Isolated Hyperacute T-Waves in West Nile Encephalitis Indicating Atypical Variant of Stress-Induced Cardiomyopathy

Several cardiac outcomes have been reported with West Nile-encephalitis;however, the underlying pathophysiology remains complex. We present a 42-year-old female, with multiple sclerosis, whose neurological symptoms and respiratory decline were finally explained by the diagnosis of West Nile-encephalitis. During her admission, the isolated peaked T-waves indicated the underlying stress-induced cardiomyopathy. The absence of all other causes of hyperacute T-waves, their subsequent resolution with the resolution of infection and improvement in wall motion abnormalities, further supported the association. This case highlights the importance of considering hyperacute T-waves in an approach towards the diagnosis of WNV-encephalitis related atypical variant of stress-induced cardiomyopathy.

CHARACTERISTICS OF STRESS-INDUCED TRANSFORMATION AND MICROSTRUCTURE EVOLUTION IN Cu-BASED SMA

The mechanical behavior of shape memory alloys （SMAs） is closely related to the formation and evolution of its microstructures. Through theoretical analysis and experimental observations, it was found that the stress-induced martensitic transformation process of single crystal Cu-based SMA under uniaxial tension condition consisted of three periods： nucleation, mixed nucleation and growth, and merging due to growth. During the nucleation, the stress dropped rapidly and the number of interfaces increased very fast while the phase fraction increased slowly. In the second period, both the stress and the interface number changed slightly but the phase fraction increased dramatically. Finally, the stress and the phase fraction changed slowly while the number of interfaces decreased quickly. Moreover, it was found that the transformation could be of multi-stage： sharp stress drops at several strains and correspondingly, the nucleation and growth process occurred quasi-independently in several parts of the sample.

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.

Proteomics of the mediodorsal thalamic nucleus of rats with stress-induced gastric ulcer

BACKGROUND Stress-induced gastric ulcer(SGU) is one of the most common visceral complications after trauma. Restraint water-immersion stress(RWIS) can cause serious gastrointestinal dysfunction and has been widely used to study the pathogenesis of SGU to identify medications that can cure the disease. The mediodorsal thalamic nucleus(MD) is the centre integrating visceral and physical activity and contributes to SGU induced by RWIS. Hence, the role of the MD during RWIS needs to be studied.AIM To screen for differentially expressed proteins in the MD of the RWIS rats to further elucidate molecular mechanisms of SGU.METHODS Male Wistar rats were selected randomly and divided into two groups, namely, a control group and an RWIS group. Gastric mucosal lesions of the sacrificed rats were measured using the erosion index and the proteomic profiles of the MD were generated through isobaric tags for relative and absolute quantitation(iTRAQ) coupled with two-dimensional liquid chromatography and tandem mass spectrometry. Additionally, iTRAQ results were verified by Western blot analysis.RESULTS A total of 2853 proteins were identified, and these included 65 dysregulated(31 upregulated and 34 downregulated) proteins(fold change ratio ≥ 1.2). Gene Ontology(GO) analysis showed that most of the upregulated proteins are primarily related to cell division, whereas most of the downregulated proteins are related to neuron morphogenesis and neurotransmitter regulation. Ingenuity Pathway Analysis revealed that the dysregulated proteins are mainly involved in the neurological disease signalling pathways. Furthermore, our results indicated that glycogen synthase kinase-3 beta might be related to the central mechanismthrough which RWIS gives rise to SGU.CONCLUSION Quantitative proteomic analysis elucidated the molecular targets associated with the production of SGU and provides insights into the role of the MD. The underlying molecular mechanisms need to be further dissected.

Influence of bedding structure on stress-induced elastic wave anisotropy in tight sandstones

To understand the evolution of stress-induced elastic wave anisotropy,three triaxial experiments were performed on sandstone specimens with bedding orientations parallel,perpendicular,and oblique to the maximum principal stress.P-wave velocities along 64 different directions on each specimen were monitored frequently to understand the anisotropy change at various stress levels by fitting Thomsen’s anisotropy equation.The results show that the elastic wave anisotropy is very sensitive to mechanical loading.Under hydrostatic loading,the magnitude of anisotropy is reduced in all three specimens.However,under deviatoric stress loading,the evolution of anisotropic characteristics(magnitude and orientation of the symmetry axis)is bedding orientation dependent.Anisotropy reversal occurs in specimens with bedding normal/oblique to the maximum principal stress.P-wave anisotropyε0 is linearly related to volumetric strain Sv and dilatancy,indicating that stress-induced redistribution of microcracks has a significant effect on P-wave velocity anisotropy.The closure of initial cracks and pores aligned in the bedding direction contributes to the decrease of the anisotropy.However,opening of new cracks,aligned in the maximum principal direction,accounts for the increase of the anisotropy.The experimental results provide some insights into the microstructural behavior under loading and provide an experimental basis for seismic data interpretation and parameter selection in engineering applications.

