全文获取类型
收费全文 | 61950篇 |
免费 | 5884篇 |
国内免费 | 3455篇 |
专业分类
耳鼻咽喉 | 516篇 |
儿科学 | 882篇 |
妇产科学 | 1021篇 |
基础医学 | 7055篇 |
口腔科学 | 1094篇 |
临床医学 | 7350篇 |
内科学 | 9922篇 |
皮肤病学 | 745篇 |
神经病学 | 2923篇 |
特种医学 | 2537篇 |
外国民族医学 | 34篇 |
外科学 | 7423篇 |
综合类 | 9340篇 |
现状与发展 | 15篇 |
一般理论 | 16篇 |
预防医学 | 4033篇 |
眼科学 | 1488篇 |
药学 | 6634篇 |
53篇 | |
中国医学 | 3181篇 |
肿瘤学 | 5027篇 |
出版年
2024年 | 186篇 |
2023年 | 861篇 |
2022年 | 2113篇 |
2021年 | 2900篇 |
2020年 | 2096篇 |
2019年 | 1914篇 |
2018年 | 2053篇 |
2017年 | 1823篇 |
2016年 | 1812篇 |
2015年 | 2517篇 |
2014年 | 3213篇 |
2013年 | 3213篇 |
2012年 | 4502篇 |
2011年 | 4764篇 |
2010年 | 3108篇 |
2009年 | 2553篇 |
2008年 | 3398篇 |
2007年 | 3494篇 |
2006年 | 3235篇 |
2005年 | 3016篇 |
2004年 | 2427篇 |
2003年 | 2238篇 |
2002年 | 2022篇 |
2001年 | 1691篇 |
2000年 | 1628篇 |
1999年 | 1487篇 |
1998年 | 790篇 |
1997年 | 813篇 |
1996年 | 647篇 |
1995年 | 550篇 |
1994年 | 478篇 |
1993年 | 323篇 |
1992年 | 514篇 |
1991年 | 416篇 |
1990年 | 393篇 |
1989年 | 353篇 |
1988年 | 281篇 |
1987年 | 266篇 |
1986年 | 206篇 |
1985年 | 164篇 |
1984年 | 118篇 |
1983年 | 84篇 |
1982年 | 60篇 |
1981年 | 75篇 |
1980年 | 39篇 |
1979年 | 72篇 |
1978年 | 37篇 |
1974年 | 36篇 |
1973年 | 33篇 |
1972年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Vanaporn Wuthiekanun Varunee Desakorn Gumphol Wongsuvan Premjit Amornchai Allen C. Cheng Bina Maharjan Direk Limmathurotsakul Wirongrong Chierakul Nicholas J. White Nicholas P. J. Day Sharon J. Peacock 《Clinical and Vaccine Immunology : CVI》2005,12(4):555-556
An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were prospectively compared with the culture results for 776 specimens from patients with suspected melioidosis. The sensitivities of both IF tests were 66%, and the specificities were 99.5 and 99.4%, respectively. 相似文献
93.
Huang Guo-Shu MD Chang Wei-Chou MD Lee Herng-Sheng MD † Taylor John A. M. DC DACBR ‡ Cheng Tiang-Yeu MD § Chen Cheng-Yu MD 《Dermatologic surgery》2005,31(6):717-719
BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis. 相似文献
94.
Hiroko Utsunomiya Wanninayake M. Tilakaratne Kazufumi Oshiro Satoshi Maruyama Makoto Suzuki Hiroko Ida-Yonemochi Jun Cheng Takashi Saku 《Journal of oral pathology & medicine》2005,34(8):498-507
BACKGROUND: Oral submucous fibrosis (OSF) is a chewing habit-related pre-cancerous condition of the oral mucosa affecting predominantly south Asians. It is histopathologically characterized by epithelial atrophy and fibrosis of the subepithelial connective tissue. Fibrosis extends all the way into the muscle layer, leading to difficulty in mouth opening. However, the dynamics of extracellular matrix (ECM) remodeling with OSF progression is largely unknown. METHODS: Forty biopsy specimens of OSF and 10 of normal buccal mucosa were examined for expression/deposition modes of eight ECM molecules by histochemistry, immunohistochemistry, and in situ hybridization. RESULTS: In the early stage of OSF, tenascin, perlecan, fibronectin, collagen type III were characteristically enhanced in the lamina propria and the submucosal layer. In the intermediate stage, the ECM molecules mentioned above and elastin were extensively and irregularly deposited around muscle fibers. In the advanced stage, such ECM depositions decreased and were entirely replaced with collagen type I only. Their gene expression levels varied with progression of fibrosis, but the mRNA signals were confirmed in fibroblasts in the submucosal fibrotic areas. CONCLUSIONS: The results indicate that the ECM remodeling steps in OSF are similar to each phase of usual granulation tissue formation. Restricted mouth opening may be a result of loss of variety of ECM molecules including elastin into the homogeneity of collagen type I replacing muscle fibers. 相似文献
95.
