全文获取类型
收费全文 | 45956篇 |
免费 | 2771篇 |
国内免费 | 295篇 |
专业分类
耳鼻咽喉 | 491篇 |
儿科学 | 750篇 |
妇产科学 | 505篇 |
基础医学 | 5989篇 |
口腔科学 | 1200篇 |
临床医学 | 3230篇 |
内科学 | 11287篇 |
皮肤病学 | 1137篇 |
神经病学 | 3194篇 |
特种医学 | 1842篇 |
外科学 | 7538篇 |
综合类 | 357篇 |
一般理论 | 22篇 |
预防医学 | 2065篇 |
眼科学 | 984篇 |
药学 | 3319篇 |
中国医学 | 104篇 |
肿瘤学 | 5008篇 |
出版年
2023年 | 223篇 |
2022年 | 496篇 |
2021年 | 866篇 |
2020年 | 544篇 |
2019年 | 696篇 |
2018年 | 868篇 |
2017年 | 810篇 |
2016年 | 870篇 |
2015年 | 967篇 |
2014年 | 1246篇 |
2013年 | 1558篇 |
2012年 | 2407篇 |
2011年 | 2513篇 |
2010年 | 1485篇 |
2009年 | 1280篇 |
2008年 | 2257篇 |
2007年 | 2374篇 |
2006年 | 2273篇 |
2005年 | 2415篇 |
2004年 | 2171篇 |
2003年 | 2274篇 |
2002年 | 2126篇 |
2001年 | 1418篇 |
2000年 | 1435篇 |
1999年 | 1323篇 |
1998年 | 555篇 |
1997年 | 505篇 |
1996年 | 434篇 |
1995年 | 405篇 |
1994年 | 332篇 |
1993年 | 312篇 |
1992年 | 877篇 |
1991年 | 772篇 |
1990年 | 777篇 |
1989年 | 736篇 |
1988年 | 745篇 |
1987年 | 651篇 |
1986年 | 635篇 |
1985年 | 621篇 |
1984年 | 418篇 |
1983年 | 354篇 |
1982年 | 176篇 |
1981年 | 154篇 |
1980年 | 161篇 |
1979年 | 332篇 |
1978年 | 226篇 |
1977年 | 179篇 |
1974年 | 226篇 |
1973年 | 166篇 |
1972年 | 176篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
Takashi Shuto Yutaka Ohtsubo Ken'ichi Sekido Hiroko Iwamoto Isao Yamamoto 《Child's nervous system》1996,12(2):107-109
We report the case of an infant with a cerebellar astrocytoma that showed marked calcification within only 6 months. In general, only slow-growing tumors tend to calcify. To our knowledge, no other case of such rapid calcification in cerebellar astrocytoma has been reported. 相似文献
62.
Detection of nephritogenic antigen from the Lewis rat renal tubular basement membrane 总被引:1,自引:0,他引:1
H Yoshida Y Wakashin S Ueda R Azemoto K Iesato S Yamamoto T Mori M Ogawa Y Mori M Wakashin 《Kidney international》1990,37(5):1286-1294
Immunopathogenicity of trypsin-solubilized or non-solubilized renal tubular basement membrane (TBM) of the Lewis (LEW) rat was investigated. Autoimmune tubulointerstitial nephritis (TIN) was induced in BALB/c mice by immunization with trypsin-solubilized LEW rat TBM, while immunization with non-solubilized TBM did not produce the disease. Based on this preliminary experiment we studied the characterization of immunogenic and nephritogenic TBM antigen of the LEW rat. TIN was characterized by severe mononuclear cell infiltrates with multi-nucleated giant cells in the interstitium, tubular destruction and intensive IgG and C3 deposits along the TBM. Anti-TBM antisera and eluate from the nephritic mouse kidneys reacted with the TBM of normal LEW rat kidney by immunofluorescence. LEW rat TBM was also detected immunofluorescently by using antisera from BALB/c mice immunized with autologous trypsin-solubilized TBM. A competitive inhibition test revealed a higher titer of anti-TBM antibody in the eluate than in the adsorption-treated antisera per microgram IgG. Immunoblotting showed one reactive band with a molecular weight of 45,000 daltons, and the blotting patterns in tryptic TBM of the Brown Norway (BN) and LEW rats appeared similar. Amino acid analysis of nephritogenic LEW rat tryptic TBM showed that it contained no hydroxyproline and hydroxylysine, suggesting that this TBM preparation was not collagenous. These findings suggest that tryptic digestion contributes to the release of nephritogenic antigen from the LEW rat TBM and that this antigen system might participate in the immune system involved in the anti-TBM associated TIN that is well known to be induced by non-digested TBM of TBM antigen positive animals. 相似文献
63.
