Atomically thin MoSe_(2) layers,as a core member of the transition metal dichalcogenides(TMDs)family,benefit from their appealing properties,including tunable band gaps,high exciton binding energies,and giant oscillat...Atomically thin MoSe_(2) layers,as a core member of the transition metal dichalcogenides(TMDs)family,benefit from their appealing properties,including tunable band gaps,high exciton binding energies,and giant oscillator strengths,thus pro-viding an intriguing platform for optoelectronic applications of light-emitting diodes(LEDs),field-effect transistors(FETs),sin-gle-photon emitters(SPEs),and coherent light sources(CLSs).Moreover,these MoSe_(2) layers can realize strong excitonic emis-sion in the near-infrared wavelengths,which can be combined with the silicon-based integration technologies and further encourage the development of the new generation technologies of on-chip optical interconnection,quantum computing,and quantum information processing.Herein,we overview the state-of-the-art applications of light-emitting devices based on two-dimensional MoSe_(2) layers.Firstly,we introduce recent developments in excitonic emission features from atomically thin MoSe_(2) and their dependences on typical physical fields.Next,we focus on the exciton-polaritons and plasmon-exciton polaritons in MoSe_(2) coupled to the diverse forms of optical microcavities.Then,we highlight the promising applications of LEDs,SPEs,and CLSs based on MoSe_(2) and their heterostructures.Finally,we summarize the challenges and opportunities for high-quality emis-sion of MoSe_(2) and high-performance light-emitting devices.展开更多
In this work, we prepared three simple arylamine-based hole transporting materials from commercially available starting materials. The effect of extending z-conjugation length or increasing the number of side groups c...In this work, we prepared three simple arylamine-based hole transporting materials from commercially available starting materials. The effect of extending z-conjugation length or increasing the number of side groups compared with reference compound on the photophysical, electrochemical, hole mobility properties and performance in perovskite solar cells were further studied. It is noted that these two kinds of molecular modifications can significantly lower the HOMO level and improve the hole mobility, thus improving the hole injection from valence band of perovskite. On the other hand, the compound with more side groups showed higher hole injection efficiency due to lower HOMO level and higher hole mo- bility compared with the compound with extending π-conjugation length. The perovskite solar cells with the modified molecules as hole transporting materials showed a higher efficiency of 15.40% and 16.95%, respectively, which is better than that of the reference compound （13.18%）. Moreover, the compound with increasing number of side groups based devices showed comparable photovoltaic performance with that of conventional spiro-OMeTAD （16.87%）.展开更多
Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance a...Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance against multiple pathogens.However,little is known about how the red light signal affects pepper resistance to P.capsici infection(PCI).Here,we report that red light regulates salicylic acid(SA)accumulation by activating elongated hypocotyl5(CaHY5),a basic leucine zipper(bZIP)transcription factor,thereby decreasing pepper susceptibility to PCI.Exogenous SA treatment reduced pepper susceptibility to PCI,while silencing of CaPHYB(a red light photoreceptor)increased its susceptibility.PCI significantly induced CaHY5 expression,and silencing of CaHY5 reduced SA accumulation,accompanied by decreases in the expression levels of phenylalanine ammonia-lyase 3(CaPAL3),CaPAL7,pathogenesis-related 1(CaPR1),and CaPR1L,which finally resulted in higher susceptibility of pepper to PCI.Moreover,CaHY5 was found to activate the expression of CaPAL3 and CaPAL7,which are essential for SA biosynthesis,by directly binding to their promoters.Further analysis revealed that exogenous SA treatment could restore the resistance of CaHY5-silenced pepper plants to PCI.Collectively,this study reveals a critical mechanism through which red light induces SA accumulation by regulating CaHY5-mediated CaPAL3 and CaPAL7 expression,leading to enhanced resistance to PCI.Moreover,red light-induced CaHY5 regulates pepper resistance to PCI,which may have implications for PCI control in protected vegetable production.展开更多
Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogen...Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography（XCT） and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional（3-D） rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy（FE-SEM） to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.展开更多
