关键词： 急性左心衰竭   序贯机械通气   血流动力学   心功能  

摘要： 目的:分析序贯机械通气治疗改善老年急性左心衰竭患者血流动力学、心功能及神经体液状态的作用。方法:90例老年急性左心衰竭患者随机分为观察组及对照组,对照组接受常规机械通气治疗,观察组接受序贯机械通气治疗,对比两组治疗后血流动力学、心功能及神经体液状态差异。结果:治疗后24h时,观察组接受治疗后的mPAP、PCWP、RAP水平低于对照组,CO水平高于对照组,差异具有统计学意义(P<0.05);LVEF值高于对照组,SVR、LVEDV、LVESV值低于对照组,差异具有统计学意义(P<0.05);治疗后12、24h时,观察组血浆Nt-proBNP、ANP、R、AngⅡ、ALD水平均显著低于对照组,差异具有统计学意义(P<0.05)。结论:序贯机械通气治疗可优化老年急性左心衰竭患者病情,在促进患者心功能恢复、恢复内环境稳态等方面有积极作用。

关键词： 多体动力学   机械工程领域   应用  

摘要： 多体系统是一般机械系统最为全面的完整抽象、高度概括和有效描述,是分析和研究机械系统的最优模型形式。多体动力学是在当代先进制造技术、航空航天工业、人体和假肢等科学技术推动下发展起来的一门高新学科。基于此,文中对多体动力学在机械工程领域的应用进行了分析,仅供业内人士参考。

关键词： 机械设计制造   学院   三峡大学   能源与动力工程   机械电子工程   材料成型   机械工程   控制工程  

摘要： 2014年1月原机械与材料学院更名为机械与动力学院，学院现设有机械设计制造及其自动化、机械电子工程、材料成型及控制工程、工业工程、能源与动力工程、核工程与核技术六个本科专业，其中机械设计制造及其自动化为国家特色专业、第二批卓越工程师教育培养计划专业和省本科品牌专业，材料成型及控制工程为第三批卓越工程师教育培养计划专业。拥有机械工程一级硕士点、机械工程专业学位点、机械工程领域工程硕士点、工业工程专业学位点，机械制造及其自动化为湖北省重点学科。

关键词： Industrial clusters   cluster evolution   cluster life cycles   evolutionary economic geography   lock-in  

摘要： This paper explores the driving forces for divergent trajectories of cluster evolution within the same branch of industry using the example of two packaging machinery clusters located in the German regions of Schwaebisch-Hall and Mittelhessen. Between 1998 and 2010 the Schwaebisch-Hall cluster recorded an increase in employment of almost two thirds. On the other hand, employment in the Mittelhessen cluster declined by about 15% and the cluster is characterised by negative functional and cognitive lock-in. This study tackles the existing lack of comparative in-depth longitudinal case studies with regard to cluster evolution. In doing so, the driving forces from recent conceptual approaches to cluster dynamics are exemplified empirically, which has rarely been done before. It is pointed out that dynamics at individual firm level (e.g. routines, spin-offs) are equally important - albeit highly interdependent - as those dynamics of relations (e.g. learning, rivalry, policy) and those operating at a systemic level (e.g. cluster heterogeneity, markets). Therefore we consider conceptual approaches to cluster evolution, which combine several driving forces to really understand changes, as necessary.

关键词： Biochemistry   Biology and life sciences   Cell biology   Cell cycle and cell division   Cell processes   DNA   DNA damage   Dose prediction methods   Genetics   Ionizing radiation   Medicine and health sciences   Non-homologous end joining   Nuclear physics   Nucleic acids   Pharmaceutics   Physical sciences   Physics   Proteins   Radiation   Research and analysis methods   Research Article   Simulation and modeling  

摘要： DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational events. Despite DNA repair being of crucial importance, the relative contribution of these mechanisms and their regulatory interactions remain to be fully elucidated. Understanding these mutational processes will have a profound impact on our knowledge of genomic instability, with implications across health, disease and evolution. Here we present a new method to model the combined activation of non-homologous end joining, single strand annealing and alternative end joining, following exposure to ionising radiation. We use Bayesian statistics to integrate eight biological data sets of double-strand break repair curves under varying genetic knockouts and confirm that our model is predictive by re-simulating and comparing to additional data. Analysis of the model suggests that there are at least three disjoint modes of repair, which we assign as fast, slow and intermediate. Our results show that when multiple data sets are combined, the rate for intermediate repair is variable amongst genetic knockouts. Further analysis suggests that the ratio between slow and intermediate repair depends on the presence or absence of DNA-PKcs and Ku70, which implies that non-homologous end joining and alternative end joining are not independent. Finally, we consider the proportion of double-strand breaks within each mechanism as a time series and predict activity as a function of repair rate. We outline how our insights can be directly tested using imaging and sequencing techniques and conclude that there is evidence of variable dynamics in alternative repair pathways. Our approach is an important step towards providing a unifying theoretical framework for the dynamics of DNA repair processes.

