511 research outputs found
Amorphous Oxides Prepared from Organometallic Compounds Part2. Structure Evolution in Sodium Borosilicate Gels
Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O (wt%) were prepared from hydrolysis and polycondensation of metal alkoxides under the HCl catalysis. Variation of specific surface area and porosity with temperature indicated that closed pores were opened below 400℃, and collapsed above 450℃ after the porosity reached a maximum value around 450℃. The structural evolution was examined due to IR spectra and a phase separation in the gels was observed. The solubility of the gels into 1N-HCl was studied as a function of the treatment temperature
Amorphous Oxides Prepared from Organometallic Compounds Part 1. Preparation of Sodium Borosilicate Gels
Sodium borosilicate gels of compositions similar to that of Vycor(R) glass like 80SiO(2).15B(2)O(3).5Na(2)O(wt%) were prepared from hydrolysis and polycondensation of tetraethyl orthosilicate, trimethyl borate, and sodium methylate under the HCl catalysis. Variation of the gelation time is examined as a function of the mixing ratio of the starting materials and the catalyst. The thermal behavior of the gels has been discussed on the basis of their TG and DTA traces
Effects of atmospheric sphericity on stratospheric chemistry and dynamics over Antarctica
Atmospheric sphericity is an important factor that must be considered in order to evaluate an accurate ozone loss rate in the polar stratosphere. The built-in plane-parallel radiative transfer scheme of a nudging chemical transport model (CTM) and an atmospheric general circulation model (AGCM) with coupled chemistry is modified by a pseudospherical approximation. The plane-parallel atmosphere radiative transfer version (PPA version) is compared with the pseudospherical atmosphere radiative transfer version (SA version) for both the nudging CTM and AGCM. The nudging CTM can isolate the chemical effects for a given dynamical field, while the interaction among the chemical, radiative, and dynamical processes can be studied with the AGCM. The present analysis focuses on Antarctica during an ozone hole period. In the ozone loss period over Antarctica, ozone starts to decrease earlier and minimum value of total ozone becomes lower in the SA versions of both the nudging CTM and the AGCM than in the corresponding PPA versions. The ozone mixing ratio decreases earlier in the SA version because of an earlier increase of ClO concentration initiated by the upward actinic flux at solar zenith angles greater than 90°. Dynamics plays an important role as well as the chemical processes. During the ozone recovery period, the ozone distribution becomes almost the same in the SA and PPA versions of the nudging CTM, while in the AGCM the ozone amount in the SA version remains at lower values compared to those of the PPA version. In the AGCM, a decrease of ozone over Antarctica enhances the latitudinal gradient of temperature and thus strengthens the polar vortex in the SA version. A resultant delay of the polar vortex breakup causes the delay of the ozone recovery. For the AGCM, ensemble runs are performed. The ensemble experiment exhibits large ozone variances after the middle of December, when the ozone recovery is dynamically controlled. Most ensemble members of the AGCM show a delay of the polar vortex breakup in the SA version, while a few members show opposite results. In the latter members, the polar vortex breakup is strongly affected by the enhanced EP flux from the troposphere around 100 hPa, which causes the variances in the ozone recovery period. Most members, however, do not show large statistical variances; that justifies the conclusions from the ensemble means
Melanocortin Systems on Pigment Dispersion in Fish Chromatophores
α-Melanocyte-stimulating hormone (α-MSH) is responsible for pigment dispersion in the chromatophores of fish and other tetrapods such as amphibians and reptiles. Recently, we discovered that α-MSH did not always stimulate pigment dispersion because this hormonal peptide exerted no effects on the melanophores of flounders. We assumed that the reduction of α-MSH activity was related to the co-expression of different α-MSH receptor subtypes – termed melanocortin receptors (MCR) – a member of G-protein-coupled receptors (GPCR) – based on several reports demonstrating that GPCR forms heterodimers with various properties that are distinct from those of the corresponding monomers. In this review, we summarize the relationships between the pigment-dispersing activity of α-MSH-related peptides, molecular forms of α-MSH-related peptides, and mcr subtypes expressed in fish chromatophores
A systematic immunohistochemical survey of the distribution patterns of GH, prolactin, somatolactin, β-TSH, β-FSH, β-LH, ACTH, and α-MSH in the adenohypophysis of Oreochromis niloticus , the Nile tilapia
