全文获取类型
收费全文 | 4036篇 |
免费 | 314篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 139篇 |
妇产科学 | 131篇 |
基础医学 | 674篇 |
口腔科学 | 268篇 |
临床医学 | 383篇 |
内科学 | 650篇 |
皮肤病学 | 62篇 |
神经病学 | 381篇 |
特种医学 | 102篇 |
外科学 | 590篇 |
综合类 | 15篇 |
一般理论 | 6篇 |
预防医学 | 335篇 |
眼科学 | 22篇 |
药学 | 371篇 |
中国医学 | 4篇 |
肿瘤学 | 198篇 |
出版年
2021年 | 35篇 |
2020年 | 35篇 |
2019年 | 40篇 |
2018年 | 83篇 |
2017年 | 72篇 |
2016年 | 80篇 |
2015年 | 75篇 |
2014年 | 78篇 |
2013年 | 160篇 |
2012年 | 163篇 |
2011年 | 123篇 |
2010年 | 103篇 |
2009年 | 92篇 |
2008年 | 161篇 |
2007年 | 144篇 |
2006年 | 142篇 |
2005年 | 157篇 |
2004年 | 106篇 |
2003年 | 146篇 |
2002年 | 139篇 |
2001年 | 107篇 |
2000年 | 129篇 |
1999年 | 120篇 |
1998年 | 58篇 |
1997年 | 61篇 |
1996年 | 48篇 |
1995年 | 39篇 |
1994年 | 37篇 |
1993年 | 53篇 |
1992年 | 144篇 |
1991年 | 130篇 |
1990年 | 124篇 |
1989年 | 114篇 |
1988年 | 86篇 |
1987年 | 92篇 |
1986年 | 90篇 |
1985年 | 73篇 |
1984年 | 74篇 |
1983年 | 55篇 |
1982年 | 35篇 |
1980年 | 30篇 |
1979年 | 51篇 |
1978年 | 42篇 |
1977年 | 38篇 |
1976年 | 34篇 |
1975年 | 30篇 |
1974年 | 38篇 |
1973年 | 43篇 |
1971年 | 32篇 |
1970年 | 30篇 |
排序方式: 共有4354条查询结果,搜索用时 15 毫秒
21.
C. Köhler A. Persson T. Melander E. Theodorsson G. Sedvall T. Hökfelt 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1989,75(2):375-380
Summary Using X-ray film autoradiography the distribution of 125I-galanin binding sites was studied in the forebrain of monkey and man. In the monkey a high density was found in all areas of the neocortex, especially layer 4, and in certain subfields in the hippocampal region. Also in the human brain high activity was seen in neocortex, mainly layer 6 and in hippocampal areas, as well as in amygdala, piriform cortex and hypothalamus. These results suggest that the 29-amino acid peptide galanin may be involved in the regulation of higher cortical functions in primates. 相似文献
22.
A Kierkegaard L Norgren C G Olsson J Castenfors G Persson S Persson 《Acta medica Scandinavica》1987,222(5):409-414
In order to detect deep vein thrombosis (DVT), 101 patients with acute medical or infectious disorders were examined with the 125I-fibrinogen uptake test. All patients were bedridden on admission and were scanned daily from the second to the eighth day. Thirteen patients developed a positive fibrinogen uptake test. Thus, if a positive test is interpreted as DVT, the incidence of DVT was 13% in our bedridden patients. Of the patients admitted because of heart disease or pneumonia 20% had DVT, but only 4% of those admitted with other diagnoses. Other clinical "risk factors" studied, could not identify patients who developed DVT. 相似文献
23.
The tracheobronchial mucosa of anaesthetized guinea-pigs (normal or sensitized with ovalbumin to produce IgE and IgG antibodies) was superfused (0.02 ml min-1, 5 min) with saline, mediators, and (in sensitized animals) ovalbumin via a catheter atraumatically introduced orally. The intravascular blood pool and amount of macromolecules in excised trachea and adjoining main bronchi were quantified by measuring erythrocytes, that had been labelled in vivo with 99Tcm, and analysing for FITC-dextran, MW = 70,000, that had been given i.v. Extravasation of macromolecules was determined as the analysed total content minus the calculated intravascular content of FITC-dextran. Capsaicin 0.1 nmol extravasated 223 micrograms of FITC-dextran per g wet weight of airway tissue (P less than 0.001). Substance P 0.1 nmol, 41 micrograms g-1 (P greater than 0.05); substance P 0.3 nmol, 142 micrograms g-1 (P less than 0.001); eledoisine 0.1 nmol, 101 micrograms g-1 (P less than 0.01); ovalbumin 0.1 microgram, 179 micrograms g-1 (P less than 0.001); LTC4 0.2 pmol, 180 micrograms g-1 (P less than 0.001); LTD4 0.2 pmol 223 micrograms ml-1 (P less than 0.001). Bronchi and trachea were similarly affected by these agents. Prior superfusion (0.02 ml min-1, 30 min) with terbutaline 0.06 nmol, enprofylline 12 nmol, or lidocaine 6 nmol significantly reduced the effect of capsaicin. Enprofylline also reduced significantly the effect of LTC4. The degree of extravasation in this study was smaller than could be detected by changes in tissue wet to dry weight ratios. The present data support the view that tracheobronchial vascular permeability to macromolecules is subject to physiological and pharmacological control. 相似文献
24.
