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A diastereoselective synthesis of spirocyclopentene-1H-indene-1,3(2H)-diones through a three-component reaction of alkyl isocyanides, dialkyl acetylenedicarboxylates, and 2-(alkylamino)-2-(1,3-dioxo-1H-inden-2(3H)-ylidene)acetonitriles is described. This reaction forms two stereogenic centers with remarkable diastereoselectivity. The crystal structure of a typical product has been determined by X-ray diffraction.

Hydrogen-bond-assisted azomethine ylides, generated from 2-(benzylamino)-2-(1,3-dioxo-1,3-dihydro-2H-inden-2-ylidene)acetonitriles, undergo a formal Huisgen 1,3-dipolar cycloaddition with β-bromo-β-nitrostyrenes to afford a diastereoselective synthesis of highly substituted pyrrolidin-2-ylidene derivatives. When β-nitrostyrenes were used as the...

A convenient regio- and diastereoselective synthesis of functionalized 5a,5b-dihydro-5H,13H-naphtho[1′′,8′′:4′,5′,6′]pentaleno[1′:3,4]pyrrolo[2,1-a]isoquinolin-5-ones via 1,3-dipolar cycloaddition reaction of 8H-cyclopenta[a]acenaphthylen-8-ones with carbonyl-stabilized isoquinolinium N-ylides, is described. Based on DFT calculations at b3lyp/6-311+g(d,p) level of theory, a nonconcerted mechanism is proposed to explain the regioselectivity of this reaction. The structure of a typical product was confirmed by X-ray crystallographic analysis.

A regioselective 1,3-dipolar cycloaddition of nitrilimines, generated from hydrazonoyl chlorides, with both C = C double bonds of cyclopentadienone moiety of cyclopenta[a]acenaphthylen-8-ones in the presence of Et3N is described. This dual cycloaddition reaction affords a nearly 3:2 mixture of symmetrical and unsymmetrical hexacyclic bis-dihydropyrazol derivatives in good yields. The stereochemistry of diethyl 3,7-bis(4-chlorophenyl)-4-oxo-1,5-diphenyl-1H-naphtho[1′,8′:4,5,6]pentaleno[1,6a-c:3a,3-c′]dipyrazole-3a,4a(4H,5H)-dicarboxylate was established by X-ray crystallography.

A one-pot synthesis of spiro-heterocyclic systems containing a 1,2,4-triazolidine moiety via 1,3-dipolar cycloaddition reaction of azomethine ylides (generated in situ from α-amino acids and ninhydrin) with diisopropyl azodicarboxylate in 50% aqueous MeOH at room temperature, is described. The structure of a typical product was confirmed by X-ray crystallography. The 1H NMR spectra of diisopropyl 1,3-dioxo-1,3-dihydrospiro[indene-2,3′-[1,2,4]triazolidine]-1′,2′-dicarboxylate exhibited dynamic NMR effects, which were attributed to the fast positional change of the ester groups and their interaction with N–H as well as with methylene protons, and restricted bond rotation of the carbamate groups. The calculated free-energy of activation (ΔG#) for these dynamic processes are 64 ± 2 kJ mol−1 and 55 ± 2 kJ mol−1, respectively.

Over the last years of research on drug delivery systems (DDSs), natural polymer-based hydrogels have shown many scientific advances due to their intrinsic properties and a wide variety of potential applications. While drug efficacy and cytotoxicity play a key role, adopting a proper DDS is crucial to preserve the drug along the route of administration and possess desired therapeutic effect at the targeted site. Thus, drug delivery technology can be used to overcome the difficulties of maintaining drugs at a physiologically related serum concentration for prolonged periods. Due to their outstanding biocompatibility, polysaccharides have been thoroughly researched as a biological material for DDS advancement. To formulate a modified DDS, polysaccharides can cross-link with different molecules, resulting in hydrogels. According to our recent findings, targeted drug delivery at a certain spot occurs due to external stimulation such as temperature, pH, glucose, or light. As an adjustable biomedical device, the hydrogel has tremendous potential for nanotech applications in involved health areas such as pharmaceutical and biomedical engineering. An overview of hydrogel characteristics and functionalities is provided in this review. We focus on discussing the various kinds of hydrogel-based systems on their potential for effectively delivering drugs that are made of polysaccharides.

