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1.
J Virol ; 97(9): e0076723, 2023 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-37671863

RESUMEN

Maternal-to-fetal transmission of respiratory syncytial virus (RSV) has been shown to occur but whether late prenatal exposure to RSV season influences offspring postnatal RSV-lower respiratory illness (LRI) risk in early life or RSV immune status at birth is unclear. In this study, the duration of third trimester RSV season exposure was determined for 1,094 newborns of the Tucson Children's Respiratory Study (TCRS) and found to show an inverse relation to risk for first RSV-LRI in the first year. Cord blood anti-RSV antibody is related to third trimester RSV season exposure but not to first year RSV-LRI risk. In a separate birth cohort (the Infant Immune Study), supernatants from cord blood mononuclear cells stimulated with the recall antigen, UV-inactivated RSV, were assayed for IFN-γ and IL-4. The frequency of detectable IFN-γ (but not IL-4) was increased for those with at least 2 mo of third trimester RSV season exposure, suggestive of a fetal immune response to RSV. IMPORTANCE Our study found that duration of third trimester exposure to RSV season related inversely to subsequent risk of postnatal RSV-LRI in the first year, thus implicating this exposure as an important factor in reducing risk of postnatal RSV-LRIs, a risk reduction that appears to be independent of maternally transferred anti-RSV antibody level. The increase in frequency of detectable IFN-γ and not IL-4 in response to UV-inactivated RSV in cord blood immune cells for infants with greater third trimester exposure to RSV season is suggestive of a Type-1 immune response to RSV occurring in utero.


Asunto(s)
Efectos Tardíos de la Exposición Prenatal , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Femenino , Humanos , Recién Nacido , Embarazo , Inmunidad , Infecciones por Virus Sincitial Respiratorio/inmunología , Interleucina-4/sangre , Interferón gamma/sangre , Tercer Trimestre del Embarazo
2.
J Fluoresc ; 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39271600

RESUMEN

The recent discovery of a new class of nanomaterials called nanozymes, which have the action of enzymes and are thus of tremendous significance, has altered our understanding of these previously believed to be biologically inert nanomaterials. As a significant and exciting class of synthetic enzymes, nanozymes have distinct advantages over natural enzymes. They are less expensive, more stable, and easier to work with and store, making them a viable substitute. This practical advantage of nanozymes over natural enzymes reassures us about the potential of this new technology. Peroxidase-like nanozymes have been investigated for the purpose of creating adaptable biosensors via the use of molecularly imprinted polymers (MIPs) or particular bio recognition ligands, including enzymes, antibodies, and aptamers. This review delves into the distinctions between synthetic and natural enzymes, explaining their structures and analytical applications. It primarily focuses on carbon-based nanozymes, particularly those that contain both carbon and hydrogen, as well as metal-based nanozymes like Fe, Cu, and Au, along with their metal oxide (FeO, CuO), which have applications in many fields today. Analytical chemistry finds great use for nanozymes for sensing and other applications, particularly in comparison with other classical methods in terms of selectivity and sensitivity. Nanozymes, with their unique catalytic capabilities, have emerged as a crucial tool in the early diagnosis of COVID-19. Their application in nanozyme-based sensing and detection, particularly through colorimetric and fluorometric methods, has significantly advanced our ability to detect the virus at an early stage.

3.
J Allergy Clin Immunol ; 151(4): 809-817, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36528110

RESUMEN

The Precision Interventions for Severe and/or Exacerbation-Prone Asthma clinical trials network is actively assessing novel treatments for severe asthma during the coronavirus disease (COVID-19) pandemic and has needed to adapt to various clinical dilemmas posed by the COVID-19 pandemic. Pharmacologic interactions between established asthma therapies and novel drug interventions for COVID-19 infection, including antivirals, biologics, and vaccines, have emerged as a critical and unanticipated issue in the clinical care of asthma. In particular, impaired metabolism of some long-acting beta-2 agonists by the cytochrome P4503A4 enzyme in the setting of antiviral treatment using ritonavir-boosted nirmatrelvir (NVM/r, brand name Paxlovid) may increase risk for adverse cardiovascular events. Although available data have documented the potential for such interactions, these issues are largely unappreciated by clinicians who treat asthma, or those dispensing COVID-19 interventions in patients who happen to have asthma. Because these drug-drug interactions have not previously been relevant to patient care, clinicians have had no guidance on management strategies to reduce potentially serious interactions between treatments for asthma and COVID-19. The Precision Interventions for Severe and/or Exacerbation-Prone Asthma network considered the available literature and product information, and herein share our considerations and plans for treating asthma within the context of these novel COVID-19-related therapies.


