Surgical sutures are the most well-known surgical biomaterial device for ligating blood vessels. The primary goal of wound closure is to align wound margins to provide a closed and stable ...environment. Sutures with lesser tensile strength are susceptible to break throughout the healing process due to edema. To evaluate the tensile strength of absorbable and nonabsorbable suture materials after immersion in fruit juices. In this in vitro study, eight samples of commercially available sutures such as black silk and vicryl were divided into two groups: sample -1 were immersed in grape juice and sample -2 were immersed in lemon juice for 1 week. Universal testing machine INSTRON E300 UTM was used to test the tensile strength of various suture materials. The data are statistically analyzed using an independent t-test. The P < 0.05 was considered to be statistically significant. The mean of vicryl suture after immersion in grape and lemon juice was found to be 34.445 and 43.39; the mean value of black silk after immersion in grape and lemon juice was found to be 36.95 and 33.1. The tensile strength of black silk was slightly lower than the vicryl. Independent sample t-test showed that P = 0.561 (>0.05) which is statistically insignificant. Vicryl suture tested to have the highest tensile strength along with excellent knot holding capacity than black silk suture after immersion in fruit juices.
Let R be a commutative Artinian ring and let
be the compressed zero-divisor graph associated to R. The question of when the clique number
was raised by J. Coykendall, S. Sather-Wagstaff, L. ...Sheppardson, and S. Spiroff. They proved that if
(where
is the largest length of any of its chains of ideals), then
When
they gave an example of a local ring R where
is possible by using the trivial extension of an Artinian local ring by its dualizing module. The question of what happens when
was stated as an open question. We show that if
then
We first reduce the problem to the case of a local ring
We then enumerate all possible Hilbert functions of R and show that the k-vector space
admits a symmetric bilinear form in some cases of the Hilbert function. This allows us to relate the orthogonality in the bilinear space
with the structure of zero-divisors in R. For instance, in the case when
is principal and
we show that R is Gorenstein if and only if the symmetric bilinear form on
is non-degenerate. Moreover, in the case when
our techniques also yield a simpler and shorter proof of the finiteness of
avoiding, for instance, the Cohen structure theorem.
Background and Aims: Opioids have nowadays become superfluous because of their adverse effects involving post-operative recovery of the patients. So, we aimed at comparing opioid-free anaesthesia ...with opioid-based technique for post-operative pain relief in laparoscopic surgeries. The primary objective was to assess the pain scores in the post-operative period using visual analogue scale (VAS) for 24 h, and the secondary objective was to compare intraoperative haemodynamic parameters, duration of postoperative analgesia and total analgesics consumed in the first 24 h. Methods: This study was conducted in 60 patients aged between 20 and 70 years, belonging to the American Society of Anesthesiologists physical class I and II posted for laparoscopic surgeries. Anaesthetic doses of lidocaine, magnesium and paracetamol in combination with fascial plane block for post-operative pain relief were given for 30 patients, and the other 30 patients received the conventional opioid-based anaesthesia. Mann-Whitney test was used for VAS scores, and Friedman test was used for repeated measures comparison. Results: VAS scores were higher in the conventional group as compared to the opioid-free group at 0, 2, 4, and 6 h during rest and at 0, 2, 4, 6, 24 h during movement and were statistically significant (P-value < 0.05). The duration of analgesia for the conventional group was 13.8 + 6.7 h, and for opioid-free anaesthesia was 6.7 + 2.2 hours. Intraoperative haemodynamic parameters did not show a statistically significant difference except for systolic blood pressure which was higher in the opioid-free group but was clinically insignificant. (P-value 0.013). Conclusion: Opioid-free anaesthesia along with erector spinae plane block provides better post-operative pain relief when compared to conventional opioid anaesthesia.
In the present study, hot deformation behavior of a FCC high-entropy alloy CoCuFeMnNi has been investigated to explore the stress–strain response for a wide range of temperatures and strain rates. ...The deformation response has been examined by plotting a processing map and examining the evolution of microstructure and texture in each of the temperature–strain rate domain. Hot compression tests were carried out in the temperature range 850–1050 °C at strain rates varying from 0.001 s−1 to 10 s−1. Stress–strain curves indicate characteristic softening behavior due to dynamic recrystallization (DRX). DRX has been observed along grain boundaries, shear bands, as well as in the interior of deformed grains. The size of dynamically recrystallized grains shows a strong dependence on deformation temperature and increases with temperature. A high degree of twin formation takes place in the DRX grains evolved inside the shear bands, and the extent of twinning decreases at high temperatures. The optimal processing window has been estimated based on strain rate sensitivity and has been validated with detailed analyses of microstructure and texture. The best region for thermo-mechanical processing has been identified as in the temperature range 850–950 °C at strain rate 10−1 s−1.
We herein report hydrazine-directed, Rh(III) catalyzed (4+2) annulation of
-alkyl aryl hydrazines with sulfoxonium ylides as a safe carbene precursor. The reaction shows excellent functional group ...tolerance with broad substrate scope, scalability and site selectivity. Finally, photophysical studies indicated that some of these compounds have interesting fluorescence properties.
Composite is usually a mixture of two phases. The composites used in dentistry have high durability. The individual properties of each phase are important to increase the mechanical property of the ...composite. This study aimed to determine the surface roughness changes of two composite resin restorative materials after thermocycling. Two of the commercially available composites were chosen (RestoFill and SwissTEC). The composite disks of dimension 10 mm diameter and 3 mm height were prepared using silicone molds, and every increment was light cured for 30 s. A stylus profilometer was used to assess the surface roughness prethermocycling, and then, the disks were subjected to an integrated thermocycler (T.S-4.4) for 1000 cycles. The postsurface roughness was obtained after the thermocycling process using the same stylus profilometer. The surface parameter values before and after thermocycling of the SwissTEC sample is less than that of RestoFill. There was a significant difference between the Rz and Rq values of the two different commercially available composite materials. Thus, the present study concludes that thermocycling influenced the surface roughness of composite resin and increased the surface roughness of both the RestoFill and SwissTEC composites.
