不同术式联合Toric IOL植入术治疗硬核年龄相关性白内障

目的:比较不同术式联合Toric IOL植入术治疗硬核年龄相关性白内障的疗效。方法:回顾性研究。选取2020-01/2021-12我院确诊为硬核年龄相关性白内障患者104例104眼,按照不同手术方式分为超声乳化组52眼采用超声乳化术联合Toric IOL植入术,小切口组52眼采用小切口水平空间劈核术联合Toric IOL植入术。比较两组患者手术前后最佳矫正远视力(BCDVA)、角膜散光、角膜内皮细胞数量和正常六边形细胞比例、泪膜功能及并发症情况。结果:术前和术后3mo两组患者BCDVA(LogMAR)比较均无差异(均P>0.05);术后1wk,小切口组患者BCDVA(LogMAR)优于超声乳化组(0.15±0.04 vs 0.20±0.05,P<0.001)。两组患者各组内术后1wk,3mo角膜散光均低于术前,术后3mo低于术后1wk(均P<0.05),而两组间手术前后角膜散光比较均无差异(均P>0.05)。术后1wk、3mo,小切口组患者角膜内皮细胞数量高于超声乳化组(术后1wk:2363.8±315.3 vs 2231.4±326.4cells/mm2,P<0.05;术后3mo:2414.6±245.7 vs 2322.9±221.0cells/mm2,P<0.05)。术前、术后1wk两组角膜正常六边形细胞比例比较均无差异(均P>0.05);术后3mo,小切口组正常六边形细胞比例高于超声乳化组(21.77%±1.91%vs 20.59%±1.65%,P<0.001)。术前、术后3mo时两组BUT和OSDI评分的比较无差异(P>0.05);术后1wk小切口组患者BUT长于超声乳化组(6.8±0.8 vs 5.9±1.0s,P<0.001),OSDI评分低于超声乳化组(17.62±5.47 vs 20.34±6.18分,P<0.05)。小切口组术后并发症发生率低于超声乳化组(3.9%vs 17.3%,P<0.05)。结论:小切口水平空间劈核术联合Toric IOL植入术可明显改善硬核年龄相关性白内障患者视力及散光,对角膜内皮和泪膜功能损伤轻微。

Sinogram denoising via attention residual dense convolutional neural network for low-dose computed tomography

The widespread use of computed tomography(CT)in clinical practice has made the public focus on the cumulative radiation dose delivered to patients.Low-dose CT(LDCT)reduces the X-ray radiation dose,yet compromises quality and decreases diagnostic performance.Researchers have made great efforts to develop various algorithms for LDCT and introduced deep-learning techniques,which have achieved impressive results.However,most of these methods are directly performed on reconstructed LDCT images,in which some subtle structures and details are readily lost during the reconstruction procedure,and convolutional neural network(CNN)-based methods for raw LDCT projection data are rarely reported.To address this problem,we adopted an attention residual dense CNN,referred to as AttRDN,for LDCT sinogram denoising.First,it was aided by the attention mechanism,in which the advantages of both feature fusion and global residual learning were used to extract noise from the contaminated LDCT sinograms.Then,the denoised sinogram was restored by subtracting the noise obtained from the input noisy sinogram.Finally,the CT image was reconstructed using filtered back-projection.The experimental results qualitatively and quantitatively demonstrate that the proposed AttRDN can achieve a better performance than state-of-the-art methods.Importantly,it can prevent the loss of detailed information and has the potential for clinical application.

UAV flight test of plasma slats and ailerons with microsecond dielectric barrier discharge

