Design and Fabrication of Starting Lever Using Freewheel

The objective of our project is to design and fabricate an innovative type of starting lever combined with freewheel or overrunning clutch. The traditional engine starter by manual energy has certain disadvantage like slipping apart once the engine starts because of high centrifugal force. Our design utilizes the benefit of freewheel (also known as overrunning clutch, one way clutch) which transmits torque when N1 > N2 but will transmit no torque when N1 < N2 , where N1 and N2 represents the rpm of shaft 1 and shaft 2. This mechanism is utilized by us to develop a good and efficient starting lever. The conditions of a driven shaft spinning faster than its driveshaft exists in most bicycles when the rider holds his or her feet still, no longer pushing the pedals. In a fixed gear bicycle, without a free wheel, the rear wheel would drive the pedals around

Oscillatory surface rheotaxis of swimming E. coli bacteria

Bacterial contamination of biological conducts, catheters or water resources is a major threat to public health and can be amplified by the ability of bacteria to swim upstream. The mechanisms of this rheotaxis, the reorientation with respect to flow gradients, often in complex and confined environments, are still poorly understood. Here, we follow individual E. coli bacteria swimming at surfaces under shear flow with two complementary experimental assays, based on 3D Lagrangian tracking and fluorescent flagellar labelling and we develop a theoretical model for their rheotactic motion. Three transitions are identified with increasing shear rate: Above a first critical shear rate, bacteria shift to swimming upstream. After a second threshold, we report the discovery of an oscillatory rheotaxis. Beyond a third transition, we further observe coexistence of rheotaxis along the positive and negative vorticity directions. A full theoretical analysis explains these regimes and predicts the corresponding critical shear rates. The predicted transitions as well as the oscillation dynamics are in good agreement with experimental observations. Our results shed new light on bacterial transport and reveal new strategies for contamination prevention.Comment: 12 pages, 5 figure

Activation of Multiple ERBB Family Receptors Mediates Glioblastoma Cancer Stem-like Cell Resistance to EGFR-Targeted Inhibition12

Epidermal growth factor receptor (EGFR) signaling is strongly implicated in glioblastoma (GBM) tumorigenesis. However, molecular agents targeting EGFR have demonstrated minimal efficacy in clinical trials, suggesting the existence of GBM resistance mechanisms. GBM cells with stem-like properties (CSCs) are highly efficient at tumor initiation and exhibit therapeutic resistance. In this study, GBMCSC lines showed sphere-forming and tumor initiation capacity after EGF withdrawal from cell culture media, compared with normal neural stem cells that rapidly perished after EGF withdrawal. Compensatory activation of related ERBB family receptors (ERBB2 and ERBB3) was observed in GBM CSCs deprived of EGFR signal (EGF deprivation or cetuximab inhibition), suggesting an intrinsic GBM resistance mechanism for EGFR-targeted therapy. Dual inhibition of EGFR and ERBB2 with lapatinib significantly reduced GBM proliferation in colony formation assays compared to cetuximab-mediated EGFR-specific inhibition. Phosphorylation of downstream ERBB signaling components (AKT, ERK1/2) and GBM CSC proliferation were inhibited by lapatinib. Collectively, these findings show that GBM therapeutic resistance to EGFR inhibitors may be explained by compensatory activation of EGFR-related family members (ERBB2, ERBB3) enabling GBM CSC proliferation, and therefore simultaneous blockade of multiple ERBB family members may be required for more efficacious GBM therapy

Risk scoring system to predict contrast induced nephropathy following percutaneous coronary intervention

