全文获取类型
收费全文 | 1066篇 |
免费 | 41篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 12篇 |
妇产科学 | 3篇 |
基础医学 | 68篇 |
口腔科学 | 28篇 |
临床医学 | 131篇 |
内科学 | 386篇 |
皮肤病学 | 6篇 |
神经病学 | 119篇 |
特种医学 | 24篇 |
外科学 | 184篇 |
综合类 | 12篇 |
预防医学 | 16篇 |
眼科学 | 3篇 |
药学 | 60篇 |
中国医学 | 1篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 7篇 |
2022年 | 22篇 |
2021年 | 32篇 |
2020年 | 20篇 |
2019年 | 26篇 |
2018年 | 35篇 |
2017年 | 28篇 |
2016年 | 22篇 |
2015年 | 37篇 |
2014年 | 59篇 |
2013年 | 38篇 |
2012年 | 77篇 |
2011年 | 90篇 |
2010年 | 62篇 |
2009年 | 38篇 |
2008年 | 49篇 |
2007年 | 51篇 |
2006年 | 66篇 |
2005年 | 55篇 |
2004年 | 49篇 |
2003年 | 44篇 |
2002年 | 51篇 |
2001年 | 15篇 |
2000年 | 15篇 |
1999年 | 14篇 |
1998年 | 14篇 |
1997年 | 18篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 9篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1974年 | 2篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1929年 | 2篇 |
排序方式: 共有1126条查询结果,搜索用时 15 毫秒
41.
Jun An Guo‐Gang Feng Lei Huang Tsuyoshi Kurokawa Toshiaki Nonami Tatsuro Koide Fumio Kondo Toru Komatsu Koji Tsunekawa Yoshihiro Fujiwara Hidemi Goto Hiroshi Nishikawa Tokutaro Miki Satoru Sugiyama Naohisa Ishikawa 《Hepatology research》2010,40(6):613-621
Aim: The present study was undertaken to evaluate the effects of 1‐O‐hexyl‐2,3,5‐trimethylhydroquinone (HTHQ), a synthesized vitamin E derivative, on carbon tetrachloride (CCl4)‐induced cirrhosis. Methods: Rats were treated with hypodermic injections of CCl4 twice a week to induce the hepatic cirrhosis, and given drinking water containing HTHQ or solvent. Primary cultures of rat hepatocytes were performed to evaluate the effects of HTHQ on the expression of inducible nitric oxide synthase (iNOS). Results: Masson's staining of rat livers showed fibrosis around pseudo‐lobules in the CCl4 group, the lesions being reduced in the CCl4 HTHQ group. Increases in liver tissue hydroxyproline and α1(I) collagen, α‐smooth muscle actin and iNOS induced by CCl4, were also markedly diminished by HTHQ. Furthermore, both HTHQ and vitamin E attenuated interleukin‐1β‐induced iNOS protein expression in cultured hepatocytes, the potency of HTHQ being 10‐times higher than that of vitamin E. Conclusion: HTHQ may inhibit development of hepatic cirrhosis in rats, more potently than vitamin E, by inhibiting the iNOS expression in hepatocytes. Because vitamin E has a radical scavenging action, roles of NO and peroxynitrite will be discussed in the effects of HTHQ on the fibrosis. 相似文献
42.
Tachibana H Matsumoto N Cheng XJ Tsukamoto H Yoshihara E 《Clinical and diagnostic laboratory immunology》2004,11(6):1085-1088
We previously produced, in Escherichia coli, a human monoclonal antibody Fab fragment, CP33, specific for the galactose- and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica. To prepare antibodies with a higher affinity to the lectin, recombination PCR was used to exchange Ser91 and Arg96 in the third complementarity-determining region of the light chain with other amino acids. The screening of 200 clones of each exchange by an indirect fluorescent antibody test showed that 14 clones for Ser91 and nine clones for Arg96 reacted strongly with E. histolytica trophozoites. Sequence analyses revealed that the substituted amino acids at Ser91 were Ala in five clones, Gly in three clones, Pro in two clones, and Val in two clones, while the amino acid at position 96 was substituted with Leu in three clones. The remaining eight clones exhibited no amino acid change at position 91 or 96. These mutant Fab fragments were purified and subjected to a surface plasmon resonance assay to measure the affinity of these proteins to the cysteine-rich domain of lectin. Pro or Gly substitution for Ser91 caused an increased affinity of the Fab, but substitution with Ala or Val did not. The replacement of Arg96 with Leu did not affect affinity. These results demonstrate that modification of antibody genes by recombination PCR is a useful method for affinity maturation and that amino acid substitution at position 91 yields Fabs with increased affinity for the lectin. 相似文献
43.
