710 research outputs found
FAILURE MODES AND EFFECTS ANALYSIS OF DRIVING MECHANISM IN HORIZONTAL PLANNING MACHINE
In this paper the failure analysis and optimization of horizontal mechanism in a horizontal planning machine rack and pinion arrangement is needed for the translation movement. The relative motion between the fixed and movable bed are being in friction with the ability of V guide ways. And the drive of this mechanism is rack and pinion arrangement. In general, wear occurring in V-Guides ways and drive mechanism are not equal. So that, the variation of the wear amount should affect the surface level of to be machined component. The failure is rectified to implement the new mechanism (arrangement) in driven portion of the horizontal mechanism. The main concept of this paper is that the surface level of the machined component has to be fine. The modification of the mechanism is to change the position of gear rack and pinion. In existing, the gear tooth is in horizontal and crosswise to the guide ways. Instead of that, the gear tooth is perpendicular to the guide ways. If the wear occurred in this modified one, the gear engaging length will increase. The modified mechanism does not affect the addendum and dedundum of the gear profile
First results from the CAWSES-India Tidal Campaign
The first CAWSES-India Tidal Campaign was conducted by the Indian scientific community during March–April 2006. The objectives of this campaign were: (1) To determine the characteristics of tides in the troposphere and lower stratosphere (0–20 km) and mesosphere and lower thermosphere (MLT) region (80–100 km), (2) to explore and identify what lower atmospheric processes drive middle atmospheric tides in the Indian continental region and (3) to provide information on those short-term variabilities of MLT tides that are likely to have an impact on the ionospheric variabilities and contribute to the upper atmospheric weather. Data sets from experiments conducted at the three low latitude radar sites, namely, Trivandrum (8.5° N, 76.9° E), Tirunelveli (8.7° N, 77.8° E) and Gadanki (13.5° N, 79.2° E) and fortnightly rocket launches from Thumba were made use of in this study. An important observational finding reported in this work is that the radar observations at Tirunelveli/Trivandrum indicate the presence of 15–20 day modulation of diurnal tide activity at MLT heights during the February–March period. A similar variation in the OLR fields in the western Pacific (120–160° longitude region) suggests a possible link between the observed tidal variabilities and the variations in the deep tropical convection through the nonmigrating tides it generates
Calibration of YSZ Sensors for the Measurement of Oxygen Concentration in Liquid Pb-Bi Eutectic
Although liquid lead-bismuth eutectic (LBE) is a good candidate for coolant in the subcritical transmutation blanket, it is known to be corrosive to stainless steel, the material of the carrying tubes and containers. Such longterm corrosion problem can be prevented by producing and maintaining a protective oxide layer on the exposed surface of stainless steel. For this purpose, it is required to accurately control the concentration of oxygen dissolved in LBE. Currently, YSZ (Yttria Stabilized Zirconia) oxygen sensors, based on an existing automotive oxygen sensor, with molten bismuth saturated with oxygen as the reference, have been selected for oxygen-concentration measurement. The oxygen concentration difference across the solid electrolyte and the resultant oxygen ion conduction inside the electrolyte establishes an electromagnetic force that is used to measure the ppb level concentration of oxygen dissolved in liquid LBE. A set of calibration curves of voltage vs. temperature ranging from 300 0C to 500 0C under various oxygen concentrations in liquid LBE for the YSZ oxygen sensor has been obtained and is presented in this paper. Although the current calibration strategy using the direct injection of hydrogen and oxygen is still inadequate to determine the oxygen concentration in the system, we have found a good candidate for our purpose, which is varying hydrogen to water steam ratio in the system
3′-Benzoyl-1′-methyl-4′-phenylspiro[acenaphthylene-1(2H),2′-pyrrolidin]-2-one
In the title compound, C29H23NO2, the pyrrolidine ring adopts a twisted conformation about one of the C—N bonds. The acenaphthone ring (r.m.s. deviation = 0.025 Å) lies almost perpendicular to the pyrrolidine ring [dihedral angle = 88.08 (8)°]. The dihedral angle between the phenyl rings is 88.12 (11)°. In the crystal structure, weak C—H⋯π interactions connect the molecules
A Glycosaminoglycan Based, Modular Tissue Scaffold System for Rapid Assembly of Perfusable, High Cell Density, Engineered Tissues
