全文获取类型
收费全文 | 8267篇 |
免费 | 469篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 183篇 |
妇产科学 | 643篇 |
基础医学 | 915篇 |
口腔科学 | 132篇 |
临床医学 | 934篇 |
内科学 | 1673篇 |
皮肤病学 | 81篇 |
神经病学 | 539篇 |
特种医学 | 261篇 |
外科学 | 1090篇 |
综合类 | 225篇 |
预防医学 | 451篇 |
眼科学 | 73篇 |
药学 | 647篇 |
中国医学 | 141篇 |
肿瘤学 | 768篇 |
出版年
2023年 | 43篇 |
2022年 | 78篇 |
2021年 | 185篇 |
2020年 | 103篇 |
2019年 | 155篇 |
2018年 | 262篇 |
2017年 | 175篇 |
2016年 | 161篇 |
2015年 | 223篇 |
2014年 | 266篇 |
2013年 | 407篇 |
2012年 | 586篇 |
2011年 | 610篇 |
2010年 | 397篇 |
2009年 | 324篇 |
2008年 | 508篇 |
2007年 | 556篇 |
2006年 | 557篇 |
2005年 | 447篇 |
2004年 | 388篇 |
2003年 | 328篇 |
2002年 | 320篇 |
2001年 | 268篇 |
2000年 | 275篇 |
1999年 | 205篇 |
1998年 | 65篇 |
1997年 | 59篇 |
1996年 | 66篇 |
1995年 | 41篇 |
1994年 | 49篇 |
1993年 | 26篇 |
1992年 | 128篇 |
1991年 | 93篇 |
1990年 | 68篇 |
1989年 | 43篇 |
1988年 | 49篇 |
1987年 | 47篇 |
1986年 | 44篇 |
1985年 | 32篇 |
1984年 | 36篇 |
1983年 | 11篇 |
1982年 | 7篇 |
1981年 | 16篇 |
1979年 | 16篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 6篇 |
1973年 | 7篇 |
1972年 | 8篇 |
1971年 | 10篇 |
排序方式: 共有8816条查询结果,搜索用时 125 毫秒
991.
Echocardiographic features of primary cardiac sarcoma 总被引:6,自引:0,他引:6
Hsieh PL Lee D Chiou KR Kung MH Lin SL Liu CP Chiang HT 《Echocardiography (Mount Kisco, N.Y.)》2002,19(3):215-220
Primary cardiac sarcoma is extremely rare and seldom causes symptoms until late in its course. Discomfort may occur only when the mass causes obstruction to the intracardiac flow. Early diagnosis is vital because it allows prompt and relevant management. We describe the history and echocardiographic features in four patients with primary cardiac sarcoma and review the current literature. 相似文献
992.
Transcatheter coil occlusion of persistent ductus arteriosus (PDA) is now a widely accepted treatment for PDA. However, late complication might occur due to thrombolytic treatment during the interventional period. We discuss a case with late coil migration due to thrombolysis after successful implantation of a coil. It should be emphasized that early thrombus formation is important for successful closure of PDA shunt using coil. 相似文献
993.
