175 research outputs found
Internal Finishing of Aluminium Tube with Sintered Magnetic Abrasive
There has been a rapid growth in the development of harder and complex shapes to machine metals and alloys during the last few years. Conventional edged tool machining is difficult and uneconomical for such materials and degree of surface finish attainable is poor. In view of the seriousness of this problem, recently new non-conventional fine machining processes like Magnetic Abrasive Polishing, Magnetic Abrasive Flow Machining (MAFM), Magnetic Float Machining (MFM) and Magnetic Abrasive Machining (MAM), Magneto ndashRheological Machining (MRM), Chemo-Mechanical Polishing (CMP) have been developed. Among these processes lsquoMagnetic Abrasive Finishing processes are widely used for obtaining quality finish on metallic (ferrous and non ferrous) as well as non metallic (ceramics) components. MAF process has been recently used in its variant forms such as Magnetic float polishing, Magneto-rheological machining, Electrolytic magnetic polishing but the problem of development of magnetic abrasive powders is still present and efforts are in continuous progress at global to remove this problem.nbspIn the MAF method, a magnetic field is used to generate cutting force to treat the surface of a machined part. The magnetic field helps to form a flexible magnetic abrasives brush for finishing of surface.nbsp Finishing force can be controlled with magnetic field and a low surface temperature is generated during finishing operations. Magnetic abrasives are not easily available. Very few studies have been reported till date on the development of alternative magnetic abrasives. The aim of study is to evaluate the performance of developed sintered magnetic abrasives for internal finishing of aluminium tubes using MAF process. PISF is calculated nbspconsidering different variables like speed (rpm) , quantity of abrasive and gap of magnetic pole and work piece.nbsp Preparation of sintered magnetic abrasive was difficult and time consuming. The best result came at 425 rpm and quantity of abrasive used 6 gm. PISF value obtained in present case was 84 % . nbs
Association of clinical features, comorbidities and laboratory profile with outcomes among dengue patients admitted in a tertiary care hospital, Delhi NCR
Background: Dengue fever is an endemic disease across multiple countries. Dengue infection results in a wide spectrum of non-specific clinical manifestations with unpredictable clinical course and outcome. Objective of the study was to understand the association of different clinical features, comorbidities and laboratory profile with outcomes (ICU use, ventilation use and blood transfusion) among dengue patients admitted in a tertiary care hospital in Delhi, National Capital Region.Methods This cross-sectional study included 75 dengue patients with fever <1 week confirmed based on NS-1 antigen and/or IgM antibody positivity. Descriptive analysis was used.Results: Gender was not significantly associated with the outcomes. The duration of fever was significantly higher among those with ICU use (median: 6 versus 4 days; p=0.005), ventilator use (median: 5.5 versus 4.0 days; p=0.049] and blood transfusion (median: 6 versus 4 days; p=0.013). Dengue patients with co-morbidities (diabetes, hypertension, or chronic obstructive pulmonary disease) or co-infection had a significantly higher odds of the outcomes. The platelet level was significantly lower while liver enzymes were significantly higher among those with the outcomes.Conclusions: The clinical features, comorbidities and laboratory profile can help in identifying critical patients for ICU admission and timely intervention to improve outcome
The effects of hippocampal lesions on MRI measures of structural and functional connectivity.
Focal lesions can affect connectivity between distal brain regions (connectional diaschisis) and impact the graph-theoretic properties of major brain networks (connectomic diaschisis). Given its unique anatomy and diverse range of functions, the hippocampus has been claimed to be a critical "hub" in brain networks. We investigated the effects of hippocampal lesions on structural and functional connectivity in six patients with amnesia, using a range of magnetic resonance imaging (MRI) analyses. Neuropsychological assessment revealed marked episodic memory impairment and generally intact performance across other cognitive domains. The hippocampus was the only brain structure exhibiting reduced grey-matter volume that was consistent across patients, and the fornix was the only major white-matter tract to show altered structural connectivity according to both diffusion metrics. Nonetheless, functional MRI revealed both increases and decreases in functional connectivity. Analysis at the level of regions within the default-mode network revealed reduced functional connectivity, including between nonhippocampal regions (connectional diaschisis). Analysis at the level of functional networks revealed reduced connectivity between thalamic and precuneus networks, but increased connectivity between the default-mode network and frontal executive network. The overall functional connectome showed evidence of increased functional segregation in patients (connectomic diaschisis). Together, these results point to dynamic reorganization following hippocampal lesions, with both decreased and increased functional connectivity involving limbic-diencephalic structures and larger-scale networks. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc.Medical Research Council (Grant ID: MC-A060-5PR10); Biotechnology and Biological Sciences Research Council (Grant ID: BB/L02263X/1); Netherlands Organization for Scientific ResearchThis is the final version of the article. It first appeared from Wiley via https://doi.org/10.1002/hipo.2262
No effect of hippocampal lesions on stimulus-response bindings.
