Analysis of the optical quality by determining the modulation transfer function for anterior corneal surface in myopes

AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anterior corneal surface in myopes. METHODS: Four hundred eyes from 200 patients were examined under SIRIUS corneal topography system. Phoenis analysis software was applied to simulate the MTF curves of anterior corneal surface at vertical and horizontal meridians at the 3, 4, 5, 6, 7mm optical zones of cornea. The MTF values at spatial frequencies of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 cycles/degree (c/d) were selected. RESULTS: The MTF curve of anterior corneal surface decreased rapidly from low to intermediate frequency (0-15cpd) at various optical zones of cornea, the value decreased to 0 slowly at higher frequency (>15cpd). With the increase of the optical zones of cornea, MTF curve decreased gradually. 3) In the range of 3 mm- 6 mm optical zones of the cornea, the MTF values measured at horizontal meridian were greater than the corresponding values at horizontal meridian of each spatial frequency, the difference was statistically significant (P<0.05). At 7 mm optical zones of cornea, the MTF values measured at horizontal meridian were less than the corresponding values at vertical meridian at 10-60 spatial frequencies (cpd), and the difference was statistically significant in 25, 30, 35, 40, 45, 50 cpd(P<0.05). CONCLUSION: MTF can be used to describe the imaging quality of optical systems at anterior corneal surface objectively in detail.

Evolution trend of the water quality in Dongping Lake after South-North Water Transfer Project in China

To investigate the evolution trend of water quality in Dongping Lake after South-North Water Transfer Project operation as well as to ensure the safe usage of the water receiving areas, water samples were collected and determined before and after water delivery in different hydrological seasons. Then, comprehensive pollution index method, comprehensive nutrition state index method and health risk assessment model were utilized to evaluate the quality, nutrition, and health risk of Dongping Lake water. Results showed that the quality of Dongping Lake water still met level Ⅲ (light pollution) no matter before or after water delivery. The nutrition state was improved from light eutropher before water delivery to mesotropher after water delivery. The health risk level was reduced from high-medium before water delivery to medium level after water delivery. In summary, the operation of the eastern route of South-North Water Transfer Project is beneficial for water environment improvement of Dongping Lake.

Effect of Structural Parameters on the Performance of NS High-efficiency Composite TraysⅠ.The Effect of Aperture and Opening Ratio on NS High-efficiency Composite Trays

In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture and opening ratio of plate on the fluid dynamics of the NS high-efficiency composite trays,such as the dry tray pressure drop,the wet tray pressure drop,the entrainment,the froth height,the leakage and mass transfer characteristics,were investigated.As a result, the low pressure drop,the high efficiency and the high capacity are the main advantages of the NS high-efficiency composite trays compared to other types of trays.According to this study,small aperture is useful for reducing the pressure drop and entrainment with a high mass transfer efficiency;while large aperture can achieve high capacity and efficiency in a broader operating range at the same pressure drop and entrainment.

Pregnancy Outcomes for Day 5 Versus Day 6 Single Frozen-thawed Blastocyst Transfer with Different Qualities of Embryos: A Large Matched-cohort Study

Objective This study aimed to determine whether the day of blastocyst expansion affects pregnancy outcomes in frozen-thawed blastocyst transfer(FBT)cycles.Methods A retrospective match-cohort study was conducted.Patients who underwent blastocyst transfer in frozen-thawed cycles at day 5 or 6 were matched for potential confounding factors.A total of 2207 matched pairs of FBT cycles were included from January 2016 to December 2019 in our Reproductive Medicine Center.Results The clinical pregnancy rate(CPR)and live birth rate(LBR)were significantly increased in day 5 blastocyst transfers when compared to day 6 blastocyst transfers,in terms of the same embryo quality.For FBT cycles with good-quality embryo,the CPR at day 5 and 6 was 61.30%and 57.56%,respectively(P=0.045),and the LBR was 44.79%and 36.16%,respectively(P<0.001).For FBT cycles with poor-quality embryo,the CPR at day 5 and 6 was 48.61%and 40.89%,respectively(P=0.006),and the LBR was 31.71%and 25.74%,respectively(P=0.019).The CPR for FBT cycles with good-quality embryo was statistically higher at day 6 than that at day 5 with poor-quality embryo transferred(57.56%vs.48.61%,P=0.001).Maternal age,anti-Müllerian hormone(AMH),endometrial thickness,embryo quality,and the day of blastocyst expansion were independently correlated with the CPR and LBR.The FBT cycles at day 5 had significantly higher CPR(adjusted odds ratio[OR]=1.246,95%confidence intervals[CI]:1.097–1.415,P=0.001)and LBR(adjusted OR=1.435,95%CI:1.258–1.637,P<0.001)than those at day 6.Conclusion The embryo quality is the primary indicator for FBT cycles.Day 5 blastocysts should be preferred when the quality of embryo at day 5 is the same as that at day 6.

