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1.
Inorg Chem ; 59(2): 968-971, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31891256

RESUMO

A dithiolate/hydride bridged Fe-Ni complex, [(CN)(CO)2FeII(µ-pdt)(µ-H)NiII(CN)(PCy3)]- (2, pdt = propane-1,3-dithiolate) has been synthesized by the reaction of [(CN)2(CO)2FeII(pdt)]2- with [NiII(Cl)(H)(PCy3)2] as a synthetic analogue of the Ni-R state of the active site of the [Ni-Fe] hydrogenase. X-ray crystallography of this model complex suggests that the hydride unsymmetrically binds to Ni and Fe similar to natural [Ni-Fe] hydrogenases.


Assuntos
Monóxido de Carbono/química , Complexos de Coordenação/química , Cianetos/química , Hidrogenase/química , Tolueno/análogos & derivados , Monóxido de Carbono/metabolismo , Domínio Catalítico , Complexos de Coordenação/metabolismo , Cianetos/metabolismo , Hidrogenase/metabolismo , Ferro/química , Ferro/metabolismo , Modelos Moleculares , Conformação Molecular , Níquel/química , Níquel/metabolismo , Tolueno/química , Tolueno/metabolismo
2.
Science ; 367(6474): 148-149, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31919211
3.
Forensic Sci Int ; 306: 110063, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31790891

RESUMO

Diagnosis of carbon monoxide (CO) poisonings has always been a challenging task due to the susceptibility to alterations of the optical state and degradation of blood samples during sampling, transport and storage, which highly affects the analysis with spectrophotometric methods. Methodological improvements are then required urgently because of increased reports of cases with discrepancies between results of the measured biomarker carboxyhemoglobin (COHb) and reported symptoms. Total blood CO (TBCO) measured chromatographically was thus proposed in a previous study as alternative biomarker to COHb. This approach was investigated in this study by comparing the two biomarkers and assessing the effects of various storage parameters (temperature, preservative, time, tube headspace (HS) volume, initial saturation level, freeze- and thaw- and reopening-cycles) over a period of one month. Results show that while for TBCO, concentrations are relatively stable over the observation period regardless of parameters such as temperature, time and HS volume, for COHb, concentrations are altered significantly during storage. Therefore, the use of TBCO as alternative biomarker for CO poisonings has been proposed, since it provides more valid results and is more stable even under non-optimal storage conditions. Additionally, it can be used to predict COHb in cases where sample degradation hinders optical measurement. Furthermore, a correction formula for COHb and TBCO is provided to be used in laboratories or circumstances where optimal storage or analysis is not possible, to obtain more accurate results.


Assuntos
Intoxicação por Monóxido de Carbono/diagnóstico , Monóxido de Carbono/sangue , Carboxihemoglobina/análise , Medicina Legal/métodos , Biomarcadores/sangue , Cromatografia Gasosa , Interpretação Estatística de Dados , Humanos , Oximetria , Manejo de Espécimes , Espectrofotometria
4.
Bioresour Technol ; 297: 122436, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31787515

RESUMO

CO dehydrogenase (CODH) employed in a dissolved CO biosensor development study harbors a solvent-exposed cofactor capable of DET to electrode. Here, CODH was immobilized on arrays of AuNPs of various dimensions to determine the effect of the size and shape of the electrode surface on the direct electrical connection between CODH and electrode surface. The results showed the degree of proximity between the CODH cofactor and electrode surface, which varied with AuNP size and caused significant changes to the electrical connection at the interface as well as to the substrate accessibility. Consequently, a high-density nanoscale SRS was fabricated on electrode to further facilitate direct electrical connection as well as to enable distribution of CODH into monolayer or near-monolayer for lowering the barrier of CO diffusion toward enzyme. The findings show the feasibility of controlling the direct electrical connection between CODH and the electrode as well as controlling the substrate accessibility.


