• 【面包果种子提取物的绿色合成银纳米颗粒及其抗菌活性。】 复制标题 收藏 收藏
    DOI:10.2174/1389201021666200107115849 复制DOI
    作者列表:Shobana S,Veena S,Sameer SSM,Swarnalakshmi K,Vishal LA
    BACKGROUND & AIMS: AIMS:To evaluate the antibacterial activity of Artocarpus hirsutus mediated seed extract for nanoparticle synthesis. BACKGROUND:Gastrointestinal bacteria are known for causing deadly infections in humans. They also possess multi-drug resistance and interfere with clinical treatments. Applied nanotechnology has been known to combat such infectious agents with little interference from their special attributes. Here we synthesize silver nanoparticles from Artocarpus hirsutus seed extract against two gastro-intestinal bacterial species: Enterobacter aerogenes and Listeria monocytogenes. OBJECTIVE:To collect, dry, and process seeds of Artocarpus hirsutus for nanoparticle synthesis. To evaluate the morphological interaction of silver nanoparticles with bacteria. METHODS:Artocarpus hirsutus seeds were collected and processed and further silver nanoparticles were synthesized by the co-precipitation method. The synthesized nanoparticles were characterized using XRD, UV, FTIR, and SEM. These nanoparticles were employed to study the antibacterial activity of nanoparticles against Enterobacter aerogenes and Listeria monocytogenes using well diffusion method. Further, morphological interaction of silver nanoparticles on bacteria was studied using SEM. RESULTS:Silver nanoparticles were synthesized using Artocarpus hirsutus seed extract and characterization studies confirmed that silver nanoparticles were spherical in shape with 25-40 nm size. Antibacterial study exhibited better activity against Enterobacter aerogenes with a maximum zone of inhibition than on Listeria monocytogenes. SEM micrographs indicated that Enterobacter aerogenes bacteria were more susceptible to silver nanoparticles due to the absence of cell wall. Also, the size and charge of silver nanoparticles enable easy penetration of the bacterial cell wall. CONCLUSION:In this study, silver nanoparticles were synthesized using the seed extract of Artocarpus hirsutus for the first time exploiting the fact that Moraceae species have high phytonutrient content which aided in nanoparticle synthesis. This nanoparticle can be employed for large scale synthesis which when coupled with the pharmaceutical industry can be used to overcome the problems associated with conventional antibiotics to treat gastrointestinal bacteria.
    背景与目标: 目的:评价面包果介导的种子提取物对纳米粒子合成的抗菌活性。
    背景:胃肠道细菌导致人类致命的感染。它们还具有多药耐药性并干扰临床治疗。已知应用纳米技术可在不受其特殊属性干扰的情况下与此类传染源抗争。在这里,我们从面包果种子提取物中合成了针对两种胃肠道细菌的银纳米颗粒:产气肠杆菌和单核细胞增生李斯特菌。
    目的:收集,干燥和加工面包果种子进行纳米颗粒合成。评估银纳米粒子与细菌的形态相互作用。
    方法:收集和处理面包果种子,并通过共沉淀法合成银纳米颗粒。使用XRD,UV,FTIR和SEM对合成的纳米颗粒进行表征。这些纳米颗粒被用于通过良好扩散方法研究纳米颗粒对产气肠杆菌和单核细胞增生性李斯特菌的抗菌活性。此外,使用SEM研究了银纳米颗粒在细菌上的形态相互作用。
    结果:利用面包果种子提取物合成了银纳米颗粒,表征研究证实银纳米颗粒为球形,尺寸为25-40 nm。抗菌研究显示,与单核细胞增生李斯特菌相比,对产气肠杆菌具有最大的抑制作用,具有更好的抑制作用。 SEM显微照片表明,由于不存在细胞壁,所以产气肠杆菌对银纳米颗粒更敏感。而且,银纳米颗粒的大小和电荷使细菌细胞壁易于渗透。
    结论:在这项研究中,利用禾本科物种具有高植物营养素含量的事实,首次利用面包果种子提取物合成了银纳米颗粒。该纳米颗粒可用于大规模合成,当与制药工业结合使用时,可用于克服与常规抗生素相关的治疗胃肠道细菌的问题。
  • 【用于生物活性和抗菌应用的具有TiO2 @ Ag杂合体的壳聚糖/黄ga胶背胶复合材料薄膜的绿色制造。】 复制标题 收藏 收藏
    DOI:10.1016/j.ijbiomac.2020.06.163 复制DOI
    作者列表:Mallakpour S,Ramezanzade V
    BACKGROUND & AIMS: :Common materials used in tissue engineering are not cost-effective and natural origin. Hence, we designed green, safe, and antibacterial bionanocomposite (bio-NC) films based on polysaccharides, chitosan (CS) and gum tragacanth (GT) for the bone tissue engineering. For this aim, different percentages of titanium dioxide nanoparticles (TiO2 NPs) and green silver (Ag)-doped TiO2 NPs (TiO2@Ag hybrid) were employed as nanofiller to improve the properties of the CS-GT film. Moreover, the physicochemical characteristics of the bio-NC films were examined with a field-emission scanning electron microscope (FE-SEM), Fourier transform infrared, X-ray diffraction, and transmission electron microscopy (TEM). The FE-SEM images showed a rough surface for the CS-GT/TiO2@Ag bio-NC films, and TEM images showed better dispersion of TiO2@Ag hybrid than TiO2 NPs into the CS-GT matrix. Also, these bio-NC films were considered for the bioactivity test and the results showed formation of hydroxyapatite on the surface of the prepared bio-NC films. Furthermore, addition of GT led to an increase in the bioactivity of the CS-GT blend. Finally, antibacterial behavior of the prepared bio-NC films was investigated against Escherichia coli and Staphylococcus aureus bacteria with/without ultraviolet irradiation and the results indicated better antibacterial performance for the CS-GT/TiO2@Ag bio-NC film (TiO2:Ag = 1:1) under both conditions.
