Correlation Study of Neurotransmitter and Immune Levels in Pre-Hospital Emergency Nurses with Post-Traumatic Stress Disorder

Objective: To investigate the occurrence of PTSD in pre-hospital emergency nurses and its related factors, and to compare the differences of neurotransmitter and immune-related factors between pre-hospital emergency nurses who experienced traumatic events and those who did not develop PTSD and healthy people. How: Post-traumatic Stress Disorder Self-Rating Scale (PCL-C) tests were performed on pre-hospital emergency nurses in PTSD group, non-PTSD group and healthy control group, and the plasma monoamine neurotransmitters and serum cytokines were determined by double-antibody sandwich ABC-ELISA assay using enzyme-linked adsorption kit provided by Shanghai Xitang Biotechnology Co., Ltd. Results: 1) There were statistically significant differences in PCL-C scores between PTSD group, non-PTSD group and healthy group (p α between PTSD group, non-PTSD group and healthy group (p Conclusion: Pre-hospital emergency nurses should have early psychological intervention and guidance to reduce the occurrence of PTSD in emergency and emergency nurses.

Controlling of weld hot cracks of aluminum alloy sheets by transverse pre-stressing

A new ideological and theoretical model—a technology to control weld hot cracks by transverse compressive pre-stress in the welding of aluminum alloy was put forward,which was further proved by the subsequent self-designed test setup.Experiments are conducted on the fishbone shaped specimen under conventional welding and welding with various pre-stress values.The experimental results turn out that,the initiation rate of the weld hot cracks decreases with increasing values of the compressive pre-stress.When the pre-stress reaches 0.3-0.4 of the yield stress,the cracks even disappear.In mechanical viewpoint,the researches here develop a new way to control weld cracks.

Experimental study on seismic behavior of circular RC columns strengthened with pre-stressed FRP strips

Bonding fiber reinforced polymer （FRP） has been commonly used to improve the seismic behavior of circular reinforced concrete （RC） columns in engineering practice. However, FRP jackets have a significant stress hysteresis effect in this strengthening method, and pre-tensioning the FRP can overcome this problem. This paper presents test results of 25 circular RC columns strengthened with pre-stressed FRP strips under low cyclic loading. The pre-stressing of the FRP strips, types of FRP strips and longitudinal reinforcement, axial load ratio, pre-damage degree and surface treatments of the specimens are considered as the primary factors in the tests. According to the failure modes and hysteresis curves of the specimens, these factors are analyzed to investigate their effect on bearing capacity, ductility, hysteretic behavior, energy dissipation capacity and other important seismic behaviors. The results show that the initial lateral confined stress provided by pre-stressed FRP strips can effectively inhibit the emergence and development of diagonal shear cracks, and change the failure modes of specimens from brittle shear failure to bending or bending-shear failure with better ductility. As a result, the bearing capacity, ductility, energy dissipation capacity and deformation capacity of the strengthened specimens are all significantly improved.

Pre-Stressed Rope Reinforced Anti-Sliding Pile

Pre-stressed rope reinforced anti-sliding pile is a composite anti-sliding structure. It is made up of pre-stressed rope and general anti-sliding pile. It can bring traditional anti-sliding pile＇s retaining performance into full play, and to treat with landslide fast and economically. The difference between them is that the pre-stressed rope will transfix the whole anti- sliding pile through a prearranged pipe in this structure. The working mechanics, the design method and economic benefit are studied. The results show that the pre-stressed rope reinforced anti-sliding pile can treat with the small and middle landslides or high slopes well and possess the notable advantage of technology and economic.

Design and Preparation of High Elastic Modulus Self-compacting Concrete for Pre-stressed Mass Concrete Structures

Requirements of self-compacting concrete （SCC） applied in pre-stressed mass concrete structures include high fluidity, high elastic modulus, low adiabatic temperature rise and low drying shrinkage, which cannot be satisfied by ordinary SCC. In this study, in order to solve the problem, a few principles of SCC design were proposed and the effects of binder amount, fly ash （FA） substitution, aggregate content and gradation on the workability, temperature rise, drying shrinkage and elastic modulus of SCC were investigated. The results and analysis indicate that the primary factor influencing the fluidity was paste content, and the main methods improving the elastic modulusof SCC were a lower sand ratio and an optimized coarse aggregate gradation. Lower adiabatic temperature rise and drying shrinkage were beneficial for decreasing the cement content. Further, based on the optimization of mixture, a C50 grade SCC （with binder amount of only 480 kg/ m3, fly ash substitution of 40%, sand ratio of 51% and proper coarse aggregate gradation （Vs.~0 mm： V10-16 ram： V16.20 mm= 30%： 30%：40%）） with superior workability was successfully prepared. The temperature rise and drying shrinkage of the prepared SCC were significantly reduced, and the elastic modulus reached 37.6 GPa at 28 d.

