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1.
Phys Rev Lett ; 131(11): 112701, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37774292

RESUMO

The ^{22}Mg(α,p)^{25}Al reaction rate has been identified as a major source of uncertainty for understanding the nucleosynthesis flow in Type-I x-ray bursts. We report a direct measurement of the energy- and angle-integrated cross sections of this reaction in a 3.3-6.9 MeV center-of-mass energy range using the MUlti-Sampling Ionization Chamber (MUSIC). The new ^{22}Mg(α,p)^{25}Al reaction rate is a factor of ∼4 higher than the previous direct measurement of this reaction within temperatures relevant for x-ray bursts, resulting in the ^{22}Mg waiting point of x-ray burst nucleosynthesis flow to be significantly bypassed via the (α,p) reaction.

2.
Nature ; 491(7425): 566-9, 2012 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-23172214

RESUMO

Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos. Makemake is another icy dwarf planet with a spectrum similar to Eris and Pluto, and is currently at a distance to the Sun intermediate between the two. Although Makemake's size (1,420 ± 60 km) and albedo are roughly known, there has been no constraint on its density and there were expectations that it could have a Pluto-like atmosphere. Here we report the results from a stellar occultation by Makemake on 2011 April 23. Our preferred solution that fits the occultation chords corresponds to a body with projected axes of 1,430 ± 9 km (1σ) and 1,502 ± 45 km, implying a V-band geometric albedo p(V) = 0.77 ± 0.03. This albedo is larger than that of Pluto, but smaller than that of Eris. The disappearances and reappearances of the star were abrupt, showing that Makemake has no global Pluto-like atmosphere at an upper limit of 4-12 nanobar (1σ) for the surface pressure, although a localized atmosphere is possible. A density of 1.7 ± 0.3 g cm(-3) is inferred from the data.

3.
Nature ; 478(7370): 493-6, 2011 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-22031441

RESUMO

The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1 AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163 ± 6 kilometres, density 2.52 ± 0.05 grams per cm(3) and a high visible geometric albedo, Pv = 0.96(+0.09)(-0.04). No nitrogen, argon or methane atmospheres are detected with surface pressure larger than ∼1 nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun.

4.
Plant Mol Biol ; 90(6): 589-603, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26801330

RESUMO

Herbaspirillum seropedicae is a diazotrophic and endophytic bacterium that associates with economically important grasses promoting plant growth and increasing productivity. To identify genes related to bacterial ability to colonize plants, wheat seedlings growing hydroponically in Hoagland's medium were inoculated with H. seropedicae and incubated for 3 days. Total mRNA from the bacteria present in the root surface and in the plant medium were purified, depleted from rRNA and used for RNA-seq profiling. RT-qPCR analyses were conducted to confirm regulation of selected genes. Comparison of RNA profile of root attached and planktonic bacteria revealed extensive metabolic adaptations to the epiphytic life style. These adaptations include expression of specific adhesins and cell wall re-modeling to attach to the root. Additionally, the metabolism was adapted to the microxic environment and nitrogen-fixation genes were expressed. Polyhydroxybutyrate (PHB) synthesis was activated, and PHB granules were stored as observed by microscopy. Genes related to plant growth promotion, such as auxin production were expressed. Many ABC transporter genes were regulated in the bacteria attached to the roots. The results provide new insights into the adaptation of H. seropedicae to the interaction with the plant.


Assuntos
Regulação Bacteriana da Expressão Gênica , Herbaspirillum/citologia , Herbaspirillum/genética , Raízes de Plantas/microbiologia , Triticum/microbiologia , Adaptação Fisiológica/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fatores Quimiotáticos/genética , Herbaspirillum/fisiologia , Ácidos Indolacéticos/metabolismo , Fixação de Nitrogênio/genética , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Rizosfera , Plântula/microbiologia , Análise de Sequência de RNA , Microbiologia do Solo , Transcriptoma
5.
J Appl Microbiol ; 121(4): 1071-8, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27427217

RESUMO

AIMS: In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil. METHODS AND RESULTS: Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand. CONCLUSION: The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products. SIGNIFICANCE AND IMPACT OF THE STUDY: This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures.


