全文获取类型
收费全文 | 1009篇 |
免费 | 47篇 |
国内免费 | 5篇 |
专业分类
儿科学 | 7篇 |
妇产科学 | 4篇 |
基础医学 | 100篇 |
口腔科学 | 36篇 |
临床医学 | 66篇 |
内科学 | 210篇 |
皮肤病学 | 56篇 |
神经病学 | 79篇 |
特种医学 | 76篇 |
外科学 | 186篇 |
预防医学 | 23篇 |
眼科学 | 13篇 |
药学 | 58篇 |
肿瘤学 | 147篇 |
出版年
2023年 | 2篇 |
2022年 | 10篇 |
2021年 | 19篇 |
2020年 | 17篇 |
2019年 | 16篇 |
2018年 | 31篇 |
2017年 | 27篇 |
2016年 | 23篇 |
2015年 | 28篇 |
2014年 | 44篇 |
2013年 | 39篇 |
2012年 | 64篇 |
2011年 | 89篇 |
2010年 | 40篇 |
2009年 | 38篇 |
2008年 | 66篇 |
2007年 | 68篇 |
2006年 | 70篇 |
2005年 | 67篇 |
2004年 | 59篇 |
2003年 | 51篇 |
2002年 | 40篇 |
2001年 | 7篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1974年 | 3篇 |
1971年 | 1篇 |
1970年 | 8篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
排序方式: 共有1061条查询结果,搜索用时 15 毫秒
1.
Hidetaro Mori Keisuke Hiraoka Ryoichi Yorifuji Tohru Iwasaki Syuzo Gomikawa Ohshi Inagaki Seishi Inoue Yoshihiro Takamitsu Yoshikazu Fujita 《Artificial organs》1994,18(10):725-728
Abstract: The adsorptive characteristics of 5 dialysis membranes for recombinant human erythropoietin (EPO) were studied in vitro in a closed circuit system. For 120 min, EPO added with bovine serum was significantly adsorbed by polymethylmetacrylate (PMMA) and polyacry–lonitrile (PAN) membranes but not by Cuprophan, ethylene vinyl alcohol (EVAL), or polysulfone (PS) membranes. In addition the EPO adsorptive rate, as well as that of β2 –microglobulin (β2 –MG), was greater with a PMMA membrane than with a PAN membrane. EPO was not detected in the ultrafiltrate at 15 min with 5 membranes. These results indicate that EPO was eliminated by membrane adsorption only with some dialysis membranes. 相似文献
2.
Yukiko Hasuike Takeshi Nakanishi Rintarou Moriguchi Yoshinaga Otaki Masayoshi Nanami Yasue Hama Miki Naka Koji Miyagawa Masaaki Izumi Yoshihiro Takamitsu 《Nephrology, dialysis, transplantation》2004,19(6):1474-1479
BACKGROUND: Cyanide is a toxic agent, and its detoxification product, thiocyanate, may be a major pathogenetic substance in uraemia. Recent studies examining the myeloperoxidase(MPO)/thiocyanate system have suggested a link between thiocyanate and atherosclerosis. However, inaccuracies in conventional assays for cyanide and thiocyanate have limited the understanding of their metabolism in haemodialysis (HD) patients. METHODS: We used high-performance liquid chromatography to measure cyanide in erythrocytes and thiocyanate in plasma in 43 HD patients and in a group of 46 healthy controls that included 15 current smokers. To clarify the metabolic conversion of cyanide to thiocyanate in uraemic patients, we also measured cysteine and sulfate. We then used stepwise regression analysis to analyse factors that determine erythrocyte cyanide and plasma thiocyanate. RESULTS: Mean cyanide and thiocyanate were significantly greater in HD patients than in non-smoking controls. However, cyanide was far below lethal concentrations in dialysis patients. Thiocyanate was six to seven times greater in HD patients than in non-smoking controls, and decreases in thiocyanate following dialysis were only 19.3+/-3.5%. Multiple regression analysis showed a positive correlation between cyanide and thiocyanate in controls, but a negative correlation in HD patients. In patients, an inverse relationship between thiocyanate and BUN was also observed. CONCLUSIONS: The elevation of thiocyanate in patients undergoing dialysis probably is secondary to both limited efficiency of HD and deranged metabolism of cyanide and thiocyanate. Because thiocyanate is a preferred substrate for MPO, it may play a role in uraemic complications including cardiovascular events. 相似文献
3.
