首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   235篇
  免费   7篇
  242篇
  2024年   1篇
  2023年   1篇
  2022年   3篇
  2021年   3篇
  2020年   3篇
  2019年   5篇
  2018年   6篇
  2017年   3篇
  2016年   5篇
  2015年   13篇
  2014年   13篇
  2013年   23篇
  2012年   19篇
  2011年   19篇
  2010年   14篇
  2009年   8篇
  2008年   21篇
  2007年   16篇
  2006年   12篇
  2005年   8篇
  2004年   12篇
  2003年   16篇
  2002年   8篇
  2001年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   4篇
  1989年   2篇
排序方式: 共有242条查询结果,搜索用时 15 毫秒
1.
Symptoms of fairy rings caused by Lepista sordida have been reported on Zoysiagrass (Zoysia spp.) turf maintained at fairway height (2 cm), but not on bentgrass (Agrostis spp.) maintained at putting green height (0.5 cm). The mycelia of this fungus inhabit primarily the upper 0–2 cm layer of the soil extending into the thatch. To compare conditions for the mycelial growth in Z. matrella turf to those in A. palustris turf, we examined the effects of nutrients, temperature, water potential, and pH in the field as well as in the laboratory. Greater growth of the mycelia was observed in medium that included hot water extracts from soil of the 0–1 cm zone in Z. matrella turf compared to that from A. palustris. The upper soil layer in Z. matrella turf contained more organic matter from clippings than that in A. palustris. The temperature and water potential of the 0–2 cm soil zone in Z. matrella turf were also more favorable for the mycelial growth. The soil pH values of this zone in Z. matrella turf were less favorable compared to A. palustris but within the range for accelerating mycelial growth. Part of this study was presented orally at the 46th meeting of the Mycological Society of Japan in 2002  相似文献   
2.
3.
LL5β has been identified as a microtubule-anchoring factor that attaches EB1/CLIP-associating protein (CLASP)–bound microtubule plus ends to the cell cortex. In this study, we show that LL5β and its homologue LL5α (LL5s) colocalize with autocrine laminin-5 and its receptors, integrins α3β1 and α6β4, at the basal side of fully polarized epithelial sheets. Depletion of both laminin receptor integrins abolishes the cortical localization of LL5s, whereas LL5 depletion reduces the amount of integrin α3 at the basal cell cortex. Activation of integrin α3 is sufficient to initiate LL5 accumulation at the cell cortex. LL5s form a complex with the cytoplasmic tails of these integrins, but their interaction might be indirect. Analysis of the three-dimensional distribution of microtubule growth by visualizing EB1-GFP in epithelial sheets in combination with RNA interference reveals that LL5s are required to maintain the density of growing microtubules selectively at the basal cortex. These findings reveal that signaling from laminin–integrin associations attaches microtubule plus ends to the epithelial basal cell cortex.  相似文献   
4.
    
Immune checkpoint inhibitors improved the survival rate of patients with unresectable melanoma. However, some patients do not respond, and variable immune‐related adverse events have been reported. Therefore, more effective and antigen‐specific immune therapies are urgently needed. We previously reported the efficacy of an immune cell therapy with immortalized myeloid cells derived from induced pluripotent stem cells (iPS‐ML). In this study, we generated OX40L‐overexpressing iPS‐ML (iPS‐ML‐Zsgreen‐OX40L) and investigated their characteristics and in vivo efficacy against mouse melanoma. We found that iPS‐ML‐Zsgreen‐OX40L suppressed the progression of B16‐BL6 melanoma, and prolonged survival of mice with ovalbumin (OVA)‐expressing B16 melanoma (MO4). The number of antigen‐specific CD8+ T cells was higher in spleen cells treated with OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L than in those without OX40L. The OVA peptide‐pulsed iPS‐ML‐Zsgreen‐OX40L significantly increased the number of tumor‐infiltrating T lymphocytes (TILs) in MO4 tumor. Flow cytometry showed decreased regulatory T cells but increased effector and effector memory T cells among the TILs. Although we plan to use allogeneic iPS‐ML in the clinical applications, iPS‐ML showed the tumorgenicity in the syngeneic mice model. Incorporating the suicide gene is necessary to ensure the safety in the future study. Collectively, these results indicate that iPS‐ML‐Zsgreen‐OX40L therapy might be a new method for antigen‐specific cancer immunotherapy.  相似文献   
5.
    

