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   9273篇
  免费   479篇
  国内免费   51篇
耳鼻咽喉   169篇
儿科学   201篇
妇产科学   80篇
基础医学   1206篇
口腔科学   250篇
临床医学   644篇
内科学   2682篇
皮肤病学   74篇
神经病学   658篇
特种医学   327篇
外科学   1414篇
综合类   33篇
预防医学   230篇
眼科学   269篇
药学   703篇
中国医学   18篇
肿瘤学   845篇
  2023年   76篇
  2022年   136篇
  2021年   223篇
  2020年   130篇
  2019年   152篇
  2018年   178篇
  2017年   129篇
  2016年   203篇
  2015年   164篇
  2014年   227篇
  2013年   275篇
  2012年   406篇
  2011年   457篇
  2010年   273篇
  2009年   207篇
  2008年   420篇
  2007年   419篇
  2006年   383篇
  2005年   441篇
  2004年   441篇
  2003年   414篇
  2002年   428篇
  2001年   324篇
  2000年   317篇
  1999年   272篇
  1998年   129篇
  1997年   89篇
  1996年   82篇
  1995年   70篇
  1994年   61篇
  1993年   52篇
  1992年   209篇
  1991年   168篇
  1990年   177篇
  1989年   168篇
  1988年   163篇
  1987年   152篇
  1986年   133篇
  1985年   112篇
  1984年   102篇
  1983年   73篇
  1982年   49篇
  1981年   43篇
  1979年   78篇
  1978年   55篇
  1976年   45篇
  1972年   47篇
  1971年   41篇
  1970年   43篇
  1968年   45篇
排序方式: 共有9803条查询结果,搜索用时 15 毫秒
141.
This study was undertaken to examine whether males develop schizophrenia at a younger age than females, and whether temporal socioeconomic change affects the age at onset of schizophrenia. The subjects were 848 ICD-9 schizophrenics who were admitted to Nihon University Hospital, Tokyo, Japan, during the period of 1955-64 (n = 468 (214 males and 254 females), group A) or during the period of 1982-91 (n = 380 (220 males and 160 females). group B). Schizophrenic males showed an earlier age at onset than schizophrenic females. However, the mean age at onset of schizophrenia did not differ significantly between group A and group B. These results indicate that the gender difference in age at onset of schizophrenia has not been influenced by temporal socioeconomic change.  相似文献   
142.
We report the case of a 52-year-old woman with hepatitis B virus (HBV) reactivation during treatment for chronic graft vs. host disease (GVHD) after peripheral bone marrow transplantation (PBSCT) to treat chronic myelocytic leukemia. She was given cyclosporine and prednisolone orally to treat chronic GVHD after PBSCT. Liver dysfunction first developed 25 months after transplantation with the appearance of hepatitis B s antigen (HBsAg), hepatitis B e antigen (HBeAg), and elevation of HBV-DNA up to 4.5 log copies/ml. Retrospective examination of her serum before PBSCT proved negative for HBsAg and HBeAg, and positive for anti-HBsAg, anti-HBeAg, anti-hepatitis B core antigen, and HBV-DNA (2.7 log copies/ml), showing that she was in a state of occult HBV infection. Nucleotide sequences of the HBV genome obtained from her serum showed no core promoter mutations at nt 1762 and 1764 and no pre-core mutation at nt 1896. Polymerase chain reaction-restriction fragment length polymorphism showed that she was infected with HBV genotype B. The administration of lamivudine, a nucleoside analog, improved her liver function and reduced HBV-DNA replication. We conclude that antiviral agents, such as lamivudine, are effective for treating hepatitis B reactivation during immunosuppressive treatment, such as for GVHD. The administration of a nucleoside analog before transplantation should also be considered in the light of HBV genotypes and mutations, even if HBsAg was negative and the viral load was low before transplantation.  相似文献   
143.
Inhibition of homodimerization of Toll-like receptor 4 by curcumin   总被引:6,自引:0,他引:6  
Toll-like receptors play a key role in sensing microbial components and inducing innate immune responses. Ligand-induced dimerization of TLR4 is required for the activation of downstream signaling pathways. Thus, the receptor dimerization may be one of the first lines of regulation in activating TLR-mediated signaling pathways and induction of subsequent immune responses. LPS induces the activation of NF-kappaB and IRF3 through MyD88- or TRIF-dependent pathways. Curcumin, a polyphenol found in the plant Curcuma longa, has been shown to suppress the activation of NF-kappaB induced by various pro-inflammatory stimuli by inhibiting IKKbeta kinase activity in MyD88-dependent pathway. Curcumin also inhibited LPS-induced IRF3 activation. These results imply that curcumin inhibits both MyD88- and TRIF-dependent pathways in LPS-induced TLR4 signaling. However, in TRIF-dependent pathway, curcumin did not inhibit IRF3 activation induced by overexpression of TRIF in 293T cells. These results suggest that TLR4 receptor complex is the molecular target of curcumin in addition to IKKbeta. Here, we report biochemical evidence that phytochemicals (curcumin and sesquiterpene lactone) inhibit both ligand-induced and ligand-independent dimerization of TLR4. Furthermore, these results demonstrate that small molecules with non-microbial origin can directly inhibit TLRs-mediated signaling pathways at the receptor level. These results imply that the activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain dietary phytochemicals we consume daily.  相似文献   
144.
