首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   40036篇
  免费   3447篇
  国内免费   1403篇
耳鼻咽喉   438篇
儿科学   1075篇
妇产科学   464篇
基础医学   3184篇
口腔科学   1589篇
临床医学   4897篇
内科学   7054篇
皮肤病学   1180篇
神经病学   1661篇
特种医学   1733篇
外科学   2694篇
综合类   6903篇
现状与发展   10篇
一般理论   4篇
预防医学   5986篇
眼科学   945篇
药学   2741篇
  26篇
中国医学   1764篇
肿瘤学   538篇
  2024年   44篇
  2023年   798篇
  2022年   1287篇
  2021年   1926篇
  2020年   1960篇
  2019年   1568篇
  2018年   1475篇
  2017年   1377篇
  2016年   1557篇
  2015年   1378篇
  2014年   2728篇
  2013年   2900篇
  2012年   2511篇
  2011年   2694篇
  2010年   2187篇
  2009年   2068篇
  2008年   1958篇
  2007年   1974篇
  2006年   1659篇
  2005年   1556篇
  2004年   1218篇
  2003年   1107篇
  2002年   879篇
  2001年   856篇
  2000年   671篇
  1999年   500篇
  1998年   471篇
  1997年   391篇
  1996年   267篇
  1995年   359篇
  1994年   299篇
  1993年   194篇
  1992年   226篇
  1991年   198篇
  1990年   167篇
  1989年   166篇
  1988年   153篇
  1987年   144篇
  1986年   118篇
  1985年   136篇
  1984年   139篇
  1983年   80篇
  1982年   80篇
  1981年   80篇
  1980年   71篇
  1979年   61篇
  1978年   49篇
  1977年   39篇
  1976年   54篇
  1975年   38篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
"异病同证"是中医学对病证关系的特殊认识,起初是指不同的病具有相同的病机,从而表现出相同的证候,反映了中医学辨证论治的特点,在临证中主要体现在一方用于治疗多种病证。随着病证结合诊疗模式的形成,"异病同证"的含义也发生了变化,多指西医诊断不同疾病在其发展的过程中出现了相同的病机,从而表现出相同的证候。股骨头坏死、髋骨关节炎、类风湿性髋关节炎是发于髋关节骨骼、软骨及滑膜的3个不同解剖组织的3种疾病,在疾病的晚期出现了髋关节疼痛、活动受限的症状和腰膝酸软、行走无力的证候,无论是症状体征或中医证候,均表现出其相似性,体现着中医学"异病同证"的思想,本文从临床症状、影像变化、中医证候特点、病因病机及临床治疗方面探析3种疾病的趋同性和差异性,结果发现,除了临床症状体征相似,3种髋关节骨病晚期均见关节软骨退变、关节间隙狭窄、关节积液、滑膜增厚、骨质增生及软骨下骨囊变等相似X射线表现;肾藏精、主骨生髓,只有肾精充足,筋骨方可得以骨髓充养,肝藏血、主筋,肝血充足筋骨才能濡养,病至晚期,3种疾病与肝肾脏腑功能失常密切相关,肝肾不足、经脉筋骨失养是3种髋关节骨病晚期的共同病机,肝肾亏虚、腰膝酸软、行走无力亦成为其共同证候。不仅为"同证"提供理论依据,也有助于"异病"的鉴别诊断、提高髋关节疾病的诊断水平、丰富中医学"异病同证"的内涵。  相似文献   
102.
Background: Benign breast disease (BBD) is one of main breast cancer risk factors. Dysfunctions on p53 protein, which has a genome protective role, have been related to breast cancer developments. However, its role on BBD development is still unclear. Methods: A systematic review of literature was proceeded according to PRISMA-P guidelines. PubMed, BVS, MEDLINE and Scholar Google were used as databases, complemented by a manual search in articles references.  Articles searches were conducted from May to July 2019 and publications in English, Spanish and Portuguese were selected. P53 expression was set as outcome among women with BBD and were included only articles with good quality according STROBE tools. Data concerning p53 expression frequencies were independently extracted by two review authors, and eligible articles were synthesized. Results: From 12 studies selected for this review, the majority analyzed p53 expression in non-proliferative lesions and general p53 expressions ranged from 0 to 100%. P53 expression was more frequently observed in cases series studies (91.7%) and in studies conducted in Occidental Europe (41.7%). P53 expression was more frequent among tissues with fibrocystic disease (22.5%) and fibroadenoma (22.5%). Conclusion: When compared with all breast tissues types, benign breast disease corresponds to 34.39% of p53 expression. Second outcomes were not evaluated because the heterogeneity observed in selected studies. In addition, more studies considering ethnicity and benign breast disease classification should also be considered for further analysis.  相似文献   
103.
