Investigation on influence of SiCp on three-body abrasive wear behaviour of glass/epoxy composites

The present study present the influence of SiCp incorporation on three-body abrasive wear behavior of glass/epoxy composites. The investigations was carried out using dry sand rubber wheel abrasive wear test apparatus. 2k factorial design of experiment was used to capture the experimental data. The parameters considered are abrading distance, load and speed. The wear volume loss  found to increase with the increasing values of wear parameters. The applied load has exhibited significant effect on volume loss. Incorporation of SiCp contributed to enhance wear resistance of glass/epoxy composites. The linear regression was also presented in the study to correlate abrasion parameters with wear volume loss. SEM image analysis of abraded surface revealed the occurrence of ploughing, micro-cutting, matrix removal and fiber breakage

Natural product inhibitors of ocular angiogenesis

Natural products are characterized by high chemical diversity and biochemical specificity; therefore, they are appealing as lead compounds for drug discovery. Given the importance of angiogenesis to many pathologies, numerous natural products have been explored as potential anti-angiogenic drugs. Ocular angiogenesis underlies blinding eye diseases such as retinopathy of prematurity (ROP) in children, proliferative diabetic retinopathy (DR) in adults of working age, and age-related macular degeneration (AMD) in the elderly. Despite the presence of effective therapy in many cases, these diseases are still a significant health burden. Anti-VEGF biologics are the standard of care, but may cause ocular or systemic side effects after intraocular administration and patients may be refractory. Many anti-angiogenic compounds inhibit tumor growth and metastasis alone or in combination therapy, but a more select subset of them has been tested in the context of ocular neovascular diseases. Here, we review the promise of natural products as anti-angiogenic agents, with a specific focus on retinal and choroidal neovascularization. The multifunctional curcumin and the chalcone isoliquiritigenin have demonstrated promising anti-angiogenic effects in mouse models of DR and choroidal neovascularization (CNV) respectively. The homoisoflavanone cremastranone and the flavonoid deguelin have been shown to inhibit ocular neovascularization in more than one disease model. The isoflavone genistein and the flavone apigenin on the other hand are showing potential in the prevention of retinal and choroidal angiogenesis with long-term administration. Many other products with anti-angiogenic potential in vitro such as the lactone withaferin A, the flavonol quercetin, and the stilbenoid combretastatin A4 are awaiting investigation in different ocular disease-relevant animal models. These natural products may serve as lead compounds for the design of more specific, efficacious, and affordable drugs with minimal side effects

Parametric optimization MRR and surface roughness in wire electro discharge machining (WEDM) of D2 steel using Taguchi based utility approach

Abstract: This paper reports the effect of process parameters on material removal rate (MRR) and surface roughness (Ra) in wire electro discharge machining of AISI D2 steel. The experiments were performed by different cutting conditions of pulse on time (Ton), pulse off time (Toff), servo voltage (SV) and wire feed (WF) by keeping workpiece thickness constant. Taguchi L27 orthogonal array of experimental design is employed to conduct the experiments. Multi-objective optimization was performed using Taguchi based utility approach to optimize MRR and Ra. Analysis of means and variance on to signal to noise ratio was performed for determining the optimal parameters. It reveals that the combination of Ton3, Toff1, SV1, WF2 parameter levels is beneficial for maximizing the MRR and minimizing the Ra simultaneously. The results indicated that the pulse on time is the most significant parameter affects the MRR and Ra. The melted droplets, solidified debris around the craters, cracks, and blow holes were observed on the machined surface for a higher pulse on time and lower servo voltage. Recast layer thickness increased from an increase in pulse on time duration. The machined surface hardness of D2 steel is increased due to the repetitive quenching effect and formation oxides on the machined surface

A Single Day of 5-Azacytidine Exposure during Development Induces Neurodegeneration in Neonatal Mice and Neurobehavioral Deficits in Adult Mice