No-Reference Stereo Image Quality Assessment Based on Transfer Learning

In order to apply the deep learning to the stereo image quality evaluation,two problems need to be solved:The first one is that we have a bit of training samples,another is how to input the dimensional image’s left view or right view.In this paper,we transfer the 2D image quality evaluation model to the stereo image quality evaluation,and this method solves the first problem;use the method of principal component analysis is used to fuse the left and right views into an input image in order to solve the second problem.At the same time,the input image is preprocessed by phase congruency transformation,which further improves the performance of the algorithm.The structure of the deep convolution neural network consists of four convolution layers and three maximum pooling layers and two fully connected layers.The experimental results on LIVE3D image database show that the prediction quality score of the model is in good agreement with the subjective evaluation value.

Secondary cooling technology for high-efficiency continuous billet-casting

The mathematical model of high-efficiency continuous billet casting was developed, incorporating the effective spraying water coefficient and the effective specific spraying water flowrate of secondary cooling. To realize uniform cooling in secondary cooling zones, the spraying cooling structure and the arrangement of nozzles were redesigned and optimized, and an additional spraying cooling zone was used. A new secondary cooling model of spraying water was built. It was found that the required spraying water flowrate of a cooling zone was related with the casting speed, the casting temperature, the compositions of liquid steel and the cooling water temperature of secondary cooling. The operation of the reformed caster proved that the spraying cooling structure and the new secondary cooling model were suitable, and the casting speed was greatly enhanced. The highest casting speed was （3.8 to 4.0） m/min for billet with a section of 150× 150 mm^2. The quality And the outout of the billet were imoroved, andthe economical benefit was heightened.

Fighting Poor Quality Medicines: Development, Transfer and Validation of Generic HPLC Methods for Analyzing Two WHO Recommended Antimalarial Tablets

As serious but neglected public health problems, poor quality medicines, i.e. for antimalarial medicines, urged to be fought. One of the approaches is to consider the analytical chemistry and separative techniques. In this study, a generic liquid chromatographic method was firstly developed for the purpose of screening 8 antimalarial active ingredients, namely amodiaquine (AQ), piperaquine (PPQ), sulfalene (SL), pyrimethamine (PM), lumefantrine (LF), artesunate (AS), artemether (AM) and dihydroartemisinine (DHA) by applying DoE/DS optimization strategy. Since the method was not totally satisfying in terms of peak separation, further experiments were undergone applying the same development strategy while splitting the 8 ingredients into five groups. Excellent prediction was observed prior to correlation between retention times of predicted and observed separation conditions. Then, a successful geometric transfer was realized to reduce the analysis time focusing on the simultaneous quantification of two WHO’s recommended ACTs in anti-malarial fixed-dose combination (AM-LF and AS-AQ) in tablets. The optimal separation was achieved using an isocratic elution of methanol-ammonium formate buffer (pH 2.8;10 mM) (82.5:17.5, v/v) at 0.6 ml/min through a C18 column (100 mm × 3.5 mm, 3.5 μm) thermostated at 25℃. After a successful validation stage based on the total error approach, the method was applied to determine the content of AM/LF or AS/AQ in seven brands of antimalarial tablets currently marketed in West, Central and East Africa. Satisfying results were obtained compared to the claimed contents.

Technology Transfer as the Process of Pharmaceutical Quality System： Modelling Technology Transfer as a Process Strategy

The recent GMP （good medical practice） rules actualisation and its requirements introduction widened the GMP guidelines for every life cycle of medicinal products, including the stage of processes scaling and technology transfer. This requires the technology transfer process to be regulated as the part of pharmaceutical quality system and the following development of corresponding written procedures. The following publication is dedicated to the development of TTP （technology transfer process） and its accessible graphic formalisation alongside the definition of main stages and possible procedures limited by the offered model. According to the actualized GMP rules, the technology transfer is an essential part of pharmaceutical quality system at a modem pharmaceutical company.

