Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
Add more filters










Publication year range
1.
Heliyon ; 9(11): e22364, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38034680

ABSTRACT

Polyoxymethylene dimethyl ethers (PODEn, n = 1-8) as an oxygenated fuel are a promising alternative fuel with a high oxygen concentration, a low C:H ratio, and no C-C bonds in their chemical structure. This could lead to smoke-free combustion. In this study, we chose to focus on PODE1 because of its lower cetane number, which makes it more suitable for use in spark ignition (SI) engines. However, its lower boiling point and octane number remain challenges. A low boiling point may lead to high vapour pressure and require storage and handling comparable to gaseous fuels. We investigated the effect of adding PODE1 to gasoline-ethanol blends (E10) on fuel properties, including distillation curve, octane number, phase stability, C/O/H ratio, heat of combustion, kinematic viscosity, and density. Our results showed that the blended fuels of E10 and PODE1 are stable up to 10 % PODE1, and there was no phase separation. Additionally, up to 10 % PODE1 additive had no significant side effect on the fuel properties of E10, particularly boiling point and octane number. Thus, work offers creative points by proposing a new candidate for additive fuel to gasoline-ethanol blends, which contributes to reducing the soot emission of GDI engines.

2.
ACS Omega ; 8(38): 34959-34971, 2023 Sep 26.
Article in English | MEDLINE | ID: mdl-37779939

ABSTRACT

Water emulsified heavy fuel oil (HFO) has been a promising alternative fuel for reducing oil consumption and preventing environmental pollution. However, the intrinsic challenges such as fuel formula, emulsion stability, and preparation process normally limit its further applications in energy-saving and emission reduction applications. In this study, the glucose obtained from biomass was added to a dispersed-phase aqueous solution of water emulsified HFO to prepare a novel alternative emulsified fuel. First, based on the preliminary experimental design, the effects of glucose and surfactant on the stability of the HFO emulsion were systematically evaluated through the appearance of emulsion separation, droplet size distribution, and rheological characteristics. It indicated that the surfactant ratio, hydrophilic-lipophilic balance value, solution ratio, and glucose/water ratio had significant impacts on emulsion stability. Subsequently, the optimum range of influencing factors of emulsion stability was determined by a single factor experiment and determined by the response surface methodology based on the Box-Behnken design; the optimal values of the above factors were 2.439 v/v%, 5.807, 26.462 v/v%, and 35.729%, respectively. Under these conditions, an optimal glucose solution emulsified HFO with a uniform brown color and long-term stability was obtained, making the unseparated emulsion ratio reach 98% (lasting for 7 days at 85 °C). Meanwhile, it emerged that the influence of multifactor on emulsion stability was not a simple linear correlation, and there were significant interactions between the solution ratio and the surfactant ratio, as well as between the glucose/water ratio and the surfactant ratio.

3.
Cell Chem Biol ; 30(10): 1277-1294.e12, 2023 10 19.
Article in English | MEDLINE | ID: mdl-37473760

ABSTRACT

Nitro-fatty acids (NFAs) are endogenous lipid mediators causing a spectrum of anti-inflammatory effects by covalent modification of key proteins within inflammatory signaling pathways. Recent animal models of solid tumors have helped demonstrate their potential as anti-tumorigenic therapeutics. This study evaluated the anti-tumorigenic effects of NFAs in colon carcinoma cells and other solid and leukemic tumor cell lines. NFAs inhibited the ubiquitin-proteasome system (UPS) by directly targeting the 26S proteasome, leading to polyubiquitination and inhibition of the proteasome activities. UPS suppression induced the unfolded protein response, resulting in tumor cell death. The NFA-mediated effects were substantial, specific, and enduring, representing a unique mode of action for UPS suppression. This study provides mechanistic insights into the biological actions of NFAs as possible endogenous tumor-suppressive factors, indicating that NFAs might be key structures for designing a novel class of direct proteasome inhibitors.