Chia-Yen Dai Ming-Lung Yu Ming-Yen Hsieh Li-Po Lee Nai-Jen Hou Jee-Fu Huang Shinn-Cherng Chen Zu-Yau Lin Ming-Yuh Hsieh Liang-Yen Wang Jun-Fa Tsai Wen-Yu Chang Wan-Long Chuang 《Liver international》2007,27(10):1364-1370
This study aimed to elucidate the rate and predictors of early (6 months) therapeutic responses to lamivudine, the rate of early mortality and the use of the model for end-stage liver disease (MELD) and Index in predicting the survival in patients with a clinical diagnosis of non-cirrhotic chronic hepatitis B with decompensation. Ninety-eight patients with lamivudine therapy were enrolled and MELD and Index scores were calculated. Surviving patients were treated with lamivudine for more than 6 months. Four (4.1%) of the 98 patients died after initiation of lamivudine therapy. After a 6-month lamivudine therapy, 80 (85.1%) patients and 71 (75.5%) patients had normal alanine aminotransferase (ALT) values and negative hepatitis B virus (HBV) DNA (<200 copies/mL), respectively, and hepatitis B e antigen (HBeAg)-negative patients had a significantly higher rate of negative HBV DNA than HBeAg-positive patients (P=0.002). The rates of HBeAg seroconversion and negative HBV DNA were 28.8 and 63.5%, respectively, and patients with HBeAg seroconversion had a significantly higher rate of negative HBV DNA (P=0.004). By multivariate analyses, older age, HBV nongenotype B infection, negative HBeAg and higher ALT levels were factors associated with negative HBV DNA, and a higher ALT level was associated with HBeAg seroconversion at month 6 after lamivudine therapy. MELD score and Index score were significantly associated with death and areas under the receiver operating characteristic curve for predicting survival were 0.936 and 0.907 respectively. We concluded that after 6-month lamivudine therapy, the patients who survived achieved favourable biochemical, virological responses and rate of HBeAg seroconversion. Both MELD and Index scoring systems are good models to predict the 6-month survival. 相似文献
994.
Real-time detection of DNA hybridization and melting on oligonucleotide arrays by using optical wave guides. 总被引:4,自引:0,他引:4
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D I Stimpson J V Hoijer W T Hsieh C Jou J Gordon T Theriault R Gamble J D Baldeschwieler 《Proceedings of the National Academy of Sciences of the United States of America》1995,92(14):6379-6383
The challenge of the Human Genome Project is to increase the rate of DNA sequence acquisition by two orders of magnitude to complete sequencing of the human genome by the year 2000. The present work describes a rapid detection method using a two-dimensional optical wave guide that allows measurement of real-time binding or melting of a light-scattering label on a DNA array. A particulate label on the target DNA acts as a light-scattering source when illuminated by the evanescent wave of the wave guide and only the label bound to the surface generates a signal. Imaging/visual examination of the scattered light permits interrogation of the entire array simultaneously. Hybridization specificity is equivalent to that obtained with a conventional system using autoradiography. Wave guide melting curves are consistent with those obtained in the liquid phase and single-base discrimination is facile. Dilution experiments showed an apparent lower limit of detection at 0.4 nM oligonucleotide. This performance is comparable to the best currently known fluorescence-based systems. In addition, wave guide detection allows manipulation of hybridization stringency during detection and thereby reduces DNA chip complexity. It is anticipated that this methodology will provide a powerful tool for diagnostic applications that require rapid cost-effective detection of variations from known sequences. 相似文献
995.
Cytidine methylation of regulatory sequences near the pi-class glutathione S-transferase gene accompanies human prostatic carcinogenesis. 总被引:1,自引:0,他引:1
W H Lee R A Morton J I Epstein J D Brooks P A Campbell G S Bova W S Hsieh W B Isaacs W G Nelson 《Proceedings of the National Academy of Sciences of the United States of America》1994,91(24):11733-11737
Hypermethylation of regulatory sequences at the locus of the pi-class glutathione S-transferase gene GSTP1 was detected in 20 of 20 human prostatic carcinoma tissue specimens studied but not in normal tissues or prostatic tissues exhibiting benign hyperplasia. In addition, a striking decrease in GSTP1 expression was found to accompany human prostatic carcinogenesis. Immunohistochemical staining with anti-GSTP1 antibodies failed to detect the enzyme in 88 of 91 prostatic carcinomas analyzed. In vitro, GSTP1 expression was limited to human prostatic cancer cell lines containing GSTP1 alleles with hypomethylated promoter sequences; a human prostatic cancer cell line containing only hypermethylated GSTP1 promoter sequences did not express GSTP1 mRNA or polypeptides. Methylation of cytidine nucleotides in GSTP1 regulatory sequences constitutes the most common genomic alteration yet described for human prostate cancer. 相似文献
996.
