Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO) is a promising solid-state electrolyte for Li-ion batteries,but Li-dendrite's formation greatly limits the applications.In this paper,we systematically investigate the st...Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO) is a promising solid-state electrolyte for Li-ion batteries,but Li-dendrite's formation greatly limits the applications.In this paper,we systematically investigate the stability,electronic properties,and Li-ion mobility of the LLZO surface by the ifrst-principles calculations.We consider the(110) and(001) slab structures with different terminations in the t-and c-LLZO.Our results indicate that both(110) and(001) surfaces prefer to form Li-rich termination due to their low surface energies for either t-or c-LLZO.Moreover,with the decrease of Li contents the stability of Li-rich surfaces is improved initially and degrades later.Unfortunately,the localized surface states at the Fermi level can induce the formation of metallic Li on the Li-rich surfaces.In comparison,Li/La-termination has a relatively low metallic Li formation tendency due to its rather low diffusion barrier.In fact,Li-ion can spontaneously migrate along path II(Li3→Li2) on the Li/La-T(001) surface.In contrast,it is more difficult for Li-ion diffusion on the Li-T(001) surface,which has a minimum diffusion barrier of 0.50 eV.Interestingly,the minimum diffusion barrier decreases to 0.34 eV when removing four Li-ions from the Li-T(001) surface.Thus,our study suggests that by varying Li contents,the stability and Li-ion diffusion barrier of LLZO surfaces can be altered favorably.These advantages can inhibit the formation of metallic Li on the LLZO surfaces.展开更多
In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment...In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment of the existing genetic variability to generate reliable molecular markers for selection of high oil yielding variety. EST derived SSR markers are more useful than genomic markers as they represent the transcriptome, thus, directly linked to functional genes. The present report describes the in silico mining of the microsatellites (SSRs) using J. curcas ESTs from various tissues viz. embryo, root, leaf and seed available in the public domain of NCBI. A total of 13,513 ESTs were downloaded. From these ESTs, 7552 unigenes were obtained and 395 SSRs were generated from 377 SSR-ESTs. These EST-SSRs can be used as potential microsatellite markers for diversity analysis, MAS etc. Since the Jatropha genes carrying SSRs have been identified in this study, thus, EST-SSRs directly linked to genes will be useful for developing trait linked markers.展开更多
The plants are the primary producers and an indispensible source of food and nutrition, medicine and fuel/biofuel. Unsustainable overharvesting and indiscriminate felling of plants due to ever increasing needs of popu...The plants are the primary producers and an indispensible source of food and nutrition, medicine and fuel/biofuel. Unsustainable overharvesting and indiscriminate felling of plants due to ever increasing needs of population pressure are causes of great concern. The IUCN includes, the species facing a high risk of extinction in the wild as threatened, and “endangered” is one of the sub-categories under “threatened” category. Commiphora wightii (Arnott) Bhandari is an arid region plant, highly valued for its medicinally important guggul gum-resin as a source of guggulsterone. It is listed in IUCN’s Red Data List of threatened plants and now it is becoming endangered. Its population is fast depleting in its natural habitat, primarily due to over-exploitation, unsustainable and destructive methods of gum-extraction coupled with natural dry-arid habitat, slow growth and poor regeneration of the plant. Several other reasons have also been indicated for its declining population. Therefore, it demands severe measures for its conservation before we completely lose this important medicinal plant. A lot of research and study is underway but has vast scope for improvement, requiring efforts to supplement with such information that would aid transgenic development and breeding programmes for production and cultivation of improved varieties. The article presents the importance of this plant and its conservation in a nut-shell.展开更多
A good deal of studies have proven that effective exciton dissociation and fast hole transport can operate efficiently in non-fullerene organic photovoltaics(OPVs)despite nearly zero driving force.Even so,whether such...A good deal of studies have proven that effective exciton dissociation and fast hole transport can operate efficiently in non-fullerene organic photovoltaics(OPVs)despite nearly zero driving force.Even so,whether such a phenomenon is universal and how small the driving force can realize the best photovoltaic performance still require a thorough understanding.Herein,despite the zero driving force based on PM6:F8IC system,a maximum short-circuit current(J_(sc))of 23.0 mA/cm^(2) and high power conversion efficiency(PCE)of 12.2%can still be achieved.Due to the continuously adjustable energy levels can be realized in organic semiconducting alloys including F8IC:IT-4F and F8IC:Y6,the suitable third components can play the role of energy level regulator.Therefore,the HOMO energy level offset(DEHOMO(D A))from zero to 0.07 and 0.06 eV is accomplished in the optimized IT-4F and Y6 ternary devices.Consequently,both ternary devices achieved substantially increased PCE of 13.8%and Jsc of 24.4 and 25.2 mA/cm^(2),respectively.Besides,pseudo-planar heterojunction(PPHJ)devices based on alloyed acceptors through sequential spin-coating method further improve the photovoltaic performance.Our work puts forward the concept of energy level regulator and prove that the ternary alloy strategy has unique advantages and huge research potential in continuously adjusting the driving force.展开更多