Addition silicone is a newer type of silicone impression material which has high dimensional stability, accuracy, and flexibility. They are mostly used for fixed restorations such as crowns and ...bridges. They have high tear strength; however, this strength may be altered upon disinfection. Disinfection of addition silicone prior use is important to reduce the microbial load. The aim of this study is to check whether there is any change in tear strength of addition silicone on disinfection with two commercially available disinfectants. Zhermack Elite HD + Putty material was tested in this study. Base and catalyst material was mixed and the material was cut into strips of dimension 70 mm × 10 mm × 2 mm. Five strips were immersed in sterillium and five strips were immersed in glutaraldehyde solution. These strips were then tested for their tear strength using Instron E3000 Universal Testing Machine. The values obtained were recorded in SPSS software version 22 (IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp.) for analysis and the P was obtained. The mean tear strength of Group 1, addition silicone immersed in sterillium disinfecting solution was found to be 7.148 ± 2.654 kN/m. The mean tear strength of Group 2, addition silicone immersed in glutaraldehyde disinfectant solution was found to be 7.326 ± 4.062 kN/m. An unpaired Student's t-test was done and P was found to be 0.235. The tear strength values between the groups was statistically not significant. Hence the tear strength of addition silicone was found to be greater in the glutaraldehyde disinfectant solution group.
The influence of 8 MeV energy electron beam (EB) irradiation on optical properties and ionic conductivity of PVDF-HFP/LiClO
4
(90 : 10 PHL10) electrolyte film with 40, 80 and 120 kGy doses. The FT-IR ...results show that C&z.dbd;O bond stretching at 1654 cm
−1
is due to the degradation of polymer chains and the CH
2
bond wagging intensity at 1405 cm
−1
corresponds to C-H bond scissioning in the 120 kGy dose irradiated film.
1
H and
13
C NMR spectroscopy was performed and the
13
C NMR spectra confirm the effect of EB irradiation of the PHL10 polymer electrolyte by sharpening and splitting the spectral lines with increasing EB dose and revealing a new spectral line at 162.80 ppm with a 120 kGy EB dose. The size and shape of the porous morphology was drastically changed, becoming deeply porous with a visible inner hollow shaped structure, suggesting increased amorphous character upon irradiation. The absorption band of the unirradiated film observed at 202 nm in the ultraviolet region is shifted to 274 nm after irradiation due to inter band transition of electrons from the valence band to the conduction band and the optical band gap decreasing from 3.49 eV in the unirradiated film to 2.64 eV with a 120 kGy EB dose. Segmental motion in the polymer matrix leads to a decrease in the local viscosity by increasing the mobility of ions upon irradiation. Nyquist plots show semicircles at high frequency due to Li-ion migration through the porous surface of the electrolyte film. A maximum ionic conductivity of 8.28 × 10
−4
S cm
−1
was obtained with a 120 kGy EB dose and the observed cyclic voltammetry of the irradiated polymer electrolyte suggests it is electrochemically stable.
A study into the effect of 8 MeV energy electron beam irradiation on the optical properties and ionic conductivity of a PVDF-HFP/LiClO
4
electrolyte film.
Posner’s theorems in semirings Ganesh, S.; Selvan, V.
Indian journal of pure and applied mathematics,
06/2024, Letnik:
55, Številka:
2
Journal Article
Recenzirano
Various researchers extended and generalized the two main theorems of Posner
3
in multiple directions. In this paper we generalize these two main results to semirings. The main tool we use to ...accomplish this generalization is by defining derivation (
d
Δ
) in the ring of differences (
R
Δ
) of a semiring (
R
) corresponding to the derivation
d
of
R
.
Phase-pure hexagonal lanthanide-doped NaYF4 nanocrystals possess enhanced luminescence properties due to their low phonon energy and chemical stability compared to their cubic phase counterpart. ...However, the phase-pure hexagonal NaYF4 nanoparticle forms only at high temperature (≥180 °C) and in the presence of certain ligands (e.g., oleic acid), whereas the cubic phase forms at a low reaction temperature. To this end, we report the low temperature (∼48 °C) synthesis of phase-pure hexagonal NaYF4 nanoparticles by converting cubic NaYF4 nanoparticles into the hexagonal phase through surface oxidation of oleic acid (C-18) ligand to azelaic acid (C-9). The mechanism behind the transformation is investigated using density functional theory (DFT) based studies. DFT studies reveal that the phase transformation from cubic → hexagonal phase involves a disorder → order phase transition since all cationic sites are occupied by either Na or Y in the cubic phase, while the hexagonal phase has a more ordered structure with one Y having full occupancy at its cationic site. As carboxyl groups of adsorbents strongly adsorb on Y-terminated surfaces while having no interaction with Na-terminated surfaces of the cubic phase, the surface-ligand interaction promotes surface segregation of Y. This biasing of occupancy toward a more ordered arrangement promotes the formation of a more ordered phase and correspondingly reduces the energy barrier for transformation to the more ordered hexagonal phase. The surface coverage achieved by oleic acid is low due to its bulky long alkyl chains (C-18) imposing steric restriction that is removed on shortening of the alkyl chain length. As a consequence, there is greater surface–ligand interaction leading to further surface segregation of Y and cationic ordering in the cubic phase and making the phase transformation to the hexagonal phase less energy intensive. In addition, oxidation of oleic acid makes nanoparticles hydrophilic, making it suitable for biological applications.
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