检索结果-内蒙古大学图书馆

DISTRIBUTIONS Of THE PRODUCT AND THE QUOTIENT fROM BIVARIATE-T, BIVARIATE-f AND PARETO DISTRIBUTION

COMMUNICATIONS IN STATISTICS-THEORY AND METHODS 1985年第12期14卷 2951-2962页

作者： MALIK, HJ TRUDEL, R AGR CANADA OTTAWAONTARIOCANADA

This paper deals with the probability density functions of two correlated Pareto, two correlated t and two correlated f random variables.

关键词： probability density function product quotient bivariate random variable pareto t f distributions

来源：评论

学校读者我要写书评

暂无评论

fORMATION Of MUTAGENS, 2-AMINO-3,8-DIMETHYLIMIDAZO[4,5-f]QUINOXALINE (MEIQX) AND 2-AMINO-3,4,8-TRIMETHYLIMIDAZO[4,5-f]QUINOXALINE (4,8-DIMEIQX), IN HEATED fISH MEATS

引用

MUTATION RESEARCH 1987年第1期179卷 5-14页

作者： KIKUGAWA, K KATO, T Tokyo College of Pharmacy 1432-1 Horinouchi Hachioji Tokyo 192-03 Japan

fish meats were heated under conditions close to those used for cooking and processing. The mutagenic activity of the heated fish meats was estimated toward Salmonella typhimurium TA98 with metabolic activation after extraction with boiling water and adsorption to blue cotton. The numbers of His+ revertant colonies/5 g of the meat heat-dried without charring at ***. C for 15 min were about 3000 for bonito, about 1000 for tunny, less than 500 for mackerel, salmon, swordfish, sardine, horse mackerel and cod, and 0 for cuttlefish. The mutagens in the heat-dried bonito meat were purified by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC). They were identified as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) by comparison with the authentic specimen with respect to Rf values in TLC, retention times in HPLC, ultraviolet absorption spectra and mass spectra. The contents of MeIQx and 4,8-DiMeIQx in the bonito meat were estimated to be 5.2 and 5.4 ng/g, respectively. The major mutagens produced in the bonito, tunny and mackerel meats heated without charring at ***. C for 48 h and at ***. C for 15 min were found to be MeIQx and 4,8-DiMeIQx. It is interesting to note that the bonito and sardine meats grilled with charring for 15 min contained MeIQx and 4,8-DiMeIQx but higher mutagenicity was observed in the fraction that may contain 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ) and/or 2-aminodipyrido[1,2-a:3'',2''-d]imidazole (Glu-P-2).

关键词： fish meats, heated MeIQx 4,8-DiMeIQX Trp-P-1 3-amino-1,4-dimethyl-5 H -pyrido[4,3- b ]indole Trp-P-2 3-amino-1-methyl-5 H -pyrido[4,3- b ]indole Glu-P-1 2-amino-6-methyldipyrido[1,2- a : 3′,2′-d ]imidazole Glu-P-2 2-aminodipyrido[1,2- a : 3′,2′-d] imidazole AαC 2-amino-9 H -pyrido[2,3- b ]indole MeAαC, 2-amino-3-methyl-9 H -pyrido[2,3- b ]indole IQ 2-amino-3-methylimidazo[4,5- f ]quinoline MeIQ 2-amino-3,4-dimethylimidazo[4,5- f ]quinoline MeIQx 2-amino-3,8-dimethylimidazo[4,5- f ]quinoxaline 4,8-DiMeIQx 2-amino-3,4,8-trimethylimidazo[4,5- f ]quinoxaline 7,8-DiMeIQx 2-amino-3,7,8-trimethylimidazo[4,5- f ]quinoxaline

来源：评论

学校读者我要写书评

暂无评论

fusobacterium nucleatum facilitates ulcerative colitis through activating IL-17f signaling to Nf-κB via the upregulation of CARD3 expression

