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An electronic nose using a single graphene FET and machine learning for water, methanol, and ethanol

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Microsystems & Nanoengineering 2020年第1期6卷 969-981页

作者： Takeshi Hayasaka Albert Lin Vernalyn C.Copa Lorenzo p.Lopez jr.Regine A.Loberternos Laureen Ida M.Ballesteros Yoshihiro Kubota Yumeng Liu Arnel A.Salvador Liwei Lin Berkeley Sensor and Actuator Center&Department of Mechanical Engineering University of California at BerkeleyBerkeleyCA 94720USA Materials Science and Engineering program College of ScienceUniversity of the Philippines Diliman1101 Quezon CityPhilippines National Institute of physics College of ScienceUniversity of the Philippines Diliman1101 Quezon CityPhilippines

The poor gas selectivity problem has been a long-standing issue for miniaturized chemical-resistor gas *** electronic nose(e-nose)was proposed in the 1980s to tackle the selectivity issue,but it required top-down chemical functionalization processes to deposit multiple functional ***,we report a novel gas-sensing scheme using a single graphene field-effect transistor(GFET)and machine learning to realize gas selectivity under particular conditions by combining the unique properties of the GFET and e-nose *** of using multiple functional materials,the gas-sensing conductivity profiles of a GFET are recorded and decoupled into four distinctive physical properties and projected onto a feature space as 4D output vectors and classified to differentiated target gases by using machine-learning *** single-GFET approach coupled with trained pattern recognition algorithms was able to classify water,methanol,and ethanol vapors with high accuracy quantitatively when they were tested ***,the gas-sensing patterns of methanol were qualitatively distinguished from those of water vapor in a binary mixture condition,suggesting that the proposed scheme is capable of differentiating a gas from the realistic scenario of an ambient environment with background *** such,this work offers a new class of gas-sensing schemes using a single GFET without multiple functional materials toward miniaturized e-noses.

关键词： methanol selectivity electronic

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贵州氟中毒病区燃煤的潜在氟化氢释放

科学通报 2011年第27期56卷 2311-2314页

作者：梁汉东梁言慈 GARDELLA Joseph A. jr. 何平 YATZOR Brett p. 中国矿业大学煤炭资源与安全开采国家重点实验室北京100083 University at Buffalo State University of New York New York 14260 USA 贵州省疾病预防控制中心贵阳550001 池州学院池州247000

采用飞行时间二次离子质谱(TOFSIMS)分析了21件煤样,它们取自贵州普安和普定等地的5个氟中毒地方病流行自然村,总硫和总氟含量分别为0.24%～5.58%(质量分数)和90.2～149.2mg/kg,系日常生活用燃煤,出产于地表及临近地表,故曾遭一定程度风... 详细信息

采用飞行时间二次离子质谱(TOFSIMS)分析了21件煤样,它们取自贵州普安和普定等地的5个氟中毒地方病流行自然村,总硫和总氟含量分别为0.24%～5.58%(质量分数)和90.2～149.2mg/kg,系日常生活用燃煤,出产于地表及临近地表,故曾遭一定程度风化.全部煤样被检出H3O+,H2SO4+,HSO4-,F-及K+和Na+等质谱特征离子,前三者直接标志了水合硫酸(H2SO4H2O)的存在,后者指出了氟呈盐的形式.结论是当地生活燃煤天然含有酸(H2SO4H2O)与碱(F-).推论是此酸与碱在加热或燃烧条件下必将发生化学中和反应而释放出氟化氢(HF)(Bp19.5℃).室内200℃加热煤试验结果和普安县青山乡等农户煤炉现场检验结果均直接再现氟化氢释放.

