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1.
J Synchrotron Radiat ; 30(Pt 1): 76-83, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36601928

RESUMO

This report presents testing of a prototype cantilevered liquid-nitrogen-cooled silicon mirror. This mirror was designed to be the first mirror for the new soft X-ray beamlines to be built as part of the Advanced Light Source Upgrade. Test activities focused on fracture, heat transfer, modal response and distortion, and indicated that the mirror functions as intended.

2.
Appl Environ Microbiol ; 84(11)2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29625974

RESUMO

The Cuatro Ciénegas Basin (CCB) is located in the Chihuahuan desert in the Mexican state of Coahuila; it has been characterized as a site with high biological diversity despite its extreme oligotrophic conditions. It has the greatest number of endemic species in North America, containing abundant living microbialites (including stromatolites and microbial mats) and diverse microbial communities. With the hypothesis that this high biodiversity and the geographic structure should be reflected in the virome, the viral communities in 11 different locations of three drainage systems, Churince, La Becerra, and Pozas Rojas, and in the intestinal contents of 3 different fish species, were analyzed for both eukaryotic and prokaryotic RNA and DNA viruses using next-generation sequencing methods. Double-stranded DNA (dsDNA) virus families were the most abundant (72.5% of reads), followed by single-stranded DNA (ssDNA) viruses (2.9%) and ssRNA and dsRNA virus families (0.5%). Thirteen families had dsDNA genomes, five had ssDNA, three had dsRNA, and 16 had ssRNA. A highly diverse viral community was found, with an ample range of hosts and a strong geographical structure, with very even distributions and signals of endemicity in the phylogenetic trees from several different virus families. The majority of viruses found were bacteriophages but eukaryotic viruses were also frequent, and the large diversity of viruses related to algae were a surprise, since algae are not evident in the previously analyzed aquatic systems of this ecosystem. Animal viruses were also frequently found, showing the large diversity of aquatic animals in this oasis, where plants, protozoa, and archaea are rare.IMPORTANCE In this study, we tested whether the high biodiversity and geographic structure of CCB is reflected in its virome. CCB is an extraordinarily biodiverse oasis in the Chihuahuan desert, where a previous virome study suggested that viruses had followed the marine ancestry of the marine bacteria and, as a result of their long isolation, became endemic to the site. In this study, which includes a larger sequencing coverage and water samples from other sites within the valley, we confirmed the high virus biodiversity and uniqueness as well as the strong biogeographical diversification of the CCB. In addition, we also analyzed fish intestinal contents, finding that each fish species eats different prey and, as a result, presents different viral compositions even if they coexist in the same pond. These facts highlight the high and novel virus diversity of CCB and its "lost world" status.


Assuntos
Bacteriófagos/classificação , Biodiversidade , Vírus de DNA/classificação , Peixes/virologia , Microbiota , Vírus de RNA/classificação , Animais , Bacteriófagos/isolamento & purificação , Vírus de DNA/isolamento & purificação , DNA Bacteriano/genética , Variação Genética , Geografia , Intestinos/virologia , México , Filogenia , Vírus de RNA/isolamento & purificação , RNA Ribossômico 16S/genética , Microbiologia da Água
3.
Int J Biometeorol ; 60(11): 1753-1760, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27094916

RESUMO

The incidence of geomagnetic storms may be associated with changes in circulatory physiology. The way in which the natural variations of the geomagnetic field due to solar activity affects the blood pressure are poorly understood and require further study in controlled experimental designs in animal models. In the present study, we tested whether the systolic arterial pressure (AP) in adult rats is affected by simulated magnetic fields resembling the natural changes of a geomagnetic storm. We exposed adult rats to a linear magnetic profile that simulates the average changes associated to some well-known geomagnetic storm phases: the sudden commencement and principal phase. Magnetic stimulus was provided by a coil inductor and regulated by a microcontroller. The experiments were conducted in the electromagnetically isolated environment of a semi-anechoic chamber. After exposure, AP was determined with a non-invasive method through the pulse on the rat's tail. Animals were used as their own control. Our results indicate that there was no statistically significant effect in AP when the artificial profile was applied, neither in the sudden commencement nor in the principal phases. However, during the experimental period, a natural geomagnetic storm occurred, and we did observe statistically significant AP increase during the sudden commencement phase. Furthermore, when this storm phase was artificially replicated with a non-linear profile, we noticed a 7 to 9 % increase of the rats' AP in relation to a reference value. We suggested that the changes in the geomagnetic field associated with a geomagnetic storm in its first day could produce a measurable and reproducible physiological response in AP.


