Case Report: Observation of Postoperative Refractive Status of Glaucoma Combined with Cataract and Irregular Astigmatism

Significance: So far, many scholars have studied the astigmatism caused by glaucoma surgery, but they cannot provide enough useful help for the clinic. When a patient has glaucoma, cataracts and irregular astigmatism at the same time, it is often difficult to achieve satisfactory results. Purpose: This study intends to describe a case of a patient with glaucoma, irregular astigmatism, and cataract who was successfully treated. Additionally, it can serve as a useful source of inspiration for the future care of patients like this. Case Presentation: A 24-year-old male with keratoconus in the past. He had undergone a corneal crosslinking operation in the right eye and a penetrating keratoplasty in the left eye due to his long history of keratoconus in both eyes. Right now, the keratoconus in that eye is stable. Unfortunately, he has now been diagnosed with open-angle glaucoma and complicated cataracts in both eyes, and he was admitted to our hospital for surgery. The right eye had significant irregular astigmatism, which was discovered during the preoperative assessment, and the implantation of a Toric intraocular lens was unable to produce good results. Finally, we chose to perform EXPRESS glaucoma drainage device implantation + phacoemulsification + intraocular lense (ZEISS CT ASPHINA 409MP) implantation. The patient had stable postoperative astigmatism with rule thanks to the traction effect of the scleral flap suture. Astigmatism was typically stable six months after surgery, and the corrected visual acuity with glasses had improved to 20/25. Conclusion: This patient suffers from cataracts, keratoconus, glaucoma, and irregular astigmatism. Due to the interconnectedness of these four disorders, simultaneous success is challenging. We realized that surgically induced astigmatism, frequently affects vision early after filtering surgery for glaucoma patients. In the instance of this patient, we tightly sutured the scleral flap and using tractive action, established regular astigmatism. After the patient’s astigmatism stabilized, optometry was given to correct the vision. This technique should result in much better visual acuity. Finally, it came to pass.

A Meta-Analysis: Safety and Efficacy of Phacoemulsification with Goniosynechialysis versus Trabeculectomy for Acute Angle Closure Glaucoma in China

Aim: The aim is to evaluate the safety and efficacy of phacoemulsification with goniosynechialysis versus trabeculectomy in the treatment of acute angle closure glaucoma (AACG) systematically. Methods: From January 1, 2000 to August 31, 2022, we searched PubMed, Science Citation Index Database, China National Knowledge Infrastructure, and Wanfang Database for pertinent material about the treatment of AACG with various operations. The imported literature was carefully vetted using the inclusion and exclusion criteria, assessed for quality, and the raw data were retrieved and integrated into EndNoteX9. For the meta-analysis, STATA 16.0 and RevMan 5.3 were used as the tools. Results: The meta-analysis includes 20 clinical investigations in all, involving 1463 eyes. The quality of the literature was rated as excellent and the data homogeneity among the studies was excellent based on the various study types that were included in the literature. According to a meta-analysis, phacoemulsification with goniosynechialysis is superior to trabeculectomy for treating acute angle-closure glaucoma because it results in improved postoperative visual acuity, lower intraocular pressure, a broader anterior chamber depth, and fewer complications. Conclusion: If conditions allow, phacoemulsification in conjunction with goniosynechialysis performs better than trabeculectomy in terms of visual acuity, intraocular pressure, anterior chamber depth, and comorbidities.

A Meta-Analysis: Safety and Efficacy of Phacoemulsification with Goniosynechialysis versus Trabeculectomy for Acute Angle Closure Glaucoma in China

Aim: The aim is to evaluate the safety and efficacy of phacoemulsification with goniosynechialysis versus trabeculectomy in the treatment of acute angle closure glaucoma (AACG) systematically. Methods: From January 1, 2000 to August 31, 2022, we searched PubMed, Science Citation Index Database, China National Knowledge Infrastructure, and Wanfang Database for pertinent material about the treatment of AACG with various operations. The imported literature was carefully vetted using the inclusion and exclusion criteria, assessed for quality, and the raw data were retrieved and integrated into EndNoteX9. For the meta-analysis, STATA 16.0 and RevMan 5.3 were used as the tools. Results: The meta-analysis includes 20 clinical investigations in all, involving 1463 eyes. The quality of the literature was rated as excellent and the data homogeneity among the studies was excellent based on the various study types that were included in the literature. According to a meta-analysis, phacoemulsification with goniosynechialysis is superior to trabeculectomy for treating acute angle-closure glaucoma because it results in improved postoperative visual acuity, lower intraocular pressure, a broader anterior chamber depth, and fewer complications. Conclusion: If conditions allow, phacoemulsification in conjunction with goniosynechialysis performs better than trabeculectomy in terms of visual acuity, intraocular pressure, anterior chamber depth, and comorbidities.

