Software‐defined networking to improve handover in mobile edge networks

Mobility management and handover for a seamless connection are among all‐time challenges of wireless networks. Software‐defined networking (SDN) has opened new horizons toward research by adding intelligence in edge networks while decoupling the control and data planes. The flexibility and centralized nature of SDN further improve the handover decision algorithms. In this paper, we have improved the network performance with respect to the number of handovers and the handover delay by applying an LTE‐SDN architecture and a novel handover decision algorithm based on predicting the future locations of a moving vehicle. The proposed algorithm decouples the handover procedure into two phases of preparation and execution. In the preparation phase, which occurs in the control plane, the handover decision and resource allocation take place, and in the execution phase, handover gets executed similar to the LTE architecture. The results of our research indicate that our proposed LTE‐SDN performance is improved with respect to the number of handovers, handover delay, and signaling overhead by 24%, 16%, and 20%, respectively. On the other hand, average Reference Signal Received Quality (RSRQ) value is decreased by 4% as a tradeoff for the improvements gained.     

Polymer branching and first normal stress differences in small-amplitude oscillatory shear flow

General rigid bead-rod theory explains polymer viscoelasticity from macromolecular orientation. By means of general rigid bead-rod theory, we relate the normal stress differences of polymeric liquids to the branch position on a backbone branched macromolecule. In this work, we explore the first normal stress differences coefficients of different axisymmetric polymer configurations. When non-dimensionalized with the zero-shear first normal stress difference coefficient, the normal stress differences depend solely on the dimensionless frequency. In this work, in this way, we compare and contrast the normal stress differences of macromolecular chains that are branched. We explore the effects of branch position, length, functionality, spacing, and multiplicity, along a straight chain, in addition to rings and star-shaped macromolecules in small-amplitude oscillatory shear flow.     

Optical,FTIR and DC Conductivity of Soda Lime Silicate Glass Containing Cement Dust and Transition Metal Ions

Four soda lime silicate glass samples of composition (70 % SiO₂+ 20 % Na₂O+ 10 % CaO mol %) were prepared after adding 5 wt% cement dust to each sample mixture besides 0.1 wt% of one transition metal (TM) oxide of Fe, Co or Cu. The four samples were melted by a conventional melt-annealing technique at 1400 ^°C for 2.5 h. Density, UV/VIS, FTIR and DC conductivity measurements were performed for each glass. Experimental results indicate that there are only slight differences in the density values. The optical spectra reveal that the TM free sample and the sample containing iron ions have the same spectral features while the samples containing copper or cobalt exhibit distinct characteristic absorption bands due to each TM ion. FTIR spectra reveal characteristic vibrational bands due to stretching and bending modes of the silicate network. DC conductivity data show variations in the values of the studied samples according to the type of TM ions added. All the experimental results were correlated with each other in accordance with the current views on the constitution of the studied glasses.     

Super Magnetic Niosomal Nanocarrier as a New Approach for Treatment of Breast Cancer: A Case Study on SK-BR-3 and MDA-MB-231 Cell Lines

