全文获取类型
收费全文 | 54942篇 |
免费 | 3919篇 |
国内免费 | 2265篇 |
专业分类
耳鼻咽喉 | 485篇 |
儿科学 | 676篇 |
妇产科学 | 783篇 |
基础医学 | 8757篇 |
口腔科学 | 3657篇 |
临床医学 | 6447篇 |
内科学 | 5802篇 |
皮肤病学 | 1007篇 |
神经病学 | 3975篇 |
特种医学 | 2107篇 |
外国民族医学 | 9篇 |
外科学 | 6661篇 |
综合类 | 8538篇 |
现状与发展 | 11篇 |
一般理论 | 2篇 |
预防医学 | 2713篇 |
眼科学 | 1165篇 |
药学 | 3768篇 |
23篇 | |
中国医学 | 1832篇 |
肿瘤学 | 2708篇 |
出版年
2024年 | 67篇 |
2023年 | 655篇 |
2022年 | 815篇 |
2021年 | 1473篇 |
2020年 | 1583篇 |
2019年 | 1505篇 |
2018年 | 1550篇 |
2017年 | 1541篇 |
2016年 | 1694篇 |
2015年 | 1727篇 |
2014年 | 3236篇 |
2013年 | 4330篇 |
2012年 | 2849篇 |
2011年 | 3331篇 |
2010年 | 2652篇 |
2009年 | 2656篇 |
2008年 | 2778篇 |
2007年 | 2921篇 |
2006年 | 2701篇 |
2005年 | 2516篇 |
2004年 | 2200篇 |
2003年 | 1954篇 |
2002年 | 1544篇 |
2001年 | 1339篇 |
2000年 | 1059篇 |
1999年 | 1039篇 |
1998年 | 853篇 |
1997年 | 772篇 |
1996年 | 698篇 |
1995年 | 683篇 |
1994年 | 574篇 |
1993年 | 462篇 |
1992年 | 503篇 |
1991年 | 489篇 |
1990年 | 417篇 |
1989年 | 373篇 |
1988年 | 358篇 |
1987年 | 320篇 |
1986年 | 318篇 |
1985年 | 420篇 |
1984年 | 357篇 |
1983年 | 237篇 |
1982年 | 310篇 |
1981年 | 278篇 |
1980年 | 244篇 |
1979年 | 172篇 |
1978年 | 156篇 |
1977年 | 102篇 |
1976年 | 114篇 |
1975年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
21.
22.
目的:探讨建立一种放射治疗全身器官剂量数据库平台的可行性。方法:使用基于深度学习的自动勾画软件DeepViewer?1例食管癌患者的全身CT上勾画全身器官,然后利用基于GPU加速的蒙特卡罗软件ARCHER计算相应的器官剂量分布,最后利用Lyman-Kutcher-Burman(LKB)模型评估放疗患者正常组织并发症概率(NTCP)。结果:针对该病例,成功建立基于DeepViewer?ARCHER和LKB模型的全身器官剂量数据库,发现距离靶区越近的器官剂量越大,其中心脏与靶区间距离最小,剂量为14.11 Gy,但因其模型参数特殊,通过LKB模型计算的NTCP为0.00%;左、右肺的剂量分别为3.19和1.16 Gy,但是NTCP值却很大,分别为2.13%和1.60%。对于距离靶区较远的头颈部器官(视交叉、视神经和眼)和腹部器官(直肠、膀胱和股骨头)剂量分别约为9和2 mGy,并且NTCP均近似为0.00%。结论:研究结果证明通过自动勾画软件DeepViewer?蒙特卡罗软件ARCHER和LKB模型建立全身器官剂量数据库的可行性。 相似文献
23.
