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   2809篇
  免费   182篇
  国内免费   16篇
耳鼻咽喉   33篇
儿科学   79篇
妇产科学   43篇
基础医学   379篇
口腔科学   103篇
临床医学   235篇
内科学   683篇
皮肤病学   109篇
神经病学   202篇
特种医学   131篇
外国民族医学   1篇
外科学   251篇
综合类   13篇
预防医学   123篇
眼科学   100篇
药学   222篇
中国医学   16篇
肿瘤学   284篇
  2024年   6篇
  2023年   46篇
  2022年   82篇
  2021年   147篇
  2020年   76篇
  2019年   109篇
  2018年   137篇
  2017年   109篇
  2016年   102篇
  2015年   99篇
  2014年   121篇
  2013年   142篇
  2012年   233篇
  2011年   266篇
  2010年   128篇
  2009年   98篇
  2008年   188篇
  2007年   157篇
  2006年   161篇
  2005年   139篇
  2004年   129篇
  2003年   116篇
  2002年   99篇
  2001年   15篇
  2000年   8篇
  1999年   14篇
  1998年   24篇
  1997年   10篇
  1996年   13篇
  1995年   11篇
  1994年   3篇
  1993年   5篇
  1992年   3篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1987年   4篇
  1985年   4篇
排序方式: 共有3007条查询结果,搜索用时 15 毫秒
991.
992.
993.
PURPOSE: The authors studied the utility of Ga-67 citrate scintigraphy in patients with breast lymphoma. METHODS: Seven patients with histologically proved breast lymphoma were examined. In three patients, both breasts were involved, and all patients had rapidly growing breast masses. Planar and SPECT images were obtained 72 hours after injection of Ga-67. RESULTS: Ga-67 scintigraphy showed intense accumulation in all lymphomas. SPECT images provided better contrast than did planar images. In one of the seven patients, the axilla and mediastinum were also involved. In six of the seven patients, Ga-67 scintigraphy was also performed after treatment and showed the disappearance of Ga-67 accumulation. In one patient with local recurrence and lung involvement, abnormal accumulation was depicted on follow-up Ga-67 scintigraphy. CONCLUSIONS: Ga-67 scintigraphy was helpful to confirm the diagnosis and the systemic extent of lymphoma and to evaluate the therapeutic effect during follow-up in patients with breast lymphoma.  相似文献   
994.
We have developed a rotational speed (RS) modulation system for a continuous‐flow left ventricular assist device (EVAHEART) that can change RS in synchronization with a patient's electrocardiogram. Although EVAHEART is considered not to cause significant acquired von Willebrand syndrome, there remains a concern that the repeated acceleration and deceleration of the impeller may degrade von Willebrand factor (vWF) multimers. Accordingly, we evaluated the influence of our RS modulation system on vWF dynamics. A simple mock circulation was used. The circulation was filled with whole bovine blood (650 mL), and the temperature was maintained at 37 ± 1°C. EVAHEART was operated using the electrocardiogram‐synchronized RS modulation system with an RS variance of 500 rpm and a pulse frequency of 60 bpm (EVA‐RSM; n = 4). The pumps were operated at a mean flow rate of 5.0 ± 0.2 L/min against a mean pressure head of 100 ± 3 mm Hg. The continuous‐flow mode of EVAHEART (EVA‐C; n = 4) and ROTAFLOW (ROTA; n = 4) was used as controls. Whole blood samples were collected at baseline and every 60 min for 6 h. Complete blood counts (CBCs), normalized indexes of hemolysis (NIH), vWF antigen (vWF:Ag), vWF ristocetin cofactor (vWF:Rco), the ratio of vWF:Rco to vWF:Ag (Rco/Ag), and high molecular weight multimers (HMWM) of vWF were evaluated. There were no significant changes in CBCs throughout the 6‐h test period in any group. NIH levels of EVA‐RSM, EVA‐C, and ROTA were 0.0035 ± 0.0018, 0.0031 ± 0.0007, and 0.0022 ± 0.0011 g/100 L, respectively. Levels of vWF:Ag, vWF:Rco, and Rco/Ag did not change significantly during the test. Immunoblotting analysis of vWF multimers showed slight degradation of HMWM in all groups, but there were no significant differences between groups in the ratios of HMWM to low molecular weight multimers, calculated by densitometry. This study suggests that our RS modulation system used with EVAHEART does not have marked adverse influences on vWF dynamics. The low NIH and the absence of significant decreases in CBCs indicate that EVAHEART is hemocompatible, regardless of whether it is operated with the RS modulation system.  相似文献   
995.
