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火星陨石和火星表面泥岩中蚀变过程对比研究

地学前缘 2020年第4期27卷 340-354页

作者：付晓辉凌宗成周琴 bradley l.jolliff 尹庆柱王阿莲李勃武中臣张江山东大学山东省光学天文与日地空间环境重点实验室空间科学与物理学院空间科学研究院山东威海264209 中国科学院国家天文台月球与深空探测实验室北京100012 Department of Earth and Planetary Sciences Washington UniversitySt.LouisMO 63130USA Department of Earth and Planetary Sciences University of California DavisOne Shields AvenueDavisCA 95616USA

火星次生含水蚀变矿物是火星地质历史时期水环境和气候演变历史的真实记录,一直以来都是火星探测、火星陨石研究的重点,是认识火星环境特征和气候演化的重要研究对象。文中对比研究了表土角砾岩NWA7034、火成堆晶岩MIl03346等两块最富... 详细信息

火星次生含水蚀变矿物是火星地质历史时期水环境和气候演变历史的真实记录,一直以来都是火星探测、火星陨石研究的重点,是认识火星环境特征和气候演化的重要研究对象。文中对比研究了表土角砾岩NWA7034、火成堆晶岩MIl03346等两块最富蚀变矿物火星陨石,以及Gale撞击坑出露的Sheepbed泥岩3种岩石类型的蚀变程度及其蚀变矿物类型和组合,分析了层状硅酸盐、铁氧化物/氢氧化物、钙硫酸盐等蚀变矿物的成因及环境指示意义。发现这3类岩石的蚀变作用各不相同。火星陨石NWA7034的蚀变作用以氧化和加热作用为主,无蒸发盐类矿物。火星陨石MIl03346的蚀变程度最低,为后期水溶液进入缝隙而引发的,蚀变作用以橄榄石的伊利石化、裂隙和缝隙中填充次生矿物细脉为主。而火星Sheepbed泥岩经历了后期的等化学风化过程(isochemical weathering),次生过程包括成岩蚀变和成岩后蚀变两个阶段。其中,成岩过程中的蚀变以橄榄石蚀变为铁氧化物和蒙皂石矿物为主,成岩后以形成蒸发盐类矿物硫酸钙为主。以上3种岩石蚀变矿物组成差异反映了火星上不同地质背景中、不同气候条件下蚀变过程的复杂性。文中对火星含水矿物及部分典型矿物的形成条件和过程进行系统总结,这对于理解未来火星探测任务、识别含水矿物的形成、揭示火星水环境和地质历史具有重要指导意义。

关键词：次生矿物蚀变过程火星陨石 “好奇”号

Using our mini-brains: cerebral organoids as an improved cellular model for human prion disease

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Neural Regeneration Research 2020年第6期15卷 1019-1020页

作者： bradley R.Groveman Ryan walters Cathryn l.Haigh laboratory of Persistent Viral Diseases National Institute of Allergy and Infectious Diseases Division of Intramural ResearchRocky Mountain Laboratories National Institutes of Health

Neurodegenerative diseases are an ever-increasing burden in an aging *** no cure is available for any of these diseases and treatment is based on managing *** many candidate therapeutics demonstrating promise in animal models,none has yet shown efficacy in human *** is self-evident that humans are different from the animals used to model our diseases,especially models that have been highly manipulated to generate a disease in an animal that does not naturally have such a *** differences are likely the reason for the failures of drug candidates in human trials but,until recently,human models of neurodegenerative diseases were *** development of the human cerebral organoid model,by differentiating three-dimensional human neuronal tissue from pluripotent stem cells,represents a significant advance in studying human brain *** organoids have been used to model Alzheimer’s disease,Parkinson’s disease,Down’s syndrome dementia and we have now shown they can be infected with human prions creating a new model of human prion diseases.

