Assessing the Effectiveness of a Cervical Cancer Screening Program in a Hospital-based Study

This study compared HPV testing and liquid-based cytology （LCT） as performance indicators for cervical cancer screening in a hospital-based study. A total of 61,193 outpatients were screened initially by LCT. Samples with screening results showing atypical squamous cells of undetermined significance （ASC-US） or worse were referred for colposcopy, and some samples were tested for high-risk HPV types with the Hybrid Capture II system （HC II）. Data on LCT （n=61,193） and HC II （n=1056） results were analysed. Overall test positivity for LCT was 2.53% using an ASC-US threshold, 3.11% using a low-grade squamous intraepithelial lesion （LSIL） threshold, and 0.67% using a high-grade squamous intraepithelial lesion （HSIL） threshold. A total of 1839 women （84% of the 3893 patients with abnormal cytology） underwent colposcopy-directed biopsy. HPV was positive in 80.3% of women with cervical intraepithelial neoplasia 1 （CIN1）, 88.3% of those with CIN2, 79.2% of women with CIN3 and 50% （2 of 4） of women with invasive cancer. There was a significant increase in the detection of CIN2 or worse with adjunct HPV testing of women with ASC-US and LSIL However, there were detection of CIN2＋ cases no differences in the with adjunct HPV testing of women with HSlI.. The results indicate that HPV testing for HSlL triage should not be recommended in cervical cancer screening.

The effect of dynamical screening on helium(e,2e) fully differential cross-sections

This paper presents the fully differential cross sections （FDCS） for 102eV electron impact single ionization of helium for both the coplanar and perpendicular plane asymmetric geometries within the framework of dynamically screened three-Coulomb-wave theory. Comparisons are made with the experimental data and those of the three-Coulomb wave function model and second-order distorted-wave Born method. The angular distribution and relative heights of the present FDCS is found to be in very good agreement with the experimental data in the perpendicular plane geometry. It is shown that dynamical screening effects are significant in this geometry. Three-body coupling is expected to be weak in the coplanar geometry, although the precise absolute value of the cross section is still sensitive to the interaction details.

Application of the homotopy analysis method to nonlinear characteristics of a piezoelectric semiconductor fiber

Based on the nonlinear constitutive equation,a piezoelectric semiconductor(PSC)fiber under axial loads and Ohmic contact boundary conditions is investigated.The analytical solutions of electromechanical fields are derived by the homotopy analysis method(HAM),indicating that the HAM is efficient for the nonlinear analysis of PSC fibers,along with a rapid rate of convergence.Furthermore,the nonlinear characteristics of electromechanical fields are discussed through numerical results.It is shown that the asymmetrical distribution of electromechanical fields is obvious under a symmetrical load,and the piezoelectric effect is weakened by an applied electric field.With the increase in the initial carrier concentration,the electric potential decreases,and owing to the screen-ing effect of electrons,the distribution of electromechanical fields tends to be symmetrical.

Nonlinear magneto-mechanical-thermo coupling characteristic analysis for transport behaviors of carriers in composite multiferroic piezoelectric semiconductor nanoplates with surface effect

In this paper,to better reveal the surface effect and the screening effect as well as the nonlinear multi-field coupling characteristic of the multifunctional piezoelectric semiconductor(PS)nanodevice,and to further improve its working performance,a magneto-mechanical-thermo coupling theoretical model is theoretically established for the extensional analysis of a three-layered magneto-electro-semiconductor coupling laminated nanoplate with the surface effect.Next,by using the current theoretical model,some numerical analyses and discussion about the surface effect,the corresponding critical thickness of the nanoplate,and the distributions of the physical fields(including the electron concentration perturbation,the electric potential,the electric field,the average electric displacement,the effective polarization charge density,and the total charge density)under different initial state electron concentrations,as well as their active manipulation via some external magnetic field,pre-stress,and temperature stimuli,are performed.Utilizing the nonlinear multi-field coupling effect induced by inevitable external stimuli in the device operating environment,this paper not only provides theoretical support for understanding the size-dependent tuning/controlling of carrier transport as well as its screening effect,but also assists the design of a series of multiferroic PS nanodevices.

