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Chemically modified cellulose as a potential oil adsorbent of contaminated marine ecosystems 化学改性纤维素作为污染海洋生态系统潜在的石油吸附剂
Pub Date : 2020-04-01 DOI: 10.26850/1678-4618eqj.v45.2.2020.p54-63
A. A. Madeira, A. L. Silva, B. Dias, C. Peña, R. Oliveira
Petroleum exploration, as well as environmental impacts descendant of aquatic contaminations involving sea oil spills, foments the development of new technologies of marine ecosystems protection. Acknowledged like the most abundant polymer available today worldwide, cellulose is a linear 1.4-β-glucan, composed of D-anhydroglucopyranose units, linked together by β-(l→4)-glycosidic bonds. In this study, a chemical modification route of the cellulose polymer was accomplished using glycidyl methacrylate and stearin to test its oily adsorption capacity of soybean, diesel, and residual oils. Scanning Electron Microscopy (SEM) and Fourier-Transform Infrared (FT-IR) Analyses were applied to the characterization of the morphological and functional structure of microcrystalline cellulose. The results obtained proved the reach of an average hydrophobicity grade of 78.3±0.9% and a mass gain of MG = 2.89%, suggesting the possible insertion of hydrophobic groups onto the cellulose molecule and corroborating the hypothesis of successful grafting of glycidyl methacrylate and stearin onto the polymer. The oily adsorption tests showed a satisfactory capacity of the modified cellulose to adsorb small amounts of viscous oils, like residual oil.
石油勘探以及涉及海洋石油泄漏的水生污染对环境的影响,促进了海洋生态系统保护新技术的发展。纤维素是目前世界上最丰富的聚合物,它是一种线性的1.4-β-葡聚糖,由d -无氢葡萄糖醛酸单元组成,通过β-(l→4)-糖苷键连接在一起。本研究采用甲基丙烯酸甘油酯和硬脂酸对纤维素聚合物进行化学改性,测试其对大豆、柴油和残油的吸附能力。利用扫描电镜(SEM)和傅里叶变换红外(FT-IR)对微晶纤维素的形态和功能结构进行了表征。结果表明,该聚合物的平均疏水等级为78.3±0.9%,质量增益MG = 2.89%,表明在纤维素分子上可能插入了疏水基团,并证实了甲基丙烯酸缩水甘油酯和硬脂脂成功接枝的假设。油吸附试验表明,改性纤维素具有较好的吸附残油等少量粘性油的能力。
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引用次数: 3
Estrogenic mycotoxins in surface waters of the Rico Stream micro-basin, São Paulo, Brazil: occurrence and potential estrogenic contribution 巴西圣保罗<s:1>里科河微盆地地表水中的雌激素真菌毒素:发生和潜在的雌激素贡献
Pub Date : 2020-04-01 DOI: 10.26850/1678-4618eqj.v45.2.2020.p23-32
E. S. Emídio, Claudia Pereira Da Silva, M. D. de Marchi
The aim of this study was to assess the occurrence of zearalenone (ZEN) and its metabolites zearalanone (ZAN), α-zearalenol (α-ZEL), β-zearalenol (β-ZEL) α-zearalanol (α-ZAL), and β-zearalanol (β-ZAL) in the surface waters of northern São Paulo state (Brazil) and to evaluate the associated potential estrogenic contribution to the aquatic environment. The determination of the estrogenic mycotoxins in water samples from the Rico Stream microbasin yielded levels of up to 59 ng L-1 and their corresponding calculated estrogenic equivalent (cEEQ) values were between < 0.03 and 1.4 ng L-1, which are associated with negative effects on the reproduction and growth of some fish species. The physicochemical and microbiological parameters were evaluated to determine the water quality in the Rico stream region. This study revealed the first data about the presence of estrogenic mycotoxins in the Brazilian river waters and emphasizes the need to include these substances in future public policies concerning water quality, since these compounds are not yet legally regulated. From an environmental aspect, it is necessary to take into account the continuous introduction into surface water of microcontaminants associated with wastewater effluent, such as estrogenic mycotoxins.