Wu WC Chen SC Dia CY Yu ML Hsieh MY Lin ZY Wang LY Tsia JF Chang WY Chuang WL 《Journal of gastroenterology and hepatology》2003,18(11):1320-1322
We report a case of 19-year-old male with an underlying case of chronic hepatitis C infection who suffered from two types of benign liver tumor: focal nodular hyperplasia (FNH) and pseudotumor due to focal fatty spared area in a fatty liver. These two kinds of lesions rarely occur simultaneously. The spectral Doppler ultrasound (US) images of these lesions were also provided. We suggest that spectral Doppler US provides an alternative diagnostic tool for the differentiation of liver tumors regarding their vascular pattern, which might help ensure a correct diagnosis. 相似文献
997.
Wang PW Liou CW Wang ST Eng HL Liu RT Tung SC Chien WY Lu YC Kuo MC Hsieh CJ Chen CH Chen JF Chu JW Reaven GM 《Metabolism: clinical and experimental》2002,51(2):255-259
The relative effect of an increase in low-density lipoprotein-cholesterol (LDL-C) concentration, as compared with insulin resistance and its manifestations, on intimal medial thickening (IMT) of the common carotid artery was defined in 72 healthy men and women. Insulin-mediated glucose disposal was quantified by the insulin suppression tests, in which the height of the steady-state plasma glucose (SSPG) concentration during the last 30 minutes of a 180-minute infusion of octreotide, insulin, and glucose provides an estimate of insulin resistance. IMT was determined by high-resolution B-mode ultrasonography. Univariate analyses defined statistically significant correlation coefficients between IMT and LDL-C concentration (r =.25, P <.05), SSPG concentration (r =.32, P <.01), triglycerides (TG) (r =.25, P <.05), and high-density lipoprotein-cholesterol (HDL-C) (r = -.28, P <.05) concentrations (changes associated with insulin resistance) and ratio of waist-to-hip girth (r =.29, P <.05). When forward step-wise linear regression analysis was used, concentrations of SSPG, LDL-C and HDL-C all emerged as independent predictors of IMT (P <.05). Furthermore, the magnitude of their relationship to IMT values was comparable. These results provide evidence that insulin resistance is as significant a predictor of degree of atherogenesis (estimated by IMT) of the common carotid artery as a high LDL-C concentration. 相似文献
998.
Fifteen consecutive adult patients with uncomplicated atrial septal defects (ASD) underwent echocardiographic examinations both before and 3-8 days (mean 7 days) after surgery to study the early postoperative changes in cardiac dimensions and interventricular septal motion. Echocardiographic analyses included patterns of interventricular septal motion, right and left ventricular dimensions at end-diastole (RVDd & LVDd), aortic root dimension at end-diastole (ARDd) and left atrial dimension at end-systole (LADs). The results showed that the septal motion was abnormal in 87% (13/15) before and 40% (6/15) after operation. RVDd decreased from 36 +/- 7 mm to 27 +/- 7 mm (p less than 0.01) while LVDd increased from 33 +/- 6 mm to 39 +/- 4 mm (p less than 0.01). There were no significant changes in LADs and ARDd after surgery. These observations suggest that in patients with ASD the ventricular dimensions and patterns of interventricular septal motion are changed significantly shortly after surgical repair. 相似文献
999.
