3,596 research outputs found
Construction of capital procurement decision making model to optimize supplier selection using Fuzzy Delphi and AHP-DEMATEL
Purpose – Supplier selection for capital procurement is a major strategic decision for any automobile company. The decision determines the success of the company and must be taken systematically with the utmost transparency. Therefore, the aim of this study is the construction of capital procurement decision making models to optimize supplier selection in the Indian automobile industry. Design/methodology/approach – To achieve the stated objective, a combined approach of fuzzy theory and AHP-DEMATEL is applied. Evaluation parameters are identified through an extensive literature review and criteria validation has been introduced through a Fuzzy Delphi method by using fuzzy linguistic scales to handle the vagueness of information. AHP is employed to find the priority weight of criteria although an inter-relationship map among criteria is not possible through AHP alone since it considers all criteria as independent. To overcome this, DEMATEL is used to establish cause-effect relationships among criteria. Findings – The results show that the total cost of ownership is the first weighted criterion in supplier selection for capital procurement, followed by manufacturing flexibility and maintainability, then conformity with requirement. The cause-effect model shows that supplier profile, total cost of ownership, service support and conformity with requirement are in the cause group and are considered to be the most critical factors in selecting the supplier. Originality/value – The study’s outcome can help the automobile industry to optimize their selection process in selecting their suppliers for capital procurement; the proposed model can provide guidelines and direction in this regard.N
Mechanisms involved in regulation of MHC class I molecules in murine embryonic stem cells
Major histocompatibility complex (MHC) is at the center of immune responses that support survival, fitness and adaptation of mammalian species to the environment. These molecules are not only crucial for adaptive and innate immune responses against microorganisms and cancer cells but also play an important role in reproduction process and development of embryo during the preimplantation period. In the present study, we use murine embryonic stem cells (ESCs) as model to dissect the molecular mechanism involved in the regulation of MHC class I molecules during differentiation in vitro. MHC class I molecules are expressed at very low levels on murine ESCs and they are not induced by the immunomodulatory cytokine interferon gamma (IFN) despite the presence of IFN receptors on their cell surface. First, we showed that removal of leukemia inhibitory factor (LIF), a standard component of murine ES cell culture media required for the maintenance of a pluripotent state, did not result in up regulation of MHC class I expression in murine ESCs, presumably due to incomplete inactivation under these experimental conditions of STAT3 signaling pathway, which is used by LIF. However, the addition of LIF to differentiated cells in embryoid bodies strongly suppressed the expression of these molecules. Down regulation of STAT3 in undifferentiated ESCs cultured in the presence of LIF significantly increased the expression of MHC class I molecules and this was further enhanced by IFN treatment. Flow cytometric analysis revealed that STAT1 is phosphorylated by IFN in STAT3 knockdown (KD) ESCs, whereas there was only weak or no phophorylation detected in mock siRNA 647-treated ESCs exposed to IFN. Luciferase reporter assay also indicated that GAS promoter responded to IFN much strongly in STAT3-depleted ESCs than in intact cells, suggesting that ESCs do not respond to IFN at least partially due to inhibitory effects of STAT3-signaling components on STAT1-phosphorylation. Moreover, the down regulation of suppressor of cytokine signaling 3 (SOCS3) in STAT3 KD ESCs increases the possible regulation of STAT1 phosphorylation by SOCS3. No effect in MHC class I molecules induction was observed in STAT3 KD ES-derived cardiomyocytes (ESCMs) indicating the differential regulation of these molecules during the course of differentiation from undifferentiated stage (ESCs) to differentiated stage (ESCMs).
An additional mechanism by which STAT3 regulates MHC class I expression may involve epigenetic modification of MHC class I gene expression since Dnmt knockout (KO) murine ESCs showed upregulation of MHC class I molecules. Chromatin modifying gene Eed1 but not Dnmt1 and Jmjd1 was significantly downregulated in STAT3 KD murine ESCs. Additionally, murine ESCs showed increased MHC class I expression and enhanced response to IFN after treatment with the DNA-methyltransferase inhibitor 2,5-azacytidine and histone deacetylase inhibitor Trichostatin A.