Assuntos
Monóxido de Carbono , Nanopartículas Metálicas , Aldeído Oxirredutases , Ouro , Complexos Multienzimáticos
5.
Bioresour Technol ; 295: 122296, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31670205

RESUMO

Synthesis gas (Syngas) biomethanation is an environmentally friendly technology for fuel calorific value improvement. However, the slow mass transfer and poor product quality limit its development. In this study, the effects of temperature, hydrogen/carbon monoxide (H2/CO) ratio and trace element addition on simulated syngas biomethanation were investigated in three batches of experiments. Results showed that (1) the temperature influenced little on the quality of produced biogas; (2) the methane content in the biogas production were 66.37 ±â€¯4.04%, 70.61 ±â€¯6.06% and 73.35 ±â€¯2.39% respectively with the H2/CO ratio of 3:1, 4:1 and 5:1; (3) after the addition of Fe, Co and Ni elements, the biogas quality was significantly improved (methane content was 79.76 ±â€¯7.35%), but the microbial community structure did not change. This experiment provided a guidance for improving the biogas production performance of syngas biomethanation.


Assuntos
Monóxido de Carbono , Oligoelementos , Anaerobiose , Biocombustíveis , Reatores Biológicos , Hidrogênio , Metano , Temperatura Ambiente
6.
Bioresour Technol ; 298: 122549, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31859133

RESUMO

This study employed a simultaneous gas feeding and cell-recycled reaction (SGCR) system to ferment CO using Eubacterium limosum KIST612. A bubble column reactor was equipped with an ex-situ hollow fiber membrane module to enable cell recycling. The internal gas circulation rate was adjusted by controlling the pump speed to provide sufficient gas supplement to the microorganism. Gas feedings were conducted by either the use of a gas-tight bag (Batch), a pressurized gas cylinder (Continuous), or a sequential combination of the two (Mixed feeding). Mixed feeding mode achieved higher biomass (9.7 g/L) and acetate (9.8 g/L) concentrations than Batch mode (3.2 g/L biomass and 7.0 g/L acetate) or Continuous mode (5.0 g/L biomass and 8.1 g/L acetate). The high acetate titer in Mixed feeding mode was achieved due to the high concentration of cells secured in a short time at the initial operation stage and maintaining a high specific growth rate.


Assuntos
Reatores Biológicos , Monóxido de Carbono , Acetatos , Biomassa , Fermentação
7.
Chemosphere ; 239: 124740, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31527005

RESUMO

Bromochloroacetic acid is classified as one of the typical disinfection byproducts (DBPs). In this work, supported palladium catalysts on different supports (CeO2, Al2O3, SiO2 and activated carbon (AC)) (labelled as Pd/support) were synthesized via the deposition-precipitation method (D-P method) and their activities for the complete dehalogenation of bromochloroacetic acid by liquid phase catalytic hydrogenation were evaluated. Comprehensive characterizations of the catalysts were conducted by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), point of zero charge (PZC), X-ray photoelectron spectroscopy (XPS) and CO chemisorption. Results indicated that the PZCs of the supports varied with each other. The stronger Pd-support interaction and higher Pd dispersion of Pd/CeO2 and Pd/Al2O3 than those of Pd/AC and Pd/SiO2 were confirmed by X-ray photoelectron spectroscopy and CO chemisorption. Pd/CeO2 had a higher ratio of positively charged Pd to metallic Pd (Pdn+/Pd0) than Pd/Al2O3 and Pd/AC due to a stronger metal-support interaction. Accordingly, a negligible bromochloroacetic acid conversion was observed on Pd/SiO2, whereas bromochloroacetic acid was found to be readily decomposed on Pd/CeO2, Pd/Al2O3 and Pd/AC. However, the dechlorination reaction could not further proceed on Pd/Al2O3 and Pd/AC catalysts after the bromine functionality was removed from bromochloroacetic acid. A complete dehalogenation of bromochloroacetic acid occurred only on Pd/CeO2. Furthermore, the dechlorination rate constants of monochloroacetic acid and bromochloroacetic acid over Pd(1.40)/CeO2 were 0.018 and 0.031 min-1 respectively, confirming an induced synergistic effect due to the existence of bromine atoms. It was worth noting that a stepwise-concerted pathway was verified during the liquid phase catalytic hydrodehalogenation of bromochloroacetic acid.


