Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 273
Filtrar
Mais filtros

Eixos temáticos
Intervalo de ano de publicação
1.
Nature ; 618(7967): 967-973, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37380694

RESUMO

Observational evidence shows the ubiquitous presence of ocean-emitted short-lived halogens in the global atmosphere1-3. Natural emissions of these chemical compounds have been anthropogenically amplified since pre-industrial times4-6, while, in addition, anthropogenic short-lived halocarbons are currently being emitted to the atmosphere7,8. Despite their widespread distribution in the atmosphere, the combined impact of these species on Earth's radiative balance remains unknown. Here we show that short-lived halogens exert a substantial indirect cooling effect at present (-0.13 ± 0.03 watts per square metre) that arises from halogen-mediated radiative perturbations of ozone (-0.24 ± 0.02 watts per square metre), compensated by those from methane (+0.09 ± 0.01 watts per square metre), aerosols (+0.03 ± 0.01 watts per square metre) and stratospheric water vapour (+0.011 ± 0.001 watts per square metre). Importantly, this substantial cooling effect has increased since 1750 by -0.05 ± 0.03 watts per square metre (61 per cent), driven by the anthropogenic amplification of natural halogen emissions, and is projected to change further (18-31 per cent by 2100) depending on climate warming projections and socioeconomic development. We conclude that the indirect radiative effect due to short-lived halogens should now be incorporated into climate models to provide a more realistic natural baseline of Earth's climate system.


Assuntos
Atmosfera , Mudança Climática , Modelos Climáticos , Clima , Temperatura Baixa , Halogênios , Atmosfera/análise , Atmosfera/química , Halogênios/análise , Hidrocarbonetos Halogenados , Oceanos e Mares , Água do Mar/análise , Água do Mar/química , Mudança Climática/estatística & dados numéricos , Atividades Humanas
2.
Proc Natl Acad Sci U S A ; 121(12): e2315058121, 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38466839

RESUMO

Mercury (Hg) is a contaminant of global concern, and an accurate understanding of its atmospheric fate is needed to assess its risks to humans and ecosystem health. Atmospheric oxidation of Hg is key to the deposition of this toxic metal to the Earth's surface. Short-lived halogens (SLHs) can provide halogen radicals to directly oxidize Hg and perturb the budget of other Hg oxidants (e.g., OH and O3). In addition to known ocean emissions of halogens, recent observational evidence has revealed abundant anthropogenic emissions of SLHs over continental areas. However, the impacts of anthropogenic SLHs emissions on the atmospheric fate of Hg and human exposure to Hg contamination remain unknown. Here, we show that the inclusion of anthropogenic SLHs substantially increased local Hg oxidation and, consequently, deposition in/near Hg continental source regions by up to 20%, thereby decreasing Hg export from source regions to clean environments. Our modeling results indicated that the inclusion of anthropogenic SLHs can lead to higher Hg exposure in/near Hg source regions than estimated in previous assessments, e.g., with increases of 8.7% and 7.5% in China and India, respectively, consequently leading to higher Hg-related human health risks. These results highlight the urgent need for policymakers to reduce local Hg and SLHs emissions. We conclude that the substantial impacts of anthropogenic SLHs emissions should be included in model assessments of the Hg budget and associated health risks at local and global scales.


Assuntos
Mercúrio , Humanos , Mercúrio/toxicidade , Mercúrio/análise , Monitoramento Ambiental/métodos , Ecossistema , China , Índia
3.
Proc Natl Acad Sci U S A ; 120(31): e2303974120, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37487065

