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1.
Mater Today Commun ; 34: 105192, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36570033

RESUMO

We carried out theoretical and experimental analyses of ZnO and ZnS nanoparticles as smart semiconductor materials in light-activated antimicrobial coating for application in masks. We used low-cost hydrothermally processable precursors to direct the growth of the coatings on cotton fabric. Both ZnO and ZnS coatings had high reactivities as disinfection agents in photocatalysis reactions for the degradation of a methylene blue dye solution. Also, these coatings showed excellent UV protection properties. For understanding at the molecular level, the broad-spectrum biological activities of the ZnO and ZnS coatings against Fusarium Oxysporum fungi, Escherichia coli bacteria, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus and their variants, were investigated computationally. Hexagonal Zn6O6 and Zn6S6 clusters were used as models for the simulations through excited- and ground-state calculations. The theoretical findings show that changes in the local chemical environment in these excited systems have a profound impact on their physical and chemical properties and thus, can provide a better understanding to engineer new functional materials in light-activated antimicrobial coatings for the mitigation of SARS-CoV-2 infection.

2.
Semergen ; 47(5): 332-336, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-34034982

RESUMO

INTRODUCTION: RT-qPCR is the reference test for the detection of SARS-CoV-2 infection, however, rapid antigen detection tests (RADT) are now available. In this work, the internal validity of the RADT was evaluated in the context of an outbreak in a nursing home. METHODS: Nasopharyngeal exudate samples were analyzed by RADT and RT-qPCR from 61 residents of a nursing home. The sensitivity and specificity of RADT with respect to RT-qPCR was calculated. RESULTS: Specificity was 100% (95% CI 54.1-100.0), while sensitivity in asymptomatic people was 70.3% (95% CI 53.0-84.1) and in symptomatic people 83.3% (95% CI 51.6-97.9). CONCLUSIONS: The RADTs are sufficiently sensitive and specific to be used as screening tests in nursing homes, especially in situations of outbreaks or suspected outbreaks due to the presence of symptoms.


Assuntos
COVID-19 , Teste para COVID-19 , Humanos , Casas de Saúde , SARS-CoV-2
3.
Analyst ; 146(12): 4010-4021, 2021 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-34019607

RESUMO

Here we show a new and significant application area for mass spectrometry imaging. The potential for fingerprints to reveal drug use has been widely reported, with potential applications in forensics and workplace drug testing. However, one unsolved issue is the inability to distinguish between drug administration and contamination by contact. Previous work using bulk mass spectrometry analysis has shown that this distinction can only be definitively made if the hands are washed prior to sample collection. Here, we illustrate how three mass spectrometry imaging approaches, desorption electrospray ionisation (DESI), matrix assisted laser desorption ionisation (MALDI) and time of flight secondary ion mass spectrometry (ToF-SIMS) can be used to visualise fingerprints at different pixel sizes, ranging from the whole fingerprint down to the pore structure. We show how each of these magnification scales can be used to distinguish between cocaine use and contact. We also demonstrate the first application of water cluster SIMS to a fingerprint sample, which was the sole method tested here that was capable of detecting excreted drug metabolites in fingerprints, while providing spatial resolution sufficient to resolve individual pore structure. We show that after administration of cocaine, lipids and salts in the fingerprint ridges spatially correlate with the cocaine metabolite, benzoylecgonine. In contrast after contact, we have observed that cocaine and its metabolite show a poor spatial correlation with the flow of the ridges.


Assuntos
Cocaína , Lipídeos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massa de Íon Secundário , Detecção do Abuso de Substâncias
4.
Food Chem ; 337: 127770, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795858

RESUMO

Sorbic acid and its potassium and calcium salts used as food preservatives and sorbic chloride were submitted to thermal analysis in order to characterize their thermal behavior on heating and cooling processes, using TG/DTG/DTA, TG-MS, DSC, hot stage microscopy and DRX analysis. Sorbic acid melted and decomposed under dynamic heating. Under isothermal it sublimated without decomposition before melting (T < 134 °C). The potassium salt presented a solid-solid phase transition before decomposition. Both potassium and calcium salts decomposed in temperatures higher than the acid without melting, producing the respective carbonates and oxides as final residues. Sorbic chloride evaporate without condensation, on dynamic heating.


