AANA journal course: update for nurse anesthetists--advances in ventilating the patient with severe lung disease

Mechanical ventilation has become commonplace in critical care environments and a number of improvements designed to improve the interface between patient and machine are finding their way into the operating room as well. Strategies which are discussed include differential lung ventilation, inspiratory pause, inverse ratio ventilation, mandatory minute volume, pressure support ventilation, and airway pressure release ventilation. These strategies are discussed individually in terms of both their theoretical and clinical utility. A user-friendly classification of ventilatory approaches based on the rate of breathing is also provided as is treatment of the issue of the cardiovascular effects of positive end-expiratory pressure. Conditions which increase ventilatory demand in mechanically ventilated patients are reviewed, as these require consideration when caring for the patient receiving mechanical ventilation. While conventional positive pressure approaches are suitable for the majority of patients who present for anesthesia and surgery, patients with significant pulmonary dysfunction should be availed the newer approaches to management when possible. This will only become feasible when practitioners recognize the importance and application of these approaches and urge their introduction into operating room based equipment.     

Solar photochemical process engineering for production of fuels and chemicals

The engineering costs and performance of a nominal 25000 scmd (883000 scfd) photochemical plant to produce dihydrogen from water have been studied. Two systems were considered, one based on flat-plate collector/reactors and the other on linear parabolic troughs. Engineering subsystems were specified including the collector/reactor, support hardware, field transport piping, gas compression equipment, and balance-of-plant (BOP) items. Overall plant efficiencies of 10.3 and 11.6% are estimated for the flat-plate and trough systems, respectively, based on assumed solar photochemical efficiencies of 12.9 and 14.6%. Because of the opposing effects of concentration ratio and operating temperature on efficiency, it was concluded that reactor cooling would be necessary with the trough system. Both active and passive cooling methods were considered. Capital costs and energy costs, for both concentrating and non-concentrating systems, were determined and their sensitivity to efficiency and economic parameters were analyzed. Results predict energy costs in the range of $34–55 per 10⁶ kJ ($36–59 per 10⁶ Btu) for the flat-plate system and $94–141 per 10⁶ kJ ($99 to $149 per 10⁶ Btu) for the trough system. The overall plant efficiency is the single most important factor in determining the cost of the fuel. Therefore, solar quantum conversion processes were reviewed for the purpose of identifying processes which promise better performance and lower costs.     

Changes in dialysis units'' quality improvement practices from 1994 to 1996

We studied the effect of gravity on cerebral cortical blood flow (CBF), mean arterial blood pressure (BPa) and heart rate in six rabbits exposed to parabolic flights. The CBF was obtained using a laser-Doppler probe fixed on to a cranial window. Before weightlessness, the animals were exposed to chest-to-back directed acceleration (1.8-2.0 g). The CBF values were expressed as a percentage of CBFo (mean CBF during 60 s before the 1st parabola). Propranolol (1 mg x kg[-1] i.v.) was given after the 11th parabola and pentobarbital (12-15 mg x kg[-1] i.v.) after the 16th parabola. Before the administration of the drugs, CBF increased (P < 0.01) during hypergravity [i.e. maximal CBF 151 (SD 64)% CBFo. Simultaneously BPa increased [maximal BPa, 119 (SD 11) mmHg (P < 0.01)]. At the onset of weightlessness, CBF and BPa reached maximal values [194 (SD 96)% CBFo (P < 0.01) and 127 (SD 19) mmHg, (P < 0.01) respectively]. The microgravity-induced increase in CBF was transient since CBF returned to its baseline value after 8 (SD 2) s of microgravity. After propranolol administration, CBF was not statistically different during hypergravity but an elevation of CBF was still observed in weightlessness. The increases in CBF and BPa also persisted during weightlessness after pentobarbital administration. These data would indicate that CBF of nonanesthetized rabbits increases during the first seconds of weightlessness and demonstrate the involvement of rapid active regulatory mechanisms since CBF returned to control values within 8 (SD 2) s. We concluded that this elevation in blood flow was not related to stress because it persisted after the administration of propranolol and pentobarbital.     