关键词：地方氟中毒氟化氢水合硫酸二次离子质谱贵州

photoluminescence emissions of Ca_(1-x)WO_(4):xEu^(3+):Bridging between experiment and DFT calculations

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Journal of Rare Earths 2022年第10期40卷 1527-1534页

作者： Amanda Fernandes Gouveia Marcelo Assis Lara Kelly Ribeiro Aline Estefany Brandao Lima Eduardo de Oliveira Gomes Daniele Souza Yara Gobato Galvao Ieda Lucia Viana Rosa Geraldo Eduardo da Luz jr.Eva Guillamón Elson Longo Juan Andrés Miguel Angel San-Miguel Department of physical and Analytical Chemistry University Jaume I(UJI)12071CastelloSpain Institute of Chemistry State University of Campinas(Unicamp)13083-970CampinasSPBrazil CDMF Federal University of S?o Carlos(UFSCar)P0.Box 67613565-905Sao CarlosSao PauloBrazil Departamento de Química Federal University of Piauí(UFPI)64049-550TeresinaPiautBrazil physics Department Federal University of S?o Carlos(UFSCar)P.0.Box 67613565-905Sao CarlosSao PauloBrazil

In this work,the impact of the doping process on the photoluminescence emission of CaWO_(4) as a function of the concentration of Eu^(3+) cation(0.01 mol%,0.02 mol%,0.04 mol%,0.06 mol%,0.08 mol%,and 0.10 mol%) is discussed in ***_(1-x)WO~4:xEu^(3+) samples were successfully synthesized by a simple coprecipitation method followed by microwave *** blue shift in the absorption edge confirms the quantum confinement effect and the band gap energy covers the range from 3.91 to 4.18 eV,as the amount of Eu^(3+) cations *** experimental results are sustained by first-principles calculations,at the density functional theory level,to decipher the geometry and electronic properties,thereby enabling a more accurate and direct comparison between theory and experiment for the Ca_(1-x)WO_(4):xEu^(3+) structure.

关键词： Ca_(1-x)WO_(4):xEu^(3+) DFT calculations photoluminescence emissions Rare earths

Round spermatid injection into human oocytes:a systematic review and meta-analysis

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Asian Journal of Andrology 2021年第4期23卷 363-369页

作者： Brent M Hanson Taylor p Kohn Alexander W pastuszak Richard T Scott jr.philip J Cheng James M Hotaling Department of Reproductive Endocrinology and Infertility IVI-Reproductive Medicine Associates of New JerseyBasking RidgeNJ 07920USA Department of Urology The Brady Urological Institute at Johns Hopkins UniversityBaltimoreMD 21287USA Department of Surgery University of Utah Center for Reconstructive Urology and Men's HealthSalt Lake CityUT 84108USA

Many azoospermic men do not possess mature spermatozoa at the time of surgical sperm *** study is a systematic review and meta-analysis evaluating outcomes following round spermatid injection(ROSI),a technique which utilizes immature precursors of spermatozoa for *** electronic search was performed to identify relevant articles published through October *** cohort studies in English involving male patients who had round spermatids identified and used for fertilization with human oocytes were *** rate,pregnancy rate,and resultant delivery rate were assessed following ***-analysis outcomes were analyzed using a random-effects *** were extracted from 22 studies involving 1099 couples and 4218 embryo *** fertilization rate after ROSI was 38.7%(95%confidence interval[CI]:31.5%–46.3%),while the pregnancy rate was 3.7%(95%CI:3.2%–4.4%).The resultant delivery rate was low,with 4.3%of embryo transfers resulting in a delivery(95%CI:2.3%–7.7%).The pregnancy rate per couple was 13.4%(95%CI:6.8%–19.1%)and the resultant delivery rate per couple was 8.1%(95%CI:6.1%–14.4%).ROSI has resulted in clinical pregnancies and live births,but success rates are considerably lower than those achieved with mature *** this technique may be a feasible alternative for men with azoospermia who decline other options,couples should be aware that the odds of a successful delivery are greatly diminished and the prognosis is relatively poor.

关键词： azoospermia in vitro fertilization infertility spermatozoa testis

The First Row Anomaly and Recoupled pair Bonding the Late p-Block Halides

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The First Row Anomaly and Recoupled Pair Bonding the Late p-...

