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1.
Philos Trans A Math Phys Eng Sci ; 378(2167): 20190447, 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32008452

RESUMO

Superhydrophobicity is a physical feature of surfaces occurring in many organisms and has been applied (e.g. lotus effect) in bionic technical applications. Some aquatic species are able to maintain persistent air layers under water (Salvinia effect) and thus become increasingly interesting for drag reduction and other 'bioinspired' applications. However, another feature of superhydrophobic surfaces, i.e. the adsorption (not absorption) and subsequent superficial transportation and desorption capability for oil, has been neglected. Intense research is currently being carried out on oil-absorbing bulk materials like sponges, focusing on oleophilic surfaces and meshes to build membranes for oil-water separation. This requires an active pumping of oil-water mixtures onto or through the surface. Here, we present a novel passive, self-driven technology to remove oil from water surfaces. The oil is adsorbed onto a superhydrophobic material (e.g. textiles) and transported on its surface. Vertical and horizontal transportation is possible above or below the oil-contaminated water surface. The transfer in a bioinspired novel bionic oil adsorber is described. The oil is transported into a container and thus removed from the surface. Prototypes have proven to be an efficient and environmentally friendly technology to clean oil spills from water without chemicals or external energy supply. This article is part of the theme issue 'Bioinspired materials and surfaces for green science and technology (part 3)'.


Assuntos
Adsorção , Biodegradação Ambiental , Técnicas de Química Analítica/métodos , Óleos/análise , Água/análise , Araceae , Materiais Biocompatíveis , Brassicaceae , Cistaceae , Cistus , Simulação por Computador , Elastômeros , Desenho de Equipamento , Química Verde , Interações Hidrofóbicas e Hidrofílicas , Poluição por Petróleo , Robótica , Estreptófitas , Propriedades de Superfície , Têxteis , Fatores de Tempo , Viscosidade
3.
Artigo em Alemão | MEDLINE | ID: mdl-23114435

RESUMO

In 2007, the Robert Koch Institute established the infrastructure for the national Antimicrobial Resistance Surveillance (ARS) system. Laboratories submit data of routine susceptibility testing of clinical samples from hospitals as well as from outpatient care settings in a standardized format to the Robert Koch Institute for central processing. The database for the period 2008-2011 comprises data of about 1.3 million samples from patients in hospital care and almost 800,000 samples from outpatients. Based on SIR interpretations of susceptibility, the trends of methicillin resistance of Staphylococcus aureus (MRSA) and cefotaxime non-susceptibility as an indicator of extended-spectrum beta-lactamases (ESBL) of Escherichia coli and Klebsiella pneumoniae were analyzed for four care settings or categories: hospital care, outpatient care, intensive care units, and isolates from blood cultures. After constant high levels of above 20%, the proportion of MRSA isolates showed a decline for the first time from 2010 to 2011 in hospital care overall, in intensive care units as well as in blood cultures; in outpatient care, MRSA proportions of about 13% were observed. Within the observed period, non-susceptibility to cefotaxime as an indicator of ESBL in E. coli showed an increasing trend in hospital care at a level above 10% in intensive care units, while cefotaxime non-susceptibility in K. pneumoniae was more frequent but without any trend. In outpatient care, the proportions of cefotaxime non-susceptibility increased year by year in both species resulting in nearly a doubling to 6%.


Assuntos
Cefotaxima/uso terapêutico , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecção Hospitalar/tratamento farmacológico , Farmacorresistência Bacteriana , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae , Staphylococcus aureus Resistente à Meticilina , Vigilância de Evento Sentinela , Infecções Estafilocócicas/tratamento farmacológico , beta-Lactamases/metabolismo , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Estudos Transversais , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologia , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Alemanha , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Infecções por Klebsiella/epidemiologia , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
4.
Eur J Clin Microbiol Infect Dis ; 31(8): 1855-65, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22210264

RESUMO

Data from the German Antibiotic Resistance Surveillance system (ARS) and statutory notification of methicillin-resistant Staphylococcus aureus (MRSA) in blood cultures are presented. ARS is a voluntary laboratory-based surveillance system providing resistance data of all clinical pathogens and sample types from hospitals and ambulatory care. Statutory notification includes MRSA detected in blood and cerebrospinal fluid by microbiological laboratories. Resistance data from 2008 to 2010 and MRSA-bacteraemia incidences from 2010 are presented. From 2008 to 2010, resistance data from 70,935 Staphylococcus aureus isolates were transferred to the national health institution. MRSA proportions in hospitals and outpatient care account for 19.2% and 10.6%, respectively. In hospital care high proportions of MRSA were found in nephrological, geriatric, neurological general wards and surgical ICUs (49.4%, 45.8%, 34.2%, and 27.0%, respectively), while in community outpatient care urological practices (29.2%) account for the highest values. In both healthcare settings urinary tract samples stand out with high proportions of MRSA (hospitals, 32.9%; outpatients, 20.5%). In 2010, 3900 cases of MRSA bacteraemia were reported, accounting for an incidence of MRSA bacteraemia of 4.8/100,000 inhabitants/year. Stratification by federal states shows considerable regional differences (range, 1.0-8.3/100,000 inhabitants/year). Vulnerable areas in hospitals and outpatient care have been pointed out as subjects for further inquiries.


