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1.
Nature ; 625(7996): 728-734, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38200314

RESUMO

Trees structure the Earth's most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1-6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth's 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world's most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.


Assuntos
Florestas , Árvores , Clima Tropical , Biodiversidade , Árvores/anatomia & histologia , Árvores/classificação , Árvores/crescimento & desenvolvimento , África , Sudeste Asiático
2.
Lancet ; 401(10373): 281-293, 2023 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-36566761

RESUMO

BACKGROUND: The safety, effectiveness, and cost-effectiveness of molnupiravir, an oral antiviral medication for SARS-CoV-2, has not been established in vaccinated patients in the community at increased risk of morbidity and mortality from COVID-19. We aimed to establish whether the addition of molnupiravir to usual care reduced hospital admissions and deaths associated with COVID-19 in this population. METHODS: PANORAMIC was a UK-based, national, multicentre, open-label, multigroup, prospective, platform adaptive randomised controlled trial. Eligible participants were aged 50 years or older-or aged 18 years or older with relevant comorbidities-and had been unwell with confirmed COVID-19 for 5 days or fewer in the community. Participants were randomly assigned (1:1) to receive 800 mg molnupiravir twice daily for 5 days plus usual care or usual care only. A secure, web-based system (Spinnaker) was used for randomisation, which was stratified by age (<50 years vs ≥50 years) and vaccination status (yes vs no). COVID-19 outcomes were tracked via a self-completed online daily diary for 28 days after randomisation. The primary outcome was all-cause hospitalisation or death within 28 days of randomisation, which was analysed using Bayesian models in all eligible participants who were randomly assigned. This trial is registered with ISRCTN, number 30448031. FINDINGS: Between Dec 8, 2021, and April 27, 2022, 26 411 participants were randomly assigned, 12 821 to molnupiravir plus usual care, 12 962 to usual care alone, and 628 to other treatment groups (which will be reported separately). 12 529 participants from the molnupiravir plus usual care group, and 12 525 from the usual care group were included in the primary analysis population. The mean age of the population was 56·6 years (SD 12·6), and 24 290 (94%) of 25 708 participants had had at least three doses of a SARS-CoV-2 vaccine. Hospitalisations or deaths were recorded in 105 (1%) of 12 529 participants in the molnupiravir plus usual care group versus 98 (1%) of 12 525 in the usual care group (adjusted odds ratio 1·06 [95% Bayesian credible interval 0·81-1·41]; probability of superiority 0·33). There was no evidence of treatment interaction between subgroups. Serious adverse events were recorded for 50 (0·4%) of 12 774 participants in the molnupiravir plus usual care group and for 45 (0·3%) of 12 934 in the usual care group. None of these events were judged to be related to molnupiravir. INTERPRETATION: Molnupiravir did not reduce the frequency of COVID-19-associated hospitalisations or death among high-risk vaccinated adults in the community. FUNDING: UK National Institute for Health and Care Research.


Assuntos
COVID-19 , Adulto , Humanos , Pessoa de Meia-Idade , SARS-CoV-2 , Vacinas contra COVID-19 , Teorema de Bayes , Estudos Prospectivos , Resultado do Tratamento
3.
Clin Trials ; 20(1): 36-46, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36541257

RESUMO

BACKGROUND: Platelet transfusion is a potentially life-saving therapy for actively bleeding patients, ranging from those undergoing planned surgical procedures to those suffering unexpected traumatic injuries. Platelets are currently stored at room temperature (20°C-24°C) with a maximum storage duration of 7 days after donation. The CHIlled Platelet Study trial will compare the efficacy and safety of standard room temperature-stored platelets with platelets that are cold-stored (1°C-6°C), that is, chilled, with a maximum of storage up to 21 days in adult and pediatric patients undergoing complex cardiac surgical procedures. METHODS/RESULTS: CHIlled Platelet Study will use a Bayesian adaptive design to identify the range of cold storage durations for platelets that are non-inferior to standard room temperature-stored platelets. If cold-stored platelets are non-inferior at durations greater than 7 days, a gated superiority analysis will identify durations for which cold-stored platelets may be superior to standard platelets. We present example simulations of the CHIlled Platelet Study design and discuss unique challenges in trial implementation. The CHIlled Platelet Study trial has been funded and will be implemented in approximately 20 clinical centers. Early randomization to enable procurement of cold-stored platelets with different storage durations will be required, as well as a platelet tracking system to eliminate platelet wastage and maximize trial efficiency and economy. DISCUSSION: The CHIlled Platelet Study trial will determine whether cold-stored platelets are non-inferior to platelets stored at room temperature, and if so, will determine the maximum duration (up to 21 days) of storage that maintains non-inferiority. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04834414.


