Can Swimming Microalgal Cells be Vehicles for ZnO Nanoparticle Transportation and Thus Lead to Zn Diffusion?

The concentration of eco-toxic zinc oxide nanoparticles (nZnO) in aquatic ecosystems is increasing, and an effective method for their removal is needed. We hypothesize that microalgal cells may act as nZnO vehicles—if the nZnO concentration does not affect their swimming ability—enabling Zn diffusion and sedimentation. We conducted experiments using flasks connected via a U-type vessel; the first flask contained nZnO suspensions and second flask contained artificial seawater, respectively. We added microalgae to the first flask and illuminated the second. The microalgae appeared to promote sedimentation. However, only a few microalgal cells passed via phototaxis into the second flask, so the detection of nZnO or Zn ions in the second flask was not possible. Therefore, to confirm whether the microalgae affect Zn transportation, a more accurate method to detect nZnO or Zn ions at very low concentrations is needed.

     

2004-2018年中国老年居民慢性非传染性疾病死亡水平与变化趋势

目的分析2004-2018年中国≥65岁老年居民慢性非传染性疾病(慢性病)死亡水平及变化趋势,预测2019-2023年慢性病年龄标化死亡率。方法利用2004-2018年中国死因监测数据集中老年居民死亡数据,分析不同性别、城乡、地区的慢性病粗死亡率、年龄标化死亡率、构成比及变化趋势。采用2010年第六次全国人口普查的人口构成计算年龄标化死亡率;采用加权最小二乘法拟合Joinpoint回归模型,计算全时间段内平均年度变化百分比(AAPC)及95%可信区间;采用对数线性模型预测年龄标化死亡率。结果2004-2018年我国老年居民慢性病年龄标化死亡率从4697.05/10万降至3555.35/10万,平均每年下降2.0%(95%CI:-2.7%~-1.3%)。不同性别、城乡、地区间年龄标化死亡率呈下降趋势。东部地区(AAPC=-2.1%,95%CI:-2.8%~-1.3%)、中部地区(AAPC=-2.8%,95%CI:-3.4%~-2.1%)下降速度均快于西部地区(AAPC=-0.8%,95%CI:-1.8%~0.2%)。慢性病死亡构成比从89.82%上升至91.41%,平均每年上升0.1%(95%CI:0.1%~0.2%)。预计至2023年,男性年龄标化死亡率(3906.23/10万)仍高于女性(2708.43/10万);农村年龄标化死亡率(3283.20/10万)与城市(3250.01/10万)相接近;西部地区(3782.48/10万)与东部地区(3037.01/10万)、中部地区(3249.24/10万)的年龄标化死亡率的差距将进一步拉大。结论2004-2018年我国老年居民慢性病年龄标化死亡率呈下降趋势,死亡构成比呈上升趋势,建议以老年人群中男性居民和西部地区居民作为今后慢病防控关注的重点人群。     

IgG抗体亲和力试验判定麻疹病例的价值

目的评价麻疹IgG抗体亲和力试验对判定麻疹病例的价值。方法以中国疾病预防控制信息系统2013-2015年天津市麻疹实验室确诊病例和麻疹排除病例为研究对象。回顾性追溯保存的病例血清,开展麻疹IgG抗体亲和力试验,重新对麻疹排除病例进行归类。结果共收集到326例麻疹病例血标本,其中实验室确诊病例267例,排除病例59例,≥20岁病例占92.33%(301/326)。麻疹IgG抗体亲和力试验显示,确诊病例和排除病例中麻疹IgG高亲和力抗体的比例分别为66.95%(158/236)和91.23%(52/57),差异有统计学意义(χ²⁼13.33,P<0.001)。根据判定标准,15.25%(9/59)排除病例被重新判定为麻疹病例,其中8例是高亲和力抗体,有含麻疹成分疫苗(MCV)免疫史,判定为继发性免疫失败病例;1例为低亲和力抗体,有典型的麻疹临床症状,无MCV免疫史。结论麻疹IgG抗体亲和力试验能够提供有参考意义的血清学证据,可以减少麻疹急性期血清学诊断中由于IgM抗体假阴性而造成的错误排除。     

Fluorescence and Laser Photon Counting: Measurements of Epithelial [Ca2+]i or [Na+]i with Ciliary Beat Frequency

