A new tube chamber system for evaluation of anterior chamber pressure during phacoemulsification tested in porcine eyes

AIM:To measure the optimal anterior chamber pressure(ACP)for safe phacoemulsification using a new tube chamber system with internal pressure measurement function in the porcine eye.METHODS:The 20-gauge and 21-gauge straight tips with yellow and orange sleeves,respectively,were covered by a test chamber combined with a pressure sensor for measuring ACP.This was measured for 20s from 10s after starting aspiration in the linear mode using vacuum levels of 200 and 150 mm Hg with a 20-gauge tip,and 300 and 250 mm Hg with a 21-gauge tip.Using a porcine eye,a pressure sensor fixed with a 0.9 mm corneal incision measured ACP.For the posterior capsule contact assay,porcine eyes were treated as described above,and the ultrasonic needle tip was held at the height of the iris and aspirated for 30s in linear mode at a vacuum of 200 and 150 mm Hg for the 20-gauge tip,and 300 and 250 mm Hg for the 21-gauge tip.The bottle height at which the posterior capsule accidentally contacted the ultrasonic tip was recorded,and the estimated ACP was calculated.RESULTS:The internal pressure of the new tube chamber system and ACP from the porcine eye closely matched proportional changes at vacuum levels of 200 and 150 mm Hg with 20-gauge tips.Similarly,proportional changes at vacuum levels of 300 and 250 mm Hg with the 21-gauge tip were nearly equal.The bottle height at which the posterior capsule contacted with the tip and estimated ACP were 57.5±12.6 cm(20.2±7.9 mm Hg)at 200 mm Hg with a 20-gauge tip,35.0±10.0 cm(16.6±6.3 mm Hg)at 150 mm Hg with a 20-gauge tip,47.5±12.6 cm(18.7±8.7 mm Hg)at 300 mm Hg with a 21-gauge tip,and 32.5±5.0 cm(15.7±3.5 mm Hg)at 250 mm Hg with a 21-gauge tip.CONCLUSION:A comprehensive understanding of this chamber system’s characteristics and usage can resolve anterior chamber instability caused by changing preoperative settings on the phaco machine.

Topographic factors associated with anterior chamber angle narrowing in patients with keratoconus

AIM:To identify topographic determinants of the anterior chamber angle(ACA)in patients with keratoconus(KCN).METHODS:Four hundred and ten eyes of 294 patients with KCN were recruited for this study.First,complete ocular examinations were performed for all patients,including visual acuity measurement,refraction,and slit-lamp biomicroscopy.Then,all participants underwent corneal imaging by the Oculus Pentacam HR.RESULTS:The mean age of the participants was 32.40±8.52y(15-60y)and 69.5%of them were male.The mean ACA was 38.47°±5.75°(range:14.40°to 56.50°)in the whole sample,38.24°±6.00°in males,and 38.98°±5.11°in females(P=0.447).The mean ACA was significantly different among different groups of cone morphology,as patients with nipple cones showed the lowest mean ACA.Moreover,there were statistically significant differences in the mean ACA among different groups of cone locations,with patients having central cones exhibiting the lowest mean ACA(P<0.001).Anterior and posterior Q values were significantly,directly correlated with ACA(anterior Q:r=0.122,P=0.014,posterior Q:r=0.192,P<0.001).CONCLUSION:This study provides critical insights into the risk factors for ACA narrowing in KCN patients,which is essential for planning intraocular surgeries.Patients with nipple and central cones exhibited the most significant ACA narrowing.Additionally,more negative Q-values are associated with increased ACA narrowing,highlighting the need for targeted diagnostic and therapeutic strategies.

Promotion of Semiautomatic Piecing Quality in Rotor Spinning

Discussed in the article are the factors for the imperfect quality of piecing based on the principles and the key technologies of semiautomatic piecing. Furthermore, three measures including changing the shape of seed yarn tail, changing the feed speed and removing the damaged fibers are put forward. Experimental results prove that the former two, especial the second one, offers better piecing quality.

