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A tri-layer approach to controlling nanopore formation in oxide supports

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Nano Research 2019年第6期12卷 1223-1228页

作者： Abha A.Gosavi James L.Hedrick Peng-Cheng Chen Justin M.Notestein chad A.Mirkin Department of Chemical and Biological Engineering Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA International Institute for Nanotechnology Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA Department of Materials Science and Engineering Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA Department of Chemistry Northwestern University2145 Sheridan RoadEvanstonIllinois 60208USA

A novel tri-layer approach for immobilizing metal nanoparticles in SiO2 supports is *** this work,we show that under rapid heating to temperatures of approximately 1,000 ℃,metal nanoparticles less than 15 nm in size will entrench in the SiO2 layer on a silicon wafer to create pores as deep as 250 *** studied and characterized this entrenching behavior and subsequent nanopore formation for a wide variety of metal nanoparticles,including Au,Ag,Pt,Pd,and *** also demonstrate that an Al2O3 layer acts as a barrier to such pore ***,by creating a tri-layer architecture consisting of SiO2 on Al2O3 on silicon wafers,we can control the depth to which nanoparticles entrench between 3-5 *** small range allows one to entrench particles for the purpose of immobilization but still present them above the *** two advances of moving into the sub-15 nm size regime and of controlled particle immobilization through entrenchment have important implications in studying site-isolated and stabilized metal nanoparticles for applications in sensing,separations,and catalysis.

关键词： nanopore formation nanoparticle entrenchment nanoparticle stabilization atomic force microscopy Au nanoparticles

Re–Os Dating of Bitumen from Paleo–Oil Reservoir in the Qinglong Antimony Deposit, Guizhou Province, China and Its Geological Significance

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Acta Geologica Sinica(English Edition) 2017年第6期91卷 2153-2163页

作者： WANG Pengpeng HU Yuzhao LIU Lu JIANG Xiaojun LI Chao chad Joseph Bartholomew ZHANG Guiquan Faculty of Land and Resource Engineering Kunming University of Science and Technology Yunnan Tin Vocation Technical College National Research Center for Geoanalysis Institute of Sinopec Exploration Southern Company

Abundant organic inclusions are present in the Qinglong antimony deposit. However, the source rocks of these organic matters have not been reliably identified. Recently, a paleo--oil reservoir was found in the Qinglong antimony deposit. In view of similar components of gaseous hydrocarbon, we propose that the organic matters observed in inclusions in Qinglong antimony deposit would come from this paleo-oil reservoir. We used the Re-Os dating method to determine the age of the bitumen from this paleo-oil reservoir, and obtained an isochron age of 254.3~2.8 Ma. The age indicates that the oil- generation from source rock occurred in the early Late Permian, earlier than the Sb mineralization age （-148~8.5 Ma） in the Qinglong antimony deposit area. After oil generation from Devonian source rock, first and secondary migration, the crude oil have probably entered into the fractures and pores of volcanic rocks and limestone and formed a paleo-oil reservoir in the western wing of Dachang anticline. As burial process deepened, the crude oil has turned into natural gas, migrates into the core of Dachang anticline and formed a paleo-gas reservoir. The hydrocarbons （including CH4） in the reservoirs can serve as reducing agent to provide the sulfur required for Sb mineralization through thermal chemical reduction of sulfates. Therefore, the formation of oil-gas in the area is a prerequisite for the Sb mineralization in the Qinglong antimony deposit.

关键词： bitumen Re-Os isotopic dating paleo-oil reservoir relationship between hydrocarbon accumulation and mineralization the Qinglong antimony deposit

Informatic analysis reveals Legionella as a source of novel natural products

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Synthetic and Systems Biotechnology 2016年第2期1卷 130-136页

作者： chad W.Johnston Jonathan Plumb Xiang Li Sergio Grinstein Nathan A.Magarvey The Michael G.DeGroote Institute for Infectious Disease Research Department of Biochemistry and Biomedical SciencesMcMaster UniversityHamiltonONCanada L8N 3Z5 Department of Chemistry and Chemical Biology McMaster UniversityHamiltonONCanada L8N 3Z5 Cell Biology Program Hospital for Sick ChildrenTorontoOntarioCanada M5G 1X8

