Potential seismic landslide hazard and engineering effect in the Ya’an-Linzhi section of the Sichuan-Tibet transportation corridor, China

The Sichuan-Tibet transportation corridor is located at the eastern margin of the Qinghai-Tibet Plateau,where the complex topography and geological conditions,developed geo-hazards have severely restricted the planning and construction of major projects.For the long-term prevention and early control of regional seismic landslides,based on analyzing seismic landslide characteristics,the Newmark model was used to carry out the potential seismic landslide hazard assessment with a 50-year beyond probability 10%.The results show that the high seismic landslide hazard is mainly distributed along large active tectonic belts and deep-cut river canyons,and are significantly affected by the active tectonics.The low seismic landslide hazard is mainly distributed in the flat terrain such as the Quaternary basins,broad river valleys,and plateau planation planes.The major east-west linear projects mainly pass through five areas with high seismic landslide hazard:Luding-Kangding section,Yajiang-Xinlong(Yalong river)section,Batang-Baiyu(Jinsha river)section,Basu(Nujiang river)section,and Bomi-Linzhi(eastern Himalaya syntaxis)section.The seismic action of the Bomi-Linzhi section can also induce high-risk geo-hazard chains such as the high-level glacial lake breaks and glacial debris flows.The early prevention of seismic landslides should be strengthened in the areas with high seismic landslide hazard.

飞秒激光微切口角膜基质透镜取出术术后并发症分析及处理

目的:分析飞秒激光微切口角膜基质透镜取出术(small incision lenticule extraction,SMILE)术后并发症,探讨其发生的原因、处理对策及对预后的影响。方法:回顾性分析我院2016-06/2017-05进行的SMILE患者1127例2236眼的临床资料,随访时间为6mo。结果:术后并发症总体发生率为8.05%,包括弥漫性层间角膜炎74眼(3.31%)、视力恢复延迟58眼(2.59%)、角膜层间异物残留14眼(0.63%)、视物重影34眼(1.52%)。1眼存在严重偏中心切削者术后3mo视力尚未恢复,行角膜地形图引导的准分子激光上皮下角膜磨镶术(laser-assisted subepithelial keratomileusis,LASEK)。所有患者并发症经适当处理后结果良好,术后裸眼视力均达到或超过术前最佳矫正视力。结论:尽管SMILE存在一定比例术后并发症,但手术总体是安全的。术中注意手术技巧,调整手术参数,术后合理用药可以减少并发症的发生。

圆锥角膜患者角膜光密度与形态及生物力学的相关性研究

目的:探讨圆锥角膜患者角膜光密度与角膜形态参数及生物力学特性的相关性。方法:回顾性病例研究。收集2020-01/12在郑州市第二人民医院就诊的原发性圆锥角膜患者48例70眼,使用Pentacam眼前段分析系统测量角膜形态,包括角膜前表面中央扁平子午线曲率(K1)、角膜前表面陡峭子午线曲率(K2)、角膜前表面中央平均曲率(Km)、角膜前表面最大曲率(Kmax)、角膜前表面高度(ACE)、角膜后表面高度(PCE)、最薄点角膜厚度(TCT),以及圆锥锥顶距角膜顶点的距离(DCA)。测量不同分区不同层次的角膜光密度。使用可视化角膜生物力学测量仪观察角膜形变过程并测量相关参数,包括第一次压平时间(AT1),第一次压平长度(AL1),第一次压平速度(V1),第二次压平时间(AT2),第二次压平长度(AL2),第二次压平速度(V2),最大压陷时间(HCT),最大压陷形变幅度(HCDA),最大压陷曲率半径(HCR),最大压陷峰距(HCPD),硬度参数(SPA1),水平方向Ambrósio相关厚度(ARTh)。结果:圆锥角膜患者距角膜顶点≤2mm前层光密度与K1、K2、Km、Kmax均呈正相关(r=0.291、0.315、0.315、0.387;P=0.015、0.008、0.008、0.001)。距角膜顶点≤2mm、>2mm且≤6mm前层及全层、>2mm且≤6mm后层光密度与ACE均呈正相关(r=0.465、0.302、0.317、0.291、0.335;P<0.01、P=0.011、0.008、0.014、0.005);上述各区域各层的光密度与PCE均呈正相关(r=0.565、0.369、0.348、0.306、0.284;P<0.01、P=0.002、0.003、0.010、0.017)。距角膜顶点≤2mm前、中、后及全层光密度,>2mm且≤6mm中、后及全层光密度均与AL1均呈负相关(r=-0.284、-0.290、-0.245、-0.326、-0.282、-0.395、-0.310;P=0.017、0.015、0.041、0.006、0.018、0.001、0.009)。距角膜顶点≤2mm中层光密度、>2mm且≤6mm中、后层光密度与AL2呈负相关(r=-0.246、-0.256、-0.256;P=0.041、0.032、0.032)。距角膜顶点≤2mm前层光密度与HCR呈负相关(r=-0.308,P=0.010)。距角膜顶点≤2mm中、后层光密度、>2mm且≤6mm中层光密度与HCT均呈负相关(r=-0.292、-0.340、-0.262;P=0.014、0.004、0.028)。距角膜顶点≤2mm前层及全层光密度、>2mm且≤6mm后层光密度与ARTh呈负相关(r=-0.430、-0.293、-0.319;P<0.01,P=0.014、0.007)。结论:圆锥角膜患者角膜光密度测定值与角膜形态和生物力学特性相关,可能成为圆锥角膜的潜在诊断指标。

