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The hot corrosion behaviours of 5-mm-thick plates of dissimilar AISI 904L and Inconel 625 weldments produced by continuous current gas tungsten arc welding process using Ni-Cr-Mo-enriched filler wires (ERNiCrMo-4 and ERNiCrCoMo-1) were investigated. Optical microscopy was used to examine the microstructure of these weldments. The corrosion performance of the weldments and base metals was determined in the mixture of K2SO4 + 60% NaCl molten salt (MS) and air oxidation conditions at 700°C for 50 cycles. The thermogravimetric plots derived the corrosion kinetics of the weldments. The microstructure and the elemental analysis of the scales formed on the corroded samples were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The phases developed on the oxide layers during the corrosion were analysed using X-ray diffraction. The fusion zones of ERNiCrCoMo-1 weldment and AISI 904L base metal were vulnerable to degradation in the MS environment, causing severe cracks and spallation compared to ERNiCrCoMo-1 weldment. [ABSTRACT FROM AUTHOR]

The precipitation effects on the mechanical behavior of electron beam welded joints of Inconel 625 in the as-welded [AW] and post-weld heat treatment [PWHT] conditions have been investigated in this research study. A PWHT comprising of direct aging [DA] treatment at 700 °C for 100 h in vacuum at a pressure of 10−5 mbar was performed on the weld joints. The microstructure of the base alloy opined the precipitation of MC system carbides and γ′′ strengthening phase after subjecting to DA. Also, Nb–Mo rich precipitates and the Laves phase was noticed in the inter-dendritic arms of the fusion zone (FZ) of welded joints in the AW conditions. DA treatment has a notable effect on the weld mechanical characteristics of Inconel 625 joints. The precipitation of γ′′ strengthening phase is reasoned for the significant rise in the yield strength [YS] and tensile strength [TS] of the base alloy and EBW joints. • Grain boundary precipitation of MC carbides on EB weld seams of Incoloy 925. • Formation of M 23 C 6 , M 6 C carbides in the grain boundaries of weld microstructures in both the conditions. • Improved yield and tensile strengths after subjecting to PWHT conditions. [ABSTRACT FROM AUTHOR]

A frequency doubler for rectangular inputs is described. This circuit works independently of the frequency and duty cycle of the input signal and does not need critical adjustment of any components. A 2[sup n] frequency multiplier can be constructed using n such frequency doublers. [ABSTRACT FROM AUTHOR]

Proposes a static random access memory (RAM) cell based on the unijunction transistor (UJT). Current-controlled negative resistance characteristic at input; Voltage-controlled negative resistance characteristic at output; Possibility of using the UJT-based static RAM cell to solve the problem of realization of high-density memories.

Presents a Schmitt trigger circuit based on the lambda bipolar transistor (LBT). Usability of the Schmitt trigger; Description of the LBT; Computation of the V-I characteristics of the LBT for different values of input bias.

This paper presents an analysis of the effects of ambients-temperature and light intensity on the V-I characteristics of bipolar transistors under electrical breakdown. The analysis is based on the transportation and storage of majority carriers in the base region. It is shown that this analysis can explain the observed shift in the V-I characteristics to lower voltages with increase in either temperature or light intensity. [ABSTRACT FROM AUTHOR]

This paper describes a new analysis of the avalanche breakdown phenomenon in bipolar transistors for different bias conditions of the emitter-base junction. This analysis revolves around the transportation and storage of majority carriers in the base region. Using this analysis one can compute all the voltage-current characteristics of a transistor under avalanche breakdown. [ABSTRACT FROM AUTHOR]

Analyzes the cell-free filtrates from high-density Chlorella vulgaris (Chlorellaceae) for the presence of any inhibitory /cell cycle inhibitory compounds. Effect of conditioned medium; Characterization of factors responsible for cell cycle modulation; Effect of bicarbonate concentration; Effect of bicarbonate-free conditioned medium.

