基弧区非球面设计角膜塑形镜对近视青少年角膜屈光度、角膜内皮及眼轴增长的影响

目的:探讨基弧区非球面设计角膜塑形镜对近视青少年角膜屈光度、角膜内皮及眼轴增长的影响。方法:回顾性分析98例近视(-1.00 D~-3.50 D)患者的病历资料。根据所选基弧区设计的不同角膜塑形镜分为两组,基弧区球面设计为S组(n=50);基弧区非球面设计为A组(n=48)。比较两组患者戴镜前及配戴3个月后角膜地形图上角膜4个轴方向及顶点处角膜的屈光力值、角膜相对屈光力,戴镜前及1年后角膜内皮相关系数与眼轴。结果:S组除T1、S1、I1.5,A组除I1外其余各点位角膜相对屈光力均发生变化(P<0.05),两组戴后角膜相对屈光力由戴前的负屈光力朝正屈光力方向改变。戴镜后两组在角膜直径3 mm内的各点位上比较有统计学差异(P<0.05)。1年后S组眼轴增长(0.31±0.20)mm,A组增长(0.20±0.19)mm,两组比较有统计学差异(P<0.05)。结论:近视青少年佩戴基弧区非球面设计角膜塑形镜后角膜相对屈光力朝正屈光力方向改变,在角膜直径3 mm内表现出更明显的非球面治疗区,眼轴增长更慢,对角膜内皮相关指数无影响。

基弧区非球面设计与球面设计角膜塑形镜在近视伴中高度散光青少年中的应用效果比较

目的:比较基弧区非球面设计与球面设计角膜塑形镜在近视伴中高度散光青少年中的应用效果。方法:选取2019年2月—2022年2月于江苏大学附属武进医院诊治的190例(380眼)近视伴中高度散光青少年患儿作为研究对象。依据随机数表法将患儿均分为对照组(95例190眼)和研究组(95例190眼)。对照组予以基弧区球面设计角膜塑形镜,研究组予以基弧区非球面设计角膜塑形镜。比较两组临床应用效果及佩戴不良反应发生情况。结果:干预前,两组近视度、散光度及裸眼视力(UCVA)比较,差异无统计学意义(P>0.05)。干预后,两组近视度、散光度均优于干预前,且研究组优于对照组,差异有统计学意义(P<0.05);干预后,两组UCVA低于干预前,且研究组低于对照组,差异有统计学意义(P<0.05)。两组干预前后眼表形态及组内睑板腺缺失程度评分比较,差异无统计学意义(P>0.05);干预后,两组仅眼表疾病指数量表(OSDI)评分低于干预前,差异有统计学意义(P<0.05)。两组干预前后泪膜稳定性比较,差异无统计学意义(P>0.05);干预后,两组泪膜破裂时间(BUT)、泪液分泌实验(LST)低于干预前,角膜荧光素染色实验(FL)高于干预前,差异有统计学意义(P<0.05)。两组佩戴不良反应发生率比较,差异无统计学意义(P>0.05)。结论:在青少年近视伴中高度散光的临床矫正治疗中,基弧区非球面设计角膜塑形镜的矫正效果明显优于基弧区球面设计角膜塑形镜;两种塑形镜对患者眼表形态和泪膜稳定性影响无明显差异,且在佩戴过程出现的不良反应无差异。

配戴基弧非球面设计角膜塑形镜控制近视的临床效果

目的:评价配戴基弧非球面设计角膜塑形镜控制近视的临床效果。方法:前瞻性研究。选取2020-01/2021-07于我院验配角膜塑形镜的8~13岁近视患者94例94眼(单眼接受角膜塑形镜治疗者,选取该眼作为观察眼,双眼均接受角膜塑形镜治疗的患者则以右眼作为观察眼),根据患者所配戴的角膜塑形镜基弧区的设计不同分为观察组:配戴基弧非球面设计的角膜塑形镜患者46例;对照组:配戴基弧球面设计的角膜塑形镜患者48例。根据两组患者戴镜前等效球镜(SE)不同进一步分为低度近视组(-3.00D<SE≤-0.75D)52例52眼和中度近视组(-6.00D<SE≤-3.00D)中度近视组42例42眼。评估戴镜后1d,1wk,1、3、6、9mo,1a裸眼视力,并于戴镜后6mo,1a分别测量眼轴。结果:所有患者均完成随访,戴镜1mo后观察组裸眼视力(LogMAR)-0.12±0.08与对照组(-0.17±0.07)比较无差异(P>0.05);两组患者戴镜后6mo,1a眼轴增长平均值均无差异(均P>0.05)。低度近视组中,观察组戴镜1a眼轴增长值为0.19±0.17mm,明显低于对照组(0.31±0.18mm)(P<0.05);中度近视组中,观察组戴镜1a眼轴增长值为0.22±0.18mm,与对照组(0.19±0.12mm)比较无差异(P>0.05)。戴镜后6mo,1a观察组低度近视组与中度近视组眼轴增长值无差异(P>0.05),而对照组低度近视与中度近视组戴镜后6mo(0.15±0.13 vs 0.05±0.12mm)、1a(0.31±0.18 vs 0.19±0.12mm)眼轴增长值均有差异(均P<0.05)。结论:配戴基弧非球面设计角膜塑形镜可以有效提高裸眼视力,延缓眼轴增长。对于低度近视患者,基弧非球面设计角膜塑形镜延缓眼轴增长的效果优于基弧球面设计。