Plasma flow control（PFC） is a promising active flow control method with its unique advantages including the absence of moving components, fast response, easy implementation, and stable operation. The effectiveness of plasma flow control by microsecond dielectric barrier discharge（μs-DBD）, and by nanosecond dielectric barrier discharge（NS-DBD） are compared through the wind tunnel tests, showing a similar performance between μs-DBD and NS-DBD. Furthermore, theμs-DBD is implemented on an unmanned aerial vehicle（UAV）, which is a scaled model of a newly developed amphibious plane. The wingspan of the model is 2.87 m, and the airspeed is no less than 30 m/s. The flight data, static pressure data,and Tufts images are recorded and analyzed in detail. Results of the flight test show that the μs-DBD works well on board without affecting the normal operation of the UAV model. When the actuators are turned on, the stall angle and maximum lift coefficient can be improved by 1.3° and 10.4%, and the static pressure at the leading edge of the wing can be reduced effectively in a proper range of angle of attack, which shows the ability of μs-DBD to act as plasma slats. The rolling moment produced by left-side μs-DBD actuation is greater than that produced by the maximum deflection of ailerons,which indicates the potential of μs-DBD to act as plasma ailerons. The results verify the feasibility and efficacy of μs-DBD plasma flow control in a real flight and lay the foundation for the full-sized airplane application.

Dynamic stall control over an airfoil by NS-DBD actuation

The wind tunnel test was conducted with an NACA 0012 airfoil to explore the flow control effects on airfoil dynamic stall by NS-DBD plasma actuation. Firstly, light and deep dynamic stall states were set, based on the static stall characteristics of airfoil at a Reynolds number of 5.8 × 105. Then, the flow control effect of NS-DBD on dynamic stall was studied and the influence law of three typical reduced frequencies (k = 0.05, k = 0.05, and k = 0.15) was examined at various dimensionless actuation frequencies (F+ = 1, F+ = 2, and F+ = 3). For both light and deep dynamic stall states, NS-DBD had almost no effect on upstroke. However, the lift coefficients on downstroke were increased significantly and the flow control effect at F+ = 1 is the best. The flow control effect of the light stall state is more obvious than that of deep stall state under the same actuation conditions. For the same stall state, with the reduced frequency increasing, the control effect became worse. Based on the in being principles of flow separation control by NS-DBD, the mechanism of dynamic stall control was discussed and the influence of reduced frequency on the dynamic flow control was analyzed. Different from the static airfoil flow separation control, the separated angle of leading-edge shear layer for the airfoil in dynamic stall state is larger and flow control with dynamic oscillation is more difficult. The separated angle is closely related to the effective angle of attack, so the effect of dynamic stall control is greatly dependent on the history of angles of attack.

Feasibility study on determining the conventional true value of gamma-ray air kerma in a minitype reference radiation

A minitype reference radiation(MRR) with dimensions of only 1 m × 1 m × 1 m has been developed for the in situ calibration of photon dosimeters.The present work conducts a feasibility study on determining the conventional true value of gamma-ray air kerma at the point of test in the MRR.Owing to its smaller dimensions,the scattered gamma-rays in the MRR are expected to induce a non-negligible interference with the radiation field compared with conditions in the standard reference radiation stipulated by ISO4037-1 or GB/T12162.1.A gamma-ray spectrometer was employed to obtain the spectra of scattered gamma-rays within the MRR,and the feature components of the spectra were extracted by principal component analysis to characterize the interference of a dosimeter probe in the radiation field.A prediction model of the CAK at the point of test was built by least squares support vector machine based on the feature component data obtained from nine sample dosimeters under five different dose rates.The mean prediction error of the CAK prediction model was within ±4.5%,and the maximum prediction error was about ±10%.

有机化学课程思政体系的构建方法与实践

理工科类专业课融入思政元素,实现知识传授的同时,发挥价值引领作用是践行“立德树人根本任务”的关键环节。基于有机化学课程教学方法改革,构建了“三个载体+四种途径”的有机化学课程思政体系,即以“理论教学、实验应用和卓越创新”三个教学模块为载体,“显性引导与隐性熏陶相结合、情境体验式、任务驱动式和专题嵌入式”为四种实现途径。并以“重氮化合物和偶氮化合物”为教学案例阐述全方位、多途径将思政元素与理论知识相融合的方法,培养出“有理想、有追求、有担当、有作为、有品质、有修养”的六有化学本科生,促进学生的全面发展。

Hybrid reconstruction algorithm for computed tomography based on diagonal total variation

Inspired by total variation(TV), this paper represents a new iterative algorithm based on diagonal total variation(DTV) to address the computed tomography image reconstruction problem. To improve the quality of a reconstructed image, we used DTV to sparsely represent images when iterative convergence of the reconstructed algorithm with TV-constraint had no effect during the reconstruction process. To investigate our proposed algorithm, the numerical and experimental studies were performed, and rootmean-square error(RMSE) and structure similarity(SSIM)were used to evaluate the reconstructed image quality. The results demonstrated that the proposed method could effectively reduce noise, suppress artifacts, and reconstruct highquality image from incomplete projection data.