Asunto(s)
Asma , COVID-19 , Humanos , Pandemias , Asma/tratamiento farmacológico , Quimioterapia Combinada
4.
Geriatr Nurs ; 55: 270-276, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38096658

RESUMEN

Poor self-management in patients with diabetes is a consistent issue, leading to diabetes complications. The purpose of this study was to examine the relationships of demographic, cognitive, psychological, social, and physiological factors to self-management in patients with diabetes. In this cross-sectional, correlational study, data were collected from 98 patients through REDCap in 2023. Multiple regression analysis was used to address the study purpose. In the sample, adherence to adequate self-management was poor. Knowledge, self-efficacy, and body mass index (BMI) were associated with overall diabetes self-management. Self-efficacy and BMI were associated with diet and exercise. Knowledge and self-efficacy were associated with blood glucose testing. No factors were associated with smoking and foot care. In conclusion, different factors were associated with different types of self-management, but BMI and self-efficacy were associated with most types of self-management. Clinicians and researchers can target BMI, self-efficacy, and knowledge to improve self-management in patients with diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Automanejo , Humanos , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/psicología , Estudios Transversales , Conductas Relacionadas con la Salud , Ejercicio Físico/psicología , Autocuidado/métodos , Autoeficacia
5.
Environ Sci Technol ; 57(2): 896-908, 2023 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-36603843

RESUMEN

The hydroxyl radical (OH) is the dominant oxidant in the outdoor environment, controlling the lifetimes of volatile organic compounds (VOCs) and contributing to the growth of secondary organic aerosols. Despite its importance outdoors, there have been relatively few measurements of the OH radical in indoor environments. During the House Observations of Microbial and Environmental Chemistry (HOMEChem) campaign, elevated concentrations of OH were observed near a window during cooking events, in addition to elevated mixing ratios of nitrous acid (HONO), VOCs, and nitrogen oxides (NOX). Particularly high concentrations were measured during the preparation of a traditional American Thanksgiving dinner, which required the use of a gas stove and oven almost continually for 6 h. A zero-dimensional chemical model underpredicted the measured OH concentrations even during periods when direct sunlight illuminated the area near the window, which increases the rate of OH production by photolysis of HONO. Interferences with measurements of nitrogen dioxide (NO2) and ozone (O3) suggest that unmeasured photolytic VOCs were emitted during cooking events. The addition of a VOC that photolyzes to produce peroxy radicals (RO2), similar to pyruvic acid, into the model results in better agreement with the OH measurements. These results highlight our incomplete understanding of the nature of oxidation in indoor environments.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Ozono , Radical Hidroxilo/análisis , Radical Hidroxilo/química , Fotólisis , Contaminación del Aire Interior/análisis , Óxidos de Nitrógeno/análisis , Ozono/análisis , Culinaria , Ácido Nitroso/análisis , Ácido Nitroso/química , Contaminantes Atmosféricos/análisis
6.
J Cardiovasc Nurs ; 38(6): 581-592, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37816085