Assuntos
Conservantes de Alimentos/química , Ácido Sórbico/análogos & derivados , Cálcio/química , Conservantes de Alimentos/metabolismo , Transição de Fase , Potássio/química , Ácido Sórbico/metabolismo , Temperatura
6.
Science ; 361(6405): 894-899, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-30139911

RESUMO

The yellow fever virus (YFV) epidemic in Brazil is the largest in decades. The recent discovery of YFV in Brazilian Aedes species mosquitos highlights a need to monitor the risk of reestablishment of urban YFV transmission in the Americas. We use a suite of epidemiological, spatial, and genomic approaches to characterize YFV transmission. We show that the age and sex distribution of human cases is characteristic of sylvatic transmission. Analysis of YFV cases combined with genomes generated locally reveals an early phase of sylvatic YFV transmission and spatial expansion toward previously YFV-free areas, followed by a rise in viral spillover to humans in late 2016. Our results establish a framework for monitoring YFV transmission in real time that will contribute to a global strategy to eliminate future YFV epidemics.


Assuntos
Surtos de Doenças/prevenção & controle , Monitoramento Epidemiológico , Genômica/métodos , Febre Amarela/prevenção & controle , Febre Amarela/transmissão , Vírus da Febre Amarela/isolamento & purificação , Aedes/virologia , Fatores Etários , Animais , Brasil/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Evolução Molecular , Humanos , Filogenia , Reação em Cadeia da Polimerase , Risco , Fatores Sexuais , Análise Espaço-Temporal , Febre Amarela/epidemiologia , Febre Amarela/virologia , Vírus da Febre Amarela/classificação , Vírus da Febre Amarela/genética
8.
Food Chem ; 258: 199-205, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-29655723

RESUMO

Inosine 5'-monophosphate in acidic form and its lithium, potassium, magnesium, calcium, strontium and barium were prepared from the sodium salt, characterized by elemental analysis and Fourier transform infrared spectroscopy and submitted to thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC) and thermogravimetry coupled to infrared spectroscopy (TG-FTIR) of the volatile products evolved during heating. All the salts were hydrated containing from 4 to 7.5 H2O. After dehydration these salts decomposed releasing the nitrogenous base followed by the ribose group, and producing pyrophosphates as final residue. Evolved Gas Analysis (EGA) reveled the release of water, isocyanic acid and hydrocyanic acid during decomposition of the organic moiety. It was observed only water loss up to 200 °C. At temperatures above 200 °C, the nucleotides were unstable and decomposed, implying that foods containing those additives should be processed below this temperature. Finally, a general mechanism for the decomposition of the inosinates was proposed.


Assuntos
Inosina Monofosfato/química , Bário/química , Varredura Diferencial de Calorimetria , Lítio/química , Magnésio/química , Potássio/química , Sais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Estrôncio/química , Temperatura , Termogravimetria , Água/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-29127992

RESUMO

Kupffer cells (KC) are the liver macrophage population that resides in the hepatic sinusoids and efficiently phagocyte pathogens by establishing an intimate contact with circulating blood. KC constitute the liver host cells in Leishmania infection, nevertheless little is described about their role, apart from their notable contribution in granulomatous inflammation. The present study aims to investigate how canine KC sense and react to the presence of Leishmania infantum promastigotes and amastigotes by evaluating the gene expression of specific innate immune cell receptors and cytokines, as well as the induction of nitric oxide and urea production. Complementarily, the impact of a leishmanicidal drug - meglumine antimoniate (MgA) - in infected KC was also explored. KC revealed to be susceptible to both parasite forms and no major differences were found in the immune response generated. L. infantum parasites seem to interact with KC innate immune receptors and induce an anergic state, promoting immune tolerance and parasite survival. The addition of MgA to infected KC breaks the parasite imposed silence and increased gene expression of Toll-like receptors (TLR) 2 and TLR4, possibly activating downstream pathways. Understanding how KC sense and react to parasite presence could bring new insights into the control or even elimination of canine leishmaniasis.