Microbial natural products are a crucial source of bioactive molecules and unique chemical *** their importance,rediscovery of known natural products from established productive microbes has led to declining interest,even while emergent genomic data suggest that the majority of microbial natural products remain to be ***,new sources of microbial natural products must be defined in order to provide chemical scaffolds for the next generation of small molecules for therapeutic,agricultural,and industrial *** this work,we use specialized bioinformatic programs,genetic knockouts,and comparative metabolomics to define the genus Legionella as a new source of novel natural *** show that Legionella *** a diverse collection of biosynthetic gene clusters for the production of polyketide and nonribosomal peptide natural *** confirm this bioinformatic survey,we create targeted mutants of *** and use comparative metabolomics to identify a novel polyketide *** spectroscopic techniques,we show that this polyketide possesses a new chemical scaffold,and firmly demonstrate that this unexplored genus is a source for novel natural products.

关键词： Natural products Legionella Polyketides PRISM

Case of hepatocellular carcinoma in a patient with hereditary tyrosinemia in the post-newborn screening era

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World Journal of Hepatology 2017年第9期9卷 487-490页

作者： Essam M Imseis John S Bynon chad Thornhill Department of Pediatrics Gastroenterology Divisionthe University of Texas Health Science Center at HoustonHouston McG overn Medical School Department of Surgery the University of Texas Health Science Center at Houston Mc Govern Medical School

Hereditary tyrosinemia type 1(HT-1) is a metabolic disorder caused by a defect in tyrosine degradation. Without treatment, symptoms of hepatomegaly, renal tubular dysfunction, growth failure, neurologic crises resembling porphyrias, rickets and possible hepatocellular carcinoma can develop. The use of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione and early diagnosis through newborn screening initiatives have resulted in a sharp decline in morbidity and mortality associated with this disease. We present a case report of a 7-year-old patient with HT-1 who was born prior to the addition of tyrosinemia to the newborn screening in her birth area. At her time of diagnosis, the patient had developed many of the symptoms associated with her disease, including chronic kidney disease, rickets, and myopathy that left her non-ambulatory. During her initial evaluation, she was also noted to have hepatocellular carcinoma. With cadaveric liver transplantation and nutritional support, her symptoms all either resolved or stabilized. Her case il ustrates the severity of the disease if left untreated, the need for vigilance in populations who do not routinely receive newborn screens, and the markedly improved outcomes in patients following transplant.

关键词： Tyrosinemia Screening Hepatocellular carcinoma Liver transplantation

Interactions between maternal parity and feed additives drive the composition of pig gut microbiomes in the post‑weaning period

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Journal of Animal Science and Biotechnology 2024年第3期15卷 1241-1257页

作者： Kayla Law Eduardo Rosa Medina Garcia chad Hastad Deborah Murray Pedro E.Urriola Andres Gomez Department of Animal Science University of Minnesota1364 Eckles AvenueSaint PaulMN 55108USA New Fashion Pork 164 Industrial ParkwayJacksonMN 56143USA

