508 research outputs found
Solid state oxidation of aromatic sulfides to corresponding phenyl and p-tolyl sulfoxides and sulfone using oxone®
1069-107
Relative stereochemistry of the thermodynamic and kinetic addition of lithiated methyl phenyl sulfoxide to oxaziridine
329-33
Simvastatin decreases hepatic ischaemia/reperfusion-induced liver and lung injury in rats
Liver failure is still a significant clinical problem after transplantation surgery,
tissue resections (the Pringle manoeuvre) and haemorrhagic shock. The restoration
of blood flow to an ischaemic region leads to tissue injury at a greater
rate than the original ischaemic insult, an event termed "ischaemia-reperfusion
injury" (I/R). Despite advances in surgical techniques, I/R still poses a problem
of clinical importance. In this research, we studied the effect of simvastatin
pretreatment on liver and lung injury induced by hepatic I/R.
Rats were subjected to 30 min of ischaemia followed by 24 h of reperfusion.
Simvastatin (10 mg/kg) was administered orally from three days before the
operation. After the reperfusion time, serum ALT, AST, LDH and TNF a levels
were studied and liver and lung tissues were stained with haematoxylin and
eosin and TUNEL to detect apoptotic cells.
Serum aminotransferase activity and LDH and TNFα levels were increased markedly
by hepatic I/R, and these were suppressed significantly by simvastatin. The
tissue injury index and the number of apoptotic cells via TUNEL staining in the
liver and lungs were higher in the I/R group than in the I/R + simvastatin group.
These results suggest that simvastatin ameliorates I/R-induced liver and lung tissue
damage by inhibiting the level of inflammation and the apoptotic pathways.
Simvastatin administration may therefore provide protection against the adverse
effects of I/R injury in liver transplantation
1-Benzyl-1-aza-4-azoniabicyclo[2.2.2]- octane periodate as new oxidant for oxidation of thiols and sulfides to the corresponding disulfides and sulfoxides under anhydrous conditions
1041-104
Mitigating the Inrush Current of V/V Transformers using Railway Conditioners
Inrush current is high-magnitude current drawn by power transformers upon energization. The severity of inrush current depends on factors such as the transformer’s residual flux and the voltage phase angle at the energization instant. This paper proposes a flux matching method for the energization of V/V traction transformers to mitigate inrush current. This is achieved by adjusting the residual flux of the core to an appropriate reference value and then obtaining the proper energization instant. To this end, the method only requires knowledge of nominal voltage and excitation current, eliminating the need to acquire transformer’s parameters/design information. The railway power conditioner, typically present at the low voltage side of the V/V transformer, is used as a current source to inject sinusoidal current into the transformer windings before its energization. The reference residual flux is calculated based on the circuit breaker operating characteristics. The energization instant is determined such that the adjusted flux density matches the steady-state flux expected with respect to the applied voltage. The proposed method is validated by conducting over 14,000 simulations under different conditions using PSCAD/EMTDC. The method is also implemented and successfully tested on a laboratory-scale test rig, which verifies its effectiveness in more realistic conditions
The most common laboratory procedures for the evaluation of EPB TBMs excavated material ecotoxicity in Italy: A review
The rapid development of the mechanized tunneling in current decades has raised serious concerns about the environmental impact of large quantities of the muck. EPB-TBMs require the use of foaming agents for optimizing the soil conditioning.These agents could contain some chemicals (e.g., sodium lauryl ether sulfate – SLES) that are not included in the current legislation at the Italian or EU level. In order to minimize the project costs, it is useful to re-use the excavated soil as a reusable by-product that requires that it does not have any environmental impact on the ecosystems. For this purpose, to draw up a site-specific protocol is a practical and successful tool to evaluate the environmental compatibility of excavated soil during the tunneling. It can rely on one-month experiments at a microcosm or mesocosm scale using soil coming from the excavated site.At fixed times (from 0 to 28 days) the chemical degradation of the chemical together with ecotoxicological tests can be performed on soil or soil-water extracts. Both aquatic and terrestrial organisms are used and the choice of the tests depends on the final destination site.The results of the residual concentration of SLES in soil and in the elutriates, together with those of the ecotoxicological tests, make it possible to evaluate the temporary storage of spoil material and the time necessary for obtaining a safe soil debris to be used as a by-product.These data are usually included in the site-specific protocol to be applied during the excavation phase.This paper describes the main methodological aspects regarding microcosm experiments
Simvastatin attenuates intestinal ischaemia/reperfusion-induced injury in rat
Ischaemia/reperfusion (I/R) injury is commonly seen in the field of intestine surgical
interventions, shock, trauma, and many other clinical conditions. Simvastatin
is known to have antioxidant and anti-inflammatory properties. This study investigated
the effect of simvastatin administration in a warm intestinal I/R model on
TNF-α, antioxidant enzymes and intestinal tissue morphology.