RESUMO

Active chlorine in the atmosphere is poorly constrained and so is its role in the oxidation of the potent greenhouse gas methane, causing uncertainty in global methane budgets. We propose a photocatalytic mechanism for chlorine atom production that occurs when Sahara dust mixes with sea spray aerosol. The mechanism is validated by implementation in a global atmospheric model and thereby explaining the episodic, seasonal, and location-dependent 13C depletion in CO in air samples from Barbados [J.E. Mak, G. Kra, T. Sandomenico, P. Bergamaschi, J. Geophys. Res. Atmos. 108 (2003)], which remained unexplained for decades. The production of Cl can also explain the anomaly in the CO:ethane ratio found at Cape Verde [K. A. Read et al., J. Geophys. Res. Atmos. 114 (2009)], in addition to explaining the observation of elevated HOCl [M. J. Lawler et al., Atmos. Chem. Phys. 11, 7617-7628 (2011)]. Our model finds that 3.8 Tg(Cl) y-1 is produced over the North Atlantic, making it the dominant source of chlorine in the region; globally, chlorine production increases by 41%. The shift in the methane sink budget due to the increased role of Cl means that isotope-constrained top-down models fail to allocate 12 Tg y-1 (2% of total methane emissions) to 13C-depleted biological sources such as agriculture and wetlands. Since 2014, an increase in North African dust emissions has increased the 13C isotope of atmospheric CH4, thereby partially masking a much greater decline in this isotope, which has implications for the interpretation of the drivers behind the recent increase of methane in the atmosphere.

4.
Proc Natl Acad Sci U S A ; 119(7)2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35131938

RESUMO

The catalytic depletion of Antarctic stratospheric ozone is linked to anthropogenic emissions of chlorine and bromine. Despite its larger ozone-depleting efficiency, the contribution of ocean-emitted iodine to ozone hole chemistry has not been evaluated, due to the negligible iodine levels previously reported to reach the stratosphere. Based on the recently observed range (0.77 ± 0.1 parts per trillion by volume [pptv]) of stratospheric iodine injection, we use the Whole Atmosphere Community Climate Model to assess the role of iodine in the formation and recent past evolution of the Antarctic ozone hole. Our 1980-2015 simulations indicate that iodine can significantly impact the lower part of the Antarctic ozone hole, contributing, on average, 10% of the lower stratospheric ozone loss during spring (up to 4.2% of the total stratospheric column). We find that the inclusion of iodine advances the beginning and delays the closure stages of the ozone hole by 3 d to 5 d, increasing its area and mass deficit by 11% and 20%, respectively. Despite being present in much smaller amounts, and due to faster gas-phase photochemical reactivation, iodine can dominate (∼73%) the halogen-mediated lower stratospheric ozone loss during summer and early fall, when the heterogeneous reactivation of inorganic chlorine and bromine reservoirs is reduced. The stratospheric ozone destruction caused by 0.77 pptv of iodine over Antarctica is equivalent to that of 3.1 (4.6) pptv of biogenic very short-lived bromocarbons during spring (rest of sunlit period). The relative contribution of iodine to future stratospheric ozone loss is likely to increase as anthropogenic chlorine and bromine emissions decline following the Montreal Protocol.


Assuntos
Atmosfera/análise , Iodo/química , Perda de Ozônio , Ozônio Estratosférico/química , Poluentes Atmosféricos/química , Regiões Antárticas , Estações do Ano
5.
BMC Psychiatry ; 24(1): 463, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902683

RESUMO

INTRODUCTION: Although psychoeducational group interventions are increasingly used for adults diagnosed with attention-deficit/hyperactivity disorder (ADHD), a comprehensive review focused on the feasibility and acceptability indicators of these interventions remains lacking. Furthermore, although previous research has explored various aspects of psychoeducation for ADHD, such as its definition and approaches, limited research has focused on the synthesis for outcome measures and patients' experiences related to these interventions. Therefore, this scoping review aims to map the existing evidence reported on psychoeducational group interventions for adults diagnosed with ADHD. The objective is to provide a comprehensive overview of feasibility indicators, acceptability, and outcome measures used in psychoeducational group interventions. METHOD: A comprehensive structured literature search on the topic was performed in seven bibliographic databases, and the resulting records were independently screened, and their data extracted by two reviewers. We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-S) to ensure the transparency and rigor of this scoping review. RESULTS: The searches yielded 7510 records. Eight studies met the inclusion criteria. These included studies were conducted in European countries and the United States. Among these, six studies used a randomized control design, one an open feasibility trial, and one a pre-post intervention design. All the studies reported some feasibility and acceptability indicators. While all the studies reported on the severity of symptoms of ADHD as an outcome measure, some also reported on outcomes related to psychological or mental-health problems, quality of life, changes in knowledge regarding ADHD, or the level of self-esteem, functioning, and impairment. CONCLUSION: This scoping review revealed that psychoeducational group interventions are generally acceptable for patients in terms of patient satisfaction with the group intervention. All included studies reported some feasibility indicators, with some reporting good attendance and relatively low dropout rates. Most studies reported positive effects on ADHD and mental health symptoms, suggesting that these interventions are beneficial for adults with ADHD. However, several gaps exist regarding the reporting on the feasibility indicators, acceptability, and outcome measures employed across studies.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Psicoterapia de Grupo , Humanos , Transtorno do Deficit de Atenção com Hiperatividade/terapia , Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Psicoterapia de Grupo/métodos , Adulto , Estudos de Viabilidade , Educação de Pacientes como Assunto/métodos , Avaliação de Resultados em Cuidados de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/psicologia
6.
Proc Natl Acad Sci U S A ; 118(4)2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33479177

