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排序方式: 共有410条查询结果,搜索用时 15 毫秒
91.
Satoh K Doi K Nagata T Kishimoto N Suzuki K Otomo Y Kawai J Nakamura M Hirozane-Kishikawa T Kanagawa S Arakawa T Takahashi-Iida J Murata M Ninomiya N Sasaki D Fukuda S Tagami M Yamagata H Kurita K Kamiya K Yamamoto M Kikuta A Bito T Fujitsuka N Ito K Kanamori H Choi IR Nagamura Y Matsumoto T Murakami K Matsubara K Carninci P Hayashizaki Y Kikuchi S 《PloS one》2007,2(11):e1235
92.
Long-circulating near-infrared fluorescence core-cross-linked polymeric micelles: synthesis, characterization, and dual nuclear/optical imaging 总被引:2,自引:0,他引:2
Yang Z Zheng S Harrison WJ Harder J Wen X Gelovani JG Qiao A Li C 《Biomacromolecules》2007,8(11):3422-3428
We report the synthesis of PEG-coated, core-cross-linked polymeric micelles (CCPMs) derived from an amine-terminated amphiphilic block copolymer, poly(PEG-methacrylate)-b-poly(triethoxysilyl propylmethacrylate). The block copolymer self-assembled to form micellar nanoparticles, and a Cy-7-like near-infrared fluorescence (NIRF) dye was entrapped in the core bearing reactive ethoxysilane functional groups through a subsequent sol-gel process. The fluorescent signal of CCPMs on the molar basis was 16-fold brighter than that of Cy7. With an average diameter of 24 +/- 8.9 nm, CCPMs exhibited a prolonged blood half-life (t1/2,alpha = 1.25 h; t1/2,beta = 46.18 h) and moderate uptake by the mononuclear phagocytic system. Significant accumulation of CCPMs in human breast tumor xenografts allowed noninvasive monitoring of the uptake kinetics with both NIRF optical and gamma imaging techniques. Our data suggest that Cy7-entrapped CCPM nanoparticles are suitable for NIRF imaging of solid tumors and have potential applications in the imaging of tumor-associated molecular markers. 相似文献
93.
Shepperd LA Meadows JC Sochaj AM Lancaster TC Zou J Buttrick GJ Rappsilber J Hardwick KG Millar JB 《Current biology : CB》2012,22(10):891-899
The spindle assembly checkpoint (SAC) is the major surveillance system that ensures that sister chromatids do not separate until all chromosomes are correctly bioriented during mitosis. Components of the checkpoint include Mad1, Mad2, Mad3 (BubR1), Bub3, and the kinases Bub1, Mph1 (Mps1), and Aurora B. Checkpoint proteins are recruited to kinetochores when individual kinetochores are not bound to spindle microtubules or not under tension. Kinetochore association of Mad2 causes it to undergo a conformational change, which promotes its association to Mad3 and Cdc20 to form the mitotic checkpoint complex (MCC). The MCC inhibits the anaphase-promoting complex/cyclosome (APC/C) until the checkpoint is satisfied. SAC silencing derepresses Cdc20-APC/C activity. This triggers the polyubiquitination of securin and cyclin, which promotes the dissolution of sister chromatid cohesion and mitotic progression. We, and others, recently showed that association of PP1 to the Spc7/Spc105/KNL1 family of kinetochore proteins is necessary to stabilize microtubule-kinetochore attachments and silence the SAC. We now report that phosphorylation of the conserved MELT motifs in Spc7 by Mph1 (Mps1) recruits Bub1 and Bub3 to the kinetochore and that this is required to maintain the SAC signal. 相似文献
94.
Bulić-Jakus F Ulamec M Vlahović M Sincić N Katusić A Jurić-Lekć G Serman L Kruslin B Belicza M 《Collegium antropologicum》2006,30(4):921-924
Teratomas and teratocarcinomas are tumors containing tissue derivatives of all three germ-layers. They can be induced by transplantation of animal embryos to ectopic microenvironment. Development of malignant teratocarcinomas depends on embryonic stage, species-specificity and immunological competence of the host. In the man, teratomas and teratocarcinomas usually represent a subtype of germ-cell tumors but sacrococcygeal teratomas arise from the remnants of the pluripotent primitive streak. Undifferentiated embryonal carcinoma (EC) cells are responsible for the malignancy of experimental mouse teratocarcinomas. Mouse EC cells injected to the adult give rise to tumors and upon injection to early embryos to differentiated tissues--thus resembling normal mouse embryonic stem cells (mESC). Epigenetic changes rather than mutations are associated with transformation of mESC to EC cells. Human EC and ES cell-lines (hESC) contain chromosomal abnormalities and can form teratocarcinoma after transplantation. ES cells are among those proposed for cell replacement therapy in the man. Suicide gene introduction should be recommended prior to their use in vivo to ablate them in case of malignant transformation. 相似文献
95.
96.
Vlahović M Bulić-Jakus F Jurić-Lekić G Fucić A Marić S Serman D 《The International journal of developmental biology》1999,43(8):843-846
DNA methylation is an important mechanism for regulation of gene expression during vertebrate development. 5-azacytidine is used as an experimental tool for demethylation. In this work, a single dose of 5-azacytidine (5 mg/kg body weight) was administered to rats at different stages of development. After 5-azacytidine administration on the first or third day of pregnancy, no changes were detected. After administration on the fourth day of pregnancy or later, a reduction in growth was observed. After treatment on day five and on any other day till day eleven of pregnancy, no living fetuses were found. Of those treated on day twelve, 24% of fetuses survived, but forelimb and hindlimb malformations were present. Administered on day thirteen, 5-azacytidine did not interfere with survival, but malformations were still present. From day fourteen on, 5-azacytidine caused no gross external malformations. Placentas were also influenced by 5-azacytidine. They were significantly smaller and histological evaluation showed the labyrinthine part to be severely reduced. In contrast, trophoblast giant cells were more abundant than in controls. 相似文献
97.
