全文获取类型
收费全文 | 13202篇 |
免费 | 1257篇 |
国内免费 | 691篇 |
专业分类
耳鼻咽喉 | 139篇 |
儿科学 | 134篇 |
妇产科学 | 116篇 |
基础医学 | 1673篇 |
口腔科学 | 209篇 |
临床医学 | 1685篇 |
内科学 | 1931篇 |
皮肤病学 | 324篇 |
神经病学 | 782篇 |
特种医学 | 652篇 |
外国民族医学 | 5篇 |
外科学 | 1730篇 |
综合类 | 1757篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 861篇 |
眼科学 | 249篇 |
药学 | 1268篇 |
3篇 | |
中国医学 | 701篇 |
肿瘤学 | 926篇 |
出版年
2024年 | 43篇 |
2023年 | 177篇 |
2022年 | 413篇 |
2021年 | 586篇 |
2020年 | 434篇 |
2019年 | 465篇 |
2018年 | 454篇 |
2017年 | 407篇 |
2016年 | 412篇 |
2015年 | 610篇 |
2014年 | 794篇 |
2013年 | 720篇 |
2012年 | 1008篇 |
2011年 | 1068篇 |
2010年 | 700篇 |
2009年 | 521篇 |
2008年 | 704篇 |
2007年 | 675篇 |
2006年 | 669篇 |
2005年 | 658篇 |
2004年 | 461篇 |
2003年 | 551篇 |
2002年 | 477篇 |
2001年 | 372篇 |
2000年 | 295篇 |
1999年 | 242篇 |
1998年 | 170篇 |
1997年 | 131篇 |
1996年 | 120篇 |
1995年 | 106篇 |
1994年 | 81篇 |
1993年 | 56篇 |
1992年 | 77篇 |
1991年 | 73篇 |
1990年 | 54篇 |
1989年 | 66篇 |
1988年 | 45篇 |
1987年 | 52篇 |
1986年 | 40篇 |
1985年 | 27篇 |
1984年 | 25篇 |
1983年 | 13篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 11篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
汉防己甲素对翼状胬肉成纤维细胞抑制作用的实验研究 总被引:1,自引:1,他引:1
目的观察汉防己甲素对体外培养的翼状胬肉成纤维细胞的抑制作用,寻找治疗翼状胬肉和预防其复发的有效药物。方法用MTT比色法测定不同浓度的汉防己甲素对体外培养的翼状胬肉成纤维细胞增生的抑制作用,并与丝裂霉素C(MMC)进行比较;用荧光定量PCR检测10^-5mol/L的汉防己甲素对翼状胬肉成纤维细胞基质金属蛋白酶(MMP)MMP-3 mRNA的表达的影响。结果不同浓度的汉防己甲素对体外培养的翼状胬肉成纤维细胞的增生均有明显的抑制作用(P〈0.01);10^-5mol/L的汉防己甲素作用24h其MMP-3 mRNA的表达量下降了27.12%。结论汉防己甲素对翼状胬肉成纤维细胞具有明显的抑制作用,可望用于对翼状胬肉的治疗。 相似文献
993.
Scaravilli T Pramstaller PP Salerno A Egarter-Vigl E Giometto B Vitaliani R An SF Revesz T 《Annals of neurology》2000,48(1):97-101
Disorders of micturition have been reported only sporadically in patients with progressive supranuclear palsy (PSP). We report the results of a clinicopathological study of 3 patients with a definite diagnosis of PSP at various stages of their illness with sphincter abnormalities. Electromyography of the sphincter muscles was performed in all 3 patients and was abnormal in 2. Morphological and morphometric evaluation of Onuf's nucleus in the sacral spinal cord, which is involved in sphincter control, showed severe cell loss, presence of neurofibrillary tangles, neuropil threads, and glial inclusions. We conclude that bladder dysfunction and abnormal sphincter electromyographic results are due to pathological changes in Onuf's nucleus, and we propose that sphincter abnormalities should be included in the list of possible symptoms of PSP. 相似文献
994.
