Comprehensive investigation of HBV-related hepatocellular carcinoma and choice of anti-HBV therapy

Chronic hepatitis B virus(HBV)infection is a global public health problem,which can cause chronic hepatitis,liver cirrhosis,hepatocellular carcinoma(HCC),and other diseases.Antiviral therapy is the most critical measure to slow down the progression of chronic hepatitis B,prevent or delay cirrhosis,HCC,and other kinds of liver decompensation events.At present,the anti-hepatitis B virus drugs are mainly nucleoside(acid)analogues(NAs)and interferon.Each kind of antiviral drug has different effects on the clinical outcome of hepatitis B patients(such as HCC).In this paper,we discussed the biological characteristics,natural course and prognosis of HBV infection,the mechanism of HBV-related HCC,the effect of different antiviral drugs on patients’outcome,predictive biomarkers and model for HBV clinical outcome,predictors of sustained response and recurrence after withdrawal of antiviral therapy,consideration of expanding therapeutic indications and antiviral therapy,hoping to give a hand to the clinical diagnosis and treatment of HBV.

Side Polished Fiber:A Versatile Platform for Compact Fiber Devices and Sensors

Side polished fiber(SPF)has a controllable average roughness and length of the side-polishing region,which becomes a versatile platform for integrating multiple materials to interact with the evanescent field to fabricate all-fiber devices and sensors.It has been widely used in couplers,filters,polarizers,optical attenuators,photodetectors,modulators,and sensors for temperature,humidity,strain,biological molecules,chemical gas,and vector magnetic monitoring.In this article,an overview of the development history,fabrication techniques,fiber types,transmission characteristics,and varied recent applications of SPFs are reviewed.Firstly,the fabrication techniques of SPFs are reviewed,including the V-groove assisted polishing technique and wheel polishing technique.Then,the different types of SPFs and their characteristics are discussed.Finally,various applications of SPFs are discussed and concluded theoretically and experimentally,including their principles and structures.When designing the device,the residual thickness and polishing lengths of the SPF need to be appropriately selected in order to obtain the best performance.Developing all-fiber devices and sensors is aimed at practical usability under harsh environments and allows to avoid the high coupling loss between optical fibers and on-chip integrated devices.

Early Serum HBsAg Kinetics as Predictor of HBsAg Loss in Patients with HBeAg-Negative Chronic Hepatitis B after Treatment with Pegylated Interferonα-2a

Hepatitis B surface antigen(HBsAg)loss is an ideal treatment endpoint for patients with chronic hepatitis B(CHB).We investigated the predictive value of on-treatment HBsAg levels for HBsAg loss in hepatitis B e antigen(HBe Ag)-negative CHB patients who received 120-week PEG-IFNα-2a treatment.Serum HBV DNA,HBsAg,and anti-HBs levels were assayed at baseline and every 3 months during the treatment.Of 81 patients,12 achieved HBsAg loss,20 achieved HBsAg\100 IU/mL,and 49 maintained HBs Ag C 100 IU/mL.HBsAg loss rate was only 3.7%at 48 weeks,while it reached to 11.1%and 14.8%after treatment of 96 weeks and 120 weeks.The cutoff HBs Ag levels at 12 weeks predicting HBsAg loss at 96 weeks and 120 weeks of treatment were 400 IU/mL and 750 IU/mL,with AUC 0.725 and 0.722,positive predictive value(PPV)29.41%and 30.56%,and negative predictive value(NPV)93.75%and 97.78%,respectively.The cutoff HBsAg levels at 24 weeks predicting HBsAg loss at 96 weeks and 120 weeks of treatment were 174 IU/m L and 236 IU/mL respectively,with AUC 0.925 and 0.922,PPV 40.0%and 46.15%,and both NPV 100%.The predictive ability of the cutoff HBsAg levels at 24 weeks was better than that at 12 weeks for HBs Ag loss at either 96 or 120 weeks(χ~2=3.880,P=0.049 andχ~2=4.412,P=0.036).These results indicate that extended therapy is critical to HBsAg loss in HBe Ag-negative CHB patients during PEG-IFN treatment,and the HBsAg level at 24 weeks can be used to predict HBsAg loss during tailoring PEG-IFN therapy.