Assuntos
Pressão Arterial , Campos Magnéticos , Animais , Masculino , Ratos Wistar
4.
Int J Pharm ; 641: 123064, 2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37211236

RESUMO

In scope of achieving real-time release of tablets, quality attributes need to be monitored and controlled through Process Analytical Technology tools such as near-infrared spectroscopy (NIRS). The authors evaluated the suitability of NIR-Spatially Resolved Spectroscopy (NIR-SRS) for continuous real-time monitoring and control of content uniformity, hardness and homogeneity of tablets with challenging dimensions. A novel user-friendly research and development inspection unit was used as standalone equipment for the analysis of small oblong tablets with deep-cut break lines. A total of 66 tablets varying in hardness and Active Pharmaceutical Ingredient (API) content were inspected, with each tablet being analysed five times and measurements repeated on three different days. Partial Least Squares (PLS) models were developed to assess content uniformity and hardness, of which the former showed higher accuracy. The authors attempted to visualize tablet homogeneity through NIR-SRS spectra by regressing all spectra obtained during a single measurement using a content uniformity PLS model. The NIR-SRS probe demonstrated its potential towards real-time release testing through its ability to quickly monitor content uniformity, hardness and visualize homogeneity, even for tablets with challenging dimensions.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho , Tecnologia Farmacêutica , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Tecnologia Farmacêutica/métodos , Comprimidos/química , Análise dos Mínimos Quadrados , Dureza
5.
Neurotoxicology ; 99: 244-253, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37944760

RESUMO

Misused volatile solvents typically contain toluene (TOL) as the main psychoactive ingredient. Cyclohexane (CHX) can also be present and is considered a safer alternative. Solvent misuse often occurs at early stages of life, leading to permanent neurobehavioral impairment and growth retardation. However, a comprehensive examination of the effects of TOL and CHX on stress regulation and energy balance is lacking. Here, we compared the effect of a binge-pattern exposure to TOL or CHX (4,000 or 8,000 ppm) on body weight, food intake, the hypothalamus-pituitary-adrenal (HPA) and hypothalamus-pituitary-thyroid (HPT) axes in male adolescent Wistar rats. At 8,000 ppm, TOL decreased body weight gain without affecting food intake. In addition, TOL and CHX altered the HPA and HPT axes' function in a solvent- and concentration-dependent manner. The highest TOL concentration produced HPA axis hyperactivation in animals not subjected to stress, which was evidenced by increased corticotropin-releasing-factor (CRF) release from the median eminence (ME), elevated adrenocorticotropin hormone (ACTH) and corticosterone serum levels, and decreased CRF mRNA levels in the hypothalamic paraventricular nucleus (PVN). TOL (8,000 ppm) also increased triiodothyronine (T3) serum levels, decreased pro-thyrotropin-releasing-hormone (pro-TRH) mRNA transcription in the PVN, pro-TRH content in the ME, and serum thyroid stimulating hormone (TSH) levels. CHX did not affect the HPA axis. We propose that the increased HPT axis activity induced by TOL can be related to the impaired body weight gain associated with inhalant misuse. These findings may contribute to a better understanding of the effects of the misused solvents TOL and CHX.


