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Fungal contamination of stored automobile-fuels in a tropical environment

Journal of environmental Sciences 2010年第10期22卷 1595-1601页

作者： Carlos e.Rodríguez-Rodríguez evelyn Rodríguez Rigoberto Blanco Ivannia Cordero daniel Segura Research Center in Tropical Diseases and Laboratory of Research in Anaerobic Bacteriology Faculty of MicrobiologyUniversity of Costa Rica department of Chemical engineering School of EngineeringAutonomous University of Barcelona Research Center in electrochemistry and Chemical energy University of Costa Rica

Because of the lack of reports, the base levels of microbial contamination on stored fuels are unknown in tropical regions and it is unclear whether these levels have some influence on fuel quality parameters. Therefore, fungal quality in automobile fuels stored across Costa Rican territory was evaluated during two years according to the standard ASTM D6974-04. For a total of 96 samples, counts and identification of molds and yeasts were performed on regular gas, premium gas and diesel taken from the bottom and superior part of the container tanks. The highest contamination was found on the bottom of the tanks, where an aqueous phase was usually identified, showing populations over the ones present in the hydrocarbon itself （up to 108 CFU/L）. Diesel was the most contaminated fuel （up to 107 CFO/L）; however, an alteration on the physicochemical parameters was not observed in any kind of fuel. Seventy-five mold strains were isolated, Penicillium sp. being the most common genus （45.8% of the samples）, and ten yeast strains, from the genera Candida sp. and Rhodotorula sp. Four of the yeasts were able to grow on diesel as the sole carbon source, at concentrations ranging from 0.5% to 25%. Increasing the frequency of tank cleaning, adding antimicrobial agents and monitoring microbial populations are recommended strategies to improve microbial quality of stored fuels.

关键词： fuel microbial contamination biodegradation molds yeasts

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Adsorptive removal of resorcinol on a novel ordered mesoporous carbon(OMC) employing COK-19 silica scaffold:Kinetics and equilibrium study

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Journal of environmental Sciences 2019年第1期31卷 307-317页

作者： Zaki Uddin Ahmad Qiyu Lian Mark e.Zappi Prashanth R.Buchireddy daniel Dianchen Gang department of Civil engineering University of Louisiana at Lafayette Center for environmental Technology The Energy Institute of Louisiana department of Chemical engineering University of Louisiana at Lafayette

Phenolic compounds and their derivatives have been found in industrial wastewater, which pose threats to the natural environment. Ordered mesoporous carbon(OMC) has been identified as an ideal adsorbent possessing high specific surface area and large pore volume to alleviate these pollutants. A novel ordered mesoporous carbon was prepared using COK-19 template with the cubic Fm3 m structure for the first time. Ordered mesoporous silica COK-19 was synthesized and reported in 2015. Sucrose as the carbon precursor was impregnated into the mesopores of silica and converted to carbon through carbonization process using sulfuric acid as a catalyst. Ordered mesoporous carbon was obtained after the removal of silica framework using hydrofluoric acid. Boric acid was employed for the preparation of OMCs with tunable pore sizes in the range of 6.9–16.6 nm. Several characterization techniques such as nitrogen adsorption–desorption isotherms, transmission electron microscope(TeM), Fourier transform infrared spectroscopy, Boehm titration and elemental analysis were employed to characterize the OMCs. The pore size analysis and TeM images confirmed that OMC has replicated the mesostructure of the COK-19. Results obtained from adsorption kinetics and isotherms suggest that the Pseudo-second-order model and Langmuir isotherm well described the experimental data.

关键词： Ordered mesoporous carbon COK-19 TeM image Resorcinol Adsorption isotherm Adsorption kinetics

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Adjusting the physico-chemical properties of collagen scaffolds to accommodate primary osteoblasts and endothelial cells

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Regenerative Biomaterials 2023年第1期10卷 590-602页

作者： Nima Meyer daniel V.Bax Jochen Beck Ruth e.Cameron Serena M.Best department of Materials Science and Metallurgy University of CambridgeCambridge CB30FSUK Geistlich Pharma AG Product DevelopmentWolhusenSwitzerland

Collagen-based biomaterials are used widely as tissue engineering scaffolds because of their excellent bioactivity and their similarity to the natural *** regeneration of healthy bone tissue requires simultaneous support for both osteoblasts and,where angiogenesis is intended,endothelial *** it is important to tailor carefully the biochemical and structural characteristics of the scaffold to suit the needs of each cell *** work describes for the first time a systematic study to gain insight into the cell type-specific response of primary human osteoblast(hOBs)and human dermal microvascular endothelial cells(HDMeCs)to insoluble collagen-based *** behaviour was evaluated on both 2D films and 3D scaffolds,produced using *** collagen was cross-linked at various eDC/NHS concentrations and mono-cultured with hOBs and HDMeCs to assess the effect of architectural features and scaffold stabilization on cell *** was observed that 3D scaffolds cross-linked at 30%of the standard conditions in literature offered an optimal combination of mechanical stiffness and cellular response for both cell types,although endothelial cells were more sensitive to the degree of cross-linking than *** features have a time-dependent impact on the cell migration profile,with alignment being the most influential parameter overall.