Assuntos
Antiprotozoários/farmacologia , Doenças do Cão/parasitologia , Células de Kupffer/parasitologia , Leishmania infantum/fisiologia , Leishmaniose Visceral/veterinária , Meglumina/farmacologia , Compostos Organometálicos/farmacologia , Animais , Doenças do Cão/imunologia , Doenças do Cão/metabolismo , Cães , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/imunologia , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Antimoniato de Meglumina , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
10.
J Environ Manage ; 200: 186-195, 2017 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-28577454

RESUMO

This work evaluates the use of biomasses and their biochars as adsorbents to remove polycyclic aromatic hydrocarbons from water. Coconut waste (CW) and orange waste (OW) were pyrolyzed at 350 °C to produce the corresponding biochars (BCW and BOW). Adsorption tests using a mixed solution of benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, and dibenzo(a,h)anthracene showed removal percentages of 30.33-83.43% (CW), 47.09-83.02% (BCW), 24.20-74.25% (OW), and 23.84-84.02% (BOW). The adsorption mechanisms appeared to involve π-π interactions of similar groups of the adsorbate and adsorbent, together with hydrophobic effects. There was no indication of competition between the PAHs for the adsorption sites, and there was evidence of cooperative adsorption. The PAHs could be desorbed from the adsorbents with efficiencies in the range 34.88-72.32%, and the reuse of the adsorbents in two further cycles demonstrated their potential for use in the removal of PAHs from water.


Assuntos
Carvão Vegetal , Hidrocarbonetos Policíclicos Aromáticos , Purificação da Água , Benzo(a)pireno , Biomassa
11.
Nature ; 546(7658): 406-410, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28538727

RESUMO

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.


Assuntos
Infecção por Zika virus/transmissão , Infecção por Zika virus/virologia , Zika virus/isolamento & purificação , América/epidemiologia , Número Básico de Reprodução , Brasil/epidemiologia , Variação Genética , Genoma Viral/genética , Humanos , Microcefalia/epidemiologia , Microcefalia/virologia , Epidemiologia Molecular , Filogeografia , Análise Espaço-Temporal , Zika virus/genética , Infecção por Zika virus/epidemiologia
12.
Eur J Surg Oncol ; 42(6): 808-12, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27038996

RESUMO

INTRODUCTION: Minimally invasive surgery for rectal cancer (RC) is now widely performed via the laparoscopic approach, but robotic-assisted surgery may overcome some limitations of laparoscopy in RC treatment. We compared the rate of positive circumferential margins between robotic, laparoscopic and open total mesorectal excision (TME) for RC in our institution. METHODS: Mid and low rectal adenocarcinoma patients consecutively submitted to robotic surgery were compared to laparoscopic and open approach. From our prospective database, 59 patients underwent robotic-assisted rectal surgery from 2012 to 2015 (RTME group) were compared to our historical control group comprising 200 open TME (OTME group) and 41 laparoscopic TME (LTME group) approaches from July 2008 to February 2012. Primary endpoint was to compare the rate of involved circumferential resection margins (CRM) and the mean CRM between the three groups. Secondary endpoint was to compare the mean number of resected lymph nodes between the three groups. RESULTS: CRM involvement was demonstrated in 20 patients (15.5%) in OTME, 4 (16%) in LTME and 9 (16.4%) in the RTME (p = 0.988). The mean CRM in OTME, LTME and RTME were respectively 0.6 cm (0-2.7), 0.7 cm (0-2.0) and 0.6 cm (0-2.0) (p = 0.960). Overall mean LN harvest was 14 (0-56); 16 (0-52) in OTME, 13 (1-56) in LTME and 10 (0-45) in RTME (p = 0.156). CONCLUSION: Our results suggest that robotic TME has the same oncological short-term results when compared to the open and laparoscopic technique, and it could be safely offered for the treatment of mid and low rectal cancer.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/instrumentação , Laparoscopia , Margens de Excisão , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Procedimentos Cirúrgicos Robóticos , Adulto , Idoso , Idoso de 80 Anos ou mais , Bases de Dados Factuais , Procedimentos Cirúrgicos do Sistema Digestório/métodos , Feminino , Humanos , Laparoscopia/métodos , Excisão de Linfonodo , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Duração da Cirurgia , Estudos Retrospectivos , Resultado do Tratamento
13.
Eur J Surg Oncol ; 41(11): 1456-63, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26362228