    背景与目标: :在组织工程中使用的常用材料并非具有成本效益和天然来源。因此,我们设计了基于多糖,壳聚糖(CS)和黄tr胶(GT)的绿色,安全和抗菌的仿生复合材料(bio-NC)膜,用于骨组织工程。为了这个目的,采用不同百分比的二氧化钛纳米颗粒(TiO2 NPs)和掺杂绿银(Ag)的TiO2 NPs(TiO2 @ Ag杂化)作为纳米填料,以改善CS-GT膜的性能。此外,用场发射扫描电子显微镜(FE-SEM),傅立叶变换红外,X射线衍射和透射电子显微镜(TEM)检查了生物NC膜的理化特性。 FE-SEM图像显示CS-GT / TiO2 @ Ag生物NC膜的表面粗糙,而TEM图像显示TiO2 @ Ag杂化物比TiO2 NPs更好地分散到CS-GT基质中。另外,考虑将这些生物NC膜进行生物活性测试,结果表明在制备的生物NC膜的表面上形成了羟基磷灰石。此外,添加GT导致CS-GT共混物的生物活性增加。最后,研究了制备的生物NC膜在有/无紫外线照射下对大肠杆菌和金黄色葡萄球菌的抗菌性能,结果表明CS-GT / TiO2 @ Ag生物NC膜具有更好的抗菌性能(TiO2:Ag = 1:1)。
  • 【来自中国的渡边进化枝(Trebouxiophyceae,Chlorophyta)内的叶绿藻的四个新成员。】 复制标题 收藏 收藏
    DOI:10.1111/jeu.12787 复制DOI
    作者列表:Li S,Sun H,Hu Y,Liu B,Zhu H,Hu Z,Liu G
    BACKGROUND & AIMS: :Members of the Watanabea clade of Trebouxiophyceae are genetically diverse and widely distributed in all kinds of habitats, especially in most terrestrial habitats. Ten new strains of terrestrial algae isolated from the tropical rainforest in China, and four published strains were investigated in this study. Morphological observation and molecular phylogenetic analyses based on the 18S, ITS, rbcL, and tufA genes were used to identify the new strains. Four previously described species were reinvestigated to supplement molecular data and autospores' morphological photographs. The phylogenetic analyses based on 18S only, the concatenated dataset of 18S and ITS, as well as the concatenated dataset of rbcL and tufA, showed the same phylogenetic positions and relationships of these new strains. According to the phylogenetic analysis and morphological comparisons results, we described these 10 strains as four new members within the Watanabea clade, Polulichloris yunnanensis sp. nov., Polulichloris ovale sp. nov., Massjukichlorella orientale sp. nov., and Massjukichlorella minus sp. nov., and two known species, Massjukichlorella epiphytica, and Mysteriochloris nanningensis. Additionally, we provide strong evidence proving that Phyllosiphon, Mysteriochloris, Polulichloris, and Desertella all reproduce through unequal sized autospores.
