全文获取类型
收费全文 | 1238篇 |
免费 | 53篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 50篇 |
妇产科学 | 17篇 |
基础医学 | 133篇 |
口腔科学 | 19篇 |
临床医学 | 106篇 |
内科学 | 272篇 |
皮肤病学 | 2篇 |
神经病学 | 48篇 |
特种医学 | 30篇 |
外科学 | 147篇 |
综合类 | 18篇 |
预防医学 | 129篇 |
眼科学 | 13篇 |
药学 | 218篇 |
中国医学 | 10篇 |
肿瘤学 | 87篇 |
出版年
2023年 | 9篇 |
2022年 | 18篇 |
2021年 | 37篇 |
2020年 | 23篇 |
2019年 | 23篇 |
2018年 | 34篇 |
2017年 | 17篇 |
2016年 | 28篇 |
2015年 | 35篇 |
2014年 | 44篇 |
2013年 | 70篇 |
2012年 | 84篇 |
2011年 | 81篇 |
2010年 | 46篇 |
2009年 | 58篇 |
2008年 | 78篇 |
2007年 | 67篇 |
2006年 | 65篇 |
2005年 | 51篇 |
2004年 | 58篇 |
2003年 | 49篇 |
2002年 | 48篇 |
2001年 | 29篇 |
2000年 | 30篇 |
1999年 | 24篇 |
1998年 | 12篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 22篇 |
1991年 | 10篇 |
1990年 | 10篇 |
1989年 | 13篇 |
1988年 | 9篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 9篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1974年 | 6篇 |
1973年 | 4篇 |
1972年 | 7篇 |
1970年 | 5篇 |
排序方式: 共有1302条查询结果,搜索用时 12 毫秒
1.
Conclusions Limitation of this analysis is participation of limited centers. Though all the regions of the country are represented total
number of procedures reported are less. Isolated CABG is commonest procedure performed in 2004. Congenital surgical procedures
are more than the valvular heart disease procedure. For appropriate categorization we need standard nomenclature for various
congenital surgical procedures. 相似文献
2.
Effects of medium-chain triglycerides on brush border membrane-bound enzyme activity in rat small intestine 总被引:2,自引:0,他引:2
The effects of various types of dietary fat on brush border membrane-bound enzymes in rat intestinal mucosa were examined. Four groups of five rats were pair-fed defined diets for 10 d. The control group was fed a diet containing 57% sucrose and 2% corn oil as a fixed carbohydrate reference; the three experimental groups received diets containing 57% sucrose and 2% corn oil plus 13% fat in the form of medium-chain triglycerides (MCT) or long-chain triglycerides (LCT) (either lard as a highly saturated fat or corn oil as a highly unsaturated fat). Feeding LCT compared to the control diet, decreased sucrase activity in mucosal brush borders of the duodenum and jejunum. In these segments of MCT-fed rats, sucrase activity was similar to that in the control animals. In another experiment, measuring immunoreactive sucrase-isomaltase in jejunal brush border membranes revealed that feeding a high corn oil diet, but not a high MCT diet, led to a reduction in the sucrase catalytic activity per unit weight of enzyme protein, suggesting that the degradation status of sucrase-isomaltase might be altered by the different types of dietary fats. With MCT feeding, jejunal alkaline phosphatase activity was enhanced to a large extent compared to the activity in other groups. Feeding MCT, compared to lard or corn oil, also increased microvillus phospholipids of the jejunal mucosa. These results suggest that MCT, unlike LCT, do not suppress the activity of mucosal microvillus membrane enzymes in rat small intestine. 相似文献
3.
Two distinct cellular retinol-binding proteins were detected in chicken small intestine. A predominant form was purified to homogeneity. The apparent molecular weight of this protein was estimated to be 17,200. This form was larger than a second minor form partially purified (molecular weight of 15,000). The absorption and fluorescence spectra of the bound retinol to the purified proteins were typical for the known cellular retinol-binding proteins. The results suggest that the purified binding protein corresponds to CRBP(II), previously identified in small intestine of rats and humans. To gain an insight into the possible role of CRBP(II) in chicken small intestine, the CRBP(II) contents in cytosols of small intestine of embryonic and post-hatch chicks were determined by enzyme-linked immunosorbent assay. The amount of CRBP(II) per unit DNA in small intestine was low at 15- and 17-day embryonic stage, but rapidly increased around the period of hatching. The increased level was still maintained in 6-week-old chicks, which accounted for 0.9% of total proteins in duodenum. The developmental pattern and the presence of abundant amount of CRBP(II) in chicken small intestine supports the hypothesis that CRBP(II) might play some role in the intestinal absorption of retinoids. Thus the involvement of a tissue-specific cellular retinol-binding protein in the intestinal absorption of retinoids appears to be common in mammalian and avian species. 相似文献
4.
5.
Profile of a cancer detection camp 总被引:1,自引:0,他引:1
G Satyanarayana 《Journal of the Indian Medical Association》1991,89(1):3-6
The organisation and management of a cancer detection camp in rural area of Andhra Pradesh with the help of Lions Club and medical college staff were described. People with any one of the seven warning signals of cancer were asked to attend the camp. More women, most of them in reproductive age, attended the camp with unusual vaginal bleeding and lump in the breast. Among men, a large group complained of chronic cough. Smear for Papanicolaou's stain was used as a tool for screening of cervical cancer. Ten patients (2.5%) had malignant lesions and 16 patients (4.0%) had premalignant lesions. The programme of prevention, public health education and early detection of cancer can be put into action, successfully through cancer detection camps organised in rural areas. 相似文献
6.
