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Aline G. Cunha Angelo A. T. da Silva Mateus G. Godoy Rodrigo V. Almeida Alessandro B. C. Simas Denise M. G. Freire 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2013,88(2):205-211
BACKGROUND: The response surface methodology was successfully applied to the optimization of the reaction variables for the kinetic resolution of a precursor of high‐value myo‐inositols, ( ± )‐1,2‐O‐isopropylidene‐3,6‐di‐O‐benzyl‐myo‐inositol (( ± )‐1), by Novozym 435. The resolutions were run separately, with two acylating agents, ethyl acetate and vinyl acetate, in a solvent‐free system. The variables analyzed were reaction temperature, substrate concentration, water concentration and enzyme activity. A statistical model was employed for the evaluation of the influence of the variables on conversion and enantiomeric excess (ee). RESULTS: The optimal conditions for this resolution using vinyl acetate as acylating agent were 45 °C, 5 mg mL?1 of substrate, 71 U of enzyme activity and 0%w/w of water concentration. The high conversion (49.2 %) and ee (>99%) reached in the chemoenzymatic synthesis of acylated product, L‐(?)‐5‐O‐Acetyl‐3,6‐di‐O‐benzyl‐1,2‐O‐isopropylidene‐myo‐inositol, secure the efficient synthesis of the D enantiomorph present in the original racemic mixture (( ± )‐1) as well. CONCLUSIONS: The use of the experimental design strategy was productive, leading to a 14‐fold increase in the productivity of the reaction compared with the non‐optimized conditions. Both derivative L‐(?)‐2 and remaining substrate D‐(+)‐1 were obtained at high ee. © 2012 Society of Chemical Industry 相似文献
53.
Gross PA Patriaco D McGuire K Skurnick J Teichholz LE 《The Joint Commission journal on quality improvement》2002,28(10):566-573
BACKGROUND: Telemetry monitoring is widely used in hospitals; the importance of being able to monitor and examine dysrhythmias has been universally accepted. Yet it is often used for patients who do not actually require this technology. A model to improve the efficiency of telemetry use entailed the use of an advanced practice nurse (APN; identical to a nurse practitioner) to provide concurrent review and intervention of floating telemetry, which is available for patients independently of the floor location and who do not need an intensive care unit bed. ADDRESSING OVERUSE: The demand for floating telemetry at Hackensack University Medical Center had equaled or exceeded the telemetry availability virtually 100% of the time, even after local guidelines had been disseminated in 1998. The APN carried out concurrent monitoring and intervened with the attending physician when patients were on telemetry for longer than 48 hours and did not meet the local telemetry guidelines. RESULTS: The mean number (standard error [SE]) of hours per patient declined from 65.2 +/- 0.7 hours (95% confidence interval, 63.8 to 66.6 hours) for the 11 months before the intervention to a mean of 49.6 +/- 0.4 hours (95% confidence interval, 48.7 to 50.2 hours) for the 29 months after intervention--representing a decrease of 34% (p < 0.0001). This decrease led to an increase in the number of patients per month put on telemetry. DISCUSSION: The APN model, an aggressive approach that induced change almost immediately, was then applied to other quality improvement projects. 相似文献
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The influence of adolescents' autonomy and relatedness to parents on romantic relationships was examined longitudinally over 5 years in 76 middle-class African American late adolescents (mean age = 18.43 years). Relatedness to parents in early adolescence led to longer duration and more supportive romantic relationships in late adolescence, but longer duration was concurrently associated with more negative romantic relationships. Cluster analyses yielded 3 profiles of early adolescent autonomy and relatedness; early adolescents who were high in relatedness and low in autonomy to parents in early adolescence reported longer duration romantic relationships in late adolescence than did adolescents who were moderate or high in relatedness and high in autonomy. The implications for romantic development in African American middle-class youth are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
55.
Chen Edith; Hermann Cathy; Rodgers Denise; Oliver-Welker Tina; Strunk Robert C. 《Canadian Metallurgical Quarterly》2006,25(3):389
This study tested the relationship of anxiety and asthma severity to symptom perception. Eighty-six children diagnosed with mild or moderate asthma had symptom perception and pulmonary function measured throughout methacholine challenge (to induce bronchoconstriction). Higher trait anxiety was associated with heightened symptom perception (controlling for pulmonary function) at baseline. Greater asthma severity was associated with blunted symptom perception (controlling for pulmonary function) at the end of methacholine challenge and with a slower rate of increase in symptom perception across methacholine challenge. These results suggest that anxiety plays a role when children's symptoms are mild, whereas medical variables such as severity play a role in perception of changes in asthma symptomatology as bronchoconstriction worsens. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
In 3 experiments, novices were required to answer questions while reading a series of problems. The questions required them either to analyze individual problem structures (intraproblem processing) or compare problem structures (analogical comparison processing) to derive answers. Ss who engaged in problem comparison processing were found to categorize and describe problems on the basis of problem structure, whereas those who engaged in intraproblem processing, or simply read the problems, categorized and described them on the basis of surface features. Analogical comparisons also facilitated selection and construction of equations relative to intraproblem processing. These results suggest that analogical comparison is an important component in the induction of problem categories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Reisenzein Rainer; B?rdgen Sandra; Holtbernd Thomas; Matz Denise 《Canadian Metallurgical Quarterly》2006,91(2):295
Eight experiments examined facial expressions of surprise in adults. Surprise was induced by disconfirming a previously established schema or expectancy. Self-reports and behavioral measures indicated the presence of surprise in most participants, but surprise expressions were observed only in 4%-25%, and most displays consisted of eyebrow raising only; the full, 3-component display was never seen. Experimental variations of surprise intensity, sociality, and duration/complexity of the surprising event did not change these results. Electromyographic measurement failed to detect notably more brow raisings and, in one study, revealed a decrease of frontalis muscle activity in the majority of the participants. Nonetheless, most participants believed that they had shown a strong surprise expression. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
Addresses the ethical issues associated with establishing a fee structure in private practice based on current trends in Canadian psychology and the existing ethical codes and standards for Canadian psychologists. A number of forces impacting on the delivery and nature of psychological service in Canada are reviewed followed by a critique of relevant codes and standards. Recommendations for establishing a fee structure in private practice are provided based on the critique, alternative ethical codes, and existing literature. It is suggested that when economic necessity forces Canadian psychologists to turn to private practice as their primary source of income, potential conflict between self interest and public interest may arise. Exploration of this conflict raises many unanswered questions regarding the combination of business ethics with the ethics of psychology. To answer these questions and help resolve potential ethical conflicts, further examination and discussion amongst psychologists and their professional associations is recommended. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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We investigated the influences of odor exposure on performance and on breathing measures. The task was composed of tracking, short-term memory, and peripheral reaction parts. During rest or while performing the task, 12 participants were exposed to 4 different odors in 2 intensities. The higher intensity of the malodors induced a short-term decrement in mean inspiration flow (Vi/Ti) after stimulus onset and impaired performance in the short-term memory task, as compared with control trials; no effect was found for the positively judged odors. The study suggests that a distractor as simple as a bad smell may pull a person off task, however briefly, and may result in a detriment to performance. Actual or potential applications of this research involve designing or securing tasks in such a way that a brief withdrawal of attention does not have fatal consequences. 相似文献