The meso-dynamical behaviour of a high-speed rail ballast bed with under sleeper pads(USPs)was studied.The geometrically irregular refined discrete element model of the ballast particles was constructed using 3D scann...The meso-dynamical behaviour of a high-speed rail ballast bed with under sleeper pads(USPs)was studied.The geometrically irregular refined discrete element model of the ballast particles was constructed using 3D scanning techniques,and the 3D dynamic model of the rail-sleeper-ballast bed was constructed using the coupled discrete element method-multiflexible-body dynamics(DEM-MFBD)approach.We analyse the meso-mechanical dynamics of the ballast bed with USPs under dynamic load on a train and verify the correctness of the model in laboratory tests.It is shown that the deformation of the USPs increases the contact area between the sleeper and the ballast particles,and subsequently the number of contacts between them.As the depth of the granular ballast bed increases,the contact area becomes larger,and the contact force between the ballast particles gradually decreases.Under the action of the elastic USPs,the contact forces between ballast particles are reduced and the overall vibration level of the ballast bed can be reduced.The settlement of the granular ballast bed occurs mainly at the shallow position of the sleeper bottom,and the installation of the elastic USPs can be effective in reducing the stress on the ballast particles and the settlement of the ballast bed.展开更多
Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming a...Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming and labor-intensive.Herein,an antibody-modified graphene transistor assay is developed for sensitive and minute-level detection of Met in complex environments.The anti-Met probe captured charged targets within 120 s,leading to a p-doping effect near the graphene channel.The limit of detection reaches 50 aM(5.0×10^(-17)M)Met in solution.The graphene transistor would be a valuable tool for Met detection effective prevention of drug abuse.展开更多
Objective:Systemic chemotherapy has limited efficacy in the treatment of peritoneal metastasis(PM)in gastric cancer(GC).Hyperthermic intraperitoneal chemotherapy(HIPEC)combined with complete cytoreductive surgery(CRS)...Objective:Systemic chemotherapy has limited efficacy in the treatment of peritoneal metastasis(PM)in gastric cancer(GC).Hyperthermic intraperitoneal chemotherapy(HIPEC)combined with complete cytoreductive surgery(CRS)has shown promising outcomes but remains controversial.The present study aimed to evaluate the safety and efficacy of HIPEC without CRS in GC patients with PM.Methods:This retrospective propensity score-matched multicenter cohort study included GC patients with PM treated with either chemotherapy alone(Cx group)or with HIPEC combined with chemotherapy(HIPEC-Cx group)in four Chinese high-volume gastric medical centers between 2010 and 2017.The primary outcomes were median survival time(MST)and 3-year overall survival(OS).Propensity score matching was performed to compensate for controlling potential confounding effects and selection bias.Results:Of 663 eligible patients,498 were matched.The MST in the Cx and HIPEC-Cx groups was 10.8 and 15.9 months,respectively[hazard ratio(HR)=0.71,95%confidence interval(95%CI),0.58-0.88;P=0.002].The 3-year OS rate was 10.1%(95%CI,5.4%-14.8%)and 18.4%(95%CI,12.3%-24.5%)in the Cx and HIPEC-Cx groups,respectively(P=0.017).The complication rates were comparable.The time to first flatus and length of hospital stay for patients undergoing HIPEC combined with chemotherapy was longer than that of chemotherapy alone(4.6±2.4 d vs.2.7±1.8 d,P<0.001;14.2±5.8 d vs.11.4±7.7 d,P<0.001),respectively.The median follow-up period was 33.2 months.Conclusions:Compared with standard systemic chemotherapy,HIPEC combined with chemotherapy revealed a statistically significant survival benefit for GC patients with PM,without compromising patient safety.展开更多
