Nervous mechanisms of restraint water-immersion stress-induced gastric mucosal lesion

Stress-induced gastric mucosal lesion(SGML)is one of the most common visceral complications after trauma.Exploring the nervous mechanisms of SGML has become a research hotspot.Restraint water-immersion stress(RWIS)can induce GML and has been widely used to elucidate the nervous mechanisms of SGML.It is believed that RWIS-induced GML is mainly caused by the enhanced activity of vagal parasympathetic nerves.Many central nuclei,such as the dorsal motor nucleus of the vagus,nucleus of the solitary tract,supraoptic nucleus and paraventricular nucleus of the hypothalamus,mediodorsal nucleus of the thalamus,central nucleus of the amygdala and medial prefrontal cortex,are involved in the formation of SGML in varying degrees.Neurotransmitters/neuromodulators,such as nitric oxide,hydrogen sulfide,vasoactive intestinal peptide,calcitonin gene-related peptide,substance P,enkephalin,5-hydroxytryptamine,acetylcholine,catecholamine,glutamate,γ-aminobutyric acid,oxytocin and arginine vasopressin,can participate in the regulation of stress.However,inconsistent and even contradictory results have been obtained regarding the actual roles of each nucleus in the nervous mechanism of RWIS-induced GML,such as the involvement of different nuclei with the time of RWIS,the different levels of involvement of the sub-regions of the same nucleus,and the diverse signalling molecules,remain to be further elucidated.

Clarification of abrasive jet precision finishing with wheel as restraint mechanisms and experimental verification

According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.

Determinants of mechanical restraint in an acute psychiatric care unit

BACKGROUND Despite numerous attempts to reduce the use of mechanical restraint(MR),this technique continues to be widely applied in many acute psychiatric care settings.In order to reduce MR,a better understanding of the variables associated with its use and duration in different clinical environments is essential.AIM To determine the proportion of patients subjected to MR and the duration thereof in two acute care psychiatric units;and to identify the variables associated with the use and duration of MR.METHODS Descriptive study of all patients admitted to the acute psychiatric units at the Parc de Salut Mar(Barcelona,Spain)in the year 2018.The number and percentage of patients subjected to MR,as well as the duration of each episode were assessed.The following data were also registered:sociodemographic characteristics,psychiatric diagnosis,and presence of cultural and/or language barriers.Multivariate analyses were performed to assess determinants of MR and its duration.RESULTS Of the 464 patients,119(25.6%)required MR,with a median of 16.4 h per MR.Two factors-a diagnosis of psychotic disorder[Odds ratios(OR)=0.22;95%CI:0.06-0.62;P=0.005]and the presence of a language barrier(OR=2.13;95%CI:1.2-3.7;P=0.007)-were associated with a significantly higher risk of MR.Male sex was associated with a longer duration of MR(B=-19.03;95%CI:-38.06-0.008;P=0.05).CONCLUSION The presence of a language barrier and a psychotic disorder diagnosis are associated with a significantly higher risk of MR.Furthermore,male sex is associated with a longer duration of MR.Individualized restraint protocols that include the required tools are necessary to ultimately limit the use of mechanical restraint.

Effect of heating time on bonding interface, atom diffusion and mechanical properties of dissimilar titanium joints produced by thermal self-compressing bonding

Solid-state bonding between pure titanium and Ti6Al4V(TC4)alloy was conducted by a new bonding method named as rigid restraint thermal self-compressing bonding.Effects of heating time on bonding interface,atom diffusion and mechanical properties of the joints were studied.Results show that atom diffusion between pure titanium and TC4 alloy significantly takes place during bonding.The diffusion depths of Al and V in pure titanium side are increased with increasing heating time.Due to the enhancement of atom diffusion,bond quality of the bonding interface is improved along with the increase of heating time.The heating time seems to have little effect on microhardness distribution across the joint.However,the tensile strength and ductility of the joint have close relation to heating time.Prolonging heating time can improve the tensile strength and ductility of the joint,especially the latter.When the heating time increases to 450 s,solid-state joint with good combination of strength and ductility is attained.

