全文获取类型
收费全文 | 23919篇 |
免费 | 1673篇 |
国内免费 | 1583篇 |
专业分类
耳鼻咽喉 | 130篇 |
儿科学 | 269篇 |
妇产科学 | 135篇 |
基础医学 | 2597篇 |
口腔科学 | 392篇 |
临床医学 | 3051篇 |
内科学 | 760篇 |
皮肤病学 | 33篇 |
神经病学 | 5567篇 |
特种医学 | 942篇 |
外国民族医学 | 1篇 |
外科学 | 6277篇 |
综合类 | 3448篇 |
现状与发展 | 3篇 |
预防医学 | 414篇 |
眼科学 | 1280篇 |
药学 | 1038篇 |
12篇 | |
中国医学 | 411篇 |
肿瘤学 | 415篇 |
出版年
2024年 | 77篇 |
2023年 | 415篇 |
2022年 | 636篇 |
2021年 | 862篇 |
2020年 | 869篇 |
2019年 | 709篇 |
2018年 | 771篇 |
2017年 | 827篇 |
2016年 | 789篇 |
2015年 | 833篇 |
2014年 | 1362篇 |
2013年 | 1718篇 |
2012年 | 1208篇 |
2011年 | 1283篇 |
2010年 | 1196篇 |
2009年 | 1093篇 |
2008年 | 1089篇 |
2007年 | 1192篇 |
2006年 | 1066篇 |
2005年 | 911篇 |
2004年 | 811篇 |
2003年 | 801篇 |
2002年 | 689篇 |
2001年 | 554篇 |
2000年 | 435篇 |
1999年 | 431篇 |
1998年 | 440篇 |
1997年 | 376篇 |
1996年 | 317篇 |
1995年 | 275篇 |
1994年 | 263篇 |
1993年 | 216篇 |
1992年 | 216篇 |
1991年 | 188篇 |
1990年 | 177篇 |
1989年 | 200篇 |
1988年 | 132篇 |
1987年 | 127篇 |
1986年 | 180篇 |
1985年 | 290篇 |
1984年 | 265篇 |
1983年 | 224篇 |
1982年 | 179篇 |
1981年 | 163篇 |
1980年 | 134篇 |
1979年 | 47篇 |
1978年 | 62篇 |
1977年 | 31篇 |
1976年 | 20篇 |
1975年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
BDNF基因修饰神经干细胞移植后大鼠脊髓损伤移植处的基因表达变化 总被引:5,自引:0,他引:5
目的:了解脑源性神经营养因子(Brain-derived neurotrophic factor,BDNF)基因修饰神经干细胞移植到大鼠脊髓损伤处后的基因表达变化,为脊髓损伤修复提供基础研究资料。方法:大鼠随机分为4组:正常对照组,手术对照组,神经干细胞(Neural stem cells,NSCs)移植组,BDNF-NSCs移植组,各组分4个时相点(7d、1个月、2个月、3个月),利用细胞移植、X-gal组化、免疫组化、原位杂交等方法,观察了移植处细胞的标记基因(LacZ)表达和BDNF、胶质纤维酸性蛋白(GFAP)、神经丝-200(NF-200)的表达。结果:大鼠脊髓损伤移植处细胞中,有标记基因阳性细胞,BDNF强烈表达,尤其是BDNF-NSCs移植组的移植后1周和1个月时。各组各时相点均有GFAP和NF-200免疫反应阳性细胞和纤维。结论:BDNF基因修饰神经干细胞能在脊髓损伤移植处存活,强烈表达BDNF,BDNF基因修饰神经干细胞可以作为脊髓损伤修复的移植材料。 相似文献
102.
