability after 40 separation cycles. Meanwhile, the electrochemical corrosion test results indicated that the superhydrophobic coating maintained excellent chemical stability and corrosion resistant effect in 3.5 wt% NaCl solutions. Therefore, our work provides a facile method to fabricate the superhydrophobic diatomite coatings with outstanding anti-corrosive property that can be used for removal oils from harsh environment.

Asian swamp eel (Monopterus albus, Zuiew 1793) is a commercially important fish due to its nutritional value in Eastern and Southeastern Asia. One local strain of M. albus distributed in the Jianghan Plain of China has been subjected to a selection breeding program because of its preferred body color and superiority of growth and fecundity. Some members of the genus Monopterus have been reclassified into other genera recently. These classifications require further phylogenetic analyses. In this study, the complete mitochondrial genomes of the breeds of M. albus were decoded using both PacBio and Illumina sequencing technologies, then phylogenetic analyses were carried out, including sampling of M. albus at five different sites and 14 species of Synbranchiformes with complete mitochondrial genomes. The total length of the mitogenome is 16,621 bp, which is one nucleotide shorter than that of four mitogenomes of M. albus sampled from four provinces in China, as well as one with an unknown sampling site. The gene content, gene order, and overall base compositions are almost identical to the five reported ones. The results of maximum likelihood (ML) and Bayesian inference analyses of the complete mitochondrial genome and 13 protein-coding genes (PCGs) were consistent. The phylogenetic trees indicated that the selecting breed formed the deepest branch in the clade of all Asian swamp eels, confirmed the phylogenetic relationships of four genera of the family Synbranchidae, also providing systematic phylogenetic relationships for the order Synbranchiformes. The divergence time analyses showed that all Asian swamp eels diverged about 0.49 million years ago (MYA) and their common ancestor split from other species about 45.96 MYA in the middle of the Miocene epoch. Altogether, the complete mitogenome of this breed of M. albus would serve as an important dataset for germplasm identification and breeding programs for this species, in addition to providing great help in identifying the phylogenetic relationships of the order Synbranchiformes.

Methanol to aromatics (MTA) is an effective way to produce aromatics by non-petroleum route. The acidity and structure of zeolite catalysts are the key to aromatics yield and stability of catalysts in MTA reaction. Here, Zn-modified HZSM-5 catalysts were prepared by physical mixing method (PM), in-situ hydrothermal synthesis method (SH) and steam-assisted crystallization method (SAC) using ZIF-8 as sacrificial template and Zn source. XRD, SEM, TEM, N2 adsorption-desorption, ICP-OES, NH3-TPD, Py-IR, XPS, H2-TPR, TG characterization methods were used to investigate the physical and chemical properties of the catalysts. The influence of preparation methods of catalysts, the addition amount of ZIF-8, different Zn sources and reaction conditions on the products distribution in MTA reaction were investigated. The results showed that the crystallinity of ZnZ8(SAC)/Z5 catalyst was improved and the hierarchical pore structure was obtained successfully after introduced ZIF-8 by steam-assisted crystallization method. Among them, ZnZ8 mainly exists as ZnOH+ species, which improved the utilization rate of Zn atoms and more L acid sites and moderate acid concentration were formed. The addition amount of ZIF-8 can affect the crystalline size, pore structure and the concentration of ZnOH+ species of ZnZ8(SAC)/Z5. An appropriate ratio of B/L acid concentration was formed when adding an appropriate amount of ZIF-8. Compared with the traditional Z5 catalyst modified with Zn(NO3)2 as Zn source (1% ZnZN(SAC)/Z5), there are smaller particle size, larger specific surface area and mesopore volume as well as suitable acid distribution in 1% ZnZ8(SAC)/Z5 catalyst. The preparation method of catalyst, the addition amount of ZIF-8, different Zn sources and reaction conditions have a significant effect on the selectivity of BTX.

Sentinel-2 imagery is an unprecedented data source with high spatial, spectral and temporal resolution in addition to free access. The objective of this paper was to evaluate the potential of using Sentinel-2 data to map winter crops in the early growth stage. Analysis of three winter crop types—winter garlic, winter canola and winter wheat—was carried out in two agricultural regions of China. We analysed the spectral characteristics and vegetation index profiles of these crops in the early growth stage and other land cover types based on Sentinel-2 images. A decision tree classification model was built to distinguish the crops based on these data. The results demonstrate that winter garlic and winter wheat can be distinguished four months before harvest, while winter canola can be distinguished two months before harvest. The overall classification accuracy was 96.62% with a kappa coefficient of 0.95. Therefore, Sentinel-2 images can be used to accurately identify these winter crops in the early growth stage, making them an important data source in the field of agricultural remote sensing.

