High-voltage direct current(HVDC) transmission is a crucial way to solve the reverse distribution of clean energy and loads. The line commutated converter-based HVDC(LCCHVDC) has become a vital structure for HVDC due ...High-voltage direct current(HVDC) transmission is a crucial way to solve the reverse distribution of clean energy and loads. The line commutated converter-based HVDC(LCCHVDC) has become a vital structure for HVDC due to its high technological maturity and economic advantages. During the DC fault of LCC-HVDC, such as commutation failure, the reactive power regulation of the AC grid always lags the DC control process, causing overvoltage in the AC sending grid, which brings off-grid risk to the wind power generation based on power electronic devices. Nevertheless, considering that wind turbine generators have fast and flexible reactive power control capability, optimizing the reactive power control of wind turbines to participate in the transient overvoltage suppression of the sending grid not only improves the operational safety at the equipment level but also enhances the voltage stability of the system. This paper firstly analyses the impact of wind turbine's reactive power on AC transient overvoltage. Then, it proposes an improved voltage-reactive power control strategy, which contains a reactive power control delay compensation and a power command optimization based on the voltage time series prediction. The delay compensation is used to reduce the contribution of the untimely reactive power of wind turbines on transient overvoltage, and the power command optimization enables wind turbines to have the ability to regulate transient overvoltage, leading to the variation of AC voltage, thus suppressing the transient overvoltage. Finally, the effectiveness and feasibility of the proposed method are verified in a ±800kV/5000MW LCC-HVDC sending grid model based on MATLAB/Simulink.展开更多
This study aimed to investigate the relationship between mental health literacy(MHL)and workplace well-being(WWB)of Chinese grassroots civil servants,with regulatory emotional self-efficacy(RESE)and resilience as media...This study aimed to investigate the relationship between mental health literacy(MHL)and workplace well-being(WWB)of Chinese grassroots civil servants,with regulatory emotional self-efficacy(RESE)and resilience as mediating variables.A questionnaire survey was conducted among Chinese grassroots civil servants,with a valid sample size of 2673 after excluding missing values and conducting relevant data processing.The PROCESS was used to examine the relationship between MHL,RESE,resilience,and WWB.The study found that MHL among grassroots civil servants was positively and significantly correlated with WWB(r=0.73,p<0.01).RESE partially mediated the relationship between MHL and WWB(β=0.25,95%CI[0.22,0.28]).Resilience partially mediated the relationship between MHL and WWB(β=0.22,95%CI[0.19,0.26]).MHL had a positive effect on WWB through the chain mediating effect of RESE and resilience(β=0.05,95%CI[0.03,0.07]).There is a close relationship between MHL and WWB,where Chinese grassroots civil servants with higher levels of MHL can develop stronger RESE and resilience,leading to higher WWB.The results of this study remind organizational institutions of Chinese grassroots civil servants that enhancing MHL,RESE,and resilience is an important pathway to promoting their WWB.展开更多
Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Met...Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Method:We included 42 patients,aged 65-75,who required general anesthesia and single-lumen endotracheal intubation for elective surgery.The first patient was administered remazolam toluenesulfonate at a dose of 0.20 mg/kg.Once the patient lost consciousness,their alertness/sedation score(OAA/S score)was≤1,and their BIS score was≤60,and a subthreshold dose(0.3 mg/kg)of esketamine was given.The subsequent doses were adjusted using a sequential approach based on the cardiovascular response to tracheal intubation observed in the previous patient.The dose was modified in increments or decrements of 0.01 mg/kg.The ED_(50)and 95%CI of remazolam toluenesulfonate were calculated using the Dixon and Massey sequential distribution test method.Result:The inhibition of endotracheal intubation response was positively correlated with the dose of remazolam toluenesulfonate,and the depth of sedation could not be achieved when the amount was≤0.22 mg/kg.The ED_(50)of remazolam toluenesulfonate combined with a subthreshold dose of esketamine in inhibiting cardiovascular response to tracheal intubation in elderly patients was 0.30(0.28,0.33)mg/kg.There was no statistically significant difference in blood pressure between the induction of anesthesia and before the operation.Conclusion:When compounded with 0.3 mg/kg esketamine,the ED_(50)of Remazolam toluenesulfonate in inhibiting cardiovascular response to endotracheal intubation in elderly patients was 0.30 mg/kg(95%CI0.28-0.33 mg/kg).展开更多
Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divid...Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.展开更多