Research on Cam-linkage Mechanism of Automatic Piecing Device

The principle of an automatic piecing device is presented, and the mathematic model of a specific combined mechanism of the automatic piecing device is analysed. The kinematics and dynamics equation of the combined mechanism is established on the basis of the mathematic model. By the virtual prototype technology, the motion of this mechanism is simulated, whose result is post-processed by ADAMS. To improve the output motion, according to the simulation output and automatic piecing device's practical working condition, the optimisation of the cam mechanism is carried out by finite difference method. The simulation result of this combined mechanism turns out in accordance with its theoretical analysis of virtual prototype in this research, which, therefore, lays a principle basis for the further study of automatic piecing device.

One-piece coal mine mobile refuge chamber with safety structure and less sealing risk based on FEA

In order to reduce the risk of sealing and improve the structural strength for a coal mine mobile refuge chamber,a new type of one-piece model was designed.Mechanical and mathematical calculation performed an important role.Calculated according to statics and relevant contents,the structure had the same total volume as the traditional segmented structure,but had shorter length,wider width and greater height.Those prevented the structure from stress or deformation failure.Some reinforcing ribs with enough moments of inertia were welded in the external shell.Because of the one-piece structure,this refuge chamber reduced the risk of sealing which was a serious problem of segmented structure.Impact load with 300 ms duration and0.6 MPa over-pressure was settled.Explicit nonlinear dynamic analysis program was used to simulate the response of the refuge chamber.The maximum stress and the maximum displacement were obtained.The refuge chamber including blast airtight doors could meet the rigidity requirement.Weak parts of the chamber were the front and back end shell where bigger displacement values occurred than others.Thus,the calculation indicated that the refuge chamber could meet structural safety requirements.Based on the numerical analysis,suggestions were put forward for further resistance ability improvement.Only large inclined shaft with larger wellhead was suitable for this one-piece coal mine mobile refuge chamber.

Cognate Mafic Enclaves Formed by Cumulated Mush Convection in a Granitic Magma Chamber:Evidence from Mineral Chemistry of the Triassic Zhashui Pluton,Qinling Orogen

Mafic enclaves in granites are generally considered to represent coeval mafic melts that derived from metasomatized mantle,which can provide valuable information about crust-mantle interaction.Exploring the genetic links between the mafic enclaves and their host monzogranite from the Triassic Zhashui Pluton,Qinling orogenic belt.The enclaves(220±4.6 Ma)and the monzogranite(220±2.8 Ma)display identical zircon U-Pb ages,and they also share similar trace element and zircon Lu-Hf isotopes,indicating a cognate source.The monzogranite displays zirconεHf(t)values of−0.99 to+1.98,while the mafic enclaves show similar values of−0.45 to+3.26;however,differences in mineral chemistry reveal different crystallization conditions.The amphibole from the mafic enclaves has higher temperature and pressure(757℃;2.65 kbar)compared to those of the host monzogranite(733℃;1.96 kbar),suggesting that mafic minerals in the enclaves crystallized at an early stage.Moreover,apatite in the mafic enclaves displays slightly higher volatile contents(0.72 wt%)than those of the monzogranite(0.66 wt%),indicating a volatile-rich condition.These results suggest that the mafic enclaves represent early hydrous mafic cumulates in the granitic chamber,and subsequent magma convection would have led to the formation of the mafic enclaves.

Simulation and reconstruction of particle trajectories in the CEPC drift chamber

The circular electron-positron collider(CEPC)is designed to precisely measure the properties of the Higgs boson,study electroweak interactions at the Z-boson peak,and search for new physics beyond the Standard Model.As a component of the 4th conceptual CEPC detector,the drift chamber facilitates the measurement of charged particles.This study implemented a Geant4-based simulation and track reconstruction for the drift chamber.For the simulation,detector construction and response were implemented and added to the CEPC simulation chain.The development of track reconstruction involves track finding using the combinatorial Kalman filter method and track fitting using the tool of GenFit.Using the simulated data,the tracking performance was studied.The results showed that both the reconstruction resolution and tracking efficiency satisfied the requirements of the CEPC experiment.

