高动态光学血管造影成像

我们提出一种高动态光学血管造影成像(HDOA)方法来实现活体生物样本血管造影成像.该方法通过设置高动态范围曝光时间,依据动态积分效应和吸收效应以实现高动态积分时间调制.通过该方法,不仅能够同时获得各级血管清晰的造影图像,还能消除样品厚度不均、吸收系数不同对成像造成的影响.论文以仿体和活体金鱼为样品,通过实验验证了HDOA方法根据动态积分调制效应和吸收效应,能有效实现各级血管同时成像.     

The binding of anionic and nonionic surfactants to collagen through the hydrophobic effect

The adsorption of nonionic surfactants on hide powder previously treated with anionic surfactants has been studied. The adsorption of nonionic surfactants takes place through hydrophobic interactions. A mechanism has been proposed for this interaction, assuming that the nonionic surfactant has been fixed by means of secondary adsorption (hydrophobic interaction) after the primary adsorption of the anionic surfactant (ionic and hydrophobic interaction) which makes it possible.     

我国三大城市群地区城市和农业用地地表热环境效应对比研究

以大中小城市协同发展为特征的城市群已成为我国城市化发展的主要形式,城市化和农业作为城市群地区最主要的土地利用活动,其气候效应是国际研究的热点。然而过去研究多关注大城市的热岛效应,对更为普遍的农业活动以及中小城市城市化的气候效应认识十分薄弱。基于MODIS地表温度数据,以自然林地为参照,提出了一种可逐像元估算土地利用地表热环境效应的新方法,进而对比分析了我国三大城市群地区（京津冀、长三角和珠三角）城市和农业用地地表热环境效应及其驱动因子差异。结果表明各城市群白天城市热岛效应明显,地级以上城市年平均热岛强度达3.2℃以上,但最强热岛均未发生在核心城市。夜晚热岛效应明显减弱,京津冀和长三角部分城市甚至出现冷岛效应。农业用地在白天亦表现出明显的增温效应,特别是在京津冀地区,而在夜晚除珠三角城市群外,降温效应明显,京津冀和长三角地区平均降温2.3℃和0.7℃。虽然城市用地平均增温强度大于农业用地,但农业用地因面积优势对区域温度变化起控制作用。白天城市和农业用地整体导致各城市群温度明显增加,京津冀增温最高（4.0℃）,夜晚二者导致长三角和京津冀地区平均温度降低。研究还发现各城市群城市和农业用地地表热环境效应时空异质性极大,主要受植被、地表反照率、气候背景和人口密度控制。本文对制定缓解气候变化的土地利用策略具有重要的指导意义。     

Parasitism rate of Plebejus argyrognomon (Lepidoptera: Lycaenidae) under different levels of mowing management

Plebejus argyrognomon is an endangered grassland butterfly species in Japan. In this study we focused on the parasitism rate of tachinid flies under different mowing management to obtain knowledge of this possible top-down effect that has been largely ignored. We established three mowing treatments differing in the intensity of mowing, as represented by vegetation height. The results showed that the parasitism rate of P. argyrognomon increased with vegetation height; the parasitism rate in blocks subjected to the highest mowing intensity was 8%, whereas in blocks subjected to the lowest mowing intensity, the rate was 42%. We suggest that clarifying interspecific interactions is important for understanding how habitat management affects grassland-inhabiting butterflies in general.     

