Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catal...Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.展开更多
The northern Andaman Sea off Myanmar is one of the relatively high productive regions in the Indian Ocean.The abundance,biomass and species composition of mesozooplankton and their relationships with environmental var...The northern Andaman Sea off Myanmar is one of the relatively high productive regions in the Indian Ocean.The abundance,biomass and species composition of mesozooplankton and their relationships with environmental variables in the epipelagic zone(~200 m)were studied for the first time during the Sino-Myanmar joint cruise(February 2020).The mean abundance and biomass of mesozooplankton were(1916.7±1192.9)ind./m3and(17.8±7.9)mg/m3,respectively.A total of 213 species(taxa)were identified from all samples.The omnivorous Cyclopoida Oncaea venusta and Oithona spp.were the top two dominant taxa.Three mesozooplankton communities were determined via cluster analysis:the open ocean in the Andaman Sea and the Bay of Bengal(Group A),the transition zone across the Preparis Channel(Group B),and nearshore water off the Ayeyarwady Delta and along the Tanintharyi Coast(Group C).Variation partitioning analysis revealed that the interaction of physical and biological factors explained 98.8%of mesozooplankton community spatial variation,and redundancy analysis revealed that column mean chlorophyll a concentration(CMCHLA)was the most important explanatory variable(43.1%).The abundance and biomass were significantly higher in Group C,the same as CMCHLA and column mean temperature(CMT)and in contrast to salinity,and CMT was the dominant factor.Significant taxon spatial variations were controlled by CMCHLA,salinity and temperature.This study suggested that mesozooplankton spatial variation was mainly regulated by physical processes through their effects on CMCHLA.The physical processes were simultaneously affected by heat loss differences,freshwater influx,eddies and depth.展开更多
Objective： The recommended dose of prophylactic pegylated recombinant human granulocyte-colony stimulating factor（PEG rhG-CSF） is 100 μg/kg once per cycle for patients receiving intense-dose chemotherapy.However, ...Objective： The recommended dose of prophylactic pegylated recombinant human granulocyte-colony stimulating factor（PEG rhG-CSF） is 100 μg/kg once per cycle for patients receiving intense-dose chemotherapy.However, few data are available on the proper dose for patients receiving less-intense chemotherapy. The aim of this phase I study is to explore the proper dose and administration schedule of PEG rhG-CSF for patients receiving standard-dose chemotherapy.Methods：Eligible patients received 3-cycle chemotherapy every 3 weeks.No PEG rhG-CSF was given in the first cycle.Patients experienced grade 3 or 4 neutropenia would then enter the cycle 2 and 3.In cycle 2,patients received a single subcutaneous injection of prophylactic PEG rhG-CSF on d 3,and received half-dose subcutaneous injection in cycle 3 on d 3 and d 5,respectively.Escalating doses（30,60,100 and 200μg/kg）of PEG rhG-CSF were investigated.Results：A total of 26 patients were enrolled and received chemotherapy,in which 24 and 18 patients entered cycle 2 and cycle 3 treatment,respectively.In cycle 2,the incidence of grade 3 or 4 neutropenia for patients receiving single-dose PEG rhG-CSF of 30,60,100 and 200 μg/kg was 66.67%,33.33%,22.22% and 0,respectively,with a median duration less than 1（0–2）d.No grade 3 or higher neutropenia was noted in cycle 3 in all dose cohorts.Conclusions：The pharmacokinetic and pharmacodynamic profiles of PEG rhG-CSF used in cancer patients were similar to those reported,as well as the safety.Double half dose administration model showed better efficacy result than a single dose model in terms of grade 3 neutropenia and above.The single dose of 60 μg/kg,100 μg/kg and double half dose of 30 μg/kg were recommended to the phase Ⅱ study,hoping to find a preferable method for neutropenia treatment.展开更多
Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing act...Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.展开更多
The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, ...The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, respectively.FTIR and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring.展开更多
The turbidity maximum zone(TMZ)is a distinctive aquatic environment marked by consistently higher turbidity compared to upstream and downstream section.In the TMZ,physicochemical properties such as intense light limit...The turbidity maximum zone(TMZ)is a distinctive aquatic environment marked by consistently higher turbidity compared to upstream and downstream section.In the TMZ,physicochemical properties such as intense light limitation,abundant nutrients,and rapid salinity shifts play a crucial role in shaping phytoplankton dynamics.The Qiantang River estuary-Hangzhou Bay(QRE-HZB)is a macrotidal estuary system known for its exceptionally high suspended solids concentration.To investigate the impact of TMZ on the standing crop and size structure of phytoplankton in the QRE-HZB,we conducted three cruises in dry,wet,and dry-to-wet transition seasons during 2022-2023,by assessing parameters including size fractionated chlorophyll a(chl a),turbidity,Secchi depth,temperature,salinity,nutrients,and mesozooplankton.Results reveal significant variations in the TMZ and associated environmental factors in different periods,which markedly influenced the phytoplankton chl-a concentration,size structure,and cell activity(pheophytin/chl a).The chl-a concentration was high with micro-phytoplankton predominance in wet season,while nano-phytoplankton dominated in dry season.Within the TMZ,lower chl-a concentrations and pico-chl-a contributions,alongside higher pheophytin/chl-a and micro-chl-a contributions,were observed.The Spearman’s rank correlation and generalized additive model analyses indicated strong correlations of chl-a concentrations with turbidity,nutrients,and mesozooplankton.Redundancy analysis further revealed that salinity,nutrients,and turbidity significantly regulated variations in size structure.Phytoplankton mortality within the TMZ was primarily driven by high turbidity and salinity fluctuations,reflecting the vigorous resuspension and mixing of freshwater and seawater in the QRE-HZB.These findings highlight that the standing crop and size structure of phytoplankton were strongly regulated by the TMZ and associated physicochemical factors in the macrotidal QRE-HZB.展开更多
