Effects of Metal (periodic group VI) Hexacarbonyls on the Autoxidation of Methyl Oleate and the Decomposition of Methyl Oleate Hydroperoxide

The ultimate goal of replantation and microsurgical reconstructive operations is to regain or improve impaired function of the tissue. However, the data related to the influence of NO on tissue function are limited. This study evaluated the effects of the NO donor S-nitroso- N-acetylcysteine (SNAC) on contractile function of skeletal muscle during reperfusion. Forty-nine rats were divided into six groups. The extensor digitorum longus (EDL) muscles in groups I and II were not subjected to ischemia-reperfusion but were treated with a low (100 nmol/min) or high (1 μmol/min) dose of SNAC. In groups III- V, the EDL underwent 3 h of ischemia and 3 h of reperfusion and was also treated with low (100 nmol/min) or high doses (1 or 5 μmol/min) of SNAC. Group VI was a phosphate-buffered saline (PBS)-treated control group. Twenty additional animals were used to document systemic effects of SNAC and PBS only. SNAC or PBS was infused for 6.5 h, beginning 30 min before ischemia and continuing throughout the duration of reperfusion. Contractile testing compared the maximal twitch force, isometric tetanic contractile forces, fatigue, and fatigue half time of the experimental EDL and the contralateral nontreated EDL. The findings indicate that 1) SNAC does not influence contractile function of EDL muscle not subjected to ischemia-reperfusion, 2) SNAC significantly protects the contractile function of ischemic skeletal muscle against reperfusion injury in the early reperfusion period, and 3) the protective role of SNAC is critically dosage dependent; protection is lost at higher doses. The conclusion from this study is that supplementation with exogenous NO exerts a protective effect on the tissue against reperfusion injury.

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Evaluation of efficacy of Aloe vera (L.) Burm. f. gel solution in methylcellulose-induced ocular hypertension in New Zealand white rabbits

Journal of Basic and Clinical Physiology and Pharmacology ◽

10.1515/jbcpp-2019-0158 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Jhanvi J. Vaghela ◽

Manish J. Barvaliya ◽

Sugnesh J. Parmar ◽

Chandrabhanu R. Tripathi

Keyword(s):

Disease Control ◽

Ocular Hypertension ◽

Aloe Vera ◽

Group Iv ◽

Control Group ◽

Group Vi ◽

Concurrent Treatment ◽

Maximum Reduction ◽

New Zealand White Rabbits ◽

Time Point

AbstractObjectivesThe present study aimed to evaluate the efficacy of Aloe vera in the methylcellulose-induced ocular hypertension model.MethodsFifty-six rabbits were randomly divided into seven groups. Intraocular pressure (IOP) was raised by anterior chamber injection of 2% methylcellulose in all the groups except the normal control group. Disease control animals were treated with sterile water and active control with topical 0.5% timolol 12 hourly; 6 and 12% A. vera gel topical solutions 8 hourly were given in group IV and V, respectively; 6 and 12% A. vera gel solutions along with timolol were given in group VI and VII animals, respectively. Mean IOP values and percentage of reduction in IOP were compared at 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 36 h, and 48 h.ResultsA. vera gel solutions (6 and 12%) showed a significant reduction in mean IOP from 4 to 2 h time points, respectively, whereas, A. vera gel solutions (6 and 12%) + timolol showed significant less mean IOP from a 30 min time point as compared with disease control. A. vera gel solutions (6 and 12%) showed 8.6 and 10.4% more reduction in IOP, respectively (66.8 ± 4.9% and 68.6 ± 5.4% vs. 58.2 ± 2.3%; p > 0.05), whereas 6 and 12% A. vera gel solutions along with timolol showed 14.5 and 16.2% more reduction in IOP, respectively (72.7 ± 4.7% and 74.4 ± 4.1% vs. 58.2 ± 2.3%; p < 0.05), than disease control group at 48 h.ConclusionsSix and twelve percent A. vera gel solutions reduced the IOP effectively. Concurrent treatment with 12% A. vera gel and timolol produced the maximum reduction in IOP.

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First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

Scientific Reports ◽

10.1038/s41598-021-91594-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

R. Salloom ◽

S. A. Mantri ◽

R. Banerjee ◽

S. G. Srinivasan

Keyword(s):

Mechanical Properties ◽

Young’S Modulus ◽

First Principles ◽

Young's Modulus ◽

Group Vi ◽

Group V ◽

Β Phase ◽

Ti Alloys ◽

Ω Phase ◽

Stabilizer Concentration

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

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