The limited ability to vascularize and perfuse thick, cell-laden tissue constructs has hindered efforts to engineer complex tissues and organs, including liver, heart and kidney. The emerging field of modular tissue engineering aims to address this limitation by fabricating constructs from the bottom up, with the objective of recreating native tissue architecture and promoting extensive vascularization. In this paper, we report the elements of a simple yet efficient method for fabricating vascularized tissue constructs by fusing biodegradable microcapsules with tunable interior environments. Parenchymal cells of various types, (i.e. trophoblasts, vascular smooth muscle cells, hepatocytes) were suspended in glycosaminoglycan (GAG) solutions (4%/1.5% chondroitin sulfate/carboxymethyl cellulose, or 1.5 wt% hyaluronan) and encapsulated by forming chitosan-GAG polyelectrolyte complex membranes around droplets of the cell suspension. The interior capsule environment could be further tuned by blending collagen with or suspending microcarriers in the GAG solution These capsule modules were seeded externally with vascular endothelial cells (VEC), and subsequently fused into tissue constructs possessing VEC-lined, inter-capsule channels. The microcapsules supported high density growth achieving clinically significant cell densities. Fusion of the endothelialized, capsules generated three dimensional constructs with an embedded network of interconnected channels that enabled long-term perfusion culture of the construct. A prototype, engineered liver tissue, formed by fusion of hepatocyte-containing capsules exhibited urea synthesis rates and albumin synthesis rates comparable to standard collagen sandwich hepatocyte cultures. The capsule based, modular approach described here has the potential to allow rapid assembly of tissue constructs with clinically significant cell densities, uniform cell distribution, and endothelialized, perfusable channels
Single tertiary care centre experience of ovarian granulosa cell tumour in Chennai, India: a retrospective analysis
Background: Granulosa cell tumours of ovary are rare sex-cord stromal tumours characterized by long natural history and favourable prognosis. The present study was done to evaluate the clinical presentation, treatment, outcome, and prognostic factors for patients diagnosed as granulosa cell tumours.Methods: A Retrospective study of Granulosa cell tumour of the ovary was done for a period of five years from January 2011 to December 2015 at a tertiary care centre, Institute of Obstetrics and Gynaecology, Madras Medical College, Chennai. The clinical data and the treatment details were retrieved from the records of medical oncology department and the data were analysed.Results: Twenty five patients were diagnosed as granulose cell tumours of ovary during the study period. The median patient age was 48 years. The most common clinical presentation at diagnosis was vaginal bleeding (76%) followed by abdominal pain (40%). Mean tumor size was 9.6cm. The majority of patients were diagnosed in FIGO stage Ia (84%, n = 21). Thirteen patients (52%) underwent complete staging laparotomy. Twenty three patients (92%) had Adult Granulosa cell tumour. Two patients (8%)had juvenile Granulosa cell tumour. After surgery, all patients were put on observation except two patients who received adjuvant chemotherapy (EP: Etoposide, Cisplatin). The median followup period was 48 months. Five patients (20%) had recurrence; The average time to relapse was 29.6 months. Patients who had tumour size more than 9.7cm had more recurrence events (Hazard Ratio(HR):1.058), but their association is not significant (P value-0.839). The association between menopausal status, torsion of tumour mass, tumour stage with recurrence rate were not significant. The estimated mean overall survival was 84.8 months. Following univariate Cox regression modeling, survival appeared to be independent of age range, post operative residual tumour and the FIGO stage.Conclusions: Granulosa cell tumours of ovary are rare, often diagnosed in early stage. Patients who had tumour size of more than 9.7cm had more recurrence events. A prolonged post therapeutic follow-up is necessary to pick up the late relapses
Complete Design and Finite Element Analysis of an all Terrain Vehicle
We have tried to design an all terrain vehicle that meets international standards and is also cost effective at the same time. We have focused on every single system to improve the performance of each component. Our vehicle can navigate through almost all terrain, which ultimately is the objective behind the making of any all terrain vehicle. We began the task of designing by conducting extensive research of each main component of the vehicle. We did not want to design certain areas such as the frame, and then make the rest to fit. We considered each component to be significant, and thereby designed the vehicle as a whole trying to optimize each component while constantly considering how other components would be affected. This forced us to think outside the box, research more thoroughly, and redesign components along the way in order to have a successful design. We used the necessary parameters to create a Qualitative Function Diagram (QFD) to determine which parameters were the most critical. These key parameters ranging from most critical to least critical are safety, reliability, low cost, ease of operation and maintenance, and overall performance
Turbo-discharging turbocharged internal combustion engines
Turbo-discharging is a novel approach that can better utilize the energy recoverable by a turbine (or series of turbines) mounted in the exhaust flow of internal combustion engines. The recovery of blowdown pulse energy in isolation of displacement pulse energy allows the discharging (depressurization) of the exhaust system to reduce engine pumping work and improve engine fuel economy. This is a novel approach to air system optimization that has previously been studied for naturally aspirated engines. However, to be successful, turbo-discharging should be applicable to turbocharged engines, as downsizing is a promising direction for future powertrain systems.