Assuntos
Hormônio Liberador da Corticotropina , Sistema Hipotálamo-Hipofisário , Ratos , Masculino , Animais , Ratos Wistar , Hormônio Liberador da Corticotropina/genética , Hormônio Liberador da Corticotropina/metabolismo , Tolueno/toxicidade , Sistema Hipófise-Suprarrenal/metabolismo , Hipotálamo/metabolismo , Peso Corporal , RNA Mensageiro , Solventes/toxicidade , Corticosterona
6.
Rev Chilena Infectol ; 26(1): 21-5, 2009 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-19350155

RESUMO

UNLABELLED: The aim of this study was to determine the frequency of renal abnormalities in HIV positive children hospitalized in one pediatric hospital in Chile. METHOD: a cross sectional study was performed during April 2007. RESULTS: A total of 18 patients were evaluated, ten male and eight female ranging in age from 4 to 19 years. The average age at the time of HIV diagnosis and nephrologic evaluations were 2,69 and 10,7 years respectively. All patients had acquired HIV infection by vertical transmission. Uriñe samples of two children had microalbuminuria; two had monosymptomatic hematuria, and ten had ¿squamous? cells. Hypercalciuria was detected in one patient, renal lithiasis in another and two patients had abnormal renal ultrasonography. All 19 patients had normal blood pressures. Overall 7 patients (39%) had a renal abnormality. CONCLUSIONS: The relatively high incidence of renal abnormalities in our series support the need for a nation-wide screening program to assess the incidence of renal impairment in pediatric HIV positive patients.


Assuntos
Nefropatia Associada a AIDS/diagnóstico , Adolescente , Criança , Pré-Escolar , Chile , Estudos Transversais , Feminino , Hospitais Pediátricos/estatística & dados numéricos , Humanos , Testes de Função Renal , Masculino , Adulto Jovem
7.
Rev Chilena Infectol ; 36(3): 318-330, 2019 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-31859751

RESUMO

BACKGROUND: Since the incorporation of antiretroviral therapy (ART) HIV has become a chronic condition, improving survival and allowing children with the virus to come in better conditions to adolescence, where they are faced with a series of changes, among them, to sexual awakening. AIM: To explore the main beliefs, perceptions and experiences in sexuality of a group of adolescents with HIV infection acquired through vertical transmission. METHODS: A qualitative research was carried out with exploratory and descriptive scope. Semi-structured interviews were applied to 28 adolescents, under control in hospitals in Santiago and Valparaíso, with HIV infection. The analysis was carried out according to the Grounded Theory. RESULTS: There was a lack of sexual education and a vision that focuses on risks, such as sexually transmissible infections or teenage pregnancy. There are fears about the possibility of rejection by others and of transmitting the virus to the couple or the children and they are invaded by feelings of shame and anger. CONCLUSION: It is important to train health professionals who work with this group, because they are identified as a reliable source of information and education.


Assuntos
Comportamento do Adolescente/psicologia , Infecções por HIV/transmissão , Conhecimentos, Atitudes e Prática em Saúde , Transmissão Vertical de Doenças Infecciosas , Comportamento Sexual/psicologia , Adolescente , Adulto , Criança , Cultura , Feminino , Infecções por HIV/psicologia , Humanos , Acontecimentos que Mudam a Vida , Masculino , Percepção , Educação Sexual , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
8.
Eur J Pharm Biopharm ; 127: 92-103, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29452241

RESUMO

Active Pharmaceutical Ingredients (API) raw material variability is not always thoroughly considered during pharmaceutical process development, mainly due to low quantities of drug substance available. However, synthesis, crystallization routes and production sites evolve during product development and product life cycle leading to changes in physical material attributes which can potentially affect their processability. Recent literature highlights the need for a global approach to understand the link between material synthesis, material variability, process and product quality. The study described in this article aims at explaining the raw material variability of an API using extensive material characterization on a restricted number of representative batches using multivariate data analysis. It is part of a larger investigation trying to link the API drug substance manufacturing process, the resulting physical API raw material attributes and the drug product continuous manufacturing process. Eight API batches produced using different synthetic routes, crystallization, drying, delumping processes and processing equipment were characterized, extensively. Seventeen properties from seven characterization techniques were retained for further analysis using Principal Component Analysis (PCA). Three principal components (PCs) were sufficient to explain 92.9% of the API raw material variability. The first PC was related to crystal length, agglomerate size and fraction, flowability and electrostatic charging. The second PC was driven by the span of the particle size distribution and the agglomerates strength. The third PC was related to surface energy. Additionally, the PCA allowed to summarize the API batch-to-batch variability in only three PCs which can be used in future drug product development studies to quantitatively evaluate the impact of the API raw material variability upon the drug product process. The approach described in this article could be applied to any other compound which is prone to batch-to-batch variability.


