全文获取类型
收费全文 | 10440篇 |
免费 | 502篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 176篇 |
儿科学 | 210篇 |
妇产科学 | 185篇 |
基础医学 | 1756篇 |
口腔科学 | 236篇 |
临床医学 | 841篇 |
内科学 | 2063篇 |
皮肤病学 | 184篇 |
神经病学 | 1054篇 |
特种医学 | 644篇 |
外国民族医学 | 1篇 |
外科学 | 1261篇 |
综合类 | 73篇 |
预防医学 | 437篇 |
眼科学 | 253篇 |
药学 | 1000篇 |
中国医学 | 64篇 |
肿瘤学 | 539篇 |
出版年
2022年 | 57篇 |
2021年 | 136篇 |
2020年 | 90篇 |
2019年 | 113篇 |
2018年 | 146篇 |
2017年 | 126篇 |
2016年 | 170篇 |
2015年 | 227篇 |
2014年 | 292篇 |
2013年 | 397篇 |
2012年 | 545篇 |
2011年 | 596篇 |
2010年 | 349篇 |
2009年 | 359篇 |
2008年 | 610篇 |
2007年 | 665篇 |
2006年 | 617篇 |
2005年 | 643篇 |
2004年 | 633篇 |
2003年 | 613篇 |
2002年 | 595篇 |
2001年 | 133篇 |
2000年 | 113篇 |
1999年 | 141篇 |
1998年 | 138篇 |
1997年 | 129篇 |
1996年 | 102篇 |
1995年 | 85篇 |
1994年 | 89篇 |
1993年 | 99篇 |
1992年 | 82篇 |
1991年 | 64篇 |
1990年 | 61篇 |
1989年 | 80篇 |
1988年 | 61篇 |
1987年 | 62篇 |
1986年 | 50篇 |
1985年 | 69篇 |
1984年 | 59篇 |
1983年 | 57篇 |
1982年 | 59篇 |
1981年 | 68篇 |
1980年 | 47篇 |
1979年 | 52篇 |
1978年 | 45篇 |
1977年 | 62篇 |
1976年 | 44篇 |
1975年 | 44篇 |
1973年 | 35篇 |
1963年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
101.
Milos G Gallo LM Sosic B Uebelhart D Goerres G Haeuselmann HJ Eich D 《Calcified tissue international》2011,89(3):228-233
Little is known about bone mineral density (BMD) in patients with heroin addiction and subsequent methadone substitution.
The goal of this study was to compare bone mass density of young HIV-negative women on long-term methadone treatment to a
local group of young healthy women. Eleven women (aged 20–29) with previous heroin dependence and current methadone substitution
(20–140 mg, median 60, daily) for 1.5–9 (median 3) years were compared to 30 healthy women (aged 20–28). Participants were
examined with dual-energy X-ray absorptiometry of the lumbar spine (L2–L4), of the total proximal hip area, and of the femoral
neck. Patients and controls had neither current nor lifetime underweight condition, had comparable ages at menarche, and did
not differ significantly in current body mass index (21.9 ± 4.0, respectively, 20.5 ± 1.5 kg/m2) in spite of a largely unhealthy lifestyle (cigarette, alcohol, and cocaine consumption in patients). Patients’ total-hip
parameters were marginally lower than those of controls (BMD P = 0.054, T score P = 0.049), whereas the femoral neck and lumbar spine parameters did not differ significantly between the two groups. Long-term
methadone substitution in HIV-negative women seems to slightly affect bone mass density. 相似文献
102.
Diederichs CG Staib L Glasbrenner B Guhlmann A Glatting G Pauls S Beger HG Reske SN 《Clinical positron imaging : official journal of the Institute for Clinical P.E.T》1999,2(3):131-136
This study was done to evaluate if the accuracy of FDG-PET concerning the differentiation of benign and malignant pancreatic masses differs for patients with and without elevated C-Reactive Protein (CRP). Three hundred-four patients (165 neoplasms, 98 chronic pancreatitis, and 41 benign lesions) received FDG-PET of the abdomen prior to planned resective surgery. CRP was unknown, normal, and elevated with 211, 71, and 22 patients, respectively. For differentiation of benign and malignant lesions, specificity was 87% for patients with unknown or normal CRP, and it was 40% for patients with elevated CRP (P < 0.01). Thirty-five percent of those patients with both a positive PET and elevated CRP were false positive. On the contrary, sensitivity was slightly higher in the group with elevated CRP (92% vs. 80%, NS). FDG-PET is a sensitive and specific test for patients with normal CRP, however, FDG-PET may be false positive if CRP is elevated. Proper patient selection is therefore important. CRP or other parameters indicative of active inflammation appear useful adjuncts for the interpretation of increased FDG-accumulation. 相似文献
103.
