全文获取类型
收费全文 | 9305篇 |
免费 | 880篇 |
国内免费 | 123篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 265篇 |
妇产科学 | 150篇 |
基础医学 | 1302篇 |
口腔科学 | 225篇 |
临床医学 | 1217篇 |
内科学 | 2301篇 |
皮肤病学 | 208篇 |
神经病学 | 1001篇 |
特种医学 | 564篇 |
外国民族医学 | 1篇 |
外科学 | 779篇 |
综合类 | 236篇 |
一般理论 | 2篇 |
预防医学 | 815篇 |
眼科学 | 200篇 |
药学 | 537篇 |
中国医学 | 3篇 |
肿瘤学 | 455篇 |
出版年
2021年 | 123篇 |
2020年 | 92篇 |
2019年 | 143篇 |
2018年 | 170篇 |
2017年 | 99篇 |
2016年 | 107篇 |
2015年 | 145篇 |
2014年 | 222篇 |
2013年 | 281篇 |
2012年 | 411篇 |
2011年 | 397篇 |
2010年 | 238篇 |
2009年 | 224篇 |
2008年 | 328篇 |
2007年 | 413篇 |
2006年 | 363篇 |
2005年 | 395篇 |
2004年 | 329篇 |
2003年 | 288篇 |
2002年 | 341篇 |
2001年 | 317篇 |
2000年 | 294篇 |
1999年 | 267篇 |
1998年 | 202篇 |
1997年 | 176篇 |
1996年 | 185篇 |
1995年 | 143篇 |
1994年 | 123篇 |
1993年 | 123篇 |
1992年 | 204篇 |
1991年 | 206篇 |
1990年 | 204篇 |
1989年 | 209篇 |
1988年 | 209篇 |
1987年 | 236篇 |
1986年 | 206篇 |
1985年 | 201篇 |
1984年 | 142篇 |
1983年 | 104篇 |
1982年 | 82篇 |
1981年 | 79篇 |
1980年 | 89篇 |
1979年 | 100篇 |
1978年 | 99篇 |
1977年 | 84篇 |
1976年 | 80篇 |
1975年 | 76篇 |
1974年 | 76篇 |
1972年 | 56篇 |
1971年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
61.
R Mokni A Chakar F Bleiberg-Daniel JL Mahu PA Walravens P Chappuis J Navarro D Lemonnier 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(6-7):539-543
Biochemical markers of nutritional status (albumin, transthyretin, insulin-like growth factor-I and zinc) were measured in slowly growing two- to five-year-old, low-income Parisian children whose weight-for-height or height-for-age z scores (WHZ or HAZ) were between — 1 and — 2 SD of the NCHS median. The results were compared to controls who were matched for age, sex, and ethnic origin with WHZ and HAZ between — 1 and + 2 SD. Mean serum levels of transthyretin, albumin and insulin-like growth factor-I and mean plasma zinc concentrations were significantly lower in the growth-impaired children than in the controls ( p = 0.002, p = 0.006, p = 0.015, and p = 0.035, respectively). While the height-retarded children had low mean serum insulin-like growth factor-I values, the weight-retarded subjects had decreased levels of albumin, transthyretin and zinc when compared to controls. Lower mean levels of nutritional markers in healthy, slowly growing children suggest that inadequate dietary intakes of zinc, protein and/or energy may result in marginal delays in weight and height gains. 相似文献
62.
JI Elizalde ; J Clemente ; JL Marin ; J Panes ; B Aragon ; A Mas ; JM Pique ; J Teres 《Transfusion》1997,37(6):573-576
BACKGROUND: Equilibration of hemoglobin concentration after transfusion has been estimated to take about 24 hours, but some studies have shown that earlier measurements reflect steady-state values in persons who have not bled recently. This study was aimed at assessing the changes over time in hemoglobin concentration after transfusion in acutely anemic patients because of recent bleeding. STUDY DESIGN AND METHODS: Thirty-two normovolemic patients recovering from an acute bleeding episode who were no longer thought to be bleeding and who received a 2- unit red cell transfusion were studied. At baseline and 15, 30, 60, and 120 minutes and 24 hours after transfusion, hemoglobin concentration and hematocrit values were measured. RESULTS: The administration of 2 units of packed red cells elicited a 24-hour increase of 22.4 +/− 6.8 g per L in hemoglobin concentration. Hemoglobin values were not different at any of the defined posttransfusion times. Hematocrit levels experienced similar changes over time. Agreement between 15-minute and 24-hour values was excellent, as only 6 percent of patients exhibited a clinically significant difference (> 6 g/L) between the hemoglobin measurements. CONCLUSION: Hemoglobin and hematocrit values rapidly equilibrate after transfusion in normovolemic patients who are recovering from an acute bleeding episode. This fact would allow a rapid assessment of the effects of transfusion and of the recurrence of bleeding in patients remaining at risk. 相似文献
63.
