全文获取类型
收费全文 | 629篇 |
免费 | 39篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 15篇 |
妇产科学 | 5篇 |
基础医学 | 97篇 |
口腔科学 | 4篇 |
临床医学 | 36篇 |
内科学 | 126篇 |
皮肤病学 | 3篇 |
神经病学 | 113篇 |
特种医学 | 11篇 |
外科学 | 138篇 |
综合类 | 10篇 |
预防医学 | 10篇 |
药学 | 28篇 |
肿瘤学 | 69篇 |
出版年
2022年 | 8篇 |
2021年 | 12篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 17篇 |
2011年 | 22篇 |
2010年 | 16篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 24篇 |
2002年 | 21篇 |
2001年 | 20篇 |
2000年 | 27篇 |
1999年 | 24篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 15篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 15篇 |
1992年 | 13篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 22篇 |
1985年 | 17篇 |
1984年 | 15篇 |
1983年 | 13篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 16篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 8篇 |
1972年 | 6篇 |
1971年 | 7篇 |
1968年 | 5篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有673条查询结果,搜索用时 30 毫秒
1.
2.
To clarify the participation of endothelial-cell-derived growth factors (ECDGFs) in astrocytosis, the effects of endothelial-cell-conditioned medium (ECCM) derived either from normotensive rats or spontaneously hypertensive, stroke-prone rats (SHRSPs) on proliferation of C6 cells of an established rat glioma cell line were bioassayed. The ECCM from both strains stimulated proliferation of astrocytes, but the ECCM from SHRSPs showed a higher mitogenic activity for astrocytes than that from normotensive rats. Growth-promoting activity of the ECCM derived from SHRSPs showed an increase that was linear to the conditioning time. These results seem to indicate that endothelial cells produce and release factors that promote the growth of astrocytes. It seems also probable that chronic hypertension causes an increase in production and release of such ECDGFs that correlated with astrocytic proliferation. 相似文献
3.
Five cynomolgus monkeys treated with unilateral carotid ligation, renal hypertension, and beta-aminopropionitrile feeding were studied repeatedly by cerebral angiography to clarify the growth process of saccular cerebral aneurysms. Repeated angiography demonstrated saccular cerebral aneurysms in three of five monkeys; two aneurysms were found 15 months and a third 12 months after the operation. At autopsy, one saccular aneurysm was found to be bilocular in shape, and the others were unilocular. Fusiform aneurysms were also observed in four monkeys. Microscopic studies revealed the walls of the saccular aneurysms were very thin and consisted of fibrous tissue. In one aneurysm, the aneurysmal sac was almost obstructed by a well-organized thrombus. No evidence of intramural hemorrhage was found in any of the saccular cerebral aneurysms. The conversion of early aneurysmal changes into saccular aneurysms was found to occur abruptly, and no consistent growth rate was noted. The multiloculation of saccular aneurysms was closely related to the size of an aneurysm. The present study indicates that a saccular cerebral aneurysm may grow abruptly from one of several different kinds of early aneurysmal changes. 相似文献
4.
Effects of blood coagulation factor XIII on the development of experimental cerebral aneurysms in rats 总被引:1,自引:0,他引:1
Pathological and experimental studies have shown that cerebral aneurysms develop in part as a result of injury to the blood vessel wall. One of the peculiar aspects of aneurysm development is a defective proliferative or healing response to such injury. To examine this phenomenon, blood coagulation Factor XIII, which is known to enhance the healing process of wounds in general, was given to rats to induce experimental cerebral aneurysms. The rats were subjected to ligation of one common carotid artery and induction of hypertension, and were fed beta-aminoproprionitrile. Two weeks thereafter, Factor XIII was injected intravenously daily for 5 days (10 U/100 gm body weight/day). Twelve days after the start of Factor XIII injections, the rats were sacrificed and examined under light and electron microscopy. In seven of 12 bifurcations which developed small aneurysms, prominent intimal thickening was observed in the aneurysm lumen. In the most advanced cases, the aneurysm lumen was completely filled with proliferated smooth-muscle cells and collagen. In five of nine bifurcations that showed no aneurysm development, apparent intimal thickening was found at the site where aneurysms might be expected to grow. In the group of rats studied for induction of cerebral aneurysms but not given Factor XIII, none of 11 bifurcations with or without aneurysms showed such intimal thickening. The results indicated that the proliferative response at the sites of aneurysm development was modified by exogenous Factor XIII. 相似文献
5.
6.
7.
In order to obtain information about preaneurysmal changes, the junction of the internal carotid artery/posterior communicating artery (ICA/PComA) in the circles of Willis in subjects with aneurysms at sites other than the junction, and in control subjects without aneurysms, were studied by light microscopy.
