全文获取类型
收费全文 | 23458篇 |
免费 | 1257篇 |
国内免费 | 174篇 |
专业分类
耳鼻咽喉 | 326篇 |
儿科学 | 426篇 |
妇产科学 | 581篇 |
基础医学 | 2767篇 |
口腔科学 | 754篇 |
临床医学 | 1871篇 |
内科学 | 6334篇 |
皮肤病学 | 413篇 |
神经病学 | 2320篇 |
特种医学 | 753篇 |
外科学 | 3469篇 |
综合类 | 84篇 |
一般理论 | 9篇 |
预防医学 | 1094篇 |
眼科学 | 313篇 |
药学 | 1535篇 |
1篇 | |
中国医学 | 42篇 |
肿瘤学 | 1797篇 |
出版年
2024年 | 19篇 |
2023年 | 161篇 |
2022年 | 346篇 |
2021年 | 664篇 |
2020年 | 386篇 |
2019年 | 554篇 |
2018年 | 642篇 |
2017年 | 474篇 |
2016年 | 565篇 |
2015年 | 609篇 |
2014年 | 919篇 |
2013年 | 1174篇 |
2012年 | 1812篇 |
2011年 | 1794篇 |
2010年 | 1074篇 |
2009年 | 945篇 |
2008年 | 1645篇 |
2007年 | 1566篇 |
2006年 | 1481篇 |
2005年 | 1485篇 |
2004年 | 1380篇 |
2003年 | 1262篇 |
2002年 | 1161篇 |
2001年 | 158篇 |
2000年 | 158篇 |
1999年 | 180篇 |
1998年 | 190篇 |
1997年 | 185篇 |
1996年 | 181篇 |
1995年 | 160篇 |
1994年 | 132篇 |
1993年 | 122篇 |
1992年 | 120篇 |
1991年 | 69篇 |
1990年 | 87篇 |
1989年 | 70篇 |
1988年 | 82篇 |
1987年 | 79篇 |
1986年 | 62篇 |
1985年 | 64篇 |
1984年 | 77篇 |
1983年 | 72篇 |
1982年 | 69篇 |
1981年 | 59篇 |
1980年 | 56篇 |
1979年 | 30篇 |
1978年 | 37篇 |
1977年 | 26篇 |
1976年 | 22篇 |
1975年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
92.
Friedman D Cuneo S Valenzano M Marinari GM Adami GF Gianetta E Traverso E Scopinaro N 《Obesity surgery》1995,5(3):308-313
Background: 239 pregnancies occurred in 1136 women who had undergone biliopancreatic diversion (BPD). Methods: There were
73 abortions, and 14 pregnancies are presently in their course. The 152 term pregnancies (six twins) occurred in 129 women
2-173 months (mean 42.7) after BPD. Mean age and current excess weight were 31.4 years (20-42) and 29.1% (-6.9-78.2), and
mean excess weight loss was 72.9% (30.4-110.5). Results: Mean weight gain during pregnancy was 6.2 kg (-21-25). In 32 patients
(21%), parenteral nutritional support was needed. In all the other patients (79%), the usual supplementations were given.
Of the newborns, 122 were delivered at term (84.7%) with a mean weight of 2842.4 g (1760-4600 g) and a mean length of 48.5
cm (43-59 cm), while the 22 preterm babies (15.3%) weighed 2151.1 g (1400-3850 g) and had a length of 44.6 cm (33-56 cm).
Forty infants (27.8%) were small for gestational age but 17 of them weighed more than 2500 g. Eleven twins (one abortion at
26th week) were also delivered, with a mean weight of 2088.6 g (1200-3100 g) and a mean length of 45.6 cm (35-50 cm). Delivery
was spontaneous in 85 instances (56%), while vacuum extractor was used in one, and 66 cesarean sections were performed. There
were two birth malformations, one infant died after surgery for meconium obstruction and two died from unknown causes. Of
the 129 women, 35 had been infertile before BPD. Conclusions: Disappearance of infertility and decrease of pregnancy risk
are to be considered among the beneficial effects of weight reduction following BPD. 相似文献
93.
