全文获取类型
收费全文 | 215092篇 |
免费 | 2867篇 |
国内免费 | 319篇 |
专业分类
耳鼻咽喉 | 1462篇 |
儿科学 | 7333篇 |
妇产科学 | 3450篇 |
基础医学 | 21798篇 |
口腔科学 | 2693篇 |
临床医学 | 14689篇 |
内科学 | 40677篇 |
皮肤病学 | 1706篇 |
神经病学 | 19195篇 |
特种医学 | 10503篇 |
外科学 | 35561篇 |
综合类 | 2497篇 |
一般理论 | 1篇 |
预防医学 | 19209篇 |
眼科学 | 3602篇 |
药学 | 11812篇 |
中国医学 | 771篇 |
肿瘤学 | 21319篇 |
出版年
2023年 | 232篇 |
2022年 | 594篇 |
2021年 | 965篇 |
2020年 | 510篇 |
2019年 | 728篇 |
2018年 | 22675篇 |
2017年 | 17930篇 |
2016年 | 20203篇 |
2015年 | 1800篇 |
2014年 | 1979篇 |
2013年 | 2261篇 |
2012年 | 9314篇 |
2011年 | 23548篇 |
2010年 | 20289篇 |
2009年 | 12706篇 |
2008年 | 21687篇 |
2007年 | 24111篇 |
2006年 | 3012篇 |
2005年 | 4835篇 |
2004年 | 5876篇 |
2003年 | 6843篇 |
2002年 | 5059篇 |
2001年 | 927篇 |
2000年 | 991篇 |
1999年 | 827篇 |
1998年 | 842篇 |
1997年 | 718篇 |
1996年 | 560篇 |
1995年 | 512篇 |
1994年 | 466篇 |
1993年 | 393篇 |
1992年 | 432篇 |
1991年 | 427篇 |
1990年 | 442篇 |
1989年 | 392篇 |
1988年 | 325篇 |
1987年 | 289篇 |
1986年 | 261篇 |
1985年 | 259篇 |
1984年 | 222篇 |
1983年 | 177篇 |
1982年 | 135篇 |
1981年 | 110篇 |
1980年 | 138篇 |
1979年 | 126篇 |
1978年 | 87篇 |
1977年 | 67篇 |
1976年 | 66篇 |
1975年 | 71篇 |
1969年 | 68篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Cindy L. Grines 《Journal of nuclear cardiology》1994,1(5):S131-S133
During the past few decades, management of patients with myocardial infarction has dramatically evolved. High-risk patients are now identified by a variety of noninvasive tests, and aggressive use of reperfusion strategies has improved clinical outcomes. Despite the benefits of reperfusion, only a few patients are eligible to receive thrombolytic therapy. Mortality rates among patients excluded from thrombolytic trials (15% to 20%) have been far greater than those eligible for treatment (3% to 10%). Because most deaths occur within the first few days of infarction, interventions designed to reduce mortality should be performed acutely. Immediate catheterization allows identification of high-risk anatomy that may benefit from surgery and allows coronary angioplasty to be performed as a reperfusion strategy (when appropriate). Furthermore, catheterization allows documentation of ejection fraction, vessel patency, number of diseased vessels, and residual stenosis, all of which have been predictive of prognosis. Conversely, frequently repeated noninvasive diagnostic tests are associated with increased cost, are generally performed in low-risk patients, and 60% to 80% of patients with myocardial infarction ultimately require catheterization anyway. It is possible that early catheterization and percutaneous transluminal coronary angioplasty when indicated may effectively risk stratify patients (eliminating the need for noninvasive testing), may reduce morbidity and mortality, and shorten the length of hospital stay. 相似文献
102.