In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance b...In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance between the loss rate and ionization rate of plasma particles(electrons and ions)maintains quasi-neutrality of the bulk plasma.In the presence of an external perturbation,it tries to retain its quasi-neutrality condition.In this work,we studied how the properties of bulk plasma are affected by an external DC potential perturbation.An auxiliary biased metal disk electrode was used to introduce a potential perturbation to the plasma medium.A single Langmuir probe and an emissive probe,placed in the line of the discharge axis,were used for the characterization of the bulk plasma.It is observed that only positive bias to the auxiliary metal disk increases the plasma potential,electron temperature,and plasma density but these plasma parameters remain unaltered when the disk is biased with a negative potential with respect to plasma potential.The observed plasma parameters for two different-sized,positively as well as negatively biased,metal disks are compared and found inconsistent with the existing theoretical model at large positive bias voltages.The role of the primary energetic electrons population in determining the plasma parameters is discussed.The experimentally observed results are qualitatively explained on the basis of electrostatic confinement arising due to the loss of electrons to a biased metal disk electrode.展开更多
Objective:To assess the role of oxidative stress on anaemia in pregnancy.Methods:Blood samples were collected from pregnant and non-pregnant women who came for antenatal clinic and medical check at Comprehensive Healt...Objective:To assess the role of oxidative stress on anaemia in pregnancy.Methods:Blood samples were collected from pregnant and non-pregnant women who came for antenatal clinic and medical check at Comprehensive Health Center,Akungba-Akoko and Iwaro General Hospital in Akoko Area of Ondo State,Nigeria.Thick and thin blood films were prepared and used for malaria parasite counts.Haemoglobin level was determined by colorimetric method using Drabkin’s solution.Oxidative status was determined using malondiadelhyde level as an indicator of lipid peroxidation,while ascorbic acid and reduced glutathione levels were measured by standard spectrophotometric methods.Results:Mean parasite density was significantly higher in pregnant women than non-pregnant women(P【0.05).Haemoglobin level was significantly reduced in malaria positive pregnant and non-pregnant women than malaria negative(8.3-10.0 g/dL)(P【0.05).The oxidative status indicated that malondialdehyde(MDA) was significantly increased in pregnant[(2.5±0.7) nmol/mL]than non-pregnant women[(1.8±0.1) nmol/mL] (P【0.05),while Vit C and superoxide dismutase(SOD) levels were significantly reduced in pregnant than non-pregnant women(P【0.05).There was an inverse correlation between Hb and MDA levels in pregnant women studied.Positive correlation was observed between the mean MDA level and parasite density(r = 0.53).The Hb level decreased as the parasite density and MDA level increased in pregnant women.Conclusions:This study shows that oxidative stress, caused by malaria infection could be part of the contributing factors responsible for anaemia in pregnancy.展开更多
In the era of coronavirus disease 2019(COVID-19)pandemic,imported COVID-19 cases pose great challenges to many countries.Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detecti...In the era of coronavirus disease 2019(COVID-19)pandemic,imported COVID-19 cases pose great challenges to many countries.Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detection and diagnosis.Wie report the first community infected COVID-19 patient by an imported case in Beijing,which manifested as nodular lesions on chest CT imaging at the early stage.Deep Learning(DL)-based diagnostic systems quantitatively monitored the progress of pulmonary lesions in 6 days and timely made alert for suspected pneumonia,so that prompt medical isolation was taken.The patient was confirmed as COVID-19 case after nucleic acid test,for which the community transmission was prevented timely.The roles of DL-assisted diagnosis in helping radiologists screening suspected COVID cases were discussed.展开更多
The Vilsmeier reagent is well-known electrophilic reagent for synthetically useful organic transformations. Its ionic liquid version has been prepared from DMF-like ionic liquid. Apart from its other reported applicat...The Vilsmeier reagent is well-known electrophilic reagent for synthetically useful organic transformations. Its ionic liquid version has been prepared from DMF-like ionic liquid. Apart from its other reported applications, presently it has been used as an efficient organo reagent for efficient esterification. Variety of esters has been prepared from versatile carboxylic acids and alcohols under ionic liquid conditions with excellent yields. The present system offers an economically and environmentally better alternative to routine procedures.展开更多
Neuroinflammation following immune activation in the central nervous system(CNS)leads to neuronal loss in specific areas of the CNS resulting in neurodegenerative disorders.Thus,fine tuning the immune responses with...Neuroinflammation following immune activation in the central nervous system(CNS)leads to neuronal loss in specific areas of the CNS resulting in neurodegenerative disorders.Thus,fine tuning the immune responses within the brain is essential,because most of the brain diseases are associated with chronic inflammation,展开更多
We collated and synthesized previous studies that reported the impacts of microplastics on soil parameters.The data were classified and integrated to screen for the proportion of significant effects,then we suggest se...We collated and synthesized previous studies that reported the impacts of microplastics on soil parameters.The data were classified and integrated to screen for the proportion of significant effects,then we suggest several directions to alleviate the current data limitation in future experiments.We compiled 106 datasets capturing significant effects,which were analyzed in detail.We found that polyethylene and pellets(or powders)were the most frequently used microplastic composition and shape for soil experiments.The significant effects mainly occurred in broad size ranges(0.1–1 mm)at test concentrations of 0.1%–10%based on soil dry weight.Polyvinyl chloride and film induced significant effects at lower concentrations compared to other compositions and shapes,respectively.We adopted a species sensitivity distribution(SSD)and soil property effect distribution(SPED)method using available data from soil biota,and for soil properties and enzymes deemed relevant for microplastic management.The predicted-no-effect-concentration(PNEC)-like values needed to protect 95%of soil biota and soil properties was estimated to be between 520 and 655 mg kg^(-1).This study was the first to screen microplastic levels with a view toward protecting the soil system.Our results should be regularly updated(e.g.,quarterly)with additional data as they become available.展开更多