Saviano MS Fundarò S Gelmini R Begossi G Perrone S Farinetti A Criscuolo M 《Surgery today》1999,29(2):174-177
(Received for publication on Apr. 28, 1997; accepted on May 15, 1998) 相似文献
94.
Paola Queirolo MD Marco Ponte MD Marco Gipponi MD Ferdinando Cafiero MD Alberto Peressini MD Claudia Semino PhD Gabriella Pietra PhD Rita Lionetto MD Stefania Vecchio MD Iole Ribizzi MD Giovanni Melioli MD Mario R. Sertoli MD 《Annals of surgical oncology》1999,6(3):272-278
Background: On the basis of our previous experience, we designed this study to determine the activity and toxicity of outpatient treatment with autologous tumor-infiltrating lymphocytes (TIL) together with intermediate-dose recombinant interleukin-2 (rIL-2) and low-dose recombinant interferon alfa-2a (rIFN-2a), for patients with metastatic melanoma.Methods: Between April 1992 and October 1994, we processed 38 melanoma samples derived from 36 patients with metastases. Proliferative cultures of expanded lymphocytes (TIL) were infused only once into patients with metastatic melanoma. rIL-2 was administered subcutaneously for 1 month, starting on the day of TIL infusion, at an escalating dose of 6–18 × 106 IU/m2/day for the first week and at the maximum-tolerated dose for the subsequent 3 weeks and then, after a 15-day interval, for 1 week/month for 3 months. rIFN-2a was administered subcutaneously at 3 × 106 IU three times each week until progression.Results: Of 38 melanoma samples, 19 (50%) resulted in proliferative cultures and were infused. The median number of expanded lymphocytes was 18 × 109 (range, 1–43 × 109), and the median period of culture was 52 days (range, 45–60). rIL-2 was administered at doses ranging between 6 and 18 × 106 IU/m2/day. Toxicity was mild or moderate, and no life-threatening side effects were encountered. Two of 19 treated patients experienced complete responses of their metastatic sites (soft tissue), 10 had stable disease, and 7 showed progressive disease. The response rate was 11% (95% confidence interval, 2–35%).Conclusions: Outpatient treatment with TIL plus rIL-2 and rIFN-2a is feasible, although, within the context of the small sample size, the activity of the combination was no different from the reported activity of any of the components used alone. 相似文献
95.
Mario B Marrero Bernhard Schieffer Kenneth E Bernstein Brian N Ling 《Clinical and experimental pharmacology & physiology》1996,23(1):83-88
- 1 Angiotensin II (AngII)-induced, activation of phospholipase C (PLC) and Ca2+-dependent Cl? channels is an important signal transduction pathway for the regulation of vascular smooth muscle cell (VSMC) and glomerular mesangial cell contraction and growth. While AT receptors are traditionally thought to be G-protein coupled to the β isoform of PLC, recent evidence suggests that in some tissues AT receptors may also activate the PLC-γ isoform via tyrosine phosphorylation.
- 2 By western analysis, we identified PLC-γ1 in the above cell types. We found that within 3 min of exposure to 10?7 mol/L AngII, tyrosine phosphorylation of PLC-γ1 was observed; however, peak response (> 3-fold increase) occurred within 0.5 min. In addition, pre-incubation of these cells with the tyrosine kinase inhibitor genistein blocked the tyrosine phosphorylation of PLC-γ1 by AngII. In contrast, preincubation with the tyrosine phosphatase inhibitor sodium vanadate increased the levels of tyrosine phosphorylation of PLC-γ1. Similar results were found when intracellular levels of 1,4,5-IP3 were measured after AngII exposure.
- 3 By using patch clamp techniques on cultured rat mesangial cells exposed to AngII, we found that the release of 1,4,5-IP3-sensitive intracellular Ca2+ stores stimulated low conductance Cl? channels. Preincubation with genistein, abolished the usual 10-fold increase in Cl? channel activity observed with AngII.