The hippocampus is believed to be important for rapid learning of arbitrary stimulus-response contingencies, or S-R bindings. In support of this, Schnyer et al. (2006) (Experiment 2) measured priming of reaction times (RTs) to categorise visual objects, and found that patients with medial temporal lobe damage, unlike healthy controls, failed to show evidence of reduced priming when response contingencies were reversed between initial and repeated categorisation of objects (a signature of S-R bindings). We ran a similar though extended object classification task on 6 patients who appear to have selective hippocampal lesions, together with 24 age-matched controls. Unlike Schnyer et al. (2006), we found that reversing response contingencies abolished priming in both controls and patients. Bayes Factors provided no reason to believe that response reversal had less effect on patients than controls. We therefore conclude that it is unlikely that the hippocampus is needed for S-R bindings
Understanding enhanced rotational dynamics of active probes in rod suspensions
Active Brownian particles (APs) have recently been shown to exhibit enhanced rotational diffusion (ERD) in complex fluids. Here, we experimentally observe ERD and numerically corroborate its microscopic origin for a quasi-two-dimensional suspension of colloidal rods. At high density, the rods form small rafts, wherein they perform small-amplitude, high-frequency longitudinal displacements. Activity couples AP-rod contacts to reorientation, with the variance therein leading to ERD. This is captured by a local, rather than a global relaxation time, as used in previous phenomenological modeling. Our result should prove relevant to the microrheological characterization of complex fluids and furthering our understanding of the dynamics of microorganisms in such media
Immune response to Mycobacterium tuberculosis specific antigen ESAT-6 among south Indians
The 6-kDa early secreted antigenic target (ESAT-6) is a T-cell antigen recognized by individuals infected
with Mycobacterium tuberculosis. The aim of the study was to identify ‘‘protective epitopes’’ of ESAT-6
protein in the south Indian population. Proliferative and Interferon gamma (IFN-g) responses to ESAT-6
peptides were studied by flow cytometry and Enzyme linked immunosorbent assay (ELISA). Healthy
household contacts (HHC) recognized Esp1 (10/17) and Esp6 (9/17) peptides. Among pulmonary tuberculosis
patients (PTB), Esp1 (3/11) and Esp6 (5/11) were recognized. Maximal response (7/10) was found
for Esp1 and Esp8 in treated patients (TR). Median values for the responding subjects gave the following
results: Esp1 (76 pg/ml), Esp6 (64 pg/ml), induced IFN-g production in HHC; PTB gave low IFN-g
responses for the peptides. TR responded to the peptides Esp1 (141 pg/ml), Esp8 (102 pg/ml). The
proliferation of CD4 cells was similar in both PTB and TR for all peptides; but HHC showed an increase for
Esp1 (p < 0.05) and Esp6 (p < 0.01). Esp1 (amino acids aa 1–20) and Esp6 (aa 51–70) were the immunogenic
peptides recognized by the alleles HLA DRB1*04 and HLA DRB1*10 among HHC. But the
association of the alleles with ESAT-6 peptide presentation needs to be confirmed in a large cohort of
subjects. We speculate that ESAT-6 can be used along with other immune-eliciting proteins for vaccine
design strategies in south Indian population
Primary cutaneous melanoma of the breast: A case report
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Primary cutaneous melanoma of the breast is a very rare tumour, accounting for < 5 % of all malignant melanomas. Case presentation: A young lady was seen in the breast clinic for a skin lesion in the right breast. Clinical examination and investigations confirmed a diagnosis of a primary cutaneous melanoma of the breast. The lesion was excised and the patient made good recovery. She has shown no signs of local recurrence and is under regular follow-up in the dermatology clinic. Conclusion: This case is educational as it shows that the treatment of breast cutaneous melanoma is similar to that for any skin parts with surgery remaining the main therapeutic option. It also shows that mastectomy is unnecessary as it does not improve the results obtained by wide local excision of melanoma. Background Primary cutaneous melanoma rarely affects the breast, accounting for less than 5 % of all malignant melanomas