25.
Extended voluntary running inhibits exercise-induced adult hippocampal progenitor proliferation in the spontaneously hypertensive rat 总被引:4,自引:0,他引:4
Naylor AS Persson AI Eriksson PS Jonsdottir IH Thorlin T 《Journal of neurophysiology》2005,93(5):2406-2414
Previous work has shown that voluntary running increases cell proliferation and neurogenesis in the dentate gyrus of the adult hippocampus. Here we report that long-term running for 24 days results in a down-regulation of hippocampal progenitor proliferation to one-half the level of nonrunning controls compared with a fivefold increase in progenitor proliferation seen after 9 days of voluntary running (short-term running). The negative effects seen on proliferation after 24 days of running were prevented by restricting daily running distances (by 30-50%) during 24 days. Long-term running for 24 days increases the response of the hypothalamic-pituitary-adrenal axis, with an increase in adrenal gland weight and increased plasma corticosterone levels, as well as decreased thymus weight, indicating a stress response as a possible mediator of decreased progenitor proliferation. Furthermore, the negative effects seen on the observed stress response after 24 days of running were prevented by restricting daily running distance. Short-term running did not alter these stress parameters compared with nonrunning controls. However, it increased phosphorylated cyclic AMP response element binding protein (pCREB) in the dentate gyrus, an increase that was not seen in nonrunning controls or after 24 days of running. Taken together, these data suggest that voluntary running does not always enhance proliferation and that the decrease in progenitor proliferation seen in long-term running is possibly mediated by mechanisms involving a stress response in the animal. However, a moderate level of long-term running was able to prevent the negative stress-related changes seen in unrestricted long-term running. 相似文献
26.
Larsson J Persson C Tengvall P Lundqvist-Gustafsson H 《Journal of biomedical materials research. Part A》2004,68(3):448-457
Polymorphonuclear neutrophils (PMN) are among the first inflammatory cells to arrive at an implant interface, where they encounter with the foreign material and may produce reactive oxygen species (ROS). During the interaction between titanium and ROS, titanium-peroxy (Ti-peroxy) compounds may be formed. We used a Ti-peroxy gel, made from titanium and hydrogen peroxide, to study the effects of Ti-peroxy compounds on PMN. In the absence of serum, the Ti-peroxy gel decreased the oxidative response of PMN to yeast and PMA and reduced PMN apoptosis without inducing necrosis. These effects could not be ascribed to the release of hydrogen peroxide from the Ti-peroxy gel, because a steady-state hydrogen peroxide producing system failed to mimic the effects of the gel. The effects were similarly unaffected when PMN were preincubated with beta(2)-integrin antibodies, questioning the involvement of adhesion molecules. Nevertheless, when a filter was used to separate the Ti-peroxy gel from the cells, the gel effect on PMN life span was abolished, pointing to a contact-dependent mechanism. In the presence of serum, the Ti-peroxy gel had no effect on the PMN oxidative response and life span, but appeared rather inert. In summary, this study demonstrates that the Ti-peroxy gel has potentially anti-inflammatory properties through a combined peroxide and physical contact effect, supporting the notion that interactions between titanium and inflammatory cells are responsible for the good performance of titanium in vivo. 相似文献
27.
28.
Favourable results of acrylic cementation for giant cell tumors 总被引:1,自引:0,他引:1
A consecutive series from two university hospitals of 50 patients with giant cell tumors was reviewed and histologically reconfirmed. The patients treated with curettage and acrylic cement were re-examined concerning function. Two of 14 cemented tumors had recurred but could be treated by additional cementation, so that no final failure of this method had occurred, compared to one of 19 radically resected and 12 of 22 with bone-graft after curettage. Joint function was normal in 11 and radiographic arthrosis of low grade was found in only two of 14 patients. It is concluded that this method gives a minimum of recurrence and a maximum of function. It is suggested that the old name of "giant cell sarcoma" should be reintroduced, bringing the tumor into the group of low-grade sarcomas where it belongs. 相似文献
29.
Elin Vimefall Mattias Persson Sara Olofsson Lars Hultkrantz 《The European journal of health economics》2022,23(2):261-275
The European Journal of Health Economics - This paper compares the value per statistical life (VSL) in the context of suicide prevention to that of prevention of traffic fatalities. We conducted... 相似文献
30.
Olofsson Sara Graln Katarina Hoxer Christina Okhuoya Paul Persson Ulf 《The European journal of health economics》2022,23(6):993-1005
The European Journal of Health Economics - Phenylketonuria (PKU) is a metabolic disorder leading to a deficiency in the metabolism of phenylalanine (Phe). Elevated Phe levels in the blood, tissue... 相似文献