Observation of a uniform temperature dependence in the electrical resistance across the structural phase transition in thin film vanadium oxide (VO2VO_{2})

An electrical study of thin $VO_{2}$ films in the vicinity of the structural phase transition at $68^{0}C$ shows (a) that the electrical resistance $R$ follows $log (R)$ $\propto$ $-T$ over the $T$-range, $20 < T < 80 ^{0}C$ covering both sides of the structural transition, and (b) a history dependent hysteresis loop in $R$ upon thermal cycling. These features are attributed here to transport through a granular network.Comment: 3 pages, 3 color figure

Demonstration of a 1/4 cycle phase shift in the radiation-induced oscillatory-magnetoresistance in GaAs/AlGaAs devices

We examine the phase and the period of the radiation-induced oscillatory-magnetoresistance in GaAs/AlGaAs devices utilizing in-situ magnetic field calibration by Electron Spin Resonance of DiPhenyl-Picryl-Hydrazal. The results confirm a $f$-independent 1/4 cycle phase shift with respect to the $hf = j\hbar\omega_{c}$ condition for $j \geq 1$, and they also suggest a small ($\approx$ 2%) reduction in the effective mass ratio, $m^{*}/m$, with respect to the standard value for GaAs/AlGaAs devices.Comment: 4 pages, 4 color figure

Injection ranitidine induced death

Ranitidine is a histamine-2-receptor antagonist. It was a commonly used drug. It holds excellent safety record. Anaphylactic reactions to ranitidine is uncommonly encountered. Death due to ranitidine is extremely a rare event and very few cases are reported world-wide. Clinical history, Lab investigations and histological data of a 43-Years old woman with negative history of allergic events, who died suddenly after the intra-venous administration of 50mg of intravenous ranitidine which was prescribed as a routine pre medication prior hysterectomy is presented below. Though the incidence of anaphylactic reactions is less with ranitidine, precautions to be taken prior administration of the drug and when such an event is encountered it should be promptly managed

Radiopharmaceuticals Pattern of Development and Utilisation in India

The availability of research reactors at an early stage of our Atomic Energy Programme led to developmental efforts in the field of radiopharmaceuticals. Starting with temporary laboratories for this work, a sophisticated and dedicated Radiopharmaceutical Laboratory is now installed at Vashi in New Bombay. The use of several /sup 125/I-labelled compounds like Rose-Bengal, hippuran, etc. for imaging has been replaced over the years by /sup 99m/Tc compounds; the final formulations are prepared at the hospital using generators and cold kits supplied by the Board of Radioisotope Technology. Parallel with the development of short lived generators in radiopharmaceuticals came advances in imaging and instrumentation techniques, the scanners being replaced by sophisticated gamma cameras, with capabilities for tomography and computerisation. About 40 centres in India have the modern instrumentation and equipment needed for carrying out nuclear medicine procedures. Further growth of nuclear medicine centres in the country has, however, been limited by the need to import such advanced high cost instrumentation not currently available from indigenous sources. Regarding in-vitro radiopharmaceuticals, some RIA and IRMA kits and procedures have been developed. These include assay of T/sub 3/, T/sub 4/ and TSH in the thyroid group of hormones. Kits for several other important procedures are still being imported by some large medical centres. There are over a hundred and fifty medical laboratories carrying out RIA procedures

Radiation-induced magnetoresistance oscillations in two-dimensional electron systems under bichromatic irradiation

We analyze the magnetoresistance $R_{xx}$ oscillations in high-mobility two-dimensional electron systems induced by the combined driving of two radiation fields of frequency $\omega_1$ and $\omega_2$, based on the balance-equation approach to magnetotransport for high-carrier-density systems in Faraday geometry. It is shown that under bichromatic irradiation of $\omega_2\sim 1.5 \omega_1$, most of the characterstic peak-valley pairs in the curve of $R_{xx}$ versus magnetic field in the case of monochromatic irradiation of either $\omega_1$ or $\omega_2$ disappear, except the one around $\omega_1/\omega_c\sim 2$ or $\omega_2/\omega_c\sim 3$. $R_{xx}$ oscillations show up mainly as new peak-valley structures around other positions related to multiple photon processes of mixing frequencies $\omega_1+\omega_2$, $\omega_2-\omega_1$, etc. Many minima of these resistance peak-valley pairs can descend down to negative with enhancing radiation strength, indicating the possible bichromaticzero-resistance states.Comment: 5 pages, 3 figures. Accepted for publication in Phys. Rev.