This study uses one-dimensional gas dynamics modelling to explore the effect of turbo-discharging on a turbocharged gasoline engine, particularly focusing on the interaction with the turbocharging system. The results show that the peak engine torque is increased at low to mid speeds with high speed torque slightly reduced due to restrictions in engine breathing with low lift exhaust valves. The engine peak torque as a function of speed with a larger turbocharger and turbo-discharging was comparable to that of the smaller turbocharger without turbo-discharging. Fuel economy improvements were evident over most part-load regions of the engine map, with peak values varying from 2 to 7% depending on the baseline engine air system strategy. Hot trapped residual mass was consistently reduced across a large fraction of the engine map, with the exception of high power conditions, where the valve pressure drop effect dominated. This is expected to enable spark advance and further fuel economy benefit.
The results from this study are promising and show that the use of some of the available exhaust gas energy for turbo-discharging in preference to turbocharging can have a positive effect on both part-load and full-load engine performance. There remains significant potential for further optimization with application of variable valve actuation and turbocharger control systems (for example, variable geometry turbines)
Bioresponsive microspheres for on‐demand delivery of anti‐inflammatory cytokines for articular cartilage repair
Despite innovations in surgical interventions, treatment of cartilage injury in osteoarthritic joints remains a challenge due to concomitant inflammation. Obstructing a single dominant inflammatory cytokine has shown remarkable clinical benefits in rheumatoid arthritis, and similar strategies are being suggested to target inflammatory pathways in osteoarthritis (OA). Here, we describe the utility of gelatin microspheres that are responsive to proteolytic enzymes typically expressed in arthritic flares, resulting in on‐demand and spatiotemporally controlled release of anti‐inflammatory cytokines for cartilage preservation and repair. These microspheres were designed with a net negative charge to sequester cationic anti‐inflammatory cytokines, and the magnitude of the negative charge potential increased with an increase in crosslinking density. Collagenase‐mediated degradation of the microspheres was dependent on the concentration of the enzyme. Release of anti‐inflammatory cytokines from the loaded microspheres directly correlated with the degradation of the gelatin matrix. Exposure of the IL‐4 and IL‐13 loaded microspheres reduced the inflammation of chondrocytes up to 80%. Hence, the delivery of these microspheres in an OA joint can attenuate the stimulation of chondrocytes and the resulting secretion of catabolic factors such as proteinases and nitric oxide. The microsphere format also allows for minimally invasive delivery and is less susceptible to mechanically induced drug release. Consequently, bioresponsive microspheres can be an effective tool for cartilage preservation and arthritis treatment.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153665/1/jbma36852_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153665/2/jbma36852.pd
The role of glucocorticoid receptor phosphorylation in Mcl-1 and NOXA gene expression
<p>Abstract</p> <p>Background</p> <p>The cyclin-dependent kinase (CDK) and mitogen-activated protein kinase (MAPK) mediated phosphorylation of glucocorticoid receptor (GR) exerts opposite effects on GR transcriptional activity and affects other posttranslational modifications within this protein. The major phosphorylation site of human GR targeted by MAPK family is the serine 226 and multiple kinase complexes phosphorylate receptor at the serine 211 residue. We hypothesize that GR posttranslational modifications are involved in the determination of the cellular fate in human lymphoblastic leukemia cells. We investigated whether UV signalling through alternative GR phosphorylation determined the cell type specificity of glucocorticoids (GCs) mediated apoptosis.</p> <p>Results</p> <p>We have identified putative Glucocorticoid Response Elements (GREs) within the promoter regulatory regions of the Bcl-2 family members NOXA and Mcl-1 indicating that they are direct GR transcriptional targets. These genes were differentially regulated in CEM-C7-14, CEM-C1-15 and A549 cells by glucocorticoids and JNK pathway. In addition, our results revealed that the S211 phosphorylation was dominant in CEM-C7-14, whereas the opposite was the case in CEM-C1-15 where prevalence of S226 GR phosphorylation was observed. Furthermore, multiple GR isoforms with cell line specific patterns were identified in CEM-C7-14 cells compared to CEM-C1-15 and A549 cell lines with the same antibodies.</p> <p>Conclusions</p> <p>GR phosphorylation status kinetics, and site specificity as well as isoform variability differ in CEM-C7-14, CEM-C1-15, and A549 cells. The positive or negative response to GCs induced apoptosis in these cell lines is a consequence of the variable equilibrium of NOXA and Mcl-1 gene expression potentially mediated by alternatively phosphorylated GR, as well as the balance of MAPK/CDK pathways controlling GR phosphorylation pattern. Our results provide molecular base and valuable knowledge for improving the GC based therapies of leukaemia.</p
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