全文获取类型
收费全文 | 926篇 |
免费 | 68篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 53篇 |
妇产科学 | 17篇 |
基础医学 | 204篇 |
口腔科学 | 24篇 |
临床医学 | 94篇 |
内科学 | 206篇 |
皮肤病学 | 12篇 |
神经病学 | 19篇 |
特种医学 | 122篇 |
外科学 | 72篇 |
综合类 | 9篇 |
预防医学 | 27篇 |
眼科学 | 9篇 |
药学 | 83篇 |
肿瘤学 | 32篇 |
出版年
2021年 | 10篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 10篇 |
2013年 | 21篇 |
2012年 | 27篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 21篇 |
2008年 | 17篇 |
2007年 | 33篇 |
2006年 | 12篇 |
2005年 | 20篇 |
2004年 | 15篇 |
2003年 | 21篇 |
2002年 | 15篇 |
2001年 | 21篇 |
2000年 | 21篇 |
1999年 | 28篇 |
1998年 | 45篇 |
1997年 | 51篇 |
1996年 | 57篇 |
1995年 | 47篇 |
1994年 | 31篇 |
1993年 | 36篇 |
1992年 | 28篇 |
1991年 | 24篇 |
1990年 | 26篇 |
1989年 | 34篇 |
1988年 | 33篇 |
1987年 | 21篇 |
1986年 | 21篇 |
1985年 | 24篇 |
1984年 | 20篇 |
1983年 | 10篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 12篇 |
1976年 | 15篇 |
1975年 | 15篇 |
1974年 | 5篇 |
1973年 | 11篇 |
1971年 | 5篇 |
1970年 | 6篇 |
1969年 | 6篇 |
排序方式: 共有1021条查询结果,搜索用时 15 毫秒
1.
D Mahalanabis H Ashraf MM Rahman GJ Fuchs 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(11):1113-1115
One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg−1 ) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea. 相似文献
2.
3.
Ashok N. Kukadia Cesar J. Ercole Paul Gleich Hugh Hensleigh Jon L. Pryor 《The Journal of urology》1996,156(5):1643-1646
Purpose
The long-term effects of testicular trauma on reproductive function are unknown. In an effort to define the relationship between testicular injury and fertility in humans, we identified patients with a history of testicular trauma and assessed parameters commonly associated with fertility.Materials and Methods
We reviewed 15 patients 23 to 59 years old who underwent immediate exploration after testicular trauma between 1972 and 1991. Of the patients 11 were contacted and 8 returned for prospective followup. Reproductive and sexual histories, physical examination, measurements of serum hormones and antisperm antibodies, semen analysis and scrotal ultrasound were done.Results
Of the 8 patients 1 (13 percent) achieved and 7 (87 percent) did not attempt conception. Hormonal status was normal in all 8 patients. Six men had objective evidence of subfertility by semen analysis only, although none had severe oligospermia or asthenospermia and only 1 had severe teratospermia. Five of 9 traumatized testes were atrophic. Interestingly, only 1 patient had antisperm antibodies, the levels of which were probably low enough to be clinically insignificant.Conclusions
There was definite evidence of subfertility as assessed by abnormal semen analyses and atrophic testes following testicular trauma. However, the subfertility did not appear to be immune mediated nor did the patients present with infertility. Since only 1 patient had severely compromised fertility according to semen analysis we conclude that early repair can help preserve hormonal function as well as fertility. 相似文献4.
S. N. Desai G. Van J. Robson L. G. Letts R. H. Gundel G. J. Gleich P. J. Piper T. C. Noonan 《Inflammation research》1993,39(Z1):C132-C135
The direct effect of intratracheal (IT) administration of human major basic protein (MBP) on pulmonary inspiratory pressure (PIP), and the effect on agonist-induced change in PIP, were determined in anesthetized, ventilated guinea pigs. 500 g MBP increased PIP from 24.1±4.3 to 49.8±7.4 cm H2O (p<>n=10). Maximum PIP was achieved within 30 min after 500 g MBP. The direct PIP response to 250 g MBP was not different from vehicle. The PIP responses to intravenous (IV) acetylcholine (Ach) and 5-hydroxytryptamine (5-HT) were measured before and after administration of 250 g MBP (n=12). MBP caused a modest, but significant potentiation of the increase in PIP induced by 1, 3 and 10 g/kg Ach (24, 32 and 28%, respectively,p<0.02) and=" to=" 1=">0.02)>g/kg 5-HT (43%p<0.02). we=" conclude=" that=" mbp=" at=" a=" dose=" that=" does=" not=" directly=" affect=" inspiratory=" pressure=" is=" capable=" of=" augmenting=" the=" pip=" response=" to=" iv=" ach=" and=">0.02).>in vivo. 相似文献
5.