All-polymer solar cells(all-PSCs)have made significant progress recently,but few studies have been conducted to investigate the lab-to-manufacturing translation from the spin-coating method to the printing process.Her...All-polymer solar cells(all-PSCs)have made significant progress recently,but few studies have been conducted to investigate the lab-to-manufacturing translation from the spin-coating method to the printing process.Here,the random copolymerization method and non-conjugated backbone approach are integrated to manipulate the morphology and photoelectric properties of the active layer for large-area printed all-PSCs.A series of non-conjugated terpolymer acceptors PYSe-TC_(6)T(x)(x=5,10,and 20,refers to the molar ratio of TC_(6)T unit)are developed by covalently introducing non-conjugated unit TC_(6)T into the PYSe host bipolymer by random copolymerization.The spin-coated PYSe-TC_(6)T(10)-based all-PSC demonstrates the best power conversion efficiency(PCE)of 13.54%,superior to the PYSe-based one(12.45%).More intriguingly,morphological studies reveal that a combination of the random polymerization and non-conjugated backbone strategy can effectively prevent the active layer from overaggregation and improve the film quality during the printing process,thereby minimizing the efficiency and technology gap between spin-coated small-area devices and blade-coated large-area devices.By directly using the same preparation condition of spin-coating,the blade-coated small-area(0.04 cm^(2))delivers a PCE of 12.83%and the large-area(1.21 cm^(2))device achieves a PCE of 11.96%with a small PCE loss.Both PCE value and PCE loss are one of the most outstanding performances of the bladecoated all-PSCs.These findings reveal that a combination of the non-conjugated flexible backbone with random copolymerization to develop non-conjugated terpolymers is an attractive design concept to smoothly realize the lab-to-manufacturing translation.展开更多
Microplastics(MPs)are found worldwide in high abundance,posing a potential threat to ecosystems.Despite the ubiquity of MPs in the environment,very little is known about the regional distribution of MPs and underlying...Microplastics(MPs)are found worldwide in high abundance,posing a potential threat to ecosystems.Despite the ubiquity of MPs in the environment,very little is known about the regional distribution of MPs and underlying factors affecting this distribution in the field,which likely include human activity,but also features of the environment itself.Here,out of a total of 1157 datapoints investigated in 53 Chinese studies,9.68%datapoints were removed as outliers in the heterogeneity analysis.This review revealed that the abundance of MPs was highly heterogeneous.In addition,microplastic(MP)distribution maps based on China demonstrated that the highest abundance of MPs tended to occur near large rivers and central land affected by the intersection of two monsoons.The model-fitting and previous studies showed that MP abundance in China was correlated with longitude,agricultural mulching film usage per capita,temperature,and precipitation.However,due to the heterogeneity of MPs and the low matching degree between the current environmental data and the sampling points,this pattern was not as evident as reported in any single study.Factors affecting the distribution of MPs can not be captured by linear relationships alone,and systematic selection of suitable environmental factors and further model optimization are needed to explore the cause of MP pollution in soil.Overall,this review revealed an uneven distribution of MPs and serves as a reference for model prediction to assess and control plastic pollution in natural soil environments.展开更多
Soils are impacted globally by several anthropogenic factors,including chemical pollutants.Among those,perfluoroalkyl and polyfluoroalkyl substances(PFAS)are of concern due to their high environmental persistence,and ...Soils are impacted globally by several anthropogenic factors,including chemical pollutants.Among those,perfluoroalkyl and polyfluoroalkyl substances(PFAS)are of concern due to their high environmental persistence,and as they might affect soil structure and function.However,data on impacts of PFAS on soil structure and microbially-driven processes are currently lacking.This study explored the effects of perfluorooctanesulfonic acid(PFOS),perfluorooctanoic acid(PFOA)and perfluorobutanesulfonic acid(PFBS)at environmental-relevant concentrations on soil health,using a 6-week microcosm experiment.PFAS(even at 0.5 ng g-1 for PFBS)significantly increased litter decomposition,associated with positive effects on-glucosidase activities.This effect increased with PFAS concentrations.Soil pH was significantly increased,likely as a direct consequence of increased litter decomposition affected by PFAS.Soil respiration was significantly inhibited by PFAS in week 3,while this effect was more variable in week 6.Water-stable aggregates were negatively affected by PFOS,possibly related to microbial shifts.PFAS affected soil bacterial and fungal abundance,but not microbial and certain enzyme activities.Our work highlights the potential effects of PFAS on soil health,and we argue that this substance class could be a factor of environmental change of potentially broad relevance in terrestrial ecosystem functioning.展开更多
Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configura...Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configuration of metal-N_(4)sites and their catalytic performance.Addressing the catalytic contribution of additional axial coordination to such symmetric configuration remains a challenge.Theoretical calculations revealed that axially anchoring an extra pyridine on the tetra-coordinated cobalt porphyrin(Co-N4)to construct penta-coordinated cobalt porphyrin(Co-N_(5))renders cobalt a higher electron density,thereby favoring the rate-determining O_(2)adsorption/activation and reducing the oxygen electroreduction barrier.Therefore,a well-defined Co-N_(5)site is rationally introduced into the azo-linked polymer framework for a fundamental structure-catalytic performance correlation study.As-prepared Co-N_(5)catalyst exhibits a 26 mV positive shift in half-wave potential compared with the pyridine-free Co-N_(4)counterpart,discloses a markedly higher power density(141.4 mW cm^(−2)),and possesses better long-term durability(over 160 h cycles)in a Zn-air battery.Moreover,such a Co-N_(5)catalyst also showcases potential applications for CO_(2)reduction with high CO_(2)-to-CO conversion faradic efficiency and better selectivity than the Co-N_(4)counterpart because coordination of the fifth pyridine evokes electronic localization that suppresses a competitive side reaction.This work proves the positive electrocatalytic contribution of axial penta-coordination on well-defined metalporphyrin-based catalysts and offers atomic understanding of the structure-performance correlation on single atom catalysts for future catalyst design.展开更多
Background:Acute pulmonary embolism(APE)is a fatal cardiovascular disease,yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs.A simple,objective technique will help clinicians make...Background:Acute pulmonary embolism(APE)is a fatal cardiovascular disease,yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs.A simple,objective technique will help clinicians make a quick and precise diagnosis.In population studies,machine learning(ML)plays a critical role in characterizing cardiovascular risks,predicting outcomes,and identifying biomarkers.This work sought to develop an ML model for helping APE diagnosis and compare it against current clinical probability assessment models.Methods:This is a single-center retrospective study.Patients with suspected APE were continuously enrolled and randomly divided into two groups including training and testing sets.A total of 8 ML models,including random forest(RF),Naïve Bayes,decision tree,K-nearest neighbors,logistic regression,multi-layer perceptron,support vector machine,and gradient boosting decision tree were developed based on the training set to diagnose APE.Thereafter,the model with the best diagnostic performance was selected and evaluated against the current clinical assessment strategies,including the Wells score,revised Geneva score,and Years algorithm.Eventually,the ML model was internally validated to assess the diagnostic performance using receiver operating characteristic(ROC)analysis.Results:The ML models were constructed using eight clinical features,including D-dimer,cardiac troponin T(cTNT),arterial oxygen saturation,heart rate,chest pain,lower limb pain,hemoptysis,and chronic heart failure.Among eight ML models,the RF model achieved the best performance with the highest area under the curve(AUC)(AUC=0.774).Compared to the current clinical assessment strategies,the RF model outperformed the Wells score(P=0.030)and was not inferior to any other clinical probability assessment strategy.The AUC of the RF model for diagnosing APE onset in internal validation set was 0.726.Conclusions:Based on RF algorithm,a novel prediction model was finally constructed for APE diagnosis.When compared to the current clinical assessment strategies,the RF model achieved better diagnostic efficacy and accuracy.Therefore,the ML algorithm can be a useful tool in assisting with the diagnosis of APE.展开更多
Aims Plants directly and indirectly interact with many abiotic and biotic soil components.Research so far mostly focused on direct,indi-vidual abiotic or biotic effects on plant growth,but only few studies tested the ...Aims Plants directly and indirectly interact with many abiotic and biotic soil components.Research so far mostly focused on direct,indi-vidual abiotic or biotic effects on plant growth,but only few studies tested the indirect effects of abiotic soil factors on plant growth.therefore,we investigated how abiotic soil conditions affect plant performance,via changes induced by soil biota.Methods In a full-factorial experiment,we grew the widespread grass Dactylis glomerata either with or without soil biota and investigated the impact of soil temperature,fertility and moisture on the soil biota effects on plant growth.We measured biomass production,root traits and colonization by arbuscular mycorrhizal fungi as well as microbial respiration.Important Findings We found significant interaction effects between abiotic soil con-ditions and soil biota on plant growth for fertility,but especially for soil temperature,as an increase of 10°c significantly changed the soil biota effects on plant growth from positive to neutral.However,if tested individually,an increase in soil temperature and fertility per se positively affected plant biomass production,whereas soil biota per se did not affect overall plant growth,but both influenced root architecture.By affecting soil microbial activ-ity and root architecture,soil temperature might influence both mutualistic and pathogenic interactions between plants and soil biota.Such soil temperature effects should be considered in soil feedback studies to ensure greater transferability of results from artificial and experimental conditions to natural environmental conditions.展开更多
Fluorescent rare-earth ions are useful for efficient energy transfer via multi- channels with different properties. Tuning these transfer processes in functional rare-earth materials has attracted considerable attenti...Fluorescent rare-earth ions are useful for efficient energy transfer via multi- channels with different properties. Tuning these transfer processes in functional rare-earth materials has attracted considerable attention to satisfy the various demands of diverse practical applications. In this study, strong tunabilities of cooperative energy transfer and nonlinear upconversion emissions are realized using (Yb3+, Er3+)/NaYF4 nanocrystals with and without doped Mn2~ ions by adopting a plasmonic nanocavity composed of a silver nanorod array. The plasmon nanocavity can not only increase the energy transfer between Mn2+ and (Yb3+, Er3+) but also significantly enhance the radiative emission. This reveals a prominent nonlinear gain in the nanocavity nanosystems. These observations suggest the prospective applications in the design and preparation of rare-earth nanocrystals with excellent tunabilities of multiple functionalities.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 12064015 and 12064014)。
