Floatation

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  • 文章类型: Journal Article
    埃塞俄比亚狼(EW)Canissimensis,是世界上最稀有的犬科动物和非洲最濒危的食肉动物,在埃塞俄比亚高地的六个孤立的栖息地碎片中发现。以前关于贝尔山国家公园(BMNP)EW中寄生虫患病率的报道有限,几乎没有关于他们的蠕虫动物的信息。这项研究旨在了解BMNP中EW中蠕虫寄生虫的患病率,埃塞俄比亚。在这项研究中,粪便样本是从Web谷(WV)的43个EW中收集的,BMNP,从2020年6月至10月,使用粪便沉降法和显微镜离心浮选法评估了蠕虫卵的存在。狼的43个粪便样本中有42个(98%)含有来自两个分类蠕虫组的卵。来自Capillariaspp的鸡蛋。和寻常毛虫最常见,其次是犬弓形虫,二叶草。,弓形虫Leonina,和嗜气毛细血管.记录了一个EW(2%),因为藏有Monieziaexpossa。43例EW中约有9例(21%)出现单特异性感染:9例EW(21%)携带2种寄生虫,9个EW(21%)托管了3种寄生虫,11例EW(26%)感染了4种寄生虫,2例EW(5%)感染了5种寄生虫,1个EW(2%)呈现6种寄生虫,1个EW(2%)携带7种寄生虫,1个EW(2%)被诊断为无寄生虫物种。并发蠕虫感染与女性EW高度相关。Megeti3与并发蠕虫感染水平低有关。在研究区域的狼中发现的蠕虫寄生虫的流行表明,环境被肠道寄生虫高度污染。定期控制EW中的寄生虫传播,家养狗,以及BMNP及其周围的人类,公共教育,必须进行进一步的寄生虫流行病学研究。
    Ethiopian wolves (EWs), Canis simensis, are the rarest canids in the world and Africa\'s most endangered carnivore, found in only six isolated habitat fragments in the highlands of Ethiopia. Previous reports on the prevalence of parasites in the EW in Bale Mountains National Park (BMNP) are limited, with little information on their helminth fauna. This study seeks to understand the prevalence of helminth parasites in the EW in BMNP, Ethiopia. In this study, fecal samples were collected from 43 EWs in Web Valley (WV), BMNP, from June to October 2020, and the presence of helminth eggs was assessed using fecal sedimentation and centrifugal floatation methods with microscopy. Forty-two out of 43 fecal samples from wolves (98%) contained eggs from two taxonomic groups of helminths. Eggs from Capillaria spp. and Trichuris vulpis were found most frequently, followed by Toxocara canis, Diphyllobothrium spp., Toxascaris leonina, and Capillaria aerophila. One EW (2%) was recorded for harboring the cestode Moniezia expansa. About 9 of the 43 EWs (21%) presented monospecific infection: 9 EWs (21%) harbored 2 parasite species, 9 EWs (21%) hosted 3 parasite species, 11 EWs (26%) had infection involving 4 parasite species, 2 EWs (5%) were infected with 5 parasite species, 1 EW (2%) presented 6 parasite species, 1 EW (2%) harbored 7 parasite species, and 1 EW (2%) was diagnosed without parasite species. Concurrent helminth infection was highly associated with female EW. Megeti 3 was associated with a low level of concurrent helminth infection. The prevalence of helminth parasites found in wolves in the study area suggests that the environment is highly contaminated with intestinal parasites. Regular control of parasite transmission in EW, domestic dogs, and humans in and around BMNP, public education, and further parasite epidemiological studies must be conducted.