Jack L. Gluckman Zlatko P. Pavelic Hans-Jurgen Welkoborsky Wolf Mann Peter Stambrook Lyon Gleich Keith Wilson Paul Righi Louis G. Portugal John McDonald Paul Biddinger David Steward Peter Gartside 《The Laryngoscope》1997,107(9):1239-1244
Fifty-three patients with T1 squamous cell cancer of the floor of mouth and ventral surface of the tongue with a known clinical outcome were retrospectively analyzed and arbitrarily divided into “aggressive” and “nonaggressive” groups based on their clinical behavior. Various host and tumor factors were then evaluated in an attempt to determine whether the tumor behavior could have been predicted. The paraffin-embedded tumor specimens were evaluated for tumor differentiation, tumor thickness and tumor invasion, microvessel density, and p53 expression. In addition, a composite morphologic grading score was obtained by combining cell differentiation, nuclear polymorphism, mitosis activity, depth of infiltration, type of infiltration, and lymphatic infiltration. No single technique appeared capable of identifying “aggressive” behavior, although possibly an evaluation of composite factors might show promise in the future. 相似文献
6.
We studied the relationship between nutritional status and infection due to specific enteropathogens in young children with diarrhoea. Overall, 26% of the children were severely underweight, 27% were severely wasted and 19% were severely stunted. Children with Shigellae and V. cholerae O1 were significantly more severely underweight, wasted and stunted than those with rotavirus diarrhoea ( p < 0:0001). Our results indicate that an effective nutrition programme for young children might have greater impact on diarrhoeal illness caused by Shigella and V. cholerae than by rotavirus diarrhoea. 相似文献
7.
D'Andrea RJ; Barry SC; Moretti PA; Jones K; Ellis S; Vadas MA; Goodall GJ 《Blood》1996,87(7):2641-2648
The hypothesis that extracellular truncation of the common receptor subunit for interleukin-3 (IL-3), granulocyte-macrophage colony- stimulating factor, and IL-5 (h beta c) can lead to ligand-independent activation was tested by infecting factor-dependent hematopoietic cell lines with retroviruses encoding truncated forms of h beta c. A truncation, resembling that in v-Mpl, and retaining 45 h beta c-derived extracellular residues, led to constitutive activation in the murine myeloid cell line, FDC-P1. However, infection of cells with retrovirus encoding a more severely truncated receptor, retaining only 7 h beta c- derived extracellular residues, did not confer factor independence on these cells. These experiments show that truncation activates the receptor and define a 37-amino acid segment of h beta c (H395-A431) which contains two motifs conserved throughout the cytokine receptor superfamily (consensus Y/H XX R/Q VR and WSXWS), as essential for factor-independent signaling. The mechanism of activation was also investigated in less severe truncations. A receptor that retains the entire membrane-proximal domain (domain 4) also conferred factor independent growth on FDC-P1 cells; however, a retrovirus encoding a truncated form of h beta c having two intact membrane proximal domains did not have this ability, suggesting that domain 3 may have an inhibitory role in h beta c. The ability of these receptors to confer factor independence was cell specific as demonstrated by their inability to confer factor-independent growth when introduced into the murine IL-3-dependent pro-B cell line BaF-B03. These results are consistent with a model in which activation requires unmasking of an interactive receptor surface in domain 4 and association with a myeloid- specific receptor or accessory component. We suggest that in the absence of ligand intramolecular interactions prevent inappropriate signaling. 相似文献
8.
9.
10.
Repair of large midline incisional hernias with polypropylene mesh: Comparison of three operative techniques 总被引:9,自引:0,他引:9
de Vries Reilingh TS van Geldere D Langenhorst BLAM de Jong D van der Wilt GJ van Goor H Bleichrodt RP 《Hernia》2004,8(1):56-59
Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay, and underlay. The records of 53 consecutive patients with a large midline incisional hernia — 25 women and 28 men, mean age 60.4 (range 28–94) — were reviewed. Polypropylene mesh was implanted using the onlay technique in 13 patients, inlay in 23 patients, and underlay in 17 patients. Either the greater omentum or a polyglactin mesh was interponated between the mesh and the viscera. The records of these 53 patients were reviewed with respect to: size and cause of the hernia, pre- and postoperative mortality and morbidity, with special attention to wound complications. Patients were invited to attend the outpatient clinic at least 12 months after implantation of the mesh for physical examination of the abdominal wall. Postoperative complications occurred in 14 (26.4%) patients. The onlay technique had significantly more complications, as compared to both other techniques. Reherniation occurred in 15 (28.3%) patients. The reherniation rate of the inlay technique was significantly higher than after the underlay technique (44% vs 12%, P=0.03) and tended to be higher than the onlay technique (44% vs 23%, P=0.22). Repair of large midline incisional hernias with the use of a polypropylene mesh carries a high risk of complications and has a high reherniation rate. The underlay technique seems to be the better technique. 相似文献