关键词： angiogenesis collagen scaffolds cell migration eDC/NHS cross-linking

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development of a multicellular 3D-bioprinted microtissue model of human periodontal ligament-alveolar bone biointerface:Towards a pre-clinical model of periodontal diseases and personalized periodontal tissue engineering

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Genes & Diseases 2022年第4期9卷 1008-1023页

作者： Murat Taner Vurat ŞükranŞeker Özge Lalegül-Ülker Mahmut Parmaksiz Ayşe eser elçin Yaşar Murat elçin Tissue engineering Biomaterials and Nanobiotechnology LaboratoryAnkara University Faculty of ScienceAnkara University Stem Cell InstituteAnkara 06100Turkey Biovalda Health Technologies Inc.Ankara 06100Turkey

While periodontal (PD) disease is among principal causes of tooth loss worldwide, regulation of concomitant soft and mineralized PD tissues, and PD pathogenesis have not been completely clarified yet. Besides, relevant pre-clinical models and in vitro platforms have limitations in simulating human physiology. Here, we have harnessed three-dimensional bioprinting (3DBP) technology for developing a multi-cellular microtissue model resembling PD ligament-alveolar bone (PDL-AB) biointerface for the first time. 3DBP parameters were optimized;the physical, chemical, rheological, mechanical, and thermal properties of the constructs were assessed. Constructs containing gelatin methacryloyl (Gel-MA) and hydroxyapatite-magnetic iron oxide nanoparticles showed higher level of compressive strength when compared with that of Gel-MA constructs. Bioprinted self-supporting microtissue was cultured under flow in a microfluidic platform for >10 days without significant loss of shape fidelity. Confocal microscopy analysis indicated that encapsulated cells were homogenously distributed inside the matrix and preserved their viability for >7 days under microfluidic conditions. Immunofluorescence analysis showed the cohesion of stromal cell surface marker-1+ human PDL fibroblasts containing PDL layer with the osteocalcin+ human osteoblasts containing mineralized layer in time, demonstrating some permeability of the printed constructs to cell migration. Preliminary tetracycline interaction study indicated the uptake of model drug by the cells inside the 3D-microtissue. Also, the non-toxic levels of tetracycline were determined for the encapsulated cells. Thus, the effects of tetracyclines on PDL-AB have clinical significance for treating PD diseases. This 3D-bioprinted multi-cellular periodontal/osteoblastic microtissue model has potential as an in vitro platform for studying processes of the human PDL.

关键词： 3D bioprinting Alveolar bone Microtissue model Organ-on-a-chip .Periodontal ligament Periodontal tissue engineering Periodontal-osteoblastic biointer face Periodontium-on-a-chip

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An experimental and theoretical investigation of a small,high aspect-ratio,free-piston,two-stroke engine

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Propulsion and Power Research 2020年第4期9卷 326-343页

作者： Chiluwata e.Lungu Mael Disseau daniel C.Stubbs Jechiel Jagoda David e.Scarborough General electric Company GreenvilleSouth Carolina29615USA Georgia Institute of Technology AtlantaGeorgia30332USA Truett McConnel University ClevelandGeorgia30528USA Auburn University AuburnAlabama36849USA

This paper presents a design for a novel,palm sized,high-aspect-ratio *** simplify fabrication and keep the device unobtrusive,a design incorporating a two-cycle engine having a flat,rectangular piston with spring return was *** experimental engine based on this concept producing a significant amount of useful work was *** results were encouraging,this geometry raised many issues to be investigated and resolved,including the effects of piston sealing,scavenging,heat losses,and combustion *** to the complex interplay between these effects,experimental investigation was time consuming and simple models were found to be ***,a more complex theoretical model accounting for these effects was developed and used to evaluate the sensitivity of engine performance to each of these *** predictions of this model were used to develop recommendations for improving the experimentally developed engine.