文摘Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO) is a promising solid-state electrolyte for Li-ion batteries,but Li-dendrite's formation greatly limits the applications.In this paper,we systematically investigate the stability,electronic properties,and Li-ion mobility of the LLZO surface by the ifrst-principles calculations.We consider the(110) and(001) slab structures with different terminations in the t-and c-LLZO.Our results indicate that both(110) and(001) surfaces prefer to form Li-rich termination due to their low surface energies for either t-or c-LLZO.Moreover,with the decrease of Li contents the stability of Li-rich surfaces is improved initially and degrades later.Unfortunately,the localized surface states at the Fermi level can induce the formation of metallic Li on the Li-rich surfaces.In comparison,Li/La-termination has a relatively low metallic Li formation tendency due to its rather low diffusion barrier.In fact,Li-ion can spontaneously migrate along path II(Li3→Li2) on the Li/La-T(001) surface.In contrast,it is more difficult for Li-ion diffusion on the Li-T(001) surface,which has a minimum diffusion barrier of 0.50 eV.Interestingly,the minimum diffusion barrier decreases to 0.34 eV when removing four Li-ions from the Li-T(001) surface.Thus,our study suggests that by varying Li contents,the stability and Li-ion diffusion barrier of LLZO surfaces can be altered favorably.These advantages can inhibit the formation of metallic Li on the LLZO surfaces.
文摘In recent years, Jatropha curcas L. has gained popularity as a potential biodiesel plant. The varying oil content, reported between accessions belonging to different agroclimatic zones, has necessitated the assessment of the existing genetic variability to generate reliable molecular markers for selection of high oil yielding variety. EST derived SSR markers are more useful than genomic markers as they represent the transcriptome, thus, directly linked to functional genes. The present report describes the in silico mining of the microsatellites (SSRs) using J. curcas ESTs from various tissues viz. embryo, root, leaf and seed available in the public domain of NCBI. A total of 13,513 ESTs were downloaded. From these ESTs, 7552 unigenes were obtained and 395 SSRs were generated from 377 SSR-ESTs. These EST-SSRs can be used as potential microsatellite markers for diversity analysis, MAS etc. Since the Jatropha genes carrying SSRs have been identified in this study, thus, EST-SSRs directly linked to genes will be useful for developing trait linked markers.
文摘The plants are the primary producers and an indispensible source of food and nutrition, medicine and fuel/biofuel. Unsustainable overharvesting and indiscriminate felling of plants due to ever increasing needs of population pressure are causes of great concern. The IUCN includes, the species facing a high risk of extinction in the wild as threatened, and “endangered” is one of the sub-categories under “threatened” category. Commiphora wightii (Arnott) Bhandari is an arid region plant, highly valued for its medicinally important guggul gum-resin as a source of guggulsterone. It is listed in IUCN’s Red Data List of threatened plants and now it is becoming endangered. Its population is fast depleting in its natural habitat, primarily due to over-exploitation, unsustainable and destructive methods of gum-extraction coupled with natural dry-arid habitat, slow growth and poor regeneration of the plant. Several other reasons have also been indicated for its declining population. Therefore, it demands severe measures for its conservation before we completely lose this important medicinal plant. A lot of research and study is underway but has vast scope for improvement, requiring efforts to supplement with such information that would aid transgenic development and breeding programmes for production and cultivation of improved varieties. The article presents the importance of this plant and its conservation in a nut-shell.
基金support the National Natural Science Foundation of China(NSFC)(51973032,and 21905043)support from the National Natural Science Foundation of China(NSFC)(51833004)financial support by the National Key Research and Development Program of China(2017YFA0207700)。
文摘A good deal of studies have proven that effective exciton dissociation and fast hole transport can operate efficiently in non-fullerene organic photovoltaics(OPVs)despite nearly zero driving force.Even so,whether such a phenomenon is universal and how small the driving force can realize the best photovoltaic performance still require a thorough understanding.Herein,despite the zero driving force based on PM6:F8IC system,a maximum short-circuit current(J_(sc))of 23.0 mA/cm^(2) and high power conversion efficiency(PCE)of 12.2%can still be achieved.Due to the continuously adjustable energy levels can be realized in organic semiconducting alloys including F8IC:IT-4F and F8IC:Y6,the suitable third components can play the role of energy level regulator.Therefore,the HOMO energy level offset(DEHOMO(D A))from zero to 0.07 and 0.06 eV is accomplished in the optimized IT-4F and Y6 ternary devices.Consequently,both ternary devices achieved substantially increased PCE of 13.8%and Jsc of 24.4 and 25.2 mA/cm^(2),respectively.Besides,pseudo-planar heterojunction(PPHJ)devices based on alloyed acceptors through sequential spin-coating method further improve the photovoltaic performance.Our work puts forward the concept of energy level regulator and prove that the ternary alloy strategy has unique advantages and huge research potential in continuously adjusting the driving force.
