全文获取类型
收费全文 | 10287篇 |
免费 | 468篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 154篇 |
儿科学 | 144篇 |
妇产科学 | 112篇 |
基础医学 | 1030篇 |
口腔科学 | 328篇 |
临床医学 | 599篇 |
内科学 | 2339篇 |
皮肤病学 | 354篇 |
神经病学 | 822篇 |
特种医学 | 417篇 |
外科学 | 1580篇 |
综合类 | 40篇 |
一般理论 | 1篇 |
预防医学 | 365篇 |
眼科学 | 142篇 |
药学 | 923篇 |
中国医学 | 11篇 |
肿瘤学 | 1424篇 |
出版年
2023年 | 64篇 |
2022年 | 116篇 |
2021年 | 175篇 |
2020年 | 112篇 |
2019年 | 150篇 |
2018年 | 199篇 |
2017年 | 165篇 |
2016年 | 163篇 |
2015年 | 180篇 |
2014年 | 234篇 |
2013年 | 259篇 |
2012年 | 436篇 |
2011年 | 493篇 |
2010年 | 269篇 |
2009年 | 215篇 |
2008年 | 416篇 |
2007年 | 427篇 |
2006年 | 452篇 |
2005年 | 459篇 |
2004年 | 433篇 |
2003年 | 392篇 |
2002年 | 405篇 |
2001年 | 409篇 |
2000年 | 402篇 |
1999年 | 383篇 |
1998年 | 132篇 |
1997年 | 97篇 |
1996年 | 94篇 |
1995年 | 85篇 |
1994年 | 75篇 |
1993年 | 58篇 |
1992年 | 260篇 |
1991年 | 249篇 |
1990年 | 257篇 |
1989年 | 254篇 |
1988年 | 214篇 |
1987年 | 208篇 |
1986年 | 167篇 |
1985年 | 180篇 |
1984年 | 126篇 |
1983年 | 108篇 |
1982年 | 49篇 |
1979年 | 87篇 |
1978年 | 57篇 |
1977年 | 56篇 |
1974年 | 53篇 |
1971年 | 49篇 |
1969年 | 46篇 |
1967年 | 46篇 |
1966年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Asai J Suzuki R Fujimoto T Suzuki T Nakagawa N Nagashima G Miyo T Hokaku H Takei A 《Clinical neurology and neurosurgery》1999,101(4):1139-234
Infiltration of brain neoplasms by mononuclear cells including monocytes/macrophages has attracted little attention since they have marked morphological heterogeneity. Twenty-seven meningiomas were studied by anti-CD68 antibody-gated flow cytometry and by immunohistochemical analysis using the anti-CD68 antibodies. Flow cytometric analysis divided cells contained within tumor tissues into CD68-positive and -negative cells. In addition, eight gliomas, eight metastatic brain tumor, and 12 pituitary adenomas were investigated in the same way to compare meningiomas. The mean contents of CD68-positive cells were 24.0±3.7% in meningiomas, 4.4±1.4% in gliomas, 9.5±3.9% in metastatic brain tumors, and 4.5±1.8% in pituitary adenomas. Immunohistochemically, CD68-positive cells showed significant heterogeneity and were detected as round, rod-shaped, ameboid and ramified cells in meningiomas. Although the infiltrated mononuclear cells in gliomas have been investigated to some degree and showed that they express cytokines and/or growth factors, these infiltrated cells in meningioma have barely been studied. The CD68-positive cells detected in this study are likely to be monocytes, macrophages and microglias, and are presumed to be in various functional stages and to play important roles in growth regulation in meningioma. 相似文献
82.
BACKGROUND: CTLA4 immunoglobulin (Ig)G that binds to B7 effectively inhibits the signaling of CD28/CTLA4-B7 pathway and induces antigen specific T cell unresponsiveness in vitro and in vivo. Using CTLA4IgG, we examined induction of long-term graft survival and the mechanism of maintenance of tolerance in rat allogeneic small bowel transplantation. METHODS: Small bowels of Brown-Norway rats (RT1n) were heterotopically transplanted into Lewis rats (RT1l). Recipients were treated with an i.p. injection of either CTLA4IgG or control IgG for 7 days. RESULTS: Long-term survival was observed in rats treated with CTLA4IgG, whereas control rats died within 16 days after transplantation. To examine whether a tolerant state was established in long-term survival rats, secondary transplantation was performed using small bowels of Brown-Norway rats or ACI (RT1b) rats. It was demonstrated that small bowels of Brown-Norway rats were accepted; however, those of ACI rats were rejected within 10 days. Serum concentrations of interleukin (IL)-4 were maintained at >50 microg/ml for 7 days after transplantation in rats treated with CTLA4IgG but <15 microg/ml in control rats. IL-2 concentration was reduced to half in CTLA4IgG-treated rats compared with that in control recipients. Serum IFN-gamma in CTLA4IgG-treated recipients increased after transplantation and was not distinguishable from that of control recipients during the first 7 days after transplantation. Conclusion. We demonstrated that CTLA4IgG treatment alone for 7 days induced a long-term donor specific tolerance in rat allogeneic small bowel transplantation. The induction of long-term acceptance of small bowel allografts by CTLA4IgG is not caused by simply the shift of anti-alloimmune responses from Thl to Th2 cytokine production. 相似文献
83.
