Catheter-Assisted Interlaminar Approach for Cervical Epidural Steroid Injection in Patient with Cervical Stenosis Caused by Ossification of Posterior Longitudinal Ligament: A Case Report

We present the case of a 64-year-old man with cervical ossification of the posterior longitudinal ligament (OPLL) experiencing chronic neck pain and radiculopathy for 6 months. A catheter-assisted interlaminar Cervical Epidural Steroid Injection (CESI) was performed under fluoroscopic guidance, targeting the affected C2-C6 levels. Significant improvement was observed after this procedure, with decreased pain scores (visual analogue scale (VAS) 8 to 2) and improved mobility. This technique not only enhances the effectiveness of CESI but also reduces the likelihood of complications such as stroke or epidural hematoma and thus provides an alternative treatment option for patients with multiple stenotic levels who are unsuitable for surgery or are unresponsive to conservative therapy such as medication or physical therapy.

Water-Assisted Injection Molding System Based on Water Hydraulic Proportional Control Technique

Water-assisted injection molding（WAIM）, an innovative process to mold plastic parts with hollow sections, is characterized with intermittent, periodic process and large pressure and flow rate variation. Energy savings and injection pressure control can not be .attained based on conventional valve control system. Moreover, the injection water can not be supplied directly by water hydraulic proportional control system. Poor efficiency and control performance are presented by current trial systems, which pressurize injection water by compressed air. In this paper, a novel water hydraulic system is developed applying an accumulator for energy saving. And a new differential pressure control method is proposed by using pressure cylinder and water hydraulic proportional pressure relief valve for back pressure control. Aiming at design of linear controller for injection water pressure regulation, a linear load model is approximately built through computational fluid dynamics（CFD） simulation on two-phase flow cavity filling process with variable temperature and viscosity, and a linear model of pressure control system is built with the load model and linearization of water hydraulic components. According to the simulation, model based feedback is brought forward to compensate the pressure decrease during accumulator discharge and eliminate the derivative element of the system. Meanwhile, the steady-state error can be reduced and the capacity of resisting disturbance can be enhanced, by closed-loop control of load pressure with integral compensation. Through the developed experimental system in the State Key Lab of Fluid Power Transmission and Control, Zhejiang University, China, the static characteristic of the water hydraulic proportional relief valve was tested and output pressure control of the system in Acrylonitrile Butadiene Styrene（ABS） parts molding experiments was also studied. The experiment results show that the dead band and hysteresis of the water hydraulic proportional pressure relief valve are large, but the control precision and linearity can be improved with feed-forward compensation. With the experimental results of injection water pressure control, the applicability of this WAIM system and the effect of its linear controller are verified. The novel proposed process of WAIM pressure control and study on characteristics of control system contribute to the application of water hydraulic proportional control and WAIM technology.

Simulation and Experiment Research on the Proportional Pressure Control of Water-assisted Injection Molding

Water-assisted injection molding（WAIM）,a newly developed fluid-assisted injection molding technology has drawn more and more attentions for the energy saving,short cooling circle time and high quality of products.Existing research for the process of WAIM has shown that the pressure control of the injecting water is mostly important for the WAIM.However,the proportional pressure control for the WAIM system is quite complex due to the existence of nonlinearities in the water hydraulic system.In order to achieve better pressure control performance of the injecting water to meet the requirements of the WAIM,the proportional pressure control of the WAIM system is investigated both numerically and experimentally.A newly designed water hydraulic system for WAIM is first modeled in AMEsim environment,the load characteristics and the nonlinearities of water hydraulic system are both considered,then the main factors affecting the injecting pressure and load flow rate are extensively studied.Meanwhile,an open-loop model-based compensation control strategy is employed to regulate the water injection pressure and a feedback proportional integrator controller is further adopted to achieve better control performance.In order to verify the AMEsim simulation results WAIM experiment for particular Acrylonitrile Butadiene Styrene（ABS） parts is implemented and the measured experimental data including injecting pressure and flow rate results are compared with the simulation.The good coincidence between experiment and simulation shows that the AMEsim model is accurate,and the tracking performance of the load pressure indicates that the proposed control strategy is effective for the proportional pressure control of the nonlinear WAIM system.The proposed proportional pressure control strategy and the conclusions drawn from simulation and experiment contribute to the application of water hydraulic proportional control and WAIM technology.