BACKGROUND: Rat coagulating gland epithelial cells export proteins by an apocrine secretion mode within membrane blebs arising from the apical plasma membrane. Using a pan-PMCA antibody, we have recently shown the plasma membrane Ca(2+)-ATPase (PMCA) being part of the apical plasma membrane of epithelial cells and incorporated into the aposomal membrane. The mRNA of PMCA isoforms 1 and 4 respectively, have been detected by RT-PCR in rat coagulating gland. METHODS: In order to identify which PMCA isoform is integrated into aposomes during apocrine secretion and whether or not PMCA export is influenced by androgens RT-PCR, in situ hybridization, Western blotting, and immunofluorescence experiments were performed. RESULTS: PMCA1b is the isoform which is expressed and located in the apical plasma membrane of coagulating gland epithelial cells and is integrated into the aposomal membrane. In contrast, PMCA4 mRNA and protein are restricted to the stroma. Androgen deprivation by castration within 14 days leads to an accumulation of PMCA1b in coagulating gland epithelium, while aposomes are not detected anymore. CONCLUSIONS: We showed for the first time that PMCA isoform 1b is released via aposomes of the epithelial cells of the rat coagulating gland and that the localization of PMCA1b in the epithelial cells is influenced by androgens. 相似文献
104.
Andreas Straub Daniela Schiebold Hans Peter Wendel Carole Hamilton Thomas Wagner Eckhard Schmid Klaus Dietz Gerhard Ziemer 《European journal of cardio-thoracic surgery》2008,34(3):641-647
Objective: Cardiac surgery employing cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) can induce coagulation disturbances and bleeding complications that may be especially severe in infants. A better understanding of the coagulopathy and a quick method for its evaluation would be helpful in the management of patients exposed to CPB and DHCA. This study aimed to monitor coagulation defects in congenital heart surgery using rotational thromboelastometry (ROTEM((R))), standard coagulation tests and platelet flow cytometry. Methods: The study comprised 10 infants undergoing surgery for congenital heart disease on CPB and DHCA. Blood was sampled at skin incision, after heparinisation during CPB (directly pre- and directly post-DHCA) and after protamine administration post-CPB. ROTEM((R)) using different reagents including a heparinase-containing assay to evaluate coagulation during heparinisation, APTT and INR, and flow cytometry to evaluate platelet activation were performed. Results: During CPB, the ROTEM((R)) indicated CPB-induced clotting factor depletion and platelet dysfunction that persisted after CPB and heparin neutralisation. ROTEM((R)) results were available within 15min and therefore much faster than standard tests. ROTEM((R))-guided specific blood product treatment resulted in satisfactory coagulatory function. The highest degree of platelet activation was found directly after DHCA. Conclusions: A major benefit of ROTEM((R)) is the quick detection of a developing coagulopathy already during CPB. ROTEM((R)) guides quick and specific blood product treatment after CPB, which may decrease bleeding complications in cardiac surgery. The finding of maximal platelet activation directly after DHCA suggests that not only CPB but also hypothermia activates platelets in vivo, thereby contributing to platelet dysfunction. 相似文献
105.