《Journal of thoracic oncology》2021,16(10):1694-1704
IntroductionIn patients with NSCLC, the prognostic significance of the tumor microenvironment (TME) immune composition has been revealed using single- or dual-marker staining on sequential tissue sections. Although these studies reveal that relative abundance and localization of immune cells are important parameters, deeper analyses of the NSCLC TME are necessary to refine the potential application of these findings to clinical care. Currently, the complex spatial relationships between cells of the NSCLC TME and potential drivers contributing to its immunologic composition remain unknown.MethodsWe used multispectral quantitative imaging on the lung adenocarcinoma TME in 153 patients with resected tumors. On a single slide per patient, we evaluated the TME with markers for CD3, CD8, CD14, CD19, major histocompatibility complex II (MHCII), cytokeratin, and 4′,6-diamidino-2-phenylindole (DAPI). Image analysis, including tissue segmentation, phenotyping, and spatial localization, was performed.ResultsSpecimens wherein greater than or equal to 5% of lung cancer cells expressed MHCII (MHCIIhi TME) had increased levels of CD4+ and CD8+ T cells and CD14+ cell infiltration. In the MHCIIhi TME, the immune infiltrate was closer to cancer cells and expressed an activated phenotype. Morphologic image analysis revealed cancer cells in the MHCIIhi TME more frequently interfaced with CD4+ and CD8+ T cells. Patients with an MHCIIhi TME experienced improved overall survival (p = 0.046).ConclusionsLung cancer cell-specific expression of MHCII associates with levels of immune cell infiltration, spatial localization, and activation status within the TME. This suggests that cancer cell-specific expression of MHCII may represent a biomarker for the immune system’s recognition and activation against the tumor. 相似文献
24.
25.
Judith Brock Andreas Schmid Thomas Karrasch Petra Pfefferle Jutta Schlegel Inga Busse Annette Hauenschild Barbara Schmidt Maria Koukou Efthymia Arapogianni Andreas Schultz Miriam Thomalla Secil Akinci Johannes Kruse Winfried Padberg Andreas Schffler Jens Albrecht 《Clinical endocrinology》2019,91(3):400-410
26.
《Clinical oncology (Royal College of Radiologists (Great Britain))》2020,32(5):303-315
The lung is the preferred site of metastasis from soft tissue sarcoma (STS). This systematic review aims to evaluate the outcomes of stereotactic body radiotherapy (SBRT) and metastasectomy (MTS) for the treatment of lung metastases from STS. A systematic review was carried out according to the PRISMA protocol. PubMed, Medline, EMBASE, Cochrane Library, Ovid and Web of Knowledge databases were searched for English-language articles to December 2018 using a predefined strategy. Retrieved studies were independently screened and rated for relevance. Data were extracted by two researchers. In total, there were 1306 patients with STS: 1104 underwent MTS and 202 had SBRT. The mean age ranged from 40 to 55.8 years in the MTS group and from 47.9 to 64 years in the SBRT group. The cumulative death rate was 72% (95% confidence interval 59–85%) in the MTS group and 56% (38–74%) in the SBRT group. The cumulative mean overall survival time was 46.7 months (36.4–57.0%) in the MTS group and 47.6 months (33.7–61.5%) in the SBRT group. The cumulative rate of patients alive with disease was 5% (2–9%) in the MTS group and 15% (6–36%) in the SBRT group. Finally, the cumulative rate of patients alive without disease in the two groups was 19% (9–29%) and 20% (10–50%), respectively. Our study showed that local treatment of pulmonary metastases from STS with SBRT, compared with surgery, was associated with a lower cumulative overall death rate and similar overall survival time and survival rates without disease. By contrast, SBRT was associated with a higher survival rate with disease than MTS. Large randomised trials are necessary to confirm these findings and to establish whether SBRT may be a reliable option for early stage disease. 相似文献
27.