Assuntos
Arachis/microbiologia , Enterobacteriaceae/isolamento & purificação , Contaminação de Alimentos/análise , Brasil , Contagem de Colônia Microbiana , Enterobacteriaceae/classificação , Enterobacteriaceae/crescimento & desenvolvimento , Manipulação de Alimentos , Microbiologia de Alimentos , Humanos
6.
Genet Mol Res ; 14(4): 12102-10, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26505357

RESUMO

In the present study, we assessed the agro-industrial performance of 22 sugarcane genotypes adaptable to edaphoclimatic conditions in production microregions in the State of Pernambuco, Brazil, and we recommended the commercial cultivation of select genotypes. The variables analyzed were as follows: sucrose percentage in cane juice, tonnage of saccharose per hectare (TPH), sugarcane tonnage per hectare (TCH), fiber, solid soluble contents, total recoverable sugar tonnage (ATR), and total recoverable sugar tonnage per hectare (ATR t/ha). A randomized block design with 4 repeats was used. Combined variance of the experiments, genetic parameter estimates, and environment stratification were analyzed. Phenotypic adaptability and stability were analyzed using the Annicchiarico and Wricke methods and analysis of variance. Genetic gain was estimated using the classic index and sum of ranks. Genotype selection was efficient for TPH, TCH, and ATR t/ha. Genotypes presented a great potential for improvement and a similar response pattern in Litoral Norte and Mata Sul microregions for TPH and TCH and Litoral Norte and Litoral Sul microregions for ATR t/ha. Genotypes SP78-4764, RB813804, and SP79-101 showed better productivity and phenotypic adaptability and stability, according to the Wricke and Annicchiarico methods. These genotypes can be recommended for cultivation in the sugarcane belt in the State of Pernambuco.


Assuntos
Adaptação Biológica , Genótipo , Fenótipo , Saccharum/genética , Brasil , Meio Ambiente , Interação Gene-Ambiente
7.
Genet Mol Res ; 13(3): 6865-77, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25177966

RESUMO

We assessed the agroindustrial performance of 25 sugarcane genotypes adapted to the edaphoclimatic conditions of the State of Pernambuco, Brazil, within the microregions Mata Norte, Mata Sul, Região Central, Litoral Norte, and Litoral Sul. The variables analyzed were POL tonnage per hectare, sugarcane tonnage per hectare, fiber and total recoverable sugar tonnage per hectare, using a randomized block design with four repetitions. Combined variance of experiments, genetic parameter estimates, decomposition of the genotype-environment interaction, and environment stratification were analyzed. Phenotype adaptability and stability were also analyzed. The various genotypes presented great potential for improvement and a similar response pattern to the microregions Centro and Mata Sul of the state of Pernambuco. Genotypes RB863129, RB867515, RB92579, RB953180, SP81-3250, RB75126, and RB942520 were better in productivity and phenotype adaptability and stability compared to genotypes RB892700, RB943365, SP79-1011, Q138, RB943538, SP78-4764, RB953281, RB943066, RB928064, RB93509, RB72454, RB952675, RB952991, RB943161, RB942898, RB872552, RB952900, and RB942849. These genotypes are recommended as cultivation options in the sugarcane belt in the state of Pernambuco, since they stand out in terms of phenotype adaptability and stability as evaluated using the method by Annicchiarico, Lin and Bins, and the method by Eberhart and Russel.