Hisashi Masugata Shoichi Senda Fuminori Goda Yumiko Yoshihara Kay Yoshikawa Norihiro Fujita Hiroyuki Daikuhara Hiroyuki Nakamura Teruhisa Taoka Masakazu Kohno 《Hypertension research》2006,29(11):897-903
The purpose of the present study was to elucidate the cardiac structure and function in patients who have metabolic syndrome but no history of cardiovascular disease by analyzing echocardiographic findings. Echocardiographic examination was performed to screen for cardiovascular disease in 135 patients who were in their sixties. Patients were divided into metabolic syndrome (n=65, age: 65+/-2.7 years) and non-metabolic syndrome (n=70, age: 66+/-2.5 years) groups based on the criteria for metabolic syndrome proposed by the Japanese Society of Hypertension and seven other societies in 2005. The left ventricular (LV) wall thickness and dimension were measured by M-mode echocardiography. The relative wall thickness, LV mass index, and LV ejection fraction (LVEF) were calculated. LV diastolic function was assessed by the peak velocity of early rapid filling (E velocity) and the peak velocity of atrial filling (A velocity), and the ratio of E to A (E/A) was assessed by the transmitral flow. The Tei index, which reflects both LV diastolic and systolic function, was also calculated. There were no differences in relative wall thickness, LV mass index, or LVEF between the two groups. However, both the EIA and Tei index were significantly different between the metabolic syndrome (0.66+/-0.14 and 0.36+/-0.07, respectively) and non-metabolic syndrome (0.88+/-0.25 and 0.29+/-0.09) groups (p<0.001). These results indicate that patients with metabolic syndrome can have cardiac diastolic dysfunction even if they have neither LV hypertrophy nor systolic dysfunction. 相似文献
7.
8.
Toshiaki Nakashima Fuminori Goda Jinge Jiang Toshihide Shima Harold M. Swartz 《Magnetic resonance in medicine》1995,34(6):888-892
The partial pressure of oxygen (pO2) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO2 below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO2 measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO2 decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI4)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI4-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI4-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO2 of the liver in vivo and that the pO2 in the Kupffer cells is decreased when the liver is damaged by CCI4. 相似文献
9.
Bioavailability studies on guar gum-based three-layer matrix tablets of trimetazidine dihydrochloride in human volunteers. 总被引:1,自引:0,他引:1
Y S R Krishnaiah R S Karthikeyan P Bhaskar V Satyanarayana 《Journal of controlled release》2002,83(2):231-239
Guar gum-based three-layer matrix tablets of a highly water-soluble drug, trimetazidine dihydrochloride, were evaluated for their in vivo release in healthy volunteers in comparison with commercially available conventional immediate release tablets. Six healthy volunteers participated in the study and a two-way crossover design was followed. The plasma concentration of trimetazidine dihydrochloride was estimated by reverse-phase HPLC. The pharmacokinetic parameters were calculated from the plasma concentration of trimetazidine dihydrochloride versus time data. The delayed T(max), decreased C(max) and K(a), unaltered bioavailability, and prolonged t(1/2) and MRT indicated a slow and prolonged release of trimetazidine dihydrochloride from guar gum three-layer matrix tablets in comparison with the immediate release tablet dosage form. The guar gum three-layer matrix tablets of trimetazidine dihydrochloride may be useful in providing constant drug delivery with minimum fluctuations. 相似文献
10.
Tanaka G Kanaji S Hirano A Arima K Shinagawa A Goda C Yasunaga S Ikizawa K Yanagihara Y Kubo M Kuriyama-Fujii Y Sugita Y Inokuchi A Izuhara K 《International immunology》2005,17(6):797-805
It is widely known that IL-4 and IL-13 act on various kinds of cells, including B cells, resulting in enhancement of proliferation, class switching to IgE and expression of several surface proteins. These functions are important for the recognition of the various antigens in B cells and are known to be involved in the pathogenesis of allergic diseases. However, it has not been known whether IL-4/IL-13 is involved in the metabolism of various kinds of xenobiotics including 2,3,7,8-tetra-chlorodibenzo-p-dioxin (TCDD), and it remains undetermined whether TCDD, an environmental pollutant, influences IgE production in B cells, exaggerating allergic reactions. We identified IL-4- or IL-13-inducible genes in a human Burkitt lymphoma cell line, DND-39, using microarray technology, in which the AHR gene was included. The AHR gene product, the aryl hydrocarbon receptor (AhR), was induced by IL-4 in both mouse and human B cells in a STAT6-dependent manner. IL-4 alone had the ability to translocate the induced AhR to the nuclei. TCDD, a ligand for AhR, rapidly degraded the induced AhR by the proteasomal pathway, although IL-4-activated AhR sustained its expression. AhR activated by IL-4 caused expression of a xenobiotic-metabolizing gene, CYP1A1, and TCDD synergistically acted on the induction of this gene by IL-4. However, the induction of AhR had no effect on IgE synthesis or CD23 expression. These results indicate that the metabolism of xenobiotics would be a novel biological function of IL-4 and IL-13 in B cells, whereas TCDD is not involved in IgE synthesis in B cells. 相似文献