全文获取类型
收费全文 | 52226篇 |
免费 | 5229篇 |
国内免费 | 3658篇 |
专业分类
耳鼻咽喉 | 502篇 |
儿科学 | 683篇 |
妇产科学 | 418篇 |
基础医学 | 4806篇 |
口腔科学 | 886篇 |
临床医学 | 5833篇 |
内科学 | 6655篇 |
皮肤病学 | 571篇 |
神经病学 | 2383篇 |
特种医学 | 2051篇 |
外国民族医学 | 14篇 |
外科学 | 5830篇 |
综合类 | 11554篇 |
现状与发展 | 14篇 |
预防医学 | 4425篇 |
眼科学 | 971篇 |
药学 | 5659篇 |
59篇 | |
中国医学 | 4014篇 |
肿瘤学 | 3785篇 |
出版年
2024年 | 171篇 |
2023年 | 607篇 |
2022年 | 1429篇 |
2021年 | 2009篇 |
2020年 | 1725篇 |
2019年 | 1375篇 |
2018年 | 1466篇 |
2017年 | 1598篇 |
2016年 | 1472篇 |
2015年 | 2156篇 |
2014年 | 2720篇 |
2013年 | 3069篇 |
2012年 | 4253篇 |
2011年 | 4677篇 |
2010年 | 3755篇 |
2009年 | 3314篇 |
2008年 | 3627篇 |
2007年 | 3516篇 |
2006年 | 3249篇 |
2005年 | 2741篇 |
2004年 | 2342篇 |
2003年 | 2268篇 |
2002年 | 2011篇 |
2001年 | 1396篇 |
2000年 | 1025篇 |
1999年 | 671篇 |
1998年 | 416篇 |
1997年 | 388篇 |
1996年 | 292篇 |
1995年 | 256篇 |
1994年 | 234篇 |
1993年 | 147篇 |
1992年 | 106篇 |
1991年 | 129篇 |
1990年 | 82篇 |
1989年 | 66篇 |
1988年 | 58篇 |
1987年 | 41篇 |
1986年 | 40篇 |
1985年 | 38篇 |
1984年 | 25篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1980年 | 12篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1974年 | 8篇 |
1965年 | 6篇 |
1963年 | 6篇 |
1957年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
We report clinical, neuroradiologic features, and neuropathologic findings of a 76‐year‐old man with coexistent Pick’s disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bed‐ridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau‐ and ubiquitin‐positive in neurons of layers II–III of the above‐mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau‐positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned‐astrocytes and coiled bodies but no‐tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick’s disease and coexistence with progressive supranuclear palsy without tuft‐shaped astrocytes. 相似文献
2.
颅内肿瘤切除术后颅内感染危险因素分析 总被引:1,自引:0,他引:1
目的 探讨颅内肿瘤切除术后颅内感染的危险因素和预防措施。方法 回顾性分析442例颅内肿瘤切除术患者的临床资料。结果 442例颅内肿瘤切除术患者发生颅内感染33例,感染率为7.47%。非脑膜瘤手术颅内感染率为10.04%,高于脑膜瘤术后颅内感染率3.83%(P〈0.05);手术时间≥4h者颅内感染率为9.87%,高于手术时间〈4h者颅内感染率4.78%(P〈0.05);有脑脊液漏者颅内感染率为15.00%,高于无脑脊液漏者颅内感染率6.28%(P〈0.05);引流管留置≥24h者颅内感染率为11.58%,高于未留置或留置〈24h者颅内感染率5.03%(P〈0.05)。结论 手术时间≥4h、引流管留置时间≥24h、存在脑脊液漏是颅内肿瘤切除术后发生颅内感染的危险因素。 相似文献
3.
用放射配体结合分析法分别测定了正常组、特布他林组、特布他林十曲尼司特组豚鼠的肺组织β受体最大结合力和解离常数,结果显示:给特布他林后豚鼠肺组织β受体发生明显的向下调节.曲尼司特可预防此向下调节的发生. 相似文献
4.
阴沟肠杆菌超广谱β—内酰胺酶、诱导酶的检出与耐药相关性的分析 总被引:8,自引:0,他引:8
目的:了解阴沟肠杆菌超广谱β-内酰胺酶和诱导酶的产生和分布情况。并分析产酶特性和耐药表型的相关性。方法:用纸片扩散确证法和相邻纸片法对104株阴沟肠杆菌进行超广谱β-内酰胺酶及诱导酶的检测,用VITEK全自动药敏分析系统和K-B琼脂扩散法检测其对20种抗生素的耐药性。结果:104例阴沟肠杆菌中,检出超广谱β-内酰胺酶阳性株77株,占74%,诱导酶阳性株26株,占25%,13株两种酶同时阳性。超广谱β-内酰胺酶阳性株主要集中在几个病区,诱导酶阳性株则无此倾向,104株菌对多种怀素高度耐药,产超广谱β-内酰胺酶株的耐药率明显高于非产酶株,产诱导酶株的耐药率反而低于非产酶株。结论:阴沟肠杆菌产酶情况和耐药性均十分严重。多重耐药的主要原因是由于菌株产生超广谱β-内酰胺酶,产酶株对三代头孢的体外敏感试验不能正确反映临床的治疗效果。实验室应加强阴肠杆菌产酶情况的检测,治疗产酶阴沟肠杆菌引起的感染,首选亚胺培南,其次为舒普深,任何情况下应避免使用三代头孢。 相似文献
5.
