Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Heliyon ; 10(2): e24704, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38312692

RESUMO

High-performance fibre-reinforced concrete (HPFRC), a type of cementitious composite material known for its exceptional mechanical performance, has widespread applications in structures exposed to severe dynamic loading conditions. However, understanding nonlinear HPFRC fracture behaviour, particularly under high strain rates, remains challenging given the complexities of assessment procedures and cost-intensive nature of experiments. This study presents an interpretable framework for modelling and analysing HPFRC fracture strength at high strain rates. A wide range of machine learning methods, including ensemble techniques, were employed to capture multivariate effects of eight essential input features (e.g., mortar compressive strength, fibre physical and mechanical properties, cross-sectional area, and strain rate) on fracture strength response. To assess the derived models, a novel evaluation procedure was proposed involving a data-based analysis, employing established metrics (i.e., coefficient of determination, root mean squared error, and mean absolute error via K-fold cross-validation) and a domain experts-involved evaluation utilising global sensitivity analysis to discern first-order and higher-order interactions among input factors. The proposed approach efficiently yielded both quantitative and qualitative insights into crucial input factors governing HPFRC fracture strength with limited experimental data. The obtained findings highlight the significance of multivariate effects, such as the interaction between strain rate and fibre tensile strength, and between fibre volume and fibre diameter, on fracture behaviour. The proposed interpretable framework aims to provide a powerful tool for proactive material failure analysis by understanding fracture behaviour and identifying potential weak and strong interactions among input factors of HPFRC-based samples. Moreover, the utilisation of the proposed approach enables researchers and civil engineers to efficiently focus on the most critical input parameters during the early design stage and ensuring the structural integrity and safety of HPFRC-based constructions.

2.
Int J Cardiol Cardiovasc Risk Prev ; 19: 200222, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37920809

RESUMO

Background: CYP2C19 gene polymorphism combination with inflammatory cell ratios was significant in the prognosis of coronary heart disease. Materials and methods: A cross-sectional analysis study, with 6 months follow-up on 142 patients with acute coronary syndrome. Patients were analyzed for CYP2C19 gene polymorphisms by real-time polymerase chain reaction (PCR) and complete blood count to determine inflammatory cell ratios and recorded cardiovascular events (CEs) after following up to 6 months. Results: For 90-day CEs, CYP2C19 gene polymorphism (Hazard Ratio (HR): 1.965, 95 % Confidence Interval (CI): 1.012-3.814), the combination of a neutrophil and lymphocyte ratio (NLR) ≥ 2.982 (HR: 13.001, 95 % CI: 1.37-97.304) or a platelet to lymphocyte ratio (PLR) ≥ 162.42 (HR: 2.878, 95 % CI: 1.212-6.835) was independent predictors of CEs. For 180-day CEs, CYP2C19 gene polymorphism combination with NLR ≥3.02 (HR: 13.946, 95 % CI: 1.833-106.121) or PLR ≥160.38 (HR: 5.349, 95 % CI: 1.379-20.745) or monocyte to lymphocyte ratio (MLR) ≥ 0.3 (HR: 4.699, 95 % CI: 1.032-31.393) were independent predictors of CEs. Conclusion: NLR, PLR or MLR combined with CYP2C19 gene polymorphism were stronger independent predictors of cardiovascular events in patients with acute coronary syndromes compared to CYP2C19 gene polymorphism and inflammatory cell ratios separately. CYP2C19 polymorphism and high NLR was the strongest predictor of both CEs at 90 days and 180 days.

3.
Allergy Asthma Proc ; 44(2): 130-135, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36872442

RESUMO

Background: Pneumonia is the most common reason for pediatric hospitalizations. The impact of penicillin allergy labels among children with pneumonia has not been well studied. Objective: This study assessed the prevalence and impact of penicillin allergy labels among children admitted with pneumonia over a 3-year period at a large academic children's center. Methods: Inpatient charts of pneumonia admissions with a documented allergy to a type of penicillin from January to March in 2017, 2018, and 2019 were reviewed and compared with pneumonia admissions without the label over the same time with regard to days of antimicrobial treatment, route of antimicrobial therapy, and days of hospitalization. Results: There were 470 admissions for pneumonia during this time period, of which 48 patients (10.2%) carried a penicillin allergy label. Hives and/or swelling comprised 20.8% of the allergy labels. Other labels included nonpruritic rashes, gastrointestinal GI symptoms, unknown/undocumented reactions, or other reasons. There were no significant differences between those with a penicillin allergy label to those without regarding days of antimicrobial treatment (inpatient and outpatient), route of antimicrobial therapy, and days of hospitalization. Those with a penicillin allergy label were less likely to be prescribed a penicillin product (p < 0.002). Of the 48 patients who were allergy labeled, 23% (11/48) were given a penicillin medication without adverse reaction. Conclusion: Ten percent of pediatric admissions for pneumonia had a label of penicillin allergy, similar to the overall population. The hospital course and clinical outcome were not significantly affected by the penicillin allergy label. The majority of documented reactions were of low risk for immediate allergic reactions.