Talita da Silva Mendes de Farias Ariclécio Cunha de Oliveira Sandra Andreotti Fernanda Gaspar do Amaral Patrícia Chimin André Ricardo Alves de Proença Francisco Leonardo Torres Leal Rogério Antonio Laurato Sertié Amanda Baron Campana Andressa Bolsoni Lopes Arnaldo Henrique de Souza José Cipolla‐Neto Fabio Bessa Lima 《Journal of pineal research》2015,58(3):251-261
Melatonin, the main hormone produced by the pineal gland, is secreted in a circadian manner (24‐hr period), and its oscillation influences several circadian biological rhythms, such as the regulation of clock genes expression (chronobiotic effect) and the modulation of several endocrine functions in peripheral tissues. Assuming that the circadian synchronization of clock genes can play a role in the regulation of energy metabolism and it is influenced by melatonin, our study was designed to assess possible alterations as a consequence of melatonin absence on the circadian expression of clock genes in the epididymal adipose tissue of male Wistar rats and the possible metabolic repercussions to this tissue. Our data show that pinealectomy indeed has impacts on molecular events: it abolishes the daily pattern of the expression of Clock, Per2, and Cry1 clock genes and Pparγ expression, significantly increases the amplitude of daily expression of Rev‐erbα, and affects the pattern of and impairs adipokine production, leading to a decrease in leptin levels. However, regarding some metabolic aspects of adipocyte functions, such as its ability to synthesize triacylglycerols from glucose along 24 hr, was not compromised by pinealectomy, although the daily profile of the lipogenic enzymes expression (ATP‐citrate lyase, malic enzyme, fatty acid synthase, and glucose‐6‐phosphate dehydrogenase) was abolished in pinealectomized animals. 相似文献
28.
André Ricardo Adriano Tiago Silveira Lima Maxime Battistella Martine Bagot 《Anais brasileiros de dermatologia》2015,90(6):892-895
Granulomatous slack skin is an indolent T-cell lymphoma, considered to be a
variant of mycosis fungoides. Clinically it is characterized by areas of
redundant skin, wrinkled, inelastic, with variable erythema and
infiltration besides a poikilodermic surface. A differential diagnosis
unknown to most dermatologists is the giant cell tumor of soft tissue,
which is an extremely rare low-grade sarcoma. The authors report a patient
who had undergone extensive surgery because of a primary diagnosis of giant
cell tumor of soft tissue, but which proved to be granulomatous slack skin
after a second interventional procedure with confirmatory
histopathology. 相似文献
29.
尿毒清颗粒治疗慢性肾功能衰竭临床研究 总被引:1,自引:0,他引:1
目的:观察尿毒清颗粒治疗慢性肾功能衰竭(CRF)的临床疗效及其对钙磷代谢、结缔组织生长因子(CTGF)的影响。方法:选取120例CRF患者,按随机数字表法分为对照组和观察组各60例。对照组采用常规治疗,包括控制饮食、纠正酸碱、水电解质平衡;观察组在对照组的基础上加用尿毒清颗粒治疗。2组均连续治疗2个月,观察比较2组肾功能[肌酐(SCr)、血尿素氮(BUN)]、血磷(P3-)、血钙(Ca2+)、甲状旁腺激素(PTH)、CTGF指标水平变化,并评定2组临床疗效及不良反应情况。结果:观察组总有效率为80.00%,对照组为61.67%,2组比较,差异有统计学意义(P<0.05)。治疗后,2组SCr、BUN水平均较治疗前降低(P<0.05),且观察组SCr、BUN水平均低于对照组(P<0.05)。治疗后,2组PTH、CTGF、P3-水平较治疗前降低(P<0.05),Ca2+水平较治疗前升高(P<0.05);观察组PTH、P3-、CTGF水平均低于对照组(P<0.05),Ca2+水平高于对照组(P<0.05)。观察组不良反应发生率为3.33%,对照组为16.67%,2组比较,差异有统计学意义(P<0.05)。结论:尿毒清颗粒治疗CRF临床疗效显著,可有效调节钙磷代谢、CTGF平衡,改善肾功能,且安全性较高。 相似文献
30.
中医药文化是中医药事业发展的根基和灵魂,社会主义文化建设的重要组成。本文考察改革开放40年以来中医药文化发展的演进过程,从“社会矛盾—政策方针—中医药文化发展”的中观视角,构建了中医药文化发展分析模型,发现中医药文化先后经历了资产化发展(1978年-21世纪初)、情景化发展(21世纪初-中国共产党第十八次全国代表大会(中共十八大)前后)、生态化发展(中共十八大至今)三个阶段,每个阶段中医药文化发展的策略、重点和面临的问题具有明显的不同特点。因此,本文提出以社会矛盾为导向,优化政策引导,构建中医药文化生态体系,从个人、社会和国家发展的不同层面采取多元双向发展路径,推进健康中国发展,提升文化自信,打造文化强国。 相似文献