2,640 research outputs found

    Products of incomplete combustion from biomass reburning

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    Fuel reburning usually serves in mitigating NOx formation in stationary combustion sources. However, the use of biomass as reburning fuel could facilitate the production of relatively more nitrogen-containing aromatic products of incomplete combustion. This study investigates the heterogeneous reaction between biomass and mixtures of NO/O2 gases, employing isothermal high-temperature experiments in a vertically-entrained reactor, and in situ diffuse reflective infrared Fourier transform spectroscopy (DRIFTS) under a non-isothermal heating condition ranging from ambient temperature to 700 °C. The method enables sensitive evaluation of the surface species ensuing during the thermal reaction. Results from this study elucidate the formation of nitrated structures as active intermediate species of the heterogeneous reaction. The nitrogenated signatures persist on the surface of the residual ash, suggesting the production of N-aromatics such as nitro-PAH. Considering the severe toxicity and bioaccumulative properties of these by-products, further research should focus on the relative contribution of various reburning fuels, while favouring sustainable fuels such as non-charring plastics

    Atmospheric emission of NOx from mining explosives: A critical review

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    High-energy materials such as emulsions, slurries and ammonium-nitrate fuel-oil (ANFO) explosives play crucial roles in mining, quarrying, tunnelling and many other infrastructure activities, because of their excellent transport and blasting properties. These explosives engender environmental concerns, due to atmospheric pollution caused by emission of dust and nitrogen oxides (NOx) from blasts, the latter characterised by the average emission factor of 5 kg (t AN explosive)−1. This first-of-its-kind review provides a concise literature account of the formation of NOx during blasting of AN-based explosives, employed in surface operations. We estimate the total NOx emission rate from AN-based explosives as 0.05 Tg (i.e., 5 × 104 t) N per annum, compared to the total global annual anthropogenic NOx emissions of 41.3 × 106 t N y−1. Although minor in the global sense, the large localised plumes from blasting exhibit high NOx concentration (500 ppm) exceeding up to 3000 times the international standards. This emission has profound consequences at mining sites and for adjacent atmospheric environment, necessitating expensive management of exclusion zones. The review describes different types of AN energetic materials for civilian applications, and summarises the essential properties and terminologies pertaining to their use. Furthermore, we recapitulate the mechanisms that lead to the formation of the reactive nitrogen species in blasting of AN-based explosives, review their implications to atmospheric air pollution, and compare the mechanisms with those experienced in other thermal and combustion operations. We also examine the mitigation approaches, including guidelines and operational-control measures. The review discusses the abatement technologies such as the formulation of new explosive mixtures, comprising secondary fuels, spin traps and other additives, in light of their effectiveness and efficiency. We conclude the review with a summary of unresolved problems, identifying possible future developments and their impacts on the environment with emphasis on local and workplace loads

    Point-of-care measurement of blood lactate in children admitted with febrile illness to an African District Hospital.

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    BACKGROUND: Lactic acidosis is a consistent predictor of mortality owing to severe infectious disease, but its detection in low-income settings is limited to the clinical sign of "deep breathing" because of the lack of accessible technology for its measurement. We evaluated the use of a point-of-care (POC) diagnostic device for blood lactate measurement to assess the severity of illness in children admitted to a district hospital in Tanzania. METHODS: Children between the ages of 2 months and 13 years with a history of fever were enrolled in the study during a period of 1 year. A full clinical history and examination were undertaken, and blood was collected for culture, microscopy, complete blood cell count, and POC measurement of blood lactate and glucose. RESULTS: The study included 3248 children, of whom 164 (5.0%) died; 45 (27.4%) of these had raised levels of blood lactate (>5 mmol/L) but no deep breathing. Compared with mortality in children with lactate levels of ≤ 3 mmol/L, the unadjusted odds of dying were 1.6 (95% confidence interval [CI].8-3.0), 3.4 (95% CI, 1.5-7.5), and 8.9 (95% CI, 4.7-16.8) in children with blood lactate levels of 3.1-5.0, 5.1-8.0, or >8.0 mmol/L, respectively. The prevalence of raised lactate levels (>5 mmol/L) was greater in children with malaria than in children with nonmalarial febrile illness (P < .001) although the associated mortality was greater in slide-negative children. CONCLUSIONS: POC lactate measurement can contribute to the assessment of children admitted to hospital with febrile illness and can also create an opportunity for more hospitals in resource-poor settings to participate in clinical trials of interventions to reduce mortality associated with hyperlactatemia