Assuntos
Hipersensibilidade Imediata , Pneumonia , Urticária , Humanos , Criança , Hospitalização , Penicilinas
4.
Medicine (Baltimore) ; 102(7): e32978, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36800606

RESUMO

This study aimed to investigate the correlation between beta-2 microglobulin (B2M) concentration and some nerve conduction indices and evaluate the changes in some nerve conduction indices after treatment with hemodialysis (HD) combined with hemodiafiltration online in end-stage renal disease patients. From July 2021 to July 2022, a cross-sectional study was conducted on 80 end-stage renal disease patients on HD at Can Tho General Hospital, Viet Nam. All the patients had B2M testing and nerve conduction measurements. Patients with nerve conduction disorders were treated and remeasured after 6 months to evaluate the treatment results. At baseline, there was a moderate negative correlation between B2M and the tibial nerve and motor branch of the ulnar conduction velocity (V) (r = -0.305 and -0.315, P < .05). There was a moderate positive correlation between B2M and motor latency of the tibial and peroneal nerve (r = 0.434 and 0.440, P < .05). After 6 months of using the combination of HD and hemodiafiltration online, the V (31.3 ± 7.96 up to 44.88 ± 9.67 m/s) and the amplitude (A) (1.71 ± 1.16 up to 2.61 ± 1.51 mV) of the peroneal nerve increased, the motor latency decreased (8.21 ± 2.65 down to 5.23 ± 3.58 ms). With the tibial nerve, motor conduction V increased from 30.53 ± 8.05 m/s to 43.56 ± 8.99 m/s and the A increased from 5.04 ± 3.16 mV to 7.75 ± 4.45 mV. With the ulnar nerve, the A increased, and motor latency decreased after 6 months. The nerve conduction indices also improved significantly in the median nerve.


Assuntos
Hemodiafiltração , Falência Renal Crônica , Humanos , Estudos Transversais , Diálise Renal , Condução Nervosa/fisiologia , Falência Renal Crônica/terapia , Nervo Ulnar , Nervo Mediano
5.
Int J STD AIDS ; 33(14): 1183-1192, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36220789

RESUMO

BACKGROUND: Tenofovir-Emtricitabine (TDF-FTC) is known to cause bone loss in about 1-3% of HIV treated patients. Current studies lack evidence in minority groups and long-term bone loss effects in PrEP patients. SETTING: To address the risk of osteopenia/osteoporosis in patients on TDF-FTC therapy for HIV PrEP and to address the breakthrough incidence of HIV. METHODS: A retrospective analysis was performed in Kaiser Permanente patients from 2012-2021. Patients on TDF-FTC for PrEP without any prior history of osteopenia/osteoporosis (N = 7698) were analyzed to determine the relationship between PrEP adherence and osteopenia/osteoporosis. Descriptive statistics and Cox proportional hazards model were used to compare and analyze patient characteristics between those who developed osteopenia/osteoporosis and those who didn't. RESULTS: 3% were found to have osteopenia/osteoporosis. Patients who developed osteopenia/osteoporosis were more likely to have a proportion of days covered (PDC) ratio ≥90%, older, had history of Hep B, DM, CVD, CKD, hypertension, and baseline eGFR ≥90 mL/min/1.73 m2. Kaplan-Meier curve showed the event-free rate of osteopenia/osteoporosis decreased with time, with a greater reduction in patients with high adherence. Survival analysis showed only PDC of ≥90% was significantly associated with the risk of osteopenia/osteoporosis when adjusted. No incidence of HIV infection was detected. CONCLUSIONS: This retrospective cohort analysis showed that TDF-FTC offered superior PrEP protection. Although high PrEP adherence ensured protection from HIV infection, it was significantly associated with a higher risk of developing osteopenia/osteoporosis. These findings suggest that routine check-ups for osteopenia/osteoporosis may be needed.