RESUMEN

BACKGROUND: Diabetes complications are prevalent and cause adverse effects on the physical, psychological, and economic status of adult patients with type 2 diabetes. Meditation may positively affect self-management and, in turn, reduce diabetes complications. However, the systematic examination of the effects of meditation without additional components on self-management in this population have been rarely examined. PURPOSE: The aim of this study was to examine the effects of meditation interventions on self-management (ie, control of glucose, blood pressure, cholesterol, and obesity and self-management) among adult patients with type 2 diabetes in randomized controlled trials. METHODS: In this systematic review and meta-analysis, 6 electronic databases were searched using major keywords of meditation , diabetes , and self-management during March 2022. RESULTS: Eight studies (9 articles) using mindfulness-based meditation were included. The meta-analysis showed that meditation improved hemoglobin A 1c (effect size = -0.75; 95% confidence interval, -1.30 to -0.21; P = .007) but not fasting blood glucose. Only a few studies examined meditation effects on other types of self-management (eg, blood pressure, body mass index, cholesterol, diet, exercise, foot care, and monitoring of blood glucose), and the effects were inconsistent. In 1 study, meditation improved diabetes self-management. CONCLUSIONS: Mindfulness-based meditation reduced hemoglobin A 1c levels in adult patients with type 2 diabetes but did not consistently improve other types of self-management in a few studies examined. This may imply the need for additional intervention components to improve different types of self-management. Further studies are needed to examine the effects of different types of meditations with additional components on different types of self-management.


Asunto(s)
Complicaciones de la Diabetes , Diabetes Mellitus Tipo 2 , Meditación , Automanejo , Humanos , Adulto , Diabetes Mellitus Tipo 2/terapia , Glucemia , Colesterol , Ensayos Clínicos Controlados Aleatorios como Asunto
7.
J Allergy Clin Immunol ; 149(2): 488-516.e9, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34848210

RESUMEN

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. A current challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.


Asunto(s)
Asma/tratamiento farmacológico , Medicina de Precisión , Comités Consultivos , Asma/diagnóstico , Biomarcadores , Protocolos Clínicos , Ensayos Clínicos Fase II como Asunto , Humanos , Proyectos de Investigación , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X
8.
J Am Chem Soc ; 144(2): 751-756, 2022 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-34982936

RESUMEN

Heterogeneous processes can control atmospheric composition. Snow and ice present important, but poorly understood, reaction media that can greatly alter the composition of air in the cryosphere in polar and temperate regions. Atmospheric scientists struggle to reconcile model predictions with field observations in snow-covered regions due in part to experimental challenges associated with monitoring reactions at air-ice interfaces, and debate regarding reaction kinetics and mechanisms has persisted for over a decade. In this work, we use wavelength-resolved fluorescence microscopy to determine the distribution and chemical speciation of the pollutant anthracene at environmentally relevant frozen surfaces. Our results indicate that anthracene adsorbs to frozen surfaces in monomeric form, but that following lateral diffusion, molecules ultimately reside within brine channels at saltwater ice surfaces, and in micron-sized clusters at freshwater ice surfaces; emission profiles indicate extensive self-association. We also measure anthracene photodegradation kinetics in aqueous solution and artificial snow prepared from frozen freshwater and saltwater solutions. Our results suggest that anthracene─and likely other aromatic pollutants─undergo bimolecular photodegradation at the surface of freshwater ice and sea ice, but not at the surface of frozen organic matter. These results will improve predictions of pollutant fate and exposure risk in the cryosphere. The techniques used can be applied to numerous surfaces within and beyond the atmospheric sciences.

9.
Semin Respir Crit Care Med ; 43(5): 709-719, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35714626

RESUMEN

Asthma represents one of the biggest global health concerns with increasing prevalence and influence on global health. Several distinct asthma phenotypes have been identified with one of the most common, earliest recognized, and described being the allergic asthma phenotype, in which allergens trigger asthma through mechanisms involving allergen-specific immunoglobulin E (IgE). Allergen-specific immunotherapy (AIT), in the forms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT), has been used for many decades as a tool for reducing IgE-mediated sensitization and controlling symptoms of allergic disease, most commonly for allergic rhinitis, and it remains the only currently available disease modifying therapy in atopic patients. AIT has been studied for use in mild to moderate allergic asthma. While the data are often inconsistent, and utilize a multitude of different methods, antigens, and outcome measures, in general, AIT may have several beneficial effects on asthma disease control, quality of life, and requirement for medication. These benefits are notable when immunotherapy is used as an adjunct to pharmacologic treatment in carefully selected and monitored patients with mild to moderate persistent asthma. Patients with severe asthma are excluded from these trials. Importantly, patients with asthma, and in particular severe asthma, may have a higher rate of systemic adverse reactions to SCIT, including anaphylaxis; however, these events are overall rare. Future research in the area is needed to definitively assess the benefit of SCIT and SLIT for patients with asthma, comparing outcomes with different methods, addressing the role of AIT in severe asthma, significance of multiallergen AIT in allergic asthma, and safety concerns in asthma.


