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91.
Phosphorylation of both tyrosine and serine residues of focal adhesion kinase (FAK) was stimulated by the adhesion of BALB/c mouse 3T3 cells to fibronectin, but phosphorylation of threonine was not detectable. Acidic and basic fibroblast growth factors also stimulated the phosphorylation of serine and tyrosine of FAK in cells adhered to poly-L-lysine, but epidermal growth factor and platelet-derived growth factor did not. A fusion protein of fibronectin and basic fibroblast growth factor effectively induced the phosphorylation of FAK. Phosphorylation of FAK in the rat myoblast L-6 cell line, which lacks fibroblast growth factor receptors, was not stimulated by fibroblast growth factors, suggesting that the interaction of fibroblast growth factors with their receptors might cause the phosphorylation of FAK. 相似文献
92.
Stimulated Raman scattering (SRS) experiments in hydrogen have been performed with a collimated beam from ane -beam pumped XeF laser operating at 353 nm. An unstable resonator provided good beam quality at energies of about 1.2 J and pulse lengths of about 320 ns. A folded-path Raman cell allowed cell lengths to be continuously varied up to 11 m at a hydrogen pressure of 10 atm. Energy conversion efficiencies of >45 percent to first Stokes (S1 ) at 414 nm and >40 percent to second Stokes (S2 ) at 500 nm were observed with no indication of significant four-wave processes. 相似文献
93.
94.
VM Cheremisin VE Savello IE Tiurin NA Anosov NL Turanov MV Shapovalov 《Canadian Metallurgical Quarterly》1998,(4):4-9
The paper presents the data available in the literature on computed tomographic angiography and the first experience with it to study thoracic vessels. It details the principles of spiral computed tomography and CT angiography. Practical aspects of their implementation, as well as basic concepts are outlined. It is concluded that CT angiography is promising in studying thoracic vessels in various abnormalities. 相似文献
95.
IE Afthentopoulos S Panduranga Rao R Mathews DG Oreopoulos 《Canadian Metallurgical Quarterly》1998,49(4):251-257
Merkel cell carcinoma (MCC) of the skin is a rare, primary malignant skin neoplasm which can present as a cutaneous nodule. These neoplasms are seen primarily in the elderly and located in the head and neck area or extremities. Twenty-nine aspirates from primary and metastatic lesions obtained by percutaneous fine-needle aspiration in 19 patients have been studied. The cytomorphologic features, clinical information, and immunocytochemical (ICC) findings are detailed. Aspirate smears demonstrated small-to-intermediate-sized cells with a loosely cohesive pattern. Nuclei were round with finely granular chromatin and multiple, small nucleoli. Cells possessed a thin rim of cytoplasm, and infrequent pseudorosette formations were noted in cell groups. ICC results were universally positive for cytokeratin, which showed a paranuclear "dot-like" pattern. Neuron-specific enolase, epithelial membrane antigen, and S-100 protein were positive in varying degrees. Leukocyte common antigen was universally negative. The diagnosis of MCC of the skin by FNA can be made by applying cytologic features in addition to ancillary studies and clinical information. 相似文献
96.
CD44 is a cell surface receptor for the glycosaminoglycan hyaluronan (HA). Not all CD44-positive cells bind HA, and binding ability is strictly regulated. Three different HA binding states have been defined: inactive, inducible (by certain CD44-specific monoclonal antibodies), and constitutively active. The observation that sets of genetically related cell lines representing different HA binding states showed correlated differences in N-glycosylation of CD44, and that inhibition of N-glycosylation enhanced HA binding (Lesley et al., J. Exp. Med., 182: 431-437, 1995) led us to examine directly whether specific N-glycosylation site modifications were involved in regulating the HA binding function. CD44-negative, -active, and inducible cell lines were stably transfected with mutant constructs in which each of the five N-glycosylation sites of murine CD44 had been separately inactivated. Ability to bind soluble HA was examined over a range of CD44 expression levels. For the active cell line, AKR1, transfectants for all N-glycosylation mutants bound HA as well as did transfectants for wild type CD44. No inhibitory effects of inactivating specific N-glycosylation sites were observed. HA binding was activated when two of the mutant constructs were transfected into a novel CD44-negative inducible cell line. Inactivation of N-glycosylation sites at residues 25 or 120 converted the inducible cell line to constitutively active, whereas inactivation of other sites had little or no effect. Fusion proteins secreted from inactive, inducible, or active cell lines were purified, bound to beads, and assayed for HA binding activity by flow cytometric analysis. Fusion proteins derived from inactive, inducible, and constitutively active cells exhibited three distinguishable "threshold" densities required for HA binding ability. The results imply that the CD44 molecules produced in cells in these three activation states have intrinsic differences in HA binding function. Treatment of the fusion proteins with neuraminidase altered the HA binding state, and glycosylation mutations that affected the phenotype of the inducible cell line lowered the threshold required for HA binding of CD44-immunoglobulin fusion proteins derived from the inducible cell line. Thus, alterations of glycosylation of CD44 itself can affect HA binding ability as manifested by a change in HA binding state. 相似文献
97.
