检索结果-南通市图书馆

Comparative analysis of two nonlethal methods for the study of the gut bacterial communities in wild lizards

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2023年第6期18卷 1056-1071页

作者： Mauricio HERnÁndeZ Sergio AnCOnA Stephanie HEREIRA-PACHECO Aníbal HDÍAZ de LA VEGA-PÉREZ Yendi E.nAVARRO-nOYA Doctorado en Ciencias Biológicas Centro de Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico departamento de Ecología Evolutiva Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Estación Científica la Malinche Centro de Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Consejo nacional de Ciencia y Tecnología—centro Tlaxcala de Biología de la Conducta Universidad Autónoma de TlaxcalaTlaxcalaMexico Laboratorio de Interacciones Bióticas Centro de Investigación en Ciencias BiológicasUniversidad Autónoma de TlaxcalaTlaxcalaMexico

Fecal samples or cloacal swabs are preferred over lethal dissections to study vertebrate gut microbiota for ethical reasons,but it remains unclear which nonlethal methods provide more accurate information about gut *** compared the bacterial communities of three gastrointestinal tract(GIT)segments,that is,stomach,small intestine(midgut),and rectum(hindgut)with the bacterial communities of the cloaca and feces in the mesquite lizard Sceloporus *** hindgut had the highest taxonomic and functional alpha diversity,followed by midgut and feces,whereas the stomach and cloaca showed the lowest *** taxonomic assemblages of the GIT segments at the phylum level were strongly correlated with those retrieved from feces and cloacal swabs(rs>0.84 in all cases).The turnover ratio of Amplicon Sequence Variants(ASVs)between midgut and hindgut and the feces was lower than the ratio between these segments and the *** than half of the core-ASVs in the midgut(24 of 32)and hindgut(58 of 97)were also found in feces,while less than 5 were found in the *** the ASVs level,however,the structure of the bacterial communities of the midgut and hindgut were similar to those detected in feces and *** findings suggest that fecal samples and cloacal swabs of spiny lizards provide a good approximation of the taxonomic assemblages and beta diversity of midgut and hindgut microbiota,while feces better represent the bacterial communities of the intestinal segments at a single nucleotide variation level than cloacal swabs.

关键词： animal microbiome cloacal swabs fecal samples intestinal tract reptile gut microbiome

Lanthanum-exchanged zeolite and clay as anticorrosive pigments for galvanized steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2014年第4期32卷 352-359页

作者： S.Roselli n.Bellotti C.deyá M.Revuelta B.del Amo R.Romagnoli CIdePInT(centro de investigación y desarrollo en Tecnología de Pinturas)(COnICET-CIC)

A wide variety of inhibitive pigments is now being offered as possible alternatives to chromate and lead compounds for painted metals protection. Unfortunately, the most wide spread of these substitute pigments, zinc phosphate, has, at present, raised some environmental concern because phosphate causes the eutrophication of water courses and zinc itself is toxic. The aim of this re-search was to study the anticorrosive performance of a mixture consisting of zinc phosphate, modified zeolite and clay （bentonite） in order to diminish phosphate content in paints. The zeolite and the clay were exchanged with La（III） ions, as inorganic green inhibitor. In the first step, the anticorrosion protection by La（III） ions in solution was assessed by electrochemical tests. In the second step, an epoxy-polyamide paint formulated with the pigment mixture applied on galvanized panels was studied by salt spray test and electro-chemical noise measurements （enM）. The results showed that it was possible to replace part of the zinc phosphate content in the paint with the exchanged zeolite and the clay.

关键词： exchanged pigments corrosion anticorrosive paints electrochemical noise measurements rare earths

Onto the sense of smell in macaws, amazons and toucans: can they use volatile cues of fruits to make foraging decisions?

