全文获取类型
收费全文 | 258026篇 |
免费 | 8917篇 |
国内免费 | 5685篇 |
专业分类
耳鼻咽喉 | 1988篇 |
儿科学 | 7915篇 |
妇产科学 | 3861篇 |
基础医学 | 24163篇 |
口腔科学 | 2993篇 |
临床医学 | 23403篇 |
内科学 | 40683篇 |
皮肤病学 | 1531篇 |
神经病学 | 19609篇 |
特种医学 | 11827篇 |
外国民族医学 | 26篇 |
外科学 | 35618篇 |
综合类 | 20863篇 |
现状与发展 | 18篇 |
一般理论 | 2篇 |
预防医学 | 25767篇 |
眼科学 | 5011篇 |
药学 | 19328篇 |
111篇 | |
中国医学 | 6003篇 |
肿瘤学 | 21908篇 |
出版年
2024年 | 274篇 |
2023年 | 1084篇 |
2022年 | 3088篇 |
2021年 | 3964篇 |
2020年 | 3350篇 |
2019年 | 2378篇 |
2018年 | 24208篇 |
2017年 | 19902篇 |
2016年 | 21722篇 |
2015年 | 4760篇 |
2014年 | 5689篇 |
2013年 | 5759篇 |
2012年 | 14063篇 |
2011年 | 28621篇 |
2010年 | 24472篇 |
2009年 | 16227篇 |
2008年 | 24826篇 |
2007年 | 26697篇 |
2006年 | 5392篇 |
2005年 | 6277篇 |
2004年 | 6282篇 |
2003年 | 6994篇 |
2002年 | 4628篇 |
2001年 | 2007篇 |
2000年 | 1885篇 |
1999年 | 1448篇 |
1998年 | 983篇 |
1997年 | 985篇 |
1996年 | 664篇 |
1995年 | 639篇 |
1994年 | 562篇 |
1993年 | 314篇 |
1992年 | 315篇 |
1991年 | 363篇 |
1990年 | 309篇 |
1989年 | 239篇 |
1988年 | 188篇 |
1987年 | 161篇 |
1986年 | 116篇 |
1985年 | 99篇 |
1984年 | 68篇 |
1983年 | 47篇 |
1982年 | 47篇 |
1980年 | 51篇 |
1974年 | 24篇 |
1938年 | 60篇 |
1937年 | 25篇 |
1934年 | 30篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Thirty-five posters were presented at the Workshop on Brain Uptake And Utilization Of Fatty Acids, Lipids, and Lipoproteins.
They were grouped into four categories: (1) mechanisms of lipid uptake and transport to the brain, (2) lipoproteins and polyunsaturated
fatty acids, (3) eicosanoids in brain function, and (4) fatty acids and lipids in brain disorders. This article summarizes
the highlights of the research presented in these posters. The individual abstracts follow these synopses. 相似文献
992.
目的探讨胃肠道间质瘤的CT表现及临床诊断价值。方法回顾性分析经手术病理证实的31例胃肠道间质瘤CT表现。结果本组中胃间质瘤7例,小肠间质瘤16例,结肠间质瘤2例,直肠间质瘤1例,难以确定部位者5例。31例中良性3例,交界性6例,恶性22例。肿瘤呈类圆形或不规则形,密度均匀实性者6例,不均匀实性者14例,囊实性混合者11例,有2例有钙化灶。增强扫描有3例均匀强化,3例不均匀强化,内有斑点状变性坏死灶;25例呈不均匀明显强化,肿块内可见不同程度的变性、坏死区。3例良性者为均匀类圆形实性肿块,直径<5cm。交界性与恶性者形态、大小、密度等无明显差别,肿瘤直径均>5cm。结论对胃肠道间质瘤CT检查有助于发现肿块,定位准确,帮助判断肿瘤的良恶性程度。 相似文献
993.
994.
本文报告了我科1978~1990年间收治的降突性皮纤维肉瘤23例,均经组织学证实.治疗以手术切除为主,术后局部复发率为65.2%.无一例发生转移.切除不彻底是复发的主要原因.作者指出广泛切除是防止复发的主要措施,手术前后的放疗有可能减少复发. 相似文献
995.
996.
Not many data exist to guide us in the management of patients with chronic hepatitis B virus infection and “normal” alanine
aminotransferase levels. Many of these patients may not have normal levels on long-term follow-up or when the upper limit
of normal is determined from a truly healthy reference population. These patients may have significant histologic disease
and benefit from further investigation or treatment. This article focuses on the disease course of such patients. 相似文献
997.
Jens Jordan 《Clinical autonomic research》2007,17(6):331-333
Genes influencing the autonomic nervous system continue as a focus of research. Recent publications applied different methods
to identify genes influencing autonomic cardiovascular regulation in humans. Two reports relied on a candidate gene approach.