Assuntos
Fármacos Anti-HIV , Doenças Ósseas Metabólicas , Infecções por HIV , Osteoporose , Humanos , Emtricitabina/efeitos adversos , Tenofovir/efeitos adversos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Fármacos Anti-HIV/efeitos adversos , Estudos Retrospectivos , Doenças Ósseas Metabólicas/induzido quimicamente , Doenças Ósseas Metabólicas/epidemiologia , Doenças Ósseas Metabólicas/tratamento farmacológico , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico
6.
Retin Cases Brief Rep ; 15(1): 5-9, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29470301

RESUMO

PURPOSE: To report a case of ABCA4-related retinopathy and potential complications. METHODS: The authors describe a case report of intraretinal neovascularization in a patient with ABCA4-related retinopathy and describe the multimodal retinal imaging findings. RESULTS: A 49-year-old woman presents with cystoid macular edema and diffuse intraretinal and perivascular hyperpigmentation in both eyes. Genetic testing confirmed ABCA4-related retinopathy. Fluorescein angiography revealed peripapillary intraretinal neovascularization in the absence of any other identifiable retinal pathology. CONCLUSION: To the authors' knowledge, this is the first reported case of intraretinal neovascularization-associated ABCA4-related retinopathy. Ancillary testing of ABCA4-related retinopathy with fluorescein angiography or optical coherence tomography angiography may be helpful in identifying this rare complication.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Imagem Multimodal , Doenças Retinianas/complicações , Neovascularização Retiniana/diagnóstico , Acuidade Visual , Feminino , Angiofluoresceinografia/métodos , Fundo de Olho , Humanos , Pessoa de Meia-Idade , Gravidez , Doenças Retinianas/diagnóstico , Doenças Retinianas/metabolismo , Neovascularização Retiniana/etiologia , Neovascularização Retiniana/metabolismo , Tomografia de Coerência Óptica/métodos
7.
Materials (Basel) ; 13(16)2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32824557

RESUMO

This article considers semi-flexible composite (SFC) pavement materials made with reclaimed asphalt planings (RAP) and geopolymer cement-based grouts. Geopolymer grouts were developed and used to fill the internal void structure of coarse RAP skeletons with varying levels of porosity. The geopolymer grouts were formulated at ambient temperature using industrial by-products to offer economic and environmental savings relative to conventional Portland cement-based grouting systems. They were characterised on flowability, setting time, and compressive strength. The effect of grout and RAP on SFC material performance was evaluated using permeable porosity, compressive strength, and ultrasonic pulse velocity. SFC performance was significantly influenced by both grout type and RAP content. Improved performance was associated with mixtures of high-flowability/high-strength grout and low RAP content. A practical limitation was identified for combination of grout with low-flowability/fast-setting time and well-compacted RAP skeletons. Solids content exceeding 49% by volume was not feasible, owing to inadequate grout penetration. A suite of SFC materials was produced offering performance levels for a range of practical pavement applications. Preliminary relationships enabling prediction of SFC elastic modulus based on strength and/or ultrasonic pulse velocity test data are given. A pavement design is given using SFC as a sub-base layer for an industrial hardstanding.

8.
Int J Cosmet Sci ; 42(2): 146-155, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31880361

RESUMO

OBJECTIVE: Waxes are used as structuring agents in lipsticks. There are a variety of waxes combined in a single lipstick to provide good stability, pleasant texture and good pay-off. Due to a significant growth for natural, green and sustainable products, there is a constant search for alternatives to animal-derived and petroleum-derived ingredients. In this study, a green, non-animalderived wax, namely long-chain ketones (referred to as alkenones), sourced from marine microalgae was formulated into lipsticks and evaluated as a structuring agent. METHODS: Alkenones were used as a substitute for microcrystalline wax, ozokerite and candelilla wax, typical structuring agents. In total, 384 lipsticks were formulated: L1 (control, no alkenones), L2 (alkenones as a substitute for ozokerite), L3 (alkenones as a substitute for microcrystalline wax) and L4 (alkenones as a substitute for candelilla wax). Products were tested for hardness (bending force), stiffness, firmness (needle penetration), pay-off (using a texture analyser and a consumer panel), friction, melting point and stability for 12 weeks at 25 and 45°C. RESULTS: Alkenones influenced each characteristic evaluated. In general, lipsticks with alkenones (L2-L4) became softer and easier to bend compared to the control (L1). In terms of firmness, lipsticks were similar to the control, except for L4, which was significantly (P < 0.05) firmer. The effect on pay-off was not consistent. L2 and L3 had higher pay-off to skin and fabric than L1. In addition, L4 had the lowest amount transferred, but it still had the highest colour intensity on skin. Alkenones influenced friction (glide) positively; the average friction decreased for L2-L4. The lowest friction (i.e. best glide) was shown in L4. Melting point of the lipsticks was lower when alkenones were present. Overall, L4, containing 7% of 4 alkenones in combination with microcrystalline wax, ozokerite and carnauba wax, was found to have the most desirable attributes, including ease of bending, high level of firmness, low pay-off in terms of amount, high colour intensity on skin and low friction (i.e. better glide). Consumers preferred L4 the most overall. CONCLUSION: Results of this study indicate that alkenones offer a sustainable, non-animal and non-petroleum-derived choice as a structuring agent for lipsticks.


