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171.
Gokalp Cosan Cenk Serhan Ozverel Duygu Yigit Hanoglu Kemal Husnu Can Baser Yasar Meric Tunca 《Molecules (Basel, Switzerland)》2022,27(9)
Background: Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and Mentha spicata (M. spicata) essential oils. Materials and Methods: O. dubium and M. spicata, collected from Lefke, Cyprus, were separately subjected to hydrodistillation. The obtained essential oil compositions were analysed simultaneously by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The compositions were then divided into groups and mixed with calcium hydroxide at a 1:1 concentration; after that, the pastes were tested on Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans), which are the most common resistant pathogenic microorganisms in the root canal. The antibacterial activity of the pastes was measured using a disk diffusion assay. Results: The GC and GC-MS analyses revealed that O. dubium and M. spicata had major compositions of carvacrol (75.8%) and carvone (71.3%), respectively. Antimicrobial activity was found to be significantly higher when study groups with O. dubium essential oil were applied to both E. faecalis and C. albicans. The results also show that M. spicata, together with calcium hydroxide, demonstrated a significant antifungal effect on C. albicans when incubated for 72 h. Conclusions: M. spicata was found to be an effective antimicrobial agent on C. albicans, whereas O. dubium was found to be very effective on both E. faecalis and C. albicans. These data demonstrate that these natural essential oils may be promising candidates for alternative intracanal medicament in future routine clinical applications. 相似文献
172.
In this study, an impedimetric immunosensor based on polymer poly(thiophene)‐graft‐poly(methacrylamide) polymer (P(Thi‐g‐MAm)) modified indium tin oxide (ITO) electrode is developed for the detection of the Neuron Specific Enolase (NSE) cancer biomarker. First, the P(Thi‐g‐MAm) polymer is synthesized and coated on the ITO electrode by using a spin‐coating technique. P(Thi‐g‐MAm) polymer acts as an immobilization platform for immobilization of NSE‐specific monoclonal antibodies. Anti‐NSE antibodies are utilized as biosensing molecules and they bind to the amino groups of P(Thi‐g‐Mam) polymer via glutaraldehyde cross‐linking. Spin‐coating technique is employed for bioelectrode fabrication and this technique provides a thin and uniform film on the ITO electrode surface. This bioelectrode fabrication technique is simple and it generates a suitable platform for large‐scale loadings of anti‐NSE antibodies. This immunosensor exhibits a wide linear detection range from 0.02 to 4 pg mL?1 and with an ultralow detection limit of 6.1 fg mL?1. It reveals a good long‐term stability (after 8 weeks, 78% of its initial activity), an excellent reproducibility (1.29% of relative standard deviation (RSD)), a good repeatability (5.55% of RSD), and a high selectivity. In addition, the developed immunosensor is proposed as a robust diagnostic tool for the clinical detection of NSE and other cancer biomarkers. 相似文献
173.
174.
Kemal Altıparmak 《International Journal of Mathematical Education in Science & Technology》2013,44(8):1146-1166
In mathematic courses, construction of some concepts by the students in a meaningful way may be complicated. In such circumstances, to embody the concepts application of the required technologies may reinforce learning process. Onset of learning process over daily life events of the student's environment may lure their attention and may enable them to gain from the preliminary knowledge. Therefore, a good initiation may be realized in the course of meaningful learning. The underlying meaning of the abstract concepts by computer animations may be accomplished in class environments. That study is conducted searching out to discover the effects of animations over the learning process in mathematic courses. The study was performed over the 58 university freshman students selected randomly. Thirty-two students constituted the experiment group and 26 students constituted the control group. Computer animations-aided instruction model in constructive form were applied on the experiment group and non-computer-aided instruction model in constructive form were implemented on the control group. Student academic success via a test method developed by explored group with confidence rate .819 (Cronbach's alpha) revealed that data were evaluated by two-way variance analyses. The findings provided from the final test shows that the experiment group students were significantly higher according to the control group students in terms of academic success average scores. Computer animations were observed to be significant to assimilate the derivative concept in a discrete way over the students, to appeal their attention, animations of real life events observed to transform the abstract meanings in the events to a concrete manner. Students of whom the concrete stage is constructed meaningfully found to be tactful in reaching to semi-abstract and abstract stages. 相似文献
175.
