Effect of hippocampal lesions and intertrial interval on single-alternation performance in the rat.

Trained 7 unoperated male Long-Evans hooded rats and 14 Ss with bilateral hippocampal or cortical lesions made by aspiration on a go, no-go task in which bar presses were reinforced on alternate trials. Performance was evaluated with both latency ratios (latency to 1st response on go trials/latency to 1st response on no-go trials) and response ratios (total responses on no-go trials/total responses on go trials). Ss were trained to criterion at successively increasing durations of ITI (10, 20, 40, and 80 sec.). While Ss with hippocampal lesions acquired the task more rapidly than controls with the initial 10-sec ITI, they were severely impaired when tested with the longer ITIs. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Laparoscopic colonic resection

We present our initial experience with laparoscopic colonic resection in 15 patients: adenocarcinoma of the colon, 10 cases, giant villous adenoma (2), arteriovenous malformation (2), and a case of benign stricture. Mean operating time was 190 minutes and there were no intraoperative complications. The margins of resection and number of resected lymph nodes in patients with malignancy were comparable to those in the conventionally operated. Mean postoperative hospital stay was 6.1 days. During a maximum follow-up of 15 months there were no wound or trocar-site recurrences. We conclude that laparoscopic colonic resection is technically feasible and safe. However, its use for treating malignant diseases of the colon needs further study.     

Aluminum bisphenoxides: Promising challengers for a catalyzed copolymerization of cyclohexene oxide with CO2

Reacting triethyl aluminum and diethyl aluminum chloride with the chelating bisphenol ligands mdtbpH2 and mmcpH2 [mmcpH2: 2,2′-methylenebis(4-methyl-6-(1-methyl-cyclohexyl)phenol); mdtbpH2: 2,2′-methylenebis(4,6-di-tert-butyl-phenol)] afforded monomeric and dimeric aluminum bisphenoxides with reactive Al–Cl and Al–C₂H₅ moieties. We present here the X-ray structure determination of some of the isolated compounds as well as the preliminary catalytic tests in copolymerization reactions with cyclohexene oxide and carbon dioxide.     

Indirect electrochemical detection of type-B trichothecene mycotoxins.

Trichothecene mycotoxins in animal feed and human food can cause fatalities in livestock and disease in humans. In addition, these toxins are suspected chemical warfare agents. Therefore, development of a simple and sensitive method for the screening of trichothecenes is important to prevent economic loss and health hazards. A simple and inexpensive method for the detection of type-B trichothecene mycotoxins has been developed in our laboratory. By hydrolyzing the toxin under basic conditions at 80 degrees C for 1 h it is possible to detect the toxin with simple electrochemical techniques. Deoxynivalenol (DON), commonly known as vomitoxin, was used as a representative compound for type-B trichothecenes in this detection scheme. The detection limit for DON using our procedures was determined to be 9.1 microM in solution, corresponding to 0.24 ppm in a 25-g grain sample if the final extraction volume is 2.2 mL. The linear dynamic detection range was determined to be from 0.32 ppm to greater than 32 ppm. In addition to standard solutions, this method was used on rice samples spiked with DON. It was demonstrated that there is no electrochemical interference from rice extract and that 1 ppm of DON in rice samples can be quantified. This method may be ideal for toxin screening in animal feeds or in runoff from sites that produce the compounds as chemical warfare agents. Since the active moiety in DON is common to virtually all type-B trichothecenes, our approach may be ideal for type-specific screening.     

Two-dimensional matrix addressed vertical cavity top-surfaceemitting laser array display

We present the design, fabrication, and demonstration of a 10×10 matrix-addressed vertical-cavity top-surface-emitting laser (VCSEL) array. These arrays are batch-fabricated from full 3-in diameter GaAs/AlGaAs wafers. We show that no performance-penalty is paid using top-contacted matrix addressed pixels over conventional planar VCSEL devices. A computer-controlled display system for electrically addressing the array was designed and constructed to permit video demonstration and array testing