H Koyama K Honda K Okuda K Tsuchiya S Tanaka H Kawasaki 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(9):1111-1118
Community-acquired pneumonia is one of the major respiratory diseases causing hospital admission in previously healthy patients. Prompt and appropriate antibiotic selection is essential for recovery. The authors tried to determine the distribution of the etiologic agents of community-acquired pneumonias and to analyze predictive factors. Out of 188 cases of community-acquired pneumonia presenting to our hospital, etiologic agents were determined in 106 cases (56%). Twenty-nine cases were due to Streptococcus pneumoniae, 27 cases due to Mycoplasma, 17 cases due to Haemophilus influenzae and 21 cases due to Mycobacterium tuberculosis. M. tuberculosis was the cause in 11% of all cases and the importance of pulmonary tuberculosis must be emphasized as a community-acquired pneumonia. Out of 58 cases under 50 years old, Mycoplasma pneumoniae was the etiologic agent in 23 cases (40%) and S. pneumoniae in 7 cases (12%). Out of 62 cases not less than 70 years old. M. tuberculosis was the most common etiologic agent (15 cases, 24%). S. pneumoniae followed, being causative in 13 cases (21%). M. tuberculosis was the cause in 10 cases out of 31 cases who did not complain of fever at presentation. In 86 cases who did not show leukocytosis on admission, 21 cases were due to Mycoplasma (24%) and 15 cases were due to M. tuberculosis (17%). In particular 17 cases were due to Mycoplasma among 28 cases under 50 years old without leukocytosis (61%), and 11 cases were due to M. tuberculosis in the 27 cases no less than 70 years old without leukocytosis (41%).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
103.
Takashi Natsuume Norimasa Nakamura Konsei Shino Yukiyoshi Toritsuka Shuji Horibe Takahiro Ochi 《Journal of orthopaedic research》1997,15(6):837-843
We investigated the temporal and spatial expression of transforming growth factor-β in the healing patellar ligament of the rat by immunohistochemistry. The mid-portion of the medial half of the patellar ligament in 14-week-old male Wistar rats was cut transversely with a scalpel. On day 1 after ligament injury, diffuse staining for transforming growth factor-β was observed in the extracellular matrix filling the wound, and the staining in the adjacent ligament tissue was as weak as it was in the normal ligament. On day 3, the intensity of the diffuse extracellular staining decreased, and the staining was observed in correspondence with the cellular distribution in the wound site and in the adjacent uninjured ligament tissue. On day 7, the intense staining was widely distributed over the whole length of the ligament tissue. On day 28, the staining for transforming growth factor-β was still observed at the wound site and in the adjacent uninjured ligament tissue, where the staining was reduced in intensity but still stronger than it was in the normal ligament. On day 56, the expression of transforming growth factor-β was still detectable at the wound site: however, in the adjacent uninjured ligament tissue, it had almost subsided to the normal level. The results of the present study suggest that ligament healing may be accompanied by extensive changes in the expression of transforming growth factor-β over the whole length of ligament tissue. 相似文献
104.
H Honda H Onitsuka J Murakami K Kaneko S Murayama E Adachi T Kanematsu K Sugimachi K Masuda 《Gastrointestinal radiology》1992,17(3):245-249
The sensitivity, specificity, and accuracy of ultrasonography (US), dynamic incremented computed tomography (CT) with delayed phase imaging, and magnetic resonance imaging (MRI) with or without Gd-DTPA were studied for detecting the characteristic appearances of hepatocellular carcinomas (HCC): fibrous capsules, fibrous septa, and mosaic appearances. Results were prospectively evaluated in 30 patients who subsequently underwent hepatic lobectomies or segmentectomies. Pathologic evaluations of the resected liver specimens demonstrated fibrous capsules in 20 tumors (66.7%), fibrous septa in 13 tumors (43.3%), and mosaic appearances in 19 tumors (63.3%). The accuracies for fibrous capsules were 71.4% (20 of 28) for US, 81.5% (22 of 27) for CT, and 92.3% (24 of 26) for MRI. The accuracies for fibrous septa were 57.1% (16 of 28) for US, 59.3% (16 of 27) for CT, and 73.1% (19 of 26) for MRI. The accuracies for mosaic appearances were 71.4% (20 of 28) for US, 51.9% (14 of 27) for CT, and 69.2% (18 of 26) for MRI. Gd-DTPA administered MRI showed higher accuracies than did conventional MRI for all manifestations. In conclusion, the fibrous capsules of HCCs were readily detected by CT and MRI. Gd-DTPA administration demonstrated an advantage in clarifying fibrous capsules, as well as fibrous septa and mosaic appearances. 相似文献
105.