Examining the Quality Metrics of a Communication Network with Distributed Software-Defined Networking Architecture

Software-Defined Networking(SDN),with segregated data and control planes,provides faster data routing,stability,and enhanced quality metrics,such as throughput(Th),maximum available bandwidth(Bd(max)),data transfer(DTransfer),and reduction in end-to-end delay(D(E-E)).This paper explores the critical work of deploying SDN in large-scale Data Center Networks(DCNs)to enhance its Quality of Service(QoS)parameters,using logically distributed control configurations.There is a noticeable increase in Delay(E-E)when adopting SDN with a unified(single)control structure in big DCNs to handle Hypertext Transfer Protocol(HTTP)requests causing a reduction in network quality parameters(Bd(max),Th,DTransfer,D(E-E),etc.).This article examines the network performance in terms of quality matrices(bandwidth,throughput,data transfer,etc.),by establishing a large-scale SDN-based virtual network in the Mininet environment.The SDN network is simulated in three stages:(1)An SDN network with unitary controller-POX to manage the data traffic flow of the network without the server load management algorithm.(2)An SDN network with only one controller to manage the data traffic flow of the network with a server load management algorithm.(3)Deployment of SDN in proposed control arrangement(logically distributed controlled framework)with multiple controllers managing data traffic flow under the proposed Intelligent Sensing Server Load Management(ISSLM)algorithm.As a result of this approach,the network quality parameters in large-scale networks are enhanced.

土地流转与农业碳排放:理论机制与实证检验

文章基于2006—2022年中国30个省份面板数据,实证检验土地流转对农业碳排放的影响效应及作用机制。研究发现,土地流转对农业碳排放有显著负向影响;土地流转通过技术创新效应、规模经营效应和结构优化效应三种渠道显著降低农业碳排放。异质性结果表明,土地流转对农业碳排放的抑制作用在东部和西部地区、粮食主销区、种植业区尤为显著。基于此,应加快推进土地流转,发挥其对农业碳排放的减量效应;提升科技创新水平、发展适度规模经营、优化产业结构,因地制宜制定差异化政策。

平火茶标准汤剂的质量分析

目的建立平火茶标准汤剂指纹图谱和多指标含量测定的方法,并探究饮片-标准汤剂化学成分的量值传递关系。方法制备15批平火茶标准汤剂,测定其出膏率;采用高效液相色谱(HPLC)法建立该制剂的指纹图谱,并进行相似度评价和共有峰确定,同时进行化学计量学分析;同法测定该制剂中指标性成分含量并计算含量的转移率。色谱柱为Venusil C18,流动相为乙腈-0.1%磷酸溶液(梯度洗脱),柱温为30℃,检测波长为238 nm(0~37 min、85~102 min)、330 nm(37~85 min),流速为1.0 mL/min,进样量为10μL。结果15批平火茶标准汤剂HPLC指纹图谱的相似度均不小于0.968;共标定出24个共有峰,指认出了其中9个,分别为新绿原酸(峰3)、绿原酸(峰6)、栀子苷(峰9)、甘草苷(峰10)、木犀草苷(峰11)、异绿原酸A(峰14)、木犀草素(峰21)、山柰酚(峰23)、甘草酸(峰24)。聚类分析、主成分分析与正交偏最小二乘判别分析结果一致,均可将15批样品分为3类。15批平火茶标准汤剂的指标性成分栀子苷、木犀草苷、异绿原酸A、甘草苷、甘草酸的线性范围分别为0.020580~0.411600、0.001617~0.080850、0.006076~0.607600、0.005125~0.071740、0.017288~0.432200 mg/mL;精密度、重复性、稳定性、加样回收率试验的RSD均不高于4%(n均为6);含量范围分别为3.2279~10.0022、0.2974~0.5546、3.3501~6.1596、0.7206~1.0733、2.0031~3.0301 mg/g,饮片-标准汤剂含量的转移率范围分别为19.7628%~35.8405%、12.1233%~21.2540%、46.0972%~82.8694%、58.7088%~91.6296%、39.1143%~63.7106%。15批平火茶标准汤剂出膏率的转移率范围为61.15%~84.68%。结论本研究所建立的HPLC指纹图谱和含量测定方法简单且准确度高,可为平火茶标准汤剂的量值传递研究、质量控制、临床应用及后续制剂的开发提供参考。

