Linear formulations and valid inequalities for a classic location problem with congestion: a robust optimization application

This study investigates a classic stochastic location problem in a service system with immobile servers that are represented by M/G/1 queues. It shows that     

Polystyrene resin-supported CuI-cryptand 22 complex: a highly efficient and reusable catalyst for three-component synthesis of 1,4-disubstituted 1,2,3-triazoles under aerobic conditions in water

Polystyrene resin-supported copper(I) iodide-cryptand-22 complex (PS–C22–CuI) was synthesized and characterized by FT-IR, EDX, SEM, XPS, and TG-DTA analysis. This complex was found to be a highly active and robust heterogeneous catalyst for either three-component reaction of organic halides, sodium azide, and terminal alkynes, or the reaction of organic azides and alkynes to form 1,4-disubstituted 1,2,3-triazoles in good to excellent yields at room temperature, using water as the green solvent. The catalyst can be not only easily isolated from the final product by filtration but also reused without significant loss of catalytic activity.     

CAN-catalyzed microwave promoted reaction of indole with Betti bases under solvent-free condition and evaluation of antibacterial activity of the products

CAN-catalyzed reaction of Betti bases with indoles under microwave irradiation gives 3-(α,α-diarylmethyl)indoles. Better yield of the products, especially when one of the aryl ring is phenol were achieved. The reaction is performed in solvent-free condition. The antibacterial studies of the synthesized compounds were performed and some of the compounds showed good activity against Methicillin-resistant Staphylococcus aureus bacteria.     

Cu@KCC-1-NH-CS2 as a new and highly efficient nanocatalyst for the synthesis of 2-amino-4H-chromene derivatives

In the present work, Cu@KCC-1-NH-CS₂ as a green, efficient, and reusable nano-reactor was designed and used for the one-pot, three-component synthesis of 2-amino-4H-chromene derivatives using the reaction of cyclic 1,3-diketones, arylglyoxals, and malononitrile, under reflux conditions in EtOH. Engineered nanocatalyst characterized using different methods including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), adsorption/desorption analysis (BET), and energy dispersive X-ray spectroscopy (EDS). According to the obtained results, presented protocol for the synthesis of 2-amino-4H-chromenes using Cu@KCC-1-NH-CS₂ gave the desired products in higher yields (89–98%) with short reaction times. Also, under mild reaction conditions this green nanocatalyst indicated recyclable behavior five times with minor reduce in its catalytic activity.     

New ciprofloxacin–dithiocarbamate–benzyl hybrids: design,synthesis, antibacterial evaluation,and molecular modeling studies

Research on Chemical Intermediates - We designed and synthesized a series of new ciprofloxacin–dithiocarbamate–benzyl hybrids 5a–n as potential antibacterial agents. All of the...     

Glycerol‐lactic acid star‐shaped oligomers as efficient biobased surface modifiers for improving superabsorbent polymer hydrogels

The glycerol‐lactic acid‐based star‐shaped modifier (SM) were synthesized and employed for surface modification of hygienic superabsorbent polymer (SAP) hydrogels for the first time. Surface crosslinking was carried out to increase the saline‐absorbency under load (AUL) and the swollen gel strength. The surface treatment process was analyzed employing free absorbency and AUL tests, salt sensitivity, attenuated total reflectance‐Fourier‐transform infrared spectroscopy (ATR‐FTIR), oscillatory rheometry, as well as scanning electron microscopy analysis. The effect of the branched architecture and the contents of SM on the properties of the modified SAPs were studied. The implementation of surface treatment leads to increase up to a 28% in the AUL of the modified SAP. Moreover, the loss modulus was surprisingly increased, while the storage modulus was enhanced (possibly due to the star architecture of oligomers). M_c and crosslink density values have been estimated based on modified rubber elasticity theory. Salt sensitivity factor (f) was calculated; the modified samples showed lower salt sensitivity in NaCl (f = 0.7) and CaCl₂ (f = 0.93–0.95) compared with the intact SAP (f = 0.84 for NaCl, and f = 0.95–0.97 for CaCl₂).     