Subject(s)
Proteasome Endopeptidase Complex , Ubiquitin , Animals , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolism , Fatty Acids/pharmacology , Proteasome Inhibitors/pharmacology
4.
Chemosphere ; 338: 139347, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37437619

ABSTRACT

Today, hydrogen is produced in refineries and petrochemicals using the methane reforming process, followed by a water gas shift reaction stage. The hydrogen produced has a purity of approximately 75%, and is purified further through an adsorption process. In this project, the feasibility of achieving a purity level greater than 90% through the use of a more effective adsorbent and the periodic process of pressure vacuum swing adsorption (PVSA) with a double-layer bed of active carbon and zeolite will be investigated. The design, simulation, and optimization of the hydrogen purification unit will also be conducted. The results of this study indicate that the proposed process can achieve a purity level of up to 97% for the output hydrogen.


Subject(s)
Hydrogen , Zeolites , Vacuum , Adsorption , Charcoal
5.
Int J Mol Sci ; 23(16)2022 Aug 18.
Article in English | MEDLINE | ID: mdl-36012587

ABSTRACT

The biomedical consequences of allogeneic blood transfusions and the possible pathomechanisms of transfusion-related morbidity and mortality are still not entirely understood. In retrospective studies, allogeneic transfusion was associated with increased rates of cancer recurrence, metastasis and death in patients with colorectal cancer. However, correlation does not imply causation. The purpose of this study was to elucidate this empirical observation further in order to address insecurity among patients and clinicians. We focused on the in vitro effect of microparticles derived from red blood cell units (RMPs). We incubated different colon carcinoma cells with RMPs and analyzed their effects on growth, invasion, migration and tumor marker expression. Furthermore, effects on Wnt, Akt and ERK signaling were explored. Our results show RMPs do not seem to affect functional and phenotypic characteristics of different colon carcinoma cells and did not induce or inhibit Wnt, Akt or ERK signaling, albeit in cell culture models lacking tumor microenvironment. Allogeneic blood transfusions are associated with poor prognosis, but RMPs do not seem to convey tumor-enhancing effects. Most likely, the circumstances that necessitate the transfusion, such as preoperative anemia, tumor stage, perioperative blood loss and extension of surgery, take center stage.


Subject(s)
Carcinoma , Cell-Derived Microparticles , Colonic Neoplasms , Carcinoma/complications , Cell-Derived Microparticles/pathology , Colonic Neoplasms/pathology , Humans , Neoplasm Recurrence, Local/etiology , Proto-Oncogene Proteins c-akt , Retrospective Studies , Tumor Microenvironment
6.
Sci Rep ; 12(1): 7714, 2022 May 11.
Article in English | MEDLINE | ID: mdl-35545627

ABSTRACT

Impacts of blending fusel oil with gasoline on fuel combustion have been investigated experimentally in the current research to evaluate engine performance improvement and exhaust emission. Tested fuel include F10, F20 (10% and 20% of fusel oil by volume) and pure gasoline as baseline fuel have been used to operate 4-cylinder SI engine at increasing engine speed and constant throttle valve of 45%. The present results reveal a shorter combustion duration and better engine performance with F10 over engine speeds with maximum value of 33.9% for the engine brake thermal efficiency. The lowest BSFC of 251 g/kW h was recorded at 3500 rpm engine speed also with F10. All blended fuel have almost similar COVIMEP. Less NOx emission was measured with F10 at 4500 engine speed compared to gasoline. However, CO emissions reduced while higher CO2 was observed with introducing fusel oil in the blend. Moreover, HC emission increased an average by 11% over speed range and the highest value was achieved with 10% fusel oil addition compared to 20% and pure gasoline. Accordingly, higher oxygen content of fusel oil and octane number contribute to improve combustion of fuel mixture.