RESUMO

Reactive iodine plays a key role in determining the oxidation capacity, or cleansing capacity, of the atmosphere in addition to being implicated in the formation of new particles in the marine boundary layer. The postulation that heterogeneous cycling of reactive iodine on aerosols may significantly influence the lifetime of ozone in the troposphere not only remains poorly understood but also heretofore has never been observed or quantified in the field. Here, we report direct ambient observations of hypoiodous acid (HOI) and heterogeneous recycling of interhalogen product species (i.e., iodine monochloride [ICl] and iodine monobromide [IBr]) in a midlatitude coastal environment. Significant levels of ICl and IBr with mean daily maxima of 4.3 and 3.0 parts per trillion by volume (1-min average), respectively, have been observed throughout the campaign. We show that the heterogeneous reaction of HOI on marine aerosol and subsequent production of iodine interhalogens are much faster than previously thought. These results indicate that the fast formation of iodine interhalogens, together with their rapid photolysis, results in more efficient recycling of atomic iodine than currently considered in models. Photolysis of the observed ICl and IBr leads to a 32% increase in the daytime average of atomic iodine production rate, thereby enhancing the average daytime iodine-catalyzed ozone loss rate by 10 to 20%. Our findings provide direct field evidence that the autocatalytic mechanism of iodine release from marine aerosol is important in the atmosphere and can have significant impacts on atmospheric oxidation capacity.

7.
J Clin Psychopharmacol ; 43(5): 400-402, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37683226

RESUMO

BACKGROUND: ChatGPT3 is a new artificial intelligence program released on February 13, 2023. METHOD: The authors tested ChatGPT3 on February 18, 2023, and repeated the test a week later. They used their expertise on the effects of ethnic ancestry in the stratification of clozapine dosing and the new idea that they published in March 2022 that African-Americans need higher clozapine doses because they have higher clozapine clearance. RESULTS: In the first interaction on February 18, ChatGPT3 provided reasonable and very up-to-date information, which included a comment that patients of African ancestry have higher clozapine metabolism. The other 4 interactions became progressively more concerning as we asked ChatGPT3 to provide references to justify the latter statement. ChatGPT3 provided non-existent "references" using articles from real journals, with real authors, false PubMed identifiers, and false titles. Moreover, ChatGPT3 said that the first author wrote in 2003 that African-Americans had higher CYP1A2 activity when that did not happen until 2022. One week later, the second author repeated the same set of questions. This time ChatGPT3 described the opposite, that African-Americans have "lower" CYP1A2 activity and "slower" metabolism. ChatGPT3 provided another set of articles to justify the information; some were real but did not comment on clozapine metabolism in African-Americans while others did not exist. CONCLUSIONS: ChatGPT3 provided a mixture of truth, twisted reality, and non-existent "facts." Within one week it defended opposite positions regarding a clinically relevant issue such as using higher or lower clozapine doses in African-Americans.


Assuntos
Antipsicóticos , Clozapina , Humanos , Citocromo P-450 CYP1A2/metabolismo , Inteligência Artificial , Negro ou Afro-Americano
8.
J Clin Psychopharmacol ; 43(3): 239-245, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37068034

