全文获取类型
收费全文 | 202377篇 |
免费 | 28604篇 |
国内免费 | 6716篇 |
专业分类
耳鼻咽喉 | 1695篇 |
儿科学 | 1464篇 |
妇产科学 | 5149篇 |
基础医学 | 14822篇 |
口腔科学 | 2159篇 |
临床医学 | 16098篇 |
内科学 | 19263篇 |
皮肤病学 | 1359篇 |
神经病学 | 934篇 |
特种医学 | 5937篇 |
外国民族医学 | 253篇 |
外科学 | 28826篇 |
综合类 | 26283篇 |
现状与发展 | 39篇 |
一般理论 | 3篇 |
预防医学 | 9488篇 |
眼科学 | 111篇 |
药学 | 14492篇 |
131篇 | |
中国医学 | 4984篇 |
肿瘤学 | 84207篇 |
出版年
2024年 | 186篇 |
2023年 | 4215篇 |
2022年 | 5954篇 |
2021年 | 10480篇 |
2020年 | 10473篇 |
2019年 | 9474篇 |
2018年 | 9092篇 |
2017年 | 9529篇 |
2016年 | 10247篇 |
2015年 | 11855篇 |
2014年 | 17063篇 |
2013年 | 16907篇 |
2012年 | 13552篇 |
2011年 | 13742篇 |
2010年 | 9954篇 |
2009年 | 10210篇 |
2008年 | 10449篇 |
2007年 | 9776篇 |
2006年 | 8628篇 |
2005年 | 7072篇 |
2004年 | 5864篇 |
2003年 | 4876篇 |
2002年 | 4127篇 |
2001年 | 3804篇 |
2000年 | 3130篇 |
1999年 | 2567篇 |
1998年 | 1994篇 |
1997年 | 1730篇 |
1996年 | 1400篇 |
1995年 | 1482篇 |
1994年 | 1237篇 |
1993年 | 973篇 |
1992年 | 837篇 |
1991年 | 760篇 |
1990年 | 554篇 |
1989年 | 524篇 |
1988年 | 446篇 |
1987年 | 390篇 |
1986年 | 286篇 |
1985年 | 377篇 |
1984年 | 313篇 |
1983年 | 213篇 |
1982年 | 210篇 |
1981年 | 198篇 |
1980年 | 173篇 |
1979年 | 118篇 |
1978年 | 76篇 |
1977年 | 66篇 |
1976年 | 56篇 |
1975年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
《Arab Journal Of Gastroenterology》2022,23(1):52-57
Background and study aimsGastrointestinal (GI) cancer is one of the top five common cancers in Lebanon. To implement a strategy for screening and early diagnosis through the initiation of prevention programs, a detailed study of GI cancers in Lebanon was conducted by focusing on the frequency and characteristics of each type.Patients and MethodsThis retrospective study was conducted in Lebanon between 2001 and 2015 and included patients diagnosed with different GI cancer types. Data were collected from the registry of the National Institute of Pathology (NIP). The frequency of each type was calculated according to sex, age at diagnosis, anatomic location, histological type, and stage.ResultsThe total number of patients diagnosed with GI cancers who had their histology done at the NIP between 2001 and 2015 was 5239. The sex (male/female) ratio was 1.016, with a mean age of 62.2 years. Colorectal cancer ranked first among GI cancers, with more than half of the cases (53.4%). More than 70% of the cases were located on the left side, followed by gastric (15.5%) and pancreatic (12.7%) cancers. Regarding gastric cancer, cardia became the dominant location. A shift from squamous cell carcinoma to adenocarcinoma in esophageal cancer was found during this period. Also, most GI cancers in Lebanon were diagnosed in the late stages.ConclusionThis study is the first to evaluate GI cancers in Lebanon, which will help in screening strategies and burden studies. 相似文献
33.
《Value in health》2022,25(1):69-76
ObjectivesThere is limited knowledge about the cost patterns of patients who receive a diagnosis of de novo and recurrent advanced cancers in the United States.MethodsData on patients who received a diagnosis of de novo stage IV or recurrent breast, colorectal, or lung cancer between 2000 and 2012 from 3 integrated health systems were used to estimate average annual costs for total, ambulatory, inpatient, medication, and other services during (1) 12 months preceding de novo or recurrent diagnosis (preindex) and (2) diagnosis month through 11 months after (postindex), from the payer perspective. Generalized linear regression models estimated costs adjusting for patient and clinical factors.ResultsPatients who developed a recurrence <1 year after their initial cancer diagnosis had significantly higher total costs in the preindex period than those with recurrence ≥1 year after initial diagnosis and those with de novo stage IV disease across all cancers (all P < .05). Patients with de novo stage IV breast and colorectal cancer had significantly higher total costs in the postindex period than patients with cancer recurrent in <1 year and ≥1 year (all P < .05), respectively. Patients in de novo stage IV and those with recurrence in ≥1 year experienced significantly higher postindex costs than the preindex period (all P < .001).ConclusionsOur findings reveal distinct cost patterns between patients with de novo stage IV, recurrent <1-year, and recurrent ≥1-year cancer, suggesting unique care trajectories that may influence resource use and planning. Future cost studies among patients with advanced cancer should account for de novo versus recurrent diagnoses and timing of recurrence to obtain estimates that accurately reflect these care pattern complexities. 相似文献
34.