Background Nursery pigs undergo stressors in the post-weaning period that result in production and welfare *** challenges disproportionately impact the offspring of primiparous sows compared to those of mul-tiparous *** is known regarding potential interactions between parity and feed additives in the post-weaning period and their effects on nursery pig ***,the objective of this study was to investigate the effects of maternal parity on sow and offspring microbiomes and the influence of sow parity on pig fecal microbi-ome and performance in response to a prebiotic *** weaning,piglets were allotted into three treat-ment groups:a standard nursery diet including pharmacological doses of Zn and Cu(Con),a group fed a commercial prebiotic only(Preb)based on an Aspergillus oryzae fermentation extract,and a group fed the same prebiotic plus Zn and Cu(Preb+ZnCu).Results Although there were no differences in vaginal microbiome composition between primiparous and mul-tiparous sows,fecal microbiome composition was different(R^(2)=0.02,P=0.03).The fecal microbiomes of primiparous offspring displayed significantly higher bacterial diversity compared to multiparous offspring at d 0 and d 21 post-weaning(P<0.01),with differences in community composition observed at d 21(R^(2)=0.03,P=0.04).When analyzing the effects of maternal parity within each treatment,only the Preb diet triggered significant microbiome distinc-tions between primiparous and multiparous offspring(d 21:R^(2)=0.13,P=0.01;d 42:R^(2)=0.19,P=0.001).Composi-tional differences in pig fecal microbiomes between treatments were observed only at d 21(R^(2)=0.12,P=0.001).Pigs in the Con group gained significantly more weight throughout the nursery period when compared to those in the Preb+ZnCu *** Nursery pig gut microbiome composition was influenced by supplementation with an Aspergillus oryzae fermentation extract,with varying effects on performance

关键词： Aspergillus prebiotic Copper Feed additives Maternal Nursery pig microbiome Parity Swine microbiome Trace minerals Zinc

Using the United States Wind Turbine Database to Identify Increasing Turbine Size, Capacity and Other Development Trends

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Energy and Power Engineering 2020年第7期12卷 407-431页

作者： chad Walker Department of Geography University of Exeter Exeter UK

The purpose of this article was to analyze data associated with advances in wind energy across the United States. While governments, academia, and the private sector generally know patterns of wind turbine development (i.e. turbine size and capacity growing in recent years), there is no known independent, reliable, and/or updated summary of these variables. Using data collected by the Lawrence Berkeley National Laboratory and partners, this study used descriptive statistics to show turbine development and growth patterns from 1981-2019. The newly created United States Wind Turbine Database (USWTDB) represents the most comprehensive account of wind turbine information and was updated in January 2020. Variables I am interested in here are turbine manufacturer, state of project, turbine and project capacity, and turbine size. Findings provide empirical evidence to support the common, yet previously unrefined statements that wind turbines are growing larger in number, size and capacity. This growth is varied over spatial and temporal scales. I also provide evidence to show patterns of turbine manufacturing, with GE Wind dominating much of the US wind energy landscape today. I hope this work provides a timely resource for those interested in a variety of questions surrounding wind energy development in the United States. Perhaps more importantly, this analysis will hopefully inspire others to use what the USWTDB provides and answer larger questions surrounding wind energy futures.

关键词： Wind Energy Wind Turbines USWTDB Renewable Energy Turbine Capaci-ty Turbine Size

Intramedullary bone pedestal formation contributing to femoral shaft fracture nonunion:A case report and review of the literature

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World Journal of Orthopedics 2022年第5期13卷 528-537页

作者： Charles B Pasque Alexander J Pappas chad A Cole Jr Department of Orthopaedic Surgery and Rehabilitation University of Oklahoma College of MedicineOklahoma CityOK 73104United States University of Colorado School of Medicine AuroraCO 80045United States

BACKGROUND Femoral shaft fracture is a commonly encountered orthopedic injury that can be treated operatively with a low overall delayed/nonunion *** the case of delayed union after antegrade or retrograde intramedullary nail fixation,fracture dynamization is often attempted *** after dynamization has been shown to occur due to infection and other aseptic *** present a unique case of diaphyseal femoral shaft fracture nonunion after dynamization due to intramedullary cortical bone pedestal formation at the distal tip of the *** SUMMARY A 37-year-old male experienced a high-energy trauma to his left thigh after coming down hard during a motocross *** was consistent with an isolated,closed,left mid-shaft femur *** was initially managed with reamed antegrade intramedullary nail fixation but had continued thigh *** at four months demonstrated no evidence of fracture union and failure of the distal locking screw,and dynamization by distal locking screw removal was *** patient continued to have pain eight months after the initial procedure and 4 mo after dynamization with serial radiographs continuing to demonstrate no evidence of fracture *** decision was made to proceed with exchange nailing for aseptic fracture *** the exchange procedure,an obstruction was encountered at the distal tip of the failed nail and was confirmed on magnified fluoroscopy to be a pedestal of cortical bone in the *** obstruction required further distal reaming.A longer and larger diameter exchange nail was placed without difficulty and without a distal locking screw to allow for dynamization at the fracture ***-operative radiographs showed proper fracture and hardware *** was subsequently radiographic evidence of callus formation at one year with subsequent fracture consolidation and resolution of thigh pain at eighteen *** The risk of fracture nonunion caused by int