RESUMO

INTRODUCTION: Surgery is the standard treatment of rectal cancer after neoadjuvant therapy. Some authors advocate a nonoperative management (NOM) after complete clinical response (cCR) following chemoradiotherapy (CRT). We compare our results with NOM to standard resection in a retrospective analysis. METHODS: Rectal adenocarcinomas submitted to NOM after CRT between September 2002 and December 2013 were compared to surgical patients that had pathological complete response (pCR) during the same period. Endpoints were Overall Survival (OS), Disease Free Survival (DFS), Local Relapse (LR) and Distant Relapse (DR). RESULTS: Forty-two NOM patients compared to 69 pCR patients operated after a median interval of 35 weeks after CRT. NOM tumors were distal (83.3% vs 59.4%, p = 0.011), less obstructive (26.2% vs 54.4%, p = 0.005) and had a lower digital rectal score (p = 0.024). Twelve (28.0%) recurrences in NOM group and eight (11.5%) in the surgical group occurred after a follow-up of 47.7 and 46.7 months respectively. Isolated LR occurred in five (11%) NOM patients and one (1.4%) in the surgical group. Four (80%) LR were surgically salvaged in NOM group. No difference in OS was found (71.6% vs 89.9%, p = 0.316) but there was a higher DFS favoring surgical group (60.9% vs 82.8%, p = 0.011). Distal tumors had worse OS compared to proximal tumors in surgical group (5-year OS of 85.5% vs 96.2%, p = 0.038). CONCLUSION: The NOM achieved OS comparable to surgical treatment and spared patients from surgical morbidity but it resulted in more recurrences. This approach cannot be advocated routinely and controlled trials are warranted.


Assuntos
Adenocarcinoma/terapia , Antineoplásicos/uso terapêutico , Colectomia/métodos , Neoplasias Retais/terapia , Quimiorradioterapia/métodos , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
14.
J Parasitol ; 100(1): 73-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24147835

RESUMO

Diseases such as leishmaniases are important causes of morbidity and mortality in Brazil, and their diagnoses need to be improved. The use of monoclonal antibodies has ensured high specificity to immunodiagnosis. The development of an immunosensor, coupling a monoclonal antibody to a bioelectronic device capable of quickly detecting Leishmania sp. antigens both qualitatively and quantitatively, is a promising alternative for the diagnosis of leishmaniasis due to its high specificity, low cost, and portability, compared with conventional methods. The present work was aimed at developing an immunosensor-based assay for detecting Leishmania infantum antigens in tissues of infected hosts. Four hybridomas producing monoclonal antibodies against L. infantum had their specificity confirmed by enzyme-linked immunosorbent assay. These antibodies were immobilized on a gold surface, covered with a thin film of 2-aminoethanethiol (cysteamine) and glutaraldehyde, blocked with glycine, and placed into contact with extracts of L. infantum -infected and noninfected control hamster spleens. The assay was able to detect 1.8 × 10(4) amastigotes/g of infected tissue. These results demonstrated that this assay may be useful for quantifying L. infantum amastigotes in organs of experimental animals for studies on pathogenesis and immunity and that it is a promising tool for the development of a diagnostic method, based on antigen detection, of human and dog visceral leishmaniasis.


Assuntos
Anticorpos Monoclonais , Antígenos de Protozoários/isolamento & purificação , Leishmania infantum/imunologia , Leishmaniose Visceral/diagnóstico , Baço/parasitologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antiprotozoários/imunologia , Especificidade de Anticorpos , Técnicas Biossensoriais/métodos , Cricetinae , Ensaio de Imunoadsorção Enzimática , Imunoglobulina G/imunologia , Leishmania infantum/isolamento & purificação , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Organismos Livres de Patógenos Específicos , Baço/imunologia
15.
Nutr Diabetes ; 3: e98, 2013 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-24366370

