全文获取类型
收费全文 | 651篇 |
免费 | 39篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 20篇 |
妇产科学 | 13篇 |
基础医学 | 47篇 |
口腔科学 | 21篇 |
临床医学 | 112篇 |
内科学 | 147篇 |
皮肤病学 | 37篇 |
神经病学 | 13篇 |
特种医学 | 87篇 |
外国民族医学 | 1篇 |
外科学 | 50篇 |
综合类 | 40篇 |
一般理论 | 5篇 |
预防医学 | 26篇 |
眼科学 | 2篇 |
药学 | 42篇 |
中国医学 | 1篇 |
肿瘤学 | 25篇 |
出版年
2022年 | 16篇 |
2021年 | 14篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 15篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 15篇 |
2014年 | 19篇 |
2013年 | 20篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 32篇 |
2009年 | 29篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 18篇 |
2003年 | 9篇 |
2002年 | 6篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 21篇 |
1997年 | 13篇 |
1996年 | 24篇 |
1995年 | 19篇 |
1994年 | 25篇 |
1993年 | 28篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 18篇 |
1988年 | 15篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1957年 | 9篇 |
1955年 | 6篇 |
1954年 | 6篇 |
1949年 | 8篇 |
1948年 | 8篇 |
排序方式: 共有691条查询结果,搜索用时 15 毫秒
581.
Heterogeneity of T-cell lymphoblastic malignancies 总被引:1,自引:0,他引:1
To determine the T-cell lineage of the malignant lymphoblast in lymphoblastic lymphoma, tumor cells from nine patients were phenotyped employing a T-cell subset specific heteroantisera, TH2. The normal human peripheral blood T-cell compartment is composed of 80% TH2- negative and 20% TH2-positive T cells, as defined by reactivity with subset specific heteroantisera. Human suppressor cells are TH2 reactive, whereas helper cells are TH2 unreactive. Tumor cells from the majority of patients with lymphoblastic lymphoma were TH2 reactive in contrast to the lack of reactivity previously described in the majority of patients with T-cell acute lymphoblastic leukemia. Comparative clinical studies, including disease presentation and course, were correlated with the presence of the TH2 antigen on the tumor cell. These results provide evidence to support the notion of heterogeneity in the T-lymphoblastic malignancies and suggest that lymphoblastic lymphoma and T-cell acute lymphoblastic leukemia are probably not a single disease process. 相似文献
582.
The mechanism by which influenza virus interferes with polymorphonuclear leukocyte (PMN) chemotaxis was investigated. Incubation of human PMN with influenza A virus in vitro for 30 minutes significantly decreased PMN migration under agarose in response to N- formyl-methionyl-leucyl-phenylalanine (FMLP) or zymosan-activated serum. Virus-treated PMN tended to aggregate in the under-agarose assay. Aggregation was avoided by using a more dilute PMN suspension in filter assays. Virus treatment significantly decreased migration through 100-micron thick cellulose nitrate filters but had no effect on migration through 10-micron thick polycarbonate filters or on PMN bipolar shape change. Virus was not chemotactic in the polycarbonate filter assay and did not induce shape change in purified PMN. It was concluded that influenza virus did not interfere with the ability of PMN to recognize a chemoattractant, undergo shape change, and move a short distance but did limit the extent of migration. Inhibition could not be explained by chemotactic deactivation, since the virus was not chemotactic. 相似文献
583.
584.
Boniface S Donati Y Romanet-Manent S Lorec AM Dupuy P Mamessier E Badier M EL Biaze M Koscher V Vervloet D Magnan A 《Revue des maladies respiratoires》2002,19(6):747-759
Asthma is an inflammatory condition. Traditionally bronchoalveolar lavage and bronchial biopsies obtained by bronchoscopy have been used to demonstrate inflammation. Induced-sputum is a non-invasive, reliable, reproducible and safer technique for monitoring inflammatory activity in patients with asthma. Studies have shown that induced-sputum measures aspects of inflammation distinct to that measured by bronchoalveolar lavage or bronchial biopsies. Numerous studies have suggested that induced-sputum is a potentially useful tool for early diagnosis of exacerbation, monitoring of therapy, identification of the lowest effective dose and assessing compliance in asthmatics. In this respect, we suggest that this test can be routinely used in the management of difficult asthmatics. 相似文献
585.
