全文获取类型
收费全文 | 127674篇 |
免费 | 9615篇 |
国内免费 | 3640篇 |
专业分类
耳鼻咽喉 | 1000篇 |
儿科学 | 2482篇 |
妇产科学 | 1795篇 |
基础医学 | 7096篇 |
口腔科学 | 2912篇 |
临床医学 | 15306篇 |
内科学 | 19023篇 |
皮肤病学 | 2325篇 |
神经病学 | 6566篇 |
特种医学 | 4132篇 |
外国民族医学 | 39篇 |
外科学 | 12553篇 |
综合类 | 18567篇 |
现状与发展 | 23篇 |
一般理论 | 2篇 |
预防医学 | 5743篇 |
眼科学 | 2065篇 |
药学 | 10407篇 |
81篇 | |
中国医学 | 11274篇 |
肿瘤学 | 17538篇 |
出版年
2024年 | 323篇 |
2023年 | 2301篇 |
2022年 | 4227篇 |
2021年 | 5691篇 |
2020年 | 5321篇 |
2019年 | 4831篇 |
2018年 | 4469篇 |
2017年 | 4914篇 |
2016年 | 5218篇 |
2015年 | 5007篇 |
2014年 | 9111篇 |
2013年 | 11463篇 |
2012年 | 7482篇 |
2011年 | 7976篇 |
2010年 | 6564篇 |
2009年 | 6040篇 |
2008年 | 5902篇 |
2007年 | 6343篇 |
2006年 | 5662篇 |
2005年 | 5008篇 |
2004年 | 4067篇 |
2003年 | 3662篇 |
2002年 | 3017篇 |
2001年 | 2656篇 |
2000年 | 2198篇 |
1999年 | 1737篇 |
1998年 | 1426篇 |
1997年 | 1195篇 |
1996年 | 996篇 |
1995年 | 900篇 |
1994年 | 713篇 |
1993年 | 544篇 |
1992年 | 487篇 |
1991年 | 448篇 |
1990年 | 381篇 |
1989年 | 331篇 |
1988年 | 320篇 |
1987年 | 280篇 |
1986年 | 221篇 |
1985年 | 256篇 |
1984年 | 228篇 |
1983年 | 172篇 |
1982年 | 171篇 |
1981年 | 164篇 |
1980年 | 132篇 |
1979年 | 121篇 |
1978年 | 66篇 |
1977年 | 44篇 |
1976年 | 51篇 |
1975年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
51.
H. Isoniemi J. Ahonen B. Eklund K. Höckerstedt K. Salmela E. von Willebrand P. Häyry 《Transplant international》1990,3(1):121-127
Abstract. A prospective randomized study was conducted to evaluate the impact of four different conversion protocols on graft outcome in long-term follow-up. Between January 1986 and May 1987, 128 patients with first cadaveric kidney allografts were randomized at the time of transplantation to four treatment groups of 32 patients each, to be assigned 10 weeks post-transplantation. During the first 10 weeks, all patients received triple therapy with low-dose azathioprine (Aza), cyclosporin (CyA), and methylprednisolone (MP). After 10 weeks, one group continued with triple therapy (group A) while the three other groups received different combinations of two drugs, namely, Aza and CyA (group B), Aza and MP (group C), or CyA and MP (group D). Withdrawal of MP (group B) or especially of CyA (group C) was associated with 4/29 (14%) and 10/28 (36%) acute rejection episodes, respectively, for 60 days after conversion. All rejections were mild and reversible. There were no rejections after Aza withdrawal or in the group that continued on triple therapy during the corresponding time period. The most common reason for dropping out after withdrawal, for those patients who could not continue on the originally randomized medication, was azathioprine intolerance (n= 12). Five patients were switched back to triple therapy after CyA withdrawal due to rejection. Steroid intolerance was rare and CyA in low doses was very well tolerated. At 1 year there were no statistically significant differences in graft survival between groups A, B, C, and D-81 %, 88%, 88%, and 88%, respectively-or in patient survival-88%, 88%, 88%, and 97%, respectively. For those patients continuing with the originally randomized treatment protocol, there were no differences in patient or graft survival either, the means being 91% and 89%, respectively. The most common cause of death after withdrawal was cardiovascular in nature, and there were no more fatal infections under triple drug treatment than with double drug regimens. There were no statistically significant differences in mean serum creatinine values at 1 year. The median serum creatinine values for groups A, B, C, and D were 112, 132, 133, and 133 μmol/l, respectively. At 1 year the mean CyA dose in the groups that continued with CyA was 3. 5–4. 2 mg/kg per day and CyA concentrations were equal. 相似文献
52.
Abstract: Lipid peroxidation, measured by malonyldial-dehyde (MDA) and vitamin E in red blood cells (RBC) and plasma, was investigated in 25 hemodialysis (HD) patients before and after 6 months rhEPO therapy. RBC-MDA was significantly elevated, but plasma MDA was in the reference range. After recombinant human erythro-poietin (rhEPO) treatment, the MDA level was significantly decreased in both compartments. Marked vitamin E deficiency was established in RBC as well as in plasma. rhEPO therapy restored vitamin E levels in both compartments. Our data suggest a possible positive rhEPO-antioxidant effect in HD patients. 相似文献
53.