OBJECTIF: Les cires sont utilisées comme agents de structuration dans les rouges à lèvres. Un rouge à lèvres contient plusieurs cires, afin d'obtenir une bonne stabilité, une texture agréable et un bon transfert de matière. En raison d'une croissance significative de la demande en produits naturels, écologiques et durables, les chercheurs s'efforcent constamment de trouver des alternatives aux ingrédients d'origine animale et dérivés du pétrole. Dans cette étude, les cétones à longue chaîne (appelés alkénones), une cire verte qui n'est pas d'origine animale, mais provenant de microalgues marines, a été formulée pour les rouges à lèvres et évaluée comme agent de structuration. MÉTHODES: Les alkénones ont été utilisés comme substitut pour la cire microcristalline, l'ozokérite et la cire de candelilla, des agents de structuration courants. Au total, 384 rouges à lèvres ont été formulés : L1 (contrôle, sans alkénone), L2 (alkénones comme substitut de l'ozokérite), L3 (alkénones comme substitut de la cire microcristalline) et L4 (alkénones comme substitut de la cire de candelilla). Des tests ont été réalisés sur les produits pour évaluer la dureté (force de flexion), la rigidité, la fermeté (pénétration de l'aiguille), le transfert de matière (à l'aide d'un analyseur de texture et d'un panel de consommateurs), la friction, le point de fusion et la stabilité pendant 12 semaines à 25 et 45 °C. RÉSULTATS: Les alkénones ont eu une influence sur chacune des caractéristiques évaluées. En général, les rouges à lèvres contenant des alkénones (L2 à L4) sont devenus plus mous et ont présenté une flexion plus facile que dans le cas du contrôle (L1). En termes de fermeté, les rouges à lèvres étaient similaires au contrôle, à l'exception de L4, qui était significativement (P < 0,05) plus ferme. L'effet sur le transfert de matière a été variable. L2 et L3 ont présenté un transfert de matière sur la peau et le tissu supérieur à celui de L1. En outre, dans le cas de L4, la quantité transférée était la plus faible, mais l'intensité de la couleur sur la peau était toujours la plus élevée. Les alkénones ont eu un effet positif sur la friction (glissement) ; la friction moyenne a diminué pour L2 à L4. La friction la plus basse (c.-à-d. le meilleur glissement) a été observée dans le cas de L4. Le point de fusion des rouges à lèvres était plus bas lorsque des alkénones étaient présents. Dans l'ensemble, L4, contenant 7 % d'alkénones en combinaison avec de la cire microcristalline, de l'ozokérite et de la cire de carnauba, s'est révélée avoir les caractéristiques les plus souhaitables, notamment une facilité de flexion, une fermeté élevée, un faible transfert de matière en termes de quantité, une intensité de couleur élevée sur la peau et une faible friction (c.-à-d. un meilleur glissement). En général, les consommateurs ont préféré L4. CONCLUSION: Les résultats de cette étude indiquent que les alkénones offrent un choix durable, non issu de l'animal et non dérivé du pétrole comme agent de structuration pour les rouges à lèvres.


Assuntos
Alcenos/química , Cosméticos/química , Plantas/química , Ceras/química
9.
Int J Pharm ; 569: 118549, 2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31394188

RESUMO

Trial-and-error approach to formulation development is long and costly. With growing time and cost pressures in the pharmaceutical industry, the need for computer-based formulation design is greater than ever. In this project, emulgels were designed and optimized using Formulating for Efficacy™ (FFE) for the topical delivery of ibuprofen. FFE helped select penetration enhancers, design and optimize emulgels and simulate skin penetration studies. pH, viscosity, spreadability, droplet size and stability of emulgels were evaluated. Franz cell studies were performed to test in vitro drug release on regenerated cellulose membrane, drug permeation in vitro on Strat-M® membrane and ex vivo on porcine ear skin, a marketed ibuprofen gel served as control. Emulgels had skin compatible pH, viscosity and spreadability comparable to a marketed emulgel, were opaque and stable at 25 °C for 6 months. Oleyl alcohol (OA), combined with either dimethyl isosorbide (DMI) or diethylene glycol monoethyl ether (DGME) provided the highest permeation in 24 h in vitro, which was significantly higher than the marketed product (p < 0.01). OA + DGME significantly outperformed OA ex vivo (p < 0.05). The computer predictions, in vitro and ex vivo penetration results correlated well. FFE was a fast, valuable and reliable tool for aiding in topical product design for ibuprofen.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Ibuprofeno/administração & dosagem , Ibuprofeno/química , Absorção Cutânea , Animais , Química Farmacêutica , Simulação por Computador , Composição de Medicamentos , Etilenoglicóis/administração & dosagem , Etilenoglicóis/química , Álcoois Graxos/administração & dosagem , Álcoois Graxos/química , Técnicas In Vitro , Isossorbida/administração & dosagem , Isossorbida/análogos & derivados , Isossorbida/química , Pele/metabolismo , Solubilidade , Suínos
10.
Free Radic Biol Med ; 89: 248-62, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26409224