Estimating individual tree biomass is critical to forest carbon accounting and ecosystem service modeling.In this study,we developed one-（tree diameter only） and two-variable（tree diameter and height） biomass equa...Estimating individual tree biomass is critical to forest carbon accounting and ecosystem service modeling.In this study,we developed one-（tree diameter only） and two-variable（tree diameter and height） biomass equations,biomass conversion factor（BCF） models,and an integrated simultaneous equation system（ISES） to estimate the aboveground biomass for five conifer species in China,i.e.,Cunninghamia lanceolata（Lamb.） Hook.,Pinus massoniana Lamb.,P.yunnanensis Faranch,P.tabulaeformis Carr.and P.elliottii Engelm.,based on the field measurement data of aboveground biomass and stem volumes from 1055 destructive sample trees across the country.We found that all three methods,including the one-and two-variable equations,could adequately estimate aboveground biomass with a mean prediction error less than 5%,except for Pinus yunnanensis which yielded an error of about 6%.The BCF method was slightly poorer than the biomass equation and the ISES methods.The average coefficients of determination（R^2） were 0.944,0.938 and 0.943 and the mean prediction errors were 4.26,4.49 and 4.29% for the biomass equation method,the BCF method and the ISES method,respectively.The ISES method was the best approach for estimating aboveground biomass,which not only had high accuracy but also could estimate stocking volumes simultaneously that was compatible with aboveground biomass.In addition,we found that it is possible to develop a species-invariant one-variable allometric model for estimating aboveground biomass of all the five coniferous species.The model had an exponent parameter of 7/3 and the intercept parameter a_0 could be estimated indirectly from stem basic density（a_0= 0.294 q）.展开更多
Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is -100 μM. IntraceUular ATP levels are generally in t...Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is -100 μM. IntraceUular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration （between 50 and 100μM） stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intraceHular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.展开更多
AIM:To investigate the role of inositol-requiring enzyme 1α(IRE1α) in gut development of Xenopus lavies embryos.METHODS:Xenopus embryos were obtained with in vitro fertilization and cultured in 0.1 × MBSH.One a...AIM:To investigate the role of inositol-requiring enzyme 1α(IRE1α) in gut development of Xenopus lavies embryos.METHODS:Xenopus embryos were obtained with in vitro fertilization and cultured in 0.1 × MBSH.One and half nanogram of IRE1α,1 ng of IRE1α-GR mRNA,1 ng of IRE1αΔC-GR mRNA,and 50 ng of IRE1α morpholino oligonucleotide(MO) or XBP1(C)MO were injected into four blastomeres at 4-cell stage for scoring the phenotype and marker gene analysis.To rescue the effect of IRE1α MO,1 ng of IRE1α-GR mRNA was coinjected with 50 ng of MO.For the activation of the GR-fusion proteins,dexamethasone was prepared as 5 mmol/L stock solutions in 100% ethanol and applied to the mRNA injected embryos at desired stages in a concentration of 10 μmol/L in 0.1 × MBSH.Embryos were kept in dexamethasone up to stage 41.Whole-mount in situ hybridization was used to determine specific gene expression,such as IRE1α,IRE1β,Xbra and Xsox17α.IRE1α protein expression during Xenopus embryogenesis was detected by Western blotting.RESULTS:In the whole-mount in situ hybridization analysis,xenopus IRE1α and IRE1β showed quite different expression pattern during tadpole stage.The relatively higher expression of IRE1α was observed in the pancreas,and significant transcription of IRE1β was found in the liver.IRE1α protein could be detected at all developmental stages analyzed,from stage 1 to stage 42.Gain-of-function assay showed that IRE1α mRNA injected embryos at tailbud stage were nearly normal and the expression of the pan-mesodermal marker gene Xbra and the endodermal gene Xsox17α at stage 10.5 was not significantly changed in embryos injected with IRE1α mRNA as compared to uninjected control embryos.And at tadpole stage,the embryos injected with IRE1α-GR mRNA did not display overt phenotype,such as gut-coiling defect.Loss-of-function assay demonstrated that the IRE1α MO injected embryos were morphologically normal before the tailbud stages.We did not observe a significant change of mesodermal and endodermal marker gene expression,while after stage 40,about 80% of the MO injected embryos exhibited dramatic gut defects in which the guts did not coil,but other structures outside the gastrointestinal tract were relatively normal.To test if the phenotypes were specifically caused by the knockdown of IRE1α,a rescue experiment was performed by co-injection of IRE1α-GR mRMA with IRE1α MO.The data obtained demonstrated that the gut coiling defect