Quantum Work Statistics at Strong Reservoir Coupling.

Determining the statistics of work done on a quantum system while strongly coupled to a reservoir is a formidable task, requiring the calculation of the full eigenspectrum of the combined system and reservoir. Here, we show that this issue can be circumvented by using a polaron transformation that maps the system into a new frame where weak-coupling theory can be applied. Crucially, this polaron approach reproduces the Jarzynski fluctuation theorem, thus ensuring consistency with the laws of stochastic thermodynamics. We apply our formalism to a system driven across the Landau-Zener transition, where we identify clear signatures in the work distribution arising from a non-negligible coupling to the environment. Our results provide a new method for studying the stochastic thermodynamics of driven quantum systems beyond Markovian, weak-coupling regimes.

Capturing non-Markovian polaron dressing with the master equation formalism.

Understanding the dynamics of open quantum systems in strong coupling and non-Markovian regimes remains a formidable theoretical challenge. One popular and well-established method of approximation in these circumstances is provided by the polaron master equation (PME). In this work, we re-evaluate and extend the validity of the PME to capture the impact of non-Markovian polaron dressing, induced by non-equilibrium open system dynamics. By comparing with numerically exact techniques, we confirm that while the standard PME successfully predicts the dynamics of system observables that commute with the polaron transformation (e.g., populations in the Pauli z-basis), it can struggle to fully capture those that do not (e.g., coherences). This limitation stems from the mixing of system and environment degrees of freedom inherent to the polaron transformation, which affects the accuracy of calculated expectation values within the polaron frame. Employing the Nakajima-Zwanzig projection operator formalism, we introduce correction terms that provide an accurate description of observables that do not commute with the transformation. We demonstrate the significance of the correction terms in two cases, the canonical spin-boson model and a dissipative time-dependent Landau-Zener protocol, where they are shown to impact the system dynamics on both short and long timescales.

Role of Block Copolymers in Tissue Engineering Applications.

Research on synthesis, characterization, and understanding of novel properties of nanomaterials has led researchers to exploit their potential applications. When compared to other nanotechnologies described in the literature, electrospinning has received significant interest due to its ability to synthesize novel nanostructures (such as nanofibers, nanorods, nanotubes, etc.) with distinctive properties such as high surface-to-volume ratio, porosity, various morphologies such as fibers, tubes, ribbons, mesoporous and coated structures, and so on. Various materials such as polymers, ceramics, and composites have been fabricated using the electrospinning technique. Among them, polymers, especially block copolymers, are one of the useful and niche systems studied recently owing to their unique and fascinating properties in both solution and solid state due to thermodynamic incompatibility of the blocks, that results in microphase separation. Morphology and mechanical properties of electrospun block copolymers are intensely influenced by quantity and length of soft and hard segments. They are one of the best studied systems to fit numerous applications due to a broad variety of properties they display upon varying the composition ratio and molecular weight of blocks. In this review, the synthesis, fundamentals, electrospinning, and tissue engineering application of block copolymers are highlighted.

Uniqueness of the Phase Transition in Many-Dipole Cavity Quantum Electrodynamical Systems.

The possibility of a superradiant phase transition in light-matter systems is the subject of much debate, due to numerous apparently conflicting no-go and counter no-go theorems. Using an arbitrary-gauge approach we show that a unique phase transition does occur in archetypal many-dipole cavity QED systems, and that it manifests unambiguously via a macroscopic gauge-invariant polarization. We find that the gauge choice controls the extent to which this polarization is included as part of the radiative quantum subsystem and thereby determines the degree to which the abnormal phase is classed as superradiant. This resolves the long-standing paradox of no-go and counter no-go theorems for superradiance, which are shown to refer to different definitions of radiation.

Photon Statistics of Filtered Resonance Fluorescence.

Spectral filtering of resonance fluorescence is widely employed to improve single photon purity and indistinguishability by removing unwanted backgrounds. For filter bandwidths approaching the emitter linewidth, complex behavior is predicted due to preferential transmission of components with differing photon statistics. We probe this regime using a Purcell-enhanced quantum dot in both weak and strong excitation limits, finding excellent agreement with an extended sensor theory model. By changing only the filter width, the photon statistics can be transformed between antibunched, bunched, or Poissonian. Our results verify that strong antibunching and a subnatural linewidth cannot simultaneously be observed, providing new insight into the nature of coherent scattering.