关键词： Micro-combustion Power generation Free-piston engine Internal combustion engine Palm power

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estimating the geographic range of a threatened shark in a data-poor region： Cetorhinus maximus in the South Atlantic Ocean

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Current Zoology 2015年第5期61卷 811-826页

作者： Luis O. LUCIFORA Santiago A. BarBINI edgardo e. DI GIACOMO Juan A. WAeSSLe daniel e. FIGUeROA Instituto de Biologia Subtropical - Iguazu Consejo Nacional de Investigaciones Cientificas y Tecnicas Universidad Nacional de Misiones Puerto Iguazu Misiones Argentina Laboratorio de Ictiologia Instituto de Investigaciones Marinas y Costeras Consejo Nacional de Investigaciones Cientificas y Tecnicas Universidad Nacional de Mar del Plata Mar del Plata Provincia de Buenos Aires Argentina Grupo Condros Instituto de Biologia Marina y Pesquera "Almirante Stomi" Universidad Nacional del Comahue San Antonio Oeste Rio Negro Argentina Instituto Nacional de Investigacion y desarrollo Pesquero Mar del Plata Provincia de Buenos Aires Argentina

The distribution of the planktivorous basking shark Cetorhinus maximus is influenced by zooplankton abundance at small scales and temperature at medium scales in the North Atlantic. Here, we estimate the distribution of basking sharks on South Atlantic continental shelves, and the relative importance of chlorophyll concentration, as a proxy for zooplankton abun- dance, and temperature in determining habitat suitability for basking sharks at large scales. We used maximum entropy （Maxent） and maximum likelihood （MaxLike） species distribution modelling to test three hypotheses： the distribution of basking sharks is determined by （1） temperature, （2） chlorophyll concentration, or （3） both chlorophyll and temperature, while considering other factors, such as oxygen and salinity. Off South America, basking shark habitat included subtropical, temperate and cool-temperate waters between approximately 20°S and 55°S. Off Africa, basking shark habitat was limited to cool-temperate waters off Namibia and southern South Africa. MaxLike models bad a better fit than Maxent models. The best model included minimum chlorophyll concentration, dissolved oxygen concentration, and sea surface temperature range, supporting hypothesis 3. However, of all variables included in the best model, minimum chlorophyll concentration had the highest influence on basking shark distribution. Unlike the North Atlantic distribution, the South Atlantic distribution of basking sharks includes subtropical and cool-temperate waters. This difference is explained by high minimum chlorophyll concentration off southern Brazil as compared to North Atlantic subtropical areas. Observations in other regions of the world support this conclusion. The highest habitat suitability for basking sharks is located close to nearshore areas that experience high anthropogenic impact [Current Zoology 61 （5）： 811-826, 2015].

关键词： Basking shark Chondrichthyes Geographic range Maxent MaxLike Southern Hemisphere

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Recent developments in topoisomerase-targeted cancer chemotherapy

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Acta Pharmaceutica Sinica B 2018年第6期8卷 844-861页

作者： Kirk e.Hevener Tatsiana A.Verstak Katie e.Lutat daniel L.Riggsbee Jeremiah W.Mooney department of Pharmaceutical Sciences University of Tennessee Health Science Center

The DNA topoisomerase enzymes are essential to cell function and are found ubiquitously in all domains of life. The various topoisomerase enzymes perform a wide range of functions related to the maintenance of DNA topology during DNA replication, and transcription are the targets of a wide range of antimicrobial and cancer chemotherapeutic agents. Natural product-derived agents, such as the camptothecin, anthracycline, and podophyllotoxin drugs, have seen broad use in the treatment of many types of cancer. Selective targeting of the topoisomerase enzymes for cancer treatment continues to be a highly active area of basic and clinical research. The focus of this review will be to summarize the current state of the art with respect to clinically used topoisomerase inhibitors for targeted cancer treatment and to discuss the pharmacology and chemistry of promising new topoisomerase inhibitors in clinical and preclinical development.

关键词： Topoisomerase Inhibition Cancer Oncology Clinical Pre-clinical

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Quark-Novae Ia in the Hubble diagram: implications for dark energy

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Research in Astronomy and Astrophysics 2014年第5期14卷 497-519页

作者： Rachid Ouyed Nico Koning denis Leahy Jan e.Staff daniel T.Cassidy department of Physics and Astronomy University of Calgary 2500 University Drive NWCalgary Alberta T2N 1N4 Canada department of Physics and Astronomy Macquarie University NSW 2109 Australia department of engineering Physics McMaster University Hamilton Ontario L8S 4L7 Canada

