我国市售茶叶包装接触面积/体积比调查研究

目的 了解我国茶叶包装材料的使用情况,构建不同类别茶叶不同食品接触材料的接触面积/体积比（S/V）基础数据库。方法 采集市场销售的不同包装和类型的7大类茶叶,通过直接测量法及应用3D表面积测量仪获得413份茶叶样品的接触面积,结合不同类别茶叶产品的质量、规格等数据信息,计算其S/V。结果 茶叶的接触材料均为单一材质,不同类别茶叶接触材料的S/V的平均值为93.0 dm²/kg,范围为3.5~595.6 dm²/kg。 99.8%（412/413）的茶叶接触材料S/V≥6.0 dm²/kg,87.2%（360/413）的S/V介于6.0~200.0 dm²/kg之间。结论 我国大部分市售茶叶的S/V大于欧盟评估时采用的6.0 dm²/kg,利用本次调查研究获得的参数将会降低食品接触材料风险评估中的不确定性。     

我国调味品食品接触材料膳食暴露评估基础参数市场调查研究

目的 建立我国调味品食品接触材料膳食暴露评估基础参数。方法 采用接触面积法对调味品食品接触材料进行研究,根据调查食品接触材料的相关数据信息获得接触面积法中食品接触材料与单位质量食品的接触面积参数。结果 共调查分析800份调味品,获取相关数据25600个,食品接触材料与单位质量或单位体积食品的接触面积(S/V)最大值为322.67dm²/kg,最小值为1.63dm²/kg。本次调查中调味品S/V 有86.9%的数据高于6 dm²/kg。结论 基于调味品市场调查构建的调味品食品接触材料基础参数为我国调味品食品接触材料安全性评估工作提供数据支持。     

我国市售饮料与包装接触面积/体积比调查

目的 了解我国饮料包装材料使用情况,研究构建饮料不同类型接触材料的接触面积/体积比(S/V)参数。方法 采集市场销售的不同包装、不同类型的饮料,采用直接测量法或3D面积测量仪计算不同类型饮料的接触面积,结合不同类型饮料的规格,计算S/V。结果 共采集214种不同类型、不同食品接触材料的饮料。72.0%(154/214)的饮料主体接触材料为单一材质,28.0%(60/214)的饮料接触材料为纸(涂层)和马口铁(涂层)等复合材质。不同类型饮料的接触材料S/V的平均值为11.29 dm²/kg,范围为4.26～64.32 dm²/kg。85.0%(182/214)的饮料接触材料的S/V≥6 dm²/kg,73.4%(157/214)介于≥6～12 dm²/kg之间。结论 我国市售大部分饮料的平均S/V大于欧盟评估时采用的6 dm²/kg,利用调查研究获得的参数将会降低食品接触材料风险评估中的不确定性。     

中国畜禽源单核细胞增生李斯特菌流行性的系统回顾及荟萃分析

目的 为明确我国畜禽源单核细胞增生李斯特菌（单增李斯特菌）的流行特性,本文通过荟萃（Meta）分析对我国畜禽源食品单增李斯特菌污染与流行情况进行了系统回顾,以期为我国畜禽肉生产过程中单增李斯特菌的防控提供参考依据。方法 首先在PubMed、Web of Science、万方数据库、中国知网等数据平台通过输入关键检索词检索2001—2022年发表的有关我国畜禽食品中单增李斯特菌检出率的文献,之后利用Stata软件对文献数据进行Meta分析。结果 共纳入中、英文研究文献277篇,总样本数据为110 066例,单增李斯特菌的合并检出率为7.2%（95%CI：6.4%~8.0%）。不同区域的亚组分析发现,吉林和黑龙江等地的检出率高于其他地区;不同时间的亚组分析发现单增李斯特菌的检出率随着时间的推移而降低。熟肉食品中单增李斯特菌的检出率（2.9%,95%CI：2.4%~3.5%）远低于生肉（10.7%,95%CI：9.5%~12.0%）;生肉中鸡肉的检出率为11.0%（95%CI：8.3%~14.0%）与猪肉的检出率10.9%（95%CI：7.9%~14.2%）略高于其他种类的生肉。结论 我国畜禽源食品单增李斯特菌检出率依然处于比较高的水平。     

