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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Physical Chemistry Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Alanine,C60 Fullerene,Functionalized C60 fullerenes,Doped functionalized C60 fullerenes
- چکیده:
- چکیده انگلیسی: In this study, the adsorption of alanine on pristine, functionalized, and boron and/or nitrogen doped functionalized C60 fullerenes was studied by theoretical methods. For this purpose, the structures of alanine, C60 fullerenes derivatives and complexes (C60-alanine) were optimized by using M062X/6-31G* level of theory. Then, it was calculated the adsorption energies, global DFT reactivity indices, the atomic charges and the global electron density transfer (GEDT). The results showed that the maximum adsorption energy occurs for the adsorption of alanine on C60H-OH derivative in both gaseous and aqueous phases. In addition, the doping three nitrogen/boron atoms with the functionalized carbon atom in C60H-OH increases the adsorption energy significantly. The results were confirmed by global DFT reactivity indices such as chemical potential and electrophilicity indices. In addition, analysis of the GEDT values showed that the charge transfer occurs from alanine toward C60H-OH fullerene in both phases upon adsorption. AIM results indicated that the interaction between alanine and C60H-OH in both gaseous and aqueous phases is non-covalent and hydrogen interaction.
- انتشار مقاله: 28-01-1399
- نویسندگان: Hossein Dashti Khavidaki,Mousa Soleymani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: Color,Disinfection,Sterilization,3D Master shade guide
- چکیده:
- چکیده انگلیسی: Purpose:Dental shade guides are commonly used for color determination and should be disinfected and sterilized. The purpose of this study was to evaluate the color change of Vita 3D Master shade tabs after disinfection and sterilization. Material and methods:Overall, 98 samples (shade tabs) were randomly selected from 14 new, unused Vita 3D sets, including the following shades: 2M1, 3L1.5, 3M1, 3M2, 3M3, 3R1.5 and 4M1. In each set, values of 2, 3 and 4, chroma of 1, 2 and 3 and hue were selected for the comparison of different shades. All tabs were measured using the Vita Easyshade device at baseline. The first group was disinfected with Deconex and the second group was sterilized by autoclaving in a simulated annual application. All the tabs were measured again using the same device. This process was repeated to simulate 2 and 3 years of usage. Statistical analysis was conducted by repeated measures analysis of variance (ANOVA) and independent t-test and paired sample t-test. Results:In the disinfected group, we observed significant differences in value and chroma in all periods (p˂0.001). However, hue showed no significant difference after the first year of simulated treatment (p=0.527), though it was significantly different in the second and third simulations (p˂0.001). In the sterilized group, all variables showed a significant difference for each year (p˂0.05). Considering total color difference (ΔE), there was a significant difference between the two groups in the first, second and third simulated years; ΔE increased in the sterilized group more than in the disinfected samples (p˂0.001). Conclusions: The color change of shade tabs was significant both after disinfection by a chemical solution and by sterilization through autoclaving. However, although disinfectants may not have a clinically important effect, sterilization should be considered as an interfering factor during color-matching procedure.
- انتشار مقاله: 24-07-1395
- نویسندگان: Hossein Dashti,Azizollah Moraditalab,Mohammadreza Mohammadi,Hamidreza Rajati Haghi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Dental Materials and Techniques
- نوع مقاله: Journal Article
- کلمات کلیدی: Bond strength,Polyamide,flexible dentures,denture base materials
- چکیده:
- چکیده انگلیسی: Introduction: Detachment of denture teeth from denture base is one of the most common reasons for costly denture repairs .This study aimed at evaluating the bond strength of an acrylic denture tooth to polyamide injection-molded thermoplastic denture base material compared with three conventional polymethylmethacrylate (PMMA) denture base resins.
Materials and Method: A total of 40 acrylic denture molar teeth were randomly allocated into four groups (n=10) of heat-polymerized (HP), Auto-polymerized (AP), Injection molded (IM) and Polyamide thermoplastic (PT). All denture base/acrylic teeth combinations underwent 5000 thermal cycles (5-55◦C).Samples were subjected to shear bond strength test by a universal testing machine with a 1 mm/min crosshead speed .Data were analyzed using ANOVA and Tukey’s tests(α=0.05). Results: Mean ±SD of shear bond strength values were (MPa) 4.82±1.21, 4.52±1.67, 3.7±0.84 and 4.13±2.21 for groups HP, AP, IM and PT respectively. No significant difference was found among the experimental groups (P=0.429). Conclusion: Polyamide thermoplastic denture base resin was similar to conventional PMMA denture base materials in terms of bond strength to artificial denture teeth.