Thirty-six male wistar rats underwent laparotomy under general anaesthesia. Simvastatin
was administered from four days before ischaemia induction. The
rats were divided in to three groups (n = 12): the sham goup, the I/R group, and
the I/R + simvastatin group. Intestinal ischaemia was induced by superior mesenteric
artery ligation with microvascular clamps for 60 minutes, and after ischaemia,
blood perfusion was released into the tissue and a reperfusion phase
was started, which lasted for 3 hours. After 3 hours, the animals were sacrificed
and serum and tissue obtained for biochemical and histological study.
In the simvastatin treated group, intestinal tissue injury, TNF-α level, and tissue
malondealdehyde levels were significantly lower than in the I/R group (p < 0.05).
Glutathion peroxidase and superoxide dismutase levels were significantly higher
in the simvastatin treated group than in the I/R group (p < 0.05).
Simvastatin pretreatment reduced intestinal I/R injury and was associated with down-
-regulation of serum TNF-α and tissue malondealdehyde level, and simvastatin
administration maintained cellular antioxidant enzyme contents compared to the
I/R group after 3 hours reperfusion time
MILD AND EFFICIENT METHOD FOR OXIDATION OF ALCOHOLS IN IONIC LIQUID MEDIA
In this study the strong oxidative agent, potassium permanganate, has been moderated with using under ionic liquid media for selective oxidation of some benzylic and aliphatic alcohols to their corresponding carbonyl compounds under mild and green conditions. 1-Butyl-3-methylimidazoliumbromide ([bmim]Br) (BMIM) associated with acetonitrile has been employed as modified media for oxidation of benzylic alcohols. This chemoselective and efficient process produced aldehydes and ketones with higher purity and yields and shorter reaction period in [bmim]Br as ionic liquid than conventional solvents
Synergistic Antibacterial Effects of Metallic Nanoparticle Combinations
© The Author(s) 2019.Metallic nanoparticles have unique antimicrobial properties that make them suitable for use within medical and pharmaceutical devices to prevent the spread of infection in healthcare. The use of nanoparticles in healthcare is on the increase with silver being used in many devices. However, not all metallic nanoparticles can target and kill all disease-causing bacteria. To overcome this, a combination of several different metallic nanoparticles were used in this study to compare effects of multiple metallic nanoparticles when in combination than when used singly, as single elemental nanoparticles (SENPs), against two common hospital acquired pathogens (Staphylococcus aureus and Pseudomonas. aeruginosa). Flow cytometry LIVE/DEAD assay was used to determine rates of cell death within a bacterial population when exposed to the nanoparticles. Results were analysed using linear models to compare effectiveness of three different metallic nanoparticles, tungsten carbide (WC), silver (Ag) and copper (Cu), in combination and separately. Results show that when the nanoparticles are placed in combination (NPCs), antimicrobial effects significantly increase than when compared with SENPs (P < 0.01). This study demonstrates that certain metallic nanoparticles can be used in combination to improve the antimicrobial efficiency in destroying morphologically distinct pathogens within the healthcare and pharmaceutical industry.Peer reviewe
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