Cardiovascular complications are a side effect of cancer therapy, potentially through reduced blood vessel function. ONC201 (TIC10) is currently used in phase 2 clinical trials to treat high-grade gliomas. TIC10 is a phosphatidylinositol 3-kinase (PI3K)/AKT/extracellular signal-regulated kinase (ERK) inhibitor that induces apoptosis via upregulation of TNF-related apoptosis-inducing ligand, which via stimulation of FOXO and death receptor could increase eNOS upregulation. This has the potential to improve vascular function through increased NO bioavailability. Our aim was to investigate the role of TIC10 on vascular function to determine if it would affect the risk of CVD. Excised abdominal aorta from White New Zealand male rabbits were cut into rings. Vessels were incubated with TIC10 and AS1842856 (FOXO1 inhibitor) followed by cumulative doses of acetylcholine (Ach) to assess vessel function. Vessels were then processed for immunohistochemistry. Incubation of blood vessels with TIC10 resulted in enhanced vasodilatory capacity. Combination treatment with the FOXO1 inhibitor and TIC10 resulted in reduced vascular function compared to control. Immunohistochemical analysis indicated a 3-fold increase in death receptor 5 (DR5) expression in the TIC10-treated blood vessels but the addition of the FOXO1 inhibitor downregulated DR5 expression. The expression of DR4 receptor was not significantly increased in the presence of TIC10; however, addition of the FOXO1 inhibitor downregulated expression. TIC10 has the capacity to improve the function of healthy vessels when stimulated with the vasodilator Ach. This highlights its therapeutic potential not only in cancer treatment without cardiovascular side effects, but also as a possible drug to treat established CVD.  相似文献   
104.
Cutaneous leishmaniasis represents a public health problem that affects 85 countries. It is an endemic disease in Brazil, having an important socioeconomic impact. An exuberant case of cutaneous leishmaniasis is reported herein. A 28-year-old male patient with Down syndrome had had verrucous plaques on the back for over a year, with progressive growth. PCR of a lesion sample was positive for Leishmania braziliensis. The patient's condition was classified as atypical cutaneous leishmaniasis. He was successfully treated with amphotericin B and miltefosine. The treatment remains a challenge, given the toxicity and low cure rate of the currently recommended drugs.  相似文献   
105.
Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions.Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms' population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.  相似文献   
106.
目的 探讨表没食子儿茶素-3-没食子酸酯(EGCG)对宫内生长受限(IUGR)大鼠肝脏脂代谢的影响和机制。方法 采用母鼠孕期全程限食法建立IUGR大鼠模型,随机分为IUGR组和EGCG组,EGCG组大鼠在离乳后用含EGCG的饮用水喂养至10周,同时设立正常对照组,每组8只。13周龄时,测量各组大鼠体重后,采集大鼠血液及肝脏组织标本,检测各组大鼠血清空腹总胆固醇(TC)、甘油三酯(TG)、游离脂肪酸(FFA)、血糖(FPG)、胰岛素(FINS)和肝脏脂质水平,计算稳态模型评估胰岛素抵抗(HOMA-IR)和脂肪组织胰岛素抵抗(adipo-IR),观察肝脏组织病理切片,并采用实时荧光定量PCR法检测肝脏相关基因的相对表达水平。结果 13周龄时,各组大鼠体重比较差异无统计学意义(P=0.067)。各组间的FPG、FFA、FINS、HOMA-IR和adipo-IR水平比较差异均有统计学意义(P < 0.05)。各组间的血清TC和TG水平比较差异无统计学意义(P > 0.05),但在肝脏中IUGR组TC和TG水平均明显高于EGCG组(P < 0.05)。油红染色结果提示,IUGR大鼠的肝脏脂肪储积明显增加,而EGCG能够改善该现象。PCR结果显示,与对照组相比,IUGR组的Ampk mRNA及Adipor1 mRNA表达水平降低,Srebf1 mRNA表达水平增加(P < 0.05),EGCG能逆转IUGR大鼠Ampk mRNA及Srebf1 mRNA的表达水平,且与对照组比较差异无统计学意义(P > 0.05)。结论 早期EGCG干预可能通过Ampk/Srebf1通路下调脂肪酸的从头合成,并通过改善肝细胞的胰岛素抵抗,从而降低IUGR大鼠的肝脏脂肪积累。  相似文献   
107.