It is of great significance to investigate effect of multiple heat treatments on fracture property of centrifugal casting stainless steels Z3CN20.09M cut from pump casing with long-term thermal aging degradation for n...It is of great significance to investigate effect of multiple heat treatments on fracture property of centrifugal casting stainless steels Z3CN20.09M cut from pump casing with long-term thermal aging degradation for nuclear power plants to consider actual operation of nuclear power plants.Both multiple heat treatments and accelerated thermal aging experiment at the same temperature of 400℃ for different time were successively carried out on centrifugal casting stainless steels Z3CN20.09M in order to examine the metallographic modification and impact properties.Finally,an additional investigation on the related fracture properties was carried out,in which the critical initial fracture toughness Ji was determined by stretch zone width and 0.2 mm offset line methods.These results indicated that the multiple heat treatments led to the dispersed distribution of ferrite phases in austenite matrix and thus microhardness increased,but impact energy exhibited a decreasing tendency significantly.After long-term aging,the metallographic structure remained almost unchanged,but the size of ferrite phases showed a slight increasing trend because of spinodal decomposition in ferrite phases and G-phase precipitation.In addition,centrifugal casting stainless steels Z3CN20.09M with multiple heat treatments exhibited the higher microhardness,Charpy impact toughness,critical initial fracture toughness J_(IC)(J-integral determined by 0.2 mm offset line method),and J_(SZW)(J-integral determined by stretch zone width method)than those with primary heat treatment,while the specific number of the heat treatment had a low influence on fracture toughness.展开更多
Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two methods...Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two methods.An abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was considered.Based on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and analyzed.The in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the measurements.The consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air interface.The synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1×10^(−11) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.展开更多
Magnesium hydride(MgH_(2))is an exceptional material for hydrogen storage,but its high desorption temperature and slow kinetics limit its applicability.In this study,the hydrogen storage performance of MgH_(2)was enha...Magnesium hydride(MgH_(2))is an exceptional material for hydrogen storage,but its high desorption temperature and slow kinetics limit its applicability.In this study,the hydrogen storage performance of MgH_(2)was enhanced using highly dispersed Ni-nanoparticle–doped hollow spherical vanadium nitride(Ni/VN),which was synthesized via a solvothermal process.The MgH_(2)system doped with the synthesized Ni/VN exhibited an outstanding hydrogen-storage capability.Specifically,5.6 wt.%of H_(2)was released within 1 h at a relatively low temperature of 513 K,whereas 6.4 wt.%of H_(2)was released within 180 s at 598 K,followed by an almost complete dehydrogenation after 10 min at 598 K.At 423 K,the developed material absorbed~6.0 wt.%of H_(2)within 5 min.The activation energy for dehydrogenation was determined to be 78.07±2.91 k J·mol^(-1),which was considerably lower than that of MgH_(2)produced by ball milling(120.89±5.74 k J·mol^(-1)),corresponding to a reduction of 35.4%.It was deduced that the formation of Mg_(2)Ni/Mg_(2)NiH_(4)(hydrogen pump)through the reaction of Ni nanoparticles during dehydrogenation/hydrogenation facilitated hydrogen transport and synergistically catalyzed hydrogen absorption and desorption by MgH_(2),improving its hydrogen storage capability.These findings offer novel perspectives for the utilization of MgH_(2)in large-scale applications.展开更多
A regional ocean reanalysis system for the coastal waters of China and adjacent seas has been developed by the National Marine Data and Information Service（NMDIS）.It produces a dataset package called CORA （China oc...A regional ocean reanalysis system for the coastal waters of China and adjacent seas has been developed by the National Marine Data and Information Service（NMDIS）.It produces a dataset package called CORA （China ocean reanalysis）.The regional ocean model used is based on the Princeton Ocean Model with a generalized coordinate system（POMgcs）.The model is parallelized by NMDIS with the addition of the wave breaking and tidal mixing processes into model parameterizations.Data assimilation is a sequential three-dimensional variational（3D-Var） scheme implemented within a multigrid