Four kinds of nitroamine propellants with different RDX contents(10%,20%,30%and 40%)were prepared to study the effect of RDX content on the mechanical properties and combustion properties of nitroamine propellant.The ...Four kinds of nitroamine propellants with different RDX contents(10%,20%,30%and 40%)were prepared to study the effect of RDX content on the mechanical properties and combustion properties of nitroamine propellant.The mechanical properties and combustion properties of nitroamine propellant at the normal temperature(20C)and low temperature(à40C)were test by using impact testing machine,drop hammer impact test machine and closed bomb vessel.The test results show that the impact strength of30%RDX-contained nitramine propellant is maximum,but 40%RDX-contained nitramine propellant has the minimum impact strength.And the crushing height of propellant with 20%RDX-contained was the highest,but the crushing height of propellant with 40%RDX-contained the lowest.With the increase in RDX content in nitramine propellant,the energy of nitramine propellant increases and its burning rate reduces,but 40%RDX-contained nitramine propellant did not meet this trend at the low temperature because of its poor mechanical properties.展开更多
The purpose of this study was to prepare the oleanolic acid–phospholipid complex (OAPC) and then solidify it employing fumed silica by simple solvent evaporation technique to improve dissolution rate of oleanolic aci...The purpose of this study was to prepare the oleanolic acid–phospholipid complex (OAPC) and then solidify it employing fumed silica by simple solvent evaporation technique to improve dissolution rate of oleanolic acid and oleanolic acid–phospholipid complex. The process of OA-PC was optimized and the type and proportion of fumed silica were studied by dissolution text. The structures of the phospholipid complex and solidified powder were also characterized by differential scanning calorimetry, X-ray diffraction, and scanning electron microscope. In the dissolution tests, OA from solidified powder was further released compared with that from pure OA and OA-PC in different kinds of dissolution media. These results suggest that the method of preparing solidified powder of oleanolic acid–phospholipid complex is suitable for enhancing the dissolution rate of OA and OA-PC.展开更多
Background People living with HIV/AIDS(PLWHA)must contend with a significant burden of disease.However,current studies of this demographic have yielded wide variations in the incidence of suicidality(defined as suicid...Background People living with HIV/AIDS(PLWHA)must contend with a significant burden of disease.However,current studies of this demographic have yielded wide variations in the incidence of suicidality(defined as suicidal ideation,suicide attempt and suicide deaths).Aims This systematic review and meta-analysis aimed to assess the lifetime incidence and prevalence of suicidality in PLWHA.Methods Publications were identified from PubMed(MEDLINE),SCOPUS,OVID(MEDLINE),Joanna Briggs Institute EBP and Cochrane Library databases(from inception to before 1 February 2020).The search strategy included a combination of Medical Subject Headings associated with suicide and HIV.Researchers independently screened records,extracted outcome measures and assessed study quality.Data were pooled using a random-effects model.Subgroup and meta-regression analyses were conducted to explore the associated risk factors and to identify the sources of heterogeneity.Main outcomes were lifetime incidence of suicide completion and lifetime incidence and prevalence of suicidal ideation and suicide attempt.Results A total of 185199 PLWHA were identified from 40 studies(12 cohorts,27 cross-sectional and 1 nested case-control).The overall incidence of suicide completion in PLWHA was 10.2/1000 persons(95%CI:4.5 to 23.1),translating to 100-fold higher suicide deaths than the global general population rate of 0.11/1000 persons.The lifetime prevalence of suicide attempts was 158.3/1000 persons(95%CI:106.9 to 228.2)and of suicidal ideation was 228.3/1000 persons(95%CI:150.8 to 330.1).Meta-regression revealed that for every 10-percentage point increase in the proportion of people living with HIV with advanced disease(AIDS),the risk of suicide completion increased by 34 per 1000 persons.The quality of evidence by Grading of Recommendations,Assessment,Development and Evaluations for the suicide deaths was graded as‘moderate’quality.Conclusions The risk of suicide death is 100-fold higher in people living with HIV than in the general population.Lifetime incidence of suicidal ideation and attempts are substantially high.Suicide risk assessments should be a priority in PLWHA,especially for those with more advanced disease.展开更多
During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the...During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.展开更多
Conspecific seagrass living in differing environments may develop different root system acclimation patterns.We applied X-ray computed tomography(CT)for imaging and quantifying roots systems of Zostera japonica collec...Conspecific seagrass living in differing environments may develop different root system acclimation patterns.We applied X-ray computed tomography(CT)for imaging and quantifying roots systems of Zostera japonica collected from typical oligotrophic and eutrophic sediments in two coastal sites of northern China,and determined sediment physicochemical properties that might influence root system morphology,density,and distribution.The trophic status of sediments had little influence on the Z.japonica root length,and diameters of root and rhizome.However,Z.japonica in oligotrophic sediment developed the root system with longer rhizome node,deeper rhizome distribution,and larger allocation to below-ground tissues in order to acquire more nutrients and relieve the N deficiency.And the lower root and rhizome densities of Z.japonica in eutrophic sediment were mainly caused by fewer shoots and shorter longevity,which was resulted from the more serious sulfide inhibition.Our results systematically revealed the effect of sediment trophic status on the phenotypic plasticity,quantity,and distribution of Z.japonica root system,and demonstrated the feasibly of X-ray CT in seagrass root system research.展开更多