关键词： cerebral likely spite

Placental accommodations for transport and metabolism during intra-uterine crowding in pigs

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Journal of Animal Science and Biotechnology 2015年第2期6卷 163-176页

作者： Jeffrey l Vallet Anthony K Mc Neel Jeremy R Miles bradley A Freking U.S. Department of Agriculture Agricultural Research Service U.S. Meat Animal Research CenterState Spur 18D Clay Center NE 68933 USA

litter size and birth weights are limited by uterine capacity, defined as the ability of the uterus to maintain the appropriate development of some number of conceptuses. Uterine capacity is the result of the combined effects of uterine, placental and embryo/fetal function. The number of living conceptuses that the uterus is capable of supporting is greater during early gestation compared to later gestation. Plots of log fetal weight versus log placental weight also indicate that fetal weights are less sensitive to reduced placental weight （and therefore reduced intrauterine space） in early gestation compared to late gestation. However, even in late gestation, mechanisms still exist that maintain fetal growth when the size of the placenta is reduced. One such mechanism is likely to be improved development of the folded placental-epithelial/maternal-epithelial bilayer. Fold depth, and therefore the maternal fetal interactive surface, increases as gestation advances and is greater in placenta from smal fetuses. On the fetal side of the placenta, the epithelial bilayer is embedded in stromal tissue. Glycosaminoglycans are major components of stroma, including hyaluronan and heparan sulfate. Hyaluronidases and heparanases are present within placental tissues, and likely play roles in modification of stromal components to facilitate fold development. Glycosaminoglycans are polymers of forms of glucose （glucosamine, glucuronic acid, iduronic acid） suggesting that glycosaminoglycan synthesis may compete with the glucose needs of the developing fetus. Pig conceptuses are fructogenic, such that a substantial portion of glucose transferred from mother to fetus is converted to fructose. Fructose is an intermediate product in the synthesis of glucosamine from glucose, and glucosamine is linked to regulation of trophoblast cell proliferation through regulation of mTOR. These findings suggest a link between glucose, fructose, glucosamine synthesis, GAG production, and placental m

关键词： Glycosaminoglycans Nutrient transport Placenta

Glucosamine supplementation during late gestation alters placental development and increases litter size

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Journal of Animal Science and Biotechnology 2018年第1期9卷 135-144页

作者： Jeffrey l.Vallet Jeremy R.Miles bradley A.Freking Shane Meyer USDA ARS U.S. Meat Animal Research Center (USMARQ P.O. Box 166 Clay Center NE Nebraska 68933 USA Plymouth Ag Group Diller NE Nebraska 68342 USA

Background： During late gestation the placental epithelial interface becomes highly folded, which involves changes in stromal hyaluronan. Hyaluronan is composed of glucoronate and N-acetyl-glucosamine. We hypothesized that supplementing gestating dams with glucosamine during this time would support placental folded-epithelial-bilayer development and increase litter size. In Exp. 1, gilts were unilaterally hysterectomizedovariectomized（UHO）. UHO gilts were mated and then supplemented daily with 10 g glucosamine（n = 16） or glucose（control, n = 17） from d 85 of gestation until slaughter（d 105）. At slaughter, the number of live fetuses was recorded and each live fetus and its placenta was weighed. Uterine wall samples adjacent to the largest and smallest fetuses within each litter were processed for histology. In Exp. 2, pregnant sows in a commercial sow farm were supplemented with either 10 g glucosamine or glucose daily from d 85 of gestation to farrowing. Total piglets born and born alive were recorded for each litter. In Exp. 3, the same commercial farm and same protocol were used except that the dose of glucosamine and glucose was doubled to 20 g/***： In Exp. 1, the number of live fetuses tended to be greater in glucosamine-treated UHO gilts（P = 0.098）.Placental morphometry indicated that the width of the folded bilayer was greater（P = 0.05） in glucosamine-treated gilts. In Exp. 2, litter size did not differ between glucosamine-and glucose-treated sows. However in Exp. 3, the increased dose of glucosamine resulted in a significant treatment by parity interaction（P ≤ 0.01）, in which total piglets born and born alive were greater in glucosamine treated sows of later parity（5 and 6）.Conclusions： These results indicated that glucosamine supplementation increased the width of the folds of the placental bilayer and increased litter size in later parity, intact pregnant commercial sows.