7.
Front Pharmacol ; 12: 715076, 2021.
Article in English | MEDLINE | ID: mdl-34867322

ABSTRACT

Endogenous nitro-fatty acids (NFA) are potent electrophilic lipid mediators that exert biological effects in vitro and in vivo via selective covalent modification of thiol-containing target proteins. The cytoprotective, anti-inflammatory, and anti-tumorigenic effects of NFA in animal models of disease caused by targeted protein nitroalkylation are a valuable basis for the development of future anti-phlogistic and anti-neoplastic drugs. Considering the complexity of diseases and accompanying comorbidities there is an urgent need for clinically effective multifunctional drugs. NFA are composed of a fatty acid backbone containing a nitroalkene moiety triggering Michael addition reactions. However, less is known about the target-specific structure-activity relationships and selectivities comparing different NFA targets. Therefore, we analyzed 15 NFA derivatives and compared them with the lead structure 9-nitro-oleic acid (9NOA) in terms of their effect on NF-κB (nuclear factor kappa B) signaling inhibition, induction of Nrf-2 (nuclear factor erythroid 2-related factor 2) gene expression, sEH (soluble epoxide hydrolase), LO (lipoxygenase), and COX-2 (cyclooxygenase-2) inhibition, and their cytotoxic effects on colorectal cancer cells. Minor modifications of the Michael acceptor position and variation of the chain length led to drugs showing increased target preference or enhanced multi-targeting, partly with higher potency than 9NOA. This study is a significant step forward to better understanding the biology of NFA and their enormous potential as scaffolds for designing future anti-inflammatory drugs.

8.
Front Pharmacol ; 11: 1297, 2020.
Article in English | MEDLINE | ID: mdl-33013366

ABSTRACT

Nitro fatty acids (NFAs) are endogenously generated lipid mediators deriving from reactions of unsaturated electrophilic fatty acids with reactive nitrogen species. Furthermore, Mediterranean diets can be a source of NFA. These highly electrophilic fatty acids can undergo Michael addition reaction with cysteine residues, leading to post-translational modifications (PTM) of selected regulatory proteins. Such modifications are capable of changing target protein function during cell signaling or in biosynthetic pathways. NFA target proteins include the peroxisome proliferator-activated receptor γ (PPAR-γ), the pro-inflammatory and tumorigenic nuclear factor-κB (NF-κB) signaling pathway, the pro-inflammatory 5-lipoxygenases (5-LO) biosynthesis pathway as well as soluble epoxide hydrolase (sEH), which is essentially involved in the regulation of vascular tone. In several animal models of inflammation and cancer, the therapeutic efficacy of well-tolerated NFA has been demonstrated. This has already led to clinical phase II studies investigating possible therapeutic effects of NFA in subjects with pulmonary arterial hypertension. Albeit Michael acceptors feature a broad spectrum of bioactivity, they have for a rather long time been avoided as drug candidates owing to their presumed unselective reactivity and toxicity. However, targeted covalent modification of regulatory proteins by Michael acceptors became recognized as a promising approach to drug discovery with the recent FDA approvals of the cancer therapeutics, afatanib (2013), ibrutinib (2013), and osimertinib (2015). Furthermore, the Michael acceptor, neratinib, a dual inhibitor of the human epidermal growth factor receptor 2 and epidermal growth factor receptor, was recently approved by the FDA (2017) and by the EMA (2018) for the treatment of breast cancer. Finally, a number of further Michael acceptor drug candidates are currently under clinical investigation for pharmacotherapy of inflammation and cancer. In this review, we focus on the pharmacology of NFA and other Michael acceptor drugs, summarizing their potential as an emerging class of future antiphlogistics and adjuvant in tumor therapeutics.

9.
Sci Total Environ ; 718: 137302, 2020 May 20.
Article in English | MEDLINE | ID: mdl-32109813

ABSTRACT

Gasoline direct injection (GDI), which is one of the fuel injection technologies extensively used in internal combustion engines, is a viable alternative for port fuel injection technology in premium gasoline (petrol)-run vehicles; furthermore, it provides a better fuel economy, higher thermal efficiency, and greater power output. However, the particulate emissions ejected from modern GDI engines are an environmental and health hazard. As a result, stringent emission legislations are imposed on the production/incorporation of GDI engines. This study reviews the particle masses (PMs) and particle numbers (PNs) of various GDI engines. The backgrounds and highlights of current and future PM emission regulations (Euro 5-6 and China 5-6 GDI engine legislations) are discussed. In addition to the effects of cold-start and oxygenated fuel on PM emissions, this paper also reviews the impacts of engine parameters. Another area of discussion is the particulate filter technology as a solution for pollution control. Concerns about PM emissions from GDI engines are conceptually similar to those about emissions from diesel engines. Finally, this paper discusses the technical and commercial aspects of the use of the particulate matter control technology of GDI engines, such as particulate gasoline filters, as dedicated GDI filtration devices.