RESUMO

Intracellular free heme predisposes to oxidant-mediated tissue damage. We hypothesized that free heme causes alterations in myocardial contractility via disturbed structure and/or regulation of the contractile proteins. Isometric force production and its Ca(2+)-sensitivity (pCa50) were monitored in permeabilized human ventricular cardiomyocytes. Heme exposure altered cardiomyocyte morphology and evoked robust decreases in Ca(2+)-activated maximal active force (Fo) while increasing Ca(2+)-independent passive force (F passive). Heme treatments, either alone or in combination with H2O2, did not affect pCa50. The increase in F passive started at 3 µM heme exposure and could be partially reversed by the antioxidant dithiothreitol. Protein sulfhydryl (SH) groups of thick myofilament content decreased and sulfenic acid formation increased after treatment with heme. Partial restoration in the SH group content was observed in a protein running at 140 kDa after treatment with dithiothreitol, but not in other proteins, such as filamin C, myosin heavy chain, cardiac myosin binding protein C, and α-actinin. Importantly, binding of heme to hemopexin or alpha-1-microglobulin prevented its effects on cardiomyocyte contractility, suggesting an allosteric effect. In line with this, free heme directly bound to myosin light chain 1 in human cardiomyocytes. Our observations suggest that free heme modifies cardiac contractile proteins via posttranslational protein modifications and via binding to myosin light chain 1, leading to severe contractile dysfunction. This may contribute to systolic and diastolic cardiac dysfunctions in hemolytic diseases, heart failure, and myocardial ischemia-reperfusion injury.


Assuntos
Ventrículos do Coração/patologia , Heme/farmacologia , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/patologia , Quinase de Cadeia Leve de Miosina/metabolismo , Citoesqueleto de Actina , Actinina/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Transporte/metabolismo , Células Cultivadas , Filaminas/metabolismo , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/metabolismo , Humanos , Immunoblotting , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Oxidantes/farmacologia , Processamento de Proteína Pós-Traducional , Proteínas de Protozoários/metabolismo
11.
J Nutr Educ Behav ; 36(6): 305-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15617612

RESUMO

OBJECTIVE: To assess the accuracy of parents as reporters of both their own and their 2- to 5-year-old children's fruit and vegetable intake. DESIGN: Observational study with a 1-meal intake assessment by an independent observer, followed by a telephone survey to determine the previous day's consumption using a 29-item fruit, juice, and vegetable food frequency questionnaire. SETTING: Two separate meal assessments in community-based settings. PARTICIPANTS: A convenience sample of 61 parent-child dyads from Eastern Missouri was recruited from a school health fair and the Parents as Teachers program. The mean age of the parents was 31.1 years, and 91% were female. The mean age for children was 39.0 months, and 60% were female. VARIABLES MEASURED: Parent and child fruit and vegetable intake. ANALYSIS: Interobserver agreement using a kappa statistic. RESULTS: Parents accurately reported their children's intake on most fruits and vegetables (kappa=0.59-0.61). Parents were the least accurate in recalling the consumption of raisins from oatmeal cookies (kappa=0.05) and 100% juice (kappa=0.17). CONCLUSIONS AND IMPLICATIONS: Parents can serve as accurate proxies to report fruit and vegetable consumption by their preschoolers on a food frequency questionnaire used to determine intake for the previous day. This can be a helpful evaluation method for research involving young children.


Assuntos
Dieta , Comportamento Alimentar/psicologia , Frutas , Pais/psicologia , Verduras , Adulto , Pré-Escolar , Inquéritos sobre Dietas , Ingestão de Alimentos/fisiologia , Ingestão de Alimentos/psicologia , Comportamento Alimentar/fisiologia , Feminino , Humanos , Masculino , Variações Dependentes do Observador , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...