Assuntos
Plaquetas , Preservação de Sangue , Adulto , Humanos , Criança , Teorema de Bayes , Preservação de Sangue/métodos , Transfusão de Plaquetas/métodos , Criopreservação/métodos
4.
Pediatr Dermatol ; 40(1): 84-89, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36373243

RESUMO

BACKGROUND/OBJECTIVES: Pediatric lichen planus (LP) is rare with variable prevalence and atypical presentations compared to adults. Data on LP are lacking for the pediatric population in the United States. We present demographics, presentations, and treatments for a pediatric LP cohort. METHODS: We reviewed 26 patients diagnosed with LP at 20 years or younger. Treatment responses were defined as no response, partial response, and complete response. RESULTS: Demographics included 54% females and median diagnosis age of 16 years (range 6-20). Most patients presented with cutaneous LP (65%), with fewer having associated oral (23%), nail (7.7%), or genital (3.8%) involvement. Some had cutaneous-only LP (38%) or strictly mucosal LP (oral-only 19% and genital-only 15%). LP lesions were pruritic (50%), painful (19%), and/or asymptomatic (35%). Complete/partial responses occurred with medium-potency topical corticosteroids in cutaneous (n = 7; 64%), oral (n = 3; 75%), and genital LP (n = 3; 100%), with high/ultra-high potency topical corticosteroids in oral LP (n = 6; 86%), and with topical calcineurin inhibitors in genital LP (n = 2; 100%). Side effects were clobetasol-related oral candidiasis and biopsy-related penile depressed scar. Most patients with available follow-up achieved remission (n = 17; 81%). CONCLUSIONS: Pediatric LP usually presents in adolescence with cutaneous involvement and is symptomatic. However, patients frequently can have oral, genital, or nail lesions or may be asymptomatic, so they need thorough examinations and follow-up. Long-term remission is common due to treatment or natural disease course. Medium-potency corticosteroids are recommended for cutaneous, oral, and genital LP. Various other local and systemic therapies exist with successful treatment responses.


Assuntos
Líquen Plano Bucal , Líquen Plano , Adulto , Feminino , Humanos , Criança , Adolescente , Adulto Jovem , Masculino , Seguimentos , Estudos Retrospectivos , Líquen Plano/diagnóstico , Líquen Plano/tratamento farmacológico , Líquen Plano/patologia , Líquen Plano Bucal/diagnóstico , Líquen Plano Bucal/tratamento farmacológico , Corticosteroides/uso terapêutico
5.
Lancet ; 398(10303): 843-855, 2021 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-34388395

