资源类型

期刊论文 272

年份

2024 2

2023 28

2022 26

2021 21

2020 16

2019 15

2018 12

2017 9

2016 13

2015 13

2014 12

2013 12

2012 10

2011 11

2010 21

2009 4

2008 7

2007 11

2006 5

2005 5

展开 ︾

关键词

风险分析 9

风险管理 7

风险评估 5

安全风险 3

风险 3

风险控制 3

南京长江隧道 2

危险性分析 2

安全设计 2

建筑火灾 2

风险决策 2

1)模型 1

2型糖尿病 1

ANP 1

COVID-19 1

F-N图 1

GIS 1

GM(1 1

IgG 1

展开 ︾

检索范围：

排序： 展示方式：

Risk stratification system for skin and soft tissue infections after allogeneic hematopoietic stem celltransplantation: PAH risk score

《医学前沿（英文）》 2022年 第16卷 第6期   页码 957-968 doi: 10.1007/s11684-021-0910-1

摘要： Skin and soft tissue infections (SSTIs) refer to infections involving the skin, subcutaneous tissue, fascia, and muscle. In transplant populations with hematological malignancies, an immunocompromised status and the routine use of immunosuppressants increase the risk of SSTIs greatly. However, to date, the profiles and clinical outcomes of SSTIs in hematopoietic stem cell transplantation (HSCT) patients remain unclear. This study included 228 patients (3.67%) who developed SSTIs within 180 days after allogeneic HSCT from January 2004 to December 2019 in Peking University People’s Hospital. The overall annual survival rate was 71.5%. We compared the differences between survivors and non-survivors a year after transplant and found that primary platelet graft failure (PPGF), comorbidities of acute kidney injury (AKI), and hospital-acquired pneumonia (HAP) were independent risk factors for death in the study population. A PPGF–AKI–HAP risk stratification system was established with a mortality risk score of 1×PPGF+1×AKI+1×HAP. The areas under the curves of internal and external validation were 0.833 (95% CI 0.760–0.906) and 0.826 (95% CI 0.715–0.937), respectively. The calibration plot revealed the high consistency of the estimated risks, and decision curve analysis showed considerable net benefits for patients.

关键词： skin and soft tissue infections     hematopoietic stem cell transplantation     risk stratification system     mortality    

HTML PDF 收藏

Molecular pathogenesis of acute myeloid leukemia: A diverse disease with new perspectives

Felicitas THOL, Arnold GANSER

《医学前沿（英文）》 2010年 第4卷 第4期   页码 356-362 doi: 10.1007/s11684-010-0220-5

摘要： Acute myeloid leukemia (AML) is a very heterogeneous neoplasm of the hematopoietic stem cell. Despite important achievements in the treatment of AML, the long term survival of patients with the disease remains poor. Understanding the pathogenesis of AML better is crucial for finding new treatment approaches. During AML development hematopoietic precursor cells undergo clonal transformation in a multistep process through acquisition of chromosomal rearrangements and/or different gene mutations. Over recent years, novel gene mutations have been found in patients with AML. These mutations can be divided into two important categories, class I mutations that confer a proliferation advantage and class II mutations that inhibit myeloid differentiation. Screening for some of these mutations is now part of the initial diagnostic work-up in newly diagnosed AML patients. Information about the mutation status of specific genes is useful for risk-stratification, minimal residual disease (MRD) monitoring and increasingly also for targeted therapy, especially for patients with cytogenetically normal AML (CN-AML). Besides chromosomal rearrangements and gene mutations, epigenetic regulation of genes – meaning changes in gene expression by mechanisms other than changes in the underlying DNA sequence – also represents an important mechanism of leukemogenesis. This article reviews some of the most common mutations in CN-AML and gives a perspective of the translation of these discoveries from bench to bedside.

关键词： acute myeloid leukemia     mutations     risk stratification    

HTML PDF 收藏

A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

《能源前沿（英文）》 2023年 第17卷 第5期   页码 678-691 doi: 10.1007/s11708-022-0859-z

摘要： Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (Rm-2) shortens the injection duration and increases the mean mixing time. Optimized Rm-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

关键词： gasoline compression ignition     injection strategy     fuel stratification     high efficiency     high load    

HTML PDF 收藏

Comparison of prechilling stratification and sulfuric acid scarification on seed germination of