基弧区非球面设计角膜塑形镜对青少年近视伴中高度散光眼表的影响

目的:探究基弧区非球面设计角膜塑形镜矫正青少年近视伴中高度散光的疗效及其对眼表形态与泪液的影响。方法:选取2018-12/2020-03于本院接受治疗的近视伴中高度散光青少年患者232例464眼为研究对象,随机分为对照组(116例232眼)和观察组(116例232眼),对照组采用基弧区球面设计角膜塑形镜矫正,观察组采用基弧区非球面设计角膜塑形镜矫正。配戴12mo后,比较两组患者矫正效果,配戴前后客观视觉质量、眼表形态、泪液相关指标及并发症发生率。结果:与配戴前比较,两组患者配戴后裸眼视力(UCVA)、屈光度均明显改善,且观察组UCVA、屈光度均显著优于对照组(均P<0.05);与配戴前比较,两组患者配戴后全眼与角膜彗差、球差、高阶像差上升,而斯特列尔比值、调制传递函数下降,角膜三叶草差明显上升(均P<0.05),观察组患者全眼与角膜彗差、球差、高阶像差、斯特列尔比值、调制传递函数均优于对照组,角膜三叶草差优于对照组(均P<0.05);与配戴前比较,两组患者配戴后角膜上皮荧光染色评分、眼表疾病指数(OSDI)量表评分均明显下降(P<0.05),但两组间无差异(P>0.05);与配戴前比较,两组患者配戴后非侵入式泪膜破裂时间(NI-BUT)显著下降(P<0.05),但两组间无差异(P>0.05),且配戴前后两组患者泪液基础分泌量及泪河高度均无差异(P>0.05)。观察组与对照组配戴后并发症发生率无差异(6.9%vs 6.0%,P>0.05)。结论:基弧区非球面设计角膜塑形镜矫正青少年近视伴中高度散光的矫正效果及客观视觉质量优于球面设计角膜塑形镜,而两种角膜塑形镜对眼表形态与泪液影响相当。

不同基弧软性角膜接触镜对 LASEK 的影响

目的:探讨不同基弧软性角膜接触镜对准分子激光上皮下角膜磨镶术(LASEK)的影响。方法:对186例372眼近视患者施行LASEK手术,随机分为观察组和对照组,激光切削后分别配戴-1.0D基弧为8.7,8.5mm的软性角膜接触镜。术后1,3,5d比较两组术后角膜刺激症状,术后5d比较角膜上皮愈合时间、裸眼视力,术后1mo比较两组裸眼视力,术后3mo比较角膜上皮下雾状混浊(haze)程度。结果:术后1,3,5d观察组角膜刺激症状明显好于对照组,差异有统计学意义(P<0.05)。术后5d角膜上皮愈合时间、裸眼视力观察组明显好于对照组,差异有统计学意义(P<0.05)。术后1mo两组裸眼视力无明显差别,差异无统计学意义(P>0.05)。术后3mo两组haze比较差异无统计学意义(P>0.05)。结论:LASEK术后应适当增加需配戴的软性角膜接触镜的基弧,可以减轻角膜刺激症状,促进角膜上皮愈合和视力恢复。

浅谈角膜接触镜的基弧和直径及配镜时应注意的问题

软性角膜接触镜(俗称隐形眼镜)的基弧和直径是其基本光学性能的反映,近几年国家食品药品监督管理局(以下简称国家局)的抽验及四川省医疗器械检测中心抽验的结果均反映出:这两个项目的不合格率很高。假如戴了质量不合格的眼镜,容易引起角膜炎、结膜炎、角膜血管增生甚至白内障等严重疾病。因此患者在选购时一定要注意选择合适自己眼睛的质量合格的隐形眼镜,并应早戴晚摘,保持清洁卫生,定期复查。

泪液镜中0.05mm基弧差带来0.25D屈光度的差异是标准吗?

