全文获取类型
收费全文 | 8806篇 |
免费 | 370篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 135篇 |
妇产科学 | 268篇 |
基础医学 | 985篇 |
口腔科学 | 169篇 |
临床医学 | 524篇 |
内科学 | 2292篇 |
皮肤病学 | 87篇 |
神经病学 | 516篇 |
特种医学 | 323篇 |
外科学 | 1627篇 |
综合类 | 36篇 |
预防医学 | 301篇 |
眼科学 | 170篇 |
药学 | 498篇 |
中国医学 | 21篇 |
肿瘤学 | 1159篇 |
出版年
2023年 | 54篇 |
2022年 | 136篇 |
2021年 | 204篇 |
2020年 | 102篇 |
2019年 | 130篇 |
2018年 | 156篇 |
2017年 | 123篇 |
2016年 | 177篇 |
2015年 | 171篇 |
2014年 | 235篇 |
2013年 | 298篇 |
2012年 | 467篇 |
2011年 | 500篇 |
2010年 | 299篇 |
2009年 | 246篇 |
2008年 | 416篇 |
2007年 | 494篇 |
2006年 | 452篇 |
2005年 | 449篇 |
2004年 | 468篇 |
2003年 | 473篇 |
2002年 | 454篇 |
2001年 | 225篇 |
2000年 | 226篇 |
1999年 | 196篇 |
1998年 | 122篇 |
1997年 | 106篇 |
1996年 | 77篇 |
1995年 | 66篇 |
1994年 | 69篇 |
1993年 | 60篇 |
1992年 | 155篇 |
1991年 | 128篇 |
1990年 | 134篇 |
1989年 | 132篇 |
1988年 | 129篇 |
1987年 | 153篇 |
1986年 | 92篇 |
1985年 | 93篇 |
1984年 | 75篇 |
1983年 | 63篇 |
1982年 | 39篇 |
1981年 | 26篇 |
1979年 | 34篇 |
1978年 | 20篇 |
1976年 | 23篇 |
1975年 | 23篇 |
1974年 | 27篇 |
1973年 | 22篇 |
1966年 | 21篇 |
排序方式: 共有9205条查询结果,搜索用时 35 毫秒
41.
Two Puralpha-binding proteins (PurBPs) were found in nuclear extract from mouse brain during P4-P10 by the overlay assay. At P14, they were decreased significantly in nuclear extract and increased in the S3 fraction, indicating their dynamic translocation during development. Western blot analysis also demonstrated concomitant translocation of Puralpha with the PurBPs during P7-P14, when neuronal circuit proceeds. Immunocytochemical study with cultured hippocampal neurons from rat E18 confirmed that nuclear Puralpha was translocated to cytoplasm after plating for 7-14 days. These results suggest that spatiotemporal translocation of Puralpha with the PurBPs from nuclei to cytoplasm has a crucial role in neuronal development. 相似文献
42.
Narazaki H Watari E Shimizu M Owaki A Das H Fukunaga Y Takahashi H Sugita M 《Immunology letters》2003,86(1):113-119
The T-cell subset expressing Vdelta2 paired primarily with Vgamma2 comprises a majority of gammadelta T-cells in human adult peripheral blood and expands significantly during a variety of infectious diseases. In contrast, the other subset of gammadelta T-cells that express Vdelta1 is rare among circulating T-cells and its function is poorly understood. Here, we show that a Vgamma1Vdelta1(+) T-cell line, 3-D, established from human peripheral blood by immortalization with Herpesvirus saimiri was able to specifically recognize tumor cells, such as K562 cells, and release cytotoxic granules containing perforin for target cell killing. Some tumor cells, including Daudi cells that are known to be susceptible to killing by Vdelta2(+) T-cells, were resistant to 3-D killing, implicating distinct pathways for tumor cell control by Vdelta1(+) and Vdelta2(+) T-cells. The 3-D T-cell receptor (TCR):CD3 complex reconstituted in TCR-deficient Jurkat cells was capable of transmitting signals, evidenced by activation of the interleukin 2 (IL-2) gene following ligation with anti-CD3 antibody, yet the TCR-reconstituted cells failed to produce IL-2 in response to the target cells. Thus, these results raise the possibility that some Vgamma1Vdelta1(+) T-cells could potentially be stimulated and lyse tumor cells via ligation of TCR/CD3-unassociated molecules. 相似文献
43.