Suzuki J Kato A Maeda N Hashimoto C Uchikoshi M Mizutani T Doke C Matsuzawa T 《Primates; journal of primatology》2003,44(3):273-280
We examined growth changes in concentrations of plasma insulin-like growth factor-1 (IGF-1) and testosterone, and somatometric
parameters in two captive male agile gibbons from birth to about 4 years of age, to examine the evolution of growth patterns
in primates. Plasma IGF-1 concentrations in agile gibbons generally increased with age with values ranging from 200 to 1,100 ng/ml.
The growth profiles in plasma IGF-1 in the gibbons were similar to those reported for chimpanzees. The highest concentrations
of plasma testosterone (230 and 296 ng/dl) were observed within the first 0.3 years from birth, then the concentrations rapidly
decreased and fluctuated below 100 ng/dl. Continuously higher IGF-1 concentrations were observed after 2.6 and 3.5 years of
age. The profiles of plasma testosterone in these gibbons also resembled those of other primates including humans. However,
their plasma testosterone levels in both neonate and adult stages (60 ng/dl) were lower than those reported for macaques and
chimpanzees of respective stages. The obtained growth profiles of plasma IGF-1 and testosterone suggest that the adolescent
phase starts around 2.6 or 3.5 years of age in male agile gibbons. The growth trend in many morphological parameters including
body weight showed a linear increase without a significant growth spurt at approximately the onset of puberty. Head length
and first digit length had reached a plateau during the study period. Brachial index, which indicates the relative length
of forearm to upper arm, significantly increased gradually through the growth period. This result indicates that forearm becomes
relatively longer than the upper arm with growth, which may be an evolutionary adaptation for brachiation. 相似文献
98.
Elena Magenau John Clifton-Brown Catherine Parry Chris Ashman Danny Awty-Carroll Andrea Ferrarini Mislav Kontek Enrico Martani Stefano Amaducci Chris Davey Oene Dolstra Vanja Jurišić Jason Kam Luisa M. Trindade Iris Lewandowski Andreas Kiesel 《Global Change Biology Bioenergy》2023,15(5):559-574
Due to its versatility and storability, biomass is an important resource for renewable materials and energy. Miscanthus hybrids combine high yield potential, low input demand, tolerance of certain marginal land types and several ecosystem benefits. To date, miscanthus breeding has focussed on increasing yield potential by maximising radiation interception through: (1) selection for early emergence, (2) increasing the growth rate to reach canopy closure as fast as possible, and (3) delayed flowering and senescence. The objective of this study is to compare early season re-growth in miscanthus hybrids cultivated across Europe. Determination of differences in early canopy development on end-of-year yield traits is required to provide information for breeding decisions to improve future crop performance. For this purpose, a trial was planted with four miscanthus hybrids (two novel seed-based hybrids M. sinensis × sinensis [M sin × sin] and M. sacchariflorus × sinensis [M sac × sin], a novel rhizome-based M sac × sin and a standard Miscanthus × giganteus [M × g] clone) in the UK, Germany, Croatia and Italy, and was monitored in the third and fourth growing season. We determined differences between the hybrids in base temperature, frost sensitivity and emergence strategy. M × g and M sac × sin mainly emerged from belowground plant organs, producing fewer but thicker shoots at the beginning of the growing season but these shoots were susceptible to air frosts (determined by recording 0°C 2 m above ground surface). By contrast, M sin × sin emerged 10 days earlier, avoiding damage by late spring frosts and producing a high number of thinner shoots from aboveground shoots. Therefore, we recommend cultivating M sac × sin at locations with low risk and M sin × sin at locations with higher risk of late spring frosts. Selecting miscanthus hybrids that produce shoots throughout the vegetation period is an effective strategy to limit the risk of late frost damage and avoid reduction in yield from a shortened growing season. 相似文献
99.
100.
Campostrini N Areces LB Rappsilber J Pietrogrande MC Dondi F Pastorino F Ponzoni M Righetti PG 《Proteomics》2005,5(9):2385-2395
In the analysis of a neuroblastoma xenograft implanted in mice using two-dimensional maps, some 85 proteins were found to be up- or down-regulated (out of a total of 264 detected by a medium-sensitivity colloidal Coomassie stain). When these spots were eluted and analysed by mass spectrometry in a quadrupole time of flight mass spectrometer, a number of spots were found to be envelopes of different polypeptide chains. Out of a total of 74 proteins identified, 52 (71%) were found to be singlets, 14 (19%) were doublets, 6 (8%) were triplets, 1 was a quadruplet and 1 a quintuplet. Analysis of the DeltapI and DeltaMr of all species contained in a single gel segment eluted helped point out potential errors in protein identification. This was a unique case, in that very minute bioptic sample loads were applied to the gel. In normal cases, where sample loads of ca. 1 mg of total protein are applied and typically at least 1000 spots are visualised, the singlets will be the minority, rarely exceeding 30% of all spots analysed. The experimental data on the abundance of overlapping spots were in excellent agreement with theoretical data calculated on the basis of the statistical theory of spot overlapping, originally proposed by Davis and further developed by some of the authors. Ways and means for minimizing spot overlap and visualising a greater number of spots in a two-dimensional map are discussed. 相似文献