RGP临床验配时,验配师在遇到患者弧度超出厂家试戴片弧度范围的时候,一般会采取如下3种处理方式:1.如果这个品牌试戴片没有验配师需要的基弧,那么就换另外品牌的试戴片;2.先预测几个相应大小的弧度,然后联系厂家定制试戴片,待试戴片到医院后再进行试戴,然后确定患者的弧度和度数.

从戴用SCL不适者看基弧检测的重要性

配戴软件隐形眼镜(SCL)前未测角膜曲率和镜片的内基弧(BC),或检测不准确而配戴不合适基弧的镜片时都会给配戴者带来不必要的痛苦与损失。 配戴软性隐形眼镜之前,检测眼的屈光状态,测定基弧和检查眼睛有无不适合配戴隐形眼镜的疾病,是必不可少的三项主要检测项目,据此才能对每一位配戴者作出正确的评估,选配合适的隐形眼镜。

急性分离的肺泡Ⅱ型上皮细胞钠通道亚基mRNA表达

目的研究急性大鼠肺泡II型细胞钠通道各亚基的表达。方法20只健康SD大鼠,对其肺泡II型上皮细胞进行分离、纯化,逆转录-聚合酶链反应(RT-PCR)技术半定量检测ENaC三个亚单位α、β、γmRNA水平。结果急性分离纯化大鼠肺泡Ⅱ型上皮细胞ENaC三个亚单位均有表达,其中α-亚基mRNA表达最强,显著高于β-和γ-亚基,β-和γ-亚基mRNA表达无显著性差别。结论大鼠肺泡II型细胞钠通道在DNA水平上表达以α-亚基为主,α-亚基在肺水清除中起主要作用。

软性抛弃型角膜接触镜基弧的选择及评价

本文用Ｓｕｒｅｖｕｅ抛弃型镜片对１５３例软性角膜接触镜配戴者做镜片基弧选择和配戴临床评价的研究。分为三组：①基弧为８．８ｍｍ配戴组；②先戴基弧为８．８ｍｍ，后换戴８．４ｍｍ对照组；③一眼戴基弧８．８ｍｍ，另眼戴基弧８．４ｍｍ同时对照组。所有镜片的直径为１４ｍｍ。评价项目：角膜曲率、镜片中心位置、镜片活动度、配戴者的主观感觉评价。结果表明：角膜曲率计读数在镜片基弧选择中仅起参考作用，基弧的选择应根据临床配戴评价而定。对于Ｓｕｒｅｖｕｅ抛弃型镜片（直径１４ｍｍ），８．８ｍｍ基弧镜片为首选镜片。

Surface modification of biomedical magnesium alloy wires by micro-arc oxidation

Magnesium alloy wires were processed by micro-arc oxidation （MAO） in a modified silicate-phosphate composite electrolyte containing hydroxyapatite （HA） nanopowders and NaOH. Effects of NaOH content in the composite electrolyte on the microstructure and properties of the MAO ceramic coatings on magnesium alloy wires were studied. It is found that the arc voltage of magnesium alloy wires in the micro-arc oxidation process is significantly reduced while the oxidation rate is accelerated. Addition of 2 g/L NaOH in the composite electrolyte is a better choice for improving corrosion resistance of magnesium alloy wires. During early simulated body fluids （SBF） immersion, the micro-arc oxidized magnesium alloy wires undergo a slow and stable degradation. After soaking for 28 d, the protective ceramic coating still shows no damage but significant degradation is observed for magnesium alloy wires after immersion for more than 60 d.

Construction of a vscC in-frame Deletion Mutant of Vibrio alginolyticus

[Objective] The purpose of this study was to construct a vscC in-frame deletion mutant of Vibrio alginolyticus with no antibiotic resistance marker. [Method] The first vscC mutant molecules in vitro were generated by SOE-PCR and then lig- ated to a suicide vector pDM4 to construct a suicide recombinant vector pDM4- A vscC. To clone the recombinant vector, it was transformed to E. coli SY327 strain, and then positive clones were selected and proved by PCR analysis. After that, the pDM4-AvscC DNA was extracted in large numbers and transformed to the E. coil S17-1 strain that acted as a donor in bacterial conjugation using the heat shock method. The recombinant E. coli S17-1 strains then transferred the pDM4-AvscC to V. alginolyticus ZJ51-O by conjugation method; transconjugants were screened and selected sequentially using antibiotic selection strategy and sucrose based counter-selection system to find the suspected mutants wanted. Finally the putative mutants were identified by PCR and confirmed by sequencing analysis. [Result] ZJ51-OAvscC was successfully constructed. [Conclusion] This study laid foundation for further research on the function of vscC gene and molecular mechanism of type Ⅲ secretion system in V. alginolyticus. Simultaneously, by the effective method other unknown functional genes in V. alginolyticus genome would be researched.