基于贝叶斯模型的北京市李斯特菌病发病率估计

目的 评估2017—2019年北京市李斯特菌病发病水平,为李斯特菌病的预防控制策略的制定提供科学依据。方法 在北京市李斯特菌病哨点监测的基础上,利用2017—2019年8个区10所二级及以上综合医院及7所妇产专科医院年入院人数和李斯特菌病报告发病数,采用贝叶斯模型估算北京市全人群和妊娠人群李斯特菌病发病率。结果 贝叶斯模型估计2017—2019年北京市李斯特菌病全人群发病率为0.25/10万（95%CI：0.17~0.33）,年发病人数53人（95%CI：38~71）。妊娠人群发病率为12.89/10万（95%CI：9.03~17.39）,约为全人群的52倍;年发病人数31人（95%CI：20~43）,约占全人群的58%。结论 2017—2019年北京市李斯特菌病全人群发病水平与其他国家接近,应引起足够重视,而妊娠人群发病率处于国际较高水平,提示应进一步分析成因,在加大全人群宣教监测力度的基础上针对妊娠人群高发特点制定差异化防控策略。     

广西某医科院校大一新生营养知信行和膳食模式与体质关联分析

目的 评价广西某医科院校大学一年级新生营养知识-态度-行为（KAP）、膳食状况、膳食模式和体质水平，探究其营养知信行、膳食模式与体质水平间的关联，为大学生的健康膳食教育提供参考依据。方法 自2021年5月起，对该校全体2 125名大学一年级新生进行营养知信行问卷、膳食频率表问卷调查和体质测试，采用因子分析法建立大学一年级新生的膳食模式，以Pearson相关性分析和Logistic回归分析探究膳食模式与体质测试总分及各项目间的关联性。同时，采用描述性分析统计全体对象的营养知信行得分、总能量及各营养素的平均摄入量，并用χ²检验比较营养行为在不同体测成绩之间人数分布的差异。结果 大学一年级新生碳水化合物、维生素A、钙和膳食纤维等营养素摄入不足。Pearson相关分析显示“健康膳食”模式（r=0.064，P<0.01）和“水产畜禽肉”模式（r=0.062，P<0.01）均与体测成绩呈显著正相关，“油炸与甜食”模式呈显著负相关（r=-0.057，P=0.01）。大一新生营养知信行、营养态度、营养行为得分分别为14.54±2.63、24.60±3.73和15.61±2.51分。体测及格与不及格学生在吃早餐行为中的分布具有显著差异（χ²=9.05，P<0.05）。二元Logistic回归分析显示“水产畜禽肉”模式分别与男生（OR=0.35，95%CI：0.14~0.91）和女生（OR=0.41，95%CI：0.19~0.87）体测不及格风险呈显著负相关，“腌制食物”模式与女生体测成绩不及格风险呈显著正相关（OR=2.21，95%CI：1.15~4.27）。结论 广西某医科院校的大一新生膳食结构不尽合理，营养知识水平与营养行为不相匹配，应根据大学生饮食行为习惯特点，进行针对性的营养教育干预，逐步养成健康饮食习惯，从而提升体质水平。     

