Sharif Digital Repository

The 3D structure of vitamin P, an important bioflavonoid, has been studied in solution by 2D NMR spectroscopy and QM calculations. Rutin, vitamin P, was extracted from Salvia macrosiphon and identified by 1H, 13C, 1H-1H COSY, HMQC, and HMBC spectroscopy. In parallel, density functional theory (DFT) using B3LYP functional and split-valance 6-311G basis set has been used to optimize the structures and conformers of rutin. Also experimental and theoretical methods have been used to correlate the dependencies of 1J, 2J, and 3J involving 1H and 13C on the C5″-C6″ (ω), C6″-O6″ (θ), and C1‴-O6″ () torsion angles in the glycosidic moiety. New Karplus equations are proposed to assist in the... 

Energy consumption is one of the most important design criteria in Wireless Sensor Networks. Sensor nodes are expected to be battery-equipped. Due to their working environments, recharging or replacing batteries for each node is difficult and uneconomical. So prolonging the service lifetime of sensor nodes is a critical issue. The MAC protocol for WSNs plays a very important role in the control of energy consumption. Many of proposed MAC protocols attempt only to prolong the network lifetime for energy-efficiency. In this paper, we are going to reduce end-to-end latency in addition to extending the network lifetime. To reach this purpose, we propose a new adaptively ProLong MAC protocol... 

In this work, two important opioid antagonists, naltrexone and oxycodone, were prepared from thebaine and were characterized by IR, 1H NMR and 13C NMR spectroscopy. Moreover, computational NMR and IR parameters were obtained using density functional theory (DFT) at B3LYP/6-311++G* * level of theory. Complete NMR and vibrational assignment were carried out using the observed and calculated spectra. The IR frequencies and NMR chemical shifts, determined experimentally, were compared with those obtained theoretically from DFT calculations, showed good agreements. The RMS errors observed between experimental and calculated data for the IR absorptions are 85 and 105 cm-1, for the 1H NMR peaks are... 

Spiro thio-oxindoles are prepared in situ by the reaction of the corresponding aldehydes and thio-oxindoles in a straightforward, environmentally friendly, highly efficient and simple procedure. The reaction took place in water with no catalyst added. This one-pot reaction afforded regio- and diastereoselective products in high yields (61-93%)  

An efficient, single-step synthesis of hitherto unknown indole-annulated pentacyclic indolylhydroisoquinolines via tandem S-alkylation and intramolecular C-alkylation of indolin-2-thiones with N-alkylisoquinolinium salts is reported. This new approach provides a powerful entry into polycyclic structures containing nitrogen and sulfur related to alkaloids  

An efficient synthesis of polycyclic indole derivatives is achieved via domino Knoevenagel - hetero-Diels - Alder reaction of O-acrylated salicylaldehyde derivatives with dihydroindole-2-thiones in H2O as solvent. The products are formed in good-to-excellent yields with high regio- and stereoselectivity  

In this work, a high-order weighted essentially nonoscillatory (WENO) finite-difference lattice Boltzmann method (WENOLBM) is developed and assessed for an accurate simulation of incompressible flows. To handle curved geometries with nonuniform grids, the incompressible form of the discrete Boltzmann equation with the Bhatnagar-Gross-Krook (BGK) approximation is transformed into the generalized curvilinear coordinates and the spatial derivatives of the resulting lattice Boltzmann equation in the computational plane are solved using the fifth-order WENO scheme. The first-order implicit-explicit Runge-Kutta scheme and also the fourth-order Runge-Kutta explicit time integrating scheme are... 

A statistical algorithm is introduced to improve the false inference of active loci, in the population in which members are admixture. The algorithm uses an advanced clustering algorithm based on a Bayesian approach. The proposed algorithm simultaneously infers the hidden structure of the population. In this regard, the Monte Carlo Markov Chain (MCMC) algorithm has been used to evaluate the posterior probability distribution of the model parameters. The proposed algorithm is implemented in a bundle, and then its performance is widely evaluated in a number of artificial databases. The accuracy of the clustering algorithm is compared with the STRUCTURE method based on certain criterion. © 2019... 

