Designing of epoxy composites reinforced with carbon nanotubes grown carbon fiber fabric for improved electromagnetic interference shielding

In this letter, we report preparation of strongly anchored multiwall carbon nanotubes (MWCNTs) carbon fiber (CF) fabric preforms. These preforms were reinforced in epoxy resin to make multi scale composites for microwave absorption in the X-band (8.2-12.4GHz). The incorporation of MWCNTs on the carbon fabric produced a significant enhancement in the electromagnetic interference shielding effectiveness (EMI-SE) from -29.4 dB for CF/epoxy-composite to -51.1 dB for CF-MWCNT/epoxy multiscale composites of 2 mm thickness. In addition to enhanced EMI-SE, interlaminar shear strength improved from 23 MPa for CF/epoxy-composites to 50 MPa for multiscale composites indicating their usefulness for making structurally strong microwave shields. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported Licens

A randomised clinical study to compare the haemodynamic effects of etomidate with propofol during induction of general anaesthesia

Background: Induction agents are frequently associated with changes in heart rate and blood pressure and various adverse effects. Since the introduction of general anaesthesia, no ideal induction agent has yet been discovered in term of providing a stable hemodynamic with fewer adverse effects. This prospective randomized clinical study was conducted to compare propofol and etomidate for their effect on hemodynamic and various adverse effects on patients scheduled for elective surgeries during the induction of general anesthesia.Methods: 50 patients of ASA I and II of age group 18-60 years scheduled for elective surgeries under general anaesthesia were randomly assigned in two groups (n=25) receiving etomidate (0.3 mg/kg) in group E and propofol (2.5 mg/kg) in group P as an induction agent. Hemodynamic parameters were recorded at various time intervals. Any adverse effect pain on injection and myoclonus was carefully watched. VAS score was recorded for pain on injection. Statistical analysis was done using software (SPSS IBM version 20). P value was considered significant if (p0.05). Patients in propofol group showed significant fall of  systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP) and compared to etomidate (P<0.05).) Pain on injection was more in propofol group (P=0.021), While incidence of myoclonus activity was higher in etomidate group (P=0.0027).Conclusions: Etomidate is a better induction agent over propofol as it provides more hemodynamic stability and less pain on injection as compared to propofol

Effect of Bleaching on Color Change and Surface Topography of Composite Restorations

This study was conducted to determine the effect of 15% carbamide peroxide bleaching agent on color change and surface topography of different composite veneering materials (Filtek Z350 (3M ESPE), Esthet X (Dentsply India), and Admira (Voco, Germany). Methods. 30 samples were fabricated for evaluation of color change using CIELAB color system and Gonioreflectometer (GK 311/M, ZEISS). 45 disc-shaped specimens were made for evaluation of surface topography after bleaching (Nupro White Gold; Dentsply) using SEM. Statistical analysis. One way ANOVA and Multiple comparison tests were used to analyze the data. Statistical significance was declared if the P value was .05 or less. Results and conclusion. All the specimens showed significant discoloration (ΔE > 3.3) after their immersion in solutions representing food and beverages. The total color change after bleaching as compared to baseline color was significant in Filtek Z350 (P = .000) and Esthet X (P = .002), while it was insignificant for Admira (P = .18). Esthet X showed maximum surface roughness followed by Admira and Filtek Z350. Bleaching was effective in reducing the discoloration to a clinically acceptable value in all the three groups (ΔE < 3.3)

A prospective randomized study for comparison of haemodynamic changes and recovery characteristics with propofol and sevoflurane anaesthesia during laparoscopic cholecystectomies

Background: Day care laparoscopic surgical procedures are rapidly increasing nowadays. Rapid emergence and early recovery from anaesthesia with minimal complications are desired. Both propofol and sevoflurane meet above criteria and established as agents of choice in laparoscopic surgeries for induction and maintenance of anaesthesia. So this study aimed to compare sevoflurane with propofol for intraoperative haemodynamic changes with postoperative recovery profile in patient’s undergone laparoscopic cholecystectomies under general anaesthesia.Methods: In this prospective randomized study, sixty patients of either sex, 18-60 years with ASA grade 1 and 2 scheduled for laparoscopic cholecystectomies under general anaesthesia were randomly allocated into two groups. In Group S, patients were maintained on sevoflurane anaesthesia (0.5-2.5%) while in Group P, patients were maintained with propofol infusion (75-125 µg/kg/min) along with O2 (50%) and N2O (50%).The intraoperative haemodynamic parameters, recovery characteristics and postoperative nausea and vomiting (PONV) were observed in both groups.Results: The mean baseline haemodynamic parameters (HR, SBP, DBP, MBP, SpO2 and EtCO2) were comparable in both groups, (P>0.05). No significant difference in HR was at observed any time interval, P>0.05, however, SBP, DBP and MBP were significantly lower in propofol group at different time intervals, P<0.05, but clinically not significant and patients remained haemodynamically stable in both groups. The mean time for all recovery characteristics were significantly shorter in sevoflurane group as compared to propofol group, (P<0.01). However the incidence of PONV was significantly more in sevoflurane group.Conclusions: Sevoflurane can be used as an effective alternative to propofol for maintenance of anaesthesia in day care laparoscopic procedures as it has better recovery profile with stable haemodynamic parameters

