冰温干燥贮藏食品的研究     

季瑞溶  岩田隆 《上海交通大学学报(农业科学版)》1993,(2)

本文在阐述了冰温干燥食品研究的基础上,剖析了各种食品解冻方法的利弊后得出,冰温干燥贮藏过的食品,在营销过程中仍可确保鲜度,将质量好的食品从生产者转移到消费者。  相似文献   

Metabolic regulation of brain Abeta by neprilysin     

Iwata N  Tsubuki S  Takaki Y  Shirotani K  Lu B  Gerard NP  Gerard C  Hama E  Lee HJ  Saido TC 《Science (New York, N.Y.)》2001,292(5521):1550-1552

Amyloid beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We examined the role of neprilysin, a candidate Abeta-degrading peptidase, in the metabolism using neprilysin gene-disrupted mice. Neprilysin deficiency resulted in defects both in the degradation of exogenously administered Abeta and in the metabolic suppression of the endogenous Abeta levels in a gene dose-dependent manner. The regional levels of Abeta in the neprilysin-deficient mouse brain were in the distinct order of hippocampus, cortex, thalamus/striatum, and cerebellum, where hippocampus has the highest level and cerebellum the lowest, correlating with the vulnerability to Abeta deposition in brains of humans with AD. Our observations suggest that even partial down-regulation of neprilysin activity, which could be caused by aging, can contribute to AD development by promoting Abeta accumulation.  相似文献   

Molecular basis of proton motive force generation: structure of formate dehydrogenase-N     

Jormakka M  Törnroth S  Byrne B  Iwata S 《Science (New York, N.Y.)》2002,295(5561):1863-1868

The structure of the membrane protein formate dehydrogenase-N (Fdn-N), a major component of Escherichia coli nitrate respiration, has been determined at 1.6 angstroms. The structure demonstrates 11 redox centers, including molybdopterin-guanine dinucleotides, five [4Fe-4S] clusters, two heme b groups, and a menaquinone analog. These redox centers are aligned in a single chain, which extends almost 90 angstroms through the enzyme. The menaquinone reduction site associated with a possible proton pathway was also characterized. This structure provides critical insights into the proton motive force generation by redox loop, a common mechanism among a wide range of respiratory enzymes.  相似文献   

Differentiation of polychlorinated biphenyls from DDT by carbon-skeleton chromatography     

R I Asai  F A Gunther  W E Westlake  Y Iwata 《Journal of agricultural and food chemistry》1971,19(2):396-398

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Involvement of Gonadotropin-Releasing Hormone in Thyroxine Release in Three different forms of Teleost Fish: Barfin Founder, Masu Salmon and Goldfish     

H. Chiba  M. Amano  H. Yamada  Y. Fujimoto  D. Ojima  K. Okuzawa  T. Yamanome  K. Yamamori  M. Iwata 《Fish physiology and biochemistry》2004,30(3-4):267-273

Effects of gonadotropin-releasing hormone (GnRH) on thyroxine (T₄) release in vivo and in vitro were studied in barfin flounder Verasper moseri, masu salmon Oncorhynchus masou and goldfish Carassius auratus. Seabream GnRH (sbGnRH) at a dose of 200 ng/50 g body weight (BW) significantly increased plasma T₄ levels 1 h after the in vivo injection in the barfin flounder, but thereafter the levels normalized. Salmon GnRH (sGnRH) significantly increased plasma T₄ levels l h after the injection with a significant return to initial levels in male masu salmon and male goldfish. In contrast, sGnRH and cGnRH-II in barfin flounder, and cGnRH-II in male masu salmon and male goldfish were not effective in stimulating T₄ release. To clarify direct involvement of GnRH in T₄ release, dissected lower jaw including scattered thyroid follicles was incubated with sbGnRH (1 μg/well) in barfin flounder, and with two doses (0.1 and 1 μg/well) of sGnRH in masu salmon and goldfish in vitro. T₄ concentrations of control were stable during 24 h. Incubation of lower jaw with high dose (1 μg/well) of GnRH significantly (P<0.05) increased T₄ concentrations of incubation medium at 1 h in all experimental fishes. These results indicate that direct stimulation of T₄ secretion by GnRH occurs widely in teleost fish.  相似文献   

Whole animal transepithelial potential (TEP) of coho salmon during the parr-smolt transformation and effects of thyroxine,prolactin and hypophysectomy     

Munehico Iwata  Richard S. Nishioka  Howard A. Bern 《Fish physiology and biochemistry》1987,3(1):25-38