Calculation of Beam Intensity Distribution for the Neutral Beam Injection in EAST

Theoretical beam intensity distribution is derived for the neutral-beam-injection ion source with a multi-slot extraction in EAST. The beam intensity profile, both along and perpendicular to the injecting direction and the beam power deposition to the inner elements in the neutral beam injector （NBI） are evaluated. The results indicate that the transverse beam intensity is much higher than the longitudinal one. This study could provide information for the design of vacuum system, structure of inner elements and cooling system of the neutral beam injector in EAST.

Small intestinal hemolymphangioma treated with enteroscopic injection sclerotherapy: A case report and review of literature

BACKGROUND Hemolymphangiomas are rare malformations composed of both lymphatic and vascular vessels and are located in the pancreas,spleen,mediastinum,etc.Small intestinal hemolymphangioma is extremely rare and often presents as obscure gastrointestinal bleeding.It is rarely diagnosed correctly before the operation.Endoscopic injection sclerotherapy is usually used as a management of bleeding in esophageal varices and was occasionally reported as a treatment of vascular malformation.The treatment of small intestinal hemolymphangioma with enteroscopic injection sclerotherapy has not been reported.CASE SUMMARY A 42-year-old male complained of recurrent episodes of melena and dizziness,fatigue and reduced exercise capacity for more than 2 mo.Gastroduodenoscopy and blood test revealed a gastric ulcer and anemia.Treatment with oral protonpump inhibitors and iron did not improve symptoms.We then performed a capsule endoscopy and anterograde balloon-assisted enteroscopy and revealed a hemolymphangioma.Considering it is a benign tumor without malignant potential,we performed enteroscopic injection sclerotherapy.He was discharged 4 days later.At follow-up 3 mo later,the melena disappeared.Balloon-assisted enteroscopy revealed an atrophied tumor atrophied and no bleeding.Argon plasma coagulation was applied to the surface of the hemolymphangioma to accelerated healing.When he returned for follow-up 1 year later,anemia was resolved and the tumor had been cured.CONCLUSION Balloon-assisted enteroscopy and capsule endoscopy are effective methods for diagnosis of hemolymphangioma.Enteroscopic injection sclerotherapy is an effective treatment.

Clinical study of different fertilization methods of assisted reproductive technology on neonatal birth defects

Objective:To investigate the incidence of neonatal birth defects in assisted reproductive technology(ART)by in vitro fertilization(IVF)and intracytoplasmic sperm injection(ICSI).Methods:The clinical data of 4229 cases of singleton deliver by infertile patients under 35 years old who received IVF/ICSI-ET in our center were analyzed.According to different fertilization methods,they were divided into IVF group(2967 cases)and ICSI group(1262 cases).The general situation of birth,birth defects and the location of defects were compared between the two groups.Results:a total of 38 cases of neonatal birth defects were found,the incidence of birth defects was 0.89%,including 30 cases(1.01%)in IVF group and 8 cases(0.64%)in ICSI group.There was no significant difference in the incidence of birth defects between the two groups(P>0.05).There was also no significant difference in birth weight,gestational age and gender ratio between the two groups(P>0.05).Conclusion:Different fertilization methods in assisted reproductive technology do not increase the incidence of neonatal birth defects.

聚碳酸酯气体辅助注射成型制品内应力分布及改善工艺

聚碳酸酯(PC)注塑制品出模后在无外加约束条件下内部应力得不到松弛释放,易导致制品产生开裂,严重影响制品的服役性能。为探究PC制品内应力分布规律,找到有效降低内应力的工艺措施,基于气体辅助注射成型(GAIM)工艺和自行设计制造的带有半圆形加强筋的平板试验模具,结合光弹法和溶剂检测法,研究GAIM制品内应力的分布特点,讨论注气压力和气体保压压力两种工艺参数对GAIM制品内应力的影响规律,提出两种改善制品内应力的工艺方法。研究发现:通过光弹法观测到的应力条纹分布与溶剂浸泡后的裂纹开裂区域一致,即GAIM制品末端及边缘处内应力较大,沿气道两侧应力分布较均匀;较高的注气压力和较低的气体保压压力可以更加有效减小GAIM制品的内应力;通过对GAIM制品24 h即时退火和延长二次注气的卸压时间可以有效降低制品内应力。