COMPARISON OF PREDICTORS OF DIFFICULT INTUBATION

Context: Unanticipated difficult laryngoscopy and tracheal intubation always remain a primary concern for an anaesthesiologist as the failure to maintain a patent airway during induction of anaesthesia may lead to anaesthesia related morbidity and mortality. Aims: The aim of our study was to predict difficult intubation and to identify best predictor(s) among them and also to compare the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of various airway parameters.Airway parameters taken in our study were Modified Mallampati Classification (MMT), Thyromental Distance (TMD), Sternomental Distance (SMD), Interincisor Gap (IIG), Upper Lip Bite Test (ULBT), Degree of Neck Extension (DNE), Anterior Subluxation of Mandible (ASM) and Protruding Teeth (PT). Methods and Material: 350 patients of ASA Grade 1 and 2 scheduled for various elective surgeries under general anaesthesia were included in our study and were assessed preoperatively for different airway parameters. Intraoperatively all patients were classified as difficult and easy intubation group according to Cormack and Lehane laryngoscopic view. Clinical data of each test was collected, tabulated and analyzed to obtain the sensitivity, specificity, positive predictive value and negative predictive value. Results: The upper lip bite test had the highest sensitivity (80%); Anterior subluxation of mandible had highest specificity (99.06%) and both of above were most accurate tests. The overall incidence of difficult intubation was 8.57%. Conclusion: Upper lip bite test was the best predictor of difficult intubation and it should be included as a routine test along with Modified mallampati test in preanaesthetic evaluation

COMPARISON OF PREDICTORS OF DIFFICULT INTUBATION

Context: Unanticipated difficult laryngoscopy and tracheal intubation always remain a primary concern for an anaesthesiologist as the failure to maintain a patent airway during induction of anaesthesia may lead to anaesthesia related morbidity and mortality. Aims: The aim of our study was to predict difficult intubation and to identify best predictor(s) among them and also to compare the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of various airway parameters.Airway parameters taken in our study were Modified Mallampati Classification (MMT), Thyromental Distance (TMD), Sternomental Distance (SMD), Interincisor Gap (IIG), Upper Lip Bite Test (ULBT), Degree of Neck Extension (DNE), Anterior Subluxation of Mandible (ASM) and Protruding Teeth (PT). Methods and Material: 350 patients of ASA Grade 1 and 2 scheduled for various elective surgeries under general anaesthesia were included in our study and were assessed preoperatively for different airway parameters. Intraoperatively all patients were classified as difficult and easy intubation group according to Cormack and Lehane laryngoscopic view. Clinical data of each test was collected, tabulated and analyzed to obtain the sensitivity, specificity, positive predictive value and negative predictive value. Results: The upper lip bite test had the highest sensitivity (80%); Anterior subluxation of mandible had highest specificity (99.06%) and both of above were most accurate tests. The overall incidence of difficult intubation was 8.57%. Conclusion: Upper lip bite test was the best predictor of difficult intubation and it should be included as a routine test along with Modified mallampati test in preanaesthetic evaluation

A comparative study of propofol and N2O versus sevoflurane and N2O with respect to haemodynamic response and ease of laryngeal mask airway insertion: a prospective randomized double blinded study

Background: Laryngeal mask airway (LMA) is an accepted airway device for spontaneous and modest positive pressure ventilation. Propofol is widely used Induction agent. Sevoflurane is a newer pleasant volatile anaesthetic with rapid induction and recovery with stable haemodynamics. The aim of this study was to compare propofol and sevoflurane with respect of haemodynamic changes and conditions for LMA insertion.Methods: This study was done on 60 female patients of ASA I, II grade between 20-60 years of age. Patients were randomized into two groups (n=30). All patients were preoxygenated and received inj. fentanyl 2µg/kg. Induction agent was propofol 2.5mg/kg (group P) or sevoflurane 8% with vital capacity breath (group S). Loss of eyelash reflex was the end point of induction. Induction time, conditions for LMA insertion, number of attempts, time of successful LMA insertion and haemodynamic parameters were noted.Results: time for induction and LMA insertion was significantly faster in propofol group than group S (p<0.05). Successful LMA insertion in first attempt was 100% in group P with excellent conditions (score 18) while in group S, it was 86.7% with excellent to satisfactory conditions (score 16-17). A significant fall in mean arterial pressure (p<0.05) was noted in group P while pulse rates were comparable in both groups.  Conclusions: Sevoflurane vital capacity breath inhalational induction can be used as an effective alternative to propofol though it requires greater time for LMA insertion but with better haemodynamic stability.

Certifications of citizenship: the history, politics and materiality of identity documents in South Asian states and diasporas

Experiences in the post-partition Indian subcontinent refute the conventional expectation that the 'possession of citizenship enables the acquisition of documents certifying it' (Jayal, 2013, 71). Instead, identity papers of various types play a vital part in certifying and authenticating claims to citizenship. This is particularly important in a context where the history of state formation, continuous migration flows and the rise of right-wing majoritarian politics has created an uncertain situation for individuals deemed to be on the ‘margins’ of the state. The papers that constitute this special issue bring together a range of disciplinary perspectives in order to investigate the history, politics and materiality of identity documents, and to dismantle citizenship as an absolute and fixed notion, seeking instead to theorise the very mutable ‘hierarchies’ and ‘degrees’ of citizenship. Collectively they offer a valuable lens onto how migrants, refugees and socio-economically marginal individuals negotiate their relationship with the state, both within South Asia and in South Asian diaspora communities. This introduction examines the wider context of the complex intersections between state-issued identity documents and the nature of citizenship and draws out cross-cutting themes across the papers in this collection