引用

JOURNAL Of PATHOLOGY 2020年第2期250卷 170-182页

作者： Chen, Yongyu Chen, Yan Cao, Pan Su, Wenhao Zhan, Na Dong, Weiguo Wuhan Univ Renmin Hosp Dept Gastroenterol Wuhan Hubei Peoples R China Key Lab Hubei Prov Digest Syst Dis Wuhan Hubei Peoples R China Renmin Hosp Cent Lab Wuhan Hubei Peoples R China

Accumulating evidence links fusobacterium nucleatum with ulcerative colitis (UC). The mechanism by which f. nucleatum promotes intestinal inflammation in UC remains poorly defined. Here, we first examined the abundance and impact of f. nucleatum on disease activity in UC tissues. Next, we isolated a strain of f. nucleatum from UC tissues and explored whether f. nucleatum aggravates the intestinal inflammatory response in vitro and in vivo. We also examined whether f. nucleatum infection involves the Nf-kappa B or IL-17f signaling pathways. Our data showed that f. nucleatum was enriched in 51.78% of UC tissues and was correlated with the clinical course, clinical activity and refractory behavior of UC (p < 0.05). furthermore, we demonstrated that f. nucleatum promoted intestinal epithelial damage and the expression of the inflammatory cytokines IL-1 beta, Il-6, IL-17f and TNf-alpha. Mechanistically, f. nucleatum targeted caspase activation and recruitment domain 3 (CARD3) through NOD2 to activate the IL-17f/Nf-kappa B pathway in vivo and in vitro. Thus, f. nucleatum orchestrates a molecular network involving CARD3 and IL-17f to control the UC process. Measuring and targeting f. nucleatum and its associated pathways will yield valuable insight into the prevention and treatment of UC. (c) 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

关键词： microbe gene regulation gene targeting ulcerative colitis f nucleatum IL-17f CARD3 Nf-kappa B NOD2 intestinal inflammation

来源：评论

学校读者我要写书评

暂无评论

fORMATION Of 2-AMINO-3,8-DIMETHYLIMIDAZO[4,5-f]QUINOXALINE IN A MODEL SYSTEM BY HEATING CREATININE, GLYCINE AND GLUCOSE

引用

MUTATION RESEARCH 1984年第3期126卷 239-244页

作者： JAGERSTAD, M OLSSON, K GRIVAS, S NEGISHI, C WAKABAYASHI, K TSUDA, M SATO, S SUGIMURA, T UNIV LUND CTR CHEM DEPT NUTR S-22007 LUND 7 SWEDEN SWEDISH UNIV AGR SCI DEPT CHEM & MOLEC BIOL S-75007 UPPSALA SWEDEN NATL CANC CTR RES CTR DIV BIOCHEM CHUO KU TOKYO 104 JAPAN

A mixture of creatinine, glucose and Gly was heated in diethylene glycol containing 14% water for 2 h at ***. C, and the mutagens formed were purified by XAD-2 column chromatography, acid-base partition. Sephadex LH-20 column chromatography, blue cotton treatment and HPLC [high performance liquid chromatography]. Two mutagenic substances were isolated by HPLC. The major mutagen was identified by its UV absorption and mass and NMR spectra as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline, which was originally isolated from fried beef. The idea that creatinine, amino acids and sugars present in meat are precursors in the formation of the mutagenic imidazoquinoxaline derivative is supported.

关键词： Trp-P-1 3-amino1,4-dimethyl-5 H -pyrido[4,3- b ]indole 62450-06-0 Trp-P2 3-amino-1-methyl-5 H -pyrido[4,3- b ]indole, 62450-07-1 Glu-P-1 2-amino-6-methyldipyrido[1,2- a :3′,2′- d ]imidazole, 67730-11-4 Glu-P-2 2-aminodipyrido[1,3- a :3′,2′- d ]imidazole, 67730-10-3 Orn-P-1 4-amino-6-methyl-1 H -2,5,10,10b-tetraazafluoranthene, 78859-36-6 Phe-P-1 2-amino-5-phenylpyridine, 33421-40-8 AαC 2-amino-9 H -pyrido[2,3- b ]indole, 26148-68-5 MeAαC 2-amino-3-methyl-9 H -pyrido[2,3- b ]indole, 68006-83-7 IQ 2-amino-3-methylimidaza[4,5- f ]quinoline, 76180-96-6 MeIQ 2-amino-3,4-dimethylimidazo[4,5- f ]quinoline, 77094-11-2 MeIQx 2-amino-3,8-dimethylimidazo[4,5- f ]quinoxaline, 77500-04-0 HPLC high performance liquid chromatography