Spontaneous Epidural Haematoma (SEH) of cervical spine is a rare entity with incidence of 0.1 per 1,00,000 population and they represent less than 1% of spinal space occupying lesions. Patients usually present with sudden neck pain and rapidly progressing neurological deficit. Coagulopathy, neoplasm, infections, vascular malformation and trauma are the usual causative factors. The rest of the cases are idiopathic. Early detection and prompt decompression of the cord is essential to limit serious neurological complications. This case is being reported due to the rare presentation and to emphasise the need for urgent decompression. [ABSTRACT FROM AUTHOR]

The pulsating current approach in tungsten inert gas (TIG) welding is adapted for joining Hastelloy C-276. Microstructure examination revealed the absence of micro-segregation while employing UNS N06022 filler. Due to the prevalence of higher tensile stresses in the un-peened conditions, tensile failures were observed in the weld regions of both the joints irrespective of fillers. Low energy laser shock peening without coating (LSPwC) was carried out on the weld zones on both the sides of the joints with the pulse densities 2500 and 7500 pulses per cm2. This laser surface treatment had remarkably increased the tensile strength of the welded joints by shifting the location of tensile failures well away from the fusion zones for all the cases. Similarly, a considerable increase is observed in the notch toughness of both the joints in the LSPwC condition. The enhancement in tensile strength and notch impact toughness of the welds could be ascribed to the residual compressive stresses induced which were then confirmed by Sin2ψ method in X-ray diffraction (XRD) technique. [ABSTRACT FROM AUTHOR]

This paper aims at describing a low-temperature thermal sensor based on superconductor films which can be designed to have required variation of resistance with temperature through an appropriate geometry. Further, it has been shown that the temperature range can be varied to some extent by controlling the bias current. [ABSTRACT FROM AUTHOR]

Heterotopic Ossification (HO) is usually seen in laparotomy wounds following gastrointestinal surgeries. The presence of marrow elements in an area of HO is very rare. A 57-year-old male with a history of omento-myelo-synangiosis for syringomyelia was admitted with an incisional hernia. A calcified nodule was detected in the wall of the hernia sac on Computed Tomography (CT). Histopathology of the excised nodule showed HO with marrow elements exhibiting trilineage haematopoiesis. HO is commonly an incidental finding during abdominal imaging for another condition. The presence of trilineage haematopoiesis within HO is extremely rare. As most of these patients are asymptomatic, conservative management is sufficient. Surgical excision is indicated, if any associated complications arise. [ABSTRACT FROM AUTHOR]

Nickel-based alloy Inconel 625 is used in higher mechanical stress applications because of their superior oxidation and creep resistance. However, their undesirable tribological behaviour is the major technical issues in several applications. This research carried out the comparative investigation of Inconel 625 (IN625) and Colmonoy 6 deposition over IN625 substrate by laser cladding technique. The metallurgical, mechanical and tribological properties were investigated. Results showed that the presence of hard laves and γ-Ni phases were observed on Colmonoy 6 and IN625 clad surface, respectively. Besides, Colmonoy 6 clad contains more than 60% of the hard laves phase which has capable of providing higher hardness and wear resistance. The hard laves phase and higher hardness in Colmonoy 6 clad provided a strong network to enhance the wear resistance and reduced the roughness average compared to IN625 clad and base material. The Colmonoy 6 clad was the promising one for the sliding components to resist the sliding wear. [ABSTRACT FROM AUTHOR]

This note attempts to describe a current controlled variable resistor conceived based on the property of critical current associated with a superconductor. This idea has been tested using high-temperature superconductor films. [ABSTRACT FROM AUTHOR]

