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41.
Nguyen Thanh Long Pham Ngoc Dinh Alain 《Mathematical Methods in the Applied Sciences》1993,16(4):281-295
We study the following initial and boundary value problem: In section 1, with u0 in L2(Ω), f continuous such that f(u) + ? non-decreasing for ? positive, we prove the existence of a unique solution on (0,T), for each T > 0. In section 2 it is proved that the unique soluition u belongs to L2(0, T; H ∩ H2) ∩ L∞(0, T; H) if we assume u0 in H and f in C1(?,?). Numerical results are given for these two cases. 相似文献
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45.
Wall DB Kachman MT Gong SS Parus SJ Long MW Lubman DM 《Rapid communications in mass spectrometry : RCM》2001,15(18):1649-1661
A liquid-phase three-dimensional protein separation method has been developed that is used to separate the cytosolic fraction of a HEL cell lysate via isoelectric focusing (IEF), nonporous silica (NPS) reversed-phase high-performance liquid chromatography (RP-HPLC) and electrospray ionization time-of-flight mass spectrometry (ESI-TOFMS), respectively. Several hundred unique protein molecular weights were observed in a pI range from 4.8 to 8.5 and a mass range from 5 to 85 kDa. Proteins were positively identified by analysis of the pI (+/-0.5 pI units), an intact protein molecular weight (+/-150 ppm), and peptide mass mapping results. Using the molecular weight (MW) and peptide mapping results of identified proteins it was possible to characterize their posttranslational (PTMs) and/or sequence modifications. PTMs were detected on both forms of cytosolic actin, heat shock 90 beta, HINT and alpha-enolase. Sequence modifications or conflicts were observed for beta-and gamma-actin, ATP beta-synthase and heat shock 90 beta. IEF-NPS-RP-HPLC/ESI-TOFMS was used to determine experimental pI, MW and relative hydrophobicity values for each protein detected. This data was used to generate a 2-D pI-MS protein map, where proteins are displayed according to their pI and molecular weight. Protein molecular weight peaks are represented as bands in the 2-D pI-MS image where the gray scale of each band is proportional to the intensity of the protein molecular weight peak. In addition, a third hydrophobicity dimension (%B) was added as the % acetonitrile elution to generate a 3-D pI-MS-%B plot where each protein can be tagged according to three parameters. 相似文献
46.
[structure: see text] Total synthesis of a cyclic depsipeptide with proposed structure of palau'amide is achieved, which features a stereoselective elaboration of its 5,7-dihydroxy-2,6-dimethyldodec-2-en-11-ynoic acid unit. The synthetic compound has potent cytotoxicity against three tumor cell lines but different rotation and NMR data compared to those reported for palau'amide, which implies that its conformation is close to that of palau'amide but that some stereochemistry in palau'amide was misassigned. 相似文献
47.
Blake AJ Brett MT Champness NR Khlobystov AN Long DL Wilson C Schröder M 《Chemical communications (Cambridge, England)》2001,(21):2258-2259
4,4'-Bipyridine N,N'-dioxide (L) acts as a hydrogen-bond acceptor in the compounds ([M(NO3)2(H2O)4].L2) (M = Co, Ni) to form doubly-interpenetrated framework materials with sixfold topological connectivity. 相似文献
48.
John Fielden Patrick T. Gunning De-Liang Long Margaret Nutley Arkady Ellern Paul Kgerler Leroy Cronin 《Polyhedron》2006,25(18):3474-3480
The coordination chemistry of the tetradentate pyridyl N-donor ligand cis-3,5-bis-[2-pyridinyleneamin]-trans-hydroxycyclohexane (DDOP) has been investigated with zinc(II) nitrate and triflate. The resulting complexes, [Zn(DDOP)(H2O)(NO3)](NO3) (1), and [Zn(DDOP)(H2O)(OTf)](OTf) (2) differ not only in their counterions, but also the arrangement of the axial ligands and their solid state hydrogen bonded networks. Isothermal titration calorimetry was used to assess the difference in binding properties exhibited by the two zinc complexes at physiological pH in an aqueous environment. A series of coordinating amino acids were found to preferentially bind to the mononuclear zinc triflate (1) complex over the corresponding nitrate (2) assembly, with histidine exhibiting a two centre binding mode. 相似文献
49.
Effect of amphiphilic molecules upon the chromatic transitions of polymerized 10,12-pentacosadiynoic acid (PCDA) vesicles in aqueous solutions was reported. The colorimetric response of polymerized PCDA vesicles for 1-pentanol is higher than that for ethanol due to more hydrophobic property of 1-pentanol. The colorimetric response of polymerized PCDA vesicles for sodium dodecyl sulfate (SDS) and Triton X-100 is lower than that for cetyltrimethylammonium bromide (CTAB). The strong ability of CTAB to induce chromatic transition of the vesicles is related to the positively charged headgroups of CTAB, which favors approach of CTAB to the negatively charged carboxylate groups at the vesicle surface. The insertion of alkyl chain of CTAB into the hydrophobic domain perturbs the conformation of the conjugated polymer backbone and induces color change of polydiacetylene vesicles. For a series of alkylamine hydrochloric salts, the longer the alkyl chain, the stronger the ability of alkylamine to induce chromatic transition of polydiacetylene vesicles. 相似文献
50.
Sodium phosphate tellurite glasses in the system (NaPO(3))(x)(TeO(2))(1-) (x) were prepared and structurally characterized by thermal analysis, vibrational spectroscopy, X-ray photoelectron spectroscopy (XPS) and a variety of complementary solid-state nuclear magnetic resonance (NMR) techniques. Unlike the situation in other mixed-network-former glasses, the interaction between the two network formers tellurium oxide and phosphorus oxide produces no new structural units, and no sharing of the network modifier Na(2)O takes place. The glass structure can be regarded as a network of interlinked metaphosphate-type P(2) tetrahedral and TeO(4/2) antiprismatic units. The combined interpretation of the O 1s XPS data and the (31)P solid-state NMR spectra presents clear quantitative evidence for a nonstatistical connectivity distribution. Rather, the formation of homoatomic P--O--P and Te--O--Te linkages is favored over mixed P--O--Te connectivities. As a consequence of this chemical segregation effect, the spatial sodium distribution is not random, as also indicated by a detailed analysis of (31)P/(23)Na rotational echo double-resonance (REDOR) experiments. 相似文献