Controllable Synthesis of Multifunctional, Two-Dimensional Carbon Sheets at Low Temperatures

Department of Materials Science and EngineeringThis dissertation studies that a monolithic form of Graphene Oxide (GO) sheets can be physically synthesized on a copper (Cu) surface at low temperatures (≤ 260°C), with tunable oxygen-to-carbon (O/C) composition. In our approach, we build a graphene framework on the reverse side of a Cu foil at a Cu/substrate interface by exploiting the solid-state diffusion of C atoms across a diffusion couple composed of a C-Cu/substrate. A combined experimental and theoretical study shows that the Cu foil provides an effective pathway for C diffusion, trapping the O species dissolved in Cu and enabling the formation of monolithic GO sheets on its surface after an incubation time. In contrast to chemically-derived GO, the as-synthesized GO sheets were electrically active and the O/C composition in GO can be tuned during synthesis process by controlling the O content in the Cu foil prior to the solid-state diffusion process. The resulting GO sheets exhibited tunable bandgap energy by varying the O/C composition, making them potentially useful for flexible and transparent semiconducting applications. The GO films showed the ambipolar transfer characteristics in bottom-gate field-effect transistor (FET) architectures and the electronic properties were found to correlate closely with the bandgap energy. These results suggest that monolithic, two-dimensional chemically-modified C sheets with controllable composition can be prepared at low temperatures, which is highly desirable for graphene-based device production.ope

Enhancement of seawater corrosion resistance in copper using acetone-derived graphene coating

We show that acetone-derived graphene coating can effectively enhance the corrosion efficiency of copper (Cu) in a seawater environment (0.5-0.6 M (???3.0-3.5%) sodium chloride). By applying a drop of acetone (???20 ??l cm-2) on Cu surfaces, rapid thermal annealing allows the facile and rapid synthesis of graphene films on Cu surfaces with a monolayer coverage of almost close to ???100%. Under optimal growth conditions, acetone-derived graphene is found to have a relatively high crystallinity, comparable to common graphene grown by chemical vapor deposition. The resulting graphene-coated Cu surface exhibits 37.5 times higher corrosion resistance as compared to that of mechanically polished Cu. Further, investigation on the role of graphene coating on Cu surfaces suggests that the outstanding corrosion inhibition efficiency (IE) of 97.4% is obtained by protecting the underlying Cu against the penetration of both dissolved oxygen and chlorine ions, thanks to the closely spaced atomic structure of the graphene sheets. The increase of graphene coating thickness results in the enhancement of the overall corrosion IE up to ???99%, which can be attributed to the effective blocking of the ionic diffusion process via grain boundaries. Overall, our results suggest that the acetone-derived graphene film can effectively serve as a corrosion-inhibiting coating in the seawater level and that it may have a promising role to play for potential offshore coating.close0

Increased Circulating Endothelial Microparticles and Carotid Atherosclerosis in Obstructive Sleep Apnea