视觉功能训练联合托吡卡胺滴眼液治疗假性近视的临床疗效观察

摘要 目的：探讨视觉功能训练联合托吡卡胺滴眼液在治疗假性近视中的临床疗效。方法：选取中国人民解放军陆军特色医学中心眼科和重庆佑佑宝贝妇儿医院眼科2019年2月至2019年8月收治的400例假性近视患儿作为研究对象,将其随机分为对照组和观察组(n=200)。对照组给予滴眼液缓解眼疲劳治疗,观察组则采用视觉功能训练联合托吡卡胺滴眼液治疗。比较两组患儿治疗前及治疗2个月、6个月后裸眼视力、眼轴长度、屈光度、正相对调节量和视疲劳评分的变化。结果：治疗2个月和6个月后,观察组患儿裸眼视力分别为(0.75±0.05)和(0.81±0.04),较对照组显著上升(P<0.05);屈光度分别为(+0.05±0.50)和(+0.06±0.48),明显高于对照组(P<0.05);正相对调节量检测结果依次是(-1.98±0.07)和(-2.51±0.24),较对照组明显增加(P<0.05)。两组患儿视觉感知双眼视功能均有明显改善,其中观察组视觉功能恢复显著高于对照组(P<0.05)。视疲劳调查显示观察组患儿视疲劳评分分别为(6.90±0.89)分和(3.91±0.89)分,显著低于对照组(P<0.05)。结论：视觉功能训练联合托吡卡胺滴眼液治疗能有效提高患儿裸眼视力、改善屈光度、正相对调节量和视觉感知功能,从而减少视疲劳,预防近视。     

Heat shock proteins: A dual carrier-adjuvant for an anti-drug vaccine against heroin

Heroin is a highly abused opioid that has reached epidemic status within the United States. Yet, existing therapies to treat addiction are inadequate and frequently result into rates of high recidivism. Vaccination against heroin offers a promising alternative therapeutic option but requires further development to enhance the vaccine’s performance. Hsp70 is a conserved protein with known immunomodulatory properties and is considered an excellent immunodominant antigen. Within an antidrug vaccine context, we envisioned Hsp70 as a potential dual carrier-adjuvant, wherein immunogenicity would be increased by co-localization of adjuvant and antigenic drug hapten. Recombinant Mycobacterium tuberculosis Hsp70 was appended with heroin haptens and the resulting immunoconjugate granted anti-heroin antibody production and blunted heroin-induced antinociception. Moreover, Hsp70 as a carrier protein surpassed our benchmark Her-KLH cocktail through antibody-mediated blockade of 6-acetylmorphine, the main mediator of heroin’s psychoactivity. The work presents a new avenue for exploration in the use of hapten-Hsp70 conjugates to elicit anti-drug immune responses.     

昆虫病原线虫Heterorhabditis beicherriana LF品系与Bt HBF-18菌株混用对华北大黑鳃金龟幼虫的防治效果

【目的】明确昆虫病原线虫 Heterorhabditis beicherriana LF品系(LF)与苏云金芽孢杆菌 Bacillus thuringiensis HBF-18菌株(Bt HBF-18)混用后对华北大黑鳃金龟 Holotrichia oblita 幼虫的致病力的协同增效作用,为该害虫的防治提供新的技术措施。【方法】在室内测定了LF在不同使用剂量、不同环境温度及不同土壤湿度条件下对华北大黑鳃金龟7-10日龄幼虫的致病力;通过室内生测测定了Bt HBF-18对LF存活的影响,以及Bt HBF-18与LF两者混用后对7-10日龄华北大黑鳃金龟幼虫的防治效果;同时通过室外盆栽试验测定了两者混用对华北大黑鳃金龟幼虫的防治效果。【结果】华北大黑鳃金龟幼虫死亡率随LF施用剂量和处理时间的增加而升高,其中,侵染期线虫(infective juveniles, IJs)800 IJs/100 μL及以上剂量处理7 d后幼虫死亡率达到了100%;25℃为该线虫侵染的最适宜环境温度;适宜土壤湿度范围为14%~20%,湿度过低或过高都会显著影响其侵染效率。室内生测结果表明, Bt HBF-18处理9 d对华北大黑鳃金龟幼虫的致死中浓度(LC 50 )为 1.44× 10^8 CFU/g土,此浓度对LF的存活基本没有影响。另外,室内生测和室外盆栽试验结果均表明,将LF与Bt HBF-18混用能显著提高对华北大黑鳃金龟幼虫的防治效果,混用后具有不同程度的加成或协同增效作用。室内生测试验中LC 50 Bt+200 IJs/100 μL LF混用处理3 d后,较单独LF和Bt HBF-18处理幼虫死亡率分别提高了约43.07%和36.05%,具有显著的协同增效作用;室外盆栽试验中1/2 LC 50 Bt+1 000 IJs/mL LF, LC 50 Bt+1 000 IJs/mL LF和1/2 LC 50 Bt+1 500 IJs/mL LF均具有协同增效作用,其中1/2 LC 50 Bt+1 500 IJs/mL LF增效作用最佳,较单独LF和Bt HBF-18处理幼虫死亡率分别提高了约38.89%和80.55%。【结论】将昆虫病原线虫LF与Bt HBF-18混用对华北大黑鳃金龟幼虫的防治具有加成或协同增效作用。     