Assuntos
Preparações Farmacêuticas/química , Química Farmacêutica/métodos , Cristalização/métodos , Tamanho da Partícula , Análise de Componente Principal/métodos , Tecnologia Farmacêutica/métodos
9.
Int J Tuberc Lung Dis ; 11(3): 289-92, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17352094

RESUMO

SETTING: Tuberculosis (TB) program in Ensenada, Mexico. OBJECTIVE: To evaluate the impact of the DOTS strategy on adherence and cure rates in everyday practice. DESIGN: Retrospective analysis of 629 patients diagnosed with TB. MEASUREMENTS AND RESULTS: A total of 70% of the patients under directly observed treatment (DOT) were cured vs. 72.8% of those under self-administered treatment (SAT, P = 0.57). There was no difference on the length of therapy according to treatment regimen (4.82 +/- 2.41 for DOT vs. 4.93 +/- 2.16 for SAT, P = 0.61); 16.8% of patients under DOT abandoned treatment vs. 14.1% in the SAT group (P = 0.40). Logistic regression analysis confirmed the previous findings, with length of treatment under 6 months being the strongest predictive variable for treatment failure (OR 18.8, P < 0.00). The type of regimen (DOT vs. SAT) was not predictive of treatment failure (OR for failure for SAT regimen 0.65, P = 0.14). CONCLUSIONS: Cure and completion of treatment rates in our population under study did not differ significantly when comparing DOT vs. SAT. Those in charge of the DOTS programs in a given country need to assess which are the most important ingredients for success in their particular program.


Assuntos
Antituberculosos/uso terapêutico , Controle de Doenças Transmissíveis/normas , Terapia Diretamente Observada/normas , Tuberculose Pulmonar/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Modelos Logísticos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Cooperação do Paciente , Estudos Retrospectivos , Resultado do Tratamento , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar/epidemiologia
10.
Rev Chilena Infectol ; 24(5): 368-71, 2007 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-17989840

RESUMO

The identification of various risk factors of vertical human immunodeficiency virus (HIV) transmission resulted in the development of strategies whose aim was to decrease the mother's viral load, to reduce her child's exposure to it during delivery, and to avoid the subsequent viral exposure due to breastfeeding. The administration of antiretroviral treatment during pregnancy, delivery and to the neonate (PACTG 076) proved to be useful. At a first stage, zidovudine was used. A triple combination therapy was then administered. Initially, the viral transmission in mothers who were enrolled in protocols for vertically transmitted HIV prophylaxis was reduced to 9.5%, whereas the last measurement carried out between 1998 and 2005, the initial figure was brought down to 2%. Nevertheless, the delivery of infected children whose mother's HIV status was unknown is still considered likely to happen. The main step to be taken to reduce HIV infection among children is to perform universal HIV tests during pregnancy, so that HIV positive pregnant patients conveniently receive proper prophylaxis. We look forward to achieving this by following the new prevention guidelines of vertically-transmitted HIV infection, developed by the Comisión Nacional del SIDA of the Chilean Health Ministry.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/transmissão , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Complicações Infecciosas na Gravidez/tratamento farmacológico , Chile/epidemiologia , Protocolos Clínicos , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/terapia , Humanos , Recém-Nascido , Transmissão Vertical de Doenças Infecciosas/estatística & dados numéricos , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia
11.
J Endocrinol ; 232(1): 15-28, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27729464