Background and Purpose Endothelial impairment is a linking mechanism between obstructive sleep apnea (USA) and cardiovascular diseases Profiles of endothelial micropanicles (EMPs) and endothelial progenitor cells (EPCs) reflect the degree of endothelial impairment The aims of this study were to measure the levels of EMI`s and progenitor cells in USA, determine the correlations between these factors and USA severity and the deuce of atherosclerosis, and document any changes in these factors after therapy Methods Subjects with (n=82) and without (n=22) OSA were recruited prospectively We measured the number of colony-forming units (CM) in cell cultuie as the endothelial progenitor cell index, and the number of EMPs using flow cytometry with CD31 [platelet endothelial cell adhesion molecule (PECAM)], CD42 (platelet glycoprotem), annexm V, and CD62E (E-selectin) antibodies at baseline and Act 4-6 weeks of continuous positive airway pressure (CPA P) therapy Carotid int ima-media thickness (IMT) was regarded as a marker of atherosclerosis Results The levels of PECAM(+)CD42(-) (p<0 001). PECAM(+)annexin V(+) (p<0 001), and E-selectin(+) micropamcles (p=0 001) were higher in USA subjects than in non-USA subjects The number of CRJ did not differ between the two groups OSA severity independently predicted the levels of PECAM(+)CD42(-) (p=0 02) and PECA(+)annexin V(+) (p=0 004) Carotid IMT was correlated with USA severity (p<0 001), PECAM(+)CD42: (p=0 03), and PECAM(+)annexin (p=0 01) Neither USA severity nor carotid IMT was correlated with either the number of CFI) or E-selectin(+) CPAP therapy decreased the occurrence of E-selecte (p<0 001) in 21 of the USA subjects, but had no effect on the other micioparticles of the number CFU Conclusions USA led to the overproduction of EMI`s, which moderately correlated with USA seventy and the degree of atherosclerosis, and partly responded to therapy The endothelial impairment might contribute to future cardiovascular events J Clin Neurol 2010;6`89-98This research was supported by the Stem Cell Research Center of the 21st Century Frontier Research Program funded by the Ministry of Science and Technology, Republic of Korea (#SC4120).de Lima AMJ, 2010, RESPIRATION, V79, P370, DOI 10.1159/000227800Jung KH, 2009, ANN NEUROL, V66, P191, DOI 10.1002/ana.21681Ayers L, 2009, EUR RESPIR J, V33, P574, DOI 10.1183/09031936.00107408Akinnusi ME, 2009, AM J RESP CRIT CARE, V179, P328Christou K, 2009, SLEEP MED, V10, P87, DOI 10.1016/j.sleep.2007.10.011Barcelo A, 2008, THORAX, V63, P946, DOI 10.1136/thx.2007.093740Dorkova Z, 2008, CHEST, V134, P686, DOI 10.1378/chest.08-0556Robinson GV, 2008, THORAX, V63, P855, DOI 10.1136/thx.2007.088096Somers VK, 2008, CIRCULATION, V118, P1080, DOI 10.1161/CIRCULATIONAHA.107.189375Hirschi KK, 2008, ARTERIOSCL THROM VAS, V28, P1584, DOI 10.1161/ATVBAHA.107.155960Daniel L, 2008, NEPHROL DIAL TRANSPL, V23, P2129, DOI 10.1093/ndt/gfn029Martin K, 2008, LUNG, V186, P145, DOI 10.1007/s00408-008-9073-yAmabile N, 2008, AM J RESP CRIT CARE, V177, P1268, DOI 10.1164/rccm.200710-1458OCHeiss C, 2008, J AM COLL CARDIOL, V51, P1760, DOI 10.1016/j.jacc.2008.01.040Chu K, 2008, STROKE, V39, P1441, DOI 10.1161/STROKEAHA.107.499236Jelic S, 2008, CIRCULATION, V117, P2270, DOI 10.1161/CIRCULATIONAHA.107.741512Lee ST, 2008, NEUROLOGY, V70, P1510Bakouboula B, 2008, AM J RESP CRIT CARE, V177, P536, DOI 10.1164/rccm.200706-840OCLopez-Jimenez F, 2008, CHEST, V133, P793, DOI 10.1378/chest.07-0800de la Pena M, 2008, RESPIRATION, V76, P28, DOI 10.1159/000109643WON CHJ, 2008, P AM THORAC SOC, V5, P193Kloner RA, 2007, CIRCULATION, V116, P1306, DOI 10.1161/CIRCULATIONAHA.106.678375El Solh AA, 2007, AM J RESP CRIT CARE, V175, P1186, DOI 10.1164/rccm.200611-1598OCIBER C, 2007, AASM MANUAL SCORINGMONTSERRAT JM, 2007, AM J RESP CRIT CARE, V176, P6Pirro M, 2006, ARTERIOSCL THROM VAS, V26, P2530, DOI 10.1161/01.ATV.0000243941.72375.15Ryan S, 2006, AM J RESP CRIT CARE, V174, P824, DOI 10.1164/rccm.200601-066OCBoulanger CM, 2006, HYPERTENSION, V48, P180, DOI 10.1161/01.HYP.0000231507.00962.b5Arteaga RB, 2006, AM J CARDIOL, V98, P70, DOI 10.1016/j.amjcard.2006.01.054Robinson GV, 2006, EUR RESPIR J, V27, P1229, DOI 10.1183/09031936.06.00062805Werner N, 2005, NEW ENGL J MED, V353, P999Mezentsev A, 2005, AM J PHYSIOL-HEART C, V289, pH1106, DOI 10.1152/ajpheart.00265.2005Minoguchi K, 2005, AM J RESP CRIT CARE, V172, P625, DOI 10.1164/rccm.200412-1652OCMassa M, 2005, BLOOD, V105, P199, DOI 10.1182/blood-2004-05-1831Kim J, 2004, AM J RESP CRIT CARE, V170, P1108, DOI 10.1164/rccm.200404-519OCJy W, 2004, J THROMB HAEMOST, V2, P1842Tramontano AF, 2004, BIOCHEM BIOPH RES CO, V320, P34, DOI 10.1016/j.bbrc.2004.05.127Ip MSM, 2004, AM J RESP CRIT CARE, V169, P348, DOI 10.1164/rccm.200306.767OCBarba C, 2004, LANCET, V363, P157Bernal-Mizrachi L, 2003, AM HEART J, V145, P962, DOI 10.1016/S0002-8703(03)00103-0Jimenez JJ, 2003, THROMB RES, V109, P175, DOI 10.1016/S0049-3848(03)00064-1Hill JM, 2003, NEW ENGL J MED, V348, P593Preston RA, 2003, HYPERTENSION, V41, P211, DOI 10.1161/01.HYP.0000049760.15764.2DSabatier F, 2002, DIABETES, V51, P2840, DOI 10.2337/diabetes.51.9.2840El-Solh AA, 2002, CHEST, V121, P1541Boulanger CM, 2001, CIRCULATION, V104, P2649Barbe F, 2001, ANN INTERN MED, V134, P1015Chin K, 2000, AM J MED, V109, P562Lusis AJ, 2000, NATURE, V407, P233Ohga E, 1999, J APPL PHYSIOL, V87, P10YOUNG T, 1993, NEW ENGL J MED, V328, P1230JOHNS MW, 1991, SLEEP, V14, P540