本研究的目的是评估玉米赤霉烯酮(ZEN)及其代谢产物玉米赤霉烯酮(ZAN)、α-玉米赤霉烯醇(α-ZEL)、β-玉米赤霉烯醇(β-ZEL)、α-玉米赤霉烯醇(α-ZAL)和β-玉米赤霉烯醇(β-ZAL)在巴西圣保罗州北部地表水中的存在情况,并评估其对水生环境的潜在雌激素贡献。对Rico溪流微流域水样中雌激素真菌毒素的测定结果显示,其含量高达59 ng L-1,其相应的计算雌激素当量(cEEQ)值在< 0.03 ~ 1.4 ng L-1之间,这对某些鱼类的繁殖和生长产生了负面影响。利用理化和微生物学参数评价了Rico河流域的水质。这项研究首次揭示了巴西河水中存在雌性真菌毒素的数据,并强调有必要将这些物质纳入有关水质的未来公共政策,因为这些化合物尚未受到法律管制。从环境方面来看,有必要考虑到与废水有关的微污染物不断进入地表水,例如雌激素真菌毒素。
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引用次数: 4
Larvicidal activity, molluscicide and toxicity of the essential oil of Citrus limon peels against, respectively, Aedes aegypti, Biomphalaria glabrata and Artemia salina 柠檬皮挥发油对埃及伊蚊、光斑生物蛉和盐蒿的杀幼虫活性、杀软体虫活性和毒性
Pub Date : 2019-10-01 DOI: 10.26850/1678-4618eqj.v44.4.2019.p85-95
Paulo Roberto Barros Gomes, Marlucy Bezerra Oliveira, D. A. De Sousa, Jeremias Caetano da Silva, R. Fernandes, H. C. Louzeiro, Rayone Wesly Santos de Oliveira, Maria do Livramento de Paula, V. E. Mouchrek Filho, M. A. Fontenele
In this present work, we tested the larvicidal activity, molluscicide and toxicity of the oil extracted from Citrus limon peels, respectively against third stage larvae of Aedes aegypti, snail Biomphalaria glabrata, and Artemia salina. For this, we extract the essential oil by hydrodistillation. Then, we identified and quantified the components by gas chromatography coupled to mass spectrometry (GC-MS). We tested the larvicidal and molluscicidal activity, respectively, using the method adopted by the Brazilian Ministry of Health and the World Health Organization. We calculated the lethal concentration (LC50) from the Probit method for the three biological activities with 95 %. The results of the chromatographic analysis showed that the oil has 58.81% of Limonene (major constituent) and 0.11% α-Mulene (minority component). The essential oil presented lethal concentration (LC50) for larvicidal activity, molluscicide and toxicity, respectively at 15.48, 13.05 and 743.35 mg∙L-1. Therefore, the essential oil is active against larvae of A. aegypti and snail B. glabrata and non-toxic against larvae of A. salina.
本文研究了柠檬皮提取油对埃及伊蚊、光斑蜗牛和盐蒿三期幼虫的杀幼虫活性、杀软体动物活性和毒性。为此,我们用加氢蒸馏法提取精油。然后,我们用气相色谱-质谱联用(GC-MS)对其成分进行了鉴定和定量。我们分别采用巴西卫生部和世界卫生组织采用的方法测试了杀幼虫和杀软体动物的活性。采用Probit法计算三种生物活性的致死浓度(LC50),均为95%。色谱分析结果表明,柠檬烯(主要成分)含量为58.81%,α-木烯(次要成分)含量为0.11%。精油的杀虫活性、杀贝活性和毒性分别为15.48、13.05和743.35 mg∙L-1。因此,精油对埃及伊蚊和光斑蜗牛幼虫有活性,对盐纹伊蚊幼虫无毒。
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引用次数: 10
Occurrence of caffeine in wastewater and sewage and applied techniques for analysis: a review 废水和污水中咖啡因的存在及应用分析技术综述
Pub Date : 2019-10-01 DOI: 10.26850/1678-4618eqj.v44.4.2019.p11-26
C. A. Marasco Júnior, Natália da Costa Luchiari, P. C. F. Lima Gomes
Emerging contaminants are substances found in the environment whose concentrations vary from µg to ng L-1 and whose presence in wastewater has gained popularity in the scientific community due to the potential impacts these compounds can cause to the environment. This designation concerns the lack of legislation to regulate their discharge or even to monitor these compounds. Moreover, emerging contaminants are capable of causing harmful effects to nontarget organisms and therefore affect the ecosystem balance. There are several compounds classified as emerging contaminants such as pharmaceuticals, illicit drugs, hormones, pesticides, among others. And among them, caffeine is considered an emerging contaminant and can be highlighted due its presence in medicines, beverages, foodstuff and several other products. In addition, it is a compound used worldwide recognized as a marker of anthropogenic activity. In this review, we present a discussion about emerging contaminants, focusing on caffeine, regulatory aspects that involve the theme, as well as effects on organisms, removal technologies and techniques for analyzing these compounds in environmental matrices.