Magnetic spin–orbit interaction of light

We study the directional excitation of optical surface waves controlled by the magnetic field of light.We theoretically predict that a spinning magnetic dipole develops a tunable unidirectional coupling of light to transverse electric(TE)polarized Bloch surface waves(BSWs).Experimentally,we show that the helicity of light projected onto a subwavelength groove milled into the top layer of a 1D photonic crystal(PC)controls the power distribution between two TE-polarized BSWs excited on both sides of the groove.Such a phenomenon is shown to be solely mediated by the helicity of the magnetic optical field,thus revealing a magnetic spin-orbit interaction of light.Remarkably,this magnetic optical effect is clearly observed via a near-field coupler governed by an electric dipole moment:it is of the same order of magnitude as the electric optical effects involved in the coupling.This opens up new degrees of freedom for the manipulation of light and offers desirable and novel opportunities for the development of integrated optical functionalities.

Sensitivity-enhanced surface plasmon resonance sensor utilizing a tungsten disulfide (WS_2) nanosheets overlayer

Tungsten disulfide(WS_2), as a representative layered transition metal dichalcogenide(TMDC) material, possesses important potential for applications in highly sensitive sensors. Here, a sensitivity-enhanced surface plasmon resonance(SPR) sensor with a metal film modified by an overlayer of WS_2 nanosheets is proposed and demonstrated. The SPR sensitivity is related to the thickness of the WS_2 overlayer, which can be tailored by coating a WS_2 ethanol suspension with different concentrations or by the number of times of repeated post-coating.Benefitting from its large surface area, high refractive index, and unique optoelectronic properties, the WS_2 nanosheet overlayer coated on the gold film significantly improves the sensing sensitivity. The highest sensitivity(up to 2459.3 nm∕RIU) in the experiment is achieved by coating the WS_2 suspension once. Compared to the case without a WS_2 overlayer, this result shows a sensitivity enhancement of 26.6%. The influence of the WS_2 nanosheet overlayer on the sensing performance improvement is analyzed and discussed. Moreover, the proposed WS_2 SPR sensor has a linear correlation coefficient of 99.76% in refractive index range of 1.333 to 1.360. Besides sensitivity enhancement, the WS_2 nanosheet overlayer is able to show additional advantages, such as protection of metal film from oxidation, tunability of the resonance wavelength region, biocompatibility, capability of vapor,and gas sensing.

Resonant enhancement of second harmonic generation in etchless thin film lithium niobate heteronanostructure

Lithium niobate has received interest in nonlinear frequency conversion due to its wide transparency window,from ultraviolet to mid-infrared spectral regions,and large second-order nonlinear susceptibility.However,its nanostructure is generally difficult to etch,resulting in low-Q resonance and lossy nanostructures for second harmonic generation.By applying the concept of bound states in the continuum,we performed theoretical and experimental investigations on high-Q resonant etchless thin-film lithium niobate with Si O_(2) nanostructures on top for highly efficient second harmonic generation.In the fabricated nanostructured devices,a resonance with a Q factor of 980 leads to the strong enhancement of second harmonic generation by over 1500 times compared with that in unpatterned lithium niobate thin film.Although the pump slightly deviates from central resonance,an absolute conversion efficiency of 6.87×10^(-7) can be achieved with the fundamental pump peak intensity of 44.65 MW/cm^(2),thus contributing to the normalized conversion efficiency of 1.54×10^(-5)cm^(2)/GW.Our work establishes an etchless lithium niobate device for various applications,such as integrated nonlinear nanophotonics,terahertz frequency generation,and quantum information processing.

Optimized weak measurement of orbital angular momentum-induced beam shifts in optical reflection

Tiny but universal beam shifts occur when a polarized light beam is reflected upon a planar interface.Although the beam shifts of Gaussian beams have been measured by the weak measurement technique, the weak measurement for orbital angular momentum(OAM)-induced spatial shifts of vortex beams is still missing.Here, by elaborately choosing the preselection and postselection states, the tiny OAM-induced Goos–H?nchen and Imbert–Fedorov shifts are amplified at an air–prism interface. The maximum shifts along directions both parallel and perpendicular to the incident plane are theoretically predicted and experimentally verified with optimal preselection and postselection states. These maximum shifts can be used to determine the OAM of vortex beams.

