RESUMO

Graphene-TiO2 composites have been investigated in various photocatalytic reactions showing successful synergy compared to pristine TiO2. In the present work, graphene oxide (GO) was synthesized by the Hummers method and then reduced graphene oxide-TiO2 composites (rGO/TiO2) were obtained by an in situ GO photoreduction route. X-ray diffraction, FTIR, Raman, UV-vis DRS, and photoluminescence were the main characterization techniques. The obtained composites containing 1 and 3 wt.% rGO were evaluated in the cyanide (50 mg/L) oxidation and Au-cyanide complex (300 mg/L) degradation under UV-A light. The composites showed higher photocatalytic activity than TiO2, mainly with the 1% rGO content. Cyanate and gold nanoparticles, deposited on the photocatalyst's surface, were the main byproducts during the photocatalyst assessment. The improved photocatalytic activity of the composites was attributed to a higher rate of electron transfer and a lower rate of charge recombination due to the chemical interaction of rGO with TiO2.

RESUMO

Poly(vinyl alcohol) (PVA) displays ice recrystallization inhibition (IRI) properties as many antifreeze proteins found in cold tolerant organisms. The molecular architecture and composition (molecular weight and distribution of pendant OH and acetate groups) have been studied to improve the antifreezing properties of PVA, suggesting that the molecular architecture of PVA plays an important role in IRI activity. The present work deals with the preparation of PVA microparticles using an alkaline treatment. The effect of PVA molecular weight on the morphology and antifreezeing properties of PVA microparticles was investigated. The antifreezeing property of PVA microparticles on the susceptibility of flower bud tissues to freeze damage was also evaluated. The alkaline treatment of an aqueous PVA solution produced stable polymer chain aggregates with spherical shapes. The average size of the PVA microparticles increased significantly with the increasing molecular weight of the PVA macromolecule precursor. The PVA microparticles inhibited the growth of ice crystals and blocked ice growth at concentrations as low as 0.01 % w/v. The effect of impeding ice crystal growth by preventing the joining of adjacent ice crystals is attributed to the larger size of the PVA particles adsorbed on the ice surface compared to the aggregated PVA macromolecules in saline solution. The thermal hysteresis activity of PVA macromolecules and microparticles was not detected by differential scanning calorimetry analysis. The PVA microparticles reduced the incidence of freeze injuries in flower bud tissues by 55% and their application, considering the low toxicity of PVA, has a high potential for freeze protection in fruit crops.

RESUMO

In this work, we report a facile strategy for 4-nitrophenol (4-NP) sensing using highly luminescent nitrogen-doped oxidized carbon dots. The quenching of fluorescence (turn OFF), with the addition of trace amounts of organic pollutant (4-NP) in NOCDs, has been attributed to the complete reduction of nitrogen-doped oxidized carbon dots (NOCDs) to reduced nitrogen-doped oxidized carbon dots (rNOCDs) and its formation was confirmed by infrared, X-ray diffraction and X-ray photoelectron spectroscopy measurements. The chemical changes in oxygen-containing functional groups of NOCDs, in the presence of 4-NP, are elucidated and corresponding characterization through XPS reveals the changes in the peak intensities of CC (284.5 eV) and OCO (288.6 eV), indicating a decrement in hydroxyl groups that hinder its complete reduction to NOCDs. The sensitivity of NOCDs towards 4-NP has been tested in spiked tap water in the concentration range 2 µM to 2 mM with the minimum detection limit of 2 µM (linear detection range from 2 to 100 µM with regression coefficient R2 =0.99). The proposed simple sensing platform can be used to reduce NOCDs and simultaneously sense low concentrations of 4-NP. Finally, an effective treatment to improve the reduction of nitrogen-doped graphene oxide is proposed.