- انتشار مقاله: 26-06-1396
- نویسندگان: Mohammadreza Nakhaei,Hossein Dashti,Reza Barazandeh,Nafiseh Teimouri
- مشاهده
- جایگاه : پژوهشی
- مجله: Biquarterly Iranian Journal of Analytical Chemistry
- نوع مقاله: Journal Article
- کلمات کلیدی: Ionic liquids,Li-air Battery,Simple Design,Nano-Catalyst of MnFe2O4,Green Electrolyte,High Discharge Capacity
- چکیده: یک طراحی ساده، جدید و کم هزینه برای باتری لیتیم-هوا معرفی شده است. یک نانوکاتالیست کارا و موثر برای اصلاح کاتد هوا، کاغذ صافی به عنوان جدا کننده ساده و مایع یونی رسانای 1-اکتیل-3-متیل ایمیدازولیوم هگزافلوئوروفسفات با نام اختصار [Omim][PF6] به عنوان الکترولیت غیر آبی و سبز (دوست دار محیط زیست) باتری بکار برده شده است. نانوذرات MnFe2O4 شامل اکسید فلزات-فلزات واسطه بوده و در آزمایشگاه تحقیقاتی ما سنتز شده است. ظرفیت دشارژ بالا، الکترولیت غیر قابل اشتعال، برگشت پذیری بالا، طول عمر زیاد و اورولتاژ کم در تستهای الکتروشیمیایی باتری مشاهده شد. نانوکاتالیست سنتز شده بوسیله تکنیکهای XRD، FTR و SEM مشخصه یابی شد. نتایج XRD نشان داد که نانوکاتالیست دارای اندازه ذرات بین 16-28 نانومتر بوده که به طور یکنواخت بر روی کاتد پراکنده شده و کارایی آن به بیش از 1000 سیکل در مقایسه با باتری بدون کاتالیست افزایش یافته است. ظرفیت دشارژ در دانسیته جریان mA cm-2 2/0 و پتانسیل شارژ 0/2 تا 2/4 ولت برای باتری دارای کاتالیست/الکترولیت یونی و بدون حضور کاتالیست/الکترولیت آلی به ترتیب برابر باmAh g-1 3391 و 1012 حاصل شد. علاوه بر این، استفاده از مایعات یونی به عنوان الکترولیت باعث افزایش ایمنی و طول عمر باتری شده است. بخاطر اینکه الکترولیت مورد استفاده دارای نقطه جوش بیشتر از 350 درجه سلسیوس میباشد، بنابراین اگر به دلیل پایان یافتن عمر باتری یا تخریب آن وارد محیط زیست گردد، براحتی تبحیر نمی گردد.
- چکیده انگلیسی: A simple, new and low-cost design of Li-air battery was introduced. An effective synthesized nanocatalyst for modifiying of air cathode, filter paper as a simple separator and a conductive ionic liquid namely 1-Octyl-3-methyl imidazolium hexafluorophosphate abbreviated [Omim][PF6] as a non-aqueous and green electrolyte in battery were used. The MnFe2O4 nanoparticles (NP-MnFe2O4) which consistingof transition metal-metal oxide components was synthesized in our labrature. High discharge capacity, non-flammability of electrolyte, high reversibility, long lifetime and low over potential were observed in electrochemical tests of the battery. Synthesized nanocatalyst was characterized using XRD, FTIR and SEM techniques. XRD results show that a nanocatalyst have a particle sizes of 16-28 nm that distributed on cathode uniformly and performance of battery was improved to more than 1000 cycles compared to battery without any catalyst. The discharge capacity at current density of 0.2 mA cm-2 and charge potential range of 2.0-4.2 V for battery with catalyst/green electrolyte and without catalyst/common organic electrolyte were 3391 and 1012 mAh g-1,respectively. Furthermore, the usage of an ionic liquid as electrolyte leads to the increase the safety and lifetime of battery. Because of used electrolyte have high boiling point amount (>350 Celcius), so if it released to the environment due to the destruction or life expires of battery, don’t seriously damage to the environment because it is not easily evaporated.
- انتشار مقاله: 11-03-1398
- نویسندگان: Mehdi Hosseini,Mousa Soleymani,Hossein Dashti Khavidaki
- مشاهده
- جایگاه : پژوهشی
- مجله: Avicenna Journal of Phytomedicine
- نوع مقاله: Journal Article
- کلمات کلیدی: ileum,Acetylcholine,Antispasmodic,Humulus lupulus
- چکیده:
- چکیده انگلیسی: O
Objective: Many biological studies have been done to determine the activity of medicinal plants on gastrointestinal function. Since acetylcholine is the major transmitter involved in the gastrointestinal motility and there are some evidences regarding the cholinergic modulatory effect of hops extract, in the present study spasmolytic and antispasmodic action of hops(Humulus lupulus) on acetylcholine-induced contraction in isolated rat's ileum was evaluated.
Material and Methods: In this study, pieces of isolated rat's ileum were mounted in the internal chamber of an organ bath which was filled with Tyrode’s solution and tightly tied to the lever of an isotonic transducer. The contractile responses were recorded by using an oscillograph device. In the presence of normal saline and different concentrations of hops (0.1, 0.3, and 0.5 mg/ml), the amplitude of contractions induced by10-12 up to 10-2 M acetylcholine was determined. The spasmolytic action of the same extract concentrations was also examined on contraction induced by 10-4 acetylcholine.
Results: Our findings indicate that hops extract reduces acetylcholine-induced contraction in all concentrations. The significant inhibitory effects of 0.1, 0.3, and 0.5 mg/ml hops extract on contraction induced by 10-3 M acetylcholine were 81.9, 77, and 29.3, respectively (p< 0.05).
Conclusion: According to our findings, hops extract poses a potent spasmolytic and antispasmodic action on acetylcholine-induced contraction in isolated rat’s ileum which may be mediated by cholinergic systems.- انتشار مقاله: 09-12-1391
- نویسندگان: Seyed Hassan Hejazian,Seyyed Majid Bagheri,Mohammad Hossein Dashti-R
- مشاهده