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As-cast and extruded Mg-Zn-Ca systems for biodegradable implants:Characterization and corrosion behavior

Journal of Magnesium and Alloys 2023年第3期11卷 1102-1120页

作者： Lara Moreno Endzhe Matykina Kiryl A.Yasakau Carsten Blawert Raul Arrabal Marta Mohedano departamento de Ingeniería Química y de Materiales Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040 MadridSpain department of Materials and Ceramic Engineering CICECO-Aveiro institute of materialsUniversity of Aveiro3810-193 AveiroPortugal Institute of Surface Science Helmholtz-Zentrum HereonMax-Planck Strasse 1Geesthacht 21502Germany

The aim of the present study is to evaluate the effect of alloy processing and composition as well as the pH control and testing medium on the in vitro corrosion performance of Mg-Zn-Ca systems for biodegradable *** grain size and secondary phases were analyzed by optical microscopy,scanning electron microscopy,transmission electron microscopy,and X-ray *** kelvin probe force microscopy(SKPFM)was used to analyze the Volta potential values of the second *** corrosion performance of the three alloys was evaluated by electrochemical and hydrogen evolution methods inα-MEM with and without organic species(*** and inorganicα-MEM).Two strategies were followed to evaluate the influence of the pH on the corrosion behavior:daily solution replacement and CO_(2)flow based pH *** all the materials,the organic medium accelerates the corrosion *** pH maintained by CO_(2)flow through the medium results in considerably higher corrosion rates for all *** impact of pH is lesser on the as-cast alloys due to the barrier effect of the secondary phases,particularly pronounced in the Mg1Zn1Ca alloy which showed the lowest corrosion *** wrought Mg0.5Zn0.2Ca alloy that lacks the refined secondary phase network and exhibits high number of twins undergoes accelerated uniform corrosion under constant pH conditions.

关键词： MgZnCa Magnesium Biomaterials Characterization Corrosion

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development of a microcomposite with single-walled carbon nanotubes and Nd_2O_3 for determination of paracetamol in pharmaceutical dosage by adsorptive voltammetry

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Journal of Pharmaceutical Analysis 2019年第1期9卷 62-69页

作者： Verónica Arancibia Johisner Penagos-Llanos Edgar Nagles Olimpo García-Beltrán John J.Hurtado Pontificia Universidad Católica de Chile Facultad de Química facultad de Ciencias Naturales y Matemáticas Universidad de Ibagué departamento de Química Universidad de los Andes

This study presents for the first time a new composite of carbon paste(CP), single-walled carbon nanotubes(SWCNTs) and Nd2 O3(NdOX). This versatile composite(NdOX-SWCNT/CPE) was applied to the oxidation of paracetamol(PCM). The newly formed surface was characterized by scanning electron microscopy(SEM), electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV). The results showed greater conductivity and a higher surface area for the composite than those of the carbon paste alone. Moreover, the anodic peak currents for PCM increased from 1.6 to 3.6 m A with CPE and NdOXSWCNT/CPE, indicating an increase of nearly 51.0% for the anodic peak current. On the other hand, the anodic peak potentials shifted from 0.67 to 0.57 V. The detection limits were 0.05 mmol/L with NdOXSWCNT/CPE and 0.50 mmol/L with SWCNT/CPE. The relative standard deviations(RSDs) were 1.5%(n=7). The accuracy and interference of the methods were evaluated with a urine chemistry control spiked with known quantities of PCM, uric acid, dopamine, ascorbic acid, caffeine, acetylsalicylic acid,tartrazine, sunset yellow, allure red, rutin, morin and metal ions. Finally, the novelty and usefulness of the composite were evaluated to quantify PCM in pharmaceutical dosage forms such as tablets, powders and syrups for children.

关键词： Paracetamol Neodymium(Ⅲ) Oxide Single-walled carbon nanotubes Pharmaceutical dosage

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Progesterone for the treatment of central nervous system disorders: the many signaling roads for a single molecule

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Neural Regeneration Research 2020年第10期15卷 1846-1847页

作者： Susana Laura González Universidad de Buenos Aires Facultad de Medicina Departamento de Bioquímica Humana Buenos Aires Laboratorio de Nocicepción y Dolor Neuropático Instituto de Biología y Medicina Experimental

Central nervous system(CNS)injuries and neurodegenerative diseases show a broad spectrum of common pathophysiological processes,including oxidative stress,neuroinflammation,excitotoxicity,demyelination and neurotransmission *** the past decades,valuable experimental investigations have helped to clarify the role and timing of these multiple molecular and cellular mechanisms in each of these particular disorders,which usually overlap and critically contribute to long-term ***,up to now,no definite cures or effective disease-modifying therapies are available for any of these *** has led to an active search of novel therapeutic approaches,including the repositioning of existing drugs for new indications,as a valid approach to promptly move candidate molecules to clinical trials.