Fish pituitary plays a central role in the control of growth, development, reproduction and adaptation to the environment. Several types of hormone-secreting adenohypophyseal cells have been characterised and localised in diverse teleost species. The results suggest a similar distribution pattern among the species investigated. However, most studies deal with a single hormone or hormone family. Thus, we studied adjacent sections of the pituitary of Oreochromis niloticus, the tilapia, by conventional staining and immunohistochemistry with specific antisera directed against growth hormone (GH), prolactin (PRL), somatolactin (SL), thyrotropin (β-TSH), follicle-stimulating hormone (β-FSH), luteinising hormone (β-LH), adrenocorticotropic hormone (ACTH) and melanocyte-stimulating hormone (α-MSH). The pituitary was characterised by a close interdigitating neighbourhood of neurohypophysis (PN) and adenohypophysis. PRL-immunoreactive and ACTH-immunoreactive cells were detected in the rostral pars distalis. GH-immunoreactive cells were present in the proximal pars distalis (PPD). A small region of the PPD contained β-TSH-immunoreactive cells, and β-LH-immunoreactive cells covered approximately the remaining parts. Centrally, β-FSH-immunoreactive cells were detected in the vicinity of the GH-containing cells. Some of these cells also displayed β-LH immunoreactivity. The pars intermedia was characterised by branches of the PN surrounded by SL-containing and α-MSH-immunoreactive cells.The ACTH and α-MSH antisera were observed to cross-react with the respective antigens. This cross-reactivity was abolished by pre-absorption. We present a complete map of the distinct localisation sites for the classical pituitary hormones, thereby providing a solid basis for future research on teleost pituitar
Expression of melanotropin-related genes in goldfish brain, pituitary, and skin in response to background color
Poster presentado en el 17th International Congress of Comparative Endocrinology celebrado en Barcelona del 15 al 19 de julio de 2013In teleost fish, body color varies in response to changes in background color. The color is lighter in a white background than in a black background. Melanin- concentrating hormone (MCH) produced in hypothalamiand agouti signaling protein (ASP) in skins turn body color pale by aggregating pigments, while melanocyte-stimulating hormone (MSH) encoded on a proopiomelanocortin (POMC) gene disperses pigments. In the present study, we investigated the effects of a black or white background on expression levels of the genes for the hormonal peptides and corresponding receptors by real time RT-PCR in goldfish (Carassiusauratus).Peer Reviewe
Factors Relating to Coagulation, Fibrinolysis and Hepatic Damage After Liver Resection
A survey of the blood of twenty-two patients who had undergone hepatic resection was performed.
Serum levels of α-2 plasmin inhibitor-plasmin complex initially decreased from 1.58 ± 0.31 μg/ml on the preoperative day (PREOP), to 0.92 ± 0.14 μ/ml on the first postoperative day (POD 1), and then increased to 3.13 ± 0.92 μg/ml on the seventh postoperative day (POD 7) (mean ± SE)). Thrombin-anti-thrombin III complex (14.2 ± 4.3 ng/ml on PREOP and 26.0 ± 4.1 ng/ml on POD 7
(mean ± SE)) and D-dimer (335 ± 96 ng/ml on PREOP and 1859 ± 258 ng/ml on POD 7 (mean ±
SE)) increased in the early postoperative stage. The level of 6-keto-prostaglandin F1α increased after
the operations (from 13.2 ± 1.8 pg/ml on PREOP to 37.8 ± 12.8 pg/ml on POD 7 (mean ± SE)). The
level of thromboxane B-2 decreased at first, and then gradually increased and returned to its
preoperative level on POD 7 (144.7 ± 43.8 pg/ml on PREOP, 57.6 ± 27.5 pg/ml on POD1 and 152.5
± 58.4 pg/ml on POD 7 (mean ± SE)). Superoxide dismutase activity increased at first, and then
gradually decreased, postoperatively (2.8 ± 0.5 NU/ml on PREOP, 4.8 ± 0.8 NU/ml on POD1 and 2.6
± 0.3 NU/ml on POD 7 (mean ± SE)). That is, biodefensive reactions which protect patients against
the shift to disseminated intravascular coagulation (DIC) were inferred with by the increase in antiplatelet
aggregation, despite the activation of coagulation and fibrinolytic mechanisms after hepatic
resection
Pigment-dispersing activities and cortisol-releasing activities of melanocortins and their receptors in xanthophores and head kidneys of the goldfish Carassius auratus
The five subtypes of melanocortin receptors (MCRs) mediate the functions of α-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH). In fish, these hormones are involved in pigment dispersion and cortisol release, respectively. α-MSH-related peptides exhibit ACTH-like activity in certain fishes. We recently found that multiple Mcr transcripts are expressed in some cell types in the barfin flounder, which is related to regulation of α-MSH activities. Similar results were also observed for the cortisol-releasing activity of α-MSH-related peptides in the head kidney. The present study was undertaken to assess relationship between the expression of multiply expressed Mcrs and α-MSH activities using goldfish. We also determined if α-MSH-related peptides exhibit ACTH-like activity in goldfish. The transcripts of Mc1r, but not those of other subtypes, were observed in xanthophores. α-MSH, which has an acetyl group at the N-terminus, was found to disperse pigment in a dose-dependent manner in xanthophores. This potency was found to be slightly greater than that of desacetyl-α-MSH. These results support our findings that MCR has a higher affinity for α-MSH when single Mcr subtype is expressed. On the other hand, transcripts of Mc2r, but not those of other subtypes, were observed in the head kidney. ACTH1-24-stimulated cortisol release was observed in a dose-dependent manner, while α-MSH-related peptides showed no activity. It therefore appears that MC2R also acts as an ACTH-specific receptor in goldfish and that association of α-MSH-related peptides upon release of cortisol is uncommon in fishes. © 2011 Elsevier Inc.Peer Reviewe
Microorganisms Relating to Color Development in Cured Meats
Article信州大学農学部紀要 11(2): 271-280(1974)departmental bulletin pape
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