地鳖中的纤溶活性蛋白是从地鳖中提取的具有抗栓及抗肿瘤作用的有效成分,其口服易被上消化道酶分解从而限制了应用。采用恒流泵滴制法开发地鳖纤溶活性蛋白时间/pH依赖口服结肠靶向微囊(EnpolypHaga fibrinolytic protein oral colon targeting microcapsules, CTM-EFP)。采用单因素实验和正交实验相结合的方法寻找到包封率为60.17 % ± 2.72 %、载药量为15.50 % ± 0.44 % 的最佳配方。扫描电子显微镜(SEM)显示微囊呈球形、表面光滑,在人工肠液中24 h的累积释放度为99.53 % ± 0.69 %,在人工胃液中24 h累积释放度为7.43 ± 1.04 %,通过时间/pH依赖达到结肠靶向作用。CTM-EFP在人工肠液中的体外释放曲线符合Korsmeyer方程,提示地鳖纤溶活性蛋白(EnpolypHaga fibrinolytic protein, EFP)是通过扩散和侵蚀机制结合释放的。CTM-EFP为EFP的口服给药提供了一种新的剂型,为EFP应用于临床提供参考。 相似文献
35.
Curcumin Encapsulated into Biocompatible Co-Polymer PLGA Nanoparticle Enhanced Anti-Gastric Cancer and Anti-Helicobacter Pylori Effect 下载免费PDF全文
Jawed AlamFahima DilnawazSanjeeb Kumar SahooDurg Vijai Singh Asish Kumar MukhopadhyayTahziba HussainSanghamitra Pati 《Asian Pacific journal of cancer prevention》2022,23(1):61-70
Background: The current disadvantages (high cost, toxicity, resistance) of chemotherapy for gastric cancer opted people for alternative therapy from natural source. Curcumin (natural product) possess multiple biological activities but low bio-availability limits their uses as therapeutic. The Nano-formulation of curcumin increased the bioavailability and productivity of anti-cancer and anti-bacterial properties. The present study was initiated to determine the anti-cancer and anti-bacterial effect of Nano curcumin against gastric cancer and H. pylori. Methods: Curcumin loaded PLGA nanoparticles (CUR-NPs) was prepared by single emulsion solvent evaporation method. The MIC were determined using agar dilution method to find the anti-H. Pylori activity of Nano curcumin. The cytotoxicity of Nano curcumin was evaluated by MTT assay and the apoptotic effect (cell cycle arrest and morphology change) was shown by PI staining and microscopy. Results: The MIC of nanocurcumin and curcumin for all four H. pylori strains were 8 µg/ml and 16 µg/ml respectively. The inhibition rate of gastric cancer cells after treatment with curcumin was increased from 6% to 67% for 24h, from 8% to 75% for 48h, from 10% to 83% for 72h. In case of nanocurcumin, the inhibition rate increased from 7% to 69% for 24h, 11% to 87% for 48h and 16% to 97% for 72h. The IC50 of curcumin and Nano-curcumin were 24.20 µM and 18.78 µM respectively for 72 h. The population of cells in sub-G0 population increased from 4.1% in the control group to 24.5% and 57.8% when treated with curcumin and nanocurcumin respectively. After 72h of treatment with nanocurcumin, the apoptotic cells population increased as compared to native curcumin treated cells. Conclusion: The Nano curcumin might be used as a potential therapeutics against gastric cancer and H. Pylori. There is need of further in vivo study in order to validate CUR-NPs activity. 相似文献
36.
37.
38.
目的:分析基于几何不确定性的鲁棒优化计划对肝癌立体定向放疗(SBRT)剂量分布的影响。方法:选取12例肝癌SBRT患者,对每例制作3个调强计划:①基于PTV(ITV-PTV 5 mm)的常规优化(PTV-Based Plan);②基于ITV非均匀几何不确定性(本中心计算的不确定性值:进出方向7 mm,左右和前后方向4 mm)的鲁棒优化(Robust Planactual);③基于ITV均匀5 mm几何不确定性的鲁棒优化(Robust Plan5 mm)。所有计划都以95%的PTV满足处方剂量作为目标,以等中心均匀偏移4、5、7 mm计算扰动剂量评估鲁棒性。结果:计划①②③的均匀性指数(HI)分别为0.083±0.027、0.099±0.035、0.096±0.026,不具有统计学意义;计划①②③的适形性指数(CI)分别为0.98±0.02、1.02±0.05、1.00±0.04,计划②③相对于计划①的CI具有统计学意义。计划③的正常肝组织平均受量和V2500相对于计划①②分别下降了4.1%、2.5%和5.4%、3.0%,且具有统计学意义(P=0.034、P=0.021和P=0.004、P=0.004),计划②相对于计划①的正常肝组织平均受量和V2500不具有统计学意义(P=0.308和P=0.182),但下降了1.6%和2.5%。对于其鲁棒性,计划②③的5 mm-D99%、5 mm-D98%、5 mm-D95%的剂量-体积直方图带宽(DVHBW)差值相对于计划①更小,随着摆位不确定度的增大,其DVHBW差值越大。结论:在肝脏SBRT治疗中,采用鲁棒优化能够提高靶区剂量分布质量,即使在摆位不确定度有所增加的情况下,仍可以保证ITV的剂量覆盖同时不增加正常组织的照射剂量。 相似文献
39.
《Diagnostic Histopathology》2022,28(3):156-160
Breast core biopsies are a standard component of the triple approach that includes clinical examination, imaging and tissue sampling. Conventional cores, diagnostic vacuum assisted biopsy and vacuum assisted excisions are established methods for sampling and managing breast lesions. It is important to be aware of the potential pitfalls in the technical handling and interpretation of the limited core biopsy samples. Here, we present a clinically oriented, well illustrated overview of the common diagnostic pitfalls based on the author's diagnostic and second opinion practice, emphasize the value of clinicopathological correlation and provide histological tips and clues with useful immunohistochemistry to aid the reporting pathologists in their daily interpretation of breast core biopsies. 相似文献
40.