10.
Sci Total Environ ; 715: 136849, 2020 May 01.
Article in English | MEDLINE | ID: mdl-32007882

ABSTRACT

The combustion of conventional fuels within the transportation sector is a crucial driver of global warming and produces a number of harmful emissions. To decrease these adverse factors, the development of synthetic fuels produced from renewable energy sources via the catalytic conversion of carbon dioxide (CO2) and hydrogen (H2) has progressed significantly. Eco-friendly fuels have a reduced impact on the environment throughout their production and use cycles. In recent years, the use of polyoxymethylene dimethyl ethers (PODEn) as fuels has received an increasing amount of attention, owing to their engine performance and reduced environmental impact. The specific target of this paper is to systematically review the field of PODEn application-based additives as fuel for internal combustion engines. The background and highlights of current and future applications of PODEn are also discussed, and the challenges associated with the use of this additive are also briefly reviewed. A number of studies have shown that the use of fuel mixtures with up to 10% PODE3-4 can have a significant impact on the reduction of engine emissions. PODEn have been shown to reduce the emissions of soot, particulates, CO, and HC under different parameters and working conditions, although NOx and brake-specific fuel consumption (BSFC) emissions have been found to increase. Additionally, PODEn can be produced from natural gas or electric power via CO2 activation in a sustainable manner, which represents a significant benefit with regard to the use of oil-based products. Finally, fossil fuels blended with PODEn can be easily ignited and burned at stoichiometric conditions.

11.
Sci Total Environ ; 675: 13-30, 2019 Jul 20.
Article in English | MEDLINE | ID: mdl-31026637

ABSTRACT

This study explores the environmental, economic, and technical feasibility of using spent coffee grounds as parent feedstock for biodiesel production. Biodiesel is produced from the spent coffee grounds, and four blends are prepared-B5, B10, B15, and B20. The effects of two extraction solvents (hexane and petroleum ether) on oil yields of the spent coffee grounds are investigated, employing the Soxhlet extraction technique. The properties of any intermediate yield throughout the production process are characterised and adjusted by post processes to ensure the conformity of the final biodiesel product with the standards (ASTM D6751 and ISO EN14214). The major part of the study investigates the effects of blends on tailpipe emissions and performance of a naturally aspirated single-cylinder compression ignition engine. A wide range of engine speeds (1600-3600rpm at 200-rpm increments) has been considered at three engine loads (100, 75, and 50%). The standard diesel fuel is set as a basis for comparison. Results show that the post processes on the extracted oil yielded water content of 0.038%, free fatty acid fraction of 0.41%, and acid number of <2mg KOH/g. The highest oil extraction (14.12%) was obtained over a 45-min extraction time using a hexane solvent. Biodiesel blends produced lower levels of CO2, CO, and HC. Blend B5 showed average reductions of 0.34, 12.5, and 4.23% at full load for the three aforementioned emissions, respectively; B10 reductions were 3.12, 29.85, and 19.14%, respectively. Higher levels of NOx emissions were detected from all blends. At full load, the average NOx increments of B5, B10, B15, and B20 were 0.35, 1.28, 1.8, and 2.3%, respectively. The outstanding environmental and ecological benefits of using the spent coffee grounds as a potential feedstock for biodiesel production are apparent.


Subject(s)
Biofuels , Environment , Gasoline , Coffee , Vehicle Emissions
12.
Int J Angiol ; 26(4): 241-248, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29142491