A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the...A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.展开更多
Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathwa...Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathways may compete for substrates.However,the mechanism regulating this potential competition remains unclear.Here,we identified GhMYB1a,an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in gerbera(Gerbera hybrida).GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis.In addition,GhMYB1a is also phylogenetically grouped with these proteins.The overexpression of GhMYB1a in gerbera and tobacco(Nicotiana tabacum)resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis.We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors.These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression.The functional characterization of GhMYB1a provides insight into the biosynthesis and regulation of flavonols and anthocyanins.展开更多
Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the p...Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.展开更多
Understanding the effects of vegetation cover on seedling survival is helpful for promoting vegetation restoration in environmentally fragile zones. This study was conducted in the desertified, moving sand dunes of Ho...Understanding the effects of vegetation cover on seedling survival is helpful for promoting vegetation restoration in environmentally fragile zones. This study was conducted in the desertified, moving sand dunes of Horqin Sandy Land, Inner Mongolia, northeastern China. We hyphothesized that （1） seed density （i.e., number/m2） increases as vegetation cover increases, and （2） there will be more surviving seedlings in locations with higher vegetation covers. Total vegetation cover and initial densities of seeds, germinated seeds and surviving seedlings of Ulmus pumilia were evaluated under various vegetation covers in trying to clarify the effects of vegetation cover on the early stages of the plant life history. In agreement with the first hypothesis, initial seed densities were greater （P〈0.05） under higher vegetation covers. The relationship between vegetation cover and initial seed density was represented by a quadratic regression, where a threshold occurred with a vegetation cover of 36% （P〈0.05）. The higher total vegetation covers, however, did not result in increased densities of germinated seeds （P〉0.05）, which on average represented 16.7% of initial seed densities. Even more, three months after the study initiation, total vegetation covers were similar （P〉0.05） at all positions in the dunes, and they determined a similar number （P〉0.05） of surviving seedlings at those positions （i.e. the second hypothesis had to be rejected）. The mean number of seedlings that survived at all positions was only 4.5% of germinated seeds. The number of surviving elm seedlings （0 to 1.7 seedlings/m2） under various vegetations covers （12.2% to 20.8%） at all dune positions by late summer would most likely not contribute to vegetation restoration in the study area.展开更多
Pregnancy-induced hypertension(PIH),including gestational hypertension and preeclampsia,accounts for the majority of maternal and perinatal morbidity and mortality.Strontium(Sr)has been recently associated with preecl...Pregnancy-induced hypertension(PIH),including gestational hypertension and preeclampsia,accounts for the majority of maternal and perinatal morbidity and mortality.Strontium(Sr)has been recently associated with preeclampsia in a small group of women;however,the role of Sr in PIH is not fully understood and warrants further investigation.In this study,we examined the association between urinary Sr levels and PIH,and assessed the effect of maternal age on the association.Urinary Sr concentrations were measured in 5423 pregnant women before delivery by inductively coupled plasma mass spectrometry(ICP-MS).Logistic regression analysis adjusting for potential confounders was applied to explore the association between Sr and PIH,and to evaluate the Sr-PIH relationship stratified by maternal age.Among the participants,200(3.83%)women were diagnosed with PIH.Compared with non-PIH women,women who developed PIH had lower urinary Sr concentrations(131.26 us.174.98μg/L creatinine,P<0.01).With the natural log-transformed urinary creatinine-standardized Sr concentrations increasing,the risk of PIH decreased significantly[adjusted OR=0.60(95%CI:0.51,0.72)].Furthermore,the significant association of Sr with PIH was found among women under 35 years(P<0.01).Our finding suggested that Sr may play a potential protective role in the pathogenesis of PIH,especially among young pregnant women under 35 years old.展开更多
Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°C and strain rate range of 0.01-10 s-1.A physically-bas...Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°C and strain rate range of 0.01-10 s-1.A physically-based model was developed to accurately predict the flow stress.Meanwhile,processing maps were established to optimize hot working parameters.It is found that decreasing the strain rate or increasing the deformation temperature reduces the flow stress.The high activation energy is closely related to the pinning of dislocations from Si-containing dispersoids.Moreover,the deformed grains and the Si-containing dispersoids in the matrix are elongated perpendicular to the compression direction,and incomplete dynamic recrystallization(DRX)is discovered on the elongated boundaries in domain with peak efficiency.The flow instability is mainly attributed to the flow localization,brittle fracture of eutectic Si phase,and formation of adiabatic shear band.The optimum hot working window is 380-420°C and 0.03-0.28 s-1.展开更多
A novel hollow microsphere structure with cancrinite zeolite grown from the shell of fly ash cenosphere has been successfully prepared through in situ transformation in vapor phase; the orientation and morphology of c...A novel hollow microsphere structure with cancrinite zeolite grown from the shell of fly ash cenosphere has been successfully prepared through in situ transformation in vapor phase; the orientation and morphology of cancrinite can be greatly improved by adding tetrapropylammonium hydrate into the synthetic system.展开更多
Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who ...Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.展开更多
Dear editor,This letter presents an automatic data augmentation algorithm for medical image segmentation.To increase the scale and diversity of medical images,we propose a differentiable automatic data augmentation al...Dear editor,This letter presents an automatic data augmentation algorithm for medical image segmentation.To increase the scale and diversity of medical images,we propose a differentiable automatic data augmentation algorithm based on proximal update by finding an optimal augmentation policy.Specifically,on the one hand,a dedicated search space is designed for the medical image segmentation task.On the other hand,we introduce a proximal differentiable gradient descent strategy to update the data augmentation policy,which would increase the searching efficiency.Results of the experiments indicate that the proposed algorithm significantly outperforms state-of-the-art methods,and search speed is 10 times faster than state-of-the-art methods.展开更多
Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisi...Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.展开更多
Cathodic electrocatalytic reactions, such as hydrogen evolution and CO_(2)/N_(2) reduction, are the key processes that store intermittent electricity into stable chemical energy. Although a great progress has been mad...Cathodic electrocatalytic reactions, such as hydrogen evolution and CO_(2)/N_(2) reduction, are the key processes that store intermittent electricity into stable chemical energy. Although a great progress has been made to boost activity and selectivity via elaborative catalyst design, the structure–property relationships have not been sufficiently understood in the context of surface reconfiguration under working conditions. Recent efforts devoted to tracking dynamic evolution of electrocatalysts using in-situ and/or operando techniques gave new insights into the real structure and working mechanism of active sites,and provided principles to design better catalysts. The achievement of cathodic electrocatalysts in this subject is herein summarized, focusing on the correlations between reconstructed surface and electrocatalytic performance. Briefly, the thermodynamics of reconstruction at cathodes is discussed at first, and then the representative progresses in H_(2) evolution and CO_(2)/N_(2) reduction are introduced in sequence to acquire insights into electrochemical processes on in-situ reconfigured surfaces or interfaces. Finally, a perspective is offered to guide future investigations. This review is anticipated to shed some new light on in-depth understanding cathodic electrocatalysis and exploiting prominent electrocatalysts.展开更多
Some studies have shown that left ventricular structure and function play an important role in the risk stratifi cation and prognosis of cardiovascular disease.The clinical application of left atrial function in cardi...Some studies have shown that left ventricular structure and function play an important role in the risk stratifi cation and prognosis of cardiovascular disease.The clinical application of left atrial function in cardiovascular disease has gradually attracted attention in the cardiovascular fi eld.There are many traditional methods to evaluate left atrial function.Left atrial function related indexes measured by echocardiography has been identifi ed as a powerful predictor of cardiovascular disease in recent years,but they have some limitations.The left atrial function index has been found to evaluate left atrial function more effectively than traditional parameters.Furthermore,it is a valuable predictor of the risk stratifi cation and prognosis in patients with clinical cardiovascular disease such as heart failure,atrial fi brillation,hypertension,and coronary heart disease.展开更多