关键词： injuries disorders drugs

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Oxidative stress in Microcystis aeruginosa as a consequence of global climate change

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BIOCELL 2016年第1期40卷 23-25页

作者： MARCELO HERNANDO CHRISTIAN HOUGHTON LEDA GIANNUZZI BERND KROCK DARIO ANDRINOLO GABRIELA MALANGA departamento de Radiobiología Comisión Nacional de Energía AtómicaBuenos AiresArgentina Area de Toxicología Dpto.de Cs BiológicasFacultad de Ciencias Exactas.UNLP Alfred Wegener Institute BremerhavenGermany Instituto de bioquímica y Medicina Molecular(IBIMOL)-Universidad de Buenos Aires(UBA) CONICETFisicoquímicaFacultad de Farmacia y BioquímicaJunín 956(C1113AAD)Buenos Aires.Argentina

Cyanobacteria are phototrophic organisms with great ecological and economical *** of the genus Microcystis are known for their potential ability to synthesize toxins,notably *** is a growing interest in the evaluation of oxidative stress in relation to the impact of global climate change on natural ecosystems in different trophic *** studies have focused on the analysis of organismal responses to mitigate the damage by controlling the generation of reactive oxygen *** in environ-mental factors caused by climate change generate a situation of oxidative damage in Microcystis aeruginosa as a direct or indirect *** this study we evaluate the effects of ultraviolet radiation and temperature on physiological and biochemical responses of a native ***(strain CAAT 2005-3).The results from the exposure to ultraviolet radiation doses and temperature changes suggest a high ability of *** to detect a potential stress situation as a consequence of reactive species production and to rapidly initiate antioxidant *** catalase activity is an antioxidant protection mechanism in *** for short and long term exposure to different changes in environmental ***,we found a ultraviolet-B radiation threshold dose above which oxidative stress exceeds the antioxidant protection and damage *** addition our results are in agreement with recent findings suggesting that microcystins may act as protein-modulating metabolites and protection against reactive oxygen *** is concluded that cyanobacteria have adaptative mechanisms that could lead to the replacement of species highly susceptible to oxidative stress by others with a higher system of antioxidant protection.

关键词： oxidative stress Cyanobacteria UVR temperature

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New approaches to identification and characterization of tioconazole in raw material and in pharmaceutical dosage forms

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Journal of Pharmaceutical Analysis 2019年第1期9卷 40-48页

作者： Natalia L.Calvo Vera A.Alvarez María C.Lamas Darío Leonardi Instituto de Química Rosario (IQUIR CONICET-UNR) área Análisis de Medicamentos Facultad de Ciencias Bioquímicas y Farmacéuticas Universidad Nacional de Rosario Grupo de Materiales Compuestos Termoplásticos (CoMP) Instituto de Investigaciones de Cienciay Tecnología de Materiales (INTEMA CONICET-UNMdP) área Técnica Farmacéutica Facultad de Ciencias Bioquímicas y Farmacéuticas Universidad Nacional de Rosario

Tioconazole(TCZ), a broad-spectrum antifungal agent, has significant activity against Candida albicans and other Candida species, and therefore, it is indicated for the topical treatment of superficial *** main goal of this work is to report an exhaustive identification and characterization procedure to improve and facilitate the online quality control and continuous process monitoring of TCZ in bulk material and loaded in two different dosage forms: ovules and nail lacquer. The methodologies were based on thermal(differential scanning calorimetry(DSC), melting point, and thermogravimetry(TG)),spectroscopic(ultraviolet(UV), Raman, near infrared(NIR), infrared spectroscopy coupled to attenuated total reflectance(FTIR-ATR), and nuclear magnetic resonance(NMR)), microscopic and X-ray diffraction(XRD). The TCZ bulk powder showed a high crystallinity, as observed by XRD, with a particles size distribution(3–95 mm) resolved by microscopic measurements. TCZ melting point(82.8 °C) and a degradation peak centered at 297.8 °C were obtained by DSC and DTG, respectively. An unambiguous structure elucidation of TCZ was obtained by mono-and two-dimensional1 H and13 C NMR spectral data analysis. The FTIR-ATR, Raman and NIR spectra of both the raw material and the commercial products were analyzed and their characteristic bands were tabulated. The best methods for TCZ identification in ovules were DSC, TG, XRD, NIR and Raman, while NIR and FTIR-ATR were the most appropriate techniques to analyze it in the nail lacquer. DSC, TG, DRX, Raman, FTIR-ATR and NIR spectroscopy are effective techniques to be used in online process analysis, because they do not require sample preparation, and they are considerably sensitive to analyze complex samples.