肘关节后脱位伴桡骨头和尺骨冠突骨折 (恐怖三联征)5例初步报告 总被引:12,自引:0,他引:12
[目的]介绍"肘关节恐怖三联征"的概念(肘关节后脱位同时伴有桡骨头和尺骨冠突骨折),并报告5例患者的临床治疗体会。[方法]自2004年4月~2007年3月,作者共收治肘关节三联征损伤5例。桡骨头骨折按Mason法分类:Ⅱ型4例,Ⅲ型1例;按Schatzker法分类:Ⅰ型1例,Ⅱ型3例,Ⅲ型1例。尺骨冠突骨折按Regan-Morrey法分类:Ⅰ型1例,Ⅱ型4例;按O′Driscoll法分类:5例均为Ⅰ型。4例采取了手术内固定治疗,以3 mm钛空心拉力螺钉或1 mm K针分别固定冠突和桡骨头,并缝合修复肘内外侧副韧带。术后屈肘90°前臂旋转中立位石膏外固定3周,开始屈伸和旋转康复训练。[结果]4例手术治疗的患者经3个月~3年随访,骨折愈合,肘关节稳定,无疼痛。肘关节屈伸幅度平均120°,前臂旋转幅度平均110°。3例随访1年以上,Mayo肘关节功能评分:优2例,良1例。未手术治疗的1例功能评定为差,有肘关节不稳定和疼痛。[结论]肘关节恐怖三联征的骨折片虽然很小,但伴有肘内外侧副韧带撕裂,肘关节严重不稳定。只有在重建了骨关节和软组织结构稳定的基础上,及早(3周内)进行康复锻炼,才能获得较好的功能恢复。 相似文献
103.
Spinal cord restitution following compression injuries in rats 总被引:22,自引:0,他引:22
Spinal cord compression injuries were produced in rats by applying weights to a plate 2.2 x 50 mm in size, placed on the exposed midthoracic dura covering the spinal cord. The influence of force and duration of compression was studied by using 3 different weights, 20, 35 and 50 g, applied for 1, 5 and 10 min. Postoperative neurological function was tested by the inclined plane method and the rats were observed for 3 weeks. Neurological impairment increased with force and duration of compression. It is therefore reasonable to conclude that patients suffering from spinal cord injury should be investigated immediately for signs of persistent cord compression. If this is present, early decompression might be of value, although nothing is known in man concerning the limits of force and duration of compression permitting postoperative neurological recovery. 相似文献
104.
红外热像图在神经外科疾病中应用价值的评价 总被引:1,自引:0,他引:1
目的 评价红外热像图在神经外科疾病中应用的价值。方法 应用红外热像图对39例脊髓损伤患者进行躯体温度监测,对31例颅内肿瘤、76例脑梗死、2480例头痛、21例头面部血管瘤进行头部温度监测。结果 红外热像图监测脊髓损伤39例,测出脊髓损伤平面上下无温差14例,平面以下温度增高1-3℃ 13例,下降1-3℃ 12例。经大网膜脊髓移植手术13例,术前脊髓损伤平面以下34℃,术后1个月复查皮肤温度,上升至35℃并伴有麻胀和皮肤湿润感7例,皮肤温度下降0.6℃者6例。热像图可显示血管性头痛颞部高温区,眶上神经痛同侧前额部皮肤低温区,枕大神经痛同侧枕颈部热区;热像图可显示梗死侧有低温区;显示颅内肿瘤颈外血管供血情况;基本上能反映头面部血管瘤血管侵及范围。结论 红外热像图在神经外科有其独特的价值,本技术具有无创、可重复、价廉和检查的非接触性等优点,反映组织代谢活跃状态与程度,是CT等形态学诊断方法的补充,在医学科学的研究和临床应用中具有很大的潜力。 相似文献
105.
组织工程支架在犬急性脊髓损伤修复中应用的初步研究 总被引:6,自引:1,他引:5
目的探讨携带神经干细胞的聚碳酸亚丙酯[poly(propylene carbonate),PPC]可降解支架移植在犬脊髓急性损伤后修复中的作用。方法制作犬T13脊髓左侧半切损伤模型。将实验动物随机分为3组:细胞支架组在损伤后1周时将填充神经干细胞的PPC可降解支架植入损伤区.支架组只植入支架,对照组不作移植。8周后观察支架的组织反应、降解情况及神经干细胞的迁移分化和脊髓轴突再生情况。结果支架部分降解,管腔内未见瘢痕侵入。神经干细胞向支架邻近部位广泛迁移、扩散,并分化为3种神经细胞表型。神经丝蛋白(NF)及髓鞘碱性磷酯蛋白(MBP)免疫组化显示细胞支架组脊髓损伤区邻近部位的继发损害较其他组轻。结论携带神经干细胞的PPC可降解支架在犬脊髓组织中无明显组织反应.能够抵御瘢痕侵入:其携带的神经干细胞能够整合入邻近脊髓组织并起到一定保护作用。 相似文献
106.
