106 research outputs found

    Groovy and gnarly : surface wrinkles as a multifunctional motif for terrestrial and marine environments

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    From large ventral pleats of humpback whales to nanoscale ridges on flower petals, wrinkled structures are omnipresent, multifunctional, and found at hugely diverse scales. Depending on the particulars of the biological system—its environment, morphology, and mechanical properties—wrinkles may control adhesion, friction, wetting, or drag; promote interfacial exchange; act as flow channels; or contribute to stretching, mechanical integrity, or structural color. Undulations on natural surfaces primarily arise from stress-induced instabilities of surface layers (e.g., buckling) during growth or aging. Variation in the material properties of surface layers and in the magnitude and orientation of intrinsic stresses during growth lead to a variety of wrinkling morphologies and patterns which, in turn, reflect the wide range of biophysical challenges wrinkled surfaces can solve. Therefore, investigating how surface wrinkles vary and are implemented across biological systems is key to understanding their structure-function relationships. In this work, we synthesize the literature in a metadata analysis of surface wrinkling in various terrestrial and marine organisms to review important morphological parameters and classify functional aspects of surface wrinkles in relation to the size and ecology of organisms. Building on our previous and current experimental studies, we explore case studies on nano/micro-scale wrinkles in biofilms, plant surfaces, and basking shark filter structures to compare developmental and structure-vs-function aspects of wrinkles with vastly different size scales and environmental demands. In doing this and by contrasting wrinkle development in soft and hard biological systems, we provide a template of structure-function relationships of biological surface wrinkles and an outlook for functionalized wrinkled biomimetic surfaces

    Uncommon Endoscopic Findings in a Tylosis Patient: A Case Report

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    Palmoplantar tylosis is a focal non epidermolytic palmoplantar hyperkeratosis and is associated with a very high lifetime risk of developing squamous cell carcinoma of the esophagus (OSCC). It is generally inherited as an autosomal dominant trait with complete penetrance involving the RHBDF2 gene located on 17q25.1. The data regarding endoscopic appearance of the mucosa in patients with tylosis before development of cancer is limited. Surveillance endoscopy is recommended in family members which include annual esophagogastroscopy with biopsy of suspicious lesion with quadratic biopsies from upper, middle and lower esophagus. We describe characteristic endoscopy findings in a tylosis with no evidence of cancer. Prospective documentation of endoscopic findings of similar mucosal changes and disease process to establish a better screening protocol and supplemental intervention with agents like carotenoids (beta-carotene, alpha-carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin) may delay the progression and possibly revert to normal

    Albuminuria Testing in Hypertension and Diabetes:An Individual-Participant Data Meta-Analysis in a Global Consortium

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    Albuminuria is an under-recognized component of chronic kidney disease definition, staging, and prognosis. Guidelines, particularly for hypertension, conflict on recommendations for urine albumin-to-creatinine ratio (ACR) measurement. Separately among 1 344 594 adults with diabetes and 2 334 461 nondiabetic adults with hypertension from the chronic kidney disease Prognosis Consortium, we assessed ACR testing, estimated the prevalence and incidence of ACR ≥30 mg/g and developed risk models for ACR ≥30 mg/g. The ACR screening rate (cohort range) was 35.1% (12.3%-74.5%) in diabetes and 4.1% (1.3%-20.7%) in hypertension. Screening was largely unrelated to the predicted risk of prevalent albuminuria. The median prevalence of ACR ≥30 mg/g across cohorts was 32.1% in diabetes and 21.8% in hypertension. Higher systolic blood pressure was associated with a higher prevalence of albuminuria (odds ratio [95% CI] per 20 mm Hg in diabetes, 1.50 [1.42-1.60]; in hypertension, 1.36 [1.28-1.45]). The ratio of undetected (due to lack of screening) to detected ACR ≥30 mg/g was estimated at 1.8 in diabetes and 19.5 in hypertension. Among those with ACR/g, the median 5-year incidence of ACR ≥30 mg/g across cohorts was 23.9% in diabetes and 21.7% in hypertension. Incident albuminuria was associated with initiation of renin-angiotensin-aldosterone system inhibitors (incidence-rate ratio [95% CI], diabetes 3.09 [2.71-3.53]; hypertension 2.87 [2.29-3.59]). In conclusion, despite similar risk of albuminuria to those with diabetes, ACR screening in patients with hypertension was low. Our findings suggest that regular albuminuria screening should be emphasized to enable early detection of chronic kidney disease and initiation of treatment with cardiovascular and renal benefits

    Conversion of Urine Protein-Creatinine Ratio or Urine Dipstick Protein to Urine Albumin-Creatinine Ratio for Use in Chronic Kidney Disease Screening and Prognosis : An Individual Participant–Based Meta-analysis

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    Financial Support: The CKD-PC Data Coordinating Center is funded in part by a program grant from the U.S. National Kidney Foundation and the National Institute of Diabetes and Digestive and Kidney Diseases (R01DK100446). Various sources have supported enrollment and data collection, including laboratory measurements and follow-up, in the collaborating cohorts of the CKD-PC. These funding sources include government agencies, such as national institutes of health and medical research councils, as well as the foundations and industry sponsors listed in Supplemental Appendix 3 (available at Annals.org).Peer reviewedPostprin

    Role of Androgen Receptor CAG Repeat Polymorphism and X-Inactivation in the Manifestation of Recurrent Spontaneous Abortions in Indian Women

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    The aim of the present study was to investigate the role of CAG repeat polymorphism and X-chromosome Inactivation (XCI) pattern in Recurrent Spontaneous Abortions among Indian women which has not been hitherto explored. 117 RSA cases and 224 Controls were included in the study. Cases were recruited from two different hospitals - Lakshmi Fertility Clinic, Nellore and Fernandez Maternity Hospital, Hyderabad. Controls were roughly matched for age, ethnicity and socioeconomic status. The CAG repeats of the Androgen Receptor gene were genotyped using a PCR-based assay and were analysed using the GeneMapper software to determine the CAG repeat length. XCI analysis was also carried out to assess the inactivation percentages. RSA cases had a significantly greater frequency of allele sizes in the polymorphic range above 19 repeats (p = 0.006), which is the median value of the controls, and in the biallelic mean range above 21 repeats (p = 0.002). We found no evidence of abnormal incidence of skewed X-inactivation. We conclude that longer CAG repeat lengths are associated with increased odds for RSA with statistical power estimated to be ∼90%

    Some soil-related issues in the disposal of effluent on land

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    Pneumothorax following ultrasound-guided jugular vein puncture for central venous access in interventional radiology: 4 years of experience

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    PURPOSE: The purpose of our study was to review the rate of pneumothorax following central venous access, using real-time ultrasound guidance. MATERIALS AND METHODS: Data related to ultrasound-guided venous puncture, for central venous access, performed between July 1, 2004 and June 30, 2008 was retrospectively and prospectively collected. Access route, needle gauge, catheter type, and diagnosis of pneumothorax on the intraprocedure spot radiographs and or the postprocedure chest radiographs, were recorded. RESULTS: A total of 1262 ultrasound-guided jugular venous puncture for central venous access were performed on a total of 1066 patients between July 1, 2004 and June 30, 2008. Access vessels included 983 right internal jugular veins, 275 left internal jugular veins, and 4 right external jugular veins. No pneumothorax (0%) was identified. CONCLUSION: Due to an extremely low rate of pneumothorax following ultrasound-guided central venous access, 0% in our study and other published studies, we suggest that routine postprocedure chest radiograph to exclude pneumothorax may be dispensed unless it is suspected by the operator or if the patient becomes symptomatic
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