    Securing the Skies: Cybersecurity Strategies for Smart City Cloud using Various Algorithams

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    As smart cities continue to evolve, their reliance on cloud computing technologies becomes increasingly apparent, enabling the seamless integration of data-driven services and urban functionalities. However, this transformation also raises concerns about the security of the vast and interconnected cloud infrastructures that underpin these cities' operations. This paper explores the critical intersection of cloud computing and cybersecurity within the context of smart cities. This research is dealing with challenges posed by the rapid expansion of smart city initiatives and their reliance on cloud-based solutions. It investigates the vulnerabilities that emerge from this technological convergence, emphasizing the potential risks to data privacy, urban services, and citizen well-being. The abstract presents a comprehensive overview of the evolving threat landscape that smart cities face in the realm of cloud computing. To address these challenges, the abstract highlights the importance of proactive cybersecurity strategies tailored specifically to the unique needs of smart cities. It underscores the significance of adopting a multi-layered approach that encompasses robust encryption protocols, intrusion detection systems, threat intelligence sharing, and collaborative efforts among stakeholders. Drawing insights from existing research and real-world case studies, the abstract showcases innovative solutions that leverage advanced technologies like artificial intelligence and blockchain to fortify the security posture of smart city cloud infrastructures. It explores the role of data governance, user authentication, and anomaly detection in creating a resilient cybersecurity framework that safeguards critical urban systems

    Hyperglycemia and risk of ventricular tachycardia among patients hospitalized with acute myocardial infarction

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    BACKGROUND: Little is known about the association of hyperglycemia Tranwith the development of ventricular tachycardia (VT) in patients hospitalized with acute myocardial infarction (AMI) which we examined in the present study. The objectives of this community-wide observational study were to examine the relation between elevated serum glucose levels at the time of hospital admission for AMI and occurrence of VT, and time of occurrence of VT, during the patient\u27s acute hospitalization. METHODS: We used data from a population-based study of patients hospitalized with AMI at all central Massachusetts medical centers between 2001 and 2011. Hyperglycemia was defined as a serum glucose level \u3e /= 140 mg/dl at the time of hospital admission. The development of VT was identified from physicians notes and electrocardiographic findings by our trained team of data abstractors. RESULTS: The average age of the study population was 70 years, 58.0% were men, and 92.7% were non-Hispanic whites. The mean and median serum glucose levels at the time of hospital admission were 171.4 mg/dl and 143.0, respectively. Hyperglycemia was present in 51.9% of patients at the time of hospital admission; VT occurred in 652 patients (15.8%), and two-thirds of these episodes occurred during the first 48 h after hospital admission (early VT). After multivariable adjustment, patients with hyperglycemia were at increased risk for developing VT (adjusted OR = 1.48, 95% CI = 1.23-1.78). The presence of hyperglycemia was significantly associated with early (multivariable adjusted OR = 1.39, 95% CI = 1.11-1.73) but not with late VT. Similar associations were observed in patients with and without diabetes and in patients with and without ST-segment elevation AMI. CONCLUSIONS: Efforts should be made to closely monitor and treat patients who develop hyperglycemia, especially early after hospital admission, to reduce their risk of VT

    Continuous low dose Thalidomide: a phase II study in advanced melanoma, renal cell, ovarian and breast cancer

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    To grow and metastasize, solid tumours must develop their own blood supply by neo-angiogenesis. Thalidomide inhibits the processing of mRNA encoding peptide molecules including tumour necrosis factor-alpha (TNF-α) and the angiogenic factor vascular endothelial growth factor (VEGF). This study investigated the use of continuous low dose Thalidomide in patients with a variety of advanced malignancies. Sixty-six patients (37 women and 29 men; median age, 48 years; range 33–62 years) with advanced measurable cancer (19 ovarian, 18 renal, 17 melanoma, 12 breast cancer) received Thalidomide 100 mg orally every night until disease progression or unacceptable toxicity was encountered. Three of 18 patients with renal cancer showed partial responses and a further three patients experienced stabilization of their disease for up to 6 months. Although no objective responses were seen in the other tumour types, there were significant improvements in patients' sleeping (P< 0.05) and maintained appetite (P< 0.05). Serum and urine concentrations of basic fibroblast growth factor (bFGF), TNF-α and VEGF were measured during treatment and higher levels were associated with progressive disease. Thalidomide was well tolerated: Two patients developed WHO Grade 2 peripheral neuropathy and eight patients developed WHO grade 2 lethargy. No patients developed WHO grade 3 or 4 toxicity. Further studies evaluating the use of Thalidomide at higher doses as a single agent for advanced renal cancer and in combination with biochemotherapy regimens are warranted. © 2000 Cancer Research Campaig