was rescued.The deletion mutant of IRE1α was constructed,consisting of the N-terminal part without the C-terminal kinase and RNase domains named IRE1αΔC,to investigate the functional domain of IRE1α.Injection of IRE1αΔCGR mRNA caused similar morphological alterations with gut malformation by interfering with the function of endogenous xIRE1α.In order to investigate if IRE1α/XBP1 pathway was involved in gut development,50 ng of XBP1 MO was injected and the results showed that knockdown of XBP1 resulted in similar morphological alterations with gut-coiling defect at tadpole stage.CONCLUSION:IRE1α is not required for germ layer formation but for gut development in Xenopus lavies and it may function via XBP1-dependent pathway.展开更多
There are two distinct types of domains,design-and cross-classes domains,with the former extensively studied under the topic of small-area estimation.In natural resource inventory,however,most classes listed in the co...There are two distinct types of domains,design-and cross-classes domains,with the former extensively studied under the topic of small-area estimation.In natural resource inventory,however,most classes listed in the condition tables of national inventory programs are characterized as cross-classes domains,such as vegetation type,productivity class,and age class.To date,challenges remain active for inventorying cross-classes domains because these domains are usually of unknown sampling frame and spatial distribution with the result that inference relies on population-level as opposed to domain-level sampling.Multiple challenges are noteworthy:(1)efficient sampling strategies are difficult to develop because of little priori information about the target domain;(2)domain inference relies on a sample designed for the population,so within-domain sample sizes could be too small to support a precise estimation;and(3)increasing sample size for the population does not ensure an increase to the domain,so actual sample size for a target domain remains highly uncertain,particularly for small domains.In this paper,we introduce a design-based generalized systematic adaptive cluster sampling(GSACS)for inventorying cross-classes domains.Design-unbiased Hansen-Hurwitz and Horvitz-Thompson estimators are derived for domain totals and compared within GSACS and with systematic sampling(SYS).Comprehensive Monte Carlo simulations show that(1)GSACS Hansen-Hurwitz and Horvitz-Thompson estimators are unbiased and equally efficient,whereas thelatter outperforms the former for supporting a sample of size one;(2)SYS is a special case of GSACS while the latter outperforms the former in terms of increased efficiency and reduced intensity;(3)GSACS Horvitz-Thompson variance estimator is design-unbiased for a single SYS sample;and(4)rules-ofthumb summarized with respect to sampling design and spatial effect improve precision.Because inventorying a mini domain is analogous to inventorying a rare variable,alternative network sampling procedures are also readily available for inventorying cross-classes domains.展开更多
Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil ...Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.展开更多
In order to analysis the abnormal vehicle behavior by trajectory fitting effectively, the whole process is divided into three steps: target detection and tracking, vehicle trajectory analysis, vehicle behavior detecti...In order to analysis the abnormal vehicle behavior by trajectory fitting effectively, the whole process is divided into three steps: target detection and tracking, vehicle trajectory analysis, vehicle behavior detection. Firstly, a three-frame-differencing method is used to achieve initial target location and an improved tracking algorithm based on Kalman predictor is proposed;then, an adaptive segmented linear fitting algorithm is proposed to achieve vehicle trajectory fitting;finally, two parameters including the rate of velocity variation and the rate of direction variation are used to establish vehicle abnormal behavior detection model. Experiment result shows that the three high dangerous vehicle behaviors in road surveillance videos can be detected effectively: sharp brake, sharp turn, and sharp turn brake.展开更多