Assuntos

Hepatite A/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Chile/epidemiologia , Feminino , Hepatite A/sangue , Hepatite A/prevenção & controle , Vírus da Hepatite A/imunologia , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Estudos Soroepidemiológicos , Fatores de Tempo , Saúde da População Urbana , Adulto Jovem

RESUMO

OBJECTIVE: To determine the prevalence of hypokalemia in patients with methylprednisolone pulse therapy. DESIGN: We carried out a descriptive, cross-sectional study. MATERIAL AND METHODS: We enrolled 110 outpatients who received pulse doses of 1 g of intravenous methylprednisolone for three consecutive days. Demographic variables, serum electrolytes and an electrocardiogram were documented. RESULTS: The study group consisted of 31 men (28.2%) and 79 women (71.8%). Average age was 40 +/- 13.6 years. Mild hypokalemia was present in 19 patients (17.27% [95% CI 9.75-24.79]); moderate potassium levels were found in just one patient 0.9% [IC 95 0.023-4.96]); no cases of severe hypokalemia occurred. Total prevalence was 18.18% (95% CI 10.5-25.8). There were no significant electrocardiographic changes. DISCUSSION AND CONCLUSION: Mild and moderate hypokalemia was 18.18% without clinical or electrocardiographic consequences. Since there were no cases of severe hypokalemia, close monitoring of potassium levels should be restricted to those patients with other risk factors.

Assuntos

Anti-Inflamatórios/efeitos adversos , Hipopotassemia/induzido quimicamente , Metilprednisolona/efeitos adversos , Adulto , Assistência Ambulatorial , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/uso terapêutico , Doenças Autoimunes/tratamento farmacológico , Estudos Transversais , Feminino , Doenças Hematológicas/tratamento farmacológico , Humanos , Hipopotassemia/epidemiologia , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Masculino , Metilprednisolona/administração & dosagem , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/tratamento farmacológico , Prevalência , Pulsoterapia

RESUMO

We sought to determine the frequency of serological markers of selected infections in a population of psychiatric patients in Durango City, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infections. One hundred and five inpatients of a public psychiatric hospital of Durango were examined for HBsAg, anti-HCV antibodies, anti-HIV antibodies, anti-Brucella antibodies, rapid plasma reagin and anti-Cysticercus antibodies by commercially available assays. Anti-Cysticercus antibodies were confirmed by Western blot and HBsAg by neutralization assay. Epidemiological data from each participant were also obtained. Seroprevalences of HBsAg, anti-HCV, anti-HIV, anti-Brucella, rapid plasma reagin and anti-Cysticercus antibodies found were 0.0%, 4.8%, 0.9%, 0.0%, 1.9%, and 0.9%, respectively. Overall, 9 (8.6%) inpatients showed seropositivity to any infection marker. We concluded that our psychiatric inpatients have serological evidence of a number of infections. HCV is an important pathogen among our psychiatric inpatients. Health care strategies for prevention and control of infections in Mexican psychiatric patients should be considered.

Assuntos

Cisticercose/epidemiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Viroses/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Anti-Helmínticos/sangue , Anticorpos Antivirais/sangue , Biomarcadores/sangue , Estudos Transversais , Cisticercose/diagnóstico , Feminino , Infecções por Bactérias Gram-Negativas/diagnóstico , Hospitais Psiquiátricos/estatística & dados numéricos , Hospitais Públicos/estatística & dados numéricos , Humanos , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Viroses/diagnóstico

RESUMO

We sought to determine the frequency of serological markers of selected infections in a population of psychiatric patients in Durango City, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infections. One hundred and five inpatients of a public psychiatric hospital of Durango were examined for HBsAg, anti-HCV antibodies, anti-HIV antibodies, anti-Brucella antibodies, rapid plasma reagin and anti-Cysticercus antibodies by commercially available assays. Anti-Cysticercus antibodies were confirmed by Western blot and HBsAg by neutralization assay. Epidemiological data from each participant were also obtained. Seroprevalences of HBsAg, anti-HCV, anti-HIV, anti-Brucella, rapid plasma reagin and anti-Cysticercus antibodies found were 0.0 percent, 4.8 percent, 0.9 percent, 0.0 percent, 1.9 percent, and 0.9 percent, respectively. Overall, 9 (8.6 percent) inpatients showed seropositivity to any infection marker. We concluded that our psychiatric inpatients have serological evidence of a number of infections. HCV is an important pathogen among our psychiatric inpatients. Health care strategies for prevention and control of infections in Mexican psychiatric patients should be considered.