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2023年第4期18卷 762-771页

作者： M.Carmen HERnÁndeZ Ana María VILLADA Isabel BARJA Unidad Zoología Departamento de BiologíaUniversidad Autónoma de MadridCampus Universitario de CantoblancoMadridSpain Toucan Rescue Ranch HerediaCosta Rica centro de investigación en Biodiversidad y Cambio Global(CIBC-UAM)Universidad Autónoma de Madrid MadridSpain

Over the past decades,empirical evidence has been accumulated indicating that olfactory information plays a fundamental role in bird life ***,many aspects of avian olfaction remain poorly *** purpose was to broaden the knowledge about the importance of the sense of smell in some neglected bird groups:psittaciformes and ramphastids,and to compare how the response varied between the *** of the lack of information about the use of chemical cues for locating food in fruit-eating species,we also aimed to delve into this *** conducted a 3-choice(water/vinegar/papaya and banana juice)scent test in 5 Costa Rican native species:scarlet macaw(Ara macao),red-lored amazon(Amazona autumnalis),yellow-naped amazon(Amazona auropalliata),keel-billed toucan(Ramphastos sulfuratus),and yellow-throated toucan(Ramphastos ambiguus).Results revealed that macaws and toucans allocated signiﬁcantly more time to interacting with the fruit scent container,indicating that these species can perceive the volatile chemicals emitted by ripe fruits and that they can use this information to make foraging ***,amazons did not dedicate more time to interact with the fruit *** research provides theﬁrst evidence of the ability to exploit chemical volatile cues in macaws and toucans.

关键词： avian olfaction bird senses frugivorous birds psittaciformes ramphastids scent test

Proline and Oxidative Metabolism in Young Pecan Trees Associated with Sulphate Accumulation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Phyton-International Journal of Experimental Botany 2022年第6期91卷 1141-1152页

作者： Dalila Jacqueline Escudero-Almanza Oscar Cruz-Alvarez Ofelia Adriana Hernández-Rodríguez Juan Luis Jacobo-Cuellar Esteban Sánchez-Chávez Pablo Preciado-Rángel Dámaris Leopoldina Ojeda-Barrios Facultad de Ciencias Agrotecnológicas Universidad Autónoma de ChihuahuaChihuahua31350México centro de investigación en Alimentación y desarrollo A.C.Delicias33088México InstitutoTecnologico nacional de México-Instituto Tecnológico de Torreón Coahuila27170México

Pecan[Carya illinoinensis(Wangenh.)***.]is a deciduous tree whose fruits(nuts)are of high economic value and offer excellent nutritional ***,soils high in sulphates can limit its growth and *** with 5-year-old trees of‘Western Schley’pecan grown in soils high in sulphates,the levels of proline and oxidative metabolism were recorded in the *** showed that different levels of visible leaflet damage(‘sufficiency’,‘low’,‘moderate’or‘severe’)were associated with different levels of leaflet sulphates(mg kg^(−1)):‘sufficiency’(≤40),‘low’(41–60),‘moderate’(61–80)and‘severe’(80–100).‘Severe’sulphate damage was associated with significant reductions in chlorophyll(TChl)(17.04μg g^(−1)),relative water content(RWC)(50%)and leaf area(LA),and with increases in the concentrations of total carotenoids(TC)and proline(Prl).Increases were also observed in the activities of the oxidative metabolism enzymes:superoxide dismutase(SOD)(1.82 units min^(−1) g^(−1)),catalase(CAT)(2.86μmol H_(2)O_(2) min^(−1) g^(−1))and antioxidant capacity(AC)(87%DPPH inhibition).However,guaiacol peroxidase(GP)showed a reduction(2.97 nmol GSH min^(−1) g^(−1)).An inverse relationship was found between the sulphate concentration in the leaflets with respect to the evaluated parameters of TChl,TC,RWC,LA,AC,and *** synthesis and antioxidant enzymatic activity indicate salt stress in pecan leaflets in orchards irrigated with deep-well water high in sulphates.