A novel n-MgFe2O4–n-ZnS heterojunction catalyst was employed via two step approach for photodegradation of organic dyes such as Methylene Blue (MB) and Crystal Violet (CV) dyes under visible light irradiation. The synthesized MgFe2O4/ZnS NCs were characterized using PXRD, FTIR, UV–Visible spectroscopy, PL and FESEM analysis which reveals the formation of flake like structure with size as to be ~ 50 nm. The photocatalytic experimental result demonstrates that the MgFe2O4/ZnS nanocomposites (NCs) improve photodegradation performance with 98.0% and 91% decomposition of MB and CV dyes within 120 min illumination during simulated visible light irradiation. From the result, MgFe2O4/ZnS NCs has higher photocatalytic performance than that of MgFe2O4, and ZnS due to efficient separation of the photo-induced electron–hole pairs and effective electron–hole generation transfer by the formation of n-MgFe2O4–n-ZnS heterojunction. Hence, photodegradation performance implies that the synthesized MgFe2O4/ZnS NCs can be effectively utilized in waste water purification systems. [ABSTRACT FROM AUTHOR]

This investigation presents a fault diagnosis methodology for detecting sensor faults in cement industries pyro processing section. It works in three steps: (a) modelling, (b) analysis, and (c) validation. In the modelling, the actual data from the cement pyro processing is used to do a correlation analysis between output and input variables. The structural model is obtained from the correlation tests. During the analysis phase the Structural analysis Tool (SaTool) is used to detect the detectability and isolability of the faults. The results of the structural analysis are validated in a cement industry using residual analysis performed using structural sensor model and real-time measurements. The main advantages of this fault diagnosis technique are: (a) it requires only correlation analysis to obtain the structural model without a detailed physical model as in other methods, (b) conclusions regarding detectability and isolability can be easily drawn during the analysis stage itself, and (c) the method is simple compared to the model-based, and data-history based methods. The effectiveness of the proposed method is illustrated using data from cement pyro processing plant and its performance is compared with model based approaches for four different types of sensor faults: (1) bias, (2) drift, (3) stuck, and (4) measurement failures. Our results demonstrate that the structural method is able to detect the sensor faults even in the presence of noisy information, and its performance is comparable with that of model based approaches without employing a physical model. [ABSTRACT FROM AUTHOR]

High temperature corrosion resistance of welded components in power plant industry, hot sections of gas turbines, boilers, industrial waste incinerators, metallurgical furnaces and petrochemical installations is one of the serious necessity. The failure of hot sections of welded component is due to the deposition of molten salt which accelerates the hot corrosion reactions in the weld joint. In this research work, the oxy-chlorination of dissimilar weldments between AISI 304L austenitic stainless steel and AISI 4340 alloy steel at 600°C in eutectic mixture of K2SO4 + 60% NaCl under molten salt conditions was investigated. Corrosion kinetics for this dissimilar joints calculated from the thermogravimetric charts were represented. Corrosion on the dissimilar joint employing E309L filler in pulsed current gas tungsten arc welding process is found to be very aggressive, due to the fragmented delta ferrites at numerous locations resulting in the formation of the micro electrochemical cells, which act as sites for corrosion initiation and thus leading to higher corrosion rate. However, in the case of continuous current, the joint is able to protect itself better in this environment due to lower amounts of delta ferrites in weld zone, which is attributed to the higher temperature available in continuous mode leading to austenisation of delta ferrites in the multipass welding. [ABSTRACT FROM AUTHOR]

Thin-wall structures are promising for lightweighting with widened applications in topology-optimized lattice structures. Also, they are extensively used in heat exchangers because of their rapid heat transfer rate. This work presents the effects of thin-wall thickness on the microstructures, property, and anisotropy of the laser-powder bed fusion processed thin-walled structures with varied wall thicknesses of 0.3 mm, 0.5 mm, 1.0 mm, and 1.5 mm. The epitaxial columnar growth is favored, and the columnar grain aspect ratio increases with the wall thickness. Further, the columnar grain size increases and the geometrically necessary dislocation density decreases with increasing thickness. These microstructural differences significantly affected the tensile properties; the yield and the tensile strengths reduced, and the elongation increased with the wall thickness increase. Further, the L-PBF processed thin walls presented anisotropic properties. The samples tested along the build direction showed lower strength than those across the build direction. Moreover, the drop in strength with increasing thickness is less in the samples taken across the build direction than that along the build direction. Importantly, the degree of anisotropy increased with increasing wall thickness. [ABSTRACT FROM AUTHOR]

