Decreased Carbon Monoxide Research Articles

A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends.

Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.

Longitudinal Evaluation of Lung Function in Patients With Advanced Non-Small Cell Lung Cancer Treated With Concurrent Chemoradiation Therapy

In lung cancer patients, radiation therapy modifies lung architecture, resulting in functional deterioration, which worsens symptoms and reduces quality of life. A multicenter, prospective, longitudinal study was conducted in a cohort of patients with locally advanced and oligometastatic non-small cell lung cancer treated with concurrent chemoradiation therapy (CCRT). A wide array of pulmonary function tests (forced spirometry, body plethysmography, impulse oscillometry, carbon monoxide diffusing capacity, fraction of exhaled nitric oxide, arterial blood gases, and 6-minute walk test) were used to evaluate lung function at baseline; after radiation therapy; and at 6, 12, 24, and 48weeks after CCRT. Relative changes in test results (percentages) were estimated at the aforementioned intervals and compared with baseline results. Thirty-seven patients completed the follow-up and were included in the analysis. After CCRT, patients showed a maximum decline in lung volumes as follows: (1) 31% in forced expiratory volume in the first second after 24weeks (P=.008), (2) 9.6% in forced vital capacity after 48weeks (P=.04), and (3) 15.1% in total lung capacity after 48weeks (P=.0015).Similarly, at 12weeks after CCRT, patients showed a 21.8% decrease in carbon monoxide diffusing capacity (P=.002). Increases were found in total airway resistance (respiratory system resistance at 5Hz), frequency dependence of resistance (change in respiratory system resistance at 5 Hz-respiratory system resistance at 20Hz, P=.012), and reactance (P=.0003 for respiratory system reactance at 5Hz and P=.001 for reactance area), which together indicate small-airway dysfunction. The longitudinal evaluation of lung function through pulmonary function tests detects CCRT-induced damage before the appearance of clinical symptoms associated with CCRT lung toxicity.

Impact of Carbon Dioxide Tension on Survival After Lung Transplantation for Pulmonary Fibrosis

Low forced vital capacity (FVC), decreased carbon monoxide diffusing capacity, and hypoxemia have been linked to poor prognosis in pulmonary fibrosis. The restrictive physiology may result in an increased respiratory rate, lower carbon dioxide tension (PaCO2), and less functional transplanted lung volume. We hypothesize that a low recipient PaCO2 at the time of listing negatively impacts post-lung transplant survival in patients with pulmonary fibrosis.

A study of a GCI engine fueled with gasoline-biodiesel blends under pilot and main injection strategies

A study was conducted to compare gasoline with the addition of 5% by volume of biodiesel (GB05) to 100% neat diesel using the multiple injection strategies in a gasoline compression ignition (GCI) engine. The engine was tested at 1200 rpm using 70 MPa of injection pressure and multiple injections, which consisted of a pilot injection at the 350-degree crank angle before top dead center (°C A BTDC) for approximately 1140 μs, followed by the main injection at 40 °C A BTDC for around 350 μs. The results show that low-temperature combustion can be achieved for GB05 with multiple injections at an in-cylinder temperature of approximately 1800 K. The heat release rates (HRR) for multiple injections of GB05 were lower than that for a single injection of 100% diesel. However, it is higher than those of multiple injections of 100% diesel and a single injection of GB05. Using multiple injections and increasing the temperatures of the intake, oil and engine coolant could result in improved combustion and engine efficiency. Multiple injections of GB05 showed decreased carbon monoxide (CO) emissions, which could be due to the pilot injection of GB05. The biodiesel content and using gasoline as a highly volatile fuel in GB05 showed the significant effect of lowering total hydrocarbon (THC) and CO emissions. However, nitrogen oxide (NOx) emissions from GB05 for both the multiple and single-injection modes seem to be higher than those of multiple injections of 100% diesel and even higher than those of a single injection of 100% diesel, which is due to the oxygen content in the GB05 fuel.