RESUMO

Feeding patterns are important factors in obesity evolvement. Time-restricted feeding schedules (tRF) during resting phase change energy homeostasis regulation, disrupting the circadian release of metabolism-regulating hormones, such as leptin, insulin and corticosterone and promoting body weight gain. Thyroid (HPT) and adrenal (HPA) axes exhibit a circadian regulation and are involved in energy expenditure, thus studying their parameters in tRF paradigms will elucidate their role in energy homeostasis impairments under such conditions. As tRF in young animals is poorly studied, we subjected prepuberal rats to a tRF either in light (LPF) or in darkness phase (DPF) and analyzed HPT and HPA response when they reach adulthood, as well as their arcuate (ARC) and paraventricular (PVN) hypothalamic nuclei neurons' sensitivity to leptin in subsets of 10-week-old animals after fasting and with i.p. leptin treatment. LPF group showed high body weight and food intake, along with increased visceral fat pads, corticosterone, leptin and insulin serum levels, whereas circulating T4 decreased. HPA axis hyperactivity was demonstrated by their high PVN Crf mRNA expression; the blunted activity of HPT axis, by the decreased hypophysiotropic PVN Trh mRNA expression. Trh impaired expression to the positive energy balance in LPF, accounted for their ARC leptin resistance, evinced by an increased Npy and Socs3 mRNA expression. We concluded that the hyperphagia of prepuberal LPF animals could account for the HPA axis hyperactivity and for the HPT blocked function due to the altered ARC leptin signaling and impaired NPY regulation on PVN TRH neurons.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Leptina/farmacologia , Núcleo Hipotalâmico Paraventricular/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Corticosterona/sangue , Hormônio Liberador da Corticotropina/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Insulina/sangue , Leptina/sangue , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Ratos , Tiroxina/sangue
12.
J Neuroendocrinol ; 29(11)2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28984394

RESUMO

Negative energy balance promotes physiological adaptations that ensure the survival of animals. The hypothalamic-pituitary-thyroid axis regulates basal energy expenditure and its down-regulating adaptation to negative energy balance is well described: in fasting, the serum content of thyrotrophin (TSH) and thyroid hormones (TH) decreases, enhancing the survival odds of individuals. By contrast, dehydration-induced anorexic (DIA) rats present an impaired hypothalamic-pituitary-thyroid (HPT) axis adaptation despite their negative energy balance: increased circulating TSH levels. The implication of cocaine- and amphetamine-regulated transcript (CART), an anorexic peptide, in HPT axis function impairment and food-avoidance behaviour displayed by DIA animals is unknown. Because CART is co-expressed with the peptide that regulates the HPT axis in hypophysiotrophic paraventricular nucleus (PVN) neurones (TSH-releasing hormone), we analysed CART expression and possible implications with respect to high TSH levels of DIA animals. We examined whether changes in CART expression from the lateral hypothalamic area (LHA) and arcuate nucleus (ARC) could participate in food-avoidance of DIA rats. DIA and forced-food restricted (FFR) animals reduced their body weight and food intake. FFR rats had a down-regulation of their HPT axis (reduced serum TH and TSH content), whereas DIA animals had reduced TH but increased TSH levels. CART mRNA expression in the ARC decreased similarly between experimental groups and diminished in anterior, medial PVN and in LHA of FFR animals, whereas DIA animals showed unchanged levels. This impaired CART mRNA expression in the anterior PVN and LHA could be related to the aberrant feeding behaviour of DIA rats but not to their deregulated HPT axis function.


Assuntos
Anfetaminas/farmacologia , Anorexia/genética , Cocaína/farmacologia , Região Hipotalâmica Lateral/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Animais , Anorexia/etiologia , Regulação do Apetite/genética , Núcleo Arqueado do Hipotálamo/metabolismo , Núcleo Arqueado do Hipotálamo/fisiopatologia , Aprendizagem da Esquiva , Peso Corporal/genética , Desidratação/complicações , Desidratação/genética , Comportamento Alimentar , Região Hipotalâmica Lateral/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Núcleo Hipotalâmico Paraventricular/metabolismo , Ratos , Hormônios Tireóideos/sangue , Tireotropina/sangue
13.
Rev. chil. obstet. ginecol. (En línea) ; 86(2): 241-246, abr. 2021. ilus
Artigo em Espanhol | LILACS | ID: biblio-1388644

RESUMO

RESUMEN El dispositivo intrauterino (DIU) es un método anticonceptivo muy popular, eficaz y seguro. Aunque posee complicaciones bien descritas como es la migración, la que puede ser a otros órganos dentro de la cavidad peritoneal. La fístula uteroyeyunal es un evento clínico poco frecuente, pero de gran repercusión si no es diagnosticada y tratada. Se presenta el caso de una paciente usuaria de DIU, el que migra a cavidad abdominal, con posterior formación de fístula uteroyeyunal.


