全文获取类型
收费全文 | 8364篇 |
免费 | 414篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 170篇 |
妇产科学 | 73篇 |
基础医学 | 1020篇 |
口腔科学 | 161篇 |
临床医学 | 500篇 |
内科学 | 1927篇 |
皮肤病学 | 162篇 |
神经病学 | 411篇 |
特种医学 | 379篇 |
外科学 | 1855篇 |
综合类 | 40篇 |
预防医学 | 208篇 |
眼科学 | 122篇 |
药学 | 796篇 |
中国医学 | 5篇 |
肿瘤学 | 929篇 |
出版年
2023年 | 46篇 |
2021年 | 137篇 |
2020年 | 79篇 |
2019年 | 120篇 |
2018年 | 137篇 |
2017年 | 109篇 |
2016年 | 129篇 |
2015年 | 131篇 |
2014年 | 181篇 |
2013年 | 256篇 |
2012年 | 365篇 |
2011年 | 428篇 |
2010年 | 255篇 |
2009年 | 198篇 |
2008年 | 382篇 |
2007年 | 360篇 |
2006年 | 342篇 |
2005年 | 389篇 |
2004年 | 324篇 |
2003年 | 326篇 |
2002年 | 365篇 |
2001年 | 293篇 |
2000年 | 331篇 |
1999年 | 300篇 |
1998年 | 119篇 |
1997年 | 95篇 |
1996年 | 96篇 |
1995年 | 91篇 |
1994年 | 74篇 |
1993年 | 57篇 |
1992年 | 241篇 |
1991年 | 198篇 |
1990年 | 217篇 |
1989年 | 178篇 |
1988年 | 168篇 |
1987年 | 179篇 |
1986年 | 146篇 |
1985年 | 162篇 |
1984年 | 92篇 |
1983年 | 66篇 |
1982年 | 45篇 |
1979年 | 85篇 |
1978年 | 47篇 |
1977年 | 42篇 |
1974年 | 41篇 |
1973年 | 33篇 |
1972年 | 36篇 |
1971年 | 28篇 |
1970年 | 32篇 |
1969年 | 42篇 |
排序方式: 共有8810条查询结果,搜索用时 656 毫秒
81.
Effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in undifferentiated thyroid carcinoma 总被引:3,自引:0,他引:3
Kim R Tanabe K Uchida Y Emi M Toge T 《International journal of molecular medicine》2003,11(6):799-804
Although attempts have been made to treat undifferentiated thyroid carcinoma using multidisciplinary therapeutic procedures including surgery, radiotherapy, and chemotherapy, the prognosis of undifferentiated thyroid carcinoma remains quite poor. New approaches to increase the sensitivity of patients to anticancer drugs and radiation will be needed to improve the survival rate for undifferentiated thyroid carcinoma. We examined the effect of Bcl-2 antisense oligonucleotide on drug-sensitivity in association with apoptosis in the 8305C undifferentiated thyroid carcinoma cell line. The drug sensitivity was evaluated by MTT assay for 48 h, while apoptosis was assessed according to the formation of internucleosomal DNA ladders. The Bcl-2 antisense was introduced into 8305C cells by using a 18-mer phosphorothioate oligonucleotide by lipopolyamine-mediated transfection twice for 12 h. The expression of apoptosis genes was assessed by Western blotting. The 8305C cells were sensitive to adriamycin (ADM), mitomycin (MMC), docetaxel (TXT), and paclitaxel (TXL), showing mean IC50 values of 0.72, 1.1, 1.3, and 4.1 microM, respectively. In contrast, the 8305C cells were resistant to cisplatin (CDDP) and 5-fluorouracil (5-FU), with mean IC50 values of 42.0 and 48.0 microM, respectively. Treatment with Bcl-2 antisense suppressed the protein level of Bcl-2 in 8305C cells in a dose-dependent manner up to 1.0 microM. Drug-sensitivity was increased by pretreatment with Bcl-2 antisense as assessed by the IC50 (x-fold): 0.48 (1.5-fold) in ADM; 0.42 (2.6-fold) in MMC, 0.56 (2.3-fold) in TXT, 1.5 (2.7-fold) in TXL, 8.6 (4.9-fold) in CDDP, and 25.0 (1.9-fold) in 5-FU, respectively. The increased drug-sensitivity was associated with the induction of apoptosis-related proteins, Fas, caspase 8, cytochrome c, caspase 3, and to subsequent apoptosis, as determined by the formation of internucleosomal DNA ladders and PARP in the treated cells. Susceptibility in apoptotic cell death following treatment with anticancer drugs was associated with induction of apoptosis-related genes in undifferentiated thyroid carcinoma cells, and induction of apoptosis was enhanced by pretreatment with Bcl-2 antisense oligonucleotide. These results imply a potential new strategy targeting an antiapoptotic protein, Bcl-2, by its antisense oligonucleotide for enhancement of chemotherapeutic efficacy in undifferentiated thyroid carcinomas. 相似文献
82.