Yamamoto K Okamura A Minagawa K Yakushijin K Urahama N Gomyo H Shimoyama M Itoh M Matsui T 《Cancer Genetics and Cytogenetics》2003,147(2):128-133
Follicular lymphoma is characterized genetically by t(14;18)(q32;q21), whereas t(18;22)(q21;q11), a rare variant form of t(14;18), has been preferentially observed in chronic lymphocytic leukemia (CLL). We describe here an unusual case of follicular lymphoma with a t(18;22)(q21;q11), that progressed to diffuse large cell lymphoma with a novel t(2;6)(p12;q23). Spectral karyotyping revealed that add(2)(p12) and add(6)(q23) were derived from a t(2;6)(p12;q23). Fluorescence in situ hybridization analysis confirmed rearrangements of the BCL2 gene at 18q21 and the BCL6 gene at 3q27. Our results indicate that a reciprocal translocation involving 6q23 could be implicated in the progression of follicular lymphoma and that t(18;22) may have a specific role in the pathogenesis of follicular lymphoma as well as CLL. 相似文献
44.
F Kawakami K Fukui H Okamura N Morimoto N Yanaihara T Nakajima Y Ibata 《Neuroscience letters》1984,51(2):225-230
The influence of ascending noradrenergic neuronal input on the neurotensin (NT)-like immunoreactive neuronal perikarya located in the dorsal part of the central nucleus of the amygdala (CNA) was examined using fluorescence histochemistry and peroxidase-antiperoxidase (PAP) immunocytochemistry. Unilateral hemitransection of the ascending noradrenergic pathway by injection of 6-hydroxydopamine into the caudal mesencephalon just rostral to the locus coeruleus caused a marked depletion of immunoreactivity in NT-like immunoreactive neuronal perikarya in the CNA. Ascending noradrenergic neuronal input, therefore, is considered to facilitate production of NT-like immunoreactive substances in neuronal perikarya and to influence on the functional role of the amygdaloid complex. In addition, we obtained evidence of unilateral direct ascending projections of NT-like immunoreactive neurons into the CNA since the disappearance of NT-like immunoreactive processes occurred mainly in the ventral part of the CNA after surgical hemitransection of the ascending neuronal pathway that interrupts the ascending NT-like immunoreactive pathway arising from the neurons in the brain stem. 相似文献
45.
Shunsuke Imai Susumu Sekigawa Yoshitaka Ohno Hiroaki Yamamoto Yoshihiko Tsubura 《Pathology international》1981,31(1):129-133
A case of giant cell carcinom of the pancreas is reported herein. The patient is a 67-year-old Japanese woman complaining of ascites, general fatigue, loss of weight, abdominal distention, nausea, and vomiting. Cytological diagnosis of ascites revealed adenocarcinoma. At autopsy, a whitish tumor measuring around 5 cm in diameter was found at the head of the pancreas. Metastasis was seen only in the liver. Histological examination displayed bizarre multinucleated giant cells occasionally phagocytosing the tumor cells and neutrophils. 相似文献
46.
Kanamycin ototoxicity in glutamate transporter knockout mice 总被引:2,自引:0,他引:2
Glutamate-aspartate transporter (GLAST), a powerful glutamate uptake system, removes released glutamate from the synaptic cleft and facilitates the re-use of glutamate as a neurotransmitter recycling system. Aminoglycoside-induced hearing loss is mediated via a glutamate excitotoxic process. We investigated the effect of aminoglycoside ototoxicity in GLAST knockout mice using the recorded auditory brainstem response (ABR) and number of hair cells in the cochlea. Kanamycin (100 mg/mL) was injected directly into the posterior semicircular canal of mice. Before the kanamycin treatment, there was no difference in the ABR threshold average between the wild-type and knockout mice. Kanamycin injection aggravated the ABR threshold in the GLAST knockout mice compared with the wild-type mice, and the IHC degeneration was more severe in the GLAST knockout mice. These findings suggest that GLAST plays an important role in preventing the degeneration of inner hair cells in aminoglycoside ototoxicity. 相似文献
47.
Therapeutic effect of topical administration of SN50, an inhibitor of nuclear factor-kappaB, in treatment of corneal alkali burns in mice 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Saika S Miyamoto T Yamanaka O Kato T Ohnishi Y Flanders KC Ikeda K Nakajima Y Kao WW Sato M Muragaki Y Ooshima A 《The American journal of pathology》2005,166(5):1393-1403
We evaluated the therapeutic efficacy of topical administration of SN50, an inhibitor of nuclear factor-kappaB, in a corneal alkali burn model in mice. An alkali burn was produced with 1 N NaOH in the cornea of C57BL/6 mice under general anesthesia. SN50 (10 microg/microl) or vehicle was topically administered daily for up to 12 days. The eyes were processed for histological or immunohistochemical examination after bromodeoxyuridine labeling or for semi-quantification of cytokine mRNA. Topical SN50 suppressed nuclear factor-kappaB activation in local cells and reduced the incidence of epithelial defects/ulceration in healing corneas. Myofibroblast generation, macrophage invasion, activity of matrix metalloproteinases, basement membrane destruction, and expression of cytokines were all decreased in treated corneas compared with controls. To elucidate the role of tumor necrosis factor (TNF)-alpha in epithelial cell proliferation, we performed organ culture of mouse eyes with TNF-alpha, SN50, or an inhibitor of c-Jun N-terminal kinase (JNK) and examined cell proliferation in healing corneal epithelium in TNF-alpha-/- mice treated with SN50. An acceleration of epithelial cell proliferation by SN50 treatment was found to depend on TNF-alpha/JNK signaling. In conclusion, topical application of SN50 is effective in treating corneal alkali burns in mice. 相似文献
48.
