PdTe a 4.5K Type II BCS Superconductor

We report on the structure and physical properties of bulk Palladium Tellurium superconductor, which is synthesized via quartz vacuum encapsulation technique at 750 C. The as synthesized compound is crystallized in hexagonal crystal structure. Magnetization and Magneto-transport measurements provided the values of lower and upper critical field to be 250 and 1200 Gauss respectively at 2 Kelvin. The Coherence length and GL parameter are estimated from the experimentally determined upper and lower critical fields, which are 45 nm and 1.48 respectively. The jump in Cp(T) at Tc is found to be 1.33 and the Debye temperature and electronic specific heat constant are 203 Kelvin and 6.01mJ/mole-K2 respectively.Comment: 13 pages Text + Figs: Accepted in Sup. Sci. and Tec

The microstructure of bimetallic Ru---Cu/SiO2 catalysts: A chemisorption and analytical electron microscopy study

Supported bimetallic Ru---Cu/SiO2 catalysts are characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, electron microdiffraction, and chemisorption. Metal particles up to 4 nm in diameter are bimetallic, while particles larger than 4 nm contain only Cu. Considerable compositional nonuniformity is observed from one individual metal particle to the next. Microdiffraction patterns obtained from individual particles can be attributed to either Ru or Cu suggesting no significant modification in crystallographic structure of either metal component. Addition of Cu to Ru results in a drastic suppression of H2 chemisorption while the extent of O2 chemisorption is not as strongly affected. The suppressed H2 chemisorption capability of Ru in the bimetallic catalysts is an indication of atomic interdispersion of Ru and Cu on the surface of the bimetallic clusters, leading to the break-up of the Ru ensembles which would be necessary for dissociation of molecular hydrogen. The influence of catalyst preparation techniques on the relative interdispersion of Ru and Cu and consequent discrepancies in the Ru---Cu literature are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26092/1/0000168.pd

Prevention of tracheal cartilage injury with modified Griggs technique during percutaneous tracheostomy - Randomized controlled cadaver study

Introduction: Tracheal stenosis is the most common severe late complication of percutaneous tracheostomy causing significant decrease in quality of life. Applying modified Griggs technique reduced the number of late tracheal stenoses observed in our clinical study. The aim of this study was to investigate the mechanism of this relationship. Materials and methods: Forty-six cadavers were randomized into two groups according to the mode of intervention during 2006-2008. Traditional versus modified Griggs technique was applied in the two groups consequently. Wider incision, surgical preparation, and bidirectional forceps dilation of tracheal wall were applied in modified technique. Injured cartilages were inspected by sight and touch consequently. Age, gender, level of intervention, and number of injured tracheal cartilages were registered. Results: Significantly less frequent tracheal cartilage injury was observed after modified (9%) than original (91%) Griggs technique (p<0.001). A moderate association between cartilage injury and increasing age was observed, whereas the level of intervention (p=0.445) and to gender (p=0.35) was not related to injury. Risk of cartilage injury decreased significantly (OR: 0.0264, 95%, CI: 0.005-0.153) with modified Griggs technique as determined in adjusted logistic regression model. Discussion: Modified Griggs technique decreased the risk of tracheal cartilage injury significantly in our cadaver study. This observation may explain the decreased number of late tracheal stenosis after application of the modified Griggs method. © 2012 Akadémiai Kiadó, Budapes

Suppression of fentanyl-induced cough. A priming dose of intravenous dexmedetomidine–magnesium sulfate: A double blind, randomized, controlled s

Introduction: Fentanyl induced cough (FIC) often follows bolus fentanyl administration in 18% up to 65% of cases. Several researches have been done to reduce such side effect. Our hypothesis is that pretreatment with intravenous dexmedetomidine–magnesium sulfate could effectively suppress fentanyl induced cough. Patients and methods: 200 patients of (ASA) I and I aged 18–60 years, weighting from 40 to 90 kg, undergoing elective surgeries, were randomized into four groups using sealed envelope system. Patients belong to (D) group received DEX 0.5 μg/kg. Patients belong to group (M) received magnesium sulfate 20 mg/kg, and those of group (D + M) received DEX 0.5 μg/kg + magnesium sulfate 20 mg/kg. The above preparations were reconstructed by saline to reach a volume of 20 ml. Patients belong to group (S) received 20 ml normal saline. Patients of each group received their cross bonding drug one minute before fentanyl bolus injection (2 μg/kg within 5 s). The primary end points were the onset time, frequency and severity of cough from time of fentanyl injection till 1 min. According to four point scale, severity of cough was graded as follows: grade 0 = no cough; grade 1 = single cough; grade 2 = more than one attack of non-sustained cough; grade 3 = repeated and sustained cough with head lift. Results: Nineteen (38%) cases had cough in group (S), 8(16%) in group (D) and 14(28%) cases in group (M). No patients in group (D + M) experienced any cough. Patients of groups (D) and (D + M) showed a significantly lower incidence of cough compared with group (S) (P < 0.05). There was no significant difference regarding the onset time or severity of cough between groups. Conclusion: Pretreatment with dexmedetomidine–magnesium sulfate could effectively suppress fentanyl induced cough following injection of 2 μg/kg fentanyl injected within 5 s