Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 24
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38537173

RESUMO

Nanostructured microelectrodes (NMEs) are an attractive alternative to yield sensitive bioassays in unprocessed samples. However, although valuable for different applications, nanoporous NMEs usually cannot boost the sensitivity of diffusion-limited analyses because of the enlarged Debye length within the nanopores, which reduces their accessibility. To circumvent this limitation, nanopore-free gold NMEs were electrodeposited from 45 µm SU-8 apertures, featuring nanoridged microspikes on a recessed surface of gold thin film while carrying interconnected crown-like and spiky structures along the edge of a SU-8 passivation layer. These structures were grown onto ultradense, vertical array chips that offer a promising strategy for translating reproducible, high-resolution, and cost-effective sensors into real-world applications. The NMEs yielded reproducible analyses, while machine learning allowed us to predict the analytical responses from NME electrodeposition data. By taking advantage of the high surface area and accessible structure of the NMEs, these structures provided a sensitivity for [Fe(CN)6]3-/4- that was 5.5× higher than that of bare WEs while also delivering a moderate antibiofouling property in undiluted human plasma. As a proof of concept, these electrodes were applied toward the fast (22 min) and simple determination of Staphylococcus aureus by monitoring the oxidation of [Fe(CN)6]4-, which acted as a cellular respiration rate redox reporter. The sensors also showed a wide dynamic range, spanning 5 orders of magnitude, and a calculated limit of detection of 0.2 CFU mL-1.

2.
Adv Healthc Mater ; 13(11): e2303509, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38245830

RESUMO

Multiplexing is a valuable strategy to boost throughput and improve clinical accuracy. Exploiting the vertical, meshed design of reproducible and low-cost ultra-dense electrochemical chips, the unprecedented single-response multiplexing of typical label-free biosensors is reported. Using a cheap, handheld one-channel workstation and a single redox probe, that is, ferro/ferricyanide, the recognition events taking place on two spatially resolved locations of the same working electrode can be tracked along a single voltammetry scan by collecting the electrochemical signatures of the probe in relation to different quasi-reference electrodes, Au (0 V) and Ag/AgCl ink (+0.2 V). This spatial isolation prevents crosstalk between the redox tags and interferences over functionalization and binding steps, representing an advantage over the existing non-spatially resolved single-response multiplex strategies. As proof of concept, peptide-tethered immunosensors are demonstrated to provide the duplex detection of COVID-19 antibodies, thereby doubling the throughput while achieving 100% accuracy in serum samples. The approach is envisioned to enable broad applications in high-throughput and multi-analyte platforms, as it can be tailored to other biosensing devices and formats.


Assuntos
Técnicas Biossensoriais , COVID-19 , Técnicas Eletroquímicas , SARS-CoV-2 , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , Humanos , SARS-CoV-2/isolamento & purificação , COVID-19/diagnóstico , COVID-19/sangue , Eletrodos , Anticorpos Antivirais/sangue , Ouro/química , Imunoensaio/métodos , Imunoensaio/instrumentação
3.
Anal Bioanal Chem ; 415(18): 3683-3692, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36637495

RESUMO

The so-coined fourth paradigm in science has reached the sensing area, with the use of machine learning (ML) toward data-driven improvements in sensitivity, reproducibility, and accuracy, along with the determination of multiple targets from a single measurement using multi-output regression models. Particularly, the use of supervised ML models trained on large data sets produced by electrical and electrochemical bio/sensors has emerged as an impacting trend in the literature by allowing accurate analyses even in the presence of usual issues such as electrode fouling, poor signal-to-noise ratio, chemical interferences, and matrix effects. In this trend article, apart from an outlook for the coming years, we present examples from the literature that demonstrate how helpful ML algorithms can be for dispensing the adoption of experimental methods to address the aforesaid interfering issues, ultimately contributing to translate testing technologies into on-site, practical, and daily applications.