来源：评论

学校读者我要写书评

暂无评论

Re-determination and re-evaluation of the f and α parameters in channels Y4 and S84 of the BR1 reactor, for use in k_o-NAA at DSM Research

引用

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT 2006年第2期564卷 636-640页

作者： De Wispelaere, A. De Corte, f. Bossus, D. A. W. Swagten, J. J. M. G. Vermaercke, P. Univ Ghent INW Lab Analyt Chem Inst Nucl Sci B-9000 Ghent Belgium DSM Res & Patents Dept Resolve NL-6160 MD Geleen Netherlands CEN SCK Belgian Nucl Res Ctr B-2040 Mol Belgium

Since the introduction of k(o)-based NAA as an analytical tool in 1989, all irradiations by DSM Research are done in channels Y4 and S84 of the BR1 reactor in Mol (Belgium). The last determination off and alpha-values for these channels was performed in 1993. Although the configuration of the reactor did not change over all these years and therefore no change in f and a was to be expected, DSM Research decided to re-determine both parameters in both channels. Having much experience in this field, the INW k(0)-group was asked by DSM Research to perform this re-determination, in co-operation with the SCK, Mol. As the flux in channel Y4 is not constant during the start up and the scramming of the reactor, a numerical integration method was applied. This is a new approach in comparison with all previous reported data from DSM Research, where this change in flux was not taken into account. for the work presented here, use was made of the most recent nuclear data available in the literature. (c) 2006 Elsevier B.V. All rights reserved.

关键词： k(o)-NAA f alpha cadmium ratio method BR1 reactor calibration

来源：评论

学校读者我要写书评

暂无评论

Mechanistic insights into f₄₂₀-dependent glucose-6-phosphate dehydrogenase using isotope effects and substrate inhibition studies

引用

BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018年第2期1866卷 387-395页

作者： Oyugi, Mercy A. Bashiri, Ghader Baker, Edward N. Johnson-Winters, Kayunta Univ Texas Arlington Dept Chem & Biochem Arlington TX 76019 USA Univ Auckland Sch Biol Sci Lab Struct Biol Auckland 1010 New Zealand Univ Auckland Sch Biol Sci Maurice Wilkins Ctr Mol Biodiscovery Auckland 1010 New Zealand

f-420-dependent glucose-6-phosphate dehydrogenase (fGD) is involved in the committed step of the pentose phosphate pathway within mycobacteria, where it catalyzes the reaction between glucose-6-phosphate (G6P) and the f-420 cofactor to yield 6-phosphogluconolactone and the reduced cofactor, f420H2. Here, we aim to probe the fGD reaction mechanism using dead-end inhibition experiments, as well as solvent and substrate deuterium isotope effects studies. The dead-end inhibition studies performed using citrate as the inhibitor revealed competitive and uncompetitive inhibition patterns for G6P and f-420 respectively, thus suggesting a mechanism of ordered addition of substrates in which the f-420 cofactor must first bind to fGD before G6P binding. The solvent deuterium isotope effects studies yielded normal solvent kinetic isotope effects (SKIE) on kcat and k(cal)/K-m for both G6P and f-420. The proton inventory data yielded a fractionation factor of 0.37, suggesting that the single proton responsible for the observed SKIE is likely donated by Glu109 and protonates the cofactor at position Ni. The steady state substrate deuterium isotope effects studies using G6P and G6P-d(1) yielded KIE of 1.1 for both koo, and K-cat/K-m while the pre-steady state KIE on k(obs), was 1.4. Because the hydride transferred to C5 of f-420 was the one targeted for isotopic substitution, these KIE values provide further evidence to support our previous findings that hydride transfer is likely not rate-limiting in the fGD reaction.

