Synthesis and crystal structure of trans-[Ni(pyzdcH)M2(H2O) 2] based on pyrazine-2,3-dicarboxylic acid

The determined structure of the title compound C24H20Ni2N8O20 consists of the mononuclear trans-[Ni(pyzdc)2(H2O)2], (pyzdc = pyrazine-2,3- dicarboxylate). The Ni(II) atom is hexa-coordinated by two (pyzdcH)- groups and two water molecules. The coordinated water molecules are in trans-diaxial positions and the (pyzdcH)- anion acts as a bidentate ligand through an O atom of the carboxylate group and the N atom of the pyrazine ring. There are diverse hydrogen bonding interactions such as O—H···N and O—H···O contacts, which lead to the formation of a three-dimensional supramolecular architecture. KEY WORDS: Ni(II), Pyrazine-2,3-dicarboxylic acid, Coordination chemistry, Supramolecular  chemistry, Hydrogen bond, Proton transferDOI: http://dx.doi.org/10.4314/bcse.v26i1.1

Tetra­kis{4-[(2H-tetra­zol-5-yl)meth­yl]morpholin-4-ium} dodeca­tungstosilicate hexa­hydrate

The crystal structure of the title compound, (C6H12N5O)4[W12(SiO4)O36]·6H2O, consists of an α-Keggin-type [W12(SiO4)O36]4− polyoxidoanion, four [(2H-tetra­zol-5-yl)meth­yl]morpholinium cations and six uncoordinated water mol­ecules. In the cations, the morpholine rings display chair conformations. Extensive N—H⋯O, N—H⋯N, O—H⋯O and O—H⋯N hydrogen bonds are present in the crystal structure

Intelligent Energy Management with IoT Framework in Smart Cities Using Intelligent Analysis: An Application of Machine Learning Methods for Complex Networks and Systems

Smart buildings are increasingly using Internet of Things (IoT)-based wireless sensing systems to reduce their energy consumption and environmental impact. As a result of their compact size and ability to sense, measure, and compute all electrical properties, Internet of Things devices have become increasingly important in our society. A major contribution of this study is the development of a comprehensive IoT-based framework for smart city energy management, incorporating multiple components of IoT architecture and framework. An IoT framework for intelligent energy management applications that employ intelligent analysis is an essential system component that collects and stores information. Additionally, it serves as a platform for the development of applications by other companies. Furthermore, we have studied intelligent energy management solutions based on intelligent mechanisms. The depletion of energy resources and the increase in energy demand have led to an increase in energy consumption and building maintenance. The data collected is used to monitor, control, and enhance the efficiency of the system

A Survey of MANET Routing Protocols in Large-Scale and Ordinary Networks

An ad hoc network (MANET) consists of mobile nodes that communicate with each other. Routing in ad hoc network is a challenging task because nodes are mobile. Efficient routing protocols have better performance in such networks. Many protocols have been proposed for ad hoc networks such as: Ad hoc on-demand Distance Vector (AODV), Optimized Link State Routing (OLSR), Dynamic Source Routing (DSR), and Geographic routing protocol (GRP). these approaches have not been evaluated for the same conditions in pervious researches. But in this study, the performance of these protocols is evaluated in various network conditions and with different packet size patterns. Also, different MAC layers like 802.11b, 802.11g in ordinary and large-scale networks are considered. For the evaluation, Different metrics like packet delivery ratio, end-to-end delay, Mac delay and Routing traffic received/sent, are applied. All simulations have been done using OPNET

One-Pot Synthesis of Tetrasubstituted Imidazoles Catalyzed by Preyssler-Type Heteropoly Acid

Abstract: A simple one-pot four-component synthetic method was reported for the preparation of tetrasubstituted imidazole derivatives from benzil, aromatic aldehydes, primary amines and ammonium acetate in the presence of Preyssler-type heteropoly acid catalyst. This method was proved to be ecobenign, easy work-up, convenient, relatively short reaction times and the products were isolated with high yields

Combination of Intravitreal Bevacizumab and Topical Dorzolamide versus Intravitreal Bevacizumab Alone for Diabetic Macular Edema: A Randomized Contralateral Clinical Trial

Purpose. To evaluate the efficacy of three intravitreal bevacizumab (IVB) injections versus the same combined with 2% of topical dorzolamide in the treatment of diabetic macular edema (DME). Methods. In this randomized double-masked clinical trial, 32 eyes of 16 treatment-naive patients with bilateral DME were enrolled. The eyes were randomly assigned to receive three monthly injections of IVB (1.25 mg) plus topical dorzolamide 2% twice daily or IVB (1.25 mg) plus topical artificial tear twice daily. Best-corrected visual acuity (BCVA) was the primary outcome of the study followed by the central macular thickness (CMT) and central macular volume (CMV) as the secondary outcomes. Results. Mean BCVA changes were insignificant in both groups. It changed from 0.21 ± 0.08 logMAR at baseline to 0.23 ± 0.09 (P=0.24) in the combination group and from 0.18 ± 0.09 logMAR to 0.21 ± 0.09 (P=0.11) in the IVB alone group, at 3 months, respectively. Changes in mean CMT and CMV were significant in both groups. However, the difference between the groups was not significant at all the visits. In the study, no major ocular complication or systemic side effects were noted regarding IVB or topical dorzolamide. Conclusion. This randomized contralateral clinical trial demonstrated that adjuvant topical dorzolamide with IVB injection had no additional effects on IVB in the treatment of DME over a three-month course. This trial is registered with the Iranian Registry of Clinical Trials under the registration code IRCT20131229015975N5

Efficient synthesis of novel azo compounds based on pyrimido[4,5-e][1,3,4]thiadiazine

Some new 5-bromo-2,4-dichloro-6-alkylpyrimidines were prepared by sequential treatment of 6-alkyl-pyrimidin-2,4(1<i>H</i>,3<i>H</i>)-diones with bromine and phosphoryl chloride. Condensation of the dithizone with 5-bromo-2,4-dichloro-6-alkylpyrimidines in alkaline acetonitrile achieved 5-alkyl-7-chloro-3-phenylazo-1-phenyl-1<i>H</i>-pyrimido[4,5-<i>e</i>][1,3,4] thiadiazines. 7-chlorine atom of these compounds was replaced by secondary amines in boiling ethanol to afford their 7-amino derivatives. DOI: http://dx.doi.org/10.4314/bcse.v26i1.1