Analytical solutions for the restraint effect of isolation piles against tunneling-induced vertical ground displacements

This paper presents a simplified elastic continuum method for calculating the restraint effect of isolation piles on tunneling-induced vertical ground displacement,which can consider not only the relative sliding of the pile‒soil interface but also the pile rowesoil interaction.The proposed method is verified by comparisons with existing theoretical methods,including the boundary element method and the elastic foundation method.The results reveal the restraining mechanism of the isolation piles on vertical ground displacements due to tunneling,i.e.the positive and negative restraint effects exerted by the isolation piles jointly drive the ground vertical displacement along the depth direction from the original tunneling-induced nonlinear variation situation to a relatively uniform situation.The results also indicate that the stiffness of the pile‒soil interface,including the pile shaft‒surrounding soil interface and pile tip-supporting soil interface,describes the strength of the pile‒soil interaction.The pile rows can confine the vertical ground displacement caused by the tunnel excavation to the inner side of the isolation piles and effectively prevent the vertical ground displacement from expanding further toward the outer side of the isolation piles.

新时代高校中层干部担当作为的激励机制探析——基于江西省属本科高校

新时代,高校中层干部不同程度存在担当作为不力的问题。通过深入分析我省高校中层干部担当作为的现实困境,借鉴现代激励理论和相关研究成果,从“不愿为、不善为、不敢为、为的好不好”等4个维度,探析干部担当作为激励机制的内在机理,从而提出健全高校中层干部担当作为激励机制的具体路径,即运用动力型机制解决“不愿为”问题、运用赋能机制解决“不善为”问题、运用有限责任机制解决“不敢为”问题、运用锦标赛机制解决“为的好不好”问题。

多塔斜拉桥设置非对称交叉索时塔、梁力学机理

为了提高多塔斜拉桥的结构刚度,提出了交叉索的最优布置策略,以增强其对结构刚度的贡献。基于交叉索对中塔约束刚度的解析表达式,推导出了交叉索的纵向约束刚度与其在主梁上锚固位置之间的关系。通过分析发现,当多塔斜拉桥的高跨比介于0.2~0.3时,交叉索锚固在距离中塔约0.7倍跨长的位置处,其对中塔的约束刚度最大。基于此,提出了一种交叉索非对称布置方式。为了验证这一理论,构建了设置交叉索的三塔斜拉桥的有限元模型,对比分析了交叉索非对称布置与对称布置时,在桥塔、主梁变形以及结构受力状态方面的差异。在活荷载作用下,中塔塔顶偏位分别减少19.92%和33.99%,主梁下挠分别减少10.02%和12.60%,主梁最大正弯矩分别减少17.38%和25.39%。此外,交叉索对称布置时中塔塔底弯矩略有增大,而非对称布置时塔底弯矩减少了18.23%。结果表明,在主跨增设交叉索可以有效提升三塔斜拉桥的刚度,改善活载作用下主梁和桥塔的受力及变形。在保持索系用钢量不变的前提下,交叉索非对称布置在改善结构刚度方面优于对称布置,为多塔斜拉桥采用交叉索的设计方案提供了新的优化方向。

引入风险共管机制的企业激励机制建设及应用

负债企业激励机制与风险共管机制是现代企业治理中的重要议题。目前的研究主要集中在负债企业激励机制对企业绩效的影响上,而对于风险共管机制的探讨相对较少。文章将从风险共管的角度出发,探讨负债企业激励机制与风险共管机制之间有机结合的可行性。激励机制可以激发企业内部的创新活力,而引入风险共管机制,促进风险共管机制的有效实施,可以提升负债企业的风险管理能力,降低负债企业决策的盲目性和激进性,进而降低企业决策风险水平。构建良性的激励与风险共管双向互动机制,实现企业内外部的风险共同承担,对提高企业的整体风险抵御能力和企业的长期发展具有重要意义。

慢性束缚应激对小鼠小肠屏障的损伤研究

肠屏障由机械屏障、免疫屏障、化学屏障和生物屏障共同组成,在维持肠腔内环境稳态和肠上皮结构完整性等方面发挥重要作用.首先建构小鼠慢性束缚应激模型并进行血浆激素水平检测和小鼠旷场实验,验证模型是否建构成功.随后通过常规组织学染色、免疫组化、 TUNEL免疫荧光、 ELISA等方法研究慢性束缚应激对小鼠小肠的损伤作用.结果显示,慢性束缚应激显著提高小鼠血浆NE和CORT水平(p<0.05),降低小鼠小肠绒毛高度(V,p<0.05)、增加隐窝深度(C,p<0.05),降低V/C比值(p<0.05)及紧密连接蛋白ZO-1表达量(p<0.01);显著减少小肠杯状细胞和内皮单核淋巴细胞数量(p<0.01),提示慢性束缚应激造成了小鼠肠道损伤和免疫功能抑制.进一步研究发现,慢性应激小鼠肠道内PCNA阳性表达显著减少(p<0.01)、凋亡细胞显著增多(p<0.01);血浆中TNF-α,IL-1β,IL-18含量显著升高(p<0.01),而IL-10显著降低(p<0.01).血浆氧化-抗氧化指标结果显示,慢性束缚应激显著增加小鼠血浆MDA含量(p<0.05),降低T-AOC,SOD,CAT,GSH-Px(p<0.05)活性,提示慢性束缚应激诱导机体氧化应激.该研究表明慢性束缚应激通过引发机体氧化应激,造成肠上皮细胞更新抑制和肠道屏障结构损伤,加重机体炎症反应.