Influence of the Compression Ratio and Duration Injection on Performance and Emission of Sinjai Engine Type Flexible Fuel Engine 150 cc Fueled Bioethanol E70

In this study, the effects of using gasoline (E0) and gasoline-ethanol blends E70 on engine performance and exhaust emissions have been experimentally investigated. The investigation was conducted on a single-cylinder, four-stroke, spark ignition engine. The experiments were performed by varying the compression ratio and duration injection (100%, 125%, 150%, 175% and 200%) at a speed of 2000 up to 8000 rpm at full open throttle. The experimental results showed that blending gasoline with ethanol slightly increased the torque and decreased carbon monoxide (CO) and hydrocarbon (HC) emissions. It was also found that blending with ethanol allows increasing the compression ratio without knock occurrence

Exhaust Emission Reduction from Compression Ignition Engine by Using Palm Biodiesel Blended with Nano Zinc Oxide Additive

Biofuel modifications play a major role in a substitution for fossil fuel to be used in diesel engines and reducing exhaust emission. The most amounts of crude palm oil produced from Asian region can be an alternative fuel, sustainably. By the modifying crude palm oil into pure palm oil biodiesel (POB100), alkali trans-esterification procedure was operated. In the present, the high-quality POB products have been investigated considerably for alternative fuel in 4-cylinders high-speed diesel engine. The aim of this paper is to study in the improvement of POB quality by repeated-distillation and blending POB with nanoZnO additive. The high-speed engine combustion from consuming blended POB fuel were investigated the influences of exhaust emission under speed engine operation of 2,000 rpm and 3,000 rpm. The experimental results were shown that the POB fuel yielded at 84.54% from using 400 g. of raw materials. Both of redistilled POB and POB blended with nanoZnO additive showed the improvement of physical properties including viscosity, specific gravity and cetane number values being under ASTM standard values for high-speed engine. In addition, the results of exhaust emission from the engine showed the effective decrease of carbon monoxide (CO), carbon dioxide (CO2) around 13% due to using redistilled POB and POB blended nanoZnO additive compared with diesel fuel. Unburned hydrocarbon (HC) and nitric oxide (NOx) emissions of the diesel fuel condition. Therefore, this study suggests that nanoZnO blending POB in the small fraction about 0.005 wt% is able to provide the high potentiality for as a clean and alternative fuel.

Experimental Investigations on LHR Single Cylinder Air Cooled Diesel Engine using Simarouba Biodiesel and its Blends as Alternate to Diesel Fuel

Experiments are conducted to study the performance, exhaust emissions and combustion characteristics of a conventional and LHR diesel engine running with simarouba biodiesel (100%) and its blends (10, 20 and 30% by volume) with diesel as an alternate fuel to neat diesel. The conventional engine is modified as LHR engine by coating 300 μm of PSZ on the piston crown which acts as thermal barrier and reduces heat loss to cooling medium and increases in-cylinder temperature by 50 to 100°C. Conventional and LHR engine are tested with neat diesel, biodiesel and biodiesel blends at an injection pressure of 200 bar and injection timing of 23° btdc. The load is applied in steps of 25% from no load to full load and results obtained are analyzed. LHR engine performed better compared to conventional engine; improved performance, significant reductions in exhaust emissions (except NOX) and improved combustion characteristics for all the blends tested. The percentage increase in brake thermal efficiency of neat diesel, SBD10, SBD20, SBD30 and SBD100 in LHR engine is 1.98, 5.61, 6.0, 3.98 and 2.98, respectively compared to conventional engine at 75% of full load. Amongst the blends tested, SBD20 proved to be better in both the engines. In LHR engine with SBD20 the percentage increase in brake thermal efficiency, pressure rise and heat release rates are 11.28, 6.35 and 14.0, respectively compared to diesel in conventional engine. Percentage decrease in carbon monoxide, hydrocarbon and smoke opacity is 50.0, 46.43 and 40.0, respectively as compared to diesel in conventional engine.

Application of Cigeratte Filter from Algae Spyrogira peipingensis to Reduce Nicotine, Tar, and Carbon Monoxide

Algae Spirogyra peipingensis is a group of green algae from the order Zygnematales. Spirogyra algae serves as a bioremediation agent. In addition Spirogyra algae has great potential in reducing toxin levels in cigarette smoke. Because the biomass of alga Spirogyra has an irregular shaped surface texture and consists of amino acid, amide, carboxylic, hydroxyl, and carbonyl group that can bind various heavy metals and other harmful compounds. Alga Spirogyra peipingensis samples used are algae from Bone, South Sulawesi. Prior to the trial, the first pretreatment and processed to become powder. Algae powder was then applied to cigarette filters and tested on several respondents. Results showed that there was a significant decrease tar, nicotine and carbon monoxide levels in cigarette smoke by using Spirogyra peipingensis algae but the most significant decrease of carbon monoxide, while tar and nicotine decreased even though not as high as carbon monoxide.