In the present study, a magnetic niosomal nanocarrier for co-delivery of curcumin and letrozole into breast cancer cells has been designed. The magnetic NiCoFe₂O₄ core was coated by a thin layer of silica, followed by a niosomal structure, allowing us to load letrozole and curcumin into the silica layer and niosomal layer, respectively, and investigate their synergic effects on breast cancer cells. Furthermore, the nanocarriers demonstrated a pH-dependent release due to the niosomal structure at their outer layer, which is a promising behavior for cancer treatment. Additionally, cellular assays revealed that the nanocarriers had low cellular uptake in the case of non-tumorigenic cells (i.e., MCF-10A) and related high viability but high cellular uptake in cancer cell lines (i.e., MDA-MB-231 and SK-BR-3) and related low viability, which is evidenced in their high cytotoxicity against different breast cancer cell lines. The cytotoxicity of the letrozole/curcumin co-loaded nanocarrier is higher than that of the aqueous solutions of both drugs, indicating their enhanced cellular uptake in their encapsulated states. In particular, NiCoFe₂O₄@L-Silica-L@C-Niosome showed the highest cytotoxicity effects on MDA-MB-231 and SK-BR-3 breast cancer cells. The observed cytotoxicity was due to regulation of the expression levels of the studied genes in breast cancer cells, where downregulation was observed for the Bcl-2, MMP 2, MMP 9, cyclin D, and cyclin E genes while upregulation of the expression of the Bax, caspase-3, and caspase-9 genes was observed. The flow cytometry results also revealed that NiCoFe₂O₄@L-Silica-L@C-Niosome enhanced the apoptosis rate in both MDA-MB-231 and SK-BR-3 cells compared to the control samples. The findings of our research show the potential of designing magnetic niosomal formulations for simultaneous targeted delivery of both hydrophobic and hydrophilic drugs into cancer cells in order to enhance their synergic chemotherapeutic effects. These results could open new avenues into the future of nanomedicine and the development of theranostic agents.     

Phase morphology and thermomechanical analysis of poly(styrene‐co‐acrylonitrile)/ethylene–propylene–diene monomer blends: Uncompatibilized and reactively compatibilized blends with two mixing sequences

The phase morphology developing in immiscible poly(styrene‐co‐acrylonitrile) (SAN)/ethylene–propylene–diene monomer (EPDM) blends was studied with an in situ reactively generated SAN‐g‐EPDM compatibilizer through the introduction of a suitably chosen polymer additive (maleic anhydride) and 2,5‐dimethyl‐2,5‐di‐(t‐butyl peroxy) hexane (Luperox) and dicumyl peroxide as initiators during melt blending. Special attention was paid to the experimental conditions required for changing the droplet morphology for the dispersed phase. Two different mixing sequences (simple and two‐step) were used. The product of two‐step blending was a major phase surrounded by rubber particles; these rubber particles contained the occluded matrix phase. Depending on the mixing sequence, this particular phase morphology could be forced or could occur spontaneously. The composition was stabilized by the formation of the SAN‐g‐EPDM copolymer between the elastomer and addition polymer, which was characterized with Fourier transform infrared. As for the two initiators, the blends with Luperox showed better mechanical properties. Scanning electron microscopy studies revealed good compatibility for the SAN/EPDM blends produced by two‐step blending with this initiator. Dynamic mechanical thermal analysis studies showed that the two‐step‐prepared blend with Luperox had the best compatibility. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The Effect of Different Plasticizers on Lactose Crystallization During Spray Drying

Lactose crystallization may occur during spray drying, depending on the operating conditions for drying, and this work reviews previous and new evidence for the effects of different additives or plasticizers on retarding or accelerating the rate of crystallization. The effects of different operating conditions during spray drying are also considered in the experimental work reviewed and performed here, which was mainly carried out with Buchi B-290 laboratory-scale spray dryers (Buchi, Flawil, Switzerland), although some work on pilot-scale equipment is also discussed. The additives used and reviewed in this article include milk proteins, such as casein and whey protein isolate, polyethylene glycol, and ascorbic acid. The key physical properties, such as glass transition temperature and drying characteristics of the material, are discussed, allowing degrees of amorphicity in spray-dried lactose to be controlled over a wide range, from close to 0% to nearly 100%.     

Covalent Fragment Screening Identifies Rgl2 RalGEF Cysteine for Targeted Covalent Inhibition of Ral GTPase Activation

Ral GTPases belong to the RAS superfamily, and they are directly activated by K-RAS. The RalGEF pathway is one of the three major K-RAS signaling pathways. Ral GTPases do not possess a cysteine nucleophile to develop a covalent inhibitor following the strategy that led to a K-RAS G12C therapeutic agent. However, several cysteine amino acids exist on the surface of guanine exchange factors that activate Ral GTPases, such as Rgl2. Here, we screen a library of cysteine electrophile fragments to determine if covalent bond formation at one of the Rgl2 surface cysteines could inhibit Ral GTPase activation. We found several chloroacetamide and acrylamide fragments that inhibited Ral GTPase exchange by Rgl2. Site-directed mutagenesis showed that covalent bond formation at Cys-284, but not other cysteines, leads to inhibition of Ral activation by Rgl2. Follow-up time- and concentration-dependent studies of derivatives identified by substructure search of commercial libraries further confirmed Cys-284 as the reaction site and identified the indoline fragments as the most promising series for further development. Cys-284 is located outside of the Ral ⋅ Rgl2 interface on a loop that has several residues that come in direct contact with Ral GTPases. Our allosteric covalent fragment inhibitors provide a starting point for the development of small-molecule covalent inhibitors to probe Ral GTPases in animal models.     

Development of Isatin-Based Schiff Bases Targeting VEGFR-2 Inhibition: Synthesis,Characterization, Antiproliferative Properties,and QSAR Studies

Three sets of isatin-based Schiff bases were synthesized utilizing the molecular hybridization approach. Some of the synthesized Schiff bases show significant to moderate antiproliferative properties against MCF7 (breast), HCT116 (colon), and PaCa2 (pancreatic) cancer cell lines with potency compared to reference drugs 5-fluorouracil (5-FU) and Sunitinib. Among all, compound 17 f (3-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)-1-((1-(2-methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)-5-methylindolin-2-one) exhibits promising antiproliferative properties against the MCF7 cancer cell line with 2.1-fold more potency than Sunitinib. However, among all the synthesized compounds, three (5-methylisatin derivatives) were the most effective against HCT116 in comparison to 5-FU. Compound 17 f exhibited the highest anti-angiogenic effect on the vasculature as it significantly reduced BV from 43 mm to 2 mm in comparison to 5.7 mm for Sunitinib and flow cytometry supports the arrest of the cell cycle at G1/S phases. In addition, compound 17 f also showed high VEGFR-2 inhibition properties against breast cancer cell lines. Robust 2D-QSAR studies supported the biological data.     

Optochemical Control of Bacterial Gene Expression: Novel Photocaged Compounds for Different Promoter Systems

Photocaged compounds are applied for implementing precise, optochemical control of gene expression in bacteria. To broaden the scope of UV-light-responsive inducer molecules, six photocaged carbohydrates were synthesized and photochemically characterized, with the absorption exhibiting a red-shift. Their differing linkage through ether, carbonate, and carbamate bonds revealed that carbonate and carbamate bonds are convenient. Subsequently, those compounds were successfully applied in vivo for controlling gene expression in E. coli via blue light illumination. Furthermore, benzoate-based expression systems were subjected to light control by establishing a novel photocaged salicylic acid derivative. Besides its synthesis and in vitro characterization, we demonstrate the challenging choice of a suitable promoter system for light-controlled gene expression in E. coli. We illustrate various bottlenecks during both photocaged inducer synthesis and in vivo application and possibilities to overcome them. These findings pave the way towards novel caged inducer-dependent systems for wavelength-selective gene expression.     

Synthesis and characterization of novel anti-inflammatory poly(spiro thiazolidinone)s

A new series of spirothiazolidinone polymers has been accomplished by solution polycondensation of 4,12-dioxa-1,9-dithiadispiro[4.2.4.2]tetradecane-3,11-dione (3) with different aliphatic and aromatic diamines. A model compound 4 was prepared by the reaction of spiro-monomer 3 with benzyl amine and was characterized by elemental and spectral analyses. These polymers were characterized by elemental and spectral analyses. The thermal properties of these polymers were investigated by thermogravimetric analysis and differential thermal analysis measurements. The morphological properties of selected polymers 5c and 5e were tested using scanning electron microscope to study their surface morphology. The molar masses of polymers 5a, 5b, and 5d were determined by gel permeation chromatography. In addition, the anti-inflammatory activities were studied for these spiro-polymers in comparison with the model compound by determination in vivo using acute carrageenan-induced paw edema in rats.