The effects of mass concentration and injection pressure on the atomization characteristics of low-viscosity fuel spray are studied in a constant-volume chamber.Microscopic spray parameters are measured by laser diffr...The effects of mass concentration and injection pressure on the atomization characteristics of low-viscosity fuel spray are studied in a constant-volume chamber.Microscopic spray parameters are measured by laser diffraction at different axial and radial positions downstream of the nozzle.The results show that the atomization effect is inhibited linearly with the increase of mass concentration.The increase of injection pressure promotes the droplet breakup.However,the trend gradually weakens and becomes more noticeable at high concentrations.Comparing with the concentration,the influence of the injection pressure on the atomization characteristics is dominant.Although low concentration and high injection pressure can promote the droplet breakup,they also increase the probability of droplet collision,resulting in droplet aggregation.This is more evident in low-viscosity fuels.The droplet size increases in the axial direction owing to the aggregation.However,the diameter decreases in the radial direction owing to the outward deflection of small droplets caused by air turbulence and entrainment.In addition,the high-velocity airflow significantly promotes the droplet breakup near the nozzle and spray axis regions and inhibits the aggregation effect.However,the lower-viscosity fuels keep smaller droplet sizes and better atomization in the whole spraying process,which is easier to realize than the higher-viscosity fuels.Overall,low concentration,high injection pressure,and low viscosity of fuel have beneficial effects on the droplet breakup.This is very important for improving the atomization effect of fuel.展开更多
1 Introduction Rapid socioeconomic progress has greatly affected the lifestyle in China.Consequently,owing to lifestyle changes,urbanization,and accelerated population aging,the risk of cardiovascular diseases(CVD)has...1 Introduction Rapid socioeconomic progress has greatly affected the lifestyle in China.Consequently,owing to lifestyle changes,urbanization,and accelerated population aging,the risk of cardiovascular diseases(CVD)has increased.The incidence of CVD has been increasing continuously and this upward trend is projected to continue in the next decade.The growing burden of CVD has become a major public health issue.展开更多
Objective: Measures of ventilation-co_2 output relationship have been shown to be more prognostic than peak O_2 uptake in assessing life expectancy in patients with chronic heart failure(CHF). Because both the ratios(...Objective: Measures of ventilation-co_2 output relationship have been shown to be more prognostic than peak O_2 uptake in assessing life expectancy in patients with chronic heart failure(CHF). Because both the ratios(V4e/V4co_2) and slopes(V4e-vs-V4co_2) of ventilation-co_2 output of differing durations can be used, we aim to ascertain which measurements best predicted CHF life expectancy. Methods: Two hundred and seventy-one CHF patients with NYHA class II-IV underwent incremental cardiopulmonary exercise testing(CPET) and were followed-up for a median duration of 479 days. Four different linear regression V4e-vsV4co_2 slopes were calculated from warm-up exercise onset to: 180 s, anaerobic threshold(AT), ventilatory compensation point(VCP); and peak exercise. Five V4e/V4co_2 ratios were calculated for the following durations: rest(120 s), warm-up(30 s), AT(60 s), lowest value(90 s), and peak exercise(30 s). Death or heart transplant were considered end-points. Multiple statistical analyses were performed. Results: CHF patients had high lowest V4e/V4co_2(41.0±9.2, 141±30%pred), high V4e/V4co_2 at AT(42.5±10.4, 145±35%pred), and high V4e-vs-V4co_2 slope to VCP(37.6±12.1, 126±41%pred). The best predictor of death was a higher lowest V4e/V4co_2(≥42, ≥141%pred), whereas the V4e-vs-V4co_2 slope to VCP was less variable than other slopes. For death prognosis in 6 months, %pred values were superior: for longer times, absolute values were superior. Conclusion: The increased lowest V4e/V4co_2 ratio easily identifiable and simply measured during exercise, is the best measurement to assess the ventilation-co_2 output relationship in prognosticating death in CHF patients.展开更多
A generalized simulation method of the tracking,telemetry and control(TT&C) channel,which is applicable to wideband and arbitrary radio frequency(RF) signal,is proposed.It can accurately simulate the dynamic tran...A generalized simulation method of the tracking,telemetry and control(TT&C) channel,which is applicable to wideband and arbitrary radio frequency(RF) signal,is proposed.It can accurately simulate the dynamic transmission delay of the arbitrary RF signal in channels,especially regardless of any prior knowledge including signal form,signal parameters,and so on.The proposed method orthogonally demodulates the wideband and arbitrary RF signal to complex baseband by a known local oscillator(LO) signal.Whereafter,it takes measures to obtain the delay reconstruction signal of baseband signals based on the dynamic transmission delay between a ground station and a responder.Meanwhile,it manages to obtain the delay reconstruction signal of LO signals.The simulation output signal(the delayed RF signal) can be achieved through the synthesis of the two delay reconstruction signals mentioned above.The principle and its related key technology are described in detail,and the realizable system architecture is given.展开更多