The study of China s carbon emissions and carbon sequestration potential is of great practical significance to the formulation of carbon neutrality strategies and methods of China.Carbon emission is an inevitable outc...The study of China s carbon emissions and carbon sequestration potential is of great practical significance to the formulation of carbon neutrality strategies and methods of China.Carbon emission is an inevitable outcome of the initial stage of economic development,especially the right of developing countries existence and development.The carbon emission of China has been maintained at a low level for a long time and reached the top of the world in 2005.However,per capita carbon emission was still only 46.28%of the United States in 2016.China s total CO_(2) emissions are expected to reach 17-19 Gt/a by 2030.To achieve the goal of carbon neutrality in 2060,the main problems are the low technical capacity of emission reduction and the unreasonable structure of energy consumption.Therefore,replacing coal with gas is one of the most effective ways of emission reduction.By 2060,the carbon sequestration capacity of forest vegetation will reach or exceed 759.14 Mt/a and the CO_(2) sequestration capacity will reach 2783.5 Mt/a.According to that,China s carbon intensity must reduce by 95.39%on the basis of the carbon intensity in 2017,reaching 640 t/100 million yuan.The carbon sequestration capacity of terrestrial vegetation(forest,grassland)will reach or exceed 1380.3 Mt/a and the CO_(2) sequestration capacity will reach 5069.3 Mt/a.According to that,China s carbon intensity must reduce by 91.07%on the basis of the carbon intensity in 2017,reach 1152 t C per 100 million yuan.展开更多
Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for ...Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants degradation.This Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and growth.Mechanism study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,respectively.The improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation capability.Additionally,a S-scheme charge transfer mechanism including multiple charge transfer channels was proposed.This work could provide an effective strategy for organic pollutants degradation in wastewater.展开更多
基金supported by the National Natural Science Foundation of China under Grants Nos.52165013 and 51565021.
文摘The meso-dynamical behaviour of a high-speed rail ballast bed with under sleeper pads(USPs)was studied.The geometrically irregular refined discrete element model of the ballast particles was constructed using 3D scanning techniques,and the 3D dynamic model of the rail-sleeper-ballast bed was constructed using the coupled discrete element method-multiflexible-body dynamics(DEM-MFBD)approach.We analyse the meso-mechanical dynamics of the ballast bed with USPs under dynamic load on a train and verify the correctness of the model in laboratory tests.It is shown that the deformation of the USPs increases the contact area between the sleeper and the ballast particles,and subsequently the number of contacts between them.As the depth of the granular ballast bed increases,the contact area becomes larger,and the contact force between the ballast particles gradually decreases.Under the action of the elastic USPs,the contact forces between ballast particles are reduced and the overall vibration level of the ballast bed can be reduced.The settlement of the granular ballast bed occurs mainly at the shallow position of the sleeper bottom,and the installation of the elastic USPs can be effective in reducing the stress on the ballast particles and the settlement of the ballast bed.
基金funded by the National Key R&D Program of China(No.2021YFE0201400)the National Natural Science Foundation of China(Nos.51773041,61890940,22066011)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB30000000)the Department of Education of Jiangxi Province(No.GJJ211105)Jiangxi Science&Technology Normal University(No.2021QNBJRC002)State Key Laboratory of Molecular Engineering of Polymers.
文摘Effective detection of methamphetamine(Met)requires a fast,sensitive,and cheap testing assay.However,commercially available methods require expensive instruments and highly trained operators,which are time-consuming and labor-intensive.Herein,an antibody-modified graphene transistor assay is developed for sensitive and minute-level detection of Met in complex environments.The anti-Met probe captured charged targets within 120 s,leading to a p-doping effect near the graphene channel.The limit of detection reaches 50 aM(5.0×10^(-17)M)Met in solution.The graphene transistor would be a valuable tool for Met detection effective prevention of drug abuse.