framework.Observations include satellite remote sensing sea surface temperature（SST）,altimetry sea level anomaly（SLA）,and temperature/salinity profiles.The reanalysis fields of sea surface height,temperature,salinity,and currents begin with January 1986 and are currently updated every year. Error statistics and error distributions of temperature,salinity and currents are presented as a primary evaluation of the reanalysis fields using sea level data from tidal gauges,temperature profiles,as well as the trajectories of Argo floats.Some case studies offer the opportunity to verify the evolution of certain local circulations.These evaluations show that the reanalysis data produced provide a good representation of the ocean processes and phenomena in the coastal waters of China and adjacent seas.展开更多
AIM:To investigate different methods of creating incomplete intestinal obstruction in a rat model and to compare their electrophysiologic,morphologic and histologic characteristics. METHODS:Rat ileum was partially obs...AIM:To investigate different methods of creating incomplete intestinal obstruction in a rat model and to compare their electrophysiologic,morphologic and histologic characteristics. METHODS:Rat ileum was partially obstructed by the respective application of:braided silk(penetrated the mesentery and surrounded intestine);half ligation (penetrated directly and ligated 1/2 cross-section of the intestine);wide pipe(6 mm in width,surrounded the intestine);narrow pipe(2 mm in width,surrounded the intestine).A control was also included(no obstruction). Various behavioral and electrophysiologic variables, as well as morphologic and immunohistochemical observations were recorded by blinded investigators at different time points(12,24,48,72 h),including daily general condition,ileal wet weight and circumference, macromorphous and micromorphous intestine,bowel movement capability in vivo and in vitro,slow wave and neural electrical activity,and the number of c-Kit positive interstitial cells of Cajal(ICC). RESULTS:Despite being of a similar general condition, these methods resulted in different levels of obstruction in each group compared with the control at different time points(12,24,48,72 h).However,these fields of the wide pipe rat showed significantly differences when compared with the other three obstructed groups at 12 to 72 h,including macroscopic and histological presentation,intestinal transit ratio and contractility,circumference and wet weight,amplitude and frequency of nerve electrical discharge and slow wave,and ICC numbers(all P<0.01). CONCLUSION:The wide pipe rat method is significantly more reliable and stable than the other methods of obstruction,demonstrating that use of the wide pipe method can be a useful model of incomplete intestinal obstruction.展开更多
A convenient competitive enzyme-linked immunosorbent assay(ELISA) for ciprofloxacin(CPFX) was developed by using rabbit monoclonal antibodies(RabMAbs) against a hapten-protein conjugate of CPFX-bovine serum albumin(BS...A convenient competitive enzyme-linked immunosorbent assay(ELISA) for ciprofloxacin(CPFX) was developed by using rabbit monoclonal antibodies(RabMAbs) against a hapten-protein conjugate of CPFX-bovine serum albumin(BSA).The indirect competitive ELISA of CPFX had a concentration at 50% inhibition(IC50) of 1.47 ng/ml and a limit of detection(LOD) of 0.095 ng/ml.The mAb exhibited some cross-reactivity,however,not so high with enrofloxacin(28.8%),ofloxacin(13.1%),norfloxacin(11.0%),fleroxacin(22.6%),and pefloxacin(20.4%).And it showed almost no cross-reactivity with other antibiotics or sulfonamides evaluated in this study.The competitive ELISA kit developed here could be used as a screening tool to detect and control illegal addition of CPFX in food products.This kit had been applied to milk detection and the recovery rates from samples spiked by CPFX were in a range of 63.02%-84.60%,with coefficients of variation of less than 12.2%.展开更多
Copper (Cu) is a kind of micronutrient element that is essential for human metabolism.However,it is also considered as an environmental pollutant which is toxic to organisms at a high concentration level.Probiotics,re...Copper (Cu) is a kind of micronutrient element that is essential for human metabolism.However,it is also considered as an environmental pollutant which is toxic to organisms at a high concentration level.Probiotics,regarded as beneficial microorganisms for promoting human health,have functions of antioxidant capacity,immune-enhancing properties,intestinal barrier protection and regulation.Several studies have reported that probiotics show positive effects on alleviating and intervening heavy metals toxicity.However,evidence for relieving copper-induced toxicity by probiotics is still limited.In this study,we firstly conducted a zebrafish larvae model to