Mapping development and health effects of cooking with solid fuels in low-income and middle-income countries, 2000-18 : a geospatial modelling study

Background More than 3 billion people do not have access to clean energy and primarily use solid fuels to cook. Use of solid fuels generates household air pollution, which was associated with more than 2 million deaths in 2019. Although local patterns in cooking vary systematically, subnational trends in use of solid fuels have yet to be comprehensively analysed. We estimated the prevalence of solid-fuel use with high spatial resolution to explore subnational inequalities, assess local progress, and assess the effects on health in low-income and middle-income countries (LMICs) without universal access to clean fuels.Methods We did a geospatial modelling study to map the prevalence of solid-fuel use for cooking at a 5 km x 5 km resolution in 98 LMICs based on 2.1 million household observations of the primary cooking fuel used from 663 population-based household surveys over the years 2000 to 2018. We use observed temporal patterns to forecast household air pollution in 2030 and to assess the probability of attaining the Sustainable Development Goal (SDG) target indicator for clean cooking. We aligned our estimates of household air pollution to geospatial estimates of ambient air pollution to establish the risk transition occurring in LMICs. Finally, we quantified the effect of residual primary solid-fuel use for cooking on child health by doing a counterfactual risk assessment to estimate the proportion of deaths from lower respiratory tract infections in children younger than 5 years that could be associated with household air pollution.Findings Although primary reliance on solid-fuel use for cooking has declined globally, it remains widespread. 593 million people live in districts where the prevalence of solid-fuel use for cooking exceeds 95%. 66% of people in LMICs live in districts that are not on track to meet the SDG target for universal access to clean energy by 2030. Household air pollution continues to be a major contributor to particulate exposure in LMICs, and rising ambient air pollution is undermining potential gains from reductions in the prevalence of solid-fuel use for cooking in many countries. We estimated that, in 2018, 205000 (95% uncertainty interval 147000-257000) children younger than 5 years died from lower respiratory tract infections that could be attributed to household air pollution.Interpretation Efforts to accelerate the adoption of clean cooking fuels need to be substantially increased and recalibrated to account for subnational inequalities, because there are substantial opportunities to improve air quality and avert child mortality associated with household air pollution. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.Peer reviewe

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Global injury morbidity and mortality from 1990 to 2017 : results from the Global Burden of Disease Study 2017

Correction:Background Past research in population health trends has shown that injuries form a substantial burden of population health loss. Regular updates to injury burden assessments are critical. We report Global Burden of Disease (GBD) 2017 Study estimates on morbidity and mortality for all injuries. Methods We reviewed results for injuries from the GBD 2017 study. GBD 2017 measured injury-specific mortality and years of life lost (YLLs) using the Cause of Death Ensemble model. To measure non-fatal injuries, GBD 2017 modelled injury-specific incidence and converted this to prevalence and years lived with disability (YLDs). YLLs and YLDs were summed to calculate disability-adjusted life years (DALYs). Findings In 1990, there were 4 260 493 (4 085 700 to 4 396 138) injury deaths, which increased to 4 484 722 (4 332 010 to 4 585 554) deaths in 2017, while age-standardised mortality decreased from 1079 (1073 to 1086) to 738 (730 to 745) per 100 000. In 1990, there were 354 064 302 (95% uncertainty interval: 338 174 876 to 371 610 802) new cases of injury globally, which increased to 520 710 288 (493 430 247 to 547 988 635) new cases in 2017. During this time, age-standardised incidence decreased non-significantly from 6824 (6534 to 7147) to 6763 (6412 to 7118) per 100 000. Between 1990 and 2017, age-standardised DALYs decreased from 4947 (4655 to 5233) per 100 000 to 3267 (3058 to 3505). Interpretation Injuries are an important cause of health loss globally, though mortality has declined between 1990 and 2017. Future research in injury burden should focus on prevention in high-burden populations, improving data collection and ensuring access to medical care.Peer reviewe

