MicroRNA-34a通过上调Cdc42和Rac1促进人晶状体上皮细胞衰老和凋亡

目的:观察MicroRNA-34a对人晶状体上皮细胞系SRA01/04衰老和凋亡的影响及作用机制。方法:qRT-PCR检测年龄相关性白内障(ARC)晶状体和透明晶状体上皮细胞中MicroRNA-34a表达水平,采用脂质体转染试剂盒将MicroRNA-34a mimics(过表达组)、MicroRNA-34a inhibitors(抑制组)和空脂质体(对照组)转染至SRA01/04细胞,qRT-PCR检测MicroRNA-34a的表达量;采用β-半乳糖苷酸(SA-β-gal)染色检测转染后细胞的衰老情况。Annexin V-FITC/PI双染色流式细胞仪检测MicroRNA-34a对人晶状体细胞系SRA01/04细胞凋亡的影响;蛋白免疫印迹检测Cdc42、Rac1蛋白的表达。结果:透明晶状体前囊膜组织中MicroRNA-34a的表达量显著低于ARC晶状体前囊膜组织(P<0.05);MicroRNA-34a过表达组、对照组、MicroRNA-34a抑制组SA-β-gal阳性率分别为(87.56±2.34)%、(12.22±2.74)%、(3.45±0.45)%。MicroRNA-34a过表达组明显高于对照组,而MicroRNA-34a抑制组SA-β-gal阳性率明显低于对照组(P<0.05);MicroRNA-34a抑制组、对照组和MicroRNA-34a过表达组的细胞凋亡率分别为(5.87±1.22)%、(12.26±2.14)%、(29.45±3.12)%,MicroRNA-34a抑制组细胞凋亡率明显低于对照组,而MicroRNA-34a过表达组细胞凋亡率明显高于对照组(P<0.05);MicroRNA-34a过表达组中Cdc42和Rac1的表达明显高于对照组(P<0.05),MicroRNA-34a抑制组中Cdc42和Rac1的表达明显低于对照组(P<0.05)。结论:MicroRNA-34a可能通过上调Cdc42和Rac1促进人晶状体上皮细胞衰老和凋亡。

自制单孔与三孔后腹腔镜肾蒂淋巴管结扎术治疗乳糜尿的临床疗效比较

目的探讨自制单孔后腹腔镜肾蒂淋巴管结扎术治疗乳糜尿的安全性及临床疗效。方法回顾性分析2013年2月-2016年3月接受单孔后腹腔镜肾蒂淋巴管结扎术或三孔后腹腔镜肾蒂淋巴管结扎术治疗乳糜尿的34例患者临床资料,其中单孔组(16例)和三孔组(18例)。两组患者的年龄、体质指数(BMI)比较差异无统计学意义(P>0.05)。比较两组的手术时间、术中出血量、术后引流管留置天数、术后住院天数、术后疼痛评分和外观满意度评分等指标。结果所有手术均获成功,无中转开放手术。单孔组平均手术时间长于三孔组[(132.4±21.6)vs(102.3±16.1)min,P<0.05],两组在术中出血量、术后拔管时间和术后住院天数方面比较差异无统计学意义,但单孔组术后满意度评分、疼痛评分优于三孔组。结论自制单孔后腹腔镜肾蒂淋巴管结扎术治疗乳糜尿是一种安全有效、经济、微创的方法,术后疼痛较轻,美容效果更好。

Performance characterization of Ni60-WC coating on steel processed with supersonic laser deposition

Ni60-WC particles are used to improve the wear resistance of hard-facing steel due to their high hardness. An emerging technology that combines laser with cold spraying to deposit the hard-facing coatings is known as supersonic laser deposition. In this study, Ni60-WC is deposited on low-carbon steel using SLD. The microstructure and performance of the coatings are investigated through SEM, optical microscopy, EDS, XRD, microhardness and pin-on-disc wear tests. The experimental results of the coating processed with the optimal parameters are compared to those of the coating deposited using laser cladding.