screen out microorganisms which are helpful for CuSO_(4)toxicity resistance and one novel strain named as Bacillus coagulans XY2 was discovered with the best protective activity.B.coagulans XY2 significantly reduced the mortality of zebrafish larvae exposed to 10μmol/L CuSO_(4)for 96 hr,as well as alleviated the neutrophils infiltration in the larvae lateral line under a 2 hr exposure.B.coagulans XY2 exhibited a high in vitro antioxidant activity and against CuSO_(4)-induced oxidative stress in zebrafish larvae by up-regulating sod1,gstp1 and cat gene transcriptional levels and relevant enzymatic activities.CuSO_(4)stimulated the inflammation process resulting in obvious increases of gene il-1βand il-10 transcription,which were suppressed by B.coagulans XY2 intervention.Overall,our results underline the bio-function of B.coagulans XY2 on protecting zebrafish larvae from copper toxicity,suggesting the potential application values of probiotics in copper toxicity alleviation on human and the environment.展开更多
目的:分析睑板腺功能障碍型干眼(MGD)和水液缺乏型干眼(ADDE)患者的像差和散射相关参数,评估两种干眼类型患者的视觉质量。方法:将2018-01/10在我院门诊就诊的MGD患者25例(MGD组),ADDE患者25例(ADDE组),同时期就诊的健康人25例(对照组)...目的:分析睑板腺功能障碍型干眼(MGD)和水液缺乏型干眼(ADDE)患者的像差和散射相关参数,评估两种干眼类型患者的视觉质量。方法:将2018-01/10在我院门诊就诊的MGD患者25例(MGD组),ADDE患者25例(ADDE组),同时期就诊的健康人25例(对照组)纳入此次研究。三组受试对象填写眼表疾病指数量表(OSDI),接受泪液相关检查:泪液分泌试验(SⅠt)、泪膜破裂时间(TBUT)、角膜荧光染色(FL)。使用iTrace分析仪记录三组受试对象的高阶像差(HO)、球差(SA)、彗差(CA)和三叶草差(TA)的均方根值(RMS)。利用双通道视觉分析仪(OQASⅡ)记录三组受试对象自然状态下的散射值,包括调制传递函数截止频率(MTF cutoff)、斯特列尔比(SR)、客观散射指数(OSI),以及持续睁眼状态下OSI动态变化值(OSI均值)。结果:MGD组的OSDI评分明显高于ADDE组(38.2±5.6 vs 32.2±7.2分,P<0.01)。ADDE组的SⅠt明显低于MGD组(1.98±0.92 vs 12.52±6.80mm/5min,P<0.001)。MGD组的TBUT和FL显著低于ADDE组(TBUT:3.27±1.91 vs 6.02±1.05s,FL:3.27±2.18 vs 6.23±2.19,均P<0.001)。MGD组和ADDE组的HO、CA、TA、SA的RMS值均显著高于对照组(均P<0.001)。MGD组和ADDE组的HO、CA、TA、SA均无显著性差异(HO:0.385±0.081 vs 0.344±0.092,CA:0.210±0.062 vs 0.175±0.075,TA:0.107±0.056 vs 0.086±0.042,SA:0.322±0.078 vs 0.273±0.097,HO:t=1.67,P>0.05;CA:t=1.80,P>0.05;TA:t=1.50,P>0.05;SA:t=1.97,P>0.05)。MGD和ADDE组之间的MTF cutoff、SR、OSI无差异(MTF cutoff:33.28±8.28 vs 37.12±9.53,SR:0.19±0.06 vs 0.22±0.08,OSI:1.30±0.32 vs 1.12±0.52,MTF cutoff:t=1.52,P>0.05;SR:t=1.50,P>0.05;OSI:t=1.47,P>0.05)。持续睁眼状态下MGD组的OSI均值明显高于ADDE组(2.386±0.118 vs 1.554±0.058,P<0.001)。结论:治疗干眼的同时需要关注改善患者的视觉质量,MGD患者的视觉质量影响比ADDE患者更加严重。泪膜动态状态下的OSI均值是评估干眼患者视觉质量的敏感指标。展开更多
BACKGROUND Gastric cancer is the most common cause of cancer-related deaths,and is classified according to its location in the proximal,middle,or distal stomach.Surgical resection is the primary approach for treating ...BACKGROUND Gastric cancer is the most common cause of cancer-related deaths,and is classified according to its location in the proximal,middle,or distal stomach.Surgical resection is the primary approach for treating gastric cancer.This prospective study aimed to determine the best reconstruction method after distal gastrectomy for gastric cancer.AIM To explore the efficacy of different staplers and digestive tract reconstruction(DTR)methods after radical gastrectomy and their influence on prognosis.METHODS Eighty-seven patients who underwent radical gastrectomy for distal gastric cancer at our institution between April 2017 and April 2020 were included in this study,with a follow-up period of 12-26 mo.The patients were assigned to four groups based on the stapler and DTR plan as follows:BillrothⅠ(B-I)reconstruction+linear stapler group(group A,22 cases),B-I reconstruction+circular stapler group(group B,22 cases),Billroth II(B-II)reconstruction+linear stapler group(group C,22 cases),and B-II reconstruction+circular stapler group(group D,21 cases).The pathological parameters,postoperative gastrointestinal function recovery,postoperative complications,and quality of life(QOL)were compared among the four groups.RESULTS No significant differences in the maximum diameter of the gastric tumors,total number of lymph nodes dissected,drainage tube removal time,QLQ(QOL questionnaire)-C30 and QLQ-STO22 scores at 1 year postoperatively,and incidence of complications were observed among the four groups(P>0.05).However,groups A and C(linear stapler)had significantly lower intraoperative blood loss and significantly shorter anastomosis time,operation time,first fluid diet intake time,first exhaust time,and length of postoperative hospital stay(P<0.05)than groups B and D(circular stapler).CONCLUSION Linear staplers offer several advantages for postoperative recovery.B-I and B-II reconstruction methods had similar effects on QOL.The optimal solution can be selected according to individual conditions and postoperative convenience.展开更多
基金This work is supported by the National Natural Science Foundation of China(No.61904151)the National Key Research and Development Program of China(No.2021YFA1200803)the Joint Research Funds of the Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-020).