关键词： 低氧血症   急性心源性肺水肿   有创-无创机械通气   血流动力学   Acute cardiac pulmonary edema   Hemodynamics   Hyoxemia   Invasive-noninvasive mechanical ventilation   低氧血症   急性心源性肺水肿   有创-无创机械通气   血流动力学   Language of Keywords: English   Chinese  

摘要： Objective: To explore the influence of sequential invasive-noninvasive mechanical ventilation on hyoxemia and hemodynamics in patients with acute cardiac pulmonary edema. Methods: 49 patients with acute cardiac pulmonary edema treated in our hospital from March 2013 to March 2015 were divided into two groups according to the random number table method. The control group was received routine anti heart failure therapy combined with invasive mechanical ventilation, and the observation group based on the treatment of control group underwent noninvasive nasal mask bi level positive airway pressure ventilation. The comparisons of hyoxemia and hemodynamics parameters of two groups before and after treatment were conducted, and the invasive mechanical ventilation time, total mechanical ventilation time, incidence of VAP, rate of recurrent heart failure and death cases between two groups were compared. Results: There was no deaths in the process of treatment. After treatment, the hyoxemia and hemodynamics parameters of two groups had improvement with different degree, the difference was statistically significant (P<0.05). No statistical difference on hyoxemia and hemodynamics parameters between two groups after treatment was found(P>0.05). The invasive mechanical ventilation time, total mechanical ventilation time of observation group were less than those of control group, and the rate of VAP was less than that of control group, the differences were statistically significant (P<0.05). There was no statistical significance on the rate of heart failure recurrence(P>0.05). Conclusions: Sequential invasive-noninvasive mechanical ventilation can obviously improve the the hyoxemia and hemodynamics in patients with acute cardiac pulmonary edema, which is safe an effective and has important value as the treating measures of acute cardiac pulmonary edema. [ABSTRACT FROM AUTHOR]

关键词： Actin-cytoskeleton network   cell wall   mechanical properties   plant-insect interaction   specialized metabolism   terpenoid   tomato (Solanum lycopersicum)   trichome  

摘要： This study implicates actin dynamics in glandular trichome development, cytosolic control of specialized metabolism, and mechanical properties of plant *** are epidermal structures that provide a first line of defense against arthropod herbivores. The recessive hairless (hl) mutation in tomato (Solanum lycopersicum L.) causes severe distortion of trichomes on all aerial tissues, impairs the accumulation of sesquiterpene and polyphenolic compounds in glandular trichomes, and compromises resistance to the specialist herbivore Manduca sexta. Here, we demonstrate that the tomato Hl gene encodes a subunit (SRA1) of the highly conserved WAVE regulatory complex that controls nucleation of actin filaments in a wide range of eukaryotic cells. The tomato SRA1 gene spans a 42-kb region containing both Solyc11g013280 and Solyc11g013290. The hl mutation corresponds to a complex 3-kb deletion that removes the last exon of the gene. Expression of a wild-type SRA1 cDNA in the hl mutant background restored normal trichome development, accumulation of glandular trichome-derived metabolites, and resistance to insect herbivory. These findings establish a role for SRA1 in the development of tomato trichomes and also implicate the actin-cytoskeleton network in cytosolic control of specialized metabolism for plant defense. We also show that the brittleness of hl mutant stems is associated with altered mechanical and cell morphological properties of stem tissue, and demonstrate that this defect is directly linked to the mutation in SRA1.

关键词： Hydration   Acceleration   Calcium-silicate-hydrate   Amorphous material   Ageing  

摘要： The hydration of one mechanically activated alite passing through different drying procedures is examined by heat flow calorimetry and quantitative in-situ XRD analysis. The reactivity of the alite powders is strongly affected by the drying technique. It is shown that the reactivity of the amorphous part of the activated alite sample is particularly affected. Due to the fast initial dissolution of the amorphous "alite" part, the hydration progression is speeded up significantly. However, if the hydration is not speeded up by the amorphous "alite" dissolution, as in the case of surface passivation, the heat released until the transition to the deceleration period will increase. It is discussed that a crystalline alite dissolution by etch pit opening could increase the reactive alite surface and therefore increase the reaction degree at the transition to the deceleration period. (C) 2016 Elsevier Ltd. All rights reserved.

关键词： Drosophila suzukii   Mechanistic model   Continuous time   Temperature dependent development   Reproductive diapause   Fruit quality  

摘要： Drosophila suzukii is a relatively new threat to the soft-skinned fruit industry in North America. The presence of this pest in North America is a concern and assessing the risk of potential infestation and damage can help guide regional management strategies. We have developed a continuous time stage structured population model parameterized with empirical data based on laboratory observations. The principle environmental driver of vital rates (mortality, fecundity and development) for the model is temperature though our results suggest that reproductive diapause and quality of fruit available to the population may also have significant effect on population size. The model was run with several generalized temperature profiles and various observed temperature data sets for locations known to be important for berry production. While southern regions appear to be most suitable for supporting high population densities due to warm temperatures throughout the year, northern regions with moderate temperatures may also be susceptible due to a lack of extreme cold or heat, both of which limit development and increase mortality. (C) 2016 Elsevier B.V. All rights reserved.

关键词： LIQUID ammonia   QUANTUM mechanics   MOLECULAR dynamics   AQUEOUS solutions   SOLVATION  

摘要： An investigation of structural and dynamical properties of Ni2+ in liquid ammonia has been carried out via Quantum Mechanical Charge Field Molecular Dynamics. By extending the quantum mechanical region to include first and second solvation shell, a more realistic representation of the system was achieved yielding improved results on present computational facilities. The structural results obtained from the 16 ps trajectory agree well with experimental investigations for various nitrogen-containing Ni2+ systems. Detailed analysis of mean residence time and vibrational properties highlights a rather flexible structure of the first and second shells compared to Ni2+ in aqueous solution. (C) 2016 Elsevier B.V. All rights reserved.