全文获取类型
收费全文 | 297955篇 |
免费 | 23918篇 |
国内免费 | 8876篇 |
专业分类
耳鼻咽喉 | 2122篇 |
儿科学 | 5219篇 |
妇产科学 | 3224篇 |
基础医学 | 32232篇 |
口腔科学 | 7750篇 |
临床医学 | 31887篇 |
内科学 | 38678篇 |
皮肤病学 | 3823篇 |
神经病学 | 13795篇 |
特种医学 | 8717篇 |
外国民族医学 | 60篇 |
外科学 | 31411篇 |
综合类 | 45204篇 |
现状与发展 | 35篇 |
一般理论 | 26篇 |
预防医学 | 16634篇 |
眼科学 | 5739篇 |
药学 | 27351篇 |
124篇 | |
中国医学 | 26586篇 |
肿瘤学 | 30132篇 |
出版年
2024年 | 767篇 |
2023年 | 4474篇 |
2022年 | 8858篇 |
2021年 | 12100篇 |
2020年 | 11276篇 |
2019年 | 10228篇 |
2018年 | 9858篇 |
2017年 | 10545篇 |
2016年 | 10898篇 |
2015年 | 10482篇 |
2014年 | 18959篇 |
2013年 | 21934篇 |
2012年 | 16484篇 |
2011年 | 18264篇 |
2010年 | 15396篇 |
2009年 | 14162篇 |
2008年 | 14030篇 |
2007年 | 15271篇 |
2006年 | 13695篇 |
2005年 | 12829篇 |
2004年 | 11011篇 |
2003年 | 9789篇 |
2002年 | 7567篇 |
2001年 | 7126篇 |
2000年 | 5779篇 |
1999年 | 5082篇 |
1998年 | 3788篇 |
1997年 | 3349篇 |
1996年 | 3210篇 |
1995年 | 3045篇 |
1994年 | 2572篇 |
1993年 | 2252篇 |
1992年 | 1925篇 |
1991年 | 1670篇 |
1990年 | 1419篇 |
1989年 | 1339篇 |
1988年 | 1272篇 |
1987年 | 1018篇 |
1986年 | 776篇 |
1985年 | 889篇 |
1984年 | 890篇 |
1983年 | 600篇 |
1982年 | 688篇 |
1981年 | 604篇 |
1980年 | 505篇 |
1979年 | 440篇 |
1978年 | 328篇 |
1977年 | 256篇 |
1976年 | 301篇 |
1975年 | 189篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Interstitial cystitis/bladder pain syndrome (IC/BPS) and vulvodynia are chronic pain syndromes that appear to be intertwined from the perspectives of embryology, pathology and epidemiology. These associations may account for similar responses to various therapies. 相似文献
72.
73.
Stephanie Kay Kolar 《Addiction Research & Theory》2016,24(1):25-31
Aims: Relapse rates among cigarette smokers are high. Few studies have examined time-to-relapse using survival analysis in racially/ethnically diverse smokers and initial abstinence criteria have been inconsistent or unspecified. This study compared survival curves using two common definitions of initial abstinence. We hypothesized greater relapse rates among participants abstinent for only 24 hours (h) at the end-of-therapy (EOT) compared with 7 days. Methods: Adult smokers (59% Black, 22% Hispanic and 17% White) received 8-sessions of group cognitive behavioural therapy (CBT) plus transdermal nicotine patches and were assessed monthly up to 12 months post-EOT. Participants reporting abstinence (7-day point prevalence abstinence [ppa] or 24-h ppa) at the EOT were included in Kaplan–Meier curves. Results: Of 301 participants, 120 (40%) reported 7-day ppa at the EOT and an additional 29 (10%) reported 24-h ppa only. Over the 12-month follow-up period, nearly 50% remained abstinent. Of those who resumed smoking, most relapses occurred within the first three months. Survival curves indicated that median survival was 207 and 225 days for 7-day and 24-h definitions of abstinence, respectively. The difference in time-to-relapse between participants abstinent for 24?h at the EOT versus 7-days was not significant (p?=?0.14). Conclusions: Operationalization of initial abstinence is important for relapse analyses and comparisons of survival curves across samples. Participants reported high rates of abstinence and relapse rates were relatively low. Contrary to expectations, 24-h ppa at the EOT was not associated with greater relapse than 7-day abstinence. This suggests either measure may be utilized in relapse prevention research in racially/ethnically diverse treatment-seekers. 相似文献
74.