基金the Guangzhou Key Medical Discipline Construction Project Fundthe Guangzhou High-Level Clinical Key Specialty Construction+2 种基金the Clinical Research Promotion Project of Guangzhou Medical University for Building High Level Universitythe National Natural Science Foundation of China(No.81972918)the Guangzhou Major Clinical Technology Program(No.2019ZD16)。
文摘Objective:Systemic chemotherapy has limited efficacy in the treatment of peritoneal metastasis(PM)in gastric cancer(GC).Hyperthermic intraperitoneal chemotherapy(HIPEC)combined with complete cytoreductive surgery(CRS)has shown promising outcomes but remains controversial.The present study aimed to evaluate the safety and efficacy of HIPEC without CRS in GC patients with PM.Methods:This retrospective propensity score-matched multicenter cohort study included GC patients with PM treated with either chemotherapy alone(Cx group)or with HIPEC combined with chemotherapy(HIPEC-Cx group)in four Chinese high-volume gastric medical centers between 2010 and 2017.The primary outcomes were median survival time(MST)and 3-year overall survival(OS).Propensity score matching was performed to compensate for controlling potential confounding effects and selection bias.Results:Of 663 eligible patients,498 were matched.The MST in the Cx and HIPEC-Cx groups was 10.8 and 15.9 months,respectively[hazard ratio(HR)=0.71,95%confidence interval(95%CI),0.58-0.88;P=0.002].The 3-year OS rate was 10.1%(95%CI,5.4%-14.8%)and 18.4%(95%CI,12.3%-24.5%)in the Cx and HIPEC-Cx groups,respectively(P=0.017).The complication rates were comparable.The time to first flatus and length of hospital stay for patients undergoing HIPEC combined with chemotherapy was longer than that of chemotherapy alone(4.6±2.4 d vs.2.7±1.8 d,P<0.001;14.2±5.8 d vs.11.4±7.7 d,P<0.001),respectively.The median follow-up period was 33.2 months.Conclusions:Compared with standard systemic chemotherapy,HIPEC combined with chemotherapy revealed a statistically significant survival benefit for GC patients with PM,without compromising patient safety.
基金funded by National Natural Science Foundation of China(Grant Nos.31270697,31370634,31570628)supported by State Forestry Administration of China(Grant No.2030208)
文摘Estimating individual tree biomass is critical to forest carbon accounting and ecosystem service modeling.In this study,we developed one-（tree diameter only） and two-variable（tree diameter and height） biomass equations,biomass conversion factor（BCF） models,and an integrated simultaneous equation system（ISES） to estimate the aboveground biomass for five conifer species in China,i.e.,Cunninghamia lanceolata（Lamb.） Hook.,Pinus massoniana Lamb.,P.yunnanensis Faranch,P.tabulaeformis Carr.and P.elliottii Engelm.,based on the field measurement data of aboveground biomass and stem volumes from 1055 destructive sample trees across the country.We found that all three methods,including the one-and two-variable equations,could adequately estimate aboveground biomass with a mean prediction error less than 5%,except for Pinus yunnanensis which yielded an error of about 6%.The BCF method was slightly poorer than the biomass equation and the ISES methods.The average coefficients of determination（R^2） were 0.944,0.938 and 0.943 and the mean prediction errors were 4.26,4.49 and 4.29% for the biomass equation method,the BCF method and the ISES method,respectively.The ISES method was the best approach for estimating aboveground biomass,which not only had high accuracy but also could estimate stocking volumes simultaneously that was compatible with aboveground biomass.In addition,we found that it is possible to develop a species-invariant one-variable allometric model for estimating aboveground biomass of all the five coniferous species.The model had an exponent parameter of 7/3 and the intercept parameter a_0 could be estimated indirectly from stem basic density（a_0= 0.294 q）.
基金Acknowledgments This work was supported by the National High Technol- ogy Research and Development Program of China （Project 2006AA02Z4B5）, the National Natural Science Foundation of China （Project 2010）, and a Key Project （9251018201002） of Guangdong Province Natural Science Foundation （to JL）. It was also supported in part by Grants HL072166, HL085629, and HL068936 of the NIH and an Established Investigator Award （0740025N） of the American Heart Association （to XW）.
文摘Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is -100 μM. IntraceUular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration （between 50 and 100μM） stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intraceHular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.