Variants in KCNQ1 increase type II diabetes susceptibility in South Asians: A study of 3,310 subjects from India and the US
<p>Abstract</p> <p>Background</p> <p>Polymorphisms in intron 15 of potassium voltage-gated channel, KQT-like subfamily member 1 (<it>KCNQ1</it>) gene have been associated with type II diabetes (T2D) in Japanese genome-wide association studies (GWAS). More recently a meta-analysis of European GWAS has detected a new independent signal associated with T2D in intron 11 of the <it>KCNQ1 </it>gene. The purpose of this investigation is to examine the role of these variants with T2D in populations of Asian Indian descent from India and the US.</p> <p>Methods</p> <p>We examined the association between four variants in the <it>KCNQ1 </it>gene with T2D and related quantitative traits in a total of 3,310 Asian Indian participants from two different cohorts comprising 2,431 individuals of the Punjabi case-control cohort from the Sikh Diabetes Study and 879 migrant Asian Indians living in the US.</p> <p>Results</p> <p>Our data confirmed the association of a new signal at the <it>KCNQ1 </it>locus (rs231362) with T2D showing an allelic odds ratio (OR) of 1.24 95%CI [1.08-1.43], p = 0.002 in the Punjabi cohort. A moderate association with T2D was also seen for rs2237895 in the Punjabi (OR 1.14; p = 0.036) and combined cohorts (meta-analysis OR 1.14; p = 0.018). Three-site haplotype analysis of rs231362, rs2237892, rs2237895 exhibited considerably stronger evidence of association of the GCC haplotype with T2D showing OR of 1.24 95%CI [1.00-1.53], p = 0.001, permutation p = 8 × 10<sup>-4 </sup>in combined cohorts. The 'C' risk allele carriers of rs2237895 had significantly reduced measures of HOMA-B in the US cohort (p = 0.008) as well as in combined cohort in meta-analysis (p = 0.009).</p> <p>Conclusions</p> <p>Our investigation has confirmed that the variation within the <it>KCNQ1 </it>locus confers a significant risk to T2D among Asian Indians. Haplotype analysis further suggested that the T2D risk associated with <it>KCNQ1 </it>SNPs may be derived from 'G' allele of rs231362 and 'C' allele of rs2237895 and this appears to be mediated through β cell function.</p
Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017
Background
Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.
Methods
The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.
Findings
Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.
Interpretation
Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI
Integrated Functional, Gene Expression and Genomic Analysis for the Identification of Cancer Targets
The majority of new drug approvals for cancer are based on existing therapeutic targets. One approach to the identification of novel targets is to perform high-throughput RNA interference (RNAi) cellular viability screens. We describe a novel approach combining RNAi screening in multiple cell lines with gene expression and genomic profiling to identify novel cancer targets. We performed parallel RNAi screens in multiple cancer cell lines to identify genes that are essential for viability in some cell lines but not others, suggesting that these genes constitute key drivers of cellular survival in specific cancer cells. This approach was verified by the identification of PIK3CA, silencing of which was selectively lethal to the MCF7 cell line, which harbours an activating oncogenic PIK3CA mutation. We combined our functional RNAi approach with gene expression and genomic analysis, allowing the identification of several novel kinases, including WEE1, that are essential for viability only in cell lines that have an elevated level of expression of this kinase. Furthermore, we identified a subset of breast tumours that highly express WEE1 suggesting that WEE1 could be a novel therapeutic target in breast cancer. In conclusion, this strategy represents a novel and effective strategy for the identification of functionally important therapeutic targets in cancer
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