RESUMO

PURPOSE/BACKGROUND: A recent article in this journal presented a US perspective regarding the modernization of clozapine prescription and proposed an escape from the long shadow cast by agranulocytosis. METHODS: Here, an international group of collaborators discusses a point of view complementary to the US view by focusing on worldwide outcomes of clozapine usage that may be uneven in terms of frequency of clozapine adverse drug reactions. FINDINGS/RESULTS: Studies from the Scandinavian national registries (Finland and Denmark) did not find increased mortality in clozapine patients or any clear evidence of the alleged toxicity of clozapine. Data on clozapine-associated fatal outcomes were obtained from 2 recently published pharmacovigilance studies and from the UK pharmacovigilance database. A pharmacovigilance study focused on physician reports to assess worldwide lethality of drugs from 2010 to 2019 found 968 clozapine-associated fatal outcomes in the United Kingdom. Moreover, the United Kingdom accounted for 55% (968 of 1761) of worldwide and 90% (968 of 1073) of European fatal clozapine-associated outcomes. In a pharmacovigilance study from the UK database (from 2008 to 2017), clozapine was associated with 383 fatal outcomes/year including all reports from physicians and nonphysicians. From 2018 to 2021, UK clozapine-associated fatal outcomes increased to 440/year. IMPLICATIONS/CONCLUSIONS: The interpretation of fatal outcomes in each country using pharmacovigilance databases is limited and only allows gross comparisons; even with those limitations, the UK data seem concerning. Pneumonia and myocarditis may be more important than agranulocytosis in explaining the uneven distribution of fatal outcomes in clozapine patients across countries.


Assuntos
Agranulocitose , Antipsicóticos , Clozapina , Humanos , Clozapina/efeitos adversos , Antipsicóticos/efeitos adversos , Farmacovigilância , Agranulocitose/induzido quimicamente , Reino Unido
9.
Virol J ; 20(1): 207, 2023 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-37679779

RESUMO

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection induces a spectrum of clinical manifestations that depend on the immune response of the patient, i.e., from an asymptomatic form to an inflammatory response with multiorgan deterioration. In some cases, severe cases of SARS-CoV-2 are characterized by an excessive, persistent release of inflammatory mediators known as a cytokine storm. This phenomenon arises from an ineffective T helper (Th)-1 response, which is unable to control the infection and leads to a reinforcement of innate immunity, causing tissue damage. The evolution of the disease produced by SARS-CoV2, known as COVID-19, has been of interest in several research fields. Asthma patients have been reported to present highly variable outcomes due to the heterogeneity of the disease. For example, the Th2 response in patients with allergic asthma is capable of decreasing Th1 activation in COVID-19, preventing the onset of a cytokine storm; additionally, IL-33 released by damaged epithelium in the context of COVID-19 potentiates either Th1 or T2-high responses, a process that contributes to poor outcomes. IL-13, a T2-high inflammatory cytokine, decreases the expression of angiotensin converting enzyme-2 (ACE2) receptor, hindering SARS-CoV-2 entry; finally, poor outcomes have been observed in COVID-19 patients with severe neutrophilic asthma. In other contexts, the COVID-19 lockdown has had interesting effects on asthma epidemiology. The incidence of asthma in the most populated states in Mexico, including Tamaulipas, which has the highest asthma incidence in the country, showed similar tendencies independent of how strict the lockdown measures were in each state. As described worldwide for various diseases, a decrease in asthma cases was observed during the COVID-19 lockdown. This decrease was associated with a drop in acute respiratory infection cases. The drop in cases of various diseases, such as diabetes, hypertension or depression, observed in 2020 was restored in 2022, but not for asthma and acute respiratory infections. There were slight increases in asthma cases when in-person classes resumed. In conclusion, although many factors were involved in asthma outcomes during the pandemic, it seems that acute respiratory infection is intimately linked to asthma cases. Social distancing during remote learning, particularly school lockdown, appears to be an important cause of the decrease in cases.


Assuntos
Asma , COVID-19 , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Síndrome da Liberação de Citocina/epidemiologia , RNA Viral , Controle de Doenças Transmissíveis , Asma/epidemiologia
10.
Proc Natl Acad Sci U S A ; 117(49): 30949-30956, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33229529