RESUMO

BACKGROUND: A previous efficacy trial found benefit from inhaled budesonide for COVID-19 in patients not admitted to hospital, but effectiveness in high-risk individuals is unknown. We aimed to establish whether inhaled budesonide reduces time to recovery and COVID-19-related hospital admissions or deaths among people at high risk of complications in the community. METHODS: PRINCIPLE is a multicentre, open-label, multi-arm, randomised, controlled, adaptive platform trial done remotely from a central trial site and at primary care centres in the UK. Eligible participants were aged 65 years or older or 50 years or older with comorbidities, and unwell for up to 14 days with suspected COVID-19 but not admitted to hospital. Participants were randomly assigned to usual care, usual care plus inhaled budesonide (800 µg twice daily for 14 days), or usual care plus other interventions, and followed up for 28 days. Participants were aware of group assignment. The coprimary endpoints are time to first self-reported recovery and hospital admission or death related to COVID-19, within 28 days, analysed using Bayesian models. The primary analysis population included all eligible SARS-CoV-2-positive participants randomly assigned to budesonide, usual care, and other interventions, from the start of the platform trial until the budesonide group was closed. This trial is registered at the ISRCTN registry (ISRCTN86534580) and is ongoing. FINDINGS: The trial began enrolment on April 2, 2020, with randomisation to budesonide from Nov 27, 2020, until March 31, 2021, when the prespecified time to recovery superiority criterion was met. 4700 participants were randomly assigned to budesonide (n=1073), usual care alone (n=1988), or other treatments (n=1639). The primary analysis model includes 2530 SARS-CoV-2-positive participants, with 787 in the budesonide group, 1069 in the usual care group, and 974 receiving other treatments. There was a benefit in time to first self-reported recovery of an estimated 2·94 days (95% Bayesian credible interval [BCI] 1·19 to 5·12) in the budesonide group versus the usual care group (11·8 days [95% BCI 10·0 to 14·1] vs 14·7 days [12·3 to 18·0]; hazard ratio 1·21 [95% BCI 1·08 to 1·36]), with a probability of superiority greater than 0·999, meeting the prespecified superiority threshold of 0·99. For the hospital admission or death outcome, the estimated rate was 6·8% (95% BCI 4·1 to 10·2) in the budesonide group versus 8·8% (5·5 to 12·7) in the usual care group (estimated absolute difference 2·0% [95% BCI -0·2 to 4·5]; odds ratio 0·75 [95% BCI 0·55 to 1·03]), with a probability of superiority 0·963, below the prespecified superiority threshold of 0·975. Two participants in the budesonide group and four in the usual care group had serious adverse events (hospital admissions unrelated to COVID-19). INTERPRETATION: Inhaled budesonide improves time to recovery, with a chance of also reducing hospital admissions or deaths (although our results did not meet the superiority threshold), in people with COVID-19 in the community who are at higher risk of complications. FUNDING: National Institute of Health Research and United Kingdom Research Innovation.


Assuntos
Budesonida/administração & dosagem , Tratamento Farmacológico da COVID-19 , Glucocorticoides/administração & dosagem , Administração por Inalação , Idoso , Teorema de Bayes , COVID-19/mortalidade , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , SARS-CoV-2 , Resultado do Tratamento
6.
Clin Trials ; 19(5): 490-501, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35993547

RESUMO

BACKGROUND: Multi-arm platform trials investigate multiple agents simultaneously, typically with staggered entry and exit of experimental treatment arms versus a shared control arm. In such settings, there is considerable debate whether to limit analyses for a treatment arm to concurrent randomized control subjects or to allow comparisons to both concurrent and non-concurrent (pooled) control subjects. The potential bias from temporal drift over time is at the core of this debate. METHODS: We propose time-adjusted analyses, including a "Bayesian Time Machine," to model potential temporal drift in the entire study population, such that primary analyses can incorporate all randomized control subjects from the platform trial. We conduct a simulation study to assess performance relative to utilizing concurrent or pooled controls. RESULTS: In multi-arm platform trials with staggered entry, analyses adjusting for temporal drift (either Bayesian or frequentist) have superior estimation of treatment effects and favorable testing properties compared to analyses using either concurrent or pooled controls. The Bayesian Time Machine generally provides estimates with greater precision and smaller mean square error than alternative approaches, at the risk of small bias and small Type I error inflation. CONCLUSIONS: The Bayesian Time Machine provides a compromise between bias and precision by smoothing estimates across time and leveraging all available data for the estimation of treatment effects. Prior distributions controlling the behavior of dynamic smoothing across time must be pre-specified and carefully calibrated to the unique context of each trial, appropriately accounting for the population, disease, and endpoints.


Assuntos
Projetos de Pesquisa , Teorema de Bayes , Viés , Protocolos Clínicos , Simulação por Computador , Humanos
7.
Clin Trials ; 19(6): 636-646, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35786002

