飞秒激光小切口透镜取出术治疗屈光不正后的角膜形态变化研究进展

飞秒激光小切口透镜取出术（small incision lenticule extraction,SMILE）作为目前最前沿的治疗屈光不正的激光手术方式,因其耗时短、并发症少、疗效好等优势而被广泛应用。SMILE在我国的开展已超过5 a,有很多针对其术后角膜形态变化的研究以检验手术的可靠性。本文将对SMILE术后的角膜形态变化进行综述。     

Analysing the Porosity Distribution in Stone Surfaces by Means of Unilateral NMR after Long-Term Outdoor Weathering

Porosity changes in the near-surface area of sandstones due to long-term weathering can produce deterioration. Therefore, porosity analyses on weathered sandstones are significant for detecting possible influences on the pore structure. Classical methods for determining the porosity and pore size distribution in sandstones can only investigate the entire sample volume. In contrast, in this publication, the porosity was analysed in 0.2 mm steps over a depth of 5 mm by means of single-sided NMR measurements on water-saturated sandstones under vacuum. Evaluations of Obernkirchener and Schleeriether Sandstones that were weathered outdoors in Germany for over 30 years are presented. The results showed that the water content in Vol.-% strongly correlated with the normalised NMR signal. The unweathered sandstones showed a uniform distribution of micro and capillary pores throughout the stone depth. As a result of 30 years of outdoor weathering, changes in the pore structure occurred at the sandstone surface due to weathering down to depths of about 0.6 mm. The porosity of the Schleeriether Sandstone samples, mainly the microporosity, clearly increased in this region. Due to the dominance of capillary pores in the Obernkirchener Sandstone, the changes were not as pronounced, but a shift towards smaller pores in the surface area was observable.     

脑梗死患者T淋巴细胞亚群监测及其临床意义的研究

目的探讨急性脑梗死患者T淋巴细胞亚群的动态变化及其临床意义。方法用流式细胞仪对32例急性脑梗死患者发病后第3、5、7、14天的外周血CD4+、CD8+T淋巴细胞进行动态检测。结果急性脑梗死患者发病后第3、5天外周血CD4+T淋巴细胞和CD4+/CD8+比值均较健康对照组低(均P<0.05),而第14天的CD4+T淋巴细胞和CD4+/CD8+比值与健康对照组相比差异无显著性意义(P>005)。结论急性脑梗死患者第3、5天的细胞免疫功能明显降低,第7天开始逐渐恢复,第14天基本恢复正常,提示急性脑梗死后预防感染的重点时期是发病后2周内。     

圆锥角膜快速跨上皮交联手术前后Corvis ST参数的重复性及差异性

目的:评估圆锥角膜快速跨上皮交联手术前以及术后1mo Corvis ST参数的重复性及差异性。方法:研究纳入了30例30眼圆锥角膜患者进行分析。圆锥角膜患者术前和术后1mo分别进行三次Corvis ST重复测量。采用组内相关系数(ICC)、克伦巴赫alpha系数(Cronbach'α)、可重复性系数(RC)和变异系数(CV)评估Corvis ST参数的可重复性。采用配对t检验或Wilcoxon秩和检验评估术前与术后Corvis ST参数的差异。结果:术前39个Corvis ST参数中,26个(66.67%)参数重复性较好,6个(15.38%)参数重复性中等,7个(17.95%)参数的重复性较差。交联术后1mo,34个(87.18%)参数的重复性较好,3个(7.69%)参数重复性中等,2个(5.13%)参数的重复性较差。与术前相比,交联术后1mo圆锥角膜患者的眼压、生物力学校正眼压、第一次压平时间、曲率半径、第一次压平时的形变幅度、最大压陷偏离长度、角膜硬度参数值增加;而陡峭曲率、平坦曲率、平均曲率、第二次压平时间、2 mm最大形变幅度比值和综合半径值降低(均P<0.05)。结论:交联手术前和术后1mo Corvis ST参数均具有较好的可重复性,术后1mo圆锥角膜患者的角膜硬度较术前增加。     

天葵生长发育习性与药材形态形成相关性研究

目的:探讨天葵的生长发育特性及规律,以及与不同形状药材的关系。方法:在生长期对天葵进行连续的观察与研究,并对市售天葵药材进行观察与测量。结果:种子萌发植株及其后主根萌发的第1～2年植株只有基生叶,无地上茎不开花;此后每年从主根顶端萌发植株并开花结果,地上茎数、开花数、根的大小逐渐增加。天葵的药用部位不是块根,应为肉质直根。天葵地上植株的生长经过从秋季-冬季-次年春季,春季开花结果,以肉质直根越夏。天葵的生长习性与温度有较大关系。不同生长年限天葵药材性状不同,野生状态下天葵药材形成约需3年以上。结论:为天葵的栽培及进一步利用提供参考,为天葵药材鉴别提供依据。     