RESUMO

Mercury (Hg), a global contaminant, is emitted mainly in its elemental form Hg0 to the atmosphere where it is oxidized to reactive HgII compounds, which efficiently deposit to surface ecosystems. Therefore, the chemical cycling between the elemental and oxidized Hg forms in the atmosphere determines the scale and geographical pattern of global Hg deposition. Recent advances in the photochemistry of gas-phase oxidized HgI and HgII species postulate their photodissociation back to Hg0 as a crucial step in the atmospheric Hg redox cycle. However, the significance of these photodissociation mechanisms on atmospheric Hg chemistry, lifetime, and surface deposition remains uncertain. Here we implement a comprehensive and quantitative mechanism of the photochemical and thermal atmospheric reactions between Hg0, HgI, and HgII species in a global model and evaluate the results against atmospheric Hg observations. We find that the photochemistry of HgI and HgII leads to insufficient Hg oxidation globally. The combined efficient photoreduction of HgI and HgII to Hg0 competes with thermal oxidation of Hg0, resulting in a large model overestimation of 99% of measured Hg0 and underestimation of 51% of oxidized Hg and ∼66% of HgII wet deposition. This in turn leads to a significant increase in the calculated global atmospheric Hg lifetime of 20 mo, which is unrealistically longer than the 3-6-mo range based on observed atmospheric Hg variability. These results show that the HgI and HgII photoreduction processes largely offset the efficiency of bromine-initiated Hg0 oxidation and reveal missing Hg oxidation processes in the troposphere.


Assuntos
Atmosfera/química , Mercúrio/análise , Processos Fotoquímicos , Simulação por Computador , Modelos Teóricos , Oxirredução
11.
Proc Natl Acad Sci U S A ; 117(4): 1860-1866, 2020 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-31932452

RESUMO

Oceanic emissions of iodine destroy ozone, modify oxidative capacity, and can form new particles in the troposphere. However, the impact of iodine in the stratosphere is highly uncertain due to the lack of previous quantitative measurements. Here, we report quantitative measurements of iodine monoxide radicals and particulate iodine (Iy,part) from aircraft in the stratosphere. These measurements support that 0.77 ± 0.10 parts per trillion by volume (pptv) total inorganic iodine (Iy) is injected to the stratosphere. These high Iy amounts are indicative of active iodine recycling on ice in the upper troposphere (UT), support the upper end of recent Iy estimates (0 to 0.8 pptv) by the World Meteorological Organization, and are incompatible with zero stratospheric iodine injection. Gas-phase iodine (Iy,gas) in the UT (0.67 ± 0.09 pptv) converts to Iy,part sharply near the tropopause. In the stratosphere, IO radicals remain detectable (0.06 ± 0.03 pptv), indicating persistent Iy,part recycling back to Iy,gas as a result of active multiphase chemistry. At the observed levels, iodine is responsible for 32% of the halogen-induced ozone loss (bromine 40%, chlorine 28%), due primarily to previously unconsidered heterogeneous chemistry. Anthropogenic (pollution) ozone has increased iodine emissions since preindustrial times (ca. factor of 3 since 1950) and could be partly responsible for the continued decrease of ozone in the lower stratosphere. Increasing iodine emissions have implications for ozone radiative forcing and possibly new particle formation near the tropopause.


Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Radicais Livres/química , Iodo/análise , Ozônio/análise , Movimentos do Ar , Aeronaves , Radicais Livres/análise , Humanos
12.
Proc Natl Acad Sci U S A ; 117(9): 4505-4510, 2020 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-32071211

RESUMO

Dimethyl sulfide (DMS), emitted from the oceans, is the most abundant biological source of sulfur to the marine atmosphere. Atmospheric DMS is oxidized to condensable products that form secondary aerosols that affect Earth's radiative balance by scattering solar radiation and serving as cloud condensation nuclei. We report the atmospheric discovery of a previously unquantified DMS oxidation product, hydroperoxymethyl thioformate (HPMTF, HOOCH2SCHO), identified through global-scale airborne observations that demonstrate it to be a major reservoir of marine sulfur. Observationally constrained model results show that more than 30% of oceanic DMS emitted to the atmosphere forms HPMTF. Coincident particle measurements suggest a strong link between HPMTF concentration and new particle formation and growth. Analyses of these observations show that HPMTF chemistry must be included in atmospheric models to improve representation of key linkages between the biogeochemistry of the ocean, marine aerosol formation and growth, and their combined effects on climate.

