全文获取类型
收费全文 | 60419篇 |
免费 | 5687篇 |
国内免费 | 2068篇 |
专业分类
耳鼻咽喉 | 943篇 |
儿科学 | 669篇 |
妇产科学 | 2362篇 |
基础医学 | 6131篇 |
口腔科学 | 1038篇 |
临床医学 | 6468篇 |
内科学 | 4879篇 |
皮肤病学 | 458篇 |
神经病学 | 3917篇 |
特种医学 | 2094篇 |
外国民族医学 | 30篇 |
外科学 | 9343篇 |
综合类 | 10296篇 |
现状与发展 | 11篇 |
一般理论 | 1篇 |
预防医学 | 4946篇 |
眼科学 | 1033篇 |
药学 | 4025篇 |
65篇 | |
中国医学 | 4383篇 |
肿瘤学 | 5082篇 |
出版年
2024年 | 254篇 |
2023年 | 1300篇 |
2022年 | 2349篇 |
2021年 | 3113篇 |
2020年 | 2798篇 |
2019年 | 2245篇 |
2018年 | 2329篇 |
2017年 | 2472篇 |
2016年 | 2661篇 |
2015年 | 2403篇 |
2014年 | 4725篇 |
2013年 | 4396篇 |
2012年 | 4016篇 |
2011年 | 4188篇 |
2010年 | 3359篇 |
2009年 | 2999篇 |
2008年 | 2848篇 |
2007年 | 2876篇 |
2006年 | 2457篇 |
2005年 | 2054篇 |
2004年 | 1720篇 |
2003年 | 1663篇 |
2002年 | 1102篇 |
2001年 | 1077篇 |
2000年 | 798篇 |
1999年 | 729篇 |
1998年 | 570篇 |
1997年 | 520篇 |
1996年 | 481篇 |
1995年 | 441篇 |
1994年 | 402篇 |
1993年 | 288篇 |
1992年 | 265篇 |
1991年 | 214篇 |
1990年 | 213篇 |
1989年 | 202篇 |
1988年 | 181篇 |
1987年 | 154篇 |
1986年 | 140篇 |
1985年 | 202篇 |
1984年 | 172篇 |
1983年 | 132篇 |
1982年 | 145篇 |
1981年 | 96篇 |
1980年 | 113篇 |
1979年 | 59篇 |
1978年 | 70篇 |
1977年 | 42篇 |
1976年 | 41篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
不能切除肿瘤的恶性梗阻性黄疸的外科姑息治疗方法繁多,本文介绍自1989年以来,采取开腹经不同途径的带支撑导管胆肠内引流的方法治疗30例,减黄确切,尚对7例高位胆管癌在解除胆道梗阻的基础上行术后(192)Ir和(60)Co联合放疗,提高了病人生存质量及延长了生命。 相似文献
152.
Jan Stulik Tobias Rainer Pitzen Jan Chrobok Sabine Ruffing Jörg Drumm Laurentius Sova Ravel Kucera Tomas Vyskocil Wolf Ingo Steudel 《European spine journal》2007,16(10):1689-1694
Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior
cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide
a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling.
Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated
spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily
mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and
the rate of implant complications using either rigid- or dynamic plates. The study design is prospective, randomized, controlled,
and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two
patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1- or level-2
anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap - position
(ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were
compared after 3- and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results
after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the
time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLP- group the measurements were 1.0, 1.8, and
1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after
6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were
observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior
spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate.
These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed
2 years postoperatively. 相似文献
153.
Howard B. Yeon Jacob Weinberg Vincent Arlet Jean A. Ouelett Kirkham B. Wood 《European spine journal》2007,16(9):1379-1385
Fifteen skeletally immature patients with double major adolescent idiopathic scoliosis with large lumbar curves and notable L4 and L5 coronal plane obliquity were retrospectively studied. Seven patients who underwent anterior release and fusion of the lumbar curve with segmental anterior instrumentation and subsequent posterior instrumentation ending at L3 were compared with eight patients treated with anterior release and fusion without anterior instrumentation followed by posterior instrumentation to L3 or L4. At 4.5 years follow-up (range 2.5-7 years), curve correction, coronal balance and fusion rate were not statistically different between the two groups; however, the group with anterior instrumentation had improved coronal plane, near normalangulation in the distal unfused segment compared with the group without anterior instrumentation. In cases involving severe lumbar curvatures in the context of double major scoliosis, when as a first stage anterior release is chosen, the addition of instrumentation appears to restore normal coronal alignment of the distal unfused lumbar segment, and may in certain cases save a level compared with traditional fusions to L4. 相似文献
154.
Radiologic long-term results after cervical vertebral interbody fusion with Polymethyl Methacrylat (PMMA) 总被引:4,自引:0,他引:4
Long-term results of cervical interbody fusion with PMMA were evaluated in a retrospective study. X-ray films of 83 patients were obtainable. Post-operative follow-up in this series was between 15 and 20 years. The results show that PMMA is engrafted after about 2 years. Stable vertebral interbody fusion is obtained in about 90% of cases. Development of malignoma was not observed. Resorptive bone alterations, which can be seen in about 2% of cases one to two years after operation are shown not to be progressive. This process heals and stable fusion develops. 相似文献
155.