Asunto(s)
Asma , Calidad de Vida , Alérgenos , Asma/etiología , Desensibilización Inmunológica/efectos adversos , Desensibilización Inmunológica/métodos , Humanos , Inmunoglobulina E
10.
Indoor Air ; 32(1): e12964, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34854500

RESUMEN

We made intensive measurements of wavelength-resolved spectral irradiance in a test house during the HOMEChem campaign and report diurnal profiles and two-dimensional spatial distribution of photolysis rate constants (J) of several important indoor photolabile gases. Results show that sunlight entering through windows, which was the dominant source of ultraviolet (UV) light in this house, led to clear diurnal cycles, and large time- and location-dependent variations in local gas-phase photochemical activity. Local J values of several key indoor gases under direct solar illumination were 1.8-7.4 times larger-and more strongly dependent on time, solar zenith angle, and incident angle of sunlight relative to the window-than under diffuse sunlight. Photolysis rate constants were highly spatially heterogeneous and fast photochemical reactions in the gas phase were generally confined to within tens of cm of the region that were directly sunlit. Opening windows increased UV photon fluxes by 3 times and increased predicted local hydroxyl radical (OH) concentrations in the sunlit region by 4.5 times to 3.2 × 107  molec cm-3 due to higher J values and increased contribution from O3 photolysis. These results can be used to improve the treatment of photochemistry in indoor chemistry models and are a valuable resource for future studies that use the publicly available HOMEChem measurements.


Asunto(s)
Contaminación del Aire Interior , Ácido Nitroso , Contaminación del Aire Interior/análisis , Gases , Radical Hidroxilo/análisis , Fotólisis
11.
J Biomech Eng ; 144(7)2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-34897371

RESUMEN

In vitro biomechanical testing is common in the field of orthopedics when novel devices are investigated prior to human trials. It is typically necessary to apply loads through tendons to simulate normal activities, such as walking during a foot and ankle study. However, attachment of tendons to linear actuators has proven challenging because of the tendency of clamps to either slip off or rupture the tendon. Various techniques have been utilized. Freeze clamping is generally accepted as the gold standard for very high load testing in excess of 3000 N, but is expensive, time-consuming, and requires significant ancillary equipment. Purely mechanical solutions such as metal jaw clamps, wire meshes, and others have been explored, but these techniques are either costly, have low load capacities, or have not proven to be reproducible. We have developed a novel tendon clamping technique that utilizes a slip-resistant polyester mesh sleeving that encases the tendon and is fixated at the bottom of the tendon/sleeve interaction with a giftbox suture. The loose end of the sleeving can then be tied in to the linear actuator or load cell apparatus using a timber hitch knot. The sleeving technique allows for loads of 2000-2500 N on the Achilles tendon, and is inexpensive, reproducible, and can be modified to apply loads to smaller tendons as well, though a length of tendon/sleeve overlap of at least 16 cm is required to reach maximum loads. This technique should assist researchers in integrating muscle forces into future biomechanical study designs.


Asunto(s)
Tendón Calcáneo , Mallas Quirúrgicas , Tendón Calcáneo/cirugía , Fenómenos Biomecánicos , Constricción , Humanos , Rotura/cirugía
12.
J Allergy Clin Immunol ; 147(5): 1594-1601, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33667479

RESUMEN

Severe asthma accounts for almost half the cost associated with asthma. Severe asthma is driven by heterogeneous molecular mechanisms. Conventional clinical trial design often lacks the power and efficiency to target subgroups with specific pathobiological mechanisms. Furthermore, the validation and approval of new asthma therapies is a lengthy process. A large proportion of that time is taken by clinical trials to validate asthma interventions. The National Institutes of Health Precision Medicine in Severe and/or Exacerbation Prone Asthma (PrecISE) program was established with the goal of designing and executing a trial that uses adaptive design techniques to rapidly evaluate novel interventions in biomarker-defined subgroups of severe asthma, while seeking to refine these biomarker subgroups, and to identify early markers of response to therapy. The novel trial design is an adaptive platform trial conducted under a single master protocol that incorporates precision medicine components. Furthermore, it includes innovative applications of futility analysis, cross-over design with use of shared placebo groups, and early futility analysis to permit more rapid identification of effective interventions. The development and rationale behind the study design are described. The interventions chosen for the initial investigation and the criteria used to identify these interventions are enumerated. The biomarker-based adaptive design and analytic scheme are detailed as well as special considerations involved in the final trial design.