The primary goal of this paper is to design and analyse the entire double wishbone suspension system for a commercial vehicle in order to improve the vehicle’s stability and handling. The suspension system has seen tremendous advancement. A commercial vehicle’s suspension system must be long-lasting, light in weight, efficient, and cost-effective. The vehicle must be able to withstand the harsh off-road terrain environment. As a result, it is critical to concentrate on the stress strain analysis study of the lower wishbone arm in order to improve and modify the existing design. [ABSTRACT FROM AUTHOR]

This study employed green chemistry to synthesize copper nanoparticles (CuNPs) using fresh root extract of Withania somnifera. The size, shape, morphology, and stability of resultant CuNPs were investigated by UV-Vis spectroscopy, FTIR, transmission electron microscopy (TEM), and energy-dispersive spectrophotometer. Crude extracts were assessed phytochemically to determine the presence of alkaloids, flavonoids, phenols, saponins, steroids, and tannins. The UV-Vis absorption spectra show maximum absorption at 330 nm, and FTIR showed the presence of biological molecules responsible for reducing Cu+ ions. In TEM and EDS analyses, the average diameter of the synthesized NPs was found to be 6.28 ± 1.13 nm. The crystal structure of synthesized nanoparticle was determined using XRD analysis and showed its peak at 36.34°, 43.33°, 50.47°, and 73.57°, which corresponds to the cubic lattice of copper. The synthesized nanoparticles (NPs) were tested for their in vitro antimicrobial activity against bacterial strains E. coli and S. aureus by the agar well diffusion method which showed higher efficiency against S. aureus. The antioxidant activity of the synthesized NPs was evaluated by DPPH assay, and the percentage of inhibition was found to be 62% at the concentration of 400 μg/ml and the IC50 value was 51.53 μg/ml. The present investigation suggests that the biosynthesized CuNPs showed prominent antibacterial and free radical scavenging potential. The result proved that root extract of W. somnifera could be applied for synthesis of nanoparticle CuNPs with high uniform particle size along with potent biological activity. [ABSTRACT FROM AUTHOR]

In semiconductor industry, at nanoscale dimensions, numerous field effect devices have been proposed and investigated for further improvement in performance of low power circuit and system. In the present research report, a novel low power FET device structure namely: Surrounding Gate Triple Material Heterojunction Tunnel Field Effect Transistor (SGTM-heTFET) has been proposed with the analytical modeling approach. The benefits of surrounding gate and tunnel FETs are coupled to create a new structure, to decrease short channel effects. Three different gate materials with different work functions replace the gate material that surrounds the device. An analytical model of surface potential(ψ), electric field(E) and drain current (I DS) have been developed for SGTM-heTFET. With the use of low work function material such as 4.0eV, 4.6eV and 4.0eV, the proposed model shows a better ON current of 10−5 A/μm for a V GS of 0.7V, ON-OFF ratio of 1010 with the sub-threshold swing of 50mV/dec. The developed model's for SGTM-heTFET shows excellent device characteristics and have been verified using TCAD simulation, ensuring the model's accuracy. • A Novel device structure called Surrounding Gate Triple Material Heterojunction TFET is proposed. • The electrical parameters are analytically calculated and also compared with the simulated output. • Along with triple material, hetero-dielectric (HfO 2 /SiO 2) arrangement is also proposed to reduce leakage current. • Improved ON current and I ON /I OFF ratio is achieved with SS less than 60mV/dec. [ABSTRACT FROM AUTHOR]

