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1.
ABSTRACT Ausforming is being widely used to overcome the kinetics barrier in nanostructured bainitic steels and to enhance its practical industrial applications. It would also affect the microstructural characteristics and consequently the resultant mechanical performance. This article aims to investigate the tensile behaviour of nano bainite obtained from plastically deformed primary austenite at three different heat treatment stages. 10% of ausforming has been implemented and nanostructured bainite obtained after austempering at 300°C for 2, 4 and 6?h in salt bath furnaces. Results indicated that ausforming could successfully increase the volume fraction of bainite within the microstructure and refine the bainite packets sizes. Moreover, it has been demonstrated that higher mechanical stability of retained austenite and therefore more effective TRIP effect could be attained during the tensile test which consequently resulted in elongation improvement without deteriorating the strength properties. This claimed to be beneficial for materials performance during practical applications. 相似文献
2.
Sahand Safari Reza Ghavimi Nima Razzaghi-Asl Saghi Sepehri 《Journal of heterocyclic chemistry》2020,57(3):1023-1033
A series of dihydropyrimidine analogues were prepared via one-pot Biginelli three-component condensation reaction and characterized by NMR, FT-IR, MS spectra, and element analysis. Subsequently, they were screened for in vitro anticancer effect. These analogues revealed good cytotoxic activity against three human cancer cell lines including MCF-7, HepG-2, and A549. Among these analogues, compounds 4d and 4h were the most potent against three cell lines. Cell viability assays indicated 4a and 4c had lower cytotoxicity. In vitro cytotoxicity study on all synthesized compounds demonstrated that introduction of electron withdrawing substituents on C4 position of phenyl ring of dihydropyrimidine contributed to the antiproliferative potency. Moreover, in silico molecular docking results stipulated a sign of good correlation between experimental activity and calculated binding affinity. It proved 4d and 4h as the strongest compounds. Binding modes of analogues proposed the involvement of hydrophobic interactions and hydrogen bonds with Eg5 active site. Structure activity relationship studies indicated that incorporating electron withdrawing substituents on C4 position of phenyl ring of dihydropyrimidine are important for this biological activity. 相似文献
3.
Ali Golchin Simzar Hosseinzadeh Aytak Jouybar Masumeh Staji Masoud Soleimani Abdolreza Ardeshirylajimi Arash Khojasteh 《先进技术聚合物》2020,31(7):1519-1531
Wound healing, one of the most complex processes of the body involving the cooperation of several important biomolecules and pathways, is one of the major therapeutic and economic issues in regenerative medicine. The present study aimed to introduce a novel electrospun curcumin (Cur)‐incorporated chitosan/polyvinyl alcohol/carbopol/polycaprolactone nanofibrous composite for concurrent delivery of the buccal fat pad‐derived mesenchymal stem cells (BFP‐MSCs) and Cur to a full‐thickness wound on the mouse model. Scaffolds were characterized structurally using scanning electron microscopy (SEM), fluorescence microscopy imaging and Fourier‐transform infrared spectroscopy, and toxicity of the scaffolds was also evaluated after BFP‐MSC seeding by SEM imaging and 3‐(4,5 dimethyiazol‐2‐1)‐2‐5‐diphenyl tetrazolium bromide (MTT) assay. Then, its influence on the wound‐healing process was investigated as a wound dressing for a full‐thickness skin defect in mouse model. Results demonstrated that the designed composite scaffolds have the capability for cell seeding and support their growth and proliferation. Macroscopic and histopathological characteristics were evaluated at the end of the 7 and 14 days after surgery, and their results showed that our designed scaffold groups accelerated the wound‐healing process compared with the control group. Among those, scaffold/Cur, scaffold/Cur/BFP‐MSC and scaffold/BFP‐MSC groups demonstrated more wound repair efficacy. These results indicated that the combined grafts can be used to improve the wound‐healing process, and therefore, the electrospun nanofibers presented in this study, Cur and BFP‐MSC together, were demonstrated to have promising potential for wound‐dressing applications. 相似文献
4.