Stability of the positively charged manganese centre in GaAs heterostructures examined theoretically by the effective mass approximation calculation near the Γ critical point

This paper describes an n-i-p-i-n model heterostructure with a manganese （Mn）-doped p-type base region to check the stability of a positively charged manganese A＋Mn centre with two holes weakly bound by a negatively charged 3dS（Mn） core of a local spin S = 5/2 in the framework of the effective mass approximation near the F critical point （k -0）. By including the carrier screening effect, the ground state energy and the binding energy of the second hole in the positively charged centre A＋Mn are calculated within a hole concentration range from 1 ×10^16 cm-3 to 1 × 10^17 cm^-3, which is achievable by biasing the structure under photo-excitation. For comparison, the ground-state energy of a single hole in the neutral AMn centre is calculated in the same concentration range. It turns out that the binding energy of the second hole in the A＋Mn centre varies from 9.27 meV to 4.57 meV. We propose that the presence of the A＋Mn centre can be examined by measuring the photoluminescence from recombination of electrons in the conduction band with the bound holes in the A＋Mn centre since a high frequency dielectric constant of ε∞ = 10.66 can be safely adopted in this case. The novel feature of the ability to tune the impurity level of the A＋Mn centre makes it attractive for optically and electrically manipulating local magnetic spins in semiconductors.

Edge and Core Impurity Transport Study With Spectroscopic Instruments in LHD

Impurity transport was investigated at both edge and core regions in large helical de- vice （LHD） with developed spectroscopic instruments which can measure one- and two-dimensional distributions of impurities. The edge impurity behavior was studied recently using four carbon resonant transitions in different ionization stages of CIII （977A）, CIV （1548A）, CV （40.3A） and CVI （33.7A）. When the line-averaged electron density, ne, is increased from 1 to 6 × 10^13 cm-3, the ratio of （CIII^CIV）/ne increases while the ratio of （CV＋CVI）/ne decreases. Here, CIII^CIV （CV＋CVI） expresses the sum of CIII （CV） and CIV （CVI） intensities. The CIII＋CIV indicates the carbon influx and the CV＋CVI indicates the emissions through the transport in the ergodic layer. The result thus gives experimental evidence on the impurity screening by the ergodic layer in LHD, which is also supported by a three-dimensional edge particle simulation. The core impu- rity behavior is also studied in high-density discharges （ne 〈 1 × 10^15 cm 3） with multi H2-pellets injection. It is found that the ratio of V/D （V： convection velocity, D： diffusion coefficient） decreases after pellet injection and Zeff profile shows a flat one at values of 1.1,-1.2. These results confirm no impurity accumulation occurs in high-density discharges. As a result, the iron density, rife, is analyzed to be 6 × 10^-7（=- nFe/ne） of which the amount can be negligible as radiation source even in such high-density discharges. One- and two-dimensional impurity distributions from space-resolved VUV and EUV spectrometers newly developed for further impurity transport study are also presented with their preliminary results.

Instantly Investigating the Adsorption of Polymeric Corrosion Inhibitors on Magnesium Alloys by Surface Analysis under Ambient Conditions

Surface engineering of magnesium alloys requires adequate strategies, processes and materials permitting corrosion protection. Liquid formulations containing corrosion inhibitors often are to be optimized according to the demands of the respective substrate and following the service conditions during its application. As an interdisciplinary approach, a combination of several techniques for instantly monitoring or elaborately analyzing the surface state of magnesium was accomplished in order to characterize the performance of new adsorbing sustainable amphiphilic polymers which recently were developed to facilitate a multi-metal corrosion protection approach. The application of established techniques like Contact Angle measurements and X-ray Photoelectron Spectroscopy investigations was supplemented by introducing related and yet faster online-capable and larger-scale techniques like Aerosol Wetting Test and Optically Stimulated Electron Emission. Moreover, an inexpensive setup was configured for scaling the inset and the extent of degradation processes which occur at local electrochemical circuits and lead to hydrogen bubble formation. Using these analytical tools, changes of the surface state of emeried AM50 samples were investigated. Even in contact with water, being a moderate corrosive medium, the online techniques facilitated detecting surface degradation of the unprotected magnesium alloy within some seconds. In contrast, following contact with a 1 weight% formulation of a polymeric corrosion inhibitor, surface monitoring indicated a delay of the onset of degradation processes by approximately two orders of magnitude in time. Mainly based on the spectroscopic investigations, the corrosion inhibiting effects of the investigated polymer are attributed to the adsorption of a primary polymer layer with a thickness of a few nanometers which occurs within some seconds. Immersion of magnesium for several hours brings up a protective film with around ten nanometers thickness.

The enhanced performance of piezoelectric nanogenerator via suppressing screening effect with Au particles/ZnO nanoarrays Schottky junction

This paper describes a novel strategy to weaken the piezopotential screening effect by forming Schottky junctions on the ZnO surface through the introduction of Au particles onto the surface. With this approach, the piezoelectric-energyconversion performance was greatly enhanced. The output voltage and current density of the Au@ZnO nanoarray-based piezoelectric nanogenerator reached 2 V and 1 μA/cm^2, respectively, 10 times higher than the output of pristine ZnO nanoarray-based piezoelectric nanogenerators. We attribute this enhancement to dramatic suppression of the screening effect due to the decreased carrier concentration, as determined by scanning Kelvin probe microscope measurements and impedance analysis. The lowered capacitance of the Au@ZnO nanoarraybased piezoelectric nanogenerator also contributes to the improved output. This work provides a novel method to enhance the performance of piezoelectric nanogenerators and possibly extends to piezotronics and piezophototronics.