Down-regulation of mi R-30a-3p/5p promotes esophageal squamous cell carcinoma cell proliferation by activating the Wnt signaling pathway

AIM To investigate the potential role of micro RNA-30 a(mi R-30 a) in esophageal squamous cell carcinoma(ESCC).METHODS Expression of mi R-30 a-3 p/5 p was analyzed using microarray data and fresh ESCC tissue samples. Both in vitro and in vivo assays were used to investigate the effects of mi R-30 a-3 p/5 p on ESCC cell proliferation. Furthermore,Kyoto Encyclopedia of Genes and Genomes analysis was performed to explore underlying mechanisms involved in ESCC,and then,assays were carried out to verify the potential molecular mechanism of mi R-30 a in ESCC.RESULTS Low expression of mi R-30 a-3 p/5 p was closely associated with advanced ESCC progression and poor prognosis of patients with ESCC. Knock-down of mi R-30 a-3 p/5 p promoted ESCC cell proliferation. Increased mi R-30 a-3 p/5 p expression inhibited the Wnt signaling pathway by targeting Wnt2 and Fzd2.CONCLUSION Down-regulation of mi R-30 a-3 p/5 p promotes ESCC cell proliferation by activating the Wnt signaling pathway through inhibition of Wnt2 and Fzd2.

Novel Door-opening Method for Six-legged Robots Based on Only Force Sensing

Current door-opening methods are mainly developed on tracked, wheeled and biped robots by applying multi-DOF manipulators and vision systems. However, door-opening methods for six-legged robots are seldom studied, especially using 0-DOF tools to operate and only force sensing to detect. A novel door-opening method for six-legged robots is developed and imple- mented to the six-parallel-legged robot. The kinematic model of the six-parallel-legged robot is established and the model of measuring the positional relationship between the robot and the door is proposed. The measurement model is completely based on only force sensing. The real- time trajectory planning method and the control strategy are designed. The trajectory planning method allows the maximum angle between the sagittal axis of the robot body and the normal line of the door plane to be 45°. A 0-DOF tool mounted to the robot body is applied to operate. By integrating with the body, the tool has 6 DOFs and enough workspace to operate. The loose grasp achieved by the tool helps release the inner force in the tool. Experiments are carried out to validate the method. The results show that the method is effective and robust in opening doors wider than 1 m. This paper proposes a novel door-opening method for six-legged robots, which notably uses a O-DOF tool and only force sensing to detect and open the door.

Observational results of MUSER during 2014–2019

The solar radio signal that can be received by the ground-based telescopes covers a wide frequency range,allowing us to monitor the complex physical processes occurred from the solar surface to the vast interplanetary space.MingantU SpEctral Radioheliograph(MUSER),as the latest generation of solar dedicated radio spectral-imaging instrument in the centimeter-decimeter wavelengths,has accumulated a large number of observational data since its commissioning observation in 2014.This paper presents the main observational results identified by MUSER from 2014 to 2019,including the quiet Sun and 94 solar radio burst events.We find that there are 81 events accompanied with Geostationary Operational Environmental Satellites(GOES)soft X-ray(SXR)flares,among which the smallest flare class is B1.0.There are 13 events without accompanying any recorded flares,among which the smallest SXR intensity during the radio burst period is equivalent to level-A.The main characteristics of all radio burst events are presented,which shows the powerful ability of MUSER to capture the valuable information of the solar non-thermal processes and the importance for space weather.This work also provides a database for further in-depth research.

Effectiveness and the nomogram of small incision lenticule extraction in the correction of myopic anisometropia in adults

AIM:To evaluate the safety,effectiveness,and predictability of small incision lenticule extraction(SMILE)for the treatment of anisometropia,and to explore the personalized design scheme of SMILE in correcting adult myopia anisometropia based on the nomogram.METHODS:It’s a prospective cohort study.Patients with anisometropic myopia of refractive difference≥2.0 diopters(D)who underwent SMILE between September 2020 and March 2021 were enrolled.Clinical features and visual function were assessed preoperatively and at 1wk,1,3,and 6mo after the operation.The examination included tests for uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),refractive errors,effectiveness index(preoperative CDVA/postoperative UDVA),safety index(postoperative CDVA/preoperative CDVA),nomogram and stereoscopic function.Paired t-test,Wilcoxon signed-rank test and repeated-measures analyses of variance were used for continuous variables,and Pearson Chi-squared test was used for categorical variables.RESULTS:The study involved 45 consecutive patients(average age:25.0±6.9y;82 out of 90 eyes underwent SMILE,while 8 eyes were not operated).The average preoperative spherical equivalent(SE)was-4.74±0.22 D.Six months after surgery,the effectiveness index was 1.05±0.12,and the safety index was 1.09±0.11.Seventy eyes(85.4%)exhibited SE correction error within±0.5 D.The percentage of eyes with Titmus stereoscopic function equal to or less than 200”significantly increased from 55.6%preoperatively to 88.9%postoperatively(P<0.05).There was statistically significant difference between higher myopia eyes and contralateral eyes in average nomogram value/spherical refraction ratio.CONCLUSION:SMILE is safe,effective and predictable in correcting myopic anisometropia,and it improves stereoscopic visual function of anisometropia patients.The precise and individualized design of the nomogram is a vital element to ensure the balance of both eyes after SMILE.