New indeno- and naphtho-fused thiophenes were synthesized from reaction of 2-bromo-1-indanone and 2-bromo-1-tetralone with arylthioacetamides in good yields  

Various thioamides, especially thiobenzanilides and thioacetomorpholides, bearing a heterocycle ring were efficiently prepared by a modified Willgerodt-Kindler reaction of quinaldine and α- and γ-picoline with anilines and morpholine in the presence of sulfur, and a catalytic amount of DABCO under microwave irradiation  

A huge amount of energy consumption, the cost of this usage and environmental effects have become serious issues for commercial cloud providers. Solar energy is a promising clean energy source, to provide some portion of the Internet data center's (IDC's) energy usage which can reduce environmental effects and total energy costs. Moreover, due to the high energy consumption of the cooling system, considering cooling power in job scheduling can provide efficient solutions to reduce total energy consumption. In this article, we investigate the problem of minimizing the energy cost of an IDC and propose an algorithm which schedules heterogeneous IDC workloads, by considering available renewable... 

An efficient and one-pot synthesis of thiopyrano[2,3-b]indole derivatives via Hetero Diels-Alder reaction of α,β-Unsaturated thio-oxindoles with electron poor acetylenes and Cyclic Dienophiles is described. In the proposed method the reaction is performed under neutral and one-pot reaction conditions, and also the substances can be mixed without any activation or modification and without using any catalysts  

The efficient synthesis of bridged polycyclic naphthooxazocines 3 via addition of naphthalenols 1 as a bis-nucleophile to N-alkylquinolinium salts 2 is described (Scheme 1 and Table 2). This new approach provides a powerful entry into polycyclic structures containing bicyclic N,O-acetals related to bioactive compounds  

This paper proposes an efficient crosstalk mitigation method for Network-on-Chips (NoCs). The proposed method investigates flits in each packet to minimize the number of harmful transition patterns appearing on the communication channels of NoC. To do this, the content of every flit is rotated with respect to the previously flit sent through the channel. Rotation is done to find a rotated version of the flit which minimizes the number of harmful transition patterns. A tag field is added into the rotated flit to enable the receiving side to recover the original flit. Maximum number of rotations is bounded by a fixed value to minimize the timing and power overheads of the proposed method.... 

Dibenzazocines were prepared via tandem dinucleophilic addition of phenols to quinolinium salts in good yields. The procedure is efficient, simple and the substrates are easily available  

A new one-pot synthesis of hitherto unknown polyheterocyclic systems via tandem C-alkylation and intramolecular O-alkylation of 4-hydroxycoumarin or 4-hydroxypyran-2-one with quinolinium salts in excellent yields (71-89%) is reported. The present approach provides a powerful route into polycyclic structures containing nitrogen and oxygen related to alkaloids  

The synthesis of a series of benzoxazocines has been achieved in good yields by tandem C-alkylation and intramolecular O-alkylation of 1,3-dicarbonyl compounds with quinolinium salts. This is a novel example of the synthesis of eight-membered rings via a tandem process, which provides a method for the synthesis of medium-ring heterocycles  

An efficient, single step synthesis of hitherto unknown indole-annulated pentacyclic indolylhydroquinolines via tandem C-alkylation and intramolecular S-alkylation of indolin-2-thiones with N-alkylquinolinium salts in excellent yields (83-95%) is reported. This facile approach provides a powerful entry into polycyclic structures containing nitrogen and sulfur related to alkaloids. The structure of the product was determined by Röntgen crystal structure analysis  

A new one-pot synthesis of thieno[2,3-b]indole ring systems is described. Condensation of cyclohexyl isocyanide with indolin-2-thiones yielded 3-cyclohexyaminomethylene-indolin-2-thiones, which upon reaction with α-halocarbonyl compounds produced the title compounds. © Georg Thieme Verlag Stuttgart  

A novel sulfoxide containing bis(ether amine) monomer, 2,2'-sulfoxide- bis[4-methyl(2-trifluoromethyl)4-aminophenoxy) phenyl ether] (M2), was synthesized from the halogen displacement of 2-chloro-5-nitrobenzotrifluoride with dibenzosulfoxide (DH) in the presence of potassium carbonate, followed by catalytic reduction of bis(ether nitro) intermediate with Zinc/Ammonium chloride. A series of organic-soluble poly(ether amide)s (PA1-7) bearing sulfoxide and electronwithdrawing trifiuoromethyl group were synthesized from bis(ether amine) with various aromatic diacids (1-7) via a direct polycondensation with triphenyl phosphite and pyridine. The resulting polymers had inherent viscosities ranging...