Assuntos
Adaptação Fisiológica/genética , Saccharum/genética , Saccharum/metabolismo , Sacarose/metabolismo , Agricultura/métodos , Brasil , Meio Ambiente , Interação Gene-Ambiente , Variação Genética , Genótipo , Fenótipo
8.
Braz J Biol ; 84: e278013, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38422288

RESUMO

Colloidal systems have been used to encapsulate, protect and release essential oils in mouthwashes. In this study, we investigated the effect of cetylpyridinium chloride (CPC) on the physicochemical properties and antimicrobial activity of oil-in-water colloidal systems containing tea tree oil (TTO) and the nonionic surfactant polysorbate 80. Our main aim was to evaluate whether CPC could improve the antimicrobial activity of TTO, since this activity is impaired when this essential oil is encapsulated with polysorbate 80. These systems were prepared with different amounts of TTO (0-0.5% w/w) and CPC (0-0.5% w/w), at a final concentration of 2% (w/w) polysorbate 80. Dynamic light scattering (DLS) results revealed the formation of oil-swollen micelles and oil droplets as a function of TTO concentration. Increases in CPC concentrations led to a reduction of around 88% in the mean diameter of oil-swollen micelles. Although this variation was of only 20% for the oil droplets, the samples appearance changed from turbid to transparent. The surface charge of colloidal structures was also markedly affected by the CPC as demonstrated by the transition in zeta potential from slightly negative to highly positive values. Electron paramagnetic resonance (EPR) studies showed that this transition is followed by significant increases in the fluidity of surfactant monolayer of both colloidal structures. The antimicrobial activity of colloidal systems was tested against a Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureaus) bacteria. Our results revealed that the inhibition of bacterial growth is observed for the same CPC concentration (0.05% w/w for E. coli and 0.3% w/w for S. aureus) regardless of TTO content. These findings suggest that TTO may not act as an active ingredient in polysorbate 80 containing mouthwashes.


Assuntos
Óleos Voláteis , Óleo de Melaleuca , Emulsões/química , Emulsões/farmacologia , Polissorbatos/farmacologia , Polissorbatos/química , Micelas , Staphylococcus aureus , Escherichia coli , Antissépticos Bucais/farmacologia , Tensoativos/farmacologia , Tensoativos/química , Óleos Voláteis/farmacologia , Antibacterianos/farmacologia , Óleo de Melaleuca/farmacologia
9.
Adv Colloid Interface Sci ; 328: 103166, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38728773

RESUMO

Despite significant efforts by scientists in the development of advanced nanotechnology materials for smart diagnosis devices and drug delivery systems, the success of clinical trials remains largely elusive. In order to address this biomedical challenge, magnetic nanoparticles (MNPs) have gained attention as a promising candidate due to their theranostic properties, which allow the simultaneous treatment and diagnosis of a disease. Moreover, MNPs have advantageous characteristics such as a larger surface area, high surface-to-volume ratio, enhanced mobility, mass transference and, more notably, easy manipulation under external magnetic fields. Besides, certain magnetic particle types based on the magnetite (Fe3O4) phase have already been FDA-approved, demonstrating biocompatible and low toxicity. Typically, surface modification and/or functional group conjugation are required to prevent oxidation and particle aggregation. A wide range of inorganic and organic molecules have been utilized to coat the surface of MNPs, including surfactants, antibodies, synthetic and natural polymers, silica, metals, and various other substances. Furthermore, various strategies have been developed for the synthesis and surface functionalization of MNPs to enhance their colloidal stability, biocompatibility, good response to an external magnetic field, etc. Both uncoated MNPs and those coated with inorganic and organic compounds exhibit versatility, making them suitable for a range of applications such as drug delivery systems (DDS), magnetic hyperthermia, fluorescent biological labels, biodetection and magnetic resonance imaging (MRI). Thus, this review provides an update of recently published MNPs works, providing a current discussion regarding their strategies of synthesis and surface modifications, biomedical applications, and perspectives.