China has entered the era of post-poverty alleviation,which effectively links poverty alleviation achievements with rural revitalization strategies.In the era of post-poverty alleviation,in order to effectively promot...China has entered the era of post-poverty alleviation,which effectively links poverty alleviation achievements with rural revitalization strategies.In the era of post-poverty alleviation,in order to effectively promote the sustainable development of poor rural areas,local colleges and universities should actively nurture the self-development skills of the needy.Local colleges and universities should guide the transformation of ideas and concepts,scientifically optimize the allocation of poverty alleviation resources,improve the interest linkage mechanism between colleges and universities,strengthen the investigation and analysis of poverty alleviation projects,improve the convergence of assistance and practice,actively create a good spiritual and cultural environment,uphold the mission of helping cadres,attach importance to the support for the development of characteristic industries,and lastly,promote the convergence of rural revitalization strategies.展开更多
Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed s...Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.展开更多
Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data,but the key challenge is how to provide enough training data for the mach...Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data,but the key challenge is how to provide enough training data for the machine learning models.Therefore this article proposes an image data augmentation method that combines few-shot learning and generative adversarial networks.The Galaxy10 DECaLs data set is selected for the experiments with consistency,variance,and augmentation effects being evaluated.Three popular networks,including AlexNet,VGG,and ResNet,are used as examples to study the effectiveness of different augmentation methods on galaxy morphology classifications.Experiment results show that the proposed method can generate galaxy images and can be used for expanding the classification model’s training set.According to comparative studies,the best enhancement effect on model performance is obtained by generating a data set that is 0.5–1 time larger than the original data set.Meanwhile,different augmentation strategies have considerably varied effects on different types of galaxies.FSL-GAN achieved the best classification performance on the ResNet network for In-between Round Smooth Galaxies and Unbarred Loose Spiral Galaxies,with F1 Scores of 89.54%and 63.18%,respectively.Experimental comparison reveals that various data augmentation techniques have varied effects on different categories of galaxy morphology and machine learning models.Finally,the best augmentation strategies for each galaxy category are suggested.展开更多
Ocean fronts play important roles in nutrient transport and in the shaping ecological patterns.Frontal zones in small bays are typically small in scale,have a complex structure,and they are spatially and temporally va...Ocean fronts play important roles in nutrient transport and in the shaping ecological patterns.Frontal zones in small bays are typically small in scale,have a complex structure,and they are spatially and temporally variable,but there are limited data on how biological communities respond to this variation.Hangzhou Bay,a mediumsized estuary in China,is an ideal place in which to study the response of plankton to small-scale ocean fronts,because three water masses(Qiantang River Diluted Water,Changjiang River Diluted Water,and the East China Sea current) converge here and form dynamic salinity fronts throughout the year.We investigate zooplankton communities,and temperature,salinity and chlorophyll a(Chl a) in Hangzhou Bay in June(wet perio d) and December(dry period) of 2022 and examine the dominant environmental factors that affect zooplankton community spatial variability.We then match the spatial distributions of zooplankton communities with those of salinity fronts.S alinity is the most important explanatory variable to affect zooplankton community spatial variability during both wet and dry periods,in that it contributes>60% of the variability in community structure.Furthermore,the spatial distributions of zooplankton match well with salinity fronts.During December,with weaker Qiantang River Diluted Water and a stronger secondary Changjiang River Plume,zooplankton communities occur in moderate salinity(MS,salinity range 15.6±2.2) and high salinity(HS,22.4±1.7) regions,and their ecological boundaries closely match the Qiantang River Diluted Water front.In June,different zooplankton communities occur in low salinity(LS,3.9±1.0),MS(11.7±3.6) and HS(21.3±1.9) regions.Although the LS region occurs abnormally in the central bay rather than its apex because of the anomalous influence of rising and falling tides during the sampling perio d,the ecological boundaries still match salinity interfaces.Low-salinity or brackish-water zooplankter taxa are relatively more abundant in LS or MS regions,and the biomass and abundance of zooplankton is higher in the MS region.展开更多
Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learnin...Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learning costs since it needs a lot of labeled data to be effective.FixMatch,a semi-supervised learning algorithm that serves as a good method,is now a key tool for using large amounts of unlabeled data.Nevertheless,the performance degrades significantly when dealing with large,imbalanced data sets since FixMatch relies on a fixed threshold to filter pseudo-labels.Therefore,this study proposes a dynamic threshold alignment algorithm based on the FixMatch model.First,the class with the highest amount has its reliable pseudo-label ratio determined,and the remaining classes'reliable pseudo-label ratios are approximated in accordance.Second,based on the predicted reliable pseudo-label ratio for each category,it dynamically calculates the threshold for choosing pseudo-labels.By employing this dynamic threshold,the accuracy bias of each category is decreased and the learning of classes with less samples is improved.Experimental results show that in galaxy morphology classification tasks,compared with supervised learning,the proposed algorithm significantly improves performance.When the amount of labeled data is 100,the accuracy and F1-score are improved by 12.8%and 12.6%,respectively.Compared with popular semisupervised algorithms such as FixMatch and MixMatch,the proposed algorithm has better classification performance,greatly reducing the accuracy bias of each category.When the amount of labeled data is 1000,the accuracy of cigar-shaped smooth galaxies with the smallest sample is improved by 37.94%compared to FixMatch.展开更多