Influence of pre- plastic deformation on thermal residual stress and yield strength of SiC_w/Al composites

With a micro mechanical model, the feasibility of modification of thermal residual stress of the composites treated by tensile pre plastic deformation was analyzed. The relationship between pre plastic strain and variation of thermal residual stress was established. By using the method of tensile pre plastic deformation, the thermal residual stress in 20%SiC w/6061Al composites was modified. The results show that, with increasing tensile pre plastic strain, the tensile residual stress in the matrix was decreased to zero gradually, and then it was turned into compressive stress. By comparison, it was found that the changing tendency of the test results is similar to that of theoretical analysis. In addition, due to pre plastic deformation, the dislocation density in the matrix was increased, and the yield strength of the composites was improved. The increasing yield strength is mainly due to the decreasing tensile residual stress and the changing of distribution of dislocation in the matrix.

Mechanism of biaxial pre-stress method on welding residual stress and hot cracks controlling

Based on the conventional uniaxial pre-tensile stress method during welding, this study presents a new method of welding with biaxial pre-stress. With the help of numerical simulation, experiments were carried out on the self-designed device. Except for the control on residual stress and distortion us-welded, the experimental results also show its effect on the prevention of hot cracks, thus this method can make up for the disadvantage of the conventional pre-stress method. Hot cracks disappear when the value of pre-stress surpasses 0. 2 σs（yield limit）. Welded thin plates with low-level residual stress, little distortion and no hot cracks are obtained with longitudinal pre-tensile stress level between 0. 6σsand 0. 7σs and precompressive stress between 0. 2 σs and 0. 3 σs in transverse direction.

Stress Analysis of New Type Pre-Stressed Anchor Bearing Plate Combining Stamping with Welding Forming and Its Anchorage Zone

An anchor bearing plate transfers the anchoring force from anchor plate to the concrete and the pre-stress is formed in the concrete structure. Currently, the main type of anchor bearing plate is cast iron. It is brittle during transportation and tension process. This paper presents a new type of anchor bearing plate combined stamping with welding forming. The structure of the new type anchor bearing plate is introduced. The stress states of the anchor bearing plate and anchorage zone under work are studied. Various specifications of anchor bearing plate are studied by ANSYS finite element analysis software following the AASHTO specification. The analysis results are compared with the results of the same type of OVM round-shaped anchor plate. The study results show that the new pre-stressed anchor plates combined stamping with welding forming are feasible and more sturdy which can meet the engineering demand.

Primary prevention of posttraumatic stress disorder: drugs and implications

Because posttraumatic stress disorder(PTSD) is a highly debilitating condition, prevention is an important research topic. This article reviews possible prevention approaches that involve the administration of drugs before the traumatic event takes place. The considered approaches include drugs that address the sympathetic nervous system, drugs interfere with the hypothalamic-pituitary-adrenal(HPA) axis, narcotics and other psychoactive drugs, as well as modulators of protein synthesis. Furthermore, some thoughts on potential ethical implications of the use of drugs for the primary prevention of PTDS are presented. While there are many barriers to overcome in this field of study, this paper concludes with a call for additional research, as there are currently no approaches that are well-suited for regular daily use.

Effect of pre-deformation on the stress corrosion cracking susceptibility of aluminum alloy 2519

The effects of pre-deformation and strain rate on the stress corrosion cracking （SCC） behavior of aluminum alloy 2519 in air and in 3.5% NaCI water solution were investigated by means of slow strain rate tension （SSRT）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results indicate that the alloy is susceptible to SCC in 3.5% NaCI water solution and not in air. At the same pre-deformation, the alloy is more susceptible to SCC at 1.33 × 10^-5 s^-1 than at 6.66 × 10^-5 s^-1. Moreover, it is more susceptible to SCC at free pre-deformation than at 10% pre-deformation at the same strain rate. The number of 0 precipitated along the grain boundaries is reduced and distributed discontinuously, at the same time, the precipitate-free zones （PFZ） become narrow and the susceptibility to stress corrosion cracking is reduced after 10% pre-deformation.