Fudan multi-purpose active target time projection chamber(fMeta-TPC)for photonuclear reaction experiments

Active target time projection chambers are state-of-the-art tools in the field of low-energy nuclear physics and are particularly suitable for experiments using low-intensity radioactive ion beams or gamma rays.The Fudan multi-purpose active target time projection chamber(fMeta-TPC)with 2048 channels was developed to studyα-clustering nuclei.This study focused on the photonuclear reaction with a laser Compton scattering gamma source,particularly for the decay of the highly excitedαcluster state.The design of fMeta-TPC is described in this paper.A comprehensive evaluation of its offline performance was conducted using an ultraviolet laser and ^(241)Amαsource.The results showed that the intrinsic angular resolution of the detector was within 0.30°,and the detector had an energy resolution of 6.85%for 3.0 MeVαparticles.The gain uniformity of the detector was approximately 10%(RMS/Mean),as tested by the ^(55)Fe X-ray source.

Effect of coil and chamber structure on plasma radial uniformity in radio frequency inductively coupled plasma

Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial manufacturing.This study utilized a two-dimensional self-consistent fluid model to investigate how different coil configurations and chamber aspect ratios affect the radial uniformity of plasma in radio frequency ICP.The findings indicate that optimizing the radial spacing of the coil enhances plasma uniformity but with a reduction in electron density.Furthermore,optimizing the coil within the ICP reactor,using the interior point method in the Interior Point Optimizer significantly enhances plasma uniformity,elevating it from 56%to 96%within the range of the model sizes.Additionally,when the chamber aspect ratio k changes from 2.8 to 4.7,the plasma distribution changes from a center-high to a saddleshaped distribution.Moreover,the plasma uniformity becomes worse.Finally,adjusting process parameters,such as increasing source power and gas pressure,can enhance plasma uniformity.These findings contribute to optimizing the etching process by improving plasma radial uniformity.

Origin of Felsic Microgranitoid Enclaves in Granite in Zhangjiakou District,China:Implication for Process and Lifespan of Granitic Magma Chambers

Sparse felsic microgranitoid enclaves(FMEs)in the Shangshuiquan granite of the Zhangjiakou district,the north margin of the North China Craton,are fine-grained,dark-colored and exhibit subangular to subspherical shapes.They share similar mineral assemblages,chemical compositions,and zircon Hf isotope compositions to the host granite.New zircon U-Pb geochronology reveals that the FMEs crystallized at 156-153 Ma,while the Shangshuiquan granite formed at ca.146 Ma.The FEMs are,therefore,10 to 7 Ma older than the host granite.Combined with petrological evidence,we suggest that the FMEs are fragments of rapidly crystalized magmas,which were captured by the younger Shangshuiquan magma.Magmas of the FMEs and Shangshuiquan granite originated from the same reservoir.The Shangshuiquan granite is the result of small batches of magma being built up incrementally,and the FMEs belong to the earlier batches of magma.The lifespan of the Shangshuiquan magma reservoir exceeds 10 Ma.FMEs derived from cogenetic fragments have the potential to offer critical information about the formation process and timescale of granitic plutons.

AEROpiecing技术的创新

R40转杯纺纺纱机配置的新型AEROpiecing气动接头装置可有效地提高转杯纺纱线的质量,以及用这种纱线生产的成品质量。诚然,在开发过程中,也开发了必须的计算方法和测量方法,以便能产生更好的和更近似原纱的均匀的接头质量。

