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Self-pierce riveting of three thin sheets of 980 MPa steel and 5052 aluminum alloy was performed to investigate the effect of sheet configuration on the deforming behaviors of the sheets and the rivet and joint strength. When the lower sheet was aluminum alloy, the joining range was relatively wide, i.e., the interlock hooking the rivet leg tended to be large. In the sheet configuration in which the upper and lower sheets were A5052 and the middle sheet was 980 MPa steel, the rivet leg spread out moderately and the joint without defects was obtained. In the lower 980 MPa steel sheet, fracture tended to occur due to the low ductility of the lower sheet, and the joining range was narrow with the small interlock although the three sheets were joined by an appropriate die shape. In joint strength of joined three sheets, fracture occurred in the lower-strength aluminum alloy sheet if interlocks of about 300 µm and 150 µm could be formed in the lower aluminum alloy sheet and 980 MPa steel sheet, respectively.
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A low pressure sealed-air hot tube gas forming process of ultra-high strength steel tubes was developed not only to change the cross-section of the hollow products by bulging but also to increase the strength of components. Gas-formed components are typically formed by a controlled-gas pressure with extremely high internal pressure, which leads to affected production costs and safety. Moreover, compressing the gas with high pressure requires high energy during its preparation. Therefore, to simplify the internal pressure controlling system and improve the safety factor in gas forming processes, the sealed-air tubes are formed with a quite low initial pressure. The pressure of the sealed air increased with increasing temperature of the air inside the resistance-heated tube, and the bulging deformation was controlled only by axial feeding. The effects of the initial pressure and heating temperature on the bulging deformation and quenchability of the tubes, and the effect of the starting time of axial feeding on the bulging behavior were examined. Consequently, ultra-high strength steel bulged parts were produced even in low initial internal pressure and with the rapid heating of the tubes.
RESUMO
One thin 5000 series aluminium alloy sheet and two thin 980 MPa grade cold rolled ultra-high strength steel sheets were joined by self-pierce riveting and mechanical clinching processes. The joinabilities for a combination of the aluminium and steel sheets in both processes were investigated for different die shapes in the experiment and finite element simulation. In self-pierce riveting, the three sheets were successfully joined for both combinations of the upper and lower aluminium alloy sheets by optimizing the shapes of a die and rivet. In mechanical clinching, the three sheets were successfully joined by an optimum die for the configuration of the upper aluminium alloy sheet. On the other hand, the three sheets for the configuration of the lower aluminium alloy sheet were not joined even by optimizing the die shape in the both finite element simulation and experiment, because the material flow of the steel sheets was insufficient to form the two interlocks. The tension-shear loads for the clinched and riveted sheets with the adhesive were almost the same, because the load for the adhesive was the highest. In the cross-tension test, however, the load by the adhesive was comparatively small.
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Mannan-binding lectin (MBL) was first discovered as a collectin in animal blood, and was shown to have such unique characteristics as a collage-like domain and a carbohydrate recognition domain. We recently identified human collectin kidney 1 (CL-K1, COLEC11) from a human kidney cDNA library. To quantitate the CL-K1 concentration in blood, we developed several polyclonal and monoclonal antibodies using recombinant human CL-K1 in CHO cells and the CL-K1 fragment in Escherichia coli. Using these antibodies, we established a sandwich enzyme-linked immunosorbent assay (ELISA) system. The concentration of CL-K1 in human plasma was 0.34 ± 0.13 µg/ml and that in MBL was 1.72 ± 1.51 µg/ml. Concentrations of MBL are often low due to its single nucleotide polymorphisms (SNPs) which seem to be related to an opsonic defect. However, no low concentrations of CL-K1 were observed on testing over two hundred blood samples. We also found that the blood concentration of CL-K1 was not dependent on gender or age and did not correlate completely with that of MBL. The ELISA system developed in this study will be useful for elucidating the physiological and pathophysiological role of CL-K1 in humans.