Improvement in electrical properties of high-κ film on Ge substrate by an improved stress relieved pre-oxide method

High-κ /Ge gate stack has recently attracted a great deal of attention as a potential candidate to replace planar silicon transistors for sub-22 generation. However, the desorption and volatilization of GeO hamper the development of Ge-based devices. To cope with this challenge, various techniques have been proposed to improve the high-κ /Ge interface. However,these techniques have not been developed perfectly yet to control the interface. Therefore, in this paper, we propose an improved stress relieved pre-oxide（SRPO） method to improve the thermodynamic stability of the high-κ /Ge interface. The x-ray photoelectron spectroscopy（XPS） and atomic force microscopy（AFM） results indicate that the GeO volatilization of the high-κ /Ge gate stack is efficiently suppressed after 500℃ annealing, and the electrical characteristics are greatly improved.

Intraplate Strike-Slip Reactivation of the Sinnyeong Fault in the Cretaceous Gyeongsang Basin, Korea, Due to the Concentration of Later Compressional Stress

This study focuses on the geometry and kinematics of the Sinnyeong Fault which is the most conspicuous fault among the WNW-trending Gaeum Fault System in the Gyeongsang Basin,SE Korea. The fault is traced for over ca.70 kmand has a consistent WNW-trending strike with a nearly vertical dip. It has an asymmetric fault damage zone of several meters to several tens of meters in width and a several meter-thick fault core. Its main movement is interpreted as sinistral-reverse oblique-slip or sinistral strike-slip under NE-SW compressional stress regime, although it could have experienced other faultings with different senses before/after this movement. Cylindrical folds, having the NW-trending fold axes of low angle plunge, are only observed along the southern damage zone of the fault with a continuous narrow width of several tens of meters. It is thus interpreted that the formation of the folds and sinistral movement of the fault were almost contemporaneously generated due to the concentration of the regional NE-SW compressional stress along pre-existing WNW-trending faults or densely populated fracture zone in a relatively stable intraplate region.

Modified Layer-Removal Method for Measurement of Residual Stress in Pre-stretched Aluminium Alloy Plate

Residual stress is one of the factors affecting the machining deformation of monolithic structure parts in the aviation industry. Thus, the studies on machining deformation rules induced by residual stresses largely depend on correctly and efficiently measuring the residual stresses of workpieccs. A modified layer-removal method is proposed to measure residual stress by analysing the characteristics of a traditional, layer-removal method. The coefficients of strain release are then deduced according to the simulation results using the finite element method （FEM）. Moreover, the residual stress in a 7075T651 aluminium alloy plate is measured using the proposed method, and the results are then analyzed and compared with the data obtained by the traditional methods. The analysis indicates that the modified layer-removal method is effective and practical for measuring the residual stress distribution in pre-stretched aluminium alloy plates.

装配式独立基础受力性能试验研究

为探究变电站装配式独立基础的抗弯性能,两块由“抗剪键-预应力筋”进行拼装的基础在模拟均布荷载下进行了试验研究。主要对比了有、无黏结预应力筋基础的受力性能,分析了拼缝环氧树脂胶涂抹不均匀、预应力筋灌浆不密实的拼装缺陷对基础抗弯性能的影响。结果表明:相较于无黏结预应力筋基础,有黏结预应力筋基础的抗弯刚度和承载力得到大幅提升;拼缝环氧树脂胶涂抹不均匀主要影响试件开裂后的抗弯刚度,对破坏时的刚度和承载力影响不大;预应力筋灌浆不密实会导致预应力筋和混凝土之间出现黏结滑移,降低试件开裂后的抗弯刚度。

南流江预应力连续梁式渡槽抗震性能

预应力连续梁式渡槽具有整体受力条件好、施工工艺成熟且方便的优势,在实际工程中运用广泛,其具有良好的抗震性能是保证工程安全运行的关键。以采用预应力连续梁式渡槽形式的南流江大渡槽为例,通过Midas-civil分析软件建立有限元模型并施加拟合生成的地震波,对渡槽的抗震性能进行研究。结果表明,在拟合生成的地震波与场地类别、分区特征周期相近的人工地震波E1、E2作用下,南流江大渡槽的顺桥向及横桥向的桥墩强度验算和变形均满足要求,具有安全可靠的抗震性能。