目的:提高对椎管内神经鞘瘤的MRI诊断水平。方法:回顾性分析手术病理证实的11例椎管内神经鞘瘤的病理组织学所见及MRI表现。结果:11例MRI检查均清晰显示椎管内神经鞘瘤的形态,信号特征,其中8例在硬膜内,2例居硬膜内外,1例位于硬膜外,1例为多发,增强后瘤体明显强化。结论:MRI对椎管内神经鞘瘤的定位及定性诊断颇有价值。 相似文献
107.
q-Space diffusion of myelin-deficient spinal cords. 总被引:1,自引:0,他引:1
The apparent water diffusion anisotropy in white matter (WM) of excised spinal cords of myelin-deficient (md) rats and their age-matched controls was studied by high-b-value q-space diffusion MRS and MRI at different diffusion times. Non-monoexponential signal decay was observed at long diffusion times. The mean displacements in the md spinal cords were found to be higher than those of the controls. The apparent anisotropy (AA) of the fast-diffusing component was found to decrease more dramatically with the increase in diffusion time for the md spinal cords as compared with controls, whereas the AA of the slow-diffusing component in the controls was found to increase with the increase in diffusion time while that of the md cords decreased with the increase in diffusion time. When diffusion MRI was performed, similar diffusion anisotropy was extracted for the md and control spinal cords at diffusion times of 22 and 50 ms. Only at a diffusion time of about 200 ms was a significant difference obtained in the AA of the two groups. This originates from the much smaller increase in the mean displacement perpendicular to the fiber direction in the control group vs. the md group when the diffusion time was increased. 相似文献
108.
The role of JOA score as an indication for surgical or conservative treatment of symptomatic degenerative lumbar spinal stenosis 总被引:1,自引:0,他引:1
G. Costanzo P. Cellocco A. Di Francesco C. Rossi 《Journal of orthopaedics and traumatology》2005,6(3):150-153
Abstract
The aim of this study was to evaluate the short- to medium-term results (up to 2 years) of conservative and surgical treatments
of patients with symptomatic lumbar stenosis. To our knowledge, no previous study has provided strict indications for conservative
or surgical treatment. We retrospectively studied 184 patients, who were divided into 3 groups according to JOA (Japanese
Orthopaedic Association) score. A cutoff JOA score was arbitrarily fixed at 7.
Patients with a score ≤7 (n=12; group A) underwent surgery, while patients with a score >7 (n=172) were conservatively treated.
Group A included patients surgically treated within two months from diagnosis. Group B consisted of 144 patients who received
conservative treatment, while group C (28 patients) represented patients who underwent surgery after a period of failed conservative
treatment. The outcomes of surgical and conservative treatments were evaluated after 12 and 24 months, and were rated as satisfactory,
not totally satisfactory, not satisfactory or totally unsatisfactory. Conservative treatment consisted of physical, orthotic
and drug therapy, whereas surgical treatment included spinal decompression and instrumentation (if indicated), either rigidly
or dynamically performed. Surgery was indicated in 22% of all patients and we obtained excellent results in 85% of them. Operative
treatment provides excellent results for patients with severe clinical presentation (JOA score ≤7), while individuals with
mild to moderate spinal stenosis (JOA score >7) should receive conservative treatment. 相似文献
109.
110.
M. Truin P. van Venrooij V. Duysens R. Deumens M. van Kleef E. A. J. Joosten 《Neuromodulation》2007,10(4):358-362
Objective. Development of a spinal cord stimulation (SCS) system in a mouse model of chronic neuropathic pain. Materials and Methods. Male C57BL/6 mice (N = 6) underwent a partial ligation of the sciatic nerve. Development of mechanical hyperalgesia was tested using the withdrawal response to tactile stimuli with the von Frey test. An SCS system was implanted on day 14. On day 16, the mice were stimulated for 30 min (f = 50 Hz; pulse width 0.2 msec and stimulation at 2/3 of motor threshold). Repeated measure analysis of variance (anova ) and paired Student's t‐test with Bonferroni correction were used to evaluate the development of mechanical hyperalgesia and the therapeutic effect of SCS. Results. Five out of six mice developed marked mechanical hyperalgesia in the nerve‐lesioned paw that persisted for the duration of the study (16 days). No changes contralateral to the injury were observed. In four out of five mice, a successful implantation of the electrodes followed by stimulation was achieved. Then, SCS resulted in a fast and robust increase of withdrawal threshold back to pre‐injury levels. After termination of the SCS, the withdrawal threshold of the ipsilateral paw slowly decreased. No effect of SCS on the contralateral paw was noted. Conclusion. The development of a mouse SCS system is described that is practical in use, is reproducible, and shows a comparative therapeutic effect in treatment of chronic neuropathic pain as reported in rat. 相似文献