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   253134篇
  免费   20054篇
  国内免费   9269篇
耳鼻咽喉   1871篇
儿科学   3423篇
妇产科学   3108篇
基础医学   40356篇
口腔科学   4063篇
临床医学   17433篇
内科学   43999篇
皮肤病学   3542篇
神经病学   22958篇
特种医学   4888篇
外国民族医学   68篇
外科学   16645篇
综合类   32546篇
现状与发展   26篇
一般理论   6篇
预防医学   11174篇
眼科学   2457篇
药学   41719篇
  47篇
中国医学   9333篇
肿瘤学   22795篇
  2024年   603篇
  2023年   4418篇
  2022年   9338篇
  2021年   11569篇
  2020年   8882篇
  2019年   7791篇
  2018年   7634篇
  2017年   7715篇
  2016年   7934篇
  2015年   9367篇
  2014年   14467篇
  2013年   16967篇
  2012年   14390篇
  2011年   16583篇
  2010年   13777篇
  2009年   14077篇
  2008年   14042篇
  2007年   12812篇
  2006年   11342篇
  2005年   9879篇
  2004年   8485篇
  2003年   7580篇
  2002年   6073篇
  2001年   5051篇
  2000年   4327篇
  1999年   3889篇
  1998年   3781篇
  1997年   3538篇
  1996年   3201篇
  1995年   2715篇
  1994年   2495篇
  1993年   2159篇
  1992年   1774篇
  1991年   1661篇
  1990年   1331篇
  1989年   1136篇
  1988年   1043篇
  1987年   898篇
  1986年   853篇
  1985年   1243篇
  1984年   1157篇
  1983年   784篇
  1982年   848篇
  1981年   683篇
  1980年   552篇
  1979年   429篇
  1978年   283篇
  1977年   231篇
  1976年   215篇
  1975年   152篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的探讨喉癌患者血小板表面血小板膜糖蛋白Ⅱb/Ⅲa纤维蛋白原受体(PAC-1)、血小板P-选择素(CD62P)阳性表达率以及与患者临床病理特征和复发的关系。方法选取2014年1月~2015年12月间在我院耳鼻喉科手术治疗的116例喉癌患者,随访≥2年,并选取同期在我院体检的健康人群60例为对照组,采用流式细胞仪检测法检测外周血PAC-1和CD62P阳性率,并分析与临床病理特征、复发的关系。结果喉癌患者PAC-1和CD62P阳性表达率分别为(17.82±1.76)%和(22.87±3.13)%,明显高于健康人群(P<0.05);而且在喉癌患者PAC-1表达和CD62P表达呈正相关性(r=0.238,P<0.05)。T3-T4分期或N2-N3分期患者PAC-1和CD62P阳性表达率高于T1-T2分期或N0-N1分期患者(P<0.05)。另外远处转移组PAC-1和CD62P阳性表达率高于未发生转移组(P<0.05);随访期间有24例患者复发,复发率为20.69%。复发喉癌患者PAC-1、CD62P阳性表达率分别为(17.02±0.85)%和(21.84±1.17)%,明显高于未复发的喉癌患者(P<0.05)。经Logistics回归分析,PAC-1和CD62P是喉癌患者复发的独立危险因素(P<0.05)。结论PAC-1和CD62P阳性表达率与喉癌患者T分期、淋巴结转移和远处转移密切相关,同时可作为喉癌局部复发、区域淋巴结转移、远处转移的预测指标。  相似文献   
62.
习洋  陶泽璋 《疑难病杂志》2020,(2):207-211,216
慢性鼻窦炎(CRS)是一种常见的慢性非特异感染性鼻部疾病,病理分型主要分为Th2细胞介导的嗜酸性粒细胞性鼻窦炎(ECRS)和Th1细胞介导的非嗜酸性粒细胞性鼻窦炎(非ECRS)2种表型。欧洲国家CRS患病人群主要表现为ECRS,而随着亚洲国家的急剧工业化发展,其ECRS的比例也在急剧增加。ECRS发病机制复杂,涉及多种免疫细胞和相关因子相互作用。其治疗方法包括抗生素、激素药物治疗及手术治疗等,但仍有部分患者症状难以改善或存在复发的风险。Ⅱ型固有淋巴样细胞(ILC2s)是一种非B、非T的新型淋巴细胞,与Th2免疫应答关系密切。文章就ILC2s在ECRS发病机制中的作用进行综述,以期为ECRS的诊断和治疗提供理论参考。  相似文献   
63.
