• 【梅花叶乙醇提取物对Wistar大鼠全层皮肤伤口的影响。】 复制标题 收藏 收藏
    DOI:10.1111/dth.13077 复制DOI
    作者列表:Thangavel P,Pathak P,Kuttalam I,Lonchin S
    BACKGROUND & AIMS: :In recent years, the therapeutic effects of phyto-principles have been appreciated for their promising effects on wound healing. Melia dubia (Malabar neem) possesses anti-cancer, anti-diabetic, anti-tumor, anti-inflammatory, antioxidant, antibacterial, and fungicidal properties. Here, we studied the wound healing efficacy of ethanolic extract of M. dubia leaves on cutaneous wound healing for the first time. The ethanolic extract of M. dubia was applied topically on the wounds of the experimental rats until the wounds heal completely. Wounds of the control rats were treated with PBS. Granulation tissues formed on wound surfaces of the excision wound were harvested on days 4 and 8 and analyzed to determine the total collagen and hexosamine content. Total collagen and hexosamine were significantly (p < .001) higher in M. dubia treated rats compared to control. The rate of wound closure was significantly higher (p < .001) and period of epithelialization was shorter in M. dubia treated rats. Incision wound tissue was used for the tensile strength measurement. Tensile strength was improved in M. dubia treated wound tissues. Results concluded that the topical application of ethanolic extracts of M. dubia improved the rate of wound contraction and tensile strength by increased synthesis of collagen.
    背景与目标: : 近年来,植物原理的治疗作用因其对伤口愈合的有希望的作用而受到赞赏。Melia dubia (Malabar neem) 具有抗癌,抗糖尿病,抗肿瘤,抗炎,抗氧化,抗菌和杀真菌的特性。在这里,我们首次研究了M. dubia叶片的乙醇提取物对皮肤伤口愈合的功效。将M. dubia的乙醇提取物局部涂在实验大鼠的伤口上,直到伤口完全愈合。用PBS治疗对照组大鼠的伤口。在第4天和第8天收获在切除伤口的伤口表面上形成的肉芽组织,并进行分析以确定总胶原蛋白和六糖胺含量。与对照组相比,在dubia M治疗的大鼠中,总胶原蛋白和己糖胺显着升高 (p  < .001)。在dubia M. dubia治疗的大鼠中,伤口闭合率明显较高 (p  < .001),上皮形成时间较短。切口伤口组织用于拉伸强度测量。M. dubia治疗的伤口组织的拉伸强度得到改善。结果得出结论,局部应用M. dubia的乙醇提取物可通过增加胶原蛋白的合成来提高伤口的收缩率和拉伸强度。
  • 【百菌清的比较毒性: 紫花紫花和Pimephales promelas。】 复制标题 收藏 收藏
    DOI:10.1016/s0147-6513(02)00073-8 复制DOI
    作者列表:Sherrard RM,Murray-Gulde CL,Rodgers JH Jr,Shah YT
    BACKGROUND & AIMS: :Chlorothalonil is a commonly used fungicide in rural and urban environments and can be incidentally introduced into aquatic systems through rainfall runoff or direct overspray and drift from aerial applications. Few studies have been published regarding risks to aquatic organisms exposed to chlorothalonil, so this study was performed to provide a first-order risk characterization for receiving system biota. Definitive laboratory toxicity tests were conducted with aqueous solutions of chlorothalonil and sentinel aquatic organisms (Ceriodaphnia dubia Richard and Pimephales promelas Rafinesque). P. promelas was more sensitive (7-day potency=6.1% mortality/mug/L) than C. dubia (7-day potency=0.94% mortality/mug/L) to chlorothalonil exposures. All mortality of P. promelas and C. dubia resulting from these chlorothalonil exposures occurred within the first 96h and no sublethal effects (i.e., growth or reproduction) were detected under these experimental conditions following 7-day exposures.
