Chemotherapy of fascioliasis: I.—Derivatives of di-(p-aminophenyl) methane and p-aminophenol

Di-(p-aminophenyl)methane and certain p-aminophenyl ethos, known to possess activity against the trematodes Schistosoma mansoni and Fasciola hepatica, have been converted into various derivatives in an attempt to enhance their effect on F. hepatica. Other compounds studied include 4-amino-7-chloro-quinolines and 6-aminobenz-l,3-dioxans.     

Social perception and the motivational structure of interpersonal relations.

An extension of a previous research (see 28: 673). The introduction of another variable, viz., the knowledge of the result of cooperative or competitive ventures, affected the perception of the partner. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus generalization as a function of clinical anxiety.

"It was hypothesized that the state inferred from manifest clinical symptoms of anxiety would show functionally similar motivational properties to the state of anxiety defined in terms of an implicit response that has been conditioned to situations involving noxious stimulation. It was predicted that both types of anxiety would exhibit the energizing properties of a drive and therefore elevate response gradients of generalization… . The results showed that the groups designated as high in clinical anxiety showed significantly more generalization than the low-clinical anxiety groups under the strong-shock condition. No difference was found between the 2 levels of clinical anxiety for either the weak-shock or buzzer condition." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of polarity reversal on defibrillation success with biphasic shocks and a transvenous/subcutaneous defibrillator system in a porcine animal model

Clinical studies show that polarity reversal affects defibrillation success in transvenous monophasic defibrillators. Current devices use biphasic shocks for defibrillation. We investigated in a porcine animal model whether polarity reversal influences defibrillation success with biphasic shocks. In nine anesthetized, ventilated pigs, the defibrillation efficacy of biphasic shocks (14.3 ms and 10.8 ms pulse duration) with "initial polarity" (IP, distal electrode = cathode) and "reversed polarity" (RP, distal electrode = anode) delivered via a transvenous/subcutaneous lead system was compared. Voltage and current of each defibrillating pulse were recorded on an oscilloscope and impedance calculated as voltage divided by current. Cumulative defibrillation success was significantly higher for RP than for IP for both pulse durations (55% vs 44%, P = 0.019) for 14.3 ms (57% vs 45%, P < 0.05) and insignificantly higher for 10.8 ms (52% vs 42%, P = ns). Impedance was significantly lower with RP at the trailing edge of pulse 1 (IP: 44 +/- 8.4 vs RP: 37 +/- 9.3 with 14.3 ms, P < 0.001 and IP: 44 +/- 6.2 vs RP: 41 +/- 7.6 omega with 10.8 ms, P < 0.001) and the leading edge of pulse 2 (IP: 37 +/- 5 vs RP: 35 +/- 4.2 omega with 14.3 ms, P = 0.05 and IP: 37.5 +/- 3.7 vs RP: 36 +/- 5 omega with 10.8 ms, P = 0.02). In conclusion, in this animal model, internal defibrillation using the distal coil as anode results in higher defibrillation efficacy than using the distal coil as cathode. Calculated impedances show different courses throughout the shock pulses suggesting differences in current flow during the shock.     

Evaluation of catalytic properties of tungsten carbide for the anode of microbial fuel cells

In this communication we discuss the properties of tungsten carbide, WC, as anodic electrocatalyst for microbial fuel cell application. The electrocatalytic activity of tungsten carbide is evaluated in the light of its preparation procedure, its structural properties as well as the pH and the composition of the anolyte solution and the catalyst load. The activity of the noble-metal-free electrocatalyst towards the oxidation of several common microbial fermentation products (hydrogen, formate, lactate, ethanol) is studied for microbial fuel cell conditions (e.g., pH 5, room temperature and ambient pressure). Current densities of up to 8.8 mA cm⁻² are achieved for hydrogen (hydrogen saturated electrolyte solution), and up to 2 mA cm⁻² for formate and lactate, respectively. No activity was observed for ethanol electrooxidation.