EFFECT OF STRESS-INDUCED REACTIONS ON MORPHOLOGICAL STRUCTURE AND PROCESSABILITY OF PVC DURING PAN-MILLING

The effect of pan-milling on morphological structure,processability and properties of PVC was studied throughSEM,FTIR,granulometer,GPC and mechanical properties test in the hope of gaining ease in operation,needless ofplasticizers,a clean and efficient route for improving the processability of PVC through stress-induced reactions,fulfilling the idea of“plasticizing PVC by itself”.The experimental results show that during pan-milling at ambienttemperature,within 2-3 min,the microcrystalline structure of PVC becomes indistinct,the grain size of PVC is reducedfrom 130-160 μm to 1-50 μm the molecular weight of PVC is slightly decreased,the variation of molecular weightdistribution is indistinct,the plasticizing time and torque at balance drop a great deal from 71-132 s to 31-33 s and from18.2-22.1 Nm to 14.7-18.4 Nm,respectively,the processability of PVC is markedly improved,and the mechanicalproperties get enhanced too.

Stress-Induced Precipitation of Fineγ'-Phase and Thermodynamics Analysis

The microstructures of a single crystal Ni-base superalloy with [001] orientation were observed by means of TEM. Results showed that the fine γ' particles were precipitated in the γ matrix channels during the tensile deformation of the alloy. Thermodynamics analysis indicated that the solubility of elements M(Al,Ta) within the γ matrix may be changed when the alloy was deformed by the external applied stress. The tensile stress reduced the solubility of elements Al and Ta so as to occur the over-saturation and agglomeration of them, which promoted the precipitation of fine γ'-phase in the γ matrix.

Studies on Genetic Transformation of Fresh-cut Chrysanthemum Using DREB1A Promoted by Stress-induced Promoter rd29A

In this study, DERB1A transcription factor and stress-induced promoter rd29A were isolated respectively and amplified from Arabidopsis thaliana, se- quenced and analyzed by DNAsis. In addition, the stress-induced promoter rd29A was utilized to construct the plant expression vector of DERB1A, which was transformed into Agrobacterium tumefaciens. Furthermore, the transgenic regeneration system of fresh-cut chrysanthemum from callus to plantlets was established successfully. On this basis, chrysanthemum leaf-disc explants were genetically transformed with Agrobacterium-mediated method. Two positive transgenie plantlets were obtained in vitro. Based on PCR detection, DREB1A transcription factor was integrated into chrysanthemum genome, which laid the foundation for breeding new transgenie cultivars of fresh-cut chrysanthemum with high comprehensive stress resistance, good cmalitv and high field.

Preparation and evaluation of silymarin nanosuspensions for protective effects on stress-induced liver injury

OBJECTIVE To fabricate Silymarin(SM) nanosuspensions(NSs) and evaluate their protective effect on stress-induced liver injury. METHODS SM nanosuspensions were tailored by combination of the anti-solvent precipitation and high pressure homogenization(HPH); the formulations were optimized by central composite design. The pharmacokinetics and pharmacodynamics of SM-NSs were also performed.RESULTS In light of the quadratic mathematical equations derived from the Design of Expert Software,the optimal formulation of SM-NSs consisted of PVP 0.34% and F188 0.36%. The morphology of NSs was found to be spherical with a diameter of about 150 nm using transmission electron microscope(TEM)observation. The pharmacokinetics experiment demonstrated that oral administration of SM-NSs significantly increased its bioavailability compared to the coarse powder(Cmax: 9.03 ± 2.39 mg · L^(-1);AUMC_(0→∞):3757.35±227.19 mg·L^(-1)·h; AUC_(0→∞):171.84±26.61 mg·L^(-1)·h). In pharmacodynamics,it was found that restraint stress produced oxidative effects and increased serum AST and ALT levels in mice,both of which were significantly inhibited by SM and SM-NSs; in addition,administration of SM-NSs showed more effective prevention against acute liver injury than SM coarse suspensions(r^2=0.986,0.984,P<0.05). CONCLUSION The results suggest that fabricated SM-NSs exert potent hepatoprotective effects and attenuate restraint stress-induced liver injury. The study provides an effective approach to improving the property of SM,which can be used for treatment of liver diseases.

Research on Stress-Induced Nucleation ofε-Martensite in Fe-17Mn-10Cr-5Si-4Ni Polycrystalline Alloy

The relation between stacking fault overlap and martensitic nucleation in Fe-17Mn-10Cr-5Si-4Ni alloy was studied.The arrayed structure of dislocations and characteristics ofε-martensite formation under stress were in-situ observed by TEM.The results reveal thatε-martensite nucleates at the top of stacking faults overlapped band,where the ordered arrayed structure of Shockley partial dislocations exists.External stress promotesε-martensitic nucleation ability because of accelerated ordering of Shockley partial dislocations in stacking faults overlapped band.