M P Joseph M L Goodman B Z Pilch F R Bieber L B Holmes E Reardon 《Head & neck surgery》1986,8(6):456-462
Heterotopic cervical salivary gland tissue was found in a 4-yr-old girl with branchial and otologic abnormalities. Her mother and sister also had heterotopic cervical salivary tissue in association with anomalies that suggest the branchio-otorenal (BOR) syndrome. Heterotopic cervical salivary gland tissue may result from abnormal branchial development. 相似文献
64.
Diarrhea has been reported as an early, mild, and uncommon complication of carbamazepine (CBZ) therapy. We report three cases of intractable diarrhea induced by CBZ necessitating discontinuation of the drug. 相似文献
65.
Andres A; Morales JM; Praga M; Campo C; Lahera V; Garcia-Robles R; Rodicio JL; Ruilope LM 《Nephrology, dialysis, transplantation》1997,12(7):1437-1440
BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction
and to have an antinatriuretic effect. The existence of an interference of
cyclosporin with the vasodilating properties of endothelium mediated by
nitric oxide production could mediate these effects. On the other hand, the
infusion of the nitric oxide precursor L-arginine has been shown to induce
renal vasodilatation and to facilitate natriuresis in normal volunteers. We
have investigated the renal effects of the administration of an infusion of
L-arginine in renal transplant patients chronically treated with
cyclosporin. To facilitate the analysis of the data the effects of the
administration of a similar dose of cyclosporin on renal function during
the infusion of a vehicle were also investigated during the administration
of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients,
chronically treated with cyclosporin and with a stable renal function were
studied during 2 consecutive days after the administration of the usual
morning dose of cyclosporin. The first day they received an intravenous
infusion of vehicle and the second the infusion of graded doses of
L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The
first day, after cyclosporin administration a significant fall (P <
0.01) was observed in natriuresis and kaliuresis in the absence of changes
in renal plasma flow and glomerular filtration rate. After the
administration of L-arginine significant (P < 0.01) increases of renal
plasma flow, glomerular filtration rate, and natriuresis were seen. The
increase in blood levels of cyclosporin after its administration did not
differ between days 1 and 2. CONCLUSION: These results indicate that
L-arginine facilitates renal vasodilatation and natriuresis in renal
transplant patients. Furthermore, the observed increase in sodium excretion
could indicate that L-arginine counteracts the antinatriuretic effect of
cyclosporin.
相似文献
66.
Uroscopy in the 21st century: high-field NMR spectroscopy 总被引:1,自引:1,他引:0
Neild GH; Foxall PJ; Lindon JC; Holmes EC; Nicholson JK 《Nephrology, dialysis, transplantation》1997,12(3):404-417
From the experiments described, it can be seen that there are different
research approaches that can be taken and these are summarized in Table 1.
Whereas much scientific research is principally hypothesis led, there
remains, nevertheless, an important place for exploratory research. High
resolution NMR can measure, directly and simultaneously, a wide range of
endogenous metabolites in biological fluids and has the unique capability
of providing structural information on the metabolites detected. It has
proved to be a powerful research tool with which to study inherited
metabolic diseases, renal disease, drug metabolism, and toxicity, and can
be used to monitor the effects of drug therapy. For instance, by using a
library of experimental toxins one can map the metabolic profile of
site-specific nephron injury. With this approach in man one could
eventually take an unknown disease such as Balkan nephropathy and predict
the initial site of tubular injury, the mode of injury and therefore the
kind of toxin capable of producing that injury. NMR spectroscopic
techniques are still advancing rapidly, with ever increasing sensitivity
and sophistication of NMR pulse sequences to enhance structural elucidation
in complex mixtures. Given the advances in directly coupled HPLC-NMR and
even HPLC-NMR-mass spectroscopy it is likely that these technologies in
conjunction with pattern recognition will make major contribution to our
understanding of renal processes and provide new diagnostic insights in the
21st century.
相似文献
67.
68.
69.
Coralline hydroxyapatite bone graft substitutes: preliminary report of radiographic evaluation 总被引:1,自引:0,他引:1
A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties. 相似文献
70.