Assuntos
Bacteriemia/epidemiologia , Meningites Bacterianas/epidemiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Sangue/microbiologia , Líquido Cefalorraquidiano/microbiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Meningites Bacterianas/microbiologia , Pessoa de Meia-Idade , Prevalência , Vigilância de Evento Sentinela , Adulto Jovem
5.
Infection ; 39(4): 289-97, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21717149

RESUMO

PURPOSE: Current efforts to prevent antimicrobial resistance include limiting antimicrobial use, providing education about appropriate use, and developing better point-of-care tests, but what do physicians actually think of rational prescribing and potential interventions? We tried to ascertain which factors can influence a physician's decision to start antimicrobial therapy on a patient, and their opinions on measures to promote rational prescribing. METHODS: We conducted a nationwide, cross-sectional survey of 10,600 physicians from medical registries of all known board-certified physicians in Germany. RESULTS: Among respondents (n = 3,492; 33%; detailed non-response bias analysis included), 90% indicated that they decide to start antimicrobial therapy on a patient at least weekly, and 66% reported that they decide daily. We identified correlates for deciding to start antimicrobial therapy on a patient. Predictors were status as a hospital physician (odds ratio (OR) 1.29 (95% confidence interval (CI) 1.00-1.68)), male physician (OR 1.81 (95% CI 1.42-2.31)), being age 50-59 (OR 1.56 (95% CI 1.10-2.21)), and practising in states in the former East Germany (OR 1.60 (95% CI 1.15-2.21)). Each specialist was significantly less likely to decide to start a course of antimicrobial therapy than ENTs and urologists. Other predictors were agreeing to prescribe to be on the safe side (OR 1.34 (95% CI 1.03-1.76)), believing that the quality of prescribing practice improves after receiving continuing education from pharmaceutical companies (OR 1.43 (95% CI 1.11-1.84)), and having experience with failed therapy for resistant pathogens (OR 2.42 (95% CI 1.83-3.19)). CONCLUSIONS: Physicians in our sample decide to start antimicrobial therapy on a patient, and they value intervention to support prudent use, for example continuing education, practice guidelines and implementation of surveillance measures. Socio-behavioural factors, regional variation, gender, and age merit further research to promote rational antimicrobial prescribing and explore related influencing factors.


Assuntos
Anti-Infecciosos/uso terapêutico , Tomada de Decisões , Médicos/psicologia , Padrões de Prática Médica/estatística & dados numéricos , Adulto , Instituições de Assistência Ambulatorial , Estudos Transversais , Feminino , Alemanha , Pesquisas sobre Atenção à Saúde , Hospitais , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Médicos/classificação , Médicos/estatística & dados numéricos , Inquéritos e Questionários
6.
Artigo em Inglês | MEDLINE | ID: mdl-24786253

RESUMO

The presence of ochratoxin A (OTA) is evaluated using thin layer chromatography (TLC) with a charge-coupled detector (CCD) in 88 red wine samples (2009 vintage) from Brazil. Samples included 75 wines from Rio Grande do Sul, nine from Santa Catarina and four from Paraná state; 56 wines were Cabernet Sauvignon and 32 were Merlot varieties. The method included the analysis of fluorescent images, acquired under UV light, using ImageJ software. Mean recovery of OTA was 82.3% using immunoaffinity columns (IAC). The limits of quantification (LOQ) and detection (LOD) were 0.8 and 0.2 µg l(-1), respectively. Results showed a 5.7% contamination of OTA, with five positive samples--three Cabernet Sauvignon and two Merlot. Santa Catarina and Paraná showed one positive sample each, although the concentrations were below the limit of quantification. The highest concentration found was 0.84 µg l(-1) in one sample from Rio Grande do Sul.