Asunto(s)
Asma , Biomarcadores , Medicina de Precisión , Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Proyectos de Investigación
13.
Public Health Nurs ; 39(4): 856-864, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35005796

RESUMEN

OBJECTIVES: The purpose of this study was to test the psychometric properties of a brief attitudes and beliefs toward human papillomavirus (HPV) vaccination instrument in college students. DESIGN: Cross-sectional, observational study. SAMPLE: Eighty-six nursing students. MEASUREMENTS: The Attitudes and Beliefs Toward Human Papillomavirus Vaccination was used to test the reliability (Cronbach's alpha), homogeneity (item-analyses), and validity (factor analysis and correlations). RESULTS: The reliability of this 8-item instrument was supported by a Cronbach's alpha of .854. Item homogeneity was supported by coefficients for all items > .30. Convergent validity was supported by significant correlations of attitudes and beliefs assessed by this instrument to attitudes, subjective norm, and perceived behavioral control assessed by different instruments (all ps < .001). Construct validity was supported by exploratory and confirmatory factor analyses (all factor loadings ≥ .40). Predictive validity was supported by a significant relationship of attitudes and beliefs to completion of the vaccination (p < .001). CONCLUSIONS: The Attitudes and Beliefs Toward Human Papillomavirus Vaccination Questionnaire was a reliable and valid instrument. This short instrument can be used to assess and improve attitudes and beliefs toward HPV vaccination, and, in turn, to facilitate the completion of the vaccination.


Asunto(s)
Alphapapillomavirus , Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Estudiantes de Enfermería , Estudios Transversales , Conocimientos, Actitudes y Práctica en Salud , Humanos , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/uso terapéutico , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios , Vacunación
14.
J Community Health Nurs ; 39(3): 178-192, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35653794

RESUMEN

PURPOSE: To examine factors associated with overall human papillomavirus (HPV) vaccination status, completion of HPV vaccination, and intention to receive vaccination among nursing students. DESIGN: A Cross-sectional, correlational study. METHODS: Data from 86 students were analyzed using logistic and multiple regression. FINDINGS: Among knowledge, attitudes and beliefs, and recommendation, more positive attitudes and beliefs were the only factors associated with initiation and/or completion of HPV vaccination and the intention to receive HPV vaccination. CONCLUSIONS: More positive attitudes and beliefs need to be enhanced for HPV vaccination. CLINICAL EVIDENCE: Changes in attitudes and beliefs can be important targets of interventions to increase HPV vaccination.


Asunto(s)
Alphapapillomavirus , Bachillerato en Enfermería , Infecciones por Papillomavirus , Vacunas contra Papillomavirus , Estudiantes de Enfermería , Estudios Transversales , Conocimientos, Actitudes y Práctica en Salud , Humanos , Intención , Infecciones por Papillomavirus/prevención & control , Vacunas contra Papillomavirus/uso terapéutico , Encuestas y Cuestionarios , Vacunación
15.
Ecol Food Nutr ; 61(5): 638-648, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36031931

RESUMEN

Women living below the federal poverty level have low breastfeeding rates and historically have lacked access to doula care. This disparity is particularly evident among African American women. The objective of this pilot study was to assess doulas' experiences delivering lactation education to racially/ethnically diverse, primarily Medicaid-eligible pregnant women and describe doulas' perceptions of client barriers to breastfeeding. We also wanted to understand doulas' views of infant feeding and lactation education during their participation in a quality improvement intervention that trained doulas to provide lactation education and breastfeeding support at 4 clinics serving low-income clients. Two focus groups were conducted with 7 doulas. Focus group data were transcribed, coded, and analyzed using qualitative thematic analysis. Doulas reported close relationships with their clients and provided consistent breastfeeding support and education to women in prenatal, birth, and postpartum phases of care. Doulas emphasized the need for more lactation education, especially to overcome clients' perceived milk insufficiency and early termination due to breastfeeding barriers. Doula-led breastfeeding education and support may improve breastfeeding outcomes for diverse women from underserved areas.


