Comparison of prednisolone with piroxicam in complex regional pain syndrome following stroke: a randomized controlled trial

Background: Complex regional pain syndrome (CRPS) following stroke aggravates morbidity. CRPS is categorized as CRPSI when no clear nerve injury is defined, and CRPSII when associated with clear nerve injury. Aim: To compare the effect of prednisolone with that of piroxicam in patients with CRPSI following stroke. Design: Randomized controlled trial. Methods: Patients with CRPSI fulfilling the inclusion criteria (n = 60) underwent a detailed neurological examination, cranial CT scan, radiograph of chest and shoulder joint, blood counts and serum chemistry. Severity of stroke was assessed by the Canadian Neurological Scale (CNS), CRPS by scoring sensory, autonomic and motor symptoms, and activity of daily living by Barthel index (BI) score. Patients were randomly assigned prednisolone 40 mg or piroxicam 20 mg daily, and outcome was assessed at 1 month on the basis of CRPS and BI score. Results: Mean patient age was 56 years and 20 were female. Baseline clinical and radiological parameters were comparable between the two groups. In the prednisolone group, 83.3% patients showed significant improvement, compared to 16.7% in the piroxicam group. The mean change in CRPS score in prednisolone group was 6.47 (95%CI 4.37-7.36), whereas in piroxicam group it was only 0.47. The mean change in BI score was 7.9 (95%CI 0.82-5.98) in the prednisolone group, and 4.5 in the piroxicam group. Discussion: In this patient group, prednisolone resulted in significant improvement in the symptoms and signs of CRPSI following stroke, compared to piroxicam. Both drugs produced an improvement in the BI score

Synthesis of SmFeAsO by an Easy and Versatile Route and its Physical Property Characterization

We report synthesis, structure, electrical transport and heat capacity of SmFeAsO. The title compound is synthesized by one-step encapsulation of stoichiometric FeAs, Sm, and Sm2O3 in an evacuated (10-5 Torr) quartz tube by prolong (72 hours) annealing at 1100oC. The as synthesized compound is crystallized in tetragonal structure with P4/nmm space group having lattice parameters a = 3.93726(33) A and c = 8.49802(07) A. The resistance (R-T) measurements on the compound exhibited ground state spin-density-wave (SDW)-like metallic steps below 140 K. Heat capacity CP(T) measurements on the title compound, showed an anomaly at around 140 K, which is reminiscent of the SDW ordering of the compound. At lower temperatures the CP(T) shows a clear peak at around 4.5 K. At lower temperature below 20 K, Cp(T) is also measured under an applied field of 7 Tesla. It is concluded that the CP(T) peak at 4.5 K is due to the anti-ferromagnetic(AFM) ordering of Sm3+ spins. These results are in confirmation with ordering of Sm in Sm2-xCexCuO4.Comment: 9 pages Text + Figs Contact Author ([email protected]

Persistently high HIV seroprevalence among adult tuberculosis patients at a tertiary care centre in Delhi

Background & Objective: This study was designed to estimate HIV seroprevalence among tuberculosis patients presenting to tertiary care centre in Delhi. Methods: Cross-sectional prevalence study among all patients presenting to the inpatient and outpatient departments of All India Institute of Medical Sciences (AIIMS), New Delhi, and receiving anti-tuberculosis treatment from May 2003 to April 2005. Results: Of the 448 patients who presented to the TB clinic during the study period, 23 (5.1%) were previously tested HIV-positive. An additional 21 patients (4.6%) refused testing, and 30 (6.7%) were lost to follow up. Of the remaining 374 patients who consented to testing, 31 (8.3%) were found to be HIV-positive. Risk factors for HIV seropositivity included high-risk sexual behaviours (48% in HIV-TB co-infected vs. 6% in TB infected patients, P<0.001) and history of blood transfusion (23% vs. 5%; P=0.002). Interpretation & Conclusion: Previous studies from the same hospital published in 2000 and 2003 reported HIV seroprevalence among TB patients to be 0.4 and 9.4 per cent respectively. The current study documents a persistently high seropositivity among TB patients. These results emphasize the acute need for improved detection and treatment for HIV among TB patients in northern India