The fragile X in cattle 总被引:1,自引:0,他引:1
In search of an animal model for the human fragile X syndrome, the chromosomes of Holstein cows were examined. This breed was chosen because of previous studies on the baldy calf syndrome. An achromatic gap was observed at a specific site on the X chromosome closer to the centromere than that identified in humans. This unstained gap was found in 3%-4% of cells of the following four animals: an affected calf, her sister, their mother, and an unrelated Holstein cow. The bovine fragile X may not be analogous to the human fragile X but its location may be important as a genetic marker in linkage studies involving the loci for hypoxanthine phosphoribosyltransferase (HPRT) and glucose-6-phosphate dehydrogenase (G-6-PD). 相似文献
83.
84.
Three-dimensional two-layer collagen matrix gel culture model for evaluating complex biological functions of monocyte-derived dendritic cells 总被引:4,自引:0,他引:4
Tasaki A Yamanaka N Kubo M Matsumoto K Kuroki H Nakamura K Nakahara C Onishi H Kuga H Baba E Tanaka M Morisaki T Katano M 《Journal of immunological methods》2004,287(1-2):79-90
Dendritic cell-like cells (Mo-DCs) generated from peripheral blood monocytes with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been used as tools to treat cancer patients (DC-vaccines). Because Mo-DCs have multiple antigen presentation-related functions, including phagocytosis, migration, cytokine production, and T cell stimulation, establishment of a method for simultaneously evaluating the various functions of Mo-DCs is important. We developed a new in vitro three-dimensional two-layer collagen matrix culture model that consists of a collagen gel containing Mo-DCs as the lower layer and a collagen gel containing necrotic GCTM-1 tumor cells and/or T cells as the upper layer. We used this system to observe simultaneously multiple functions of Mo-DCs by phase-contrast or fluorescence microscopy and to assess IL-12 secretion during more than 2 weeks of culture. We also observed interactions between Mo-DCs and necrotic GCTM-1 or T cells on an individual cell basis by time-lapse videomicroscopy. In addition, we collected Mo-DCs from the collagen gels by collagenase treatment and analyzed the expression of antigen presentation-related molecules such as HLA-DR, CD80, CD83, and CD86 on Mo-DCs. This model may be a useful tool for evaluation of the various functions of Mo-DCs used as DC vaccines and for studies of the complex behaviors of Mo-DCs in vivo. 相似文献
85.
T. Yambe S. Nanka S. Naganuma S. Kobayashi S. Nitta T. Fukuju N. Uchida K. Tabayashi A. Tanaka K. Abe H. Takayasu M. Yoshizawa H. Takeda 《Journal of artificial organs》2002,5(1):1-5
Artificial circulation has been analyzed by decomposing it into parts. However, the sum of the decomposed parts is not equal
to the whole system, especially in nonlinear dynamic systems such as biological systems. To evaluate prosthetic circulation
as an entity, not as decomposed parts, nonlinear mathematical analytic techniques, including fractal dimension analyzing theory,
were used. Two pneumatically actuated ventricular assist devices were implanted as biventricular bypasses (BVB) in chronic
animal experiments using four healthy adult goats. For comparison between natural and prosthetic circulation in the same experimental
animals, the BVB-type complete prosthetic circulation model with ventricular fibrillation was adopted. All hemodynamic parameters
with natural and prosthetic circulation were recorded under awake conditions and calculated by a personal computer system.