ABSTRACT The intrauterine device is a popular, efficient and safe contraceptive. Although it has some well described complications, such as migration, which may be to the different organs inside of the peritoneal cavity. The uterus-jejunal fistula is a rare clinical event, but with great repercussion if it is not well assessed and treated properly. We present the clinical case of a patient with a migrated intrauterine device and a fistula uterus-jejunal formation.


Assuntos
Humanos , Feminino , Adulto , Doenças Uterinas/etiologia , Migração de Dispositivo Intrauterino/efeitos adversos , Fístula/etiologia , Doenças do Jejuno/etiologia , Doenças Uterinas/cirurgia , Laparoscopia , Fístula/cirurgia , Perfuração Intestinal , Doenças do Jejuno/cirurgia
14.
Bioresour Technol ; 96(15): 1730-6, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15936942

RESUMO

Removal of organic material from poultry slaughter wastewater as determined by changes in biological oxygen demand (BOD5) was investigated by adding three different types of inoculum combining cow manure, yeast extract or hydraulic residence time as variables with response vector of reduction of BOD5. In a 3-l reactors, a 95% removal of BOD5 from poultry slaughter wastewater was obtained with organic loading rates up to 31 kg BOD5 m(-3) d(-1) without loss of stability. This 95% removal was obtained between 25 and 39 degrees C with a hydraulic residence time between 3.5 and 4.5 h. The growth of the consortium of micro-organisms in the reactor followed a first-order kinetic with a constant specific growth rate of 0.054 h(-1). It was concluded that an inoculum from cow manure added with nutrients and yeast extract allowed a 95% removal of BOD5 from poultry slaughter wastewater at ambient temperatures within a hydraulic residence time of 4 h, sharply reducing possible environmental hazards.


Assuntos
Matadouros , Reatores Biológicos , Aves Domésticas , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Anaerobiose , Animais , Análise Fatorial , Esterco , Oxigênio/metabolismo , Fatores de Tempo , Eliminação de Resíduos Líquidos/instrumentação , Purificação da Água/instrumentação
15.
J Phys Condens Matter ; 27(46): 462001, 2015 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-26523547

RESUMO

Highly electrochemically doped poly(2,5-bis(3-dodecyl-2-yl)-thieno[3,2-b]thiophene (pBTTT) thin films exhibiting remarkably high conductivities values reaching 3000-5000 Ω(-1) cm(-1) are investigated. Experimental evidence of delocalized transport properties of this material at the onset of metallicity makes it an ideal candidate for spin valve device integration. Nevertheless, the interface resistance between the polymer and metallic electrodes is orders of magnitudes larger than the expected spin resistance of the active channel. This prevents the collection of a spin current. This finding can explain the lack of success in making lateral organic spin valves reported in the literature, especially the related absence of spin signals in non-local spin valve and Hanle current measurements in organic thin films.

16.
Anal Chim Acta ; 888: 118-25, 2015 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-26320966

RESUMO

Bisphenol A (BPA) is well known for its use in plastic manufacture and thermal paper production despite its risk of health toxicity as an endocrine disruptor in humans. Since the publication of new legislation regarding the use of BPA, manufacturers have begun to replace BPA with other phenolic molecules such as bisphenol F (BPF) and bisphenol B (BPB), but there are no guarantees regarding the health safety of these compounds at this time. In this context, a very simple, cheap and fast surface-enhanced Raman scattering (SERS) method was developed for the sensitive detection of these molecules in spiked tap water solutions. Silver nanoparticles were used as SERS substrates. An original strategy was employed to circumvent the issue of the affinity of bisphenols for metallic surfaces and the silver nanoparticles surface was functionalized using pyridine in order to improve again the sensitivity of the detection. Semi-quantitative detections were performed in tap water solutions at a concentrations range from 0.25 to 20 µg L(-1) for BPA and BPB and from 5 to 100 µg L(-1) for BPF. Moreover, a feasibility study for performing a multiplex-SERS detection of these molecules was also performed before successfully implementing the developed SERS method on real samples.