Whole animal transepithelial potentials (TEP) of yearling coho salmon (Oncorhynchus kisutch) in fresh water and after transfer to seawater were recorded throughout parr-smolt transformation (smoltification) from February to August 1984, along with plasma Na⁺ and Cl^– concentrations and osmolality. Based on plasma ion regulation in seawater, the yearling coho in this study completed smoltification and attained sea-water adaptability in April. TEP in freshwater fish decreased (became inside-negative) after smoltification, and the TEP increased significantly (P < 0.01) after seawater transfer. When fish were transferred into seawater, thyroxine increased TEP of the transferred smolts by approximately 30% over the control level (P < 0.01) in April, but this did not occur when freshwater postsmolts were transferred in July and August. Hypophysectomy increased TEP (P < 0.01) in fresh water; it did not affect the TEP of the fish after seawater transfer. Ovine prolactin (3 g/g body weight) implanted into seawater-adapted fish caused a reduction in TEP (P < 0.01) when fish were exposed to fresh water. Whole-animal TEP appears to provide a valuable index of the completion of smoltification (April–May) and a useful tool for investigating the endocrine control of salmonid osmoregulation.  相似文献   

Residues of acephate,amitraz, chlorpyrifos and formetanate hydrochloride on and in fruits after low-volume applications to orange trees     

Yutaka Iwata  Gregory P. Walker  Janet R. O'neal  James H. Barkley 《Pest management science》1985,16(2):172-178

Acephate, amitraz, chlorpyrifos and formetanate hydrochloride were applied to orange trees. Test plots were treated at the maximum dose rates currently permitted in California in order to determine the consequent residues on and in the fruits. Applications were made with a low-volume airblast sprayer and used 0.94 klitres of spray per hectare. Fruit samples were collected at or near the legally prescribed California fruit-harvest waiting intervals. All residues were below the US tolerances for whole fruit. Analytical procedures for the gas chromatographic analysis of intact amitraz and formetanate and of 2,4-xylidine residues, without the necessity for derivative formation, are presented.  相似文献   

Expression in Escherichia coli and purification of the functional feline granulocyte colony-stimulating factor     

Akira Yamamoto  Akira Iwata  Toshiki Saitoh  Kotaro Tuchiya  Tomoko Kanai  Hajime Tsujimoto  Atsuhiko Hasegawa  Akira Ishihama  Susumu Ueda 《Veterinary immunology and immunopathology》2002,90(3-4)

Feline granulocyte colony-stimulating factor (G-CSF) with an N-terminal histidine hexamer tag was expressed as inclusion bodies in E. coli. The G-CSF solubilized in 6 M guanidine solution was absorbed onto a Ni-NTA column and, after washing with decreasing concentrations of guanidine, eluted with imidazole in a soluble and apparently pure form. The activity of the recombinant feline G-CSF was 3×10⁶ U/mg protein, as assayed by its stimulatory effect on NFS-60 cell proliferation. When a low level of purified feline G-CSF was administered once a day for two successive days to cats, the number of neutrophil increased 4-fold while the levels of other blood cell types remained virtually unchanged. Daily administration of G-CSF for a total of 11 days led to a more than 10-fold increase in neutrophils, an 8-fold increase in the number of monocytes and 2-fold increase in lymphocytes. No severe side effects or antibody production was observed in cats after administration of G-CSF.  相似文献   

Changes in the aroma compounds of sake during aging     

Isogai A  Utsunomiya H  Kanda R  Iwata H 《Journal of agricultural and food chemistry》2005,53(10):4118-4123

Changes in the aroma of sake during aging were investigated by aroma extract dilution analysis (AEDA) and quantitative analysis using the stir bar sorptive extraction method. In AEDA, more odor zones were detected in aged sake than in fresh sake. The dilution factors of aldehydes, polysulfides, and some esters were greater in the aged sake, and their increase during aging was confirmed through a quantitative analysis of sake stored for 0-35 years. Among these compounds, 3-methylbutanal, methional, and dimethyltrisulfide (DMTS) were present in aged sake at concentrations exceeding their odor thresholds, and the highest odor active value was observed for DMTS. Sensory tests showed that supplementation with DMTS contributed to both the total odor intensity and the sulfury odor of aged sake aroma.  相似文献   

Evaluation of estrogenic activity in diets for experimental animals using in vitro assay     

Kato H  Iwata T  Katsu Y  Watanabe H  Ohta Y  Iguchi T 《Journal of agricultural and food chemistry》2004,52(5):1410-1414

We used a modified yeast-based human estrogen receptor alpha (ER alpha) bioassay to determine the estrogenic activity in 22 kinds of diets for experimental animals. The estrogenic activity of each diet was reevaluated by comparison with a calibration curve of 17 beta-estradiol. Almost all of the diets had estrogenic activity. The diets for rabbits and guinea pigs had the highest estrogenic activity compared to any other diets, including those for rats and mice. Estrogenic activity was found in dried skim milk, fishmeal, soybean meal, and alfalfa meal. In the NIH-07 diet opened for the ingredients, estrogenic activity was nearly all derived from the alfalfa meal. Multiple assays were performed to evaluate potential seasonal variations in the estrogenic potency in the raw materials of the rat and mouse diets. We found that the estrogenic activity in these raw materials changed throughout the year.  相似文献