By the use of nonlinear mathematical techniques, time-series data of the hemodynamics were embedded into the phase space,
and correlation dimension analysis was performed to evaluate the reconstructed attractor. Our results suggest that the correlation
dimension of the arterial blood pressure does not linearly increase according to the increase of the embedding dimension,
even during artificial circulation, suggesting those are the fractal time series data. Dimensional analysis of the hemodynamics
revealed that lower dimensional fractal dynamics were observed during prosthetic circulation. Fractal time series data are
suggested to have robustness and error resistance. Thus, our results suggest that the circulatory regulatory system with the
artificial heart may have these desirable characteristics.
Accepted: July 14, 1995 相似文献
86.
Hiroshi Nagashima Katsuhisa Uchida Keiko Yamamoto Shigehiro Kuraku Ryo Usuda Shigeru Kuratani 《Developmental dynamics》2005,232(1):149-161
Turtles have a body plan unique among vertebrates in that their ribs have shifted topographically to a superficial layer of the body and the trunk muscles are greatly reduced. Identifying the developmental factors that cause this pattern would further our understanding of the evolutionary origin of the turtles. As the first step in addressing this question, we replaced newly developed epithelial somites of the chicken at the thoracic level with those of the Chinese soft-shelled turtle Pelodiscus sinensis (P. sinensis somites into a chicken host) and observed the developmental patterning of the grafted somites in the chimera. The P. sinensis somites differentiated normally in the chicken embryonic environment into sclerotomes and dermomyotomes, and the myotomes differentiated further into the epaxial and hypaxial muscles with histological morphology similar to that of normal P. sinensis embryos and not to that of the chicken. Epaxial dermis also arose from the graft. Skeletal components, however, did not differentiate from the P. sinensis sclerotome, except for small fragments of cartilage associated with the host centrum and neural arches. We conclude that chicken and P. sinensis share the developmental programs necessary for the early differentiation of somites and that turtle-specific traits in muscle patterning arise mainly through a cell-autonomous developmental process in the somites per se. However, the mechanism for turtle-specific cartilage patterning, including that of the ribs, is not supported by the chicken embryonic environment. 相似文献
87.
Okano A Nakano S Namura K Yamada N Uchida R Fuchida S Okamoto M Ochiai N Shimazaki C 《Cancer Genetics and Cytogenetics》2005,159(2):174-176
A 43-year-old woman was diagnosed as having stage IV follicular lymphoma. Phenotypically, the lymphoma cells were CD5(-), CD10(+), CD19(+), CD20(+), CD23(-), HLA-DR(+), and IgM-lambda(+). Conventional chromosomal analysis showed a three-way t(3;14;18)(q27;q32;q21) in the lymphoma cells, which was confirmed by spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH). Immunohistochemistry revealed that both BCL2 and BCL6 proteins were expressed in the lymphoma cells, whereas only the BCL6 gene, and not the BCL2 gene, was rearranged by Southern blotting. The patient received combination chemotherapy and has been well for 3 years. This is the first reported case showing a three-way translocation involving 2 major lymphoma-specific abnormalities, 3q27 and t(14;18)(q32;q21). 相似文献
88.