Effect of arc-ultrasound on microstructures and mechanical properties of plasma arc welded joints of SiC_p/Al MMCs

The effect of arc-ultrasound on microstructures and mechanical properties of SiCp/6061A1 MMCs joints produced by arc-ultrasound plasma arc ＂in-situ＂ alloy-welding with different excitation frequencies was investigated, in which argon-nitrogen mixture was used as plasma gas, Ti wire as filler and the arc-ultrasound was produced by modulating the plasma arc with high frequency. The results show that arc-ultrasound could refine the new reinforced composites such as TiC, TiN significantly, and improve their distribution greatly. And new phase A13Ti becomes finer and less. The test results of mechanical properties indicate that the maximum tensile strength of welded joints is gained when the excitation frequency is 50 kHz, and the maximum is 225 MPa, raising by about 7% comoared with conventional nlasma arc welding （PAW） （20q MPa）.

Effect of alkali treatments on apatite formation of microarc-oxidized coating on titanium alloy surface

Alkali treatments with three concentrations were used to modify a microarc-oxidized(MAO) coating on titanium alloy surface in order to further improve its surface bioactivity. Morphology, chemical compositions and phase constitues, roughness, contact angle and apatite induction of the alkali-treated coatings were studied and compared. Scanning electron microscope(SEM) was applied to observe the morphologies, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) were used to detect the phase constitutes and chemical compositions, a surface topography profilometer was used to analyze the surface roughness, and contact angle was measured by liquid drop method. Alkali treatements result in the formation of Na2Ti6O13 and Na2Ti3O7 phase on the MAO coating, which leads to the increase of surface roughness and the decrease of contact angle. Experimental results showed that the apatite induction of the alkali-treated coatings was dependent on the applied alkali concentrations during treatments, and Na+concentration can promote the formation of apatite phase.

Effect of Ti-Si-Mg-Al wire on microstructure and mechanical properties of plasma arc in-situ welded joint of SiC_p/Al composites

The influence of Ti-Si-Mg-AI wire on microstructure and mechanical properties of SiCp/A1 metal matrix composite joints produced by plasma arc in-situ weld-alloying was investigated. Argon-nitrogen mixture was used as plasma gas and Ti-Si-Mg-A1 flux-cored wires as filled composites. Weldments were submitted to tensile test. Meanwhile, the macro morphology and microstructure of the joints were examined. The result shows that the formation ofneedie-like harmful phase A14C3 is effectively inhibited and the wettability of molten pool is improved by adding Ti-Si-Mg-A1 flux-cored wires. With 15Ti-5Si-5Mg-A1 flux-cored wire as filled composite, the maximum tensile strength of the welded joint is 267 MPa, which is up to 83% that of the matrix composites under annealed condition.

马尼拉俯冲带北段增生楔形态结构及演化过程

为揭示马尼拉增生楔的形态结构并加深对其演化过程的理解,本文对横穿马尼拉俯冲带北段的几条典型地震剖面进行了深度偏移处理,得到叠前深度偏移剖面和深度-速度模型,并对马尼拉增生楔的形态结构及内部特征进行了精细解释,将马尼拉增生楔分为原始沉积段、褶皱变形段、逆冲推覆段和背逆冲段四个部分,分别代表增生楔演化的不同阶段。推断马尼拉增生楔下部存在由早期仰冲的菲律宾海板块的残留块体构成的弧前基盘,弧前基盘是控制马尼拉增生楔形成演化的关键构造。弧前基盘前端是拆离滑脱面突然降阶并在地震剖面上“隐没”的部位;弧前基盘向增生楔底部的不断挤入导致了逆冲脱序断层的渐次发育以及增生楔向弧前基盘之上的不断爬升,导致了增生楔上、下陆坡地貌的分化,并为褶皱变形段和逆冲推覆段的地层形变提供了主要的应力。