Assuntos
Cromatografia em Camada Fina/métodos , Ocratoxinas/análise , Vinho/análise , Brasil , Cromatografia de Afinidade , Limite de Detecção
7.
Infection ; 38(1): 47-51, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20108161

RESUMO

BACKGROUND: Acinetobacter baumannii can cause severe infections, mainly in critically ill inpatients. Treatment is complicated by multidrug-resistance (MDR). In Germany, to date, little is known on the extent of MDR in A. baumannii isolated from inpatients in German hospitals and potential factors influencing the emergence of MDR. MATERIALS AND METHODS: We retrospectively analysed the data of A. baumannii isolates from the inpatients of four German university hospitals, tested for antimicrobial resistance with the broth dilution method between 2002 and 2006. We defined MDR as resistance to three or more classes of recommended drugs. After calculating the proportions of MDR in A. baumannii isolates, we investigated the association between MDR in A. baumannii and year of pathogen isolation, hospital, ward type, specimen and demographics.We performed descriptive analysis and multivariable logistic regression. Additionally, proportions of in vitro drug effectiveness against multidrug-resistant and non-multidrug resistant A. baumannii isolates were determined. RESULTS: MDR was found in 66 of 1,190 (5.6%)A. baumannii isolates and increased from 2.1% in 2002 to 7.9% in 2006. The highest proportions of MDR were found in hospital A (8.9%), in intensive care units (7.3%), in isolates from blood (7.6%) and in male patients aged 60 years or older (6.6%). In multivariable analysis, the chance of MDR in A. baumannii isolates increased with the successive years of pathogen isolation (odds ratio [OR] 1.3,95% confidence interval [CI] 1.1-1.5) and there was a higher risk of MDR in A. baumannii in intensive care units(OR 1.8, 95% CI 1.1-2.9). The lowest in vitro antibiotic resistance was found in meropenem, imipenem and ampicillin/sulbactam, with 33, 37 and 39% for multidrug-resistant and 0.4, 1 and 3% in non-multidrug-resistant A. baumannii isolates, respectively. CONCLUSIONS: The increase of MDR in A. baumannii isolates from 2002 to 2006 in four hospitals suggests that clinicians in Germany may expect a rising proportion of MDR inA. baumannii isolates among inpatients. The antimicrobial susceptibility testing of A. baumannii isolates against recommended drugs, combined with in-house antimicrobial resistance surveillance, is needed to ensure appropriate treatment.


Assuntos
Infecções por Acinetobacter/epidemiologia , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla , Acinetobacter baumannii/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha/epidemiologia , Hospitais Universitários , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Genetics ; 152(4): 1335-41, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10430564

RESUMO

Methanococcus voltae harbors genetic information for two pairs of homologous [NiFe]-hydrogenases. Two of the enzymes contain selenocysteine, while the other two gene groups encode apparent isoenzymes that carry cysteinyl residues in the homologous positions. The genes coding for the selenium-free enzymes, frc and vhc, are expressed only under selenium limitation. They are transcribed out of a common intergenic region. A series of deletions made in the intergenic region localized a common negative regulatory element for the vhc and frc promoters as well as two activator elements that are specific for each of the two transcription units. Repeated sequences, partially overlapping the frc promoter, were also detected. Mutations in these repeated heptanucleotide sequences led to a weak induction of a reporter gene under the control of the frc promoters in the presence of selenium. This result suggests that the heptamer repeats contribute to the negative regulation of the frc transcription unit.


Assuntos
Proteínas Arqueais/genética , Regulação da Expressão Gênica em Archaea , Genes Arqueais , Genes Reguladores , Hidrogenase/genética , Mathanococcus/genética , Transcrição Gênica , Proteínas Arqueais/biossíntese , Sequência de Bases , Indução Enzimática , Hidrogenase/biossíntese , Dados de Sequência Molecular , Regiões Promotoras Genéticas
9.
Hum Pathol ; 26(1): 47-52, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7821916

RESUMO

Grading of tumor malignancy in breast cancer should contribute essential information both for the prospective outcome of the individual patient as well as for TNM staging. In a series of 104 breast cancer patients we tested the prognostic validity and reproducibility of mitotic figure counting compared with TNM staging, Bloom and Richardson grading, DNA single cell cytometry, and morphometry. Four-micrometer thick hematoxylin-eosin-stained routine slides were investigated. Mitotic figures were counted in representative areas of the tumor in 10 159-microns 2-sized high power fields (HPFs) at a 400X magnification; the median value was seven and the threshold for the 25th percentile was three. This value should replace the common but prognostically invalid threshold of 10. Univariate survival analysis showed that mitotic figure counting allows the identification of three groups of patients (< or = 3, 4 to 20, > 20 mitoses per HPF) with significantly different survival probabilities (P < .0001; P = .0178). Depending on the number of mitotic figures, length of survival was significantly different within the group of T1N0 tumors (P = .0082) and the group of T1N1 or T2N0 tumors (P = .0251). In a Cox stepwise regression model mitotic frequency counting added prognostic information to tumor size and was of higher prognostic significance than lymph node status, DNA ploidy, or mean nuclear area. The 95% confidence limit for interobserver reproducibility, tested in 20 cases, was plus/minus 8 mitoses. After quartilization an agreement of 75% was observed.


Assuntos
Neoplasias da Mama/patologia , Índice Mitótico , Idoso , Neoplasias da Mama/mortalidade , Limiar Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Variações Dependentes do Observador , Prognóstico , Reprodutibilidade dos Testes , Análise de Sobrevida
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