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  • 文章类型: Journal Article
    当前的研究试图设计和评估通过基于单单元流体动力学平衡系统(HBS)的漂浮胶囊的持续胃特异性氧氟沙星递送。这些基于HBS的氧氟沙星漂浮胶囊是使用两种相反的离子聚合物制备的,即阳离子型低分子质量壳聚糖(LMMCH)和阴离子型羧甲基罗望子胶(CMTG)。FTIR结果表明,在两个带相反电荷的聚合物之间原位形成了聚电解质复合物(即,在阳离子型LMMCH的-NH2基团和阴离子型CMTG的-COOH基团之间),并且在这些配制的氧氟沙星HBS胶囊中不存在任何药物-聚合物相互作用。所有这些LMMCH-CMTG氧氟沙星HBS胶囊均表现出药物含量均匀性,持续10小时的体外药物释放曲线。氧氟沙星HBS胶囊(用75mgLMMCH和25mgCMTG配制),被选为最佳配方(用于进一步研究),在6小时内,在SGF(pH1.2)中表现出优异的体外漂浮行为,没有任何漂浮滞后时间,而含有硫酸钡(100mg)而不是药物的相同制剂在使用兔的体内X射线成像研究中显示出延长的胃特异性胃潴留。因此,这些类型的HBS漂浮胶囊可用于胃特异性胃滞留漂浮递送其他药物.
    The current research attempted to design and evaluate sustained stomach-specific ofloxacin delivery by single-unit hydrodynamically balanced system (HBS)-based floating capsules. These HBS-based floating capsules of ofloxacin were prepared using two oppositely ionic polymers, namely cationic-natured low molecular mass chitosan (LMMCH) and anionic-natured carboxymethyl tamarind gum (CMTG). FTIR results indicated the in situ formation of a polyelectrolyte complex in-between two oppositely charged polymers (i.e., in-between -NH2 group of the cationic natured LMMCH and -COOH groups of the anionic natured CMTG) and the nonexistence of any drug-polymer interaction(s) within these formulated ofloxacin HBS capsules. All these LMMCH-CMTG ofloxacin HBS capsules exhibited drug content uniformity, a sustained in vitro drug-releasing profile over 10 h. The ofloxacin HBS capsules (formulated with 75 mg LMMCH and 25 mg CMTG), which was selected as best formulation (for further studies), exhibited excellent in vitro floatation behaviour in SGF (pH 1.2) over 6 h without any floating lag-time, whereas the same formulation containing barium sulfate (100 mg) instead of drug demonstrated prolonged stomach-specific gastroretention in an in vivo X-ray imaging study using rabbits. Therefore, these types of HBS floating capsules can be useful for stomach-specific gastroretentive floating delivery of other drugs.
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  • 文章类型: Journal Article
    在阿根廷,有些人往啤酒里加花生。一旦浸入,花生最初沉入啤酒中,然后气泡在花生表面成核并生长并保持附着。花生在啤酒杯中以许多重复的循环上下移动。在这项工作中,我们提出了这种跳舞的花生奇观的物理描述。我们将问题分解为组成部分的物理现象,提供每个的经验约束:(i)花生表面上发生异质气泡成核,这在能量上优先于啤酒玻璃表面上的成核;(ii)覆盖在附着气泡中的花生在临界附着气体体积以上的啤酒中积极漂浮;(iii)在啤酒顶面,气泡分离和流行,花生旋转和重排促进;(iv)含有较少气泡的花生在啤酒和水槽中具有负浮力;和(v)该过程重复,只要啤酒在气相中保持足够过饱和以继续成核。我们使用实验室实验和计算来支持这种描述,包括啤酒-气体-花生系统的密度和润湿特性的约束。我们将这种花生舞周期性与广泛关注的工业和自然过程进行类比,最终得出结论,这种条边现象可以成为理解更复杂的工具,具有普遍兴趣和效用的应用系统。
    In Argentina, some people add peanuts to their beer. Once immersed, the peanuts initially sink part way down into the beer before bubbles nucleate and grow on the peanut surfaces and remain attached. The peanuts move up and down within the beer glass in many repeating cycles. In this work, we propose a physical description of this dancing peanuts spectacle. We break down the problem into component physical phenomena, providing empirical constraint of each: (i) heterogeneous bubble nucleation occurs on peanut surfaces and this is energetically preferential to nucleation on the beer glass surfaces; (ii) peanuts enshrouded in attached bubbles are positively buoyant in beer above a critical attached gas volume; (iii) at the beer top surface, bubbles detach and pop, facilitated by peanut rotations and rearrangements; (iv) peanuts containing fewer bubbles are then negatively buoyant in beer and sink; and (v) the process repeats so long as the beer remains sufficiently supersaturated in the gas phase for continued nucleation. We used laboratory experiments and calculations to support this description, including constraint of the densities and wetting properties of the beer-gas-peanut system. We draw analogies between this peanut dance cyclicity and industrial and natural processes of wide interest, ultimately concluding that this bar-side phenomenon can be a vehicle for understanding more complex, applied systems of general interest and utility.
