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排序方式: 共有159条查询结果,搜索用时 15 毫秒
1.
Lubomir V. Kolev 《Reliable Computing》2006,12(3):193-202
Recently, a direct method for outer solution of linear parametric systems has been suggested for the general case where the
elements of the system are nonlinear functions of independent interval parameters. In this paper, an improvement of the method
is introduced which may lead to a narrower outer solution. 相似文献
2.
J Kuczera S Witek TE Kral J H?adyszowski J Luczyński S Przestalski 《Canadian Metallurgical Quarterly》1998,53(5-6):389-397
The effect of a group of model lysosomotropic compounds on the process of Ca2+ ion desorption from lecithin liposome membranes was studied. The compounds studied were: hydrochlorides of fatty acids 2-dimethylaminoethyl esters (DM-n) for n = 9, 11, 13 and 15 carbon atoms in the fatty acid alkyl chain and methochloride of 2-dimethylaminoethyl laurate (DMS-11). It was found that all the compounds studied caused increased desorption with increasing concentration of the compound. Most effective was the quaternary ammonium salt, DMS-11. Moreover, it was found that the process of Ca2+ desorption from the membrane depended on pH of the medium. Compound DM-11 was more active at pH 8 than at pH 5. The action of DM-n compounds depended on the alkyl chain length, DM-11 and DM-13 being the most active. Apparently free amines penetrate the phospholipid membranes and incorporate into its hydrophobic core causing structural deformations. Hydrochlorides of fatty acids and the quaternary ammonium salt induce desorption of calcium ions mostly as a result of competitive electrostatic interactions. By quantum chemistry, PM3 method, and methods of molecular modelling we established the higher hydrophilicity of the polar head of DM-n series with respect to the polar head of the DMS-n compounds. DM-n compounds possess both acceptor and donor properties for hydrogen bonding while DMS-n are instrumental as acceptors only. It should be noted, that the results obtained in this paper for model membranes are in accordance with those for biological ones. 相似文献
3.
Discusses retouching of the Kallikak family photographs in H. H. Goddard's (1912) study of mental retardation and heredity, with reference to analyses by R. E. Fancher (see record 1987-31600-001) and S. J. Gould (1981), and concurs with Fancher that the retouching was probably not done for deceitful purposes. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
5.
Maria Giretova Lubomir Medvecky Radoslava Stulajterova Tibor Sopcak Jaroslav Briancin Monika Tatarkova 《Journal of materials science. Materials in medicine》2016,27(12):181
Polyhydroxybutyrate/chitosan/calcium phosphate composites are interesting biomaterials for utilization in regenerative medicine and they may by applied in reconstruction of deeper subchondral defects. Insufficient informations were found in recent papers about the influence of lysozyme degradation of chitosan in calcium phosphate/chitosan based composites on in vitro cytotoxicity and proliferation activity of osteoblasts. The effect of enzymatic chitosan degradation on osteoblasts proliferation was studied on composite films in which the porosity of origin 3D scaffolds was eliminated and the surface texture was modified. The significantly enhanced proliferation activity with faster population growth of osteoblasts were found on enzymatically degraded biopolymer composite films with α-tricalcium phosphate and nanohydroxyapatite. No cytotoxicity of composite films prepared from lysozyme degraded scaffolds containing a large fraction of low molecular weight chitosans (LMWC), was revealed after 10 days of cultivation. Contrary to above in the higher cytotoxicity origin untreated nanohydroxyapatite films and porous composite scaffolds. The results showed that the synergistic effect of surface distribution, morphology of nanohydroxyapatite particles, microtopography and the presence of LMWC due to chitosan degradation in composite films were responsible for compensation of the cytotoxicity of nanohydroxyapatite composite films or porous composite scaffolds. 相似文献
6.
In this paper the problem of finding the set of all real solutions to a system of n non-linear equations contained in a given n-dimensional box (the global solution problem) is considered. A new method for solving the global solution problem is suggested. It is based on a transformation of the original system into a larger system of separable form. The global solution of the latter system is then found in a most efficient manner by a new interval method which exploits the separabily property. Numerical examples illustrating the efficiency of the method suggested are provided. 相似文献
7.
Lubomir Mraz Vladimir Cervenka Dan Komosny Milan Simek 《Wireless Personal Communications》2013,71(4):2783-2803
Although the ZigBee technology is massively deployed the performance question still remains unanswered. There is a lack of serious performance evaluations and thus this paper provides a comprehensive and unbiased study of the ZigBee PRO technology. An extensive real measurement was conducted to accomplish this task. We found out a big performance gap among ZigBee implementations even though they are compliant with the ZigBee standard. The presented results and analysis could be beneficial for many wireless sensor network developers. 相似文献
8.
Structure–Activity Relationships of JMV4463, a Vectorized Cathepsin D Inhibitor with Antiproliferative Properties: The Unique Role of the AMPA‐Based Vector 下载免费PDF全文
Dr. Lubomir L. Vezenkov Clément A. Sanchez Dr. Virginie Bellet Dr. Vincent Martin Dr. Marie Maynadier Dr. Nadir Bettache Prof. Vincent Lisowski Prof. Jean Martinez Dr. Marcel Garcia Dr. Muriel Amblard Dr. Jean‐François Hernandez 《ChemMedChem》2016,11(3):302-308
Cathepsin D (CathD) is overexpressed and secreted by several solid tumors and stimulates their growth, the mechanism of which is still not understood. In this context, the pepstatin bioconjugate JMV4463 [Ac‐arg‐O2Oc‐(Val)3‐Sta‐Ala‐Sta‐(AMPA)4‐NH2; O2Oc=8‐amino‐3,6‐dioxaoctanoyl, Sta=statine, AMPA=ortho‐aminomethylphenylacetyl], containing a new kind of cell‐penetrating vector, was previously shown to exhibit potent antiproliferative effects in vitro and to delay the onset of tumors in vivo. In this study, we performed a structure–activity relationship analysis to evaluate the significance of the inhibitor and vector moieties of JMV4463. By modifying both statine residues of pepstatin we found that the antiproliferative activity is correlated with CathD inhibition, supporting a major role of the catalytic activity of intracellular CathD in cancer cell proliferation. Replacing the vector composed of four AMPA units with other vectors was found to abolish cytotoxicity, although all of the conjugates enabled pepstatin transport into cells. In addition, the AMPA4 vector must be localized at the C terminus of the bioconjugate. The unexpected importance of the vector structure and position for cytotoxic action suggests that AMPA4 enables pepstatin to inhibit the proteolysis of critical CathD substrates involved in cell proliferation via a unique mechanism of action. 相似文献
9.
The microstructures of two as-cast heats of niobium-modified HP stainless steels were characterized. Particular attention
was paid to the interdendritic niobium-rich carbides formed during solidification of these alloys. At low magnifications,
these precipitates are grouped in colonies of similar lamellae. Higher magnifications revealed that the lamellae actually
obtain two distinct morphologies. The type I morphology exhibits broad planar interfaces with a smooth platelike shape. Type
II lamellae have undulating interfaces and an overall reticulated shape. To provide further insight into the origin of these
two different morphologies, the microstructure and crystallography of each have been studied in detail using high resolution
scanning electron microscopy, transmission electron microscopy, various electron diffraction methods (electron backscatter
diffraction (EBSD), selected area diffraction (SAD), and convergent beam electron diffraction (CBED)), and energy dispersive
X-ray spectroscopy. 相似文献
10.