13.
J Adolesc ; 95(8): 1603-1616, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37583064

RESUMO

PURPOSE: This study examines the relationship between social support and victimization of Latino youth over time, utilizing the stress prevention and support deterioration models. METHODS: To address the research questions we utilized data from Waves 1 and 2 (n = 574) of the Dating Violence among Latino Adolescents (DAVILA) study, a national bilingual phone survey of self-identified Latino youth and their caregiver. Cross-lagged panel modeling was used to assess the fit of the two theoretical models to observed patterns of covariance among the victimization and social support variables specified. RESULTS: Results show that victimization at Wave 1 was positively and strongly related to victimization at Wave 2 and social support at Wave 1 was positively and moderately associated with social support at Wave 2. As hypothesized, higher levels of victimization at Wave 1 were significantly related to decreases in social support at Wave 2 (ß = -.15). Wave 1 social support was not significantly related to victimization at Wave 2. CONCLUSIONS: We did not find support for the stress prevention model but did find support for the support deterioration model. Teens who were victimized tended to have lower levels of subsequent social support, highlighting the need to equip peers, family, and significant others to adequately respond to victimization disclosures.


Assuntos
Vítimas de Crime , Apoio Social , Adolescente , Humanos , Hispânico ou Latino
14.
Telemed J E Health ; 29(1): 102-108, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35549720

RESUMO

Introduction: The COVID-19 pandemic has renewed the interest in telepsychiatry as a way to help psychiatrists care for their patients, but mental health providers' unfamiliarity and concerns may impede implementation of such services. This study aimed to determine the effect of an online educational intervention on awareness, knowledge, attitude, and skills (AKAS) of telepsychiatry among psychiatrists. Methods: The study used a pre-post-test design to compare AKAS of telepsychiatry among psychiatrists participating in an online course of practical telepsychiatry. The telemedicine AKAS questionnaire adapted to telepsychiatry was applied before and after the educational intervention, during the months of October to December 2020. Results: Responses from 213 participants were analyzed before the educational intervention and from 152 after it. The knowledge showed by Spanish psychiatrists before the educational intervention was good in 61% of participants, fair in 37%, and inadequate in 2%. With respect to attitudes toward telepsychiatry, 62% self-reported a high attitude, 33% moderate, and 5% low. With regard self-reported skills, 57% of the participating psychiatrists were highly skilled or experts, 22% moderately skilled, and 9% unskilled in handling telepsychiatry equipment. Despite the high baseline values, the educational intervention significantly improved psychiatrists' awareness, knowledge and attitudes toward telepsychiatry although not their skills. Conclusions: Online course of practical telepsychiatry was effective although future editions need to improve its focus on skills. This educational intervention represents an effort to promote the implementation of telepsychiatry as a health care alternative.


Assuntos
COVID-19 , Psiquiatria , Telemedicina , Humanos , Conhecimentos, Atitudes e Prática em Saúde , Pandemias , COVID-19/epidemiologia
15.
Geophys Res Lett ; 49(6): e2021GL097567, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35859565

RESUMO

Heterogeneous uptake of hypoiodous acid (HOI), the dominant inorganic iodine species in the marine boundary layer (MBL), on sea-salt aerosol (SSA) to form iodine monobromide and iodine monochloride has been adopted in models with assumed efficiency. Recently, field measurements have reported a much faster rate of this recycling process than previously assumed in models. Here, we conduct global model simulations to quantify the range of effects of iodine recycling within the MBL, using Conventional, Updated, and Upper-limit coefficients. When considering the Updated coefficient, iodine recycling significantly enhances gaseous inorganic iodine abundance (∼40%), increases halogen atom production rates (∼40% in I, >100% in Br, and ∼60% in Cl), and reduces oxidant levels (-7% in O3, -2% in OH, and -4% in HO2) compared to the simulation without the process. We appeal for further direct measurements of iodine species, laboratory experiments on the controlling factors, and multiscale simulations of iodine heterogeneous recycling.