The zwitterionic intermediates, generated in situ from Ph3P and dialkyl acetylenedicarboxylates, are trapped by N–H acidic 2-(alkylamino)-2-(1,3-dioxo-1H-inden-2(3H)-ylidene)acetonitriles in refluxing toluene to afford dialkyl 2-alkyl-1-cyano-9-oxo-3,9-dihydro-2H-indeno[2,1-c]pyridine-3,4-dicarboxylates in good yields. The structure of a typical product was confirmed by X-ray crystallography.

In this study, active poly lactic acid (PLA) films containing 0, 10, 20 and 40% w/w propolis extract (PE), as active agent, were developed. A high amount of phenolic content (PC) was measured in PE. The antioxidant effect of active PLA films was determined by measuring the PC of sausage slices after 0, 2 and 4 days storage at refrigerator. Results showed that phenolic compounds of PE were released from PLA films in quantities proportional to PE concentration. Disc diffusion test indicated that PE showed an inhibitory effect against Staphylococcus aureus and Pseudomonas aeruginosa bacterial species but was more effective against gram-positive species. PE containing PLA films had antimicrobial effect on S. aureus while in the case of P. aeruginosa, PLA/PE films needed polyethylene glycol (PEG)/CaCO(3) content to show inhibitory effect. Addition of PE changed the tensile strength, elongation at break and elastic modulus of PLA films negatively. However, addition of PEG/CaCO(3) improved the film mechanical properties and antimicrobial effect of films.

A simple, efficient, and general method has been developed for the one-pot synthesis of oxazine derivatives, under solvent-free conditions, with the use of NH4Cl as a catalyst. These compounds were...

The reaction between dialkyl 8-oxo-8H-cyclopenta[a]acenaphthylene-7,9-dicarboxylates and zwitterionic intermediates, generated in situ from alkyl isocyanides and dialkyl acetylenedicarboxylates, is described. This reaction leads to the formation of tetraalkyl 5′-(alkylimino)-5′H-spiro[cyclopenta[a]acenaphthylene-8,2′-furan]-3′,4′,7,9-tetracarboxylates. The structure of a typical product was confirmed by X-ray crystallographic analysis.

Au/TNT catalysts were prepared with different gold loadings by deposition – precipitation. The catalysts were characterised by techniques including XRD, HRTEM, AAS and N2 adsorption analysis. Experimental results show that the value of surface areas and pore volumes increase with increasing Au amounts. The surface area and pore volume of catalyst with high gold loading (3.1 wt-%) are 325 m2 g−1 and 1.34 cm3 g−1. The photocatalytic performance for degradation of MTBE markedly depends on gold concentration. The activity drop is attributed to the size growth and agglomeration of the gold nanoparticles. Photoactivity improvement is related to the number of nucleation centres and fine particles size. It can be concluded that there is a 10% improvement in efficiency for deposition of gold in the highest concentration compared to pure titanium nanotubes during the first 20 min of the reaction. So the photocatalytic degradation of MTBE occurs in a shorter time.

In this paper, activated aluminas were synthesized directly using cheap precursor via a simple thermal process and short time using no sacrificial templates. The dehydration of gibbsite has been studied at different temperatures (350–1150 °C) by flash calcination. The synthesized materials were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and N2 adsorption measurements. According to the obtained results, the temperature appeared to be the key parameter at activation process. The changes of the specific surface area affected on the average pore size because the amounts of pore volume were nearly constant. The powders prepared by the flash calcination method had a monomodal pore distribution with mesopores. FE-SEM images showed particle growth in nanodimensional. The optimum temperature for powder synthesized by flash calcination was 650 °C, which the surface area, pore volume, and average pore size were 262 m2/g, 0.22 cm3/g, and 33 A, respectively. The synthesized powder had smaller nanoparticles for 650 °C in comparison of other temperatures.

In this paper, we present a new splitting scheme for pricing the American options under the Heston model. For this purpose, first the price of American put option is modeled, which its underlying asset value follows Heston’s stochastic volatility model , and then it is formulated as a linear complementarity problem (LCP) involving partial differential operator. By using new splitting scheme, the partial differential operator is decomposed into simpler operators in several fractional time steps. These operators are implicitly expressed in the implicit Adams–Moulton method. Then, the two-dimensional LCP is decomposed into three LCPs based on these operators. Each LCP is solved numerically in two steps. The numerical results obtained for the American option pricing problem based on the Heston model are compared with the reference results.