S Kimel L O Svaasand M Hammer-Wilson V Gottfried S Cheng E Svaasand M W Berns 《Lasers in surgery and medicine》1992,12(4):432-440
The chick chorioallantoic membrane (CAM) model was used to study vascular effects of photodynamic therapy (PDT) and hyperthermia (HPT) and the synergism of these modalities. The CAM is a convenient medium for monitoring the modifications of the vasculature. It is possible to view the CAM and to examine structural changes of individual blood vessels in real time. Moreover, the CAM is a closed system which lends itself to mathematical modeling of the temporal and spatial temperature profile and in which HPT can be performed quantitatively and to a selected depth, using different lasers. A porphyrin-type photosensitizer solution was applied to areas of the CAM, defined by teflon O-rings placed on the surface. Uptake dynamics of the sensitizer into the CAM was determined by analyzing its fluorescence in vivo. The CAM area was irradiated with a dual-wavelength laser system composed of a dye laser at 644 nm (to induce PDT) and a CO2 laser at 10.6 microns (to bring about HPT). Damage to the CAM vasculature, due to combined PDT+HPT, was compared to the outcome of the separate modalities, and a synergistic effect of about 40% was observed. 相似文献
54.
55.
本文报告口服Sumatriptan 100mg对偏头痛急性发作119例次的治疗结果。治疗后4h内显效91例次(76.5%),好转16例次(13.4%),无效12例次(10.1%),总有效率为89.9%。对偏头痛伴随症状恶心、呕吐和畏光、畏声的缓解率分别为94.2%、96%和94.3%。 相似文献
56.
Despite improvements in supportive care, the mortality and morbidity of asthma remain constant. The risks and incidence of morbidity related to barotrauma remain high in patients that require mechanical ventilation. The authors present three alternative strategies including the inhalation of anaesthetic agents, helium/oxygen ventilation, and extracorporeal membrane oxygenation which may be beneficial when 'conventional therapies' fail in the intubated patient with status asthmaticus. 相似文献
57.
Abstract: The optimal timing of systemic cyclophosphamide, methotrexate, 5-fluorouracil (CMF) chemotherapy and local radiation in adjuvant breast cancer has been a debatable subject. To evaluate the Lankenau Hospital experience with sequential CMF chemotherapy followed by radiation in the adjuvant therapy of stage I and stage II breast cancer we reviewed the records of patients at our center. This group of 34 patients was treated in a homogenous manner, all receiving standard CMF for six cycles followed by radiotherapy after lumpectomy with axillary lymph node dissection. The radiation course was 5040cGy to the entire breast (28 fractions in 45 elapsed days) followed by a boost to the tumor site of 1800cGy in 10 fractions. Thirty-four patients were identified and followed for an average of 5 years (range 1.5–11.5 years). One patient had local recurrence and with subsequent treatment is disease-free at 5 years postrecurrence (8 years from initial diagnosis). Two deaths were not breast-cancer related (1 myocardial infarction at year 3, 1 melanoma at year 7.5). The estimated probability of no relapse at 5 years and 8 years by Kaplan-Meier analysis is 79% and 60% respectively. Overall and disease-free survival in this group of patients treated with breast-conserving surgery and CMF chemotherapy followed by radiation is excellent. There appears to be no detriment to delaying radiotherapy until full doses of systemic treatment are given as local recurrence was rare (6%) and was amenable to further treatment. 相似文献
58.
光动力学疗法与局部化疗联合治疗进展期食管贲门癌 总被引:2,自引:0,他引:2
作应用光动力学疗法(PDT)对进展期食管贲门癌55例进行治疗,并对其中15例联合应用内镜下局部注射抗癌药物。对每一患均先静脉滴注血卟啉衍生物(HPD)5mg/kg,于用药后24,48和72h分别用波长630nm的铜蒸汽激光照射肿瘤部位。联合治疗组除PDT治疗外,于每次光照前肿瘤局部注射5-Fu250~500mg。结果:联合治疗组的近期显效率高于单纯PDT组(P〈0.05)。病例随访6~16月, 相似文献
59.
T. Vander M. Medvedovsky I. Shelef L. Duchano A. Tomer Y. Herishanu 《European journal of neurology》2004,11(8):569-571
While a dural sinus thrombosis (DST), is a well-known consequence of the use of oral contraceptives, the role of hormone replacement therapy (HRT) in DST was not previously evaluated. We report two postmenopausal women, presenting with DST under HRT. Antiphospholipid antibodies in one case and borderline protein S deficiency in another were diagnosed. Only five cases of DST under HRT were previously reported and in two of them additional prothrombotic risk factors were found. According to these and previous cases, HRT is not an independent risk factor for DST. 相似文献
60.
Recombinant human deoxyribonuclease I (rhDNase) is a new therapeutic agent developed to improve clearance of purulent sputum from the human airways. It is delivered by inhalation. Four jet nebulizers, T Up-Draft II (Hudson), Customized Respirgard II (Marquest), Acorn II (Marquest), and Airlife Misty (Baxter), were evaluated in vitro for their ability to deliver aerosols of rhDNase. The aerosols were generated from 2.5-mL aqueous solutions of rhDNase, at concentrations of either 1 or 4 mg/mL. In all experiments, the Pulmo-Aide Compressor (De Vilbiss) was used to supply the air to the nebulizers. Between 20 and 28% of the rhDNase dose initially placed in the nebulizers was delivered to the mouthpiece in the respirable range (1-6 µm). Evaluation of the rhDNase following nebulization in all four devices indicated that there was no loss in enzymatic activity and no increase in aggregation. Circular dichroism spectrophotometry indicated there was no change in either the secondary or the tertiary structure in rhDNase following nebulization. These results show that all four nebulizers are essentially equivalent in their ability to deliver respirable doses of rhDNase in an intact, fully active form. Changing the concentration of the solution in the nebulizer from 4 to 1 mg/mL rhDNase leads to a proportional reduction in the respirable dose delivered to the mouthpiece. 相似文献