Assuntos
Nanopartículas Metálicas , Propriedades de Superfície , Animais , Humanos , Sistemas de Liberação de Medicamentos , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/química , Nanopartículas Metálicas/química
10.
Acta Neurochir (Wien) ; 155(12): 2389-98, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23913108

RESUMO

BACKGROUND: The Nucleus accumbens (Acc) is the main structure of the ventral striatum. It acts as a motor-limbic interface, being involved in emotional and psychomotor functions, frequently disturbed in neuropsychiatric disorders such as obsessive compulsive disorder and addiction. Most of the studies concerning the Acc were made in animals and those performed in humans are contradictory. Nevertheless, it has become a target for stereotactic deep brain stimulation for some of those diseases, when refractory to medical treatment. Previous studies performed by our group have established the localization, limits and dimensions of the human Acc and its stereotactic coordinates. Now it is our purpose to perform the Acc anatomical three-dimensional (3D) reconstruction in order to clarify its shape and topography and to render this nucleus a safer target for stereotactic procedures. METHODS: Anatomical coronal slicing of ten Acc from human brains was performed, perpendicular to the anterior commissure-posterior commissure line and to the midline; then the Acc contours were traced and its dimensions and 3D stereotactic coordinates measured, on each slice. Finally a 3D computerized model was created. RESULTS: The human Acc was identified as a distinct brain structure, with clear-cut limits on its posterior half. It lies parallel to the midline, descends caudally, and progresses from a globose to a flattened and dorsolateral concave shape. Its main expression is subcomissural. CONCLUSION: This study defined more accurately the 3D anatomy of the human Acc, providing new tools for stereotactic procedures.


Assuntos
Núcleo Accumbens/anatomia & histologia , Núcleo Subtalâmico/cirurgia , Adulto , Encéfalo/cirurgia , Mapeamento Encefálico/métodos , Estimulação Encefálica Profunda/métodos , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Núcleo Accumbens/cirurgia , Doença de Parkinson/cirurgia , Técnicas Estereotáxicas
11.
Nature ; 439(7072): 52-4, 2006 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-16397493

RESUMO

Pluto and its satellite, Charon (discovered in 1978; ref. 1), appear to form a double planet, rather than a hierarchical planet/satellite couple. Charon is about half Pluto's size and about one-eighth its mass. The precise radii of Pluto and Charon have remained uncertain, leading to large uncertainties on their densities. Although stellar occultations by Charon are in principle a powerful way of measuring its size, they are rare, as the satellite subtends less than 0.3 microradians (0.06 arcsec) on the sky. One occultation (in 1980) yielded a lower limit of 600 km for the satellite's radius, which was later refined to 601.5 km (ref. 4). Here we report observations from a multi-station stellar occultation by Charon, which we use to derive a radius, R(C) = 603.6 +/- 1.4 km (1sigma), and a density of rho = 1.71 +/- 0.08 g cm(-3). This occultation also provides upper limits of 110 and 15 (3sigma) nanobar for an atmosphere around Charon, assuming respectively a pure nitrogen or pure methane atmosphere.

12.
Alcohol Alcohol ; 47(6): 702-10, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22986010

RESUMO

AIMS: To identify prognostic factors to outpatient alcohol treatment on admission as well as during the treatment period. METHODS: A cohort study of n = 209 alcoholic patients (DSM-IV) during 6 months of outpatient treatment. Eight medical doctors from two hospitals were involved. Co-responsible participation in treatment was a necessary condition. At admission, we documented socio demographic factors, use of other drugs and severity of alcohol consumption. During the 6 months, we observed medication for prevention of alcohol relapse [disulfiram (DIS), acamprosate], number of sessions with the doctor, number of phases of the consultation and medication for depression. Primary outcome variables were time to first heavy relapse and abstinence of heavy alcohol consumption. These were measured with Timeline Followback. Five or more alcohol units of 10 g in one relapse day were considered heavy relapse. RESULTS: The patients were 84% males, with 41 years median age; the median alcohol consumption was 192 g per day with a median duration of 13 years of heavy consumption. The median education was 6 years with 61% of the patients from lower socio-economic levels. The Kaplan-Meier heavy relapse rate at 6 months was 23%. On admission to treatment, female gender, lower socio-economic levels, cocaine use, >20 years of consumption, gamma glutamyl transferase values above normal and five or more alcohol-related problems on the Alcohol-Related Problem Questionnaire predicted worse outcomes. Having a full-time job and shorter abstinence time before treatment (until 7 days) predicted better outcomes. During the 6 months, we found that DIS for <120 days was a prognostic factor of worse outcomes. DIS for at least 120 days, >50% of adherence to consultations and more than two phases on each consultation predicted better outcomes. The combined sensitivity and specificity for DIS for at least 120 days, >50% of adherence to consultations and more than two phases on consultation regarding abstinence from heavy relapse were respectively 100 and 71%. CONCLUSIONS: During 6 months of outpatient treatment, longer adherence to DIS and consultations as well as more phases in a consultation involving necessarily a co-responsible predict a good outcome independently of the patient features at admission.