Assessment of environmentally friendly fuel emissions from in-use vehicle exhaust: low-blend iso-stoichiometric GEM mixture as example.

Gasoline-ethanol-methanol fuel blends were formulated with the same stoichiometric air-to-fuel ratio and volumetric energy concentration as any binary ethanol-gasoline blend. When the stoichiometric blends operated in a vehicle, the time period, injector voltage, and pressure for each fuel injection event in the engine corresponded to a given stoichiometric air-to-fuel ratio, and the load was essentially constant. Three low oxygen content iso-stoichiometric ternary gasoline-ethanol-methanol fuel blends were prepared, and the properties were compared with regular-type fuel without added oxygen. One of the ternary fuels was tested using a fleet of in-use vehicles for15weeks and compared to neat gasoline without oxygenated compounds as a reference. Only a small number of publications have compared these ternary fuels in the same engine, and little data exist on the performance and emissions of in-use spark-ignition engines. The total hydrocarbon emissions observed was similar in both fuels, in addition to the calculated ozone forming potential of the tailpipe and evaporative emissions. In ozone non-attainment areas, the original purpose for oxygenate gasolines was to decrease carbon monoxide emissions. The results suggest that the strategy is less effective than expected because there still exist a great number of vehicles that have suffered the progressive deterioration of emissions and do not react to oxygenation, while new vehicles are equipped with sophisticated air/fuel control systems, and oxygenation does not improve combustion because the systems adjust the stoichiometric point, making it insensitive to the origin of the added excess oxygen (fuel or excess air). Graphical abstract Low level ternary blend of gasoline-ethanol-methanol were prepared with the same stoichiometric air-fuel ratio and volumetric energy concentration, based on the volumetric energy density of the pre-blended components. Exhaust and evaporative emissions was compared with a blend having no oxygen in a fleet of 12 in-use vehicles. Vehicles that had suffer a normal deterioration of emissions and do not react to oxygenation, and new vehicles with more sophisticated air/fuel control systems do not improve combustion.

Understanding the role of low reactivity fuel stratification in a dual fuel RCCI engine – A simulation study

Natural gas - diesel, Reactivity Controlled Compression Ignition (RCCI) is currently one of the most promising combustion strategies for the next generation heavy-duty engines. A major issue to be addressed for this dual fuel concept to become practically applicable is its low combustion efficiency and associated high methane emissions in partial engine loads. Introducing gaseous fuel stratification (by direct injection) is considered to be beneficial for combustion efficiency increase. Yet, the improvement potential of such natural gas stratification in RCCI engines is unknown. Modeling studies are needed to investigate this methane reduction measure because they can provide more insight to the combustion process than measurements alone.The objective of this study is to assess the potential of RCCI with direct injected low reactivity fuel in terms of thermal efficiency and methane emissions. A broad range of measured, single point injected gas, operating points served as a basis for the simulation study. TNO’s in-house, multi-zone, chemical kinetics based model was validated for those points and used to generate simulation results for different natural gas stratification profiles.It is shown that gaseous fuel stratification in dual fuel RCCI helps to increase combustion efficiency and decrease methane and carbon monoxide emissions. At the same time, nitrogen oxides increase and (at some operating points) the emissions of non-methane hydrocarbons slightly increase too. The effect is strongest for the low load cases showing maximum improvement of combustion efficiency by 11 percentage point for in-extensive natural gas stratifications. The improvement potential reduces with increasing engine load. Thanks to the insights to the combustion process (given by the simulation results), explanations for the observed trends are provided, and important phenomena are identified that are associated with increased low reactivity fuel stratification.