    背景与目标: : 百菌清是农村和城市环境中常用的杀真菌剂,可以通过降雨径流或直接过度喷洒和从空中应用中漂移而偶然引入水生系统。关于暴露于百菌清的水生生物的风险的研究很少发表,因此进行这项研究是为了为接收系统生物群提供一阶风险表征。用百菌清和前哨水生生物 (ceriodapnia dubia Richard和Pimephales promelas Rafinesque) 的水溶液进行了明确的实验室毒性测试。P. promelas对百菌清暴露比C. dubia (7天效力 = 0.94% 死亡率/mug/L) 更敏感 (7天效力 = 6.1% 死亡率/mug/L)。这些百菌清暴露导致的P. promelas和C. dubia的所有死亡率均在最初的96小时内发生,并且在这些实验条件下暴露7天后未检测到亚致死作用 (即生长或繁殖)。
  • 【使用ceriophnia dubia比较银和金纳米颗粒之间的急性与慢性比率。】 复制标题 收藏 收藏
    DOI:10.1080/17435390.2017.1399219 复制DOI
    作者列表:Harmon AR,Kennedy AJ,Laird JG,Bednar AJ,Steevens JA
    BACKGROUND & AIMS: :As integration of nanoparticles (NPs) into products becomes more common, the need to address the paucity of chronic hazard information for aquatic environments required to determine risk potential increases. This study generated acute and chronic toxicity reference values for Ceriodaphnia dubia exposed to 20 and 100 nm silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) to generate and evaluate potential differences in acute-to-chronic ratios (ACR) using two different feeding methods. A modified feeding procedure was employed alongside the standard procedures to investigate the influence of food on organism exposure. An 8-h period before food was added allowed direct organism exposure to NP dispersions (and associated ions) without food-to-NP interactions. The AgNPs [chronic lethal median concentrations (LC50) between 18.7 and 31.9 µg/L] were substantially more toxic than AuNPs (LC50 = 21 507 to >26 384 µg/L). The modified chronic testing method resulted in greater sensitivity in AgNPs exposures. However, the modified feeding ration had less of an effect in exposures to the larger (100 nm) AgNPs compared to smaller particles (20 nm). The ACRs for AgNPs using the standard feeding ration were 1.6 and 3.5 for 20 nm and 100 nm, respectively. The ACRs for AgNPs using the modified feeding ration were 3.4 and 7.6 for 20 nm and 100 nm NPs, respectively. This supports that the addition of the standard feeding ration decreases C. dubia chronic sensitivity to AgNPs, although it must also be recognized organisms may be sensitized due to less access to food. The ACRs for 20 nm and 100 nm AuNPs (standard ration only) were 4.0 and 3.0, respectively. It is important to also consider that dissolved Ag+ ions are more toxic than AgNPs, based on both acute toxicity values in the cited literature and chronic toxicity thresholds generated in this study that support existing thresholds that Ag+ are likely protective of AgNPs effects.
    背景与目标: : 随着将纳米颗粒 (np) 集成到产品中的情况变得越来越普遍,需要解决确定潜在风险增加所需的水生环境慢性危害信息的缺乏。这项研究为暴露于20和100  nm银纳米颗粒 (AgNPs) 和金纳米颗粒 (AuNPs) 的紫花的急性和慢性毒性参考值,以使用两种不同的喂养方法产生和评估急慢性比 (ACR) 的潜在差异。与标准程序一起采用了改良的喂养程序,以研究食物对生物体暴露的影响。在添加食物之前的8小时内,可以使生物体直接暴露于NP分散体 (和相关离子),而没有食物与NP的相互作用。AgNPs [18.7至31.9  µ g/L之间的慢性致死中位浓度 (LC50)] 比AuNPs毒性明显更高 (LC50   =   21 507至> 26 384  µ g/L)。改良的慢性测试方法导致AgNPs暴露的敏感性更高。然而,与较小颗粒 (20 nm) 相比,改进的饲喂比例在暴露于较大 (100  nm) AgNPs的影响较小。使用标准给料量对AgNPs的ACRs分别为20  nm和100  nm的1.6和3.5。使用改进的给料比对20  nm和100  nm NPs的AgNPs的ACRs分别进行3.4和7.6。这支持添加标准饲喂日粮降低了杜比杆菌对AgNPs的慢性敏感性,尽管还必须认识到,由于较少获得食物,生物体可能会变得敏感。20 nm和100  nm AuNPs (仅标准定量) 的ACRs分别为4.0和3.0。根据引用文献中的急性毒性值和本研究中产生的支持Ag + 可能保护AgNPs效应的现有阈值的慢性毒性阈值,还必须考虑溶解的Ag + 离子比AgNPs更具毒性。
  • 【1894 (甲壳纲: Anomopoda) 热带锁骨的种群动态。食物类型和温度的影响。】 复制标题 收藏 收藏
    DOI: 复制DOI
    作者列表:Martinez-Jeronimo F,Ventura-Lopez C
    BACKGROUND & AIMS: :The knowledge of population effects of food on tropical, filter-feeding cladocerans is scarce because a reduced number of species has been extensively studied. Ceriodaphnia rigaudi Richard 1894, a small-sized cladoceran distributed mainly in tropical and subtropical regions of the world, was studied. The aim of this study was to contribute to the knowledge of the reproductive biology of a poor-known Cladoceran; for this we assessed the effect of feeding and temperature on the reproduction and life cycle of this species. Three microalga species (Pseudokirchneriella subcapitata, Ankistrodesmus falcatus, and Chlorella vulgaris) were supplied as food each at a concentration of 12 mg l(-1) (dry weight, equivalent to 1.3 x 10(6), 0.4 x 10(6) and 1.35 x 10(6) cell m1(-1), respectively, and equivalent to 7.8 microg C ml(-1), at two temperatures (20 and 25 degrees C). We evaluated, among other responses, longevity, total progeny, survival, life expectancy at birth and fecundity. Organisms fed with the microalgae A. falcatus and P subcapitata presented both higher longevity (30.7 +/- 5.91, 26.6 +/- 3.59 days, respectively) and total progeny (45 +/- 13.80, 40.7 +/- 0.66 neonates female (-1) values than those organisms fed C. vulgaris (13.5 +/- 4.63 days and 17.6 +/- 6.19 neonates female (-1), respectively). On the other hand, temperature affected significantly the population parameters of C. rigaudi, recording maximal longevity values (56.1 +/- 9.41 days) at 20 degrees C in organisms fed A. falcatus; however, age at first reproduction and total progeny were negatively affected by this temperature: sexual maturation of the females was delayed until the age of 16 days and the number of neonates produced was smaller (9.8 +/- 3.45 with C. vulgaris; 24.7 +/- 6.01 with P subcapitata, and 35.5 +/- 8.59 neonates female(-1) with A. falcatus). The best reproductive responses for C. rigaudi in this study were obtained with A. falcatus at degrees 25 degrees C.
