Dimethylsulfide oxidation over the tropical South Atlantic: OH and other oxidants

The general course of events in the formation of a marine cloud begins with the emission of species which can eventually serve as nuclei around which water can condense to form a cloud droplet. In remote marine regions, cloud condensation nuclei (CCN) are primarily composed of sulfate, in either its acid or ammonium salt form. Most sulfate in these regions is the product of atmospheric oxidation of dimethyl sulfide (DMS), a reduced sulfur gas that is released by phytoplankton at the ocean surface. Therefore, in order to effectively quantify the links in the cloud-formation cycle, one must begin with a well-defined description of the atmospheric chemistry of DMS. The intent of this project has been to initiate development of a comprehensive model of the chemistry and dynamics responsible for the formation of clouds in the remote marine boundary layer. The primary tool in this work has been the Global/Regional Atmospheric Chemistry Event Simulator (GRACES), a global atmospheric chemistry model, which is under development within the Atmospheric Chemistry and Dynamics Branch of NASA-Ames Research Center. In this effort, GRACES was used to explore the first chemical link between DMS and sulfate by modeling the diurnal variation of DMS

An overview of the Lagrangian experiments undertaken during the North Atlantic regional Aerosol Characterisation Experiment (ACE-2)

One of the primary aims of the North Atlantic regional Aerosol Characterisation Experiment (ACE-2) was to quantify the physical and chemical processes affecting the evolution of the major aerosol types over the North Atlantic. The best, practical way of doing this is in a Lagrangian framework where a parcel of air is sampled over several tens of hours and its physical and chemical properties are intensively measured. During the intensive observational phase of ACE-2, between 15 June 1997 and 24 July 1997, 3 cloudy Lagrangian experiments and 3 cloud-free, Lagrangian experiments were undertaken between the south west tip of the Iberian Peninsula and the Canary Islands. This paper gives an overview of the aims and logistics of all of the Lagrangian experiments and compares and contrasts them to provide a framework for the more focused Lagrangian papers in this issue and future process modelling studies and parametrisation development. The characteristics of the cloudy Lagrangian experiments were remarkably different, enabling a wide range of different physical and chemical processes to be studied. In the 1st Lagrangian, a clean maritime air mass was sampled in which salt particle production, due to increased wind speed, dominated the change in the accumulation mode concentrations. In the 2nd Lagrangian, extensive cloud cover resulted in cloud processing of the aerosol in a polluted air mass, and entrainment of air from the free troposphere influenced the overall decrease in aerosol concentrations in the marine boundary layer (MBL). Very little change in aerosol characteristics was measured in the 3rd Lagrangian, where the pollution in the MBL was continually being topped up by entraining air from a residual continental boundary layer (CBL) above. From the analysis of all the Lagrangian experiments, it has been possible to formulate, and present here, a generalised description of a European continental outbreak of pollution over the sub-tropical North Atlantic

The Design and Rationale of a Multicenter Real-World Trial: The Southeastern Collaboration To Improve Blood Pressure Control in the US Black Belt – Addressing the Triple Threat

BACKGROUND: Impoverished African Americans (AA) with hypertension face poor health outcomes. PURPOSE: To conduct a cluster-randomized trial testing two interventions, alone and in combination, to improve blood pressure (BP) control in AA with persistently uncontrolled hypertension. METHODS: We engaged primary care practices serving rural Alabama and North Carolina residents, and in each practice we recruited approximately 25 AA adults with persistently uncontrolled hypertension (mean systolic BP \u3e140 mmHg over the year prior to enrollment plus enrollment day BP assessed by research assistants ≥140/90 mmHg). Practices were randomized to peer coaching (PC), practice facilitation (PF), both PC and PF (PC + PF), or enhanced usual care (EUC). Coaches met with participants from PC and PC + PF practices weekly for 8 weeks then monthly over one year, discussing lifestyle changes, medication adherence, home monitoring, and communication with the healthcare team. Facilitators met with PF and PC + PF practices monthly to implement ≥1 quality improvement intervention in each of four domains. Data were collected at 0, 6, and 12 months. RESULTS: We recruited 69 practices and 1596 participants; 18 practices (408 participants) were randomized to EUC, 16 (384 participants) to PF, 19 (424 participants) to PC, and 16 (380 participants) to PC + PF. Participants had mean age 57 years, 61% were women, and 56% reported annual income \u3c$20,000. LIMITATIONS: The PF intervention acts at the practice level, possibly missing intervention effects in trial participants. Neither PC nor PF currently has established clinical reimbursement mechanisms. CONCLUSIONS: This trial will fill evidence gaps regarding practice-level vs. patient-level interventions for rural impoverished AA with uncontrolled hypertension