RESUMO

OBJECTIVE: Obesity in the United States is highly prevalent, approaching 60% for black women. We investigated whether nutrition education sessions at the work place added to internet-based wellness information and exercise resources would facilitate weight and fat mass loss in a racially diverse population of overweight female employees. METHODS: A total of 199 (average body mass index 33.9±6.3 kg m(-2)) nondiabetic women (57% black) at our institution were randomized to a 6-month program of either internet-based wellness information (WI) combined with dietitian-led nutrition education group sessions (GS) weekly for 3 months and then monthly with shift in emphasis to weight loss maintenance (n=99) or to WI alone (n=100). All were given access to exercise rooms convenient to their work site. Fat mass was measured by dual-energy X-ray absorptiometry. RESULTS: WI+GS subjects lost more weight than WI subjects at 3 months (-2.2±2.8 vs -1.0±3.0 kg, P>0.001). Weight (-2.7±3.9 vs -2.0±3.9 kg) and fat mass (-2.2±3.1 vs -1.7±3.7 kg) loss at 6 months was significant for WI+GS and WI groups (both P<0.001), but without significant difference between groups (both P>0.10); 27% of the WI+GS group achieved 5% loss of initial weight as did 18% of the WI group (P=0.180). Blacks and whites similarly completed the study (67 vs 74%, P=0.303), lost weight (-1.8±3.4 vs -3.3±5.2 kg, P=0.255) and fat mass (-1.6±2.7 vs -2.5±4.3 kg, P=0.532), and achieved 5% loss of initial weight (21 vs 32%, P=0.189), irrespective of group assignment. CONCLUSION: Overweight women provided with internet-based wellness information and exercise resources at the work site lost weight and fat mass, with similar achievement by black and white women. Additional weight loss benefit of nutrition education sessions, apparent at 3 months, was lost by 6 months and may require special emphasis on subjects who fail to achieve weight loss goals to show continued value.

16.
Diabetes Metab ; 39(3): 281-5, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23623699

RESUMO

AIMS: Atypical forms of diabetes may be caused by monogenic mutations in key genes controlling beta-cell development, survival and function. This report describes an insulin-dependent diabetes patient with a syndromic presentation in whom a homozygous SLC29A3 mutation was identified. METHODS: SLC29A3 was selected as the candidate gene based on the patient's clinical manifestations, and all exons and flanking regions in the patient's genomic DNA were sequenced. RESULTS: A homozygous splice mutation (c.300+1G>C) resulting in a frameshift and truncated protein (p.N101LfsX34) was identified. The patient had insulin-dependent diabetes, congenital deafness, short stature, hyperpigmented patches on the skin, dysmorphic features, cardiomegaly, arthrogryposis, hepatosplenomegaly, anaemia with erythroblastopenia, and an inflammatory syndrome with fever and arthritis; she also presented with a fibrotic mediastinal mass. These clinical features overlapped with pigmented hypertrichosis with insulin-dependent diabetes (PHID), H syndrome, Faisalabad histiocytosis and sinus histiocytosis with massive lymphadenopathy (SHML), all of which are also caused by SLC29A3 mutations. CONCLUSION: This is the most severe case reported of SLC29A3 mutations with cumulative features of all these syndromes. This extreme severity coincides with the most N-terminal location of the truncation mutation, thereby affecting all alternative transcripts of the gene. This case report extends the clinical variability of homozygous SLC29A3 mutations that result in a spectrum of multisystemic manifestations.


Assuntos
Contratura/genética , Diabetes Mellitus Tipo 1/genética , Perda Auditiva Neurossensorial/genética , Histiocitose/genética , Proteínas de Transporte de Nucleosídeos/genética , Adolescente , Criança , Análise Mutacional de DNA , Feminino , Humanos , Mutação , Síndrome
17.
Physiol Meas ; 33(1): 39-49, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22155897

RESUMO

The Premature Infant Pain Profile (PIPP) is a promising multidimensional tool for comparison and testing of new technologies in newborn pain assessment studies since it may adhere to basic psychophysical parameters of intensity, direction, reactivity, regulation and slope described in analyses of physiological pain indicators. The aim of this study was to evaluate whether these psychophysical parameters can be achieved using the PIPP in acute pain assessment. Thirty-six healthy term newborn infants were conveniently sampled whilst being videotaped before, during and after heel prick blood sampling. The images were blind-scored by three trained independent raters and scored against the PIPP. The PIPP and its facial action indicators met the parameters of intensity, reactivity and regulation (all p < 0.001). The heart rate variability did not meet any parameter (all p > 0.05). The oxygen saturation variability met only the intensity parameter (p < 0.05). The behavioural state indicator met all parameters and had the best correlation to the psychophysical parameters of all indicators of PIPP (all p < 0.001). We concluded that the overall PIPP meets the assumptions of these psychophysical parameters, being the behavioural state indicator which best fit the model.