    Surgical Aspects of Dissecting Aortic Aneurysms

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66511/2/10.1177_000331975400500313.pd

    Decade-long trends in the timeliness of receipt of a primary percutaneous coronary intervention

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    OBJECTIVES: The purpose of this study was to examine decade-long trends (2001-2011) in, and factors associated with, door-to-balloon time within 90 minutes of hospital presentation among patients hospitalized with ST-segment elevation myocardial infarction (STEMI) who received a primary percutaneous coronary intervention (PCI). METHODS: Residents of central Massachusetts hospitalized with STEMI who received a primary PCI at two major PCI-capable medical centers in central Massachusetts on a biennial basis between 2001 and 2011 comprised the study population (n=629). Multivariable regression analyses were used to examine factors associated with failing to receive a primary PCI within 90 minutes after emergency department (ED) arrival. RESULTS: The average age of this patient population was 61.9 years; 30.5% were women, and 91.7% were White. During the years under study, 50.9% of patients received a primary PCI within 90 minutes of ED arrival; this proportion increased from 2001/2003 (17.2%) to 2009/2011 (70.5%) (P \u3c 0.001). Having previously undergone coronary artery bypass graft surgery, arriving at the ED by car/walk-in and during off-hours were significantly associated with a higher risk of failing to receive a primary PCI within 90 minutes of ED arrival. CONCLUSION: The likelihood of receiving a timely primary PCI in residents of central Massachusetts hospitalized with STEMI at the major teaching/community medical centers increased dramatically during the years under study. Several groups were identified for purposes of heightened surveillance and intervention efforts to reduce the likelihood of failing to receive a timely primary PCI among patients acutely diagnosed with STEMI

    Cognitive Status, Initiation of Lifestyle Changes and Medication Adherence after Acute Coronary Syndrome: TRACE-CORE (Transitions, Risks, and Actions in Coronary Events- Center for Outcomes Research and Education)

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    Background: Lifestyle changes and medication adherence are often recommended to patients after acute coronary syndrome (ACS) as secondary prevention strategies. However, the impact of cognitive impairment (CI) on these secondary prevention strategies following ACS has not been examined. Methods: Cognitive status of 1374 patients with ACS from six hospitals in Massachusetts and Georgia enrolled in the ongoing TRACE-CORE (Transitions, Risks, and Actions in Coronary Events- Center for Outcomes Research and Education) study was assessed during hospitalization using the 41-point Telephone Interview for Cognitive Status (TICS). Information on recommendation and initiation of changes to diet, exercise, tobacco and alcohol use, stress, and cardiac rehabilitation attendance was collected through self-report one month after discharge. Medication adherence was assessed using the 8-item Morisky Scale. Among patients who reported receiving a recommendation for a lifestyle change, we modeled associations between CI and initiation of lifestyle changes and medication adherence, adjusting for demographics via logistic regression. Results: Mean age of participants was 63.0±11.1 years, 67% were male and 79% white; 526 (38.3%) screened positive for CI (TICS score ≤30) during hospitalization. Screening positive for CI was associated with being older, male, non-white, and less educated. Patients with CI more frequently received a recommendation to reduce alcohol use (25% vs. 16% of drinkers, p=.003) but were referred less often to a cardiac rehabilitation program (45% vs. 61%, p=.01). Among patients referred to cardiac rehabilitation (n=743), those with CI at baseline were less likely to report rehabilitation attendance at 1-month (OR= 0.70, 95%CI 0.50-0.97) compared to patients with normal cognitive function. Initiation of other lifestyle changes and medication adherence did not differ by cognitive status. Conclusions: CI is common among patients hospitalized for ACS and is associated with recommendation and initiation of certain lifestyle changes, making it an important factor to consider during the peri-discharge period
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