A simple, economical, and green approach to the one-pot synthesis of 3-methyl-4-aryl-2,4,5,7-tetrahydropyrazolo[3,4-b]pyridine-6-ones by multicomponent assembling of 5-methylpyrazol-3-amine, aldehydes, and Meldrum's acid using sodium dodecyl sulfate as surfactant in water is described. This protocol has the advantages of high yields, wide application scope, and an environmental benign procedure.

Background: Multicomponent processes have played powerful roles in achieving complex structures, which are also aligned with green chemistry. Thus, MCRs have attracted considerable interest due to their atom economy, simple experimental procedures, automated synthesis, convenience and synthetic efficiency. Isocyanides are one of the crucial starting material in designing MCRs methods. They are unique building blocks in many cycloaddition reactions since they are able to react with both nucleophiles and electrophiles at the same carbon. Furthermore, ammonium chloride is an inorganic compound that is highly soluble in water, inexpensive and commercially available. Solutions of ammonium chloride are mildly acidic and have been used in various reactions. Objective: This article focuses on design a convenient and straightforward method for assembling important scaffolds such imidazolidinones through one-pot three-component strategy. Conclusion: The straightforward and efficient one-pot three component method for the synthesis of 4-(cyclohexylmethylene)-5-phenylimidazolidin-2-one derivatives is described. This reaction exploits the formation of imine, which undergoes spontaneous intermolecular cycloaddition with isocyanide, and generates the desired products in a good yield.

Sulfuric acid-modified poly(vinylpyrrolidone) ((PVP–SO3H)HSO4) was prepared as a new, highly efficient, bio-degradable and reusable polymeric catalyst for the one-pot multi component synthesis of acridinediones as an important class of heterocyclic compounds. All reactions completed in short times (20–90 minutes) and the desired products were obtained in good to excellent yields (90–95%). The catalyst was recovered and reused 7 times without any change in reactivity.

Background: Schizophrenia is associated with increased cardiovascular morbidity. Asymmetric dimethylarginine (ADMA) has been suggested as a cardiovascular biomarker. Treatment with atypical antipsychotics can increase some traditional risk factors of coronary artery disease. In addition to traditional risk factors, this study is carried out as a comparison of serum levels of ADMA and non-traditional factors among patients who take two types of atypical antipsychotics. Methods: In this clinical study, 57 schizophrenic patients with multiple episodes and 20 healthy voluntaries that fulfilled inclusion and exclusion criteria were entered into the study. The patients were divided into 3 groups (18 patients received risperidone alone, 20 patients received clozapine alone and 19 patients did not receive any drug). Plasma concentrations of ADMA, high-sensitivity Creactive protein (hs-CRP) and homocysteine were measured through enzyme-linked immunosorbent assay (ELISA), and traditional risk factors of metabolic syndrome were measured. Results: Mean age of participants was 46.08±12.54 years. Moreover, the traditional (High-density lipoprotein (HDL), total cholesterol, waistline, and Body Mass Index (BMI)) and non-traditional factors (Homocysteine, hs-CRP) and ADMA were higher in patients with schizophrenia compared to healthy group (p≤ 0.05). Also, in the clozapine group, all mentioned non-traditional factors and ADMA were significantly higher than other groups (p≤ 0.05). Conclusion: In the clozapine group, levels of non-traditional factors and ADMA were significantly higher which indicates these patients are at risk of cardiovascular disease.

A highly efficient and environmentally benign procedure for the synthesis of quinazoline derivatives via the condensation of carbonyl compounds with 2-aminobenzamide using zirconium tetrakis(dodecylsulfate) [Zr(DS) 4 ] as a highly efficient, reusable Lewis acid-surfactant-combined catalyst is described. A broad range of substrates including aldehydes and ketones are successfully condensed with 2-aminobenzamide and all reactions are completed in short times and the products are obtained in good to excellent yields. The catalyst could be recycled and reused several times without any loss of efficiency. Moreover, presented procedure has been applied successfully for the synthesis of spiro-quinazolinones and fused ring-quinazolinone derivatives.