The present study was undertaken to evaluate the immediate and long-term effects of a single-day exposure to 5-Azacytidine (5-AzaC), a DNA methyltransferase inhibitor, on neurobehavioral abnormalities in mice. Our findings suggest that the 5-AzaC treatment significantly inhibited DNA methylation, impaired extracellular signal-regulated kinase (ERK1/2) activation and reduced expression of the activity-regulated cytoskeleton-associated protein (Arc). These events lead to the activation of caspase-3 (a marker for neurodegeneration) in several brain regions, including the hippocampus and cortex, two brain areas that are essential for memory formation and memory storage, respectively. 5-AzaC treatment of P7 mice induced significant deficits in spatial memory, social recognition, and object memory in adult mice and deficits in long-term potentiation (LTP) in adult hippocampal slices. Together, these data demonstrate that the inhibition of DNA methylation by 5-AzaC treatment in P7 mice causes neurodegeneration and impairs ERK1/2 activation and Arc protein expression in neonatal mice and induces behavioral abnormalities in adult mice. DNA methylation-mediated mechanisms appear to be necessary for the proper maturation of synaptic circuits during development, and disruption of this process by 5-AzaC could lead to abnormal cognitive function

Studies on wear resistance of PTFE filled with glass and bronze particles based on Taguchi technique

An attempt has been made to study the influence of wear parameters like applied load, sliding speed, sliding distance on the dry sliding wear of polytetrafluroethylene (PTFE), PTFE + 25% glass and PTFE + 40% bronze composites. Experiments, based on the techniques of Taguchi, were performed to acquire data in a controlled way. An orthogonal array and the analysis of variance were employed to investigate the influence of process parameters on the wear of composites. The worn surfaces were examined using scanning electron microscope (SEM). The experimental results show that sliding distance and applied load were found to be the more significant factors among the other control factors on wear. The objective is to establish a correlation between dry sliding wear of composites and wear parameters. These correlations were obtained by multiple regressions. A good agreement between the predicted and actual wear resistance was seen

Stimulation of cannabinoid receptor agonist 2-arachidonylglycerol by chronic ethanol and its modulation by specific neuromodulators in cerebellar granule neurons

AbstractIn an earlier study, we reported that chronic ethanol (EtOH) stimulates the formation of anandamide in human SK-N-SH cells. In the present study, we investigated the effect of chronic EtOH on the formation of yet another cannabinoid receptor (CB1) agonist, 2-arachidonylglycerol (2-AG), in cerebellar granule neurons (CGNs). The formation of 2-[3H]AG without any stimulation was more pronounced in the older cultures than in younger cultures. Exposure of CGNs to EtOH led to a significant increase in the level of 2-[3H]AG (P<0.05). Incubation with the anandamidehydrolase inhibitor phenylmethylsulfonyl fluoride and EtOH did result in an additive increase in 2-[3H]AG, but did not with E-6-(bromomethylene)tetrahydro-3-(1-naphthelenyl)-2H-pyran-2-one. The formation of 2-[3H]AG was enhanced by ionomycin in both the control and EtOH-exposed CGNs, and the ionomycin-stimulated 2-[3H]AG synthesis was inhibited by the intracellular chelating agent 1,2-bis(2-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid. Further, glutamate increased the formation of 2-[3H]AG only in control CGNs. MK-801 inhibited the EtOH-induced 2-[3H]AG synthesis, suggesting the participation of intracellular Ca2+ in EtOH-induced 2-[3H]AG synthesis. The dopamine receptor (D2) agonist did not modify the 2-AG synthesis in either the control or EtOH-exposed CGNs. However, the D2 receptor antagonist inhibited the EtOH-induced formation of 2-[3H]AG. The EtOH-induced 2-[3H]AG formation was inhibited by SR141716A and pertussis toxin, suggesting the CB1 receptor- and Gi/o-protein-mediated regulation of 2-AG. The observed increase in 2-AG level in CGNs is possibly a mechanism for neuronal adaptation to the continuous presence of EtOH. These findings indicate that some of the pharmacological actions of EtOH may involve alterations in the endocannabinoid signaling system

Epigenetic Mechanisms in Developmental Alcohol-Induced Neurobehavioral Deficits

Alcohol consumption during pregnancy and its damaging consequences on the developing infant brain are significant public health, social, and economic issues. The major distinctive features of prenatal alcohol exposure in humans are cognitive and behavioral dysfunction due to damage to the central nervous system (CNS), which results in a continuum of disarray that is collectively called fetal alcohol spectrum disorder (FASD). Many rodent models have been developed to understand the mechanisms of and to reproduce the human FASD phenotypes. These animal FASD studies have provided several molecular pathways that are likely responsible for the neurobehavioral abnormalities that are associated with prenatal alcohol exposure of the developing CNS. Recently, many laboratories have identified several immediate, as well as long-lasting, epigenetic modifications of DNA methylation, DNA-associated histone proteins and microRNA (miRNA) biogenesis by using a variety of epigenetic approaches in rodent FASD models. Because DNA methylation patterns, DNA-associated histone protein modifications and miRNA-regulated gene expression are crucial for synaptic plasticity and learning and memory, they can therefore offer an answer to many of the neurobehavioral abnormalities that are found in FASD. In this review, we briefly discuss the current literature of DNA methylation, DNA-associated histone proteins modification and miRNA and review recent developments concerning epigenetic changes in FASD

