全文获取类型
收费全文 | 8476篇 |
免费 | 394篇 |
国内免费 | 59篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 93篇 |
妇产科学 | 45篇 |
基础医学 | 1182篇 |
口腔科学 | 207篇 |
临床医学 | 481篇 |
内科学 | 1976篇 |
皮肤病学 | 115篇 |
神经病学 | 525篇 |
特种医学 | 331篇 |
外科学 | 1720篇 |
综合类 | 17篇 |
一般理论 | 1篇 |
预防医学 | 178篇 |
眼科学 | 113篇 |
药学 | 686篇 |
中国医学 | 21篇 |
肿瘤学 | 1102篇 |
出版年
2022年 | 70篇 |
2021年 | 157篇 |
2020年 | 85篇 |
2019年 | 97篇 |
2018年 | 139篇 |
2017年 | 118篇 |
2016年 | 143篇 |
2015年 | 151篇 |
2014年 | 161篇 |
2013年 | 245篇 |
2012年 | 408篇 |
2011年 | 415篇 |
2010年 | 235篇 |
2009年 | 237篇 |
2008年 | 371篇 |
2007年 | 390篇 |
2006年 | 410篇 |
2005年 | 390篇 |
2004年 | 386篇 |
2003年 | 405篇 |
2002年 | 420篇 |
2001年 | 284篇 |
2000年 | 255篇 |
1999年 | 242篇 |
1998年 | 106篇 |
1997年 | 109篇 |
1996年 | 82篇 |
1995年 | 79篇 |
1994年 | 79篇 |
1993年 | 60篇 |
1992年 | 195篇 |
1991年 | 205篇 |
1990年 | 180篇 |
1989年 | 170篇 |
1988年 | 171篇 |
1987年 | 182篇 |
1986年 | 140篇 |
1985年 | 137篇 |
1984年 | 95篇 |
1983年 | 65篇 |
1982年 | 39篇 |
1979年 | 66篇 |
1978年 | 36篇 |
1977年 | 34篇 |
1974年 | 34篇 |
1973年 | 37篇 |
1971年 | 42篇 |
1970年 | 36篇 |
1968年 | 41篇 |
1967年 | 36篇 |
排序方式: 共有8929条查询结果,搜索用时 15 毫秒
21.
Human recombinant erythropoietin directly stimulates B cell immunoglobulin production and proliferation in serum-free medium. 下载免费PDF全文
H Kimata A Yoshida C Ishioka S Masuda R Sasaki H Mikawa 《Clinical and experimental immunology》1991,85(1):151-156
The effect of human recombinant erythropoietin (Epo) on B cell responses was studied in a serum-free medium. Epo enhanced IgM production and thymidine uptake by a human IgM-producing lymphoblastoid cell line, CBL. This effect was specific to Epo since enhancement was blocked by anti-Epo antibody but not by control antibody. Among the various cytokines, interleukin-4 (IL-4) enhanced IgM production and thymidine uptake while IL-6 enhanced IgM production without affecting thymidine uptake. In contrast, other cytokines including IL-1 beta, IL-2, IL-5, interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), or granulocyte/macrophage colony-stimulating factor (GM-CSF) were without effect. However, the enhancing effect of Epo is different from that of IL-4 or IL-6, since Epo effect was not blocked by anti-IL-4 antibody or anti-IL-6 antibody. Moreover, specific binding of Epo was detected on CBL cells. Epo also enhanced immunoglobulin (IgG, IgM and IgA) production and thymidine uptake by purified tonsil small resting B cells stimulated by Staphylococcus aureus Cowan strain I (SAC) or by large activated B cells. In contrast, Epo had no effect on unstimulated small resting B cells. These results indicate that Epo could directly stimulate activated and differentiated B cells and could enhance B cell immunoglobulin production and proliferation. 相似文献
22.
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
23.
-Hydroperoxy diethyl peroxide, a novel compound found in the tunic of ascidians, has two peroxide moieties per molecule. Since ascidians are a widely served food item in Japan, human exposure to this compound potentially exists in the seafood preparation industries. No toxicological data have so far been published on this compound, and so we determined the intraperitoneal 6-day LD50 in mice and conducted histopathological examinations. The 6-day LD50, was found to be 199 mg/kg with 95% confidence limits of 126–314 mg/kg. Histopathological examination revealed necrosis induced in a variety of cells that had been directly exposed to the compound. These cells included hepatocytes, parenchymal pancreatic cells and fat cells. It is concluded that direct contact with this compound is likely to elicit cellular necrosis of various organs. The specific toxicological effects are probably dependent on the route of exposure. 相似文献
24.
MRI of the brain in chronic carbon monoxide poisoning 总被引:3,自引:0,他引:3
We examined 13 patients with chronic carbon monoxide (CO) poisoning by magnetic resonance imaging (MRI); all of them had been in an explosion in a coal mine 25 years previously. Symmetrical globus pallidus lesions were observed in 12, as was degeneration of the white matter, with focal cortical atrophy. The temporal parietal and occipital lobes were usually affected, the parietooccipital region being the most frequently and extensively damaged. Of the 12 patients with white matter degeneration 7 had definitely asymmetrical cortical and subcortical lesions. There were 6 patients with dilated temporal horns, probably due to atrophy of the hippocampal gyri. A history of CO inhalation and an awareness of the typical distributions of lesions are important for recognition of the effects of CO poisoning, especially when patients are in the chronic stage. 相似文献
25.
