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   2946篇
  免费   145篇
  国内免费   13篇
耳鼻咽喉   90篇
儿科学   61篇
妇产科学   8篇
基础医学   353篇
口腔科学   156篇
临床医学   172篇
内科学   799篇
皮肤病学   42篇
神经病学   186篇
特种医学   131篇
外科学   524篇
综合类   13篇
预防医学   99篇
眼科学   39篇
药学   157篇
中国医学   5篇
肿瘤学   269篇
  2022年   32篇
  2021年   41篇
  2020年   32篇
  2019年   39篇
  2018年   52篇
  2017年   50篇
  2016年   44篇
  2015年   61篇
  2014年   79篇
  2013年   84篇
  2012年   120篇
  2011年   145篇
  2010年   72篇
  2009年   75篇
  2008年   117篇
  2007年   137篇
  2006年   130篇
  2005年   123篇
  2004年   139篇
  2003年   144篇
  2002年   147篇
  2001年   68篇
  2000年   69篇
  1999年   69篇
  1998年   42篇
  1997年   46篇
  1996年   46篇
  1995年   34篇
  1994年   25篇
  1993年   31篇
  1992年   52篇
  1991年   60篇
  1990年   73篇
  1989年   80篇
  1988年   66篇
  1987年   55篇
  1986年   64篇
  1985年   46篇
  1984年   44篇
  1983年   26篇
  1982年   22篇
  1981年   13篇
  1980年   10篇
  1979年   42篇
  1978年   13篇
  1977年   19篇
  1976年   14篇
  1975年   16篇
  1972年   12篇
  1968年   11篇
排序方式: 共有3104条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Selected media were compared for primary isolation and detection of oral treponemes from clinical samples. Forty-eight subgingival plaque samples from 45 patients suffering from periodontitis were anaerobically cultivated for 2 weeks at 37°C. Of the 9 media studied, Medium 10 (M10), which was supplemented with 10% rabbit serum and incubated using the plate-in-bottle method, supported the highest colony-forming units of the anaerobes. The treponemal colonies were detected at least on one medium from 83% of the subgingival plaque samples. The new oral spirochete medium in an anaerobic chamber supported the highest detection frequency of the oral treponemes (64% of samples); however, M10 in the plate-in-bottle was found to produce the highest colony-forming unit recovery of the oral treponemes (median 3.6% of the total colony-forming units). This study suggests that M10 in the plate-in-bottle and new oral spirochete medium in the anaerobic chamber are essential in cultivating oral treponemes.  相似文献   
15.
A 59-year-old male was admitted to our clinic for further examination of the calcified renal cyst discovered incidentally on medical workup elsewhere. CT showed a left renal cyst associated with calcification. Ultrasound-guided puncture of the renal cyst was not successful because of thickness of the cystic wall. Renal angiography showed hypervascularity of the cystic wall. Association of renal cell carcinoma could not be ruled out, therefore the exploration was performed. Histological examination revealed benign renal cyst with calcification. A 27-year-old male presented with the chief complaint of left flank pain. Following examinations by US, CT and MRI, a renal cyst associated with renal cell carcinoma was highly suspected. Subsequent exploration revealed cluster of cysts with a yellowish lesion a few mm in diameter. Frozen section revealed no malignancy, and cystic fluid was not hemorrhagic. Therefore as many cystic walls as possible were removed without nephrectomy. Histological examination of the permanent specimen revealed renal cell carcinoma. Renal cyst associated with renal cell carcinoma was regarded as rare clinical entity, but such cases are reported in increasing number in recent years. We report such cases and review the pertinent literature in this paper.  相似文献   
16.
The present case report describes a case of ganglioglioma with a distinct sarcomatous component in the left temporal lobe of a 59‐year‐old Japanese man. Neoplastic neuroglial tissue contained both benign and anaplastic glial components with a MIB‐1 labeling index of 0.1% and 12.0%, respectively. Sarcomatous tissue adjacent to the anaplastic glial tissue was dominated by pleomorphic fibroblastic cells with a MIB‐1 labeling index of 10.8%. They were immunoreactive for smooth muscle actin, type IV collagen, and alpha 1 antitrypsin, but not for desmin and CD34. Interestingly, some of the sarcomatous cells were double‐positive for smooth muscle actin and GFAP. The p53 protein had accumulated in the anaplastic astrocytes and sarcomatous cells, but direct DNA sequencing of PCR products failed to detect any mutation in the p53 gene (from exon 4 to exon 10).  相似文献   
17.