Takafumi Nagaoka Yoichi Katayama Toshikazu Kano Kazutaka Kobayashi Hideki Oshima Chikashi Fukaya Takamitsu Yamamoto 《Neuromodulation》2007,10(3):206-215
Objective. Employing [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) to assess the correlation between the effect of deep brain stimulation (DBS) on the subthalamic nucleus (STN) and the regional cerebral metabolic rate of glucose (rCMRGlc) in advanced Parkinson's disease patients (N = 8). Materials and Methods. On the basis of patients’ diary records, we performed FDG‐PET during the off‐period of motor activity with on‐ or off‐stimulation by STN‐DBS on separate days and analyzed the correlation between changes in motor symptoms and alterations in the rCMRGlc. Result. When FDG‐PET was performed, the motor score on the unified Parkinson's disease rating scale (UPDRS) was 64% lower with on‐stimulation than with off‐stimulation (p < 0.001, Wilcoxon single‐rank test). STN‐DBS increased the rCMRGlc in the posterior part of the right middle frontal gyrus, which corresponded to the premotor area, and the right anterior lobe of the cerebellum (p < 0.005, paired t‐test). No region exhibited a decrease in rCMRGlc. Among the items of the UPDRS motor score, the changes in resting tremor and rigidity of the left extremities showed a significant correlation with the changes in rCMRGlc observed in the right premotor area (p < 0.02 and p < 0.05, respectively, Spearman's rank correlation). Conclusions. STN‐DBS either activates the premotor area or normalizes the deactivation of the premotor area. These FDG‐PET findings obtained are consistent with the idea that STN‐DBS modifies the activities of neural circuits involved in motor control. 相似文献
4.
Yuta Ishizuka Yasushi Ishida Qing-Hua Jin Ayumi Shimokawa Mitsuhiko Saita Kazuo Kato Takato Kunitake Takamitsu Hanamori Yoshio Mitsuyama Hiroshi Kannan 《Brain research》1998,789(1):10
Nitric oxide (NO) has recently been shown to modulate the hypothalamic–pituitary–adrenal axis response to interleukin-1β (IL-1β). We measured levels of nitrite (NO2−) and nitrate (NO3−) in the hypothalamic paraventricular nucleus (PVN) region using an in vivo brain microdialysis technique in conscious rats. Intraperitoneally administered IL-1β produced a significant increase in both NO2− and NO3− levels in the PVN region. We also examined the possible involvement of the abdominal vagal afferent nerves in this effect. In abdominal-vagotomized rats, the increase was significantly attenuated compared to that in sham-operated rats. Our results suggest that the abdominal vagal afferent nerves are involved in intraperitoneally administered IL-1β-induced NO release in the PVN region. 相似文献
5.
6.
Nishio J Iwasaki H Sakashita N Haraoka S Isayama T Naito M Miyayama H Yamashita Y Kikuchi M 《Human pathology》2003,34(3):246-252
Undifferentiated (embryonal) sarcoma of the liver (UESL) is a rare pediatric liver malignancy that is extremely uncommon in middle-aged individuals. We studied 2 cases of UESL in middle-aged adults (1 case in a 49-year-old woman and the other in a 62-year-old man) by histology, immunohistochemistry, and electron microscopy to clarify the cellular characteristics of this peculiar tumor. One tumor showed a mixture of spindle cells, polygonal cells, and multinucleated giant cells within a myxoid matrix and also revealed focal areas of a storiform pattern in a metastatic lesion. The other tumor was composed mainly of anaplastic large cells admixed with few fibrous or spindle-shaped components and many multinucleated giant cells. In both cases, some tumor cells contained eosinophilic hyaline globules that were diastase resistant and periodic acid-Schiff positive. Immunohistochemically, the tumor cells showed positive staining for smooth muscle markers, such as desmin, alpha-smooth muscle actin, and muscle-specific actin, and also for histiocytic markers, such as alpha-1-antitrypsin, alpha-1-antichymotrypsin, and CD68. Electron microscope examination revealed thin myofilaments with focal densities and intermediate filaments in the cytoplasm of tumor cells. Our studies suggest that UESL exhibits at least a partial smooth muscle phenotype in middle-aged adults, and this specific differentiation may be more common in this age group than in children. Tumor cells of UESL with smooth muscle differentiation in middle-aged adults show phenotypic diversity comparable to those of malignant fibrous histiocytoma with myofibroblastic differentiation. 相似文献
7.