    背景与目标: : 由于对减少的物种数量进行了广泛的研究,因此很少了解食物对热带滤食性锁骨的种群影响。研究了主要分布在世界热带和亚热带地区的一种小型枝状植物Ceriodaphnia rigaudi Richard 1894。这项研究的目的是为了解一种鲜为人知的锁骨的生殖生物学做出贡献; 为此,我们评估了摄食和温度对该物种繁殖和生命周期的影响。以12 mg l(-1) (干重,相当于1.3x10(6),0.4x10(6) 和1.35x10(6) 细胞m1(-1),分别相当于7.8 microg C ml(-1),在两个温度 (20和25 ℃) 下,我们评估了寿命,总后代,存活率,出生时的预期寿命和繁殖力。饲喂微藻A. falcatus和P subcapitata的生物具有更高的寿命 (分别为30.7/- 5.91,26.6//- 3.59天) 和总后代 (45//- 13.80,40.7 +/- 0.66的新生儿女性 (-1) 值比那些喂养寻常型C的生物 (分别为13.5 +/- 4.63天和17.6 +/- 6.19的新生儿女性 (-1) 值)。另一方面,温度显著影响了C. rigaudi的种群参数,记录饲喂A. falcatus的生物在20摄氏度下的最大寿命值 (56.1/- 9.41天); 但是,该温度对首次繁殖的年龄和总后代产生负面影响: 雌性的性成熟被推迟到16天,并且产生的新生儿数量较少 (寻常型C.9.8/- 3.45; P subcapitata 24.7/- 6.01,和35.5 +/- 8.59的新生儿女性 (-1) 与A. falcatus)。本研究中的C.Rigoudi的最佳生殖反应是在25 ℃ 下用A. falcatus获得的。
  • 【紫花中ZnO NPs的急性毒性和积累: 溶解离子和颗粒的相对贡献。】 复制标题 收藏 收藏
    DOI:10.1016/j.aquatox.2016.07.003 复制DOI
    作者列表:Bhuvaneshwari M,Iswarya V,Nagarajan R,Chandrasekaran N,Mukherjee A
    BACKGROUND & AIMS: :Although the ecotoxicological effects of various metal oxide nanoparticles on aquatic organisms are being actively studied, the contributions of particles and dissolved ions towards toxicity are still not well understood. The current study aims to assess the contribution of ZnO NP(particle) and ZnO NP(ion) to the overall toxicity and accumulation of ZnO NP(total) in Ceriodaphnia dubia. The aggregation and dissolution kinetics were studied for three different sizes (50nm, 100nm and bulk) of ZnO particles at 0.05, 0.12, 0.25 and 0.5mg/L concentrations in the sterile lake water medium at 6, 12, 24, and 48h intervals. The 48h LC50 of ZnO NP(total) was found to be 0.431, 0.605 and 0.701mg/L for 50, 100nm and bulk particles exposure. However, LC50 of Zn(ion) was found to be 1.048, 1.343 and 2.046mg/L for dissolved ions from different sizes (50nm, 100nm, and bulk) of ZnO particles. At LC50 concentration, the accumulation of 90-95% was noted for the NP(particles) across the sizes employed, while only about 4-5% contribution was from the NP(ion) to the overall accumulation NP(total). The relative contribution of ZnO NP(ion) to overall toxicity and accumulation was found to be lesser than that of ZnO NP(particles) across the sizes used in the study.