The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over WO_3/SnO_2 solid acid which was prepared by impregnating Sn(OH)_4 with aqueous ammonium metatungstate followed by evaporating, drying ...The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over WO_3/SnO_2 solid acid which was prepared by impregnating Sn(OH)_4 with aqueous ammonium metatungstate followed by evaporating, drying and calcining in air. The CFC-12 conversion over WO_3/SnO_2 at 330'C remained above 99.5% during 150 h on stream, however, parent metal oxides showed rare catalytic decomposition activity.展开更多
The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1...The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1). the CPC-12 conversion at 310C over Ti(SO_4)_2 calcined at 350C remained about 98.5% during 360 h on stream. and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.展开更多
The increasing use of power electronic devices can deteriorate the power quality by introducing voltage and current harmonics.In islanded microgrids,the presence of nonlinear loads can distort the point of common coup...The increasing use of power electronic devices can deteriorate the power quality by introducing voltage and current harmonics.In islanded microgrids,the presence of nonlinear loads can distort the point of common coupling(PCC)voltage,while the dead-time effect can also bring additional circulating current harmonics among parallel inverters.To simultaneously attenuate the PCC voltage harmonics and suppress the dead-time induced circulating current harmonics,this paper proposes a coordinated control strategy for harmonic mitigation of parallel inverters.The proposed control strategy allows inverter impedances to be properly reshaped at selective harmonic frequencies.As a consequence,the PCC voltage harmonics are filtered by the inverter operating in the harmonic compensation mode(HCM),whereas the dead-time induced circulating current harmonics are suppressed by the inverter operating in the harmonic rejection mode(HRM).Experimental results from an islanded microgrid prototype with two parallel inverters are provided to validate the effectiveness of the proposed control strategy.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant 52307141, Grant 52237005 and Grant 52177117in part by Sichuan Science and Technology Program 2021JDTD0016。
文摘High-voltage direct current(HVDC) transmission is a crucial way to solve the reverse distribution of clean energy and loads. The line commutated converter-based HVDC(LCCHVDC) has become a vital structure for HVDC due to its high technological maturity and economic advantages. During the DC fault of LCC-HVDC, such as commutation failure, the reactive power regulation of the AC grid always lags the DC control process, causing overvoltage in the AC sending grid, which brings off-grid risk to the wind power generation based on power electronic devices. Nevertheless, considering that wind turbine generators have fast and flexible reactive power control capability, optimizing the reactive power control of wind turbines to participate in the transient overvoltage suppression of the sending grid not only improves the operational safety at the equipment level but also enhances the voltage stability of the system. This paper firstly analyses the impact of wind turbine's reactive power on AC transient overvoltage. Then, it proposes an improved voltage-reactive power control strategy, which contains a reactive power control delay compensation and a power command optimization based on the voltage time series prediction. The delay compensation is used to reduce the contribution of the untimely reactive power of wind turbines on transient overvoltage, and the power command optimization enables wind turbines to have the ability to regulate transient overvoltage, leading to the variation of AC voltage, thus suppressing the transient overvoltage. Finally, the effectiveness and feasibility of the proposed method are verified in a ±800kV/5000MW LCC-HVDC sending grid model based on MATLAB/Simulink.
基金supported by the National Social Science Foundation of China(Grant No.21XDJ002).
文摘This study aimed to investigate the relationship between mental health literacy(MHL)and workplace well-being(WWB)of Chinese grassroots civil servants,with regulatory emotional self-efficacy(RESE)and resilience as mediating variables.A questionnaire survey was conducted among Chinese grassroots civil servants,with a valid sample size of 2673 after excluding missing values and conducting relevant data processing.The PROCESS was used to examine the relationship between MHL,RESE,resilience,and WWB.The study found that MHL among grassroots civil servants was positively and significantly correlated with WWB(r=0.73,p<0.01).RESE partially mediated the relationship between MHL and WWB(β=0.25,95%CI[0.22,0.28]).Resilience partially mediated the relationship between MHL and WWB(β=0.22,95%CI[0.19,0.26]).MHL had a positive effect on WWB through the chain mediating effect of RESE and resilience(β=0.05,95%CI[0.03,0.07]).There is a close relationship between MHL and WWB,where Chinese grassroots civil servants with higher levels of MHL can develop stronger RESE and resilience,leading to higher WWB.The results of this study remind organizational institutions of Chinese grassroots civil servants that enhancing MHL,RESE,and resilience is an important pathway to promoting their WWB.