Satoda T Hiyama S Karukaya E Hayashida K Uchida T 《Kaibogaku zasshi. Journal of anatomy》2003,78(3):95-101
It is difficult to teach students about the embryological transformation of the branchial arteries. In mammals, six pairs of branchial arteries develop, but all are not present at the same embryological stage. The first, second, fifth and a part of right sixth branchial artery disappear early in embryological development. The remaining third, fourth and sixth branchial arteries mainly constitute the arterial system of the breast. The aorta and pulmonary trunk are derived from the truncus arteriosus. Because of the complexity of this developmental process, we have devised a user-friendly model in order to assist with educational presentations. In this model, the shrinkage of a vessel has been represented by inserting a wire inside of the hose representing the artery. Degenerated or disappearing parts of the vessel are removable by using hooks and Velcro tape. Branchial arteries, truncus arteriosus, aortic sac and dorsal arteries are represented by different colors. The descent of the heart is represented by the relational change between larynx and heart. Additionally we represented the vagus nerve and recurrent laryngeal nerve by using strings. The right vagus nerve can move dorsally and the left ventrally by rotating the digestive tract. The right recurrent laryngeal nerve can move superiorly to hook around the right subclavian artery, and left recurrent laryngeal nerve can hook around the ductus arteriosus formed by the left sixth branchial artery. 相似文献
89.
Tanaka K Tamura J Kawanabe K Nawa M Uchida M Kokubo T Nakamura T 《Journal of biomedical materials research. Part A》2003,67(1):200-207
Recently zirconia/alumina composites have been examined by many researchers as the new generation of bearing materials in total joint replacements. In this study, the phase stability of a Ce-TZP/Al(2)O(3) nanocomposite and conventional Y-TZP after aging, and its influence on wear resistance, were investigated. Very slight phase transformation was observed in both types of ceramics 18 months after the implantation of Ce-TZP/Al(2)O(3) or Y-TZP samples into rabbit tibiae. However, Y-TZP showed marked phase transformation (approximately 80%) after aging in an autoclave (121 degrees C) for 190 h or in physiological saline at 62 degrees C for 18 months, whereas the new composite remained almost resistant to degradation. According to the results of self-pairing pin-on-disk wear tests using ceramic specimens with or without autoclave aging, the wear factor was almost the same between Ce-TZP/Al(2)O(3) samples with and without aging (6.74 +/- 0.36 x 10(-8) and 6.04 +/- 0.95 x 10(-8) mm(3)/Nm, respectively). In contrast, although non-aged Y-TZP had the lowest wear factor (4.88 +/- 0.51 x 10(-8) mm(3)/Nm) of all specimens tested, aged Y-TZP showed 10-fold greater wear than nonaged Y-TZP. The present study suggests that Ce-TZP/Al(2)O(3) nanocomposite has much greater phase stability than Y-TZP, and that its wear properties are not influenced by aging. 相似文献
90.
Sho Takahata Takafumi Okutomi Keiko Ohtsuka Shigeru Hoshiko Katsuhisa Uchida Hideyo Yamaguchi 《Medical mycology》2005,43(3):227-233
To evaluate the therapeutic potential of FX0685, a new triazole antifungal agent, for the treatment of opportunistic fungal infections, particularly systemic candidiasis and aspergillosis, in vitro and in vivo studies were performed using fluconazole (FLC), itraconazole (ITC) and/or amphotericin B (AMB) as reference drugs. A preliminary in vitro study showed that the antifungal activity of FX0685 against FLC-susceptible Candida albicans, several non-C. albicans Candida species and Cryptococcus neoformans was superior to that of FLC and comparable or superior to those of ITC and AMB, while the anti-Aspergillus fumigatus activity of FX0685 was to varying degrees lower than that of ITC. FX0685 appeared to be comparable to FLC and ITC in the treatment of murine systemic C. albicans and pulmonary A. fumigatus infection, respectively. The biological property of FX0685 was characterized by its potent in vitro and in vivo activity against FLC-resistant C. albicans. Part of this unique property was explained by the finding that it retained potent inhibitory activity against those CYP51 molecules in which amino acid substitutions confer a phenotype of resistance to FLC and some other azole derivatives. All of these results lead to the possibility that FX0685 may be a potential antifungal drug candidate for the treatment of various clinical forms of systemic candidiasis, including those caused by FLC-resistant C. albicans, as well as for the treatment of pulmonary aspergillosis. 相似文献