Assessment of functional lung impairment in patients with thyroid disorders

Many thyroid diseases can lead to pulmonary problems. Hypothyroidism reduces respiratory drive and can cause obstructive sleep apnea, pleural effusion, skeletal muscle myopathy, and decreased carbon monoxide diffusing capacity, whereas hyperthyroidism increases respiratory drive and can cause dyspnea on exertion. Thus, the aim of this study was to evaluate and compare the frequency of clinical presentations, the extent of lung functional endurance (spirometric and diffusion lung capacity), and arterial blood gases affection between patients with hypothyroidism and hyperthyroidism when compared with normal euthyroid volunteers and find out who could compromise the respiratory system more. This study included 90 participants (30 patients with hyperthyroidism, 30 patients with hypothyroidism, and the remaining 30 were normal healthy volunteers as control) referred from the Endocrinology and Internal Medicine Departments in Ain Shams University Hospitals and Misr University for Science and Technology according to their serum free thyroid hormone 3, free thyroid hormone 4, and thyroid-stimulating hormone values. Spirometric function tests and diffusing capacity of the lung for carbon monoxide evaluation were performed for all participants. Respiratory symptoms were more frequent in hypothyroid than in hyperthyroid patients, especially cough, sputum production, and chest wheezes. All spirometric functional parameters and respiratory muscle function were decreased (whether or not significant) among patients with hypothyroidism and hyperthyroidism compared with normal euthyroid controls. More statistically significant respiratory functional impairment was noticed among patients with hypothyroidism than among those with hyperthyroidism. Diffusion was more affected in the hypothyroidism group than in the hyperthyroid group, but it was statistically nonsignificant. A statistically significant increase in partial carbon dioxide pressure was observed among patients with hypothyroidism than in patients in hyperthyroidism (However, there was a statistically significant decrease in partial oxygen pressure and pH in patients with hypothyroidism than in those with hyperthyroidism.). Although oxygen saturation was lower in hypothyroidism, it was statistically nonsignificant. Hypothyroidism causes greater respiratory system endurance compared with hyperthyroidism. Early diagnosis and hormonal replacement may be of value.

Performance and Emission Characteristics of a Compression Ignition Engine Operating on Blends of Castor Oil Biodiesel–Diesel

Diesel vehicles are the nerves and veins of transportation, particularly in developing countries. With the rapid rate of modernization, increasing demand of fuel is inevitable. The exponential increase in fuel prices and the scarcity of its supply from the environment have promoted interest in the development of alternative sources of fuel. In this work, genus Ricinus communis L. was studied in order to delimit their potential as a raw material for biodiesel production. Further, castor oil, ethyl ester were prepared by transesterification using potassium hydroxide (KOH) as a catalyst and tested on a four-stroke, single-cylinder compression ignition engine. The test was carried out at a constant speed of 3000 rpm at different loads. The results represent a substantial decrease in carbon monoxide (CO) emission with an increasing biodiesel percentage. The reduction of CO in B05, B10, B15 and B20 averaged 11.75, 22.02, 24.23 and 28.79 %, respectively, compared to mineral diesel. The emission results of the comparative test indicated that CO, oxygen (O2) and smoke density emissions are found to be lower when the engine is filled with B05, B10, B15 and B20 as compared to mineral diesel, while carbon dioxide (CO2) and nitrogen oxide (NOx) with B05, B10, B15 and B20 are found to increase marginally. Brake thermal efficiency and brake specific fuel consumption decrease and increase respectively in biodiesel with different blends in comparison of mineral diesel.

Performance of biodiesel/higher alcohols blends in a diesel engine

Summary Alcohols extensively used in internal combustion engines are important renewable and sustainable energy resources from environmental and economical perspectives. Besides, bio production of alcohols decreases consumption of fossil-based fuels. Although there are many studies with regards to the use of lower alcohols such as methanol and ethanol in internal combustion engines, there are a limited number of investigations with higher alcohols. Higher alcohols such as propanol, n-butanol, and 1-pentanol are part of the next generation of biofuels, given they provide better fuel properties than lower alcohols. Biodiesel–higher alcohol blends can be used in diesel engines without any engine modification but need to be tested under various engine conditions with long periods in order to evaluate their impacts on engine performance and environmental pollutants. The objective of this study was to evaluate the effect of using propanol, n-butanol, and 1-pentanol in waste oil methyl ester (B100) on engine performance and exhaust emissions of a diesel engine running at different loads (0, 3, 6, and 9 kW) with a fixed engine speed (1800 rpm). Test fuel blends were prepared by adding propanol, n-butanol, and 1-pentanol (10 vol.%) into waste oil methyl ester to achieve blends of B90Pr10, B90nB10, and B90Pn10, respectively. According to engine performance and exhaust emissions results, the addition of propanol, n-butanol, and 1-pentanol to B100 had the effect of increasing brake specific fuel consumption and exhaust gas temperatures. The brake thermal efficiency (BTE) decreased for B90Pr10 and B90nB10, while B90Pn10 showed a slight increase in BTE as compared with B100. When compared with B100, B90Pr10, B90nB10, and B90Pn10 decreased carbon monoxide emissions at lower loads while it increased slightly at 9 kW load. The decrement in oxides of nitrogen emission was observed at whole loads for B90Pr10, B90nB10, and B90Pn10 compared with B100. When considering all loads, B90Pn10 presented the best mean hydrocarbon emission with a reduction of 45.41%. Copyright © 2016 John Wiley & Sons, Ltd.