Assuntos
Algoritmos , Inteligência Artificial , Reprodutibilidade dos Testes , Aprendizado de Máquina , Aprendizado de Máquina Supervisionado
4.
BMJ Qual Saf ; 26(6): 460-465, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27601687

RESUMO

BACKGROUND: The study aimed to identify thresholds for hospital bed utilisation which are independently associated with significantly higher risks for Clostridium difficile infections (CDI) in acute hospitals in England. METHOD: A retrospective analysis was carried out on reported data from the English National Health Service (NHS) for the financial year 2013/2014. Reported rates of CDI were used as a proxy for hospital infection rates in acute NHS hospital trusts. Multivariate linear regression was used to assess the relationship between bed utilisation values and CDI controlling for confounding factors. Hospitals were finally plotted in a Pabon Lasso graph according to their average bed occupancy rate (BOR) and bed turnover rate (BTR) per year to visualise the relationship between bed utilisation and CDI. RESULTS: Among English hospital NHS trusts, increasing BTR and decreasing BOR were associated with a decrease in CDI. However, this effect was not large, and patient mix had a larger impact on CDI rates than bed utilisation. CONCLUSIONS: While policymakers and managers wishing to target healthcare providers with high CDI rates should look at bed utilisation measures, focusing on these alone is unlikely to have the desired impact. Instead, strategies to combat CDI must take a wider perspective on contributory factors at the institutional level.


Assuntos
Ocupação de Leitos/estatística & dados numéricos , Infecções por Clostridium/epidemiologia , Infecção Hospitalar/epidemiologia , Medicina Estatal/estatística & dados numéricos , Inglaterra , Humanos , Modelos Lineares , Admissão e Escalonamento de Pessoal/estatística & dados numéricos , Estudos Retrospectivos
7.
Rev Esp Enferm Dig ; 101(11): 787-99, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20001156

RESUMO

Both the prognosis and potential treatment of chronic liver disease greatly depend on the progression of liver fibrosis, which is the ultimate outcome of chronic liver damage. Historically, liver biopsy has been instrumental in adequately assessing patients with chronic liver disease. Histological assessment allows clinicians both to obtain diagnostic information and initiate adequate therapy. However, the technique is not exempt of deleterious effects. Multiple diagnostic tests have been developed for the staging of fibrosis using noninvasive methods, most of them in the setting of chronic hepatitis C. The goal of this paper is to review available data on the staging and assessment of liver fibrosis with two methods: serum markers and transient elastography (FibroScan).


Assuntos
Técnicas de Imagem por Elasticidade , Cirrose Hepática/sangue , Cirrose Hepática/diagnóstico , Biomarcadores/sangue , Humanos
8.
Rev. esp. enferm. dig ; 101(11): 787-799, nov. 2009. tab, ilus
Artigo em Inglês | IBECS | ID: ibc-75173

RESUMO

Both the prognosis and potential treatment of chronic liver diseasegreatly depend on the progression of liver fibrosis, which isthe ultimate outcome of chronic liver damage. Historically, liverbiopsy has been instrumental in adequately assessing patients withchronic liver disease. Histological assessment allows cliniciansboth to obtain diagnostic information and initiate adequate therapy.However, the technique is not exempt of deleterious effects.Multiple diagnostic tests have been developed for the staging of fibrosisusing noninvasive methods, most of them in the setting ofchronic hepatitis C. The goal of this paper is to review availabledata on the staging and assessment of liver fibrosis with two methods:serum markers and transient elastography (FibroScan®)(AU)


Assuntos
Humanos , Masculino , Feminino , Cirrose Hepática/diagnóstico , Biópsia/métodos , Biópsia/tendências , Biomarcadores/análise , Hipertensão Portal/diagnóstico , Cirrose Hepática , Fibrose/classificação , Valor Preditivo dos Testes
12.
Rev Esp Enferm Dig ; 100(1): 17-23, 2008 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-18358056

RESUMO

OBJECTIVES: To compare subjective tolerance and secondary adverse events to bowel cleansing prior to colonoscopy with polyethylene glycol (PEG) and sodium phosphate (NaP) in adult patients and in those 65 or more years old. MATERIAL AND METHODS: Retrospective matched study, choosing 140 patients among all of those who underwent colonoscopy from March 2004 to May 2005. We investigated the presence of the next adverse events during bowel preparation: Fever, low digestive bleeding, abdominal pain, perianal pain, nausea, vomiting, thirst, somnolence, agitation, tremor and convulsions. We considered bad objective tolerance if the patient presented any one of these events. We also asked patients about subjective tolerance to preparation. RESULTS: Seventy patients prepared with PEG and seventy with NaP were included (69 women and 71 men, mean age 60.6 +/- 14.8 years). There was no relationship between subjective tolerance or the presence of adverse events and bowel cleansing with any of the products in general population or in elderly patients (p = 0.09 and p = 0.45 in the elderly). However, patients prepared with NaP showed more nausea than those who employed PEG (p < 0.009), overall women of 65 or more years old. There were no severe adverse events in patients prepared with NaP. Elderly showed better tolerance than younger patients, and women worst tolerance than men, irrespective of the lavage preparation employed. Patients prepared with PEG unfinished bowel cleansing more frequently than those with NaP. Cleanliness achieved with NaP was significantly better than that obtained with PEG. CONCLUSIONS: Bowel cleansing prior to colonoscopy with NaP is as well tolerated, safe and effective as with PEG, even in elderly healthy patients, although it causes more nausea. Cleanliness with NaP is better than that achieved with PEG.