The targeted poverty alleviation policy isone of the important methods to solve the problemof poverty in China. After the implementation of thetargeted poverty alleviation policy in China, someresults have shown posit...The targeted poverty alleviation policy isone of the important methods to solve the problemof poverty in China. After the implementation of thetargeted poverty alleviation policy in China, someresults have shown positive. However, due to theshortage of resources and talents for poverty alleviation,there are still some shortcomings in the targeted povertyalleviation work. In the process of targeted povertyalleviation, if we can promote social work to participatein targeted poverty alleviation and use a wider rangeof social forces to provide more professional andtargeted assistance work for the poor, we will achievethe final sprint for the success of targeted povertyalleviation in China and a well-off society. Based onthe actual situation of China’s current targeted povertyalleviation work, this article takes the relationship andcontent of rural social work in Sichuan Province aspart of the targeted poverty alleviation as well as thedifficulties it faces. The analysis focuses on the pathof rural social work in Sichuan Province to targetedpoverty alleviation and aims to provide more referencesuggestions for targeted poverty alleviation in China.展开更多
Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg...Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg corrosion consists of oxidation and reduction reactions that produce by-products,such as hydrogen gas,reactive oxygen species,and hydroxides.It is still unclear how all these by-products and Mg ions concomitantly alter the microenvironment and cell behaviors spatially and temporally.This study shows that Mg corrosion can enhance cell proliferation by reducing intracellular ROS.However,Mg cannot decrease ROS and promote cell proliferation in simulated inflammatory conditions,meaning the microenvironment is critical.Furthermore,cells may respond to Mg ions differently in chronic or acute alkaline pH or oxidative stress.Depending on the corrosion rate,Mg modulates HIF1αand many signaling pathways like PI3K/AKT/mTOR,mitophagy,cell cycle,and oxidative phosphorylation.Therefore,this study provides a fundamental insight into the importance of reduction reactions in Mg alloys.展开更多
基金supported by the National Key Research and Development Program of China (Nos. 2020YFA0907300, 2020YFA0907800)the National Natural Science Foundation of China (No. 22077069)+1 种基金the Natural Science Foundation of Tianjin (Nos. 19JCZDJC33400 and 21JCYBJC00310)the Fundamental Research Funds for the Central Universities, Nankai University (No. 63201111)。
文摘Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.
基金The Scientific Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources under contract No.JG2210the Global Change and Air-Sea Interaction II Program under contract No.GASI-01-EIND-STwinthe National Natural Science Foundation of China under contract Nos 42176148 and 42176039。
文摘The northern Andaman Sea off Myanmar is one of the relatively high productive regions in the Indian Ocean.The abundance,biomass and species composition of mesozooplankton and their relationships with environmental variables in the epipelagic zone(~200 m)were studied for the first time during the Sino-Myanmar joint cruise(February 2020).The mean abundance and biomass of mesozooplankton were(1916.7±1192.9)ind./m3and(17.8±7.9)mg/m3,respectively.A total of 213 species(taxa)were identified from all samples.The omnivorous Cyclopoida Oncaea venusta and Oithona spp.were the top two dominant taxa.Three mesozooplankton communities were determined via cluster analysis:the open ocean in the Andaman Sea and the Bay of Bengal(Group A),the transition zone across the Preparis Channel(Group B),and nearshore water off the Ayeyarwady Delta and along the Tanintharyi Coast(Group C).Variation partitioning analysis revealed that the interaction of physical and biological factors explained 98.8%of mesozooplankton community spatial variation,and redundancy analysis revealed that column mean chlorophyll a concentration(CMCHLA)was the most important explanatory variable(43.1%).The abundance and biomass were significantly higher in Group C,the same as CMCHLA and column mean temperature(CMT)and in contrast to salinity,and CMT was the dominant factor.Significant taxon spatial variations were controlled by CMCHLA,salinity and temperature.This study suggested that mesozooplankton spatial variation was mainly regulated by physical processes through their effects on CMCHLA.The physical processes were simultaneously affected by heat loss differences,freshwater influx,eddies and depth.
基金supported by Hangzhou Jiuyuan Gene Engineering Co., Ltdpartly funded by the Chinese National Science and Technology Major Project on Key New Drug Creation (2012ZX09303-012)Beijing Municipal Science & Technology Commission Major Project for New Drug Innovation (Z111102071011001), China
文摘Objective： The recommended dose of prophylactic pegylated recombinant human granulocyte-colony stimulating factor（PEG rhG-CSF） is 100 μg/kg once per cycle for patients receiving intense-dose chemotherapy.However, few data are available on the proper dose for patients receiving less-intense chemotherapy. The aim of this phase I study is to explore the proper dose and administration schedule of PEG rhG-CSF for patients receiving standard-dose chemotherapy.Methods：Eligible patients received 3-cycle chemotherapy every 3 weeks.No PEG rhG-CSF was given in the first cycle.Patients experienced grade 3 or 4 neutropenia would then enter the cycle 2 and 3.In cycle 2,patients received a single subcutaneous injection of prophylactic PEG rhG-CSF on d 3,and received half-dose subcutaneous injection in cycle 3 on d 3 and d 5,respectively.Escalating doses（30,60,100 and 200μg/kg）of PEG rhG-CSF were investigated.Results：A total of 26 patients were enrolled and received chemotherapy,in which 24 and 18 patients entered cycle 2 and cycle 3 treatment,respectively.In cycle 2,the incidence of grade 3 or 4 neutropenia for patients receiving single-dose PEG rhG-CSF of 30,60,100 and 200 μg/kg was 66.67%,33.33%,22.22% and 0,respectively,with a median duration less than 1（0–2）d.No grade 3 or higher neutropenia was noted in cycle 3 in all dose cohorts.Conclusions：The pharmacokinetic and pharmacodynamic profiles of PEG rhG-CSF used in cancer patients were similar to those reported,as well as the safety.Double half dose administration model showed better efficacy result than a single dose model in terms of grade 3 neutropenia and above.The single dose of 60 μg/kg,100 μg/kg and double half dose of 30 μg/kg were recommended to the phase Ⅱ study,hoping to find a preferable method for neutropenia treatment.
