Detection of bearing damage by statistic vibration analysis

The condition of bearings, which are essential components in mechanisms, is crucial to safety. The analysis of the bearing vibration signal, which is always contaminated by certain types of noise, is a very important standard for mechanical condition diagnosis of the bearing and mechanical failure phenomenon. In this paper the method of rolling bearing fault detection by statistical analysis of vibration is proposed to filter out Gaussian noise contained in a raw vibration signal. The results of experiments show that the vibration signal can be significantly enhanced by application of the proposed method. Besides, the proposed method is used to analyse real acoustic signals of a bearing with inner race and outer race faults, respectively. The values of attributes are determined according to the degree of the fault. The results confirm that the periods between the transients, which represent bearing fault characteristics, can be successfully detected

The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.

Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex

Electrical Conductivity of Electrospun Polyaniline and Polyaniline-Blend Fibers and Mats

Submicrometer fibers of polyaniline (PAni) doped with (+)-camphor-10-sulfonic acid (HCSA) and blended with poly(methyl methacrylate) (PMMA) or poly(ethylene oxide) were electrospun over a range of compositions. Continuous, pure PAni fibers doped with HCSA were also produced by coaxial electrospinning and subsequent removal of the PMMA shell polymer. The electrical conductivities of both the fibers and the mats were characterized. The electrical conductivities of the fibers were found to increase exponentially with the weight percent of doped PAni in the fibers, with values as high as 50 ± 30 S/cm for as-electrospun fibers of 100% doped PAni and as high as 130 ± 40 S/cm upon further solid state drawing. These high electrical conductivities are attributed to the enhanced molecular orientation arising from extensional deformation in the electrospinning process and afterward during solid state drawing. A model is proposed that permits the calculation of mat conductivity as a function of fiber conductivity, mat porosity, and fiber orientation distribution; the results agree quantitatively with the independently measured mat conductivities.United States. Army Research Office (Institute for Soldier Nanotechnologies, Contract ARO W911NF-07-D- 0004

Структура вірусних діарей у дітей на Сумщині

Гострі кишкові інфекції (ГКІ) стійко посідають одне з провідних місць серед усіх інфекційних захворювань, характеризуються широкою поширеністю, високою частотою розвитку тяжких форм і ускладнень. Прогрес у галузі лабораторних методів діагностики дозволив істотно розширити уявлення про етіологічні чинники хвороби: у країнах, що розвиваються, домінують діарейні інфекції бактерійної етіології, а в економічно розвинених країнах - вірусної. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/3228

Transglutaminase 2 Contributes to Apoptosis Induction in Jurkat T Cells by Modulating Ca(2+) Homeostasis via Cross-Linking RAP1GDS1

BACKGROUND: Transglutaminase 2 (TG2) is a protein cross-linking enzyme known to be associated with the in vivo apoptosis program of T cells. However, its role in the T cell apoptosis program was not investigated yet. RESULTS: Here we report that timed overexpression of both the wild type (wt) and the cross-linking mutant of TG2 induced apoptosis in Jurkat T cells, the wt being more effective. Part of TG2 colocalised with mitochondria. WtTG2-induced apoptosis was characterized by enhanced mitochondrial Ca(2+) uptake. Ca(2+)-activated wtTG2 cross-linked RAP1, GTP-GDP dissociation stimulator 1, an unusual guanine exchange factor acting on various small GTPases, to induce a yet uncharacterized signaling pathway that was able to promote the Ca(2+) release from the endoplasmic reticulum via both Ins3P and ryanodine sensitive receptors leading to a consequently enhanced mitochondrial Ca(2+)uptake. CONCLUSIONS: Our data indicate that TG2 might act as a Ca(2+) sensor to amplify endoplasmic reticulum-derived Ca(2+) signals to enhance mitochondria Ca(2+) uptake. Since enhanced mitochondrial Ca(2+) levels were previously shown to sensitize mitochondria for various apoptotic signals, our data demonstrate a novel mechanism through which TG2 can contribute to the induction of apoptosis in certain cell types. Since, as compared to knock out cells, physiological levels of TG2 affected Ca(2+) signals in mouse embryonic fibroblasts similar to Jurkat cells, our data might indicate a more general role of TG2 in the regulation of mitochondrial Ca(2+) homeostasis

Collagen density defines 3D migration of CTLs and their consequent cytotoxicity against tumor cells

Solid tumors are often characterized by condensed extracellular matrix (ECM). The impact of dense ECM on cytotoxic T lymphocytes (CTL) function is not fully understood. Here, we report that CTL-mediated cytotoxicity is substantially impaired in dense collagen matrices. Although the intrinsic killing machinery including expression of cytotoxic proteins and degranulation was intact, CTL motility was substantially compromised in dense collagen. We found that for 3D CTL migration, persistence and velocity was regulated by collagen stiffness and the porosity, respectively. Interestingly, 3D CTL velocity is strongly correlated with their nuclear deformability/flexibility during migration, which is regulated by the microtubule network. Moreover, CTL migration was completely abolished by inhibition of actin polymerization and or myosin IIA. Remarkably, disruption of the microtubule-networks significantly improves the impaired migration, search efficiency, and cytotoxicity of CTLs in dense collagen. Our work suggests the microtubule network as a promising target to rescue impaired CTL killing capacity in solid tumor related scenarios

Targeting the Microtubule-Network Rescues CTL Killing Efficiency in Dense 3D Matrices

Efficacy of cytotoxic T lymphocyte (CTL)-based immunotherapy is still unsatisfactory against solid tumors, which are frequently characterized by condensed extracellular matrix. Here, using a unique 3D killing assay, we identify that the killing efficiency of primary human CTLs is substantially impaired in dense collagen matrices. Although the expression of cytotoxic proteins in CTLs remained intact in dense collagen, CTL motility was largely compromised. Using light-sheet microscopy, we found that persistence and velocity of CTL migration was influenced by the stiffness and porosity of the 3D matrix. Notably, 3D CTL velocity was strongly correlated with their nuclear deformability, which was enhanced by disruption of the microtubule network especially in dense matrices. Concomitantly, CTL migration, search efficiency, and killing efficiency in dense collagen were significantly increased in microtubule-perturbed CTLs. In addition, the chemotherapeutically used microtubule inhibitor vinblastine drastically enhanced CTL killing efficiency in dense collagen. Together, our findings suggest targeting the microtubule network as a promising strategy to enhance efficacy of CTL-based immunotherapy against solid tumors, especially stiff solid tumors