Modulation of MHC class I expression by STAT3 KD in ESCs reduced their lysis by activated syngeneic NK cells and increased their lysis by cytotoxic T cells compared to mock siRNA 647-treated ESCs. These data indicate that STAT3 pathway plays a dual role in modulating the MHC class I expression in ESCs. Interfering with the inhibitory pathways that suppress MHC class I expression in pluripotent ESCs may help to control teratoma formation from contaminating ESCs in therapeutic cell transplants and may also help to eradicate cancer cells and virus-infected cells that are known to frequently evade immune recognition by down regulating the MHC class I expression
Investigations on Properties of Glass Fibre Reinforced Polymer Composite
The aim of present study is to investigate the water absorption, mechanical and thermal properties of glass fibre reinforced polymer composites (GFRPCs). Multi layers of woven glass fibres are reinforced into epoxy matrix to prepare the composites by hand lay-up technique. Water absorption properties are investigated in terms of percentage of water uptake, and sorption, diffusion and permeability coefficients. On the other hand, mechanical properties are investigated in terms of tensile, flexural and impact test as per ASTM standards. Moreover, thermal properties are investigated using thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The results have been shown that water absorption, mechanical and thermal properties are increased with increase in numbers of layers of woven glass fibres in epoxy matrix
Biochemical Evaluation of Forage Sorghum for Stress Tolerance
Abiotic stresses are the major limiting factors in plant growth. With continuous increment in scarcity of water and increased salinization of soil and water, it is estimated that more than 50% of all arable lands will be affected by salinity and drought by 2050. Plants are often exposed to both, soil and atmospheric water deficit during their life cycle. The frequency and intensity of droughts is increasing as a result of global climate change. Understanding how plants respond to water stress is thus crucial for the estimation of impacts of climate change on crop productivity and ecosystem functioning. The knowledge about the mechanism adapted by plant to respond to drought, salt and co-occurring stresses can play an important role in stabilizing crop performance under drought and saline conditions. Sorghum (Sorghum bicolor L.) is an important crop in many parts of the world. It is utilized as food, fodder and several industrial purposes. In general, sorghum is known to be more tolerant to any stresses including heat, drought, salinity and flooding
S-Acylation of the cellulose synthase complex is essential for its plasma membrane localization.
Plant cellulose microfibrils are synthesized by a process that propels the cellulose synthase complex (CSC) through the plane of the plasma membrane. How interactions between membranes and the CSC are regulated is currently unknown. Here, we demonstrate that all catalytic subunits of the CSC, known as cellulose synthase A (CESA) proteins, are S-acylated. Analysis of Arabidopsis CESA7 reveals four cysteines in variable region 2 (VR2) and two cysteines at the carboxy terminus (CT) as S-acylation sites. Mutating both the VR2 and CT cysteines permits CSC assembly and trafficking to the Golgi but prevents localization to the plasma membrane. Estimates suggest that a single CSC contains more than 100 S-acyl groups, which greatly increase the hydrophobic nature of the CSC and likely influence its immediate membrane environment.Biotechnology and Biological Sciences Research Council (Grant IDs: BB/H012923/1, BB/M004031/1, BB/M024911/1); Gatsby Charitable FoundationThis is the author accepted manuscript. The final version is available from the American Association for the Advancement of Science via http://dx.doi.org/10.1126/science.aaf400
Synthesis, Characterization and Anti-Microbial Activity of Indole Derivatives