RESUMO

BACKGROUND/AIMS: Fibrinolytic therapy with tenecteplase has been proposed for patients with pulmonary embolism but the optimal dose is unknown. Higher-than-necessary dosing is likely to cause excess bleeding. We designed an adaptive clinical trial to identify the minimum and assumed safest dose of tenecteplase that maintains efficacy. METHODS: We propose a Bayesian adaptive, placebo-controlled, group-sequential dose-finding trial using response-adaptive randomization to preferentially allocate subjects to the most promising doses, dual analyses strategies (continuous and dichotomized) using a gatekeeping approach to maximize clinical impact, and interim stopping rules to efficiently address competing trial objectives. The operating characteristics of the proposed design were evaluated using Monte Carlo simulation across multiple hypothetical efficacy scenarios. RESULTS: Simulation demonstrated response-adaptive randomization can preferentially allocate subjects to doses which appear to be performing well based on interim data. Interim decision-making, including the interim evaluation of both analysis strategies with gatekeeping, allows the trial to continue enrollment when success with the dichotomized analysis strategy appears sufficiently likely and to stop enrollment and declare superiority based on the continuous analysis strategy when there is little chance of ultimately declaring superiority with the dichotomized analysis. CONCLUSION: The proposed design allows evaluation of a greater number of dose levels than would be possible with a non-adaptive design and avoids the need to choose either the continuous or the dichotomized analysis strategy for the primary endpoint.


Assuntos
Embolia Pulmonar , Projetos de Pesquisa , Humanos , Doença Aguda , Teorema de Bayes , Ensaios Clínicos como Assunto , Relação Dose-Resposta a Droga , Embolia Pulmonar/tratamento farmacológico , Tenecteplase/uso terapêutico
10.
Glob Chang Biol ; 22(4): 1406-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26499288

RESUMO

We combined two existing datasets of vegetation aboveground biomass (AGB) (Proceedings of the National Academy of Sciences of the United States of America, 108, 2011, 9899; Nature Climate Change, 2, 2012, 182) into a pan-tropical AGB map at 1-km resolution using an independent reference dataset of field observations and locally calibrated high-resolution biomass maps, harmonized and upscaled to 14 477 1-km AGB estimates. Our data fusion approach uses bias removal and weighted linear averaging that incorporates and spatializes the biomass patterns indicated by the reference data. The method was applied independently in areas (strata) with homogeneous error patterns of the input (Saatchi and Baccini) maps, which were estimated from the reference data and additional covariates. Based on the fused map, we estimated AGB stock for the tropics (23.4 N-23.4 S) of 375 Pg dry mass, 9-18% lower than the Saatchi and Baccini estimates. The fused map also showed differing spatial patterns of AGB over large areas, with higher AGB density in the dense forest areas in the Congo basin, Eastern Amazon and South-East Asia, and lower values in Central America and in most dry vegetation areas of Africa than either of the input maps. The validation exercise, based on 2118 estimates from the reference dataset not used in the fusion process, showed that the fused map had a RMSE 15-21% lower than that of the input maps and, most importantly, nearly unbiased estimates (mean bias 5 Mg dry mass ha(-1) vs. 21 and 28 Mg ha(-1) for the input maps). The fusion method can be applied at any scale including the policy-relevant national level, where it can provide improved biomass estimates by integrating existing regional biomass maps as input maps and additional, country-specific reference datasets.


Assuntos
Biomassa , Mapas como Assunto , Conjuntos de Dados como Assunto , Modelos Teóricos , Árvores , Clima Tropical
11.
J Neurooncol ; 121(1): 19-29, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25344882

RESUMO

Malignant gliomas represent one of the most aggressive forms of cancer, displaying high mortality rates and limited treatment options. Specific subpopulations of cells residing in the tumor niche with stem-like characteristics have been postulated to initiate and maintain neoplasticity while resisting conventional therapies. The study presented here aims to define the role of glycogen synthase kinase 3 beta (GSK3b) in patient-derived glioblastoma (GBM) stem-like cell (GSC) proliferation, apoptosis and invasion. To evaluate the potential role of GSK3b in GBM, protein profiles from 68 GBM patients and 20 normal brain samples were analyzed for EGFR-mediated PI3kinase/Akt and GSK3b signaling molecules including protein phosphatase 2A (PP2A). To better understand the function of GSK3b in GBM, GSCs were isolated from GBM patient samples. Blocking GSK3b phosphorylation at Serine 9 attenuated cell proliferation while concomitantly stimulating apoptosis through activation of Caspase-3 in patient-derived GSCs. Increasing GSK3b protein content resulted in the inhibition of cell proliferation, colony formation and stimulated programmed cell death. Depleting GSK3b in GSCs down regulated PP2A. Furthermore, knocking down PP2A or blocking its activity by okadaic acid inactivated GSK3b by increasing GSK3b phosphorylation at Serine 9. Our data suggests that GSK3b may function as a regulator of apoptosis and tumorigenesis in GSCs. Therapeutic approaches targeting GSK3b in glioblastoma stem-like cells may be a useful addition to our current therapeutic armamentarium.