Congenital nephrotic syndrome of the Finnish type (CNF) is a rare autosomal recessive disorder. The incidence of CNF is relatively high in Finland but considerably lower in other countries. We encountered a male newborn with CNF, associated with compound heterozygous mutations in nephrosis 1, congenital, Finnish type (NPHS1). The patient was admitted to hospital as a preterm infant. Physical and laboratory findings fulfilled the diagnostic criteria of nephrotic syndrome, and were compatible with a diagnosis of CNF, but there was no family history of the disease. On genetic analysis of NPHS1 a paternally derived heterozygous frame‐shift mutation caused by an 8 bp deletion, resulting in a stop codon in exon 16 (c.2156‐2163 delTGCACTGC causing p.L719DfsX4), and a novel, maternally derived nonsense mutation in exon 15 (c.1978G>T causing p.E660X) were identified. Early genetic diagnosis of CNF is important for proper clinical management and appropriate genetic counseling.  相似文献   
996.
The Epistem Genedrive assay rapidly detects the Mycobacterium tuberculosis complex from sputum and is currently available for clinical use. However, the analytical and clinical performance of this test has not been fully evaluated. The analytical limit of detection (LOD) of the Genedrive PCR amplification was tested with genomic DNA; the performance of the complete (sample processing plus amplification) system was tested by spiking M. tuberculosis mc26030 cells into distilled water and M. tuberculosis-negative sputum. Specificity was tested using common respiratory pathogens and nontuberculosis mycobacteria. A clinical evaluation enrolled adults with suspected pulmonary tuberculosis, obtained three sputum samples from each participant, and compared the accuracy of the Genedrive to that of the Xpert MTB/RIF assay using M. tuberculosis cultures as the reference standard. The Genedrive assay had an LOD of 1 pg/μl (100 genomic DNA copies/reaction). The LODs of the system were 2.5 × 104 CFU/ml and 2.5 × 105 CFU/ml for cells spiked into water and sputum, respectively. False-positive rpoB probe signals were observed in 3/32 (9.4%) of the negative controls and also in few samples containing Mycobacterium abscessus, Mycobacterium gordonae, or Mycobacterium thermoresistibile. In the clinical study, among 336 analyzed participants, the overall sensitivities for the tuberculosis case detection of Genedrive, Xpert, and smear microscopy were 45.4% (95% confidence interval [CI], 35.2% to 55.8%), 91.8% (95% CI, 84.4% to 96.4%), and 77.3% (95% CI, 67.7% to 85.2%), respectively. The sensitivities of Genedrive and Xpert for the detection of smear-microscopy-negative tuberculosis were 0% (95% CI, 0% to 15.4%) and 68.2% (95% CI, 45.1% to 86.1%), respectively. The Genedrive assay did not meet performance standards recommended by the World Health Organization for a smear microscopy replacement tuberculosis test. Epistem is working on modifications to improve the assay.  相似文献   
997.
Inversion of chromosome 16 [inv(16)] has a good prognosis in acute myeloid leukemia (AML), but additional genetic aberrations influence the outcome. We herein describe the case of a 15‐year‐old Japanese boy with inv(16) harboring a low‐allelic burden internal tandem duplication of FLT3 (FLT3‐ITD) and KIT mutations. Conventional chemotherapy eradicated a clone with a low‐allelic burden FLT3‐ITD mutation, although another clone with a KIT mutation occurred 17 months later. Further investigation is necessary to identify AML with inv(16) conferring poor prognosis, to facilitate appropriate treatment with additional drugs, such as dasatinib or gemtuzumab ozogamicin.  相似文献   
998.
999.
1000.
We previously reported a phase II study of a cancer vaccine using five novel peptides recognized by HLA‐A*2402‐restricted CTL in combination with oxaliplatin‐containing chemotherapy (FXV study) as first‐line therapy for patients with metastatic colorectal cancer and demonstrated the safety and promising potential of our five‐peptide cocktail. The objective of this analysis was to identify predictive biomarkers for identifying patients who are likely to receive a clinical benefit from immunochemotherapy. Circulating cell‐free DNA (cfDNA) in plasma has been reported to be a candidate molecular biomarker for the efficacy of anticancer therapy. Unlike uniformly truncated small‐sized DNA released from apoptotic normal cells, DNA released from necrotic cancer cells varies in size. The integrity of plasma cfDNA (i.e. the ratio of longer fragments [400 bp] to shorter fragments [100 bp] of cfDNA), may be clinically useful for detecting colorectal cancer progression. We assessed plasma samples collected from 93 patients prior to receiving immunochemotherapy. The cfDNA levels and integrity were analyzed by semi‐quantitative real‐time PCR. Progression‐free survival was significantly better in patients with a low plasma cfDNA integrity value than in those with a high value (P = 0.0027). Surprisingly, in the HLA‐A*2402‐matched group, patients with a low plasma cfDNA integrity value had significantly better progression‐free survival than those with a high value (P = 0.0015). This difference was not observed in the HLA‐A*2402‐unmatched group. In conclusion, the integrity of plasma cfDNA may provide important clinical information and may be a useful predictive biomarker of the outcome of immunotherapy in metastatic colorectal cancer.  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