    背景与目标: : 尽管正在积极研究各种金属氧化物纳米颗粒对水生生物的生态毒理学作用,但颗粒和溶解离子对毒性的贡献仍未得到很好的理解。当前的研究旨在评估ZnO NP (颗粒) 和ZnO NP (离子) 对紫花中ZnO NP (总) 的整体毒性和积累的贡献。在6、12、24和48h的无菌湖水介质中,研究了三种不同尺寸 (50nm,100nm和散装) 的ZnO颗粒在0.05,0.12,0.25和0.5mg/L浓度下的聚集和溶解动力学。间隔。发现对于50,100nm和块状颗粒暴露,ZnO NP (总计) 的48h LC50为0.431,0.605和0.701mg/L。然而,对于来自不同尺寸 (50nm、100nm和大块) 的ZnO颗粒的溶解离子,发现Zn (离子) 的LC50为1.048、1.343和2.046mg/L。在LC50浓度下,NP (颗粒) 在所采用的尺寸上的累积为90-95%,而NP (离子) 对总累积NP (总计) 的贡献仅约4-5%。在研究中使用的大小中,发现ZnO NP (离子) 对总体毒性和积累的相对贡献小于ZnO NP (颗粒)。
  • 【五种选择性5-羟色胺再摄取抑制剂对紫花的急性和慢性毒性。】 复制标题 收藏 收藏
    DOI:10.1897/03-278 复制DOI
    作者列表:Henry TB,Kwon JW,Armbrust KL,Black MC
    BACKGROUND & AIMS: Contamination of surface waters by pharmaceutical chemicals has raised concern among environmental scientists because of the potential for negative effects on aquatic organisms. Of particular importance are pharmaceutical compounds that affect the nervous or endocrine systems because effects on aquatic organisms are possible at low environmental concentrations. Selective serotonin reuptake inhibitors (SSRIs) are drugs used to treat clinical depression in humans, and have been detected in low concentrations in surface waters. In this investigation, the acute and chronic toxicity of five SSRIs (fluoxetine, Prozac; fluvoxamine, Luvox; paroxetine, Paxil; citalopram, Celexa; and sertraline, Zoloft) were evaluated in the daphnid Ceriodaphnia dubia. For each SSRI, the 48-h median lethal concentration (LC50) was determined in three static tests with neonate C. dubia, and chronic (8-d) tests were conducted to determine no-observable-effect concentrations (NOEC) and lowest-observable-effect concentrations (LOEC) for reproduction endpoints. The 48-h LC50 for the SSRIs ranged from 0.12 to 3.90 mg/L and the order of toxicity of the compounds was (lowest to highest)Citalopram, fluvoxamine, paroxetine, fluoxetine, sertraline. Mortality data for the 8-d chronic tests were similar to the 48-h acute data. The SSRIs negatively affected C. dubia reproduction by reducing the number of neonates per female, and for some SSRIs, by reducing the number of broods per female. For sertraline, the most toxic SSRI, the LOEC for the number of neonates per female was 0.045 mg/L and the NOEC was 0.009 mg/L. Results indicate that SSRIs can impact survival and reproduction of C. dubia; however, only at concentrations that are considerably higher than those expected in the environment.

    背景与目标: 由于可能对水生生物产生负面影响,药物化学品对地表水的污染引起了环境科学家的关注。特别重要的是影响神经或内分泌系统的药物化合物,因为在低环境浓度下可能对水生生物产生影响。选择性5-羟色胺再摄取抑制剂 (SSRIs) 是用于治疗人类临床抑郁症的药物,已在地表水中以低浓度检测到。在这项研究中,在水蚤ceriodapnia dubia中评估了五种ssri的急性和慢性毒性 (氟西汀,百忧解; 氟伏沙明,Luvox; 帕罗西汀,帕罗西汀; 西酞普兰,Celexa; 和舍曲林,Zoloft)。对于每个SSRI,用新生儿杜比杆菌 (C. dubia) 在三个静态试验中确定48小时中位致死浓度 (LC50),并进行慢性 (8-d) 试验以确定生殖终点的无可观察效应浓度 (NOEC) 和最低可观察效应浓度 (LOEC)。Ssri的48小时LC50范围为0.12至3.90 mg/L,化合物的毒性顺序为 (最低至最高) 西酞普兰,氟伏沙明,帕罗西汀,氟西汀,舍曲林。8天慢性试验的死亡率数据与48小时急性试验的数据相似。SSRI通过减少每个女性的新生儿数量,对杜比乳虫的繁殖产生负面影响,对于某些SSRI,通过减少每个女性的育雏数量。对于舍曲林,毒性最强的SSRI,每个女性新生儿数量的LOEC为0.045 mg/L,NOEC为0.009 mg/L。结果表明,ssri可以影响杜比杆菌的存活和繁殖; 但是,仅在浓度比环境中预期的浓度高得多的情况下。
  • 【培养和试验水中的硬度和碱度对杜鹃繁殖的影响。】 复制标题 收藏 收藏
    DOI:10.1897/05-547r.1 复制DOI
    作者列表:Lasier PJ,Winger PV,Hardin IR
    BACKGROUND & AIMS: :Ceriodaphnia dubia were cultured in four reconstituted water formulations with hardness and alkalinity concentrations ranging from soft to the moderately hard water that is required by whole-effluent toxicity (WET) testing methods for culturing test organisms. The effects of these culture formulations alone and in combination with two levels of Cl-, SO4(2-), and HCO3- on reproduction of C. dubia were evaluated with the standard three-brood test. Reproduction was significantly reduced when test waters had lower hardness than culture waters. However, reproduction was not significantly different when animals cultured in low-hardness waters were exposed to moderately hard waters. The hardness of the culture water did not significantly affect the sensitivity of C. dubia to the three anions. Conversely, increased hardness in test waters significantly reduced the toxicities of Cl- and SO4(2-), with HCO3- toxicity following the same pattern. Alkalinity exhibited no consistent effect on Cl- and SO4(2-) toxicity. The physiological stress of placing animals cultured in moderately hard water into softer test waters might contribute to marginal failures of otherwise nontoxic effluents. The standard WET protocol should be revised to allow the culture of C. dubia under lower hardness conditions to better represent local surface water chemistries.