Assuntos
Neoplasias Encefálicas/fisiopatologia , Encéfalo/fisiopatologia , Receptores ErbB/metabolismo , Glioblastoma/fisiopatologia , Quinase 3 da Glicogênio Sintase/metabolismo , Proteína Fosfatase 2/metabolismo , Apoptose/fisiologia , Carcinogênese , Caspase 3/metabolismo , Proliferação de Células/fisiologia , Sobrevivência Celular/fisiologia , Glicogênio Sintase Quinase 3 beta , Humanos , Células-Tronco Neoplásicas/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais
12.
J Infect ; 89(4): 106248, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39216829

RESUMO

BACKGROUND: Evidence for the effect of favipiravir treatment of acute COVID-19 on recovery, hospital admissions and longer-term outcomes in community settings is limited. METHODS: In this multicentre. open-label, multi-arm, adaptive platform randomised controlled trial participants aged ≥18 years in the community with a positive test for SARS-CoV-2 and symptoms lasting ≤14 days were randomised to: usual care; usual care plus favipiravir tablets (loading dose of 3600 mg in divided doses on day one, then 800 mg twice a day for four days); or, usual care plus other interventions. Co-primary endpoints were time to first self-reported recovery and hospitalisation/death related to COVID-19, within 28 days, analysed using Bayesian models. Recovery at six months was the primary longer-term outcome. TRIAL REGISTRATION: ISRCTN86534580. FINDINGS: The primary analysis model included 8811 SARS-CoV-2 positive mostly COVID vaccinated participants, randomised to favipiravir (n = 1829), usual care (n = 3256), and other treatments (n = 3726). Time to self-reported recovery was shorter in the favipiravir group than usual care (estimated hazard ratio 1·23 [95% credible interval 1·14 to 1·33]), a reduction of 2·98 days [1·99 to 3·94] from 16 days in median time to self-reported recovery for favipiravir versus usual care alone. COVID-19 related hospitalisations/deaths were similar (estimated odds ratio 0·99 [0·61 to 1·61]; estimated difference 0% [-0·9% to 0·6%]). 14 serious adverse events occurred in the favipiravir group and 4 in usual care. By six months, the proportion feeling fully recovered was 74·9% for favipiravir versus 71·3% for usual care (RR = 1·05, [1·02 to 1·08]). INTERPRETATION: In this open-label trial in a largely vaccinated population with COVID-19 in the community, favipiravir did not reduce hospital admissions, but shortened time to recovery and had a marginal positive impact on long term outcomes.


Assuntos
Amidas , Antivirais , Tratamento Farmacológico da COVID-19 , COVID-19 , Pirazinas , SARS-CoV-2 , Humanos , Pirazinas/uso terapêutico , Pirazinas/administração & dosagem , Amidas/uso terapêutico , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Antivirais/uso terapêutico , Antivirais/administração & dosagem , COVID-19/mortalidade , Resultado do Tratamento , Idoso , Hospitalização/estatística & dados numéricos
13.
J Infect ; 88(4): 106130, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38431155

RESUMO

BACKGROUND: The evidence for whether ivermectin impacts recovery, hospital admissions, and longer-term outcomes in COVID-19 is contested. The WHO recommends its use only in the context of clinical trials. METHODS: In this multicentre, open-label, multi-arm, adaptive platform randomised controlled trial, we included participants aged ≥18 years in the community, with a positive SARS-CoV-2 test, and symptoms lasting ≤14 days. Participants were randomised to usual care, usual care plus ivermectin tablets (target 300-400 µg/kg per dose, once daily for 3 days), or usual care plus other interventions. Co-primary endpoints were time to first self-reported recovery, and COVID-19 related hospitalisation/death within 28 days, analysed using Bayesian models. Recovery at 6 months was the primary, longer term outcome. TRIAL REGISTRATION: ISRCTN86534580. FINDINGS: The primary analysis included 8811 SARS-CoV-2 positive participants (median symptom duration 5 days), randomised to ivermectin (n = 2157), usual care (n = 3256), and other treatments (n = 3398) from June 23, 2021 to July 1, 2022. Time to self-reported recovery was shorter in the ivermectin group compared with usual care (hazard ratio 1·15 [95% Bayesian credible interval, 1·07 to 1·23], median decrease 2.06 days [1·00 to 3·06]), probability of meaningful effect (pre-specified hazard ratio ≥1.2) 0·192). COVID-19-related hospitalisations/deaths (odds ratio 1·02 [0·63 to 1·62]; estimated percentage difference 0% [-1% to 0·6%]), serious adverse events (three and five respectively), and the proportion feeling fully recovered were similar in both groups at 6 months (74·3% and 71·2% respectively (RR = 1·05, [1·02 to 1·08]) and also at 3 and 12 months. INTERPRETATION: Ivermectin for COVID-19 is unlikely to provide clinically meaningful improvement in recovery, hospital admissions, or longer-term outcomes. Further trials of ivermectin for SARS-Cov-2 infection in vaccinated community populations appear unwarranted. FUNDING: UKRI/National Institute of Health Research (MC_PC_19079).


