41 research outputs found
Effects of Cyclic Strain and Growth Factors on Vascular Smooth Muscle Cell Responses
Under physiological and pathological conditions, vascular smooth muscle cells (SMC) are exposed to different biochemical factors and biomechanical forces. Previous studies pertaining to SMC responses have not investigated the effects of both factors on SMCs. Thus, in our research we investigated the combined effects of growth factors like Bfgf (basic fibroblast growth factor), TGF-β (transforming growth factor β) and PDGF (platelet-derived growth factor) along with physiological cyclic strain on SMC responses. Physiological cyclic strain (10% strain) significantly reduced SMC proliferation compared to static controls while addition of growth factors bFGF, TGF-β or PDGF-AB had a positive influence on SMC growth compared to strain alone. Microarray analysis of SMCs exposed to these growth factors and cyclic strain showed that several bioactive genes (vascular endothelial growth factor, epidermal growth factor receptor, etc.) were altered upon exposure. Further work involving biochemical and pathological cyclic strain stimulation will help us better understand the role of cyclic strain and growth factors in vascular functions and development of vascular disorders
Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial
Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council
Fusion of PET and MRI images using adaptive neuro-fuzzy inference system
651-656Fusion of the PET and MRI images provides complete
information, better visualization and higher diagnostic accuracy. This paper
proposes the fusion of PET and MRI images using adaptive neuro-fuzzy inference
system. The PET and MRI images areinitially decomposed using the second
generation wavelets. The second generation wavelet transform is shift
invariant. The second generation wavelet coefficients are then fused using the
adaptive neuro-fuzzy inference system. Then the inverse transform is applied to
the fused coefficients and the fused image is obtained. The performance of this
algorithm is validated both qualitatively and quantitatively. The metrics used
for the analysis are entropy, average gradient, average, standard deviation,
mean square error and peak signal to noise ratio. It is also compared with the
existing methods of image fusion. The proposed algorithm extracts more
information from the source images, provides better
contrast and brightness as compared to the existing fusion techniques
Simulation and Study of Power Quality Issues in a Fixed Speed Wind Farm Substation
Power quality issues associated with the fixed speed wind farm substation located at Coimbatore district are investigated as the wind generators are tripping frequently. The investigations are carried out using two power quality analyzers, Fluke 435 and Dranetz PX5.8, with one of them connected at group control breaker of the 110 kV feeder and the other at the selected 0.69 kV generator busbar during the period of maximum power generation. From the analysis of the recorded data it is found that sag, swell, and transients are the major events which are responsible for the tripping of the generators. In the present study, simulation models for wind, turbine, shaft, pitch mechanism, induction generator, and grid are developed using DIgSILENT. Using the turbine characteristics, a two-dimensional lookup table is designed to generate a reference pitch angle necessary to simulate the power curve of the passive stall controlled wind turbine. Various scenarios and their effects on the performance of the wind farm are studied and validated with the recorded data and waveforms. The simulation model will be useful for the designers for planning and development of the wind farm before implementation
Modeling, simulation and experimental analysis of permanent magnet brushless DC motors for sensorless operations
This paper presents a simplified modeling, simulation and Experimental analysis of permanent magnet brushless dc motors (PMBLDC) for sensorless operation. This model provides a mechanism for monitoring and controlling of voltage, current, Speer and torque. The sensorless scheme employs direct back emf based zero crossing detection for controlling the dynamic characteristics
Efficient feature point detection in CT images using Discrete Curvelet Transform
312-315In
this work, a multi-scale feature point detection algorithm in CT slices based
on discrete curvelet transform is presented. Discrete curvelet transformation
is applied to input CT slices and the behavior of curvelet coefficients in all
the scales are examined. The information in the fine and detail levels which
contains the edge and singularity details are processed to extract the feature
points. Performance comparison is made against wavelet and canny edge detectors
based on SSIM index
Micro-irrigation and capacity building: a success story of TNDRIP.
In Palanisami, Kuppannan; Raman, S.; Mohan, Kadiri (Eds.). Micro-irrigation: economics and outreach. New Delhi, India: Macmilla
Not Available
Not AvailableThe 4 (L) distributory of Pollachi main canal, Parambikulam-Aliyar-Palar (PAP) basin
has been selected for an in-depth water management study. The project area has been divided into
two zones namely, A zone and B zone. Each zone would get water from the canal system once in
every two years. From the analysis of rainfall data of the rain gauge stations located in
Parambikulam-Aliyar-Palar basin, it was observed that there was a wide temporal and spatial
variability in annual rainfall over the years. The lowest annual rainfall recorded was 210.6 mm
(over the plain) in 2003 and the highest of 5346.4 mm (in the hills) in 2007. The average annual
rainfall for the period 1988-2010 was 1372.1 mm. The irrigation water requirement for the crops
grown in the 4 (L) distributory was estimated using AquaCrop3.1 model for the years 2000-2010.
The total irrigation water requirement during deficit rainfall year (2002) was 58.4 percent which
is higher compared to normal year (2008). During the excess rainfall year (2007), the demand
was 5.32 percent lower than the normal year demand. Therefore, the conjunctive use management
of surface and groundwater resources in a command area can play a significant role in managing
water by distributing the water throughout the season, while also maintaining the long-term
sustainability of groundwater resources.Not Availabl
A Microprocessor-Based Full Voltage Starting of Induction Motor with Switched Capacitors
A widespread glutamine-sensing mechanism in the plant kingdom
Glutamine is the primary metabolite of nitrogen assimilation from inorganic nitrogen sources in microorganisms and plants. The ability to monitor cellular nitrogen status is pivotal for maintaining metabolic homeostasis and sustaining growth. The present study identifies a glutamine-sensing mechanism common in the entire plant kingdom except Brassicaceae. The plastid-localized PII signaling protein controls, in a glutamine-dependent manner, the key enzyme of the ornithine synthesis pathway, N-acetyl-l-glutamate kinase (NAGK), that leads to arginine and polyamine formation. Crystal structures reveal that the plant-specific C-terminal extension of PII, which we term the Q loop, forms a low-affinity glutamine-binding site. Glutamine binding alters PII conformation, promoting interaction and activation of NAGK. The binding motif is highly conserved in plants except Brassicaceae. A functional Q loop restores glutamine sensing in a recombinant Arabidopsis thaliana PII protein, demonstrating the modular concept of the glutamine-sensing mechanism adopted by PII proteins during the evolution of plant chloroplasts