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  • 文章类型: Journal Article
    采矿实践,主要是泡沫浮选,正在进行严格的重新评估,以取代他们对生物危险化学试剂的使用,而采用生物友好的替代品作为绿色工艺的途径。在这方面,这项研究旨在评估肽的相互作用,作为潜在的浮选收集器,使用噬菌体展示和分子动力学(MD)模拟的石英。石英选择性肽序列最初通过在pH=9的噬菌体展示鉴定,并通过结合经典MD的稳健模拟方案进一步建模。副本交换MD,并指导MD计算。我们对肽的残基特异性分析表明,带正电荷的精氨酸和赖氨酸残基在碱性pH下被石英表面有利地吸引。在pH值为9时带负电荷的残基(即,天冬氨酸和谷氨酸)通过与带正电荷的表面结合的Na离子的静电相互作用进一步显示出对石英表面的亲和力。最佳结合七肽组合,然而,在其组成中包含带正电荷和负电荷的残基。肽链的柔性也显示直接影响肽的吸附行为。虽然有吸引力的肽内相互作用由弱的肽-石英结合主导,肽中的排斥自相互作用改善了与石英表面的结合倾向。我们的结果表明,MD模拟完全能够揭示肽吸附到无机表面的机理细节,并且是加速合理设计用于矿物加工应用的肽序列的宝贵工具。
    Mining practices, chiefly froth flotation, are being critically reassessed to replace their use of biohazardous chemical reagents in favor of biofriendly alternatives as a path toward green processes. In this regard, this study aimed at evaluating the interactions of peptides, as potential floatation collectors, with quartz using phage display and molecular dynamics (MD) simulations. Quartz-selective peptide sequences were initially identified by phage display at pH = 9 and further modeled by a robust simulation scheme combining classical MD, replica exchange MD, and steered MD calculations. Our residue-specific analyses of the peptides revealed that positively charged arginine and lysine residues were favorably attracted by the quartz surface at basic pH. The negatively charged residues at pH 9 (i.e., aspartic acid and glutamic acid) further showed affinity toward the quartz surface through electrostatic interactions with the positively charged surface-bound Na+ ions. The best-binding heptapeptide combinations, however, contained both positively and negatively charged residues in their composition. The flexibility of peptide chains was also shown to directly affect the adsorption behavior of the peptide. While attractive intrapeptide interactions were dominated by a weak peptide-quartz binding, the repulsive self-interactions in the peptides improved the binding propensity to the quartz surface. Our results showed that MD simulations are fully capable of revealing mechanistic details of peptide adsorption to inorganic surfaces and are an invaluable tool to accelerate the rational design of peptide sequences for mineral processing applications.
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  • 文章类型: Journal Article
    目的:当前的工作旨在提供关于胃滞留药物递送系统(GRDDS)以及配制方法的完整停留,聚合物选择,和体外/体内挑战与成品剂型材料和方法:理想情况下,生物药物受阻药物由于其低水溶性和渗透性而具有快速清除和不稳定的生物利用度。此外,它还患有高的首过代谢和前系统肠壁清除。胃滞留药物递送系统已成为新兴技术,其中已使用较新的方法和科学方法来提供药物的受控释放并在胃中提供保护机制。通过使用GRDDS作为剂型,这些制剂增加胃滞留时间(GRT),从而延长剂型中药物的受控释放。
    结论:GRDDS有助于提高药物的生物利用度和靶向作用部位,这增强了治疗作用并为患者提供了显着的依从性。此外,本工作还强调了聚合物在胃滞留机制和推荐浓度范围内有利于药物在GIT中滞留的关键作用。最近十年来,已批准的药物产品和专利配方也突出了新兴技术,并以合理的方式进行了描述。
    结论:GRDDS制剂已显示出临床疗效,这得到了可以在胃中长时间保存的剂型的尖端创新专利汇编的支持。
    The current work aims to provide a complete sojourn on gastro-retentive drug delivery system (GRDDS) along with formulation methods, polymer selection, and in vitro/ in vivo challenges with finished dosage forms. Ideally, a biopharmaceutical-hindered drug has a rapid clearance and erratic bioavailability due to its low aqueous solubility and permeability. Additionally, it also suffers from high first-pass metabolism and pre-systemic gut wall clearance. Gastro-retentive drug delivery systems have become an emerging technology where newer methodologies and scientific approaches have been used to provide the controlled release of drugs and provide a protective mechanism in the stomach. By the virtue of utilizing GRDDS as a dosage form, these formulations increase Gastroretention time (GRT) which prolongs the controlled release of the drug in the dosage form. GRDDS contribute to increased drug bioavailability and targeting at a site of action, which enhances therapeutic action and offers significant patient compliance. Furthermore, the present work also highlighted the critical role of polymers in favoring drug retention across GIT with the mechanism of gastro-retention and recommended concentration ranges. The emerging technology is also highlighted by the approved drug products and patented formulations in the recent decade which is depicted in a justified manner. GRDDS formulations have demonstrated clinical efficacy, which is supported by a compilation of patents for cutting-edge innovations in dosage forms that can be held in the stomach for an extended period of time.