Environmental Nonadditivity and Franck-Condon physics in Nonequilibrium Quantum Systems.

We show that for a quantum system coupled to both vibrational and electromagnetic environments, enforcing additivity of their combined influences results in nonequilibrium dynamics that does not respect the Franck-Condon principle. We overcome this shortcoming by employing a collective coordinate representation of the vibrational environment, which permits the derivation of a nonadditive master equation. When applied to a two-level emitter our treatment predicts decreasing photon emission rates with increasing vibrational coupling, consistent with Franck-Condon physics. In contrast, the additive approximation predicts the emission rate to be completely insensitive to vibrations. We find that nonadditivity also plays a key role in the stationary nonequilibrium model behavior, enabling two-level population inversion under incoherent electromagnetic excitation.

Light Scattering from Solid-State Quantum Emitters: Beyond the Atomic Picture.

Coherent scattering of light by a single quantum emitter is a fundamental process at the heart of many proposed quantum technologies. Unlike atomic systems, solid-state emitters couple to their host lattice by phonons. Using a quantum dot in an optical nanocavity, we resolve these interactions in both time and frequency domains, going beyond the atomic picture to develop a comprehensive model of light scattering from solid-state emitters. We find that even in the presence of a low-Q cavity with high Purcell enhancement, phonon coupling leads to a sideband that is completely insensitive to excitation conditions and to a nonmonotonic relationship between laser detuning and coherent fraction, both of which are major deviations from atomlike behavior.

Comparison of UV protection properties of cotton fabrics treated with aqueous and methanolic extracts of Solanum nigrum and Amaranthus viridis plants.

Harmful effects of ultraviolet rays and protection against them have been long discussed. Numerous synthetic dyes, finishes, UV absorbers, and optical brightening agents are present in the market for decades for achieving UV protection through textiles. However, due to environmental impacts of these chemical agents, textile industry is looking for alternatives. In this regard, some natural dyes and plant extracts have shown promising results. However, use of colorless plant extracts as UV protective finishes is still rare. In this study, ultraviolet protection factor (UPF) rating of bleached cotton fabric has been improved by the application of plant extracts with minimal change in fabric's color. For this purpose, two medicinal plants, that is, Solanum nigrum and Amaranthus viridis were selected and bleached cotton fabric was treated with their methanolic and aqueous extracts. Fabrics treated with both extracts exhibited excellent UPF ratings.

Pluronic-Based Mixed Polymeric Micelles Enhance the Therapeutic Potential of Curcumin.

Curcumin is a naturally occurring constituent of turmeric that is a good substitute for synthetic medicines for the treatment of different diseases, due to its comparatively safer profile. However, there are certain shortcomings that limit its use as an ideal therapeutic agent. In order to overcome these drawbacks, we prepared novel curcumin-loaded mixed polymeric micelles using different biocompatible polymers by the thin-film hydration method. We investigated the critical micelle concentration and temperature, drug loading and encapsulation efficiency, and minimum inhibitory concentration by spectrophotometry. Surface morphology, stability, particle size, drug-polymer interaction, and physical state of the prepared formulations were investigated using scanning electron microscopy, zeta potential, particle size analyzer, Fourier-transform infrared spectroscopy, and X-ray diffraction, respectively. The drug loading and entrapment efficiency were significantly increased (P < 0.01) when curcumin was encapsulated with pluronic-based mixed polymeric micelles as compared to that of pluronic-based micelles alone. In vitro studies exhibited that pluronic-based mixed polymeric micelles significantly increased anticancer (P < 0.01), antimicrobial (P < 0.001), antioxidant (P < 0.001), and α-amylase inhibitory (P < 0.001) activities when compared to pure curcumin and/or pluronic-based micelles alone. These findings suggest that the formation of mixed polymeric micelles increases the stability and solubility of curcumin.

Energy transfer in structured and unstructured environments: Master equations beyond the Born-Markov approximations.