Assuntos
Alcoolismo/diagnóstico , Alcoolismo/terapia , Assistência Ambulatorial/tendências , Temperança/tendências , Adulto , Alcoolismo/epidemiologia , Assistência Ambulatorial/métodos , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
13.
Braz J Biol ; 82: e264933, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36350940

RESUMO

The objective of this study was to describe the histology and histochemistry of the integument covering the back and stinger of the freshwater stingray Potamotrygon rex, endemic to the Middle Upper Tocantins River. The species has a dark back and yellowish circular spots that extend to the tail, which has one to two stings located in the median portion of the tail. Through histological study it was observed that the epithelia of the back and stinger are composed of non-keratinized stratified pavement epithelial tissue, and are organized in three layers: basal, intermediate and superficial. The differences between the tissues are related to the cell types that compose them. The back is organized with epithelial cells, mucus cells, granulocyte cells and chromatophores. The mucus cells are distributed in different layers along the animal's back, influencing the thickness of the tissue. The tissue that covers the stinger is composed of epithelial cells, chromatophores and specialized cells in protein synthesis. In the histochemistry, the stinger epithelial cells were stained with Bromophenol Blue, especially those of the intermediate layer, which were called specialized cells. In the back the epithelial cells were stained with Bromophenol Blue, Alcian Blue and PAS, and the mucous cells with PAS. In both tissues the presence of protein reserves was detected, areas so called because they are stained strongly with Bromophenol Blue. The results show that the stinger presents activity directed to the production of proteins, and that the back is organized to produce different components, which constitute the cuticle that covers the animal's body.


Assuntos
Mordeduras e Picadas , Rajidae , Animais , Azul de Bromofenol/metabolismo , Água Doce , Rios
14.
J Endocrinol Invest ; 34(8): e214-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21270509

RESUMO

BACKGROUND: Pituitary tumors account for approximately 10-15% of intracranial neoplasms. AIM: Using the cDNA microarray method, we have previously compared expression under two distinct conditions: a pool of 4 clinically non-functioning pituitary adenomas (NFPA) and a spinal cord metastasis of a non-functioning pituitary carcinoma, in order to gain biological insights into genomic changes of pituitary neoplasias. In the present study, we further investigated the mRNA expression of 3 selected genes previously described as being involved in other neoplasias based on a series of 60 pituitary adenomas: CRABP1 (cellular retinoic acid binding protein 1), GRP (gastrin-releasing peptide), and RERG (Ras-related, estrogen- regulated, growth inhibitor). MATERIAL AND METHODS: The expression of CRABP1, GRP, and RERG was determined by quantitative RT-PCR. RESULTS: A significantly higher content of CRABP1 mRNA was observed in NFPA compared to functioning adenomas, and PRL-secreting adenomas showed a lower expression of this gene compared to normal pituitary. A lower expression of GRP mRNA was detected in NFPA compared to normal pituitary and also to functioning adenomas. RERG mRNA was overexpressed in NFPA in comparison to functioning adenomas and to normal pituitary. Among the functioning adenomas, only the ACTH-secreting adenomas presented a higher expression of RERG mRNA compared to normal pituitary. CONCLUSIONS: The findings of differential expression of CRABP1 in prolactinomas and of RERG in NFPA compared to normal pituitary suggests that retinoic acid and estrogen receptor, respectively, could be involved in the tumorigenesis of these adenomas subtypes. Additional studies are required to further confirm this hypothesis.