Segregation analysis of the testis-determining autosomal trait, Tda, that differs between the C57Bl/6J and DBA/2J mouse strains suggests a multigenic threshold model

The testis-determining autosomal trait (Tda) of the mouse was uncovered when the Y chromosome of the poschiavinus variety of Mus musculus domesticus was introduced into the C57BL/6J laboratory strain background. Testis development is normal in the F1 generation but, in the backcross and subsequent crosses to C57BL/6J females, XY individuals with the poschiavinus Y chromosome expressed bilateral ovaries or various combinations of an ovotestis with a contralateral ovary or testis or bilateral ovotestes and few had testes bilaterally. In other strain backgrounds, such as DBA/2J, XY individuals with the poschiavinus Y chromosome always expressed normal testes bilaterally. The first breeding analysis of this difference in the interaction of strain background with the poschiavinus Y chromosome suggested that the Tda trait was due to a single gene, but attempts to map it failed. We constructed two strains of C57BL/6J and DBA/2J that are consomic for the poschiavinus Y chromosome in order to conduct a segregation analysis of the Tda trait. In the C57BL/6J.Y-POS consomic strain, liability to express incomplete testis development is normally distributed and thresholds in development specify the probability of different classes of ovary, ovotestis, and testis combinations. Testis development is complete in the DBA/2J.Y-POS consomic strain. We demonstrated previously that the Tda trait of C57BL/6J is recessive to that of DBA/2J and the segregating first backcross generation of embryos rejected the single-gene model. We have extended our analysis to a F2 generation of embryos that also rejects a single-gene model. We also report a test mating analysis of the first backcross generation. It was initiated to provide an independent assessment of the single-gene model, but the analysis of the distribution of test mating results suggests that the difference in the Tda trait between C57BL/6J and DBA/2J may be due to a small number of loci, possibly four or five, and that the phenotypic effect between loci may be additive.     

The chemistry of ethyl silicate binders in refractory technology

The chemistry of the processes involved when an alkyl silicate such as ethyl silicate acts as a binder in refractory technology is described. The gel forming process involving catalysed hydrolysis and condensation of ethyl silicate and tetra-alkyl silicates has been studied using amine catalysts. Thermal studies of gels obtained from technical ethyl silicate and of gels obtained from technical ethyl silicate incorporated in refractory materials, together with infrared spectroscopy studies of gels obtained from technical ethyl silicate, suggest the nature of the degradation products, and the weight-loss patterns observed support the proposed mechanisms.     

Data management for an interactive graphics system oriented to planning applications

INTRANS is a man-computer interactive graphics system, intended for analysis of urban and transportation planning problems. It is designed to operate primarily under time sharing on IBM 360/370 computers. The paper describes the functional design and the structure of the data management of INTRANS.

The data management is designed to answer the specific needs of planning applications: large data-sets, comparative analysis of several alternatives, and interface with batch processing computer programs. At the same time, the system is designed to operate within an environment of extremely limited resources of core and computing time.     

Sex roles, classroom instruction, and reading achievement.

Boys learn to read more slowly than girls in American schools, and for some years American educators have been concerned about this fact and the problems it poses. Several explanations have been advanced for sex differences in reading achievement, including hypotheses based on physical maturation, female teacher bias, teacher discrimination, feminization of reading, differential response to pupil behaviors, and sex-relevant teaching styles. Each of these hypotheses is conceptualized here, and evidence for and against each hypothesis is reviewed. Current evidence is found sufficient to reject only 2 of the hypotheses, and it is suggested that more than 1 of the remaining hypotheses may be needed to explain sex differences in reading achievement. (103 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recipe for recycling

Across-the-board recyclers can keep discarded electronic products out of landfills by identifying and extracting component parts for resale and materials for reprocessing. The complete recycling of electrical and electronic equipment will in the future probably be handled by independent recyclers who become specialized in understanding the varieties of discarded equipment. They will plan the logistics of recovering any assemblies, components, and materials of value, and will develop the technologies necessary to extract them in a way that is economical and environmentally sound. The actual recycling activities will also probably take place in central locations, if for no other reason than the substantial costs of moving material and equipment. The integrated recycling approach ranks the means of disposal in order of feasibility: refurbishing; or equipment brokering, possibly to underdeveloped countries; component recovery; or full material recycling     

汽车产品的标准化方案

一直以来,半导体产业与军工和航空产业的关系非常密切。军事与政府项目加快了技术的发展,快速提高了元件的质量及其可靠性。多年来,美国政府始终通过国防后勤局（DLA)、Columbus国防供应中心(DSCC)等部门以及有关元件计划的陆海军联合项目(JNA)密切关注着军火商的活动。