Spatio-Temporal Cellular Network Traffic Prediction Using Multi-Task Deep Learning for AI-Enabled 6G

Spatio-temporal cellular network traffic prediction at wide-area level plays an important role in resource reconfiguration,traffic scheduling and intrusion detection,thus potentially supporting connected intelligence of the sixth generation of mobile communications technology(6G).However,the existing studies just focus on the spatio-temporal modeling of traffic data of single network service,such as short message,call,or Internet.It is not conducive to accurate prediction of traffic data,characterised by diverse network service,spatio-temporality and supersize volume.To address this issue,a novel multi-task deep learning framework is developed for citywide cellular network traffic prediction.Functionally,this framework mainly consists of a dual modular feature sharing layer and a multi-task learning layer(DMFS-MT).The former aims at mining long-term spatio-temporal dependencies and local spatio-temporal fluctuation trends in data,respectively,via a new combination of convolutional gated recurrent unit(ConvGRU)and 3-dimensional convolutional neural network(3D-CNN).For the latter,each task is performed for predicting service-specific traffic data based on a fully connected network.On the real-world Telecom Italia dataset,simulation results demonstrate the effectiveness of our proposal through prediction performance measure,spatial pattern comparison and statistical distribution verification.

皮纹漆在城轨地铁驾驶台的应用

对城轨地铁驾驶台用皮纹漆喷涂工艺进行了研究,获得了如下较好的喷涂参数:底漆2 道,干膜总厚度40 ~ 60 μm;面漆喷涂黏度15 ~ 20 s,施工温度20 ~ 30 °C,相对湿度70%~ 80%,干膜总厚度40 ~ 45 μm。在此工艺条件下以自制的皮纹漆助剂(含二甲基硅油、膨润土等组分)对某国产皮纹面漆进行改进,获得了客户所需的皮纹效果。

Simulation of gamma minitype reference radiation for calibration of personal dosimeter

An investigation using Monte Carlo simulation on a minitype reference radiation(MRR) for the calibration of gamma personal dosimeters is reported. The distributions of dose rate and scattering gamma spectrum are the main simulation objects with the variable physical structures of MRR and the dosimeters as parameters that are to be calibrated. Further, the influences on the reference radiation caused by these parameters are analyzed in detail.This work provides a theoretical basis for better understanding of MRR used for calibration of gamma personal dosimeters. This analysis can help in the development of a calibration technology for such tools based on MRR.

Improving flight performance of UAVs by ice shape modulation

Aircraft icing poses a great threat to flight safety.In response to the characteristics of high-power consumption,large volume,and heavy weight of traditional anti-/de-icing technologies,the concept of ice shape modulation is proposed,which is called ice tolerant flight.Firstly,the flight performance of Unmanned Aerial Vehicle(UAV)was compared in three states:no ice,full ice,and modulated ice through flight tests.It was found that ice shape modulation has a significant improvement effect on the aerodynamic performance of aircraft under icing conditions.Under the three modulated ice shape conditions in this experiment,the lift coefficient of the UAV under different ice shape modulation conditions increased by 18%–33%,and the stalling angle was delayed by 3°-5°.Subsequently,the pressure distribution,streamlines in the flow field,and detached vortex distribution of the UAV model in these three states were obtained through numerical simulation,to study the mechanism of ice shape modulation on the aerodynamic performance of aircraft.The simulation found that the reason for the improvement of the wings effect after ice shape modulation is that the modulated area forms a leading-edge protrusion structure similar to a vortex generator.This structure prolongs the mixed flow region on the wings surface and reduces the trend of flow separation,which plays a role in increasing lift and reducing drag for UAVs under icing conditions.Finally,a reverse reachable set that can be used for unexpected state recovery is used as the definition of flight safety boundaries,and an aircraft dynamics model is established to obtain flight safety boundaries for different states.Research has found that the flight safety boundary of the UAV in a no ice state is greater than that in a modulated ice state,and the safety boundary in a modulated ice state is greater than that in a full ice state.Compared with the full ice state,the flight safety boundary after modulation has expanded by 27.0%.The scheme of ice shape modulation can provide a basis for the flight safety of aircraft under icing conditions.