就业质量对农业转移人口城市落户意愿影响研究——基于CMDS数据的实证研究

提升农业转移人口城市落户意愿,对我国新型城镇化战略的实施意义重大。本研究利用全国流动人口动态监测数据,基于“推拉”理论,构建二元Logit回归模型,实证分析就业质量对农业转移人口城市落户意愿的影响。研究表明:(1)农业转移人口的城市落户意愿整体偏低,愿意将户口迁入城市的农业转移人口仅占总样本的46%。(2)就业质量对农业转移人口城市落户意愿影响显著。丰厚的薪资待遇、合理的劳动时间、完善的权益保障、良好的职业发展、较强的工作稳定性是增强其城市落户意愿的重要手段。(3)不同人口特征的农业转移人口就业质量对其城市落户意愿存在显著差异。据此,提出应当从合理控制劳动时间、提高社会保险参与率、提供公平薪资待遇、重视农村青年基本教育、增强个体获得感五个方面来加强农业转移人口的城市落户意愿,从而助力新型城镇化战略健康有序推进。

Studies of Hepatitis B Virus-Specific Transfer Factor reparation

制备一种乙型肝炎病毒特异性转移因子制剂 (HBV STF) ,为临床应用提供有价值的实验依据。从人HBsAg阳性胎盘中制备了HBV STF ,并对其理化性质、免疫学活性进行了检测和初步的临床试用。每批样品经无菌试验、热原质检查、动物安全性试验等均符合药典要求。本品最大紫外吸收光谱在 2 5 6± 2nm处 ,E2 60nm/E2 80nm比值大于 2 7。其水解氨基酸含 17种。对人T淋巴细胞E受体的激活试验结果显示 ,HBV STF的Ea RFc平均增高率在 83 47%～ 10 3 48%之间 ,抗原特异性皮肤试验表明HBV STF能刺激小鼠体内T淋巴细胞增殖 ,诱导小鼠跖趾部皮肤的迟发性变态反应。对HBV STF的初步临床试用也取得明显效果 ,显示HBV STF是一种可用于治疗乙肝的安全。

针灸调控IVF 来源卵母细胞线粒体的研究进展

卵母细胞质量直接影响辅助生殖(Assisted Reproductive Techniques,ART)患者的妊娠结局,改善卵母细胞质量、提高ART成功率,是生殖领域的研究热点。卵母细胞线粒体是评价卵母细胞质量的重要指标之一,其结构或功能受损会影响卵母细胞成熟和生育能力。近年,针灸调控线粒体和改善ART来源卵母细胞质量的研究取得一定进展。文章综述了线粒体形态结构、线粒体自噬及能量代谢在ART来源卵母细胞中的作用;探讨针灸调控线粒体功能提高卵母细胞质量及ART成功率的可能机制,以期为今后的治疗提供理论依据。

我国跨项速度滑冰运动员身体形态、机能和运动素质特征及训练策略

跨项运动员具有早期进行多项化训练、晚定项和晚进入选材与培养体系等特点,晚期定项与早期定项运动员存在较大差异性。以我国19名跨项速度滑冰运动员为研究对象,采用文献资料法、实验测试法和数理统计法,对其身体形态、机能、运动素质等进行统计分析。发现,我国跨项速度滑冰运动员体脂率和BMI等指标表现良好,但需关注下肢双侧差异、有氧能力不足以及专项技术的强化等问题。为提高跨项运动员的成才率和运动表现,未来训练应注重下肢双侧均衡发展,提升有氧与无氧能力,增加陆冰结合和技术模拟练习。

衣服中三手烟污染物的释放特性

使用质子转移反应飞行时间质谱仪(PTR-TOF-MS)从衣服释放的三手烟(THS)中鉴定出100余种挥发性有机物(含36种致癌物),并发现不同衣服面料释放的THS成分和含量存在显著差异(涤纶释放的THS显著低于棉布).进一步发现,衣服中THS的可释放量随时间呈指数衰减趋势,持续释放30min后THS含量可降低80%以上,说明烟民吸烟后在室外停留30min以上有助于降低衣服介导的THS污染.本文为研究衣服介导的THS污染问题提供了一种有效手段,深化了对衣服中THS释放特性的认识,对降低不吸烟人群的THS暴露有重要意义.