Assuntos
Compostos Benzidrílicos/análise , Água Potável/análise , Disruptores Endócrinos/análise , Fenóis/análise , Análise Espectral Raman/métodos , Poluentes Químicos da Água/análise , Estudos de Viabilidade , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Papel , Prata/química , Propriedades de Superfície
17.
J Pharm Biomed Anal ; 113: 21-33, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-25704954

RESUMO

Since the last decade, more and more Active Pharmaceutical Ingredient (API) candidates have poor water solubility inducing low bioavailability. These molecules belong to the Biopharmaceutical Classification System (BCS) classes II and IV. Thanks to Hot-Melt Extrusion (HME), it is possible to incorporate these candidates in pharmaceutical solid forms. Indeed, HME increases the solubility and the bioavailability of these drugs by encompassing them in a polymeric carrier and by forming solid dispersions. Moreover, in 2004, the FDA's guidance initiative promoted the usefulness of Process Analytical Technology (PAT) tools when developing a manufacturing process. Indeed, the main objective when developing a new pharmaceutical process is the product quality throughout the production chain. The trend is to follow this parameter in real-time in order to react immediately when there is a bias. Vibrational spectroscopic techniques, NIR and Raman, are useful to analyze processes in-line. Moreover, off-line Raman microspectroscopy is more and more used when developing new pharmaceutical processes or when analyzing optimized ones by combining the advantages of Raman spectroscopy and imaging. It is an interesting tool for homogeneity and spatial distribution studies. This review treats about spectroscopic techniques analyzing a HME process, as well off-line as in-line, presenting their advantages and their complementarities.


Assuntos
Química Farmacêutica/métodos , Temperatura Alta , Análise Espectral Raman/métodos , Vibração , Química Farmacêutica/tendências , Microespectrofotometria/métodos , Microespectrofotometria/tendências
19.
Arch Med Res ; 28(1): 5-9, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9078580

RESUMO

We report a study on the DNA organization in Entamoeba histolytica using a ribosomal DNA probe. The rDNA genes were found forming mers which were separated in a typical ladder pattern by pulse field electrophoresis. DNA rosette structures were visualized through electron microscopy in DNA eluted from bands recognized by the ribosomal probe. The in situ hybridization experiments using a DNA probe suggested that the rDNA genes are portioned between the nucleus and a cytoplasmic structure. These findings provide new data on DNA organization in E. histolytica and open the question concerning the presence of a novel organelle in this eukaryotic parasite.


Assuntos
Citoplasma/química , DNA de Protozoário/genética , DNA Ribossômico/genética , Entamoeba histolytica/genética , Animais , Núcleo Celular/química , DNA de Protozoário/ultraestrutura , DNA Ribossômico/ultraestrutura , Eletroforese em Gel de Campo Pulsado , Entamoeba histolytica/ultraestrutura , Hibridização In Situ , Microscopia Confocal , Microscopia Eletrônica , Organelas
20.
Arch Cardiol Mex ; 71(1): 88-95, 2001.
Artigo em Espanhol | MEDLINE | ID: mdl-11565367

RESUMO

OBJECTIVE: Three-dimensional echocardiography represents a new era in the contemporary cardiology, because depicts the cardiac structures in their realistic forms. This information can not be obtained using a two-dimensional perspective. Although two-dimensional (2D) and M-mode echocardiography has greatly enhanced the ability to visualize the functioning heart for more than 30 years, 3D interpretative mental skills are necessary to compile the 2D slices of the complex 3D anatomy, particularly in congenital heart disease. CONCLUSIONS: At present, its additional morphological and functional information in surgical decision-making and the increasing number of clinical questions than can be answered justify the clinical use of this technique. In the future it will the study of "virtual" pathologic anatomy.


Assuntos
Ecocardiografia Tridimensional , Cardiopatias/diagnóstico por imagem , Ecocardiografia Tridimensional/métodos , Humanos
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