关键词： Carya illinoinensis catalase guaiacol peroxidase salt stress photosynthetic pigments superoxide dismutase

Ontogeny of rat chondrocyte proliferation:studies in embryo,adult and osteoarthritic (OA) cartilage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Cell Research 2005年第2期15卷 99-104页

作者： Madaí A GóMEZ-CAMARILLO,Juan B.KOURI departamento de Patología Experimental centro de investigación y de Estudios avanzados. Instituto Politécnico nacional(CInVESTAV-IPn) México.centro de investigación en Ciencias Biológicas Universidad Autónoma de Tlaxcala México. departamento de Patología Experimental centro de investigación y de Estudios avanzados. Instituto Politécnico nacional(CInVESTAV-IPn) México

The aim of this work was to study the ontogeny of chondrocyte cell division using embryo, adult and osteoarthritic(OA) cartilage. We searched for mitosis phases and performed a comparative evaluation of mitotic index, basic fibro-blast growth factor b (FGFb), transforming growth factor β1 (TGF-β1) receptors, cyclin dependent kinase (CDK1)and Cyclin-B expression in fetal, neonate, 3, 5, 8 weeks old rats and experimental OA. Our results showed that mitosisphases were observed in all normal cartilage studied, although, we found a decrease in mitotic index in relation to tissuedevelopment. no mitosis was detected in OA cartilage. We also found a statistical significant reduction in cell number inOA cartilage, compared with the normal tissue. Furthermore, FGFb and TGF-β1 receptors diminished in relation totissue development, and were very scarce in experimental OA. Western blot assays showed CDK-1 expression in allcases, including human-OA cartilage. Similar results were observed for Cyclin-B, except for 8 weeks, when it was notexpressed. Our results suggest that cell division seems to be scarce, if not absent within the OA cartilage ***, the existence of factors essential for cell division leaves open the question concerning chondrocyteproliferation in OA cartilage, which is likely to be present in the early stages of the disease.

关键词： proliferation chondrocytes mitotic index growth factors.

Clinical Profiles at the Time of Diagnosis of SARS-CoV-2 Infection in Costa Rica During the Pre-vaccination Period Using a Machine Learning Approach

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Phenomics 2022年第5期2卷 312-322页

作者： Jose Arturo Molina-Mora Alejandra González Sergio Jiménez-Morgan Estela Cordero-Laurent Hebleen Brenes Claudio Soto-Garita Jorge Sequeira-Soto Francisco Duarte-Martínez centro de investigación en enfermedades Tropicales(CIET)and Facultad de Microbiología Universidad de Costa RicaSan José2060Costa Rica Instituto Costarricense de investigación y enseñanza en nutrición y Salud(InCIenSA) Tres Ríos 30301Costa Rica Escuela de Medicina Universidad de Costa RicaSan José2060Costa Rica

The clinical manifestations of COVID-19,caused by the SARS-CoV-2,define a large spectrum of symptoms that are mainly dependent on the human host *** Costa Rica,more than 169,000 cases and 2185 deaths were reported during the year 2020,the pre-vaccination *** describe the clinical presentations at the time of diagnosis of SARS-CoV-2 infection in Costa Rica during the pre-vaccination period,we implemented a symptom-based clustering using machine learning to identify clusters or clinical profiles at the population level among 18,974 records of positive *** were compared based on symptoms,risk factors,viral load,and genomic features of the SARS-CoV-2 sequence.A total of 18 symptoms at time of diagnosis of SARS-CoV-2 infection were reported with a frequency>1%,and those were used to identify seven clinical profiles with a specific composition of clinical *** the comparison between clusters,a lower viral load was found for the asymptomatic group,while the risk factors and the SARS-CoV-2 genomic features were distributed among all the *** other distribution patterns were found for age,sex,vital status,and *** conclusion,during the pre-vaccination time in Costa Rica,the symptoms at the time of diagnosis of SARS-CoV-2 infection were described in clinical *** host co-morbidities and the SARS-CoV-2 genotypes are not specific of a particular profile,rather they are present in all the groups,including asymptomatic *** addition,this information can be used for decision-making by the local healthcare institutions(first point of contact with health professionals,case definition,or infrastructure).In further analyses,these results will be compared against the profiles of cases during the vaccination period.

