全文获取类型
收费全文 | 413篇 |
免费 | 17篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 4篇 |
基础医学 | 44篇 |
口腔科学 | 13篇 |
临床医学 | 29篇 |
内科学 | 66篇 |
皮肤病学 | 5篇 |
神经病学 | 16篇 |
特种医学 | 52篇 |
外科学 | 39篇 |
综合类 | 122篇 |
预防医学 | 8篇 |
眼科学 | 5篇 |
药学 | 10篇 |
肿瘤学 | 18篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 4篇 |
2012年 | 15篇 |
2011年 | 5篇 |
2010年 | 11篇 |
2009年 | 21篇 |
2008年 | 26篇 |
2007年 | 16篇 |
2006年 | 26篇 |
2005年 | 16篇 |
2004年 | 13篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 19篇 |
2000年 | 9篇 |
1999年 | 10篇 |
1998年 | 23篇 |
1997年 | 28篇 |
1996年 | 22篇 |
1995年 | 5篇 |
1994年 | 12篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1966年 | 1篇 |
排序方式: 共有432条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The synthesis and localization of alternatively spliced fibronectin EIIIB in resting and thrombin-treated megakaryocytes 总被引:1,自引:1,他引:0
There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation. 相似文献
5.
6.
Summary Major changes occur in the serum level of several hormones during 5 days of heavy and continuous physical activities, with less than a total of 2 h of sleep. The present investigation was designed to evaluate the importance of caloric deficiency, energy requirement being about 8,000–10,000 kcal/24 h. A comparison between well fed subjects and those with food deprivation revealed significantly higher levels of (T3) triiodothyronin, insulin and thyroid stimulating hormone (TSH) in the well-fed subjects, who also had lower levels of growth hormone (hGH) and cortisol, whereas no difference was found between the two groups for thyroxin (T4). Increased levels were found for T3 and T4 in both groups during the first day of activity, with a concomitant decrease in TSH and a subsequent decrease of T4 during the next 2 days. T3 decreased only in the low-calory group whereas increased levels were found in the iso-calory group throughout the course. The resting levels of insulin decreased during the course in the low-calory group whereas it increased in the iso-calory group. High levels were maintained throughout the course for hGH. Cortisol showed high levels just before the start of the course and then decreased from day 2 to day 4. No difference was found between the morning and evening levels for cortisol, indicating disappearance of the circadian rhythm. The present investigation has shown that energy deficiency during prolonged physical strain is responsible for the decreased serum levels of T3 and insulin and may contribute to the decrease in TSH and the increase in hGH and cortisol. 相似文献
7.
P. Magnus A. -L. BØrresen P. K. Opstad J. F. Bugge K. Berg 《European journal of applied physiology》1984,53(1):21-24
Summary Effects of four days of intense physical activity on serum concentrations of total triglycerides, total cholesterol and apolipoproteins A-I, A-II, and B were studied in 35 well-trained young men. Serum total triglyceride levels decreased to 70% of baseline levels after 24 h, and fell further to 50% of baseline levels after 4 days. Serum levels of total cholesterol fell steadily to about 80% of baseline levels on the 4th day. Apo-B levels fell to 85% of baseline levels after 24 h, and remained at that level. Apo A-I fell to about 90%, and apo A-II to about 80% of baseline levels, causing a significant increase in the ratio of apo A-I to apo A-II. The intraindividual changes in apo B were positively correlated to changes in cholesterol during the first day (r=0.60). The changes in apo A-I and apo A-II had no significant correlation with changes in total cholesterol or triglycerides, or with one another, suggesting that apo A-I and apo A-II are metabolized independently during conditions of hard physical exercise. 相似文献
8.
The chemiluminescence response of granulocytes to serum opsonized zymosan particles (SOZ) ex vivo was investigated during
two ranger training courses lasting 7 days with continuous moderate physical activities corresponding to about 32% of maximal
oxygen uptake or 35 000 kJ · 24 h−1, with energy deficiency (energy supply 0-4000 kJ · 24 h−1), and less than 3-h sleep during the 7 days. Significant granulocytosis in combination with a lymphopenia in peripheral blood
was observed during the whole course. A priming of the granulocytes for accentuated chemiluminescence response to SOZ was
observed during the first days of the course with a maximal increase on day 3 in course A (+35% of control response) and on
day 1 in course B (+ 12%). Thereafter, reduced responses to SOZ compared to control values (−28% and −21% in course A and
B) were observed. In course A, a group (n = 8) receiving 5000 kJ · 24 h−1 of additional energy, showed a more pronounced priming (maximum +57% versus +21 % of control response) during the first days.
In course B, all the cadets had 3 h of organised rest/sleep on day 5, and a second priming of the chemiluminescence response
was observed on the subsequent 2 days. These data indicated that moderate, continuous, predominantly aerobic physical activities
for 1–3 days around the clock primed the production of reactive oxygen species in granulocytes. This priming may be beneficial
for, for example, host defence against micro-organisms, but may also contribute to inflammatory damage to normal tissues such
as muscle, tendons and joints during exercise. However, when the moderate exercise continued for several more days, a down-modulation
of the granulocyte response was observed. The findings of this study further support the possibility that moderate physical
activity stimulates immunity, while more extreme duration of the same activities may result in a down-modulation of nonspecific
(and specific) immunity. 相似文献
9.
S CHAUDHURY PK CHAKRABORTY P BHARADWAJ M AUGUSTINE 《Medical Journal Armed Forces India》1994,50(1):59-60
A rare case of viral encephalitis in an 18 year old recruit who presented with signs of catatonic schizophrenia is reported.KEY WORDS: Viral encephalitis, Catatonic schizophrenia 相似文献
10.
Role of epidural medication through caudal route was studied in 109 patients having lumbago with or without sciatica to highlight the value of this mode of treatment which relieved symptoms in more than 70% of cases without hospitalisation and without being off work for long periods as in usual methods of conservative treatment.KEY WORDS: Epidural medication, Backache, Lumbago, Sciatica 相似文献