Common genetic polymorphisms in the promoter region of the tyrosine hydroxylase gene were shown to influence catecholamine
synthesis and blood pressure. The same group tested the hypothesis that the GTP cyclohydrolase 1 (GCH1) gene influences catecholamine
excretion and cardiovascular regulation. GCH1 affects tyrosine hydroxylase function indirectly. The authors concluded that
the GCH1 gene may influence cardiovascular autonomic regulation through changes in nitric oxide production rather than a change
in tyrosine hydroxylase activity. The third genetic study used a single nucleotide polymorphism chip to analyze 100,000 genetic
polymorphisms scattered throughout the genome in participants of the Framingham study. The authors identified several polymorphisms
that may influence QT interval duration, heart rate, and heart rate variability. The respective genes have not been identified
with certainty. Another study suggested that catecholamines may be released from phagocytes and regulate pulmonary inflammation
through alpha-2 adrenoreceptor activation in an autocrine or paracrine fashion. 相似文献
998.
目的探讨女方不明原因流产和不明原因不孕与其配偶精子染色质性状之间的关系;方法通过精子染色质结构分析(SCSA)对22例不明原因流产和36例不明原因不孕妇女配偶精子,以及20例正常对照者精子进行DNA完整性检测,并比较它们之间的差异;结果对照组与不明原因流产组以及不孕组之间精子DNA完整性存在差异,且差异具有统计学意义(P<0.05),而不明原因流产组与不孕组之间精子DNA完整性比较无明显差异(P>0.05);结论精子染色质结构分析有可能作为不明原因流产和不孕的辅助诊断方法在临床应用。 相似文献
999.
Intra-observer and inter-observer agreement of the manual examination of the lumbar spine in chronic low-back pain 总被引:1,自引:1,他引:0
Etienne Qvistgaard Jens Rasmussen Jes Lætgaard Steen Hecksher-Sørensen Henning Bliddal 《European spine journal》2007,16(2):277-282
Examination is a cornerstone in the manual procedures leading to mobilisation/manipulation of the low back. The observer variation of the more specific segmental tests remains to be investigated. Two skilled specialists in manual medicine examined the segmental changes in the lumbar spine. The patients were unknown to the examiners and no information of the case history was given. All test results were recorded by an observer present in the room who ensured that no conversation was allowed during the examination. The primary outcome measures were the kappa values for each test. The matching was defined as acceptable (acc) within two neighbouring levels and perfect (per) on the same level. Intra-observer variation (tested in 33 patients and 10 subjects without low-back pain): The agreement between first and second segmental diagnosis examination was 70% (per) and 82% (per + acc). Kappa values were: segmental diagnosis 0.60 (per) and 0.70 (per + acc), multifidus test 0.51 (per) and 0.60 (per + acc), sideflexion 0.57 (per) and 0.69 (per + acc), and ventral flexion 0.31 (per) and 0.45 (per + acc). Inter-observer variation (tested in 60 patients): The agreement for segmental diagnosis between the examiner A and B was 42% (per) and 75% (per + acc). Kappa values were: segmental diagnosis 0.21 (per) and 0.57 (acc), multifidus test 0.12 (per) and 0.48 (acc), sideflexion 0.22 (per) and 0.45 (acc), and ventralflexion 0.22 (per) and 0.44 (acc). By manual tests, skilled examiners seem to be able to diagnose segmental dysfunctions in the low back. The clinical implication of these dysfunctions remains to be clarified. 相似文献
1000.
Modic changes following lumbar disc herniation 总被引:4,自引:3,他引:1
Only a small proportion (20%) of patients with LBP can be diagnosed based on a patho-anatomical entity. Therefore, the identification
of relevant subgroups, preferably on a patoanatomical basis, is strongly needed. Modic changes have been described by several
authors as being closely linked with LBP. The aims of this study were to describe the prevalence of Modic changes, their development
as well as their association to LBP, previous disc contour, and surgery in patients with previous severe sciatica. This is
a longitudinal cohort study where the patients were recruited from an RCT comparing two active conservative treatments, the
181 patients, who at baseline had radicular pain in or below the knee; all underwent a physical examination and MRI. MRI’s,
pain history and physical examination of 166 patients were obtained at follow-up 14 months later. The prevalence of Modic
changes type 1 increased from 9% at baseline to 29% at follow-up. At that time, a strong association between Modic changes
and non-specific LBP was noted. Apparently, Modic changes type 1 was more strongly associated with non-specific lumbar pain
than Modic changes type 2. The development of new Modic changes was closely related to the level of a previous disc herniation.
A lumbar disc herniation is a strong risk factor for developing Modic changes (especially type 1) during the following year.
Furthermore, Modic changes are strongly associated with LBP. 相似文献