Assuntos
Colonoscopia , Fosfatos/efeitos adversos , Polietilenoglicóis/efeitos adversos , Cuidados Pré-Operatórios , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente/estatística & dados numéricos , Estudos Retrospectivos
14.
Braz J Psychiatry ; 27(2): 124-30, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15962137

RESUMO

OBJECTIVE: To evaluate internal consistency and temporal stability trough test re-test reliability of the Portuguese version of the Social Phobia and Anxiety Inventory (SPAI) in a heterogeneous Brazilian sample. METHODS: After informed consent, the translated and adapted version of the SPAI Portuguese was tested and re-tested at a 14-day interval in a sample of 225 university students, both genders, from 4 different undergraduate courses. After double data entry, statistical analysis included Cronbach's alphas, Pearson and intra-class correlation coefficients. RESULTS: The studied sample consisted of 213 students from 4 sub-samples: 95 law students, 31 social communication students, 54 civil engineering students and 33 dental medicine students. The mean age was 23 (+/-6) years and 110 (51.6%) were female. The Cronbach' alpha was 0.96, no difference for both genders. The differential (total) score of the SPAI Portuguese showed Pearson coefficient 0.83 (95% CI 0.78-0.87) and Intra-class coefficient 0.83 (95% CI 0.78-0.86). There was no statistical difference in Pearson coefficients between genders (p = 0.121) and the 4 sub-samples (p = 0.258). CONCLUSION: The results do not ensure validity, however, the SPAI Portuguese version presented a good content homogeneity with satisfactory level of internal consistency. The temporal stability evaluated was substantial. The results showed that the Portuguese SPAI presents perfectly acceptable reliability for both genders and suggest that it can be used in Brazilian populations.


Assuntos
Transtornos de Ansiedade/diagnóstico , Transtornos Fóbicos/diagnóstico , Inquéritos e Questionários/normas , Adolescente , Adulto , Análise de Variância , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes , Distribuição por Sexo , Fatores de Tempo , Tradução
15.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 27(2): 124-130, jun. 2005. tab
Artigo em Inglês | LILACS | ID: lil-402423

RESUMO

OBJETIVO: Avaliar consistência interna e estabilidade temporal, através de fidedignidade teste-reteste, da versão em português do Inventário de Ansiedade e Fobia Social (SPAI), em uma amostra brasileira heterogênea. MÉTODOS: Após consentimento informado, a versão traduzida e adaptada para o português do SPAI foi testada e re-testada, com 14 dias de intervalo, em uma amostra de 225 estudantes universitários de ambos os gêneros, de quatro cursos de graduação. Após dupla entrada de dados, a análise estatística incluiu Alfa de Cronbach e os coeficientes de correlação de Pearson e Intra-classe. RESULTADOS: A amostra estudada consistiu de 213 estudantes de quatro sub-amostras: 95 estudantes de Direito, 31 de Comunicação Social, 54 de Engenharia Civil e 33 de Odontologia. A média de idade foi de 23 anos (± 6) e 110 (51,6%) eram do gênero feminino. O Alpha de Cronbach foi de 0,96, sem diferenças entre os gêneros. O escore diferencial (total) do SPAI português apresentou coeficiente de Pearson de 0,83 (IC95% 0,78-0,87) e coeficiente Intra-classe de 0,83 (IC95% 0,78-0,86). Não houve diferença estatística nos coeficientes de Pearson entre os gêneros (p = 0,121) ou entre as quatro sub-amostras (p = 0,258). CONCLUSAO: Os resultados não asseguram validade; a versão do SPAI português apresentou boa homogeneidade de conteúdo com nível satisfatório consistência interna. A estabilidade temporal avaliada foi consistente. Os dados demonstram que o SPAI português apresenta fidedignidade perfeitamente aceitável para ambos os gêneros e sugerem sua utilização na população brasileira.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Transtornos de Ansiedade/diagnóstico , Transtornos Fóbicos/diagnóstico , Inquéritos e Questionários/normas , Análise de Variância , Estudos Transversais , Psicometria , Reprodutibilidade dos Testes , Distribuição por Sexo , Fatores de Tempo , Tradução
16.
Acta méd. (Porto Alegre) ; 26: 553-564, 2005. ilus
Artigo em Português | LILACS | ID: lil-422628