This study aimed to observe the therapeutic effects of magnesium lithospermate B on acute and chronic colitis induced by dextran sodiumsulfate (DSS) and the role of inflammasome complex (NOD-like receptor protein, NLRP; apoptosis-associated speck-like protein containing, ASC; caspase-1). Establishment of acute and chronic colitis models were by using 5% DSS oral administration in BALB/C male mice. Magnesium lithospermate B (240 mg/kg body weight) was given by subcutaneous injection. Samples were collected for biomarker assay, histological examination, immunohistochemical evaluation and western blot. There was obvious increase in TNF-α level and NLPR3, ASC, and caspase-1 expressions in acute and chronic colitis groups compared with the normal control. Significant decrease of the tumor necrosis factor-α level and the expressions of NLPR3, ASC, and caspase-1 were observed after treatment with magnesium lithospermate B. This study showed that magnesium lithospermate B could be used to treat acute and chronic colitis by inhibiting the activation of the NLRP3/ASC/Caspase-1 pathway.  相似文献   
64.
HER2-positive breast cancer is an aggressive subtype identified in the 1980s. The development of therapies targeting the HER2 has improved outcomes. The current standard of care, established in 2012 is dual blockade with trastuzumab + pertuzumab as first-line followed by TDM-1 as second-line. Several suboptimal choices are available in third-line or more. In 2019 the presentation of several trials evaluating new drugs and regimens in third-line has re-opened questions about sequencing, treatment of triple positive disease and treatment choice after exposure to TDM-1. These include tucatinib, neratinib and trastuzumab-deruxtecan. Other agents – including other antibody drug conjugates and bispecific antibodies as well as combinations - will lead to further changes in coming years. Additionally, should the numerous putative biomarkers thus identified ever come into use at the clinic, choice of treatment and response evaluation may be substantially changed.  相似文献   
65.
Serum thromboxane-B2 (TxB2), together with arachidonic acid (AA)-induced platelet aggregation, are, at the moment, the most used tests to identify patients displaying high on-aspirin treatment platelet reactivity (HAPR). Both tests are specific for aspirin action on cyclooxygenase-1. While the correlation between serum TxB2 assay and clinical outcome is established, data are conflicting with regard to aspirin treatment and a possible association with AA-stimulated platelet markers and clinical outcome. To understand such discrepancy, we performed a retrospective study to compare both assays. We collected data from 132 patients receiving a daily dose of aspirin (100?mg/day) and data from 48 patients receiving aspirin on alternate days. All Patients who received a daily dose of aspirin were studied for AA-induced platelet aggregation together with serum TxB2 levels and AA-induced TxB2 formation was also studied in 71 patients out of entire population. Consistent with recommendations in the literature, we defined HAPR by setting a cut-off point at 3.1?ng/ml for serum levels of thromboxane B2 and 20% for AA-induced platelet aggregation. According to this cut-off point, we divided our overall population into two groups: (1) TxB2?<?3.1?ng/ml and (2) TxB2?>?3.1?ng/ml. We found low agreement between such tests to identify patients displaying HAPR. Our results show that AA-induced platelet aggregation >20% identify a smaller number of HAPR patients in comparison with TxB2. A good correlation between serum TxB2 and arachidonic acid-induced TxB2 production was found (r?=?0.76619).  相似文献   
66.
67.
Extensive research has indicated that miRNAs are crucial for the occurrence and progression of cancers. miR-451a, involved in breast cancer (BC), is one of the miRNAs. This study focused on the mechanism by which miR-451a regulates BC. The levels of miR-451a in BC tissues and cell lines were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan‒Meier analysis showed that this was intimately related to the patient's overall survival rate. Functional experiments revealed the negative effects of miR-451a on the abilities of BC cells to multiply (tested by Cell Counting Kit-8), migrate (tested by wound healing assay), and invade (tested by Transwell assay) and its positive effects on apoptosis (tested by flow cytometry). Western blotting indicated that the expression of tumor-related proteins was affected by miR-451a. Moreover, in vivo experiments suggested that tumor growth was clearly restrained by an miR-451a agonist in a xenograft tumor model. Bioinformatic analysis indicated that miR-451a directly targeted Cyclin D2 (CCND2), as demonstrated by the luciferase reporter assay. An opposite change in the level of CCND2 and miR-451a in BC was indicated by qRT-PCR, western blotting, and immunohistochemistry. Subsequently, functional experiments and western blotting analysis confirmed that CCND2 accelerated BC progression, which was regulated by miR-451a. Cumulatively, research on miR-451a may be valuable for BC treatment.  相似文献   
68.