Comparison of Microstructure and Properties of Modified 9Cr-1Mo Welds Produced by Narrow Gap Hot Wire and Cold Wire Gas Tungsten Arc Welding Processes

AbstractModified 9Cr-1Mo material is used as principal material of construction of Steam Generators (SG) for India's first of its kind 500MWe Prototype Fast Breeder Reactor (PFBR).The fabrication of Steam Generators is carried out by combination of hot wire and cold wire Gas Tungsten Arc Welding (GTAW) processes. Eventhough welds were meeting the specification requirements, limited information available on hot wire GTAW process in open literature motivated authors for characterization of welds produced using this specialized technique. The impact properties at 0°Cof modified 9Cr-1Mo welds produced by hot wire GTAW processis found inferior compared to welds produced by cold wire GTAW process. The properties such as tensile strength, hardness, impact toughness at +18°C were found almost comparable for the welds produced by both the welding processes. This paper characterizes the microstructure and various mechanical properties of modified 9Cr-1Mo welds produced by narrow gap hot wire and cold wire GTAWprocesses

Performance Evaluation of Common Rail Direct Injection (CRDI) Engine Fuelled with Uppage Oil Methyl Ester (UOME)

For economic and social development of any country energy is one of the most essential requirements. Continuously increasing price of crude petroleum fuels in the present days coupled with alarming emissions and stringent emission regulations has led to growing attention towards use of alternative fuels like vegetable oils, alcoholic and gaseous fuels for diesel engine applications. Use of such fuels can ease the burden on the economy by curtailing the fuel imports. Diesel engines are highly efficient and the main problems associated with them is their high smoke and NOx emissions. Hence there is an urgent need to promote the use of alternative fuels in place of high speed diesel (HSD) as substitute. India has a large agriculture base that can be used as a feed stock to obtain newer fuel which is renewable and sustainable. Accordingly Uppage oil methyl ester (UOME) biodiesel was selected as an alternative fuel. Use of biodiesels in diesel engines fitted with mechanical fuel injection systems has limitation on the injector opening pressure (300 bar). CRDI system can overcome this drawback by injecting fuel at very high pressures (1500-2500 bar) and is most suitable for biodiesel fuels which are high viscous. This paper presents the performance and emission characteristics of a CRDI diesel engine fuelled with UOME biodiesel at different injection timings and injection pressures. From the experimental evidence it was revealed that UOME biodiesel yielded overall better performance with reduced emissions at retarded injection timing of -10° BTDC in CRDI mode of engine operation

Assessment of knowledge, attitude and practices of universal precautions among medical and nursing students

Background: Universal precautions is an approach to infection control to treat all human blood and certain human body fluids as if they were known to be infectious for HIV, HBV and other bloodborne pathogens. The CDC recommends Standard Precautions for the care of all patients, regardless of their diagnosis or presumed infection status. Health care personals are at risk of being exposed to blood-borne pathogens. The aim of the study to determine the knowledge, attitude and practice of medical and nursing students towards universal precautions.Methods: A cross-sectional survey was carried out at S. S. Institute of Medical Sciences and Research Centre, Davangere, Karnataka. The participants were medical and Nursing undergraduate students. A questionnaire was prepared based on the WHO and CDC guidelines on Universal Precautions and was validated and pre-tested before finalization. Degree of knowledge was ascertained by means of yes-no questions on each item being evaluated.Results: All students were aware of Universal precautions, but soundness of their knowledge is very poor. Compliance in Universal precautions is good to average in nursing students but poor to average in medical students.Conclusions: It can be concluded that interventions to improve Universal precautions among medical students, nursing students urgently needed. So, there is a need for developing strategies to promote the use of Universal precautions which take into account behaviour change and accuracy of knowledge including its integration into practice. Teaching universal precautions early in their curriculum is necessary for better learning and practices during their posting