An immunoglobulin Y that specifically binds to an in silico-predicted unique epitope of Zika virus non-structural 1 antigen

2012年理论与高性能计算化学国际会议

作者： Thom H.Dunning, jr. Department of Chemistry and National Center for Supercomputing Applications University of Illinois at Urbana-Champaign

The first row anomaly-the dramatic differences between the properties of molecules formed from the late p-block elements of the first row of the periodic table and that of the corresponding elements in subsequent rows-is well known. In this article we summarize the results of recent theoretical studies of the halides of the late p-block elements, showing that many of these differences are the result of a single cause-the ability of the late p-block elements in the second and subsequent rows of the periodic table to form recoupled pair bonds. Recoupled pair bonds are formed when an electron in a singly occupied ligand orbital recouples the pair of electrons in a doubly occupied lone pair orbital on a central atom, forming a central atom-ligand bond. Recoupled pair bonds lead to new excited states in the spectra of the late p-block halides;enable these elements to form hypervalent compounds;result in dramatic oscillations in the Fn-1X-F bond energies;provide a new pathway for the inversion of heavily halogenated, tricoordinated second row species;and provide new intermediates and products in reactions involving the late p-block elements. Thus, an understanding of recoupled pair bonding is critical to understanding the properties of molecules containing the late p-block elements beyond the first row.?

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Asian pacific Journal of Tropical Medicine 2022年第1期15卷 35-43页

作者： Leonardo A.Guevarra jr.Scott Dean p.De Sagon Treena Rica D.Teh Maria Katrina Diana MCruz Nikki Cyrill C.Capistrano Austine James Z.StaMaria Laarni Grace M.Corales Leslie Michelle M.Dalmacio Department of Biochemistry and Molecular Biology College of MedicineUniversity of the Philippines ManilaPhilippines Department of Biochemistry Faculty of PharmacyUniversity of Santo TomasPhilippines Research Center for Natural and Applied Sciences University of Santo TomasPhilippines

Objective:To identify unique immunogenic epitopes of Zika virus non-structural 1(NS1)antigen and produce immunoglobulin Y(IgY)for potential use in he diagnosis of of Zika virus ***:Immunogenic epitopes were identified using in silico B-cell epitope prediction.A synthetic peptide analog of the predicted epitope was used to induce antipeptide IgY production in hens which was purified using affinity *** of purified IgY and its binding specificity were performed by gel electrophoresis and ELISA,***:Out of the nine continuous epitopes identified,the sequence at position 193-208(LKVREDYSLECDpAVI)was selected and used to produce anti-peptide *** produced IgY was found to bind to the synthetic analog of the Zika virus NS1 immunogenic epitope but not to other flaviviruses and random peptides from other ***:In this study,we identified an immunogenic epitope unique to Zika virus that can be used to develop a serodiagnostic tool that specifically detect Zika virus infection.

关键词： Immunoglobulin Y IgY B-cell epitope prediction Flavivirus Non-structural 1 antigen Zika virus

An integrated analysis of air pollution from US coal-fired power plants

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Geoscience Frontiers 2023年第2期14卷 204-216页

作者： Mikalai Filonchyk Michael p.peterson Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China Gansu provincial Engineering Laboratory for National Geographic State Monitoring Lanzhou 730070China Department of Geography/Geology University of Nebraska OmahaOmahaNE 68182USA

The United States is one of the world’s leaders in electricity production,generating about 4116 billion kWh in 2021,of which coal accounted for 21.8%of the *** study applies an integrated approach using both terrestrial and satellite data to specifically examine emissions from coal-fired power plants and its spatial *** study also highlights the effectiveness of government policies to reduce *** was found that emission of pollutants from the country’s energy sector has been steadily declining,with annual emissions of sulfur dioxide(SO_(2))and nitrogen oxides(NOx)decreasing from the US electric power sector between 1990 and 2020 by 93.4%and 84.8%,respectively,and carbon dioxide(CO_(2))by 37%between 2007 and *** overall emissions from coal-fired power plants are declining,some individual plants have yet to install environmental equipment to control *** to US government data,major emitters of SO_(2),NO_(x),and CO_(2) in the US are the Martin Lake power plant in East Texas,the Labadie power plant near ***,Missouri,and the James H Miller jr.plant near Birmingham,*** study also integrates TROpOMI satellite data to detect point emissions from individual power *** the highest levels of measured pollutants were over the country’s major cities and areas of fossil fuel extraction,TROpOMI could clearly distinguish the pollution caused by power plants in more rural *** the US has made great strides in reducing emissions from coal-fired power plants,these plants still represent a major source of pollution and remain a major *** eliminating coal as a power source will be difficult with the higher power demands resulting from the transition to electric automobiles.