文摘In a steady-state plasma,the loss rate of plasma particles to the chamber wall and surfaces in contact with plasma is balanced by the ionization rate of background neutrals in the hot-filament discharges.The balance between the loss rate and ionization rate of plasma particles(electrons and ions)maintains quasi-neutrality of the bulk plasma.In the presence of an external perturbation,it tries to retain its quasi-neutrality condition.In this work,we studied how the properties of bulk plasma are affected by an external DC potential perturbation.An auxiliary biased metal disk electrode was used to introduce a potential perturbation to the plasma medium.A single Langmuir probe and an emissive probe,placed in the line of the discharge axis,were used for the characterization of the bulk plasma.It is observed that only positive bias to the auxiliary metal disk increases the plasma potential,electron temperature,and plasma density but these plasma parameters remain unaltered when the disk is biased with a negative potential with respect to plasma potential.The observed plasma parameters for two different-sized,positively as well as negatively biased,metal disks are compared and found inconsistent with the existing theoretical model at large positive bias voltages.The role of the primary energetic electrons population in determining the plasma parameters is discussed.The experimentally observed results are qualitatively explained on the basis of electrostatic confinement arising due to the loss of electrons to a biased metal disk electrode.
文摘Objective:To assess the role of oxidative stress on anaemia in pregnancy.Methods:Blood samples were collected from pregnant and non-pregnant women who came for antenatal clinic and medical check at Comprehensive Health Center,Akungba-Akoko and Iwaro General Hospital in Akoko Area of Ondo State,Nigeria.Thick and thin blood films were prepared and used for malaria parasite counts.Haemoglobin level was determined by colorimetric method using Drabkin’s solution.Oxidative status was determined using malondiadelhyde level as an indicator of lipid peroxidation,while ascorbic acid and reduced glutathione levels were measured by standard spectrophotometric methods.Results:Mean parasite density was significantly higher in pregnant women than non-pregnant women(P【0.05).Haemoglobin level was significantly reduced in malaria positive pregnant and non-pregnant women than malaria negative(8.3-10.0 g/dL)(P【0.05).The oxidative status indicated that malondialdehyde(MDA) was significantly increased in pregnant[(2.5±0.7) nmol/mL]than non-pregnant women[(1.8±0.1) nmol/mL] (P【0.05),while Vit C and superoxide dismutase(SOD) levels were significantly reduced in pregnant than non-pregnant women(P【0.05).There was an inverse correlation between Hb and MDA levels in pregnant women studied.Positive correlation was observed between the mean MDA level and parasite density(r = 0.53).The Hb level decreased as the parasite density and MDA level increased in pregnant women.Conclusions:This study shows that oxidative stress, caused by malaria infection could be part of the contributing factors responsible for anaemia in pregnancy.
文摘In the era of coronavirus disease 2019(COVID-19)pandemic,imported COVID-19 cases pose great challenges to many countries.Chest CT examination is considered to be complementary to nucleic acid test for COVID-19 detection and diagnosis.Wie report the first community infected COVID-19 patient by an imported case in Beijing,which manifested as nodular lesions on chest CT imaging at the early stage.Deep Learning(DL)-based diagnostic systems quantitatively monitored the progress of pulmonary lesions in 6 days and timely made alert for suspected pneumonia,so that prompt medical isolation was taken.The patient was confirmed as COVID-19 case after nucleic acid test,for which the community transmission was prevented timely.The roles of DL-assisted diagnosis in helping radiologists screening suspected COVID cases were discussed.
文摘The Vilsmeier reagent is well-known electrophilic reagent for synthetically useful organic transformations. Its ionic liquid version has been prepared from DMF-like ionic liquid. Apart from its other reported applications, presently it has been used as an efficient organo reagent for efficient esterification. Variety of esters has been prepared from versatile carboxylic acids and alcohols under ionic liquid conditions with excellent yields. The present system offers an economically and environmentally better alternative to routine procedures.
基金funded by Department of Science and Technology,Government of India (Grant No.SR/CSI/59/2011(G)Gujarat State Biotechnology Mission (Grant No.GSBTM/MD/PROJECTS/.SSA/3385/2012/2013)
文摘Neuroinflammation following immune activation in the central nervous system(CNS)leads to neuronal loss in specific areas of the CNS resulting in neurodegenerative disorders.Thus,fine tuning the immune responses within the brain is essential,because most of the brain diseases are associated with chronic inflammation,
文摘We collated and synthesized previous studies that reported the impacts of microplastics on soil parameters.The data were classified and integrated to screen for the proportion of significant effects,then we suggest several directions to alleviate the current data limitation in future experiments.We compiled 106 datasets capturing significant effects,which were analyzed in detail.We found that polyethylene and pellets(or powders)were the most frequently used microplastic composition and shape for soil experiments.The significant effects mainly occurred in broad size ranges(0.1–1 mm)at test concentrations of 0.1%–10%based on soil dry weight.Polyvinyl chloride and film induced significant effects at lower concentrations compared to other compositions and shapes,respectively.We adopted a species sensitivity distribution(SSD)and soil property effect distribution(SPED)method using available data from soil biota,and for soil properties and enzymes deemed relevant for microplastic management.The predicted-no-effect-concentration(PNEC)-like values needed to protect 95%of soil biota and soil properties was estimated to be between 520 and 655 mg kg^(-1).This study was the first to screen microplastic levels with a view toward protecting the soil system.Our results should be regularly updated(e.g.,quarterly)with additional data as they become available.