We explore excitonic energy transfer dynamics in a molecular dimer system coupled to both structured and unstructured oscillator environments. By extending the reaction coordinate master equation technique developed by Iles-Smith et al. [Phys. Rev. A 90, 032114 (2014)], we go beyond the commonly used Born-Markov approximations to incorporate system-environment correlations and the resultant non-Markovian dynamical effects. We obtain energy transfer dynamics for both underdamped and overdamped oscillator environments that are in perfect agreement with the numerical hierarchical equations of motion over a wide range of parameters. Furthermore, we show that the Zusman equations, which may be obtained in a semiclassical limit of the reaction coordinate model, are often incapable of describing the correct dynamical behaviour. This demonstrates the necessity of properly accounting for quantum correlations generated between the system and its environment when the Born-Markov approximations no longer hold. Finally, we apply the reaction coordinate formalism to the case of a structured environment comprising of both underdamped (i.e., sharply peaked) and overdamped (broad) components simultaneously. We find that though an enhancement of the dimer energy transfer rate can be obtained when compared to an unstructured environment, its magnitude is rather sensitive to both the dimer-peak resonance conditions and the relative strengths of the underdamped and overdamped contributions.

Dissipation enhanced vibrational sensing in an olfactory molecular switch.

Motivated by a proposed olfactory mechanism based on a vibrationally activated molecular switch, we study electron transport within a donor-acceptor pair that is coupled to a vibrational mode and embedded in a surrounding environment. We derive a polaron master equation with which we study the dynamics of both the electronic and vibrational degrees of freedom beyond previously employed semiclassical (Marcus-Jortner) rate analyses. We show (i) that in the absence of explicit dissipation of the vibrational mode, the semiclassical approach is generally unable to capture the dynamics predicted by our master equation due to both its assumption of one-way (exponential) electron transfer from donor to acceptor and its neglect of the spectral details of the environment; (ii) that by additionally allowing strong dissipation to act on the odorant vibrational mode, we can recover exponential electron transfer, though typically at a rate that differs from that given by the Marcus-Jortner expression; (iii) that the ability of the molecular switch to discriminate between the presence and absence of the odorant, and its sensitivity to the odorant vibrational frequency, is enhanced significantly in this strong dissipation regime, when compared to the case without mode dissipation; and (iv) that details of the environment absent from previous Marcus-Jortner analyses can also dramatically alter the sensitivity of the molecular switch, in particular, allowing its frequency resolution to be improved. Our results thus demonstrate the constructive role dissipation can play in facilitating sensitive and selective operation in molecular switch devices, as well as the inadequacy of semiclassical rate equations in analysing such behaviour over a wide range of parameters.

Temperature-dependent Mollow triplet spectra from a single quantum dot: Rabi frequency renormalization and sideband linewidth insensitivity.

We investigate temperature-dependent resonance fluorescence spectra obtained from a single self-assembled quantum dot. A decrease of the Mollow triplet sideband splitting is observed with increasing temperature, an effect we attribute to a phonon-induced renormalization of the driven dot Rabi frequency. We also present first evidence for a nonperturbative regime of phonon coupling, in which the expected linear increase in sideband linewidth as a function of temperature is canceled by the corresponding reduction in Rabi frequency. These results indicate that dephasing in semiconductor quantum dots may be less sensitive to changes in temperature than expected from a standard weak-coupling analysis of phonon effects.

Blockchain-enabled EHR access auditing: Enhancing healthcare data security.

In the realm of modern healthcare, Electronic Health Records EHR serve as invaluable assets, yet they also pose significant security challenges. The absence of EHR access auditing mechanisms, which includes the EHR audit trails, results in accountability gaps and magnifies security vulnerabilities. This situation effectively paves the way for unauthorized data alterations to occur without detection or consequences. Inadequate EHR compliance auditing procedures, particularly in verifying and validating access control policies, expose healthcare organizations to risks such as data breaches, and unauthorized data usage. These vulnerabilities result from unchecked unauthorized access activities. Additionally, the absence of EHR audit logs complicates investigations, weakens proactive security measures, and raises concerns to put healthcare institutions at risk. This study addresses the pressing need for robust EHR auditing systems designed to scrutinize access to EHR data, encompassing who accesses it, when, and for what purpose. Our research delves into the complex field of EHR auditing, which includes establishing an immutable audit trail to enhance data security through blockchain technology. We also integrate Purpose-Based Access Control (PBAC) alongside smart contracts to strengthen compliance auditing by validating access legitimacy and reducing unauthorized entries. Our contributions encompass the creation of audit trail of EHR access, compliance auditing via PBAC policy verification, the generation of audit logs, and the derivation of data-driven insights, fortifying EHR access security.

