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Aim: This study aimed to determine if quinacrine–gold hybrid nanoparticles (QAuNPs) + near-infrared (NIR) deregulate HSP-70/P300 complex-mediated H3K14 acetylation in estrogen receptor/progesterone receptor (ER/PR+) breast cancer stem cells (CSCs). Materials & methods: Various cells and mouse-based systems were used as models. Results: QAuNP + NIR treatment reduced the nuclear translocation of HSP-70, affected the histone acetyltransferase activity of P300 and specifically decreased H3K14 acetylation in ER/PR+ breast CSCs. Finally, HSP-70 knockdown showed a reduction in P300 histone acetyltransferase activity, decreased H3K14 acetylation and inhibited activation of the TGF-β gene. Conclusion: This study revealed that QAuNP + NIR irradiation inhibits oncogenic activation of the TGF-β gene by decreasing H3K14 acetylation mediated through the HSP-70/P300 nuclear complex in ER/PR+ breast CSCs. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) cause drug resistance in cancer due to its extensive drug efflux, DNA repair and self-renewal capability. ATP binding cassette subfamily G member 2 (ABCG2) efflux pump afford protection to CSCs in tumors, shielding them from the adverse effects of chemotherapy. Although the role of ABCG2 in cancer progression, invasiveness, recurrence are known but its role in metastasis and angiogenesis are not clear. Here, using in vitro (CSCs enriched side population [SP] cells), ex vivo (patient derived primary cells), in ovo (fertilized egg embryo) and in vivo (patient derived primary tissue mediated xenograft (PDX)) system, we have systematically studied the role of ABCG2 in angiogenesis and the regulation of the process by Curcumin (Cur) and Quinacrine (QC). Cur + QC inhibited the proliferation, invasion, migration and expression of representative markers of metastasis and angiogenesis. Following hypoxia, ABCG2 enriched cells released angiogenic factor vascular endothelial growth factor A (VEGF A) and induced the angiogenesis via PI3K-Akt-eNOS cascade. Cur + QC inhibited the ABCG2 expression and thus reduced the angiogenesis. Interestingly, overexpression of ABCG2 in SP cells and incubation of purified ABCG2 protein in media induced the angiogenesis but knockdown of ABCG2 decreased the vascularization. In agreement with in vitro results, ex vivo data showed similar phenomena. An induction of vascularization was noticed in PDX mice but reduction of vascularization was also observed after treatment of Cur + QC. Thus, data suggested that in hypoxia, ABCG2 enhances the production of angiogenesis factor VEGF A which in turn induced angiogenesis and Cur + QC inhibited the process by inhibiting ABCG2 in breast cancer. [ABSTRACT FROM AUTHOR]

We present an algorithm to predict the linear relaxation spectra for linear polymers of fully general and arbitrary polydispersity. As is common in the tube theory descriptions of linear polymers, we assume that the stress relaxation is affected by both the constraint release and tube escape modes, but unlike most existing descriptions we consider how these two modes of relaxation affect each other. We argue that the proper description for relaxation in an arbitrary blend of linear polymers requires consideration of multiple embedded tubes affecting the different relaxation pathways; we propose a novel but minimal description involving five embedded tubes. Building on prior work for binary blends, we derive the scaling level descriptions of the relaxation pathways. We use a large number of existing experimental results on the stress and dielectric relaxations to validate our model, ensuring we explore a very broad range of parameter space. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to explore the antiangiogenic mechanism of quinacrine-gold hybrid nanoparticle (QAuNP) and near-infrared (NIR) radiation in patient-derived primary breast cancer stem cells. Materials & methods: Various cell-based in ovo angiogenesis and in vivo patient-derived xenograft mouse systems were used as models for the study. Results: The experimental results showed that QAuNP + NIR treatment deregulated the HSP-70/TGF-β physical interaction in primary breast cancer stem cells. Reduced TGF-β secretion in the tumor microenvironment inhibited angiogenesis activation in endothelial cells by deregulating the TGF-β-mediated PI3K/AKT/mTOR cascade. Conclusion: This study revealed that QAuNP + NIR irradiation downregulated HSP-70 expression, inhibited the HSP-70/TGF-β interaction, reduced the secretion of TGF-β in the tumor microenvironment and ultimately inhibited TGF-β-mediated angiogenesis. This study discovered that the formation of blood vessels in breast cancer is significantly reduced when hybrid nanoparticles and infrared laser therapy are used to treat breast cancer stem cells. The secretory cytokines in the tumor microenvironment primarily responsible for developing blood vessels in the tumor are dramatically reduced by treatment. As a result, the tumor's blood vessel growth is reduced, making it difficult for the cancer cells to get the nutrients and oxygen they need to survive. Near-infrared radiation enhances the antiangiogenic potentiality of quinacrine-gold hybrid nanoparticles in patient-derived breast cancer stem cells via deregulation of the HSP-70/TGF-β axis. [ABSTRACT FROM AUTHOR]

