(Electro)Sensing of Phenicol Antibiotics—A Review

The presence of residues from frequent antibiotic use in animal feed can cause serious health risks by contaminating products meant for human consumption such as meat and milk. The present paper gives an overview of the electrochemical methods developed for the detection of phenicol antibiotic residues (chloramphenicol, thiamphenicol, and florfenicol) in different kinds of foodstuffs. Electrochemical sensors based on different biomolecules and nanomaterials are described. The detection limit of various developed methods with their advantages and disadvantages will be highlighted.     

The optimization of the multi-atmospheric Ar-Xe laser

The quasi-steady-state conditions of the multi-atmospheric e-beam sustained Ar-Xe laser are investigated. It is observed that the duration of the stationary period depends on the e-beam current, discharge power deposition, and gas pressure. The laser efficiency can be as high as 8%. Beyond the stationary period the efficiency drops. The pulse energy with optimum efficiency depends strongly on the gas pressure. The maximum discharge efficiency of 5%-6% is at high pressure not sensitive to the input power. The best results are obtained for 4 bar with a discharge input power of 8 MW/l. The pulse duration with corresponding output energies is 12 μs with 10 J/l and 16 μs with 16 J/l for e-beam currents of 0.4 and 0.9 A/cm², respectively. An analysis of the quasi-steady-state conditions that include the effects of electron collision mixing and atomic quenching is presented. The effects of output power saturation by the fractional ionization and atomic collisions are in agreement with the observations. The analysis clarifies the optimum performance conditions     

The role of cholecystokinin and the cholinergic system in intravenous amino acid-induced gallbladder emptying

BACKGROUND: Recent studies have demonstrated that separate intravenous infusion of amino acids (IVAA) at high doses induces gallbladder emptying. However, little is known about the mechanisms mediating IVAA-induced gallbladder contraction. OBJECTIVE AND METHODS: To investigate whether the effect of IVAA on gallbladder motility is mediated by the cholinergic system and/or cholecystokinin (CCK), the major hormonal stimulus for gallbladder contraction. Six healthy male volunteers were studied in random order on five occasions using: (a) IVAA, (b) loxiglumide (CR 1505, a selective CCK-A receptor antagonist), (c) IVAA plus loxiglumide, (d) atropine and (e) IVAA plus atropine. Gallbladder volumes (ultrasonography) and plasma CCK levels (radioimmunoassay) were determined every 15 min for 60 min before and for 120 min during intravenous infusion of amino acids (Vamin 18EF; 250 mg protein/kg/h) and/or loxiglumide (10 mg/kg/h) and/or atropine (0.005 mg/kg/h). RESULTS: IVAA significantly (P < 0.05) reduced gallbladder volume from 32 +/- 5 ml to 17 +/- 2 ml but induced only a small and transient increase in plasma CCK levels. Loxiglumide given alone significantly (P < 0.05) increased fasting gallbladder volume to 190% of the basal value. IVAA-induced gallbladder emptying was completely abolished by loxiglumide. Maximal gallbladder relaxation during IVAA plus loxiglumide was not significantly different compared to loxiglumide given alone. Concomitant administration of atropine also significantly (P < 0.05) inhibited IVAA-induced gallbladder emptying. CONCLUSION: In healthy volunteers intravenous infusion of high doses of amino acids results in a significant gallbladder contraction, which is inhibited by CCK-A receptor blockade and by atropine.     

Effect of insulin on basal and cholecystokinin-stimulated gallbladder motility in humans

Rheumatoid arthritis (RA) is a chronic, systemic, progressively deteriorating, connective tissue disease characterized by inflammation of the synovial membrane of the joints, pain, immobility, and fatigue. Exacerbations of RA are frequently associated with periods of physical and/or emotional stress. It is estimated that 1 in every 100 persons throughout the world suffers from RA. In the United States, women have 2 to 3 times the incidence rate of men, with no significant radical differences noted between Caucasians and African-Americans. In this article a case study format is used to provide information pertaining to the diagnosis and treatment of the adult RA patient.     

Stationary phase method for far-field computation of defocused reflector antennas

Computation of the far field of a defocused reflector antenna using the stationary phase method is described. The positions of the stationary phase points are determined, to eliminate one of the two numerical integrations of the radiation integral. Examples of scan patterns and computational time saving are presented.