859 research outputs found
Microelectrode study of pore size, ion size, and solvent effects on the charge/discharge behavior of microporous carbons for electrical double-layer capacitors
The capacitive behavior of TiC-derived carbon powders in two different electrolytes, NEt4BF4 in acetonitrile AN and NEt4BF4 in propylene carbonate PC, was studied using the cavity microelectrode CME technique. Comparisons of the cyclic voltammograms recorded at 10–1000 mV/s enabled correlation between adsorbed ion sizes and pore sizes, which is important for understanding the electrochemical capacitive behavior of carbon electrodes for electrical double-layer capacitor applications. The CME technique also allows a fast selection of carbon electrodes with matching pore sizes different sizes are needed for the negative and positive electrodes for the respective electrolyte system. Comparison of electrochemical capacitive behavior of the same salt, NEt4BF4, in different solvents, PC and AN, has shown that different pore sizes are required for different solvents, because only partial desolvation of ions occurs during the double-layer charging. Squeezing partially solvated ions into subnanometer pores, which are close to the desolvated ion size, may lead to distortion of the shape of cyclic voltammograms
Stable Determination of the Electromagnetic Coefficients by Boundary Measurements
The goal of this paper is to prove a stable determination of the coefficients
for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary
measurements
Tumor Necrosis Factor-Alpha Signaling May Contribute to Chronic West Nile Virus Post-Infectious Proinflammatory State
Background: West Nile virus (WNV) causes a spectrum of human disease ranging from a febrile illness (WNV fever) to severe neuroinvasive disease (meningitis, encephalitis, acute flaccid paralysis). Since WNV gained entry into North America in 1999, clinicians caring for WNV survivors have observed persistent neurological symptoms occurring long-after the production of neutralizing antibodies and clearance of the virus. Accordingly, alternative pathogeneses other than direct viral invasion have been hypothesized to explain these post-infectious symptoms. The dominant hypothesis is that antiviral inflammatory responses triggered initially to clear WNV may persist to promote a post-infectious proinflammatory state.
Methods: In 4 serologically-confirmed WNV patients with persistent post-infectious symptoms (3 WNV fever, 1 neuroinvasive disease), we ordered a comprehensive cytokine panel at weeks 8, 10, 12, and 36 months post-onset of illness, respectively, to better understand the pathophysiology of the protracted symptoms.
Results: All patients had abnormally elevated tumor necrosis factor alpha (TNF-α), a major molecule triggering antiviral cytokines and chronic inflammation in many human autoimmune diseases, but heretofore not reported to be upregulated in human WNV infection. Three patients also had elevations of other proinflammatory proteins. Major symptoms included fatigue, arthralgias, myalgias, generalized or multifocal pain or weakness, imbalance, headaches, cognitive problems, and symptoms of dysautonomia.
Conclusion: The findings provide support for an extended post-infectious proinflammatory state that may contribute to chronic inflammation and long-term morbidity in some WNV survivors and further suggest that TNF-α may play a pathogenic role in initiating this inflammatory environment. Clinical trials may be warranted to determine if TNF-α inhibitors or other immunosuppressive agents can improve patient outcomes
Comparison of the substrate-binding pockets of the Rous sarcoma virus and human immunodeficiency virus type 1 proteases
A steady state kinetic analysis of the avian myeloblastosis virus/Rous sarcoma virus (AMV/RSV) and human immunodeficiency virus Type 1 (HIV-1) retroviral proteases (PRs) was carried out using a series of 40 peptide substrates that are derivatives of the AMV/RSV nucleocapsid-PR cleavage site. These peptides contain single amino acid substitutions in each of the seven positions of the minimum length substrate required by the PR for specific and efficient cleavage. These peptide substrates are distinguished by the individual enzyme subsites of the AMV/RSV and HIV-1 PRs. The molecular basis for similarities and differences of the individual subsites for both proteases is discussed using steady state kinetic data and modeling based on crystal structures
Lack of correlation of stem cell markers in breast cancer stem cells
BACKGROUND: Various markers are used to identify the unique sub-population of breast cancer cells with stem cell properties. Whether these markers are expressed in all breast cancers, identify the same population of cells, or equate to therapeutic response is controversial. METHODS: We investigated the expression of multiple cancer stem cell markers in human breast cancer samples and cell lines in vitro and in vivo, comparing across and within samples and relating expression with growth and therapeutic response to doxorubicin, docetaxol and radiotherapy. RESULTS: CD24, CD44, ALDH and SOX2 expression, the ability to form mammospheres and side-population cells are variably present in human cancers and cell lines. Each marker identifies a unique rather than common population of cancer cells. In vivo, cells expressing these markers are not specifically localized to the presumptive stem cell niche at the tumour/stroma interface. Repeated therapy does not consistently enrich cells expressing these markers, although ER-negative cells accumulate. CONCLUSIONS: Commonly employed methods identify different cancer cell sub-populations with no consistent therapeutic implications, rather than a single population of cells. The relationships of breast cancer stem cells to clinical parameters will require identification of specific markers or panels for the individual cancer