关键词： Tioconazole Identification Characterization Pharmaceutical dosage forms Spectroscopic methods

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Diversity of Saxicolous Lichens along an Aridity Gradient in Central México

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Phyton-International Journal of Experimental Botany 2022年第4期91卷 827-840页

作者： JoséCarmen Soto-Correa Abraham Saldaña-Vega Víctor Hugo Cambrón-Sandoval Laura Concostrina-Zubiri Mariela Gómez-Romero facultad de Ciencias Naturales Universidad Autónoma de QuerétaroQuerétaro73230México departamento de Biología y Geología Física y Química Inorgánica Tulipán s/nUniversidad Rey Juan CarlosMóstolesMadrid28933España Cátedra CONACYT–facultad de Biología Universidad Michoacana de San Nicolás de HidalgoMoreliaMichoacán58030México

Lichens are symbiotic organisms that comprise a fungus and a photosynthetic partner wich are recognized as a good indicator of climate ***,our understanding of how aridity affects the diversity of saxicolous lichens in drylands is still *** evaluate the relationship between saxicolous lichen diversity and aridity in a central México dryland,a geographical transect was established of 100 km to build an aridity gradient in the semiarid zone of the State of Querétaro,Mexico,comprising ten sampling sites with a 10 km *** richness,abundance and diversity of soil lichen species were recorded using two sampling methods:the quadrat-intercept and the line-intercept method,to compare their performance in assessing soil lichen diversity in *** number of species and Shannon diversity of saxicolous lichens were higher at intermediate values of the aridity index(AI=0.10-0.34).Quadrat intercept and point intercept methods gave quite similar results,which means that the selected method does not influence the results in a significant *** study confirms the role of saxicolous lichens as climate change indicators and reveals the importance of the sampling method selection in the evaluation of different parameters of soil lichen diversity in drylands.

关键词： Climate change drylands ecological indicators environmental stress precipitation temperature

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Relationships between soil pollution by heavy metals and melanin-dependent coloration of a fossorial amphisbaenian reptile

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Integrative Zoology 2022年第4期17卷 596-607页

作者： JoséMARTÍN Pablo RECIO Gonzalo RODRÍGUEZ-RUIZ Isabel BARJA Eduardo GUTIÉRREZ Luis VGARCÍA departamento de Ecología Evolutiva Museo Nacional de Ciencias NaturalesCSICMadridSpain departamento de Zoología Facultad de BiologíaUniversidad Autónoma de MadridMadridSpain Centro de Investigación en Biodiversidad y Cambio Global(CIBC-UAM) Universidad Autónoma de MadridMadridSpain departamento de Biogeoquímica Ecología Vegetal y MicrobianaInstituto de Recursos Naturales y Agrobiología de SevillaCSICSevillaSpain

Melanin is the basis of coloration in many animals,and although it is often used in communication,thermoregulation,or camouflage,melanin has many other physiological *** example,in polluted habitats,melanin can have a detoxifying *** coloration would help to sequester in the skin the heavy metal contaminants from inside the body,which will be expelled to the exterior when the skin is ***,animals should have evolved more melanic colorations in more polluted habitats(“industrial melanism”hypothesis).We examined whether the fossorial amphisbaenian reptile,Trogonophis wiegmanni,is able to eliminate heavy metals,derived from soil pollution by seagull depositions,through sloughing its *** results suggest a covariation between levels of soil pollution by heavy metals and the concentration of heavy metals in the sloughed skins of *** suggests that amphisbaenians may expel heavy metals from their bodies when they slough the *** also tested whether amphisbaenians inhabiting soils with higher levels of heavy metal pollution had darker(melanin-dependent)body ***,contrary to predictions from the“industrial melanization”hypothesis,we found a negative relationship between soil pollution and proportions of melanic *** contradictory result could,however,be explained because heavy metals have endocrine disruption effects that increase physiological stress,and higher stress levels could result in decreased *** suggest that although amphisbaenians might have some detoxifying mechanism linked to melanin in the skin,this process might be negatively affected by stress and result ineffective under conditions of high soil pollution.