The accelerated expansion of the Universe was proposed through the use of Type-Ia supernovae （SNe） as standard candles. The standardization depends on an empirical correlation between the stretch/color and peak luminosity of the light curves. The use of Type-Ia SNe as standard candles rests on the assumption that their properties （and this correlation） do not vary with redshift. We consider the possibility that the majority of Type-Ia SNe are in fact caused by a Quark-Nova detonation in a tight neutron-star-CO-white-dwarf binary system, which forms a Quark-Nova Ia （QN-Ia）. The spin-down energy injected by the Quark-Nova remnant （the quark star） contributes to the post-peak light curve and neatly explains the observed correlation between peak luminosity and light curve shape. We demonstrate that the parameters describing QN-Ia are NOT constant in redshift. Simulated QN-Ia light curves provide a test of the stretch/color correlation by comparing the true distance modulus with that determined using SN light curve fitters. We determine a correction between the true and fitted distance moduli, which when applied to Type-Ia SNe in the Hubble diagram recovers the ΩM = 1 cosmology. We conclude that Type-Ia SNe observations do not necessitate the need for an accelerating expansion of the Universe （if the observed SNe Ia are dominated by QNe Ia） and by association the need for dark energy.

关键词： dark energy -- cosmology observations -- supernovae general

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A systematic review of real-time detection and classification of power quality disturbances

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Protection and Control of Modern Power Systems 2023年第1期8卷 30-66页

作者： Joaquín e.Caicedo daniel Agudelo-Martínez edwin Rivas-Trujillo Jan Meyer Faculty of engineering Universidad Distrital Francisco Joséde CaldasBogotáColombia Institute of electrical Power Systems and High Voltage engineering Technische Universität DresdenDresdenGermany Bogotá Colombia

This paper offers a systematic literature review of real-time detection and classification of Power Quality Disturbances(PQDs).A particular focus is given to voltage sags and notches,as voltage sags cause huge economic losses while research on voltage notches is still very incipient.A systematic method based on scientometrics,text similarity and the analytic hierarchy process is proposed to structure the review and select the most relevant literature.A biblio-metric analysis is then performed on the bibliographic data of the literature to identify relevant statistics such as the evolution of publications over time,top publishing countries,and the distribution by relevant topics.A set of articles is subsequently selected to be critically *** critical review is structured in steps for real-time detection and classification of PQDs,namely,input data preparation,preprocessing,transformation,feature extraction,feature selec-tion,detection,classification,and *** associated with the type of disturbance(s)addressed in the literature are also explored throughout the review,including the perspectives of those studies aimed at multiple PQDs,or specifically focused on voltage sags or voltage *** real-time performance of the reviewed tools is also ***,unsolved issues are discussed,and prospects are highlighted.

关键词： Bibliometric analysis Classification detection Power quality(PQ) Real-time Systematic review Voltage sag Voltage notch

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Trait associations in common bean genotypes grown under drought stress and field infestation by BSM bean fly

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The Crop Journal 2015年第4期3卷 305-316页

作者： daniel Ambachew Firew Mekbib Asrat Asfaw Stephen e.Beebe Matthew W.Blair South Agricultural Research Institute(SarI) Haramaya University International Potato Center (CIP) International Center for Tropical Agriculture (CIAT) Tennessee State University (TSU)

Understanding functional relations among plant traits and their modulation by growing conditions is imperative in designing selection strategies for breeding programs. This study assessed trait relationships among 196 common bean genotypes exposed to stresses for drought and field infestation of bean fly or bean stem maggot(BSM). The study was carried out at two locations and data was analyzed with linear correlation, path coefficient and genotype × trait biplot analyses. Multiple trait data related to mechanisms of drought and bean fly tolerance were collected on 196 genotypes grown under i) water deficit at mid-pod fill, or ii) unprotected against bean fly; iii) irrigated, well watered conditions, or iv) bean fly protection with chemicals. Seed yield exhibited positive and significant correlations with leaf chlorophyll content, vertical root pulling resistance, pod harvest index, pods per plant and seeds per pod at both phenotypic and genotypic levels under stress and non-stress conditions. Genotypic correlations of traits with seed yield were greater than their respective phenotypic correlations across environments indicating the greater contribution of genotypic factors to the trait correlation. Pods per plant and seeds per pod had high positive direct effects on seed yield both under stress and non-stress whereas pods per plant had the highest indirect effect on seed yield through pod harvest index under *** general, our results suggest that vertical root pulling resistance and pod harvest index are important selection objectives for improving seed yield in common beans under non-stress and stress conditions, and particularly useful for drought and BSM tolerance evaluation.

关键词： Bean stem maggot(BSM) Path coefficient Selection objective Trait linkage Pleiotropism

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