Dual heat treatment (DHT) effect is analyzed using the machining of Al6061-T6 alloy, a readily available material for quickly finding the machining properties. The heat treatments are conducted twice over the specimen by the furnace heating before processing through CNC machining. The HSS and WC milling cutters are preferred for the diameter of 10 mm for the reviewed rotational speeds of 2000 rpm and 4000 rpm, and the constant depth of cut of 0.5 mm is chosen based on various reviews. Worthy roughness could be provided mostly by the influence of feed rates preferred here as 0.05 mm/rev and 0.1 mm/rev. The influencing factors are identified by the Taguchi, genetic algorithm (GA), and Artificial Neural Network (ANN) techniques and compared within it. The simulation finding also helps to clarify the relationship between influenced machining constraints and roughness outcomes of this project. The average values of heat treated and nonheat treated Al6061-T6 are compared and it is to be evaluated that 41% improvement is obtained with the lower surface roughness of 1.78975 µm and it shows good surface finish with the help of dual heat treatment process. [ABSTRACT FROM AUTHOR]

: ObjectivesIn light of evidence that some complications of diabetes mellitus may be caused or exacerbated by oxidative damage, we investigated the effect of Gymnema montanum leaf extract (GLEt) on tissue antioxidant defense systems in alloxan-induced diabetes in rats.: MethodsGLEt was administered orally at a doses of 50, 100, and 200 mg/kg of body weight for 30 d, after which liver and kidney tissues were assayed for the degree of lipid peroxidation by means of markers, reduced glutathione content and activities of catalase, superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase.: ResultsTreatment of diabetic rats with GLEt increased the antioxidant levels. Liver and kidney from diabetic animals exhibited disturbances in antioxidant defense when compared with normal rats. GLEt at a dose of 200 mg/kg of body weight exhibited a significant effect as compared with 50 and 100 mg/kg of body weight. These effects were compared with glibenclamide, a reference drug.: ConclusionsIt may be concluded that, in diabetes, liver and kidney tissues are more vulnerable to oxidative stress and show increased lipid peroxidation. The antioxidant responsiveness mediated by G. montanum may be anticipated to have biological significance in eliminating reactive free radicals that may otherwise affect normal cell functioning and provide a scientific rationale for the use of G. montanum as an antidiabetic plant. [Copyright &y& Elsevier]

Contribution: This article explores how the Industrial Internet of Things (IIoT) could be leveraged to enhance the teaching/learning experience of advanced control techniques [e.g., model-predictive control (MPC)] for complex systems (nonlinear and multivariable) for undergraduate students. Background: The IIoTs’ features, such as ubiquitous sensing, open connectivity, and distributed control, are expected to transform the way control is implemented in the industries. The students need to be prepared for this development. Courses on advanced control techniques should be revamped considering this change. In particular, deploying advanced controllers in IIoT scenarios could make the students ready for Industrie 4.0 and enhance the teaching-learning experience. Intended Outcomes: To reduce the cost for setting up laboratories; to make students appreciate IIoT benefits in industries and study the enhancements in teaching/learning advanced control techniques, such as MPC. The focus is on implementing MPC for a complex process, i.e., nonlinear, multivariable, and having interactions and their deployment on IIoT hardware. Method: A ten-day course on IIoTs’ benefits and implementing advanced control techniques for a complex process with lecturing and hands-on sessions for undergraduate students is used. The course focuses on understanding basic concepts to deploy advanced control techniques on IIoT hardware in industries. Findings: The learning experience is enthralling, and the students are appreciative of the IIoT benefits to the industries and in their learning experience, which is demonstrated by their in-depth understanding of concepts on system complexity and implementing MPC. [ABSTRACT FROM AUTHOR]