Assuntos
Adenoma Hipofisário Secretor de ACT/metabolismo , Adenoma/metabolismo , GTP Fosfo-Hidrolases , Peptídeo Liberador de Gastrina , Neoplasias Hipofisárias/metabolismo , RNA Mensageiro/metabolismo , Receptores do Ácido Retinoico , Adenoma Hipofisário Secretor de ACT/genética , Adenoma/genética , Adolescente , Adulto , Idoso , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/metabolismo , Peptídeo Liberador de Gastrina/genética , Peptídeo Liberador de Gastrina/metabolismo , Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Hipófise/metabolismo , Neoplasias Hipofisárias/genética , Prolactina/metabolismo , RNA Mensageiro/genética , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/metabolismo , Adulto Jovem
15.
J Dairy Sci ; 93(4): 1335-44, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20338410

RESUMO

Model cheeses were manufactured according to a full factorial experimental design to help shed light on the individual and combined roles played by 3 native lactic acid bacteria (Lactococcus lactis ssp. lactis, Lactobacillus brevis, and Lactobacillus plantarum) upon proteolysis and organic acid evolution in cheese. The model cheeses were manufactured according to a generally representative Portuguese artisanal protocol, but the (ubiquitous) adventitious microflora in the cheesemaking milk were removed via sterilization before manufacture; therefore, the specific effects of only those lactic acid bacteria selected were monitored. In addition, 2 types of coagulant (animal and plant) and 3 types of cheesemaking milk (cow, sheep, and goat) were assessed to determine their influence on the final characteristics of the model cheeses. The nature of the coagulant appeared to be essential during the first stage of proteolysis as expected, whereas the contribution of those bacteria to the pools of total free AA and organic acids was crucial afterward. This was especially so in terms of the differences observed in the metabolisms of lactic acid (in the case of Lactococcus spp.) as well as acetic and citric acids (in the case of Lactobacillus spp.).


Assuntos
Queijo/microbiologia , Coagulantes/farmacologia , Manipulação de Alimentos/métodos , Lactobacillus plantarum/metabolismo , Lactococcus lactis/metabolismo , Levilactobacillus brevis/metabolismo , Ácido Acético/metabolismo , Animais , Bovinos , Ácido Cítrico/metabolismo , Fermentação , Microbiologia de Alimentos , Cabras , Ácido Láctico/metabolismo , Leite , Portugal , Ovinos
16.
J Mech Behav Biomed Mater ; 101: 103447, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31563111

RESUMO

OBJECTIVES: Dental resins filled with hydroxyapatite (HAp) nanoparticles have significantly revolutionized restorative dentistry offering advantages such as remineralization potential and increase of polymerization. However, these materials have limited radiopacity hindering the diagnosis of secondary caries. The present study investigated the development of a new radiopaque dental adhesive by incorporating novel pure strontium hydroxyapatite nanoparticles [Sr10(PO4)6(OH)2, SrHAp] synthesized by a simple hydrothermal method. METHODS: Strontium phosphates were prepared using co-precipitation (SrHAp0h) and hydrothermal treatment for 2 and 5h (SrHAp2h and SrHAp5h). The crystallinity, crystallite size, textural and morphology features of the nanoparticles were characterized by XRD, FT-IR, micro-Raman and TEM. Strontium hydroxyapatite (SrHAp) or calcium hydroxyapatite (HAp) nanoparticles were then incorporated (10 wt%) into an adhesive resin of a commercial three-step etch-and-rinse adhesive to evaluate the radiopacity of disk-shaped specimens, degree of conversion (DC) assessed by FT-IR and mechanical properties by three-point bending test. The unfilled adhesive was used as negative control. RESULTS: While SrHAp0h and SrHAp2h resulted a phase mixing, the pure and highly crystalline phase of strontium hydroxyapatite free of calcium was obtained with 5h hydrothermal treatment (SrHAp5h). The TEM images revealed nanorods morphology for SrHAp5h. SrHAps incorporated into adhesive showed higher radiopacity, no alteration on DC despite slightly reducing the mechanical properties. SIGNIFICANCE: Although the mechanical properties are slightly impaired, incorporation of SrHAp nanoparticles offers potential method to improve radiopacity of restorative dental resins, easing the tracking of actual remineralization effects and enabling diagnosis of recurrent caries.