脐血中全氟及多氟烷基化合物暴露水平及其影响因素研究

目的 了解河南省某地新生儿脐血中全氟及多氟烷基（PFASs）的暴露水平及其影响因素。方法 基于2013—2015年河南某地建立的出生队列,检测了336名新生儿脐血中11种PFASs水平,采用广义线性回归分析产妇社会人口特征、生活方式和膳食摄入对新生儿脐血PFASs水平的影响。结果 产妇年龄大（GM比值在1.03～1.05）、家庭平均月收入高（GM比值在1.30～1.63）、孕期有吸烟史（GM比值2.90;95%CI：1.11,7.56）和被动吸烟（GM比值1.84;95%CI：1.02,3.32）可能增加脐血PFASs暴露水平;产妇孕期工作（GM比值0.82;95%CI：0.67,1.00）及经产妇（GM比值0.65;95%CI：0.51,0.82）脐带血中的PFASs浓度较低。产妇孕期摄入牛羊肉、南瓜、蒜苗和咸菜频率高与脐血PFASs升高有关（GM比值在1.33～1.80）,而孕期摄入较多的橘子、牛奶、白菜和茄子等其脐血PFASs浓度较低（GM比值在0.68～0.82）。结论 产妇年龄、家庭收入、产妇孕期有吸烟史和被动吸烟、产次、牛羊肉和植物源性食物摄入可能会影响新生儿PFASs暴露水平。     

2017—2018年中国大城市成年居民蛋类食物消费状况分析

目的 了解2017—2018年我国大城市成年居民蛋类食物消费状况,为制定营养健康政策提供科学依据。方法 数据来源于“2017—2018年中国居民食物消费状况调查”,采用多阶段分层与人口成比例的整群随机抽样方法,在我国18个省（自治区、直辖市）33个大城市选取12 173名18岁及以上成人作为研究对象。利用非连续3 d 24 h回顾调查数据,分析研究对象蛋类食物消费率和消费量,采用χ²检验与秩和检验比较消费率和消费量的差异。结果 2017—2018年我国大城市成年居民蛋类食物消费率为72.9%（8 875/12 173）,全人群蛋类食物平均消费量为28.1 g/d（P25：0,P50：20.5 g/d,P75：43.9 g/d,P95：78.3 g/d）,消费人群平均消费量为38.6 g/d（P25：17.6 g/d,P50：33.3 g/d,P75：51.3 g/d,P95：86.9 g/d）。高文化程度、高家庭收入和东部地区的居民,蛋类食物的消费率和消费量较高。蛋类食物消费低于膳食推荐摄入量（40 g/d）的人群比例为71.5%（8 705/12 173）,满足推荐摄入量（40~50 g/d）的人群比例为9.9%（1 201/12 173）。结论 蛋类食物在我国大城市成年居民中的消费较为普遍,但人均消费量相对不足。建议针对蛋类食物的营养知识进行宣教科普,适量提高我国居民蛋类食物的消费量。     

9种药食同源物质重金属及农药污染状况Meta分析

目的 对杜仲叶、党参、肉苁蓉、铁皮石斛、黄芪、西洋参、天麻、灵芝及山茱萸9种试点药食同源物质重金属及农药污染水平和现状进行Meta分析。方法 检索PubMed、中国知网、维普及万方数据库,获取2000—2022年发表的9种药食同源物质中重金属、农药、环境污染物研究文献,根据文献纳入排除标准进行筛选,对纳入的文献采用Meta法进行分析。结果 本研究共纳入106篇文献,涉及来自23个省（市）9种药食同源物质中铅（Pb）、镉（Cd）、汞（Hg）、砷（As）、铬（Cr）、铜（Cu）及镍（Ni）7类重金属,有机氯类、拟除虫菊酯类和有机磷类等42种农药。9种药食同源物质重金属污染合计均值为0.22 mg/kg（95%CI：0.13~0.39）,其中杜仲叶重金属污染合计均值最高,为2.80 mg/kg（95%CI：0.75~10.37）,其次为铁皮石斛,合计均值为0.30 mg/kg（95%CI：0.18~0.49）,其余7种药食同源物质中重金属合计均值均低于0.30 mg/kg;7类重金属中铜污染水平最高,其次为镉和铅,亚组分析表明不同产地的药食同源物质中7类重金属污染水平具有较高的异质性（P<0.05）。42种农药污染水平均值存在异质性（P<0.05）,铁皮石斛、西洋参、肉苁蓉、黄芪及天麻5种药食同源物质中五氯硝基苯、六六六、滴滴涕残留量合计均值位列前3。结论 不同药食同源物质重金属及农药污染类别及污染水平存在差异,重金属污染与产地和药食同源物质种类有关,部分药食同源物质中可检出禁用农药,应进一步加强药食同源物质污染物溯源分析,同时加大对药食同源物质生产加工监管和监测力度。     

