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   85篇
  免费   3篇
  2023年   1篇
  2021年   5篇
  2020年   3篇
  2019年   4篇
  2018年   1篇
  2017年   5篇
  2016年   6篇
  2014年   6篇
  2013年   7篇
  2012年   6篇
  2011年   10篇
  2010年   1篇
  2009年   1篇
  2008年   4篇
  2007年   3篇
  2006年   2篇
  2005年   2篇
  2004年   3篇
  2003年   2篇
  2001年   3篇
  2000年   3篇
  1998年   2篇
  1997年   4篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
排序方式: 共有88条查询结果,搜索用时 265 毫秒
31.
32.
Variability of the beta-amylase gene in bread wheat, artificial amphidiploids, and derived introgression wheat lines was analyzed. Variation in homeologous beta-amylase sequences caused by the presence of MITE (Miniature Inverted-Repeat Transposable Element) and its footprint has been identified in bread wheat. The previously unknown location of MITE in Triticum urartu and T. aestivum L. beta-amylase gene has been found. These species have a MITE sequence in the third intron of beta-amylase, as opposed to Aegilops comosa and a number of other Triticeae species, which have it in the fourth intron. These two MITEs from Ae. comosa and T. aestivum were shown to have low identity scores. Miosa, an artificial amphidiploid, which has the M genome from Ae. comosa was shown to lose the MITE sequences. This loss might be caused by genomic shock due to allopolyploidization.  相似文献   
33.
JBIC Journal of Biological Inorganic Chemistry - In order to shed light on metal-dependent mechanisms for O–O bond cleavage, and its microscopic reverse, we compare herein the electronic and...  相似文献   
34.
Amino Acids - The activation of the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, by anabolic stimuli (such as muscle contraction or essential amino...  相似文献   
35.
36.
The Rif1 protein is a negative regulator of DNA replication initiation in eukaryotes. Here we show that budding yeast Rif1 inhibits DNA replication initiation at the rDNA locus. Absence of Rif1, or disruption of its interaction with PP1/Glc7 phosphatase, leads to more intensive rDNA replication. The effect of Rif1-Glc7 on rDNA replication is similar to that of the Sir2 deacetylase, and the two would appear to act in the same pathway, since the rif1Δ sir2Δ double mutant shows no further increase in rDNA replication. Loss of Rif1-Glc7 activity is also accompanied by an increase in rDNA repeat instability that again is not additive with the effect of sir2Δ. We find, in addition, that the viability of rif1Δ cells is severely compromised in combination with disruption of the MRX or Ctf4-Mms22 complexes, both of which are implicated in stabilization of stalled replication forks. Significantly, we show that removal of the rDNA replication fork barrier (RFB) protein Fob1, alleviation of replisome pausing by deletion of the Tof1/Csm3 complex, or a large deletion of the rDNA repeat array all rescue this synthetic growth defect of rif1Δ cells lacking in addition either MRX or Ctf4-Mms22 activity. These data suggest that the repression of origin activation by Rif1-Glc7 is important to avoid the deleterious accumulation of stalled replication forks at the rDNA RFB, which become lethal when fork stability is compromised. Finally, we show that Rif1-Glc7, unlike Sir2, has an important effect on origin firing outside of the rDNA locus that serves to prevent activation of the DNA replication checkpoint. Our results thus provide insights into a mechanism of replication control within a large repetitive chromosomal domain and its importance for the maintenance of genome stability. These findings may have important implications for metazoans, where large blocks of repetitive sequences are much more common.  相似文献   
37.
38.
HIV-1, an enveloped RNA virus, produces viral particles that are known to be much more heterogeneous in size than is typical of non-enveloped viruses. We present here a novel strategy to study HIV-1 Viral Like Particles (VLP) assembly by measuring the size distribution of these purified VLPs and subsequent viral cores thanks to Atomic Force Microscopy imaging and statistical analysis. This strategy allowed us to identify whether the presence of viral RNA acts as a modulator for VLPs and cores size heterogeneity in a large population of particles. These results are analyzed in the light of a recently proposed statistical physics model for the self-assembly process. In particular, our results reveal that the modulation of size distribution by the presence of viral RNA is qualitatively reproduced, suggesting therefore an entropic origin for the modulation of RNA uptake by the nascent VLP.  相似文献   
39.
We report an optical investigation of conjugated polymer (P3HT)/fullerene (PCBM) semiconductor blends sensitized by near‐infrared absorbing quantum dots (PbS QDs). A systematic series of samples that include pristine, binary and ternary blends of the materials are studied using steady‐state absorption, photoluminescence (PL) and ultrafast transient absorption. Measurements show an enhancement of the absorption strength in the near‐infrared upon QD incorporation. PL quenching of the polymer and the QD exciton emission is observed and predominantly attributed to intermaterial photoinduced charge transfer processes. Pump‐probe experiments show photo‐excitations to relax via an initial ultrafast decay while longer‐lived photoinduced absorption is attributed to charge transfer exciton formation and found to depend on the relative ratio of QDs to P3HT:PCBM content. PL experiments and transient absorption measurements indicate that interfacial charge transfer processes occur more efficiently at the fullerene/polymer and fullerene/nanocrystal interfaces compared to polymer/nanocrystal interfaces. Thus the inclusion of the fullerene seems to facilitate exciton dissociation in such blends. The study discusses important and rather unexplored aspects of exciton recombination and charge transfer processes in ternary blend composites of organic semiconductors and near‐infrared quantum dots for applications in solution‐processed photodetectors and solar cells.  相似文献   
40.

?

Claims have been made in a pilot study that a new form of short-term rehabilitation according to ?Best Practice' standards would change signs and symptoms of patients with scoliosis in the short-term. Aim of this study is to repeat the study published 2010 with a larger sample of patients using the same protocol. Both authors have undergone training in this special approach to scoliosis rehabilitation in 2010.

Materials and methods

34 patients with Adolescent Idiopathic Scoliosis (AIS), 32 girls and 2 boys, average age 13.7 years and an average Cobb angle of 28.7 degrees (21-43 degrees) underwent Scoliosis Short-Term Rehabilitation (SSTR) of seven days. Two days with an intensity of 3 × 90 min sessions/day, and five days with an intensity of 2 × 60 min sessions/day. Angle of trunk rotation (ATR) was measured before and after the time of treatment as well as the active correctability of the ATR after the programme as it has been done in the pilot investigation. Additionally to that, we also recorded the changes in Vital Capacity (VC) before and after the programme.

Results

ATR was reduced significantly from 11,5 degrees to 8,4 degrees, the active correctability as measured with the Scoliometer (TM) was also reduced significantly from the ATR after treatment 8,9 degrees to 6,5 degrees in the patients with thoracic curves. VC improved significantly (P < 0,05) from 2073 ml to 2326 ml.

Discussion

The results achieved in the pilot investigation published previously are repeatable. The deformity of the trunk can be reduced significantly after SSTR. During the pilot study VC was not investigated. In our study VC improved significantly. Therefore, also shorter rehabilitation times with an appropriate programme seem to be able to change signs and symptoms of a patient with scoliosis. Like the out-patient Schroth programme as described in a study from Turkey, the SSTR provides benefits leading to an improvement of the condition.

Conclusion

Out-patient rehabilitation following the Scoliologic (TM) ?Best Practice' standards seems to provide an improvement of signs and symptoms of scoliosis patients in this study using a pre-/post prospective design. The results of the pilot study therefore seem to be repeatable.  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