Background:Patients who undergo coronary artery bypass grafting(CABG)are known to be at a significant risk of experiencing long-term adverse events,emphasizing the importance of regular assessments.Evaluating health-r...Background:Patients who undergo coronary artery bypass grafting(CABG)are known to be at a significant risk of experiencing long-term adverse events,emphasizing the importance of regular assessments.Evaluating health-related quality of life(HRQoL)serves as a direct method to gauge prognosis.Our objective is to ascertain the prognostic significance of consecutive HRQoL assessments using the Physical Component Summary(PCS)and Mental Component Summary(MCS)derived from the Short-Form 36(SF-36)health survey in CABG patients.Methods:The study population consisted of 433 patients who underwent isolated elective CABG at Fuwai Hospital between 2012 and 2013.SF-36 assessments were conducted during both the hospitalization period and follow-up.The primary endpoint of the study was all-cause mortality,while the secondary outcome was a composite measure including death,myocardial infarction,stroke,and repeat revascularization.We assessed the relationships between the PCS and MCS at baseline,as well as their changes during the first 6 months after the surgery(referred to asΔPCS andΔMCS,respectively),and the observed outcomes.Results:The patients were followed for an average of 6.28 years,during which 35 individuals(35/433,8.1%)died.After adjusting for clinical variables,it was observed that baseline MCS scores(hazard ratio[HR]for a 1-standard deviation[SD]decrease,1.57;95%confidence interval[CI],1.07-2.30)andΔMCS(HR for a 1-SD decrease,1.67;95%CI,1.09-2.56)were associated with all-cause mortality.However,baseline PCS scores andΔPCS did not exhibit a significant relationship with all-cause mortality.Notably,there was a dose-response relationship observed betweenΔMCS and the likelihood of all-cause mortality(HRs for the 2nd,3rd and 4th quartiles compared to the 1st quartile,0.33,0.45 and 0.11,respectively).Conclusions:Baseline MCS and changes in MCS were independent predictors for long-term mortality of CABG.Better mental health status and recovery indicated better prognosis.展开更多
Kagome magnets with diverse topological quantum responses are crucial for next-generation topological engineering.The anisotropic magnetism and band evolution induced by ferromagnetic phase transition(FMPT)is reported...Kagome magnets with diverse topological quantum responses are crucial for next-generation topological engineering.The anisotropic magnetism and band evolution induced by ferromagnetic phase transition(FMPT)is reported in a newly discovered titanium-based kagome ferromagnet Sm Ti3Bi4,which features a distorted Ti kagome lattice and Sm atomic zig-zag chains.Temperature-dependent resistivity,heat capacity,and magnetic susceptibility reveal a ferromagnetic ordering temperature Tc of23.2 K.A large magnetic anisotropy,observed by applying the magnetic field along three crystallographic axes,identifies the b axis as the easy axis.Angle-resolved photoemission spectroscopy with first-principles calculations unveils the characteristic kagome motif,including the Dirac point at the Fermi level and multiple van Hove singularities.Notably,a band splitting and gap closing attributed to FMPT is observed,originating from the exchange coupling between Sm 4 f local moments and itinerant electrons of the kagome Ti atoms,as well as the time-reversal symmetry breaking induced by the long-range ferromagnetic order.Considering the large in-plane magnetization and the evolution of electronic structure under the influence of ferromagnetic ordering,such materials promise to be a new platform for exploring the intricate electronic properties and magnetic phases based on the kagome lattice.展开更多
Introduction Albumin,which is a 65-kDa liver-synthesized protein,accounts for nearly 50%of total plasma protein and contributes to approximately 80%of intravascular oncotic pressure.Albumin helps maintain microvascula...Introduction Albumin,which is a 65-kDa liver-synthesized protein,accounts for nearly 50%of total plasma protein and contributes to approximately 80%of intravascular oncotic pressure.Albumin helps maintain microvascular integrity,functions as an antioxidant,and transports hormones,fatty acid,bile salts,bilirubin,electrolytes(e.g.,calcium,magnesium,copper,zinc,et al.),and drugs.[1–3]Human serum albumin(HSA)is a sterile,liquid albumin product derived from large pools of human plasma by fractionation and pasteurization.The medical use of HAS could date back to approximately the time of World War II.展开更多
This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery(CABG).Data from 9839 consecutive CABG patients...This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery(CABG).Data from 9839 consecutive CABG patients in 43 Chinese centers were collected between 2007 and 2008 from the Chinese Coronary Artery Bypass Grafting Registry.This database was randomly divided into developmental and validation subsets(9:1).The data in the developmental dataset were used to develop the model using logistic regression.Calibration and discrimination characteristics were assessed using the validation dataset.Thresholds were defined for each model to distinguish different risk groups.After excluding 275 patients with incomplete information,the overall mortality rate of the remaining 9564 patients was 2.5%.The SinoSCORE model was constructed based on 11 variables:age,preoperative NYHA stageⅢorⅣ,chronic renal failure,extracardiac arteriopathy,chronic obstructive pulmonary disease,preoperative atrial fibrillation or flutter(within 2 weeks),left ventricular ejection fraction,other elective surgery,combined valve procedures,preoperative critical state,and BMI.In the developmental dataset,calibration using a Hosmer-Lemeshow(HL)test was at P=0.44 and discrimination based on the area under the receiver operating characteristic curve(ROC)was 0.80.In the validation dataset,the HL test was at P=0.34 and the area under the ROC(AUC)was 0.78.A logistically derived additive model for predicting in-hospital mortality among Chinese patients undergoing CABG was developed based on the most up-to-date multi-center data from China.展开更多