基弧区非球面设计角膜塑形镜对客观视觉质量的影响

目的:观察基弧区非球面设计角膜塑形镜对客观视觉质量的影响。方法:前瞻性临床研究。选择2019年8月至2020年3月在沈阳爱尔眼视光医院验配角膜塑形镜的近视患者60例(60眼),根据患者所选择的角膜塑形镜基弧区设计不同进行分组,非球面组30例(30眼)配戴基弧区非球面设计的角膜塑形镜;球面组30例(30眼)配戴基弧区球面设计的角膜塑形镜。在戴镜前和戴镜后6个月测量2组患者在5 mm瞳孔直径下的全眼和角膜的高阶像差(HOA)、球差(SA)、彗差、三叶草差和调制传递函数(MTF)、斯特列尔比值(SR)等。取左眼数据用于统计分析。组内戴镜前后波前像差及MTF、SR比较采用配对t检验进行分析,组间各项参数比较采用独立样本t检验和Mann-WhitneyU检验。结果:与戴镜前相比,2组患者配戴角膜塑形镜后全眼和角膜的HOA、SA、彗差均增加,SR、MTF均下降,差异均有统计学意义(均P<0.001)。球面组、非球面组戴镜后角膜的三叶草差均较戴镜前增加,差异有统计学意义(t=-3.69,P=0.001;t=-3.41,P=0.002)。组间全眼HOA、SA、彗差增加量比较差异具有统计学意义(t=4.36,P<0.001;t=2.13,P=0.038;t=4.51,P<0.001),组间角膜HOA、彗差增加量比较差异有统计学意义(t=2.84,P=0.006;t=2.69,P=0.009);组间其余像差和SR、MTF改变量差异均无统计学意义。结论:角膜塑形镜基弧区的不同设计影响患者的客观视觉质量。相比于基弧区球面设计角膜塑形镜,患者配戴非球面设计角膜塑形镜后客观视觉质量更好。

Cloning,Expressing,and Hemolysis of tdh,trh and tlh Genes of Vibrio parahaemolyticus

Vibrio parahaemolyticus (VP) is one of the pathogenic vibrios endangering net-cage cultured Pseudosciaena crocea,Fennerpenaeus chinensis, and shellfish in coastal areas of China. Several types of hemolysins produced by Vp have been characterized as major virulence factors.They are thermostable direct hemolysin (TDH),TDH-related hemolysin (TRH) and thermolabile hemolysin (TLH). In this study, we cloned tdh, trh, and tlh genes from the genome DNA of VP by polymerase chain reaction (PCR).We ligated the three genes into prokaryotic expression vector pET-28a (+),and transformed the recombinant plasmids into Es-cherichia coli BL21 (DE3). The expression of recombinant proteins was induced by isopropyl-β-D-thiogalacto-pyranoside (IPTG). The recombinant proteins were expressed in a form of inclusion bodies and thus purified with Ni-NTA affinity chromatography. Western blotting results showed that recombinant proteins,TDH, TRH and TLH, could be recognized by rabbit anti-VP serum. The three purified proteins were renatured by gradient dialysis.The renatured proteins exhibited hemolytic activity except for TLH in the presence of phosphatidylcholine. These results not only are helpful for better understanding these genes' functions under a single factor level, but also provide evidence for VP vaccine engineering.

Parameter optimization for tungsten carbide/Ni-based composite coating deposited by plasma transferred arc hardfacing

Ni-based composite coatings with a high content of tungsten carbides(Stelcar65composite coatings)were synthesized by plasma transferred arc(PTA)hardfacing.The welding parameters of Stelcar65composite coatings were optimized by orthogonal tests.The PTA welding parameters including welding current,powder feed rate and welding speed have significant influence on the tungsten carbide degradation.The values for the optimum welding current,powder feed rate and welding speed were determined to be100A,25g/min and40mm/min,respectively.The produced WC/Ni-based composite coatings were crack-and degradation-free.The microstructure of deposited layers,as well as the microstructure and microhardness of the optimal coating were further analyzed.

Construction and characterization of a fosmid library for pathogenic bacterium Vibrio anguillarum

Vibrio anguillarum is a common bacterial pathogen in fish.However,little is known about its pathogenic mechanism,in part,because the entire genome has not been completely sequenced.We constructed a fosmid library for V.anguillarum containing 960 clones with an average insert size of 37.7 kb and 8.6-fold genome coverage.We characterized the library by end-sequencing 50 randomly selected clones.This generated 93 sequences with a total length of 57 485 bp covering 1.4% of the whole genome.Of these sequences,58(62.4%) were homologous to known genes,30(32.3%) were genes with hypothetical functions,and the remaining 5(5.3%) were unknown genes.We demonstrated the utility of this library by PCR screening of 10 genes.This resulted in an average of 6.2 fosmid clones per screening.This fosmid library offers a new tool for gene screening and cloning of V.anguillarum,and for comparative genomic studies among Vibrio species.