全文获取类型
收费全文 | 56150篇 |
免费 | 3104篇 |
国内免费 | 598篇 |
专业分类
耳鼻咽喉 | 985篇 |
儿科学 | 630篇 |
妇产科学 | 825篇 |
基础医学 | 9754篇 |
口腔科学 | 1352篇 |
临床医学 | 4885篇 |
内科学 | 10548篇 |
皮肤病学 | 1870篇 |
神经病学 | 3981篇 |
特种医学 | 2968篇 |
外科学 | 7471篇 |
综合类 | 213篇 |
现状与发展 | 1篇 |
一般理论 | 17篇 |
预防医学 | 2711篇 |
眼科学 | 1230篇 |
药学 | 4983篇 |
中国医学 | 624篇 |
肿瘤学 | 4804篇 |
出版年
2023年 | 428篇 |
2022年 | 1326篇 |
2021年 | 2056篇 |
2020年 | 985篇 |
2019年 | 1288篇 |
2018年 | 1665篇 |
2017年 | 1240篇 |
2016年 | 1757篇 |
2015年 | 2559篇 |
2014年 | 3058篇 |
2013年 | 3487篇 |
2012年 | 5312篇 |
2011年 | 4807篇 |
2010年 | 2802篇 |
2009年 | 2360篇 |
2008年 | 3416篇 |
2007年 | 3094篇 |
2006年 | 2653篇 |
2005年 | 2352篇 |
2004年 | 2024篇 |
2003年 | 1692篇 |
2002年 | 1435篇 |
2001年 | 1364篇 |
2000年 | 1262篇 |
1999年 | 906篇 |
1998年 | 362篇 |
1997年 | 250篇 |
1996年 | 208篇 |
1995年 | 176篇 |
1994年 | 148篇 |
1993年 | 132篇 |
1992年 | 332篇 |
1991年 | 316篇 |
1990年 | 280篇 |
1989年 | 258篇 |
1988年 | 247篇 |
1987年 | 248篇 |
1986年 | 177篇 |
1985年 | 165篇 |
1984年 | 119篇 |
1983年 | 111篇 |
1982年 | 55篇 |
1981年 | 58篇 |
1979年 | 81篇 |
1978年 | 68篇 |
1975年 | 50篇 |
1974年 | 60篇 |
1973年 | 51篇 |
1972年 | 50篇 |
1970年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
Telomere length changes in patients with aplastic anaemia 总被引:5,自引:0,他引:5
Lee JJ Kook H Chung IJ Na JA Park MR Hwang TJ Kwak JY Sohn SK Kim HJ 《British journal of haematology》2001,112(4):1025-1030
To investigate telomere changes in patients with aplastic anaemia (AA) and clinical factors influencing the telomere dynamics, telomere length (TL) was measured in peripheral blood mononuclear cells using Southern blot analysis of 42 patients with AA and 39 healthy normal controls. Nineteen patients received supportive treatment only, while the remaining 23 patients received immunosuppressive therapy with anti-thymocyte globulin or anti-lymphocyte globulin +/- cyclosporin A. In AA patients, TL was on average 1.41 kb shorter than that of age-matched normal controls (P < 0.001). In patients treated with immunosuppression, the mean TL of non-responders was significantly shorter than that of age-matched normal controls (P < 0.001), while no difference in TL was detected in responders compared with controls. Positive correlation was observed between the extent of telomere shortening, the severity of neutropenia (P = 0.05) and the degree of mean corpuscular volume elevation (P = 0.005) at the time of the study. However, there was no correlation with time elapsed since diagnosis (P = 0.214). These findings suggest that haematopoietic stem cells in patients with AA rapidly lose TL at the onset of the disease. The TL shortening may reflect the severity of impairment of haematopoiesis. 相似文献
994.
995.
Kyung Soon Song Noh Jin Park Jong Rak Choi Hyun Joo Doh Kwang Hoe Chung 《Clinical and applied thrombosis/hemostasis》2006,12(3):338-343
Dysfibrinogenemia is a coagulation disorder caused by a variety of structural abnormalities in the fibrinogen molecule that result in fibrinogen function. The molecular basis of hypodysfibrinogenemia was investigated in a 66-year-old woman with peripheral artery obstructive disease and in her family members. Plasma level of functional fibrinogen determined using the Clauss method was lower (75 mg/dL; normal, 140-460 mg/dL) than that measured with immunologic nephelometric assay (137 mg/dL; normal, 180-400 mg/dL). Similar results were also observed in two family members through two generations. DNA was extracted from whole blood, and the coding regions and intron/exon boundaries of gamma chain gene (FGG) were amplified. A novel (Fibrinogen Seoul) heterozygous FGG mutation (GCT->GAT, Ala341Asp) was identified in all three affected family members. Thrombin-catalyzed polymerization was found to be defective on the analysis of purified fibinogen from the propositus. Molecular modeling also showed a conformational change of fibrinogen structure. 相似文献
996.