开放式创新平台激励与约束机制对用户创新行为的影响

平台的开放共享特征促使用户更主动地参与到价值创造活动中,企业吸纳用户参与创新过程成为其提升创新能力的重要途径。从认知—情感双重视角出发,以创新自我效能感、情感承诺为中介变量,以主动型人格为调节变量,探究开放式创新平台激励与约束机制对用户创新行为的影响机制及边界条件。结果显示,开放式创新平台激励机制、约束机制对用户创新行为均具有正向影响;创新自我效能感与情感承诺分别在开放式创新平台激励机制、约束机制与用户创新行为间发挥部分中介作用;主动型人格分别在开放式创新平台激励机制、约束机制与用户创新行为间发挥正向调节作用。

Ⅱ型套筒灌浆搭接接头单向拉伸力学性能研究

为研究Ⅱ型套筒灌浆搭接接头(简称APC接头)单向拉伸力学性能,基于ABAQUS软件提出一种带肋钢筋精细化显式动态模型,模拟分析了钢筋位置、套筒壁厚、搭接长度等对试件破坏模式、承载力、延性和套筒应变等的影响。结果表明:试件破坏形式、荷载-位移曲线、承载力和延性均与试验结果吻合较好,验证了精细化模型的准确性;后插入钢筋紧贴预留钢筋布置于套筒轴线时试件极限承载力和延性最大,后插入钢筋紧贴套筒偏心布置时试件极限承载力最小;近钢筋侧套筒中部纵向应变值大于远钢筋侧应变值,而环向应变则相反;试件承载力随套筒壁厚的增大而增大,建议套筒长边及短边壁厚分别取为8 mm和4 mm;套筒长边壁厚小于8 mm时,增大套筒壁厚可有效降低套筒环向应变;钢筋发生拉断破坏前,随着搭接长度的增加,试件承载力及延性增大;随着搭接长度的增加,套筒短边纵向应变先增大后减小,长边环向应变逐渐减小;C30混凝土可满足接头的防偏转要求;提出了Ⅱ型APC接头的黏结强度计算公式及临界搭接长度公式,研究成果可为Ⅱ型APC接头的设计提供理论基础。

Price Mechanism,Government Constraints and Carbon Trading Pilot Policy for Emission Reduction

Based on the data of 247 cities at the prefecture level in China from 2007 to 2019,this paper analyzes the impact of the carbon emissions trading(CET)pilot policy on carbon emission reduction from the perspective of the price mechanism and government constraints.The results show that the carbon emissions and carbon intensity in the pilot areas are significantly reduced by adjusting the industrial structure and promoting green technology innovation.In terms of regions,the emission reduction effect of the pilot policy in regions with a high proportion of industry is obviously weaker than that in other regions.The aim of the carbon emission trading policy in China that achieve carbon emission reduction is by coordinating the carbon emission trading price that fail to fulfill this aim independently and the degree of government punishment for enterprises.

BIM技术在地下溶洞嵌岩桩基极限承载力评定中的应用

为了提高地下溶洞嵌岩桩基的安全性,提出了BIM技术在地下溶洞嵌岩桩基极限承载力评定中的应用。计算地下溶洞嵌岩桩基在岩层的平均应力,获取的承载机理,明确地下溶洞嵌岩的地质特点,计算地下溶洞嵌岩桩基容许承载力,利用BIM技术,完成地下溶洞嵌岩桩基的BIM建模。根据地下溶洞嵌岩桩基应力分量,计算地下溶洞嵌岩桩基在含溶洞地层中的平均约束应力,通过设定极限承载力阈值,评定地下溶洞嵌岩桩基极限承载力。实验结果表明,所提方法对地下溶洞嵌岩桩基极限承载力的评定结果与工程实际相符,可以缩小评定误差。