Assuntos
Acetatos/química , Cério/química , Paládio/química , Poluentes Químicos da Água/química , Monóxido de Carbono/química , Catálise , Carvão Vegetal , Desinfetantes/química , Halogenação , Hidrogenação , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Dióxido de Silício/química , Difração de Raios X
9.
Environ Monit Assess ; 191(11): 693, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667634

RESUMO

Exposure to air pollutants and heat stress from traditional cooking fires is the leading cause of mortality and morbidity in low- and middle-income countries globally and have an adverse effect on the environment. According to the World Health Organization, 3.8 million people die annually prematurely from illness related to household air pollution. Families living in poverty are at the highest risk, especially women and children. In this study, exposure to particulate matter (PM2.5 and PM10), carbon monoxide (CO) and nitrogen dioxide (NO2) was measured among resource-poor women cassava processors. The test locations were chosen in the peri-urban settlements of Abeokuta in the Ogun State of Nigeria, where household women entrepreneurs roast garri (granulated cassava) for sale in the local market. The measurements were taken for two types of stoves which are generally existing in the study location. First, a rectangular stove (RS) with two operators and, second, a circular stove (CS) with one operator; both stoves used wood as fuel. The emissions were compared with a modern mechanical liquefied petroleum gas burner-based garri roaster (GS). Hours spent per day in front of garri stoves ranged from 6 to 12 h for both stoves, with a frequency of 1 to 3 days of operation per week. It was found that CS operators were spending significantly more time in producing garri, which is due to the low capacity of the CS. The average PM2.5 concentrations for RS and CS were 381 and 273 µg/m3, respectively, estimated to be 21 and 41 µg/m3 on an annual mean level basis. Similarly, for PM10, the mean concentration levels were 1580 and 594 µg/m3 for RS and CS, respectively. The annual mean levels for PM10 were about 89 µg/m3 for both types of stoves. CO exposure during garri processing was up to five times higher than the recommended concentrations with a 4-h mean of 48 and 50 mg/m3 for RS and CS, respectively. NO2 levels were very low, ~ 0 ppm. This investigative research concluded that wood-fired small-scale garri producers in Nigeria are exposed to very unhealthy levels of PM, CO and thermal stress. The concentration levels of both PM and CO were exceeding the global as well as Nigerian ambient air quality standard regulations. Along with air pollution, thermal stress was a significant issue, which is known to exacerbate the negative effect of air pollution on the human body.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Transtornos de Estresse por Calor/epidemiologia , Resposta ao Choque Térmico , Manihot , Adulto , Poluição do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Monóxido de Carbono/análise , Criança , Culinária , Monitoramento Ambiental , Características da Família , Feminino , Fogo , Indústria Alimentícia , Humanos , Nigéria , Dióxido de Nitrogênio , Material Particulado/análise , Madeira/química
10.
Chem Commun (Camb) ; 55(99): 14898-14901, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31687688

RESUMO

We demonstrate herein an effective cascade reaction for combined photodynamic and starvation therapy in treating breast tumors based on a photosensitizer and CO prodrug decorated NMOF. The PDT-induced ROS can further trigger CO release, and the high antitumor efficiency derived from both 1O2 and CO is well confirmed by in vitro assays and in vivo trials.


Assuntos
Compostos de Boro/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Estruturas Metalorgânicas , Nanoestruturas , Fármacos Fotossensibilizantes/uso terapêutico , Monóxido de Carbono/química , Feminino , Humanos , Manganês/química , Pró-Fármacos/uso terapêutico , Oxigênio Singlete/química
11.
Biochim Biophys Acta Bioenerg ; 1860(12): 148088, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31669488

RESUMO

Bacteria can not only encounter carbon monoxide (CO) in their habitats but also produce the gas endogenously. Bacterial respiratory oxidases, thus, represent possible targets for CO. Accordingly, host macrophages were proposed to produce CO and release it into the surrounding microenvironment to sense viable bacteria through a mechanism that in Escherichia (E.) coli was suggested to involve the targeting of a bd-type respiratory oxidase by CO. The aerobic respiratory chain of E. coli possesses three terminal quinol:O2-oxidoreductases: the heme-copper oxidase bo3 and two copper-lacking bd-type oxidases, bd-I and bd-II. Heme-copper and bd-type oxidases differ in the mechanism and efficiency of proton motive force generation and in resistance to oxidative and nitrosative stress, cyanide and hydrogen sulfide. Here, we investigated at varied O2 concentrations the effect of CO gas on the O2 reductase activity of the purified cytochromes bo3, bd-I and bd-II of E. coli. We found that CO, in competition with O2, reversibly inhibits the three enzymes. The inhibition constants Ki for the bo3, bd-I and bd-II oxidases are 2.4 ±â€¯0.3, 0.04 ±â€¯0.01 and 0.2 ±â€¯0.1 µM CO, respectively. Thus, in E. coli, bd-type oxidases are more sensitive to CO inhibition than the heme-copper cytochrome bo3. The possible physiological consequences of this finding are discussed.