气体辅助注射成型时间参数的CCD响应面法多目标优化

相比于传统塑料注射成型,延迟时长和注气时长是气体辅助注射成型(简称气辅成型)特有的工艺参数,增加了气辅成型的复杂性。为了精确设计延迟时长和注气时长的取值,获得理想的气体穿透效果和气指幅度,以具有典型气辅结构的塑件为研究对象,首先采用气辅成型全三维CAE研究了延迟时长和注气时长对气辅成型质量的影响。结果表明,适当增加延迟时长,可以减小或消除气指缺陷,提高气体穿透深度行程,但过长的延迟时长会导致“短射”,过短的延迟时长则会导致严重的气指缺陷;增加注气时长可以提高气体穿透效果,减少表面缺陷,降低内应力和翘曲变形,但注气时长过长时,气指内部的高压氮气会导致其撕裂而形成严重的气指缺陷,更甚者会使气辅塑件膨胀而报废。采用CCD响应面法进行多目标优化,精确设计了延迟时长和注气时长的取值,延迟时长为4 s、注气时长为10.37 s。通过CAE分析和成型试验验证,精确取值下成型的气辅塑件的气体穿透效果和气辅成型质量良好,提高了气辅成型质量和效率,可用于气辅成型实际生产。

气辅成型工艺参数正交精准设计优化

“双碳”目标下,气辅成型技术为塑料成型实现降低碳排放提供了有效途径。为精准规划气辅成型参数,提升气辅成型质量和效率,有效降低碳排放,采用三维数值模拟和成型实验,研究参数交互作用下气辅成型工艺正交优化。结果表明,参数交互作用对气体穿透长度影响小,而对气指缺陷的影响显著。极差分析的基础上,获得了优选参数组:熔体温度240℃,注气压力3 MPa,延迟时间4 s,模具温度40℃。经数值模拟和成型实验验证,优选参数组下得到气辅塑件的气体穿透长度及气指指标优良,可用于气辅成型实际生产。

典型结构气辅塑件成型工艺参数的多目标优化

熔体预注射量、熔体温度、模具温度、注气压力、延迟时间、注气时间等工艺参数直接影响了气辅成型质量。以具有典型气辅结构的塑件为研究对象,以气体穿透深度和最大气指幅度为衡量指标,采用正交试验和响应面法研究气辅成型工艺参数的影响程度及参数交互作用下的多目标精准优化。经正交试验极差分析和二次回归的响应面目标优化分析,得到最佳成型工艺为熔体预注射量为85%、注气时间为10 s、熔体温度为240℃、注气压力为3 MPa、延迟时间为4 s、模具温度为40℃。结果表明,最佳成型工艺下得到气辅塑件的气体穿透深度及气指指标较好,可用于气辅成型实际生产。

带油环凝析气藏衰竭式开发中——后期提高采收率

针对塔里木盆地Y5凝析气藏衰竭式开发过程中地层压力和气井产能快速降低、生产气油比逐渐下降、凝析油密度和黏度逐渐升高、开发效果迅速变差等问题,将生产动态特征与地层流体组分评价相结合,重新认识该气藏为带油环层状边水凝析气藏,并采用数值模拟方法确定其油环厚度。为改善开发效果,提高凝析油气采收率,系统开展带油环凝析气藏衰竭式开发中—后期提高采收率机理研究可知:完善井网、实施循环注气开发能大幅提高油气采收率,注入介质以二氧化碳最佳,气藏自产气次之;注气方式以重力辅助气驱模式最佳。基于气藏类型和提高采收率机理研究,编制了该气藏循环注气提高采收率方案,预测原油采收率较衰竭式开发提高29.96%。该气藏循环注气开发后累计注气0.19×10^(8) m^(3),地层压力恢复4.31 MPa,气井产能恢复到方案实施前的3.09倍,可为其他同类型气藏开发中—后期提高采收率提供借鉴。

基于Moldflow的汽车把手气辅注塑工艺多目标优化

汽车内饰把手是典型的棒状类零件,常采用气体辅助注射成型(GAIM)技术进行生产,以满足把手强度和轻量化要求。由于GAIM技术的成型参数多,塑件成型质量控制难度大,通过运用Moldflow模流仿真分析并结合Taguchi试验方法,以塑件的气体穿透长度和横截面最小壁厚为质量目标来优化成型工艺参数,选择熔体温度、模具温度、气体压力、气体保压时间和预注射量5个主要因素进行正交试验,采用极差分析研究上述5个工艺参数对气体穿透长度和横截面最小壁厚的影响规律,应用多目标综合平衡法得到优化的工艺参数组合,即熔体温度为250℃、模具温度为50℃、气体压力为10 MPa、气体保压时间为10 s、预注射量为75%。通过实际GAIM验证,塑件气体穿透效果良好,满足穿透长度和横截面最小壁厚的要求,塑件质量减轻25%以上,并具有良好的表面质量和尺寸精度,能够显著缩短成型周期,节约塑料材料,提高生产质量和效率,并满足汽车轻量化要求。