基金the support from the National Natural Science Foundation of China(NSFC)(51973087,52173170 and 22169012)Thousand Talents Plan of Jiangxi Province(jxsq2019201004)。
文摘All-polymer solar cells(all-PSCs)have made significant progress recently,but few studies have been conducted to investigate the lab-to-manufacturing translation from the spin-coating method to the printing process.Here,the random copolymerization method and non-conjugated backbone approach are integrated to manipulate the morphology and photoelectric properties of the active layer for large-area printed all-PSCs.A series of non-conjugated terpolymer acceptors PYSe-TC_(6)T(x)(x=5,10,and 20,refers to the molar ratio of TC_(6)T unit)are developed by covalently introducing non-conjugated unit TC_(6)T into the PYSe host bipolymer by random copolymerization.The spin-coated PYSe-TC_(6)T(10)-based all-PSC demonstrates the best power conversion efficiency(PCE)of 13.54%,superior to the PYSe-based one(12.45%).More intriguingly,morphological studies reveal that a combination of the random polymerization and non-conjugated backbone strategy can effectively prevent the active layer from overaggregation and improve the film quality during the printing process,thereby minimizing the efficiency and technology gap between spin-coated small-area devices and blade-coated large-area devices.By directly using the same preparation condition of spin-coating,the blade-coated small-area(0.04 cm^(2))delivers a PCE of 12.83%and the large-area(1.21 cm^(2))device achieves a PCE of 11.96%with a small PCE loss.Both PCE value and PCE loss are one of the most outstanding performances of the bladecoated all-PSCs.These findings reveal that a combination of the non-conjugated flexible backbone with random copolymerization to develop non-conjugated terpolymers is an attractive design concept to smoothly realize the lab-to-manufacturing translation.
基金supported by the specific research fund of the Innovation Platform for Academicians of Hainan Province(China)(No.YSPTZX202205)the Research Initiation Fund of Hainan University(China)(No.KYQD(ZR)20032)+3 种基金the Hainan Province Science and Technology Special Fund(China)(No.ZDYF2022SHFZ322)the Ministry of Agriculture and Rural Affairs of China(Nos.13220064 and 13210133)the Education Department of Hainan Province(China)(No.Hnjgzc2022-3)the National Nature Science Foundation of China(No.41571288).
文摘Microplastics(MPs)are found worldwide in high abundance,posing a potential threat to ecosystems.Despite the ubiquity of MPs in the environment,very little is known about the regional distribution of MPs and underlying factors affecting this distribution in the field,which likely include human activity,but also features of the environment itself.Here,out of a total of 1157 datapoints investigated in 53 Chinese studies,9.68%datapoints were removed as outliers in the heterogeneity analysis.This review revealed that the abundance of MPs was highly heterogeneous.In addition,microplastic(MP)distribution maps based on China demonstrated that the highest abundance of MPs tended to occur near large rivers and central land affected by the intersection of two monsoons.The model-fitting and previous studies showed that MP abundance in China was correlated with longitude,agricultural mulching film usage per capita,temperature,and precipitation.However,due to the heterogeneity of MPs and the low matching degree between the current environmental data and the sampling points,this pattern was not as evident as reported in any single study.Factors affecting the distribution of MPs can not be captured by linear relationships alone,and systematic selection of suitable environmental factors and further model optimization are needed to explore the cause of MP pollution in soil.Overall,this review revealed an uneven distribution of MPs and serves as a reference for model prediction to assess and control plastic pollution in natural soil environments.
文摘Soils are impacted globally by several anthropogenic factors,including chemical pollutants.Among those,perfluoroalkyl and polyfluoroalkyl substances(PFAS)are of concern due to their high environmental persistence,and as they might affect soil structure and function.However,data on impacts of PFAS on soil structure and microbially-driven processes are currently lacking.This study explored the effects of perfluorooctanesulfonic acid(PFOS),perfluorooctanoic acid(PFOA)and perfluorobutanesulfonic acid(PFBS)at environmental-relevant concentrations on soil health,using a 6-week microcosm experiment.PFAS(even at 0.5 ng g-1 for PFBS)significantly increased litter decomposition,associated with positive effects on-glucosidase activities.This effect increased with PFAS concentrations.Soil pH was significantly increased,likely as a direct consequence of increased litter decomposition affected by PFAS.Soil respiration was significantly inhibited by PFAS in week 3,while this effect was more variable in week 6.Water-stable aggregates were negatively affected by PFOS,possibly related to microbial shifts.PFAS affected soil bacterial and fungal abundance,but not microbial and certain enzyme activities.Our work highlights the potential effects of PFAS on soil health,and we argue that this substance class could be a factor of environmental change of potentially broad relevance in terrestrial ecosystem functioning.
基金financially supported by the National Natural Science Foundation of China(grant nos.52073137 and 51763018).