蔬果总摄入量与认知功能的相关性研究

目的 探究蔬果总摄入量与认知功能的相关性,为中国老年人的膳食指导提供科学依据。方法 利用2015年中国居民健康与营养调查（CHNS）湖北省的调查资料,纳入年龄55岁及以上的研究对象406人,调整年龄、性别、城乡、婚姻、教育程度、年收入、吸烟、饮酒、体力活动、红肉摄入、鱼肉摄入、总能量摄入、体质指数（BMI）和高血压等因素,采用多重线性回归评价蔬果总摄入量与认知得分的偏回归系数及95%置信区间（CI）。结果 研究对象平均年龄为64.79±7.57岁,平均蔬果总摄入量为330.18±165.56 g/d,平均认知得分为13.44±5.66分。在完全调整模型中,相较于蔬果总摄入量Q1组,蔬果总摄入量Q4组的偏回归系数与95%CI分别为1.91、0.08~3.75。与只摄入蔬菜相比,同时摄入蔬菜和水果的偏回归系数与95%CI分别为1.40、0.15~2.73。结论 较高水平的蔬果总摄入量与中老年人较好的认知功能相关,在摄入蔬菜的同时应确保水果的摄入。     

Colonization of therapeutic contact lens by dematiaceous fungi

PurposeTo report 2 patients with colonization of therapeutic contact lens with dematiaceous fungi.MethodsCase report.ResultsThe first patient had a retained soft contact lens on an opaque cornea for 4 years with brownish black multiple colonies on the soft contact lens and culture grew Bipolaris spp. The second patient was on therapeutic contact lens for pseudophakic bullous keratopathy for 4 months and developed a brownish colonization of contact lens with unidentified dematiaceous fungi. Both the patients had conjunctivitis but did not develop fungal keratitis.ConclusionJudicious use of therapeutic contact lens is required in agrarian countries with adequate emphasis on strict adherence to the standard protocols and frequent replacement of the lens.     

PLC在捻制设备应用中应注意的问题

简述PLC用户程序的工作过程,指出PLC在捻制应用中应注意的输出触点竞争、输出触点容量和报警电路设计等问题,给出解决问题的具体方法和程序,使得PLC的应用更加安全可靠。     

Ten years of disposable contact lenses - a review of benefits and risks

The performance and benefits as well as the risks and complications of disposable soft lenses (single use disposable or re-used 2-4 weeks) are reviewed in relation to corneal physiology. Modern designs and advanced technology have resulted in disposable lenses providing excellent visual performance. Fewer subjective symptoms (e.g. dryness and grittiness), slit-lamp findings (such as injection and tarsal abnormalities), and inflammatory responses (papillary conjunctivitis; contact lens-induced acute red eye) have been reported with disposable lenses than with conventional soft lenses. The risk of contact lens-induced keratitis (CLIK) has been reported to be higher for daily wear of disposable lenses than for other lens types by UK investigators. Other studies have shown the risk of CLIK with disposable lenses to be equal to that with conventional soft lenses, and in two extensive Swedish studies, the incidence of severe keratitis was found to be significantly lower for daily wear (DW) of disposable lenses than for DW of conventional soft and rigid gas permeable lenses. Both the total complication rate and the number of unscheduled visits are found to be significantly lower for disposable lenses than for conventional soft lenses in several studies. Comfort has been reported to be significantly better and overall satisfaction significantly greater with disposable lenses than with conventional soft lenses according to many studies. These may be important reasons why the success rate for disposable lens wear is reported to be fairly high, generally 70-90%. The importance of appropriate care for 're-usable disposable lenses' must be stressed. One day disposable lenses, if used as directed, will eliminate the risk factors of inadequate cleaning and disinfection as well as contaminated lens cases.     