预应力螺栓连接钢板约束混凝土圆柱轴压性能研究

螺栓连接钢板(BST)约束混凝土圆柱,由于钢板可拆卸及更换,较钢管约束混凝土具有更好的可恢复性。以BST约束混凝土圆柱为研究对象,提出在两片拼装钢板间预留间隙,并拧紧螺栓而对其施加预压应力的方法。以施加的预压应力和径厚比为参数,对6根BST约束混凝土圆柱及1根无约束混凝土圆柱进行轴心受压试验。结果表明,预留间隙并拧紧螺栓的方法能对核心混凝土有效施加预压应力,使钢板在加载前即对核心混凝土形成有效约束。相较于无约束混凝土圆柱,同条件的施加预压应力的BST约束混凝土圆柱峰值应力最大提高74.5%,且残余强度最大能保持在峰值应力的92.3%。相较于未施加预压应力的BST约束混凝土圆柱,施加预压应力的BST约束混凝土圆柱预压应力越大,峰值应力越大,最大可提高18%;径厚比越小,BST约束混凝土圆柱峰值应力越大,但随着预压应力增大,峰值应力提高的幅度降低。

圆形预应力钢丝缠绕正交预紧机架的缠绕分析计算

在预应力钢丝缠绕正交预紧机架结构的基础上提出了一种全新的机架型式——圆形预应力钢丝缠绕正交预紧机架。对该型机架的缠绕进行理论分析和计算,进而求得缠绕施工张力表,为钢丝缠绕施工提供重要理论依据。该型机架的研发是超重型承载机架结构的重要技术突破。

非线性M-C强度准则下预应力锚索加固边坡时效稳定性分析M-P法

拓展传统极限平衡方法在复杂条件下边坡稳定性分析中的适用性一直是岩土工程界的研究热点。众所周知,边坡岩土体剪切失效一般服从于非线性强度准则,而传统极限平衡方法仅适用于线性强度准则下边坡稳定性分析。此外,预应力锚索作为一种主动防护措施,可极大地即时提高边坡稳定性而被广泛应用于中、大型边坡工程加固。然而,在应力松弛、蠕变效应以及腐蚀环境影响下预应力锚索加固边坡稳定性时效特征往往被忽视。由此,基于Morgenstern-Price(M-P)法,嵌入非线性Mohr-Coulomb(M-C)强度准则,并融入应力松弛与蠕变效应下锚索预应力损失模型以及腐蚀环境下锚索性能劣化模型,从而,建立非线性强度准则下预应力锚索加固边坡安全系数时程表达式。进一步,为了解决非线性强度准则下隐式嵌套公式难以求解的问题,归零化条间法向力初始值,并应用迭代循环求解策略,在引入循环终止允许误差判别条件后,可实现边坡稳定性理论真实结果的逼近求解。经过后续算例对比分析,验证了所提方法的可行性和合理性,与此同时,还研究了不同预应力损失速率和不同锈蚀环境下预应力锚索加固边坡稳定性的时效变化规律。

预康复在促进老年肺癌手术患者术后康复中的应用研究

目的研究预康复对老年肺癌手术患者肺功能、机体应激以及情感状况的影响。方法选择2020年10月至2022年12月于成都医学院第一附属医院行手术治疗的老年肺癌患者98例作为研究对象,依照随机数字表法分为预康复组(n=49)与对照组(n=49)。对照组行常规干预,预康复组行常规干预+预康复。观察两组胸管留置时间、术后1、3 d疼痛情况、总住院时间等手术相关指标。观察两组入院时、术前及术后1 h用力肺活量(FVC)、第1秒用力呼气容积(FEV1)及每分钟最大通气量(MVV)等肺功能指标;入院时、术前及术后7 d焦虑、抑郁评分;术后并发症。结果预康复组胸管留置时间、术后1、3 d疼痛情况、总住院时间均低于对照组(P<0.05)。术后1个月,预康复组FVC、FEV1、MVV均大于对照组(P<0.05)。术后7 d,预康复组焦虑、抑郁评分低于对照组(P<0.05)。预康复组术后并发症发生率低于对照组(P<0.05)。结论预康复可有效促进老年肺癌手术患者术后康复,提高其肺功能,改善其焦虑、抑郁情绪,对于改善患者预后具有重要作用。

大跨度料场封闭结构设计问题探讨

针对大跨度料场封闭结构设计中的关键问题,对预应力管桁架弧段的模拟、节点分析、等效风荷载取值等进行了研究并给出建议。