Effect of obesity on sympathovagal activities in hypertensive Indian population

Summary: Decreased physical activity, increased psychosocial stress and work stress have contributed to the increased prevalence of obesity and Hypertension (HTN). Irrespective of the aetiology, sympathetic over activity has been recognized as the main pathophysiologic mechanism in the genesis of obesity and HTN. Sympathovagal imbalance or dysregulation of autonomic functions owing to sympathetic over activity and vagal withdrawal is reported to be the basis of many clinical disorders. Obesity, hypertension and diabetes mellitus are known to be associated with dysregulation of autonomic functions independently. Heart Rate Variability (HRV) has emerged as a practical, non-invasive tool to quantitatively investigate cardiac autonomic dysregulation. The present study was undertaken to ascertain whether obesity has any effect on further disruption of autonomic functions particularly in hypertensive patients. A total of 96 male and female adults aged between 40-50 years visiting the Primary Health Centre, Yelwala, Mysuru district, India were recruited for this study. They were grouped in to 3 (n=32) as Groups I (Obese hypertensive), II (non-obese hypertensive) and II (non-obese normotensive, control), HRV was determined using the One minute during deep breathing method. Data were presented as Mean ± SD, inferential statistics was by One Way ANOVA and Tukey’s Post Hoc test p value <0.005 at α0.05 HRV was significantly decreased in obese hypertensive patients compared to the non-obese hypertensive patients. Our present study supports that obesity and hypertension probably has additive effect in causing autonomic dysregulation.Keywords: Autonomic functions, HRV, Hypertension, Obesit

A versatile and an efficient synthesis of 5-​substituted-​1H-​tetrazoles

A simple, efficient and a versatile method for the synthesis of 5-​substituted-​1H-​tetrazoles by a [3+2]​-​cycloaddn. reaction of aryl nitriles with sodium azide in DMF using ZrOCl2·8 H2O as catalyst has been developed. The reactions work well at 100°C and give the desired products in excellent yield. The examples studied include arom. nitriles having electron donating as well as electron releasing groups on the arene nucleus

Effect of Addition of Nanoclay on Machinability of Al/Nanoclay Metal Matrix Composites

In this study, machinability test was conducted on Al-Nanoclay metal matrix composites using lathe tool dynamometer. Composites were prepared with aluminium as the matrix and nanoclay particles with 2, 4, 6 percentage by weight as reinforcement. The effect of clay particles and machining parameters such as cutting speed, feed rate and depth of cut on tangential force and chip formation was studied. From the results it is observed that the tangential force applied by the tool on MMC, facilitate chip breaking and the generation of chips significantly depends on feed but almost independent of speed. These results reveal the roles of the nanoclay reinforcement particles on the machinability of MMCs and provide a useful guide for a better control of their machining processes

Experimental Investigations & Effects of Cutting Variables on MRR and Tool Wear for AISI S2 Tool Steel

AbstractMachining is the most important of the manufacturing processes which involves the process of removing material from a work piece in the form of chips. Machining is necessary where tight tolerances on dimensions and finishes are required. Generally a machining process involves a large number of variables that affect its performance. Some of them are cutting parameters, geometry of cutting tool, coolant conditions, properties of tool material, properties of work piece, machine capabilities, etc. Among them, cutting parameters have profound effect on all kinds of performances when the same tool material and the same work piece material are used for machining. Therefore cutting parameters of speed, feed and depth of cut are considered as the process control variables and two important performance measures of CNC turning, namely, Metal Removal Rate (MRR) and Tool wear (TW) are considered for investigation. This paper presents the experimental investigations on the effects of cutting variables like Spindle speed, Feed and Depth of cut on the Material removal rate and tool wear. The experiments were conducted on AISI S2 tool steel grade on a CNC turning machine using carbide insert. The experiments were conducted as per the design of experiments. Initial trial experiments were conducted to fix the ranges for the control parameters. After conducting the experiments the MRR and Tool wear were measured and recorded. The effects were studied after plotting the graphs between the Input process parameters versus the responses using Design expert software. The results obtained in this study can by further used for optimizing the process parameters there by the optimized results help the operator to enhance the quality as well as machining rate

A Randomized Controlled Prospective Study Comparing a Low Dose Bupivacaine and Fentanyl Mixture to a Conventional Dose of Hyperbaric Bupivacaine for Cesarean Section

