Irisin/BDNF signaling in the muscle-brain axis and circadian system: A review

In mammals,the timing of physiological,biochemical and behavioral processes over a 24-h period is controlled by circadian rhythms.To entrain the master clock located in the suprachiasmatic nucleus of the hypothalamus to a precise 24-h rhythm,environmental zeitgebers are used by the circadian system.This is done primarily by signals from the retina via the retinohypothalamic tract,but other cues like exercise,feeding,temperature,anxiety,and social events have also been shown to act as non-photic zeitgebers.The recently identified myokine irisin is proposed to serve as an entraining non-photic signal of exercise.Irisin is a product of cleavage and modification from its precursor membrane fibronectin typeⅢdomain-containing protein 5(FNDC5)in response to exercise.Apart from well-known peripheral effects,such as inducing the"browning"of white adipocytes,irisin can penetrate the blood-brain barrier and display the effects on the brain.Experimental data suggest that FNDC5/irisin mediates the positive effects of physical activity on brain functions.In several brain areas,irisin induces the production of brain-derived neurotrophic factor(BDNF).In the master clock,a significant role in gating photic stimuli in the retinohypothalamic synapse for BDNF is suggested.However,the brain receptor for irisin remains unknown.In the current review,the interactions of physical activity and the irisin/BDNF axis with the circadian system are reconceptualized.

Assessing pathological features of breast cancer via the multimodal information of multiphoton and Raman imaging

For unveiling the pathological evolution of breast cancer, nonlinear multiphoton microscopic(MPM) and confocal Raman microspectral imaging(CRMI) techniques were both utilized to address the structural and constitutional characteristics of healthy(H), ductal carcinoma in situ(DCIS), and invasive ductal carcinoma(IDC) tissues. MPM-based techniques,including two-photon excited fluorescence(TPEF) and second harmonic generation(SHG), visualized label-free and the fine structure of breast tissue. Meanwhile, CRMI not only presented the chemical images of investigated samples with the K-mean cluster analysis method(KCA), but also pictured the distribution of components in the scanned area through univariate imaging. MPM images illustrated that the cancer cells first arranged around the basement membrane of the duct,then proliferated to fill the lumens of the duct, and finally broke through the basement membrane to infiltrate into the stroma.Although the Raman imaging failed to visualize the cell structure with high resolution, it explained spectroscopically the gradual increase of nucleic acid and protein components inside the ducts as cancer cells proliferated, and displayed the distribution pattern of each biological component during the evolution of breast cancer. Thus, the combination of MPM and CRMI provided new insights into the on-site pathological diagnosis of malignant breast cancer, also ensured technical support for the development of multimodal optical imaging techniques for precise histopathological analysis.

Reconstructing in vivo spatially offset Raman spectroscopy of human skin tissue using a GPU-accelerated Monte Carlo platform

As one type of spatially offset Raman spectroscopy(SORS), inverse SORS is particularly suited to in vivo biomedical measurements due to its ring-shaped illumination scheme. To explain inhomogeneous Raman scattering during in vivo inverse SORS measurements, the light–tissue interactions when excitation and regenerated Raman photons propagate in skin tissue were studied using Monte Carlo simulation. An eight-layered skin model was first built based on the latest transmission parameters. Then, an open-source platform, Monte Carlo e Xtreme(MCX), was adapted to study the distribution of 785 nm excitation photons inside the model with an inverse spatially shifted annular beam. The excitation photons were converted to emission photons by an inverse distribution method based on excitation flux with spatial offsets Δs of 1 mm, 2 mm, 3 mm and 5 mm. The intrinsic Raman spectra from separated skin layers were measured by continuous linear scanning to improve the simulation accuracy. The obtained results explain why the spectral detection depth gradually increases with increasing spatial offset, and address how the intrinsic Raman spectrum from deep skin layers is distorted by the reabsorption and scattering of the superficial tissue constituents. Meanwhile, it is demonstrated that the spectral contribution from subcutaneous fat will be improved when the offset increases to 5 mm, and the highest detection efficiency for dermal layer spectral detection could be achieved when Δs = 2 mm. Reasonably good matching between the calculated spectrum and the measured in vivo inverse SORS was achieved, thus demonstrating great utility of our modeling method and an approach to help understand the clinical measurements.