关键词： Coal-fired power plants Emissions TROpOMI Air pollution Sulfur dioxide Nitrogen oxides

Eastern Oyster (Crassostrea virginica) Filtration Efficiency of Chlorophyll-aunder Dynamic Conditions in the Hudson-Raritan Estuary at pier 40, New York City

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Open Journal of Ecology 2019年第7期9卷 238-271页

作者： Jane E. perrino Dennis R. Ruez jr. Department Environmental Studies University of Illinois Springfield Springfield IL USA

Eastern oyster (Crassostrea virginica) abundance has declined severely over the past century along the Atlantic and Gulf coasts of the United States. For varied reasons, overfishing among the foremost, bivalves no longer make up considerable reefs as was common. While discourse continues on oyster restoration and augmentation, gaps in knowledge of C. virginica and regional environmental interactions remain. Our primary aim was to examine the C. virginica filter feeding of phytoplankton in the Hudson River Estuary, New York City. Secondarily, this study examined the filtration of these oysters in relation to environmental attributes. Chlorophyll-a, the predominant photosynthesizing pigment in red and green algae, is an indicator of phytoplankton productivity in aquatic settings. Crassostrea virginica consumes first-tier plankton from the water column’s seston;thus analysis of chlorophyll-a content allows estimating phytoplankton concentrations, from which oyster filtration efficiency (FE) was quantified. Water conditions (temperature, dissolved oxygen, pH, salinity, turbidity, tide and flow rate) also were recorded. Spectrophotometric determination of chlorophyll-a concentration methodology was derived from the Standard Methods text favored by the US EpA. This project compared real-time Hudson River Estuary (HRE) water samples prior to passing through a contained oyster reef and samples of water post-filtration. This sampling scenario was unique as the contained reef used was fed by HRE water. Most studies on oyster filtration have been laboratory-based, and few assessed oysters in the field. This study took place at pier 40, the River project Wetlab, lower Hudson River along Manhattan. The FE of this reef was calculated for two months during various environmental states which can be the basis of future investigations. Statistically significant differences were found between pre- and post-filtration water samples (Z = 4.620, p provides a glimpse

关键词： Chlorophyll-a Crassostrea virginica Filtration Efficiency Hudson River

Ergot Alkaloid Effects on Bovine Sperm Motility In Vitro

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Advances in Reproductive Sciences 2019年第1期7卷 7-15页

作者： Ryan page Toby Lester Rick Rorie Charles Rosenkrans jr. Department of Animal Science Division of Agriculture University of Arkansas System Fayetteville Arkansas USA

Cattle in some parts of the world graze pastures that consist of tall fescue that may contain ergot alkaloid contamination. Those ergot alkaloids are associated with reduced reproductive rates in cattle. Our objective was to determine if ergot alkaloids [dihydroergotamine (DHET), ergonovine (EN), and ergotamine (ET)] directly affect bovine sperm characteristics. Spermatozoa were collected from mature Angus (n = 2) and Balancer (n = 4) bulls. Within bull, treatments were structured as a 3 × 5 factorial with three alkaloids (DHET, EN, and ET) and five concentrations of each alkaloid (0, 33, 66, 100, or 200 μM). Spermatozoa (25 × 106) were incubated (39?C) in 1 mL of modified sperm medium. Sperm motility characteristics were evaluated using CASA (Hamiliton Thorne IVOS, Beverly, MA) at 0, 3, and 6 h after initial alkaloid exposure. Initial sperm motility was (69% ± 1.1%) and declined (p = 0.01) to (35% ± 2.6%) at 6 h. Sperm motility decreased (p p perm motility and morphology, which adds to our understanding of how ergot alkaloids may hinder cattle reproductive rates.

关键词： CASA Bull Spermatozoa Toxins