Abstract: Despite the widespread belief that medical authority is under increasing challenge, no adequate research instrument has been available to measure relevant community attitudes. This paper reports the development of the Attitude Toward Medical Practitioners Scale (the AMPS). Samples of Australians (in total N > 1000) completed the AMPS, using three different procedures. The reliability of the scale, assessed by coefficient alpha, ranged from 0.80 to 0.86. A principal component analysis of the AMPS yielded loadings on each item exceeding 0.3 on the first unrotated factor; subsequent varimax rotation revealed dimensions associated with critical attitudes to doctors and evaluations of doctors' interpersonal competence and technical expertise. Positive and significant correlations between the AMPS and one measure of the General Attitude toward Institutional Authority (GAIAS) strongly suggested that the scale is consistent with generalised evaluations of community authorities. The specific validity of the AMPS was supported for each of three samples, using as validating criteria respondent ratings of the last doctor visited, satisfaction with the consultation and reported compliance with the doctor's advice. Significant improvements were found in the prediction of each of these criteria by the addition of the AMPS to contributions made by the GAIAS and the demographic variables, age and sex. The AMPS is an appropriate measure for assessing community attitudes towards medical practitioners conceived as institutional authorities, at least in the Australian context. 相似文献
64.
65.
S Nakano S Suzuki H Kinbara Y Maeda M Yanagawa K Tajima H Tochigi J Kawamura S Hounoki I Yamamoto 《Hinyokika kiyo. Acta urologica Japonica》1990,36(7):831-835
This is a case report on a patient with double cancer of kidney and urinary bladder. The patient was a 65-year-old female, and she was admitted with the chief complaint of gross hematuria and right flank pain. After careful examinations, she was diagnosed with right nonfunctioning kidney caused by invasive bladder cancer. Computerized tomography incidentally revealed a mass in the upper pole of the left kidney. Selective left renal arteriography showed stretched arteries and irregularity and tortuosity of the smaller vessels. She was diagnosed with double cancer of bladder and left kidney. Owing to the damage of the right renal function, left partial nephrectomy, total cystectomy, right nephroureterectomy and left ureterocutaneostomy were performed. According to DMSA scintigraphy measured 15 days later, the uptake value of the left kidney was 13.25%, compared to the preoperative value of 25.62%. To date, this case is 36th reported case in Japan. 相似文献
66.
Upon autopsy of mice injected with the crown-of-thorns starfish (Acanthaster planci) lethal factor, a change in color of the liver, swelling of the gall bladder and jaundice were observed. After administration of the lethal factor into mice, activities of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), acid phosphatase (ACP) and alkaline phosphatase (ALP) were significantly elevated in serum. Hepatic ALP also increased markedly but hepatic GOT, GPT and ACP showed a tendency to decrease. Activity of hepatic LDH first decreased and then returned to control level. Histopathological studies showed that severe degenerative changes such as enlargement and necrosis of hepatocytes were caused in the mouse liver by the lethal factor. These results strongly suggested that the A. planci lethal factor is a potent hepatotoxin. 相似文献
67.