On June 24,2021,a 40-year-old reinforced concrete flat plate structure building in Miami suffered a sudden partial collapse.This study analyzed the overall performance and key components of the collapsed building base...On June 24,2021,a 40-year-old reinforced concrete flat plate structure building in Miami suffered a sudden partial collapse.This study analyzed the overall performance and key components of the collapsed building based on the building design codes(ACI-318 and GB 50010).Punching shear and post-punching performances of typical slabcolumn joints are also studied through the refined finite element analysis.The collapse process was simulated and visualized using a physics engine.By way of these analyses,weak design points of the collapsed building are highlighted.The differences between the reinforcement detailing of the collapsed building and the requirements of the current Chinese code are discussed,together with a comparison of the punching shear and post-punching performances.The simulated collapse procedure and debris distribution are compared with the actual collapse scenes.展开更多
Background::Imprecise interpretation of coronary angiograms was reported and resulted in inappropriate revascularization.Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score i...Background::Imprecise interpretation of coronary angiograms was reported and resulted in inappropriate revascularization.Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score is a comprehensive system to evaluate the complexity of the overall lesions.We hypothesized that a real-time SYNTAX score feedback from image analysts may rectify the mis-estimation and improve revascularization appropriateness in patients with stable coronary artery disease(CAD).Methods::In this single-center,historical control study,patients with stable CAD with coronary lesion stenosis≥50%were consecutively recruited.During the control period,SYNTAX scores were calculated by treating cardiologists.During the intervention period,SYNTAX scores were calculated by image analysts immediately after coronary angiography and were provided to cardiologists in real-time to aid decision-making.The primary outcome was revascularization deemed inappropriate by Chinese appropriate use criteria for coronary revascularization.Results::A total of 3245 patients were enrolled and assigned to the control group(08/2016-03/2017,n=1525)or the intervention group(03/2017-09/2017,n=1720).For SYNTAX score tertiles,17.9%patients were overestimated and 4.3%were underestimated by cardiologists in the control group.After adjustment,inappropriate revascularization significantly decreased in the intervention group compared with the control group(adjusted odds ratio[OR]:0.83;95%confidence interval[CI]:0.73-0.95;P=0.007).Both inappropriate percutaneous coronary intervention(adjusted OR:0.82;95%CI:0.74-0.92;P<0.001)and percutaneous coronary intervention utilization(adjusted OR:0.88;95%CI:0.79-0.98;P=0.016)decreased significantly in the intervention group.There was no significant difference in 1-year adverse cardiac events between the control group and the intervention group.Conclusions::Real-time SYNTAX score feedback significantly reduced inappropriate coronary revascularization in stable patients with CAD.Clinical trial registration::Nos.NCT03068858 and NCT02880605;https://www.clinicaltrials.gov.展开更多
Background:Six epidemic waves of human infection with avian influenza A (H7N9) virus have emerged in China with high mortality. However, study on quantitative relationship between clinical indices in ill persons and H...Background:Six epidemic waves of human infection with avian influenza A (H7N9) virus have emerged in China with high mortality. However, study on quantitative relationship between clinical indices in ill persons and H7N9 outcome (fatal and nonfatal) is still unclear. A retrospective cohort study was conducted to collect laboratory-confirmed cases with H7N9 viral infection from 2013 to 2015 in 23 hospitals across 13 cities in Guangdong Province, China.Methods:Multivariable logistic regression model and classification tree model analyses were used to detect the threshold of selected clinical indices and risk factors for H7N9 death. The receiver operating characteristic curve (ROC) and analyses were used to compare survival and death distributions and differences between indices. A total of 143 cases with 90 survivors and 53 deaths were investigated.Results:Average age (Odds Ratio (OR)=1.036, 95% Confidence Interval (CI)=1.016-1.057), interval days between dates of onset and confirmation (OR=1.078, 95% CI=1.004-1.157), interval days between onset and oseltamivir treatment (OR=5.923, 95% CI=1.877-18.687), body temperature (BT) (OR=3.612, 95% CI=1.914-6.815), white blood cell count (WBC) (OR=1.212, 95% CI=1.092-1.346) were significantly associated with H7N9 death after adjusting for confounders. The chance of death from H7N9 infection was 80.0% if BT was over 38.1 °C, and chance of death is 67.4% if WBC count was higher than 9.5 (109/L). Only 27.1% of patients who began oseltamivir treatment less than 9.5 days after disease onset died, compared to 68.8% of those who started treatment more than 15.5 days after onset.Conclusions:The intervals between date of onset and confirmation of diagnosis, between date of onset to oseltamivir treatment, age, BT and WBC are found to be the best predictors of H7N9 mortality.展开更多
Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potenti...Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potential use in the early PMI has not been fully studied yet.To test this possibility in the present study,EC of three internal organs of rat liver,spleen,and kidney were determined within 24 postmortem hows,and then,EC changes at different PMIs were carefully analyzed.The overall results showed that EC of liver and spleen increased significantly with PMI while EC of kidney had minor changes during the same period.Specifically,significant linear positive correlations between EC of liver and spleen and PMI were found and the coefficients of their regression functions were R^(2)=0.98 and R^(2)=0.95,respectively.It can be concluded that determination of EC in certain internal organs such as liver and spleen may be a potential tool in the early PMI estimation.However,more researches on its influencing factors are needed to facilitate its final use in practice.展开更多
目的:癫痫是神经系统常见病,半数以上患者儿童时期便发病,癫痫病患者常需终身服用抗癫痫药。研究表明,长期服用抗癫痫药物会影响骨代谢,加速骨矿物质的丢失,导致骨质疏松。但是,每种抗癫痫药物的具体作用还不清楚。作为典型的肝酶诱导...目的:癫痫是神经系统常见病,半数以上患者儿童时期便发病,癫痫病患者常需终身服用抗癫痫药。研究表明,长期服用抗癫痫药物会影响骨代谢,加速骨矿物质的丢失,导致骨质疏松。但是,每种抗癫痫药物的具体作用还不清楚。作为典型的肝酶诱导剂的抗癫痫药物,卡马西平已经公认有降低骨密度的作用,但是作为非肝酶诱导剂的丙戊酸钠,还没有定论。在新型抗癫痫药物中,奥卡西平、托吡酯和拉莫三嗪等对骨密度似乎没有影响,但目前相关的研究很少,各研究所得结果也不一致。本研究拟通过荟萃分析评估抗癫痫药对癫痫病儿童骨密度和骨代谢的影响。创新点:目前已有荟萃分析评估抗癫痫药对成人骨密度的影响,但尚无研究分析抗癫痫药对儿童的影响。方法:检索PubMed和Web of Science数据库中评估抗癫痫药与儿童骨密度及骨代谢关系的临床试验。入选标准为:(1)至少包括一项骨代谢的标志物;(2)骨密度用双能×线吸收计量法计算;(3)研究结果包括平均的骨密度和骨密度的标准差;(4)年龄小于18岁;(5)患者采用单药或多药治疗;(6)具有健康对照组;(7)必须是观察性研究或随机对照研究。采用固定效应模型和随机效应模型对22篇文献的1492例患者中的骨密度及骨代谢资料进行荟萃分析,结果用加权均数差(WMD)或标准均数差(SMD)进行评估。结论:共22篇文献符合纳入标准,共计1492例患者。荟萃分析的结果显示,抗癫痫药物的使用可以引起儿童:(1)腰椎、转子、股骨颈的骨密度和全身骨密度的下降;(2)维生素D下降和血清碱性磷酸酶的上升;(3)甲状旁腺激素、钙和磷没有显著改变。荟萃分析的结果表明,抗癫痫药的使用可能和癫痫病患儿骨密度降低相关。展开更多
Resistance to unexpected disasters and rapid post-disaster recovery(i.e.,disaster resilience)of cities are extremely necessary owing to the concentrated risk of urbanization.Resilience quantification can adequately re...Resistance to unexpected disasters and rapid post-disaster recovery(i.e.,disaster resilience)of cities are extremely necessary owing to the concentrated risk of urbanization.Resilience quantification can adequately reflect the capacity of a city to withstand disasters.Many existing studies have focused on and proposed several frameworks on the quantitative measures of disaster resilience,and the corresponding research objects include different types of disasters(e.g.,earthquake,hurricane,flood,and fire),various domains(e.g.,engineering,social,and economic),and multiple levels(e.g.,city,community,and building).Among these research objects,studies on seismic resilience in civil engineering are relatively comprehensive.Specifically,studies on resilience in civil engineering have paid significant attention to the dynamics of engineering facilities and the engineering-related social and economic functions,including city-scale engineering,social,and economic functionalities,and essential functionalities of building,transportation,lifeline,and nonphysical subsystems of a city.Consequently,based on the review of resilience studies carried out in recent years,the framework and specifications for the quantification of disaster resilience of civil engineering systems subjected to earthquakes and other unexpected disasters are elaborated.Methods of disaster resilience assessment of cities and the corresponding subsystems are discussed.Furthermore,several case studies are reviewed,and resilience limit-state analyses of communities and buildings are performed.展开更多
Background: Secondary preventive therapies play a key role in the prevention of adverse outcomes after coronary artery bypass grafting (CABG). However, medication adherence alter CABG is often poor, and conventiona...Background: Secondary preventive therapies play a key role in the prevention of adverse outcomes after coronary artery bypass grafting (CABG). However, medication adherence alter CABG is often poor, and conventional interventions for improving adherence have limited success. With increasing penetration of smartphones, health-related smartphone applications might provide an opportunity to improve adherence. Carefully designed trials are needed to provide reliable evidence for the use of these applications in patients after CABG. Methods: The Measurement and Improvement Studies of Surgical Coronary Revascularization: Medication Adherence (MISSION-2) study is a multicenter randomized controlled trial, aiming to randomize 1000 CABG patients to the intervention or control groups in a 1 : 1 ratio. We developed the multifaceted, patient-centered, smartphone-based Heart Health Application to encourage lnedication adherence in the intervention group through a health self management program initiated dnring hospital admission for CABG. The application integrated daily scheduled reminders to take the discharge medications, cardiac edticational materials, a dynamic dashboard to review cardiovascular risk factors and secondary prevention targets, and weekly questionnaires with interactive feedback. The primary outcome was secondary preventive medication adherence measured by the Chinese version of the 8-item Morisky Medication Adherence Scale at 6 months after randomization. Secondary outcomes included all-cause death, cardiovascular rehospitalization, and a composite of death, myocardial infarction, stroke, and repeat revascularization.Discussion: Findings will not only provide evidence regarding the feasibility and effectiveness of the described intervention for improving adherence to CABG secondary preventive therapies but also explore a model tor outpatient health self-managenlent that could be translated to various chronic diseases and widely disseminated across resource-limited settings.展开更多
基金Project supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant No.11802136).