Assuntos
Monóxido de Carbono/metabolismo , Grupo dos Citocromos b/antagonistas & inibidores , Proteínas de Escherichia coli/antagonistas & inibidores , Oxirredutases/antagonistas & inibidores , Transporte de Elétrons/fisiologia , Escherichia coli , Oxigênio/metabolismo , Análise Espectral
12.
BMC Public Health ; 19(1): 1366, 2019 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-31651288

RESUMO

BACKGROUND: Many studies have reported the impact of air pollution on cardiovascular disease (CVD), but few of these studies were conducted in severe haze-fog areas. The present study focuses on the impact of different air pollutant concentrations on daily CVD outpatient visits in a severe haze-fog city. METHODS: Data regarding daily air pollutants and outpatient visits for CVD in 2013 were collected, and the association between six pollutants and CVD outpatient visits was explored using the least squares mean (LSmeans) and logistic regression. Adjustments were made for days of the week, months, air temperature and relative humidity. RESULTS: The daily CVD outpatient visits for particulate matter (PM10 and PM2.5), sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO), and ozone (O3) in the 90th-quantile group were increased by 30.01, 29.42, 17.68, 14.98, 29.34%, and - 19.87%, respectively, compared to those in the <10th-quantile group. Odds ratios (ORs) and 95% confidence intervals (CIs) for the increase in daily CVD outpatient visits in PM10 300- and 500-µg/m3, PM2.5 100- and 300-µg/m3 and CO 3-mg/m3 groups were 2.538 (1.070-6.020), 7.781 (1.681-36.024), 3.298 (1.559-6.976), 8.72 (1.523-49.934), and 5.808 (1.016-33.217), respectively, and their corresponding attributable risk percentages (AR%) were 60.6, 87.15, 69.68, 88.53 and 82.78%, respectively. The strongest associations for PM10, PM2.5 and CO were found only in lag 0 and lag 1. The ORs for the increase in CVD outpatient visits per increase in different units of the six pollutants were also analysed. CONCLUSIONS: All five air pollutants except O3 were positively associated with the increase in daily CVD outpatient visits in lag 0. The high concentrations of PM10, PM2.5 and CO heightened not only the percentage but also the risk of increased daily CVD outpatient visits. PM10, PM2.5 and CO may be the main factors of CVD outpatient visits.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Doenças Cardiovasculares/terapia , Ambulatório Hospitalar/estatística & dados numéricos , Adulto , Idoso , Monóxido de Carbono/efeitos adversos , Monóxido de Carbono/análise , Doenças Cardiovasculares/epidemiologia , China/epidemiologia , Cidades , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dióxido de Nitrogênio/efeitos adversos , Dióxido de Nitrogênio/análise , Ozônio/efeitos adversos , Ozônio/análise , Material Particulado/efeitos adversos , Material Particulado/análise , Dióxido de Enxofre/efeitos adversos , Dióxido de Enxofre/análise , Adulto Jovem
13.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 31(9): 1097-1101, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31657332