基金Supported by The National Natural Science Foundation of China,No.30971680A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, No.JX10131801101
文摘AIM:To investigate the role of inositol-requiring enzyme 1α(IRE1α) in gut development of Xenopus lavies embryos.METHODS:Xenopus embryos were obtained with in vitro fertilization and cultured in 0.1 × MBSH.One and half nanogram of IRE1α,1 ng of IRE1α-GR mRNA,1 ng of IRE1αΔC-GR mRNA,and 50 ng of IRE1α morpholino oligonucleotide(MO) or XBP1(C)MO were injected into four blastomeres at 4-cell stage for scoring the phenotype and marker gene analysis.To rescue the effect of IRE1α MO,1 ng of IRE1α-GR mRNA was coinjected with 50 ng of MO.For the activation of the GR-fusion proteins,dexamethasone was prepared as 5 mmol/L stock solutions in 100% ethanol and applied to the mRNA injected embryos at desired stages in a concentration of 10 μmol/L in 0.1 × MBSH.Embryos were kept in dexamethasone up to stage 41.Whole-mount in situ hybridization was used to determine specific gene expression,such as IRE1α,IRE1β,Xbra and Xsox17α.IRE1α protein expression during Xenopus embryogenesis was detected by Western blotting.RESULTS:In the whole-mount in situ hybridization analysis,xenopus IRE1α and IRE1β showed quite different expression pattern during tadpole stage.The relatively higher expression of IRE1α was observed in the pancreas,and significant transcription of IRE1β was found in the liver.IRE1α protein could be detected at all developmental stages analyzed,from stage 1 to stage 42.Gain-of-function assay showed that IRE1α mRNA injected embryos at tailbud stage were nearly normal and the expression of the pan-mesodermal marker gene Xbra and the endodermal gene Xsox17α at stage 10.5 was not significantly changed in embryos injected with IRE1α mRNA as compared to uninjected control embryos.And at tadpole stage,the embryos injected with IRE1α-GR mRNA did not display overt phenotype,such as gut-coiling defect.Loss-of-function assay demonstrated that the IRE1α MO injected embryos were morphologically normal before the tailbud stages.We did not observe a significant change of mesodermal and endodermal marker gene expression,while after stage 40,about 80% of the MO injected embryos exhibited dramatic gut defects in which the guts did not coil,but other structures outside the gastrointestinal tract were relatively normal.To test if the phenotypes were specifically caused by the knockdown of IRE1α,a rescue experiment was performed by co-injection of IRE1α-GR mRMA with IRE1α MO.The data obtained demonstrated that the gut coiling defect was rescued.The deletion mutant of IRE1α was constructed,consisting of the N-terminal part without the C-terminal kinase and RNase domains named IRE1αΔC,to investigate the functional domain of IRE1α.Injection of IRE1αΔCGR mRNA caused similar morphological alterations with gut malformation by interfering with the function of endogenous xIRE1α.In order to investigate if IRE1α/XBP1 pathway was involved in gut development,50 ng of XBP1 MO was injected and the results showed that knockdown of XBP1 resulted in similar morphological alterations with gut-coiling defect at tadpole stage.CONCLUSION:IRE1α is not required for germ layer formation but for gut development in Xenopus lavies and it may function via XBP1-dependent pathway.
基金supported by the Fundamental Research Funds for the Central Universities (Grant No. 2021ZY04)the National Natural Science Foundation of China (Grant No. 32001252)the International Center for Bamboo and Rattan (Grant No. 1632020029)
文摘There are two distinct types of domains,design-and cross-classes domains,with the former extensively studied under the topic of small-area estimation.In natural resource inventory,however,most classes listed in the condition tables of national inventory programs are characterized as cross-classes domains,such as vegetation type,productivity class,and age class.To date,challenges remain active for inventorying cross-classes domains because these domains are usually of unknown sampling frame and spatial distribution with the result that inference relies on population-level as opposed to domain-level sampling.Multiple challenges are noteworthy:(1)efficient sampling strategies are difficult to develop because of little priori information about the target domain;(2)domain inference relies on a sample designed for the population,so within-domain sample sizes could be too small to support a precise estimation;and(3)increasing sample size for the population does not ensure an increase to the domain,so actual sample size for a target domain remains highly uncertain,particularly for small domains.In this paper,we introduce a design-based generalized systematic adaptive cluster sampling(GSACS)for inventorying cross-classes domains.Design-unbiased Hansen-Hurwitz and Horvitz-Thompson estimators are derived for domain totals and compared within GSACS and with systematic sampling(SYS).Comprehensive Monte Carlo simulations show that(1)GSACS Hansen-Hurwitz and Horvitz-Thompson estimators are unbiased and equally efficient,whereas thelatter outperforms the former for supporting a sample of size one;(2)SYS is a special case of GSACS while the latter outperforms the former in terms of increased efficiency and reduced intensity;(3)GSACS Horvitz-Thompson variance estimator is design-unbiased for a single SYS sample;and(4)rules-ofthumb summarized with respect to sampling design and spatial effect improve precision.Because inventorying a mini domain is analogous to inventorying a rare variable,alternative network sampling procedures are also readily available for inventorying cross-classes domains.