    背景与目标: :Trebouxiophyceae的Watanabea进化枝成员在遗传上是多样的,并且广泛分布在各种生境中,尤其是在大多数陆地生境中。从中国热带雨林中分离出十种新的陆地藻菌株,并研究了四种已发表的菌株。基于18S,ITS,rbcL和tufA基因的形态学观察和分子系统发育分析用于鉴定新菌株。对四个先前描述的物种进行了重新研究,以补充分子数据和自孢子的形态照片。仅基于18S的系统发育分析,18S和ITS的串联数据集以及rbcL和tufA的串联数据集显示了这些新菌株相同的系统发生位置和关系。根据系统发育分析和形态学比较结果,我们将这10个菌株描述为Watanabea进化枝,云南Polulichloris yunnanensis sp。中的四个新成员。十一月,卵圆孢菌。东方马氏藻11月。十一月,和Massjukichlorella minus sp.。十一月,和两个已知的物种,附生马氏藻和南宁的Mysteriochloris南宁。此外,我们提供了有力的证据证明,Phyllosiphon,Mysteriochloris,Poulichloris和Desertella均通过不等大小的自生孢子繁殖。
  • 【海藻胶体和藻类复合材料在填充床塔中对铜的生物吸附。】 复制标题 收藏 收藏
    DOI:10.1016/j.biortech.2007.10.007 复制DOI
    作者列表:Vilar VJ,Botelho CM,Loureiro JM,Boaventura RA
    BACKGROUND & AIMS: :Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption-desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l(-1) of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of approximately 13 and 3 mg g(-1), respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1M HNO(3) solution was 100% effective. After two consecutive sorption-desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.
    背景与目标: :海藻胶质和藻类复合材料已被研究用于在填充床塔中从水溶液中连续去除Cu(II)。在一个流通于色谱柱中的Cu(II)的吸附-解吸循环中,在pH 5.3的水溶液中加入50和25 mg l(-1)的Cu(II),研究了其生物吸附行为。藻类胶体和复合材料的容量分别约为13和3 mg g(-1)。对于相同的流量,穿透时间随着入口铜浓度的增加而减少。废水的pH值随着铜离子的穿透时间而降低,这表明离子交换是生物吸附过程涉及的机制之一。温度对金属的吸收能力影响很小,离子强度的增加降低了吸附能力,缩短了穿透时间。解吸使用0.1M HNO(3)溶液是100%有效的。在两个连续的吸附-解吸循环之后,没有观察到复合材料的吸收能力的变化。包括膜和颗粒内电阻的传质模型,以及吸附和解吸的平衡关系,已成功地用于模拟生物吸附柱的性能。
  • 【Susac综合征中的荧光素和吲哚菁绿血管造影。】 复制标题 收藏 收藏
    DOI:10.1097/IAE.0b013e31809ff824 复制DOI
    作者列表:Martinet N,Fardeau C,Adam R,Bodaghi B,Papo T,Piette JC,Lehoang P
    BACKGROUND & AIMS: PURPOSE:Susac syndrome is a rare microangiopathy of the brain, retina, and cochlea that mainly affects young women. We studied the management of this disease using retinal fluorescein and indocyanine green angiographies. METHODS:Retrospective, observational case series of seven patients with Susac syndrome identified in ophthalmology and internal medicine departments. We reviewed medical, ophthalmologic, and angiographic records at study enrollment and during long-term treatment. Mean follow-up was 37 months. Best-corrected visual acuity, intraocular inflammation score, ophthalmoscopy data, automated perimetry score, and fluorescein and indocyanine green angiographic features were analyzed with the results of cerebral magnetic resonance imaging and spinal fluid analysis and ENT signs. RESULTS:Retinal fluorescein angiography showed focal nonperfused retinal arterioles with hyperfluorescent walls in all cases. Indocyanine green angiography showed normal choroidal circulation. Retinal vasculitis was uncontrolled in a patient treated with steroids. Improvement of retinal arteriole perfusion occurred during immunosuppressive treatment with cyclophosphamide. CONCLUSION:Absence of intraocular inflammation and focal, labile nonperfused retinal arterioles with integrity of choroidal circulation are monomorphic ophthalmologic features that could immediately suggest the diagnosis of Susac syndrome. Early ophthalmologic examination aided by retinal fluorescein angiography could be useful for managing cases of unexplained neurologic symptoms in women.