16.
Geophys Res Lett ; 49(12): e2022GL097953, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35860422

RESUMO

Mercury, a global contaminant, enters the stratosphere through convective uplift, but its chemical cycling in the stratosphere is unknown. We report the first model of stratospheric mercury chemistry based on a novel photosensitized oxidation mechanism. We find two very distinct Hg chemical regimes in the stratosphere: in the upper stratosphere, above the ozone maximum concentration, Hg0 oxidation is initiated by photosensitized reactions, followed by second-step chlorine chemistry. In the lower stratosphere, ground-state Hg0 is oxidized by thermal reactions at much slower rates. This dichotomy arises due to the coincidence of the mercury absorption at 253.7 nm with the ozone Hartley band maximum at 254 nm. We also find that stratospheric Hg oxidation, controlled by chlorine and hydroxyl radicals, is much faster than previously assumed, but moderated by efficient photo-reduction of mercury compounds. Mercury lifetime shows a steep increase from hours in the upper-middle stratosphere to years in the lower stratosphere.

17.
Pharmacopsychiatry ; 55(2): 73-86, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34911124

RESUMO

This international guideline proposes improving clozapine package inserts worldwide by using ancestry-based dosing and titration. Adverse drug reaction (ADR) databases suggest that clozapine is the third most toxic drug in the United States (US), and it produces four times higher worldwide pneumonia mortality than that by agranulocytosis or myocarditis. For trough steady-state clozapine serum concentrations, the therapeutic reference range is narrow, from 350 to 600 ng/mL with the potential for toxicity and ADRs as concentrations increase. Clozapine is mainly metabolized by CYP1A2 (female non-smokers, the lowest dose; male smokers, the highest dose). Poor metabolizer status through phenotypic conversion is associated with co-prescription of inhibitors (including oral contraceptives and valproate), obesity, or inflammation with C-reactive protein (CRP) elevations. The Asian population (Pakistan to Japan) or the Americas' original inhabitants have lower CYP1A2 activity and require lower clozapine doses to reach concentrations of 350 ng/mL. In the US, daily doses of 300-600 mg/day are recommended. Slow personalized titration may prevent early ADRs (including syncope, myocarditis, and pneumonia). This guideline defines six personalized titration schedules for inpatients: 1) ancestry from Asia or the original people from the Americas with lower metabolism (obesity or valproate) needing minimum therapeutic dosages of 75-150 mg/day, 2) ancestry from Asia or the original people from the Americas with average metabolism needing 175-300 mg/day, 3) European/Western Asian ancestry with lower metabolism (obesity or valproate) needing 100-200 mg/day, 4) European/Western Asian ancestry with average metabolism needing 250-400 mg/day, 5) in the US with ancestries other than from Asia or the original people from the Americas with lower clozapine metabolism (obesity or valproate) needing 150-300 mg/day, and 6) in the US with ancestries other than from Asia or the original people from the Americas with average clozapine metabolism needing 300-600 mg/day. Baseline and weekly CRP monitoring for at least four weeks is required to identify any inflammation, including inflammation secondary to clozapine rapid titration.


Assuntos
Antipsicóticos , Clozapina , Adulto , Antipsicóticos/efeitos adversos , Povo Asiático , Proteína C-Reativa , Clozapina/efeitos adversos , Feminino , Humanos , Masculino , Ácido Valproico/efeitos adversos
18.
Can J Microbiol ; 68(2): 139-145, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34662521

RESUMO

While monitoring the presence of antibiotic resistance in municipal wastewater bacteria from Mexico City, five Escherichia coli isolates were found to be resistant to carbapenems, antibiotics of "last resort" used mostly in hospitals. Further analysis revealed that these carbapenem-resistant isolates carried the gene encoding a metallo-beta-lactamase, NDM-5. The gene was found to be beared by a large, ∼145 kb conjugative plasmid, which also carries putative genes encoding resistance to sulfonamides, trimethoprim, tetracycline, ciprofloxacin, and chloramphenicol (although no phenotypic chloramphenicol resistance was detected) and quaternary-ammonium compounds. The plasmid also carried gene mobility determinants, such as integron integrase and two transposases. In addition to the direct public health threat posed by the presence of such multi-resistant organisms in wastewater released into the environment and used for crop irrigation; it is particularly concerning that carbapenem-resistant E. coli is rather rare in Mexican hospitals (<1%), but was found in small, 100 mL samples of municipal wastewater. This suggests that these organisms are under-reported by clinical microbiology laboratories, underlining the usefulness of wastewater monitoring, or that there is an unknown source of such carbapenem-resistant organisms that are being dumped into the wastewater. The source of these bacteria must be assessed and controlled to prevent further spread of this multi-resistance plasmid among other environmental and clinical microorganisms.