ABSTRACT

The role of remote ischemic postconditioning (RIPostC) in improving left ventricular (LV) remodeling after primary percutaneous coronary intervention (PCI) is not well established. To determine the efficacy and safety of RIPostC in improving LV remodeling and cardiovascular outcomes after primary PCI for anterior ST-elevation myocardial infarction (STEMI). Seventy-one patients with anterior STEMI were randomized to primary PCI with RIPostC protocol ( n = 36) versus conventional primary PCI ( n = 35). Primary outcomes included LV remodeling and LV ejection fraction (LVEF) at 6 month follow-up using transthoracic echocardiography. Secondary outcomes included infarct size, ST-segment resolution (STR) ≥70%, Thrombolysis in Myocardial Infarction (TIMI) flow grade, and myocardial blush grade (MBG). Major adverse cardiac events (MACEs) were also assessed at 6 months. Safety outcome included incidence of acute kidney injury (AKI) postprimary PCI. Sixty patients completed the study. At 6 months, there was no significant decrease in the incidence of LV remodeling with RIPostC group ( p = 0.42). Similarly, RIPostC failed to show significant improvement in LVEF. However, STR ≥ 70% after primary PCI was achieved more in the RIPostC group ( p = 0.04), with a trend toward less AKI in the RIPostC group ( p = 0.08). All other secondary end points, including MACEs at 6 months, were similar in both groups. RIPostC might be associated with better STR after reperfusion as well as less incidence of AKI in patients undergoing primary PCI for anterior wall STEMI, indicating potential benefit in those patients. Whether this role can be translated to better outcomes after primary PCI warrants further investigation.

13.
Am Heart J ; 160(5): 862-9, 2010 Nov.
Article in English | MEDLINE | ID: mdl-21095273

ABSTRACT

BACKGROUND: The conventional surgical aortic bioprostheses used for treatment of aortic stenosis (AS) are inherently stenotic in nature. The more favorable mechanical profile of the Medtronic CoreValve bioprosthesis may translate into a better hemodynamic and neurohormonal response. PATIENTS AND METHODS: The early hemodynamic and neurohormonal responses of 56 patients who underwent successful transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve bioprosthesis for severe symptomatic AS were compared with those of 36 patients who underwent surgical aortic valve replacement (SAVR) using tissue valves in the same period. RESULTS: At baseline, patients in the TAVI and SAVR group had comparable indexed aortic valve area (0.33 ± 0.1 vs 0.34 ± 0.1 cm² , respectively; P = .69) and mean transvalvular gradient (51.1 ± 16.5 vs 53.1 ± 14.3 mm Hg, respectively; P = .56). At 30-day follow-up, mean transvalvular gradient was lower in the TAVI group than in the SAVR group (10.3 ± 4 vs 13.1 ± 6.2 mm Hg, respectively; P = .015), and the indexed aortic valve area was larger in the TAVI group (1.0 ± 0.14 vs 0.93 ± 0.13 cm²/m²; P = .017). There was a trend toward a higher incidence of moderate patient-prosthesis mismatch in the surgical group compared with the TAVI group (30.5% vs 17.8%, respectively; P = .11). The overall incidence of prosthetic regurgitation (any degree) was higher in the TAVI group than in the SAVR group (85.7% vs 16.7%, respectively; P < .00001). The left ventricular mass index decreased after TAVI (175.1 ± 61.8 vs 165.6 ± 57.2 g/m²; P = .0003) and remained unchanged after SAVR (165.1 ± 50.6 vs 161 ± 64.8 g/m²; P = .81). Similarly, NT-ProBNP decreased after TAVI (3,479 ± 2,716 vs 2,533 ± 1,849 pg/mL; P = .033) and remained unchanged after SAVR (1,836 ± 2,779 vs 1,689 ± 1,533 pg/mL; P = .78). There was a modest correlation between natriuretic peptides and left ventricular mass index in the whole cohort (r = 0.4, P = .013). CONCLUSION: In patients with severe AS, TAVI resulted in lower transvalvular gradients and higher valve areas than SAVR. Such hemodynamic performance after TAVI may have contributed to early initiation of a reverse cardiac remodeling process and a decrease in natriuretic peptides.


Subject(s)
Aortic Valve Stenosis/surgery , Bioprosthesis , Cardiac Catheterization/methods , Heart Valve Prosthesis Implantation/methods , Hemodynamics/physiology , Natriuretic Peptides/blood , Aged , Aged, 80 and over , Aortic Valve Stenosis/blood , Aortic Valve Stenosis/physiopathology , Echocardiography, Doppler, Color , Echocardiography, Transesophageal , Female , Follow-Up Studies , Heart Ventricles/diagnostic imaging , Heart Ventricles/physiopathology , Humans , Male , Prosthesis Design , Retrospective Studies , Time Factors , Treatment Outcome
SELECTION OF CITATIONS
SEARCH DETAIL
...