Background: Contrast induced nephropathy (CIN) is associated with significant morbidity and mortality after percutaneous coronary intervention (PCI). The aim of this study is to evaluate the collective probability of CIN in Indian population by developing a scoring system of several identified risk factors in patients undergoing PCI. Methods: This is a prospective single center study of 1200 consecutive patients who underwent PCI from 2008 to 2011. Patients were randomized in 3:1 ratio into development (n = 900) and validation (n = 300) groups. CIN was defined as an increase of ≥25% and/or ≥0.5 mg/dl in serum creatinine at 48 hours after PCI when compared to baseline value. Seven independent predictors of CIN were identified using logistic regression analysis - amount of contrast, diabetes with microangiopathy, hypotension, peripheral vascular disease, albuminuria, glomerular filtration rate (GFR) and anemia. A formula was then developed to identify the probability of CIN using the logistic regression equation. Results: The mean (±SD) age was 57.3 (±10.2) years. 83.6% were males. The total incidence of CIN was 9.7% in the development group. The total risk of renal replacement therapy in the study group is 1.1%. Mortality is 0.5%. The risk scoring model correlated well in the validation group (incidence of CIN was 8.7%, sensitivity 92.3%, specificity 82.1%, c statistic 0.95). Conclusion: A simple risk scoring equation can be employed to predict the probability of CIN following PCI, applying it to each individual. More vigilant preventive measures can be applied to the high risk candidates

Coronary intervention in anomalous origin of the right coronary artery (ARCA) from the left sinus of valsalva (LSOV): A single center experience

Objective: To assess the technical challenges in percutaneous coronary intervention of Anomalous right coronary artery arising from the left sinus of valsalva. Methods: Between year 2008 and 2012, a total of 17 patients underwent PCI for an angiographically significant lesion in the right coronary artery of an anomalous origin in the LSOV. Their procedure details such as usage of catheters, radiation time, amount of contrast used were assessed. Results: A total of 17 patients with anomalous right coronary artery underwent PCI during the above mentioned period. 8 patients had type A origin, 3 had type B origin and the remaining 6 had type C origin. Type A origin RCA were successfully cannulated in 6 patients with Judkins left 5.0 and in 2 patients using Judkins left 4.0. Extra back up (EBU) 3.5 were doing well in 2 patients of Type B origin and the remaining one patient was successfully cannulated using Judkins left 4.0. In type C origin 4 patients had successful cannulation with Amplatz Left 1.0, 1 patient with Amplatz Left 2.0 and 1 patient with Judkins left 4.0. The mean fluoroscopic time was 20.7 min and amount of contrast used was 210 ml. Conclusion: PCI of anomalous RCA origin from LSOV requires appropriate guide catheter selection according to the anatomy of origin for successful cannulation and to reduce the contrast usage and radiation exposure

Outcome of primary PCI – An Indian tertiary care center experience

Objective: To assess the feasibility and outcomes of primary percutaneous coronary intervention (PPCI) for ST-segment elevation myocardial infarction (STEMI) in Indian Scenario. Methods: Between January 2005 and December 2012, consecutive STEMI patients who underwent PPCI within 12 h of onset of chest pain were prospectively enrolled in a PPCI registry. Patient demographics, risk factors, procedural characteristics, time variables and in-hospital and 30 day major adverse cardiovascular events (MACE) [death, reinfarction, bleeding, urgent coronary artery bypass surgery (CABG) and stroke] were assessed. Results: A total of 672 patients underwent PPCI during this period. The mean age was 52 ± 13.4 years and 583 (86.7%) were males, 275 (40.9%) were hypertensives and 336 (50%) were diabetics. Thirty one (4.6%) patients had cardiogenic shock (CS). Anterior myocardial infarction was diagnosed in 398 (59.2%) patients. The median chest pain onset to hospital arrival time, door-to-balloon time and total ischemic times were 200 (10–720), 65 (20–300), and 275 (55–785) minutes respectively. In-hospital adverse events occurred in 54 (8.0%) patients [death 28 (4.2%), reinfarction 8 (1.2%), major bleeding 9 (1.3%), urgent CABG 4 (0.6%) and stroke 1 (0.14%)]. Nineteen patients with CS died (mortality rate – (61.3%)). At the end of 30 days, 64 (9.5%) patients had MACE [death 35 (5.2%), reinfarction 10 (2.1%), major bleeding 10 (1.5%), urgent CABG 4 (0.6%) and stroke 1 (0.1%)]. Conclusion: Our study has shown that PPCI is feasible with good outcomes in Indian scenario. Even though the recommended door-to-balloon time can be achieved, the total ischemic time remained long. CS in the setting of STEMI was associated with poor outcomes