A Recent Advancement in Food Quality Assessment: Using MOF-Based Sensors: Challenges and Future Aspects.

Monitoring food safety is crucial and significantly impacts the ecosystem and human health. To adequately address food safety problems, a collaborative effort needed from government, industry, and consumers. Modern sensing technologies with outstanding performance are needed to meet the growing demands for quick and accurate food safety monitoring. Recently, emerging sensors for regulating food safety have been extensively explored. Along with the development in sensing technology, the metal-organic frameworks (MOF)-based sensors gained more attention due to their excellent sensing, catalytic, and adsorption properties. This review summarizes the current advancements and applications of MOFs-based sensors, including colorimetric, electrochemical, luminescent, surface-enhanced Raman scattering, and electrochemiluminescent sensors. and also focused on the applications of MOF-based sensors for the monitoring of toxins such as heavy metals, pesticide residues, mycotoxins, pathogens, and illegal food additives from food samples. Future trends, as well as current developments in MOF-based materials.

Vibronic effects on the quantum tunnelling of magnetisation in Kramers single-molecule magnets.

Single-molecule magnets are among the most promising platforms for achieving molecular-scale data storage and processing. Their magnetisation dynamics are determined by the interplay between electronic and vibrational degrees of freedom, which can couple coherently, leading to complex vibronic dynamics. Building on an ab initio description of the electronic and vibrational Hamiltonians, we formulate a non-perturbative vibronic model of the low-energy magnetic degrees of freedom in monometallic single-molecule magnets. Describing their low-temperature magnetism in terms of magnetic polarons, we are able to quantify the vibronic contribution to the quantum tunnelling of the magnetisation, a process that is commonly assumed to be independent of spin-phonon coupling. We find that the formation of magnetic polarons lowers the tunnelling probability in both amorphous and crystalline systems by stabilising the low-lying spin states. This work, thus, shows that spin-phonon coupling subtly influences magnetic relaxation in single-molecule magnets even at extremely low temperatures where no vibrational excitations are present.

Adsorption of lead ions from wastewater using electrospun zeolite/MWCNT nanofibers: kinetics, thermodynamics and modeling study.

Heavy metal contamination in water is a serious environmental issue due to the toxicity of metals like lead. This study developed zeolite and multi-walled carbon nanotube (MWCNT) incorporated polyacrylonitrile (PAN) nanofibers via needleless electrospinning and examined their potential for lead ion adsorption from aqueous solutions. The adsorption process was optimized using response surface methodology (RSM) and artificial neural network (ANN) modeling approaches. The adsorbent displayed efficient lead removal of 84.75% under optimum conditions (adsorbent dose (2.21 g), adsorption time (207 min), temperature (48 °C), and initial concentration (62 ppm)). Kinetic studies revealed that the adsorption followed pseudo-first-order kinetics governed by interparticle diffusion. Isotherm analysis indicated Langmuir monolayer adsorption with improved 5.90 mg g-1 capacity compared to pristine PAN nanofibers. Thermodynamic parameters suggested the adsorption was spontaneous and endothermic. This work demonstrates the promise of electrospun zeolite/MWCNT nanofibers as adsorbents for removing lead from wastewater.

Modulating alginate-polyurethane elastomer properties: Influence of NCO/OH ratio with aliphatic diisocyanate.

This research addresses the need for enhanced biomaterials by investigating the influence of the NCO/OH ratio on sodium alginate-based polyurethane elastomers(Al-PUEs), offering novel insights into their structural, thermal, mechanical and swelling behavior. Al-PUEs were prepared by blending the chain extenders with key ingredients in a specific molar ratio using aliphatic HMDI and HTPB monomers. The chemical linkages, crystalline behavior, homogeneity, and surface morphology of PUEs were evaluated by FT-IR, XRD, SEM, and EDX analysis. Thermo-mechanical studies were performed using TGA, DSC and tensile testing. Swelling behavior and absorption analysis were analyzed in DMSO and water. The analysis indicated that the hydrophilicity and swelling behavior of the prepared PUEs were affected by the addition of sodium alginate content. The results exhibit the tailor-made network structure of Al-PUEs, resulting in better thermal stability, elasticity of materials via stress-strain behavior and marvelous characteristic features than traditional high-tech yields. Furthermore, the resulting Al-PUEs are potential candidates for biomedical implants.