A simplified testing method for stress-induced of tunnel surrounding rock

A simple testing method for secondary or induced stress of surrounding rockwas presented by laboratory experiment, numerical simulation and in situ testing based onthe basic principle of the historical stress restoring method.First, stress equivalent coefficient,which key coefficient of stress restored testing, was obtained by laboratory experiment.Second, experimental results were examined using 3D finite element numericalanalysis and the influence factors were analyzed by 2D finite element numerical analysis.The correctness of induced stress measuring results in situ for highway tunnel wereproved by elastic mechanics theory solution and single-hole stress rescission method.Thenew simple method of induced stress measuring has important practical value for undergroundengineering induced stress field analysis.

Mechanisms of Myocardial Stunning in Stress-Induced Cardiomyopathy

Stress-induced cardiomyopathy,in contrast to acute myocardial infarction,is a type of acute heart failure characterized by reversible left ventricular dysfunction.Cardiac imaging primarily reveals left ventricle myocardial stunning,81.7%of which is apical type.Emotional or psychological stress usually precedes the onset of stress-induced cardiomyopathy,which is increasingly being recognized as a unique neurogenic myocardial stunning disease.To distinguish between acute myocardial infarction and acute viral or auto-immune myocarditis,this review summarizes specific mechanisms of myocardial stunning in stress-induced cardiomyopathy,such as calcium disorders,metabolic alterations,anatomical and histological variations in different parts of the left ventricle,and microvascular dysfunction.

Stress-induced leakage current characteristics of PMOS fabricated by a new multi-deposition multi-annealing technique with full gate last process

In the process of high-k films fabrication, a novel multi deposition multi annealing （MDMA） technique is introduced to replace simple post deposition annealing. The leakage current decreases with the increase of the post deposition annealing （PDA） times. The equivalent oxide thickness （EOT） decreases when the annealing time（s） change from 1 to 2. Furthermore, the characteristics of SILC （stress-induced leakage current） for an ultra-thin SiO2/HfO2 gate dielectric stack are studied systematically. The increase of the PDA time（s） from 1 to 2 can decrease the defect and defect generation rate in the HK layer. However, increasing the PDA times to 4 and 7 may introduce too much oxygen, therefore the type of oxygen vacancy changes.

Surface Roughness of SiGe/Si(110) Formed by Stress-Induced Twins and the Solution to Produce Smooth Surface

Lattice-strained Si thin films grown onto SiGe(110)/Si(110) are attracting because of their potential to realize high-speed transistors. In this study we observe surface morphology of Si/SiGe/Si(110) using scanning electron microscopy and we also observe microstructure of the identical position using cross-sectional transmission electron microscopy. These results reveal that crossing of stress-induced twins causes remarkable surface roughness. We propose using vicinal substrate to avoid this phenomenon and our successive experimental results are shown in this paper.

Neurogenesis-enhancing effect of sodium ferulate and its role in repair following stress-induced neuronal damage

Ferulic acid (FA) is a ubiquitous phenolic acid of low toxicity, and sodium ferulate (SF) is its sodium salt. Our previous studies have revealed that FA shows neuroprotective effect and significant antidepressant- like effect. The aim of this study was to investigate its potential neurogenesis-enhancing effect and its role in repair following stress-induced neuronal damage. MTT assay was performed to measure the effect of SF on the growth of rat pheochromocytoma (PC12) cells;morphological and immunocytochemical meth- ods were used for assessing its differentiation-induc- ing action. Chronic mild stress (CMS) tests were per- formed to establish rat model of depression. The histopathology of animal brains was studied to ana- lyze CMS-induced morphological changes and the effect of SF on the repair of CMS-induced brain in- jury. The expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) and the proliferation of neural stem cell/neural progenitor cells were assessed in the hippocampi of chronic mild stress (CMS)-induced depression-like model rats by immunohistochemistry and bromodeoxyuridine (BrdU)- incorporation assays, respectively. Our in vitro tests showed that SF promoted the proliferation of PC12 cells in the concentration range of 5 - 320 μM, and induced PC12 cells to differentiate to more mature cells with the morphological characteristics and mo- lecular marker of neuronal-like cells. In vivo tests showed that SF up-regulated the expressions of NGF and BDNF, and induced the proliferation of neural stem cell/neural progenitor cells in the hippocampi of CMS-induced depression-like model rats. This study provides evidences that SF shows neurogenesis-en- hancing effect, and its antidepressant-like effect of SF may be related directly and closely to its above-men- tioned effect.

