950 research outputs found
A review of recent advances in the synthesis of environmentally friendly, sustainable, and nontoxic bio-lubricants: Recommendations for the future implementations
Conventional petroleum-based lubricant resources are depleting rapidly, and their utilization severely threatens the environment. Environmental sustainability emphasizes the need for an alternative to petroleum resources. The lubricants play a significant role in machinery's adequate energy-saving performance. Therefore, the tribological aspects of machinery's maximum efficiency should be considered. The current study reviews the part of bio-lubricants towards environmental sustainability. This review has been conducted according to the PRISMA approach, where the sources of bio-lubricants, tribological performance, the role of additives and nanoparticles, benefits and disadvantages, production techniques, economic aspects, and future scope were explored and discussed. Bio-lubricants possess a better viscosity index, lubricity, biodegradability, and non-toxic and renewable nature than petroleum lubricants. However, lower thermo-oxidative stability and higher pour points due to moisture content require further improvements. Food security is another significant concern for bio-lubricants. Consequently, it emphasized the importance of algae-based bio-lubricant sources in reducing the threat to food security, water purification, and greenhouse gas mitigation. Further improvements and optimization of production methods are required to increase lubricant yield rates and promote sustainability. The importance of new (algae-based) bio lubricant substitutes with details of their physicochemical properties for a sustainable future is highlighted in this review research
Acetone-Gasoline Blend as an Alternative Fuel in SI Engines: A Novel Comparison of Performance, Emission, and Lube Oil Degradation
The disproportionate use of petroleum products and stringent exhaust emissions has emphasized the need for alternative green fuels. Although several studies have been conducted to ascertain the performance of acetone-gasoline blends in spark-ignition (SI) engines, limited work has been done to determine the influence of fuel on lubricant oil deterioration. The current study fills the gap through lubricant oil testing by running the engine for 120 h on pure gasoline (G) and gasoline with 10% by volume acetone (A10). Compared to gasoline, A10 produced better results in 11.74 and 12.05% higher brake power (BP) and brake thermal efficiency (BTE), respectively, at a 6.72% lower brake-specific fuel consumption (BSFC). The blended fuel A10 produced 56.54, 33.67, and 50% lower CO, CO2, and HC emissions. However, gasoline remained competitive due to lower oil deterioration than A10. The flash-point and kinematic viscosity, compared to fresh oil, decreased by 19.63 and 27.43% for G and 15.73 and 20.57% for A10, respectively. Similarly, G and A10 showed a decrease in total base number (TBN) by 17.98 and 31.46%, respectively. However, A10 is more detrimental to lubricating oil due to a 12, 5, 15, and 30% increase in metallic particles like aluminum, chromium, copper, and iron, respectively, compared to fresh oil. Performance additives like calcium and phosphorous in lubricant oil for A10 decreased by 10.04 and 4.04% in comparison to gasoline, respectively. The concentration of zinc was found to be 18.78% higher in A10 when compared with gasoline. A higher proportion of water molecules and metal particles were found in lubricant oil for A10
Recurrent Episodes of Acute Pancreatitis Present to the ED with More Severe Disease by CT than First-Time Acute Pancreatitis
Study Objective: Approximately 30% of patients with one episode of acute pancreatitis experience a recurrent episode. The objective of this study is to compare the severity of the first-time episode versus recurrent episodes of acute pancreatitis based on CT scan.
Methods: This study was conducted as part of a retrospective chart review at a single academic urban emergency department from 2012-2016. Criteria for inclusion included clinical symptoms of pancreatitis, age greater than or equal to 18 years, ED diagnosis of acute pancreatitis, and, an abdominal CT scan within 24 hours of triage. Exclusion criteria were traumatic cause of acute pancreatitis and pregnancy. Charts were reviewed by a trained abstractor using structured data collection sheets which included data elements such as a history of acute pancreatitis and the results of an abdominal CT scan. Data abstraction was confirmed for interrater reliability. CT Scans were graded using the Modified CT Severity Index (MCTSI) which grades acute pancreatitis by the presence of inflammation, fluid accumulation, necrosis or extra-pancreatic findings.
Results: 283 patients were included in the study. Of these, 110 patients resented with recurrent acute pancreatitis and 173 patients presented with first-time acute pancreatitis. We calculated the mean MCTSI score in both groups and found a significantly higher rate of severity in recurrent acute pancreatitis versus first episode (2.09 vs. 1.43, p\u3c0.05.)