Optical multiplexing techniques and their marriage for on-chip and optical fiber communication:a review

Herein,an attention-grabbing and up-to-date review related to major multiplexing techniques is presented which in-cludes wavelength division multiplexing(WDM),polarization division multiplexing(PDM),space division multiplexing(SDM),mode division multiplexing(MDM)and orbital angular momentum multiplexing(OAMM).Multiplexing is a mech-anism by which multiple signals are combined into a shared channel used to showcase the maximum capacity of the op-tical links.However,it is critical to develop hybrid multiplexing methods to allow enhanced channel numbers.In this re-view,we have also included hybrid multiplexing techniques such as WDM-PDM,WDM-MDM and PDM-MDM.It is prob-able to attain N×M channels by utilizing N wavelengths and M guided-modes by simply utilizing hybrid WDM-MDM(de)multiplexers.To the best of our knowledge,this review paper is one of its kind which has highlighted the most prom-inent and recent signs of progress in multiplexing techniques in one place.

Zener-Hollomon参数对含铁锻造铝合金热变形处理过程中亚结构和织构演变的影响（英文）

研究Zener-Hollomon参数对含铁锻造铝合金(AA8011)亚结构和织构演变的影响。采用X射线织构分析、电子背散射衍射(EBSD)和光学显微镜等技术进行表征。结果表明,Zener-Hollomon参数对含铁铝合金热变形处理过程中立方织构的演变具有显著影响。增大Zener-Hollomon参数会减少热变形过程中立方织构的数量,且能加强退火过程中的颗粒诱发形核(PSN)的能力。然而,低温热变形处理会导致活性沉淀,这些细而分散的颗粒会阻碍除了产生立方大晶粒的晶核外的所有晶核。综上,在含铁锻造铝合金中,Zener-Hollomon参数与亚晶粒尺寸之间的相关性与在3xxx系列合金中观察到的类似,可以用系列推导方程描述。

Variations in defect substructure and fracture surface of commercially pure aluminum under creep in weak magnetic field

Commercially pure polycrystalline aluminum of grade A85, as a test material, is investigated. Using scanning and transmission electron microscopy the aluminum fine structure and fracture surface are analyzed. Fractures are studied in the regime of creep with and without a simultaneous effect of 0.3-T magnetic field. It is found that the application of a magnetic field in a linear stage of creep leads to substructure imperfection increasing. Furthermore, the magnetic field effect on aluminum in the process of creep causes the average scalar density of dislocations to increase and induces the process of dislocation loop formation to strengthen. Fractographic investigation of the fracture surface shows that in the fibrous fracture zone the average size of plastic fracture pits decreases more than twice under creep in the condition of external magnetic field compared with in the conventional experimental condition. In a shear zone, the magnetic field causes the average size of fracture pits to decrease. Experimental data obtained in the research allow us to conclude that the magnetic field effect on aluminum in the process of creep leads to the fracture toughness value of the material decreasing, which will affect the state of defect substructure of the volume and surface layer of the material. The influence of the magnetic field is analyzed on the basis of the magneto-plasticity effect.

Countering DNS Amplification Attacks Based on Analysis of Outgoing Traffic

Domain name system(DNS)amplification distributed denial of service(DDoS)attacks are one of the popular types of intrusions that involve accessing DNS servers on behalf of the victim.In this case,the size of the response is many times greater than the size of the request,in which the source of the request is substituted for the address of the victim.This paper presents an original method for countering DNS amplification DDoS attacks.The novelty of our approach lies in the analysis of outgoing traffic from the victim’s server.DNS servers used for amplification attacks are easily detected in Internet control message protocol(ICMP)packet headers(type 3,code 3)in outgoing traffic.ICMP packets of this type are generated when accessing closed user datagram protocol(UDP)ports of the victim,which are randomly assigned by the Saddam attack tool.To prevent such attacks,we used a Linux utility and a software-defined network(SDN)module that we previously developed to protect against port scanning.The Linux utility showed the highest efficiency of 99.8%,i.e.,only two attack packets out of a thousand reached the victim server.

Bound states in the continuum and high-Q resonances supported by a dielectric ridge on a slab waveguide

We investigate the diffraction of the guided modes of a dielectric slab waveguide on a simple integrated structure consisting of a single dielectric ridge on the surface of the waveguide. Numerical simulations based on aperiodic rigorous coupled-wave analysis demonstrate the existence of sharp resonant features and bound states in the continuum(BICs) in the reflectance and transmittance spectra occurring at the oblique incidence of a transverseelectric(TE)-polarized guided mode on the ridge. Using the effective index method, we explain the resonances by the excitation of cross-polarized modes of the ridge. Formation of the BICs are confirmed using a theoretical model based on coupled-wave theory. The model suggests that the BICs occur due to the coupling of quasi-TE and quasi-transverse-magnetic modes of the structure. Simple analytical expressions for the angle of incidence and the ridge width predicting the location of the BICs are obtained. The existence of high-Q resonances and BICs enables using the considered integrated structure for sensing, transformation of optical signals, and enhancing nonlinear light–matter interactions. Due to the Lorentzian line shape of the resonances near the BICs, the structure is also promising for filtering applications.