Small evaginations and thinnings of the media with and without dilatation were observed at the apical areas of the forks with a significantly higher incidence in the aneurysm series than in the control, suggesting some predisposing factor in subjects with aneurysms. As well as funnel-shaped dilatations previously described as the only type of ICA/PComA preaneurysmal change, other more localized types were observed. All the small evaginations and about half of the thinnings and dilatations were observed at the apex in association with a medial gap, but the other half occured at some distance from the apex. The thinned arterial wall showed degenerative changes of the elastic lamina and media. Intimal pads were observed at the apex, the ICA/PComA lateral angle and the ICA stem/branch curve. Their combination with preaneurysmal changes was more frequent in the aneurysm series in comparison with the control.
Degenerative changes of the elastic lamina and media caused by hemodynamic stress due to branching structures including intimal pads are thus presumed to be the initial lesions existing prior to aneurysm formation. 相似文献
Small evaginations and thinnings of the media with and without dilatation were observed at the apical areas of the forks with a significantly higher incidence in the aneurysm series than in the control, suggesting some predisposing factor in subjects with aneurysms. As well as funnel-shaped dilatations previously described as the only type of ICA/PComA preaneurysmal change, other more localized types were observed. All the small evaginations and about half of the thinnings and dilatations were observed at the apex in association with a medial gap, but the other half occured at some distance from the apex. The thinned arterial wall showed degenerative changes of the elastic lamina and media. Intimal pads were observed at the apex, the ICA/PComA lateral angle and the ICA stem/branch curve. Their combination with preaneurysmal changes was more frequent in the aneurysm series in comparison with the control.
Degenerative changes of the elastic lamina and media caused by hemodynamic stress due to branching structures including intimal pads are thus presumed to be the initial lesions existing prior to aneurysm formation. 相似文献
8.
9.
Uterine myomata and outcome of assisted reproduction 总被引:5,自引:8,他引:5
Ramzy AM; Sattar M; Amin Y; Mansour RT; Serour GI; Aboulghar MA 《Human reproduction (Oxford, England)》1998,13(1):198-202
The aim of this work was to study the effect of uterine myomata on the
implantation rate and outcome in in-vitro fertilization (IVF) and
intracytoplasmic sperm injection (ICSI). Among 406 patients, 51 (12.6%)
were found to have uterine corporeal myomata. Twelve patients were excluded
from the study as they had large myomata, submucous myomata or intramural
myomata encroaching on the cavity. These patients were advised to have
myomectomy before being enrolled in the IVF/ICSI programme. The remaining
patients (n = 39) were sorted according to the number, site and size of the
myomata as assessed by transvaginal sonography. Three patients had more
than one myoma. Most of the myomata were subserous (72.7%) and the mean
diameter of the myomata was 3.5 +/- 0.9 cm. A control group (n = 367) was
chosen with normal uteri and no history of uterine reconstruction surgery.
The mean age of myoma patients was 34.7 +/- 3.6 years as compared to 34.0
+/- 4.4 years in the control group. The age, period of infertility, body
mass index, duration and number of human menopausal gonadotrophin ampoules
needed for stimulation, oestradiol levels, number of oocytes retrieved and
the fertilization rate were not significantly different in the myoma
patients compared to the control group. Fifteen myoma patients (38.5%)
subsequently showed one or more pregnancy sacs on ultrasonography of which
three (20%) spontaneously aborted during the first trimester and two
(13.3%) had preterm labour, as compared to 123 (33.5%), 19 (15.5%) and nine
(7.3%) respectively, among the control group (P = 0.27, 0.33 and 0.21). In
conclusion, uterine corporeal myomata, not encroaching on the cavity and
<7 cm in mean diameter, do not affect the implantation or miscarriage
rates in IVF or ICSI.
相似文献
10.
Shigeru Amano Hideo Kataoka Fumitada Hazama Minora Nakatake Atsuhiko Maki 《Pathology international》1985,35(4):969-974
Hepatocellular carcinoma (HCC) showing marked elevation of serum alpha fetoprotein (AFP) (maximum; 70942.0 ng/ml at the end stage) and serum carcinoembryonic antigen (CEA)(maximum; 7368.4 ng/ml at the end stage) was surgically resected. In the resected liver, there were two different tumor nodules which were adjacent to each other but clearly separated by a thin connective tissue. One of the nodules was a well differentiated and the other was poorly differentiated HCC. Immunoperoxidase study revealed that both CEA and AFP were localized in the tumor cells of the poorly differentiated HCC. This is the first report which clearly proved CEA synthesis in the cells of HCC. Serial staining showed that there was simultaneous synthesis of CEA and AFP in some of the tumor cells. ACTA PATHOL. JPN. 35: 969–974, 1985. 相似文献