The electrocatalytic activity and chemical stability of tungsten carbide is excellent in acidic to pH neutral potassium chloride electrolyte solutions, whereas higher phosphate concentrations at neutral pH support an oxidative degradation.     

Surveillance cultures of tunneled cuffed catheter exit sites in chronic hemodialysis patients are of no benefit

Catheter-related infections are a major cause of morbidity and mortality in hemodialysis (HD) patients. This study evaluated the utility of surveillance swab cultures (Ssc) of tunneled cuffed catheter (TCC) exit sites as a prediction and prevention strategy for infection. A 6-month prospective-controlled trial with 94 chronic HD patients with a TCC who received monthly Ssc and were stratified by dialysis day into topical therapy based on Ssc results (Group A) or no therapy (Group B). Outcomes were exit site infection (ESI) and catheter-associated bacteremia (CAB). The overall monthly prevalence of positive Ssc was 14.9%. There was no difference in the number of positive Ssc (17.7% vs. 11.6%, p > 0.05) or ESI (19.6% vs.16.3%, p > 0.05) between Groups A and B, respectively. Catheter-associated bacteremia was higher in Group A (17.7% vs. 4.7%, p = 0.05). There were significantly more ESI in the patients treated for a positive Ssc. In Group A, the incidence of ESI was significantly higher in those treated for a positive vs. negative Ssc (55% vs. 12%, p = 0.009) and CAB rates trended higher with positive Ssc (22.2% vs. 16.7%, p > 0.05). The strategy of treating positive surveillance cultures is not beneficial. Positive Ssc do not predict the occurrence of catheter-related infection, and treatment of these cultures may lead to increased infection rates.     

Evolutionary roots of motor planning: The end-state comfort effect in lemurs.

Humans (Homo sapiens) anticipate the consequences of their forthcoming actions. For example, they grasp objects with uncomfortable grasps to afford comfortable end positions—the end-state comfort (ESC) effect. When did such sophisticated motor planning abilities emerge in evolution? We addressed this question by asking whether humans' most distant living primate relatives—lemurs—also exhibit the ESC effect. We presented 6 species of lemurs (Lemur catta, Eulemur mongoz, Eulemur coronatus, Eulemur collaris, Hapalemur griseus, and Varecia rubra) with a food extraction task and measured the grasp used—either a canonical thumb-up posture or a noncanonical thumb-down posture. The lemurs adopted the thumb-down posture when that hand position afforded a thumb-up posture following object transport, thereby exhibiting the ESC effect. We conclude that the planning abilities underlying the ESC effect evolved at least 65 million years ago, or 25 million years earlier than previously supposed based on an earlier demonstration of the ESC effect in cotton-top tamarins (Saguinus oedipus; Weiss, Wark, & Rosenbaum, 2007). Because neither cotton-tops nor lemurs are tool users, the data suggest that the cognitive abilities implicated by the ESC effect are not sufficient, although they may be necessary, for tool use. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Statistical Procedure for Testing Nuclear Powered Cardiac Pacemakers

This article presents the results of a study of the functional case of the problem of parameter estimation when there is error in all the variables. There is consequently no distinction between independent and dependent variables. Posterior probability density functions are developed for the parameters with both linear and nonlinear, and possibly multiple, relations among the true values of the variables. There is no distinction between models that are linear or nonlinear in the parameters. The results are equivalent to generalizations of the work of some previous authors, but lead to new and efficient algorithms for finding point estimates and their precisions. For most of the results the error covariance matrix is assumed known, though a case is treated where it is known except for a scalar multiplier. The results are also shown to be valid if the covariance matrix is singular. Geometric interpretations are described.     

Electrothermal model for simulation of bulk-Si and SOI diodes in ESD protection circuits

An electrothermal diode model intended for implementation in a SPICE-like simulator is presented. The model is valid in the high current, forward-bias and reverse-breakdown regimes where diodes operate during ESD events. We also present a procedure for extracting the temperature of an SOI diode from an I–V measurement.