Indoles are probably the most widely distributed heterocyclic compound in nature. Tryptophan and essential amino acid as such is constituent of most proteins. Starting materials were identified by physical, chromatographic and spectral analysis. For substituted isonitroso acetanilide 3.6 gm (0.05M) of chloral hydrate and 48 ml of purified water was taken in it. Then 44 gm of crystallized anhydrous sodium sulfate was added in it and a solution of substituted aniline (0.05 M) in 12 ml of water with 1.7 ml (0.052M) of concentrated hydrochloric acid was added to dissolve the amine, and finally, a solution of 4.5gm (0.158M) of hydroxylamine hydrochloride in 20 ml of water.for preparation of substituted isatin from substituted isonitroso acetanilide 32.5 ml of concentrated sulfuric acid was warmed upto 50°C in a 100 ml round bottom flask with continuous stirring, and 7.5 gram of (0.046 M) of dry substituted isonitroso acetanilide was added to such a rate that to keep the temperature 60-70 but not higher. All synthesized final products were screened for in vitro antibacterial activity [ 13-19, 20-22] against four bacterial strains, namely Staphylococcus aureus (MTCC 96), Staphylococcus pyogenus, Pseudomonas aeruginosa (MTCC 1688), Escherichia coli (MTCC 443) and two fungal strains, namely Candida albicans (MTCC 227) and Aspergilla niger (MTCC 282). in-vitro antimicrobial activity with the zone Inhibition in mm 24±2 and activity index 0.89, against Staphylococcus aureus, 22±2 and 0.85 against Staphylococcus pyogenes, 26±2 and 0.96 against Pseudomonas aeruginos, 25±3 and 0.86 against Escherichia coli and two fungal strains shown 26±4 and 0.81 against Candida albicans and 14±2 & 0.88 against Aspergilla niger respectively.
Keywords: Indole, Isatin, Antibacterial activity, Staphylococcus aureus
Study of epidemiological aspects and hormone receptor status of meningiomas
Background: Meningiomas account for about a third of all central nervous system tumours worldwide. Though very common, quite less is known about its epidemiology. This study aims to establish the epidemiological parameters and hormone receptor status (Progesterone Receptor-PR) involved in the development of Meningiomas.Methods: This observational study included 50 patients. Epidemiological parameters studied included age, sex, symptoms, history of hormone intake, smoking, recurrence, family history, history of other hormone related tumours and radiological assessment of tumour site. Surgical samples were grossed and typed according to the WHO standards. Immunohistochemical staining was done using PR to establish the role of hormonal receptors in the development of meningiomas.Results: The mean age was 46.84±13.54 years. The ratio of male and female (Male:Female) was 1.0:2.3. 48.5% of females had history of hormonal pill intake and 28.6% had hormone related tumours, of which fibroid was most common. Amongst the sites involved cerebral convexity was most common (56%). Chi-square (χ2) test showed that there was a significant association between histological grade and PR expression of the patients (p=0.0002).Conclusions: Positivity for hormone receptors like PR, increased intake of hormonal pills by females and association of meningioma with hormone related tumours indicates that hormonal milieu plays a significant role in the growth of meningiomasχχ. This could thus provide an insight to the pathogenesis of meningiomas. In addition, mifepristone, an anti-progestin could be a player in the medical management of meningiomas
Effect of Stacking Sequence on Flexural and Dynamic Mechanical Properties of Hybrid Sisal/Glass Polyester Composite
In present study, flexural properties in terms of break load, percentage elongation, flexural strength and flexural modulus, and dynamic mechanical analysis (DMA) in terms of storage modulus (), loss modulus (), damping , glass transition temperature and effectiveness constant of reinforcement of hybrid sisal/glass fibre reinforced polyester composite are investigated. Polyester based hybrid composites are prepared by Hand lay-up technique followed by static compression having constant 25 wt.% of fibre content with various stacking sequences. A significant improvement in flexural properties of sisal fibre reinforced polyester composite is observed by incorporation of glass fibre. In addition, the stacking sequence has great influences on flexural and dynamic mechanical properties of hybrid composites
- …