    背景与目标: 目的:Susac综合征是一种罕见的大脑,视网膜和耳蜗微血管病变,主要影响年轻女性。我们使用视网膜荧光素和吲哚菁绿血管造影术研究了该病的治疗方法。
    方法:回顾性,观察性病例系列在眼科和内科部门确定的7例Susac综合征患者。我们在研究入组时和长期治疗期间回顾了医学,眼科和血管造影记录。平均随访37个月。分析最佳校正的视力,眼内炎症评分,检眼镜数据,自动视野检查评分以及荧光素和吲哚菁绿血管造影特征,并进行脑磁共振成像,脊髓液分析和ENT征象。
    结果:在所有病例中,视网膜荧光素血管造影显示局灶性非灌注性视网膜小动脉具有高荧光壁。吲哚菁绿血管造影显示脉络膜循环正常。接受类固醇治疗的患者的视网膜血管炎未得到控制。在用环磷酰胺进行免疫抑制治疗期间,视网膜小动脉灌注得到改善。
    结论:眼内炎症的缺乏和局灶性,不稳定的非灌注性视网膜小动脉具有脉络膜循环的完整性是眼科疾病的单形特征,可立即提示Susac综合征的诊断。视网膜荧光素血管造影术辅助的早期眼科检查可用于治疗女性无法解释的神经系统症状。
  • 【用逆转录病毒载体转染的猪胎儿成纤维细胞进行核转移后,增强的绿色荧光蛋白(EGFP)和新霉素抗性(Neo(R))基因在猪胚胎中的表达。】 复制标题 收藏 收藏
    DOI:10.1002/1098-2795(200012)57:4<331::AID-MRD4>3.0.CO 复制DOI
    作者列表:Uhm SJ,Kim NH,Kim T,Chung HM,Chung KH,Lee HT,Chung KS
    BACKGROUND & AIMS: :In this study, we demonstrated expression of enhanced green fluorescent protein (EGFP) and neomycin resistant (Neo(R)) genes in porcine embryos following nuclear transfer from porcine fetal fibroblasts (PFFs) transduced with the EGFP and Neo(R) genes by retrovirus-mediated infection. Nuclear transfer of the nonstarved transfected PFF into enucleated oocytes was accomplished by cell to cell fusion. Out of 188 porcine eggs reconstructed by nuclear transfer, 116 (61.7%) eggs cleaved and 25 (13.3%) developed to morula and blastocyst stages. Of these 25 morulae and blastocysts, 25 (100%) embryos emitted green fluorescence. Expression of the both EGFP and Neo(R) genes was detected as early as the 2-cell stage. As determined by EGFP gene expression, mosaicism was not observed in any embryo. These results suggest that porcine oocytes reconstructed by nuclear transfer with transfected PFFs can successfully develop to the blastocyst stage. In addition, this approach might be applicable to the production of transgenic pigs with complex genetic modifications.
    背景与目标: :在这项研究中,我们证明了从猪胚胎成纤维细胞(PFF)进行核转移后,猪胚胎中的绿色荧光蛋白(EGFP)和新霉素抗性(Neo(R))基因在猪胚胎中的表达通过逆转录病毒介导的感染。非饥饿转染的PFF向去核卵母细胞的核转移是通过细胞间融合来完成的。在通过核移植重建的188个猪卵中,有116个(61.7%)卵裂开,有25个(13.3%)卵发育到桑ula和胚泡期。在这25个桑ula和胚泡中,有25个(100%)胚胎发出绿色荧光。早在2细胞阶段就检测到了EGFP和Neo(R)基因的表达。如通过EGFP基因表达所确定的,在任何胚胎中均未观察到镶嵌现象。这些结果表明,用转染的PFF通过核转移重建的猪卵母细胞可以成功地发展到胚泡期。此外,这种方法可能适用于生产具有复杂基因修饰的转基因猪。
  • 【绿茶提取物对年轻和老年雄性大鼠学习,记忆,行为和乙酰胆碱酯酶活性的影响。】 复制标题 收藏 收藏
    DOI:10.1016/j.bandc.2007.10.003 复制DOI
    作者列表:Kaur T,Pathak CM,Pandhi P,Khanduja KL
    BACKGROUND & AIMS: OBJECTIVE:To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats. METHODS:Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity. RESULTS:Treatment of young and old rats with the extract resulted in no significant difference in performance on the rota rod treadmill test/righting reflex time. Green tea extract significantly improved learning and memory in older rats, with increased retention latency to enter difference in passive avoidance test. In the elevated maze test, green tea treatment resulted in significantly more number of entries in the enclosed arm by the young and old rats. Decline in acetylcholinesterase activity was observed in the cerebrum of green tea treated old rats in comparison to the green tea treated young rats. CONCLUSION:Green tea extract administration is effective in enhancing learning and memory in aged rats, and hence, may serve useful in reversing age-related deficits.