Assuntos
COVID-19 , Adulto , Humanos , Adolescente , SARS-CoV-2 , Ivermectina/uso terapêutico , Teorema de Bayes , Resultado do Tratamento
14.
J Am Chem Soc ; 135(11): 4412-24, 2013 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-23398377

RESUMO

Iron pyrite (cubic FeS2) is a promising candidate absorber material for earth-abundant thin-film solar cells. Here, we report on phase-pure, large-grain, and uniform polycrystalline pyrite films that are fabricated by solution-phase deposition of an iron(III) acetylacetonate molecular ink followed by sequential annealing in air, H2S, and sulfur gas at temperatures up to 550 °C. Phase and elemental compositions of the films are characterized by conventional and synchrotron X-ray diffraction, Raman spectroscopy, Auger electron spectroscopy, secondary ion mass spectrometry, and X-ray photoelectron spectroscopy (XPS). These solution-deposited films have more oxygen and alkalis, less carbon and hydrogen, and smaller optical band gaps (E(g) = 0.87 ± 0.05 eV) than similar films made by chemical vapor deposition. XPS is used to assess the chemical composition of the film surface before and after exposure to air and immersion in water to remove surface contaminants. Optical measurements of films rich in marcasite (orthorhombic FeS2) show that marcasite has a band gap at least as large as pyrite and that the two polymorphs share similar absorptivity spectra, in excellent agreement with density functional theory models. Regardless of the marcasite and elemental impurity contents, all films show p-type, weakly activated transport with curved Arrhenius plots, a room-temperature resistivity of ~1 Ω cm, and a hole mobility that is too small to measure by Hall effect. This universal electrical behavior strongly suggests that a common defect or a hole-rich surface layer governs the electrical properties of most FeS2 thin films.

15.
Int J Womens Dermatol ; 8(3): e009, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35822192

RESUMO

Autoimmune progesterone dermatitis (APD) is a rare hypersensitivity disorder characterized by recurring dermatologic manifestations during the luteal phase of the menstrual cycle in women. Well-defined clinical and diagnostic criteria, outcomes measurements, and standard treatments are lacking. Methods: We performed a single-institution retrospective review of adult patients (older than 20 years at the time of diagnosis) with APD. Results: Fourteen patients were included with mean age of clinical onset of 34.3 ± 7.7 (range 24-54) years. There was a delay of 3.9 ± 5.5 (range 0.4-20) years between the onset of disease symptoms and diagnosis. The onset of APD was after exposure to exogenous progesterone in 9 of 14 patients. Progesterone skin test was performed in 9 patients and 6 were positive. Patients frequently presented with urticaria (9/14, 64.3%) and dermatitis (4/14, 28.6%). Continuous combined oral contraceptives (4/14, 28.6%), gonadotropin-releasing hormone agonist (3/14, 21.4%), and hysterectomy with bilateral salpingo-oophorectomy (2/14, 14.3%) were the most common attempted treatments with reliable outcomes. Conclusions: APD is a rare disorder which lacks universal diagnostic measures and criteria, contributing to a significant delay in diagnosis. Large-scale multicenter studies are needed to develop accurate tests, establish diagnostic criteria, and define treatment outcomes.