Asunto(s)
Doulas , Lactancia Materna , Femenino , Humanos , Lactancia , Proyectos Piloto , Pobreza , Embarazo , Informe de Investigación
16.
Ann Allergy Asthma Immunol ; 127(5): 530-535, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34688426

RESUMEN

OBJECTIVE: To identify treatment approaches that can be used in the management of patients with asthma who lack significant type 2 inflammation, also called T2 low asthma. DATA SOURCES: Recent expert guideline updates on the management of asthma, recent journal articles and review articles, and foundational journal articles are referenced. STUDY SELECTIONS: This review cites clinical cohort studies of highly characterized patients with asthma, clinical interventional trials of high impact, mechanistic studies relevant to T2 low asthma, and emerging work in this area. RESULTS: T2 low asthma accounts for approximately one-third to one-half of individuals with asthma. Characteristics of participants with T2 low asthma include higher body mass index, cigarette smoking/smoke exposure, relative lack of responsiveness to steroids, less bronchodilator reversibility, and often the presence of neutrophilic inflammation. Multiple available interventions target these characteristics, including standard inhalers, azithromycin, and lifestyle interventions of weight loss and smoking cessation. CONCLUSION: Treatment of T2 low asthma should involve currently available approaches and will benefit from improved definition and understanding of disease pathobiology.


Asunto(s)
Corticoesteroides/uso terapéutico , Agonistas Adrenérgicos beta/uso terapéutico , Asma/tratamiento farmacológico , Asma/patología , Broncodilatadores/uso terapéutico , Adolescente , Adulto , Antiasmáticos/uso terapéutico , Índice de Masa Corporal , Niño , Preescolar , Humanos , Inmunoglobulina E/sangre , Inflamación/patología , Agonistas Muscarínicos/uso terapéutico , Neutrófilos/inmunología , Índice de Severidad de la Enfermedad , Cese del Hábito de Fumar
17.
J Phys Chem A ; 125(40): 8925-8932, 2021 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-34597045

RESUMEN

At the air-ice interface, some aromatic compounds such as benzene and anthracene are surprisingly unreactive toward OH. This may be a consequence of the poor solvation of these compounds at the interface, resulting in clustering there. We test this hypothesis by comparing the reaction of OH with pyrene, a 4-ring polyaromatic hydrocarbon (PAH), to reactions of OH with the more water-soluble compounds coumarin and 7-hydroxycoumarin (7OHC). We observe that OH reacts readily with coumarin and 7OHC at both liquid and frozen air-water interfaces. Pyrene, a much less soluble compound, reacts with OH at the liquid surface but not at the air-ice interface. We report evidence of pyrene aggregation at the ice surface based on its broadened and red-shifted emission spectrum alongside fluorescence mapping of anthracene, a closely related 3-ring PAH, which shows bunching at the ice surface. By contrast, fluorescence mapping shows that coumarin is fairly homogeneously distributed at the air-ice interface. Together, these results suggest that the limited reactivity of some compounds toward OH at the ice surface may be a consequence of their propensity to self-aggregate, demonstrating that chemical morphology can play an important role in reactions at the ice surface.