关键词： fGD f 420 -dependent glucose-6-phosphate dehydrogenase G6P glucose-6-phosphate G6P-d 1 glucose-6-phosphate-d 1 G6PD glucose-6-phosphate dehydrogenase f 420 cofactor 7,8-didemethyl-8-hydroxy-5-deazariboflavin-5′-phosphoryllactyl(glutamyl) n glutamate TB Tuberculosis M. smegmatis Mycobacterium smegmatis M. tuberculosis Mycobacterium tuberculosis LC-MS-IT-TOf liquid chromatography mass spectrometry-ion trap-time of flight SKIE solvent kinetic isotope effect k cat (app) apparent turn-over number K m (app) apparent Michaelis-Menten constant k cat / K m catalytic efficiency k obs apparent rate constant

来源：评论

学校读者我要写书评

暂无评论

Triculata A, a novel compound from Tricyrtis maculata (D. Don) J. f. Macbr. with biological properties

引用

NATURAL PRODUCT RESEARCH 2021年第21期35卷 3729-3737页

作者： Ren, Li Wang, Yun-Ze Zhang, Wei Zhou, Rui Zhao, Ming Tang, Zhi-Shu Sun, Jing Zhang, Dong-Bo Shaanxi Univ Chinese Med Shaanxi Innovat Drug Res Ctr Shaanxi Collaborat Innovat Ctr Chinese Med Resour State Key Lab Res & Dev Characterist Qin Med Reso Xianyang Peoples R China Xi An Jiao Tong Univ Dept Basic Med Xian Peoples R China

A novel compound, triculata A (1), and seven known compounds were obtained from the Tricyrtis maculata (D. Don) J. f. Macbr.. The structure of the new compound was determined by extensive spectroscopic methods, and its absolute configuration was assigned by single-crystal X-ray diffraction analysis. Compound 1 features a rare naphtho[b,c]pyran carbon skeleton that was found in nature for the first time. Compounds 2-4, 6 and 7 showed potential vasodilatory effects with EC50 values ranging from 7.3 to 111.3 mu M. Compounds 1, 3-5 and 7 possessed remarkable antioxidant capacity evaluated by DPPH and ABTS assays.

关键词： Liliaceae Tricyrtis maculata (D Don) J f Macbr naphtho[b c]pyran vasodilation antioxidant

来源：评论

学校读者我要写书评

暂无评论

A new basic burning raw material for simultaneous stabilization/solidification of PO4^3--P and f^- in phosphogypsum

引用

ECOTOXICOLOGY AND ENVIRONMENTAL SAfETY 2023年 252卷

作者： Bing, Li Shu, Jiancheng Chen, Mengjun Zeng, Xiangfei Liu, Renlong Yong, Yang Yangtze Normal Univ Sch Chem & Chem Engn Chongqing 408100 Peoples R China Southwest Univ Sci & Technol Key Lab Solid Waste Treatment & Resource Recycle S Minist Educ 59 Qinglong Rd Mianyang 621010 Peoples R China Chongqing Univ Sch Chem & Chem Engn Chongqing 400044 Peoples R China

Phosphogypsum (PG) contains a lot of soluble phosphate (PO43--P) and fluorine ion (f-), which seriously has hindered the sustainable development of the phosphorous chemical industry. In this study, a new burning raw material (BRM) as an intermediate product in the cement production process was used for PO43--P and f- stabilize in PG. The stabilizing mechanism of PO43--P and f- were investigated by fourier Transform infrared spectroscopy (fT-IR), X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM), X-ray fluorescence (XRf) and X-ray spectroscopy system (XPS). The effect of PG and BRM weight ratio, solid-to-liquid ratio, reaction time, and reaction temperature on the concentrations of PO43--P and f- were studied. The results showed that the concentration of f- in the PG leaching solution was 8.65 mg/L and the stabilizing efficiency of PO43--P was 99.78%, as well as the pH of the PG leaching solution was 8.12 when the weight ratio of PG and BRM was 100:2, and the solid to liquid ratio was 4:1, reacting for 24 h at the temperature of 30.. PO43--P and f- were mostly solidified as Ca-5(PO4)(3)f, CaPO3(OH), Ca-5(PO4)(3)(OH), Ca2P2O7 center dot 2H2O, CaSO4PO3(OH)center dot 4H2O, Caf2, and CafPO3 center dot 2H2O. Leaching test results indicated that the concentrations of PO43--P, f- and heavy metals were less than the integrated wastewater discharge standard (GB8978-1996). This study provides a new harmless treatment method for PG.