It is a challenge to develop heterogeneous Fenton-like catalysts with excellent performance and stability in the field of wastewater treatment. In this work, the FeS2-Fe1-xS heterostructure catalyst was prepared by solvothermal method through adding cobalt element to change the particle nucleation process and inhibit the transformation process of pyrrhotite (Fe1-xS) phase to pyrite (FeS2) phase. Then, a series of experiments were devised to clarify the catalytic activity of FeS2-Fe1-xS heterostructure. The degradation experiments exhibited that 99.9% degradation efficiency was achieved for 30 mg/L orange II solution within 15 min at the conditions of 0.2 g/L FeS2-Fe1-xS, 2 mM H2O2 and pH = 3.0. In addition, the reusability of the FeS2-Fe1-xS catalyst was also investigated and the result displayed that degradation efficiency of orange II can reach 95.2% after eight cycles. The degradation of orange II was enhanced by Fenton reaction between FeS2-Fe1-xS and dissolved oxygen, which could smoothly release Fe2+ and Fe3+ for the activation of H2O2 to produce more hydroxyl radicals. Finally, the degradation pathway of orange II was proposed by detecting intermediates produced in FeS2-Fe1-xS/H2O2 photo-Fenton-like system by liquid chromatography-mass spectrometry (LC-MS). In short, FeS2-Fe1-xS is a promising catalyst for removing the organic pollutants from solutions.

Leptin is an important hormone possessing diverse physiological roles in mammals and teleosts. However, it has been characterized only in a few amphibian species, and its evolutions are still under debate. Here, the full length of the leptin (Adlep) cDNA of Chinese giant salamander (Andrias davidianus), an early diverging amphibian species, is characterized and according to the results of the primary sequence analysis, tertiary structure reconstruction and phylogenetic analysis is confirmed to be an ortholog of mammalian leptin. An intron was identified between the coding exons of A. davidianus leptin, which indicated that the leptin is present in the salamander genome and contains a conserved gene structure in vertebrates. Adlep is widely distributed but expression levels vary among different tissues, with highest expression levels in the muscle. Additionally, the leptin receptor and other genes were mapped to three known leptin signaling pathways, suggesting that the leptin signaling pathways are present in A. davidianus. Phylogenetic topology of leptins are consistent with the generally accepted evolutionary relationships of vertebrates, and multiple leptin members found in teleosts seem to be obtained through a Cluopeocephala-specific gene duplication event. Our results will lay a foundation for further investigations into the physiological roles of leptin in A. davidianus.

A facile approach was developed for the preparation of nano-sized HZSM-5 with a hierarchical mesoporous structure by adding imidazole into conventional zeolite synthesis precursor solution. The physicochemical properties of modified HZSM-5 were characterized by X-ray diffraction (XRD), N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3-temperature-programmed desorption (NH3-TPD) and pyridine adsorption infrared spectroscopy (Py-IR). The coke in spent catalysts was characterized by thermogravimetry (TG). The results showed that hierarchical HZSM-5 zeolites with excellent textural properties, such as abundant porous structure, uniform particle size and suitable acidity, could be synthesized by the recipe of one-pot synthesis routes. Moreover, the obtained HZSM-5 exhibited higher selectivity of total aromatics as well as longer lifetime in the catalytic conversion of methanol to aromatics, comparing with conventional HZSM-5. It is expected that the synthesis approach demonstrated here will be applicable to other zeolites with particular textural properties and controllable particle sizes, facilitating the emergence of new-type porous materials and their related applications in catalysis and separation.

Oil/water separation is of great importance for the treatment of oily wastewater, including immiscible light/heavy oil-water mixtures, oil-in-water or water-in-oil emulsions. Smart surfaces with responsive wettability have received extensive attention especially for controllable oil/water separation. However, traditional smart membranes with a switchable wettability between superhydrophobicity and superhydrophilicity are limited to certain responsive materials and continuous external stimuli, such as pH, electrical field or light irradiation. Herein, a candle soot coated mesh (CSM) with a larger pore size and a candle soot coated PVDF membrane (CSP) with a smaller pore size with underwater superoleophobicity and underoil superhydrophobicity were successfully fabricated, which can be used for on-demand immiscible oil/water mixtures and surfactants-stabilized oil/water emulsion separation, respectively. Without any continuous external stimulus, the wettability of our membranes could be reversibly switched between underwater superoleophobicity and underoil superhydrophobicity simply by drying and washing alternately, thus achieving effective and switchable oil/water separation with excellent separation efficiency. We believe that such smart materials will be promising candidates for use in the removal of oil pollutants in the future.

Species with large geographic ranges are considered resilient to global decline [1]. However, human pressures on biodiversity affect increasingly large areas, in particular across Asia, where market forces drive overexploitation of species [2]. Range-wide threat assessments are often costly and thus extrapolated from non-representative local studies [3]. The Chinese giant salamander (Andrias davidianus), the world's largest amphibian, is thought to occur across much of China, but populations are harvested for farming as luxury food [4]. Between 2013 and 2016, we conducted field surveys and 2,872 interviews in possibly the largest wildlife survey conducted in China. This extensive effort revealed that populations of this once-widespread species are now critically depleted or extirpated across all surveyed areas of their range, and illegal poaching is widespread.