RESUMO

OBJECTIVE: To investigate the protective effect of carbon monoxide release molecule-2 (CORM-2) on sepsis-induced myocardial dysfunction in rats. METHODS: 140 healthy male Sprague-Dawley (SD) rats were divided into sham operation (Sham) group, model group, CORM-2 pretreatment group, inactivated carbon monoxide release molecule-2 (iCORM) pretreatment group, and dimethyl sulfoxide (DMSO) control group by random number table, with 28 rats in each group. The rat sepsis model was reproduced by intraperitoneal injection of 10 mg/kg lipopolysaccharide (LPS). The rats in the Sham group were injected intraperitoneally with the same dose of normal saline (NS). The rats in the CORM-2 and iCORM-2 pretreatment groups were injected intraperitoneally with 8 mg/kg CORM-2 or iCORM-2 at 1 hour before LPS injection, respectively, and those in the DMSO group were injected intraperitoneally with the same dose of DMSO, but the rats in the Sham group and the model group were not treated after injection of NS or LPS. Twenty rats were randomly selected from each group to observe 10-day survival rate. Transthoracic echocardiography was performed on the remaining 8 rats at 12 hours after modeling, and the left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were calculated to evaluate heart function. The blood of the inferior vena cava was harvested, then serum myocardial troponin I (cTnI) and brain natriuretic peptide (BNP) levels were measured by enzyme-linked immunosorbent assay (ELISA). Then the rats were sacrificed, and the myocardial tissues were harvested, the pathological morphology and ultrastructure of myocardium were observed. RESULTS: (1) Survival rates: all rats in the Sham group survived; compared with the Sham group, the survival rates of the model group, CORM-2 pretreatment group, iCORM-2 pretreatment group and DMSO control group were significantly decreased at 10 days [10% (2/20), 70% (14/20), 25% (5/20), 15% (3/20) vs. 100% (20/20), all P < 0.01]. However, the 10-day survival rate in the CORM-2 pretreatment group was significantly higher than those in the model group, iCORM-2 pretreatment group and DMSO control group (all P < 0.01). (2) Cardiac function: compared with the Sham group, LVEF and LVFS in the model group, CORM-2 pretreatment group, iCORM-2 pretreatment group and DMSO control group were significantly decreased, and left ventricular dilatation was obvious, indicating myocardial dysfunction in rats. However, LVEF and LVFS in the CORM-2 pretreatment group were significantly higher than those in the model group, iCORM-2 pretreatment group, and DMSO control group [LVEF: 0.760±0.029 vs. 0.634±0.021, 0.629±0.066, 0.673±0.023; LVFS: (39.32±2.38)% vs. (29.75±1.52)%, (29.61±4.15)%, (32.43±1.66)%, all P < 0.05], and the left ventricular dilatation in the septic rats was attenuated. (3) Myocardial injury markers: compared with the Sham group, serum cTnI and BNP levels were significantly higher in the model group, CORM-2 pretreatment group, iCORM-2 pretreatment group and DMSO control group. However, the levels of cTnI and BNP in the CORM-2 pretreatment group were significantly lower than those in the model group, iCORM-2 pretreatment group and DMSO control group [cTnI (ng/L): 3 283.54±803.50 vs. 6 449.18±1 105.10, 5 919.21±1 068.27, 6 349.80±1 153.08; BNP (ng/L): 3 456.62±905.85 vs. 6 070.18±1 287.62, 5 581.13±1 161.17, 5 974.89±988.89, all P < 0.05]. (4) Myocardial histopathological observation: optical microscope showed that the pathological changes in myocardial tissue of the model group, iCORM-2 pretreatment group and DMSO control group were severe. Transmission electron microscopy showed mitochondrial swelling, and some vacuoles changed. But the myocardial pathological morphology and mitochondrial ultrastructural integrity of the CORM-2 pretreatment group were significantly better than other groups of sepsis. CONCLUSIONS: CORM-2 can attenuate myocardial dysfunction and improve survival rate of septic rats, especially to protect myocardial mitochondrial integrity in sepsis.


Assuntos
Monóxido de Carbono , Miocárdio/metabolismo , Sepse , Animais , Lipopolissacarídeos , Masculino , Ratos , Ratos Sprague-Dawley
14.
Zhonghua Nei Ke Za Zhi ; 58(10): 777-781, 2019 Oct 01.
Artigo em Chinês | MEDLINE | ID: mdl-31594177

RESUMO

Objective: To detect the red blood cell lifespan in patients with polycythemia vera (PV), and explore the influencing factors. Methods: From February 2017 to December 2018, 27 patients with PV at Blood Diseases Hospital, Chinese Academy of Medical Science and 18 normal controls were recruited. Red blood cell lifespan was detected by endogenous carbon monoxide (CO) breath test. The related factors were analyzed. Results: The average red blood cell lifespan of 27 PV patients was 80 (range, 35-120) days (d), which was significantly shorter than that of the normal controls [110.5(69-166) d, P<0.05], namely 35.3 d shorter. The red blood cell lifespan of ten newly diagnosed patients and 17 patients who were treated with hydroxyurea and/or interferon were 98 (35-117) d and 69 (45-120) d, respectively, which were both shorter than that of the normal control (P=0.010, 0.000). Correlation analysis showed that red blood cell lifespan of patients with newly diagnosed PV was associated with JAK2 mutation allele burden (r=0.900, P=0.037), peripheral blood lymphocyte count (r=-0.742, P=0.014) and the level of serum vitamin B(12) (r=-0.821, P=0.023). Conclusion: The lifespan of red blood cells in patients with PV is about one-third shorter than normal, and is related to JAK2 mutation allele burden, absolute lymphocyte count, and serum vitamin B(12) level.