One of the primary issues in handling demands for auto parts in the world is to build a mutual trust between consumers and vendors. When people trust a brand, they purchase more easily and it is possible to develop market. In Iran, there is a growing interest in demand for auto parts and each year, tens of millions of auto parts are getting sold. This paper presents an empirical investigation to detect the effects of brand image on demand for auto parts. Using a sample of 202 randomly selected people who buy/sell auto parts in city of Tehran, Iran, the study determines three variables including brand strength, brand attributes and consumer trust through the implementation of structural equation modeling.

Pd supported on biguanide(metformine)-functionalized fullerene (C 60 -Met/Pd 2+ ) hybrid materials was fabricated for the first time. The catalyst prepared was characterized by X-ray diffraction spectroscopy (XRD), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The catalyst showed excellent activity Suzuki–Miyaura coupling reaction of different aryl iodides and bromides with phenylboronic acid at room temperature in the EtOH:H 2 O (1:1) mixture as solvent. The yields of the products were in the range from 85% to 98%. The catalyst can be readily recovered and reused at least 6 consecutive cycles without significant loss in its catalytic activity. This is the new example for the development of fullerene (C 60 -Met-Pd) complexes which can be used as efficient recyclable catalysts without palladium leaching.

Pd supported on biguanide(metformine)-functionalized single-walled carbon nanotubes (SWCNT-Met/Pd 2+ ) hybrid materials was fabricated for the first time. The prepared heterogeneous nanocatalyst was characterized by XRD, FT-IR, SEM, TGA and TEM. The catalytic activity of the prepared catalyst was investigated by employing Suzuki–Miyaura coupling reaction as a model reaction. A series of biphenyl compounds were synthesized through the Suzuki–Miyaura reaction using SWCNT-Met/Pd 2+ as catalyst. The yields of the products were in the range from 80% to 95%. The catalyst can be readily recovered and reused at least 5 consecutive cycles without significant loss its catalytic activity.

Article history: Received December 10, 2013 Received in revised format 16 March 2014 Accepted April 29 2014 Available online May 6 2014 These days, one of primary concerns for residence of big cities is associated with the access on shopping centers. People prefer to live in places, which are close to their works, shopping centers and schools. Local governments also prefer to find the most appropriate places in an attempt to reduce unnecessary travels and traffic jams. In this paper, we present an empirical investigation to determine the most important factors influencing facility location for fruit and vegetable market in city of Tehran, Iran. The study has implemented two methods of analytical hierarchy process (AHP) and factor analysis for the investigation. The implementation of AHP has considered two main criteria including Geographic location of market and market, amenities and existing infrastructures. In terms of Geographic location of market, cost saving and public infrastructure are found to be the most important factors while in terms of market based factors, Space and availability of parking are the most important factors. We also use factor analysis and the results of our survey have indicated that Space and Ease of access were two most important factors, which must be considered for facility location. © 2014 Growing Science Ltd. All rights reserved.

In this paper, we consider a numerical pricing of European call and put options under the Heston-Cox-Ingersoll-Ross (HCIR) model. Based on this model, the prices of options are derived by solving a three-dimensional partial differential equation. We generalize a componentwise splitting scheme for solving this equation. The idea of this scheme is to decompose the discretized HCIR partial differential equation into six one-dimensional equations in six fractional time steps. These equations are represented in tridiagonal systems, which are solved by the Thomas algorithm. Moreover, the numerical experiments show that the European option prices are affected by changes in volatility, interest rate, strike price, and correlation factors. Furthermore, numerical experiments compare the calculated prices based on our scheme with the prices reported in the literature.

An efficient synthesis of 5-arylidene-2,4-thiazolidinediones and 5-benzylidene rhodanines by the Knoevenagel condensation of 2,4-thiazolidinedione or rhodanine with aromatic aldehydes was studied. It proceeded smoothly in the presence of tetrabutylammonium hydroxide/H 2O-EtOH to afford the corresponding products in high yields at 50°C. Also, a series of dihydrothiophene derivatives were synthesized via the four-component reaction of aldehyde, malonitrile, 2,4-thiazolidinedione, and piperidine in the presence of Bu4NOH as a basic ionic liquid in aqueous medium. This new method offers several advantages, such as excellent yields, short reaction times, and simple procedure.