T Putz Z Culig IE Eder C Nessler-Menardi G Bartsch H Grunicke F Uberall H Klocker 《Canadian Metallurgical Quarterly》1999,59(1):227-233
For assays involving glycosyltransferases or transporters, several GDP-sugars are either commercially unavailable or expensive. We describe an enzymatic synthesis of GDP-d-[3H]arabinosep and GDP-l-[3H]fucose that yields 66-95% nucleotide-sugar from the appropriate radiolabeled sugar in less than 30 min. The coupled reaction requires Mg2+, ATP, and GTP along with the appropriate radioactive monosaccharide, sugar-1-kinase, and pyrophosphorylase. The latter two activities are present in a cytosolic fraction of Crithidia fasciculata, which is easily grown at room temperature in simple culture medium without serum or added CO2. Addition of commercial yeast inorganic pyrophosphatase shifts the equilibrium of the pyrophosphorylase reaction toward nucleotide-sugar formation. To verify that these nucleotide-sugars are biologically active, we tested their ability to serve as substrates for glycosyltransferases. GDP-l-[3H]fucose functions as the donor substrate for recombinant human fucosyltransferase V, and GDP-d-[3H]arabinosep serves as the donor substrate for the arabinosyltransferase activities present in Leishmania major microsomes. 相似文献
98.
Hyman H. Rehan 《Materialwissenschaft und Werkstofftechnik》2001,32(3):266-271
Anodic polymerization of o‐aminoazotoluene azo dye on platinum electrodes in 0.5 M HCl in 50% v/v ethanol/water and in MeCN was studied by cyclic voltammetry. The formed films, in both media, were electroactive in acidic solutions but electroinactive in neutral and alkaline solutions and aprotic MeCN. The pair of redox peaks due to the electroactivity is attributed to a 1:1 proton + electron elimination (on oxidation)/addition (on reduction) at the amino/imino linkages which connect the aromatic nuclei. Chronocoulometry showed that the kinetics of these processes were dominated by the transport of solvated protons and Cl− ions through the polymer films. Reduction of the polymer films in acid solutions led to their gradual degradation due to the irreversible reduction of the azo groups in the polymer skeleton, while the reversible reduction of these groups in MeCN saved the polymer from degradation. The rate of electron transfer reactions of the redox couple [Fe(CN)6]3−/4− on polymer‐covered platinum electrodes decreased substantially with increasing the polymer film thickness. 相似文献
99.
Andrews Judy A.; Foster Sharon L.; Capaldi Deborah; Hops Hyman 《Canadian Metallurgical Quarterly》2000,68(2):195
This study tested a model wherein the family conflict, depression, and antisocial behavior of 254 adolescents (mean age?=?17 years; 63% female) are prospectively related to functioning within a marital (51 %) or dating relationship in young adulthood (mean age?=?23 years). Family aversive communication in adolescence and adolescent antisocial behavior predicted couple physical aggression. Family aversive communication predicted dyadic satisfaction and aversive couple communication for married women and dating men. Among those with partners who reported little antisocial behavior, adolescent antisocial behavior inversely predicted couple satisfaction and facilitative behavior. Partner antisocial behavior did not mediate the relation between adolescent characteristics and couple functioning. Findings emphasize the importance of the early family environment and psychopathology of the adolescent in the development of adaptive couple relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Charman Steve D.; Gregory Amy Hyman; Carlucci Marianna 《Canadian Metallurgical Quarterly》2009,15(1):76
Facial composite research has generally focused on the investigative utility of composites—using composites to find suspects. However, almost no work has examined the diagnostic utility of facial composites—the extent to which composites can be used as evidence against a suspect. For example, detectives and jurors may use the perceived similarity of a suspect to a composite as evidence to determine the likelihood of a suspect's guilt. However, research in social cognition and models of cognitive coherence suggest that these similarity judgments may be biased by evaluators' preexisting beliefs of guilt. Two studies examined how preexisting beliefs of guilt influence similarity ratings between a suspect and a facial composite. Study 1 (n = 93) demonstrated that mock-investigators' beliefs in a suspect's guilt inflated their subsequent similarity ratings. Study 2 (n = 49) demonstrated that mock-jurors' beliefs in a defendant's guilt predicted their similarity ratings. These findings highlight a problem of using facial composites as evidence against a suspect, and demonstrate the malleability of similarity judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献