Do behavior changes herald physical illness in adults with mental retardation?

Nitric oxide (NO) is a major candidate in vagal-induced LOS relaxation. Vagal adrenergic fibres also innervate the gastrointestinal tract including the LOS. This study investigates the role of these two and other mechanisms in LOS responses to vagal activation in the rat, and provides functional and anatomical evidence for a smooth muscle LOS in this species. LOS, gastric and oesophageal pressures were measured in urethane anaesthetized rats during vagal stimulation. The LOS pressure (LOSP) response to Vagal stimulation (5 mA, 10 Hz, 0.5 msec pulses, 5 sec) comprised three consecutive stages: (1) brief reduction of LOSP, (2) transient increase of LOSP and (3) prolonged reduction of LOSP. The influences of additive treatment with several antagonist drugs on the LOS response to vagal stimulation were investigated. L-NAME (100 mg kg-1) reduced stage 1 and increased stage 2. Subsequent treatment with either phentolamine (1 mg kg-1) or prazosin (200 micrograms kg-1) abolished stage 1. After phentolamine, atropine treatment (400 micrograms kg-1) abolished stage 2. Stage 3 was evident throughout experiments. In five additional studies, treatment with hexamethonium (30 mg kg-1) abolished stages 2 and 3 leaving stage 1, which was later abolished by phentolamine or atropine. In the LOS response to vagal stimulation, the following major mechanisms are therefore evident: nicotinic transmission in both excitation and inhibition, alpha-adrenergic and NO-mediated inhibition, muscarinic excitation, and non-adrenergic, non-NO inhibition (not characterized further). Characteristics of these different neurotransmitter influences may be important in LOS relaxation associated with swallowing and gastro-oesophageal reflux.     

Salvaging solder joints accidentally exposed to nitric acid: A case study

This paper presents a case report where the soldered joints of Microwave Integrated Circuits were accidentally contaminated with nitric acid. On meeting with an accident a decision on whether to accept the assembled box is very crucial, particularly in complicated and high reliability hardware, where a high cost and numerous efforts of inspection are involved. The reliability of such joints were evaluated by subjecting the simulated joints of chip capacitors to a number of environmental tests and by measuring capacitance, dissipation factor and die shear strength as end parameters.     

Comments on "An Efficient SS/TDMA Time Slot Assignment Algorithm"

The time slot assignment algorithm presented in the above paper needs certain improvements for it to be an efficient one. In this correspondence, the necessary improvements are incorporated and an improved SS/TDMA time slot assignment algorithm is presented. The new algorithm is compared to the old one and the computer simulation exhibits a better performance of the present algorithm.     

Synthesis, Characterization, and Evaluation of Mesoporous MCM-41-supported Molybdenum Hydrotreating Catalysts

Mesoporous MCM-41 material with high surface area and narrow pore size distribution was synthesized and used as a support for Mo, CoMo, and NiMo catalysts. The molybdenum loading was varied from 2-14 wt% on MCM-41. On 10 wt% Mo/MCM-41, the promoter Co or Ni concentration was varied from 1-5 wt%. All the catalyst samples were characterized by surface area, low temperature oxygen chemisorption, x-ray diffraction (XRD), and temperature programmed reduction methods. Characterization results show that Mo is well dispersed on MCM-41 up to 10 wt%. The catalytic activities were evaluated for thiophene hydrodesulphurization (HDS), cyclohexene hydrogenation (HYD), and furan hydrodeoxygenation (HDO). All three catalytic functionalities vary in a similar manner to that of oxygen chemisorption as a function of Mo loading, indicating that there is a correlation between oxygen uptake and catalytic sites. The activities of these catalysts were compared with γ-Al₂O₃- and amorphous SiO₂-supported catalysts. It was found that MCM-41-supported Mo catalysts displayed superior activities.     

Nucleation of ZnTe/CdTe epitaxy on high-miller-index Si surfaces

Tellurium-adsorption studies were conducted on {111}-type Si surfaces that are off-cut from the {111} in the range of 0–30° on both nonpassivated-and arsenic-passivated Si surfaces. Relative surface coverages as a function of Te exposure time and Si-surface orientation were obtained with in-situ x-ray photoelectron spectroscopy (XPS). The XPS results indicate that Te coverage on arsenic-passivated Si surfaces increases as the step density of the surface increases. In contrast, Te-adsorption studies conducted on nonpassivated-Si surfaces showed no dependence between Te coverage and the surface-step density. Subsequent ZnTe and CdTe molecular-beam epitaxial growth on these high-Miller-index Si surfaces further validate a step-edge nucleation model. Additionally, it was observed that the CdTe-epilayer orientation did not always reproduce the Si-substrate orientation and was a function of both the initial Si surface and the growth conditions used.     

Segment III cholangiojejunostomy for carcinoma of the gallbladder

Jaundice in patients of advanced carcinoma of the gallbladder requires palliation for the distressing symptoms of pruritus and cholangitis. Intrahepatic segment III duct cholangiojejunostomy is a means for alleviating the obstruction with malignant porta block. The authors reviewed their experience with this procedure in 48 patients of carcinoma of the gallbladder. All patients had jaundice; pruritus was present in 44 (92%) and cholangitis in 14 (29%). The level of obstruction was determined preoperatively by percutaneous transhepatic cholangiography. In 32 patients the block was below the level of the bifurcation of the right and left ducts, and 16 patients had a block involving the confluence, isolating the two lobes of the liver. Following segment III cholangiojejunostomy, pruritus was relieved in all and cholangitis in 86% of patients. At the end of 6 weeks a significant fall in serum bilirubin and alkaline phosphatase levels was seen with both types of hilar obstruction. Varying degrees of pain relief was also noted in 75% of patients. Segment III biliary bypass is an effective, one-time, reliable means of palliation for carcinoma of the gallbladder with hilar obstruction. Its efficacy appears to depend on the duration and depth of the jaundice and on the anatomy of the biliary ductal system in the left hemiliver rather than on the type of hilar obstruction.     

Secrecy Outage of a Cognitive Radio Network with Selection of Energy Harvesting Relay and Imperfect CSI

Wireless Personal Communications - This paper investigates the physical layer security of an underlay cognitive radio network with relay selection scheme under threats of an eavesdropper. We...