基金Supported by the Scientifi c Research Fund of the Second Institute of Oceanography,Ministry of Natural Resources(MNR)(Nos.JB1906,JG1616,JG1910)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)+4 种基金the Key Projects of Philosophy and Social Sciences Research,Ministry of Education(No.18JZD059)the National Key Technology Research and Development Program of the Ministry of Science and Technology of the China(No.2015BAD08B01)the State Key Laboratory of Satellite Ocean Environment Dynamics(No.SOEDZZ1902)the National Natural Science Foundation of China(No.41806136)the Project of Long Term Observation and Research Plan in the Changjiang Estuary and the Adjacent East China Sea(LORCE,14282)。
文摘Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.
基金supported by the National Natural Science Foundation of China(Grant No.22305123)。
文摘The search for new green and efficient stabilizers is of great importance for the stabilization of nitrocellulose(NC). This is due to the shortcomings of traditional stabilizers, such as high toxicity. In this study, reduced polyaniline(r-PANI), which has a similar functional structure to diphenylamine(DPA) but is non-toxic, was prepared from PANI based on the action with N_(2)H_(4) and NH_(3)-H_(2)O, and used for the first time as a potential stabilizer for NC. XPS, FTIR, Raman, and SEM were used to characterize the reduced chemical structure and surface morphology of r-PANI. In addition, the effect of r-PANI on the stabilization of NC was characterized using DSC, VST, isothermal TG, and MMC. Thermal weight loss was reduced by 83% and 68% and gas pressure release by 75% and 49% compared to pure NC and NC&3%DPA, respectively.FTIR and XPS were used to characterize the structural changes of r-PANI before and after reaction with NO_(2). The 1535 cm^(-1) and 1341 cm^(-1) of the FTIR and the 404.98 eV and 406.05 eV of the XPS showed that the -NO_(2) was generated by the absorption of NO_(2). Furthermore, the quantum chemical calculation showed that NO_(2) was directly immobilized on r-PANI by forming -NO_(2) in the neighboring position of the benzene ring.
基金Supported by the National Key Research and Development Program of China(No.2021 YFC 3101702)the Key R&D Program of Zhejiang(No.2022 C 03044)+2 种基金the Scientific Research Fund of the Second Institute of Oceanography,MNR(No.JG 1521)the Project of State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography(No.SOEDZZ 2202)the National Program on Global Change and Air-Sea Interaction(Phase Ⅱ)-Hypoxia and Acidification Monitoring and Warning Project in the Changjiang River estuary,and Long-term Observation and Research Plan in the Changjiang River estuary and Adjacent East China Sea(LORCE)Project(No.SZ 2001)。
文摘The turbidity maximum zone(TMZ)is a distinctive aquatic environment marked by consistently higher turbidity compared to upstream and downstream section.In the TMZ,physicochemical properties such as intense light limitation,abundant nutrients,and rapid salinity shifts play a crucial role in shaping phytoplankton dynamics.The Qiantang River estuary-Hangzhou Bay(QRE-HZB)is a macrotidal estuary system known for its exceptionally high suspended solids concentration.To investigate the impact of TMZ on the standing crop and size structure of phytoplankton in the QRE-HZB,we conducted three cruises in dry,wet,and dry-to-wet transition seasons during 2022-2023,by assessing parameters including size fractionated chlorophyll a(chl a),turbidity,Secchi depth,temperature,salinity,nutrients,and mesozooplankton.Results reveal significant variations in the TMZ and associated environmental factors in different periods,which markedly influenced the phytoplankton chl-a concentration,size structure,and cell activity(pheophytin/chl a).The chl-a concentration was high with micro-phytoplankton predominance in wet season,while nano-phytoplankton dominated in dry season.Within the TMZ,lower chl-a concentrations and pico-chl-a contributions,alongside higher pheophytin/chl-a and micro-chl-a contributions,were observed.The Spearman’s rank correlation and generalized additive model analyses indicated strong correlations of chl-a concentrations with turbidity,nutrients,and mesozooplankton.Redundancy analysis further revealed that salinity,nutrients,and turbidity significantly regulated variations in size structure.Phytoplankton mortality within the TMZ was primarily driven by high turbidity and salinity fluctuations,reflecting the vigorous resuspension and mixing of freshwater and seawater in the QRE-HZB.These findings highlight that the standing crop and size structure of phytoplankton were strongly regulated by the TMZ and associated physicochemical factors in the macrotidal QRE-HZB.