A wall component of super-duplex stainless steel was developed using cold metal transfer (CMT)-based wire + arc additive manufacturing (WAAM) technique with an ER2594 wire. The microstructure of the as-deposited wall was explored using optical microscopy and electron backscattered x-ray diffraction (EBSD) analysis. Ferrite count analysis indicated that the austenite-ferrite phase balance was altered along the as-deposited wall body. The average ferrite count near the as-deposited wall was 24.5%, compared with 32.3% in the root region. Widmanstätten and grain boundary austenite were formed near the wall boundary, and intragranular austenite was observed in the different layers. Secondary austenite in the transition layer was also observed. EBSD analysis revealed the sigma (σ) phase and austeno-ferritic phases across the WAAM wall. The tensile and yield strengths of the samples of the as-developed WAAM wall were almost identical regardless of orientations/tropism. Unlabelled Image • CMT based WAAM technique was adopted to develop thick wall structure of ER2594. • The yield and tensile strengths of the WAAM joints were greater than those of the cast SDSS 6A in the ASTM A 890 standard. • The austeno-ferrite phase balance was greatly affected due to complex thermal cycles of WAAM. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced polymers (CFRPs) have been applied to various fields such as electronic printed circuit boards, aircraft brakes, automobile forks, and machine tool-damped structures due to their low density and high tensile strength. These application components required micro-hole and macro-hole in it for joining. In this research work, a comparison of the experimental investigation on micro- and macro-drill on CFRP using a vertical machining center has been carried out. The input machining control factors were spindle speed and rate of feed, whereas the quality characteristics of drilling CFRP were considered as thrust force, delamination, and overcut. Analysis of variance (ANOVA) and gray relational analysis were employed to identify the most significant factor and optimum process parameters, respectively. Microstructural defects of micro-hole and macro-hole were studied using scanning electron microscopy. Results showed that the rate of feed linearly affected the thrust force and delamination and is inversely proportional to overcut. [ABSTRACT FROM AUTHOR]

• The base alloy and weld seams of UNS S32750 are not immune to bacterial corrosion. • Accelerated pitting corrosion was experienced in the base alloy and FCA weld seams. • Pensive discussion on MIC behaviour due to microstructure changes. This study investigates the microbial-influenced corrosion of UNS S32750 super-duplex stainless-steel joints fabricated using different welding methods. Herein, the samples were introduced into a medium inoculated with Macrococcus equipercicus isolated from a marine environment. Confocal laser scanning microscopy and atomic force microscopy were used to characterise the topography and formation of pits in the corroded samples, respectively. Potentiodynamic polarisation studies were conducted on both the base alloy and weld seams exposed for 30 and 60 days in the experimental system inoculated with M. equipercicus and un-inoculated system. Results indicate that the thickness of the biofilm formed due to this bacterium increased and became heterogeneous with an increase in the exposure time, thereby resulting in micro-pits. Bacterial colonisation was observed in all the coupons after exposure to the inoculated medium. Although micro-pits were observed in all the coupons, the base metal and flux-cored arc weld seams showed highest sensitivity to bacterial attack. [ABSTRACT FROM AUTHOR]

Introduction: Guillian Barre is an autoimmune syndrome characterised by acute inflammatory demyelinating polyneuropathy.Patients suffering from GBS typically have pain,numbness,paraesthesia and weakness in upper limbs and lower limbs.They do mimic symptoms of lumbar canal stenosis at certain occasions which can be very misleading and lead to a wrong diagnosis and management.Here,we report a case of a 60 yr old gentleman with an atypical GBS presentation with underlying lumbar canal stenosis. [ABSTRACT FROM AUTHOR]

• Similar joining of alloy 625 was employed using ERNiCrMo-4 fillers by Pulsed GTA method. • Oxidation and corrosion studies were performed on the weldment at 700 °C. • Kinetics of weldments was expressed by the thermogravimetric method. • Oxide scale formation and damage mechanism were derived. Alloy 625 joining was employed by pulsing current gas tungsten arc (PCGTA) welding method using ERNiCrMo-4 filler wire. The cyclic high-temperature performance of the weldments was investigated at 700 °C in molten salt (MS) K 2 SO 4 -60 %NaCl and air environment. The weldments' corrosion kinetics were accessed by the weight change method. A thin scale with no significant failure was found on the surface of the oxidized weldment. The oxide scale cracking and spallation occurred on the weldment in MS condition due to the deposited salts. The damage mechanism of the scales developed on the weldments is discussed in MS condition. [ABSTRACT FROM AUTHOR]