关键词： COVID-19 Costa Rica Machine learning Diagnosis SARS-CoV-2 Clinical profiles

Understanding the precursor chemistry for one-step deposition of mixed cation perovskite solar cells by methylamine route

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of energy Chemistry 2021年第6期30卷 386-391,I0010页

作者： Manuel Vásquez-Montoya Juan F.Montoya Daniel Ramirez Franklin Jaramillo centro de investigación Innovación y Desarrollo de Materiales CIDEMATUniversidad de Antioquia UdeACalle 70 No.52-21MedellínColombia

Upscaling perovskite solar cell fabrication is one of the key challenges in the pathway for *** slow evaporation of frequently used solvents(DMF or DMSO) limits the fast perovskite layer crystallization,hindering their implementation in large scale deposition ***,methylamine-based precursors have demonstrated rapid crystallization,leading to uniform and specular ***,their application has been limited to MAPbI3 perovskites with limited efficiency and *** this work,we report the requirements for stabilizing α-phase of mixed cation perovskites with high amount of formamidinium by using a methylamine-based *** found that even though,there are many methods for incorporating the methylamine(MA) in precursors or films;the MA content determines stabilization of the α-phase and therefore the viscous-solution route is the only method to incorporate high amounts of *** low amounts of MA,perovskite tend to crystallize in 1D dimensional FA_(3)(MA)PbI5 phases due to the incomplete solvation of the *** contrast,high MA ratio induces a full solvation of the clusters,leading to a rapid crystallization and a full stabilization of the active 3D α-*** results open a window in the development and understanding of new precursors for the fabrication of high efficient,stable and scalable perovskite devices.

关键词： Methylamine Stabilizingα-phase Mixed cation perovskite precursor Formamidinium Upscaling Perovskite Solar cells

Computational Chemistry and Molecular Modeling Techniques for the Study of Micropeptin EI-964: Insights into Its Chemical Reactivity and Potential Pharmaceutical Properties

在线全文

学校读者我要写书评

暂无评论

Computational Molecular Bioscience 2023年第3期13卷 35-47页

作者： norma Flores-Holguín Juan Frau Daniel Glossman-Mitnik Laboratorio Virtual nAnOCOSMOS Departamento de Medio Ambiente y Energía Centro de Investigación en Materiales Avanzados Chihuahua Mexico departament de Química Facultat de Ciències Universitat de les Illes Balears Palma de Mallorca Spain

Micropeptin EI-964 is a cyclic peptide compound isolated from a marine cyanobacterium with potent inhibitory activity against serine proteases, particularly chymotrypsin and trypsin. It has shown promising activity against various cancer cell lines, making it a candidate for drug development. The unique structure and activity of Micropeptin EI-964 make it a promising lead compound for the development of novel serine protease inhibitors and anti-cancer drugs. Computational Chemistry and Molecular Modeling techniques can provide valuable insights into the chemical reactivity and pharmaceutical properties of Micropeptin EI-964, guiding the design and development of new compounds with enhanced bioactivity and improved drug-like properties.

关键词： Micropeptin EI-964 Chemical Reactivity Conceptual DFT Computational Pharmacokinetics Pharmaceutical Drugs

Effects of Silicon nanoparticles on the Transient Liquid Phase Bonding of 304 Stainless Steel

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2014年第3期30卷 259-262页

作者： H.M.Hdz-García A.I.Martinez R.Mu?oz-Arroyo J.L.Acevedo-Dávila F.García-Vázquez F.A.Reyes-Valdes Corporación Mexicana de investigación en materiales S.A.de C.V. Ciencia y Tecnología No.790 Fracc.Saltillo 400 Saltillo Coah.CP.25290 Mexico centro de investigación y de Estudios avanzados del IPn Carr.Mty-Saltillo km.13 Ramos Arizpe Coah.CP.25900 Mexico

Transient liquid phase （TLP） bonding of 304 stainless steel with nickel based filler metal, Bni-9, was performed to study the influence of silicon nanoparticles （nPs） on the mechanical and structural properties of the bonding area. It was found that silicon nPs act as a melting point depressant in the brazing process; the formation of silicon TLP induces the dissolution of elements of the metal filler and promotes a uniform distribution in the bonding area. Silicon nPs induce the development of smaller eutectic structures in the melting zone; it has been related to microhardness measurements, which are lower when the silicon nPs are used in the brazing process.

关键词： Brazing nanoparticles Silicon Stainless steel