T Fujita H Mori Y Osaki M Minowa S Ishihara N Masuda Y Hanzawa C Mori T Nanba H Ohta 《[Nihon kōshū eisei zasshi] Japanese journal of public health》1992,39(9):687-695
A case-control study was conducted to examine factors relating to discontinuation of domiciliary care for the bedridden elderly in Shinagawa-ku, Tokyo. Cases were bedridden residents aged 65 years and over who had abandoned home care and applied for admission to live in a special nursing home for the aged between April and September in 1990 after being recipients of welfare allowances for disabled elderly. Controls were bedridden residents who continued to be given home care and matched to cases by sex, age and beginning month of the receiving of allowances. Among 50 cases and 94 controls interviewed, we obtained responses from 31 cases (62%) and 60 controls (64%). The main results were as follows: 1. During the home-care period, ADL (activities of daily living) of cases, especially walking ability, deteriorated more severely than in controls. Night delirium also appeared more frequently in cases. 2. The primary caregivers of cases were older than those of controls. Remarkable differences between cases and controls were observed in the family structure, the number of family members and the number of sub-caregivers. Cases tended to live alone or live with a spouse only, and with smaller number of family members and caregivers. 3. Case lived more frequently in houses with small numbers of rooms and without rooms of their own. 4. As regards utilization of domiciliary care services, cases used dispatch of home helpers more frequently and used day services less frequently. 相似文献
26.
S Hayasaka M Takada T Shinohara S Imamura N Takifuji S Kudoh K Matsui Y Kusunoki N Masuda S Negoro 《Nihon Kyōbu Shikkan Gakkai zasshi》1991,29(7):802-807
Serum levels of CA-50, SLX and ST-439 were measured in 213 patients with lung cancer (92 adenocarcinomas, 63 squamous cell carcinomas, 37 small cell carcinomas and 21 large cell carcinomas) and 87 patients with benign lung disease. The overall positive rates in patients with lung cancer were 12.8% for CA-50, 29.7% for SLX and 25.3% for ST-439. The positive rates for CA-50, SLX and ST-439 in adenocarcinoma patients were 22.8%, 42.4% and 38.0%, respectively. Of the patients with benign lung disease, 4.8% were false positive for CA-50, 15.3% for SLX and 3.6% for ST-439. In the patients with adenocarcinoma of the lung, the combination assay of CEA and ST-439 had a highly accurate rate (61.9%). 相似文献
27.
Y Mochizuki H Masuda S Kanazashi Y Hosoki K Itoh K Ohishi T Nishina Y Handa K Shiozawa Y Miwa 《Kansenshōgaku zasshi. The Journal of the Japanese Association for Infectious Diseases》1992,66(1):30-36
A systematic examination was performed for environmental food contamination by Salmonella in poultry farms, broiler chickens, broiler processing plants and meat on the market. Salmonella was isolated from 219 of 1197 samples and the serotypes showed a wide distribution. (Table 1-1). S. hadar accounted for 37.1% (96) of all isolations (259). The contamination rate of broiler chickens on arrival at broiler processing plants is relatively low. However, in the broiler processing plants, containers, processing machinery, cooling water and slaughters were highly contaminated by Salmonella, S. hadar being the most prominent serotype in the plants. 64% of chicken meat on the market was contaminated by Salmonella, S. hadar being the second most prominent serotype. 11% of the pork and none of the beef or horseflesh was contaminated by Salmonella. These results indicate that poultry is the main source of S. hadar infection in humans. However, no S. hadar was isolated from cultures of 119 samples of feed for chickens from each delivery (Table 1-1). Thus, as the main source of infection by S. hadar of broiler chickens, an association with the feed seems to be ruled out. S. hadar was isolated at three of 18 poultry farms within Shizuoka Prefecture. Follow-up studies were performed at the three poultry farms which revealed that in two of them, Salmonella was completely eradicated on completion of disinfection. In the other one farm, which is still being disinfected, various strains of Salmonella including S. hadar still survived. We conclude that the main cause of the problem is the magnification of contamination of Salmonella-free material during the process at the broiler processing plants.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
28.
29.
Effects of chlorpromazine as a systemic vasodilator during cardiopulmonary bypass in neonates 总被引:1,自引:0,他引:1
Yutaka Imoto Hideaki Kado Munetaka Masuda Hisataka Yasui 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2002,50(6):241-245
OBJECTIVES: Vasodilator use during cardiopulmonary bypass is important in pediatric cardiac surgery, but the full range of their effects on hemodynamics remains to be clarified. We studied the effects of chlorpromazine, a potent alpha-blocking agent, in neonates. METHODS: Subjects were 60 neonates undergoing arterial switch operations for complete transposition of the great arteries with an intact ventricular septum. Of these, 37 received 2.1 to 6.5 mg/kg of chlorpromazine during cardiopulmonary bypass (CPZ group) and 23 received no vasodilator (control group). We then compared hemodynamic parameters between groups during and early after surgery. RESULTS: The systemic vascular resistance index and mean arterial pressure during cardiopulmonary bypass were significantly lower in the CPZ group (p < 0.05), but systolic pressure 15 minutes after cessation of cardiopulmonary bypass did not differ between groups. The rise in peripheral temperature during rewarming after hypothermia was significantly higher and the acid-base status 40 minutes after cardiopulmonary bypass less acidotic in the CPZ group. Urine output during cardiopulmonary bypass was higher in the CPZ group. CONCLUSIONS: Chlorpromazine effectively counteracts systemic vasoconstriction induced by cardiopulmonary bypass without serious side effects in neonatal cardiac surgery. 相似文献
30.
Haruo Nagayama Kounosuke Tsuchiyama Kenji Yamada Jotaro Akiyoshi 《Progress in neuro-psychopharmacology & biological psychiatry》1991,15(6):735-744
1. In our series of experiments the role of serotonin in human depression was studied by using animal models of depression.
2. The results of these studies support the hypothesis that some types of human depression may be primarily due to an excessive transmission of serotonin at the synapse. 相似文献