文摘Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Method:We included 42 patients,aged 65-75,who required general anesthesia and single-lumen endotracheal intubation for elective surgery.The first patient was administered remazolam toluenesulfonate at a dose of 0.20 mg/kg.Once the patient lost consciousness,their alertness/sedation score(OAA/S score)was≤1,and their BIS score was≤60,and a subthreshold dose(0.3 mg/kg)of esketamine was given.The subsequent doses were adjusted using a sequential approach based on the cardiovascular response to tracheal intubation observed in the previous patient.The dose was modified in increments or decrements of 0.01 mg/kg.The ED_(50)and 95%CI of remazolam toluenesulfonate were calculated using the Dixon and Massey sequential distribution test method.Result:The inhibition of endotracheal intubation response was positively correlated with the dose of remazolam toluenesulfonate,and the depth of sedation could not be achieved when the amount was≤0.22 mg/kg.The ED_(50)of remazolam toluenesulfonate combined with a subthreshold dose of esketamine in inhibiting cardiovascular response to tracheal intubation in elderly patients was 0.30(0.28,0.33)mg/kg.There was no statistically significant difference in blood pressure between the induction of anesthesia and before the operation.Conclusion:When compounded with 0.3 mg/kg esketamine,the ED_(50)of Remazolam toluenesulfonate in inhibiting cardiovascular response to endotracheal intubation in elderly patients was 0.30 mg/kg(95%CI0.28-0.33 mg/kg).
文摘Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.
文摘A method for the direct syntheses of partially and fully delaminated MWW zeolites is reported herein.Two organic amines were introduced into the hydrothermal synthetic system:hexamethyleneimine(HMI),which acted as the structure-directing agent for the MWW layered structure;and dicyclohexylamine(DCHA),in the role of an in-situ delaminating agent.By varying the amount of DCHA,partially and fully delaminated MWW zeolites having two MWW structure layers and one single layer,respectively,were obtained.These were denoted as SCM-1(Sinopec Composite Material)and SCM-6,respectively.The delaminated materials possess ultra-large external surface areas,and the transmission electron microscopy images illustrated their layered nature.In the reaction of liquid phase benzene alkylation with ethylene,SCM-1,the double-layered MWW zeolite,exhibited far superior catalytic performance compared to zeolite MCM-22.
基金supported by the Foundation of Guangzhou Science and Technology Project(201904010127 to C.Z.)National Natural Science Foundation of China(Grants 31372099,31601784,and 31672188 to X.W.,L.L.and Y.W.,respectively)+1 种基金Open Project Foundation of South China Normal University(2018KF0202 to C.Z.)Specialized Research Fund for Graduate Students at South China Normal University(2014ssxm26).
文摘Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathways may compete for substrates.However,the mechanism regulating this potential competition remains unclear.Here,we identified GhMYB1a,an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in gerbera(Gerbera hybrida).GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis.In addition,GhMYB1a is also phylogenetically grouped with these proteins.The overexpression of GhMYB1a in gerbera and tobacco(Nicotiana tabacum)resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis.We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors.These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression.The functional characterization of GhMYB1a provides insight into the biosynthesis and regulation of flavonols and anthocyanins.