T Okamura R Suzuki Y Nakagawa A Terao S Sato A Kitamura Y Naito H Imano Y Tamura M Iida Y Komachi 《[Nihon kōshū eisei zasshi] Japanese journal of public health》1999,46(8):616-623
Since 1969, community-based stroke prevention programs have been conducted in N town, Kochi prefecture. To clarify factors related to participation in medical checkups including social networks, a cross-sectional questionnaire survey was performed on 6,704 residents aged 40 and over in N town in 1996. 1. Location of the workplace, types of medical insurance and interest in health were significantly associated with participation in medical checkups. 2. Participation in medical examinations provided at the workplace was significantly, inversely related with participation rates in community checkups in the group aged 40 to 59 years. 3. Low independence level in daily activities was inversely associated with participation rates for medical checkups in groups aged 60 years and older. 4. Visiting medical facilities was inversely associated with the participation rate for medical checkups in female groups. 5. The group with the highest social networks score (5 points) had the highest participation rate for medical checkups. After adjusting for other participation related factors, social networks scores had a significantly positive association with the participation rate for medical checkups provided by the Health Services for the Elderly Act. 相似文献
84.
T Tanaka N Kato T Doi K Ichikawa S Nakagawa K Miyasaka Y Takeda T Kitajima S Oda 《[Nihon kōshū eisei zasshi] Japanese journal of public health》1999,46(5):364-372
PURPOSE: We examined the child-rearing environmental factors that affect the occurrence of sudden infant death syndrome (SIDS) by using a nation-wide survey. METHOD: Infants who died due to SIDS between January 1996 and June 1997 in Japan were identified from death certificates. Controls of the same sex, birthplace, and birth months as the corresponding SIDS were chosen from birth certificates. Interviews of both cases and controls were undergone in January and February 1998 by public health nurses. RESULTS: The following Child-rearing factors exhibited a significant relationship with the occurrence of SIDS: 1. Concerning the sleeping position, the prone position was associated with increased risk compared to the supine position, with an odds ratio of 3.02 (95% c.i. 2.07-4.65). 2. Regarding the feeding method, artificial feeding only demonstrated a higher risk than breast feeding only, with an odds ratio of 4.92 (95% c.i. 2.78-9.63). 3. With regard to smoking, infants with both parents who smoked exhibited a higher risk than infants where neither parents smoked, with an odds ratio of 3.50 (95% c.i. 1.74-8.32). 相似文献
85.
M Ishizaki Y Yamada Y Morikawa Y Noborisaka M Ishida K Miura H Nakagawa 《Occupational medicine (Oxford, England)》1999,49(3):177-182
As a marker of body fat distribution and therefore level of obesity, the waist-to-hip ratio (W:H) is a good indicator of coronary heart disease risk status. The present study investigated the association between occupational status and life-style factors, and W:H of middle-aged Japanese male (n = 2,550) and female (n = 1,283) workers in a metal-products factory. A higher W:H was observed in the management level males as compared with the other male workers and we suggest this was promoted by the sedentary aspect of their work, as well as their higher levels of alcohol consumption and lower levels of leisure-time physical activity. In contrast, a higher W:H was recorded in female labourers, whose work was typically less sedentary as compared with female managers. Life-style factors included in the study were not related to this observation. We conclude that other unmeasured psychosocial factors may be important in promoting higher W:H in female labourers. 相似文献
86.