INSURE技术联合T-piece治疗新生儿呼吸窘迫综合征的临床有效性

目的探讨新生儿呼吸窘迫综合征(respiratory distress syndrome,RDS)采用INSURE技术+Tpiece方法完成治疗的有效性。方法回顾性选取2023年1—12月齐齐哈尔医学院附属第二医院收治的50例RDS患儿的临床资料,根据不同的治疗方法分为对照组(25例,复苏囊+INSURE技术)、研究组(25例,INSURE技术+T-piece方法)。比较两组血氧饱和度最低值、平均吸氧浓度、鼻塞持续气道正压通气应用时间、心率、并发症发生率。结果研究组血氧饱和度最低值为(90.79±3.59)%,高于对照组的(81.33±2.85)%,差异有统计学意义(t=10.319,P<0.05)。研究组平均吸氧浓度、鼻塞持续气道正压通气应用时间、心率优于对照组,差异有统计学意义(P均<0.05)。两组并发症总发生率比较,差异无统计学意义(P>0.05)。结论临床对RDS患儿在治疗期间,将INSURE技术以及T-piece方法进行充分结合,可有效改善患儿的氧合及血气指标,促进病情康复。

Clinical Effect Analysis of Posterior Chamber Intraocular Lens Implantation for Correcting High Myopia and Astigmatism

Objective:To explore the corrective effect of posterior chamber intraocular lens implantation with phakic eyes in the treatment of high myopia and astigmatism.Methods:From May 2023,the hospital began to collect the case data of diagnosis and treatment of high myopia and astigmatism.By May 2024,310 cases were included,all of which were treated with posterior chamber intraocular lens implantation.The visual acuity,astigmatism and axial position of the intraocular lens were observed before and after treatment.Results:At different time points after the operation,the patient’s vision was significantly improved compared with that before the operation(P<0.05),and the vision level was equal to or greater than the best-corrected vision before the operation.At different time points after the operation,the average rotation of the intraocular lens was less than 5 degrees.Astigmatism was significantly lower than that before the operation(P<0.05).After the operation,the intraocular pressure increased in 11 cases,accounting for 3.55%,with no adverse complications such as lens turbidity,glare and obvious halo occurring.Conclusion:The posterior chamber intraocular lens implantation with phakic eyes has an ideal correction effect in the treatment of high myopia and astigmatism,which can effectively improve the vision level of patients and reduce the degree of astigmatism,and has high effectiveness and safety.

低水平γ射线空气比释动能高气压电离室研制

受限于探测器灵敏度,现有手段在防护水平和环境水平γ射线参考辐射空气比释动能的中、下段范围,即0.1~100μGy/h剂量率,量值复现的不确定度较大,无法满足科研、环境监测等发展的需求。因此,为了解决上述问题,基于理论分析与蒙卡模拟优化,开展专用于低水平γ射线参考辐射测量的高气压型标准电离室的优化设计并形成KAS型样机。通过研制的KAS电离室标准与德国PTW公司生产的空腔型标准电离室的测量结果及不确定分析结果的比对表明,利用新研制的KAS测量标准在保证测量准确度的同时能够显著降低低水平空气比释动能量值复现的不确定度,使得0.5μGy/h~1 mGy/h的γ射线空气比释动能率的不确定度降低至1.3%(k=2)。

从《伤寒杂病论》痰饮病邪的悸动性特征辨治特发性震颤

《伤寒杂病论》中与痰饮相关的条文反映了痰饮病邪的悸动性特征,如痰饮流窜躯体可致动、振、摇症,痰饮上蒙心窍可致心悸动、烦躁,痰饮上冲脑窍可致悸眩难立,等等。特发性震颤(ET)肢体颤动、症状突发突止、病症反复、病情缠绵等特点与痰饮致病的悸动性特征相符,故临床治疗ET可以《伤寒杂病论》中痰饮相关条文为参考,以蠲化痰饮为目标,遵循“温药和之”原则,急则解表疏风、调和营卫,缓则托透并举、诸脏共调。

罗丹明123经大鼠空肠黏膜的体外Ussing chamber渗透研究

目的:检测并评价罗丹明123(R123)经空肠黏膜渗透的特点,分析此法的可行性。方法:配制R123溶液,采用体外Ussing chamber实验法,考察R123经时经大鼠空肠黏膜吸收方向和分泌方向的累计透过量,并计算各自渗透系数。结果:R123吸收和分泌方向的表观渗透系数Papp(×10-5,cm.s-1)分别为(1.9±1.3)和(7.4±5.2),差异具显著性。结论:R123作为P-糖蛋白的底物,其经肠黏膜渗透以分泌方向为主;Ussing chamber实验用于评价药物在肠道内转运具有易操作,简便等特点,值得推广使用。