Twelve patients with ureteral tumours with or without ipsilateral renal pelvic neoplasms were retrospectively analysed. Haematuria was the most common symptom. Location of all tumours was preoperatively detected by conventional diagnostic methods, such as intravenous or retrograde pyelography, washing cytology of the upper urinary tract, computed tomography, echogram and abdominal aortography. Cumulative proportion survivals of 1, 3 and 5 years were 81.9%, 68.2% and 45.5%, respectively. Patients with high Karnovsky rating survived longer (p<0.05) than those with low rating. Patients with low-stage tumours (T1, T2) showed longer survival rate (p<0.001) than those with high-stage tumours (T3, T4). Vascular invasion of tumour cells was present in removed specimens in 4 out of 7 patients who died or are alive with cancer, but none in those who survived without disease. Good therapeutic response could not be achieved unless surgery was performed.  相似文献   
18.
Monoclonal antibodies directed against human, alpha-atrial natriuretic polypeptide (alpha-ANP; Human, 1-28) were obtained by somatic cell fusion between P3-X63-Ag8.653 myeloma cells and spleen cells from a BALB/c mouse immunized with human, alpha-ANP selectively coupled to keyhole limpet hemocyanin. From the analysis of polyclonal sera with respect to determinant specificity before the fusion, the strategy was primarily used to pick up monoclonal antibody specific for the N-terminal residues of human, alpha-ANP. Screening of antibodies in the hybridoma culture supernatants were performed by binding to iodinated synthetic human, alpha-ANP. Two stable clones producing anti-human, alpha-ANP antibodies, designated 13A1 and 10B1, were obtained by the limiting dilution technique. The ability of ANP(Rat, 1-28) to inhibit binding of 125I-human, alpha-ANP to these antibodies was almost equipotent to ANP(human, 1-28). However, ANP fragments (Human, 7-28) and (18-28) did not compete the binding completely. These results suggest that both 13A1 and 10B1 monoclonal antibodies can specifically recognized N-terminus of human, alpha-ANP, and may be a useful tool to investigate receptor binding of human, alpha-ANP by the antagonizing effect.  相似文献   
19.
We described a case of adult respiratory distress syndrome (ARDS) likely due to measles and Mycoplasma pneumoniae. A 24-year-old, previously healthy man was referred to our hospital because of respiratory arrest. He was unconscious and cyanotic. He had erythematous and polymorphic eruptions of his extremities and trunk, but his face was spared. His chest roentgenogram showed consolidation with air bronchograms affecting the whole bilateral lungs. After mechanical ventilation with positive end-expiratory pressure and administration of intravenous hydrocortisone and protease inhibitor "urinastatin" and so on, the patient recovered from his critical condition. No attributable organisms were isolated from the specimens investigated in his acute phase. Serological examinations of the specific IgM antibody to measles during the course indicated a recent measles infection. Mycoplasma pneumoniae indirect hemagglutination test rose from a titre of less than 1/40 to 1/60. ARDS is a rare complication of measles or Mycoplasma pneumoniae infection. Moreover he received measles vaccine before 1970 in Japan, so this case was suspected to be atypical measles.  相似文献   
20.
Summary A human glioma cell line (YKG1), which was positively identified for glial fibrillary acidic (GFA) and S-100 proteins, was established from a surgical specimen of a patient with glioblastoma. Chromosome analysis of the cells revealed a homogeneously staining region (HSR) on a marker chromosome. The assay for transforming growth factors (TGFs) in the conditioned medium of the cell line revealed that it contained high levels of - and -type TGFs, which might regulate the growth of glioblastoma and influence on the peritumoral tissues.  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