Effect of carrier screening on ZnO-based resistive switching memory devices

The carrier screening effect occurs commonly in dielectric materials. It reduces the electric potential gradient, thus negatively affecting the functionality of resistive random access memory （RRAM） devices. An Au/ZnO film/Al-doped ZnO device fabricated in this work exhibited no resistive switching （RS）, which was attributed to the carrier screening effect. Therefore, annealing was used for alleviating the screening effect, significantly enhancing the RS property. In addition, different on/off ratios were obtained for various bias values, and the screening effect was accounted for by investigating electron transport mechanisms. Furthermore, different annealing temperatures were employed to modulate the free carrier concentration in ZnO films to alleviate the screening effect. The maximal on/off ratio reached 10s at an annealing temperature of 600 ℃, yielding the lowest number of free carriers and the weakest screening effect in ZnO films. This work investigates the screening effect in RS devices. The screening effect not only modulates the characteristics of memory devices but also provides insight into the mechanism of RS in these devices.

Illumination-dependent free carrier screening effect on the performance evolution of ZnO piezotronic strain sensor

Performance modulation of ZnO optoelectronic devices in the presence of proper piezoelectric polarization charges has been widely reported, whereas relatively less work has been performed about the influence of photoexcitation on piezotronics. In this stud~ we experimentally investigated the performance evolution of ZnO piezotronic strain sensor under various 365 nm UV irradiation densities. The device demonstrated a response ratio of -200 under no illumination and under -0.53% compressive strain, and the response time is approximately 0.3 s. However, tremendous performance degradation was observed with the increase in the illumination densi~, which is attributed to the W-modulated change in the free electron concentration and Schottky barrier height. It was observed that increased carrier density intensifies the screening effect and thus, the modulation ability of piezo-polarization charges weakens. Meanwhile, the deterioration of rectifying behavior at the interface under UV illumination also jeopardizes the device performance.

Screening effects on ^(12)C+^(12)C fusion reaction

One of the important reactions for nucleosynthesis in the carbon burning phase in high-mass stars is the12C+12C fusion reaction. In this study, we investigate the influences of the nuclear potentials and screening effect on astrophysically interesting12C+12C fusion reaction observables at sub-barrier energies by using the microscopic α-αdouble folding cluster(DFC) potential and the proximity potential. In order to model the screening effects on the experimental data, a more general exponential cosine screened Coulomb(MGECSC) potential including Debye and quantum plasma cases has been considered in the calculations for the12C+12C fusion reaction. In the calculations of the reaction observables, the semi-classical Wentzel-Kramers-Brillouin(WKB) approach and coupled channel(CC)formalism have been used. Moreover, in order to investigate how the potentials between12C nuclei produce molecular cluster states of24Mg, the normalized resonant energy states of24Mg cluster bands have been calculated for the DFC potential. By analyzing the results produced from the fusion of12C+12C, it is found that taking into account the screening effects in terms of MGECSC is important for explaining the12C+12C fusion data, and the microscopic DFC potential is better than the proximity potential in explaining the experimental data, also considering that clustering is dominant for the structure of the24Mg nucleus.

Non-desolvation Zn^(2+)storage mechanism enables MoS_(2)anode with enhanced interfacial charge-transfer kinetics for low temperature zinc-ion batteries

The emerging rocking-chair aqueous zinc-ion battery(AZIB)configuration provides a promising approach for realizing their practical applications by avoiding the critical drawbacks of Zn metal anodes including unsatisfactory Coulombic efficiency and low Zn utilization.Therefore,exploiting appropriate insertion-type anodes with fast charge-transfer kinetics is of great importance,and many modifications focusing on the improvement of electron transport and bulk Zn^(2+)diffusion have been proposed.However,the interfacial Zn^(2+)transfer determined by the desolvation process actually dominates the kinetics of overall battery reactions,which is mainly overlooked.Herein,the interlayer structure of Mo S_(2)is rationally co-intercalated with water and ethylene glycol(EG)molecules(Mo S2@EG),giving rise to a fast non-desolvation Zn^(2+)storage mechanism,which is verified by the extraordinarily smaller activation energy of interfacial Zn^(2+)transfer(4.66 k J mol^(-1))compared with that of pristine Mo S_(2)(56.78 k J mol^(-1)).Furthermore,the results of theoretical calculations,in-situ Raman and ex-situ characterizations also indicate the enhanced structural integrity of Mo S2@EG during cycling due to the enlarged interlayer spacing and charge screening effect induced by interlaminar EG molecules.Consequently,the Mo S_(2)@EG anode enables excellent cycling stability of both high-energy-density Mo_S2@EG||PVO(polyaniline intercalated V_(2)O_(5))and high-voltage Mo S2@EG||Na_(3)V_(2)(PO_(4))_2O_(2)F(NVPF)full batteries with neglectable capacity decay at-20℃.