145.
Although neoantigens are one of the most favorable targets in cancer immunotherapy, it is less versatile and costly to apply neoantigen‐derived cancer vaccines to patients due to individual variation. It is, therefore, important to find highly immunogenic antigens between tumor‐specific or associated antigens that are shared among patients. Considering the cancer immunoediting theory, immunogenic tumor cells cannot survive in the early phase of tumor progression including two processes: elimination and equilibrium. We hypothesized that highly immunogenic molecules are allowed to be expressed in tumor cells after an immune suppressive tumor microenvironment was established, if these molecules contribute to tumor survival. In the current study, we focused on TWIST1 as a candidate for highly immunogenic antigens because it is upregulated in tumor cells under hypoxia and promotes tumor metastasis, which is observed in the late phase of tumor progression. We demonstrated that TWIST1 had an immunogenic peptide sequence TWIST1140–162, which effectively activated TWIST1‐specific CD4+ T‐cells. In a short‐term culture system, we detected more TWIST1‐specific responses in breast cancer patients compared with in healthy donors. Vaccination with the TWIST1 peptide also showed efficient expansion of TWIST1‐reactive HTLs in humanized mice. These findings indicate that TWIST1 is a highly immunogenic shared antigen and a favorable target for cancer immunotherapy.  相似文献   
146.
147.
148.
Genetic analyses of highly pathogenic avian influenza H5 subtype viruses isolated from the Izumi Plain, Japan, revealed cocirculation of 2 genetic groups of clade 2.3.4.4b viruses among migratory waterfowl. Our findings demonstrate that both continuous surveillance and timely information sharing of avian influenza viruses are valuable for rapid risk assessment.  相似文献   
149.
BackgroundSecondary pneumothorax with interstitial lung disease (ILD) is often difficult to treat in comparison to primary pneumothorax. The purpose of this study was to analyze the actual management and outcome, and to find the most effective treatment.MethodsAmong 180 patients with pneumothorax caused by ILD, who were managed between January 2000 and April 2021, 129 patients were included. Fifty-one patients with observation only were excluded. In the present study, a patient was considered to be cured if their chest tube could be removed.ResultsThe managements included chest tube drainage alone (n=41), pleurodesis (n=67), bronchoscopic treatment (n=14), and surgery (include overlapping cases) (n=25). The mean number of pleurodesis treatments was 2.4 (range, 1–9), and the most frequently used agent was blood-patch. All patients who received bronchoscopic treatment underwent bronchial occlusion with silicon spigots. The surgical procedures included bullectomy (n=20), lung cyst ligation (n=3), pleural covering with oxidized cellulose sheet (n=1), and spraying of fibrin glue alone (n=1). One hundred patients (77.5%) were curatively treated, 27 patients (20.9%) died, and 2 patients were transferred without chest tube removal. Among 25 patients who received surgery [including 6 patients with performance status (PS) ≥2], 24 patients (96.0%) were cured, and 1 patient died due to an acute exacerbation of ILD after surgery. The univariate analysis revealed that PS ≥2 and >3 pleurodesis treatments were significant non-curative factors, while steroid treatment before the development of pneumothorax was not.ConclusionsThe outcomes of surgery for pneumothorax in patients with ILD were good, and it is desirable to consider the surgical indications.  相似文献   
150.
Gestational diabetes mellitus (GDM) is one of the most common pregnancy‐related complications; it is associated with adverse pregnancy outcomes and metabolic disorders in offspring, consistent with the concept of the developmental origins of health and disease. This cohort study of women without diabetes (n = 761), who were part of the Yamanashi Adjunct Study of the Japan Environment and Children’s Study, aimed to explore the associations between maternal GDM and their offspring’s level of high‐sensitivity C‐reactive protein (hsCRP), a biomarker of inflammatory and cardiovascular diseases. We analyzed the associations between GDM and the offspring’s hsCRP levels using a multiple logistic regression model. A mother with GDM significantly increased the risk for high hsCRP level by 4.07‐fold (≥2.0 mg/L) in the child. As such, maternal GDM was significantly associated with increased serum hsCRP levels in 8‐year‐old children.  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