全文获取类型
收费全文 | 3958篇 |
免费 | 232篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 70篇 |
妇产科学 | 42篇 |
基础医学 | 605篇 |
口腔科学 | 82篇 |
临床医学 | 227篇 |
内科学 | 946篇 |
皮肤病学 | 90篇 |
神经病学 | 270篇 |
特种医学 | 176篇 |
外科学 | 494篇 |
综合类 | 18篇 |
预防医学 | 108篇 |
眼科学 | 134篇 |
药学 | 305篇 |
中国医学 | 10篇 |
肿瘤学 | 587篇 |
出版年
2023年 | 39篇 |
2022年 | 86篇 |
2021年 | 125篇 |
2020年 | 66篇 |
2019年 | 86篇 |
2018年 | 104篇 |
2017年 | 83篇 |
2016年 | 96篇 |
2015年 | 77篇 |
2014年 | 118篇 |
2013年 | 147篇 |
2012年 | 222篇 |
2011年 | 250篇 |
2010年 | 150篇 |
2009年 | 88篇 |
2008年 | 195篇 |
2007年 | 169篇 |
2006年 | 211篇 |
2005年 | 187篇 |
2004年 | 202篇 |
2003年 | 184篇 |
2002年 | 188篇 |
2001年 | 108篇 |
2000年 | 122篇 |
1999年 | 86篇 |
1998年 | 48篇 |
1997年 | 40篇 |
1996年 | 34篇 |
1995年 | 25篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 64篇 |
1991年 | 62篇 |
1990年 | 67篇 |
1989年 | 74篇 |
1988年 | 41篇 |
1987年 | 36篇 |
1986年 | 47篇 |
1985年 | 36篇 |
1984年 | 32篇 |
1983年 | 28篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 20篇 |
1978年 | 7篇 |
1974年 | 7篇 |
1973年 | 9篇 |
1972年 | 8篇 |
1971年 | 8篇 |
1967年 | 10篇 |
排序方式: 共有4211条查询结果,搜索用时 15 毫秒
61.
Epithelial cell density in cataractous lenses of patients with diabetes: association with erythrocyte aldose reductase 总被引:1,自引:0,他引:1
In the present study we evaluated the cell density of lens epithelium and its relation to the degree of erythrocyte aldose reductase (AR) in patients with type 2 diabetes. This prospective clinical study included 46 eyes of patients with type 2 diabetes and 48 eyes of patients without diabetes mellitus (DM). Flat preparations of lens epithelial cells (LECs) attached to the anterior capsule were studied. Multiple regression analysis was performed to evaluate the association between lens cell density and age, gender, type of cataract, duration of diabetes, diabetic retinopathy (DR), the levels of glycosylated hemoglobin (HbA1c) and erythrocyte AR. The mean density of LECs of patients with type 2 diabetes was 4,141+/-508cells/mm(2), which was significantly lower than that of patients without DM (4,560+/-458cells/mm(2); p<0.0001). Multiple regression analysis revealed that the level of erythrocyte AR was correlated with the reduction of LECs in the eyes of patients with type 2 diabetes. The correlation between the density of LECs and the amount of erythrocyte AR was significant in the diabetic group with a high value of HbA1c (>6.5%) or with DR. These results suggest that the polyol pathway via AR may be associated with the reduction of epithelial cell density in the eyes of patients with DM. 相似文献
62.
63.
64.
65.
Yuki Otani Hidefumi Mukai Yuki Fuchigami Fumiyoshi Yamashita Mitsuru Hashida 《Journal of drug targeting》2015,23(5):427-435
Background: Achieving long-term gene expression in kidney will be beneficial for gene therapy of renal and congenital diseases, genetic studies constructing animal disease models, and the functional analysis of disease-related genes.Purpose: The purpose of this study was to develop an in vivo long-term gene expression system in murine kidney using ?C31 integrase.Methods: Gene expression in cultured RENCA, TCMK-1, and HEK293 cells was assessed. The long-term in vivo gene expression system in the kidney was achieved by co-transfecting 5?µg of pORF-luc/attB as a donor plasmid and 20?µg of pCMV-luc as a helper plasmid into the right kidney of mice by electroporation. Luciferase expression levels were measured to determine longevity of the expression.Results: Significantly high luciferase expression levels were observed in cultured RENCA, TCMK-1, and HEK293 cells over 1 month compared with controls (non-integrase system). The luciferase cDNA sequence was integrated at a pseudo attP site termed mpsL1. In vivo luciferase expression levels in the integrase group were sustained and significantly higher than those in the control group over 2 months. Furthermore, ?C31 integrase-transfected cells had less genomic DNA damage caused by integrase expression.Discussion and conclusion: These results demonstrated that the ?C31 integrase system could produce long-term (2 months) in vivo gene expression in mouse kidney. 相似文献
66.