新出现的污染物是指在环境中发现的浓度从微克到ng L-1不等的物质,由于这些化合物可能对环境造成潜在影响,它们在废水中的存在已经在科学界受到欢迎。这一名称涉及缺乏立法来规范其排放,甚至监测这些化合物。此外,新出现的污染物能够对非目标生物造成有害影响,从而影响生态系统的平衡。有几种化合物被归类为新兴污染物,如药品、非法药物、激素、杀虫剂等。其中,咖啡因被认为是一种新兴的污染物,由于它存在于药品、饮料、食品和其他几种产品中,因此可以得到强调。此外,它是世界范围内公认的人类活动标记物。在这篇综述中,我们对新出现的污染物进行了讨论,重点是咖啡因,涉及主题的监管方面,以及对生物体的影响,去除技术和环境基质中这些化合物的分析技术。
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引用次数: 14
Influence of Ce(IV) ions amount on the electrochemical behavior of hybrid films in 0.1 mol L-1 NaCl solution Ce(IV)离子用量对杂化膜在0.1 mol L-1 NaCl溶液中电化学行为的影响
Pub Date : 2019-10-01 DOI: 10.26850/1678-4618eqj.v44.4.2019.p27-56
F. S. Da Silva, H. D. De Melo, A. Benedetti, P. H. Suegama
In this work, the influence of ceric ions (Ce(SO4)2) addition to the hydrolysis solution on the corrosion protection afforded by organic-inorganic hybrid coating obtained from tetraethoxysilane (TEOS) and 3-methacryloxy-propyl-trimethoxysilane (MPTS) to a carbon steel substrate in 0.1 mol L-1 NaCl solution was studied. Open circuit potential (EOC) and electrochemical impedance spectroscopy (EIS) experiments were carried out and showed that the protection afforded by the organic-inorganic hybrid coating was extremely dependent on the Ce4+ ions amount. These results were in close agreement with optical microscopy observation of the degrading surfaces, both procedures showing that more protective coating was produced when 500 ppm of Ce4+ ions were added to the organic-inorganic hybrid solution. The chemical state of the organic-inorganic hybrid coating investigated by X-ray photoelectron spectroscopy (XPS) indicated that the addition of Ce4+ ions enhances the polycondensation degree of the organic-inorganic hybrid coating leading to a denser siloxane (Si-O-Si) network. A strategy using laser-induced breakdown spectroscopy (LIBS) and UV-Vis spectrometry was set up in order to verify, respectively, the presence of Ce ions within the coating structure and its oxidation state. LIBS results confirmed the incorporation of Ce ions in the coating, which, according to UV-Vis measurements, are mainly in the (IV)-oxidation state.