A New Solar Radio Spectrometer at 1.10-2.06 GHz and First Observational Results

An improved Solar Radio Spectrometer working at 1.10-2.06 GHz with much improved spectral and temporal resolution, has been accomplished by the National Astronomical Observatories and Hebei Semiconductor Research Institute,based on an old spectrometer at 1 2 GHz. The new spectrometer has a spectral resolution of 4 MHz and a temporal resolution of 5 ms, with an instantaneous detectable range from 0.02 to 10 times of the quiet Sun flux. It can measure both left and right circular polarization with an accuracy of 10% in degree of polarization. Some results of preliminary observations that could not be recorded by the old spectrometer at 1-2 GHz are presented.

Antenna system characteristics and solar radio burst observations

The Chinese Spectral Radio Heliograph（CSRH） is an advanced aperture synthesis solar radio heliograph, independently developed by National Astronomical Observatories, Chinese Academy of Sciences. It consists of 100 reflector antennas,which are grouped into two antenna arrays（CSRH-I and CSRH-II） for low and high frequency bands respectively. The frequency band of CSRH-I is 0.4–2 GHz and that for CSRH-II is 2–15 GHz. In the antenna and feed system, CSRH uses eleven feeds to receive signals coming from the Sun. The radiation pattern has a lower side lobe and the back lobe of the feed is well illuminated. The characteristics of gain G and antenna noise temperature T affect the quality of solar radio imaging. For CSRH, the measured G is larger than 60 d Bi and T is less than 120 K. After CSRH-I was established, we successfully captured a solar radio burst between 1.2–1.6 GHz on 2010 November12 using this instrument and this event was confirmed through observations with the Solar Broadband Radio Spectrometer at 2.84 GHz and the Geostationary Operational Environmental Satellite. In addition, an image obtained from CSRH-I clearly revealed the profile of the solar radio burst. The other observational work involved the imaging the Fengyun-2E geosynchronous satellite which is assumed to be a point source.Results indicate that the data processing method applied in this study for deleting errors in a noisy image could be used for processing images from other sources.

Comparison of bilateral/unilateral lateral rectus recession and unilateral recession-resection for intermittent exotropia:a Meta-analysis

AIM: To compare the effectiveness of unilateral recession-resection(R&R) and bilateral/unilateral recession(BLR/ULR) for treatment of basic type of intermittent exotropia [IX(T)].METHODS: A comprehensive literature search was performed using PubMed, EMBASE, and the Cochrane Library, to identify randomized controlled trials and comparative studies regarding the effectiveness of R&R and BLR/ULR for IX(T). Based on which, a Meta-analysis was then performed in terms of long-term success rate, overcorrection rate, and recurrence rate.RESULTS: Nine studies in total satisfy the specified eligibility criteria. BLR is at disadvantage to R&R at a short-term follow-up [<2 y, OR 0.56(0.33-0.94) for success rate; OR 2.11(1.17, 3.81) for undercorrection rate]. However, BLR achieved a higher success rate [OR 2.49(1.61, 3.86)] and a lower undercorrection rate [OR 0.40(0.23, 0.71)], compared to that of R&R at a long-term followup(>2 y). There is no significant difference was found in overcorrection rate, regardless of the length of follow-up time [OR 0.85(0.41, 1.75)]. In the treatment for small-angle IX(T), the final outcome was significantly different between the groups, demonstrating a more successful alignment [OR 0.37(0.18, 0.74)] and a lower undercorrection [OR 3.50(1.28, 7.26)] in the R&R group than in the ULR group. While for moderate-angle IX(T)(20 PD-25 PD), the effectiveness of R&R and ULR is quite equivalent with similar success rate [OR 1.08(0.65, 1.79)] and undercorrection rate [OR 0.89(0.54, 1.48)]. CONCLUSION: As regard to the effect of BLR and R&R, R&R shows an advantage over BLR at short term. But, BLR is more effective in the long term for the basic typeIX(T) in children. R&R surgery should be a better choice for the treatment of small-angle IX(T) of ≤20 PD than ULR. However, both of ULR and R&R are recommended for moderate-angle IX(T) from 20 PD to 25 PD.