全文获取类型
收费全文 | 405篇 |
免费 | 18篇 |
专业分类
423篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 19篇 |
2014年 | 20篇 |
2013年 | 25篇 |
2012年 | 27篇 |
2011年 | 25篇 |
2010年 | 18篇 |
2009年 | 9篇 |
2008年 | 16篇 |
2007年 | 18篇 |
2006年 | 17篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 9篇 |
2002年 | 11篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 9篇 |
1998年 | 4篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 6篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1963年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有423条查询结果,搜索用时 20 毫秒
101.
Emmanuel R Marciano L Polliand C Antonio V Ziol M Poncelet C Barrat C 《Diagnostic pathology》2012,7(1):62
ABSTRACT: Cecal endometriosis and ileocolic intussusception due to a cecal endometriosis is extremely rare. We report a case of a woman who presented an ileocecal intussusception due to a cecal endometriosis. The patient gave two months history of chronic periombilical pain requiring regular hospital admission and analgesia. The symptoms were not related to menses. A laparotomy was performed and revealed an ileocolic intussusception. The abdominal exploration did not find any endometriosis lesion. Ileocaecal resection was performed. Microscopic examination showed a cystic component, lined by a regular cylindric epithelium. Foci of endometrial tissu were oberved in the cecal subserosa and muscularis mucosal, with irregular endometrial glands lined by cylindric epithelium without atypia immunostained with CK7, and characteristic endometrial stroma immunostained with CD10. Cecal endometriosis and ileocolic intussusception due to a cecal endometriosis is extremely rare. Diagnose of etiology remains challenging due to the absence of clinical and radiological specific characteristics. Virtual slide The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2975867306869166. 相似文献
102.
M. Rosaria Faraone‐Mennella Filomena De Lucia Natale Gentile Piera Quesada Benedetta Farina 《Journal of cellular biochemistry》2000,76(1):20-29
Rat testis H1 proteins were poly(ADP‐ribosyl)ated in vitro. The modifying product, poly(ADP‐ribose), was found covalently bound to each histone variant at various extents and exhibited distinct structural features (linear and short, rather than branched and long chains). Interest was focused on the somatic H1a, particularly abundant in the testis, as compared with other tissues, and the testis‐specific H1t, which appears only at the pachytene spermatocyte stage of germ cell development. These H1s were modified with poly(ADP‐ribose) by means of two in vitro experimental approaches. In the first system, each variant was incubated with purified rat testis poly(ADP‐ribose)polymerase in the presence of [32P] NAD. In parallel, poly(ADP‐ribosyl)ated H1s were also prepared following incubation of intact rat testis nuclei with [32P] NAD. In both experiments, the poly(ADP‐ribosyl)ated proteins were purified from the native forms by means of phenyl boronic agarose chromatography. The results from both analyses were in agreement and showed qualitative differences with regard to the poly(ADP‐ribose) covalently associated with H1a and H1t. Comparison of the bound polymers clearly indicated that the oligomers associated with H1a were within 10–12 units long, whereas longer chains (≤20 ADP‐R units) were linked to H1t. Individual poly(ADP‐ribosyl)ated H1s were complexed with homologous H1‐depleted oligonucleosomes (0.5–2.5 kbp) in order to measure their ability to condensate chromatin, in comparison with the native ones. Circular dichroism showed that the negative charges of the oligomeric polyanion, although present in limited numbers, highly influenced the DNA‐binding properties of the analyzed H1s. In particular, the poly(ADP‐ribosyl)ated H1a and H1t had opposite effects on the condensation of H1‐depleted oligonucleosomes. J. Cell. Biochem. 76:20–29, 1999. © 1999 Wiley‐Liss, Inc. 相似文献
103.
Magorzata Gadyszyska Justyna Bobrowska Magorzata Lekka Paulina Radwaska Lucyna Piera Jacek Szymaski Jacek Drobnik 《Journal of cellular and molecular medicine》2020,24(23):13853
Cardiac fibroblasts are able to sense the rigidity of their environment. The present study examines whether the stiffness of the substrate in cardiac fibroblast culture can influence the release of interleukin‐6 (IL‐6), interleukin‐11 (IL‐11) and soluble receptor of IL‐6 (sIL‐6R). It also examines the roles of integrin α2β1 activation and intracellular signalling in these processes. Cardiac fibroblasts were cultured on polyacrylamide gels and grafted to collagen, with an elasticity of E = 2.23 ± 0.8 kPa (soft gel) and E = 8.28 ± 1.06 kPa (stiff gel, measured by Atomic Force Microscope). Flow cytometry and ELISA demonstrated that the fibroblasts cultured on the soft gel demonstrated higher expression of the α2 integrin subunit and increased α2β1 integrin count and released higher levels of IL‐6 and sIL‐6R than those on the stiff gel. Substrate elasticity did not modify fibroblast IL‐11 content. The silencing of the α2 integrin subunit decreased the release of IL‐6. Similar effects were induced by TC‐I 15 (an α2β1 integrin inhibitor). The IL‐6 levels in the serum and heart were markedly lower in α2 integrin‐deficient mice B6.Cg‐Itga2tm1.1Tkun/tm1.1Tkun than wild type. Inhibition of Src kinase by AZM 475271 modifies the IL‐6 level. sIL‐6R secretion is not dependent on α2β1 integrin. Conclusion: The elastic properties of the substrate influence the release of IL‐6 by cardiac fibroblasts, and this effect is dependent on α2β1 integrin and kinase Src activation. 相似文献
104.