Ken Igawa Ryuji Maruyama Ichiro Katayama Kiyoshi Nishioka 《The Journal of dermatology》1997,24(5):328-331
A 72-year-old fisherman who was positive for the HCV antibody developed an annular, erythematous, infiltrated lesions on sun-exposed areas. The lesions were diagnosed as annular elastolytic giant cell granuloma both clinically and histologically. Topical corticosteroid and cryotherapy with liquid nitrogen for several months failed to improve the lesions. We then started dapsone, a known anti-oxidant, at 50 mg/day. A month later, the margins of the erythematous lesions faded, and the infiltration gradually decreased. No recurrence has been observed for one year after the start of the therapy. Anti-oxidative therapy appears to be effective for annular elastolytic giant cell granuloma and could be an alternate therapy for refractory granulomatous disease. 相似文献
68.
Hiroyuki Yamamoto Fumio Itoh Akinori Senota Yasushi Adachi Mitsuru Yoshimoto Takao Endoh Yuji Hinoda Akira Yachi Kohzoh Imai 《Journal of clinical laboratory analysis》1995,9(5):297-301
The matrix metalloproteinase matrilysin (MMP-7) is a member of the matrix metallo-proteinase gene family, which is believed to play an important role in tumor invasion and metastasis. We have previously found that matrilysin mRNA is specifically expressed in colorectal cancers and adenomas and that its message is localized in the tumor cells themselves. We examined the effects of activated Ki-ras oncogene on the expression of matrilysin in colon cancer cells. We showed that both mRNA and the enzymatic activity of matrilysin were induced by the introduction of activated Ki-ras into SW1417 colon cancer cells. To understand the mechanisms regulating this induction, we analyzed alterations of AP-1 activity induced by activated Ki-ras, using the chloramphenicol acetyltransferase assay. AP-1 activity in SW1417 cells expressing activated Ki-ras was higher than that in control cells. The gel-shift assay also showed higher levels of AP-1 binding protein in SW1417 cells expressing activated Ki-ras than those in control cells. Our results suggest that activated Ki-ras may play a role in inducing expression of matrilysin through an AP-1-dependent pathway in colon cancer cells. 相似文献
69.
70.
Perioperative cardiac events in patients undergoing noncardiac surgery: a review of the magnitude of the problem, the pathophysiology of the events and methods to estimate and communicate risk 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
P.J. Devereaux Lee Goldman Deborah J. Cook Ken Gilbert Kate Leslie Gordon H. Guyatt 《Canadian Medical Association journal》2005,173(6):627-634
THIS IS THE FIRST OF 2 ARTICLES EVALUATING cardiac events in patients undergoing noncardiac surgery. In this article, we review the magnitude of the problem, the pathophysiology of these events, approaches to risk assessment and communication of risk. The number of patients undergoing noncardiac surgery worldwide is growing, and annually 500 000 to 900 000 of these patients experience perioperative cardiac death, nonfatal myocardial infarction (MI) or nonfatal cardiac arrest. Although the evidence is limited, a substantial proportion of fatal perioperative MIs may not share the same pathophysiology as nonoperative MIs. A clearer understanding of the pathophysiology is needed to direct future research evaluating prophylactic, acute and long-term interventions. Researchers have developed tools to facilitate the estimation of perioperative cardiac risk. Studies suggest that the Lee index is the most accurate generic perioperative cardiac risk index. The limitations of the studies evaluating the ability of noninvasive cardiac tests to predict perioperative cardiac risk reveals considerable uncertainty as to the role of these popular tests. Similarly, there is uncertainty as to the predictive accuracy of the American College of Cardiology / American Heart Association algorithm for cardiac risk assessment. Patients are likely to benefit from improved estimation and communication of cardiac risk because the majority of noncardiac surgeries are elective and accurate risk estimation is important to allow informed patient and physician decision-making. 相似文献