18.
Indoor Air ; 31(4): 1187-1198, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33373097

RESUMEN

We measured wavelength-resolved ultraviolet (UV) irradiance in multiple indoor environments and quantified the effects of variables such as light source, solar angles, cloud cover, window type, and electric light color temperature on indoor photon fluxes. The majority of the 77 windows and window samples investigated completely attenuated sunlight at wavelengths shorter than 320 nm; despite variations among individual windows leading to differences in indoor HONO photolysis rate constants (JHONO ) and local hydroxyl radical (OH) concentrations of up to a factor of 50, wavelength-resolved transmittance was similar between windows in residential and non-residential buildings. We report mathematical relationships that predict indoor solar UV irradiance as a function of solar zenith angle, incident angle of sunlight on windows, and distance from windows and surfaces for direct and diffuse sunlight. Using these relationships, we predict elevated indoor steady-state OH concentrations (0.80-7.4 × 106 molec cm-3 ) under illumination by direct and diffuse sunlight and fluorescent tubes near windows or light sources. However, elevated OH concentrations at 1 m from the source are only predicted under direct sunlight. We predict that reflections from indoor surfaces will have minor contributions to room-averaged indoor UV irradiance. These results may improve parameterization of indoor chemistry models.


Asunto(s)
Contaminación del Aire Interior , Ácido Nitroso , Contaminación del Aire Interior/análisis , Radical Hidroxilo/análisis , Fotoquímica , Fotólisis , Rayos Ultravioleta
19.
Environ Sci Technol ; 54(24): 15643-15651, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33258369

RESUMEN

Activities such as household cleaning can greatly alter the composition of air in indoor environments. We continuously monitored hydrogen peroxide (H2O2) from household non-bleach surface cleaning in a chamber designed to simulate a residential room. Mixing ratios of up to 610 ppbv gaseous H2O2 were observed following cleaning, orders of magnitude higher than background levels (sub-ppbv). Gaseous H2O2 levels decreased rapidly and irreversibly, with removal rate constants (kH2O2) 17-73 times larger than air change rate (ACR). Increasing the surface-area-to-volume ratio within the room caused peak H2O2 mixing ratios to decrease and kH2O2 to increase, suggesting that surface uptake dominated H2O2 loss. Volatile organic compound (VOC) levels increased rapidly after cleaning and then decreased with removal rate constants 1.2-7.2 times larger than ACR, indicating loss due to surface partitioning and/or chemical reactions. We predicted photochemical radical production rates and steady-state concentrations in the simulated room using a detailed chemical model for indoor air (the INDCM). Model results suggest that, following cleaning, H2O2 photolysis increased OH concentrations by 10-40% to 9.7 × 105 molec cm-3 and hydroperoxy radical (HO2) concentrations by 50-70% to 2.3 × 107 molec cm-3 depending on the cleaning method and lighting conditions.


Asunto(s)
Contaminación del Aire Interior , Compuestos Orgánicos Volátiles , Contaminación del Aire Interior/análisis , Gases , Peróxido de Hidrógeno , Modelos Químicos , Compuestos Orgánicos Volátiles/análisis
20.
Environ Sci Technol ; 54(3): 1730-1739, 2020 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-31940195

RESUMEN

We report elevated levels of gaseous inorganic chlorinated and nitrogenated compounds in indoor air while cleaning with a commercial bleach solution during the House Observations of Microbial and Environmental Chemistry field campaign in summer 2018. Hypochlorous acid (HOCl), chlorine (Cl2), and nitryl chloride (ClNO2) reached part-per-billion by volume levels indoors during bleach cleaning-several orders of magnitude higher than typically measured in the outdoor atmosphere. Kinetic modeling revealed that multiphase chemistry plays a central role in controlling indoor chlorine and reactive nitrogen chemistry during these periods. Cl2 production occurred via heterogeneous reactions of HOCl on indoor surfaces. ClNO2 and chloramine (NH2Cl, NHCl2, NCl3) production occurred in the applied bleach via aqueous reactions involving nitrite (NO2-) and ammonia (NH3), respectively. Aqueous-phase and surface chemistry resulted in elevated levels of gas-phase nitrogen dioxide (NO2). We predict hydroxyl (OH) and chlorine (Cl) radical production during these periods (106 and 107 molecules cm-3 s-1, respectively) driven by HOCl and Cl2 photolysis. Ventilation and photolysis accounted for <50% and <0.1% total loss of bleach-related compounds from indoor air, respectively; we conclude that uptake to indoor surfaces is an important additional loss process. Indoor HOCl and nitrogen trichloride (NCl3) mixing ratios during bleach cleaning reported herein are likely detrimental to human health.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Cloro , Gases , Humanos , Ácido Hipocloroso , Ventilación
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