Yusuf Selim Ocak Reyhan Gul Guven Ahmet Tombak Tahsin Kilicoglu Kemal Guven Mehmet Dogru 《哲学杂志》2013,93(17):2172-2181
A metal/interlayer/semiconductor (Al/enzyme/p-Si) MIS device was fabricated using α-amylase enzyme as a thin biofilm interlayer. It was observed that the device showed an excellent rectifying behavior and the barrier height value of 0.78?eV for Al/α-amylase/p-Si was meaningfully larger than the one of 0.58?eV for conventional Al/p-Si metal/semiconductor (MS) contact. Enhancement of the interfacial potential barrier of Al/p-Si MS diode was realized using enzyme interlayer by influencing the space charge region of Si semiconductor. The electrical properties of the structure were executed by the help of current–voltage and capacitance–voltage measurements. The photovoltaic properties of the structure were executed under a solar simulator with AM1.5 global filter between 40 and 100?mW/cm2 illumination conditions. It was also reported that the α-amylase enzyme produced from Bacillus licheniformis had a 3.65?eV band gap value obtained from optical method. 相似文献
176.
Structural and mechanical properties of several rare-earth diborides were systematically investigated by first principles calculations. Specifically, we studied XB2 , where X=Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Lu in the hexagonal AlB2 , ReB2 , and orthorhombic OsB2 -type structures. The lattice parameters, bulk modulus, bond distances, second order elastic constants, and related polycrystalline elastic moduli (e.g., shear modulus, Young’s modulus, Poisson’s ratio, Debye temperature, sound velocities) were calculated. Our results indicate that these compounds are mechanically stable in the considered structures, and according to "Chen’s method", the predicted Vickers hardness shows that they are hard materials in AlB2 - and OsB2 -type structures. 相似文献
177.
We present a general control variate method for simulating path dependent options under Lévy processes. It is based on fast numerical inversion of the cumulative distribution functions and exploits the strong correlation of the payoff of the original option and the payoff of a similar option under geometric Brownian motion. The method is applicable for all types of Lévy processes for which the probability density function of the increments is available in closed form. Numerical experiments confirm that our method achieves considerable variance reduction for different options and Lévy processes. We present the applications of our general approach for Asian, lookback and barrier options under variance gamma, normal inverse Gaussian, generalized hyperbolic and Meixner processes. 相似文献
178.
Yasemin ?. ?iftci Kemal ?olako?lu Cansu ?oban Engin Delig?z 《Central European Journal of Physics》2012,10(1):197-205
The structural, elastic and thermodynamic characteristics of CeGa2 compound in the AlB2 (space group: P6/mmm) and the omega trigonal (space group: P-3m1) type structures are investigated using the methods of density
functional theory within the generalized gradient approximation (GGA). The thermodynamic properties of the considered structures
are obtained through the quasi-harmonic Debye model. The results on the basic physical parameters, such as the lattice constant,
the bulk modulus, the pressure derivative of bulk modulus, the phase-transition pressure (P
t
) from P6/mmm to P-3m1 structure, the second-order elastic constants, Zener anisotropy factor, Poisson’s ratio, Young’s modulus,
and the isotropic shear modulus are presented. In order to gain further information, the pressure and temperature-dependent
behavior of the volume, the bulk modulus, the thermal expansion coefficient, the heat capacity, the entropy, Debye temperature
and Grüneisen parameter are also evaluated over a pressure range of 0–6 GPa and a wide temperature range of 0–1800 K. The
obtained results are in agreement with the available experimental and the other theoretical values. 相似文献
179.
180.
Mustafa Kemal Berktaş Septimiu Crivei Fatma Kaynarca Derya Keskin Tütüncü 《Journal of Pure and Applied Algebra》2021,225(6):106621
Two uniqueness theorems on uniform decompositions due to Krause, Diracca and Facchini are extended from abelian categories to weakly idempotent complete exact categories. We give applications to (quasi-)abelian categories, finitely accessible additive categories and exactly definable additive categories. 相似文献