    背景与目标: 目的:研究绿茶提取物对雄性和老年雄性Wistar大鼠年龄相关认知的影响。
    方法:对成年和成年大鼠口服0.5%的绿茶提取物,持续8周,并通过被动回避,迷宫加范式和乙酰胆碱酯酶活性的变化进行评估。
    结果:用提取物处理年轻和老龄大鼠,在旋转棒跑步机测试/扶正反射时间上的表现没有显着差异。绿茶提取物可显着改善老年大鼠的学习和记忆能力,并增加保留潜伏期,从而使被动回避测试产生差异。在高迷宫测试中,绿茶处理导致幼鼠和老鼠进入封闭臂的次数明显增加。与绿茶处理的幼鼠相比,绿茶处理的老鼠的大脑中乙酰胆碱酯酶活性下降。
    结论:绿茶提取物给药可有效增强衰老大鼠的学习和记忆能力,因此可能有助于逆转与年龄有关的缺陷。
  • 【使用Anthemis atropatana提取物绿色合成银纳米颗粒:表征和体外生物活性。】 复制标题 收藏 收藏
    DOI:10.1080/21691401.2017.1304402 复制DOI
    作者列表:Dehghanizade S,Arasteh J,Mirzaie A
    BACKGROUND & AIMS: :This study aim to synthesize silver nanoparticles (AgNPs) using Anthemis atropatana extract and to evaluate their chemical characteristics and antimicrobial and cytotoxic effects. The biosynthesis of AgNPs is verified using UV-visible spectrum which showing maximum absorption in 430 nm wavelength. Transmission electron microscope (TEM) and scanning electron microscope (SEM) results revealed that AgNPs has a spherical shape with an average size of 38.89 nanometres. The crystalline structure of green synthesized AgNPs in optimal conditions was confirmed by XRD analysis. The pattern of XRD peaks related to face-centred cubic (fcc) (111), (200), (220), (311) and (222) observed. Also, FTIR results verified the AgNPs synthesis using plant extract. In biological tests, the MTT results indicate the dose dependence of cytotoxic effects of AgNPs on colon cancer cell lines (HT29). The AgNPs had maximum cytotoxicity on HT29 cancer cell line at 100 μg/ml concentration, which were statistically significant comparing control cells (p < .001). Moreover, real time PCR and flow cytometry results confirmed the apoptotic effects of AgNPs. According to the results, it seems that the green synthesis of AgNPs is an eco-friendly and cost effective approach. This research provides insight into the development of new anticancer and antibacterial agents.
    背景与目标: :这项研究旨在使用Anthemis atropatana提取物合成银纳米颗粒(AgNP),并评估其化学特性以及抗菌和细胞毒性作用。 AgNPs的生物合成使用紫外可见光谱进行验证,该光谱在430 nm波长处显示出最大吸收。透射电子显微镜(TEM)和扫描电子显微镜(SEM)结果表明,AgNPs具有球形形状,平均大小为38.89纳米。 XRD分析证实了在最佳条件下绿色合成AgNPs的晶体结构。 XRD峰的图案与观察到的面心立方(fcc)(111),(200),(220),(311)和(222)有关。同样,FTIR结果验证了使用植物提取物合成AgNPs的能力。在生物学测试中,MTT结果表明AgNP对结肠癌细胞系(HT29)的细胞毒性作用的剂量依赖性。 AgNPs在HT29癌细胞系中以100μg/ ml的浓度具有最大的细胞毒性,与对照细胞相比,具有统计学意义(p <0.001)。此外,实时PCR和流式细胞仪结果证实了AgNPs的凋亡作用。根据结果​​,似乎绿色合成AgNPs是一种生态友好且具有成本效益的方法。这项研究为新型抗癌和抗菌剂的开发提供了见识。
  • 【绿藻小球藻吸附的U(VI)物种的光谱研究。】 复制标题 收藏 收藏
    DOI:10.1007/s10534-007-9122-7 复制DOI
    作者列表:Günther A,Raff J,Geipel G,Bernhard G
    BACKGROUND & AIMS: :The green alga Chlorella vulgaris has the ability to bind high amounts of uranium(VI) in the pH range from 3 to 6. At pH 3 up to 40% of the uranium are bound by the algal cells. The uranium removal is almost complete at pH 5 and 6 under the given experimental conditions. Scanning electron microscopy and laser-induced fluorescence spectroscopy were used to characterize uranyl species formed in the selected pH range. The micrographs show a regular distribution of U(VI) on the cell surface. Fluorescence spectroscopic investigations of formed algal uranyl complexes indicate that the binding of U(VI) to carboxyl groups plays a dominating role at pH 3, whereas a minor impact of organic phosphate compounds on the U(VI) sorption cannot be excluded. In contrast, at pH 5 and 6 the phosphate groups are mainly responsible for the removal and binding of U(VI) by formation of organic and/or inorganic uranyl phosphates.