RESUMO

Os autores fazem uma breve revisão bibliográfica sobre alguns dos aspectos mais relevantes do uso de psicofármacos em populações com características particulares. Fazem algumas considerações quanto ao manejo de condições psiquiátricas mais prevalentes em gestantes, idosos, crianças e adolescentes


Assuntos
Gravidez , Criança , Adolescente , Adulto , Idoso , Masculino , Feminino , Humanos , Adolescente , Idoso , Criança , Gestantes , Psicotrópicos/efeitos adversos , Psicotrópicos/farmacologia , Transtornos Mentais/epidemiologia , Antidepressivos , Antipsicóticos/efeitos adversos , Antipsicóticos/farmacologia , Depressão
19.
Braz J Psychiatry ; 25 Suppl 1: 55-61, 2003 Jun.
Artigo em Português | MEDLINE | ID: mdl-14523513

RESUMO

Bipolar disorder (BD) is not only an endogenous condition. Severe negative life events have been shown to influence the development of the first episode and lifetime course of BD. Posttraumatic stress disorder (PTSD) is a severe and incapacitating mental condition that affect a significant proportion of the general population at some time in their lives. The concomitant presence of BD and PTSD has been shown to be more frequent than previously suggested and psychotic patients with trauma histories have a tendency to present more severe symptoms and are more proned to present substance use disorders. Trauma-related intrusive memories and nightmares of PTSD have been associated with mood changes. Also, kindling and behavioral sensitization have been proposed to explain the etiology and course of both disorders. Pharmacological approaches for this comorbidity are still based on empirical or not controlled approaches. In this article, we critically review the current literature regarding this co morbid condition, and highlight some aspects related to epidemiology, etiology, course and pharmacological treatment of both disorders. Overall, our review emphasizes the importance of systematically evaluate trauma histories in patients with BD.


Assuntos
Transtorno Bipolar/complicações , Transtornos de Estresse Pós-Traumáticos/complicações , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/fisiopatologia , Humanos , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia
20.
Braz. J. Psychiatry (São Paulo, 1999, Impr.) ; 25(supl.1): 55-61, jun. 2003. tab
Artigo em Português | LILACS | ID: lil-341323

RESUMO

O Transtorno Bipolar (THB) näo é somente uma condiçäo endógena. Severos eventos negativos durante a vida influenciam o desenvolvimento do primeiro episódio e alteram o curso do THB durante a vida. O Transtorno de Estresse Pós-Traumático (TEPT) é uma severa e incapacitante doença mental que afeta uma significativa parcela da populaçäo, em algum momento de suas vidas. A presença concomitante de TEPT e THB parece mais freqüente que anteriormente sugerido, e pacientes psicóticos com história de trauma tem sintomas mais severos e maior tendência a abusar de substância psicoativas ilícitas. Pensamentos intrusivos e pesadelos ocorrem com freqüência nos pacientes com TEPT e têm sido associados aos transtornos de humor. O tratamento farmacológico dessa comorbidade ainda está relacionado a estudo empíricos ou näo-controlados. Neste artigo, säo revisados aspectos atuais relacionados a essa comorbidade e enfatizados aspectos referentes à epidemiologia, etiologia, curso e tratamento farmacológico da comorbidade entre TEPT e THB. Especialmente, este estudo enfatiza a importância de avaliar sistematicamente a história de trauma em pacientes com THB


Assuntos
Humanos , Transtorno Bipolar/complicações , Transtornos de Estresse Pós-Traumáticos/complicações , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...