We describe a system we developed that enabled simultaneous measurements of either epithelial calcium ion concentration ([Ca²⁺]i) or sodium ion concentration [Na⁺]i with the ciliary beat frequency (CBF) in native ciliated epithelia using either Fura-2 (AM) or SBFI (AM) ratiometric fluorescence photon counting along with nonstationary laser light scattering. Studies were performed using native epithelial tissues obtained from ovine tracheae. The dynamic range of the laser light-scattering system was determined by a simulated light beating experiment. The nonstationary CBF was demonstrated by the time-frequency analysis of the raw photon count sequences of backscattered heterodyne photons from cultured and native epithelia. Calibrations of calcium and sodium ion concentrations were performed using the respective Fura-2 and SBFI impermanent salts as well as in native epithelia. The cumulative responses of 10^–6, 10^–5, and 10^–4} M nifedipine on [Ca²⁺]i together with the CBF as well as the cumulative responses of 10^–5, 10^–4, and 10^–3 M amiloride on [Na⁺]i together with the CBF were also determined. Nifedipine decreased [Ca²⁺]i but had no effect on CBF. Amiloride decreased [Na⁺]i and CBF. Stimulation of CBF corresponded with either an increase of [Na⁺]i or an increase of [Ca²⁺]i. Decreases of [Na⁺]i or substantial decreases of [Ca²⁺]i were associated with decreases in the CBF. These data demonstrate the utility of this system for investigating the regulatory mechanisms of intracellular ions dynamics and the CBF in native epithelia. © 1998 Biomedical Engineering Society. PAC98: 8780+s, 8722-q, 4262Be     

SLE患者淋巴细胞膜上IL-2R表达的动态分析

本实验采用Wu Tac单克隆抗体的间接荧光抗体法,动态观察了系统性红斑狼疮(SLE)患者和正常供血员(对照组)的外周血淋巴细胞经PHA刺激后,于不同时间(0、24、48、72小时)内细胞膜上白细胞介素2受体(IL-2R)的表达。结果表明在给予PHA刺激培养24、48和72小时后,与对照组比较SLE患者淋巴细胞的IL-2R表达明显下降,提示了SLE的T淋巴细胞反应性降低可能与被激活的T细胞表面IL-2R的表达功能缺陷有关。此结果将有助于进一步探讨SLE的免疫调节紊乱的发生机制。     

微波体模

用水、盐,聚氯乙烯粉和羧甲基纤维钠四种材料配制成一种适用的微波体模(模拟肌肉组织)。该体模的复介电系数在300～2500MHz范围内与实际人体肌肉组织的误差≤5％。这种体模的优点是材料立足国内,价廉,室温下配制,使用方便。本文也给出这种体模的温度特性,稳定性和热学特性,供电磁场生物效应和微波热疗等研究使用。     

慢性常压缺氧和缺氧伴CO_2潴留大鼠红细胞变形能力与膜收缩蛋白的研究

本文测定了慢性常压缺氧（Ⅱ组）、缺氧伴ＣＯ－２潴留（Ⅲ组）及对照组（Ⅰ组）大鼠红细胞变形能力与红细胞膜收缩蛋白二聚体（ＳＰ－Ｄ）和四聚体（ＳＰ－Ｔ）的相对含量。结果表明，Ⅱ、Ⅲ组红细胞变形指数（ＤＩ）和ＳＰ－Ｄ、ＳＰ－Ｔ相对含量与Ⅰ组均有显著差异，且Ⅱ、Ⅲ组的ＤＩ与ＳＰ－Ｄ／ＳＰ－Ｔ比值呈显著负相关。提示膜收缩蛋白的异常，可能是导致慢性缺氧和伴ＣＯ－２潴留大鼠红细胞变形能力降低的重要因素之一。     

偶联剂CGE（N）—R型处理前后牙本质的表面状态及其...

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.     

Primary study of iontophoresis of zinc ion in treatment of retinitis pigmentosa

We report here the preliminary effects of zinc iontophoresis in treatment of 26 Rp patients who had decreased zinc serum level or abnormal ratio of serum copper to zinc. Through more than 20 to 30 times of therapy, the vision of 15.38% eyes increased more than "3 lines", 4% eyes increased more than 5 degrees in the visual field, 13.46% eyes improved in dark adaptation threshold (greater than 1.0), the visual functions of the rest eyes were slightly improved or unimproved. The fundus didn't change before & after treatment. There were no changes of ERG in 8 eyes of 4 cases. In addition, the advantages and disadvantages between Zn iontophoresis and Zn compound taken orally, the improvement of vision by direct electric current therapy, the relationship between the metabolism of Zn element and Vit A and influence of Zn over the mechanism of dark adaptation were also briefly discussed.     

Management of hemangiopericytomas in the central nervous system

目的　血管外皮细胞瘤是少见的中枢神经系统肿瘤 ,由于其易复发和转移而预后不良。本文介绍 2 6例血管外皮细胞瘤的处理经验并结合文献复习其诊治要点。方法　回顾性分析 1993年 1月至 1999年 6月华山医院收治的 2 6例血管外皮细胞瘤 ,其中 5例为复发肿瘤 ,1例为术后残留。结果　 2 6例中 2 4例病灶全切除 ,2例次全切除。术后 2 1例症状好转或不变 ,4例加重 ,1例手术后死于并发症。18例术后放疗。 18例获随访 ,随访期 1- 5 8个月 ,其中 15例恢复良好 ,2例发现转移肿瘤 ,1例复发再次手术后死亡。结论　手术全切是主要治疗方法 ,术后放疗可延缓肿瘤复发。