基金the National Natural Science Foundation of China(31672694,31972836)Fujian Provincial Special Fund for Marine and Fishery Protection and Development(MCZ[2019]062)。
文摘Host-pathogen interactions are highly complex,involving large dynamic changes in gene expression during infection. These interactions are fundamental to understanding anti-infection immunity of hosts, as well as the pathogenesis of pathogens. For bacterial pathogens interacting with animal hosts, timeresolved dual RNA-seq of infected tissue is difficult to perform due to low pathogen load in infected tissue. In this study, an acute infection model of Larimichthys crocea infected by Pseudomonas plecoglossicida was established. The spleens of infected fish exhibited typical symptoms, with a maximum bacterial load at two days post-injection(dpi). Time-resolved dual RNA-seq of infected spleens was successfully applied to study hostpathogen interactions between L. crocea and P.plecoglossicida. The spleens of infected L. crocea were subjected to dual RNA-seq, and transcriptome data were compared with those of noninfected spleens or in vitro cultured bacteria. Results showed that pathogen-host interactions were highly dynamically regulated, with corresponding fluctuations in host and pathogen transcriptomes during infection. The expression levels of many immunogenes involved in cytokine-cytokine receptor,Toll-like receptor signaling, and other immunerelated pathways were significantly up-regulated during the infection period. Furthermore, metabolic processes and the use of oxygen in L. crocea were strongly affected by P. plecoglossicida infection. The WGCNA results showed that the metabolic process was strongly related to the entire immune process.For P. plecoglossicida, the expression levels of motility-related genes and flagellum assemblyrelated genes were significantly up-regulated. The results of this study may help to elucidate the interactions between L. crocea and P.plecoglossicida.
基金supported by the State Key Development Program for Basic Research (2013CB429905)the National Natural Science Foundation of China (41201052 and 41071187)the National Department Public Benefit Research Foundation (201004023)
文摘Understanding the effects of vegetation cover on seedling survival is helpful for promoting vegetation restoration in environmentally fragile zones. This study was conducted in the desertified, moving sand dunes of Horqin Sandy Land, Inner Mongolia, northeastern China. We hyphothesized that （1） seed density （i.e., number/m2） increases as vegetation cover increases, and （2） there will be more surviving seedlings in locations with higher vegetation covers. Total vegetation cover and initial densities of seeds, germinated seeds and surviving seedlings of Ulmus pumilia were evaluated under various vegetation covers in trying to clarify the effects of vegetation cover on the early stages of the plant life history. In agreement with the first hypothesis, initial seed densities were greater （P〈0.05） under higher vegetation covers. The relationship between vegetation cover and initial seed density was represented by a quadratic regression, where a threshold occurred with a vegetation cover of 36% （P〈0.05）. The higher total vegetation covers, however, did not result in increased densities of germinated seeds （P〉0.05）, which on average represented 16.7% of initial seed densities. Even more, three months after the study initiation, total vegetation covers were similar （P〉0.05） at all positions in the dunes, and they determined a similar number （P〉0.05） of surviving seedlings at those positions （i.e. the second hypothesis had to be rejected）. The mean number of seedlings that survived at all positions was only 4.5% of germinated seeds. The number of surviving elm seedlings （0 to 1.7 seedlings/m2） under various vegetations covers （12.2% to 20.8%） at all dune positions by late summer would most likely not contribute to vegetation restoration in the study area.
基金the National Natural Science Foundation of China(No.91743103)Program for HUST Academic Frontier Youth Team(No.2018QYTD12).
文摘Pregnancy-induced hypertension(PIH),including gestational hypertension and preeclampsia,accounts for the majority of maternal and perinatal morbidity and mortality.Strontium(Sr)has been recently associated with preeclampsia in a small group of women;however,the role of Sr in PIH is not fully understood and warrants further investigation.In this study,we examined the association between urinary Sr levels and PIH,and assessed the effect of maternal age on the association.Urinary Sr concentrations were measured in 5423 pregnant women before delivery by inductively coupled plasma mass spectrometry(ICP-MS).Logistic regression analysis adjusting for potential confounders was applied to explore the association between Sr and PIH,and to evaluate the Sr-PIH relationship stratified by maternal age.Among the participants,200(3.83%)women were diagnosed with PIH.Compared with non-PIH women,women who developed PIH had lower urinary Sr concentrations(131.26 us.174.98μg/L creatinine,P<0.01).With the natural log-transformed urinary creatinine-standardized Sr concentrations increasing,the risk of PIH decreased significantly[adjusted OR=0.60(95%CI:0.51,0.72)].Furthermore,the significant association of Sr with PIH was found among women under 35 years(P<0.01).Our finding suggested that Sr may play a potential protective role in the pathogenesis of PIH,especially among young pregnant women under 35 years old.