甲氨蝶呤致上呼吸道出血2例 总被引:1,自引:0,他引:1
例1女,52岁。主因多关节肿痛伴畸形6年,加重2月于2004年8月24日入院。1997年7~8月,患者无明显诱因出现左膝关节疼痛、肿胀,自行服用“芬必得”(用法不详),上述症状好转。1999年10月右膝及双腕关节肿痛。2000年11月初予“青霉胺、强的松、甲氨蝶呤”等药物治疗(量不详)(时间约10个月),症状未见好转。2001年12月至2003年9月渐出现双手小关节肿胀疼痛、畸形,双膝关节肿痛加剧,不能行走。入院前2月患者因四肢关节疼痛难忍,仍服用“甲氨蝶呤1片、1次/周”等。自发病以来患者饮食正常,二便正常,睡眠可。查体:T36.5℃,BP120/90mmH(g1mmHg=0.133… 相似文献
995.
An ethyl acetate extract of Alpinia oxyphylla was found to possess neuroprotective activity against 1-methyl-4-phenylpyridinium ion (MPP(+)) induced apotosis and oxidative stress in cultured PC12 cells. From the extract, a phenolic compound was isolated through bioassay-guided fractionation and identified as protocatechuic acid (PCA) by IR, MS, and (1)H and (13)C NMR spectroscopy. It was the first time which was isolated from the kernels of A. oxyphylla. Exposure of PC12 cells to 1mM MPP(+) may cause significant viability loss and apoptotic cell death. PCA stimulated PC12 cellular proliferation and markedly attenuated MPP(+)-induced apoptotic cell death in a dose-dependent manner. By observing the nuclear morphological changes and flow cytometric analysis, PCA showed its significant effect on protecting PC12 cells against MPP(+)-induced apoptosis. Meanwhile, PCA enhanced the activities of superoxide dismutase (SOD) and catalase (CAT) in PC12 cells. In addition, PCA also dose-dependently reduced the hydrogen peroxide (H(2)O(2))- or sodium nitroprusside (SNP)-induced cell death in PC12 cells. The results suggest that PCA may be one of the primary active components in the kernels of A. oxyphylla and provide a useful therapeutic strategy for the treatment of oxidative stress-induced neurodegenerative disease such as Parkinson's disease. 相似文献
996.
目的:探讨通过基因工程的方法在大肠杆菌中表达猪卵透明带蛋白pZP3b的核心片断。方法:采用PCR方法扩增原cDNA中编码第44-306个氨基酸的pZP3β核心片断的DNA序列,克隆入pET-3c载体进而在大肠杆菌E.coliBL21(DE3)pLysS中表达。结果:表达的pZP3β核心蛋白占菌体总蛋白的15%,并经Western-blot鉴定为目的蛋白。结论:pZP3β核心片断在大肠杆菌中获得较高的表达,有利于产物的纯化,为后续阐明pZP3β核心区域的性质和相关抗生育研究打下了基础。 相似文献
997.