    背景与目标: : 在四种重新配制的水配方中培养了杜鹃,其硬度和碱度的浓度范围从软水到中等硬水,这是全废水毒性 (湿) 测试方法培养测试生物所需的。这些培养配方单独以及与两种水平的Cl-,SO4(2-) 和HCO3-组合对杜比C繁殖的影响。用标准的三育试验进行了评估。当试水的硬度低于培养水时,繁殖显着减少。但是,当在低硬度水中培养的动物暴露于中等硬水中时,繁殖没有显着差异。培养水的硬度不会显着影响C. dubia对三种阴离子的敏感性。相反,测试水中硬度的增加会显着降低Cl-和SO4(2-) 的毒性,而HCO3毒性则遵循相同的模式。碱度对Cl-和SO4(2-) 毒性没有一致的影响。将在中等硬水中培养的动物放入较软的试验水中的生理压力可能会导致原本无毒的废水的边际失败。应修订标准的湿方案,以允许在较低硬度条件下培养杜氏杜氏菌,以更好地代表当地的地表水化学性质。
  • 【Camu camu (Myrciaria dubia) 的抗氧化剂和相关能力: 系统评价。】 复制标题 收藏 收藏
    DOI:10.1089/acm.2014.0130 复制DOI
    作者列表:Langley PC,Pergolizzi JV Jr,Taylor R Jr,Ridgway C
    BACKGROUND & AIMS: :An aging population in the United States presents important challenges for patients and physicians. The presence of inflammation can contribute to an accelerated aging process, the increasing presence of comorbidities, oxidative stress, and an increased prevalence of chronic pain. As patient-centered care is embracing a multimodal, integrative approach to the management of disease, patients and physicians are increasingly looking to the potential contribution of natural products. Camu camu, a well-researched and innovative natural product, has the potential to contribute, possibly substantially, to this management paradigm. The key issue is to raise camu camu's visibility through increased emphasis on its robust evidentiary base and its various formulations, as well as making consumers, patients, and physicians more aware of its potential. A program to increase the visibility of camu camu can contribute substantially not only to the management of inflammatory conditions and its positive contribution to overall good health but also to its potential role in many disease states.
    背景与目标: : 美国人口老龄化给患者和医生带来了重要挑战。炎症的存在可能导致加速衰老过程,合并症,氧化应激和慢性疼痛的患病率增加。由于以患者为中心的护理正在采用多模式,综合的方法来管理疾病,因此患者和医生越来越关注天然产物的潜在贡献。Camu camu是一种经过充分研究和创新的天然产品,有可能为这种管理范式做出巨大贡献。关键问题是通过更加强调其强大的证据基础和各种配方来提高camu camu的知名度,并使消费者,患者和医生更加意识到其潜力。提高camu camu知名度的计划不仅可以大大促进炎症性疾病的管理及其对整体健康的积极贡献,而且还可以促进其在许多疾病状态中的潜在作用。
  • 【50种金属对紫花的慢性毒性。】 复制标题 收藏 收藏
    DOI:10.1002/jat.4049 复制DOI
    作者列表:Okamoto A,Masunaga S,Tatarazako N
    BACKGROUND & AIMS: :Metals are essential elements for human life but may cause disorders when exposure is excessive. Previously, we reported on the acute toxicity of 50 metals; however, the chronic toxicity data of some metals are not available. Therefore, we conducted chronic toxicity tests to determine the effects of 50 metals on the water flea, Ceriodaphnia dubia. The IC20 of 20 metals (Be, Sc, Cr, Co, Ni, Cu, Zn, Y, Ru, Ag, Cd, In, Te, W, Os, Pt, Au, Hg, Tl and Pb) were <100 μg/L; nine metals (Al, V, As, Se, Zr, Nb, Rh, Sb and Bi) were 100 ≤ IC20 < 1000 μg/L; 16 metals (Li, Mg, K, Ti, Mn, Fe, Ga, Ge, Rb, Sr, Mo, Sn, Cs, Ba, Re and Ir) were 1000 ≤ IC20 ≤ 100 000 μg/L; and two metals (Na and Ca) were >100 000 μg/L. Three metals (Pd, Hf and Ta) did not show IC20 at the upper limit of respective aqueous solubility, and IC20 s were not obtained. The maximum test concentrations (almost aqueous solubility) of Pd, Hf and Ta were 83, 2400 and 5.3 μg/L, respectively. These data show the high correlation between our IC50 s for C. dubia and those for Dahpnia magna published previously. The IC50 s of 47 metals were not correlated with electronegativity, first ionization energy, atomic weight, atomic number, covalent radius, atomic radius or ionic radius.