无人机用点燃式二冲程柴油机燃烧特性研究

针对柴油燃料雾化蒸发困难导致的发动机燃烧效果差、易爆震的问题,本文采用空气辅助缸内直喷方案,对一台点燃式二冲程柴油发动机开展燃烧特性研究。建立了点燃式二冲程柴油发动机的三维仿真模型,对混合气特性和燃烧特性进行仿真研究,并通过台架试验进行了验证。研究结果表明:点燃式二冲程柴油发动机在热机工况下,点火时刻有58%的燃油蒸发,缸内平均当量比由冷起动工况下的0.2提升至0.8,混合气品质较高,缸内燃烧情况良好。通过燃用汽油、柴油两种燃料进行发动机整机性能对比试验发现,在高转速大负荷工况下,两种燃料的燃烧特性曲线十分接近,柴油燃烧的指示平均有效压力(IMEP)的分布均值仅比汽油低1.2%。总体而言,柴油燃料应用于点燃式二冲程发动机的燃烧性能与汽油燃料相似,且使用柴油燃料时缸内压力最大震荡幅值仅为0.02 MPa,远小于爆震阈值,不会出现爆震现象。

基于空气辅助喷射不同温度航空煤油喷雾特性可视化研究

为了探明燃油温度和喷油脉宽对空气辅助航空煤油喷雾特性的影响,在定容燃烧弹上搭建空气辅助燃油喷射系统,利用高速阴影成像技术探究了不同燃油温度和不同喷油脉宽下航空煤油的喷雾特性。研究表明,当喷油脉宽为12 ms时,高温燃油液滴更倾向于沿着喷嘴径向运动,低温燃油液滴更倾向于沿着喷嘴轴向运动,燃油温度从40℃降低到-40℃时,平均索特平均直径增大了14.7%,小粒径的占比大幅度减少;燃油温度为-40℃时大喷油脉宽下出现的“两段喷雾”对喷雾前后期的贯穿距和面积有不同的影响,喷雾卷吸幅度和宽度增大,喷油脉宽从5 ms增加到14 ms时,平均索特平均直径增加了22.2%。因此低温冷起动大喷油脉宽时,适当提高燃油温度可有效促进发动机顺利起动。

圆头精子注射临床疗效的Meta分析

目的探讨圆头精子注射(ROSI)应用于圆头精子症患者的临床疗效。方法检索Medline、Embase、Cochrane Library以及ClinicalTrials.gov数据库,纳入从建库至2022年10月关于圆头精子症患者应用ROSI治疗的研究,采用荟萃分析与亚组分析评估ROSI的临床疗效。结果共纳入29项研究,共计1363例患者进行分析。ROSI后的总受精率(2PN)为37.9%(95%CI:30.7%~45.4%),总妊娠率为3.8%(95%CI:0.8%~8.1%),最终分娩率为1.8%(95%CI:0%~5.6%)。改进圆头精子的鉴别方法之后,ROSI后的妊娠率(21.2%)和分娩率(13.1%)有所提高;亚洲地区的受精率(41.5%)高于非亚洲地区(33.4%),但其妊娠率和分娩率(2.8%、0.9%)低于非亚洲地区(6.4%、5.9%)。结论ROSI对圆头精子症患者的生育具有积极意义,不同地区间ROSI治疗结局有差异。改善圆头精子的鉴别方法之后,ROSI的临床疗效得到提高。

环境背压和喷射压力对航空重油空气辅助喷射喷雾特性影响

单一重油燃料的战场作战要求使航空重油活塞发动机的研发提升到一个新的高度。本文基于点燃式四冲程航空重油活塞发动机的空气辅助喷射技术,重点研究了环境背压和喷射压力对喷雾宏观形态发展和喷雾微观粒径分布的影响。结果表明,喷雾横向贯穿距和纵向贯穿距与环境背压成反比,且呈两个阶段的发展趋势,第一阶段横向和纵向贯穿距呈线性增加;第二阶段的贯穿距增加速度放缓。喷雾纵向贯穿距随喷射压力升高而增加,不同喷射压力的喷雾锥角均是先急速增加到一定值后开始回落,慢慢趋于稳定。随环境背压的降低和喷射压力的升高,小粒径的波峰逐渐增加,大粒径的波峰逐渐降低。不同喷射压力的喷雾粒径相对频率分布趋势均呈双峰分布。