Conclusion: Patients with recurrent acute pancreatitis are more likely to present with a more severe episode of acute pancreatitis than patients presenting with first-time acute pancreatitis
Evolutionary History and Population Dynamics of Hepatitis E Virus
BACKGROUND: Hepatitis E virus (HEV) is an enterically transmitted hepatropic virus. It segregates as four genotypes. All genotypes infect humans while only genotypes 3 and 4 also infect several animal species. It has been suggested that hepatitis E is zoonotic, but no study has analyzed the evolutionary history of HEV. We present here an analysis of the evolutionary history of HEV. METHODS AND FINDINGS: The times to the most recent common ancestors for all four genotypes of HEV were calculated using BEAST to conduct a Bayesian analysis of HEV. The population dynamics for genotypes 1, 3 and 4 were analyzed using skyline plots. Bayesian analysis showed that the most recent common ancestor for modern HEV existed between 536 and 1344 years ago. The progenitor of HEV appears to have given rise to anthropotropic and enzootic forms of HEV, which evolved into genotypes 1 and 2 and genotypes 3 and 4, respectively. Population dynamics suggest that genotypes 1, 3 and 4 experienced a population expansion during the 20(th) century. Genotype 1 has increased in infected population size ∼30-35 years ago. Genotype 3 and 4 have experienced an increase in population size starting late in the 19(th) century until ca.1940-45, with genotype 3 having undergone additional rapid expansion until ca.1960. The effective population size for both genotype 3 and 4 rapidly declined to pre-expansion levels starting in ca.1990. Genotype 4 was further examined as Chinese and Japanese sequences, which exhibited different population dynamics, suggesting that this genotype experienced different evolutionary history in these two countries. CONCLUSIONS: HEV appears to have evolved through a series of steps, in which the ancestors of HEV may have adapted to a succession of animal hosts leading to humans. Analysis of the population dynamics of HEV suggests a substantial temporal variation in the rate of transmission among HEV genotypes in different geographic regions late in the 20(th) Century
Excited superdeformed bands in Dy154 and cranked relativistic mean field interpretation
A Gammasphere experiment has been carried out using the Sn122(S36,4n) reaction to search for excited superdeformed (SD) structures in Dy154 to investigate the properties of neutron orbitals at superdeformation. Five new excited SD bands have been identified with intensities ranging from ~0.7% to ~0.03% relative to the Dy154 reaction channel. Bands SD1, SD3, SD5, and SD6 are interpreted within the cranked relativistic mean field theory by using the effective alignment method. High-N intruder configurations are also discussed for bands SD2 and SD4, based on a comparison of their dynamic moments of inertia, which rise with increasing rotational frequency, with those of similar bands in neighboring nuclei
Airborne rhinovirus detection and effect of ultraviolet irradiation on detection by a semi-nested RT-PCR assay
BACKGROUND: Rhinovirus, the most common cause of upper respiratory tract infections, has been implicated in asthma exacerbations and possibly asthma deaths. Although the method of transmission of rhinoviruses is disputed, several studies have demonstrated that aerosol transmission is a likely method of transmission among adults. As a first step in studies of possible airborne rhinovirus transmission, we developed methods to detect aerosolized rhinovirus by extending existing technology for detecting infectious agents in nasal specimens. METHODS: We aerosolized rhinovirus in a small aerosol chamber. Experiments were conducted with decreasing concentrations of rhinovirus. To determine the effect of UV irradiation on detection of rhinoviral aerosols, we also conducted experiments in which we exposed aerosols to a UV dose of 684 mJ/m(2). Aerosols were collected on Teflon filters and rhinovirus recovered in Qiagen AVL buffer using the Qiagen QIAamp Viral RNA Kit (Qiagen Corp., Valencia, California) followed by semi-nested RT-PCR and detection by gel electrophoresis. RESULTS: We obtained positive results from filter samples that had collected at least 1.3 TCID(50 )of aerosolized rhinovirus. Ultraviolet irradiation of airborne virus at doses much greater than those used in upper-room UV germicidal irradiation applications did not inhibit subsequent detection with the RT-PCR assay. CONCLUSION: The air sampling and extraction methodology developed in this study should be applicable to the detection of rhinovirus and other airborne viruses in the indoor air of offices and schools. This method, however, cannot distinguish UV inactivated virus from infectious viral particles
Novel and promising compounds to treat Cryptosporidium parvum infections
No fully effective approved drug therapy exists for Cryptosporidium infections of immunocompetent and immunocompromised patients. Here, we investigated 11 benzimidazole derivatives carrying substituted thioalkyl and thiobenzyl groups at position 2 of benzimidazole nucleus and additional substituents at the benzene part of benzimidazole for inhibition of the in vitro growth of the intestinal protozoan parasite, Cryptosporidium parvum. Three of them, i.e., 5-carboxy-2-(4-nitrobenzylthio)-1H-benzimidazole, 5,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, and 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, (compounds 5, 7, and 8) were the most active (IC50 28–31 μM). The concentration of compounds 5, 7, and 8 that caused 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was comparable with those obtained for paromomycin
Novel and promising compounds to treat Cryptosporidium parvum infections
No fully effective approved drug therapy exists for Cryptosporidium infections of immunocompetent and immunocompromised patients. Here, we investigated 11 benzimidazole derivatives carrying substituted thioalkyl and thiobenzyl groups at position 2 of benzimidazole nucleus and additional substituents at the benzene part of benzimidazole for inhibition of the in vitro growth of the intestinal protozoan parasite, Cryptosporidium parvum. Three of them, i.e., 5-carboxy-2-(4-nitrobenzylthio)-1H-benzimidazole, 5,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, and 4,6-dichloro-2-(4-nitrobenzylthio)-1H-benzimidazole, (compounds 5, 7, and 8) were the most active (IC50 28–31 μM). The concentration of compounds 5, 7, and 8 that caused 50% growth inhibition in human enterocytic HCT-8 cells by a quantitative alkaline phosphatase immunoassay was comparable with those obtained for paromomycin
Multiple excitation modes in Hf 163
Excited states of Hf163 were populated using the Zr94(Ge74,5n) reaction and the decay γ rays were measured with the Gammasphere spectrometer. Two previously known bands were extended to higher spins, and nine new bands were identified. In addition to bands associated with three- and five-quasiparticle configurations, two γ-vibrational bands coupled to the i13/2 excitation were also observed. The lowest level of a newly identified, negative-parity band is proposed to be the ground state of the nucleus. A systematic delay of the high-spin proton crossing frequency with increasing quadrupole deformation from Hf162 to Hf172 was established. Extensive band searches failed to reveal a triaxial, strongly deformed structure in Hf163 similar to the one observed in several nuclei around A∼165
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