    背景与目标: 绿藻:绿藻小球藻具有在3至6的pH范围内结合大量铀(VI)的能力。在pH 3时,藻类细胞会结合多达40%的铀。在给定的实验条件下,在pH 5和6下,铀的去除几乎完成。使用扫描电子显微镜和激光诱导荧光光谱来表征在选定pH范围内形成的铀酰种类。显微照片显示了U(VI)在细胞表面的规则分布。形成的藻类铀酰复合物的荧光光谱研究表明,U(VI)与羧基的结合在pH 3时起主要作用,而有机磷酸盐化合物对U(VI)吸附的影响很小。相反,在pH 5和6下,磷酸酯基团主要通过形成有机和/或无机铀酰磷酸酯而除去和结合U(VI)。
  • 【绿硫细菌光合作用装置的二维电子光谱。】 复制标题 收藏 收藏
    DOI:10.1038/srep45245 复制DOI
    作者列表:Kramer T,Rodriguez M
    BACKGROUND & AIMS: :Advances in time resolved spectroscopy have provided new insight into the energy transmission in natural photosynthetic complexes. Novel theoretical tools and models are being developed in order to explain the experimental results. We provide a model calculation for the two-dimensional electronic spectra of Cholorobaculum tepidum which correctly describes the main features and transfer time scales found in recent experiments. From our calculation one can infer the coupling of the antenna chlorosome with the environment and the coupling between the chlorosome and the Fenna-Matthews-Olson complex. We show that environment assisted transport between the subunits is the required mechanism to reproduce the experimental two-dimensional electronic spectra.
    背景与目标: :时间分辨光谱技术的进步为天然光合复合物中的能量传递提供了新的见识。为了解释实验结果,正在开发新的理论工具和模型。我们提供了一种用于温热梭菌的二维电子光谱的模型计算,该模型正确描述了最近实验中发现的主要特征和转移时间尺度。根据我们的计算,可以推断出天线中的绿体与环境的耦合以及绿体与Fenna-Matthews-Olson络合物之间的耦合。我们表明,亚基之间的环境辅助运输是再现实验二维电子光谱的必需机制。
  • 【Rubisco操纵子从原核生物到藻类的进化:褐藻毕赤酵母的rbcS基因的结构和分析。】 复制标题 收藏 收藏
    DOI:10.1007/BF00037066 复制DOI
    作者列表:Assali NE,Martin WF,Sommerville CC,Loiseaux-de Goër S
    BACKGROUND & AIMS: :The rbcS gene coding for the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of the brown alga Pylaiella littoralis is located within the plastid genome and is transcribed as a single polycistronic mRNA with the gene for the large subunit of Rubisco, rbcL. The structure of the Rubisco operon from P. littoralis was determined. Molecular phylogenies for rbcS and rbcL with a wide range of prokaryotes and eukaryotes were constructed which are congruent with recent evidence for polyphyletic plastid origins. Both rbcL and rbcS of the beta-purple bacterium Alcaligenes eutrophus clearly cluster with the rhodophyte and chromophyte proteins. The data suggest that the Rubisco operons of red algal and chromophytic plastids derive from beta-purple eubacterial antecedents, rather than the cyanobacterial lineage of eubacteria from which other of their genes derive. This implies a lateral transfer of Rubisco genes from beta-purple eubacterial ancestors to the cyanobacterial ancestor of rhodophyte and chromophyte plastids.
    背景与目标: 编码褐藻褐藻毕赤酵母的核糖-1,5-双磷酸羧化酶/加氧酶(Rubisco)的小亚基的rbcS基因位于质体基因组内,并转录成单个多顺反子mRNA,并带有大亚基的基因的Rubisco,rbcL。确定了来自滨海假单胞菌的Rubisco操纵子的结构。构建了具有广泛的原核生物和真核生物的rbcS和rbcL的分子系统学,与最近的多系统质体起源证据相吻合。 β紫色细菌嗜酸拟南芥的rbcL和rbcS都清楚地与红景天和发色团蛋白聚集在一起。数据表明,红色藻类和发色质体的Rubisco操纵子来源于β紫色的真细菌先例,而不是其其他基因的真细菌的蓝细菌谱系。这意味着Rubisco基因从β紫色真细菌祖先到红藻和生色质体的蓝细菌祖先的侧向转移。
  • 【绿藻Dunaliella parva(Volvocales,Chlorophyta)对氮源中受控增量变化的生理响应。】 复制标题 收藏 收藏
    DOI:10.1071/FP07049 复制DOI
    作者列表:Giordano M,Norici A,Gilmour DJ,Raven JA
    BACKGROUND & AIMS: :This work is aimed at obtaining information on the acclimation processes of the green flagellate Dunaliella parva Lerche to gradual changes in the N source from NO3- to NH4+, in continuous cultures. Photosynthesis, dark respiration, and light-independent carbon fixation (LICF) rates, chlorophyll a fluorescence, RUBISCO and phosphoenolpyruvate carboxylase (PEPc) activities, plasmalemma electrical potential difference, cell volume, and absolute or relative amounts of major cell constituents were measured. Two phases characterised the response to the transition from NO3- to NH4+: (1) an initial phase in which photosynthesis and anaplerosis were stimulated and protein increased; (2) a subsequent phase in which most parameters reached new values that were close to those at the beginning of the experiment (100% NO3-). The only exceptions were PEPc activity and LICF, whose rates remained at least 2-fold higher than at 100% NO3-, when NH4+ was the sole N source. The results are indicative of a tendency to re-establish homeostasis, after an initial perturbation of the intracellular composition. The roles of different metabolic processes during acclimation are discussed.