关键词： amphisbaenians coloration fossorial reptiles heavy metals melanin soil pollution

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determination of sildenafil by preconcentration on surfactant coated polymeric resin followed by spectrofluorimetry

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Journal of Pharmaceutical Analysis 2013年第3期3卷 173-179页

作者： Chien C.Wang Roxana A.Gómez Liliana P.Fernandez INQUISAL-CONICET Chacabuco y Pedernera5700-San LuisArgentina departamento de Farmacia Facultad de QuímicaBioquímica y FarmaciaUniversidad Nacional de San LuisArgentina rea de Química Analítica Facultad de QuímicaBioqímica y FarmaciaUniversidad Nacional de San LuisArgentina

The illicit addition of phosphodiesterase type-5 （Pde-5） inhibitors like sildenafil （Viagra） in product offered as herbal medicine or dietary supplement for male erectile dysfunction has concerned authorities in recent times. In this paper, we proposed a sensitive surfactant-coated Amberlite XADTM resin for sildenafil preconcentration method with spectrofluorimetric detection. Retention capacity of micellar coated XAD resin for sildenafil was studied and the obtained eluate was measured by spectrofluorometer at excitation and emission wavelengths of 350 and 430 nm, respectively. This method allowed the detection of sildenafil at 0.15 ng/mL with linear range of 0.0003-7.0 μg/mL. The method has been successfully applied to the analysis of some local commercially available herbal medicines and urine.

关键词： Sildenafil Herbal medicines Spectrofluorimetricanalysis Surfactant

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An internal control applied to RT-PCR detection of HCV and HIV-1 in human pooled plasma and plasma-derived medicinal products

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BIOCELL 2015年第2期39卷 15-23页

作者： Gonzalo RODRÍGUEZ-LOMBARDI Luciana REYNA María Susana VITALI Susana GENTI-RAIMONDI Laboratorio de Hemoderivados Universidad Nacional de Córdoba Centro de Investigaciones en bioquímica Clínica e Inmunología Departamento de Bioquímica ClínicaFacultad de Ciencias QuímicasUniversidad Nacional de Córdoba-Consejo Nacional de Investigaciones Científicas y TécnicasX5000HUA CórdobaArgentina

A competitive internal control(IC)adapted to RT-PCR in-house assay was developed for HCV RNA detection in human pooled ***,it was applied in a multiplex RT-PCR for the HIV-1 and HCV RNA screening in human pooled plasma and plasma-derived products.A 258-bp PCR product from the 5´non-coding region of HCV genome was obtained.A competitive IC template was constructed by inserting a 52-bp double strand sequence into the NheI site of the 258-bp *** sequence was cloned and the obtained plasmid was used to generate a synthetic *** IC/RNA was incorporated in in-house HCV and/or HIV PCR technique to monitor the efficiency of extraction,reverse transcription,and PCR amplification *** was also used to detect all major genotypes of HCV and HIV-1 strains with similar *** detection limit of the assay for HCV and HIV-1 was 52.7 IU/mL and 164.2 IU/mL,*** techniques have been evaluated in international programs of external quality assurance with highly satisfactory *** IC is an essential reagent in PCR techniques to detect and identify HCV and HIV-1 in pooled plasma samples involved in the manufacture of plasma-derived products as well as in the field of clinical microbiology with limited resources.

关键词： HCV HIV internal control RT-PCR

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Assessment of effectiveness of oral supplementation of isolated fiber of carrot on metabolic parameters in mature rats

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Food Science and Human Wellness 2023年第6期12卷 2022-2028页

作者： Maria Rosana Ramirez debora Manuale Juan Carlos Yori Instituto Universitario de Ciencias de la Salud Fundación BarcelóCONICETCenteno 710CP 3340Santo TomeCorrientesArgentina Consejo Nacional de Investigaciones Científi cas Técnicas(CONICET) Buenos Aires C1033AAJArgentina Instituto de Investigaciones en Catálisis y Petroquímica(INCAPE)FIQ-UNL-CONICET Parque Tecnológico Litoral Centro 3000Santa FeArgentina facultad de Ingeniería Química Universidad nacional del Litoral 3000Santa FeArgentina

This present study was conducted to evaluate the metabolic effects of isolated fi ber of carrot supplementation in *** properties of fi ber were *** groups were as follows:animals fed a standard diet,control group;high fi ber supplementation(70 mg);low fi ber supplementation(35 mg);for 12 *** samples were collected at the time of sacrifi *** weights of heart,liver,kidneys and spleen of the experimental rats with respect to body weight were *** kits were used to determine serum glucose concentration,lipid profi le(cholesterol,HDL-cholesterol,triglycerides),and the two main aminotransferases glutamic-oxalacetic transaminase(GOT)/glutamate-pyruvate transaminase(GPT).A histopathological assay was performed on the heart,liver,and spleen tissues of *** with fi ber favors weight loss in female((242.03±23.73)-(197.81±10.45)g);and male rats((262.50±32.21)-(213.96±12.56)g and induces a decrease in glucose levels in the supplemented *** the exception of total high-density lipoprotein cholesterol,the other lipid fractions decrease signifi cantly in rats *** supplementation did not induce changes in the dissected organs of the supplemented *** conclusion supplementation of fiber,improves glucose control,lower plasma lipid concentrations and reduced body weight in normal rats.

关键词： Carrot fiber Oral supplementation Animal studies

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