文摘Atomically thin MoSe_(2) layers,as a core member of the transition metal dichalcogenides(TMDs)family,benefit from their appealing properties,including tunable band gaps,high exciton binding energies,and giant oscillator strengths,thus pro-viding an intriguing platform for optoelectronic applications of light-emitting diodes(LEDs),field-effect transistors(FETs),sin-gle-photon emitters(SPEs),and coherent light sources(CLSs).Moreover,these MoSe_(2) layers can realize strong excitonic emis-sion in the near-infrared wavelengths,which can be combined with the silicon-based integration technologies and further encourage the development of the new generation technologies of on-chip optical interconnection,quantum computing,and quantum information processing.Herein,we overview the state-of-the-art applications of light-emitting devices based on two-dimensional MoSe_(2) layers.Firstly,we introduce recent developments in excitonic emission features from atomically thin MoSe_(2) and their dependences on typical physical fields.Next,we focus on the exciton-polaritons and plasmon-exciton polaritons in MoSe_(2) coupled to the diverse forms of optical microcavities.Then,we highlight the promising applications of LEDs,SPEs,and CLSs based on MoSe_(2) and their heterostructures.Finally,we summarize the challenges and opportunities for high-quality emis-sion of MoSe_(2) and high-performance light-emitting devices.
基金supported by the National Basic Research Program of China (No. 2015CB932200)the CAS-Iranian Vice Presidency for Science and Technology Joint Research Project (No. 116134KYSB20160130)+2 种基金the Natural Science Foundation of Anhui Province (No. 1508085SMF224)the National Natural Science Foundation of China (No. 51474201)the External Cooperation Program of BIC, Chinese Academy of Sciences (No. GJHZ1607)
文摘In this work, we prepared three simple arylamine-based hole transporting materials from commercially available starting materials. The effect of extending z-conjugation length or increasing the number of side groups compared with reference compound on the photophysical, electrochemical, hole mobility properties and performance in perovskite solar cells were further studied. It is noted that these two kinds of molecular modifications can significantly lower the HOMO level and improve the hole mobility, thus improving the hole injection from valence band of perovskite. On the other hand, the compound with more side groups showed higher hole injection efficiency due to lower HOMO level and higher hole mo- bility compared with the compound with extending π-conjugation length. The perovskite solar cells with the modified molecules as hole transporting materials showed a higher efficiency of 15.40% and 16.95%, respectively, which is better than that of the reference compound （13.18%）. Moreover, the compound with increasing number of side groups based devices showed comparable photovoltaic performance with that of conventional spiro-OMeTAD （16.87%）.
基金supported by grants from the National Natural Science Foundation of China(32002030)Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province,China-Young Talents Project(20204BCJL23044)+3 种基金the China Postdoctoral Science Foundation(2020 M682732)the Yan’an University Doctoral Research Initiation Project(YAU202313800)China Agriculture Research System of MOF and MARA(CARS-24-B-01)the earmarked fund for Jiangxi Agriculture Research System(JXARS-06).
文摘Pepper(Capsicum annuum L.)is frequently challenged by various pathogens,among which Phytophthora capsici is the most devastating to pepper production.Red light signal acts as a positive induction of plant resistance against multiple pathogens.However,little is known about how the red light signal affects pepper resistance to P.capsici infection(PCI).Here,we report that red light regulates salicylic acid(SA)accumulation by activating elongated hypocotyl5(CaHY5),a basic leucine zipper(bZIP)transcription factor,thereby decreasing pepper susceptibility to PCI.Exogenous SA treatment reduced pepper susceptibility to PCI,while silencing of CaPHYB(a red light photoreceptor)increased its susceptibility.PCI significantly induced CaHY5 expression,and silencing of CaHY5 reduced SA accumulation,accompanied by decreases in the expression levels of phenylalanine ammonia-lyase 3(CaPAL3),CaPAL7,pathogenesis-related 1(CaPR1),and CaPR1L,which finally resulted in higher susceptibility of pepper to PCI.Moreover,CaHY5 was found to activate the expression of CaPAL3 and CaPAL7,which are essential for SA biosynthesis,by directly binding to their promoters.Further analysis revealed that exogenous SA treatment could restore the resistance of CaHY5-silenced pepper plants to PCI.Collectively,this study reveals a critical mechanism through which red light induces SA accumulation by regulating CaHY5-mediated CaPAL3 and CaPAL7 expression,leading to enhanced resistance to PCI.Moreover,red light-induced CaHY5 regulates pepper resistance to PCI,which may have implications for PCI control in protected vegetable production.