HLA-B27相关的前葡萄膜炎眼后节并发症的临床特点 总被引:1,自引:0,他引:1
目的探讨HLA—B27阳性的前葡萄膜炎眼后节并发症的临床特点及治疗。方法2002年1月至2005年10月就诊的前葡萄膜炎患者采用流式细胞术进行外周HLA-B27的检测,筛选出71-例82眼HLA-B27阳性前葡萄膜炎患者,分为两组:实验组为眼后节受累的患者24例31眼,对照组为眼后节未受累的患者47例51眼。另有HLA—B27阴性前葡萄膜炎患者74例116眼作参考。所有患者均进行裂隙灯、眼底镜等常规眼科查体,部分行眼底荧光血管造影。分析了HLA—B27相关的前葡萄膜炎眼后节并发症的临床特点。采用x^2检验及t检验进行统计学分析。结果71例82眼HLA—B27阳性前葡萄膜炎中有24例31眼占37.8%出现眼后节并发症者,包括:黄斑囊样水肿12例15眼占48.4%,视乳头水肿7例8眼占25.8%,而玻璃体炎最多见为21例27眼占87.1%,8例10眼占32.3%患者存在两种或两种以上的眼后节表现。74例116眼HLA—B27阴性者有8例12眼占10.3%有眼后节表现。实验组中发生前房成型纤维素渗出31眼中18眼占58.06%和积脓31眼中9眼占29.03%明显高于对照组(前房纤维素渗出51眼中3眼,5.88%,X^2=27.56,P〈0.01;前房积脓51眼中1眼,1.96%,X^2=13.20,P〈0.01);实验组中伴发相关全身性疾病24例中有16例占66.67%的几率高于对照组(47例中有17例,31.66%,X^2=5.94,P〈0.05)。出现眼后节并发症的患者经全身及局部应用糖皮质激素治疗,31眼中有11眼最佳矫正视力≥1.0。结论HLA-B27阳性前葡萄膜炎易出现眼后节并发症,HLA—B27相关的前葡萄膜炎眼后节受累的患者发生相关全身性疾病和前房纤维素渗出与积脓的几率较高。 相似文献
156.
[目的]比较2,4-二氯苯胺重氮法(DCA)和钒酸盐氧化法检测血清结合胆红素的结果。[方法]根据NCCLS(EP6-P)评价方案,评估两种方法的相关性和偏倚。[结果]两种方法的检测结果相关性良好(r=0.9985),Ⅰ、Ⅱ、Ⅲ组检测结果无差异,Ⅳ组结果有差异。[结论]应建立与方法学相对应的血清结合胆红素参考值范围。 相似文献
157.
Functional vascular connections must form rapidly to prevent ischemic damage to grafted neural tissues. The temporal sequence by which transplant circulation is re-established provides information about the angiogenic capacity of either intact or damaged CNS blood vessels. This study compares the time course and mechanism of vascular reperfusion in allografts of superior cervical ganglia or adrenal medulla inserted either into the fourth ventricle or directly into the parietal cortex of perinatal rats. Tritiated thymidine was administered to recipients to determine angiogenic patterns at various postoperative time periods. After processing for light microscopic autoradiography, host and graft endothelial labelling indices were determined in order to establish the temporal sequence and location of vascular proliferation. Correlative electron microscopy depicted the morphological changes in transplant vasculature. Some recipients were prelabelled with 3H thymidine prior to transplantation to determine if host vessels invaded the grafts. Intraventricular graft vessels initially collapsed but sustained minimal ischemic damage and were completely reperfused by 24 hours postoperative. Adjacent intact host vessels attained peak 3H thymidine incorporation at 20 hours. Intrinsic graft vessels were radioactively labelled only after 48 hours. Intraparenchymal transplants surrounded by minimal trauma exhibited a similar temporal sequence of reperfusion and host endothelial proliferation. Intrinsic graft vessels in intraparenchymal grafts sustained more severe damage. With increased trauma, a concomitant delay in graft reperfusion time was observed. Grafts within prelabelled hosts rarely contained any labelled endothelium, indicating that anastomotic connections were made between original, intrinsic graft vessels and nearby host vascular sprouts. This study demonstrates that mature autonomic tissue stimulates the growth of adjacent host vessels when transplanted to undamaged brain surfaces. The anastomosis of nascent host vessels with pre-existing graft vessels is responsible for the rapid re-establishment of circulation within the transplants. A similar mechanism occurs within intraparenchymal grafts, although the rapidity of reperfusion appears to be predicated on the amount of trauma present at the graft site. 相似文献
158.
Stefan Tigges M.D. B. J. Manaster M.D. Ph.D. Gordon Carson M.D. 《Emergency radiology》1996,3(3):105-112
Although magnetic resonance imaging is the most accurate imaging method of evaluating the anterior cruciate ligament, several
plain radiographic signs suggestive of anterior cruciate ligament injury have been described. Plain radiographs also play
an important role in evaluating anterior cruciate ligament reconstruction. 相似文献
159.
Sofía A. Sanz Ana M. García Amando García 《International archives of occupational and environmental health》1993,65(3):205-207
Summary Noise levels around educational centres can negatively affect the performance of both teachers and pupils. Two public schools in Valencia, Spain, were selected for study. One of these schools was exposed to excessively high road traffic noise levels while the other was located in a relatively quiet area. The socioeconomic level of those attending the schools was very similar. A set of external and internal noise measurements were carried out, along with two different attention tests among the children. Test results were consistently better (both for tests and for children from different classrooms in each school) in the quiet school. Exposure to high traffic noise levels in the noisy school over the whole school year is a plausible determinant of these results. 相似文献
160.