基金supported by National Natural Science Foundation of China(NO.51506093)
文摘Four kinds of nitroamine propellants with different RDX contents(10%,20%,30%and 40%)were prepared to study the effect of RDX content on the mechanical properties and combustion properties of nitroamine propellant.The mechanical properties and combustion properties of nitroamine propellant at the normal temperature(20C)and low temperature(à40C)were test by using impact testing machine,drop hammer impact test machine and closed bomb vessel.The test results show that the impact strength of30%RDX-contained nitramine propellant is maximum,but 40%RDX-contained nitramine propellant has the minimum impact strength.And the crushing height of propellant with 20%RDX-contained was the highest,but the crushing height of propellant with 40%RDX-contained the lowest.With the increase in RDX content in nitramine propellant,the energy of nitramine propellant increases and its burning rate reduces,but 40%RDX-contained nitramine propellant did not meet this trend at the low temperature because of its poor mechanical properties.
文摘The purpose of this study was to prepare the oleanolic acid–phospholipid complex (OAPC) and then solidify it employing fumed silica by simple solvent evaporation technique to improve dissolution rate of oleanolic acid and oleanolic acid–phospholipid complex. The process of OA-PC was optimized and the type and proportion of fumed silica were studied by dissolution text. The structures of the phospholipid complex and solidified powder were also characterized by differential scanning calorimetry, X-ray diffraction, and scanning electron microscope. In the dissolution tests, OA from solidified powder was further released compared with that from pure OA and OA-PC in different kinds of dissolution media. These results suggest that the method of preparing solidified powder of oleanolic acid–phospholipid complex is suitable for enhancing the dissolution rate of OA and OA-PC.
基金This work was supported by a U.S.National Institutes of Health(NIH)Director’s Transformative Award 1R01AI145057(PS)。
文摘Background People living with HIV/AIDS(PLWHA)must contend with a significant burden of disease.However,current studies of this demographic have yielded wide variations in the incidence of suicidality(defined as suicidal ideation,suicide attempt and suicide deaths).Aims This systematic review and meta-analysis aimed to assess the lifetime incidence and prevalence of suicidality in PLWHA.Methods Publications were identified from PubMed(MEDLINE),SCOPUS,OVID(MEDLINE),Joanna Briggs Institute EBP and Cochrane Library databases(from inception to before 1 February 2020).The search strategy included a combination of Medical Subject Headings associated with suicide and HIV.Researchers independently screened records,extracted outcome measures and assessed study quality.Data were pooled using a random-effects model.Subgroup and meta-regression analyses were conducted to explore the associated risk factors and to identify the sources of heterogeneity.Main outcomes were lifetime incidence of suicide completion and lifetime incidence and prevalence of suicidal ideation and suicide attempt.Results A total of 185199 PLWHA were identified from 40 studies(12 cohorts,27 cross-sectional and 1 nested case-control).The overall incidence of suicide completion in PLWHA was 10.2/1000 persons(95%CI:4.5 to 23.1),translating to 100-fold higher suicide deaths than the global general population rate of 0.11/1000 persons.The lifetime prevalence of suicide attempts was 158.3/1000 persons(95%CI:106.9 to 228.2)and of suicidal ideation was 228.3/1000 persons(95%CI:150.8 to 330.1).Meta-regression revealed that for every 10-percentage point increase in the proportion of people living with HIV with advanced disease(AIDS),the risk of suicide completion increased by 34 per 1000 persons.The quality of evidence by Grading of Recommendations,Assessment,Development and Evaluations for the suicide deaths was graded as‘moderate’quality.Conclusions The risk of suicide death is 100-fold higher in people living with HIV than in the general population.Lifetime incidence of suicidal ideation and attempts are substantially high.Suicide risk assessments should be a priority in PLWHA,especially for those with more advanced disease.
基金the National Natural Science Foundation of China(Grant Nos.U1560101 and U1738I01)the National Key Research and Development Program of China(2016YFC0209302).
文摘During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.
基金Supported by the National Key Research and Development Program of China(Nos.2018YFD0900901,2019YFD0901300)the Scientific Research Fund of the Second Institute of Oceanography,MNR(Nos.JG1906,JG1616,JG1910)+4 种基金the National Natural Science Foundation of China(Nos.41606192/41176140,41706125,41806136)the National Science&Technology Basic Work Program of China(No.2015FY110600)the Key Projects of Philosophy and Social Sciences Research,Ministry of Education,China(No.18JZD059)the Zhejiang Qingshan Lake Innovation Platform for Marine Science and Technology(No.2017E80001)the Project of Long-term Observation and Research Plan in the Changjiang Estuary and Adjacent East China Sea(No.LORCE,14282)。
文摘Conspecific seagrass living in differing environments may develop different root system acclimation patterns.We applied X-ray computed tomography(CT)for imaging and quantifying roots systems of Zostera japonica collected from typical oligotrophic and eutrophic sediments in two coastal sites of northern China,and determined sediment physicochemical properties that might influence root system morphology,density,and distribution.The trophic status of sediments had little influence on the Z.japonica root length,and diameters of root and rhizome.However,Z.japonica in oligotrophic sediment developed the root system with longer rhizome node,deeper rhizome distribution,and larger allocation to below-ground tissues in order to acquire more nutrients and relieve the N deficiency.And the lower root and rhizome densities of Z.japonica in eutrophic sediment were mainly caused by fewer shoots and shorter longevity,which was resulted from the more serious sulfide inhibition.Our results systematically revealed the effect of sediment trophic status on the phenotypic plasticity,quantity,and distribution of Z.japonica root system,and demonstrated the feasibly of X-ray CT in seagrass root system research.