Two-groove narrowband transmission filter integrated into a slab waveguide

We propose a simple integrated narrowband filter consisting of two grooves on the surface of a slab waveguide.Spectral filtering is performed in transmission at oblique incidence due to excitation of an eigenmode of the structure localized at a ridge cavity between the grooves. For the considered parameters, zero reflectance and unity transmittance are achieved at resonant conditions. The width and location of the transmittance peak can be controlled by changing the widths of the grooves and of the ridge, respectively. The proposed filter may find application in waveguide-integrated spectrometers.

Highly Sensitive Refractive Index Sensor Based on Plasmonic Bow Tie Configuration

We propose a highly refractive index sensor based on plasmonic Bow Tie configuration.The sensitivity of the resonator design is enhanced by incorporating a nanowall(NW)in a modified Bow Tie design where sharp tips of V-junction are flattened.This approach provides high confinement of electric field distribution of surface plasmon polariton(SPP)mode in the narrow region of the cavity.Consequently,the effective refractive index(neff)of the mode increases and is highly responsive to the ambient medium.The sensitivity analysis of the SPP mode is calculated for six resonator schemes.The results suggest that the NW embedded cavity offers the highest mode sensitivity due to the large shift of effective index when exposed to a slight change in the medium refractive index.Moreover,the device sensitivity of the proposed design is approximated at 2300 nm/RIU which is much higher than the sensitivity of the standard Bow Tie configuration.

Mathematical formalization of the process of crossing individuals of different populations within the framework of the quasispecies model

This paper presents a mathematically formalized description of the process of crossing individuals of different populations as a break of the first kind of functional dependencies of the population state vector components.In this case,the validity of the quasispecies model as a model of population development was assumed.The practical interpretation of a mathematically formalized description is considered on the example of an artificial population of Lymantria dispar.The results of the work can be used to assess the development parameters of both natural and artificial populations.

Integrated flat-top reflection filters operating near bound states in the continuum

We propose and theoretically and numerically investigate narrowband integrated filters consisting of identical resonant dielectric ridges on the surface of a single-mode dielectric slab waveguide. The proposed composite structures operate near a bound state in the continuum(BIC) and enable spectral filtering of transverseelectric-polarized guided modes propagating in the waveguide. We demonstrate that by proper choice of the distances between the ridges, flat-top reflectance profiles with steep slopes and virtually no sidelobes can be obtained using just a few ridges. In particular, the structure consisting of two ridges can optically implement the second-order Butterworth filter, whereas at a larger number of ridges, excellent approximations to higher-order Butterworth filters can be achieved. Owing to the BIC supported by the ridges constituting the composite structure, the flat-top reflection band can be made arbitrarily narrow without increasing structure size. In addition to the filtering properties, the investigated structures support another type of BIC-the Fabry–Perot BIC-arising when the distances between adjacent ridges meet the Fabry–Perot resonance condition. In the vicinity of the Fabry–Perot BIC, an effect similar to electromagnetically induced transparency is observed, namely, sharp transmittance peaks against the background of a wide transmittance dip.

Influence of non-equilibrium reactions on the optimization of aerothrust aeroassisted maneuver with orbital change

The spaceplane is perspective vehicle due to wide maneuverability in comparison with a space capsule. Its maneuverability is expressed by the larger flight range and also by a possibility to rotate orbital inclination in the atmosphere by the aerodynamic and thrust forces. Orbital plane atmospheric rotation maneuvers can significantly reduce fuel costs compared to rocket-dynamic non-coplanar maneuver. However, this maneuver occurs at Mach numbers about 25, and such velocities lead to non-equilibrium chemical reactions in the shock wave. Such reactions change a physicochemical air property, and it affects aerodynamic coefficients. This paper investigates the influence of non-equilibrium reactions on the aerothrust aeroassisted maneuver with orbital change.The approach is to solve an optimization problem using the differential evolution algorithm with a temperature limitation. The spaceplane aerodynamic coefficients are determined by the numerical solution of the Reynolds-averaged Navier-Stokes equations. The aerodynamic calculations are conducted for the cases of perfect and non-equilibrium gases. A comparison of optimal trajectories,control laws, and fuel costs is made between models of perfect and non-equilibrium gases. The effect of a chemically reacting gas on the finite parameters is also evaluated using control laws obtained for a perfect gas.