关键词： Fructose Glucosamine Hyaluronan Swine Uterine capacity

Evolutionary lineages and Functional Diversification of Plant Hexokinases

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Molecular Plant 2010年第2期3卷 334-346页

作者： Rucha Karve Michael lauria Annie Virnig Xiaoxia Xia bradley l. Rauh Brandon d. Moore Department of Genetics and Biochemistry Clemson University Clemson SC 29634 USA

Sequencing data from 10 species show that a plant hexokinase （HXK） family contains 5-11 genes. Functionally, a given family can include metabolic catalysts, glucose signaling proteins, and non-catalytic, apparent regulatory enzyme homologs. This study has two goals. The first aim is to develop a predictive method to determine which HXK proteins within a species have which type of function. The second aim is to determine whether HXK-dependent glucose signaling proteins occur among more primitive plants, as well as among angiosperms. Using a molecular phylogeny ap- proach, combined with selective experimental testing, we found that non-catalytic HXK homologs might occur in all plants, including the relatively primitive Selaginella moellendorffi. We also found that different lineages of angiosperm HXKs have apparent conserved features for catalytic activity and for sub-cellular targeting. Most higher-plant HXKs are expressed predominantly at mitochondria, with HXKs of one lineage occurring in the plastid, and HXKs of one monocot lineage occurring in the cytosol. Using protoplast transient expression assays, we found that HXK glucose signaling pro- teins occur likely in all higher plants and in S. moellendorffi as well. Thus, the use of glucose by plant HXK isoforms in metabolism and/or as a regulatory metabolite occurs as widespread, conserved processes.

关键词： Hexokinase molecular phylogeny moonlighting proteins plant glucose signaling Selaginella.

Conclusions about testosterone therapy and cardiovascular risk

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Asian Journal of Andrology 2018年第2期20卷 152-153页

作者： bradley D Anawalt Bu B Yeap Division of Medicine University of Washington School of Medicine Seattle Washington 98195 United States School of Medicine University of Western Australia Perth Western Australia 6009 Australia Department of Endocrinology and Diabetes Fiona Stanley Hospital Perth Western Australia 6150 Australia

In this issue of Asian Journal of Andrology （AJA）, several experts have reviewed l the latest data on the potential and known effects of endogenous and exogenous testosterone （T） on cardiovascular risk. In the review by Meyer and Wittert, low endogenous serum T appears to be associated with higher risk of cardiovascular disease and overall mortality in certain populations such as Klinefelter syndrome and older men,

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Association of cardiovascular system medications with cognitive function and dementia in older adults living in nursing homes in Australia

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Journal of Geriatric Cardiology 2017年第6期14卷 407-415页

作者： Enwu liu Suzanne M Dyer lisa Kouladjian O'Donnell Rachel Milte Clare bradley Stephanie l Harrison Emmanuel Gnanamanickam Craig Whitehead Maria Crotty Department of Rehabilitation Aged and Extended Care Faculty of Medicine Nursing and Health Sciences School of Health Sciences Flinders University Daw Park Australia NHMRC Cognitive Partnership Centre The University of Sydney Sydney NSW Australia Kolling Institute of Medical Research St Leonards NSW Australia and Sydney Medical School University of Sydney Sydney NSW Australia Institute for Choice University of South Australia GPO Box 2471 Adelaide SA Australia Infection & Immunity - Aboriginal Health SAHMRI PO Box 11060 Adelaide SA Australia

Objective To examine associations between cardiovascular system medication use with cognition function and diagnosis of dementia in older adults living in nursing homes in Australia. Methods As part of a cross-sectional study of 17 Australian nursing homes examining quality of life and resource use, we examined the association between cognitive impairment and cardiovascular medication use （identified using the Anatomical Therapeutic Classification System） using general linear regression and logistic regression models. People who were receiving end of life care were excluded. Results Participants included 541 residents with a mean age of 85.5 years （± 8.5）, a mean Psychogeriatric Assessment Scale–Cognitive Impairment （PAS-Cog） score of 13.3 （± 7.7）, a prevalence of cardiovascular diseases of 44% and of hypertension of 47%. Sixty-four percent of participants had been diagnosed with dementia and 72% had received cardiovascular system medications within the previous 12 months. Regression models demonstrated the use of cardiovascular medications was associated with lower （better） PAS-Cog scores [Coefficient （β） = -3.7; 95% CI： -5.2 to -2.2; P 〈 0.0001] and a lower probability of a dementia diagnosis （OR = 0.44; 95% CI： 0.26 to 0.75, P = 0.0022）. Analysis by subgroups of medications showed cardiac therapy medications （C01）, beta blocking agents （C07）, and renin-angiotensin system agents （C09） were associated with lower PAS-Cog scores （better cognition） and lower dementia diagnosis probability. Conclusions This analysis has demonstrated an association between greater cardiovascular system medication use and better cognitive status among older adults living in nursing homes. In this population, there may be differential access to health care and treatment of cardiovascular risk factors. This association warrants further investigation in large cohort studies.