Kazue Shimmoto Shinichiro Ushigome Takashi Nikaido YaSUShi Kikuchi Naoaki Kobayashi Yohji Yamazaki 《Pediatric hematology and oncology》1991,8(2):147-157
A case is reported of Wilms' tumor associated with multiple pulmonary metastases histologically showing maturation of the tumor cells at 9 years after the resection of the primary tumor and intensive therapy. A huge tumor of a 22-month-old patient's right kidney was resected. The tumor was diagnosed as Wilms' tumor of mesenchymal type (stage 1), which consisted of predominantly immature mesenchymal tissue including rhabdomyoblasts, smooth muscle and fibrous tissue, and few blastemal and epithelial components. Intensive preoperative and postoperative chemotherapy with actinomycin D and vincristine and postoperative irradiation therapy totaling 16 Gy were carried out. The patient was regularly followed up uneventfully until 9 years after the surgery. On routine chest x ray at the age of 10 years 11 months, multiple pulmonary nodules were found. The excised nodules from the bilateral lungs disclosed similar histology, exclusively composed of dense collagen bundles and fibrocytes intermingled with mature striated muscle bundles. No immature tumor components were detected. The possible effect of intensive therapy in this maturation was stressed, although spontaneous benign differentiation of tumor cells cannot be excluded. 相似文献
106.
107.
Raymond J. Gibbons 《Journal of nuclear cardiology》1994,1(5):S118-S130
Both radionuclide angiography and myocardial perfusion imaging provide important insights that determine the management of patients with stable coronary artery disease. Both nuclear cardiology procedures have clearly demonstrated use in the noninvasvie identification of severe (left main or three-vessel) coronary artery disease and the noninvasive assessment of prognosis and thereby determine which patients should be sent to coronary angiography. Both radionuclide angiography and myocardial perfusion imaging provide prognostic information that is independent of resting left ventricular function and coronary anatomy and thereby influence the decision regarding which patients should be sent to coronary revascularization. This review considers the evidence supporting the uses of these nuclear cardiology procedures and provides suggestions regarding their cost-effective application. 相似文献
108.
Takashi Hineno M.D. Mutsuhiko Mizobuchi M.D. Oh-ichi Nishimatsu M.D. Jun Horiguchi M.D. Yasuo Kakimoto M.D. 《Psychiatry and clinical neurosciences》1994,48(3):583-587
Abstract: Studies on the circadian rhythm of urine excretion in healthy men have demonstrated that the maximal urine flow occurs in the early afternoon and the minimal around midnight. In this study, an abnormality in the variation of urine volume was found in parkinsonian patients. Urine samples were collected during daytime (9:00–21:00) and nighttime (21:00–9:00). Fifteen healthy control subjects were examined and found to excrete 60% during the daytime and 40% during the nighttime of the total urine volume. Sixteen parkinsonian patients excreted 43% during the daytime and 57% during the nighttime. In contrast to the control subjects, the parkinsonian patients excreted a smaller volume of their urine during the daytime than during the nighttime. This finding might be related to the degeneration of dopaminergic and/or nondopaminergic neurons in the brain which control urinary excretion. 相似文献
109.
110.
Richard N. Bradley 《Disease Management & Health Outcomes》2003,11(5):321-325
Acute stroke affects large numbers of people worldwide. It causes significant morbidity and mortality. Data support the hypothesis that the public is not familiar with either the risk factors or the signs of stroke. Educating the public about stroke may result in a lower incidence of the disease as individuals modify their risk factors, and in improved outcomes as a result of reductions in delays to treatment. There is clear and convincing evidence that reducing delays to treatment of patients with acute stroke results in improved outcomes. Public education programs should be broad-based, tailored to individual audiences, and carry a common theme. 相似文献