Effects of parental light environment on growth and morphological responses of clonal offspring

• Environments experienced by parent ramets of clonal plants can potentially influence fitness of clonal offspring ramets. Such clonal parental effects may result from heritable epigenetic changes, such as DNA methylation, which can be removed by application of DNA de‐methylation agents such as 5‐azacytidine.
• To test whether parental shading effects occur via clonal generation and whether DNA methylation plays a role in such effects, parent plants of the clonal herb Alternanthera philoxeroides were first subjected to two levels of light intensity (high versus low) crossed with two levels of DNA de‐methylation (no or with de‐methylation by application of 5‐azacytidine), and then clonal offspring taken from each of these four types of parent plant were subjected to the same two light levels.
• Parental shading effects transmitted via clonal generation decreased growth and modified morphology of clonal offspring. Offspring responses were also influenced by DNA methylation level of parent plants. For clonal offspring growing under low light, parental shading effects on growth and morphology were always negative, irrespective of the parental de‐methylation treatment. For clonal offspring growing under high light, parental shading effects on offspring growth and morphology were negative when the parents were not treated with 5‐azacytidine, but neutral when they were treated with 5‐azacytidine.
• Overall, parental shading effects on clonal offspring performance of A. philoxeroides were found, and DNA methylation is likely to be involved in such effects. However, parental shading effects contributed little to the tolerance of clonal offspring to shading.

     

Development of a Rapid and Simple Digestion Method of Freshwater Sediments for As,Cd, Cr,Cu, Pb,Fe, and Zn Determination by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES): An Evaluation of Dilute Nitric Acid

In this study, a simple and rapid methodology based on the hot-plate digestion method using dilute nitric acid solution was used to extract trace metals (such as As, Cd, Cr, Cu, Pb, Fe, and Zn) from freshwater sediments. The concentrations of the elements were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES). The factors (temperature, nitric acid concentration, and volume) affecting the digestion method were optimized using one-factor-at-a-time (OFAT) or univariate methodology, and the optimization process was carried out using freshwater sediment certified reference material (CRM015). The optimal conditions for temperature, nitric acid concentration, and time in the method were 180°C, 10 mL of 5 mol L^?1 HNO₃, and 45 min, respectively. Under optimum conditions, the limit of detection (LOD) ranged between 0.02 and 0.08 µg L^?1 and the limit of quantification (LOQ) ranged from 0.07 and 0.27 µg L^?1. In addition, the method detection limits (MDLs) and method quantification limits (MQLs) were 0.10–0.17 and 0.30?0.57 µg g^?1, respectively. The overall accuracy of the method determined by recovery of the trace elements in the CRMs ranged from 98 to 111% with the precision ranging from 1.4 to 5.8%. The method was successfully applied for the determination of target metals from real freshwater sediment samples.     

Enhanced formation of mouse hybridomas without hat treatment in a serum-free medium

Summary A newly developed, serum-free medium (NYSF-404) selects for antibody-producing hybridomas after fusion of antigen-sensitized mouse spleen cells with myeloma cell lines P3-X63-Ag8-U1 (P3-U1), P3-X63-Ag8-6.5.3 (Ag8.653), or P3-NSI/1-Ag4-1 (NS-1). Without the need for hypoxanthine-aminopterinthymidine (HAT) selection of hybrid cells, frequency of hybridoma formation in medium NYSF-404 is higher (twice) than that in serum- and HAT-containing medium. Colonies developed upon limiting dilution in the presence of the mortal parent myeloma cells in medium NYSF-404 and pure culture of antibody-secreting cells could be subsequently established. The results suggest that fusions can be done in serum-free medium and that the clonal growth of hybridomas is dependent on factors produced by parent myeloma cells under serum-free culture conditions. Such factors seem deficient in serum- and HAT-containing medium or are masked by serum.