开源创新绩效多元化激励机制的实证研究

近年来,随着安卓操作系统的高速发展,开源软件的概念在国内获得了广泛的关注和认可。依据开放式创新理论和公共物品理论,利用问卷调查法和因子分析法,通过对开源中国社区用户的325份有效调查问卷数据,分析开源创新绩效的影响因素。结论显示,在开源创新的过程中,财务绩效、创新能力、创新环境、社区管理对开源创新绩效有显著的正向影响,开源软件设计和知识产权保护对开源创新绩效产生显著的负向影响。最后,根据研究的结论对如何发展开源创新提出相关对策建议。

一种磁扣式高分子约束带特性分析及临床应用研究

以丙纶长丝与乳胶丝为主要材料,制备一种磁扣高分子约束带基布,进而制备磁扣高分子约束带。试验首先对磁扣高分子约束带基布基础性能进行分析,然后对磁扣高分子约束带在精神病治疗的应用效果进行分析。试验结果表明,自制磁扣高分子约束带基布弹性回复率约为95.4%,透气量约为1.27 g,抗弯长度约为2.52 cm,抗拉强度为2.35 kN,伸长比约为2.7,表现出良好的综合性能。将其用于临床试验,其在提升约束效果,降低不良反应发生率和提升患者监护人满意度方面表现出明显的优势。

生成式对抗网络估算车辆参数及路面不平度

主流的通过逆向分析得到路面不平度的方法很少从车辆的认知不确定性来考虑所识别的路面不平度是具有概率分布性。为了应对这一挑战,提出使用测试得到的车辆加速度响应的方法。基于车辆运动系统约束的生成对抗网络(GAN)进行车辆参数的动态校准和估算路面不平度。通过引入生成模型来描述估计的路面不平度和车辆参数的概率分布。在生成对抗网络训练过程中通过分别最小化其车辆运动系统约束构建物理约束,达到使生成对抗网络的最后输出符合工程问题的强物理性。然后通过使用数值模拟测得的车辆加速度响应训练来学习生成模型,进行了数值仿真实验。使用标准规范的路面不平度和经典车辆模型来证明所提出的方法的可行性。结果表明,所提出的方法可以成功地捕获车辆认识的不确定性。

激励约束视角下居民端垃圾分类的建议

本文认为,管理主体缺位与激励约束缺乏是居民端生活垃圾分类的核心难点,因此建议引入专业的垃圾处理企业管理垃圾分类,同时实施按量收费的垃圾处理收费制以提供经济激励。提出构建针对垃圾处理企业的激励约束机制,包括通过政府参与签约以明确各方的权利与义务,设计科学的绩效指标并以补贴引导垃圾分类,规划、鼓励、引导终端处理能力建设以推进垃圾分类;针对居民,则提出教育、制度、技术等多领域的激励约束措施。

大学生创新实验计划实施的实践及探索

＂大学生创新实验计划＂作为教育部推动创新人才培养的一项重要措施,对调动本科生的主动性、积极性和创造性有重要作用。结合中国地质大学开展＂大学生创新实验计划＂的具体情况,对实施过程中的管理方式、激励机制和存在的问题等进行了总结和探讨。

谈实验技术人员队伍建设

该文通过对高等学校实验技术人员队伍建设落后原因的综合分析,提出从提高认识入手,确立科学的人才评价标准,并通过建立积极有效的考核机制和激励机制,逐步提高实验技术人员队伍的整体素质。

粉煤灰对高性能混凝土早期收缩的抑制及其机理研究

自收缩是引起低水胶比高性能混凝土早期开裂的主要原因。通过不同掺量粉煤灰混凝土自收缩的测定，研究粉煤灰对高性能混凝土自收缩的抑制作用。通过水化结合水和内部孔含量的测定以及微观结构形貌分析，研究粉煤灰抑制自收缩的作用机理。研究表明：粉煤灰通过改变胶凝材料体系水化速度、徐变系数、弹性模量，可以有效抑制早期混凝土的自收缩。粉煤灰掺量在0～20％范围内，混凝土自收缩随着粉煤灰掺量的增加而减少，但粉煤灰惨量超过20％后自收缩减少的幅度变小。粉煤灰抑制自收缩的作用在初凝至1d龄期内非常突出。