Nan WANG, Jing GAO, Suiqi ZHANG, Feng YAN

《农业科学与工程前沿（英文）》 2017年 第4卷 第2期   页码 220-227 doi: 10.15302/J-FASE-2017146

摘要： In semi-arid regions of the Loess Plateau, water deficiency restricts plant performance. (switchgrass), which is a highly versatile grass, had been introduced to the Plateau as a restoration species. To determine if prechilling stratification (PCS) and sulfuric acid scarification (SAS) can optimize establishment, cvs Pathfinder, Trailblazer and Alamo were tested under different ambient water potentials by measuring germination and root and shoot growth along water potential gradients under laboratory conditions. Both PCS and SAS improved total germination percentage (TGP), with PCS being more beneficial. The effect of PCS and SAS on mean germination time (MGT) weakened gradually with increasing drought stress. Both PCS and SAS showed no obvious effect on promoting root and shoot growth. Both PCS and SAS reduced base water potential requirement for reaching 50% germination of Pathfinder and Trailblazer, with this effect greater for PCS. These results indicate that embryo dormancy may be a major factor limiting germination of under drought conditions. Pathfinder appears to be more suitable for a semi-arid environment, whereas Alamo appears to be unsuitable for drought conditions. Given the large difference between predicted value and measured value, the reliability and applicable scope of linear regression estimated Y needs further investigation, specification and optimization.

关键词： base water potential     data analysis method     embryo growth     germination    

HTML PDF 收藏

SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting in-hospital mortality in a Chinese population

null

《医学前沿（英文）》 2013年 第7卷 第4期   页码 477-485 doi: 10.1007/s11684-013-0284-0

摘要：

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 stage III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2βweeks), 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 =β0.44 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 =β0.34 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.

关键词： coronary artery bypass grafting     risk stratification     in-hospital mortality    

HTML PDF 收藏

Chaotic behavior of LNG after stratification in main stream region of storage tank

WANG Jingjing, MA Xiaoqian

《能源前沿（英文）》 2008年 第2卷 第4期   页码 514-518 doi: 10.1007/s11708-008-0076-4

摘要： A study of the chaotic behavior of liquefied natural gas (LNG) after stratification in the main stream region of a storage tank was conducted. Based on non-linear dynamics, a 2-dimensional Rayleigh-Benard convection model was developed to simulate the convection, Lorenz equations of LNG convection were deduced from conservation equations, and the Runge-Kutta method was used to solve the equations. The results showed that when = 1.33, 106 < < 1470, chaos was obtained, which meant that the velocity field and the temperature field were highly unsteady. In addition, the influence of temperature and scale factor on the solutions and the corresponding range of parameters were studied. The results revealed that the chaos in LNG convection resulted from the interaction of buoyancy and viscid forces. A small quantity of heat impacting the storage tank would lead to a strong and unstable convection of LNG in the main stream region.

关键词： Runge-Kutta     non-linear     corresponding     temperature     addition    

HTML PDF 收藏

Structure creation in earthen construction materials: information from dry soil mixtures

Christopher BECKETT, Charles AUGARDE

《结构与土木工程前沿（英文）》 2011年 第5卷 第2期   页码 151-159 doi: 10.1007/s11709-011-0109-7

摘要： There is increasing interest in the use of earthen construction materials, such as rammed earth, due to their inherent sustainability. These materials have been used by man for thousands of years and some of the earliest examples can be found in China. Features of the structures of these materials arise from the means of production. In particular, in situ earthen construction materials exhibit strong anisotropy due to their layered nature. A more subtle structure effect arises from the way that the earth mixture is deposited. This paper reviews and discusses stratification effects in dry soil mixtures, including some original experimental work, and indicates some links between the features of the dry mixtures and earthen construction materials. Improved understanding of the physical processes in play will allow more accurate specification of these materials in the future, and hence spread their use.

关键词： rammed earth     stratification     particle size distribution     pore size distribution    

HTML PDF 收藏

Numerical simulation of charge stratifications to improve combustion and NO formation of lean-burn SI engines

Zhijun PENG ,

《能源前沿（英文）》 2009年 第3卷 第3期   页码 353-358 doi: 10.1007/s11708-009-0035-8

摘要： The influences of charge stratification on spark ignition (SI) engine combustion and NO emission were analyzed using a phenomenological model. The mixture in the cylinder was divided spherically into three parts: a central core with a stoichiometric air-fuel charge, a dilution region without any combustible charge, and a mixing region lying between the core and the dilution region. Three mixture stratification parameters such as the extent of dilution in the mixing region, the extent of combustible charge in the mixing region, and the gradient of stratification in the mixing region were investigated. The results indicate that the extent of combustible charge in the mixing region could reduce in-cylinder NO formation significantly, compared with the extent of dilution in the mixing region. As long as the degree of dilution in the mixing region is within the dilution limit of the combustible charge, the gradient of dilution has little effect on combustion and NO formation.