    背景与目标: : 金属是人类生命必不可少的元素,但当暴露过度时可能会导致疾病。以前,我们报道了50种金属的急性毒性; 但是,某些金属的慢性毒性数据不可用。因此,我们进行了慢性毒性测试,以确定50种金属对水蚤,小花杜比的影响。20种金属 (Be,Sc,Cr,Co,Ni,Cu,Zn,Y,Ru,Ag,Cd,In,Te,W,Os,Pt,Au,Hg,Tl和Pb) 的IC20 <100 μ g/L; 9种金属 (Al,V,as,Se,Zr,Nb,Rh,Sb和Bi) 100 ≤ IC20 < 1000 μ g/L; 16种金属 (Li,Mg,K,Ti,Mn,Fe,Ga,Ge,Rb,Sr,Mo,Sn,Cs,Ba,re和Ir) 1000 ≤ IC20 ≤ 100 000 μ g/L; 两种金属 (Na和Ca)> 100 000 μ g/L。三种金属 (Pd,Hf和Ta) 在各自的水溶性上限未显示IC20,并且未获得IC20。Pd、Hf和Ta的最大测试浓度 (几乎水溶性) 分别为83、2400和5.3 μ g/L。这些数据显示了我们对杜氏杜氏菌的IC50与先前发表的Dahpnia magna的IC50之间的高度相关性。47种金属的IC50与电负性,第一电离能,原子量,原子序数,共价半径,原子半径或离子半径无关。
  • 【选择性5-羟色胺再摄取抑制剂的混合物和单物质急性毒性。】 复制标题 收藏 收藏
    DOI:10.1897/06-265r.1 复制DOI
    作者列表:Henry TB,Black MC
    BACKGROUND & AIMS: :Selective serotonin reuptake inhibitors (SSRIs) are neurologically active drugs that can contaminate surface waters and have the potential to negatively affect aquatic organisms. In this investigation, the 48-h acute toxicity of mixtures (binary and quaternary) of four common SSRIs (fluoxetine [Prozac], sertraline [Zoloft], paroxetine [Paxil], and citalopram [Celexa]) were determined in the daphnid Ceriodaphnia dubia. Logistic regression was used to model mortality data and to investigate the applicability of concentration addition and independent action models to explain observed mortality. The concentrations estimated to induce 50% mortality in 48 h for the individual SSRIs sertraline, fluoxetine, paroxetine, and citalopram were 0.48 to 0.66, 1.23 to 1.84, 2.23 to 3.57, and 10.47 to 14.53 microM, respectively. Concentration addition was a better predictor of mixture effects than independent action and suggested that the tested SSRIs have a similar mechanism of action. Results indicate that environmental hazard assessments should be conservative and consider that acutely toxic effects in aquatic organisms can be additive for each SSRI in a mixture.
    背景与目标: 选择性5-羟色胺再摄取抑制剂 (SSRIs) 是神经活性药物,可污染地表水,并有可能对水生生物产生负面影响。在这项研究中,在水蚤中测定了四种常见ssri (氟西汀 [百忧解],舍曲林 [Zoloft],帕罗西汀 [Paxil] 和西酞普兰 [Celexa]) 的混合物 (二元和四级) 的48小时急性毒性。使用逻辑回归对死亡率数据进行建模,并研究浓度添加和独立作用模型解释观察到的死亡率的适用性。将单个SSRIs舍曲林,氟西汀,帕罗西汀和西酞普兰的估计在48小时内引起50% 死亡的浓度分别0.48至0.66,1.23至1.84,2.23至3.57和10.47至14.53 microM。浓度添加比独立作用更好地预测了混合物的影响,并表明所测试的ssri具有相似的作用机理。结果表明,环境危害评估应保持保守,并考虑到水生生物中的急性毒性作用可能是混合物中每种SSRI的累加作用。
  • 【不同类型的二氧化钛纳米颗粒对淡水系统中紫花的毒性作用。】 复制标题 收藏 收藏
    DOI:10.1007/s11356-019-04652-x 复制DOI
    作者列表:Iswarya V,Palanivel A,Chandrasekaran N,Mukherjee A
    BACKGROUND & AIMS: :In the current study, the effect of different types of titanium dioxide (TiO2) nanoparticles (NPs) (rutile, anatase, and mixture) was analyzed on Ceriodaphnia dubia in the presence of algae under distinct irradiation conditions such as visible and UV-A. The toxicity experiments were performed in sterile freshwater to mimic the chemical composition of the freshwater system. In addition, the oxidative stress biomarkers such as MDA, catalase, and GSH were analyzed to elucidate the stress induced by the NPs on daphnids. Individually, both rutile and anatase NPs induced similar mortality under both visible and UV-A irradiations at all the test concentrations except 600 and 1200 μM where rutile induced higher mortality under UV-A. Upon visible irradiation, the binary mixture exhibited a synergistic effect at their lower concentration and an additive effect at higher concentrations. In contrast, UV-A irradiation demonstrated the additive effect of mixture except for 1200 μM which elucidated antagonistic effect. Mathematical model confirmed the effects of the binary mixture. The surface interaction between the individual NPs in the form of aggregation played a pivotal role in the induction of specific effects exhibited by the binary mixture. Oxidative stress biomarkers were highly increased upon NPs exposure especially under visible irradiation. These observations elucidated that the irradiation and crystallinity effect of TiO2 NPs were noted only on certain biomarkers and not on the mortality.