Techno-economic Evaluation of Quality Improvement of Heavy Gas Oil with Different Processes

Abstract Nowadays, high quality diesel fuels can only be produced by the hydrotreatment of various refinery streams. Preparing catalytic experiments and process engineering calculations are inevitable for selecting the most technically and economically appropriate process. There is limited information in the free literature about the complex approach of hydrotreating processes that deal with both the catalytic and process issues. This paper summarizes the results of an engineering study to evaluate the techno-economic feasibility of different types of hydrotreating processes for producing high quality gas oil blending components from heavy gas oil fraction. Hydrotreatment of feed in one-stage on nickel(Ni) molybdenum(Mo)/alumina and in two-stage on NiMo/alumina followed by on platinum(Pt) palladium(Pd)/zeolite catalysts were investigated. In one stage hydroprocessing sulphur and polyaromatic contents of the products met the requirements of the standard only if strict process parameters were applied (temperature > 370 °C and Liquid Hourly Space Velocity −1 ) which resulted in operation problems and product loss, moreover the advantageous process parameters of hydrodesulphurization and hydrodearomatization did not coincide. In two-stage hydrotreating results showed that the advantageous process parameters for reduction of sulphur and aromatics coincided. Advantageous process parameters to produce gas oil of quality meeting the requirement of the standard were determined. Based on the experimental results model for both alternatives was prepared, and heat and material balances were determined. By applying two step hydrotreating, the yield of gas oil having low sulphur and aromatic content was 6.2% higher than that obtained in one step. Heat exchanger network analysis and sizing of main equipments were accomplished. Operating and investment costs were estimated for both processes, which showed that all the cost elements were higher for the two-stage process. But it provides the following advantages in comparison to one-stage process: higher yield of gas oil, better product quality allowing the application of low value hydrocarbon streams in higher quantity at the blending, the lower density of products would be the source of extra profit due to diesel fuels are sold on volume basis at the petrol stations. Estimation of emission potential of feed and products was prepared, too. This showed that the hydrotreating of heavy gas oil contributes to significant reduction in emission of particulate matter, hydrocarbons and carbon monoxide, but the effect on the emission of nitrogen oxides was scarce. Product of two-stage process provided considerably greater decrease in carbon monoxide and hydrocarbon emissions comparing to the one-stage alternative (52% vs. 14% and 54% vs. 14%). Consequently, the estimation of emission potential of hydrotreated products can be used as one of the parameters for selecting between various process alternatives.

Techno-economic evaluation of quality improvement of heavy gas oil with different processes

Nowadays, high quality diesel fuels can only be produced by the hydrotreatment of various refinery streams. Preparing catalytic experiments and process engineering calculations are inevitable for selecting the most technically and economically appropriate process. There is limited information in the free literature about the complex approach of hydrotreating processes that deal with both the catalytic and process issues. This paper summarizes the results of an engineering study to evaluate the techno-economic feasibility of different types of hydrotreating processes for producing high quality gas oil blending components from heavy gas oil fraction. Hydrotreatment of feed in one-stage on nickel(Ni) molybdenum(Mo)/alumina and in two-stage on NiMo/alumina followed by on platinum(Pt) palladium(Pd)/zeolite catalysts were investigated. In one stage hydroprocessing sulphur and polyaromatic contents of the products met the requirements of the standard only if strict process parameters were applied (temperature > 370 °C and Liquid Hourly Space Velocity < 1.5h−1) which resulted in operation problems and product loss, moreover the advantageous process parameters of hydrodesulphurization and hydrodearomatization did not coincide. In two-stage hydrotreating results showed that the advantageous process parameters for reduction of sulphur and aromatics coincided. Advantageous process parameters to produce gas oil of quality meeting the requirement of the standard were determined. Based on the experimental results model for both alternatives was prepared, and heat and material balances were determined. By applying two step hydrotreating, the yield of gas oil having low sulphur and aromatic content was 6.2% higher than that obtained in one step. Heat exchanger network analysis and sizing of main equipments were accomplished. Operating and investment costs were estimated for both processes, which showed that all the cost elements were higher for the two-stage process. But it provides the following advantages in comparison to one-stage process: higher yield of gas oil, better product quality allowing the application of low value hydrocarbon streams in higher quantity at the blending, the lower density of products would be the source of extra profit due to diesel fuels are sold on volume basis at the petrol stations. Estimation of emission potential of feed and products was prepared, too. This showed that the hydrotreating of heavy gas oil contributes to significant reduction in emission of particulate matter, hydrocarbons and carbon monoxide, but the effect on the emission of nitrogen oxides was scarce. Product of two-stage process provided considerably greater decrease in carbon monoxide and hydrocarbon emissions comparing to the one-stage alternative (52% vs. 14% and 54% vs. 14%). Consequently, the estimation of emission potential of hydrotreated products can be used as one of the parameters for selecting between various process alternatives.