基于Ussing Chamber技术的红景天苷大鼠肠黏膜透过性研究

[目的]研究红景天苷在大鼠离体肠黏膜中的透过情况。[方法]采用Ussing Chamber技术,考察不同浓度红景天苷于大鼠肠黏膜透过情况,并考察维拉帕米(Ver)和十二烷基硫酸钠(SDS)对红景天苷大鼠肠黏膜透过的影响。[结果]不同浓度红景天苷在大鼠不同肠段的单位时间转运速率(Flux)随浓度升高而增大,不同肠段表观渗透系数(P_(app))无统计学差异(P>0.05)。Ver加入一定量的SDS后,红景天苷在回肠和结肠的P_(app)显著增加(P<0.01或P<0.05),当SDS浓度为2 g/L时,回肠P_(app)增加为对照组的2.76倍。[结论]红景天苷在大鼠全肠段均有吸收,且吸收具有浓度依赖性,以被动吸收为主,Ver对红景天苷大鼠各肠吸收无影响,SDS促进了红景天苷回肠和结肠吸收。

A Smog Chamber Facility for Qualitative and Quantitative Study on Atmospheric Chemistry and Secondary Organic Aerosol

In order to investigate the atmospheric oxidation processes and the formation of secondary organic aerosol （SOA）, an indoor environmental reaction smog chamber are constructed and characterized. The system consists of the collapsible ～830 L FEP Teflon film main reactor, in which the atmospheric chemical reactions take place and the formation of SOA occurs under the simulated atmospheric conditions, and the diverse on-line gas- and particle-phase instrumentation, such as the proton transfer reaction mass spectrometer, the synchrotron radiation photoionization mass spectrometer, the aerosol laser time-of-flight mass spectrometer, and other traditional commercial instruments. The initial characterization experiments are described, concerning the temperature and ultraviolet light intensity, the reactivity of the pure air, the wall loss rates of gaseous compounds and particulate matter. And the initial evaluation experiments for SOA yields from the ozonolysis of α-pinene and for mass spectra of the products resulting from the photooxidation of OH initiated isoprene are also presented, which indicate the applicability of this facility on the studies of gas-phase chemical mechanisms as well as the formation of SOA expected in the atmosphere.

Src-MAPK信号通路参与透明质酸寡糖片段诱导PIEC细胞的增殖

探讨透明质酸小片段(Hyaluronan oligosaccharides,o-HA)对血管内皮细胞生长的影响及机制。采用细胞计数、流式细胞术、Western blot等方法,检测o-HA作用于内皮细胞后,Src激酶、丝裂原活化蛋白激酶MAPK(ERK-1/2)的磷酸化程度及细胞周期蛋白D1的表达水平。o-HA在10μg/ml浓度时可明显地促进血管内皮细胞的增殖,包括细胞周期水平及细胞数量。继续增加o-HA的浓度及延长培养时间均未出现进一步的变化；细胞增殖在12h开始出现,72h达到高峰。1μg/ml的o-HA作用于细胞2min后,胞内Src激酶、ERK-1/2的磷酸化程度即增强,并在3h后检测到周期蛋白D1的表达水平增高。o-HA具有促进血管内皮细胞增殖的作用,其机制可能是通过激活Src激酶及细胞内MAPK信号通路,从而促进血管内皮细胞生长；该作用也可能与上调周期蛋白D1的表达有关。

Ussing Chamber技术在家禽肠道营养物质转运研究中的应用

本文简要介绍Ussing chamber(尤斯灌流)系统的基本构造和原理,总结Ussing chamber技术在家禽肠道营养物质转运中的应用,指出使用过程中可能存在的问题,并探讨解决问题的途径。