16.
Br J Gen Pract ; 72(720): e446-e455, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35440469

RESUMO

BACKGROUND: Colchicine has been proposed as a COVID-19 treatment. AIM: To determine whether colchicine reduces time to recovery and COVID-19-related admissions to hospital and/or deaths among people in the community. DESIGN AND SETTING: Prospective, multicentre, open-label, multi-arm, randomised, controlled, adaptive platform trial (PRINCIPLE). METHOD: Adults aged ≥65 years or ≥18 years with comorbidities or shortness of breath, and unwell for ≤14 days with suspected COVID-19 in the community, were randomised to usual care, usual care plus colchicine (500 µg daily for 14 days), or usual care plus other interventions. The co-primary endpoints were time to first self-reported recovery and admission to hospital/death related to COVID-19, within 28 days, analysed using Bayesian models. RESULTS: The trial opened on 2 April 2020. Randomisation to colchicine started on 4 March 2021 and stopped on 26 May 2021 because the prespecified time to recovery futility criterion was met. The primary analysis model included 2755 participants who were SARS-CoV-2 positive, randomised to colchicine (n = 156), usual care (n = 1145), and other treatments (n = 1454). Time to first self-reported recovery was similar in the colchicine group compared with usual care with an estimated hazard ratio of 0.92 (95% credible interval (CrI) = 0.72 to 1.16) and an estimated increase of 1.4 days in median time to self-reported recovery for colchicine versus usual care. The probability of meaningful benefit in time to recovery was very low at 1.8%. COVID-19-related admissions to hospital/deaths were similar in the colchicine group versus usual care, with an estimated odds ratio of 0.76 (95% CrI = 0.28 to 1.89) and an estimated difference of -0.4% (95% CrI = -2.7 to 2.4). CONCLUSION: Colchicine did not improve time to recovery in people at higher risk of complications with COVID-19 in the community.


Assuntos
Tratamento Farmacológico da COVID-19 , Adulto , Teorema de Bayes , Colchicina/uso terapêutico , Humanos , Estudos Prospectivos , SARS-CoV-2 , Resultado do Tratamento
17.
Ambio ; 51(9): 1978-1993, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35503201

RESUMO

Blue Carbon Ecosystems (BCEs) help mitigate and adapt to climate change but their integration into policy, such as Nationally Determined Contributions (NDCs), remains underdeveloped. Most BCE conservation requires community engagement, hence community-scale projects must be nested within the implementation of NDCs without compromising livelihoods or social justice. Thirty-three experts, drawn from academia, project development and policy, each developed ten key questions for consideration on how to achieve this. These questions were distilled into ten themes, ranked in order of importance, giving three broad categories of people, policy & finance, and science & technology. Critical considerations for success include the need for genuine participation by communities, inclusive project governance, integration of local work into national policies and practices, sustaining livelihoods and income (for example through the voluntary carbon market and/or national Payment for Ecosystem Services and other types of financial compensation schemes) and simplification of carbon accounting and verification methodologies to lower barriers to entry.


Assuntos
Carbono , Ecossistema , Sequestro de Carbono , Mudança Climática , Conservação dos Recursos Naturais/métodos , Humanos
18.
J Am Chem Soc ; 133(4): 716-9, 2011 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-21175173

RESUMO

Iron pyrite (FeS2) is a promising earth-abundant semiconductor for thin-film solar cells. In this work, phase-pure, single-crystalline, and well-dispersed colloidal FeS2 nanocrystals (NCs) were synthesized in high yield by a simple hot-injection route in octadecylamine and then were subjected to partial ligand exchange with octadecylxanthate to yield stable pyrite NC inks. Polycrystalline pyrite thin films were fabricated by sintering layers of these NCs at 500−600 °C under a sulfur atmosphere.

19.
Stat Anal Data Min ; 14(1): 41-60, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33664929

RESUMO

Handwritten documents can be characterized by their content or by the shape of the written characters. We focus on the problem of comparing a person's handwriting to a document of unknown provenance using the shape of the writing, as is done in forensic applications. To do so, we first propose a method for processing scanned handwritten documents to decompose the writing into small graphical structures, often corresponding to letters. We then introduce a measure of distance between two such structures that is inspired by the graph edit distance, and a measure of center for a collection of the graphs. These measurements are the basis for an outlier tolerant K-means algorithm to cluster the graphs based on structural attributes, thus creating a template for sorting new documents. Finally, we present a Bayesian hierarchical model to capture the propensity of a writer for producing graphs that are assigned to certain clusters. We illustrate the methods using documents from the Computer Vision Lab dataset. We show results of the identification task under the cluster assignments and compare to the same modeling, but with a less flexible grouping method that is not tolerant of incidental strokes or outliers.

