102 research outputs found

    Irreversible Aging Dynamics and Generic Phase Behavior of Aqueous Suspensions of Laponite

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    In this work we study the aging behavior of aqueous suspension of Laponite having 2.8 weight % concentration using rheological tools. At various salt concentration all the samples demonstrate orientational order when observed using crossed polarizers. In rheological experiments we observe inherent irreversibility in the aging dynamics which forces the system not to rejuvenate to the same state in the shear melting experiment carried out at a later date since preparation. The extensive rheological experiments carried out as a function of time elapsed since preparation demonstrate the self similar trend in the aging behavior irrespective of the concentration of salt. We observe that the exploration of the low energy states as a function of aging time is only kinetically affected by the presence of salt. We estimate that the energy barrier to attain the low energy states decreases linearly with increase in the concentration of salt. The observed superposition of all the elapsed time and the salt concentration dependent data suggests that the aging that occurs in low salt concentration systems over a very long period is qualitatively similar to the aging behavior observed in systems with high salt concentration over a shorter period.Comment: 27 pages, 8 figures. Langmuir, in pres

    Extremely short duration high intensity interval training substantially improves insulin action in young healthy males

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    Background: Traditional high volume aerobic exercise training reduces cardiovascular and metabolic disease risk but involves a substantial time commitment. Extremely low volume high-intensity interval training (HIT) has recently been demonstrated to produce improvements to aerobic function, but it is unknown whether HIT has the capacity to improve insulin action and hence glycemic control. Methods: Sixteen young men (age: 21 ± 2 y; BMI: 23.7 ± 3.1 kg·m-2; VO2peak: 48 ± 9 ml·kg-1·min-1) performed 2 weeks of supervised HIT comprising of a total of 15 min of exercise (6 sessions; 4-6 × 30-s cycle sprints per session). Aerobic performance (250-kJ self-paced cycling time trial), and glucose, insulin and NEFA responses to a 75-g oral glucose load (oral glucose tolerance test; OGTT) were determined before and after training. Results: Following 2 weeks of HIT, the area under the plasma glucose, insulin and NEFA concentration-time curves were all reduced (12%, 37%, 26% respectively, all P < 0.001). Fasting plasma insulin and glucose concentrations remained unchanged, but there was a tendency for reduced fasting plasma NEFA concentrations post-training (pre: 350 ± 36 v post: 290 ± 39 μmol·l-1, P = 0.058). Insulin sensitivity, as measured by the Cederholm index, was improved by 23% (P < 0.01), while aerobic cycling performance improved by ∼6% (P < 0.01). Conclusion: The efficacy of a high intensity exercise protocol, involving only ∼250 kcal of work each week, to substantially improve insulin action in young sedentary subjects is remarkable. This novel time-efficient training paradigm can be used as a strategy to reduce metabolic risk factors in young and middle aged sedentary populations who otherwise would not adhere to time consuming traditional aerobic exercise regimes

    Associations between weight change and biomarkers of cardiometabolic risk in South Asians:secondary analyses of the PODOSA trial

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    Background/Objectives: The association of weight changes with cardiometabolic biomarkers in South Asians has been sparsely studied. Subjects/Methods: We measured cardiometabolic biomarkers at baseline and after 3 years in the Prevention of Diabetes and Obesity in South Asians Trial. We investigated the effect of a lifestyle intervention on biomarkers in the randomized groups. In addition, treating the population as a single cohort, we estimated the association between change in weight and change in biomarkers. Results: Complete data were available at baseline and after 3 years in 151 participants. At 3 years, there was an adjusted mean reduction of 1·44 kg (95% confidence interval (95% CI): 0.18–2.71) in weight and 1.59 cm (95% CI: 0.08–3.09) in waist circumference in the intervention arm as compared with the control arm. There was no clear evidence of difference between the intervention and control arms in change of mean value of any biomarker. As a single cohort, every 1 kg weight reduction during follow-up was associated with a reduction in triglycerides (−1.3%, P=0.048), alanine aminotransferase (−2.5%, P=0.032), gamma-glutamyl transferase (−2.2%, P=0.040), leptin (−6.5%, P&lt;0.0001), insulin (−3.7%, P=0.0005), fasting glucose (−0.8%, P=0.0071), 2-h glucose (−2.3%, P=0.0002) and Homeostatic Model Assessment of insulin resistance (HOMA-IR: −4.5%, P=0.0002). There was no evidence of associations with other lipid measures, tissue plasminogen activator, markers of inflammation or blood pressure. Conclusions: We demonstrate that modest weight decrease in SAs is associated with improvements in markers of total and ectopic fat as well as insulin resistance and glycaemia in South Asians at risk of diabetes. Future trials with more intensive weight change are needed to extend these findings

    The effect of physical exercise and caloric restriction on the components of metabolic syndrome

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    2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

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    The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

    Recent advances of novel targeted therapy for squamous cell carcinoma of the head and neck

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    Targeted therapies have proven beneficial for patients suffering from a number of different malignancies, including cancers of the head and neck. Cetuximab, a monoclonal antibody targeting the epidermal growth factor receptor has shown benefit in combination with radiation for untreated patients or as a single agent for patients with platinum resistant disease. Cetuximab is the only targeted agent currently approved by the Federal Drug Administration for the treatment of head and neck cancer. A number of other agents have shown promising initial results including intracellular tyrosine kinase inhibitors, agents targeting vascular endothelial growth factor receptor, as well as other classes of novel therapies. Some of the data supporting the use of targeted therapy, including agents not yet approved in head and neck cancer, will be presented in this review. As our understanding of the cancer cell signaling pathways and novel targeted agents increases, the potential for treatment with reduced toxicity and improved clinical outcomes will become a reality
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