Lymph nodes of human immunodeficiency virus (HIV)-infected patients were studied histologically and immunohistochemically to elucidate the pattern of involution of various histiocytes in AIDS. Specimens consisted of one node with hyperplasia, five with atrophy, and three with severe atrophy. Antibodies such as L25, ID1, My4, 12, anti-Leu 3a, KiM4, OKT6 and anti-S100 protein were used for identification of the histocytes. Another antibody, VAK5, was used to demonstrate HIV antigen. T-zone histiocytes were mildly decreased in the hyperplastic node, but considerably decreased in the atrophic nodes. My4+ sinus histiocytes were unchanged in number and enlarged in the hyperplastic node, but not decreased in the atrophic nodes. Follicular dendritic cells (FDCs), defined by KiM4, were mostly depleted in the atrophic nodes. The T4 antigen was detected in some of the sinus histiocytes of the atrophic nodes. T6-positive cells were not found in any of the nodes. HIV antigen was detected only in FDCs. It is therefore suggested that various histiocytes respond differently to HIV, and that T-zone histiocytes and sinus histiocytes persist up to the late stage of AIDS. 相似文献
8.
Hidai C Kawana M Habu K Kazama H Kawase Y Iwata T Suzuki H Quertermous T Kokubun S 《The anatomical record. Part A, Discoveries in molecular, cellular, and evolutionary biology》2005,287(2):1165-1175
In the present study, we established transgenic mice overexpressing Del1, a ligand of integrins, to examine the effect of overexpression of Del1 on vascular morphogenesis. In the wild-type mouse, mesenteric vessels are shaped like rakes consisting of a long stalk and short branches at the periphery. In contrast, those in transgenic mice showed typical dendritic architecture consisting of a few large primary branches with smaller spreading branches. The phenotype of mice overexpressing Del1 suggests the existence of a tissue-specific mechanism for branching morphogenesis in the mesentery. 相似文献
9.
Tanaka T Nakanishi T Hasuike Y Inoue T Noguchi K Takamitsu Y 《Nihon Jinzo Gakkai shi》1999,41(8):754-763
Whether L-Arginine (L-ARG) ameliorates or aggravates renal function and histopathological changes in several models of renal disease remains controversial as L-ARG is the substrate for nitric oxide (NO) synthase as well as the precursor of proline and polyamines which cause renal fibrosis. These ambiguous results might be attributed to differences in the dose and period of L-ARG administration and the animal model used in each observation. Therefore, we tested the dose-dependent effect of L-ARG on mean blood pressure (MBP), 24-hour urinary excretion of protein (UP), NO metabolites (NO2(-) + NO3-) and cyclic GMP (cGMP), plasma asymmetrical dimethylarginine (ADMA), glomerular sclerosis index (SI) and % interstitial fibrosis area (%INT) in 5/6 nephrectomized SD rats. These 5/6 nephrectomized SD rats were divided into 4 groups: 1. L-ARG 0.2 g/kg/day (0.2 g ARG), 2. L-ARG 1 g/kg/day (1 g ARG), 3. L-ARG 2 g/kg/day (2 g ARG), 4. No administration of L-ARG(ARG(-)). Compared with ARG(-)MBP, UP and ADMA were significantly decreased and NO2(-) + NO3-, cGMP were significantly increased in the 0.2 g ARG. SI group and %INT were significantly increased in the 2 g ARG group and decreased in the 0.2 g ARG group. A small dose of L-ARG ameliorated glomerulosclerosis and interstitial fibrosis while a larger dose did not. SI, %INT and ADMA were inversely correlated with NO2(-) + NO3-. These data suggested that renal NO synthesis might attenuate glomerulosclerosis and interstitial fibrosis and the rise in ADMA and L-ARG might cause the decrease in NO. 相似文献
10.
Toshiaki Watanabe Takamitsu Kanazawa Yoshihiro Kazama Junichiro Tanaka Toshiaki Tanaka Soichiro Ishihara Hirokazu Nagawa 《Journal of clinical oncology》2005,23(35):9031-2; author reply 9032-3