CONTEXT: Hormonal and mechanical factors make obstetric patients need strict dose calculations of local anesthetics intrathecally for spinal anesthesia. Any greater dose of local anesthetics can cause hemodynamic instability, maternal morbidity and any lesser dose can produce inadequate block. Hence, we hypothesized in our study that by using low dose of bupivacaine with fentanyl can maintain stable hemodynamics and provide better analgesia. AIM: The aim was to compare the hemodynamics and duration of analgesia using a low dose (7.5 mg) bupivacaine fentanyl mixture to a conventional dose (10 mg) of hyperbaric bupivacaine for cesarean section. SETTINGS AND DESIGN: Double-blinded, randomized, controlled prospective study was conducted at a tertiary academic hospital from 2008 to 2011. MATERIALS AND METHODS: Fifty singleton parturient, scheduled for elective caesarean section were randomly allocated into two groups. Study group (group-S) received a combination of 25 μg fentanyl and 7.5 mg of hyperbaric bupivacaine, whereas the control group (group-C) received 10 mg of hyperbaric bupivacaine. Maternal hemodynamics, sensory and motor block, duration of analgesia and the Apgar score of the newborn were compared between the groups. STATISTICAL ANALYSIS USED: Observational descriptive statistics, statistical package for social sciences (SPSS Inc. Released 2006, SPSS for Windows, Version 15.0. Chicago), paired t-test was used as applicable. RESULTS: The blood pressure significantly decreased with \u3e25% fall from the baseline in group-C (98.76 ± 8.36) than in group-S (117.32 ± 12.21) with P \u3c 0.001. The duration of effective analgesia was significantly prolonged in the study group than in the control group (P \u3c 0.001). CONCLUSION: The combination of low dose bupivacaine and fentanyl in comparison to bupivacaine alone is hemodynamically stable and prolonged duration of analgesia in caesarean section

Polypropylene/Layered Double Hydroxide Nanocomposites: Influence of LDH Intralayer Metal Constituents on the Properties of Polypropylene

Sonication-assisted delamination of layered double hydroxides (LDHs) resulted in smaller-sized LDH nanoparticles (∼50-200 nm). Such delaminated Co-Al LDH, Zn-Al LDH, and Co-Zn-Al LDH solutions were used for the preparation of highly dispersed isotactic polypropylene (iPP) nanocomposites. Transmission electron microscopy and wide-angle X-ray diffraction results revealed that the LDH nanoparticles were well dispersed within the iPP matrix. The intention of this study is to understand the influence of the intralayer metal composition of LDH on the various properties of iPP/LDH nanocomposites. The sonicated LDH nanoparticles showed a significant increase in the crystallization rate of iPP; however, not much difference in the crystallization rate of iPP was observed in the presence of different types of LDH. The dynamic mechanical analysis results indicated that the storage modulus of iPP was increased significantly with the addition of LDH. The incorporation of different types of LDH showed no influence on the storage modulus of iPP. But considerable differences were observed in the flame retardancy and thermal stability of iPP with the type of LDH used for the preparation of nanocomposites. The thermal stability (50% weight loss temperature (T0.5)) of the iPP nanocomposite containing three-metal LDH (Co-Zn-Al LDH) is superior to that of the nanocomposites made of two-metal LDH (Co-Al LDH and Zn-Al LDH). Preliminary studies on the flame-retardant properties of iPP/LDH nanocomposites using microscale combustion calorimetry showed that the peak heat release rate was reduced by 39% in the iPP/Co-Zn-Al LDH nanocomposite containing 6 wt % LDH, which is higher than that of the two-metal LDH containing nanocomposites, iPP/Co-Al LDH (24%) and iPP/Zn-Al LDH (31%). These results demonstrated that the nanocomposites prepared using three-metal LDH showed better thermal and flame-retardant properties compared to the nanocomposites prepared using two-metal LDH. This difference might be due to the better char formation capability of three-metal LDH compared to that of two-metal LDH

Medical Comorbidities and Functional Dependent Living Are Independent Risk Factors for Short-Term Complications Following Osteotomy Procedures about the Knee

© The Author(s) 2018. Objective: To characterize rates and risk factors for adverse events following distal femoral osteotomy (DFO), high tibial osteotomy (HTO), and tibial tubercle osteotomy (TTO) procedures. Design: Patients undergoing DFO, HTO, or TTO procedures during 2005 to 2016 were identified in the American College of Surgeons National Surgical Quality Improvement Program. Rates of adverse events were characterized for each procedure. Demographic, comorbidity, and procedural factors were tested for association with occurrence of any adverse events. Results: A total of 1,083 patients were identified. Of these, 305 (28%) underwent DFO, 273 (25%) underwent HTO, and 505 (47%) underwent TTO. Mean ages for patients undergoing each procedure were the following: DFO, 51 ± 23 years; HTO, 40 ± 13 years; and TTO, 31 ± 11 years. The most common comorbidities for DFO were hypertension (34%) and smoking (17%); for HTO, hypertension (22%) and smoking (21%); and for TTO, smoking (20%) and hypertension (11%). Independent risk factors for occurrence of any adverse event were age ⩾45 years for DFO (odds ratio [OR] = 3.1, P \u3c 0.001) and HTO (OR = 2.3, P = 0.029), and body mass index \u3e30 for HTO (OR = 2.5, 95% confidence interval = 1.1-5.7, P = 0.031). When all osteotomy procedures were analyzed collectively, additional variables including diabetes mellitus (OR = 2.2, P = 0.017), chronic obstructive pulmonary disease (OR = 5.5, P = 0.003), and dependent functional status (OR = 3.0, P = 0.004) were associated with adverse events. Conclusions: The total rate of adverse events was not independently associated with the type of osteotomy procedure. In addition, patients with age \u3e45, diabetes mellitus, chronic obstructive pulmonary disease, and dependent functional status have greater odds for adverse events and should be counseled and monitored accordingly