The impact of gasoline and synthesized ethanol blends on the emissions of a spark ignition engine

Considering pollution problems and the energy crisis today, investigations have been concentrated on lowering the concentration of toxic components in combustion products and decreasing fossil fuel consumption by using renewable alternative fuels. In this work, the effect of ethanol addition to gasoline on the exhaust emissions of a spark ignition engine at various speeds was established. Ethanol was extracted from groundnut seeds using fermentation method. Gasoline was blended with 20 - 80% of the extracted ethanol in an interval of 20%. Results of the engine test indicated that using ethanol-gasoline blended fuels decreased carbon monoxide (CO) and hydrocarbon (HC) emissions as a result of the lean- burn effects caused by the ethanol, and the carbon dioxide (CO2) emission increased because of a near complete combustion. Finally, the results showed that blending ethanol in a proportion of 40% with gasoline can be used as a supplementary fuel in modern spark ignition engines as it is expected that the engine performs at its optimum in terms of air toxic pollutants reduction, by virtue of that mix.

Atypical Acute Liver Failure in Acute Myeloid Leukemia

Gastroent Question: A 65-yearold white womanwith therapy-related acute myeloid leukemia was admitted to the intensive care unit with altered mental status 33 days after completing induction chemotherapy with azacitadine, high-dose cytarabine, and mitoxantrone. She had a history of breast cancer treated 12 years prior with 4 cycles of cyclophosphamide and doxorubicin, local radiation therapy, and tamoxifen, as well as mantle cell lymphoma treated 6 years prior with bendamustine, rituximab, and radiation therapy to a lytic lesion of the L1 vertebrae. On physical examination, she was afebrile, normotensive (133/89 mmHg), but obtunded. She had scleral icterus as well as mild abdominal distension with minimal ascites. There were no recent additions to her medication list; the only potentially hepatotoxic agent present was prophylactic posaconazole, which had been discontinued several days prior. Her laboratory studies revealed neutropenia (absolute neutrophil count, 90 K/mL) and evidence of acute hepatic dysfunction (aspartate aminotransferase [AST], 4,891 U/L; alanine aminotransferase [ALT], 2,070 U/L; International Normalized Ratio [INR], 3.3). The total bilirubin (TB) was 5.4 mg/dL, alkaline phosphatase (AP) 90 U/L, and serum ammonia 61 mg/dL. There was no serologic evidence of acute varicella zoster or hepatitis A, B, C, D, or E infections. Furthermore, polymerase chain reaction assays for herpes simplex virus, Epstein-Barr virus, cytomegalovirus, human herpesvirus 6, and adenovirus were all negative. Thick and thin blood smears ruled out a transfusion-related trypanosomiasis infection; a urine toxicology screen was unremarkable, and a serum acetaminophen level was <3.0 mg/mL. Abdominal ultrasound revealed hepatomegaly (18.7 cm), ascites, a large right pleural effusion and patent hepatic vasculature. A liver biopsy had been deferred given her coagulopathy and persistent thrombocytopenia (<10 K/mL). Thus, the etiology of her acute hepatic dysfunction remained unknown. Thirteen days later, despite improvements in coagulopathy (INR 1.5), aminotransferases (AST, 68 U/L; ALT, 36 U/L) and mental status, she continued to have worsening cholestasis (TB,16.6 mg/dL; conjugated, 12.6 mg/dL; AP, 175 U/L, which peaked at 492 U/L days later). Thus, a liver biopsy was finally obtained (Figure A, B). What was the elusive etiology of this patient’s acute liver failure? See the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI.