长余辉海藻酸钠纤维的制备及其性能

为了制备出具有长余辉功能的海藻酸钠纤维,拓宽海藻酸钠纤维和长余辉发光材料的应用领域,文章首先以硝酸锶、二氧化硅、氧化镁、氧化硼、氧化铕和氧化镝为原料,通过高温固相法制备了长余辉发光材料,再采用共混方式结合海藻酸钠制备出纺丝液,最后通过湿法纺丝制备了不同浓度的长余辉海藻酸钠纤维。利用扫描电子显微镜、红外光谱仪、荧光光谱仪、荧光余辉亮度测试仪和多功能力学测试仪对长余辉海藻酸钠纤维的微观形貌、化学结构、余辉性能及力学性能进行分析。结果表明:随着加入的长余辉发光材料质量增加,长余辉海藻酸钠纤维的余辉性能在不断提高,但纤维的强力呈下降趋势;当加入的长余辉发光材料质量分数为2.0%时,所制备的长余辉海藻酸钠纤维的综合性能达到最优。所制备的长余辉海藻酸钠纤维在夜行服和防伪标志等方面具有良好的应用前景。

稀土金属基涂层织物的制备与性能表征

利用稀土金属吸收存储光能并再次释放的特性,采用稀土铝酸锶发光粉与水性聚氨酯混合制备的涂层剂对棉织物进行涂覆,开发具有发光功能的服用织物。研究表明,稀土铝酸锶发光粉与水性聚氨酯混合液的黏度与成膜后的断裂强度均随着稀土铝酸锶发光粉含量的增加呈下降的趋势,当稀土铝酸锶发光粉含量大于20%时,下降速率逐渐增大;当稀土铝酸锶发光粉含量为30%时,涂层织物的团聚现象明显,因此,需要控制稀土铝酸锶发光粉含量在25%以内,可兼顾涂层织物的服用性能。涂层织物的荧光光谱在490nm处,顶峰位置随着稀土铝酸锶发光粉含量的增加向左迁移。稀土铝酸锶发光粉含量的增加能提高涂层织物的亮度,改善余辉衰减,染色限制了涂层织物的余辉性能。因此,合理控制稀土铝酸锶发光粉的含量有利于稀土金属基涂层织物的开发与应用。

纳米长余辉发光材料在生物医学检测、生物成像与肿瘤治疗中的研究进展

长余辉发光材料是一种能储存外界激发光能量、在激发光停止激发后仍能持续发光的材料。由于其长余辉寿命、无需原位激发、无组织背景信号干扰和高信噪比等优点,纳米长余辉发光材料广泛应用于生物医学检测、生物成像和肿瘤治疗领域。本文综述了近年来纳米长余辉发光材料在生物医学检测、生物成像和肿瘤治疗(化疗、光热治疗、光动力治疗和免疫治疗)方面的应用进展,并进一步探讨了其在生物医学应用中所面临的挑战,对其未来的发展趋势也进行了展望。

长余辉水性道面标线涂料的制备与路用性能

本工作以SrAl_(2)O_(4):Eu2+,Dy^(3+)类蓄能发光粉为发光基体,采用双硅膜复合改性技术进行覆膜保护处理,然后调配制成长余辉水性标线涂料,并通过漆膜试验和路用性能测试,对制备涂料的使用性能进行了综合评估。结果表明,以硅丙乳液为基料、六偏磷酸钠为分散剂、甲基纤维素钠为防沉剂,水基比为33%,可以制得涂膜性能与发光效果俱佳的水性发光涂料。成型涂膜表干时间为1.4 h,硬度可达2H,耐水性、耐酸性24 h无异常,在40%的氢氧化钠溶液中漆膜稍有变色,耐热性、耐寒性没有异常情况,附着力可达2级;标线涂膜厚度优选为0.33 mm。路用性能表征结果表明,涂覆水性发光涂料标线后,路面抗滑值为88 BPN,界面粘附性可达2.72 MPa,15℃常温耐水性24 h无异常,不粘胎干燥时间为10 min,余晖时间为12.5 h,可基本满足路面涂料的使用性能要求,但长期的80℃高温或常温弱碱环境会对涂料发光性能产生一定的损伤。本工作为长余辉路面标线涂料的开发提供了技术参考。

一种余光目标深度及高度的单帧图像测量

在自动避障,目标监控,自动驾驶等领域,基于单目视觉的目标测量总是关键技术之一.但是,已知的单目视觉测量方法只能得到目标的距离和最低点位置坐标,目标高度需要利用其他传感器获取.本文从目标的线特征出发,创造性的提出了关于余光目标像与像平面竖直中线的夹角、余光目标偏离单目相机装置的角度以及单目镜头的俯仰角三个变量之间的关系模型.最后,在单帧目标图像和单目相机的高度已知的情况下,利用该模型实现余光目标深度和高度的测量.实验结果表明,本文提出的测量方法能有效,快速的对目标的高度和距离进行测量.