Slope stability prediction using ensemble learning techniques: A case study in Yunyang County, Chongqing, China

Slope stability prediction plays a significant role in landslide disaster prevention and mitigation.This study develops an ensemble learning-based method to predict the slope stability by introducing the random forest(RF)and extreme gradient boosting(XGBoost).As an illustration,the proposed approach is applied to the stability prediction of 786 landslide cases in Yunyang County,Chongqing,China.For comparison,the predictive performance of RF,XGBoost,support vector machine(SVM),and logistic regression(LR)is systematically investigated based on the well-established confusion matrix,which contains the known indices of recall rate,precision,and accuracy.Furthermore,the feature importance of the 12 influencing variables is also explored.Results show that the accuracy of the XGBoost and RF for both the training and testing data is superior to that of SVM and LR,revealing the superiority of the ensemble learning models(i.e.XGBoost and RF)in the slope stability prediction of Yunyang County.Among the 12 influencing factors,the profile shape is the most important one.The proposed ensemble learning-based method offers a promising way to rationally capture the slope status.It can be extended to the prediction of slope stability of other landslide-prone areas of interest.

Adaptive Attitude Control for a Coaxial Tilt-Rotor UAV via Immersion and Invariance Methodology

Dear Editor,This letter is concerned with the attitude control for a novel tiltrotor unmanned aerial vehicle with two pairs of tiltable coaxial rotors and one rear rotor.An immersion and invariance-based adaptive attitude controller for the tilt-rotor unmanned aerial vehicle is proposed.In the proposed control strategy,an adaptive update law is specially designed to compensate for the uncertainties of damping coefficients.The stability of the resulting closed-loop coaxial tiltrotor unmanned aerial vehicle(CTRUAV)system is proved by the Lyapunov methodology and LaSalle’s invariance theory.Finally。

Probabilistic assessment of slope failure considering anisotropic spatial variability of soil properties

Anisotropic spatial variability of soil properties is frequently encountered in geotechnical engineering practice due to the complex depositional process.To quantitatively evaluate the response of slope failure related to anisotropic spatial variability of soil properties and reveal the underlying influence of anisotropic spatial variability of soil properties on the slope reliability,this study integrates the random finite difference method(RFDM)into a probabilistic assessment framework and adopts general spatial variability and a cohesive-frictional soil slope example for illustration.A parametric analysis is carried out to investigate the influence of general anisotropic spatial variability of soil properties on slope failure probability and failure characteristics.The results show that the directional angles of scales of fluctuation of general anisotropic spatial variability significantly affect the slope failure probability.The dominant failure mode is the intermediate type in most cases of general anisotropic spatial variability,which is distinguished from the shallow failure mode occurring in the homogenous state.Overestimation of cross-correlation between c and u(qc;u),scales of fluctuation(dmax and dmin)in general anisotropic spatially variable soils significantly influences the average slip mass volumes of deep and multi-slip failure mode.Compared with transverse anisotropic spatial variability,general anisotropic spatial variability significantly ampli-fies the effects of qc;u,dmax and dmin on slope reliability.

A Study of <i>γ</i>-Fe₂O₃Nanoparticles Modified Using ZnCl₂during Synthesis

Surface modification of γ-Fe2O3 nanoparticles synthesized by a chemically induced transition has been attempted by adding ZnCl2 during synthesis. The structure of the modified particles was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The experimental results showed that ZnFe2O4 grew epitaxially on the γ- Fe2O3 crystallites to form composite nanoparticles with the spinel structure, on which FeCl3 might be adsorbed. The apparent grain size dc estimated by XRD using the Scherrer equation was larger rather than smaller than the average particle size measured by TEM. This paradox can be explained by the effect of absorption in the coating heterolayer.

The Structure of Modified Fe-Ni Bioxide Composite Nanoparticles Using Fe(NO₃)₃

Composite nanoparticles containing a γ-Fe2O3 core, Ni2O3 external shell and FeCl3·6H2O outermost layer can be synthesized by chemically induced transition in FeCl2 solution. These may be modified by treatment with Fe(NO3)3 to obtain particles for the preparation of ionic ferrofluids. Vibrating sample magnetometer (VSM) measurements and transmission electron microscopy (TEM) observations show that after Fe(NO3)3 treatment, the specific magnetization becomes weaker and the size becomes larger for treated particles compared with the untreated particles. Using energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the structure of the particles before and after the treatment is revealed. The experimental results show that the γ-Fe2O3 core is unchanged, the Ni2O3 is dissolved partially and the FeCl3·6H2O is replaced by Fe(NO3)3·9H2O. The percentages of molar, mass and volume of these phases are deduced, and the average density of the modified particles is also estimated.

Comparisons and Improvements of Key Operating Characteristics of Current Source Converter Applied in HVDC System

Because of its controlled power factor and no commutation failure,current source converter(CSC)made up of reverse-blocking IGCTs(RB-IGCTs)offers broad application prospects in the field of HVDC system.Valve voltage and power operating range as the most important operating characteristics should be paid attention to but they are always contradictory.First,the relationship between valve voltage and modulation index is obtained.In particular,valve voltage of converter under the three typical modulation methods is compared,analyzed,and verified.Second,with the help of the independent control strategy and coordinated control strategy of both ends,power operating ranges of the three modulation methods are comprehensively analyzed and compared.Third,in order to solve power coupling at a low active power,the improved coordination control strategy at both ends in this paper is proposed and the relationships among active power,reactive power,DC current and phase angle difference are given in detail.Finally,a 500 kV/3 kA simulation system was built in PSCAD/EMTDC to obtain comparison results of the key operating characteristics of CSC under different modulation methods and the converter can realize unity power operation under random active power after adopting the improved coordinated control strategy,and DC current does not decrease to zero,verifying effectiveness of the coordinated control strategy.