关键词： Solidification stabilization Phosphogypsum Burning raw material PO43--P f

来源：评论

学校读者我要写书评

暂无评论

Nanosilver Particles Coated with Sida acuta Burm. f. Transformed 'Hairy Root' Extract for Efficient Biocatalytic Degradation of Organic Dyes

引用

JOURNAL Of CLUSTER SCIENCE 2022年第3期33卷 1069-1082页

作者： Begum, Shahani Nayak, Bismita Chand, Pradeep K. Utkal Univ Plant Biotechnol Lab Dept Bot Bhubaneswar 751004 Odisha India Natl Inst Technol Immunol & Mol Med Lab Dept Life Sci Rourkela 769008 Odisha India

We report here the utility of Sida acuta Burm. f. root extract-mediated silver nanoparticles in catalytic degradation of organic dyes such as methyl orange (MO), methylene blue (MB), bromophenol blue (BPB), and congo red (CR) in the presence of NaBH4. Monodispersed nanosilver particles were characterized using UV-Visible spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering particle size-zeta potential analysis (DLS-Zeta) and fourier transform infrared spectroscopy (fTIR). TEM images demonstrated spherical uniform nanocrystals (10-50 nm). Catalytic removal of dyes by time-stable AgNPs was studied in a time-dependent manner. Reactions displayed pseudo-first-order rate and rate constants were figured out for removal of different dyes by the nanocatalyst. The dye removal ability of genetically transformed 'hairy root' nanoparticles (HR-AgNPs) was more pronounced in comparison with that by nanoparticles prepared from natural root extract (NR-AgNPs). Efficiency of degrading MO, MB, BPB and CR, to the extent as high as 85.99%, 79.10%, 82.65% and 70.12%, respectively were achieved in 30 min by employing HR-AgNPs;the rate constants being 0.0812, 0.0616, 0.0646, and 0.0498 min(-1), respectively. This adsorptive removal ability of such biogenic nanoparticles could be explored in wastewater treatment for removal of toxic pollutant dyes.

关键词： Organic dyes Silver nanoparticles Sida acuta Burm f Hairy roots Biocatalysts

来源：评论

学校读者我要写书评

暂无评论

OPTIMIZATION Of THE PURIfICATION Of MITOCHONDRIAL f1-ADENOSINE TRIPHOSPHATASE

引用

BIOCHIMICA ET BIOPHYSICA ACTA 1979年第1期548卷 63-71页

作者： PENIN, f GODINOT, C GAUTHERON, DC Laboratoire de Biologie et Technologie des Membranes du Centre National de la Recherche Scientifique. Université Claude Bernard de Lyon 43 Bd de 11 Novembre 1918 - 69621 Villeurbanne France

A simple technique of purification of the soluble pig heart mitochondrial f1-ATPase is described. It consists of removal of extrinsic proteins from mitochondrial membranes before extraction with chloroform and ammonium sulfate fractionation. A high degree of purity, an excellent stability and a good yield are attained after gel filtration through an Ultrogel ACA 34 column equilibrated in the presence of 50% glycerol. The tested properties of the f1-ATPase prepared by this method are similar to those of the same enzyme extracted by sonication. The enzyme is virtually devoid of tightly bound nucleotides. Some characteristics of the behavior of the .beta. subunit are shown.

关键词： f 1 -ATPase (Mitochondria, Purification) Hepes N -2-hydroxyethylpiperazine- N ′-2-ethanesulfonic acid

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：