J Suzuki H Ohguro N Oguri M Satoh S Kon K Kogawa T Nakagawa 《Japanese journal of ophthalmology》1999,43(3):155-161
PURPOSE: To identify mucosa-associated lymphoid tissue (MALT) type lymphoma in conjunctival infiltrates. METHODS: Clinical, histopathologic, immunophenotypic, and immunogenotypic studies were performed on 14 patients with conjunctival lymphoid infiltrates. Surgical biopsy specimens were subjected to histopathologic, immunohistochemical, and gene rearrangement analysis. RESULTS: Thirteen of the 14 patients (92.9%) met the diagnostic criteria for MALT lymphoma, and the remaining patient showed morphologic features of diffuse, small lymphocytic lymphoma. Genotypic analysis confirmed immunoglobulin heavy chain gene rearrangement in all of the 12 patients on whom the analysis was performed. Two patients with bilateral lesions exhibited identical immunoglobulin rearrangement patterns in each pair of lesions. All patients were alive at the last follow-up (mean: 39.9 months). Nine of the 14 patients were alive without disease, 4 had localized recurrences, and 1 had a residual tumor. CONCLUSIONS: These findings indicate that conjunctival lymphoid infiltrates usually have the features of MALT lymphoma with genotypic B lymphocytic monoclonality and a favorable prognosis. 相似文献
87.
PURPOSE: To evaluate pigmentation on the anterior chamber angle in patients with atopic dermatitis. METHODS: This study includes 61 patients suffering from atopic dermatitis who visited our hospital between 1991 and 1995. Gonioscopy, cycloscopy, and fundus examinations with a scleral depressor were performed on every patient during the initial visit, and were repeated every 6 months. Pigmentation on the anterior chamber angle was classified according to Scheie. RESULTS: The pigmentation on the anterior chamber angle at the initial visit was evaluated as grade 0 (15 eyes), grade 1 (81 eyes), grade 2 (21 eyes), and grade 3 (5 eyes). Retinal detachment was found in 9 eyes of the 26 eyes with grade 2 or 3 pigmentation, but in only one of the 96 eyes with grade 0 or 1. The pigmentation on the anterior chamber angle correlated significantly with the incidence of retinal detachment (P < .0001). Causative breaks were found in the peripheral retina or ciliary epithelium in all eyes. CONCLUSIONS: Moderate to dense pigmentation on the anterior chamber angle in patients with atopic dermatitis seems to be a sign of breaks in the retina or ciliary epithelium, and the fundus of these patients should be examined carefully for signs of retinal detachment. 相似文献
88.
Application of Akaike's information criterion (AIC) in the evaluation of linear pharmacokinetic equations 总被引:13,自引:0,他引:13
Kiyoshi Yamaoka Terumichi Nakagawa Toyozo Uno 《Journal of pharmacokinetics and pharmacodynamics》1978,6(2):165-175
According to linear pharmacokinetics, the time course of plasma concentration of a drug, Cp,is expressed by a sum of exponential functions, Cp=
i=1
n
ai
.This article describes a statistical technique to estimate the number of exponential terms, n,for the time course of drug by the application of Akaike's information criterion (AIC). Plasma concentrations of ethoxybenzamide, sulfisoxazole, bishydroxycoumarin, and diazepam measured following bolus intravenous injection were used as clinical examples for this method. Selection of models is compared between the AIC method and an Ftest method at significance levels of 5% and 1%. 相似文献
89.
A case of Schonlein-Henoch-purpura is presented. The immunofluorescent study of skin lesions of the patient showed granular deposits of IgA and C3 in the blood vessel walls perivascular deposits of plasminogen and diffuse localization of fibrin and fibrinogen in the upper dermis. Complement activation via the alternative pathway through IgA, C3 and plasminogen deposits was suggested. 相似文献
90.
Studies were undertaken to examine cholesterogenesis in the intestine of streptozotocin-diabetic rats by measuring incorporation of [2(-14)C] acetate into cholesterol and 3-hydroxy-3-methylgultaryl CoA reductase (HMG-CoA reductase, EC 1.1.1.34) activity. In these diabetic rats, the intestinal mucosal weight and food consumption were markedly high. The incorporation of [2(-14)C] acetate into cholesterol was significantly increased in all diabetic intestinal segments. However, the rates of production of fatty acids and carbon dioxide were not affected. Hepatic HMG-CoA reductase activities were markedly reduced during both the diurnal high and low periods in these diabetic rats, and there was no diurnal variation. In contrast, the specific activities of this enzyme in jejunal crypt cells during both the diurnal high and low periods were significantly higher in these diabetic rats without loss of diurnal variation. Total reductase activity per segment of intestine in jejunal and ileal mucose (villi + crypt cells) was increased in these diabetic rats. Control rats had higher total and specific activity of ileal mucosal (velli + crypt cells) reductase than of jejunal mucosal reducatse during the diurnal high period. The jejunal-ileal gradient in reductase activity and the incorporation of [2(-14)C] acetate into cholesterol did not change significantly with streptozotocin-diabetic rats. The results indicate that in streptozotocin-diabetic rats, hepatic cholesterogenesis decreases but intestinal synthesis increases. 相似文献