Structural,electronic, magnetic and vibrational properties of half-Heusler NaZrZ (Z = P,As, Sb) compounds

The structural, electronic, magnetic and vibrational properties of NaZrP, NaZrAs and NaZrSb half-Heusler alloys have been investigated on the basis of density functional theory and generalized gradient approximation. There are three types of structures for these compounds where type a is the most stable one. It is found that all of these materials are half-metallic ferromagnets with a magnetic moment of $2{\mu }_{\mathrm{B}}$. The half-metallic gaps are estimated to be 0.16, 0.35 and 0.55 eV for Z = P, As and Sb, respectively. The hybridization between s and $t_{2g}$ orbitals of Zr with s and p orbitals of Z leads to half-metallic ferromagnetism in these compounds. The effect of strain on the half-metallic property is also investigated, and we notice that the half-metallicity is conserved up to the lattice compressions of 54.43%, 48.29% and 47.55% for NaZrP, NaZrAs and NaZrSb, respectively. The dynamical stability of these compounds is confirmed using dispersion curves. The Curie temperatures are also estimated to be 501.29 K, 855.49 K and 1348.88 K for NaZrP, NaZrAs and NaZrSb, respectively. Therefore, it seems that NaZrZ (Z = P, As, Sb) could be suitable materials for spin-injector applications.     

Inhibitory Effect of Nepeta deflersiana on Climax Bacterial Community Isolated from the Oral Plaque of Patients with Periodontal Disease

Background: The red-complex bacteria are one of the most significant complexes found simultaneously in subgingival plaque next to the periodontal pocket. The current antibacterial treatment is not adequate, and multidrug resistance to it is developing. Henceforth, the antibacterial effect of the ethanolic extract of Nepeta deflersiana was put to test against red-complex bacteria in patients with chronic periodontitis. Methods: Well diffusion and micro broth dilution procedure by Alamar blue were applied to assess the zone of inhibition (ZOI), the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Anti-virulence efficacies of the plant extract that comprise of adherence and formation of biofilms were examined by the process of adherence and biofilm production assay. Results: The crude extract of Nepeta deflersiana exhibited significant inhibitory outcome against periodontopathic bacteria with noteworthy MIC (0.78–3.12 mg/mL), inhibitory zone (12–20 mm), as well as MBC (3.12–12.50 mg/mL). The N. deflersiana extract inhibited bacterial adhesion ranging from 41% to 52%, 53% to 66%, and 60% to 79% at the given MIC × 0.5, MIC × 1, and MIC × 2 in succession. Substantial suppression was also developed in the biofilm production of the investigated periodontopathic strains following exposure to numerous concentrations of N. deflersianan extract for a period of 24 and 48 h. Conclusion: These outcomes divulge a new concept that N. deflersiana extract can be utilized to manufacture valuable antibacterial compounds to treat chronic and acute periodontitis. This identifies N. deflersiana as an essential natural source for future drug development.     

Fine tuning of SAP properties via epoxy‐silane surface modification

Using 3‐[(2,3‐epoxypropoxy)‐propyl]‐trimethoxysilane as a surface modifier, superabsorbent polymers with improved gel strength in their swollen state and saline absorbency under load are synthesized. The products are characterized using attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), rheometry, scanning electron microscopy–energy dispersive X‐ray analysis, contact angle, thermogravimetric analysis, water absorbency and gel content. The temperature and the duration effect of the surface‐treatment process on residual monomer content are also investigated by high performance liquid chromatography. The gel strength (as shown by storage modulus) and absorbency under load are improved up to 3500–4000 Pa, and 30–40 g/g, respectively. It is suggested that the surface of the superabsorbent polymer particles has been modified by two mechanisms: i.e. interpenetrating polymer network and cross‐linking. Moreover, the surface modification has enhanced thermo‐stability and prohibited undesirable gel blockage. Depending on the post‐treatment method used, the wetting behavior of particles is also altered. Copyright © 2017 John Wiley & Sons, Ltd.     

Recent advances in electrochemical and electrochemiluminescence based determination of the activity of caspase-3

Caspases, especially caspase-3, play a critical role in the intrinsic and extrinsic pathways of apoptosis. In addition, caspase-3 is involved in mental disorders like Alzheimer disease. Any up and down regulation of caspase-3 activity may cause cancer. This review (with 58 references) summarizes recent advances in electrochemical and electrochemiluminescent quantitation of the activity of caspase-3 based on the use of nanomaterials. The nanomaterials and nanolabels are classified in three main subgroups, namely electrochemical signal amplification strategies, amplification based on modified electrodes, and the combination of both modes. The potential of various electrochemical and electrochemiluminescence bioassays is discussed, and methods to circumvent certain limitations are oresented. Finally, current trends in the detection of caspase-3 such as system integration and the application of advanced nanomaterials are discussed.

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Graphical abstract The review summarizes electrochemical methods for the quantitation of caspase-3 activity based on the use of nanomaterials and of nanomaterial based labels. It contains subsections on electrochemical signal amplification strategies, amplification based on modified electrodes, and the combination of both modes.