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Procuramos determinar a frequência de marcadores sorológicos de infecções em pacientes psiquiátricos da cidade de Durango, México e determinar se existem características epidemiológicas dos pacientes que podem ser associados a estas infecções. Cento e cinco pacientes internados neste hospital psiquiátrico de Durango foram examinados para HBsAg, anticorpos anti-HCV, anticorpos anti-HIV, anticorpos anti-Brucella, reaginas plasmáticos imediatas e anticorpos anti-Cysticercus por testes comerciais. Os anticorpos anti-Cysticercus foram confirmadoss por Western Blot e o HbsAg por testes de neutralização. Dados epidemiológicos de cada participante foram também obtidos. Soroprevalências encontradas de HbsAg, anti-HCV, anti-HIV, anti-Brucella, reagina plasmática imediata e anticorpos anti-Cysticercus foram respectivamente 0,0 por cento, 4,8 por cento, 0,9 por cento, 0,0 por cento, 1,9 por cento e 0,9 por cento. No conjunto, 9 (8,6 por cento) de pacientes internados mostraram soropositividade para marcador infeccioso. Concluímos que nossos pacientes psiquiátricos internados têm evidência sorológica de infecções. HCV é um patógeno importante entre os pacientes psiquiátricos internados. Estratégias de saúde pública para prevenção e controle de infecções em pacientes psiquiátricos do México devem ser consideradas.

Assuntos

Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cisticercose/epidemiologia , Infecções por Bactérias Gram-Negativas/epidemiologia , Viroses/epidemiologia , Anticorpos Antibacterianos/sangue , Anticorpos Anti-Helmínticos/sangue , Anticorpos Antivirais/sangue , Biomarcadores/sangue , Estudos Transversais , Cisticercose/diagnóstico , Infecções por Bactérias Gram-Negativas/diagnóstico , Hospitais Psiquiátricos/estatística & dados numéricos , Hospitais Públicos/estatística & dados numéricos , México/epidemiologia , Prevalência , Estudos Soroepidemiológicos , Viroses/diagnóstico

RESUMO

BACKGROUND: Patients with psychiatric disorders were found to show a high seroprevalence of Toxoplasma gondii infection. There is scarce information about the epidemiology of T. gondii infection in psychiatric patients in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic, clinical and behavioural characteristics in a population of psychiatric patients in Durango City, Mexico. Seroprevalence in patients was compared with that obtained in a control population. METHODS: One hundred and thirty seven inpatients of a public psychiatric hospital and 180 controls were examined for the presence of IgG and IgM antibodies against T. gondii by enzyme-linked immunoassay (Diagnostic Automation Inc., Calabasas, CA, USA). The control population consisted of blood donors of a public blood bank and elderly persons attending a senior center in the same city. Age in controls (42 years +/- 20.2) was comparable with that of the psychiatric patients (43.7 years +/-13.8) (p = 0.42). Socio-demographic, clinical and behavioral characteristics from the patients were also obtained. RESULTS: Anti-T. gondii IgG antibodies indicating latent infection with T. gondii was found in 25 (18.2%) of 137 psychiatric inpatients and 16 (8.9%) of 180 controls (p = 0.02). Ten (26.3%) of 38 schizophrenic patients had latent infection and this prevalence was also significantly higher than that observed in controls (p = 0.005). Prevalence of anti-T. gondii IgM antibodies was comparable among patients and controls (4.4% vs 2.2%, respectively, p = 0.22). Multivariate analysis showed that T. gondii infection in inpatients was positively associated with sexual promiscuity (adjusted OR = 15.8; 95% CI: 3.8-64.8), unwashed raw fruit consumption (adjusted OR = 5.19; 95% CI: 2.3-11.3), and a history of surgery (adjusted OR = 6.5; 95% CI: 2.6-16), and negatively associated with lamb meat consumption (adjusted OR = 0.26; 95% CI: 0.10-0.63). CONCLUSION: In the present study, psychiatric inpatients in Durango, Mexico, in general and schizophrenia inpatients in particular had a significantly higher prevalence of T. gondii infection than the control group. Results suggest that unwashed raw fruit consumption might be the most important route of T. gondii transmission in our psychiatric inpatients while lamb meat consumption the less important. Additional studies will have to elucidate the causative relation between infection with T. gondii and psychiatric disorders.

