Raoult's Formalism in Understanding Low Temperature Growth of GaN Nanowires using Binary Precursor

Growth of GaN nanowires are carried out via metal initiated vapor-liquid-solid mechanism, with Au as the catalyst. In chemical vapour deposition technique, GaN nanowires are usually grown at high temperatures in the range of 900-1100 ^oC because of low vapor pressure of Ga below 900 ^oC. In the present study, we have grown the GaN nanowires at a temperature, as low as 700 ^oC. Role of indium in the reduction of growth temperature is discussed in the ambit of Raoult's law. Indium is used to increase the vapor pressure of the Ga sufficiently to evaporate even at low temperature initiating the growth of GaN nanowires. In addition to the studies related to structural and vibrational properties, optical properties of the grown nanowires are also reported for detailed structural analysis.Comment: 24 pages, 7 figures, journa

Optical Properties of Mono-Dispersed AlGaN Nanowires in the Single-Prong Growth Mechanism

Growth of mono-dispersed AlGaN nanowires of ternary wurtzite phase is reported using chemical vapour deposition technique in the vapour-liquid-solid process. The role of distribution of Au catalyst nanoparticles on the size and the shape of AlGaN nanowires are discussed. These variations in the morphology of the nanowires are understood invoking Ostwald ripening of Au catalyst nanoparticles at high temperature followed by the effect of single and multi-prong growth mechanism. Energy-filtered transmission electron microscopy is used as an evidence for the presence of Al in the as-prepared samples. A significant blue shift of the band gap, in the absence of quantum confinement effect in the nanowires with diameter about 100 nm, is used as a supportive evidence for the AlGaN alloy formation. Polarized resonance Raman spectroscopy with strong electron-phonon coupling along with optical confinement due to the dielectric contrast of nanowire with respect to that of surrounding media are adopted to understand the crystalline orientation of a single nanowire in the sub-diffraction limit of about 100 nm using 325 nm wavelength, for the first time. The results are compared with the structural analysis using high resolution transmission microscopic study.Comment: 33 pages, 7 figures, journa

Efficacy of iv infusion of magnesium sulphate and dromperidol on the management of neuropathic and somatosensory chronic pain-a two pain center study

Introduction: Droperidol as a medicine has unique properties and it has been successfully used as analgesic, antipsychotic, antiemetic and as a sedative [1]. It is an antagonist for d2-dopamine, serotonin, histamine, and nicotinic and muscarinic cholinergic receptors. It is also a dose-dependent agonist/antagonist of GABA receptors and an agonist of a2 adrenergic receptors. Moreover, is a sodium channel blocker such as lidocaine and potentiate μ opioid receptors. Its multi-receptor action justifies its use as analgesic, antiemetic and antiphycotic medication [2]. Magnesium seems to function as an antagonist for NMDA receptors and it has been used for relief of acute and chronic pain [3, 4]. The aim of the current study is the evaluation of the efficacy of droperidol and magnesium co-administration on the patients with chronic pain Method: All patients that attended the pain clinic for chronic pain and aged over 18 years old were included in the study. Patients with atrioventricular block any grade and patients with chronic renal failure were excluded from the study. All included patients received droperidol to the dose 2.5 mg maximum and 1 gr magnesium sulphate iv. DN4 questionnaire was used to assess the presence of neuropathic pain. VAS scale and NPS scale were used to assess the intensity of pain before and after the administration. Change in the pain scales calculated as a percentage. Results: 48 patients included in the study. 23 of them had neuropathic pain. There was a 40–50% reduction of the intensity of pain after iv administration of droperidol and magnesium. There weren’t any complications. Conclusions: The co-administration of magnesium and droperidol can relieve neuropathic and somatosensory pain. Long-term evaluation is needed. © 2021, Pharmamed Mado Ltd. All rights reserved