基金The Innovation Fund of Postgraduate,Sichuan University of Science&Engineering(Grant Number:y2020102)。
文摘China has entered the era of post-poverty alleviation,which effectively links poverty alleviation achievements with rural revitalization strategies.In the era of post-poverty alleviation,in order to effectively promote the sustainable development of poor rural areas,local colleges and universities should actively nurture the self-development skills of the needy.Local colleges and universities should guide the transformation of ideas and concepts,scientifically optimize the allocation of poverty alleviation resources,improve the interest linkage mechanism between colleges and universities,strengthen the investigation and analysis of poverty alleviation projects,improve the convergence of assistance and practice,actively create a good spiritual and cultural environment,uphold the mission of helping cadres,attach importance to the support for the development of characteristic industries,and lastly,promote the convergence of rural revitalization strategies.
基金Supported by the National Key Research and Development Program of China(Nos.2018YFD0900901,2018YFD0900905)the Long Term Observation and Research Plan in the Changjiang River estuary and the Adjacent East China Sea Project(LORCE)(No.14282)+1 种基金the National Natural Science Foundation of China(Nos.41806149,41806181,41706125)the NSFC-Zhejiang Joint Fund,China(No.U1709202)。
文摘Obvious spatiotemporal heterogeneity is a distinct characteristic of ecosystems in subtropical bays.To aid targeted management and ecological restoration in long and narrow semi-enclosed subtropical bays,we analyzed seasonal and regional differences in long-term changes(1980-2019)in the biomass and abundance of large mesozooplankton(LMZ;>505μm)in Xiangshan Bay,Zhejiang,China.We found spatiotemporal heterogeneity in the historical changes of LMZ.Significant negative trends in LMZ biomass were found in the inner and middle bay during the warm season(summer and autumn),when the nutrient concentration(especially dissolved inorganic nitrogen)and temperature increased simultaneously.Nutrient changes in Xiangshan Bay began in the late 1980s or early 1990s,coinciding with large-scale fish cage development.A rapid decline in LMZ biomass occurred after 2005 when power plants commenced operation,accelerating the warming trend.Therefore,the joint stress of eutrophication and warming likely precipitated the decline in LMZ biomass.Conversely,a significant increase in LMZ biomass was found in the outer bay in spring.This trend was consistent with the trend of LMZ biomass near the Changjiang(Yangtze)River estuary,which indicates that the pelagic ecosystem in the outer bay was aff ected by water from the Changjiang River estuary during spring.Based on our results,ecosystem management and restoration in semi-enclosed subtropical bays should focus on internal waters,which have a poor capacity for water exchange.For Xiangshan Bay,the changes in the Changjiang River estuary ecosystem during the cold season(winter and spring)should also be considered.
基金supported by China Manned Space Program through its Space Application System,the National Natural Science Foundation of China(NSFC,grant Nos.11973022 and U1811464)the Natural Science Foundation of Guangdong Province(No.2020A1515010710)。
文摘Galaxy morphology classifications based on machine learning are a typical technique to handle enormous amounts of astronomical observation data,but the key challenge is how to provide enough training data for the machine learning models.Therefore this article proposes an image data augmentation method that combines few-shot learning and generative adversarial networks.The Galaxy10 DECaLs data set is selected for the experiments with consistency,variance,and augmentation effects being evaluated.Three popular networks,including AlexNet,VGG,and ResNet,are used as examples to study the effectiveness of different augmentation methods on galaxy morphology classifications.Experiment results show that the proposed method can generate galaxy images and can be used for expanding the classification model’s training set.According to comparative studies,the best enhancement effect on model performance is obtained by generating a data set that is 0.5–1 time larger than the original data set.Meanwhile,different augmentation strategies have considerably varied effects on different types of galaxies.FSL-GAN achieved the best classification performance on the ResNet network for In-between Round Smooth Galaxies and Unbarred Loose Spiral Galaxies,with F1 Scores of 89.54%and 63.18%,respectively.Experimental comparison reveals that various data augmentation techniques have varied effects on different categories of galaxy morphology and machine learning models.Finally,the best augmentation strategies for each galaxy category are suggested.
基金The National Key Research and Development Program of China under contact No.2021YFC3101702the Natural Science Foundation of Zhejiang Province under contact Nos LY22D060006 and LY14D060007+1 种基金the Key R&D Program of Zhejiang under contact No.2022C03044the Project of Long-term Observation and Research Plan in the Changjiang Estuary and Adjacent East China Sea (LORCE) under contact No.SZ2001。
文摘Ocean fronts play important roles in nutrient transport and in the shaping ecological patterns.Frontal zones in small bays are typically small in scale,have a complex structure,and they are spatially and temporally variable,but there are limited data on how biological communities respond to this variation.Hangzhou Bay,a mediumsized estuary in China,is an ideal place in which to study the response of plankton to small-scale ocean fronts,because three water masses(Qiantang River Diluted Water,Changjiang River Diluted Water,and the East China Sea current) converge here and form dynamic salinity fronts throughout the year.We investigate zooplankton communities,and temperature,salinity and chlorophyll a(Chl a) in Hangzhou Bay in June(wet perio d) and December(dry period) of 2022 and examine the dominant environmental factors that affect zooplankton community spatial variability.We then match the spatial distributions of zooplankton communities with those of salinity fronts.S alinity is the most important explanatory variable to affect zooplankton community spatial variability during both wet and dry periods,in that it contributes>60% of the variability in community structure.Furthermore,the spatial distributions of zooplankton match well with salinity fronts.During December,with weaker Qiantang River Diluted Water and a stronger secondary Changjiang River Plume,zooplankton communities occur in moderate salinity(MS,salinity range 15.6±2.2) and high salinity(HS,22.4±1.7) regions,and their ecological boundaries closely match the Qiantang River Diluted Water front.In June,different zooplankton communities occur in low salinity(LS,3.9±1.0),MS(11.7±3.6) and HS(21.3±1.9) regions.Although the LS region occurs abnormally in the central bay rather than its apex because of the anomalous influence of rising and falling tides during the sampling perio d,the ecological boundaries still match salinity interfaces.Low-salinity or brackish-water zooplankter taxa are relatively more abundant in LS or MS regions,and the biomass and abundance of zooplankton is higher in the MS region.