Dong Hyun Kim Jae Hee Cho Su Hyun Lee Hyun Ki Kim Seung Min Bang Si Young Song Jae Bock Chung Seung Woo Park 《Taehan Sohwagi Hakhoe chi》2008,51(2):142-146
Compared with other types of cancers, pancreatic cancer is one of the most dreadful malignancies and is fifth leading cause of cancer-related death in Korea. It is difficult to expect early diagnosis or improvement in prognosis due to lack of specific early symptoms and effective diagnostic methods. Whereas cystic neoplasm of the pancreas is a rare type of pancreatic tumor, surgical resection provides good prognosis because of its low possibility of local invasion or distant metastasis. In case of pancreatic cystic tumor, radiologic differentiation between benign and malignant lesions is crucial for the selection of appropriate treatment and the prediction of prognosis. And ductal adenocarcinoma of pancreas presenting in cystic form is an uncommon type of cystic tumor, making it extremely rare among all pancreatic malignancies. We report two cases of atypical pancreatic ductal adenocarcinoma presenting as solid pseudopapillary tumor and intraductal papillary mucinous neoplasm, respectively. 相似文献
997.
Horseradish peroxidase‐catalysed in situ‐forming hydrogels for tissue‐engineering applications 下载免费PDF全文
Jin Woo Bae Jong Hoon Choi Yunki Lee Ki Dong Park 《Journal of tissue engineering and regenerative medicine》2015,9(11):1225-1232
In situ‐forming hydrogels are an attractive class of implantable biomaterials that are used for biomedical applications. These injectable hydrogels are versatile and provide a convenient platform for delivering cells and drugs via minimally invasive surgery. Although several crosslinking methods for preparing in situ forming hydrogels have been developed over the past two decades, most hydrogels are not sufficiently versatile for use in a wide variety of tissue‐engineering applications. In recent years, enzyme‐catalysed crosslinking approaches have been emerged as a new approach for developing in situ‐forming hydrogels. In particular, the horseradish peroxidase (HRP)‐catalysed crosslinking approach has received increasing interest, due to its highly improved and tunable capacity to obtain hydrogels with desirable properties. The HRP‐catalysed crosslinking reaction immediately occurs upon mixing phenol‐rich polymers with HRP and hydrogen peroxide (H2O2) in aqueous media. Based on this unique gel‐forming feature, recent studies have shown that various properties of formed hydrogels, such as gelation time, stiffness and degradation rate, can be easily manipulated by varying the concentrations of HRP and H2O2. In this review, we outline the versatile properties of HRP‐catalysed in situ‐forming hydrogels, with a brief introduction to the crosslinking mechanisms involved. In addition, the recent biomedical applications of HRP‐catalysed in situ‐forming hydrogels for tissue regeneration are described. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
998.
Jonghee Yoon Kyoohyun Kim HyunJoo Park Chulhee Choi Seongsoo Jang YongKeun Park 《Biomedical optics express》2015,6(10):3865-3875
The characterization of white blood cells (WBCs) is crucial for blood analyses and disease diagnoses. However, current standard techniques rely on cell labeling, a process which imposes significant limitations. Here we present three-dimensional (3D) optical measurements and the label-free characterization of mouse WBCs using optical diffraction tomography. 3D refractive index (RI) tomograms of individual WBCs are constructed from multiple two-dimensional quantitative phase images of samples illuminated at various angles of incidence. Measurements of the 3D RI tomogram of WBCs enable the separation of heterogeneous populations of WBCs using quantitative morphological and biochemical information. Time-lapse tomographic measurements also provide the 3D trajectory of micrometer-sized beads ingested by WBCs. These results demonstrate that optical diffraction tomography can be a useful and versatile tool for the study of WBCs.OCIS codes: (170.1530) Cell analysis, (180.3170) Interference microscopy, (180.6900) Three-dimensional microscopy 相似文献
999.
1000.
Shim CY Park S Choi EY Kang SM Cha BS Ha JW Rim SJ Lee HC Chung N 《Metabolism: clinical and experimental》2008,57(4):448-452
The aim of this study was to address whether albuminuria could predict myocardial dysfunction in diabetic patients without overt heart disease. We studied 67 patients with normal left ventricular (LV) ejection fraction and no evidence of LV hypertrophy or coronary artery disease (47 patients with type 2 diabetes mellitus and hypertension and 20 patients with hypertension only). Diabetes patients were divided into 3 groups based on albuminuria status: group II = no albuminuria (n = 20, <30 mg/d), group III = microalbuminuria (n = 13, 30-300 mg/d), and group IV = macroalbuminuria (n = 14, >300 mg/d). Twenty patients with hypertension only served as a control group (group I). Conventional 2-dimensional and Doppler echocardiography was done. Peak strain, peak systolic strain rate (SR), and peak diastolic SR of 6 LV segments in the apical views were measured and averaged in each patient. Conventional 2-dimensional parameters such as LV ejection fraction; left atrium volume index; LV mass; deceleration time; and mitral early peak, mitral late peak, myocardial early peak diastolic, and myocardial peak systolic velocities were not different among the 4 groups. However, peak strains were significantly lower in group III (P = .002) and group IV (P < .001) than in group I; and the absolute value of peak systolic SR was lower in group III (P = .033) and group IV (P < .001) than in group I. Furthermore, the value of peak diastolic SR was lower in group IV than in group I (P = .014). In diabetic patients with albuminuria, Doppler strain and SR imaging detected subclinical LV systolic and diastolic dysfunction; and albuminuria was associated with myocardial dysfunction in diabetic patients without overt heart disease. 相似文献