在0.1 mol L-1 NaCl溶液中,研究了在水解溶液中加入铈离子(Ce(SO4)2对四乙氧基硅烷(TEOS)和3-甲基丙烯氧基-丙基-三甲氧基硅烷(MPTS)制备的有机-无机杂化涂层对碳钢基体的防腐性能的影响。开路电位(EOC)和电化学阻抗谱(EIS)实验表明,Ce4+离子的用量对有机-无机杂化涂层的保护作用有极大的依赖性。这些结果与光学显微镜对降解表面的观察结果一致,两种方法都表明,当有机-无机混合溶液中加入500 ppm的Ce4+离子时,产生了更多的保护涂层。x射线光电子能谱(XPS)研究了有机-无机杂化涂层的化学状态,结果表明Ce4+离子的加入提高了有机-无机杂化涂层的缩聚度,形成了更致密的硅氧烷(Si-O-Si)网络。采用激光诱导击穿光谱(LIBS)和紫外可见光谱(UV-Vis)技术分别验证了涂层结构中Ce离子的存在及其氧化状态。LIBS结果证实涂层中存在Ce离子,根据UV-Vis测量,Ce离子主要处于(IV)-氧化态。
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引用次数: 6
Rapid and selective extraction of trace amount of Pb(II) in aqueous samples using a magnetic ion-imprinted polymer and detection by flame atomic absorption spectrometry 磁性离子印迹聚合物快速选择性提取水中痕量铅(II)及火焰原子吸收光谱法检测
Pub Date : 2019-10-01 DOI: 10.26850/1678-4618eqj.v44.4.2019.p73-84
S. Babaee, S. G. Hosseini, M. Mirzaei
A magnetic Pb(II) ion-imprinted polymer was synthesized using magnetic Fe3O4@SiO2 nanospheres as supporter, n-benzoyl-n-phenyl hydroxylamine as ligand, 4-vinyl pyridine as monomer, ethylene glycol dimethacrylate as crosslinker and 2,2′-azobis(isobutyronitrile) as the initiator. The template was removed from the polymer using 4 mL of HCl (2 mol L-1). The chemical structure, morphology-particle size, elemental analysis, thermal behavior and magnetic properties of the sorbent were evaluated using Fourier-transform infrared spectroscopy, scanning electron microscopy & ImageJ software - Energy dispersive X-ray system, thermal gravimetric analysis and vibrating sample magnetometry. Various parameters such as pH, equilibrium extraction time, temperature and the eluent were optimized. The results showed the sorbent adsorption capacity was 92.3 mg g-1 in pH 6.0 media, equilibrium time of 7 min at 40 °C. Calibration linearity was 2-150 µg L-1 with detection limit of 0.3 µg L-1. The prepared sorbent had high selectivity and was successfully applied to the removing of lead in real samples.
以磁性Fe3O4@SiO2纳米球为载体,n-苯甲酰-n-苯基羟胺为配体,4-乙烯基吡啶为单体,乙二醇二甲基丙烯酸酯为交联剂,2,2′-偶氮(异丁腈)为引发剂,合成了磁性Pb(II)离子印迹聚合物。模板用4ml盐酸(2mol L-1)从聚合物中去除。采用傅里叶变换红外光谱、扫描电子显微镜和ImageJ软件-能量色散x射线系统、热重分析和振动样品磁强计对吸附剂的化学结构、形貌-粒度、元素分析、热行为和磁性能进行了评价。对pH、萃取平衡时间、萃取温度、萃取液等参数进行了优化。结果表明,在pH 6.0的介质中,吸附剂吸附量为92.3 mg g-1,平衡时间为7 min,温度为40℃。校准线性为2 ~ 150µg L-1,检出限为0.3µg L-1。所制备的吸附剂具有较高的选择性,并成功地应用于实际样品中的铅去除。
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引用次数: 3
Determination of trace amounts of selenium in natural spring waters and tea samples by catalytic kinetic spectrophotometry 催化动力学分光光度法测定天然泉水和茶叶样品中痕量硒
Pub Date : 2019-10-01 DOI: 10.26850/1678-4618eqj.v44.4.2019.p57-72
R. Gürkan, Nevalnur Zeynep Gürkan
In this work, a new kinetic method is described for the determination of trace Se(IV) in natural spring waters and commercial tea samples. The method is based on the activation of Se(IV) onto the indicator reaction in acidic medium. The reaction was monitored using a fixed time approach of 20 min at 680 nm. The variables affecting the reaction rate were evaluated and optimized. The method allows the determination of Se(IV) in the range of 0.0125-1.0 mg L-1 with a detection limit of 3.6 µg L-1. The precision was in range of 0.63-3.15% (as RSD %) with a higher recovery than 98.6%. The method has been found to be selective against matrix effect. The method was applied to the speciation analysis of inorganic Se species present in the selected samples. The method was statistically validated by analysis of two certified samples and comparing the obtained results to those of HG-AAS analysis. Also, the total Se levels of the samples were determined by using both methods after conversion of Se(VI) into Se(IV) in ultrasonic bath in acidic medium for 30 min at 85-90 °C. The results were in good agreement with those of HG-AAS. The Se(VI) level of the samples was calculated from the difference between amounts of total Se and Se(IV).