刮板式巧克力精磨机研磨诸因素的分析

本文主要对精磨机在工作时,由于转动速度、研磨位移、刮刀对齿形条接触面积大小和刮刀对齿面接触压力等因素,导致巧克力细度的变化作详细的分析,并通过实验方法来确定研磨压力的大小,以便在使用时控制刮刀与缸径面的压力,正确选择理想的研磨规范,达到满意的巧克力细度。     

千吨级注塑机十字头轴孔配合的接触分析

针对曲肘式注塑机短连杆与十字头轴孔配合接触部分容易发生疲劳失效状况,以短连杆与十字头轴孔配合接触对为研究对象,应用有限元法通过等效简化建立有限元接触模型。充分考虑轴孔配合表面接触微粒间的相互作用影响,运用大型有限元软件ANSYS中的非线性有限元仿真方法,数值计算并分析了不同作用力、不同摩擦系数下接触面的接触状态。结果表明,轴孔配合在轴受作用力变形后,接触面出现应力集中,接触应力与摩擦应力由轴外侧往内侧逐渐递增,为分析轴孔配合接触失效提供了一定的依据。     

Patterns of fitting cosmetically tinted contact lenses

Cosmetically tinted soft contact lenses are an attractive option for contact lens wearers. Data that we have gathered from annual contact lens fitting surveys demonstrate that those wearing tinted lenses are more likely to be female (4.6% of all soft lenses fitted vs. 1.6% for males; p < 0.0001) and younger (27 ± 11 years vs. 33 ± 13 years for those wearing non-tinted lenses; p < 0.0001). Tinted lenses tend to be worn more on a part-time basis and are replaced less frequently than non-tinted lenses. The decline in fitting tinted lenses over the past 12 years may be due to (a) the current limited availability of tinted lenses in silicone hydrogel materials and daily disposable replacement frequencies, which together represent a significant majority (78%) of new soft lenses fits today, (b) growing concerns among lens wearers and practitioners relating to the risks of complications associated with the wearing of tinted lenses, and (c) reduced promotion of such lenses by the contact lens industry.     

The 75th anniversary of the Tuohy corneal contact lens: A review

The aim of this review is to mark the 75th anniversary of the introduction of the original corneal contact lens of Tuohy in 1948.American documents in the public domain, such as census records and draft registration cards, were consulted in order to provide a more comprehensive biography of Kevin M Tuohy, inventor of the corneal contact lens, than those previously published.Perhaps due to a failure to consult original sources concerning the Tuohy corneal lens, some historical accounts have provided incomplete or incorrect information about its design and dimensions. The back surface specification of the bi-curve Tuohy lens in its standard diameter of 11.50 mm has been tabulated and edge lift and edge clearance values calculated. A colour photograph illustrates the fluorescein pattern of a Tuohy lens.Patients wearing Tuohy lenses were able to achieve a much longer wearing time compared to those wearing sealed scleral lenses since they eliminated corneal epithelial oedema, a frequent problem which necessitated removal of lenses after a few hours of wear due to cloudy vision. Only some of Tuohy lens wearers exhibited an adverse corneal response such as fluorescein staining after 12, or more, hours of wear.The clinical success of the Tuohy lens and the fact that its fitting procedure was simpler and quicker than that for scleral lenses encouraged optometrists to commence contact lens practice and to implement improvements in the design of the corneal lens.     

Microbial adherence to cosmetic contact lenses

AimTo investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence.MethodFifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A–C) (five lenses per brand) were also compared to their adherences on their clear counterparts.ResultsOnly two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 10⁵–1.9 × 10⁶ CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence.ConclusionSurface pigments on CCL resulted in significantly higher bacterial adherence.     