Assuntos
Testes Respiratórios/métodos , Monóxido de Carbono/análise , Monóxido de Carbono/metabolismo , Eritrócitos/patologia , Policitemia Vera/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Contagem de Eritrócitos , Feminino , Humanos , Janus Quinase 2 , Longevidade , Masculino , Pessoa de Meia-Idade
15.
Environ Pollut ; 255(Pt 2): 113260, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31622808

RESUMO

Emissions from ships at berth are small compared to the total ship emissions; however, they are one of the main contributors to pollutants in the air of densely-populated areas, consequently heavily affecting public health. This is due to auxiliary marine engines being used to generate electric power and steam for heating and providing services. The present study has been conducted on an engine representative of a marine auxiliary, which was a heavy duty, six-cylinder, turbocharged and after-cooled engine with a high pressure common rail injection system. Engine performance and emission characterisations during cold start are the focus of this paper, since cold start is significantly influential. Three tested fuels were used, including the reference diesel and two IMO (International Maritime Organization) compliant spiked fuels. The research engine was operated at a constant speed and 25% load condition after 12 h cooled soak. Results show that during cold start, significant heat generated from combustion is used to heat the engine block, coolant and lubricant. During the first minute, compared to the second minute, emissions of particle number (PN), carbon monoxide (CO), particulate matter (PM), and nitrogen oxides (NOx) were approximately 10, 4, 2 and 1.5 times higher, respectively. The engine control unit (ECU) plays a vital role in reducing engine emissions by changing the engine injection strategy based on the engine coolant temperature. IMO-compliant fuels, which were higher viscosity fuels associated with high sulphur content, resulted in an engine emission increase during cold start. It should be taken into account that auxiliary marine diesel engines, working at partial load conditions during cold start, contribute considerably to emissions in coastal areas. It demonstrates a need to implement practical measures, such as engine pre-heating, to obtain both environmental and public health advantages in coastal areas.


Assuntos
Automóveis , Temperatura Baixa , Gasolina/análise , Emissões de Veículos/análise , Poluentes Atmosféricos/análise , Monóxido de Carbono/análise , Óxidos de Nitrogênio/análise , Material Particulado/análise , Navios , Enxofre/análise , Temperatura Ambiente
17.
Environ Pollut ; 254(Pt A): 112982, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31554143

RESUMO

Muzzle emissions from firing an M4 carbine rifle in a semi-enclosed chamber were characterized for an array of compounds to provide quantitative data for future studies on potential inhalation exposure and rangeland contamination. Air emissions were characterized for particulate matter (PM) size distribution, composition, and morphology; carbon monoxide (CO); carbon dioxide (CO2); energetics; metals; polycyclic aromatic hydrocarbons; and methane. Three types of ammunition were used: a "Legacy" (Vietnam-era) round, the common M855 round (no longer fielded), and its variant, an M855 round with added potassium (K)-based salts to reduce muzzle flash. Average CO concentrations up to 1500 ppm significantly exceeded CO2 concentrations. Emitted particles were in the respirable size range with mass median diameters between 0.33 and 0.58 µm. PM emissions were highest from the M855 salt-added ammunition, likely due to incomplete secondary combustion in the muzzle blast caused by scavenging of combustion radicals by the K salt. Copper (Cu) had the highest emitted metal concentration for all three round formulations, likely originating from the Cu jacket on the bullet. Based on a mass balance analysis of each round's formulation, lead (Pb) was completely emitted for all three round types. This work demonstrated methods for characterizing emissions from gun firing which can distinguish between round-specific effects and can be used to initiate studies of inhalation risk and environmental deposition.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Armas de Fogo/estatística & dados numéricos , Exposição por Inalação/análise , Material Particulado/análise , Dióxido de Carbono/análise , Monóxido de Carbono/análise , Chumbo/análise , Metano/análise , Niacinamida/análogos & derivados , Niacinamida/análise , Tamanho da Partícula , Hidrocarbonetos Policíclicos Aromáticos/análise , Vietnã
18.
Nat Commun ; 10(1): 4413, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31562325

RESUMO

The synthesis of nucleobases in natural environments, especially in interstellar molecular clouds, is the focus of a long-standing debate regarding prebiotic chemical evolution. Here we report the simultaneous detection of all three pyrimidine (cytosine, uracil and thymine) and three purine nucleobases (adenine, xanthine and hypoxanthine) in interstellar ice analogues composed of simple molecules including H2O, CO, NH3 and CH3OH after exposure to ultraviolet photons followed by thermal processes, that is, in conditions that simulate the chemical processes accompanying star formation from molecular clouds. Photolysis of primitive gas molecules at 10 K might be one of the key steps in the production of nucleobases. The present results strongly suggest that the evolution from molecular clouds to stars and planets provides a suitable environment for nucleobase synthesis in space.