本文建立了一种新的测定天然泉水和商品茶叶样品中痕量硒(IV)的动力学方法。该方法是基于Se(IV)在酸性介质中对指示剂反应的活化。采用固定时间方法监测反应,时间为20 min,波长为680 nm。对影响反应速率的因素进行了评价和优化。本方法对硒(IV)的测定范围为0.0125 ~ 1.0 mg L-1,检出限为3.6µg L-1。精密度为0.63 ~ 3.15% (RSD %),回收率高于98.6%。该方法对基体效应具有选择性。将该方法应用于所选样品中无机硒的形态分析。通过对两个认证样品的分析,并将所得结果与HG-AAS分析结果进行比较,对该方法进行了统计验证。将Se(VI)转化为Se(IV),在85 ~ 90℃的酸性介质中超声浴30 min后,用两种方法测定样品的总Se水平。结果与HG-AAS相吻合。根据样品中总硒量与硒(IV)量之差计算样品中的硒(VI)水平。
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引用次数: 1
Characterization of nimesulide and development of immediate release tablets 尼美舒利的性质及速释片的研制
Pub Date : 2019-07-21 DOI: 10.26850/1678-4618EQJ.V44.3.2019.P20-35
H. Rocha, R. S. Augusto, Livia D. Prado, E. Carvalho
To characterize nimesulide raw materials from different manufacturers and to develop immediate release tablets, in order to register a generic product. Also raw material characteristics and the tablets final properties was investigated in order to establish a different specification for quality control. Two micronized and one non-micronized nimesulide samples were obtained from different manufacturers and were characterized by thermal analysis, spectroscopic techniques, morphological analysis, flowability and biopharmaceutical evaluation. The samples belong to the same polymorph. The formulations design and the choice of the production process were carried out based on the results obtained in the characterization assessments. The proposed formulations showed different dissolution behavior. One formulation was selected and then the dissolution was evaluated in different dissolution media containing varying concentrations of surfactant, in order to verify if the concentration of 2% (v/v) of polysorbate 80, recommended by the Brazilian Pharmacopoeia, would be overestimating the bioavailability of the drug. The results showed that the percentage of surfactant present in the dissolution medium directly impacts the amount of dissolved drug. The selected formulation demonstrated promising results to proceed with the biobatches manufacture and the pharmaceutical equivalence study.