Ming Zhao Cheng Simon C F Rawlinson Andrew A Pitsillides Gul Zaman Subburaman Mohan David J Baylink Lance E Lanyon 《Journal of bone and mineral research》2002,17(4):593-602
The mechanism by which mechanical strain and estrogen stimulate bone cell proliferation was investigated using monolayer cultures of human osteoblastic TE85 cells and female human primary (first-passage) osteoblasts (fHOBs). Both cell types showed small but statistically significant dose-dependent increases in [3H]thymidine incorporation in response to 17beta-estradiol and to a single 10-minute period of uniaxial cyclic strain (1 Hz). In both cell types, the peak response to 17beta-estradiol occurred at 10(-8) - 10(-7) M and the peak response to strain occurred at 3500 microstrain ((mu)epsilon). Both strain-related and 17beta-estradiol-related increases in [3H]thymidine incorporation were abolished by the estrogen receptor (ER) modulator ICI 182,780 (10-8 M). Tamoxifen (10(-9) - 10(-8) M) increased [3H]thymidine incorporation in both cell types but had no effect on their response to strain. In TE85 cells, tamoxifen reduced the increase in [3H]thymidine incorporation associated with 17beta-estradiol to that of tamoxifen alone but had no such effect in fHOBs. In TE85 cells, strain increased medium concentrations of insulin-like growth factor (IGF) II but not IGF-I, whereas 17beta-estradiol increased medium concentrations of IGF-I but not IGF-II. Neutralizing monoclonal antibody (MNAb) to IGF-I (3 microg/ml) blocked the effects of 17beta-estradiol and exogenous truncated IGF-I (tIGF-I; 50 ng/ml) but not those of strain or tIGF-II (50 ng/ml). Neutralizing antibody to IGF-II (3 microg/ml) blocked the effects of strain and tIGF-II but not those of 17beta-estradiol or tIGF-I. MAb aIR-3 (100 ng/ml) to the IGF-I receptor blocked the effects on [3H]thymidine incorporation of strain, tIGF-II, 17beta-estradiol, and tIGF-I. HOBs and TE85 cells, act similarly to rat primary osteoblasts and ROS 17/2.8 cells in their dose-related proliferative responses to strain and 17beta-estradiol, both of which can be blocked by the ER modulator ICI 182,780. In TE85 cells (as in rat primaries and ROS 17/2.8 cells), the response to 17beta-estradiol is mediated by IGF-I, and the response to strain is mediated by IGF-II. Human cells differ from rat cells in that tamoxifen does not block their response to strain and reduces the response to 17beta-estradiol in TE85s but not primaries. In both human cell types (unlike rat cells) the effects of strain and IGF-II as well as estradiol and IGF-I can be blocked at the IGF-I receptor. 相似文献
6.
HCC的早期诊断是其治疗的关键,HCC血清标志物的检测又为其诊断提供了有利的途径,并且操作简单,敏感性高和特异性强。目前常用的血清标志物为AFP、AFP变异体、AFP mRNA、AFU、GGT、DCP、AIF、GPC3等。这些标志物的联合使用有助于HCC的诊断及预后。 相似文献
7.
目的:探讨甲状腺全切除术在治疗分化性甲状腺癌中的临床应用价值。方法:采用我院1988年1月~2001年5月甲状腺全切除术或甲状腺侧叶切除加峡部切除术治疗分化性甲状腺癌125例,对其手术并发症发生、局部复发、转移情况及术后5年生存率进行回顾性对比分析。结果:甲状腺全切除术术后并发症发生率高于甲状腺侧叶切除加峡部切除术组;局部复发、转移率低于侧叶切除加峡部切除术组;5年生存率两组无显著性差异。结论:甲状腺全切除术是治疗甲状腺癌有效的手术方式,但应掌握手术指征,改进、提高手术技术,减少并发症。 相似文献
8.
氟尿嘧啶化放疗的现状与未来 总被引:1,自引:0,他引:1
20世纪60年代在肿瘤的根治和辅助治疗中就使用了氟尿嘧啶(Fluorouracil,FU)化放疗(外放疗同时进行化疗)。2002年.全世界约200万肿瘤患者接受了FU治疗.其中很大一部分是以FU为基础的化放疗。FU是许多肿瘤患者的基础治疗药物。总之,FU化放疗显著改善了肿瘤的局部控制.并提高了部分肿瘤患者的生存率:也提高了部分具有重要功能的器官的保留。 相似文献
9.
Lin Bo Wang Jian Guo Shen Li Feng Dong Chao Yang Xu Wen Jun Chen Shu Duo Xie Xiang Yang Song Ning Dai Xiao Ming Yuan 《Journal of gastrointestinal surgery》2008,12(8):1359-1363
We previously reported that lymphatic mapping using isosulfan blue can be used to identify sentinel nodes (SNs). This study
was undertaken to evaluate the feasibility of using the SN technique in treating early gastric cancer and to explore its usefulness
for minimal invasive surgery. Twenty-three patients with early gastric cancer who underwent SN biopsy were retrospectively
evaluated. Based on SN evaluation, individualized surgery was performed in five patients with T1N0M0 gastric cancer. When
pathological examination of frozen sections revealed metastasis in SNs, we performed a standard D2 gastrectomy. Laparoscopic
local resection was applied when the SN biopsy was negative. Our results showed that the success rate with SN biopsy in early
gastric cancer was 100%, as were the accuracy, sensitivity, and specificity. All five patients with early gastric cancer had
SNs negative for metastases both by frozen section and by postoperative pathology. Thus, all these patients underwent laparoscopic
local resection without extended lymphadenectomy. We conclude that SN biopsy is a useful tool to individualize the operative
procedure, and laparoscopic local resection can be safely performed using SN guidance in selected patients with early gastric
cancer. 相似文献
10.
1学分制产生的背景 学分制是随着课程选修制的产生、发展而建立起来的教学管理制度.它产生于18~19世纪的欧美国家,于20世纪20年代经我国的一些教育家从日本或欧美引进. 相似文献