    背景与目标: :这项工作旨在获得有关绿色鞭毛杜氏盐藻在连续培养中从N3到NH4的氮源逐渐变化的驯化过程的信息。测量了光合作用,黑暗呼吸和不依赖光的碳固定(LICF)速率,叶绿素a荧光,RUBISCO和磷酸烯醇丙酮酸羧化酶(PEPc)活性,质膜电势差,细胞体积以及主要细胞组成的绝对或相对量。从NO3-过渡到NH4的响应分为两个阶段:(1)初始阶段,其中光合作用和动脉粥样硬化受到刺激,蛋白质增加。 (2)随后的阶段,其中大多数参数达到的新值与实验开始时的值接近(100%NO3-)。唯一的例外是PEPc活性和LICF,当NH4是唯一的氮源时,它们的发生率至少比100%NO3-时高至少2倍。该结果表明在细胞内组合物的初始扰动之后有重新建立稳态的趋势。讨论了在适应过程中不同代谢过程的作用。
  • 【拟南芥变种的生物射弹共转化。 cri草菌株CG423,具有绿色荧光蛋白,对草铵膦具有抗性。】 复制标题 收藏 收藏
    DOI:10.1111/j.1574-6968.2000.tb09347.x 复制DOI
    作者列表:Inglis PW,Aragão FJ,Frazão H,Magalhães BP,Valadares-Inglis MC
    BACKGROUND & AIMS: :Metarhizium anisopliae var. acridum (syn. M. flavoviride) is recognized as a highly specific and virulent mycopathogen of locusts and grasshoppers and is currently being developed as a biological control agent for this group of insects in Brazil. Intact conidia of M. anisopliae var. acridum strain CG423 were transformed using microparticle bombardment. Plasmids used were: (1) pBARKS1 carrying the bar gene of Streptomyces hygroscopicus fused to the Aspergillus nidulans trpC promoter, encoding resistance to glufosinate ammonium (or phosphinothricin) and modified by addition of the telomeric repeat (TTAGGG)(18) of Fusarium oxysporum and 2.pEGFP/gpd/tel carrying a red-shifted variant gene for Aequorea victoria green fluorescent protein (EGFP) which we have fused to the A. nidulans gpd promoter and trpC terminator. Highly fluorescent co-transformants were selected on solid minimal medium containing 100 microg ml(-1) glufosinate ammonium using an inverted microscope with 450-490 nm excitation/510 nm emission filter set. Southern blot analysis of co-transformants revealed varying multiple chromosomal integrations of both bar and egfp genes at both telomeric and non-telomeric loci. Transformants retained pathogenicity in bioassays against Rhammatocerus schistocercoides and showed unaltered lack of pathogenicity against larvae of the non-target insect Anticarsia gemmatalis. One co-transformant from four tested, however, showed a significant, but non-dose-dependent, elevation in virulence against Tenebrio molitor.
    背景与目标: :金属异形体变种cri啶黄酮(黄萎病病毒的合成名)被认为是蝗虫和蝗虫的高度特异性和强毒性致病菌,目前正被开发为巴西这组昆虫的生物防治剂。 M. anisopliae var。的完整分生孢子使用微粒轰击转化a啶菌株CG423。使用的质粒是:(1)带有吸水链霉菌bar基因的pBARKS1与构巢曲霉trpC启动子融合,编码对草铵膦(或草丁膦)的抗性,并通过添加尖孢镰刀菌的端粒重复序列(TTAGGG)(18)和2.pEGFP / gpd / tel携带了维多利亚水母绿色荧光蛋白(EGFP)的红移变异基因,我们已将其融合到构巢曲霉gpd启动子和trpC终止子上。使用具有450-490 nm激发/ 510 nm发射滤光片组的倒置显微镜,在包含100μgml(-1)草铵膦铵盐的固体基本培养基上选择高荧光共转化体。对共转化体的Southern印迹分析显示,bar和egfp基因在端粒和非端粒位点处都存在多种染色体整合。转化子在针对鼠李糖单生菌的生物测定中保留了致病性,并显示出对非靶标昆虫抗龋齿幼虫的幼虫没有致病性的不变。然而,来自四个测试的一个共转化体显示出对黄粉虫的毒力显着但非剂量依赖性的升高。
  • 【蛋白质聚集对绿色植物LHCII色素-蛋白质复合物的光谱性质和激发态动力学的影响。】 复制标题 收藏 收藏
    DOI:10.1007/s11120-013-9924-0 复制DOI
    作者列表:Magdaong NM,Enriquez MM,LaFountain AM,Rafka L,Frank HA
    BACKGROUND & AIMS: :Steady-state and time-resolved absorption and fluorescence spectroscopic experiments have been carried out at room and cryogenic temperatures on aggregated and unaggregated monomeric and trimeric LHCII complexes isolated from spinach chloroplasts. Protein aggregation has been hypothesized to be one of the mechanistic factors controlling the dissipation of excess photo-excited state energy of chlorophyll during the process known as nonphotochemical quenching. The data obtained from the present experiments reveal the role of protein aggregation on the spectroscopic properties and dynamics of energy transfer and excited state deactivation of the protein-bound chlorophyll and carotenoid pigments.