We considered a dense plasma containing electrons, positrons, ions and dust particles in background magnetic and gravitational fields alongside collisional effects for the heavier species (ions and dust particles). Such plasmas are found in magnetars, black hole accretion disks, and so on. The quantum hydrodynamic (QHD) model was used to construct the governing equations of the plasma. Relativistic degeneracy pressure is taken as the equation of state for the electrons and positrons. Effects of exchange-correlation potential were also considered for the lighter species. We employed the reductive perturbation method (RPM) in order to obtain the Zakharov–Kuznetsov (ZK) equation describing 3-D ion acoustic waves (IAWs) with minimal lateral perturbations. Low order analytical solutions allow us to understand the parametric dependence of said structures. Our newly developed numerical technique: homotopy assisted symbolic simulation (HASS) sheds light on the gradual evolution of higher order stationary formations in the system. The results thus obtained can potentially explain certain astrophysical phenomena as well as dense laboratory plasmas. [ABSTRACT FROM AUTHOR]

In this work, we used the semi-Lagrangian method and the Vlasov code to study the instabilities in a quantum plasma with 1-D temperature anisotropy. Taking the Fermi–Dirac type of distribution function (DF) and using the semi-Lagrangian Vlasov code, we studied the gradual evolution of density and kinetic energy in a degenerate plasma with quantum effects. In this collisionless plasma, adiabatic compression will be along the direction of wave propagation and will lead to temperature anisotropy of the electron distribution that varies along the direction of wave propagation. The findings will find application for dense plasma at finite temperature as in laser-produced plasmas, fusion plasma, as well as solar plasmas. [ABSTRACT FROM AUTHOR]

In this article, we investigate the linear and nonlinear behavior of ion-plasma waves in a two-component plasma containing ions and dust particles. We have studied the linear dispersion characteristics, nonlinear KdV solitons, and amplitude modulated electrostatic waves. Such ion-plasma wave modes in dust-ion plasma have been theoretically investigated by incorporating quantum diffraction and relativistic effects. Numerical analysis of the linear dispersion relation with variations of different parameters has been carried out. By employing the reductive perturbation technique the KdV equation describing the small amplitude solitary profile has been studied. Using the standard multiple scale perturbation method, a nonlinear Schrödinger (NLS) equation has been derived by including quantum and relativistic effects, which describes the nonlinear evolution of the ion-plasma waves in dust-ion plasma. The wave is found to become modulationally unstable beyond certain critical wavenumber. The critical wavenumber and the growth rate of modulational instability are shown to depend significantly on the relativistic motion of plasma particles and the quantum diffraction effect. The results presented in the article are expected to be helpful for understanding the propagation of finite amplitude ion-plasma waves in some laboratory and astrophysical plasma systems. PACS—52.59.Hq, 67.10.Jn, 52.20 −j, 52.25 −b, 52.30 −d, 52.35 Mw, 52.65 Vv [ABSTRACT FROM AUTHOR]

Bifurcation analysis and dynamical system studies are carried out to find the stability regime and chaotic scenario in electron acoustic waves in relativistic degenerate plasma. We have obtained the quantum hydrodynamic model and obtain the Korteweg–de Vries equation describing the nature and characteristics of solitary structures. The amplitude modulated envelop soliton formation due to external perturbations has been studied by analyzing the nonlinear Schrodinger equation. Further to study the stability factors and the parametric range for such stability, the dynamical system is studied and bifurcation analysis has been carried out. The chaotic behavior of the system is studied through largest Lyapunov exponent (LLE). This work will find application in theoretically predicting the stable modes in many solar plasma and stellar plasma applications and in laser plasma in future. [ABSTRACT FROM AUTHOR]

In this work, we start with the ion-acoustic waves in galactic plasma with the degenerate matter. We use the reductive perturbation technique to derive the spherical Kadomtsev–Petviashvili (SKP) equation. We next employ homotopy-aided symbolic simulation (HASS) to study the evolution of the spherical solitary wavefront. We compare the results obtained by HPM and RPT. To understand how the system behaves, we transform the evolutionary equations into a dynamical system. The phase portraits and the superperiodic waves reflect on the intricate processes within the plasma and determine the stability criteria and possible situations of chaos. The work will find applications in many astrophysical observations, such as electrostatic wave modes, gamma-ray bursts, and double-layer solitons. PACS—95.30.Qd, 52.65.-y, 52.35.-g, 52.35.Tc. [ABSTRACT FROM AUTHOR]

In this article, we have studied the electron acoustic waves in a magnetized plasma containing Kappa distributed ions which are streaming with high velocity within the plasma and under the action of external force. We employed the homotopy perturbation method (HPM) to obtain the graphical plots of solitary structures and their evolution into an envelope soliton. Analytically, we obtained the linear dispersion relation and studied its characteristics. Further, we derived the Korteweg–De Vries (KdV) equation using the reductive perturbation technique and studied the parametric dependence on the KdV solitary profile. These findings augment the homotopy results. The analytical and simulation results thus obtained will be helpful in interpretating and identifying electron acoustic wave (EAW) modes in such a plasma system. [ABSTRACT FROM AUTHOR]

In this work, we start with the quantum hydrodynamic model equations for two temperature-populated electrons in a dense plasma with quantum effects. We obtain the KdV equation for the electron acoustic (EAW) mode. The EAW self-interacts to form a rogue wave-type envelop soliton which is described by the nonlinear Schrodinger (NLS) equation. To study the stability criteria, we transform the KdV and NLS equations into its dynamical system counterparts and analyze the phase portraits and carry out the bifurcation analysis. The possibility of hyperchaos is discussed with reference to rogue waves. The finding will be helpful in laser plasma interactions, microelectronics, as well as beam plasma physics and fusion technology. [ABSTRACT FROM AUTHOR]

A semiconductor p-n junction diode with heavy doping under consideration is kept in forward biased condition. These are oppositely propagating electron and hole currents. These two streams interact among themselves and result in recombination, which supplies additional energy to the system. Such thermal energy creates additional electrical fluctuations, which exists long after the interaction has taken place. We have carried out an analytical investigation with numerical techniques as well as carried out a simulation of the wave–wave interaction in semiconductor junction diodes. In terms of signal transmission and operation of semiconductor device, such a theoretical study is important. [ABSTRACT FROM AUTHOR]

By employing a quantum hydrodynamic (QHD) model with appropriate boundary conditions, the nonlinear self-interaction of an electrostatic surface wave on otherwise homogeneous semibounded plasma with degeneracy effects is investigated. It has been found that a part of the second harmonic generated through self-interaction does not have a true surface wave feature but propagates obliquely away from the plasma–vacuum interface into the bulk of the plasma. Such a situation is obtained in laser–plasma interaction during surface etching, plasma processing, and so on. In this article, we study the harmonics generation mechanism, associated Lagrangian chaos, and harmonic conversation rate when an intense laser is incident on an unmagnetized plasma. The dense plasma displays quantum diffraction effects and other quantum statistical effects. We made use of perturbative analysis for the field quantities. The findings will help workers dealing with laser–plasma interaction so as to enhance the tendency of harmonic generation and energy localization. [ABSTRACT FROM AUTHOR]

Impedance-source-based solar PV systems are capable of achieving both voltage boosting and inversion in a single stage, resulting in a simple design thereby enhancing reliability. One of the major concerns of PV systems is their leakage current, as it can cause hazardous operational insecurity and reliability. This article introduces a quasi-Z-source (qZS)-based five-level inverter, which displays the following advantages: 1) reactive power handling capability, 2) single-stage boosting, 3) shoot-through immunity, and 4) reduced leakage current based on VDE 0126-1-1. The proposed single-stage power converter is constituted by the fusion of a boosting stage, consisting of two back-to-back connected qZSs, with a five-level inverter produced by the combination of T-type and neutral point clamped arms. The problem of the leakage current is addressed by a modified modulation technique and a passive filter structure, which filters high-frequency variations in the common mode voltage. The working principle of the proposed power converter and the effectiveness of the modulation scheme to reduce the leakage current are assessed with the aid of simulation studies in both standalone and the grid-connected modes. The simulation results are experimentally validated with the aid of a laboratory prototype of 500 W rating. [ABSTRACT FROM AUTHOR]

The effects of developing employees' career abilities (knowing-why, knowing-how, and knowing-whom) on the employing organisation are examined in this study, as well as the function of career happiness in this relationship. The goal of this paper is to contribute to the growing body of knowledge about the effects of employees' boundaryless careers A two-wave quantitative investigation of graduates of a large public university in Hyderabad is used in this study. The findings imply that individuals contribute to company culture, competences, and connections by investing in the development of their career competencies. These contributions, however, are contingent on employees' perceptions of career satisfaction. Employees that are satisfied in their jobs are more likely to give more to their companies. Research limitations/implications - To replicate the current findings, more longitudinal research is needed, supported by a third wave of data collecting. The study emphasises the relevance of career development for employees in the workplace. This is an empirical assessment of the relationship between the development of employees' career competences and their contributions to their employers, as well as one of the first studies to look at career satisfaction as a moderating variable. [ABSTRACT FROM AUTHOR]

Grid‐connected Single‐Stage Boost Inverters (SSBI) are extensively being researched in the area of photovoltaic energy conversion systems. Owing to their single‐stage boosting capability, this class of power converters results in higher efficiency and reliability. This power circuit configuration is constituted by two mutually dependent sub‐converters, in that a front‐end quasi‐Z‐source (qZS) part is integrated to a back‐end multilevel inverter (MLI). The MLI provides the shoot‐through state to the qZS, while the qZS provides the pulsating DC input to the MLI. In general, solar photovoltaic inverters suffer from the disadvantage of leakage current that flows from solar panels to the grid/load. This paper introduces a dual quasi‐Z‐source based multilevel inverter, which achieves the following benefits: (a) five‐level output voltage, (b) reactive power capability, (c) shoot‐through immunity, (d) continuous input current, and (e) reduced leakage current based on VDE 0126‐1‐1 standards. In this paper, a modified modulation scheme, which is based on the employment of phase‐disposed and level‐shifted carrier signals, has been used to reduce the leakage current. To reduce the leakage current further, a passive filter is employed to eliminate high frequency variations across the parasitic capacitance. The working principle of the proposed power converter and the effectiveness of the modulation scheme have been validated with simulation studies in both standalone and the grid‐connected mode. Finally, the simulation studies are verified through an experimental prototype of 500 W rating. [ABSTRACT FROM AUTHOR]

In this paper we have studied the gradual evolution of stationary formations in electron acoustic waves at a finite temperature quantum plasma. We have made use of Quantum hydrodynamics model equations and obtained the KdV-Burgers equation. From here we showed how the amplitude modulated solitons evolve from double layer structures through shock fronts and ultimately converging into solitary structures. We have studied the various parametric influences on such stationary structure and also showed how the gradual variations of these parameter affect the transition from one form to another. The results thus obtained will help in the generation and structure of the structures in their respective domain. Much of the experiments on dense plasma will benefit from the parametric study. Further we have studied amplitude modulation followed by a detailed study on chaos. [ABSTRACT FROM AUTHOR]

We studied the nonlinear evolution of an amplitude-modulated envelop soliton formed in a dense plasma when a laser beam interacts with it. The employment of our newly developed technique, homotopy-assisted symbolic simulation, has been instrumental in the study of the nature and formation of envelope solitons and their dependence on various parameters. The different orders of homotopy perturbation generate a convergent series solution for such nonlinear coupled partial differential equations (PDE). Our technique bypasses the rigorous analytical derivation of coupled PDE without a loss of information. The methodology is very novel and holds promise for application in models that explain experimental observations. The results will be beneficial in interpreting various dense laser plasma interactions. [ABSTRACT FROM AUTHOR]

Impedance source-based multilevel inverters are becoming popular for emerging power generation technologies such as fuel cells, photovoltaic, and wind turbines. It is one of the most promising power electronic interfaces for single stage DC/AC conversion with inherent buck-boost capability. Therefore, in this paper, an extensive review of emerging impedance source-based multilevel inverter (Z-MLI) topologies is presented. These topologies are developed by the combination of impedance source network and multilevel inverter (MLI) with the merits of high voltage gain, enhanced reliability due to shoot-through immunity, improved input voltage regulation, reduced filter size, and better quality of supply. Most of the recent Z-MLI topologies are based on quasi-Z-source network which operates with continuous input current. In order to identify a suitable topology, an exhaustive comparison is made with various configurations of Z-MLIs in terms of component count, boost gain, switching stress, and control complexity. [ABSTRACT FROM AUTHOR]

In this theoretical study, we investigate the amplitude modulation and envelop soliton formation in a dense plasma when such a plasma interacts with a strong laser beam. We have made use of the symbolic simulation technique to find the modulation instability of an electrostatic wave with higher orders of non‐linearity. We identified the range of wavenumber in which such non‐linearity is important. Furthermore, we have analysed the formation of envelope soliton of waves localized in space. The results obtained here will be helpful in interpreting different phenomena that arise in laser plasma interaction. The importance of the relativistic contribution of streaming particles is discussed alongside the parametric influences experienced by the plasma particles. [ABSTRACT FROM AUTHOR]

In this paper, a novel seven-level Quasi-Z-Source-based T -type inverter (7L qZST 2 I) is proposed. The proposed inverter is an upgrade of Quasi-Z-source (qZs) network and seven-level T -type inverter. The 7L qZST 2 I comprises of three qZs-based impedance networks, two bidirectional switches and an H -bridge inverter. It owns the advantages of reduced switch count, improved output voltage gain, enhanced reliability and better quality of output voltage and current. The performance of the proposed topology is tested for two different pulse width modulation techniques based on shoot-through control. The first technique offers simple control and operated at a fixed shoot-through duty cycle for realizing output voltage level. The second technique facilitates independent control of each qZs network dc-link voltage and they can be operated at different shoot through duty cycle which overcomes the limitation of first technique with better quality in output voltage. The detailed operation of the proposed topology and control schemes have been elaborated for different switching states for each output voltage level generation. Extensive simulation and experimentation are performed for both the switching schemes to verify their performance under steady state and dynamic conditions. Furthermore, a brief comparison is constructed to highlight the merits of the proposed inverter with conventional topologies. [ABSTRACT FROM AUTHOR]

Using thermodynamic integration, we calculate free energies of the melt and the crystalline phases of a model system of C[SUB198]H[SUB398] with a realistic all-atom potential. We use the Gibbs-Duhem integration scheme to calculate the melting curve over the experimentally relevant pressure range. The crystal structure and the melting curve obtained from our simulation are in good quantitative agreement with the available experimental results. Using thermodynamic integration, we calculate free energies of the melt and the crystalline phases of a model system of C[SUB198]H[SUB398] with a realistic all-atom potential. We use the Gibbs-Duhem integration scheme to calculate the melting curve over the experimentally relevant pressure range. The crystal structure and the melting curve obtained from our simulation are in good quantitative agreement with the available experimental results. [ABSTRACT FROM AUTHOR]

Advance in computational rheology allows for in silico predictions of the viscoelastic responses of arbitrarily branched polymer melts. While detailed branching structure is required for the rheology predictions, rheology itself is often the most sensitive tool to detect low levels of branching. With rheological experiments and computational modeling of a set of nominally linear and model comb ethylene-butene copolymers, we show that coupled models for the synthesis and rheology can integrate diverse measurements, incorporating inherent experimental uncertainties. This approach allows us to achieve tight bounds on the branching structures of the constituent molecules. Next, we numerically explore the effects of the numbers and molar masses of side arms in comb polymers on the viscoelastic responses in both the linear and nonlinear regimes. Such computational exploration can aid in designing specific polymers suitable for a given processing scenario. Graphical abstract Coupled models for synthesis and rheology allow tight bounds on branching architecture and parametric exploration of flow properties of statistically branched polymers. [ABSTRACT FROM AUTHOR]

Because of the familiarity of gelation theories in polycondensation reaction of multifunctional groups, often the gel-point is defined as the point of diverging weight averaged molar mass. The authors present an industrially relevant counter-example to this common perception. Chain-growth polymerization in realistic reactors introduces history dependent crosslinking probability. For copolymerization of a two functional monomer (ethylene) with a four functional comonomer (nonconjugated diene), the authors show from a Monte Carlo scheme that standard gelation scaling exponents remain valid for a semibatch reactor. However, for syntheses in a continuous stirred tank reactor (CSTR), all commonly measured molar mass moments (number, weight and ' z'-averaged moment) remain finite at the gel-point; the first moment to diverge is the fourth moment. Hence, identification of the gel point from experimental observations is difficult, and cannot be achieved through monitoring of the weight averaged molar mass. The authors use a numerical scheme based on the tube model of polymer melts to predict the rheology of the generated molecules. Stress relaxation follows a power-law decay, but due to dynamic dilution effects the CSTR resins exhibit much slower increase in the zero shear viscosity as the gel point is approached as compared to the semibatch reactor resins. [ABSTRACT FROM AUTHOR]

Monoglycerides and unsaturated fatty acids, naturally present in trace amounts in the stratum corneum (top layer of skin) lipid matrix, are commonly used in pharmaceutical, cosmetic and health care formulations. However, a detailed molecular understanding of how the oil additives get incorporated into the skin lipids from topical application and, once incorporated, how they affect the properties and integrity of the lipid matrix remains unexplored. Using ceramide 2 bilayers as skin lipid surrogates, we use a series of molecular dynamics simulations with six different natural oil ingredients at multiple concentrations to investigate the effect of the oils on the properties and stability of the bilayers. The six oils: monoolein, monostearin, monoelaidin, oleic acid, stearic acid and linoleic acid – all having the same length of the alkyl chain, C18, but a varying degree of saturation, allow us to systematically address the effect of unsaturation in the additives. Our results show that at low oil concentration (∼5%) the mixed bilayers containing any of the oils and ceramide 2 (CER2) become more rigid than pure CER2 bilayers due to more efficient lipid packing. Better packing also results in the formation of larger numbers of hydrogen bonds between the lipids, which occurs at the expense of the hydrogen bonds between lipids and water. The mixed bilayers with saturated or trans-unsaturated oils remain stable over the whole range of oil concentration. In contrast, the presence of the oils with at least one cis-double bond leads to bilayer instability and complete loss of bilayer structure at the oil content of about 50–65%. Two cis-double bonds in the lipid tail induce bilayer disruption at even lower concentration (∼30%). The mixed bilayers remain in the gel phase (without melting to a fluid phase) until the phase transition to a non-bilayer phase occurs. We also demonstrate that the stability of the bilayer strongly correlates with the order parameter of the lipid tails. [ABSTRACT FROM AUTHOR]