基金Project(51375502)supported by the National Natural Science Foundation of ChinaProject(2015CX002)supported by the Innovation-driven Plan in Central South University,China+2 种基金Project(2016RS2006)supported by the Science and Technology Leading Talent in Hunan Province,ChinaProject(Q2015140)supported by the Program of Chang Jiang Scholars of Ministry of Education,ChinaProject(2016JJ1017)supported by the Natural Science Foundation for Distinguished Young Scholars of Hunan Province,China
文摘Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°C and strain rate range of 0.01-10 s-1.A physically-based model was developed to accurately predict the flow stress.Meanwhile,processing maps were established to optimize hot working parameters.It is found that decreasing the strain rate or increasing the deformation temperature reduces the flow stress.The high activation energy is closely related to the pinning of dislocations from Si-containing dispersoids.Moreover,the deformed grains and the Si-containing dispersoids in the matrix are elongated perpendicular to the compression direction,and incomplete dynamic recrystallization(DRX)is discovered on the elongated boundaries in domain with peak efficiency.The flow instability is mainly attributed to the flow localization,brittle fracture of eutectic Si phase,and formation of adiabatic shear band.The optimum hot working window is 380-420°C and 0.03-0.28 s-1.
基金suppoaed by the NNSFC(Grant No.20233030,20273016)the Doctoral fund of Education Ministry.
文摘A novel hollow microsphere structure with cancrinite zeolite grown from the shell of fly ash cenosphere has been successfully prepared through in situ transformation in vapor phase; the orientation and morphology of cancrinite can be greatly improved by adding tetrapropylammonium hydrate into the synthetic system.
基金The study was funded by the Zhejiang Provincial Traditional Chinese Medicine Administration of China(approval number 2011ZB083)the Quality of Nursing Practice Project of the Chinese Medical Association.
文摘Objective:To study the effects of prolonging small feeding volumes early in life on the incidence of necrotizing enterocolitis(NEC)in very low birth weight(VLBW)preterm infants.Methods:A total of 128 VLBW infants who could not be breastfed were assigned into the experimental group(63 cases)and the control group(65 cases)using a random number table.The experiment group was fed 12 mL/(kg·d)on day 1 which was increased to 24 mL/(kg·d)for the first 10 study days.The control group was fed 12 mL/(kg·d)for the first 14e48 hours.Then,the feeding volume increased by 24-36 mL/(kg·d)up to 140e160 mL/(kg·d)and maintained until the 10th day after birth.The incidence of feeding intolerance and NEC,duration of hospitalization,time to full enteral feedings,incidence of intrahepatic cholestasis,and the levels of gastrin and motilin in serum were assessed.Results:The incidence of feeding intolerance was significantly lower in the experimental group compared with the control group(15.87% vs.33.84%).There was a significant reduction in the incidence of NEC between the experimental and control groups(7.9% vs.16% in the control group).Conclusion:A protocol that prolongs small feeding volumes early in life can reduce the incidence and severity of NEC,but still warrants further study.
基金This work was supported by the National Natural Science Foundation of China(62073126)the Hunan Provincial Natural Science Foundation of China(2020JJ2008)+1 种基金the Key Research and Development Program of Hunan Province(2022WK2011)the Science and Technology Program of Changsha(897202102345).
文摘Dear editor,This letter presents an automatic data augmentation algorithm for medical image segmentation.To increase the scale and diversity of medical images,we propose a differentiable automatic data augmentation algorithm based on proximal update by finding an optimal augmentation policy.Specifically,on the one hand,a dedicated search space is designed for the medical image segmentation task.On the other hand,we introduce a proximal differentiable gradient descent strategy to update the data augmentation policy,which would increase the searching efficiency.Results of the experiments indicate that the proposed algorithm significantly outperforms state-of-the-art methods,and search speed is 10 times faster than state-of-the-art methods.