文摘The effects of mass concentration and injection pressure on the atomization characteristics of low-viscosity fuel spray are studied in a constant-volume chamber.Microscopic spray parameters are measured by laser diffraction at different axial and radial positions downstream of the nozzle.The results show that the atomization effect is inhibited linearly with the increase of mass concentration.The increase of injection pressure promotes the droplet breakup.However,the trend gradually weakens and becomes more noticeable at high concentrations.Comparing with the concentration,the influence of the injection pressure on the atomization characteristics is dominant.Although low concentration and high injection pressure can promote the droplet breakup,they also increase the probability of droplet collision,resulting in droplet aggregation.This is more evident in low-viscosity fuels.The droplet size increases in the axial direction owing to the aggregation.However,the diameter decreases in the radial direction owing to the outward deflection of small droplets caused by air turbulence and entrainment.In addition,the high-velocity airflow significantly promotes the droplet breakup near the nozzle and spray axis regions and inhibits the aggregation effect.However,the lower-viscosity fuels keep smaller droplet sizes and better atomization in the whole spraying process,which is easier to realize than the higher-viscosity fuels.Overall,low concentration,high injection pressure,and low viscosity of fuel have beneficial effects on the droplet breakup.This is very important for improving the atomization effect of fuel.
文摘1 Introduction Rapid socioeconomic progress has greatly affected the lifestyle in China.Consequently,owing to lifestyle changes,urbanization,and accelerated population aging,the risk of cardiovascular diseases(CVD)has increased.The incidence of CVD has been increasing continuously and this upward trend is projected to continue in the next decade.The growing burden of CVD has become a major public health issue.
基金supported by the National Natural Science Foundation of China (No.11574289)Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(2nd phase) (No.U1501501)+1 种基金"111" Project by Education Ministry of China"Materials research by Information Integration" Initiative (MI2I) Project of the Support Program for Starting Up Innovation Hub from Japan Science and Technology Agency (JST)
基金partially supported by National Center of Cardiovascular Diseases,Fuwai Hospital,Chinese Academy of Medical Sciences,Beijing,ChinaThe clinical trials of the Resynchronization for Hemod Ynamic Treatment for Heart Failure Management(RHYTHM)[38]were funded by St Jude Medical
文摘Objective: Measures of ventilation-co_2 output relationship have been shown to be more prognostic than peak O_2 uptake in assessing life expectancy in patients with chronic heart failure(CHF). Because both the ratios(V4e/V4co_2) and slopes(V4e-vs-V4co_2) of ventilation-co_2 output of differing durations can be used, we aim to ascertain which measurements best predicted CHF life expectancy. Methods: Two hundred and seventy-one CHF patients with NYHA class II-IV underwent incremental cardiopulmonary exercise testing(CPET) and were followed-up for a median duration of 479 days. Four different linear regression V4e-vsV4co_2 slopes were calculated from warm-up exercise onset to: 180 s, anaerobic threshold(AT), ventilatory compensation point(VCP); and peak exercise. Five V4e/V4co_2 ratios were calculated for the following durations: rest(120 s), warm-up(30 s), AT(60 s), lowest value(90 s), and peak exercise(30 s). Death or heart transplant were considered end-points. Multiple statistical analyses were performed. Results: CHF patients had high lowest V4e/V4co_2(41.0±9.2, 141±30%pred), high V4e/V4co_2 at AT(42.5±10.4, 145±35%pred), and high V4e-vs-V4co_2 slope to VCP(37.6±12.1, 126±41%pred). The best predictor of death was a higher lowest V4e/V4co_2(≥42, ≥141%pred), whereas the V4e-vs-V4co_2 slope to VCP was less variable than other slopes. For death prognosis in 6 months, %pred values were superior: for longer times, absolute values were superior. Conclusion: The increased lowest V4e/V4co_2 ratio easily identifiable and simply measured during exercise, is the best measurement to assess the ventilation-co_2 output relationship in prognosticating death in CHF patients.
基金supported by the Foundation of Shanghai Aerospace Science and Technology(20120541088)
文摘A generalized simulation method of the tracking,telemetry and control(TT&C) channel,which is applicable to wideband and arbitrary radio frequency(RF) signal,is proposed.It can accurately simulate the dynamic transmission delay of the arbitrary RF signal in channels,especially regardless of any prior knowledge including signal form,signal parameters,and so on.The proposed method orthogonally demodulates the wideband and arbitrary RF signal to complex baseband by a known local oscillator(LO) signal.Whereafter,it takes measures to obtain the delay reconstruction signal of baseband signals based on the dynamic transmission delay between a ground station and a responder.Meanwhile,it manages to obtain the delay reconstruction signal of LO signals.The simulation output signal(the delayed RF signal) can be achieved through the synthesis of the two delay reconstruction signals mentioned above.The principle and its related key technology are described in detail,and the realizable system architecture is given.
