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11.
Human erythrocytes bearing electroinserted full-length CD4 (RBC-CD4) can bind and fuse with a laboratory strain of human immunodeficiency virus type 1 (HIV-1) or with T cells infected by HIV-1. Here we show that RBC-CD4 neutralize primary HIV-1 strains in an assay of cocultivation of peripheral blood mononuclear cells (PBMC) from HIV-1-infected persons with uninfected PBMC. RBC-CD4 inhibited viral p24 core antigen accumulation in these cocultures up to 10,000-fold compared with RBC alone. Viral p24 accumulation was inhibited equally well when measured in culture supernatants or in call extracts. The inhibition was dose-dependent and long-lived. Two types of recombinant CD4 tested in parallel were largely ineffective. The neutralization of primary HIV-1 by RBC-CD4 in vitro was demonstrated in PBMC cultures from 21 of a total of 23 patients tested at two independent sites. RBC-CD4 may offer a route to blocking HIV-1 infection in vivo.  相似文献   
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The way data is presented can seriously affect the ease with which it can be understood. The objectives and results of a survey of different types of presentation are given. Some psychological aspects of the problem are analysed.  相似文献   
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CONTEXT: Adolescent smoking prevalence is tracked annually and has increased since 1991. In contrast, little is known about trends in smoking among college students, a group that has previously been more resistant to tobacco use than other young adults. OBJECTIVE: To examine changes in cigarette smoking among college students between 1993 and 1997 and among different types of students and colleges. DESIGN: Self-administered survey (Harvard School of Public Health College Alcohol Study). SETTING: One hundred sixteen nationally representative 4-year colleges. SUBJECTS: A total of 15103 randomly selected students in 1993 (70% response rate) and 14251 students in 1997 (60% response rate). MAIN OUTCOME MEASURES: Self-reports of cigarette smoking in the past 30 days and in the past year, age at smoking first cigarette, and number of attempts to quit. RESULTS: Over 4 years, the prevalence of current (30-day) cigarette smoking rose by 27.8%, from 22.3% to 28.5% (P<.001). The increase was observed in 99 of 116 colleges and was statistically significant (P<.05) in 27 (23%) of them. Current smoking increased across all student subgroups (defined by sex, race/ethnicity, and year in school) and in all types of colleges. Smoking is rising faster in public schools (from 22.0% to 29.3%) than in private schools (from 22.9% to 26.8%). Eleven percent of college smokers had their first cigarette and 28% began to smoke regularly at or after age 19 years, by which time most were already in college. Half of current smokers tried to quit in the previous year; 18% had made 5 or more attempts to quit. CONCLUSIONS: Cigarette use is increasing on campuses nationwide in all subgroups and types of colleges. Substantial numbers of college students are both starting to smoke regularly and trying to stop. National efforts to reduce smoking should be extended to college students.  相似文献   
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We report the generation of action potentials in crayfish neurons by magnetic pulses for analytical purposes. A copper wire toroid, containing a ferrite core, was placed around the nerve bundle, and square wave current pulses were sent through the wire to generate a magnetic field. The magnetic field generated an action potential in the neuron that was detected downfield by a pickup microelectrode. The biosensor was used to detect local anesthetics by monitoring the time necessary for complete blockage of the action potential. Techniques for improving the efficiency and lifetimes of neural biosensors are discussed.  相似文献   
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Small-cell variants of Sézary syndrome and mycosis fungoides (MF) have been described. However, in these studies the nuclear area of the small-cell variant of MF (SC-MF) as compared to histological classical MF (CL-MF) was not characterized objectively by quantitative electron microscopy. In a 14-year follow-up period, of a total of 76 patch/plaque stage MF patients seen in the Department of Dermatology of the University Hospital Utrecht, 14 (18%) had an infiltrate composed of atypical lymphocytes characterized by a distinctly smaller cell diameter and smaller, hyperchromatic, deeply indented nuclei as compared to the usual cell type of MF. The aim of the investigation was to confirm this observation objectively using quantitative electron microscopy (morphometry) and to define SC-MF as compared to CL-MF. The study was performed on the 14 patients with SC-MF, and 10 patients with clinical and histological CL-MF and 4 patients with chronic eczema. Electron micrographs of sections obtained from each biopsy were analysed by computer to produce the following data: a nuclear contour index (NCI), the mean nuclear area (MNA), the mean nuclear area of the cells above the 75th percentile (P75NA) and the percentage of cells larger than 30 microm2. The values of MNA differed significantly between patients with SC-MF and those with CL-MF (17.6 vs 23.2 microm2; P = 0.02), as did the values of P75NA (20.7 vs 27.9 microm2; P = 0.01). The NCI of the SC-MF and CL-MF patients were similar. These results are consistent with our observations that SC-MF does indeed exist.  相似文献   
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The job of a manager continues to be one of achieving outcomes through other people. However, in the current work environment, managers are finding that while their scope of responsibility is expanding, the traditional power base used to excourage high performance is shrinking. There are limited rewards a manager can use to gain commitment from their staff. Even if some of those rewards are available, many of the new employees do not see them as motivators. Employees come to the workplace with a different set of expectations. There seems to be a mismatch between the traditional management approach to getting the best from the worker and what the worker wants from their manager. In as much as the workplace and the worker are changing so too must manager's approach to "getting the job done."  相似文献   
19.
The purpose of the study was to examine the effects of manipulating lung volume (LV) on phonatory and articulatory kinematic behavior during sentence production in healthy adults. Five men and five women repeated the sentence "I sell a sapapple again" under five LV conditions. These included (1) speaking normally, (2) speaking after exhaling most of the air from the lungs, (3) speaking at end expiratory level (EEL), (4) speaking after a maximal inhalation, and (5) speaking after a maximal inhalation while attempting to maintain as normal a mode of speech as possible. From a multichannel recording, measures were made of LV, sound pressure level (SPL), fundamental frequency (F0) and semitone standard deviation (STSD), and upper and lower lip displacements and peak velocities. When compared with the reference condition, the sentence was spoken significantly more quickly at the lowest LV. SPL increased significantly for the high LV condition, as did the women's F0 and STSD. Upper lip displacements and peak velocities generally decreased for LVs other than the reference condition. Lower lip movements showed inconsistent changes as a function of LV. Adjustments to the LV for speech led to SPL and F0 changes consistent with a coordinated control of the respiratory system and the larynx. However, less consistent effects were observed in the articulatory kinematic measures, possibly because of a less direct biomechanical and neural control linkage between respiratory and articulatory structures.  相似文献   
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