75.
我国属胃癌高发国家,且以进展期胃癌为主。以手术和化疗为主的多学科治疗无法有效改善晚期胃癌患者的预后。近年来,免疫检查点抑制剂类药物的疗效在诸多癌症中得到了证实,因此,该类药物在胃癌中的治疗效果也受到了广泛的关注。本文对近年来的相关研究成果进行综述,全面介绍了免疫检查点抑制剂类药物在胃癌治疗中的临床应用情况、联合用药情况以及不良反应。对于其他治疗均失败的晚期胃癌患者,PD-1抑制剂是一个可行的治疗选项,其代表药物派姆单抗是目前唯一被美国食品药品监督管理局批准应用于胃癌治疗的免疫抑制剂类药物,而我国国家食品药品监督管理总局尚未批准任何此类药物应用于胃癌的临床治疗。如何进一步提高治疗的客观缓解率,将会是后续临床和基础研究的一大焦点。 相似文献
76.
《Diagnostic and interventional imaging》2020,101(12):821-830
PurposeTo compare morphological imaging features and CT texture histogram parameters between grade 3 pancreatic neuroendocrine tumors (G3-NET) and neuroendocrine carcinomas (NEC).Materials and methodsPatients with pathologically proven G3-NET and NEC, according to the 2017 World Health Organization classification who had CT and MRI examinations between 2006-2017 were retrospectively included. CT and MRI examinations were reviewed by two radiologists in consensus and analyzed with respect to tumor size, enhancement patterns, hemorrhagic content, liver metastases and lymphadenopathies. Texture histogram analysis of tumors was performed on arterial and portal phase CT images. images. Morphological imaging features and CT texture histogram parameters of G3-NETs and NECs were compared.ResultsThirty-seven patients (21 men, 16 women; mean age, 56 ± 13 [SD] years [range: 28-82 years]) with 37 tumors (mean diameter, 60 ± 46 [SD] mm) were included (CT available for all, MRI for 16/37, 43%). Twenty-three patients (23/37; 62%) had NEC and 14 patients (14/37; 38%) had G3-NET. NECs were larger than G3-NETs (mean, 70 ± 51 [SD] mm [range: 18 - 196 mm] vs. 42 ± 24 [SD] mm [range: 8 - 94 mm], respectively; P = 0.039), with more tumor necrosis (75% vs. 33%, respectively; P = 0.030) and lower attenuation on precontrast (30 ± 4 [SD] HU [range: 25-39 HU] vs. 37 ± 6 [SD] [range: 25-45 HU], respectively; P = 0.002) and on portal venous phase CT images (75 ± 18 [SD] HU [range: 43 - 108 HU] vs. 92 ± 19 [SD] HU [range: 46 - 117 HU], respectively; P = 0.014). Hemorrhagic content on MRI was only observed in NEC (P = 0.007). The mean ADC value was lower in NEC ([1.1 ± 0.1 (SD)] × 10−3 mm2/s [range: (0.91 - 1.3) × 10−3 mm2/s] vs. [1.4 ± 0.2 (SD)] × 10−3 mm2/s [range: (1.1 - 1.6) × 10−3 mm2/s]; P = 0.005). CT histogram analysis showed that NEC were more heterogeneous on portal venous phase images (Entropy-0: 4.7 ± 0.2 [SD] [range: 4.2-5.1] vs. 4.5 ± 0.4 [SD] [range: 3.7-4.9]; P = 0.023).ConclusionPancreatic NECs are larger, more frequently hypoattenuating and more heterogeneous with hemorrhagic content than G3-NET on CT and MRI. 相似文献
77.
78.
79.
80.
目的研究和开发支持中医和现代生物医学本体和术语集的语义标注系统。方法以MedPortal本体库和中医临床术语集等为术语资源库,设计语义标注系统工作流程和功能框架,并开发Web应用系统。结果构建了一个基于Web的中医药文献语义标注系统,支持语料库管理与维护、术语词典管理、语义标注和语义检索等功能,既可以为基于机器学习的信息抽取算法研究提供训练集,又能实现语义层面的多来源数据集成与知识融合。结论该中医药文献语义标注系统设计方案已经过实际项目验证,可为其他同类系统研发提供参考。 相似文献