Analysis for magnetic field disturbance of hybrid DC circuit breaker during breaking

The high current of hybrid DC circuit breaker(HCB)in the process of breaking generates strong transient magnetic field(MF),which may interfere with the normal operation of driver control units(DCUs).Therefore,the analysis for transient MF disturbance is of great significance.Due to the large space scale of HCB,with the large number of power electronic devices,the numerical calculation method has the disadvantages of large consumption of resources and slow calculation speed in solving the transient MF inside the HCB.In this study,the current generation mechanism of a 500 kV HCB is analysed,and the equivalent current path is obtained by considering the skin effect.Combined with the temporal and spatial distribution of transient current,the multi-process transient equivalent model of transient MF calculation is established,and the model has the advantages of high precision and high speed.Then,the breaking experiment of HCB is carried out,and the transient MF near the DCU is measured.The experiment results verify the validity of the model.Furthermore,the disturbance of transient MF at the DCU of the transfer branch during breaking 25 kA current is analysed.

Formation of highly crystalline maghemite nanoparticles from ferrihydrite in the liquid phase

Fe5O7(OH)4H2O ferrihydrite is a low-crystallinity antiferromagnetic material.c-Fe2O3(maghemite)magnetic nanoparticles were prepared from a ferrihydrite precursor,by chemically induced transformation in FeCl2/NaOH solution.The magnetization,morphology,crystal structure and chemical composition of the products were determined by vibrating sample magnetometry,transmission electron microscopy,X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy(XPS).Ferrihydrite underwent aggregation growth and transformed into a-FeO(OH)(goethite)particles,which subsequently transformed into c-Fe2O3nanoparticles,that became coated with NaCl.The c-Fe2O3particles had a flake-like morphology,when prepared from 0.01 mol/L FeCl2and a FeCl2:NaOH molar ratio of 0.4.The c-Fe2O3particles were more spherical,when prepared from a FeCl2:NaOH molar ratio of 0.6.The Fe content of the flake-like particles was lower than that of the spherical particles.Their magnetizations were similar,and the coercivity of the flake-like particles was larger.The differences in morphology and magnetization were attributed to the surface effect,and the difference in coercivity to the shape effect.

Administrative Hierarchy,Government Favoritism and Size Growth of Cities

Based on the significant difference of China’s cities at different(administrative)hierarchical levels in population growth over the past three decades,this study explains the influence of urban development policies(industrial policies and land policies)on the gap in urban population growth from the perspective of government favoritism.Taking 423 cities during 1990-2015 as samples,this paper selects two indicators,setting up national development zones and turning counties into districts,to represent government favoritism and applies the PSM-DID method.The empirical result shows government favoritism in setting up national development zones and turning counties into districts is conducive to urban population growth and helps generate synergy effects of industrial and land policies.Market potential of cities is an important condition for the effect of government favoritism.The result fi nds that government favors higher-level cities and coastal ones,but overlooks inland medium-and low-level cities,resulting in the shallow U-shaped characteristics of“higher on both ends and lower in the middle”in population growth of cities at different levels.In order to prevent inland medium-and low-level cities from“collapsing”relatively,the government should break its favoritism for high-level cities,transform industrial and land policies from“preference system”to“generalized system of preference”,and put greater favor of inland medium-and low-level cities with certain market potential.

Effective Ultra-High-Speed Identification Scheme of Lightning Strikes Suitable for VSC-Based DC Grids

To ensure their sound and continuous operation to the greatest extent,VSC-based DC girds have extremely stringent requirements for transmission line relay protection.In terms of guaranteeing their reliability,accurate identification of lightning strikes on DC transmission lines is one of the urgent key problems to be solved.An effective ultra-high-speed identification scheme of lightning strikes suitable for the VSC-based DC grid is proposed in this paper.First,an 1-mode reverse voltage traveling wave(RVTW)is constructed applying the pole-mode transformation theory.Next,fault traveling wave propagation characteristics along the DC transmission line are analyzed in depth utilizing Peterson's law.Then,differences of time-frequency electromagnetic transient characteristics of 1-mode RVTWs between disturbances and faults caused by lightning strikes are distinguished in detail by means of the classical wavelet transformation multi-resolution analysis theory.Finally,extensive simulations are carried out to evaluate the performance of the proposed identification scheme,and by which its excellent rapidity,reliability and robustness are validated.Index Terms-Lightning-strike identification,Multi-resolution analysis,Relay protection,Traveling-wave protection,VsC-based DC grid,Wavelet transformation.