Masami Kosuge Kazuo Kimura Toshiyuki Ishikawa Tomoaki Shimizu Takeshi Takamura Kengo Tsukahara Yoshio Tahara Naoki Nozawa Eri Furukawa Osamu Tochikubo Mitsugi Sugiyama Satoshi Umemura 《Circulation journal》2004,68(6):526-531
BACKGROUND: The clinical significance of the white blood cell (WBC) count on admission in relation to the duration of ischemia in acute myocardial infarction (AMI) remains unclear. METHODS AND RESULTS: The relationship of the WBC count on admission to myocardial reperfusion was examined in 135 patients with recanalization of an anterior AMI within 6 h of symptom onset. Patients were classified according to the WBC count on admission: Group L (n=75), WBC count <12,000 cells/mm(3) and group H (n=60), WBC count >or=12,000 cells/mm(3). Peak creatine kinase (CK) was higher and impaired myocardial reperfusion, defined as a myocardial blush grade of 0/1, was more frequent in group H than in group L. Among the patients in group H, those with early (3 h) recanalization; however, peak CK and the incidence of impaired myocardial reperfusion were similar in these subgroups of patients. Multivariate analysis showed that WBC count >or=12,000 cells/mm(3) on admission was an independent predictor of impaired myocardial reperfusion in patients with early recanalization (odds ratio 7.9, p=0.04), but not in those with late recanalization. CONCLUSIONS: A higher WBC count may be associated with progression of myocardial damage after recanalization in patients with early recanalization of an anterior AMI. 相似文献
67.
Highly variable sequences in the env V3 region of HIV type 1 distributing among Thai carriers from 1995 to 1997 总被引:2,自引:0,他引:2
Auwanit W Ayuthaya PI Duangchanda S Mukai T Kurata T Ikuta K 《AIDS research and human retroviruses》2000,16(3):283-289
The amino acid sequences of the Env V3 region of HIV-1 subtype E in Thailand were highly variable in the samples obtained from 1995 to 1997, compared with the previously reported sequences in samples obtained from 1990 to 1993. The sequences of the V3 region in the samples from five provinces in Thailand revealed that the variability was much higher in the samples from Bangkok and Ubonrachathani than in those from Chiangmai, Prathumthani, and Trang. There was no apparently different level of diversity at the V3 region in the samples from symptomatic and asymptomatic individuals. The V3 loop motif in most (66.7%) of the samples was GPGQ, although this motif was more heterogeneous in the samples from Bangkok and Ubonrachathani than in those from the other three provinces. The N-linked glycosylation sites in the V3 region among these samples were relatively conserved. There was no apparent difference in the presence of positively charged amino acids at positions 306 and 320 between the samples from symptomatic and asymptomatic individuals. 相似文献
68.
Shigemoto Yoko Matsuda Hiroshi Kimura Yukio Chiba Emiko Ohnishi Masahiro Nakaya Moto Maikusa Norihide Ogawa Masayo Mukai Yohei Takahashi Yuji Sako Kazuya Toyama Hiroshi Inui Yoshitaka Taki Yasuyuki Nagayama Hiroshi Ono Kenjiro Kono Atsushi Sekiguchi Kenji Hirano Shigeki Sato Noriko 《Annals of nuclear medicine》2022,36(5):460-467
Annals of Nuclear Medicine - Although previous studies have investigated age and gender effects on striatal subregional dopamine transporter (DaT) binding, these studies were mostly based on a... 相似文献
69.
Kojima H Takei N Mukai Y Hasegawa Y Suzukawa K Nagata M Noguchi M Mori N Nagasawa T 《Annals of hematology》2003,82(1):53-56
It is now well recognized that hemophagocytic syndrome (HPS) is occasionally associated with malignant lymphomas. However, its association with Hodgkin's disease has been only rarely reported. We present here a 72-year-old woman manifesting with HPS as the primary and solitary clinical symptom of Hodgkin's disease. She had been suffering from high-grade fever and anemia for more than a month. Based on the findings in bone marrow aspirates, she was diagnosed as having HPS. In spite of extensive surveys including various cultures, serological tests for collagen disease, abdominal and cardiac sonography, chest computed tomography (CT), and renal biopsy, the origin of the fever was not determined. She was treated with steroid pulse therapy and then referred. Radiological studies revealed only mild hepatosplenomegaly and small lymph node swellings around celiac and common hepatic arteries. Reevaluation of the bone marrow specimen revealed the infiltration of small numbers of CD30-, CD15-, and EBER-1-positive large-sized lymphocytes with bizarre nucleus. Under the diagnosis of Hodgkin's disease, she was treated with combination chemotherapy containing pirarubicin, cyclophosphamide, vincristine, and prednisolone. However, it was not effective and she died of rapidly progressive hepatic failure on the 5th day of the chemotherapy. Autopsy was performed, which showed proliferation of lymphoma cells in para-aortic lymph nodes. We believe that diagnostic survey to rule out the underlying lymphoma should be vigorously performed for patients with hemophagocytic syndrome of unknown origin. 相似文献
70.