Aurora M. Morariu Theo A. Schuurs Henri G. D. Leuvenink Wim van Oeveren Gerhard Rakhorst Rutger J. Ploeg 《American journal of transplantation》2008,8(5):933-941
Cerebral injury leading to brain death (BD) causes major physiologic derangements in potential organ donors, which may result in vascular-endothelial activation and affect posttransplant graft function. We investigated the kinetic of pro-coagulatory and pro-inflammatory endothelial activation and the subsequent oxidative stress and renal tubular injury, early after BD declaration. BD was induced by slowly inflating a balloon-catheter inserted in the extradural space over a period of 30 min. Rats (n = 30) were sacrificed 0.5, 1, 2 or 4 h after BD-induction and compared with sham-controls. This study demonstrates immediate pro-coagulatory and pro-inflammatory activation of vascular endothelium after BD in kidney donor rats, proportional with the duration of BD. E- and P-Selectins, Aα/Bβ-fibrinogen mRNA were abruptly and progressively up-regulated from 0.5 h BD onwards; P-Selectin membrane protein expression was increased; fibrinogen was primarily visualized in the peritubular capillaries. Plasma von Willebrand factor was significantly higher after 2 h and 4 h BD. Urine heart-fatty-acid-binding-protein and N-acetyl-glucosaminidase, used as new specific and sensitive markers of proximal and distal tubular damage, were found significantly increased after 0.5 h, with a maximum at 4 h. Unexpectedly, oxidative stress was detectable only late, after the installation of tubular injury, suggesting only a secondary role for hypoxia in triggering these injuries. 相似文献
106.
107.
Pedicled instep flaps are frequently used in weight-bearing plantar reconstruction, but may not be available after severe foot injuries. Although free instep flaps offer a viable option, they have scarcely been reported. A posttraumatic plantar forefoot defect was reconstructed with a sensate, instep free flap, because local flaps were not available and defect size did not require a distant free flap, and the current literature was reviewed for therapeutic options. The instep free flap yielded an excellent functional and aesthetic long-term result. In the literature, pedicled instep flaps are advocated for moderate size defects of the weight-bearing heel and sole, while free flaps from distant sites are preferred for large defects. Although skin-grafted muscle flaps and fasciocutaneous flaps yield similar results, reconstruction by like tissues appears favorable. We suggest the instep free flap for weight-bearing plantar foot reconstruction, when pedicled instep flaps are not available and distant free flaps are avoidable. 相似文献
108.
Favre P Exner GU Drerup B Schmid D Wetz HH Jacob HA 《Journal of pediatric orthopedics》2007,27(1):54-59
The unaffected contralateral side of patients with unilateral clubfeet has sometimes been taken as control in foot pressure measurement studies. However, it has never been shown that the pressure pattern under the contralateral foot is similar to a normal foot. Sixteen patients with unilateral clubfoot and 110 normal subjects took part in this study. All participants were aged from 4 to 8 years. Studies comprised clinical examination and foot pressure measurements in barefoot walking. Evaluations of the measurements were completed by the calculation of forces acting under 10 anatomical foot areas normalized to ground reaction force at foot-flat and push-off. Significant differences in peak pressure were observed between the control group and the contralateral foot of patients under the heel and the metatarsals 1 to 4. Significant differences in the forces at foot-flat and push-off are seen especially in the midfoot. Both sides of the patients with unilateral clubfeet exert significantly less ground reaction force than normal subjects. Different pressure and force distributions of clubfoot children on their contralateral side compared with the normal feet of the control group may indicate differences in the general control pattern generated by the central nervous system. Differences can still be observed after normalization of the forces. We therefore conclude that when foot pressure measurements are made with clubfeet, it might be advisable to use a collective of normal feet, instead of the contralateral foot, for comparison. 相似文献
109.
St?le Nordg?rd Gerhard Hein Brit Kari Stene Ketil Wichman Skj?stad Joachim T Maurer 《Otolaryngology--head and neck surgery》2007,136(5):818-822
OBJECTIVE: To evaluate long-term effectiveness of palatal implants for treatment of mild to moderate obstructive sleep apnea (OSA). STUDY DESIGN: A prospective study of 26 referred patients with a pretreatment apnea-hypopnea index (AHI) of 10 to 30 and a body mass index of < or =30, representing an extended follow-up of a subset of 41 patients enrolled in previous short-term trials. RESULTS: Twenty-one of 26 patients (80.8%) experienced a decrease in AHI. Fifteen of 26 patients (57.7%) had a follow-up AHI <10 at 1 year, whereas 13 patients (50%) had a 50% or greater reduction to an AHI <10 at 1 year. Mean AHI was reduced from 16.5 +/- 4.5 at baseline to 12.5 +/- 10.5 at 3 months (P < 0.014) and to 12.3 +/- 12.7 at 1 year (P < 0.019). CONCLUSIONS: Patients initially responding to palatal implants with improved AHI maintained improvement through long-term follow-up at 1 year. 相似文献
110.