基金Supported by the Key Research and Development Program for Industrial Keytechnologies of Shandong Province(2016CYJS05A01-2)the Key Research and Development Program for Public Welfare of Shandong Province(2018GNC111001)the Special Fund for the Construction of Oversea Taishan Scholars
文摘Field experiment carried out to test the effects of soil improver on wheat yield and soil physical-chemical properties. The results indicated that soil improver could optimize soil aggregates structure, decrease soil bulk density, soil pH and soil salt content, increase soil organic matter and 1 000-grain weight, thereby enhancing wheat yield. With the increase of soil improver application amount, soil physical-chemical properties became better and wheat yield increased. However, there was no significant difference in the treatments with the application amounts of 3%, 4% and 5%. In addition, the treatment of reducing nitrogen showed no superiority in soil physical-chemical properties and wheat yield, indicating that sufficient nitrogen was essential for the growth of wheat.
文摘In order to analysis the abnormal vehicle behavior by trajectory fitting effectively, the whole process is divided into three steps: target detection and tracking, vehicle trajectory analysis, vehicle behavior detection. Firstly, a three-frame-differencing method is used to achieve initial target location and an improved tracking algorithm based on Kalman predictor is proposed;then, an adaptive segmented linear fitting algorithm is proposed to achieve vehicle trajectory fitting;finally, two parameters including the rate of velocity variation and the rate of direction variation are used to establish vehicle abnormal behavior detection model. Experiment result shows that the three high dangerous vehicle behaviors in road surveillance videos can be detected effectively: sharp brake, sharp turn, and sharp turn brake.
文摘The study of China s carbon emissions and carbon sequestration potential is of great practical significance to the formulation of carbon neutrality strategies and methods of China.Carbon emission is an inevitable outcome of the initial stage of economic development,especially the right of developing countries existence and development.The carbon emission of China has been maintained at a low level for a long time and reached the top of the world in 2005.However,per capita carbon emission was still only 46.28%of the United States in 2016.China s total CO_(2) emissions are expected to reach 17-19 Gt/a by 2030.To achieve the goal of carbon neutrality in 2060,the main problems are the low technical capacity of emission reduction and the unreasonable structure of energy consumption.Therefore,replacing coal with gas is one of the most effective ways of emission reduction.By 2060,the carbon sequestration capacity of forest vegetation will reach or exceed 759.14 Mt/a and the CO_(2) sequestration capacity will reach 2783.5 Mt/a.According to that,China s carbon intensity must reduce by 95.39%on the basis of the carbon intensity in 2017,reaching 640 t/100 million yuan.The carbon sequestration capacity of terrestrial vegetation(forest,grassland)will reach or exceed 1380.3 Mt/a and the CO_(2) sequestration capacity will reach 5069.3 Mt/a.According to that,China s carbon intensity must reduce by 91.07%on the basis of the carbon intensity in 2017,reach 1152 t C per 100 million yuan.
基金supported by the Specialized Research Fund of Education Department of Shaanxi Province(No.22JY015)the College Students Innovation and Entrepreneurship Plan Training Program(No.S202211396006).
文摘Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of pho-tocatalyst.In this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants degradation.This Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and growth.Mechanism study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,respectively.The improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation capability.Additionally,a S-scheme charge transfer mechanism including multiple charge transfer channels was proposed.This work could provide an effective strategy for organic pollutants degradation in wastewater.