文摘Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configuration of metal-N_(4)sites and their catalytic performance.Addressing the catalytic contribution of additional axial coordination to such symmetric configuration remains a challenge.Theoretical calculations revealed that axially anchoring an extra pyridine on the tetra-coordinated cobalt porphyrin(Co-N4)to construct penta-coordinated cobalt porphyrin(Co-N_(5))renders cobalt a higher electron density,thereby favoring the rate-determining O_(2)adsorption/activation and reducing the oxygen electroreduction barrier.Therefore,a well-defined Co-N_(5)site is rationally introduced into the azo-linked polymer framework for a fundamental structure-catalytic performance correlation study.As-prepared Co-N_(5)catalyst exhibits a 26 mV positive shift in half-wave potential compared with the pyridine-free Co-N_(4)counterpart,discloses a markedly higher power density(141.4 mW cm^(−2)),and possesses better long-term durability(over 160 h cycles)in a Zn-air battery.Moreover,such a Co-N_(5)catalyst also showcases potential applications for CO_(2)reduction with high CO_(2)-to-CO conversion faradic efficiency and better selectivity than the Co-N_(4)counterpart because coordination of the fifth pyridine evokes electronic localization that suppresses a competitive side reaction.This work proves the positive electrocatalytic contribution of axial penta-coordination on well-defined metalporphyrin-based catalysts and offers atomic understanding of the structure-performance correlation on single atom catalysts for future catalyst design.
基金supported by grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2021-I2M-1-049)the Elite Medical Professionals Project of China-Japan Friendship Hospital(No.ZRJY2021-BJ02)the National High Level Hospital Clinical Research Funding(No.2022-NHLHCRF-LX-01).
文摘Background:Acute pulmonary embolism(APE)is a fatal cardiovascular disease,yet missed diagnosis and misdiagnosis often occur due to non-specific symptoms and signs.A simple,objective technique will help clinicians make a quick and precise diagnosis.In population studies,machine learning(ML)plays a critical role in characterizing cardiovascular risks,predicting outcomes,and identifying biomarkers.This work sought to develop an ML model for helping APE diagnosis and compare it against current clinical probability assessment models.Methods:This is a single-center retrospective study.Patients with suspected APE were continuously enrolled and randomly divided into two groups including training and testing sets.A total of 8 ML models,including random forest(RF),Naïve Bayes,decision tree,K-nearest neighbors,logistic regression,multi-layer perceptron,support vector machine,and gradient boosting decision tree were developed based on the training set to diagnose APE.Thereafter,the model with the best diagnostic performance was selected and evaluated against the current clinical assessment strategies,including the Wells score,revised Geneva score,and Years algorithm.Eventually,the ML model was internally validated to assess the diagnostic performance using receiver operating characteristic(ROC)analysis.Results:The ML models were constructed using eight clinical features,including D-dimer,cardiac troponin T(cTNT),arterial oxygen saturation,heart rate,chest pain,lower limb pain,hemoptysis,and chronic heart failure.Among eight ML models,the RF model achieved the best performance with the highest area under the curve(AUC)(AUC=0.774).Compared to the current clinical assessment strategies,the RF model outperformed the Wells score(P=0.030)and was not inferior to any other clinical probability assessment strategy.The AUC of the RF model for diagnosing APE onset in internal validation set was 0.726.Conclusions:Based on RF algorithm,a novel prediction model was finally constructed for APE diagnosis.When compared to the current clinical assessment strategies,the RF model achieved better diagnostic efficacy and accuracy.Therefore,the ML algorithm can be a useful tool in assisting with the diagnosis of APE.
文摘Aims Plants directly and indirectly interact with many abiotic and biotic soil components.Research so far mostly focused on direct,indi-vidual abiotic or biotic effects on plant growth,but only few studies tested the indirect effects of abiotic soil factors on plant growth.therefore,we investigated how abiotic soil conditions affect plant performance,via changes induced by soil biota.Methods In a full-factorial experiment,we grew the widespread grass Dactylis glomerata either with or without soil biota and investigated the impact of soil temperature,fertility and moisture on the soil biota effects on plant growth.We measured biomass production,root traits and colonization by arbuscular mycorrhizal fungi as well as microbial respiration.Important Findings We found significant interaction effects between abiotic soil con-ditions and soil biota on plant growth for fertility,but especially for soil temperature,as an increase of 10°c significantly changed the soil biota effects on plant growth from positive to neutral.However,if tested individually,an increase in soil temperature and fertility per se positively affected plant biomass production,whereas soil biota per se did not affect overall plant growth,but both influenced root architecture.By affecting soil microbial activ-ity and root architecture,soil temperature might influence both mutualistic and pathogenic interactions between plants and soil biota.Such soil temperature effects should be considered in soil feedback studies to ensure greater transferability of results from artificial and experimental conditions to natural environmental conditions.
文摘Fluorescent rare-earth ions are useful for efficient energy transfer via multi- channels with different properties. Tuning these transfer processes in functional rare-earth materials has attracted considerable attention to satisfy the various demands of diverse practical applications. In this study, strong tunabilities of cooperative energy transfer and nonlinear upconversion emissions are realized using (Yb3+, Er3+)/NaYF4 nanocrystals with and without doped Mn2~ ions by adopting a plasmonic nanocavity composed of a silver nanorod array. The plasmon nanocavity can not only increase the energy transfer between Mn2+ and (Yb3+, Er3+) but also significantly enhance the radiative emission. This reveals a prominent nonlinear gain in the nanocavity nanosystems. These observations suggest the prospective applications in the design and preparation of rare-earth nanocrystals with excellent tunabilities of multiple functionalities.