پیوند اعضا از ارکان مهم سیستم‌‌های سلامت است و به درمان بسیاری بیماری‌‌های صعب‌العلاج کمک شایانی کرده است. روزانه 7 تا 10 نفر بیماران نیازمند در ایران علت نرسیدن به‌موقع عضو پیوندی دنیا می‌­روند. با توجه بحرانی­‌بودن زنجیره برای سلامتی انسان، مدیریت برنامه‌ریزی این اهمیت فراوانی برخوردار انتقال بیمار یک بیمارستان محل تأثیر ثانیه‌‌ها بر کیفیت مورد­انتقال موفقیت پیوند، بسیار حائز پژوهش، مدلی ریاض...

1111 BMJ VOLUME 316 11 APRIL 1998 www.bmj.com The largest study yet to be carried out on serum screening for Down’s syndrome has shown that it can be performed accurately during the first trimester of pregnancy, confirming previous findings and backing the opinion of many leading specialists that tests should be carried out earlier. The study, carried out in the United States, screened 4412 pre...

C O N T E N T S Forward Executive Summary Introduction Disease Prevalence Diabetes Mellitus Hypertension Risk Factor Prevalence Cigarette Smoking Physical Activity Obesity Cholesterol Alcohol Consumption Angina Awareness of Cancer Screening Breast Cancer Screening Cervical Cancer Screening Survey Response Survey Methodology References Annexes Annex A: Detailed Tables Annex B:Main Findings of Na...

Walter Wunderlich was one of the most influential Austrian kinematicians in the 20th century. He wrote more than 200 scientific papers in the fields of mathematics, geometry and kinematics. Because of his influence, kinematic geometry is still an important subject in the curricula of geometry teachers’ education in Austria.

We thank all of those who have supported the continuance of chronobiology at the University of Minnesota. Special credit is due to Earl E. Bakken, who introduced the implantable cardiac pacemaker and also the concept of the free-running oscillator, an invaluable device and a fertile concept, respectively. Free-running led to the coining of “circa” rhythms. There may again be a center that does ...

Collective excitations are the fingerprints of a system and reveal many of its dynamic properties. We extended earlier work on collective excitations of a Bose-Einstein condensate by studying them at non-zero temperature and at high density where they become analogous to first and second sound in superfluid helium [1]. The existence of such two modes is characteristic of a superfluid system. Ou...

The 1998 Leroy P. Steele Prizes were awarded at the 104th Annual Meeting of the AMS in January in Baltimore. These prizes were established in 1970 in honor of George David Birkhoff, William Fogg Osgood, and William Caspar Graustein and are endowed under the terms of a bequest from Leroy P. Steele. The Steele Prizes are awarded in three categories: for expository writing, for a research paper of...

S Effects of Fluoride on Immune System Function. Sheila L M Gibson, Scotland Cancer Incidence And Mortality In Workers Exposed To Fluoride. P Grandjean et a/, Denmark Clastogenic Adivrty of Sodium Fluoride In Great Ape Cells. K Kishi and T Ishida, Japan Serum Fluoride As An Indicator of Occupational Hydrofluoric Acid Exposure. K Kono el a/, Japan Comparison of the Effect of Sodium Fluoride and ...

The most common practice to model the transistor chain, as it appears in CMOS gates, is to collapse it to a single equivalent transistor. This method is analyzed and improvements are presented in this paper. Inherent shortcomings are removed and an effective transistor width is calculated taking into account the operating conditions of the structure, resulting in very good agreement with SPICE ...