聚甲氧基二甲醚和汽油双燃料火花辅助压燃燃烧及排放试验研究

试验平台基于汽油缸内直喷(gasoline direct injection,GDI)发动机改造,缸内直喷聚甲氧基二甲醚(polyoxymethylene dimethyl ether,PODE),进气道喷射汽油,并将压缩比从10提升至15以利于压燃,以点火和直喷策略作为控制参数,获取双燃料火花辅助压燃(dualfuel spark-assisted compression ignition,DF-SACI)发动机的运行特征。试验结果表明:DFSACI呈现多阶段放热,直喷正时提前可提高混合气均匀性,减小不同燃烧阶段的界限,放热率明显提高;直喷比例可以更为有效地调节CA50和等容燃烧的比例,对热效率影响明显;同时放热率受点火正时提前的影响最小。试验中有效热效率最高可达37.5%。排放方面,DFSACI模式在合适的点火和喷射策略下,可在一定程度上降低HC和CO的排放,HC体积分数可降低至3000×10^(-6)以下,CO体积分数可降低至1500×10^(-6)以下,同时将NOx排放控制在较低水平。通过对燃烧策略的合理调整,PODE/汽油双燃料发动机借助火花辅助压燃可实现高效清洁燃烧。

基于气辅成型某汽车把手的注塑模具设计

为保证某汽车把手的注塑模具成型结构及成型质量的可靠性,基于Moldflow进行CAE注射成型模拟,确定以气辅溢流成型法作为模具设计及注射成型的方案。CAE模拟结果显示,该塑件所有效应变形量比采用气辅标准成型法塑件的变形量降低了31.3%,对充填熔体体积精准性要求较低、更容易控制,气体型芯穿透效果好,并得到最合适的浇口位置、最佳注塑工艺参数,以及气辅成型的最佳进气位置、气体延迟时间、气体注射时间、气体压力及气体保压时间等工艺参数。根据成型方案,针对性地设计了油缸驱动的气辅注气针运动机构、料道封闭运动机构及溢料槽。根据塑件产品的结构特征,利用斜导柱驱动滑块机构带动双面斜楔块运动,从而驱动一对滑块镶件相向移动,解决了在空间有限的情况下,伞形齿面及沉孔的抽芯脱模问题;设计了斜导柱驱动滑块抽芯机构,实现了筋条、转轴锥孔等特征的侧向抽芯。为确保气辅成型、塑件顶出等动作按照优化的注塑工艺安全、准确、可靠地运行,针对各运动机构,设计了相应的顺序控制及保障机构。经过注塑生产验证,模具操控调试简单方便,运行安全、准确、可靠,塑件质量稳定,符合设计要求。

新鲜周期体外受精-胚胎移植后子代单胎活产儿中小于胎龄儿的发生率及危险因素分析

目的探究女性接受新鲜周期体外受精/卵母细胞内单精子注射(IVF/ICSI)-胚胎移植(ET)助孕后子代单胎活产儿中不同程度小于胎龄儿(SGA)的发生率及危险因素。方法回顾性收集2014年4月-2020年12月于四川大学华西第二医院接受新鲜周期IVF/ICSI-ET助孕并分娩单胎活产儿的2262例患者的临床资料,根据子代出生体重在同性别、同胎龄新生儿中的百分位数将患者分为正常组(第10~第90百分位)、轻中度SGA组(第3~第10百分位)和重度SGA组(小于第3百分位)。比较不同程度SGA组与正常组患者病史及IVF/ICSI-ET相关临床资料的差异,采用多因素logistic回归筛选不同程度SGA的危险因素。结果女性接受新鲜周期IVF/ICSI-ET助孕后分娩的单胎活产儿中SGA的发生率为9.9%,其中轻中度SGA的发生率为5.0%、重度SGA的发生率为4.9%。BMI<18.5 kg/m^(2)、有自然流产史为子代发生轻中度SGA的危险因素(校正OR=4.54和1.91,95%CI=1.78~11.55和1.18~3.10);有自然流产史、早产为子代发生重度SGA的危险因素(校正OR=2.80和2.22,95%CI=1.78~4.42和1.23~3.98)。有活产史为子代发生轻中度及重度SGA的保护因素。结论接受新鲜周期IVF/ICSI-ET助孕的患者中,BMI<18.5 kg/m^(2)、有自然流产史、早产者子代发生SGA的风险增加,临床工作中应予以关注。