Assuntos
Colectinas/sangue , Lectina de Ligação a Manose/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos/imunologia , Anticorpos/metabolismo , Western Blotting , Células CHO , Colectinas/genética , Colectinas/imunologia , Cricetinae , Cricetulus , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Lectina de Ligação a Manose/genética , Lectina de Ligação a Manose/imunologia , Pessoa de Meia-Idade , Coelhos , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Valores de Referência , Adulto JovemRESUMO
BACKGROUND: Scavenger receptors are generally expressed in macrophages and vascular endothelial cells and some scavenger receptors are thought to contribute to the development of atherosclerosis. METHODS: We cloned the cDNA of a zebrafish CL-P1 (collectin placenta 1) and performed a knockdown study using its antisense morpholino oligonucleotides (MO). RESULTS: Zebrafish CL-P1 (zCL-P1) is 51% identical to human CL-P1 in its amino acid sequence. Microbes and OxLDL bound to zCL-P1 cDNA transfected cells. zCL-P1 mRNA expression gradually increased after 6hours post-fertilization (hpf), reached its highest level at 24hpf, and then decreased, which is similar to the gene expression pattern of Tie-2. The knockdown of zCL-P1 led to an increase in the number of zebrafish embryos with severe morphological abnormalities such as short body lengths and defects in the dorsal aorta at 48hpf. Simultaneous injection of both MO and synthetic zCL-P1 or zVEGF mRNA rescued the abnormal phenotype. CONCLUSIONS: In vivo knockdown study shows that zCL-P1 is implicated in vasculogenesis and those of our in vitro study support its role as a scavenger receptor. GENERAL SIGNIFICANCE: These results suggest that zCL-P1 might be essential for vasculogenesis during the early embryonic phase in bone fish.
Assuntos
Receptores Depuradores/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Células CHO , Clonagem Molecular , Cricetinae , Cricetulus , DNA Complementar , Técnicas de Silenciamento de Genes , Imuno-Histoquímica , Hibridização In Situ , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Receptores Depuradores/fisiologia , Peixe-ZebraRESUMO
Genus Lophophora (Cactaceae) has two species: Lophophora williamsii Coulter, which is called peyote, and L. diffusa Bravo. Although it was reported that L. williamsii contained mescaline and L. diffusa did not, we found L. williamsii specimens that did not contain mescaline. This finding indicated that the two species could not be differentiated in terms of mescaline content. Moreover, the relationship between mescaline content and morphology of the two species is also unknown. In this study, we attempted to clarify the difference in morphology, mescaline content, and DNA alignment of the chloroplast trnL/trnF region between L. williamsii and L. diffusa. As a result, L. williamsii specimens were classified into two groups. Group 1 had small protuberances on the epidermis, contained mescaline, and the analyzed region on the trnL/trnF sequence was 881 base pairs (bp) long in all except one (877 bp). Group 2 had large protuberances on the epidermis, did not contain mescaline, and the analyzed region was 893 bp long. On the other hand, L. diffusa had medium-sized protuberances on the epidermis, did not contain mescaline, and the analyzed region was 903 bp long. Also investigated was the potential application of the PCR-restriction fragment length polymorphism (RFLP) method as a means of identification based on the trnL/trnF sequence. By applying the PCR-RFLP method, the two species could be distinguished and L. williamsii specimens could be differentiated into group 1 and group 2.
Assuntos
Cactaceae/química , Cactaceae/genética , Mescalina/química , Cactaceae/ultraestrutura , Microscopia Eletrônica de Varredura , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de RestriçãoRESUMO
An analog of aildenafil, which is a potent and highly selective inhibitor of phosphodiesterase 5, was found in a dietary supplement marketed for enhancement of sexual function. The compound was isolated by silica gel column chromatography, and its structure was identified by means of 13C-NMR spectrometry, 1H-NMR spectrometry, high-resolution MS, and X-ray structure determination. The compound was identified to be sulfoaildenafil (other names: thioaildenafil, dimethyl sildenafil thione, and thiomethisosildenafil). Sulfoaildenafil is very similar to the compound thiohomosildenafil. As it is difficult to distinguish between them by LC-photodiode array detector analysis, ultra-performance LC (UPLC)/MS, ion trap LC/MS/MS (LC/IT-MS/MS), and GC/MS were performed. The mass spectra of thiohomosildenafil by UPLC/MS and LC/IT-MS/MS showed mass fragments of m/z 58, 72, and 355, and the mass spectrum by GC/MS showed mass fragments of m/z 56, 72, and 420. Some of these fragments had low intensities, but they were useful for distinguishing between the two compounds. The relationship between aildenafil (other names: dimethylsildenafil and methisosildenafil) and homosildenafil is similar to that between sulfoaildenafil and thiohomosildenafil. Therefore, these compounds were also examined.
Assuntos
Suplementos Nutricionais/análise , Piperazinas/análise , Sulfonas/análise , Cromatografia Líquida/métodos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Inibidores da Fosfodiesterase 5/análise , Espectrometria de Massas em Tandem/métodosRESUMO
We have designed and synthesised a new carborane derivative containing two nitronyl nitroxides. This molecule can be considered as a prototype of a three-dimensional analogue of o-benzoquinodimethane. The magnetic susceptibility of a crystalline sample revealed that this biradical possesses a weak antiferromagnetic interaction (theta = -1.05(4) K) and an ESR study in frozen matrix in the 5.4-104 K range gave an intramolecular antiferromagnetic interaction of -27(2) K. The synthesis, physical properties and DFT calculation result are also reported.