- 4 Therefore, we conclude that in VSMC and glomerular mesangial cells (i) AngII transiently stimulates PLC activity via tyrosine phosphorylation of the γ1 isoenzyme, (ii) tyrosine phosphorylation of PLC-γ1 and production of 1,4,5-IP3 in response to AngII is dramatically inhibited by tyrosine kinase inhibition and stimulated by tyrosine phosphatase inhibition, (iii) activation of Ca2+-dependent Cl? channels by AngII-induced release of 1,4,5-IP3-dependent intracellular Ca2+ stores is also abolished by tyrosine kinase inhibition. In summary, this AngII-induced signal transduction cascade provides a possible mechanism for both the contractile and growth-stimulating effects of AngII on VSMC and glomerular mesangial cells.
96.
Minghetti L Greco A Cardone F Puopolo M Ladogana A Almonti S Cunningham C Perry VH Pocchiari M Levi G 《Journal of neuropathology and experimental neurology》2000,59(10):866-871
The levels of 2 arachidonic acid metabolites formed either by enzymatic activity of cyclooxygenase, i.e. prostaglandin E2 (PGE2), or by free radical-catalyzed peroxidation, i.e. F2-isoprostane 8-epi-prostaglandin F2alpha (8-epi-PGF2alpha), were measured in the CSF of subjects with sporadic and familial Creutzfeldt-Jakob disease (CJD) and in brain homogenates of scrapie-infected mice. The CSF levels of both metabolites were increased in sporadic CJD (n = 52) and familial CJD (n = 10) patients when compared with a group of patients with noninflammatory disorders. Similarly, PGE2 and 8-epi-PGF2alpha levels were higher in brain homogenates obtained from C57BL/6J mice infected with the ME7 scrapie strain than in brain homogenates from control animals. As PGE2 is 1 of the most abundant prostaglandins released during inflammation and 8-epi-PGF2alpha is a quantitative marker of lipid peroxidation, our results provide in vivo biochemical evidence for the occurrence of inflammation and oxidative stress in human and experimental transmissible spongiform encephalopathies (TSEs), a concept so far based mainly on histopathological and in vitro evidence. Interestingly, in sporadic CJD patients, high CSF levels of PGE2, but not 8-epi-PGF2alpha, correlated with short survival time, suggesting that the inflammatory response correlates with the clinical duration of disease. 相似文献
97.
98.
99.
100.
Value of P-glycoprotein and clinicopathologic factors as the basis for new treatment strategies in high-grade osteosarcoma of the extremities. 总被引:8,自引:0,他引:8
Massimo Serra Katia Scotlandi Gemma Reverter-Branchat Stefano Ferrari Maria C Manara Stefania Benini Marina Incaprera Franco Bertoni Mario Mercuri Antonio Briccoli Gaetano Bacci Piero Picci 《Journal of clinical oncology》2003,21(3):536-542
PURPOSE: To evaluate the prognostic value of P-glycoprotein and clinicopathologic parameters in a large series of high-grade osteosarcoma (OS) patients treated at the Rizzoli Institute. PATIENTS AND METHODS: With the use of immunohistochemistry, P-glycoprotein was assessed in 149 patients with primary, nonmetastatic, high-grade OS who were homogeneously treated with chemotherapy protocols based on doxorubicin, high-dose methotrexate, and cisplatin and the addition of ifosfamide in the postoperative phase. RESULTS: P-glycoprotein positivity was found in 47 of 149 cases (32%) and was significantly associated with a higher incidence of relapse and a worse outcome, as was age younger than 12 years and tumor volume greater then 150 mL at diagnosis. Multivariate analysis further confirmed the prognostic value of these parameters, which all were independent adverse prognostic factors. Event-free survival and proportional hazards regression analyses confirmed that overexpression of P-glycoprotein at clinical onset is the most important adverse prognostic factor for high-grade OS patients treated with these chemotherapy protocols. CONCLUSION: Increased P-glycoprotein levels, together with tumor volume and age, should be taken into consideration to identify, at time of diagnosis, subgroups of OS patients with a higher risk of recurrence. This subgroup identification will constitute the basis for drawing individualized treatment protocols on the basis of risk evaluation, with the aim of using more aggressive chemotherapy, or combination chemotherapy with other adjuvants, only in those patients for which more aggressive regimens are strictly necessary and warranted. 相似文献