Interfacial Polymer Engineered Field Effect Transistor Biosensors for Rapid and Efficient Identification of SARS-CoV-2 N Antigen

With the advantages of high sensitivity,rapid response,label-free,and simple operation,field effect transistor biosensors have shown promising application prospects in large-scale pathogen screening.However,in practical biological fluids with relatively high ionic strength,such as saliva and serum,the Debye screening effect will weaken the interaction between FET biosensors and target bio-molecules,thereby affecting the sensing sensitivity and accuracy.

有机半导体增强介电屏蔽效应以制备高效稳定的钙钛矿太阳能电池

在钙钛矿太阳能电池(pero-SCs)中,载流子扩散过程中带电缺陷的捕获是其非辐射复合损失的主要来源,而常见的缺陷态钝化策略具有较强的尺寸依赖性,使得大面积应用受限.因此,本文通过精准设计合成高介电常数的p-型有机半导体,构筑了具备高介电常数的钙钛矿薄膜,增强了介电屏蔽效应,降低了载流子捕获概率,减少了非辐射复合损失.该本征策略表现出较低的钙钛矿组分和尺寸依赖性,基于此策略制备了效率为23.35%的小面积(0.062 cm^(2))和21.93%的大面积(1 cm^(2))器件;同时,该策略提高了器件的工作稳定性和热稳定性,为制备高性能的大面积pero-SCs开辟了一条新途径.

Dynamics of exciton energy renormalization in monolayer transition metal disulfides

Fundamental understandings on the dynamics of charge carriers and excitonic quasiparticles in semiconductors are of central importance for both many-body physics and promising optoelectronic and photonic applications.Here,we investigated the carrier dynamics and many-body interactions in two-dimensional(2D)transition metal dichalcogenides(TMDs),using monolayer WS2 as an example,by employing femtosecond broadband pump-probe spectroscopy.Three time regimes for the exciton energy renormalization are unambiguously revealed with a distinct red-blue-red shift upon above-bandgap optical excitations.We attribute the dominant physical process in the three typical regimes to free carrier screening effect,Coulombic exciton-exciton interactions and Auger photocarrier generation,respectively,which show distinct dependence on the optical excitation wavelength,pump fluences and/or lattice temperature.An intrinsic exciton radiative lifetime of about 1.2 picoseconds(ps)in monolayer WS2 is unraveled at low temperature,and surprisingly the efficient Auger nonradiative decay of both bright and dark excitons puts the system in a nonequilibrium state at the nanosecond timescale.In addition,the dynamics of trions at low temperature is observed to be significantly different from that of excitons,e.g.,a long radiative lifetime of^108.7 ps at low excitation densities and the evolution of trion energy as a function of delay times.Our findings elucidate the dynamics of excitonic quasiparticles and the intricate many-body physics in 2D semiconductors,underpinning the future development of photonics,valleytronics and optoelectronics based on 2D semiconductors.

Systematic study of two-proton radioactivity with a screened electrostatic barrier

In this study,a phenomenological model is proposed based on Wentzel-Kramers-Brillouin(WKB)theory and applied to investigate the two-proton(2p)radioactive half-lives of nuclei near or beyond the proton drip line.The total diproton-daughter nucleus interaction potential is composed of the Hulthen-type electrostatic term and the centrifugal term.The calculated 2p radioactive half-lives can accurately reproduce the existing 10 experimental datasets of five true 2p radioactive nuclei withσ=0.736.In addition,we extend this model to predict the half-lives of possible 2p radioactive nuclei whose 2p radioactivity is energetically allowed or observed but not yet quantified in NUBASE2016.The predicted results are in agreement with those obtained using the Gamow-like model,generalized liquid drop model,Sreeja formula,and Liu formula.

MEDICINAL PLANTS OF THE GENUS LEONURUS AND SEVENTEEN OF THEIR ISOLATED CONSTITUENTS SCREENED FOR EFFECTS ON PPARa,β/δ, and γ IN AN IN VITRO LUCIFERASE REPORTER GENE ASSAY

Leonurus japonicus Houtt.is used in TCM to treat the metabolic syndrome.However,up to now,no active constituents could be identified.Here we describe the isolation of 17 dominant constituents of L.japonicus and the related European herb Leonurus cardiaca L.-namely7R-chloro-6-desoxy-harpagide,ajugol,campneoside II,chicoric acid,ferulic acid,harpagide,isoacteoside,