Yasser EMAD Tarek EL‐GOHARY Hisham MUSTAFA Iman H. BASSYOUNI Noha A. AZAB 《International journal of rheumatic diseases》2007,10(1):43-48
Objective: This study was designed to search for a possible pathological involvement of renal arteries among patients with systemic sclerosis (SSc) and to correlate the findings with renal functions. Patients and methods: Fourteen female patients with SSc were recruited for this study. The diagnosis and classification of SSc was based on the 1980 American College of Rheumatology criteria for classification of SSc. Nine patients had diffuse‐type SSc, and the remaining five belonged to the limited type of the disease. All patients were evaluated by history‐taking, clinical examination, laboratory investigations and renal angiography. Results: Three out of the nine patients (33.3%) with diffuse SSc had tortuous renal arteries, but there were none in the limited type. Two patients (22.2%) with diffuse SSc had ectatic renal arteries and three (33.3%) had osteal renal artery stenosis. Tortuous abdominal aorta was detected in one patient (11.1%) with diffuse SSc and congenital double renal artery in another (11.1%). Two out of the five patients with limited‐type disease (40%) had osteal renal artery stenosis that was bilateral in one case. Bilateral renal artery affection was observed in 3/14 studied patients (21.42%), and two of these had diffuse disease and one had limited disease. Three patients had hypertension (two had diffuse pattern and one had limited pattern). Conclusion: We consider that renal artery stenosis is the most important among all the findings detected and should be considered in SSc patients presenting with renal crisis because use of angiotensin converting enzyme (ACE) inhibitors in this situation may be deleterious rather than beneficial. 相似文献
586.
Guido EL van den Berk L Arnold Noorduyn Ruud J van Ketel Jeannouel van Leeuwen Willem A Bemelman Jan M Prins 《BMC infectious diseases》2006,6(1):140-4
Background
Basidiobolomycosis is a rare disease caused by the fungus Basidiobolus ranarum, member of the class Zygomycetes, order Entomophthorales, found worldwide. Usually basidiobolomycosis is a subcutaneous infection but rarely gastrointestinal manifestations have been described; 13 adults and 10 children and a few retroperitoneal or pulmonary cases. In gastrointestinal basidiobolomycosis the colon is most frequently involved, usually presenting with subacute mild abdominal pain. In contrast to children only very few described adult patients had hepatic masses. Definitive diagnosis requires culture, serological testing can be helpful. The fungal morphology and the Splendore-Hoeppli phenomenon are characteristic histological features. There are no prominent risk factors. Usually surgery and prolonged antifungal therapy are required. 相似文献587.
588.
589.
Stem cell factor and basic fibroblast growth factor are synergistic in augmenting committed myeloid progenitor cell growth 总被引:3,自引:1,他引:3
Stem cell factor (SCF) and basic fibroblast growth factor (bFGF) are hematopoietic cytokines produced by bone marrow stromal cells. It is known that, although SCF and bFGF have limited clonogenic activity on their own, they can augment colony-stimulating factor (CSF)-mediated progenitor cell growth. Because these factors are both sequestered by stromal cells, we examined their interaction on progenitor cell growth in conjunction with granulocyte-macrophage-CSF (GM-CSF). In this study, we show that clonogenic growth derived from low-density bone marrow cells stimulated by GM-CSF is significantly augmented (P < .001) in the presence of maximal (100 ng/mL) concentrations of SCF in combination with 100 ng/mL of bFGF. When CD34+ cells are used, the synergistic effect of bFGF and SCF for GM-CSF-mediated progenitor cell growth is further increased, resulting in as much as a sevenfold increase in detectable colony-forming units granulocyte-macrophage (P < .001). These data suggest that the synergistic activity of bFGF and SCF is mediated directly on hematopoietic precursors. These observations suggest that bFGF and SCF, concentrated locally on stromal cell surfaces, might interact in concert with other hematopoietic cytokines to regulate stem cell proliferation and differentiation in hematopoietic niches in the bone marrow. 相似文献
590.
I. Lalya M. Amrani B. EL Khannoussi L. Kanouni E. M. Tazi T. Kebdani K. Hassouni T. Harroudi A. Jalil N. Benjaafar B. K. Elgueddari 《Journal africain du cancer / African Journal of Cancer》2013,5(1):57-60
Periductal stromal sarcoma is an extremely rare malignant fibroepithelial breast tumor, long confused with phyllodes tumors. This confusion is justified by its biphasic histology comprising two components: ductal or epithelial benign, surrounded by a sarcomatous periductal stroma made of spindle cells. Currently, it is a distinct pathological entity. Wide surgery with free margins is enough and is the only treatment currently validated, the value of adjuvant therapy based on radiation and/or chemotherapy remains to be demonstrated. The prognosis is marked by local recurrence sometimes as phyllodes tumors or specific soft tissue sarcoma more aggressive, which requires close monitoring based on clinical examination. 相似文献