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31.
32.
An earlier report indicated that a 26-amino-acid peptide (SA), comprised of the nuclear localization signal (NLS) of fibroblast growth factor-1 (FGF-1) and a membrane-permeable peptide, was able to stimulate DNA synthesis after it was taken up by NIH3T3 fibroblasts. Here, we report that SA, but not a mutant with the NLS motif destroyed, induced DNA synthesis in BALB/c3T3 murine fibroblasts, human vascular endothelial (HUVE) cells, and primary cultured hepatocytes, although the activity was weaker than that of FGF-1. The kinetics of SA-induced DNA synthesis and G1 cyclin expression were similar to those elicited by FGF-1, indicating that SA induces cell cycle progression. Kinetic analysis also suggested that SA stimulates only a fraction of the DNA replication in BALB/c3T3 cells. At high cell densities, SA-induced G1 cyclin expression and DNA synthesis were more strongly inhibited than those induced by FGF-1. SA did not induce cell division in HUVE and BALB/c3T3 cells and did not interfere with FGF-1-stimulated proliferation of HUVE cells. These results indicate that SA is able to partially induce cell cycle progression through a contact-inhibition sensitive signaling pathway, but it is insufficient to support cell mitosis. We also suggest that signaling by SA does not interfere with that of FGF-1. 相似文献
33.
We prove the existence of a Hamiltonian path in the Shuffle Exchange networkSX (n). This problem has been posed as an open problem by Leighton in [8] and Samatham and Pradhan in [11]. Its positive solution
has several consequences showing the computational abilities of theSX(n).
The extended abstract of this paper was presented at MFCS '92 (Lecture Notes in Computer Science, Vol. 629, pp. 246–254, Springer-Verlag,
Berlin, 1992). This work was partly supported by Grant No. Mo 285/3-2 from the DFG. 相似文献
34.
35.
R Feldmann F Breier P Duschet H L?w-Weiser F Gschnait 《Canadian Metallurgical Quarterly》1997,194(4):358-360
We report a single case of Weill-Marchesani syndrome, typically characterized by progressive joint stiffness, brachiymorphy, brachydactyly, and ectopia lentis. The clinical case appears particularly interesting as the patient also had primary osteoporosis, which until now has not been considered as a possible manifestation of Weill-Marchesani syndrome. 相似文献
36.
Volatilization of organotin species from municipal waste deposits: novel species identification and modeling of atmospheric stability 总被引:1,自引:0,他引:1
Krupp EM Merle JK Haas K Foote G Maubec N Feldmann J 《Environmental science & technology》2011,45(3):943-950
Organotin compounds are used as pesticides and fungicides as well as additives in plastics. This study identifies the de novo generation of novel volatile organotins in municipal waste deposits and their release via landfill gas. Besides tetramethyltin (Me(4)Sn), a strong neurotoxin, and 5 previously reported organotins, 13 novel ethylated, propylated, and butylated tetraalkyltin compounds were identified. A concentration of 2-4 μg of Sn m(-3) landfill gas was estimated for two landfill sites in Scotland. The atmospheric stability of Me(4)Sn and methylated tin hydrides was determined empirically in a static atmosphere in the dark and under UV light to simulate night- and daytime conditions. Theoretical calculations were carried out to help predict the experimentally obtained stabilities and to estimate the relative stabilities of other alkylated species. Assuming first-order kinetics, the atmospheric half-life for Me(3)SnH was found to be 33 ± 16 and 1311 ± 111 h during day- and nighttime conditions, respectively. Polyalkylation and larger alkyl substitutes tend to reduce the atmospheric stability. These results show that substantial concentrations of neurotoxic organotin compounds can be released from landfill sites and are sufficiently stable in the atmosphere to travel over large distances in night- and daytime conditions to populated areas. 相似文献
37.
We have coated gold nanorods (NRs) with thermoresponsive microgel shells based on poly(N-isopropylacrylamide) (pNIPAM). We demonstrate by simultaneous laser-heating and optical extinction measurements that the Au NR cores can be simultaneously used as fast optothermal manipulators (switchers) and sensitive optical reporters of the microgel state in a fully externally controlled and reversible manner. We support our results with optical modeling based on the boundary element method and 3D numerical analysis on the temperature distribution. Briefly, we show that due to the sharp increase in refractive index resulting from the optothermally triggered microgel collapse, the longitudinal plasmon band of the coated Au NRs is significantly red-shifted. The optothermal control over the pNIPAM shell, and thereby over the optical response of the nanocomposite, is fully reversible and can be simply controlled by switching on and off a NIR heating laser. In contrast to bulk solution heating, we demonstrate that light-triggering does not compromise colloidal stability, which is of primary importance for the ultimate utilization of these types of nanocomposites as remotely controlled optomechanical actuators, for applications spanning from drug delivery to photonic crystals and nanoscale motion. 相似文献
38.
The consistency of measures from informants' report and from objective testing, both incorporated into the CAMDEX interview, was tested for elderly persons with mild dementia (n = 46), with moderate dementia (n = 41), and without cognitive impairment (controls, n = 56). Informants' reports permitted grading severity of dementia and provided measures of memory and mental functioning in everyday activities highly related to indices derived from objective testing. 相似文献
39.
500 melanocytic lesions were examined by dermatoscopy using the ABCD rule prior to excision and histologic diagnosis. Regular nevi (n = 272) exhibited a score of 3.55 +/- 0.87, nevi with histologic signs of dysplasia (n = 190) a score of 4.0 +/- 0.68 and melanomas (n = 30) a score of 5.08 +/- 1.24. This study suggests that the ABCD rule of dermatoscopy greatly facilitates the evaluation of melanocytic lesions. When the dermatoscopic score is higher than 4.2, melanoma should be considered. 相似文献
40.