Eradication of Helicobacter pylori significantly reduced gastric damage in nonsteroidal anti-inflammatory drug-treated Mongolian gerbils 总被引:3,自引:0,他引:3
Chang CC Chen SH Lien GS Lou HY Hsieh CR Fang CL Pan S 《World journal of gastroenterology : WJG》2005,11(1):104-108
AIM: To examine the effect of eradication of Hellcobacter pylori prior to usage of NSAIDs, by investigating gastric inflammatory activity, myeloperoxidase (MPO) activity, prostaglandin (PG) E_2 synthesis in H Pylori-infected, and H pylori-eradicated gerbils followed by administration of indomethacin and rofecoxib. METHODS: Six-week-old male gerbils were orally inoculated with H pylori. Seven weeks later, anti-H pylori triple therapy and vehicle were given to gerbils respectively and followed by oral indomethacin (2 mg/kg·d) or rofecoxib (10 mg/kg·d) for 2 wk. We examined the area of lesions, gastric inflammatory activity, PGE_2 synthesis and MPO activity in the stomach. RESULTS: In indomethacin and rofecoxib-treated gerbils, the following results were obtained in H pylori-infected group vs H pylori-eradicated group respectively: hyperplasia area of the stomach (mm~2): 82.4±9.2 vs 13.9±3.5 (P<0.05), 30.5±5.1 vs 1.3±0.6 (P<0.05); erosion and ulcer area (mm~2): 14.4±4.9 vs 0.86±0.5 (P<0.05), 1.3±0.6 vs0.4±0.3 (P<0.05); score of gastritis: 7.0±0.0 vs3.6±0.5 (P<0.05), 7.0±0.0 vs 2.7±0.5 (P<0.05); MPO activity (μmol H_2O_2/min/g tissue): 104.7±9.2 vs9.0±2.3(P<0.05), 133.5±15.0 vs2.9±0.7 (P<0.05); PGE_2 synthesis (pg/mg wet weight/min): 299.2±81.5 vs102.8±26.2 (P<0.05), 321.4±30.3 vs 11.9±4.8(P<0.05). CONCLUSION: Eradication of H pylori reduced gastric damage of NSAID-treated Mongolian gerbils. Rofecoxib caused less severe gastric damage than indomethacin in H pylori-eradicated gerbils. 相似文献
1000.
Prevalence of Childhood Asthma in Taipei, Taiwan, and Other Asian Pacific Countries 总被引:14,自引:0,他引:14
Two epidemiological surveys of the prevalence of bronchial asthma in schoolchildren in Taipei, Taiwan, were conducted in 1974 and 1985. The same questionnaire and school, and schoolchildren of the same age (7-15 years), were studied in these two surveys. Bronchial asthma was defined as at least three paroxysmal, recurrent attacks of wheezing and dyspnea in the previous 12 months. A total of 23,678 children were studied in 1974 and 147,373 children in 1985. Data from other Asian Pacific countries were also reviewed.
The results: 1) The questionnaire was able to differentiate asthmatics from nonasthmatics on the basis of differences in methacholine challenge, intracutaneous skin testing, total eosinophil count, total serum IgE, and RAST between the two groups. 2) The prevalence of childhood asthma increased from 1.30% in 1974 to 5.07% in 1985, with boys dominating in both studies. 3) The increase in asthma prevalence could not be explained by air pollution or exposure to new allergens. 4) The prevalence of childhood asthma in the Asian Pacific countries are generally comparable to those of Western countries, and the present study and studies from Japan and New Guinea showed an increasing tendency.
Thus childhood asthma is a major problem in the Asian Pacific countries as well as in Western countries. 相似文献
The results: 1) The questionnaire was able to differentiate asthmatics from nonasthmatics on the basis of differences in methacholine challenge, intracutaneous skin testing, total eosinophil count, total serum IgE, and RAST between the two groups. 2) The prevalence of childhood asthma increased from 1.30% in 1974 to 5.07% in 1985, with boys dominating in both studies. 3) The increase in asthma prevalence could not be explained by air pollution or exposure to new allergens. 4) The prevalence of childhood asthma in the Asian Pacific countries are generally comparable to those of Western countries, and the present study and studies from Japan and New Guinea showed an increasing tendency.
Thus childhood asthma is a major problem in the Asian Pacific countries as well as in Western countries. 相似文献