Human endogenous retroviruses (HERV)-E consist of a family of more than 1300 elements, stably integrated in the human genome. Some of them are full-length proviruses able to synthesize the viral proteins gag, pol and env. The reactivation of HERV-E elements has been associated to placentation, cancer and autoimmunity. In this narrative review, we aimed to report the status of the art concerning the involvement of HERV-E in rheumatic autoimmune diseases. Following a research on PubMed database, a total of 87 articles were selected. The highest amount of evidence derives from studies on systemic lupus erythematosus (SLE), whereas a few to no data are available on other immune-mediated diseases. In SLE, the hyper-expression of HERV-E clone 4-1 in peripheral blood mononuclear cells or differentiated lymphocytes has been associated with disease activity and autoantibody production. It is likely that HERV-E take part to the pathogenesis of rheumatic autoimmune diseases but additional research is needed.  相似文献   
108.
BackgroundEssential tremor (ET), among the most common neurological diseases, is associated with cognitive dysfunction. Yet, nearly all knowledge of ET-related cognitive impairment is static and cross-sectional (e.g., prevalence), with virtually no dynamic information (i.e., course and progression, conversion rates, and clinical outcomes).ObjectivesTo quantify the rate of progression from mild cognitive impairment (MCI) to dementia in a cohort of elderly ET cases.Methods167 ET cases, enrolled in a prospective, longitudinal, clinical-pathological study, underwent an extensive neuropsychological testing battery at baseline (T1), 1.5 years (T2), and 3 years (T3). Results of these assessments informed clinical diagnoses of normal cognition (ET-NC), MCI (ET-MCI), and dementia (ET-D).ResultsAt baseline, 26 cases (82.7 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T2. At T2, three of 26 (11.5%) had converted to ET-D. At the start of T2, 23 cases (83.6 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T3. At T3, six of 23 (26.1%) converted to ET-D. The average annual conversion rate from ET-MCI to ET-D was 12.5%.ConclusionsThe study of cognitive impairment in ET is a nascent field, with limited data. We show that the conversion rate from ET-MCI to ET-dementia was 12.5%. Available studies on historical controls have reported conversion rates of 2.6–6.3%. Data such as these systematically fill gaps in knowledge, creating a scientifically-derived knowledge base to guide physicians and patients in clinical settings.  相似文献   
109.
110.
Although infectious mononucleosis due to Epstein-Barr virus (EBV) is a common disease among young individuals, central nervous system (CNS) complications are rare. In this report, we describe a case of CNS complications caused by EBV in a previously healthy young woman. She presented to our hospital with a 9-day history of headache and sore throat, followed by the development of fever and facial edema 6 days prior to admission. On Day 2 of admission, she was confused (Glasgow Coma Scale score: 10 points) and had fever, muscle weakness in her right arm and leg, stiff neck, and roving eye movement. We detected EBV in a cerebrospinal fluid (CSF) sample using a polymerase chain reaction (PCR) test. The magnetic resonance imaging of her brain revealed dural enhancement and right parietal and temporal lobe lesions. She was treated with acyclovir and high-dose steroid therapy. She responded well to treatment, recovered without neurologic sequelae, and was discharged home on Day 12.Our experience suggests that PCR detection of EBV DNA in CSF may be useful in diagnosing EBV encephalitis and that prognosis may be associated with an area of the brain that is affected and the time from symptom onset to starting treatment.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号