20.
Lancet Respir Med ; 9(9): 1010-1020, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34329624

RESUMO

BACKGROUND: Doxycycline is often used for treating COVID-19 respiratory symptoms in the community despite an absence of evidence from clinical trials to support its use. We aimed to assess the efficacy of doxycycline to treat suspected COVID-19 in the community among people at high risk of adverse outcomes. METHODS: We did a national, open-label, multi-arm, adaptive platform randomised trial of interventions against COVID-19 in older people (PRINCIPLE) across primary care centres in the UK. We included people aged 65 years or older, or 50 years or older with comorbidities (weakened immune system, heart disease, hypertension, asthma or lung disease, diabetes, mild hepatic impairment, stroke or neurological problem, and self-reported obesity or body-mass index of 35 kg/m2 or greater), who had been unwell (for ≤14 days) with suspected COVID-19 or a positive PCR test for SARS-CoV-2 infection in the community. Participants were randomly assigned using response adaptive randomisation to usual care only, usual care plus oral doxycycline (200 mg on day 1, then 100 mg once daily for the following 6 days), or usual care plus other interventions. The interventions reported in this manuscript are usual care plus doxycycline and usual care only; evaluations of other interventions in this platform trial are ongoing. The coprimary endpoints were time to first self-reported recovery, and hospitalisation or death related to COVID-19, both measured over 28 days from randomisation and analysed by intention to treat. This trial is ongoing and is registered with ISRCTN, 86534580. FINDINGS: The trial opened on April 2, 2020. Randomisation to doxycycline began on July 24, 2020, and was stopped on Dec 14, 2020, because the prespecified futility criterion was met; 2689 participants were enrolled and randomised between these dates. Of these, 2508 (93·3%) participants contributed follow-up data and were included in the primary analysis: 780 (31·1%) in the usual care plus doxycycline group, 948 in the usual care only group (37·8%), and 780 (31·1%) in the usual care plus other interventions group. Among the 1792 participants randomly assigned to the usual care plus doxycycline and usual care only groups, the mean age was 61·1 years (SD 7·9); 999 (55·7%) participants were female and 790 (44·1%) were male. In the primary analysis model, there was little evidence of difference in median time to first self-reported recovery between the usual care plus doxycycline group and the usual care only group (9·6 [95% Bayesian Credible Interval [BCI] 8·3 to 11·0] days vs 10·1 [8·7 to 11·7] days, hazard ratio 1·04 [95% BCI 0·93 to 1·17]). The estimated benefit in median time to first self-reported recovery was 0·5 days [95% BCI -0·99 to 2·04] and the probability of a clinically meaningful benefit (defined as ≥1·5 days) was 0·10. Hospitalisation or death related to COVID-19 occurred in 41 (crude percentage 5·3%) participants in the usual care plus doxycycline group and 43 (4·5%) in the usual care only group (estimated absolute percentage difference -0·5% [95% BCI -2·6 to 1·4]); there were five deaths (0·6%) in the usual care plus doxycycline group and two (0·2%) in the usual care only group. INTERPRETATION: In patients with suspected COVID-19 in the community in the UK, who were at high risk of adverse outcomes, treatment with doxycycline was not associated with clinically meaningful reductions in time to recovery or hospital admissions or deaths related to COVID-19, and should not be used as a routine treatment for COVID-19. FUNDING: UK Research and Innovation, Department of Health and Social Care, National Institute for Health Research.


Assuntos
Antibacterianos/administração & dosagem , Tratamento Farmacológico da COVID-19 , Doxiciclina/administração & dosagem , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/efeitos adversos , COVID-19/diagnóstico , COVID-19/mortalidade , COVID-19/virologia , Doxiciclina/efeitos adversos , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Diferença Mínima Clinicamente Importante , Fatores de Risco , SARS-CoV-2/isolamento & purificação , Autorrelato/estatística & dados numéricos , Resultado do Tratamento , Reino Unido/epidemiologia
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