Subwavelength polarization optics via individual and coupled helical traveling-wave nanoantennas

Light polarization control is a key factor in modern photonics.Recent advances in surface plasmon manipulation have introduced the prospect of more compact and more efficient devices for this purpose.However,the current plasmonic-based polarization optics remain much larger than the wavelength of light,which limits the design degrees of freedom.Here,we present a plasmonic traveling-wave nanoantenna using a gold-coated helical carbon nanowire end-fired with a dipolar aperture nanoantenna.Our nonresonant helical nanoantenna enables tunable polarization control by swirling surface plasmons on the subwavelength scale and taking advantage of the optical spin–orbit interaction.Four closely packed helical traveling-wave nanoantennas(HTNs)are demonstrated to locally convert an incoming light beam into four beams of tunable polarizations and intensities,with the ability to impart different polarization states to the output beams in a controllable way.Moreover,by near-field coupling four HTNs of opposite handedness,we demonstrate a subwavelength waveplate-like structure providing a degree of freedom in polarization control that is unachievable with ordinary polarization optics and current metamaterials.

Tunable spin splitting of Laguerre–Gaussian beams in graphene metamaterials

Optical spin splitting has attracted significant attention owing to its potential applications in quantum information and precision metrology. However, it is typically small and cannot be controlled efficiently. Here, we enhance the spin splitting by transmitting higher-order Laguerre–Gaussian(LG) beams through graphene metamaterial slabs. The interaction between LG beams and metamaterial results in an orbital-angularmomentum-(OAM) dependent spin splitting. The upper bound of the OAM-dependent spin splitting is found,which varies with the incident OAM and beam waist. Moreover, the spin splitting can be flexibly tuned by modulating the Fermi energy of the graphene sheets. This tunable spin splitting has potential applications in the development of spin-based applications and the manipulation of mid-infrared waves.

Ultra-compact on-chip slot Bragg grating structure for small electric field detection

In this paper, we present an ultra-compact 1D photonic crystal(Ph C) Bragg grating design on a thin film lithium niobate slot waveguide(SWG) via 2D-and 3D-FDTD simulations. 2D-FDTD simulations are employed to tune the photonic bandgap(PBG) size, PBG center, cavity resonance wavelength, and the whole size of Ph C. 3DFDTD simulations are carried out to model the real structure by varying different geometrical parameters such as SWG height and Ph C size. A moderate resonance quality factor Q of about 300 is achieved with a Ph C size of only 0.5 μm× 0.7 μm× 6 μm. The proposed slot Bragg grating structure is then exploited as an electric field(E-field) sensor. The sensitivity is analyzed by 3D-FDTD simulations with a minimum detectable E-field as small as 23 m V∕m. The possible fabrication process of the proposed structure is also discussed. The compact size of the proposed slot Bragg grating structure may have applications in on-chip E-field sensing, optical filtering, etc.

Resonance-assisted light–control–light characteristics of SnS_2 on a microfiber knot resonator with fast response

An all-optical light–control–light functionality with the structure of a microfiber knot resonator (MKR) coated with tin disulfide (SnS_2) nanosheets is experimentally demonstrated. The evanescent light in the MKR [with a resonance Q of ～59,000 and an extinction ratio (ER) of ～26 dB] is exploited to enhance light–matter interaction by coating a two-dimensional material SnS_2 nanosheet onto it. Thanks to the enhanced light–matter interaction and the strong absorption property of SnS_2, the transmitted optical power can be tuned quasi-linearly with an external violet pump light power, where a transmitted optical power variation rate ΔT with respect to the violet light power of ～0.22 dB∕mW is obtained. In addition, the MKR structure possessing multiple resonances enables a direct experimental demonstration of the relationship between resonance properties (such as Q and ER), and the obtained ΔT variation rate with respect to the violet light power. It verifies experimentally that a higher resonance Q and a larger ER can lead to a higher ΔT variation rate. In terms of the operating speed, this device runs as fast as ～3.2 ms. This kind of all-optical light–control–light functional structure may find applications in future all-optical circuitry, handheld fiber sensors, etc.

Emerging electrochemical sensors for life healthcare

As electrochemical sensors possess unique potential properties that are strongly related to their high sensitiv-ity,selectivity and cycling stability,making it extensively used in versatile fields of biosensing,electrochemical analysis and drug delivery.Notably,recent evidence demonstrates that electrochemical technology provides a promising platform for life healthcare by biocompatibility of mimicking human tissue to report electrical signals,potentially enabling timely disorder prediction through non-invasive real time and simultaneous health monitoring.This review focuses on the comprehensive set of advances in the field of electrochemical devices for life healthcare,including fabrication,analytical performance,and their multiple applications in clinical settings are deliberated.