    背景与目标: : 在当前的研究中,分析了不同类型的二氧化钛 (TiO2) 纳米颗粒 (NPs) (金红石,锐钛矿和混合物) 在藻类存在下在可见光和UV-A等不同辐射条件下对紫花的影响。毒性实验是在无菌淡水中进行的,以模拟淡水系统的化学成分。此外,还分析了氧化应激生物标志物,例如MDA,过氧化氢酶和GSH,以阐明NPs对水蚤引起的应激。在所有测试浓度下,金红石和锐钛矿NPs在可见光和uv-a照射下均单独诱导了相似的死亡率,除了600和1200微米,其中金红石在uv-a下诱导了更高的死亡率。在可见的照射下,二元混合物在较低的浓度下表现出协同作用,而在较高的浓度下表现出累加作用。相反,uv-a辐照显示了混合物的加性效应,除了1200 μ m,其阐明了拮抗效应。数学模型证实了二元混合物的影响。聚集形式的单个np之间的表面相互作用在诱导二元混合物表现出的特定效果中起着关键作用。NPs暴露后,氧化应激生物标志物高度增加,尤其是在可见辐射下。这些观察结果表明,TiO2 np的辐射和结晶度效应仅在某些生物标志物上被发现,而在死亡率上却没有。
  • 【Scherffelia dubia centrin的E144残基区分了DNA修复蛋白XPC和中心体蛋白sfi1。】 复制标题 收藏 收藏
    DOI:10.1016/j.fob.2013.11.005 复制DOI
    作者列表:Grecu D,Blouquit Y,Assairi L
    BACKGROUND & AIMS: :Centrins are members of the EF-hand family of calcium-binding proteins, which are highly conserved among eukaryotes. Centrins bind to several cellular targets, through a hydrophobic triad. However, the W(1)xxL(4)xxxL(8) triad in XPC (Xeroderma Pigmentosum Group C protein) is found in the reverse orientation, as in the L(8)xxxL(4)xxW(1) triad in Sfi1 (Suppressor of Fermentation-Induced loss of stress resistance protein 1). As shown by previous NMR studies of human centrin 2 in complex with XPC or Sfi1, the E148 residue of human centrin 2 is in contact with XPC but is pushed away from the triad of Sfi1. We corroborated these findings using site-directed mutagenesis to generate mutations in Scherffelia dubia centrin (SdCen) and by using isothermal titration calorimetry to analyze the binding affinity of these mutants to XPC and Sfi1. We mutated the F109 residue, which is the main residue involved in target binding regardless of triad orientation, and the E144 residue, which was thought to be involved only in XPC binding. The F109L mutation reduced the binding of SdCen to XPC and Sfi1 and the negative effect was greater upon temperature increase. By contrast, the E144A mutation reduced the binding to XPC but had no effect on Sfi1 binding. The F109L-E144A mutation enhanced the negative effect of the two single mutations on XPC binding. Sfi1 proteins from Ostreococcus lucimarinus and Ostreococcus tauri, which belong to the same clade as S. dubia, were also investigated. A comparative analysis shows that the triad residues are more conserved than those in human Sfi1.
    背景与目标: : 中枢蛋白是钙结合蛋白EF-hand家族的成员,在真核生物中高度保守。中枢蛋白通过疏水三联体与几个细胞靶标结合。然而,XPC中的W(1)xxL(4)xxxL(8) 三联体 (XPC) (着色性干皮C组蛋白) 的方向相反,如Sfi1中的L(8)xxxL(4)xxW(1) 三联体 (发酵诱导的抗逆性蛋白1损失的抑制剂)。如先前对人centrin 2与XPC或Sfi1复合物的NMR研究所示,人centrin 2的E148残基与XPC接触,但被推离Sfi1的三联体。我们通过定点诱变在Scherffelia dubia centrin (SdCen) 中产生突变,并通过等温滴定量热法分析这些突变体与XPC和sfi1的结合亲和力,证实了这些发现。我们突变了F109残基和E144残基,F109残基是参与靶结合的主要残基,而与三联体方向无关,而E144残基被认为仅参与XPC结合。F109L突变降低了SdCen与XPC和Sfi1的结合,并且随着温度升高,负面影响更大。相比之下,E144A突变降低了与XPC的结合,但对Sfi1的结合没有影响。F109L-E144A突变增强了两个单个突变对XPC结合的负面影响。还研究了与杜氏链球菌属于同一进化枝的lucimarinus和taococcus的Sfi1蛋白。比较分析表明,三联体残基比人sfi1中的残基更保守。
  • 【来自桃金娘 (H. B. & K.) McVaugh叶片的醛糖还原酶抑制剂。】 复制标题 收藏 收藏
    DOI:10.1016/j.phymed.2003.12.002 复制DOI
    作者列表:Ueda H,Kuroiwa E,Tachibana Y,Kawanishi K,Ayala F,Moriyasu M
    BACKGROUND & AIMS: :Ellagic acid (1) and its two derivatives, 4-O-methylellagic acid (2) and 4-(alpha-rhamnopyranosyl)ellagic acid (3) were isolated as inhibitors of aldose reductase (AR) from Myrciaria dubia (H. B. & K.) McVaugh. Compound 2 was the first isolated from the nature. Compound 3 showed the strongest inhibition against human recombinant AR (HRAR) and rat lens AR (RLAR). Inhibitory activity of compound 3 against HRAR (IC50 value = 4.1 x 10(-8) M) was 60 times more than that of quercetin (2.5 x 10(-6) M). The type of inhibition against HRAR was uncompetitive.