《Clinical therapeutics》2019,41(5):836-847
PurposeA role for the immune system in causing myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is long suspected, but few studies have looked for specific autoantibodies that might contribute to the symptoms. Our aim was to look for evidence of antibodies to neuronal proteins in patients with ME/CSF.MethodsSera samples from 50 patients and 50 healthy individuals were sent coded to the Neuroimmunology Laboratory in Oxford. Screening for antibody binding to neuronal tissue was performed on brain tissue and neuronal cultures. Specific serum antibodies were assessed by antigen-specific cell-based assays and radioimmunoassays. After antibody testing, the associations between seropositive status and clinical data were investigated.FindingsOverall, 8 patients and 11 participants were found to have some serum immunoreactivity toward neuronal or neuromuscular junction proteins, but only 1 patient and 2 participants had specific serum antibodies. Nevertheless, seropositive status in patients with ME was associated with shorter duration since onset and a more severe disease.ImplicationsThe results indicate no overall increased frequency of antibodies to neuronal proteins in ME/CSF and no evidence of a specific antibody that might be causative or contribute to clinical features in patients. However, the association of seropositive status with shorter duration of disease and more severe symptoms suggests a possible role of antibodies at onset in some patients and should be the focus of future studies.  相似文献   
69.
张金连    苑东敏  崔静  赵园园  王云云  杨帆  孙健平     《现代预防医学》2020,(8):1514-1518
目的 探讨血清谷丙转氨酶(ALT)与新诊2型糖尿病(T2DM)患病风险之间的关联,为T2DM的防治提供科学依据。方法 采用4阶段分层随机抽样的方法选取2006年和2009年参与青岛糖尿病预防项目的研究对象男性3 012例、女性4 422例,采用Pearson相关检验分析不同性别ALT与FPG、2 h PG的相关性,并利用多因素logistic回归分析ALT与新诊T2DM患病的关系。结果 男性中,ALT与空腹血浆血糖(FPG)、餐后2 h血浆血糖(2 h PG)的Pearson相关系数分别为0.088、0.080(均P<0.01);多因素logistic回归显示,在调整了年龄、BMI、糖尿病家族史、城乡、教育、婚姻、收入、吸烟及饮酒状况等混杂因素后,ALT的第4分位(Q4)组新诊T2DM患病风险是第1分位(Q1)组的1.832倍(OR = 1.832,95% CI:1.324~2.534,P<0.01)。女性中,ALT与FPG、2h PG的Pearson相关系数分别为0.065、0.108(均P<0.01);多因素logistic回归显示,在调整了年龄、BMI、糖尿病家族史、城乡、教育、婚姻、收入、吸烟及饮酒状况等混杂因素后,ALT的第4分位(Q4)组新诊T2DM患病风险是第1分位(Q1)组的1.445倍(OR = 1.445,95% CI:1.087~1.919,P<0.05)。结论 在男、女性人群中,ALT水平升高与T2DM患病相关,且这种相关性不受年龄、BMI、糖尿病家族史等的影响。  相似文献   
70.
Abstract

This study is a single-center, retrospective analysis of postmenopausal women presenting with dyspareunia and vulvar pain, aiming to evaluate relative effectiveness of vestibular CO2 laser therapy as a treatment. Three monthly sessions of laser were performed to each patient and thereafter a three-months follow-up was stablished. A total number of 72 patients undergoing vestibular laser treatment were recruited from patient files in the period between 2016 and 2018. Among these, 39 women also received a concomitant treatment with ospemifene (60?mg/day) during the study period. There was a statistically significant reduction of all the symptoms in both groups up to the three month follow-up. Regarding dryness and dyspareunia, the relief tent to be more prominent in the ospemifene?+?laser group at all follow-ups and remained statistically significant at three-month follow-up. Specifically, vestibular dryness was significantly lower in the ospemifene?+?laser group compared with the laser treatment group (?87% vs???34%, respectively), and the vestibular health score started declining faster in the ospemifene?+?laser group. Although, additional research is needed to understand the mechanism of action, our data shows that a combination regimen of laser and ospemifene may improve clinical effectiveness for long-term treatment of symptoms associated with the under-recognized genitourinary syndrome of menopause.  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