基金supported by China Manned Space Program through its Space Application Systemthe National Natural Science Foundation of China(NSFC,grant Nos.11973022 and U1811464)the Natural Science Foundation of Guangdong Province(No.2020A1515010710)。
文摘Machine learning has become a crucial technique for classifying the morphology of galaxies as a result of the meteoric development of galactic data.Unfortunately,traditional supervised learning has significant learning costs since it needs a lot of labeled data to be effective.FixMatch,a semi-supervised learning algorithm that serves as a good method,is now a key tool for using large amounts of unlabeled data.Nevertheless,the performance degrades significantly when dealing with large,imbalanced data sets since FixMatch relies on a fixed threshold to filter pseudo-labels.Therefore,this study proposes a dynamic threshold alignment algorithm based on the FixMatch model.First,the class with the highest amount has its reliable pseudo-label ratio determined,and the remaining classes'reliable pseudo-label ratios are approximated in accordance.Second,based on the predicted reliable pseudo-label ratio for each category,it dynamically calculates the threshold for choosing pseudo-labels.By employing this dynamic threshold,the accuracy bias of each category is decreased and the learning of classes with less samples is improved.Experimental results show that in galaxy morphology classification tasks,compared with supervised learning,the proposed algorithm significantly improves performance.When the amount of labeled data is 100,the accuracy and F1-score are improved by 12.8%and 12.6%,respectively.Compared with popular semisupervised algorithms such as FixMatch and MixMatch,the proposed algorithm has better classification performance,greatly reducing the accuracy bias of each category.When the amount of labeled data is 1000,the accuracy of cigar-shaped smooth galaxies with the smallest sample is improved by 37.94%compared to FixMatch.
基金2019 Sichuan Rural Community Governance Research Center(SQZL2019C04)2019 Sichuan New Rural Culture Construction Research Center(SCXN2019-011)+1 种基金2019 Sichuan Research Center for Application and Development of Educational Informatization(JYXX19-020)2019 Center for Early Childhood Education Research,Sichuan(CECER-2019-C03).
文摘The targeted poverty alleviation policy isone of the important methods to solve the problemof poverty in China. After the implementation of thetargeted poverty alleviation policy in China, someresults have shown positive. However, due to theshortage of resources and talents for poverty alleviation,there are still some shortcomings in the targeted povertyalleviation work. In the process of targeted povertyalleviation, if we can promote social work to participatein targeted poverty alleviation and use a wider rangeof social forces to provide more professional andtargeted assistance work for the poor, we will achievethe final sprint for the success of targeted povertyalleviation in China and a well-off society. Based onthe actual situation of China’s current targeted povertyalleviation work, this article takes the relationship andcontent of rural social work in Sichuan Province aspart of the targeted poverty alleviation as well as thedifficulties it faces. The analysis focuses on the pathof rural social work in Sichuan Province to targetedpoverty alleviation and aims to provide more referencesuggestions for targeted poverty alleviation in China.
基金supported by the National Key R&D Program of China(2021YFC2400500)Guangdong Marine Economic Development Pro-gram(GDNRC[2023]35)+3 种基金National Natural Science Foundation of China(U2001221,32161160327,and 52250410340)NSFC-RGC Joint Research Scheme(N_HKU753121)the Shenzhen Science and Technology Program(JSGGKQTD20210831174330015,JCYJ20220531095811027)Shenzhen Medical Research Fund(B2302031).
文摘Magnesium(Mg)alloys are popular biodegradable metals studied for orthopedic and cardiovascular applications,mainly because Mg ions are essential trace elements known to promote angiogenesis and osteogenesis.However,Mg corrosion consists of oxidation and reduction reactions that produce by-products,such as hydrogen gas,reactive oxygen species,and hydroxides.It is still unclear how all these by-products and Mg ions concomitantly alter the microenvironment and cell behaviors spatially and temporally.This study shows that Mg corrosion can enhance cell proliferation by reducing intracellular ROS.However,Mg cannot decrease ROS and promote cell proliferation in simulated inflammatory conditions,meaning the microenvironment is critical.Furthermore,cells may respond to Mg ions differently in chronic or acute alkaline pH or oxidative stress.Depending on the corrosion rate,Mg modulates HIF1αand many signaling pathways like PI3K/AKT/mTOR,mitophagy,cell cycle,and oxidative phosphorylation.Therefore,this study provides a fundamental insight into the importance of reduction reactions in Mg alloys.