对不同厂家的尼美舒利原料进行表征,并开发立即释放片剂,以便注册通用产品。并对原料特性和片剂的最终性能进行了考察,以建立不同的质量控制标准。采用热分析、光谱技术、形态分析、流动性和生物制药评价等方法对不同厂家的尼美舒利样品进行了微粉化和非微粉化表征。样品属于同一多晶型。根据表征评价结果进行了配方设计和生产工艺选择。所提配方表现出不同的溶解行为。选择一个配方,然后在含有不同浓度表面活性剂的不同溶解介质中评估溶出度,以验证巴西药典推荐的2% (v/v)聚山梨酸酯80的浓度是否会高估药物的生物利用度。结果表明,溶出介质中表面活性剂的含量直接影响药物的溶出量。所选择的制剂显示出良好的效果,可以进行生物批制剂生产和药物等效性研究。
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引用次数: 1
Diketopiperazines and arylethylamides produced by Schizophyllum commune, an endophytic fungus in Alchornea glandulosa 双酮哌嗪类和芳基乙胺类的产生,裂叶菌是一种内生真菌
Pub Date : 2019-07-21 DOI: 10.26850/1678-4618EQJ.V44.3.2019.P36-42
Carolina Rabal Biasetto, A. Somensi, Fernanda Sales Figueiro, Luiz Alberto Beraldo de Moraes, G. Silva, Maria Claudia Marx Young, V. da Silva Bolzani, Â. Araújo
Chemical investigation of the crude PDB extract obtained from the endophytic fungus Schizophyllum commune afforded the pure substances, cyclo(L-Pro-L-Val) (1), uracil (2), cyclo(Pro-Tyr) (3), p-hydroxybenzoic acid (4) and a mixture of Rel.cyclo(Pro-Phe) (5) and Rel.cyclo(Pro-Ile) (6). When cultured in corn, the extract of this fungus yielded N-(2-phenylethyl) acetamide (7) and N-(4-hydroxyphenylethyl) acetamide (8). The structures of all compounds were determined based on the analyses of their MS, 1D and 2D-NMR spectroscopic data. Analysis of the crude extracts obtained from small-scale cultures (in PBD, YM, Nutrient, Czapek, Malt Extract, Corn and Rice) and a large-scale culture (in PDB) by mass spectrometry showed the presence of diketopiperazines 1, 3, 5 and 6. The crude extracts showed promising antioxidant, antifungal and acetylcholinesterase (AChE) inhibitory activities. The metabolites 7 and 8 showed antifungal and AChE inhibitory activities in vitro. This is the first report of the identification and isolation of diketopiperazines, arylethylamides, p-hydroxybenzoic acid in endophytic fungus of the Schizophyllum genus.
从内生真菌裂叶菌(Schizophyllum commune)中提取的PDB粗提物进行化学研究,得到纯物质cyclo(L-Pro-L-Val)(1)、尿嘧啶(2)、cyclo(Pro-Tyr)(3)、对羟基苯甲酸(4)以及Rel.cyclo(Pro-Phe)(5)和Rel.cyclo(Pro-Ile)(6)的混合物。通过MS、1D和2D-NMR数据分析,确定了各化合物的结构,得到N-(2-苯乙基)乙酰胺(7)和N-(4-羟基苯乙基)乙酰胺(8)。通过质谱分析从小规模培养(PBD、YM、营养物、Czapek、麦芽提取物、玉米和大米)和大规模培养(PDB)中获得的粗提取物,发现存在二酮哌嗪1,3,5和6。粗提物具有良好的抗氧化、抗真菌和抑制乙酰胆碱酯酶活性。代谢物7和8在体外具有抗真菌和AChE抑制活性。本文首次从裂叶菌属内生真菌中分离鉴定出二酮哌嗪类、芳基乙胺类和对羟基苯甲酸。
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引用次数: 6
Solution of the Schrödinger equation with inversely quadratic Yukawa potential (IQYP) plus Kratzer-Fues (KFP) potential using the WKB quantum mechanical formalism 用WKB量子力学形式解反二次汤川势(IQYP)加Kratzer-Fues势(KFP) Schrödinger方程
Pub Date : 2019-07-21 DOI: 10.26850/1678-4618EQJ.V44.3.2019.P50-55
B. Ita, H. Louis, N. Nzeata-Ibe
The main objective of this research work is theoretical investigate the bound state solutions of the non-relativistic Schrödinger equation with a mixed potential composed of the Inversely Quadratic Yukawa/Attractive Coulomb potential plus a Modified Kratzer potential (IQYCKFP) by utilizing the Wentzel-Kramers-Brillouin (WKB) quantum theoretical formalism. The energy eigenvalues and its associated wave functions have successfully been obtained sequel to certain diatomic molecules includes; HCL, HBr, LiH.
本研究的主要目的是利用WKB (Wentzel-Kramers-Brillouin)量子理论形式,从理论上研究由反二次Yukawa/Attractive Coulomb势和修正Kratzer势组成的混合势(IQYCKFP)的非相对论性Schrödinger方程的束缚态解。对于某些双原子分子,已成功地获得了能量特征值及其相关波函数,包括;HCL HBr LiH。
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引用次数: 3
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Eclética Química Journal
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