High Field Performance of Nano-Diamond Doped MgB2 Superconductor

Polycrystalline MgB2-nDx (x= 0 to 0.1) samples are synthesized by solid-state route with ingredients of Mg, B and n-Diamond. The results from magneto-transport and magnetization of nano-diamond doped MgB2-nDx are reported. Superconducting transition temperature (Tc) is not affected significantly by x up to x = 0.05 and latter decreases slightly for higher x > 0.05. R(T) vs H measurements show higher Tc values under same applied magnetic fields for the nano-diamond added samples, resulting in higher estimated Hc2 values. From the magnetization measurements it was found that irreversibility field value Hirr for the pristine sample is 7.5 Tesla at 4 K and the same is increased to 13.5 Tesla for 3-wt% nD added sample at the same temperature. The Jc(H) plots at all temperatures show that Jc value is lowest at all applied fields for pristine MgB2 and the sample doped with 3-wt% nD gives the best Jc values at all fields. For the pure sample the value of Jc is of the order of 105 A/cm2 at lower fields but it decreases very fast as the magnetic field is applied and becomes negligible above 7 Tesla. The Jc is 40 times higher than pure MgB2 at 10 K at 6 Tesla field in case of 3%nD doped sample and its value is still of the order of 103 A/cm2 at 10 Tesla for the same sample. On the other hand at 20K the 5%nD sample shows the best performance at higher fields. These results are discussed in terms of extrinsic pinning due to dispersed n-Diamond in the host MgB2 matrix along with the intrinsic pinning due to possible substitution of C at Boron site and increased inter-band scattering for highly doped samples resulting in extraordinary performance of the doped system.Comment: 12 PAGES (TEXT+FIGS). ACCEPTED: J. APPL.PHYS. (MMM-2007 Proceedings

Anomalous heat capacity and X-ray photoelectron spectroscopy of Superconducting FeSe1/2Te1/2

The bulk polycrystalline sample FeSe1/2Te1/2 is synthesized by solid state reaction route in an evacuated sealed quartz tube at 750 oC. The presence of superconductivity is confirmed through magnetization/thermoelectric/resistivity studies. It is found that the superconducting transition temperature (Tc) is around 12 K. Heat capacity (Cp) of superconducting FeSe1-xTex exhibited a hump near Tc, instead of well defined Lambda transition. X-ray Photo electron spectroscopy (XPS) studies revealed well defined positions for divalent Fe, Se and Te but with sufficient hybridization of Fe (2p) and Se/Te (3d) core levels. In particular divalent Fe is shifted to higher BE (binding energy) and Se and Te to lower. The situation is similar to that as observed earlier for famous Cu based HTSc (High Tc superconductors), where Cu (3d) orbital hybridizes with O (2p). We also found the satellite peak of Fe at 712.00 eV, which is attributed to charge carrier localization induced by Fe at 2c site.Comment: 12 pages text + Figs contact Author-VPS Awana (www.freewebs.com/vpsawana

Nonlinear model predictive control using feedback linearization for a pressurized water nuclear power plant

The present work aims to introduce a nonlinear control scheme that combines intelligent feedback linearization (FBL) and a model predictive control (MPC) for a pressurized water reactor (PWR). The nonlinear plant model that is considered in this study is described by the first-principles approach, and it consists of 38 state variables. First, system identification using a dynamic neural network (DNN) structure is performed to obtain a standard affine nonlinear system. The quasi-Newton algorithm is employed to find the best DNN model. Then, an FBL is formulated to address the nonlinearity of the DNN model. An MPC controller is developed based on the FBL system to improve the system performance. The designed controller is compared with a linear MPC controller that is based on state-space models to evaluate the performance of the proposed controller. The proposed approach improves the load-following operation and offers better disturbance rejection capability than the conventional MPC. In addition, numerical measures are employed to compare and analyse the performances of the two control strategies

Dynamic Neural Network-based System Identification of a Pressurized Water Reactor

This work presents a dynamic neural network based (DNN) system identification approach for a pressurized water nuclear reactor. The presented empirical modelling approach describes the DNN structure using differential equations. Local optimization algorithms based on unconstrained Quasi-Newton and interior point approaches are used in the identification process. The efficacy of the proposed approach has been demonstrated by identifying a nuclear reactor core coupled with thermal-hydraulics. DNNs are employed to train the structure and validate it using the nuclear reactor data. The simulation results show that the neural network identified model is sufficiently able to capture the dynamics of the nuclear reactor and it is suitably able to approximate the complex nuclear reactor system

Physical property characterization of Fe-tube encapsulated and vacuum annealed bulk MgB2

We report phase formation, and detailed study of magnetization and resistivity under magnetic field of MgB2 polycrystalline bulk samples prepared by Fe-tube encapsulated and vacuum (10-5 torr) annealed (750 0C) route. Zero-field-cooled magnetic susceptibility (cZFC) measurements exhibited sharp transition to superconducting state with a sizeable diamagnetic signal at 39 K (Tc). The measured magnetization loops of the samples, despite the presence of flux jumps, exhibited a stable current density (Jc) of around 2.4 x 105 A/cm2 in up to 2 T (Tesla) field and at temperatures (T) up to 10 K. The upper critical field is estimated from resistivity measurements in various fields and shows a typical value of 8 T at 21 K. Further, cFC measurements at an applied field of 0.1 T reveal paramagnetic Meissner effect (PME) that is briefly discussed.Comment: 13 pages text + figs. accepted: solid state commun. (2006