Treatment of patients (pts) with chemotherapy-refractory chronic lymphocytic leukemia (CLL) with nonmyeloablative (NM) conditioning and hematopoietic cell transplantation (HCT) from HLA-matched related (MRD) or unrelated donors (URD)
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Maternal psychological distress in primary care and association with child behavioural outcomes at age three
Observational studies indicate children whose mothers have poor mental health are at increased risk of socio-emotional behavioural difficulties, but it is unknown whether these outcomes vary by the mothers’ mental health recognition and treatment status. To examine this question, we analysed linked longitudinal primary care and research data from 1078 women enrolled in the Born in Bradford cohort. A latent class analysis of treatment status and self-reported distress broadly categorised women as (a) not having a common mental disorder (CMD) that persisted through pregnancy and the first 2 years after delivery (N = 756, 70.1 %), (b) treated for CMD (N = 67, 6.2 %), or (c) untreated (N = 255, 23.7 %). Compared to children of mothers without CMD, 3-year-old children with mothers classified as having untreated CMD had higher standardised factor scores on the Strengths and Difficulties Questionnaire (d = 0.32), as did children with mothers classified as having treated CMD (d = 0.27). Results were only slightly attenuated in adjusted analyses. Children of mothers with CMD may be at risk for socio-emotional and behavioural difficulties. The development of effective treatments for CMD needs to be balanced by greater attempts to identify and treat women. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00787-015-0777-2) contains supplementary material, which is available to authorized users
Reliability and Validation of the Child Eating Behavior Questionnaire in 3- to 6-Year-Old Spanish Children
Introduction: Eating behavior is often established during the first years of life. Therefore, it is important to make a research on it to understand the relationships that children have with food and how this can contribute to prevent the development of childhood obesity. An appropriate assessment of eating behavior can be achieved using the “Child Eating Behavior Questionnaire” (CEBQ). This questionnaire has been validated in several populations and languages, but it has never been translated, adapted, and validated for Spanish children. Aim: To evaluate the reliability and internal consistency of the CEBQ questionnaire, culturally adapted and translated into Spanish (Spain), in Spanish families with children aged 3 to 6 years, as well as its association with children’s body mass index (BMI) to test its construct validity. Materials and Methods: Children between 3 and 6 years old were recruited from the ongoing MELI-POP randomized controlled clinical trial, as well as from public schools located in middle class neighborhoods of Zaragoza, Spain, to complete the sample. Sociodemographic characteristics and anthropometric measures were obtained according to standardized methods. The 35-item CEBQ questionnaire was completed twice with a time difference of 3 weeks between each response. Statistical analyses included the evaluation of internal consistency and reliability of the questionnaire, a confirmatory factor analysis, and the association between the different CEBQ scales and the children’s BMI. Results: A total of 197 children completed variables; 97 of them were boys (49.2%) and 100 girls (50.8%). Mean age of the total sample was 4.7 ± 0.9 years. There was a high test-re-test reliability of the questionnaire with values close to 1, with an average of 0.66 and a good internal consistency (Cronbach alpha with values above 0.7), so that a high reliability is established between the items in each scale. A gradual positive association was found between the score of different “pro-intake” scales of the CEBQ: “Food Responsiveness, ” “Emotional Overeating, ” and “Enjoyment of food” and the children’s BMI; at the opposite, negative associations were observed between BMI and the score of anti-intake scales “Satiety Responsiveness, ” “Slowness in Eating, ” and “Emotional Undereating.” Conclusion: The Spanish version of the CEBQ is a useful tool to assess the eating behavior of Spanish children because the high reliability and internal validity. There is a significant association between eating behavior and BMI in Spanish children. Copyright © 2022 Jimeno-MartĂnez, Maneschy, Moreno, Bueno-Lozano, De Miguel-Etayo, Flores-Rojas, Jurado-Castro, de Lamas, Vázquez-Cobela, Martinez-Lacruz, Portoles, MartĂnez, Navas-Carretero, Schröder, FitĂł, Babio, Salas-SalvadĂł, Leis, Gil-Campos and RupĂ©rez
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