Assuntos
Adenina/química , Citosina/química , Hipoxantina/química , Timina/química , Uracila/química , Xantina/química , Adenina/síntese química , Amônia/química , Monóxido de Carbono/química , Citosina/síntese química , Evolução Química , Meio Ambiente Extraterreno , Hipoxantina/síntese química , Gelo , Metanol/química , Estrutura Molecular , Processos Fotoquímicos/efeitos da radiação , Timina/síntese química , Raios Ultravioleta , Uracila/síntese química , Água/química , Xantina/síntese química
19.
Artigo em Alemão | MEDLINE | ID: mdl-31562538

RESUMO

BACKGROUND: Every year, hospitals in Germany treat roughly 450,000 people in the aftermath of poisoning incidents. To reduce the number of poisoning accidents, it is essential to inform the public about poisoning risks and the possibilities for prevention. OBJECTIVES: The goal was to examine risk perception of poisonings in order to derive insights into adequate communication activities from the results. As a special focus topic, the risk of carbon monoxide poisoning was chosen. METHOD: Telephone interviews were conducted with 1,012 persons aged 14 or over in Germany. They were asked about their awareness, perception, and knowledge of poisoning risks, particularly carbon monoxide. RESULTS: Most people are aware of risks such as accidental intoxications caused by alcohol, carbon monoxide, or mushrooms. Other risks that could be especially dangerous for children, like coin cell batteries, lamp oils, or liquids in e­cigarettes, are less known. Of the interviewees, 82% had already heard of poisoning incidents in connection to carbon monoxide and 41% estimated the risk of accidental carbon monoxide poisoning as rather or very high. However, only 15% had already installed a carbon monoxide detector. Although people are mostly aware of the main causes and identifiers of carbon monoxide poisoning, more than one third still believe that carbon monoxide can be identified by its odor, smoke, or the smoke alarm signal. In addition, there is a special need for information about the risks of carbon monoxide intoxication through indoor shisha smoking and indoor storage of wood pellets. CONCLUSION: The results offer first insights into the target groups and possible dissemination paths for future risk communication activities.


Assuntos
Intoxicação por Monóxido de Carbono , Sistemas Eletrônicos de Liberação de Nicotina , Acidentes , Adolescente , Monóxido de Carbono , Criança , Alemanha , Humanos
20.
Artigo em Inglês | MEDLINE | ID: mdl-31546585

RESUMO

Indoor and outdoor number concentrations of fine particulate matter (PM2.5), black carbon (BC), carbon monoxide (CO), and nitrogen dioxide (NO2) were monitored continuously for two to seven days in 28 low-income homes in Denver, Colorado, during the 2016 and 2017 wildfire seasons. In the absence of indoor sources, all outdoor pollutant concentrations were higher than indoors except for CO. Results showed that long-range wildfire plumes elevated median indoor PM2.5 concentrations by up to 4.6 times higher than outdoors. BC, CO, and NO2 mass concentrations were higher indoors in homes closer to roadways compared to those further away. Four of the homes with mechanical ventilation systems had 18% higher indoor/outdoor (I/O) ratios of PM2.5 and 4% higher I/O ratios of BC compared to other homes. Homes with exhaust stove hoods had PM2.5 I/O ratios 49% less than the homes with recirculating hoods and 55% less than the homes with no stove hoods installed. Homes with windows open for more than 12 hours a day during sampling had indoor BC 2.4 times higher than homes with windows closed. This study provides evidence that long-range wildfire plumes, road proximity, and occupant behavior have a combined effect on indoor air quality in low-income homes.


Assuntos
Poluição do Ar/análise , Monitoramento Ambiental , Pobreza , Estações do Ano , Incêndios Florestais , Poluentes Atmosféricos/análise , Monóxido de Carbono/análise , Colorado , Humanos , Estudos Longitudinais , Dióxido de Nitrogênio/análise , Tamanho da Partícula , Material Particulado/análise , Fuligem/análise , Emissões de Veículos/análise
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