新质生产力与农业经济韧性的理论分析与经验证据

农业稳则全局稳,农业经济韧性的提升对于保障国家粮食安全、促进农业可持续发展至关重要。提升农业经济韧性是实现农业农村现代化的重要内容,是我国面对国内外复杂形势的现实选择。新质生产力在实践中形成并发展,展现了习近平经济思想的最新成果,已成为推动农业经济高质量发展的重要动力。基于2010—2022年全国30个省级行政区的面板数据,采用固定效应模型系统考察新质生产力对农业经济韧性的影响效应,研究发现:第一,新质生产力能有效提升农业经济韧性,该结论在经过一系列稳健性检验后依旧成立;第二,新质生产力能够通过农业产业结构升级、加快土地流转内在路径进而作用于农业经济韧性,进一步地,门槛效应表明新质生产力对农业经济韧性的影响是非线性的;第三,异质性结果表明新质生产力对农业经济韧性的影响在东部地区、平原地区、粮食主产区更为显著。

清单式交接护理在自然分娩后产妇恢复中的效果观察

目的分析清单式交接护理在自然分娩后产妇恢复中的应用效果。方法选取2023年1月至2023年12月厦门医学院附属第二医院接收的100例自然分娩产妇,采用随机数字表法分为对照组(50例)、观察组(50例),对照组采取常规交接护理,观察组采取清单式交接护理,对比两组自然分娩后产妇心理状态、满意度、生活质量和产后不良事件发生率。结果观察组干预后SDS、SAS评分及产后不良事件均低于对照组(P<0.05);观察组干预后尊重与倾听、互动性交班、协调交班等床边交班感知量表(PVNC-BR)评分均高于对照组(P<0.05);观察组干预后生活质量评分高于对照组(P<0.05)。结论在自然分娩后产妇恢复中应用清单式交接护理可为产妇提供更优质的护理服务,减轻产妇心理负面情绪,降低产后不良事件发生率,帮助产妇获得更好的生活质量。

Environmental monitoring and fuzzy synthetic evaluation of municipal solid waste transfer stations in Beijing in 2001-2006

Transfer station(TS)is an integral part of present-day municipal solid waste(MSW)management systems.To provide information for the incorporation of waste facilities within the current integrated waste management system,the authors measured the existing environmental quality at five MSW TSs.Discharged wastewater,air,and noise were monitored and assayed at the five TSs in Beijing in 2001-2006 during rainy seasons(RSs)and dry seasons(DSs).Except Ammonia(NH_3)and hydrogen sulfide(H_2S),the analytical results of...

Relationship between Pronuclear Scoring and Embryo Quality and Implantation Potential in IVF-ET

To assess the relationship between pronuclear scoring and day-3 embryo quality and pregnancy outcome and to determine the Clinical value of pronuclear stage scoring system in human in vitro fertilization-embryo transfer （IVF-ET） program, a pronuclear scoring system was used to score zygotes 16-20 h after insemination during conventional IVF or intracytoplasmic sperm injection （ICSI）. The embryos were classified into groups Z1, Z2, Z3 and Z4, Comparisons were made of the rates of arrested embryos and excellent embryos on day 3. Comparisons of pregnancy outcome were made only in those patients in whom cohorts of similarly Z-scored embryos were transferred, The results showed that there were less arrested embryos and more excellent embryos on day 3 in groups Z1 and Z2 than those in group Z3 and Z4, More embryos arrested and less excellent embryos developed in group Z4 than group Z3. The clinical pregnancy rates resulting from the transfer of single pronuclear score homologous embryo types were similar among groups Z1, Z2 and Z3. Implantation rates of group Z1 were higher （P〈0.05） than that of group Z3, These findings suggests that pronuclear scoring can predict developmental ability on day 3 and implantation potential. A evaluation that combines the Z-score and day 3 embryo morphology is useful in the determination of the most viable embryos and the number of embryos for transfer.