Basidiomycetous yeasts in the genus Pseudozyma are known to produce extracellular glycolipids called mannosylerythritol lipids (MELs). Pseudozyma tsukubaensis produces a large amount of MEL-B using olive oil as the sole carbon source (> 70 g/L production). The MEL-B produced by P. tsukubaensis is a diastereomer type of MEL-B, which consists of 4-O-β-d-mannopyranosyl-(2R,3S)-erythritol as a sugar moiety, in contrast to the conventional type of MELs produced by P. antarctica, which contain 4-O-β-d mannopyranosyl-(2S,3R)-erythritol. In this study, we attempted to increase the production of the diastereomer type of MEL-B in P. tsukubaensis 1E5 by introducing the genes encoding two lipases, PaLIPAp (PaLIPA) and PaLIPBp (PaLIPB) from P. antarctica T-34. Strain 1E5 expressing PaLIPA exhibited higher lipase activity than the strain possessing an empty vector, which was used as a negative control. Strains of 1E5 expressing PaLIPA or PaLIPB showed 1.9- and 1.6-fold higher MEL-B production than the negative control strain, respectively, and oil consumption was also accelerated by the introduction of these lipase genes. MEL-B production was estimated using time course analysis in the recombinant strains. Strain 1E5 expressing PaLIPA produced 37.0 ± 1.2 g/L of MEL-B within 4 days of cultivation, whereas the strain expressing an empty vector produced 22.1 ± 7.5 g/L in this time. Overexpression of PaLIPA increased MEL-B production by P. tsukubaensis strain 1E5 from olive oil as carbon source by more than 1.7-fold.

  相似文献   
6.
ABSTRACT: BACKGROUND: Kleine-Levin syndrome is a rare idiopathic form of episodic hypersomnia that typically occurs during adolescence. The cardinal clinical features are recurrent hypersomnia, accompanied by cognitive disturbances and behavioral abnormalities [1]. The most typical form of classical Kleine-Levin syndrome is associated with hyperphagia [2, 3], although hyperphagia is now optional after change of the criteria. Hypersexuality, behavioral disinhibition, delusions, autonomic alteration and hallucinations have also been described, but the patients show normal cognitive function and behavior between attacks. The pathogenesis of Kleine-Levin syndrome is not yet known. Although most cases of recurrent hypersomnia are sporadic, the occurrence of nine familial cases indicate that there may be a genetic predisposition to the syndrome [4-8] However, no cases of twins affected with Kleine-Levin syndrome have been reported [9]. In this case study we describe monozygotic twins suffering from the syndrome. This is the first case report describing twins affected with Kleine-Levin syndrome thereby supporting the theory that there is an underlying genetic predisposition to the syndrome.  相似文献   
7.
Tetracycline-resistant (Tet(r)) bacteria were isolated from fishes collected at three different fish farms in the southern part of Japan in August and September 2000. Of the 66 Tet(r) gram-negative strains, 29 were identified as carrying tetB only. Four carried tetY, and another four carried tetD. Three strains carried tetC, two strains carried tetB and tetY, and one strain carried tetC and tetG. Sequence analyses indicated the identity in Tet(r) genes between the fish farm bacteria and clinical bacteria: 99.3 to 99.9% for tetB, 98.2 to 100% for tetC, 99.7 to 100% for tetD, 92.0 to 96.2% for tetG, and 97.1 to 100% for tetY. Eleven of the Tet(r) strains transferred Tet(r) genes by conjugation to Escherichia coli HB-101. All transconjugants were resistant to tetracycline, oxycycline, doxycycline, and minocycline. The donors included strains of Photobacterium, Vibrio, Pseudomonas, Alteromonas, Citrobacter, and Salmonella spp., and they transferred tetB, tetY, or tetD to the recipients. Because NaCl enhanced their growth, these Tet(r) strains, except for the Pseudomonas, Citrobacter, and Salmonella strains, were recognized as marine bacteria. Our results suggest that tet genes from fish farm bacteria have the same origins as those from clinical strains.  相似文献   
8.
9.
Mitochondrial DNA (mtDNA) is highly susceptible to mutations that result in polymorphisms and diseases including diabetes. We analyzed heteroplasmy, polymorphisms related to diabetes, and complementation by fusogenic proteins. Cytoplast fusion and microinjection allow, defects in mutated mtDNA inside a heteroplasmic cell to be complemented by fusing two mitochondria via human fusogenic proteins. We characterized three hfzos as well as two OPAls that prevent apoptosis. Two coiled coil domains and GTPase domains in these fusogenic proteins regulate membrane fusion. The hfzo genes were expressed mainly in the brain and in muscle that are postmitotic, but not in the pancreas. Under the influence of polymorphisms of mtDNA and nDNA, the vicious circle of reactive oxygen species and mutations in cell can be alleviated by mitochondrial fusion.  相似文献   
10.
We isolated a temperature-sensitive mutant with a mutation in mviN, an essential gene in Escherichia coli. At the nonpermissive temperature, mviN mutant cells swelled and burst. An intermediate in murein synthesis, polyprenyl diphosphate-N-acetylmuramic acid-(pentapeptide)-N-acetyl-glucosamine, accumulated in mutant cells. These results indicated that MviN is involved in murein synthesis.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号