Assuntos

Transtornos Mentais/complicações , Toxoplasma/isolamento & purificação , Toxoplasmose/epidemiologia , Adolescente , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Cidades , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Pacientes Internados , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Fatores de Risco , Estudos Soroepidemiológicos , Toxoplasma/imunologia , Toxoplasmose/complicações , Toxoplasmose/parasitologia

RESUMO

Chile, middle-income country with 15 million people, began an expanded access program (EAP) to antiretroviral therapy (ART) in 2001. EAP provides ART, monitoring, and funding for management of associated complications in 32 points of care. A national cohort (Chilean AIDS Cohort [ChiAC]), enrolling 98% of these patients, was created for standardized treatment and impact evaluation. Information exchange is mainly through the Internet. By December 2004, the ChiAC had 4365 participants (83.3% male). At baseline, 47.5% had clinical AIDS, 26.2% were asymptomatic, 80.2% had a CD4 count <200 cells/mm and 58.2% were ART naive; in these patients, the most frequent regimen is zidovudine, lamivudine, and efavirenz. A 6-month follow-up in 1057 patients showed a global mortality of 5% (0.5% if patients were asymptomatic at baseline and 8.3% if patients had baseline AIDS). There was a similar risk of death if the baseline CD4 count was 100 to 200 cells/mm or >200 cells/mm ( approximately 1%), but this increased to 4.8% (relative risk [RR] = 5.2) and 10.7% (RR = 11.5) if the CD4 count was 51 to 100 cells/mm or

Assuntos

Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Acessibilidade aos Serviços de Saúde/organização & administração , Avaliação de Programas e Projetos de Saúde/métodos , Infecções Oportunistas Relacionadas com a AIDS/epidemiologia , Adulto , Fármacos Anti-HIV/efeitos adversos , Chile/epidemiologia , Estudos de Coortes , Quimioterapia Combinada , Feminino , Infecções por HIV/complicações , Infecções por HIV/mortalidade , Humanos , Incidência , Masculino , Programas Nacionais de Saúde/organização & administração , Avaliação de Processos e Resultados em Cuidados de Saúde/métodos , Avaliação de Processos e Resultados em Cuidados de Saúde/organização & administração , Inibidores da Transcriptase Reversa/efeitos adversos , Inibidores da Transcriptase Reversa/uso terapêutico

RESUMO

BACKGROUND: The epidemiology of the hepatitis B virus (HBV) infection in psychiatric patients from developing countries is poorly studied. Therefore, we sought to determine the frequency of HBV surface antigen (HBsAg) and HBV surface antibody (HBsAb) serological markers of HBV infection in a population of patients of a psychiatric hospital in Durango City, Durango, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infection. METHODS: Out of 150 patients of the psychiatric hospital of Durango City, 99 were examined for HBsAg and HBsAb by AUSZYME MONOCLONAL (Abbott Laboratories, Abbott Park, IL, USA) assay and AUSAB (Abbott Laboratories, Abbott Park, IL, USA) assay, respectively. Epidemiological data from each participant was also obtained. For comparison purposes, 2505 blood donors were examined for HBsAg seropositivity. RESULTS: Out of the 99 patients studied, twelve showed serological evidence of HBV infection (12.1%); 7 of them (7.1%) were positive for HBsAg, and 5 (5.1%) were positive for HBsAb. Out of the 2505 blood donors, 2 (0.0008%) were HBsAg positive. Seropositivity to HBV markers was associated with an age of 45 years and older (OR = 4.27; 95%CI = 1.02-18.78). Other characteristics as gender, number of hospitalizations, duration of the last hospitalization, and clinical diagnosis were not associated with seropositivity to HBV infection markers. Patients showed a significantly higher HBsAg seropositivity than blood donors (p < 0.0000001). CONCLUSION: HBV was found to be an important infectious agent in the Mexican psychiatric inpatient population studied. Health care strategies for prevention and control of HBV infection in psychiatric hospitals should pay special attention to patients aged forty-five years and older.