基金supported by the Chinese Ministry of Science and Technology(No.2008AA062503)the National Natural Science Foundation Committee of China(Nos.41421064,20637020)the China Postdoctoral Science Foundation(No.20100470166)
文摘Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography（XCT） and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional（3-D） rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy（FE-SEM） to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.
基金supported by the National Key Research and Development Program of China(No.2017YFB0702200)the Natural Science Foundation of Jiangsu Province(No.BK20171223 and BK20170383).
文摘It is of great significance to investigate effect of multiple heat treatments on fracture property of centrifugal casting stainless steels Z3CN20.09M cut from pump casing with long-term thermal aging degradation for nuclear power plants to consider actual operation of nuclear power plants.Both multiple heat treatments and accelerated thermal aging experiment at the same temperature of 400℃ for different time were successively carried out on centrifugal casting stainless steels Z3CN20.09M in order to examine the metallographic modification and impact properties.Finally,an additional investigation on the related fracture properties was carried out,in which the critical initial fracture toughness Ji was determined by stretch zone width and 0.2 mm offset line methods.These results indicated that the multiple heat treatments led to the dispersed distribution of ferrite phases in austenite matrix and thus microhardness increased,but impact energy exhibited a decreasing tendency significantly.After long-term aging,the metallographic structure remained almost unchanged,but the size of ferrite phases showed a slight increasing trend because of spinodal decomposition in ferrite phases and G-phase precipitation.In addition,centrifugal casting stainless steels Z3CN20.09M with multiple heat treatments exhibited the higher microhardness,Charpy impact toughness,critical initial fracture toughness J_(IC)(J-integral determined by 0.2 mm offset line method),and J_(SZW)(J-integral determined by stretch zone width method)than those with primary heat treatment,while the specific number of the heat treatment had a low influence on fracture toughness.
基金National Natural Science Foundation of China(No.11575080)Hunan Provincial Natural Science Foundation of China(No.2022JJ30482)Hunan Provincial Innovation Foundation for Postgraduate(No.QL20220206).
文摘Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two methods.An abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was considered.Based on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and analyzed.The in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the measurements.The consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air interface.The synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1×10^(−11) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Grants no 52161036,52071092)the Guangxi Bagui Scholar Foundation。
文摘Magnesium hydride(MgH_(2))is an exceptional material for hydrogen storage,but its high desorption temperature and slow kinetics limit its applicability.In this study,the hydrogen storage performance of MgH_(2)was enhanced using highly dispersed Ni-nanoparticle–doped hollow spherical vanadium nitride(Ni/VN),which was synthesized via a solvothermal process.The MgH_(2)system doped with the synthesized Ni/VN exhibited an outstanding hydrogen-storage capability.Specifically,5.6 wt.%of H_(2)was released within 1 h at a relatively low temperature of 513 K,whereas 6.4 wt.%of H_(2)was released within 180 s at 598 K,followed by an almost complete dehydrogenation after 10 min at 598 K.At 423 K,the developed material absorbed~6.0 wt.%of H_(2)within 5 min.The activation energy for dehydrogenation was determined to be 78.07±2.91 k J·mol^(-1),which was considerably lower than that of MgH_(2)produced by ball milling(120.89±5.74 k J·mol^(-1)),corresponding to a reduction of 35.4%.It was deduced that the formation of Mg_(2)Ni/Mg_(2)NiH_(4)(hydrogen pump)through the reaction of Ni nanoparticles during dehydrogenation/hydrogenation facilitated hydrogen transport and synergistically catalyzed hydrogen absorption and desorption by MgH_(2),improving its hydrogen storage capability.These findings offer novel perspectives for the utilization of MgH_(2)in large-scale applications.
文摘A regional ocean reanalysis system for the coastal waters of China and adjacent seas has been developed by the National Marine Data and Information Service（NMDIS）.It produces a dataset package called CORA （China ocean reanalysis）.The regional ocean model used is based on the Princeton Ocean Model with a generalized coordinate system（POMgcs）.The model is parallelized by NMDIS with the addition of the wave breaking and tidal mixing processes into model parameterizations.Data assimilation is a sequential three-dimensional variational（3D-Var） scheme implemented within a multigrid framework.Observations include satellite remote sensing sea surface temperature（SST）,altimetry sea level anomaly（SLA）,and temperature/salinity profiles.The reanalysis fields of sea surface height,temperature,salinity,and currents begin with January 1986 and are currently updated every year. Error statistics and error distributions of temperature,salinity and currents are presented as a primary evaluation of the reanalysis fields using sea level data from tidal gauges,temperature profiles,as well as the trajectories of Argo floats.Some case studies offer the opportunity to verify the evolution of certain local circulations.These evaluations show that the reanalysis data produced provide a good representation of the ocean processes and phenomena in the coastal waters of China and adjacent seas.