Mastroianni CM Paoletti F Valenti C Massetti AP Vullo V Delia S 《Mediators of inflammation》1994,3(1):57-60
The local production of tumour necrosis factor-alpha (TNFalpha) was evaluated in the cerebrospinal fluid (CSF) from ten patients with tuberculous meningitis (TBM). The degree of intrathecal immune activation was also studied by assessing the CSF levels of beta(2)-microglobulin (beta(2)-M) and adenosine deaminase activity (ADA). Results indicate that elevated CSF concentrations of TNFalpha, beta(2)-M and ADA were found in all TBM patients. Moreover, TNFalpha is produced and selectively concentrated for a long period of time, while beta(2)-M and ADA values progressively decline during the course of TBM. Our findings suggest that in TBM patients, after an early activation of immune cells, there is an enhanced and continuous production of TNFalpha at the site of infection. 相似文献
105.
Vacca RA Valenti D Bobba A de Pinto MC Merafina RS De Gara L Passarella S Marra E 《FEBS letters》2007,581(5):917-922
To find out whether and how proteasome is involved in plant programmed cell death (PCD) we measured proteasome function in tobacco cells undergoing PCD as a result of heat shock (HS-PCD). Reactive oxygen species (ROS) production, cytochrome c levels and caspase-3-like protease activation were also measured in the absence or presence of MG132, a proteasome inhibitor. We show that proteasome activation occurs in early phase of HS-PCD upstream of the caspase-like proteases activation; moreover inhibition of proteasome function by MG132 results in prevention of PCD perhaps due to the prevention of ROS production, cytochrome c release and caspase-3-like protease activation. 相似文献
106.
The iron status of 26 patients with essential thrombocythaemia (ET) was evaluated at diagnosis by means of bone marrow iron and blood studies, including serum ferritin determination. Nine patients were males, 17 females, and the mean age was 53 years (range 7-81). A decreased or absent iron level by semiquantitative estimation on bone marrow smears was observed in 77% of patients, and 81% had a low sideroblast score. Such a marrow pattern of iron depletion was equally distributed between both sexes. Contrasting with this, normal Hb, MCV, serum iron and serum ferritin were registered in the majority of cases. According to these results, absent or decreased marrow iron would be a common feature in ET, generally not reflecting true iron deficiency, as it occurs in the remaining chronic myeloproliferative disorders. Thus, in patients in whom ET is suspected, the diagnostic criterion of ruling out iron deficiency would be better served by serum ferritin measurement than by bone marrow iron estimation. 相似文献
107.
Pineal cell aggregates in 5, 10 and 15 day-old chick embryos have been studied. Cell aggregates were classified into rosettes or vesicles and spheroid and ellipsoid vesicles distinguished. The number of pineal vesicles per unit of surface (vesicle density) was determined in three pineal portions: apical, anterior and posterior. By day 5, only cellular rosettes were found, mainly in the apical portion. After 10 and 15 days, the presence of rosettes was occasional. The posterior wall showed only small spheroid vesicles, while in the apical and anterior areas ellipsoid vesicles were also observed. Moreover, the spheroid/ellipsoid vesicle ratio increased from the 10th to the 15th day of incubation. The vesicle density decreased between the 10th and 15th day because of the increase in both vesicle and pineal size, without changes in the total number of vesicles. The results suggest that changes in vesicle morphology and density could be related to the functional activity of the pineal gland during embryonic development. 相似文献
108.
109.
Pinnen F Cacciatore I Cornacchia C Mollica A Sozio P Cerasa LS Iannitelli A Fontana A Nasuti C Di Stefano A 《Amino acids》2012,42(1):261-269
Parkinson’s disease (PD) is a neurodegenerative disorder associated primarily with loss of dopamine (DA) neurons in the nigrostriatal
system. With the aim of increasing the bioavailability of l-dopa (LD) after oral administration and of overcoming the pro-oxidant effect associated with LD therapy, we designed a peptidomimetic
LD prodrug (1) able to release the active agent by enzyme catalyzed hydrolysis. The physicochemical properties, as well as the chemical
and enzymatic stabilities of the new compound, were evaluated in order to check both its stability in aqueous medium and its
sensitivity towards enzymatic cleavage, providing the parent LD drug, in rat and human plasma. The radical scavenging activities
of prodrug 1 was tested by using both the DPPH–HPLC and the DMSO competition methods. The results indicate that the replacement of cysteine
GSH portion by methionine confers resistance to oxidative degradation in gastric fluid. Prodrug 1 demonstrated to induce sustained delivery of DA in rat striatal tissue with respect to equimolar LD dosages. These results
are of significance for prospective therapeutic application of prodrug 1 in pathological events associated with free radical damage and decreasing DA concentration in the brain. 相似文献
110.
Cinzia Di Pietro Marco Ragusa Davide Barbagallo Laura R Duro Maria R Guglielmino Alessandra Majorana Rosario Angelica Marina Scalia Luisa Statello Loredana Salito Luisa Tomasello Salvo Pernagallo Salvo Valenti Vito D'Agostino Patrizio Triberio Igor Tandurella Giuseppe A Palumbo Piera La Cava Viviana Cafiso Taschia Bertuccio Maria Santagati Giovanni Li Destri Salvatore Lanzafame Francesco Di Raimondo Stefania Stefani Bud Mishra Michele Purrello 《BMC medical genomics》2009,2(1):1-35