关键词： charge stratification     SI engine     lean-burn combustion     NO emission    

HTML PDF 收藏

Understanding and addressing the environmental risk of microplastics

《环境科学与工程前沿（英文）》 2023年 第17卷 第1期 doi: 10.1007/s11783-023-1612-5

摘要：

Over the past decades, the plastic production has been dramatically increased. Indeed, a category of small plastic particles mainly with the shapes of fragments, fibers, or spheres, called microplastics (particles smaller than 5 mm) and nanoplastics (particles smaller than 1 μm) have attracted particular attention. Because of its wide distribution in the environment and potential adverse effects to animal and human, microplastic pollution has been reported as a serious environment problem receiving increased attention in recent years. As one of the commonly detected emerging contaminants in the environment, recent evidence indicates that the concentration of microplastics show an increasing trend, for the reason that up to 12.7 million metric tons of plastic litter is released into aquatic environment from land-based sources each year. Furthermore, microplastic exposure levels of model organisms in laboratory studies are usually several orders of magnitude higher than those found in environment, and the microplastics exposure conditions are also different with those observed in the environment. Additionally, the detection of microplastics in feces indicates that they can be excreted out of the bodies of animal and human. Hence, great uncertainties might exist in microplastics exposure and health risk assessment based on current studies, which might be exaggerated. Policies reduce microplastic emission sources and hence minimize their environmental risks are determined. To promote the above policies, we must first overcome the technical obstacles of detecting microplastics in various samples.

关键词： Emerging contaminants     Microplastics     Environment risk     Health effect    

HTML PDF 收藏

Ecological Risk Management of Drinking Water Project: The Case Study of Kunming City

Ji-liang Zheng,Jun Hu,Xuan Zhou,Ching Yuen Luk

《工程管理前沿（英文）》 2015年 第2卷 第3期   页码 311-319 doi: 10.15302/J-FEM-2015045

摘要： Following rapid infrastructure development and industrialization, the problems of water pollution and water shortage have become more severe. Whether there is safe drinking water in cities has attracted wide attention. The ecological risk management of drinking water project is an important means of ensuring the safety of a drinking water source. Based on ecological risk assessment and management theories, this paper establishes an ecological risk management model and assessment system with the aim of providing theoretical guidance and scientific basis for formulating a policy on the safety and protection of drinking water sources in a city. Kunming is one of the cities plagued by severe water shortage in China. Its ecological risk management of drinking water has attracted the attention of both the local government and the public. Using Kunming as the case study, this paper conducts a comparative analysis and assessment on three major reservoirs that face ecological risks. It highlights the existing problems and gives helpful suggestions.

关键词： drinking water project     ecological risk     ecological risk assessment     risk management    

HTML PDF 收藏

风险矩阵方法与应用述评

朱启超,匡兴华,沈永平

《中国工程科学》 2003年 第5卷 第1期   页码 89-94

摘要：

技术项目的风险管理一直深受美国国防部的重视。介绍了在美国国防采办风险管理中广泛应用的风险矩阵方法，并对其优缺点和适用性进行分析，结合我国国防预研技术项目管理的特点，提出我国开展技术性项目风险管理的思路。

关键词： 风险矩阵     风险管理     项目管理    

HTML PDF 收藏

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

《环境科学与工程前沿（英文）》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1593-9

摘要：

● The airborne bacteria in landfills were 4–50 times higher than fungi.

关键词： Microbial aerosols     Landfill sites     Health risk assessment     CALPUFF    

HTML PDF 收藏

Epidemic obesity in children and adolescents: risk factors and prevention

Eun Young Lee, Kun-Ho Yoon

《医学前沿（英文）》 2018年 第12卷 第6期   页码 658-666 doi: 10.1007/s11684-018-0640-1

摘要： The prevalence of obesity among children and adolescents (aged 2–18 years) has increased rapidly, with more than 100 million affected in 2015. Moreover, the epidemic of obesity in this population has been an important public health problem in developed and developing countries for the following reasons. Childhood and adolescent obesity tracks adulthood obesity and has been implicated in many chronic diseases, including type 2 diabetes, hypertension, and cardiovascular disease. Furthermore, childhood and adolescent obesity is linked to adulthood mortality and premature death. Although an imbalance between caloric intake and physical activity is a principal cause of childhood and adolescent obesity, environmental factors are exclusively important for development of obesity among children and adolescents. In addition to genetic and biological factors, socioenvironmental factors, including family, school, community, and national policies, can play a crucial role. The complexity of risk factors for developing obesity among children and adolescents leads to difficulty in treatment for this population. Many interventional trials for childhood and adolescent obesity have been proven ineffective. Therefore, early identification and prevention is the key to control the global epidemic of obesity. Given that the proportion of overweight children and adolescents is far greater than that of obesity, an effective prevention strategy is to focus on overweight youth, who are at high risk for developing obesity. Multifaceted, comprehensive strategies involving behavioral, psychological, and environmental risk factors must also be developed to prevent obesity among children and adolescents.