Article history: Received December 1, 2011 Received in Revised form February, 14, 2011 Accepted 20 March 2012 Available online March 26 2012 In this paper, we present an empirical study to investigate the effects of different marketing efforts on brand equity in mobile industry. The proposed study of this paper distributes a questionnaire consists of 26 questions including loyalty, quality perception, awareness, exclusiveness, word of mouth advertisement, brand name image, advertisement, price, distribution and guarantee. A sample 428 people are selected in a city of Tehran/Iran and they are asked to reply questions on Likert based. The results show that there is a positive and meaningful relationship between marketing mix efforts and brand equity. In other words, more advertisements could help better market exposure, which means customers will have more awareness on market characteristics. Among all mixed efforts, guarantee influences more on brand equity, which means consumers care more on product services than other features. Finally, among different characteristics of brand equity, product exclusiveness plays an important role. In other words, people are interested in having exclusive product, which is different from others. © 2012 Growing Science Ltd. All rights reserved.

Article history: Received October 1, 2011 Received in Revised form November, 14, 2011 Accepted 15 February 2012 Available online 27 February 2012 There are many evidences to believe that customers select their products based on brand name. Products also maintain their own characteristics, which make them differentiable from others. In this paper, we present an empirical study to determine important factors influencing customers' purchasing intend for cellular phones in capital city of Iran, Tehran. The proposed study of this paper designs a questionnaire consists of 16 questions and distribute them among 428 people. The results of the study show that there are some positive relationships between exclusive name and quality perception, between exclusive name and word of mouth advertisement, between quality perception and fidelity, between word of mouth advertisement and brand name and between brand name image and brand name. © 2012 Growing Science Ltd. All rights reserved.

In this paper, a screening approach, involving the use of Plackett-Burman experimental design, permitted the evaluation of the effects of 8 parameters from hydrothermal synthesis of TiO2 derived nanotubes such as raw materials surface area, m, filling factor, temperature, time, aging, stirring, and HCl concentration on the surface area of products. The study highlights the role of filling factor, stirring, temperature, raw materials, and time conditions on surface area of responses. TEM micrographs showed that the morphologies for high, medium, and low surface areas of products are nanotubes, nanowires, and nanospheres, respectively. The N2 adsorption-desorption isotherms and pore size distributions showed that with decreasing surface area, the area of the hysteresis loops and gas volumes of N2 adsorbed are decreased. Also, the hysteresis loops shift to the region of higher relative pressure. Therefore, An increase in average pore size and a decrease in pore volume reduced surface area of product (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The nucleation and growth mechanisms of hydrothermal synthesized nanotitanates are proposed based on the interaction effect between agitation condition and pristine titania particle size. TEM examination and N2 adsorption measurements revealed distinct morphology and textural properties depending on TiO2 particle size in constant agitation condition. Regarding to the supersaturation degree, heterogeneous nucleation dominates for nanotubes formation from large particle size of raw material. On the other hand, homogeneous nucleation determines nanospheres formation from small particle size of raw material. The nanotubes have an outer diameter ranging from 8 to 10 nm and inner diameter of 2 to 3 nm. The nanospheres have diameters ranging from 50 to 100 nm.

In this paper, a screening approach, involving the use of Plackett–Burman experimental design, permitted the evaluation of effects of 8 parameters from hydrothermal synthesis of TiO2-derived nanotubes such as raw material surface area, $$ m_{{{\text{TiO}}_{2} }} , $$ filling factor, temperature, time, aging, stirring, and HCl concentration on the physical properties. All variables were investigated at two widely spaced levels. According to the obtained results, the influences of different factors depend on the selected response. The study highlights the role of filling factor, stirring, temperature, raw material, and time conditions on the surface area response. Also, the study highlights the role of filling factor and stirring conditions on the pore size response. No factors influenced on the pore volume response. The effects of some parameters, such as aging, $$ m_{{{\text{TiO}}_{2} }} , $$ and HCl concentration, were negligible. These factors could be eliminated from hydrothermal synthesis. The low surface area of products related to the higher surface area of raw material and stirring condition. TEM micrographs showed that the morphologies for high, medium, and low surface areas of products are nanotubes, nanowires, and nanospheres, respectively.