Estimating global injuries morbidity and mortality : methods and data used in the Global Burden of Disease 2017 study

Background While there is a long history of measuring death and disability from injuries, modern research methods must account for the wide spectrum of disability that can occur in an injury, and must provide estimates with sufficient demographic, geographical and temporal detail to be useful for policy makers. The Global Burden of Disease (GBD) 2017 study used methods to provide highly detailed estimates of global injury burden that meet these criteria. Methods In this study, we report and discuss the methods used in GBD 2017 for injury morbidity and mortality burden estimation. In summary, these methods included estimating cause-specific mortality for every cause of injury, and then estimating incidence for every cause of injury. Non-fatal disability for each cause is then calculated based on the probabilities of suffering from different types of bodily injury experienced. Results GBD 2017 produced morbidity and mortality estimates for 38 causes of injury. Estimates were produced in terms of incidence, prevalence, years lived with disability, cause-specific mortality, years of life lost and disability-adjusted life-years for a 28-year period for 22 age groups, 195 countries and both sexes. Conclusions GBD 2017 demonstrated a complex and sophisticated series of analytical steps using the largest known database of morbidity and mortality data on injuries. GBD 2017 results should be used to help inform injury prevention policy making and resource allocation. We also identify important avenues for improving injury burden estimation in the future.Peer reviewe

Adolescent transport and unintentional injuries: a systematic analysis using the Global Burden of Disease Study 2019

Background: Globally, transport and unintentional injuries persist as leading preventable causes of mortality and morbidity for adolescents. We sought to report comprehensive trends in injury-related mortality and morbidity for adolescents aged 10–24 years during the past three decades. Methods: Using the Global Burden of Disease, Injuries, and Risk Factors 2019 Study, we analysed mortality and disability-adjusted life-years (DALYs) attributed to transport and unintentional injuries for adolescents in 204 countries. Burden is reported in absolute numbers and age-standardised rates per 100 000 population by sex, age group (10–14, 15–19, and 20–24 years), and sociodemographic index (SDI) with 95% uncertainty intervals (UIs). We report percentage changes in deaths and DALYs between 1990 and 2019. Findings: In 2019, 369 061 deaths (of which 214 337 [58%] were transport related) and 31·1 million DALYs (of which 16·2 million [52%] were transport related) among adolescents aged 10–24 years were caused by transport and unintentional injuries combined. If compared with other causes, transport and unintentional injuries combined accounted for 25% of deaths and 14% of DALYs in 2019, and showed little improvement from 1990 when such injuries accounted for 26% of adolescent deaths and 17% of adolescent DALYs. Throughout adolescence, transport and unintentional injury fatality rates increased by age group. The unintentional injury burden was higher among males than females for all injury types, except for injuries related to fire, heat, and hot substances, or to adverse effects of medical treatment. From 1990 to 2019, global mortality rates declined by 34·4% (from 17·5 to 11·5 per 100 000) for transport injuries, and by 47·7% (from 15·9 to 8·3 per 100 000) for unintentional injuries. However, in low-SDI nations the absolute number of deaths increased (by 80·5% to 42 774 for transport injuries and by 39·4% to 31 961 for unintentional injuries). In the high-SDI quintile in 2010–19, the rate per 100 000 of transport injury DALYs was reduced by 16·7%, from 838 in 2010 to 699 in 2019. This was a substantially slower pace of reduction compared with the 48·5% reduction between 1990 and 2010, from 1626 per 100 000 in 1990 to 838 per 100 000 in 2010. Between 2010 and 2019, the rate of unintentional injury DALYs per 100 000 also remained largely unchanged in high-SDI countries (555 in 2010 vs 554 in 2019; 0·2% reduction). The number and rate of adolescent deaths and DALYs owing to environmental heat and cold exposure increased for the high-SDI quintile during 2010–19. Interpretation: As other causes of mortality are addressed, inadequate progress in reducing transport and unintentional injury mortality as a proportion of adolescent deaths becomes apparent. The relative shift in the burden of injury from high-SDI countries to low and low–middle-SDI countries necessitates focused action, including global donor, government, and industry investment in injury prevention. The persisting burden of DALYs related to transport and unintentional injuries indicates a need to prioritise innovative measures for the primary prevention of adolescent injury. Funding: Bill &amp; Melinda Gates Foundation