Subcapsular hepatic haematoma after endoscopic retrograde cholangiopancrea-tography: An unusual case

Subcapsular hepatic haematoma is a rare complication of endoscopic retrograde cholangiopancrea-tography (ERCP), and there are few reports about this unusual complication worldwide. The primary symptom of most cases reported in the literature is abdominal pain. We report an unusual case with the primary symptom of fever. A 56-year-old man who had a six-month history of recurrent episodes of upper abdominal pain was diagnosed with a common bile duct stone by magnetic resonance cholangiopancrea-tography. Endoscopic biliary sphincterotomy was performed, and stones from the common bile duct were successfully extracted with a basket. The patient had a persistent fever after ERCP, and treatment with intravenous antibiotics was unsuccessful. Computed tomography showed a 13 cm × 6 cm subcapsular hepatic haematoma filled with air and liquid on the surface of the right hepatic lobe. The patient was successfully treated with peritoneal drainage under B-ultra guidance. Subcapsular liver haematoma should be considered when hard-toexplain symptoms persist in the early period after ERCP. Percutaneous drainage is an effective treatment.

Wolfberry extracts inhibit Aβ1-42 aggregation and rescue memory loss of AD drosophila

This study is to investigate the potential of wolfberry water extracts for the treatment of Alzheimer’s disease(AD)and the relationship between their anti-AD property and the geographic locations in China.Total extracts of all wolfberry samples showed the potent to decrease self-induced Aβ1-42 aggregation and Cu2+-induced Aβ1-42 aggregation and the antioxidant capacity as well as the bioactivity for binding biometal.A transgenic drosophila model assay revealed that TE of S1 and S6(S1-TE and S6-TE)at 100μg/mL demonstrated the potent rescue effect on memory loss compared to the positive control memantine at 20μg/mL.Further study also revealed the polysaccharide extracts could contribute to their anti-AD property,and the anti-AD activity conspicuously depends on growing environment.Wolfberry samples S1 and S6 showed much more potent anti-AD property.Meanwhile this study demonstrated that the Chinese commonly consumed wolfberry in boiling water might have the beneficial function to prevent AD pathology.

A chaotic coverage path planner for the mobile robot based on the Chebyshev map for special missions

本文提出一种在特殊任务下基于Chebychev映射的移动机器人混沌全覆盖路径规划器的设计新策略。所设计的混沌路径规划器包含一个二维的Chebychev映射,该映射由两个一维的Chebychev映射构建而成。对规划器所产生的时间序列,进行反正弦变换,可以改善系统的混沌特性和均匀分布特性,从而提高机器人在完成特殊任务时的覆盖率和随机特性。通过仿射变换,Chebychev混沌系统映射到机器人工作空间的可行区域内,然后设计有障碍物环境下全覆盖路径规划的通用方法。仿真结果显示,所设计的混沌路径规划器在可行空间能够安全运行,不需要设计避障算法。所设计策略能够满足特殊任务下随机性、遍历性和高效率的需求。

Complete coverage path planning for an Arnold system based mobile robot to perform specific types of missions

We propose a contraction transformation algorithm to plan a complete coverage trajectory for a mobile robot to ac-complish specific types of missions based on the Arnold dynamical system. First, we construct a chaotic mobile robot by com-bining the variable z of the Arnold equation and the kinematic equation of the robot. Second, we construct the candidate sets including the initial points with a relatively high coverage rate of the constructed mobile robot. Then the trajectory is contracted to the current position of the robot based on the designed contraction transformation strategy, to form a continuous complete cov-erage trajectory to execute the specific types of missions. Compared with the traditional method, the designed algorithm requires no obstacle avoidance to the boundary of the given workplace, possesses a high coverage rate, and keeps the chaotic characteristics of the produced coverage trajectory relatively unchanged, which enables the robot to accomplish special missions with features of completeness, randomness, or unpredictability.

Comparative Neonatal Outcomes of Vitrified Versus Fresh Embryo Transfers: A Systematic Review and Meta-Analysis

Objective:Vitrification prevents ice formation within the high concentration of cryoprotectant agents and allows the cells and extracellular milieu to solidify into a glass-like state.This study aimed to provide objective information on the available data regarding singleton births comparing embryo vitrification with fresh embryo transfers.Methods:PubMed and Cochrane databases were searched for studies conducted up to 2017.Low birth weight(LBW),very low birth weight(VLBW),preterm birth(PTB),very PTB,small for gestational age(SGA),large for gestational age,perinatal mortality,cesarean section,and preeclampsia were measured.Results:The search returned 220 articles,and 13 of these met the inclusion criteria.A significantly lower risk of SGA birth was observed in the vitrified embryo transfer group than in the fresh transfer group.Conversely,a higher risk of very PTB,VLBW,large size for gestational age,and perinatal mortality was observed more frequently in the vitrified embryo transfer group.Conclusions:Vitrified embryo transfer was associated with the improved outcome of neonates regarding the SGA rate compared with fresh embryo transfer,but included a higher risk of very PTB,VLBW,large size for gestational age,and perinatal mortality.Caution should be exercised in interpreting these findings given the low level of evidence of the studies.