    背景与目标: :已经在室温和低温下对从菠菜叶绿体中分离出的聚集的和未聚集的单体和三聚体LHCII复合物进行了稳态和时间分辨的吸收和荧光光谱实验。蛋白质聚集被认为是控制非光化学猝灭过程中叶绿素过量光激发态能量消散的机制因素之一。从本实验获得的数据揭示了蛋白质聚集在蛋白质结合的叶绿素和类胡萝卜素色素的光谱性质和能量转移动力学以及激发态失活方面的作用。
  • 【绿灯在大鼠急慢性疼痛中具有持久的镇痛作用。】 复制标题 收藏 收藏
    影响因子 :
    发表时间:2017-02-01
    来源期刊:Pain
    DOI:10.1097/j.pain.0000000000000767 复制DOI
    作者列表:Ibrahim MM,Patwardhan A,Gilbraith KB,Moutal A,Yang X,Chew LA,Largent-Milnes T,Malan TP,Vanderah TW,Porreca F,Khanna R
    BACKGROUND & AIMS: :Treatments for chronic pain are inadequate, and new options are needed. Nonpharmaceutical approaches are especially attractive with many potential advantages including safety. Light therapy has been suggested to be beneficial in certain medical conditions such as depression, but this approach remains to be explored for modulation of pain. We investigated the effects of light-emitting diodes (LEDs), in the visible spectrum, on acute sensory thresholds in naive rats as well as in experimental neuropathic pain. Rats receiving green LED light (wavelength 525 nm, 8 h/d) showed significantly increased paw withdrawal latency to a noxious thermal stimulus; this antinociceptive effect persisted for 4 days after termination of last exposure without development of tolerance. No apparent side effects were noted and motor performance was not impaired. Despite LED exposure, opaque contact lenses prevented antinociception. Rats fitted with green contact lenses exposed to room light exhibited antinociception arguing for a role of the visual system. Antinociception was not due to stress/anxiety but likely due to increased enkephalins expression in the spinal cord. Naloxone reversed the antinociception, suggesting involvement of central opioid circuits. Rostral ventromedial medulla inactivation prevented expression of light-induced antinociception suggesting engagement of descending inhibition. Green LED exposure also reversed thermal and mechanical hyperalgesia in rats with spinal nerve ligation. Pharmacological and proteomic profiling of dorsal root ganglion neurons from green LED-exposed rats identified changes in calcium channel activity, including a decrease in the N-type (CaV2.2) channel, a primary analgesic target. Thus, green LED therapy may represent a novel, nonpharmacological approach for managing pain.
    背景与目标: :慢性疼痛的治疗不足,需要新的选择。非药物方法具有许多潜在优势,包括安全性,尤其具有吸引力。已经提出光疗法在某些医学病症例如抑郁症中是有益的,但是这种方法对于调节疼痛仍然有待探索。我们研究了可见光谱中的发光二极管(LED)对幼稚大鼠以及实验性神经性疼痛的急性感觉阈值的影响。接受绿色LED光(波长525 nm,8 h / d)的大鼠表现出对有害的热刺激的爪子退缩潜伏期显着增加。最后一次接触终止后,这种抗伤害感受作用持续了4天,而没有产生耐受性。没有发现明显的副作用,运动性能也没有受到损害。尽管LED暴露在外,但不透明的隐形眼镜仍能防止痛感。装有暴露于室内光线的绿色隐形眼镜的大鼠表现出抗伤害感受,认为这是视觉系统的作用。抗伤害感受不是由于压力/焦虑,而是由于脊髓中脑啡肽表达的增加。纳洛酮逆转了抗伤害感受,表明参与了中央阿片样物质回路。延髓腹侧延髓失活阻止了光诱导的抗伤害感受的表达,表明参与了递减抑制作用。绿色LED暴露还可以逆转脊髓神经结扎大鼠的热痛觉过敏和机械痛觉过敏。来自暴露于绿色LED的大鼠的背根神经节神经元的药理和蛋白质组学分析确定了钙通道活性的变化,包括N型(CaV2.2)通道(主要的镇痛目标)的减少。因此,绿色LED治疗可能代表了一种新颖的,非药理性的疼痛控制方法。

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