Biological activities of Bacteroides forsythus lipoproteins and their possible pathological roles in periodontal disease 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hasebe A Yoshimura A Into T Kataoka H Tanaka S Arakawa S Ishikura H Golenbock DT Sugaya T Tsuchida N Kawanami M Hara Y Shibata K 《Infection and immunity》2004,72(3):1318-1325
Bacteroides forsythus is a gram-negative, anaerobic, fusiform bacterium and is considered to be an etiological agent in periodontal disease. A lipoprotein fraction prepared from B. forsythus cells by Triton X-114 phase separation (BfLP) activated human gingival fibroblasts and a human monocytic cell line, THP-1, to induce interleukin-6 production and tumor necrosis factor alpha production. BfLP was found to be capable of inducing nuclear factor-kappaB translocation in human gingival fibroblasts and THP-1 cells. By using Chinese hamster ovary K1 cells transfected with Toll-like receptor genes together with a nuclear factor-kappaB-dependent CD25 reporter plasmid, it was found that signaling by BfLP was mediated by Toll-like receptor 2 but not by CD14 or Toll-like receptor 4. BfLP induced apoptotic cell death in human gingival fibroblasts, KB cells (an oral epithelial cell line), HL-60 cells (a human myeloid leukemia cell line), and THP-1 cells but not in MOLT4 cells (a T-cell leukemia cell line). Caspase-8, an initiator caspase in apoptosis, was found to be activated in these cells in response to BfLP stimulation. Thus, this study suggested that BfLP plays some etiological roles in oral infections, especially periodontal disease, by induction of cell activation or apoptosis. 相似文献
49.
Pathogenic capacity of proteases from Serratia marcescens and Pseudomonas aeruginosa and their suppression by chicken egg white ovomacroglobulin. 总被引:1,自引:3,他引:1
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The pathogenicities of three proteases from Serratia marcescens, two proteases from Pseudomonas aeruginosa, and one thermolysin from Bacillus stearothermophilus were examined. All proteases tested caused acute liquefactive necrosis of the cornea and descemetocele formation in guinea pig eyes after intrastromal injection, with the exception of the 60-kilodalton protease from S. marcescens, which produced only an opaque lesion. When injected into guinea pig skin, the protease also enhanced vascular permeability, which was followed by edema formation. The permeability-enhancing activity of the proteases increased in parallel with the concentration of the enzymes. When tested in vitro for its effect on these bacterial proteases, chicken egg white ovomacroglobulin (ovoM) inhibited the enzymatic activity of all the proteases after a short incubation period at an enzyme/inhibitor ratio (molar) of 1:1 to 1:4 or at a lower concentration after a longer incubation period. Such treatment of the proteases with chicken egg white ovoM before injection intrastromally into the eyes or intradermally into the clipped flanks of guinea pigs protected the cornea from destruction or completely prevented the permeability reaction and edema formation. No inhibitory effects of plasma protease inhibitors against these bacterial proteases were noted. Since the proteases are critical in the pathogenic processes caused by the bacteria, these results suggest a beneficial effect of ovoM against bacterial infections. 相似文献
50.
Study on effects of life review activities on the quality of life of the elderly: a randomized controlled trial 总被引:1,自引:0,他引:1
BACKGROUND: The objective of this study was to evaluate the mid-term efficacy of life review activities on the quality of life (QOL) of the elderly by conducting a randomized controlled trial, and to identify the factors that should be taken into consideration when conducting life review activities. METHODS: Written consent was obtained from 80 of the 97 eligible elderly persons. After randomly assigning them to two groups, an intervention group and a control group, group life review activities were conducted in the intervention group and discussion activities about health were conducted in the control group. In both the intervention group and the control group, life satisfaction, self-esteem, depression, and hopelessness were evaluated using self-rating scales at three points: at baseline, immediately after completion of the 8 weeks of sessions, and 3 months after completion of the intervention. RESULTS: Repeated measures analysis of covariance showed significant differences between the two groups in the changes in scores for depression (p = 0.04) and hopelessness (p = 0.04). Regarding the factors that were associated with depression and hopelessness, 3 months after completion of the intervention, depression and hopelessness of a more severe nature at baseline and having greater unresolved conflicts in the past were extracted by multiple regression analysis. CONCLUSIONS: The results suggested that group life review activities have a role in assisting the developmental stage of old age and supporting mental health, and have mid- to long-term effectiveness in maintaining and improving the QOL of the elderly. 相似文献