Assuntos
Cimentos Dentários/química , Hidroxiapatitas/química , Fenômenos Mecânicos , Nanoestruturas/química , Estrôncio/química , Precipitação Química , Testes Mecânicos
17.
Prog Urol ; 19(1): 21-6, 2009 Jan.
Artigo em Francês | MEDLINE | ID: mdl-19135638

RESUMO

PURPOSE: We studied the efficiency and the morbidity of endoscopic removal of kidney stones during laparoscopic removal of ureteral stone. MATERIAL AND METHODS: Six patients presenting with an ureteral stone resisting to ESWL and four patients presenting with an UPJ obstruction were studied. Every patient had one to five associated kidney stones. The patients were operated with transperitoneal laparoscopic ureterolithotomy or pyeloplasty. An endoscopy of the upper urinary tract was realized during the same operating time through laparoscopic access. A flexible ureteroscope (five cases) or semi-flexible ureteroscope (one case) were used after ureterolithotomy. A fibroscope (four cases) was used before pyeloplasty. The endoscope was introduced through the port of the iliac fossa and the stones were extracted with a basket grasper. The patients were followed by abdominal plain film 12 weeks after surgery, by IPV six weeks after surgery and then annually with abdominal plain film and ultrasound. RESULTS: No operative complication arose. Nine of 10 patients had a complete extraction of the kidney stones (one patient had an extraction only of four out of five kidney stones). No damage of any endoscope was observed. At a minimum follow-up of 18 months, no fistula nor stenosis of the ureter was diagnosed. CONCLUSION: Endoscopic removal of kidney stones through laparoscopic access of the upper urinary tract is effective, sure and reproducible. Such procedure requires experience in laparoscopy and endoscopy of the upper urinary tract. The evaluation of this procedure must be pursued.


Assuntos
Cálculos Renais/cirurgia , Laparoscopia , Ureteroscopia , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Pelve Renal , Laparoscopia/métodos , Masculino , Pessoa de Meia-Idade , Ureter , Ureteroscopia/métodos , Adulto Jovem
18.
Eur J Endocrinol ; 180(4): 235-241, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30668525

RESUMO

Objective Gene alterations leading to activation of the MAPK pathway are of interest for targeted therapy in patients with advanced radioactive iodine refractory (RAI-R) thyroid carcinoma. Due to technical reasons gene fusion analysis in RNA isolated from formalin-fixed tumor tissues has till now been limited. The objective of the present study was to identify targetable gene rearrangements in RNA isolated from formalin-fixed RAI-R thyroid carcinomas. Design Retrospective study in 132 patients with RAI-R thyroid carcinoma (59 papillary-, 24 follicular-, 35 Hürthle cell- and 14 anaplastic thyroid carcinoma). Methods Total nucleic acid (undivided DNA and RNA) was isolated from formalin-fixed tissue. Extensive gene fusion analysis was performed in all samples that tested negative for pathogenic BRAF, NRAS, HRAS and KRAS variants. Results Seven targetable gene fusions were identified in the remaining 60 samples without known DNA variants. This includes frequently reported gene fusions such as CCDC6/RET (PTC1), PRKAR1A/RET (PTC2) and ETV6/NTRK3 , and gene fusions that are less common in thyroid cancer (TPM3/NTRK1, EML4/ALK and EML4/NTRK3). Of note, most gene fusions were detected in papillary thyroid carcinoma and MAPK-associated alterations in Hürthle cell carcinomas are rare (2/35). Conclusion Targetable gene fusions were found in 12% of RAI-R thyroid carcinoma without DNA variants and can be effectively identified in formalin-fixed tissue. These gene fusions might provide a preclinical rationale to include specific kinase inhibitors in the treatment regimen for these patients. The latter intends to restore iodine transport and/or take advantage of the direct effect on tumor cell vitality once progressive disease is seen.