胸段食管鳞癌淋巴结转移规律的临床研究 总被引:2,自引:0,他引:2
Ying-tao Xie Shu-qin Wang Qiang Zuo Jin-qiu Huang Feng-shan An Shao-hu Chen Rong-cheng Luo 《第一军医大学学报》2005,25(5):573-574
OBJECTIVE: To analyze the patterns of lymph node metastases of thoracic esophageal carcinoma and define the adequate range of lymph node dissection. METHODS: The clinical data of 217 patients with esophageal carcinoma undergoing radical surgical resection of the lymph nodes in three regions were retrospectively analyzed. RESULTS: Lymph node metastases were found in 136 of the 217 patients (62.6%) and skip metastases of the lymph nodes in 12 patients (5.5%). In 3 989 lymph nodes desected, metastases were identified in 454 lymph nodes (11.38%). The rates of lymph node metastasis were 31.7%, 21.2% and 12.1% in the neck, thoracic mediastinum and abdominal cavity, respectively, in upper thoracic esophageal carcinoma, 21.9%, 30.5% and 15.6% in middle thoracic carcinoma, and 9.75%, 12.7% and 34.5% in lower thoracic carcinoma. The degree of tumor differentiation, depth of tumor invasion and lymphatic vessel invasion were factors influencing lymph node metastases (P<0.05). CONCLUSION: Because of the upward, downward and skip metastasis of esophageal carcinoma cells to the lymph nodes, the operable patients with thoracic esophagus carcinoma should receive radical desection of the lymph nodes in the 3 regions to promote the patients' survival. 相似文献
998.
目的 探讨在鼻内窥镜下切除鼻内翻性乳头状瘤的手术方法及疗效。方法 采用鼻内窥镜下切除鼻内翻性乳头状瘤患者32例。结果 术中出血量平均180ml,无术后并发症。随访22~48个月,2例复发。结论 鼻内窥镜下鼻内翻性乳头状瘤切除术,手术视野清晰,创伤小,面部不留瘢痕,能够准确地将肿瘤彻底切除。如适应证掌握适当,鼻内窥镜下切除肿瘤可取得良好疗效。 相似文献
999.
生物化学是医学的重要基础课之一,是目前生命科学发展的前沿学科,发展快,技术新。它与其它医学基础学科关系密切,对疾病的预防、诊断、治疗、预后观察起着决定性作用,是一门重要的工具学科。1生物化学学科特点生物化学是医学专业的基础课,研究的对象是人体。主要研究人体的组成成分,结构与功能关系;人体内的代谢途径及其调节,人体各组织器官代谢特点及其与功能的关系。包括叙述性生物化学,动态生物化学,机能生物化学。涉及到化学元素符号、物质分子式、结构式、化学反应方程式、催化剂、能量的消耗与释放及对机体细胞功能的影响、基因信息的… 相似文献
1000.
Wan T Zhou X Chen G An H Chen T Zhang W Liu S Jiang Y Yang F Wu Y Cao X 《第二军医大学学报》2005,26(11):1229-1229
Heat shock proteins (HSPs) are reported to act as effective adiuvants to elicit anti-tumor and anti-infection immunity. Here, we report that Hsp70-like protein 1 (Hsp70L1), a novel HSP derived from human dendritic cells (DCs), has potent adjuvant effects that polarize responses toward Th1. With a calculated molecular weight of 54.8 kDa, Hsp70L1 is smaller in size than Hsp70 but resembles it both structurally and functionally. Hsp70L1 shares common receptors on DCs with Hsp70 and can interact with DCs, promoting DC maturation and stimulating secretion of the proinflammatory cytokines interleukin 12p70 (IL-12p70), IL-lbeta, tumor necrosis factor-alpha (TNF-alpha), and the chemokines IP-10, macrophage inflammatory protein-lalpha (MIP-lalpha), MIP-lbeta, and normal T cell expressed and secreted (RANTES). The induction of interferon-gamma-inducible protein 10 (IP-10) secretion by Hsp70L1 is not shared by Hsp70, and other functional differences include more potent stimulation of DC IL-12p70, CC-chemokine, and CCR7 and CXCR4 expression by Hsp70L1. Immunization of mice with the hybrid peptide Hsp70L1-ovalbumin(OVA)(257-264) induces an OVA(257-264)-speeific Th1 response and cytotoxic T lymphocyte (CTL) that results in significant inhibition of E. GT-OVA tumor growth. The ability of Hsp70L1 to activate DCs indicates its potential as a novel adjuvant for use with peptide immunizations; the Hsp70L1 antigen peptide hybrid may serve as a more effective vaccine for the control of cancer and infectious diseases. 相似文献