客车在不同侧风下的受力情况及安全性评价

为研究大客车在定常侧风天气下的安全性，以BFC6120B2型大客车为参考车型，利用计算流体力学原理计算客车的受力，建立考虑悬架结构的三自由度车辆动力学模型和不考虑悬架结构的静力模型。结合2种模型研究客车在不同行驶条件下的响应，并进行安全性评价。结果表明：客车的受力并不是随着侧风风速的增大完全呈上升趋势；2种模型均预测出客车在雪、冰路面行驶有侧滑危险，在干、湿路面行驶无侧滑危险,4种路面行驶均无侧倾危险；静力模型预测到的侧滑危险情况过于乐观；三自由度动力学模型可预测因侧偏位移过大导致压线占道的危险情况。     

衍射光栅槽形隆起的数学建模及演变规律

以79g/mm的中阶梯衍射光栅为目标,研究衍射光栅机械刻划过程中铝膜的槽形隆起机制。首先,经过4次坐标变换,建立了光栅槽形的塑流剖面。然后,基于Lee and Shaffer提出的滑移线场模型,在塑流剖面内建立起包含滞留区域的滑移现场模型,并根据Dewhurst and Collins提出的矩阵算法对滑移线场进行求解,最终得到槽形隆起尺寸模型。最后,通过DEFORM软件对槽形隆起尺寸的演变规律进行模拟分析。     

侧颅底手术过程中脑及颅神经功能保护

手术是绝大部分侧颅底病变的首选治疗方式。因侧颅底解剖结构复杂,毗邻脑及重要血管神经,手术容易致死或致残,限制了该部位手术的实施。脑、后组颅神经、面神经、听力功能是该部位手术保护的重点,恰当处理功能保留和切除病变的关系、良好的外科操作技能以及合理使用介入、导航等新的辅助技术是侧颅底手术中实现器官功能保护的关键。     

基于应变监测的梁式桥横向分布状态指标研究

以监测技术为背景,研究了一种以应变监测为信息来源的横向分布状态指标,通过该指标,判断梁式桥的横向连接状态,为桥梁大修提供决策依据。通过某桥的实际例子,验证了该方法的可行性。     

山区组拼式桁架箱梁外侧模整体推拉向前施工工法

对钢桁架、倒角钢模、方木及竹胶板面板在地面平整场地上的组拼进行了介绍,总结了通过吊车将各节段吊装至首件梁支架上进行逐节拼装完成梁体制作的施工要点,并利用人工或小卷扬机牵引作用而逐孔向前进行拆装作业,采用该方法进行桥梁施工不仅加快了施工进度,而且节约了成本。     

Molecular Mechanisms Underlying TDP-43 Pathology in Cellular and Animal Models of ALS and FTLD

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are neurodegenerative disorders that exist on a disease spectrum due to pathological, clinical and genetic overlap. In up to 97% of ALS cases and ~50% of FTLD cases, the primary pathological protein observed in affected tissues is TDP-43, which is hyperphosphorylated, ubiquitinated and cleaved. The TDP-43 is observed in aggregates that are abnormally located in the cytoplasm. The pathogenicity of TDP-43 cytoplasmic aggregates may be linked with both a loss of nuclear function and a gain of toxic functions. The cellular processes involved in ALS and FTLD disease pathogenesis include changes to RNA splicing, abnormal stress granules, mitochondrial dysfunction, impairments to axonal transport and autophagy, abnormal neuromuscular junctions, endoplasmic reticulum stress and the subsequent induction of the unfolded protein response. Here, we review and discuss the evidence for alterations to these processes that have been reported in cellular and animal models of TDP-43 proteinopathy.     

Overview of the potent cyanobacterial neurotoxin β-methylamino-L-alanine (BMAA) and its analytical determination

Blue-green algae are responsible for the production of different types of toxins which can be neurotoxic, hepatotoxic, cytotoxic and dermatotoxic and that can affect both aquatic and terrestrial life. Since its discovery the neurotoxin β-methylamino-L-alanine (BMAA) has been a cause for concern, being associated with the neurodegenerative disease amyotrophic lateral sclerosis/Parkinsonism–dementia complex (ALS/PDC). The initial focus was on Guam where it was observed that a high number of people were affected by the ALS/PDC complex. Subsequently, researchers were surprised to find levels of BMAA in post mortem brains from Canadian patients who also suffered from ALS/PDC. Recent research demonstrates that BMAA has been found at different levels in the aquatic food web in the brackish waters of the Baltic Sea. There is emerging evidence to suggest that sand-borne algae from Qatar can also contain BMAA. Furthermore, there is now concern because BMAA has been found not only in warmer regions of the world but also in temperate regions like Europe. The aim of this review is to focus on the methods of extraction and analysis of the neurotoxic non-protein amino acid BMAA. We also consider the neurotoxicity, aetiology, and diverse sources and routes of exposure to BMAA. In recent years, different methods have been developed for the analysis of BMAA. Some of these use HPLC-FD, UPLC-UV, UPLC-MS and LC-MS/MS using samples that have been derivatised or underivatised. To date the LC-MS/MS approach is the most widely used analytical technique as it is the most selective and sensitive method for BMAA determination.     

Nonlinear model-based track guidance of user-defined points at the vehicle front

Preventive pedestrian protection systems are validated by means of fully automated driving tests reproducing safety-critical traffic situations on a proving ground. In order to assess these preventive safety systems, a precise and reproducible collision of a pedestrian dummy with a specific point at the vehicle front, e.g., the left corner of the vehicle, must be ensured. Hence, a track guidance of this specific point is required. Beyond the state of the art a new nonlinear model describing the lateral deviation of any point at the vehicle front to a predefined path is proposed in this paper. Based on this model the method of input–output linearization is used to design a flexible lateral guidance system for an easy application in different vehicles. Furthermore, the closed-loop stability is proven and experimental results are presented.     

Strategies toward High‐Performance Solution‐Processed Lateral Photodetectors

Due to their low cost and ease of integration, solution‐processed lateral photodetectors (PDs) are becoming an important device type among the PD family. In recent years, enormous effort has been devoted to improving their performances, and great achievements have been made. A summary of the core progress, especially from the perspective of design principles and device physics, is necessary to further the development of the field, but is currently lacking. Here, to address this need, first, the working mechanism of PDs and the device figures‐of‐merit are introduced. Second, by classifying the active materials into four categories, including inorganic, organic, hybrid, and perovskite, the developed strategies toward high performance are discussed respectively. To close, the common physical rules behind all these strategies are generalized, and suggestions for future development are given accordingly.     

Diffusion Magnetic Resonance Imaging-Based Biomarkers for Neurodegenerative Diseases

There has been an increasing prevalence of neurodegenerative diseases with the rapid increase in aging societies worldwide. Biomarkers that can be used to detect pathological changes before the development of severe neuronal loss and consequently facilitate early intervention with disease-modifying therapeutic modalities are therefore urgently needed. Diffusion magnetic resonance imaging (MRI) is a promising tool that can be used to infer microstructural characteristics of the brain, such as microstructural integrity and complexity, as well as axonal density, order, and myelination, through the utilization of water molecules that are diffused within the tissue, with displacement at the micron scale. Diffusion tensor imaging is the most commonly used diffusion MRI technique to assess the pathophysiology of neurodegenerative diseases. However, diffusion tensor imaging has several limitations, and new technologies, including neurite orientation dispersion and density imaging, diffusion kurtosis imaging, and free-water imaging, have been recently developed as approaches to overcome these constraints. This review provides an overview of these technologies and their potential as biomarkers for the early diagnosis and disease progression of major neurodegenerative diseases.