基金supported by a grant from the National Natural Science Foundation of China(No.81830072)
文摘Background:Patients who undergo coronary artery bypass grafting(CABG)are known to be at a significant risk of experiencing long-term adverse events,emphasizing the importance of regular assessments.Evaluating health-related quality of life(HRQoL)serves as a direct method to gauge prognosis.Our objective is to ascertain the prognostic significance of consecutive HRQoL assessments using the Physical Component Summary(PCS)and Mental Component Summary(MCS)derived from the Short-Form 36(SF-36)health survey in CABG patients.Methods:The study population consisted of 433 patients who underwent isolated elective CABG at Fuwai Hospital between 2012 and 2013.SF-36 assessments were conducted during both the hospitalization period and follow-up.The primary endpoint of the study was all-cause mortality,while the secondary outcome was a composite measure including death,myocardial infarction,stroke,and repeat revascularization.We assessed the relationships between the PCS and MCS at baseline,as well as their changes during the first 6 months after the surgery(referred to asΔPCS andΔMCS,respectively),and the observed outcomes.Results:The patients were followed for an average of 6.28 years,during which 35 individuals(35/433,8.1%)died.After adjusting for clinical variables,it was observed that baseline MCS scores(hazard ratio[HR]for a 1-standard deviation[SD]decrease,1.57;95%confidence interval[CI],1.07-2.30)andΔMCS(HR for a 1-SD decrease,1.67;95%CI,1.09-2.56)were associated with all-cause mortality.However,baseline PCS scores andΔPCS did not exhibit a significant relationship with all-cause mortality.Notably,there was a dose-response relationship observed betweenΔMCS and the likelihood of all-cause mortality(HRs for the 2nd,3rd and 4th quartiles compared to the 1st quartile,0.33,0.45 and 0.11,respectively).Conclusions:Baseline MCS and changes in MCS were independent predictors for long-term mortality of CABG.Better mental health status and recovery indicated better prognosis.
基金supported by the Synergetic Extreme Condition User Facility(SECUF)the National Key Research and Development Program of China(Grant Nos.2022YFA1403800,2022YFA1403900,and 2018YFE0202600)+3 种基金the National Natural Science Foundation of China(Grant Nos.U22A6005,51832010,11888101,11925408,11921004,and 12188101)the Informatization Plan of the Chinese Academy of Sciences(Grant No.CASWX2021SF-0102)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB33000000,and XDB28000000)the“Dreamline”beamline of Shanghai Synchrotron Radiation Facility(SSRF)。
文摘Kagome magnets with diverse topological quantum responses are crucial for next-generation topological engineering.The anisotropic magnetism and band evolution induced by ferromagnetic phase transition(FMPT)is reported in a newly discovered titanium-based kagome ferromagnet Sm Ti3Bi4,which features a distorted Ti kagome lattice and Sm atomic zig-zag chains.Temperature-dependent resistivity,heat capacity,and magnetic susceptibility reveal a ferromagnetic ordering temperature Tc of23.2 K.A large magnetic anisotropy,observed by applying the magnetic field along three crystallographic axes,identifies the b axis as the easy axis.Angle-resolved photoemission spectroscopy with first-principles calculations unveils the characteristic kagome motif,including the Dirac point at the Fermi level and multiple van Hove singularities.Notably,a band splitting and gap closing attributed to FMPT is observed,originating from the exchange coupling between Sm 4 f local moments and itinerant electrons of the kagome Ti atoms,as well as the time-reversal symmetry breaking induced by the long-range ferromagnetic order.Considering the large in-plane magnetization and the evolution of electronic structure under the influence of ferromagnetic ordering,such materials promise to be a new platform for exploring the intricate electronic properties and magnetic phases based on the kagome lattice.
文摘Introduction Albumin,which is a 65-kDa liver-synthesized protein,accounts for nearly 50%of total plasma protein and contributes to approximately 80%of intravascular oncotic pressure.Albumin helps maintain microvascular integrity,functions as an antioxidant,and transports hormones,fatty acid,bile salts,bilirubin,electrolytes(e.g.,calcium,magnesium,copper,zinc,et al.),and drugs.[1–3]Human serum albumin(HSA)is a sterile,liquid albumin product derived from large pools of human plasma by fractionation and pasteurization.The medical use of HAS could date back to approximately the time of World War II.
基金supported by the Key Project in the National Science&Technology Pillar Program during the 12th 5-Year Plan Period(2011BAI11B21,2011BAI11B02)Public Specialty Fund of Health Ministry(200902001)and Program for New Century Excellent Talents in University.
文摘This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery(CABG).Data from 9839 consecutive CABG patients in 43 Chinese centers were collected between 2007 and 2008 from the Chinese Coronary Artery Bypass Grafting Registry.This database was randomly divided into developmental and validation subsets(9:1).The data in the developmental dataset were used to develop the model using logistic regression.Calibration and discrimination characteristics were assessed using the validation dataset.Thresholds were defined for each model to distinguish different risk groups.After excluding 275 patients with incomplete information,the overall mortality rate of the remaining 9564 patients was 2.5%.The SinoSCORE model was constructed based on 11 variables:age,preoperative NYHA stageⅢorⅣ,chronic renal failure,extracardiac arteriopathy,chronic obstructive pulmonary disease,preoperative atrial fibrillation or flutter(within 2 weeks),left ventricular ejection fraction,other elective surgery,combined valve procedures,preoperative critical state,and BMI.In the developmental dataset,calibration using a Hosmer-Lemeshow(HL)test was at P=0.44 and discrimination based on the area under the receiver operating characteristic curve(ROC)was 0.80.In the validation dataset,the HL test was at P=0.34 and the area under the ROC(AUC)was 0.78.A logistically derived additive model for predicting in-hospital mortality among Chinese patients undergoing CABG was developed based on the most up-to-date multi-center data from China.
基金the financial support received from The National Key R&D Program(No.2019YFE0112800)the National Natural Science Foundation of China(Grant No.51778341)the Australian Research Council through an ARC Discovery Project(No.DP150100606).