Causes of increasing ozone and decreasing carbon monoxide in springtime at the Mt. Bachelor Observatory from 2004 to 2013

We report trends in springtime ozone (O3) and carbon monoxide (CO) at the Mt. Bachelor Observatory (MBO) in central Oregon, U.S.A. from 2004 to 2013. Over the 10-year period the median and 95th percentile springtime O3 increased by 0.76 ± 0.61 ppbv yr−1 (1.7 ± 1.4% yr−1) and 0.87 ± 0.73 ppbv yr−1 (1.5 ± 1.2% yr−1), respectively. These trends are consistent with reported positive trends in springtime O3 in the western U.S. In contrast, median CO decreased by −3.1 ± 2.4 ppbv yr−1 (−1.9 ± 1.4% yr−1), which is highly similar to springtime North Pacific surface flask measurements from 2004 to 2012. While a 10-year record is relatively short to evaluate long-term variability, we incorporate transport model analysis and contextualize our measurements with reported northern mid-latitude trends over similar time frames to investigate the causes of increasing O3 and decreasing CO at MBO. We performed cluster analysis of 10-day HYSPLIT back-trajectories from MBO and examined O3 and CO trends within each cluster. Significant positive O3 trends were associated with high-altitude, rapid transport from East Asia. Significant negative CO trends were most associated with transport from the North Pacific and Siberia, as well as from East Asia. The rise in springtime O3 is likely associated with increasing O3 precursor emissions in Asia and long-range transport to the western U.S. The decline in springtime CO appears linked to decreasing Northern Hemisphere background CO, largely due to anthropogenic emissions reductions in Europe and North America, and also to a recently reported decline in total CO output from China caused by more efficient combustion. These springtime O3 and CO trends suggest that hydroxyl radical (OH) mixing ratios in the North Pacific may have increased over the study period.

Pneumopathie infiltrante diffuse associée à une dermatomyosite amyopathique avec auto-anticorps anti-MDA5

Amyopathic dermatomyositis associated with anti-MDA5 autoantibodies is a rare and very recently described clinical entity. A 58-year-old woman was admitted with subacute onset of dyspnea (NYHA class IV) associated with cough, oligoarthritis of the wrists, myalgia and intermittent fever. Examination demonstrated skin lesions with heliotrope rash, Gottron's papules, "mechanics hands", and basal inspiratory crackles on lung auscultation. Pulmonary function tests showed a restrictive ventilatory defect, with decreased carbon monoxide diffusion capacity and marked hypoxemia (PaO2 61 mmHg). The chest high-resolution computed tomography appearances were consistent with organizing pneumonia. Bronchoalveolar lavage differential cell count demonstrated 22 % neutrophils. Serum creatine kinase and electromyography were normal ; the serum ferritin level was elevated. Antinuclear antibodies were present and anti-MDA5 autoantibodies were identified. Significant improvement was obtained with systemic corticosteroids, later converted to mycophenolate mofetil as a steroid-sparing agent. Amyopathic dermatomyositis associated with anti-MDA5 autoantibodies shares some characteristics with those associated with anti-synthetase antibodies. Muscular involvement may be mild or absent. Early diagnosis and treatment may improve outcome.

Satellite-Detected Carbon Monoxide Pollution during 2000–2012: Examining Global Trends and also Regional Anthropogenic Periods over China, the EU and the USA

In this paper, we test if any statistically significant periodicities are detectable in carbon monoxide emissions over China, the European Union, and the United States of America. To do this, we performed a period analysis using 10 years of daily-averaged data, from the Measurements Of Pollution In The Troposphere (MOPITT) instrument. Besides a seasonal period, we found no clearly detectable periods at any timescale with the exception of a strong signal at 2.28 days. This period was observed over all tested regions and persisted when larger (hemisphere-wide) regions were considered. However, rather than resulting from a physical variation in carbon monoxide, it resulted from day-to-day changes in the area covered by MOPITT on-board its polar-orbiting satellite platform. We also examined linear trends over the dataset, and found that MOPITT identifies several centers of increasing carbon monoxide concentration—the largest being over China—although globally MOPITT reports a significant decrease in carbon monoxide has occurred over the past decade.