基金Supported by Higher Education Quality Project of Sichuan Province:Innovative Scientific Experiment Project of SichuanProvince,Grant No.SJCX201110Chengdu Medical College Innovative Scientific Experiment Project,Grant No.CX201220and CX201115
文摘AIM:To investigate different methods of creating incomplete intestinal obstruction in a rat model and to compare their electrophysiologic,morphologic and histologic characteristics. METHODS:Rat ileum was partially obstructed by the respective application of:braided silk(penetrated the mesentery and surrounded intestine);half ligation (penetrated directly and ligated 1/2 cross-section of the intestine);wide pipe(6 mm in width,surrounded the intestine);narrow pipe(2 mm in width,surrounded the intestine).A control was also included(no obstruction). Various behavioral and electrophysiologic variables, as well as morphologic and immunohistochemical observations were recorded by blinded investigators at different time points(12,24,48,72 h),including daily general condition,ileal wet weight and circumference, macromorphous and micromorphous intestine,bowel movement capability in vivo and in vitro,slow wave and neural electrical activity,and the number of c-Kit positive interstitial cells of Cajal(ICC). RESULTS:Despite being of a similar general condition, these methods resulted in different levels of obstruction in each group compared with the control at different time points(12,24,48,72 h).However,these fields of the wide pipe rat showed significantly differences when compared with the other three obstructed groups at 12 to 72 h,including macroscopic and histological presentation,intestinal transit ratio and contractility,circumference and wet weight,amplitude and frequency of nerve electrical discharge and slow wave,and ICC numbers(all P<0.01). CONCLUSION:The wide pipe rat method is significantly more reliable and stable than the other methods of obstruction,demonstrating that use of the wide pipe method can be a useful model of incomplete intestinal obstruction.
基金Project supported by the National High-Tech R&D Program (863) of China (No. 2007AA10Z436)the Important National Science and Technology Specific Projects of China (No. 2009ZX03012-010B)
文摘A convenient competitive enzyme-linked immunosorbent assay(ELISA) for ciprofloxacin(CPFX) was developed by using rabbit monoclonal antibodies(RabMAbs) against a hapten-protein conjugate of CPFX-bovine serum albumin(BSA).The indirect competitive ELISA of CPFX had a concentration at 50% inhibition(IC50) of 1.47 ng/ml and a limit of detection(LOD) of 0.095 ng/ml.The mAb exhibited some cross-reactivity,however,not so high with enrofloxacin(28.8%),ofloxacin(13.1%),norfloxacin(11.0%),fleroxacin(22.6%),and pefloxacin(20.4%).And it showed almost no cross-reactivity with other antibiotics or sulfonamides evaluated in this study.The competitive ELISA kit developed here could be used as a screening tool to detect and control illegal addition of CPFX in food products.This kit had been applied to milk detection and the recovery rates from samples spiked by CPFX were in a range of 63.02%-84.60%,with coefficients of variation of less than 12.2%.
文摘Copper (Cu) is a kind of micronutrient element that is essential for human metabolism.However,it is also considered as an environmental pollutant which is toxic to organisms at a high concentration level.Probiotics,regarded as beneficial microorganisms for promoting human health,have functions of antioxidant capacity,immune-enhancing properties,intestinal barrier protection and regulation.Several studies have reported that probiotics show positive effects on alleviating and intervening heavy metals toxicity.However,evidence for relieving copper-induced toxicity by probiotics is still limited.In this study,we firstly conducted a zebrafish larvae model to screen out microorganisms which are helpful for CuSO_(4)toxicity resistance and one novel strain named as Bacillus coagulans XY2 was discovered with the best protective activity.B.coagulans XY2 significantly reduced the mortality of zebrafish larvae exposed to 10μmol/L CuSO_(4)for 96 hr,as well as alleviated the neutrophils infiltration in the larvae lateral line under a 2 hr exposure.B.coagulans XY2 exhibited a high in vitro antioxidant activity and against CuSO_(4)-induced oxidative stress in zebrafish larvae by up-regulating sod1,gstp1 and cat gene transcriptional levels and relevant enzymatic activities.CuSO_(4)stimulated the inflammation process resulting in obvious increases of gene il-1βand il-10 transcription,which were suppressed by B.coagulans XY2 intervention.Overall,our results underline the bio-function of B.coagulans XY2 on protecting zebrafish larvae from copper toxicity,suggesting the potential application values of probiotics in copper toxicity alleviation on human and the environment.