Practice Facilitation and Peer Coaching for Uncontrolled Hypertension Among Black Individuals: A Randomized Clinical Trial

IMPORTANCE: Rural Black participants need effective intervention to achieve better blood pressure (BP) control. OBJECTIVE: Among Black rural adults with persistently uncontrolled hypertension attending primary care clinics, to determine whether peer coaching (PC), practice facilitation (PF), or both (PCPF) are superior to enhanced usual care (EUC) in improving BP control. DESIGN, SETTING, AND PARTICIPANTS: A cluster randomized clinical trial was conducted in 69 rural primary care practices across Alabama and North Carolina between September 23, 2016, and September 26, 2019. The participating practices were randomized to 4 groups: PC plus EUC, PF plus EUC, PCPF plus EUC, and EUC alone. The baseline EUC approach included a laptop for each participating practice with hyperlinks to participant education on hypertension, a binder of practice tips, a poster showing an algorithm for stepped care to improve BP, and 25 home BP monitors. The trial was stopped on February 28, 2021, after final data collection. The study included Black participants with persistently uncontrolled hypertension. Data were analyzed from February 28, 2021, to December 13, 2022. INTERVENTIONS: Practice facilitators helped practices implement at least 4 quality improvement projects designed to improve BP control throughout 1 year. Peer coaches delivered a structured program via telephone on hypertension self-management throughout 1 year. MAIN OUTCOMES AND MEASURES: The primary outcome was the proportion of participants in each trial group with BP values of less than 140/90 mm Hg at 6 months and 12 months. The secondary outcome was a change in the systolic BP of participants at 6 months and 12 months. RESULTS: A total of 69 practices were randomized, and 1209 participants\u27 data were included in the analysis. The mean (SD) age of participants was 58 (12) years, and 748 (62%) were women. In the intention-to-treat analyses, neither intervention alone nor in combination improved BP control or BP levels more than EUC (at 12 months, PF vs EUC odds ratio [OR], 0.94 [95% CI, 0.58-1.52]; PC vs EUC OR, 1.30 [95% CI, 0.83-2.04]; PCPF vs EUC OR, 1.02 [95% CI, 0.64-1.64]). In preplanned subgroup analyses, participants younger than 60 years in the PC and PCPF groups experienced a significant 5 mm Hg greater reduction in systolic BP than participants younger than 60 years in the EUC group at 12 months. Practicewide BP control estimates in PF groups suggested that BP control improved from 54% to 61%, a finding that was not observed in the trial\u27s participants. CONCLUSIONS AND RELEVANCE: The results of this cluster randomized clinical trial demonstrated that neither PC nor PF demonstrated a superior improvement in overall BP control compared with EUC. However, PC led to a significant reduction in systolic BP among younger adults

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Evaluation of Scar Quality after Treatment of Superficial Burns with Dressilk^® and Suprathel^®—In an Intraindividual Clinical Setting

Background: Various synthetic and biological wound dressings are available for the treatment of superficial burns, and standard care differs among hospitals. Nevertheless, the search for an ideal wound dressing offering a safe healing environment as well as optimal scar quality while being economically attractive is a continuing process. In recent years, Dressilk®, which consists of pure silk, has become the standard of care for the treatment of superficial burns in our hospital. However, no long-term scar-evaluation studies have been performed to compare Dressilk® with the often-used and more expensive Suprathel® in the treatment of superficial burns. Methods: Subjective and objective scar evaluations were performed three, six, and twelve months after treatment in patients who received simultaneous treatment of 20 superficial burn wounds with both Suprathel® and Dressilk®. The evaluations were performed using the Vancouver Scar Scale, the Cutometer®, Mexameter®, Tewameter®, and the O2C®. Results: Both dressings showed mostly equivalent results in subjective scar evaluations. In the objective scar evaluations, the wounds treated with Dressilk® showed a faster return to the qualities of non-injured skin. Wound areas treated with the two dressings showed no significant differences in elasticity and transepidermal water loss after 12 months. Only oxygen saturation was significantly lower in wound areas treated with Suprathel® (p = 0.008). Subjectively, wound areas treated with Dressilk® showed significantly higher pigmentation after six months, which was not apparent after 12 months. Conclusion: Both wound dressings led to esthetically satisfying scar recovery without significant differences from normal uninjured skin after 12 months. Therefore, Dressilk® remains an economically and clinically interesting alternative to Suprathel® for the treatment of superficial burns