关键词： obesity     children     adolescents     epidemiology     risk factor     prevention    

HTML PDF 收藏

Optimal risk allocation in alliance infrastructure projects: A social preference perspective

Xiang DING, Qian LI

《工程管理前沿（英文）》 2022年 第9卷 第2期   页码 326-336 doi: 10.1007/s42524-020-0145-x

摘要： The mechanism of risk allocation is designed to protect all stakeholders, and it is vital to project success. Qualitative and quantitative ways of optimizing risk allocation have been well documented in extant literature (e.g., allocation principles, models, and solutions), and the foci of existing research are usually the maximization of rational utility. Few research has focused on partners’ social preferences affecting the output of risk allocation. This study presents a quantitative approach based on modeling alliance member (AM)’s inequity aversion (IA) to analyze risk-sharing arrangements in an alliance project. Fehr and Schmidt’s inequity-aversion model is integrated into modeling partner’s utility. This paper derives results for an alliance leader (AL)’s optimal risk-sharing ratio and AM’s optimal risk-management effort simultaneously. The derivation is based on solving a restrained optimization problem using the conception and methods from Stackelberg game theory. Results show that an AM’s IA significantly affects risk allocation between AL and AM. Specifically, envious preference is positively related to AL’s optimal risk-sharing ratio, whereas guilty preference negatively affects AL’s optimal risk-sharing ratio. These findings will be of interest to academics and practitioners involved in designing alliance negotiations.

关键词： public project     contract design     risk sharing     inequity aversion     governance    

HTML PDF 收藏

Detection of schedule delay risk of empirical construction projects

Tsegay GEBREHIWET, Hanbin LUO

《工程管理前沿（英文）》 2018年 第5卷 第2期   页码 251-267 doi: 10.15302/J-FEM-2018086

摘要： In Ethiopian construction projects, schedule delay risk is a predominant issue because it is not properly addressed. Although several studies have been focused on the various effects of risk in construction projects, limited efforts have been made to investigate the typical and the overall schedule delay risk. In this study, our aim is to detect the typical and overall schedule delay risk throughout the construction project lifecycle, which consists of the pre-construction, construction, and post-construction stages, and compare the stages with each other. Common criteria, sub-criteria, and attributes were developed for all alternatives for the purpose of making a risk decision. The methodology that was followed integrated the multiple-criteria decision-making (MCDM) model of fuzzy analytic hierarchy process comprehensive evaluation (FAHPCE) and the relative important index (RII). Data were collected from 77 participants, who were selected through purposive sampling from different contracting organizations in Ethiopian construction projects by means of questionnaires that were distributed to experienced experts. The findings showed that there is a typical delay risk either in the type or in the level of the different construction activities. Consequently, the most influenced alternative is the construction stage because of the high-risk responsibility, resource, and contract condition related criteria. The post-construction stage was the second most influenced stage because of the high-risk responsibility-related criteria. The pre-constructed stage was the least influenced stage that consist high-risk criteria of responsibility, resource, and contract condition related. These differences provided noteworthy information about risk mitigation in construction projects by identifying the exact risk level on specific activity to make appropriate decision.

关键词： fuzzy analytic hierarchy process comprehensive evaluation     construction project     detection of delay risk     relative important index    

HTML PDF 收藏

标题 作者 时间 类型 操作

Risk stratification system for skin and soft tissue infections after allogeneic hematopoietic stem celltransplantation: PAH risk score

期刊论文

Molecular pathogenesis of acute myeloid leukemia: A diverse disease with new perspectives

Felicitas THOL, Arnold GANSER

期刊论文

A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection

期刊论文

Comparison of prechilling stratification and sulfuric acid scarification on seed germination of

Nan WANG, Jing GAO, Suiqi ZHANG, Feng YAN

期刊论文

SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting in-hospital mortality in a Chinese population

null

期刊论文

Chaotic behavior of LNG after stratification in main stream region of storage tank

WANG Jingjing, MA Xiaoqian

期刊论文

Structure creation in earthen construction materials: information from dry soil mixtures

Christopher BECKETT, Charles AUGARDE

期刊论文

Numerical simulation of charge stratifications to improve combustion and NO formation of lean-burn SI engines

Zhijun PENG ,

期刊论文

Understanding and addressing the environmental risk of microplastics

期刊论文

Ecological Risk Management of Drinking Water Project: The Case Study of Kunming City

Ji-liang Zheng,Jun Hu,Xuan Zhou,Ching Yuen Luk

期刊论文

风险矩阵方法与应用述评

朱启超,匡兴华,沈永平

期刊论文

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

期刊论文

Epidemic obesity in children and adolescents: risk factors and prevention

Eun Young Lee, Kun-Ho Yoon

期刊论文

Optimal risk allocation in alliance infrastructure projects: A social preference perspective

Xiang DING, Qian LI

期刊论文

Detection of schedule delay risk of empirical construction projects

Tsegay GEBREHIWET, Hanbin LUO

期刊论文