Assuntos
Fusão Gênica/genética , Marcação de Genes/métodos , Iodo , Neoplasias da Glândula Tireoide/genética , Adolescente , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Iodo/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/tratamento farmacológico
19.
Ultrason Sonochem ; 48: 340-348, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30080559

RESUMO

TiO2 is a common inorganic filter used in sunscreens due to its photoprotective effect on the skin against UV radiation. However, the use of this kind of material in cosmetics is limited by its inherent photocatalytic activity. It is known that coating on TiO2 surface can improve some features. Although, many of the methodologies used for this purpose are still laborious and time-consuming. Thus, this work reports a novel, easy, cheap and fast strategy to coat TiO2 particles by using a sonochemistry approach, aiming to decrease photocatalytic activity and to enhance colloidal stability. For this proposal, SiO2, Al2O3, ZrO2 and sodium polyacrylate (PAANa) were used to tune the surface of commercial TiO2 particles and they were applied in a sunscreen formulation. The samples were characterized by XRPD, FT-IR, DLS, EDS, SEM and TEM. The photocatalytic activity and UV-shielding ability were also evaluated. The sunscreen formulations were prepared and characterized by zeta potential, DLS, and Sun Protection Factor (SPF). FT-IR, EDS, and charge surface of the particles confirmed the success of the sonochemistry coating. Additionally, TiO2@Al2O3, TiO2@SiO2 and TiO2@PAANa show a lower photocatalytic activity than original TiO2 with similar UV-shielding ability. The sunscreens produced with the coated TiO2 have similar SPF to the one with commercial TiO2. Specifically, the sunscreen with TiO2@PAANa shows an increase in colloidal stability. Herein, the incorporation of the sonochemical-coated TiO2 particles in sunscreen formulations may produce sunscreens with better aesthetic appearance and a greater health security due to its lower free radicals production.

20.
J Clin Invest ; 90(5): 1926-31, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1430215

RESUMO

Local production of growth factors may play a major role in vascular repair after injury. We examined the regulation of insulin-like growth factor-I (IGF-I) and its specific membrane receptor in balloon-denuded rat aorta. Aortic IGF-I mRNA and radioimmunoassayable IGF-I content increased severalfold after balloon denudation with a peak at 7 d after injury. This coincided with a reciprocal 25% decrease in IGF-I receptor mRNA content and a 40% decrease in total 125I-IGF-I binding. Scatchard analysis indicated a single class of binding sites, with a decrease in receptor number at 7 d compared to control and no change in affinity. By in situ hybridization the predominant site of IGF-I expression in the normal and the denuded vessel wall was the medial smooth muscle cell. After denudation there was a relative decrease in IGF-I receptor mRNA in the medial cells as compared to the neointima, suggesting that the site of IGF-I action was predominantly in the medial layer. These data suggest that local expression and action of IGF-I are significant in the promotion of smooth muscle cell proliferation after arterial injury.


Assuntos
Regulação da Expressão Gênica , Fator de Crescimento Insulin-Like I/genética , Músculo Liso Vascular/metabolismo , Receptor IGF Tipo 1/genética , Animais , Aorta/metabolismo , Cateterismo , Divisão Celular , Masculino , Músculo Liso Vascular/citologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
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