Assuntos
Escherichia coli/isolamento & purificação , Esgotos/microbiologia , beta-Lactamases , Antibacterianos/farmacologia , Escherichia coli/genética , Infecções por Escherichia coli , Humanos , México , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
19.
BMC Pediatr ; 22(1): 337, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35689198

RESUMO

BACKGROUND: Dating abuse (DA) is prevalent and consequential, but no brief DA screening tools are available for use in pediatric or other settings. This study was designed to determine the sensitivity, specificity, and predictive values of the MARSHA-C, which is a three-item DA victimization screening tool. METHODS: The participants were 224 U.S. youth ages 11-21 years old (20% male, 77% female, 3% non-binary gender). Youth completed an online questionnaire about adolescent relationship abuse. The survey included the Measure of Adolescent Relationship Harassment and Abuse (MARSHA), which is a comprehensive DA measurement instrument normed on a nationally representative sample. Of 34 DA victimization items from the MARSHA, the three most prevalent items were hypothesized to have good predictive validity of the full scale score as a brief, screening version (MARSHA-C). The sensitivity, specificity, positive predictive value, and negative predictive value of the MARSHA-C to identify victims of DA was calculated. RESULTS: Using the MARSHA as the reference standard, the cutpoint of 1 on the MARSHA-C screening tool was identified as optimal. The MARSHA-C had a sensitivity of 84%, a specificity of 91%, and positive predictive value of 91%. Thus, for youth who endorse ≥ 1 MARSHA-C items, there is a 91% probability that they have experienced DA in the past year. Exploratory analyses by demographic subgroups suggest that the predictive validity of the MARSHA-C is approximately equivalent for females and males, younger and older adolescents, Asian, Black, Latinx, Multiracial and White youth, and heterosexual and lesbian, gay, and bisexual youth. CONCLUSIONS: The MARSHA-C can be used to detect DA among 11-21-year-old youth via online surveys for research purposes, or in clinical care settings to facilitate proactive patient counseling or parent-oriented anticipatory guidance.


Assuntos
Bullying , Vítimas de Crime , Adolescente , Adulto , Criança , Vítimas de Crime/psicologia , Feminino , Humanos , Masculino , Pais , Inquéritos e Questionários , Adulto Jovem
20.
Nurs Ethics ; 29(3): 527-539, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35142227

RESUMO

BACKGROUND: The coronavirus disease 2019 pandemic is impacting the delivery of healthcare worldwide, creating dilemmas related to the duty to care. Although understanding the ethical dilemmas about the duty to care among nurses is necessary to allow effective preparation, few studies have explored these concerns. AIM: This study aimed to identify the ethical dilemmas among clinical nurses in Spain and Chile. It primarily aimed to (1) identify nurses' agreement with the duty to care despite high risks for themselves and/or their families, (2) describe nurses' well-being and (3) describe the associations between well-being and the duty to care. RESEARCH DESIGN: Cross-sectional self-reported anonymous data were collected between May and June 2020 via electronic survey distribution (snowball sampling). ETHICAL CONSIDERATIONS: The Institutional Ethical Review Committees in both countries approved the study (CHUC_2020_33 and 27/2020). FINDINGS: In total, 345 clinical nurses answered the primary question about the duty to care for the sick. Although in the total sample 77.4% agreed they have a duty to care for the sick, significant differences were found between the Spanish and Chilean samples. Overall, 53.6% of the nurses reported low levels of well-being; however, among those reporting low well-being, statistically significant differences were found between Spanish and Chilean nurses as 19.4% and 37.8%, respectively, disagreed with the statement regarding the duty to care. DISCUSSION: Participants in both countries reported several ethical dilemmas, safety fears, consequent stress and low well-being. These results suggest that prompt actions are required to address nurses' ethical concerns, as they might affect their willingness to work and psychological well-being. CONCLUSION: Our findings shed light on the ethical dilemmas nurses are facing related to the duty to care. Not only has the coronavirus disease 2019 pandemic given rise to ethical challenges, but it has also affected nurses' well-being and willingness to work during a pandemic.


Assuntos
COVID-19 , Enfermeiras e Enfermeiros , Estudos Transversais , Humanos , Pandemias , Inquéritos e Questionários
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa