Prospecting Quantum Correlations and Examining Teleportation Fidelity in a Pair of Coupled Double Quantum Dots System

The topic of improving the ability of quantum systems to retain non-local features and enhance the efficiency of quantum protocols continues. This study delves into the thermal investigation of quantum correlations and teleportation fidelity of a two-qubit teleported state using excess electrons in a coupled double quantum dots system as a quantum channel. The study employs three reliable quantum quantifiers to prospect the resourcefulness and non-classicality of the system. The findings suggest that preserving quantum correlations and optimizing teleportation fidelity require minimizing tunneling coupling and maximizing Coulomb interaction. The study has significant implications for quantum physics and its practical applications in quantum information processing.     

Hybrid fiber-to-the-x and free space optics for high bandwidth access networks

The authors demonstrate an implementation of hybrid fiber-to-the-x (FTTx) and free space optical (FSO) technologies as another alternative solution to bring light-speed performance to the residential users. A simulation experiment was performed with a 20 km single-mode fiber spanning from the Central Office to 1:32 splitter, before the signal propagated through the air to FSO receivers which were individually equipped with an Optical Network Unit (ONU). A downstream performance of the video signal transmitted at 1550 nm wavelength with a bit rate of 1 Gbps was studied under different weather conditions. The results show that for an acceptable bit error rate of 10⁻⁹, 32 ONUs are supportable at a combined FSO: FTTx distance ratio of 20:4.8, 20:2, and 20:1.4 km during clear weather, average and heavy rain, respectively.     

Performance Analysis of Amplify-and-Forward Relay Systems with Interference-Limited Destination in Various Rician Fading Channels

In this paper, we investigate the performance of a dual-hop fixed-gain amplify-and-forward relay system in the presence of co-channel interference at the destination node. Different fading scenarios for the desired user and interferers’ channels are assumed in this study. We consider the Rician/Nakagami- \(m\) , the Rician/Rician, and the Nakagami- \(m\) /Rician fading environments. In our analysis, we derive accurate approximations for the outage probability and symbol error probability (SEP) of the considered scenarios. The generic independent non-identically distributed (i.n.d.) case of interferers’ channels is considered for the Rician/Nakagami- \(m\) scenario; whereas, the independent identically distributed (i.i.d.) case is studied for the Rician/Rician and the Nakagami- \(m\) /Rician environments. Furthermore, to get more insights on the considered systems, high signal-to-noise ratio (SNR) asymptotic analysis of the outage probability and SEP is derived for special cases of the considered fading scenarios. Monte-Carlo simulations and numerical examples are presented in order to validate the analytical and asymptotic results and to illustrate the effect of interference and other system parameters on the system performance. Results show that the different fading models of interferers’ channels have the same diversity order and that the interference degrades the system performance by only reducing the coding gain. Furthermore, findings show that the case where the fading parameter of the desired user first hop channel is better than that of the second hop gives better performance compared to the vise versa case, especially, at low SNR values; whereas, both cases almost behave the same at high SNR values where the performance of the system is dominated by the interference affecting the worst link. Finally, results show the big gap in system performance due to approximating the Rician fading distribution with the Nakagami- \(m\) distribution which is an indication on the inaccuracy of making such approximations in systems like the considered.     

Routes toward enantiopure 2-substituted indolines: an overview

Chiral-2-substituted indolines are an important class of compounds with numerous applications in organic synthesis and as constituents of a number of biologically active molecules. Consequently, there has been a continued interest in the development of efficient methods for the syntheses of this class of chiral compounds. In this review, a detailed survey of the important efforts toward the synthesis of enantioenriched 2-substituted indolines by means of the kinetic resolution or the use of a chiral auxiliary in stoichiometric or catalytic processes is provided. The resolution of racemic mixtures through diastereomeric separation is not considered in the article.     

Estimating Drift Parameters in a Sub-Fractional Vasicek-Type Process

This study deals with drift parameters estimation problems in the sub-fractional Vasicek process given by dxt=θ(μ−xt)dt+dStH, with θ>0, μ∈R being unknown and t≥0; here, SH represents a sub-fractional Brownian motion (sfBm). We introduce new estimators θ^ for θ and μ^ for μ based on discrete time observations and use techniques from Nordin–Peccati analysis. For the proposed estimators θ^ and μ^, strong consistency and the asymptotic normality were established by employing the properties of SH. Moreover, we provide numerical simulations for sfBm and related Vasicek-type process with different values of the Hurst index H.     

Effect of Different Crosslinking Strategies on Physical Properties and Biocompatibility of Freestanding Multilayer Films Made of Alginate and Chitosan

Freestanding multilayer films prepared by layer‐by‐layer technique have attracted interest as promising materials for wound dressings. The goal is to fabricate freestanding films using chitosan (CHI) and alginate (ALG) including subsequent crosslinking to improve the mechanical properties of films while maintaining their biocompatibility. Three crosslinking strategies are investigated, namely use of calcium ions for crosslinking ALG, 1‐ethyl‐3‐(‐3‐dimethylaminopropyl) carbodiimide combined with N‐hydroxysuccinimide for crosslinking ALG with CHI, and Genipin for crosslinking chitosan inside the films. Different characteristics, such as surface morphology, wettability, swelling, roughness, and mechanical properties are investigated showing that films became thinner, exhibited rougher surfaces, had lower water uptake, and increased mechanical strength after crosslinking. Changes of wettability are moderate and dependent on the crosslinking method. In vitro cytotoxicity and cell attachment studies with human dermal fibroblasts show that freestanding CHI‐ALG films represent a poorly adhesive substratum for fibroblasts, while studies using incubation of plastic‐adherent fibroblast beneath floating films show no signs of cytotoxicity in a time frame of 7 days. Results from cell experiments combined with film characteristics after crosslinking, indicate that crosslinked freestanding films made of ALG and CHI may be interesting candidates for wound dressings.     

Intrinsically Disordered Tardigrade Proteins Self-Assemble into Fibrous Gels in Response to Environmental Stress

Tardigrades are remarkable for their ability to survive harsh stress conditions as diverse as extreme temperature and desiccation. The molecular mechanisms that confer this unusual resistance to physical stress remain unknown. Recently, tardigrade-unique intrinsically disordered proteins have been shown to play an essential role in tardigrade anhydrobiosis. Here, we characterize the conformational and physical behaviour of CAHS-8 from Hypsibius exemplaris. NMR spectroscopy reveals that the protein comprises an extended central helical domain flanked by disordered termini. Upon concentration, the protein is shown to successively form oligomers, long fibres, and finally gels constituted of fibres in a strongly temperature-dependent manner. The helical domain forms the core of the fibrillar structure, with the disordered termini remaining highly dynamic within the gel. Soluble proteins can be encapsulated within cavities in the gel, maintaining their functional form. The ability to reversibly form fibrous gels may be associated with the enhanced protective properties of these proteins.     

The role of medium radiation dose on microbiological safety and shelf-life of some traditional soups

Irradiation at medium doses in combination with cryogenic condition along the process to ensure the safety, quality and to extend the shelf-life of prepared meals have been investigated. Semi-concentrated black, ox-tail, chicken vegetable and chicken sweet corn soups were individually packed in a dry laminate pouch of PET 12 μ/LDPE adh.2 μ/Al–foil 7 μ/LDPE adh/LLDPE (C₄) 50 μ under vacuum followed by freezing for 24 h at −18 °C prior to irradiation with doses of 1, 3, 5 and 7 kGy at cryogenic condition (−79 °C), respectively. Both the non-irradiated and irradiated prepared meals were then stored in refrigerator at 5±2 °C. Non-irradiated and the irradiated samples at 1 kGy were mostly damaged after a week of storage. Gamma irradiation at doses of 5–7 kGy for the soups could reduce microbial load by about 2–3 log cycles, respectively, without affecting the physical–chemical parameters and palatability within 2–3 months while the unirradiated samples could only withstand for 1 month storage time.     

SBA-16负载金属氧化物催化剂合成、表征及催化CO氧化反应活性

将V2O5, CeO2和CuO分散到提取自稻米壳的SBA-16上,考察了其催化CO氧化反应活性,并采用X射线衍射、扫描电镜、透射电镜、程序升温还原和紫外漫反射光谱对所制催化剂进行了表征。结果表明,掺杂CuO的介孔氧化硅是一种有前景的催化剂,其CO转化率可达98%以上。     

Semiconductor quantum dots and metal nanoparticles: syntheses,optical properties,and biological applications

We review the syntheses, optical properties, and biological applications of cadmium selenide (CdSe) and cadmium selenide–zinc sulfide (CdSe–ZnS) quantum dots (QDs) and gold (Au) and silver (Ag) nanoparticles (NPs). Specifically, we selected the syntheses of QDs and Au and Ag NPs in aqueous and organic phases, size- and shape-dependent photoluminescence (PL) of QDs and plasmon of metal NPs, and their bioimaging applications. The PL properties of QDs are discussed with reference to their band gap structure and various electronic transitions, relations of PL and photoactivated PL with surface defects, and blinking of single QDs. Optical properties of Ag and Au NPs are discussed with reference to their size- and shape-dependent surface plasmon bands, electron dynamics and relaxation, and surface-enhanced Raman scattering (SERS). The bioimaging applications are discussed with reference to in vitro and in vivo imaging of live cells, and in vivo imaging of cancers, tumor vasculature, and lymph nodes. Other aspects of the review are in vivo deep tissue imaging, multiphoton excitation, NIR fluorescence and SERS imaging, and toxic effects of NPs and their clearance from the body. Figure Semiconductor quantum dots and metal nanoparticles have extensive applications, e.g., in vitro and in vivo bioimaging Tamitake Itoh and Abdulaziz Anas contributed equally to this article.