文摘On June 24,2021,a 40-year-old reinforced concrete flat plate structure building in Miami suffered a sudden partial collapse.This study analyzed the overall performance and key components of the collapsed building based on the building design codes(ACI-318 and GB 50010).Punching shear and post-punching performances of typical slabcolumn joints are also studied through the refined finite element analysis.The collapse process was simulated and visualized using a physics engine.By way of these analyses,weak design points of the collapsed building are highlighted.The differences between the reinforcement detailing of the collapsed building and the requirements of the current Chinese code are discussed,together with a comparison of the punching shear and post-punching performances.The simulated collapse procedure and debris distribution are compared with the actual collapse scenes.
基金This work was supported by grants from the Capital’S Funds for Health Improvement and Research(No.2016-1-4031)National Key Research and Development Program(No.2016YFC1302000)Beijing Municipal Commission of Science and Technology Project(No.D171100002917001).
文摘Background::Imprecise interpretation of coronary angiograms was reported and resulted in inappropriate revascularization.Synergy Between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery(SYNTAX)score is a comprehensive system to evaluate the complexity of the overall lesions.We hypothesized that a real-time SYNTAX score feedback from image analysts may rectify the mis-estimation and improve revascularization appropriateness in patients with stable coronary artery disease(CAD).Methods::In this single-center,historical control study,patients with stable CAD with coronary lesion stenosis≥50%were consecutively recruited.During the control period,SYNTAX scores were calculated by treating cardiologists.During the intervention period,SYNTAX scores were calculated by image analysts immediately after coronary angiography and were provided to cardiologists in real-time to aid decision-making.The primary outcome was revascularization deemed inappropriate by Chinese appropriate use criteria for coronary revascularization.Results::A total of 3245 patients were enrolled and assigned to the control group(08/2016-03/2017,n=1525)or the intervention group(03/2017-09/2017,n=1720).For SYNTAX score tertiles,17.9%patients were overestimated and 4.3%were underestimated by cardiologists in the control group.After adjustment,inappropriate revascularization significantly decreased in the intervention group compared with the control group(adjusted odds ratio[OR]:0.83;95%confidence interval[CI]:0.73-0.95;P=0.007).Both inappropriate percutaneous coronary intervention(adjusted OR:0.82;95%CI:0.74-0.92;P<0.001)and percutaneous coronary intervention utilization(adjusted OR:0.88;95%CI:0.79-0.98;P=0.016)decreased significantly in the intervention group.There was no significant difference in 1-year adverse cardiac events between the control group and the intervention group.Conclusions::Real-time SYNTAX score feedback significantly reduced inappropriate coronary revascularization in stable patients with CAD.Clinical trial registration::Nos.NCT03068858 and NCT02880605;https://www.clinicaltrials.gov.
基金financial support from the Ministry of Science and Technology of China (2017YFA0204503 and 2016YFB0401100)the National Natural Science Foundation of China (51725304, 51633006, 51703159, 51733004 and 21875259)+1 种基金the Strategic Priority Research Program (XDB12030300)the Chinese Academy of Sciences and the National Program for Support of Top-notch Young Professionals
文摘Background:Six epidemic waves of human infection with avian influenza A (H7N9) virus have emerged in China with high mortality. However, study on quantitative relationship between clinical indices in ill persons and H7N9 outcome (fatal and nonfatal) is still unclear. A retrospective cohort study was conducted to collect laboratory-confirmed cases with H7N9 viral infection from 2013 to 2015 in 23 hospitals across 13 cities in Guangdong Province, China.Methods:Multivariable logistic regression model and classification tree model analyses were used to detect the threshold of selected clinical indices and risk factors for H7N9 death. The receiver operating characteristic curve (ROC) and analyses were used to compare survival and death distributions and differences between indices. A total of 143 cases with 90 survivors and 53 deaths were investigated.Results:Average age (Odds Ratio (OR)=1.036, 95% Confidence Interval (CI)=1.016-1.057), interval days between dates of onset and confirmation (OR=1.078, 95% CI=1.004-1.157), interval days between onset and oseltamivir treatment (OR=5.923, 95% CI=1.877-18.687), body temperature (BT) (OR=3.612, 95% CI=1.914-6.815), white blood cell count (WBC) (OR=1.212, 95% CI=1.092-1.346) were significantly associated with H7N9 death after adjusting for confounders. The chance of death from H7N9 infection was 80.0% if BT was over 38.1 °C, and chance of death is 67.4% if WBC count was higher than 9.5 (109/L). Only 27.1% of patients who began oseltamivir treatment less than 9.5 days after disease onset died, compared to 68.8% of those who started treatment more than 15.5 days after onset.Conclusions:The intervals between date of onset and confirmation of diagnosis, between date of onset to oseltamivir treatment, age, BT and WBC are found to be the best predictors of H7N9 mortality.
基金This study was supported by the Basic and Frontier Study of Technology Project of Henan Province(Grant No.112300410082)the Doctor Foundation and the Youngs'Foundation of Henan University of Science and Technology(Grant No.09001309,2013ZCX024 and 2011QN52)Key Laboratory of Forensic Medicine Identification in Luoyang(No.11550002).
文摘Previous research has found that electrical conductivity(EC),an important index to predict meat freshness and shelflife,is very promising for estimating the late postmortem interval(PMI).However,whether it has potential use in the early PMI has not been fully studied yet.To test this possibility in the present study,EC of three internal organs of rat liver,spleen,and kidney were determined within 24 postmortem hows,and then,EC changes at different PMIs were carefully analyzed.The overall results showed that EC of liver and spleen increased significantly with PMI while EC of kidney had minor changes during the same period.Specifically,significant linear positive correlations between EC of liver and spleen and PMI were found and the coefficients of their regression functions were R^(2)=0.98 and R^(2)=0.95,respectively.It can be concluded that determination of EC in certain internal organs such as liver and spleen may be a potential tool in the early PMI estimation.However,more researches on its influencing factors are needed to facilitate its final use in practice.