关键词： Cardiovascular agents Cognitive dysfunction Dementia Residential facilities

Antioxidant, antibacterial and phytochemical properties of two medicinal plants against the wound infecting bacteria

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Asian Pacific Journal of Tropical Biomedicine 2017年第9期7卷 817-825页

作者： Idowu Jonas Sagbo Anthony Jide Afolayan Graeme bradley Department of Botany University of Fort HarePrivate Bag X1314Alice 5700South Africa Department of Biochemistry and Microbiology University of Fort HarePrivate Bag X1314Alice 5700South Africa

Objective: To investigate the antioxidant, antibacterial and phytochemical properties of ethanol extracts of Brachylaena elliptica and Brachylaena ilicifolia against wound infecting bacteria normally found in diabetic ***: The in vitro antioxidant activity of the two plants extracts were investigated spectrophotometrically using 1,1-diphenyl-2-picrylhydrazyl, nitric oxide, azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt, hydrogen peroxide(H_2O_2) and ferric reducing power. The antibacterial assay and minimum inhibitory concentration(MIC) was determined using the agar dilution method against five bacteria strains using amoxycillin and ciprofloxacin as positive control. The phytochemical analyses(tannins,total phenol, flavonoids, flavonols, proanthocyanidin, alkaloids and saponins) were assessed using standard ***: The ethanol extract of both plants exhibited strong antioxidant activities in some cases when compared to the standards(vitamin C and BHT). The antibacterial activity of both plants showed an appreciable broad spectrum activity against these wound pathogens with MIC value ranges between 0.3 mg/m l and 5 mg/m l. Tannins,phenols, flavanols, proanthocyanidins and alkaloids content of B. ilicifolia were significantly higher than those in B. elliptica. However, there were no significant differences in the flavanoid content of both plants ***: These results indicated that the ethanol leaf extracts of these plants have antioxidant and antibacterial activity against the tested bacteria possibly due to the presence of bioactive compounds and therefore could be used as alternative therapy against wound infection caused by these bacteria in diabetic patients.

关键词： Diabetes mellitus Antioxidant Phytochemical Brachylaena elliptica Brachylaena ilicifolia Wound

Cropping Pattern Modifications Change Water Resource Demands in the Beijing Metropolitan Area

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Journal of Integrative Agriculture 2012年第11期11卷 1914-1923页

作者： HUANG Jing bradley G Ridoutt XU Chang-chun ZHANGHai-lin CHEN Fu College of Agriculture and Biotechnology China Agricultural University Beijing 100193 P.R. China Commonwealth Scientific and Industrial Research Organisation (CSIRO) Sustainable Agriculture Flagship Victoria 3169 Australia

Adequate freshwater supply has become an issue of increasing local and international concern. Reducing water use in agriculture, which is the largest water using sector of the economy, is both important and urgent. The aim of this paper was to quantify how recent cropping pattern changes have influenced water resources in the great Beijing metropolitan area, an expanding megacity which also includes rural counties. Crop production affects blue water use through water consumption and water pollution, the latter assessed here using a critical dilution method. From 1990 to 2010, the total blue water used by crop production declined due to a decrease in overall cropped area, initially in response to local government policies favouring urban development. However, the average blue water use per hectare increased from 2 112 m3 ha-~ yr-~ in 1990 to 2 764 m3 ha-1 yr-1 in 2003, largely as the result of a transition from cereal to vegetable crops, and in particular an increase in intensively managed plastic and glass covered vegetable production systems. Current policies aim to conserve agricultural land, in the interests of food security, and to stimulate cereal production systems with higher ecosystem services provision. As such, in 2010 the average blue water use was 2 425 m3 ha-~ yr-l. These results demonstrate that cropping pattern changes in peri-urban regions and rural communities surrounding the Beijing metropolitan area can have a substantial impact on water resources. They also highlight the tradeoffs between food production and urban and industrial water supply and the need for integrated policy development.

关键词： blue water use water consumption water pollution cropping pattern adjustment peri-urban food production