    背景与目标: : 鞣花酸 (1) 及其两种衍生物,从杜叶桃金娘 (H. B. & K.) McVaugh中分离出4-o-甲基鞣花酸 (2) 和4-(α-鼠李糖吡喃糖基) 鞣花酸 (3) 作为醛糖还原酶 (AR) 的抑制剂。化合物2是从自然界中分离出的第一个化合物。化合物3显示出对人类最强的抑制作用重组AR (HRAR) 和大鼠晶状体AR (RLAR)。化合物3对HRAR的抑制活性 (IC50值 = 4.1 × 10(-8) M) 是槲皮素 (2.5 × 10(-6) M) 的60倍。对HRAR的抑制类型是无竞争力的。
  • 【淡水藻类和杜氏藻中量子点的水毒性和食物链转移。】 复制标题 收藏 收藏
    DOI:10.1897/07-637.1 复制DOI
    作者列表:Bouldin JL,Ingle TM,Sengupta A,Alexander R,Hannigan RE,Buchanan RA
    BACKGROUND & AIMS: :Innovative research and diagnostic techniques for biological testing have advanced during recent years because of the development of semiconductor nanocrystals. Although these commercially available, fluorescent nanocrystals have a protective organic coating, the inner core contains cadmium and selenium. Because these metals have the potential for detrimental environmental effects, concerns have been raised over our lack of understanding about the environmental fate of these products. U.S. Environmental Protection Agency test protocol and fluorescence microscopy were used to determine the fate and effect of quantum dots (QDs; Qdot 545 ITK Carboxyl Quantum Dots [Fisher Scientific, Fisher part Q21391MP; Invitrogen Molecular Probes, Eugene, OR, USA]) using standard aquatic test organisms. No lethality was measured following 48-h exposure of Ceriodaphnia dubia to QD suspensions as high as 110 ppb, but the 96-h median lethal concentration to Pseudokirchneriella subcapitata was measured at 37.1 ppb. Transfer of QDs from dosed algae to C. dubia was verified with fluorescence microscopy. These results indicate that coatings present on nanocrystals provide protection from metal toxicity during laboratory exposures but that the transfer of core metals from intact nanocrystals may occur at levels well above toxic threshold values, indicating the potential exposure of higher trophic levels. Studies regarding the fate and effects of nanoparticles can be incorporated into models for predictive toxicology of these emerging contaminants.
    背景与目标: : 近年来,由于半导体纳米晶体的发展,用于生物测试的创新研究和诊断技术得到了发展。尽管这些市售的荧光纳米晶体具有保护性有机涂层,但内核包含镉和硒。由于这些金属可能会对环境造成不利影响,因此人们对我们对这些产品的环境命运缺乏了解感到担忧。美国环境保护局测试方案和荧光显微镜用于使用标准水生测试生物确定量子点 (QDs; Qdot 545 ITK羧基量子点 [Fisher Scientific,Fisher部分Q21391MP; Invitrogen分子探针,Eugene,OR,USA]) 的命运和效果。在将杜氏假单胞菌暴露于QD悬浮液中48小时后,未测量到高达110 ppb的致死性,但在37.1 ppb下测量了对假单胞菌的96小时中位致死浓度。用荧光显微镜验证了量子点从定量藻类到杜比藻的转移。这些结果表明,纳米晶体上存在的涂层在实验室暴露期间提供了免受金属毒性的保护,但核心金属从完整的纳米晶体的转移可能发生在远高于毒性阈值的水平,这表明较高的营养水平的潜在暴露。有关纳米颗粒的命运和影响的研究可以纳入这些新兴污染物的预测毒理学模型中。
  • 【校园停车场雨水径流: 使用天花和天花的理化分析和毒性测试。】 复制标题 收藏 收藏
    DOI:10.1016/j.chemosphere.2010.02.004 复制DOI
    作者列表:McQueen AD,Johnson BM,Rodgers JH Jr,English WR
    BACKGROUND & AIMS: :Campus parking lot stormwater (CPLSW) runoff can mobilize a variety of constituents from vehicular and atmospheric deposition that may pose risks to receiving aquatic systems. The objective of this study was to characterize CPLSW and to discern potential constituents of concern that may affect aquatic biota in receiving systems. Characterization of CPLSW included analyses of metals, oil and grease, and general water chemistry. Toxicity tests were performed using two sentinel species, Ceriodaphniadubia Richard and Pimephales promelas Rafinesque. Metals measured (at their maximum) in CPLSW included 4756microg Al L(-1), 53microg Cu L(-1), 130microg Pb L(-1), and 908microg Zn L(-1). Although CPLSW varied widely in composition and toxicity, constituents of concern included: pH, alkalinity, total suspended solids, biological oxygen demand, chemical oxygen demand, metals, and oil and grease. Fish (P. promelas) were more sensitive to CPLSW than C. dubia with decreased survival in 92% and 15% of the samples (n=13), respectively.
    背景与目标: : 校园停车场雨水 (CPLSW) 径流可以从车辆和大气沉积中调动各种成分,这可能对接收水生系统构成风险。这项研究的目的是表征CPLSW并识别可能影响接收系统中水生生物区系的潜在关注成分。CPLSW的表征包括金属,油和油脂以及一般水化学的分析。使用两种哨兵物种Ceriodaphniadubia Richard和Pimephales promelas Rafinesque进行了毒性测试。在CPLSW中测得的金属 (最大值) 包括4756微克Al L(-1) 、53微克Cu L(-1) 、130微克Pb L(-1) 和908微克Zn L(-1)。尽管CPLSW的成分和毒性差异很大,但值得关注的成分包括: pH,碱度,总悬浮固体,生物需氧量,化学需氧量,金属以及油脂。Fish (P. promelas) 对CPLSW比C. dubia更敏感,分别在92% 和15% 样品 (n = 13) 中存活率降低。

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