论盛唐七律新变

七律倡于初唐,至盛唐而极。与初唐七律相比,盛唐七律在多方面力求新变,表现为：一、酬答送别的题材得到充分开拓。二、以兴趣情韵见长,在创设意境方面技法娴熟;三、意象的选择、组合,有了明显创新;四、善于借鉴歌行乐府的写作技法,使得七律在规整之中有着灵动之美。五、在平仄上既严守程法,又尝试新法。盛唐七律确“足为万世程法”。     

高效液相色谱-电感藕合等离子体质谱联用测定植物性食品中硒的形态

目的建立一种简单、有效的高效液相色谱-电感耦合等离子体质谱联用(HPLC-ICP-MS)分析食品中5种硒形态的方法。方法对植物性食品样品中不同形态硒化合物提取方法及色谱系统分离柱、流动相、洗脱程序进行交联试验。结果以5 mmol/L柠檬酸,水相pH值=4.7,流速为1.0 ml/min,HamiltonPRP-X100阴离子交换色谱柱能有效分离5种硒形态;超声波辅助链酶蛋白酶E提取30 min,硒形态提取率最高;在5μg/L^100μg/L,5种硒形态呈线性关系,相关系数r均为0.999以上,仪器检出限分别为0.53μg/L^0.96μg/L。平均加标回收率为73.73%~110.6%,相对标准偏差为1.01%~9.75%。结论采用该方法,5种硒化合物分离迅速,6 min内分离出4种化合物,22 min内全部分离完成,分离度R值均>1.5,分离效果良好;用于植物性食品中硒形态的检测,用超声波辅助链酶蛋白酶E的提取效率最高,检测到的5种硒化合物总量与总硒的百分比在75%左右,结果令人满意。     

烹调油烟所致大鼠肺部病变及肺S9中SOD,MDA变化

利用动式吸入烹调油烟（浓度为（４３±４）ｍｇ／ｍ３）持续染毒６０天制备动物模型观察肺部病理形态改变,并通过分光光度法测试肺组织匀浆Ｓ９中的ＭＤＡ、ＳＯＤ,探讨其损伤机理。结果表明：ＣＯＦ染毒组肺组织病理形态改变以炎症改变为主,尚有肺泡上皮腺样化生、不典型腺样增生病变形成。阴性对照组有轻度间质性肺炎及轻度的上皮增生。Ｂ（ａ）Ｐ组肺组织炎症病变少,以鳞状上皮化生较多见。ＣＯＦ可使肺组织匀浆Ｓ９中ＭＤＡ含量增加,ＳＯＤ酶活性降低,与阴性对照组比较,差异有显著性,（Ｐ＜０．０５）。     

Effect of Agroecosystems on Seroprevalence of St. Louis Encephalitis and West Nile Viruses in Birds,La Pampa,Argentina, 2017–2019

In Argentina, the Pampa ecoregion has been almost completely transformed into agroecosystems. To evaluate the environmental (agricultural area, tree coverage, distance to the nearest water body and urban site) and biological (dove, cowbird, and sparrow abundance) effects on free-ranging bird exposure to St. Louis encephalitis virus (SLEV) and West Nile virus (WNV), we used generalized linear mixed models. For 1,019 birds sampled during 2017–2019, neutralizing antibodies were found against SLEV in samples from 60 (5.8%) birds and against WNV for 21 (2.1%). The best variable for explaining SLEV seroprevalence was agricultural area, which had a positive effect; however, for WNV, no model was conclusive. Our results suggest that agroecosystems in the La Pampa ecoregion increase the exposure of avian hosts to SLEV, thus potentially increasing virus activity.     

Clinical profile and distribution of peripheral retinal changes in myopic population in a hospital-based study in North India

Purpose:To evaluate the prevalence of different types of peripheral retinal changes in a myopic population in North India and correlate them with axial length.Methods:This cross-sectional, hospital-based survey included 600 eyes of 300 myopic individuals, aged between 10 and 40 years, attending the outdoor ophthalmology clinic of a tertiary eye care hospital in North India were examined from July 2019 to July 2020. They were divided into mild, moderate, high, and severe myopia according to the spherical equivalent of refraction. Axial length was recorded. Peripheral retinal changes were examined by scleral indentation binocular indirect ophthalmoscopy. Standardized findings considered with their fundus location were lattice degeneration, white without pressure and white with pressure, snail-track degenerations, peripheral chorioretinal atrophy, retinal holes, tears, and detachment. The study was approved by the institutional ethics committee, and all participants provided informed consent.Results:Peripheral retinal degenerations were found in almost half (53%) of all myopes included in the study. The most common peripheral retinal degeneration found was lattice degeneration, followed by white without pressure, white with pressure, and chorioretinal atrophy. Most of the peripheral retinal degenerations were seen in the temporal quadrant of the fundus, either superotemporal or inferotemporal. There was a significant positive association between the prevalence of peripheral retinal degeneration with age, increased axial length, and severity of myopiaConclusion:The results of our study indicate the necessity for careful peripheral fundus examinations of all myopes, irrespective of age and degree of myopia, for early diagnosis and better management of visual-threatening complications like retinal detachment.