The effect analysis of the diapause duration on the hatching parameters of the artificial semi-annual population of Lymantria dispar caterpillars

The paper investigates the existence of a relationship between the diapause duration and the temperature threshold of hatching,the variances in temperature and hatching time of the artificial six-month population of Lymantria dispar caterpillars.A half-year population gives two generations a year under artificial conditions.A comparative analysis of these parameters with similar parameters of the hybrid population of L.dispar,as well as studies by other authors,has been carried out.The Eigen quasispecies model was used for the mathematical formalization of the evolution process.The results of this work can be used to study the evolution of L.dispar.

Estimate of parameters changing of the Lymantria dispar artificial population in different environmental conditions using the quasispecies model

This paper gives an interpretation of the quasispecies concept for an experiment of growing the Lymantria dispar artificial population.The changes estimate in the population parameters for a significant change in environmental conditions at the stage of hatching caterpillars from the eggs was given.Three numerical and two random parameters were used for quantitative analysis.They characterize the development of individuals of the population at this stage.The parameter changes significance was verified with using statistical tests.The results obtained do not contradict the quasispecies model.The use of fuzzy sets describes the transition from one quasispecies to another at a significant change in environmental conditions.

On the Local Solvability and Stability for the Inverse Spectral Problem of the Generalized Dirichlet–Regge Problem

For the generalized Dirichlet–Regge problem with complex coefficients,we prove the local solvability and stability for the inverse spectral problem,which indicates an improved result of the previous work([Journal of Geometry and Physics,159,103936(2021)]).

The inverse problem for differential pencils on a star-shaped graph with mixed spectral data

The partial inverse problem for differential pencils on a star-shaped graph is studied from mixed spectral data.More precisely,we show that if the potentials on all edges on the star-shaped graph but one are known a priori then the unknown potential on the remaining edge can be uniquely determined by partial information on the potential and a part of eigenvalues.

Polarization-Insensitive Hybrid Plasmonic Waveguide Design for Evanescent Field Absorption Gas Sensor

We propose a polarization-insensitive design of a hybrid plasmonic waveguide(HPWG)optimized at the 3.392µm wavelength which corresponds to the absorption line of methane gas.The waveguide design is capable of providing high mode sensitivity(Smode)and evanescent field ratio(EFR)for both transverse electric(TE)and transverse magnetic(TM)hybrid modes.The modal analysis of the waveguide is performed via 2-dimension(2D)and 3-dimension(3D)finite element methods(FEMs).At optimized waveguide parameters,Smode and EFR of 0.94 and 0.704,can be obtained for the TE hybrid mode,respectively,whereas the TM hybrid mode can offer Smode and EFR of 0.86 and 0.67,respectively.The TE and TM hybrid modes power dissipation of~3 dB can be obtained for a 20-µm-long hybrid plasmonic waveguide at the 60%gas concentration.We believe that the highly sensitive waveguide scheme proposed in this work overcomes the limitation of the polarization controlled light and can be utilized in gas sensing applications.

Simulating the stress–strain state of a thin plate after a thermal shock

The paper is devoted to simulating the impact of a thermal shock on a thin homogeneous plate in the ANSYS package.The assessment of the stress–strain state is carried out and the dynamics of changes in the temperature field of the plate is determined.The obtained results were compared with the data of other authors and can be used when taking into account the thermal shock of large elastic elements of spacecraft.

Holography with high-power CW coherent terahertz source: optical components, imaging, and applications

This paper presents the results of 15 years of studies in the field of terahertz holography at the Novosibirsk free electron laser.They cover two areas:research on obtaining holographic images in the terahertz range and the use of diffractive optical elements to form high-power terahertz radiation fields with specified characteristics(intensity,phase,and polarization),using well-studied and widely applied in the optical range methods of optical(analog),digital,and computer-generated holography.All experiments were performed with the application of high-power coherent monochromatic frequency-tunable radiation from the Novosibirsk free electron laser.The features of hologram registration in the terahertz range are described.Methods,technologies,and optical materials for terahertz holographic elements are discussed.A wide range of promising applications of high-power terahertz fields with a given spatial structure is considered.The results of the study of terahertz holograms recorded as digital holograms,as well as radiation-resistive optical elements realized as computer-synthesized holograms,are presented.