Assuntos
Comportamento do Lactente/fisiologia , Comportamento do Lactente/psicologia , Medição da Dor/normas , Dor/fisiopatologia , Dor/psicologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro/fisiologia , Recém-Nascido Prematuro/psicologia , Dor/diagnóstico , Medição da Dor/métodos , Gravação em Vídeo/normas
18.
Nanotechnology ; 19(22): 225202, 2008 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-21825754

RESUMO

A nanocrystalline Si-based paste was successfully tested as the light emitting material in a field emission display test device that employed a film of carbon nanofibers as the electron source. Stable emission in the 550-850 nm range was obtained at 16 V µm(-1). This relatively low field required for intense cathodoluminescence (CL) from the PSi paste may lead to longer term reliability of both the electron emitting and the light emitting materials, and to lower power consumption. Here we describe the synthesis, characterization, and analyses of the light emitting nanostructured Si paste and the electron emitting C nanofibers used for building the device, including x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The corresponding spectra and field emission curves are also shown and discussed.

19.
Clin Pharmacol Ther ; 82(4): 396-401, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17361120

RESUMO

Only about 70% of migraine and cluster headache (CH) patients report significant treatment responses to triptans, which are agonists at 5-HT(1B/D) receptors belonging to the family of G protein-coupled receptors. We analyzed whether a common polymorphism in the gene for the G protein beta3 subunit (GNB3 C825T) modulates responder rates to triptans among a cohort of 231 unrelated Caucasian CH patients. A total of 180 CH patients used triptans, of whom 71.1% reported treatment success. The adjusted odds ratio for treatment response to triptans for heterozygous carriers of the GNB3 825T allele was 2.96 (95% confidence interval 1.34-6.56; P=0.0074) vs carriers of the 825CC genotype. The GNB3 genotype status did not affect responses to other acute and preventive therapeutic regimes including oxygen, verapamil, and corticosteroids, i.e., drugs not directly affecting G proteins. We conclude that pain relief by triptans is significantly modulated by a common genetic GNB3 variant.


Assuntos
Cefaleia Histamínica/tratamento farmacológico , Agonistas de Dopamina/uso terapêutico , Proteínas Heterotriméricas de Ligação ao GTP/genética , Polimorfismo Genético , Agonistas do Receptor 5-HT1 de Serotonina , Triptaminas/uso terapêutico , Adulto , Cefaleia Histamínica/genética , Cefaleia Histamínica/metabolismo , Agonistas de Dopamina/farmacologia , Feminino , Frequência do Gene , Genótipo , Alemanha , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Seleção de Pacientes , Estudos Prospectivos , Receptor 5-HT1B de Serotonina/metabolismo , Receptor 5-HT1D de Serotonina/metabolismo , Inquéritos e Questionários , Resultado do Tratamento , Triptaminas/farmacologia , População Branca/genética
20.
Parasitology ; 132(Pt 2): 177-85, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16197592

RESUMO

Proteolytic activities of 5 strains of Leishmania (Viannia) braziliensis isolated from Brazilian and Colombian patients, presenting distinct clinical manifestations, were characterized and compared using whole-promastigote extracts and extracellular secretions. Zymographic assays concerning whole-cell extracts and supernatants resulted in the detection of high molecular weight bands, ranging from 50 to 125 kDa. Proteolytic activities from both whole-cell extracts and supernatants were optimal in a pH range 5.5 to 9.0 for all analysed strains. Such protease activities were inhibited when 10 mM 1,10-phenanthroline was assayed, strongly suggesting that the enzymes responsible for hydrolysis of the substrate belong to the metalloproteases class. Distinct profiles of metalloproteases were observed among the studied L. (V.) braziliensis strains. Differences among the microorganisms might be related to the geographical origin of the strains and/or to the clinical presentation.


Assuntos
Leishmania braziliensis/enzimologia , Leishmaniose Cutânea/parasitologia , Metaloproteases/metabolismo , Proteínas/metabolismo , Animais , Células Cultivadas , Eletroforese em Gel de Poliacrilamida , Humanos , Concentração de Íons de Hidrogênio , Leishmania braziliensis/isolamento & purificação , Metaloproteases/química , Metaloproteases/efeitos dos fármacos , Fenantrolinas/farmacologia , Inibidores de Proteases/farmacologia , Fatores de Tempo
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