文摘目的:分析睑板腺功能障碍型干眼(MGD)和水液缺乏型干眼(ADDE)患者的像差和散射相关参数,评估两种干眼类型患者的视觉质量。方法:将2018-01/10在我院门诊就诊的MGD患者25例(MGD组),ADDE患者25例(ADDE组),同时期就诊的健康人25例(对照组)纳入此次研究。三组受试对象填写眼表疾病指数量表(OSDI),接受泪液相关检查:泪液分泌试验(SⅠt)、泪膜破裂时间(TBUT)、角膜荧光染色(FL)。使用iTrace分析仪记录三组受试对象的高阶像差(HO)、球差(SA)、彗差(CA)和三叶草差(TA)的均方根值(RMS)。利用双通道视觉分析仪(OQASⅡ)记录三组受试对象自然状态下的散射值,包括调制传递函数截止频率(MTF cutoff)、斯特列尔比(SR)、客观散射指数(OSI),以及持续睁眼状态下OSI动态变化值(OSI均值)。结果:MGD组的OSDI评分明显高于ADDE组(38.2±5.6 vs 32.2±7.2分,P<0.01)。ADDE组的SⅠt明显低于MGD组(1.98±0.92 vs 12.52±6.80mm/5min,P<0.001)。MGD组的TBUT和FL显著低于ADDE组(TBUT:3.27±1.91 vs 6.02±1.05s,FL:3.27±2.18 vs 6.23±2.19,均P<0.001)。MGD组和ADDE组的HO、CA、TA、SA的RMS值均显著高于对照组(均P<0.001)。MGD组和ADDE组的HO、CA、TA、SA均无显著性差异(HO:0.385±0.081 vs 0.344±0.092,CA:0.210±0.062 vs 0.175±0.075,TA:0.107±0.056 vs 0.086±0.042,SA:0.322±0.078 vs 0.273±0.097,HO:t=1.67,P>0.05;CA:t=1.80,P>0.05;TA:t=1.50,P>0.05;SA:t=1.97,P>0.05)。MGD和ADDE组之间的MTF cutoff、SR、OSI无差异(MTF cutoff:33.28±8.28 vs 37.12±9.53,SR:0.19±0.06 vs 0.22±0.08,OSI:1.30±0.32 vs 1.12±0.52,MTF cutoff:t=1.52,P>0.05;SR:t=1.50,P>0.05;OSI:t=1.47,P>0.05)。持续睁眼状态下MGD组的OSI均值明显高于ADDE组(2.386±0.118 vs 1.554±0.058,P<0.001)。结论:治疗干眼的同时需要关注改善患者的视觉质量,MGD患者的视觉质量影响比ADDE患者更加严重。泪膜动态状态下的OSI均值是评估干眼患者视觉质量的敏感指标。
文摘BACKGROUND Gastric cancer is the most common cause of cancer-related deaths,and is classified according to its location in the proximal,middle,or distal stomach.Surgical resection is the primary approach for treating gastric cancer.This prospective study aimed to determine the best reconstruction method after distal gastrectomy for gastric cancer.AIM To explore the efficacy of different staplers and digestive tract reconstruction(DTR)methods after radical gastrectomy and their influence on prognosis.METHODS Eighty-seven patients who underwent radical gastrectomy for distal gastric cancer at our institution between April 2017 and April 2020 were included in this study,with a follow-up period of 12-26 mo.The patients were assigned to four groups based on the stapler and DTR plan as follows:BillrothⅠ(B-I)reconstruction+linear stapler group(group A,22 cases),B-I reconstruction+circular stapler group(group B,22 cases),Billroth II(B-II)reconstruction+linear stapler group(group C,22 cases),and B-II reconstruction+circular stapler group(group D,21 cases).The pathological parameters,postoperative gastrointestinal function recovery,postoperative complications,and quality of life(QOL)were compared among the four groups.RESULTS No significant differences in the maximum diameter of the gastric tumors,total number of lymph nodes dissected,drainage tube removal time,QLQ(QOL questionnaire)-C30 and QLQ-STO22 scores at 1 year postoperatively,and incidence of complications were observed among the four groups(P>0.05).However,groups A and C(linear stapler)had significantly lower intraoperative blood loss and significantly shorter anastomosis time,operation time,first fluid diet intake time,first exhaust time,and length of postoperative hospital stay(P<0.05)than groups B and D(circular stapler).CONCLUSION Linear staplers offer several advantages for postoperative recovery.B-I and B-II reconstruction methods had similar effects on QOL.The optimal solution can be selected according to individual conditions and postoperative convenience.