Model of the optical emission of a driven semiconductor quantum dot: phonon-enhanced coherent scattering and off-resonant sideband narrowing.

We study the crucial role played by the solid-state environment in determining the photon emission characteristics of a driven quantum dot. For resonant driving, we predict a phonon enhancement of the coherently emitted radiation field with increasing driving strength, in stark contrast to the conventional expectation of a rapidly decreasing fraction of coherent emission with stronger driving. This surprising behavior results from thermalization of the dot with respect to the phonon bath and leads to a nonstandard regime of resonance fluorescence in which significant coherent scattering and the Mollow triplet coexist. Off resonance, we show that despite the phonon influence, narrowing of dot spectral sideband widths can occur in certain regimes, consistent with an experimental trend.

A review on plasmonic-based heterojunction photocatalysts for degradation of organic pollutants in wastewater.

Organic pollutants in wastewater are the biggest problem facing the world today due to population growth, rapid increase in industrialization, urbanization, and technological advancement. There have been numerous attempts to use conventional wastewater treatment techniques to address the issue of worldwide water contamination. However, conventional wastewater treatment has a number of shortcomings, including high operating costs, low efficiency, difficult preparation, fast recombination of charge carriers, generation of secondary waste, and limited light absorption. Therefore, plasmonic-based heterojunction photocatalysts have attracted much attention as a promising method to reduce organic pollutant problems in water due to their excellent efficiency, low operating cost, ease of fabrication, and environmental friendliness. In addition, plasmonic-based heterojunction photocatalysts contain a local surface plasmon resonance that enhances the performance of photocatalysts by improving light absorption and separation of photoexcited charge carriers. This review summarizes the major plasmonic effects in photocatalysts, including hot electron, local field effect, and photothermal effect, and explains the plasmonic-based heterojunction photocatalysts with five junction systems for the degradation of pollutants. Recent work on the development of plasmonic-based heterojunction photocatalysts for the degradation of various organic pollutants in wastewater is also discussed. Lastly, the conclusions and challenges are briefly described and the direction of future development of heterojunction photocatalysts with plasmonic materials is explored. This review could serve as a guide for the understanding, investigation, and construction of plasmonic-based heterojunction photocatalysts for various organic pollutants degradation. Graphical abstract: Herein, the plasmonic effects in photocatalysts, such as hot electrons, local field effect, and photothermal effect, as well as the plasmonic-based heterojunction photocatalysts with five junction systems for the degradation of pollutants are explained. Recent work on plasmonic-based heterojunction photocatalysts for the degradation of various organic pollutants in wastewater such as dyes, pesticides, phenols, and antibiotics is discussed. Challenges and future developments are also described.

Development and Characterization of Drug Loaded PVA/PCL Fibres for Wound Dressing Applications.

Nowadays, synthetic polymers are used in medical applications due to their special biodegradable, biocompatible, hydrophilic, and non-toxic properties. The materials, which can be used for wound dressing fabrication with controlled drug release profile, are the need of the time. The main aim of this study was to develop and characterize polyvinyl alcohol/polycaprolactone (PVA/PCL) fibres containing a model drug. A dope solution comprising PVA/PCL with the drug was extruded into a coagulation bath and became solidified. The developed PVA/PCL fibres were then rinsed and dried. These fibres were tested for Fourier transform infrared spectroscopy, linear density, topographic analysis, tensile properties, liquid absorption, swelling behaviour, degradation, antimicrobial activity, and drug release profile for improved and better healing of the wound. From the results, it was concluded that PVA/PCL fibres containing a model drug can be produced by using the wet spinning technique and have respectable tensile properties; adequate liquid absorption, swelling %, and degradation %; and good antimicrobial activity with the controlled drug release profile of the model drug for wound dressing applications.