Systemic anticancer therapy for hepatocellular carcinoma (HCC) is limited by intrinsic drug resistance and accompanying liver
dysfunction. However, recent advances in molecular targeted therapy (MTT) have shed light on the treatment of advanced HCC.
A recent randomized, placebo-controlled trial demonstrated that sorafenib, a multi-target tyrosine kinase inhibitor, prolonged
overall survival and time-to-progression in patients with advanced HCC. This breakthrough highlights the potential of MTT
targeting hepatocarcinogenic pathways, such as the Raf/MAPK/ERK pathway, angiogenic pathways and the EGFR signaling pathway.
This review discusses the current status and the potential of developing novel MTTs for advanced HCC. 相似文献
96.
97.
Although many monoclonal antibodies have been made in human colon cancer, none of them are from the Chinese species. Recently, a colon cancer cell line CC-M2 established from a Chinese patient has been completely characterized and used as immunogen to produce monoclonal antibodies. Monoclonal antibodies were produced by standard hybridoma technique. The fusion rate was 95.8%. An isotype IgG1 of high proliferation named as Sam-2 was used in this study. The titers were measured around 10(4). Further studies on MoAb Sam-2 through indirect immunofluorescent and immunoperoxidase tests revealed its good specificity and sensitivity in colorectal cancer tissue. In CEA study, the result indicated that Sam-2 may react on a non-CEA related antigen. For further clinical application, the antigen was identified as a glycoprotein by chemical resistant test. In preliminary studies using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting techniques, Sam-2 could recognize two closed antigens or a dimer antigen with molecular weight 25.2 and 27 Kd respectively. 相似文献
98.
枢复宁在肺癌患者体内的药物动力学和生物利用度 总被引:3,自引:1,他引:2
9名接受顺铂化疗的原发性肺癌患者单次口服和静脉注射枢复宁8mg后,用反相高效液相色谱法测定血浆药物浓度。经用PKBP-N1程序在计算机上拟合计算表明,枢复宁在人体内表现为二房室模型。口服后主要药动学参数:T1/2Ka=0.41±0.30h,T1/2α=0.9±0.43h,T1/2β=3.3±1.2h,Cmax=28.6±9.5ng/ml,Tmax=1.7±0.9h,AUC=158±73ng·h/ml,绝对生物利用度为55%。 相似文献
99.
本研究建立了大鼠气管上皮细胞体内-体外转化模型,大鼠气管内滴注苯并芘,三天后处死大鼠,消化气管上皮细胞,接种于无血清完全培养基。细胞形成集落后,换为选择培养基继续培养五周,统计转化率。结果显示,25mg/kg和50mg/kg的苯并芘可诱导大鼠气管上皮细胞转化及微核增加,用同样方法研究了煤焦沥青提取物,结果表明,剂量为8mg/kg和25mg/kg的煤焦沥青提取物能明显诱导大鼠气管上皮细胞转化。 相似文献
100.
3种氟喹诺酮类药物抗生素后效应的研究 总被引:40,自引:2,他引:38
应用AVANTAGF分析仪的光密度法测定了环丙沙星(CPLX)、氧氟沙星(OFLX)和氟罗沙星(FLRX)的抗生素后效应(PAE).结果表明氟喹诺酮类抗菌药物对革兰氏阳性球菌和革兰氏阴性杆菌均产生明显的PAE.并随抗菌药物浓度的增大、对受试菌的PAE逐渐延长.呈现了明显的浓度依赖性;3种抗菌药物对铜绿假单胞菌的PAE都较长.MIC均较小.显示了良好的杀菌效果:氯罗沙星对除金葡球菌之外的受试菌的PAE均比其它2药较长.PAE的存在提示在临床设计给药方案时.可适当延长给药间期.减少给药次数与剂量.仍能维持抗菌效果。 相似文献