高校社区乙肝防治知识知晓与态度调查分析——以某医学院校医学本科生为例

目的了解医学本科生对乙型肝炎(乙肝)防治知识知晓程度及相关态度状况,为更好开展高校乙肝防治工作提供科学依据。方法采用校园内随机调查方式,对选取的调查对象进行网络化自填式问卷调查,经整理核对和逻辑检验后,采用χ~2检验进行统计分析。结果调查的404名在校本科生中,整体乙肝基本知识知晓率为62.9%,且高年级组知晓率高于低年级组,差异有统计学意义(χ~2=35.771,P<0.001);18.3%的医学本科生会定期检查并打疫苗;69.3%的学生会继续与感染了乙肝的同学或朋友交往;47.5%的学生愿意和乙肝感染者一起工作;在各类知识获取途径上,排在前三位的分别是网络类、书籍类和校园活动类。结论医学本科生的乙肝防治知识知晓水平偏低,预防意识和对乙肝患者态度均亟待转变,今后应重点加强乙肝预防教育中的薄弱环节,采取适宜的宣传方式积极开展乙肝疫苗接种知识普及和反歧视教育工作。

Flight safety oriented ice shape modulation using distributed plasma actuator units

Ice accretion on the wings seriously threatens the flight safety of an aircraft.From the perspectives of ensuring flight safety and saving power consumption,the ice shape modulation method using distributed plasma is proposed.Distributed plasma actuator units are designed to modulate the spanwise continuous ice at the leading edge into periodically segmented ice pieces,forming a wavy leading edge.Both airfoil and scaled aircraft model,with continuous and modulated ice,are experimentally investigated and simulated.Compared with the continuous ice,ice shape modulation can significantly improve the aerodynamic performance,flight control characteristics and flight safety.This method can save about half electric power,which is very beneficial for application.

Geometrical and electrical optimization of NS-SDBD streamwise plasma heat knife for aircraft anti-icing

Ice accretion on aircraft encountering supercooled water droplets in clouds poses great risks to flight performance and safety.With the aim of optimizing the newly developed streamwise plasma heat knife method for anti-icing,a parametric investigation is carried out in this work.The influence of the detailed voltage profile on the heating effects of a Surface Dielectric Barrier Discharge driven by Nanosecond Pulses(NS-SDBD)is investigated,and a comparison of the antiicing performance among different configurations of streamwise plasma heat knife is made.The results show that columnar high-temperature regions produced by a multi-streamer discharge appear at small pulse rise time,but become diffuse as the pulse rise time increases.An optimal pulse rise time exists to provide a wide range and high value of temperature,which is found to be 150 ns for the setup in the present study.The influence of the pulse fall time is much weaker than that of the rise time.The range and value of the temperature decrease with increasing pulse fall time.A greater pulse width is found to improve the heating effect by increasing the discharge power.When a spanwise electrode is placed connecting the streamwise electrodes of the streamwise plasma heat knife at the airfoil leading edge,the anti-icing performance becomes poorer,whereas good performance is achieved when the spanwise electrode is at the edge of the streamwise electrodes.Based on this,a three-level configuration of the plasma heat knife is proposed,and its anti-icing performance is found to be much better than that of the original configuration.

SARS-CoV-2 N protein induces acute kidney injury in diabetic mice via the Smad3-Ripk3/MLKL necroptosis pathway

Dear Editor,Kidney is one of major organs attacked by SARS-CoV-2,resulting in acute kidney injury(AKI)in critically ill COVID-19 patients,especially in the elderly and diabetic patients with diabetic kidney disease(DKD).1,2 Among SARS-CoV-2 proteins,the N protein can be detectable in damaged tubules in COVID-19 patients with AKI.