基金Supported by Research Project of Sichuan University of Science&Engineering(No.2011RC12,2014KY02)Scientific Research Foundation of the Education Department of Sichuan Province(No.15ZA0222)Research Project of Liquor Making Biological Technology and Application of Key Laboratory of Sichuan Province(NJ2013-06)
文摘Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.
基金the financial support from the National Major Research and Development Plan(2018YFA0209402)the National Natural Science Foundation of China(22175077,21773093,22088101)the Natural Science Foundation of Guangdong Province(2021A1515012351)。
文摘Cathodic electrocatalytic reactions, such as hydrogen evolution and CO_(2)/N_(2) reduction, are the key processes that store intermittent electricity into stable chemical energy. Although a great progress has been made to boost activity and selectivity via elaborative catalyst design, the structure–property relationships have not been sufficiently understood in the context of surface reconfiguration under working conditions. Recent efforts devoted to tracking dynamic evolution of electrocatalysts using in-situ and/or operando techniques gave new insights into the real structure and working mechanism of active sites,and provided principles to design better catalysts. The achievement of cathodic electrocatalysts in this subject is herein summarized, focusing on the correlations between reconstructed surface and electrocatalytic performance. Briefly, the thermodynamics of reconstruction at cathodes is discussed at first, and then the representative progresses in H_(2) evolution and CO_(2)/N_(2) reduction are introduced in sequence to acquire insights into electrochemical processes on in-situ reconfigured surfaces or interfaces. Finally, a perspective is offered to guide future investigations. This review is anticipated to shed some new light on in-depth understanding cathodic electrocatalysis and exploiting prominent electrocatalysts.
基金This work was supported by grants from the National Natural Science Foundation of China(81800056),the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(2017KJ137),and the Key Research and Development Program of Hunan Province(2019SK2021).Scientifi c research project approved by Hunan Provincial Health Commission(202103012117).
文摘Some studies have shown that left ventricular structure and function play an important role in the risk stratifi cation and prognosis of cardiovascular disease.The clinical application of left atrial function in cardiovascular disease has gradually attracted attention in the cardiovascular fi eld.There are many traditional methods to evaluate left atrial function.Left atrial function related indexes measured by echocardiography has been identifi ed as a powerful predictor of cardiovascular disease in recent years,but they have some limitations.The left atrial function index has been found to evaluate left atrial function more effectively than traditional parameters.Furthermore,it is a valuable predictor of the risk stratifi cation and prognosis in patients with clinical cardiovascular disease such as heart failure,atrial fi brillation,hypertension,and coronary heart disease.
文摘The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over WO_3/SnO_2 solid acid which was prepared by impregnating Sn(OH)_4 with aqueous ammonium metatungstate followed by evaporating, drying and calcining in air. The CFC-12 conversion over WO_3/SnO_2 at 330'C remained above 99.5% during 150 h on stream, however, parent metal oxides showed rare catalytic decomposition activity.
文摘The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1). the CPC-12 conversion at 310C over Ti(SO_4)_2 calcined at 350C remained about 98.5% during 360 h on stream. and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.
基金This research was supported by the National Research Foundation,Prime Minister’s Office,Singapore under the Energy Programme and administrated by the Energy Market Authority(EP Award No.NRF2015EWT-EIRP002-007)。
文摘The increasing use of power electronic devices can deteriorate the power quality by introducing voltage and current harmonics.In islanded microgrids,the presence of nonlinear loads can distort the point of common coupling(PCC)voltage,while the dead-time effect can also bring additional circulating current harmonics among parallel inverters.To simultaneously attenuate the PCC voltage harmonics and suppress the dead-time induced circulating current harmonics,this paper proposes a coordinated control strategy for harmonic mitigation of parallel inverters.The proposed control strategy allows inverter impedances to be properly reshaped at selective harmonic frequencies.As a consequence,the PCC voltage harmonics are filtered by the inverter operating in the harmonic compensation mode(HCM),whereas the dead-time induced circulating current harmonics are suppressed by the inverter operating in the harmonic rejection mode(HRM).Experimental results from an islanded microgrid prototype with two parallel inverters are provided to validate the effectiveness of the proposed control strategy.