Inthe present study, we attempt to shed light on the underlyingmolecular mechanism of the anticancer activity of pterostilbene (PTS)in HepG2 cells through the proteomic approach. PTS was found to induceapoptosis by altering the expression of apoptotic genes and the G2/Mphase of cell cycle arrest. Further, the 2-DE map showed the expressionof 72 differentially regulated proteins in PTS-treated HepG2 cells,of which 8 spots with >2 fold up- or down-regulated level wereidentifiedby MALDI-TOF analysis, which has a regulatory role in apoptosis. Thesefindings for the first time offer valuable insights into the mechanismof apoptotis by PTS in HepG2 cells. [ABSTRACT FROM AUTHOR]

Objective Endothelial dysfunction highlights that it is a potential contributor in the pathogenesis of vascular complications arising from endoplasmic reticulum stress ( ER stress) and has been emerging as a main causative factor in vascular failure. Here, we hypothesize that the natural flavonoid, quercetin plays an effective role in reducing ER stress in human umbilical vein endothelial cells. Materials and methods Human umbilical vein endothelial cells were pre-treated with different concentrations of quercetin (0-100 μ m) before inducing ER stress using tunicamycin ( TUN) (0.75 μg/ml); cytotoxicity was assessed by MTT assay. Expression levels of ER stress responsive genes, antioxidant enzymes and apoptotic markers were assessed by qRT- PCR, while roles of caspase-3 and PARP cleavage were measured by western blot analysis. Results Quercetin pre-treatment at 25 and 50 μ m had a cytoprotective effect on cells against TUN-induced toxicity. Quercetin administration modulated expression level of ER stress genes coding for glucose-regulated protein 78 ( GRP78) and C/EBP-homologous protein ( CHOP), and antioxidant enzymes such as superoxide dismutase and catalase, along with free radical generation assessed by malondialdehyde assay. Induction of apoptosis was prevented with reduction in expression level of Bax, and concomitant increase in Bcl-2 levels, thus proving its potential against ER stress. Conclusion The current study indicates that quercetin modulated stress responsive genes GRP78 and CHOP, helping endothelial cells prevent TUN-induced ER stress. [ABSTRACT FROM AUTHOR]

Abstract: Simulated hypobaric hypoxia (HBH), resembling high altitude hypoxia severely affects the CNS and results in several physiological changes. The hippocampus is closely associated with learning and memory and an insult to this region affects cognition. Previous studies suggest that rapid or prolonged exposures to HBH are associated with psychomotor and cognitive impairments. The defense personnel, mountain climbers and rescue teams are exposed to such harsh environment and thus it demands a systematic study emphasizing the subtle effects of such extreme environments on cognitive function. Accordingly, this study evaluated the effect of hypobaric hypoxia on structural changes in the principal neurons of the hippocampus and learning in eight-arm radial maze. Adult male Wistar rats, subjected to simulated hypobaric hypoxia equivalent to an altitude of 6000 m for a period of 2 or 7 days, in a hypoxic chamber served as hypoxic group (HY). Rats housed in a similar chamber for the same period of time, without hypoxic exposure served as sham control (SC), while normal control (NC) group of rats were housed in standard laboratory conditions. The dendritic morphology of neurons in cornu ammonis region 1 (CA1) and cornu ammonis region 3 (CA3) was studied in Golgi-impregnated hippocampal sections. Exposure for 2 days to hypobaric hypoxia had minimal deleterious effects on the CA1 pyramidal neurons, while exposure for 7 days resulted in a significant decrease in the number of branching points, intersections and dendritic length. Unlike the CA1 pyramidal neurons, the CA3 neurons exhibited dendritic atrophy following both 2 and 7 days of hypoxic exposure. Further, hippocampal-dependent spatial learning was affected marginally following 2 day exposure, while 7 day exposure severely affected learning of the partially baited radial arm maze task. Our study suggests that dendritic atrophy in the hippocampus on exposure to HBH could be one of the bases for the cognitive deficits exhibited under such conditions. [Copyright &y& Elsevier]