基金Project supported by the National High-Tech R&D Program(863)of China(No.2012AA020408)the Medical and Health General Research Plan of Zhejiang Province(No.2014KYA103),China
文摘目的:癫痫是神经系统常见病,半数以上患者儿童时期便发病,癫痫病患者常需终身服用抗癫痫药。研究表明,长期服用抗癫痫药物会影响骨代谢,加速骨矿物质的丢失,导致骨质疏松。但是,每种抗癫痫药物的具体作用还不清楚。作为典型的肝酶诱导剂的抗癫痫药物,卡马西平已经公认有降低骨密度的作用,但是作为非肝酶诱导剂的丙戊酸钠,还没有定论。在新型抗癫痫药物中,奥卡西平、托吡酯和拉莫三嗪等对骨密度似乎没有影响,但目前相关的研究很少,各研究所得结果也不一致。本研究拟通过荟萃分析评估抗癫痫药对癫痫病儿童骨密度和骨代谢的影响。创新点:目前已有荟萃分析评估抗癫痫药对成人骨密度的影响,但尚无研究分析抗癫痫药对儿童的影响。方法:检索PubMed和Web of Science数据库中评估抗癫痫药与儿童骨密度及骨代谢关系的临床试验。入选标准为:(1)至少包括一项骨代谢的标志物;(2)骨密度用双能×线吸收计量法计算;(3)研究结果包括平均的骨密度和骨密度的标准差;(4)年龄小于18岁;(5)患者采用单药或多药治疗;(6)具有健康对照组;(7)必须是观察性研究或随机对照研究。采用固定效应模型和随机效应模型对22篇文献的1492例患者中的骨密度及骨代谢资料进行荟萃分析,结果用加权均数差(WMD)或标准均数差(SMD)进行评估。结论:共22篇文献符合纳入标准,共计1492例患者。荟萃分析的结果显示,抗癫痫药物的使用可以引起儿童:(1)腰椎、转子、股骨颈的骨密度和全身骨密度的下降;(2)维生素D下降和血清碱性磷酸酶的上升;(3)甲状旁腺激素、钙和磷没有显著改变。荟萃分析的结果表明,抗癫痫药的使用可能和癫痫病患儿骨密度降低相关。
基金The authors are grateful for the financial support from the National Natural Science Founda-tion of China(No.U1709212)the Tencent Foundation through the XPLORER PRIZE.
文摘Resistance to unexpected disasters and rapid post-disaster recovery(i.e.,disaster resilience)of cities are extremely necessary owing to the concentrated risk of urbanization.Resilience quantification can adequately reflect the capacity of a city to withstand disasters.Many existing studies have focused on and proposed several frameworks on the quantitative measures of disaster resilience,and the corresponding research objects include different types of disasters(e.g.,earthquake,hurricane,flood,and fire),various domains(e.g.,engineering,social,and economic),and multiple levels(e.g.,city,community,and building).Among these research objects,studies on seismic resilience in civil engineering are relatively comprehensive.Specifically,studies on resilience in civil engineering have paid significant attention to the dynamics of engineering facilities and the engineering-related social and economic functions,including city-scale engineering,social,and economic functionalities,and essential functionalities of building,transportation,lifeline,and nonphysical subsystems of a city.Consequently,based on the review of resilience studies carried out in recent years,the framework and specifications for the quantification of disaster resilience of civil engineering systems subjected to earthquakes and other unexpected disasters are elaborated.Methods of disaster resilience assessment of cities and the corresponding subsystems are discussed.Furthermore,several case studies are reviewed,and resilience limit-state analyses of communities and buildings are performed.
文摘Background: Secondary preventive therapies play a key role in the prevention of adverse outcomes after coronary artery bypass grafting (CABG). However, medication adherence alter CABG is often poor, and conventional interventions for improving adherence have limited success. With increasing penetration of smartphones, health-related smartphone applications might provide an opportunity to improve adherence. Carefully designed trials are needed to provide reliable evidence for the use of these applications in patients after CABG. Methods: The Measurement and Improvement Studies of Surgical Coronary Revascularization: Medication Adherence (MISSION-2) study is a multicenter randomized controlled trial, aiming to randomize 1000 CABG patients to the intervention or control groups in a 1 : 1 ratio. We developed the multifaceted, patient-centered, smartphone-based Heart Health Application to encourage lnedication adherence in the intervention group through a health self management program initiated dnring hospital admission for CABG. The application integrated daily scheduled reminders to take the discharge medications, cardiac edticational materials, a dynamic dashboard to review cardiovascular risk factors and secondary prevention targets, and weekly questionnaires with interactive feedback. The primary outcome was secondary preventive medication adherence measured by the Chinese version of the 8-item Morisky Medication Adherence Scale at 6 months after randomization. Secondary outcomes included all-cause death, cardiovascular rehospitalization, and a composite of death, myocardial infarction, stroke, and repeat revascularization.Discussion: Findings will not only provide evidence regarding the feasibility and effectiveness of the described intervention for improving adherence to CABG secondary preventive therapies but also explore a model tor outpatient health self-managenlent that could be translated to various chronic diseases and widely disseminated across resource-limited settings.