关键词： Nonunion Femoral shaft fracture Diaphysis Fracture fixation Antegrade intramedullary nail Case report

Treatment technologies for aqueous perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA)

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Frontiers of Environmental Science & Engineering 2009年第2期3卷 129-151页

作者： chad D.VECITIS Hyunwoong PARK Jie CHENG Brian T.MADER Michael R.HOFFMANN W.M.Keck Laboratories California Institute of TechnologyPasadenaCalifornia 91125USA 3M Environmental Laboratory 3M CenterBuilding 260-05-N-17MaplewoodMN 55144-1000USA

Fluorochemicals(FCs)are oxidatively recalcitrant,environmentally persistent,and resistant to most conventional treatment *** have unique physiochemical properties derived from fluorine which is the most electronegative ***(PFOS),and perfluorooctanoate(PFOA)have been detected globally in the hydrosphere,atmosphere and *** treatment technologies such as reverses osmosis,nano-filtration and activated carbon can remove FCs from ***,incineration of the concentrated waste is required for complete FC ***,a number of alternative technologies for FC decomposition have been *** FC degradation technologies span a wide range of chemical processes including direct photolysis,photocatalytic oxidation,photochemical oxidation,photochemical reduction,thermally-induced reduction,and sonochemical *** paper reviews these FC degradation technologies in terms of kinetics,mechanism,energetic cost,and *** optimal PFOS/PFOA treatment method is strongly dependent upon the FC concentration,background organic and metal concentration,and available degradation time.

关键词： fluorochemical(FC)degradation technologies perfluoroctanesulfonate(PFOS) perfluorooctanoate (PFOA) oxidation reduction photolysis thermolysis review

A preliminary evaluation of throughfall sampling techniques in a mature coniferous forest

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Journal of Forestry Research 2014年第2期25卷 407-413页

作者： Darryl. E. Carlyle-Moses chad. E. Lishman Adam. J. McKee Department of Geography & Environmental Studies Thompson Rivers University Graduate Program in Environmental Science Thompson Rivers University

Rainfall, throughfall and stemflow were measured and canopy interception loss was derived for 14 rainfall events from June 22 to August 30, 2008 within a mature declining hybrid white spruce （Picea glauca （Moench） Voss x p engelmannii Parry ex Engelm.） - subalpine fir （Abies lasiocarpa （Hook.） Nutt.） - lodgepole pine （Pinus contorta vat. latifolia Dougl. ex Loud.） stand in south-central British Columbia, Can- ada. Stemflow was negligible during the study period, while, respectively throughfall and canopy interception loss accounted for approximately 59.4% and 40.6% of the 50.1 mm of cumulative rainfall. Throughfall variability was assessed with three approaches involving roving and stationary wedge-type gauges, and stationary trough gauges. Throughfall exhibited large spatial variability with the coefficient of variability of study period throughfall sampled using 16 stationary trough gauges being 30.3%, while it was 38.0% and 28.7% for 32 stationary and 32 roving wedge gauges, respectively. Our analysis suggests that a roving gauge method is better than a stationary approach since the errors associated with event mean throughfalls are summed quadratically and a greater portion of the canopy area is sampled. Trough gauges were more efficient than wedge gauges; however, this efficiency was less than expected given their much larger sampling areas, suggesting that spatial autocorrelation lengths of throughfall may be longer than the trough systems. The spatial distribution of throughfall showed a high degree of temporal persistence throughout the study suggesting the existence of stable ＂wet＂ and ＂dry＂ inputs to the floors of these coniferous forests.

关键词： throughfall canopy interception loss stemflow spatial variability temporal persistence