Interactions between monocytes/macrophages and endothelial cells play an important role in the pathogenesis of atherosclerosis, and the adherence of monocytes to the arterial endothelium is one of the early events in atherogenesis. In the present study, peritoneal macrophages harvested from green fluorescent protein (GFP) transgenic mice were used to analyze how Chlamydia pneumoniae infection affects the adherence of GFP-macrophages to mouse endothelial cells in vitro and to the aorta from normolipidemic and hyperlipidemic mice ex vivo. In vitro studies showed that C. pneumoniae-infected GFP-macrophages adhered better than uninfected macrophages to endothelial cells and GFP-macrophages adhered better to infected than uninfected endothelial cells. The ex vivo studies showed that C. pneumoniae-infected macrophages adhered better than uninfected macrophages to aortas from both normolipidemic and hyperlipidemic C57BL/6J mice and apolipoprotein E (ApoE)-deficient mice. In contrast, adherence of C. pneumoniae-infected macrophages to the aortas of intercellular adhesion molecule 1 (ICAM-1) knockout mice was not enhanced, suggesting that ICAM-1 is crucial for activation of the adherence of C. pneumoniae-infected macrophages to the endothelium. In conclusion, the present study defined a homing mechanism by which C. pneumoniae promotes the adherence of mononuclear phagocytes to the endothelium at the site of atherosclerotic lesion formation to promote the progression of atherosclerosis. 相似文献
44.
Takahashi M Ni Z Yamashita T Liang N Sugawara K Yahagi S Kasai T 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2006,171(2):272-277
To investigate whether the early effects of voluntary teeth clenching (VTC) among the first dorsal interosseous (FDI), abductor digiti minimi (ADM), and abductor pollicis brevis (APB) muscles are differently modulated depending on their muscle properties, we examined the responses of motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation with selected current directions and by brainstem magnetic stimulation (BMS). Although MEP responses with anterior-medially current direction (preferentially elicited I1-waves) were facilitated in all three muscles, those responses with posterior-laterally current direction (preferentially elicited I3-waves) were different among FDI, ADM, and APB muscles. That is, MEP responses in FDI and APB muscles were significantly reduced, whereas those responses in ADM muscle were not significantly reduced. Further, inhibitory effects of VTC in FDI muscle were more potent than those in ADM or APB muscles. On the other hand, the responses to BMS were unchanged by VTC in all three muscles, suggesting that the modulations of MEP were attributed to the cortical origin. On the basis of our previous findings that the inhibitory connections in FDI muscle are more potent than those in ADM muscle (Takahashi et al. in Clin Neurophysiol 116:2757–2764, 2005), the cortical effects of VTC among three hand muscles are differently modulated, depending on muscle properties, presumably the extents of inhibitory connections to corticospinal tract neurons. Considering that the functional capacity in FDI muscle is higher than that in ADM or APB muscles, the cortical inhibitory effect of VTC might contribute to the sophisticated regulation of the motor outputs even during VTC. 相似文献
45.
Rungarun Kriangkrai Suconta Chareonvit Koichi Yahagi Michio Fujiwara Kazuhiro Eto Sachiko Iseki 《Developmental dynamics》2006,235(8):2134-2143
In this study, we investigated the process of supernumerary upper incisor formation in the Pax6 mutant rat, rSey(2)/rSey(2), which exhibits a facial cleft between the medial nasal and maxillary processes. Histological investigation and epithelial labeling studies of wild type rat embryos indicated that the upper incisor develops by fusion of two primary dental placodes (PDPs) in the medial nasal process with a contribution from the epithelium of the maxillary process. In the rSey(2)/rSey(2) embryo, both PDPs are formed but they stay apart, then subsequently these PDPs independently develop into upper incisor tooth buds. In order to examine if the failure of the two placodes to fuse is due to the cleft between the maxillary and medial nasal processes, maxillary and medial nasal process fusion was inhibited with a barrier in wild type embryos. This resulted in the maintenance of the two distinct PDPs. These results demonstrate that fusion of the facial processes reduces the number of odontogenic placodes and is required to assemble all components at one site for rat upper incisor formation. The results also provide further insight into the mechanism of supernumerary incisor formation in human cleft lip conditions. 相似文献
46.
A Hattori H Miyajima N Tomosugi Y Tatsumi H Hayashi S Wakusawa 《Pathology international》2012,62(9):612-618
In addition to hemochromatosis, aceruloplasminemia and ferroportin disease may be complicated by iron-induced multiple organ damage. Therefore, clinicopathological features should be evaluated in a wider range of genetic iron disorders. This study included 16 Japanese patients with genetic iron overload syndromes. The responsible genes were CP in four, HAMP in one, HJV in three, TFR2 in five, and SLC40A1 in three patients. No phenotype dissociation was observed in patients with the CP, TFR2, or HAMP genotypes. Two of the three patients with the HJV genotype displayed classic hemochromatosis instead of the juvenile type. Patients with the SLC40A1 genotype were affected by mild iron overload (ferroportin A) or severe iron overload (ferroportin B). Transferrin saturation was unusually low in aceruloplasminemia patients. All patients, except those with ferroportin disease, displayed low serum hepcidin-25 levels. Liver pathology showed phenotype-specific changes; isolated parenchymal iron loading in aceruloplasminemia, periportal fibrosis associated with heavy iron overload in both parenchymal and Kupffer cells of ferroportin B, and parenchyma-dominant iron-loading cirrhosis in hemochromatosis. In contrast, diabetes occurred in all phenotypes of aceruloplasminemia, hemochromatosis, and ferroportin disease B. In conclusion, clinicopathological features were partially characterized in Japanese patients with genetic iron overload syndromes. 相似文献
47.