The interaction of dimethyltin dichloride (Me2SnCl2) with calf thymus DNA was studied at 27 °C, pH 7.6 using various techniques including isothermal titration calorimetry (ITC) and UV-Vis, fluorescence and IR spectrophotometries. The binding isotherm and enthalpy curve for Me2SnCl2-DNA interaction was a biphasic transition process. This was determined by the analysis of the binding data with the Hill equation. The first phase of the enthalpy curve (exothermic process) was consistent with the first set of binding site, the second phase (endothermic process, less exothermicity) was consistent with second set of binding site from the cited interactions. Our results showed that the first set of binding sites is occupied by one mole of ligand bound per near 1 base pair of DNA. The DNA-ethidium bromide (EB) complex, in the presence of Me2SnCl2, caused the quenching of the fluorescence emission. The Scatchard plots illustrated a non-intercalating manner for such quenching. The DNA-EB complex results indicated that the binding of Me2SnCl2 is with the phosphate groups of DNA at low ligand concentrations (<9 mM). This was confirmed with the IR spectrophotometric spectra. However, the binding at higher ligand concentrations (>9 mM) was with the base groups of DNA. Therefore, these results suggest that the Me2SnCl2 binding to DNA at low concentrations occurs through an outside interaction by an exothermic process. However, the partial unfolding of the DNA caused at higher concentrations of Me2SnCl2 is through an endothermic process involving interactions with the base groups. 相似文献
5.
Akbar Golchin 《Semigroup Forum》2003,67(2):262-270
We consider monoids $S=G\dot \cup I$ where G is a group and I is an ideal of S and show that if an S-act is principally weakly flat, (weakly) flat, torsion free or satisfies conditions (P) or (PE) as an I1-act, then it has these properties as an S-act. We also show that an S-act which is free, projective or strongly flat as an I1-act may not generally have these properties as an S-act. 相似文献
6.
Akbar Golchin 《Semigroup Forum》2005,70(2):296-301
We consider monoids $S=G\;\dot{\cup}\; I$ where $G$ is a group and $I$ is an ideal of $S$ and show that if an $S$-act is principally
weakly homoflat or weakly homoflat as an $I^1$-act, then it has
these properties as an $S$-act. We also show that an $S$-act which
is (weakly) pullback flat, equalizer flat, (principally) weakly
kernel flat, translation kernel flat or satisfies Condition $(E)$
as an $I^1$-act may not generally have these properties as an
$S$-act. The flatness notions considered in this paper were
introduced in {\it V. Laan, Pullbacks and flatness properties of
acts I, Comm. Alg. ${\bf 29}(2)$ (2001), 829--850}. 相似文献
7.
8.
Ahmadi Omid Majidi Sahand Hashemi Tari Pooyan 《Journal of Thermal Analysis and Calorimetry》2020,141(5):1753-1768
Journal of Thermal Analysis and Calorimetry - Performance improvement of a phase change material (PCM) thermal storage system is numerically investigated. A finite volume solver is employed to... 相似文献
9.
Akbar Golchin Parisa Rezaei Hossein Mohammadzadeh 《Czechoslovak Mathematical Journal》2009,59(3):595-611
By a regular act we mean an act such that all its cyclic subacts are projective. In this paper we introduce strong (P)-cyclic property of acts over monoids which is an extension of regularity and give a classification of monoids by this property
of their right (Rees factor) acts. 相似文献
10.
We consider pomonoids
, where G is a pogroup and I is a poideal of S and show that if an S-poset is principally weakly flat, (weakly) flat, po-flat, (principally) weakly po-flat, (po-) torsion free or satisfies Conditions
(P), (P
E
), (P
w
), (PWP), (PWP)
w
, (WP) or (WP)
w
as an I
1-poset, then it has these properties as an S-poset. We also show that an S-poset which is free, projective or strongly flat as an I
1-poset may not generally have these properties as an S-poset. 相似文献