Performance and predictability of a new large diameter contact lens design in keratoconic corneae

ObjectivesTo evaluate the clinical performance and predictability using corneal topography in the fitting of a new large-diameter rigid gas permeable (RGP) contact lens design in eyes with keratoconus (KCN).MethodsThis study presents a review of eyes fitted with Alexa ES lenses for nonsurgical optimisation of visual correction. Anterior steep simulated keratometry (sim-K steep), corneal diameter (HVID), the Curvature at the apex in diopters (Cc), and distance from the corneal apex to the centre of the cornea (Lc) in millimetres derived from the Cone Location and Magnitude Index (CLMI) were recorded. Visual acuity, mean wearing time, final sagittal depth and adverse events were also recorded. Correlations between topographic indices and base curve were evaluated using the Pearson correlation coefficient.ResultsForty-six eyes from 26 patients (19 males/ 7 females) were included. Mean visual acuity improved from 0.49 ± 0.32 with glasses, to -0.02 ± 0.10 with the contact lens. The mean daily wear time was 12.19 ± 1.96 hours. No complications were detected in 95.65% of the eyes [95% CI (83.9%-99.2%)] but two episodes of non-infectious keratitis. The average sagittal depth of the lenses fitted was 0.425 ± 0.15 mm, and it was positively correlated with the Cc value (r² = 0.66, p< 0.0001, n=46) derived from the CLMI index of the pre-fitting topography.ConclusionsCorneoscleral RGP contact lenses are a safe, and effective alternative for managing KCN patients to corneal lenses. Also, clinical data derived from the corneal topography could be used to help to decide the first diagnostic lens to be assessed, easing the overall fitting process.     

Randomised controlled trial of corneal vs. scleral rigid gas permeable contact lenses for keratoconus and other ectatic corneal disorders

PurposeTo compare the comfort and visual performance of corneal rigid gas permeable contact lenses (CoL) and scleral rigid gas permeable contact lenses (SL) in participants with corneal ectasia, successfully wearing “habitual” CoL.MethodsIn a randomised controlled trial (RCT) with a 2 × 2 crossover, 34 participants were recruited and randomised into two groups. Group 1 (sequence AB), were fitted in period 1, with new CoL and after a 4-week washout period, in which habitual CoL were worn, were fitted with and crossed-over to SL, period 2. Group 2 (sequence BA), were first fitted with SL in period 1 and after a washout period of 4 weeks, crossed-over to new CoL, period 2. The median lengths in weeks of Periods 1 and 2 were: 17.5 (IQR 12.4) and 14.5 (IQR 6.2) respectively. The outcome measures for visual performance were best corrected visual acuity and the contrast sensitivity function. Vision related quality of life (Qol) was assessed using the National Eye Institute Visual Function Questioannaire-25 and reported subjective perception of vision (SPV) and reported subjective perception of comfort (SPC) scores, recorded on a scale from 1–10. The final outcome measure was the selection of the preferred lens type at the completion of the RCT.ResultsFor the 30 who completed the trial, significantly higher SPC scores were found for SL compared to CoL (p = 0.002). Significantly higher SPC scores for CoL were found in participants who selected CoL as their preferred lens for future use, compared to those who selected SL (p = 0.009). All other outcomes exhibited no significant difference between the experimental lenses. There was no significant difference (p=0.86) in the proportion preferring CoL (53%) and SL (47%).ConclusionSignificantly better comfort was reported for SL compared with CoL. Significantly higher comfort in CoL was found in those who preferred CoL, than those who preferred SL. Successful CoL wearers whose SPC in CoL is <7 are likely to achieve better comfort with SL. On average, successful CoL wearers found SL more comfortable and there are unlikely to be any significant visual or visual Qol advantage or disadvantage in refitting successful CoL wearers with keratoconus and other corneal ectasia disorders, with SL and vice versa.