Juanjuan Ye Futoshi Suizu Keiko Yamakawa Yuri Mukai Motohiko Kato Hiroyuki Yoneyama Naohisa Yahagi Yoko Matsuda 《European journal of immunology》2023,53(9):2250160
Limited intratumoral T-cell infiltration in pancreatic ductal adenocarcinoma (PDAC) is an obstacle to immunotherapy, yet the efficient approach to enhance tumor-infiltrating T cells is not fully established. Here, we show that tumor-specific knockdown of carbohydrate sulfotransferase 15 (CHST15), a tumor stromal proteoglycan-synthetic enzyme, suppresses tumor growth in a T-cell-dependent manner in a murine model of PDAC. Silencing of tumoral CHST15 unexpectedly expanded CD4+ and CD8+ T cells in tumor draining LN (TDLN), leading to accelerated accumulation of EdU+ proliferating CD4+ and CD8+ T cells and granzyme B+ CD8+ T cells in the tumor. RNA expression analysis indicated that tumoral CHST15 knockdown (KD) downregulated matrix remodeling-related genes, while upregulated anti-tumor T-cell activity-related genes in both tumor and TDLN. CHST15 KD significantly diminished intratumoral and TDLN Ly6C/G+ myeloid-derived suppressor cells prior to TDLN T-cell expansion, suggesting that tumoral CHST15 remotely regulated myeloid-derived suppressor cell mediated T-cell suppression in the TDLN. Our findings illustrate a novel immunotherapeutic potential of tumoral CHST15 blockage by reactivating T cells in immune suppressive TDLN of PDAC. 相似文献
48.
Liang N Takahashi M Ni Z Yahagi S Funase K Kato T Kasai T 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,182(4):459-467
Although there were many reports relating to intermanual transfer of behavioral motor tasks in humans, it is still not well-known
whether the transfer phenomenon between the trained and untrained hand is accompanied by corresponding changes in motor system.
In the present study we applied transcranial magnetic stimulation to investigate the practice effects of unilateral fingertip
precision grip on corticospinal excitability, regarding both the trained and untrained hand muscles. The results showed that
after practice fingertip grip force became steady and safety margin dramatically decreased not only in the trained hand, but
also in the untrained hand. Regarding MEP and background EMG (B.EMG) activities, the regression slope of MEP/B.EMG ratio in
the first dorsal interosseous (FDI) muscle became significantly steeper after practice in both hands, but in the thenar (TH)
muscle there were no clear modulations. These results indicated that through practice qualitative or functional changes of
corticospinal systems related to the reorganization for a fingertip precision grip prominently reflect only on FDI muscle
which plays a dominant role in the task. More importantly, such effects were simultaneously seen in the untrained hand correspondent
to the trained hand, i.e., changes of input–output property in M1 occur not only in the trained hand, but also in the untrained
hand. Based on the present results, we suggest that training-induced neural adaptations of the central nervous system may
include improvement of its predicting fingertip grip force for self-lifting of the object in the untrained hand. 相似文献
49.
Okamura A Yazawa S Nishimura T Tanaka S Takai I Kudo S Asao T Kuwano H Matta KL Akamatsu S Kochibe N 《Clinical & experimental metastasis》2000,18(1):37-43
A new ex vivo method for assaying adhesion of cancer cells to the greater omentum has been developed using mouse greater omentum and [3H]labelled human gastric and mouse colorectal cancer cells. Since the adhesion rates were found to increase up to 18 h and labelled cells seemed to be stable during the period, the present method could be useful for investigating adhesion of cancer cells to the greater omentum, which must occur at the first step of the peritoneal dissemination. The adhesion of cancer cells to the greater omentum was inhibited by a series of chemically synthesized oligosaccharides and Galβ1,3[3OMeGalβ1,4GlcNAcβ1,6]αBn was found to be the best inhibitor. The anti-tumor effect of this novel tetrasaccharide in vivo was shown in preliminary experiments using Balb/c mice and colon26 cells. 相似文献
50.
Shinya Sahara Nobuyuki Kawai Morio Sato Hiroki Minamiguchi Motoki Nakai Isao Takasaka Kouhei Nakata Akira Ikoma Naohisa Sawa Tetsuo Sonomura Shintaro Shirai 《Japanese journal of radiology》2010,28(5):362-368