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  • 文章类型: Journal Article
    厌氧氨氧化(anammox)颗粒污泥是一种有前途的生物技术处理低碳含氮废水,并具有低能耗和足迹。先前对厌氧氨氧化颗粒污泥工艺的理论和实验研究主要集中在颗粒化(絮凝→颗粒),但很少注意造粒周期,包括造粒和再生。本文从厌氧氨氧化颗粒生命周期的角度回顾了以往的研究,提出了厌氧氨氧化颗粒的各种可持续形成机制。通过观察厌氧菌,有氧,和厌氧氨氧化造粒机制,我们总结了热力学理论的机理,异质生长,基于胞外聚合物(EPS)的粘附,基于群体感应(QS)的调节,基于生物矿化的生长,和微生物的分层,以了解厌氧氨氧化颗粒。在再生过程中,用于再造粒的前体的形成由物理破碎的机制解释,群体猝灭和色散线索传感。基于粒化循环机制,正常再生过程的重建被认为是必要的,以避免颗粒漂浮和冲刷颗粒。该综述表明,未来对厌氧氨氧化造粒循环的研究应集中在丝状菌在反硝化-厌氧氨氧化造粒循环中的作用。基于QS/群体淬火(QQ)的自动诱导剂的作用,开发多样化的机制,以了解储存颗粒的周期和周期机制。
    Anaerobic ammonium oxidation (anammox) granular sludge is a promising biotechnological process for treating low-carbon nitrogenous wastewater, and is featured with low energy consumption and footprint. Previous theoretical and experimental research on anammox granular sludge processes mainly focused on granulation (flocs → granules), but pay little attention to the granulation cycle including granulation and regeneration. This work reviewed the previous studies from the perspective of anammox granules lifecycle and proposed various sustainable formation mechanisms of anammox granules. By reviewing the anaerobic, aerobic, and anammox granulation mechanisms, we summarize the mechanisms of thermodynamic theory, heterogeneous growth, extracellular polymeric substance (EPS)-based adhesion, quorum sensing (QS)-based regulation, biomineralization-based growth, and stratification of microorganisms to understand anammox granulation. In the regeneration process, the formation of precursors for re-granulation is explained by the mechanisms of physical crushing, quorum quenching and dispersion cue sensing. Based on the granulation cycle mechanism, the rebuilding of the normal regeneration process is considered essential to avoid granule floatation and the wash-out of granules. This comprehensive review indicates that future research on anammox granulation cycle should focus on the effects of filamentous bacteria in denitrification-anammox granulation cycle, the role of QS/ quorum quenching (QQ)-based autoinducers, development of diversified mechanisms to understand the cycle and the cycle mechanisms of stored granules.
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  • 文章类型: Journal Article
    颗粒形成,微观结构和微生物空间分布对颗粒稳定性和脱氮至关重要。这里,制造了带有多孔固定圆柱体载体的上流式覆盖层过滤器(UBF)反应器,并运行了234天,以研究其整体性能和厌氧氨氧化颗粒的形成机理。结果表明,在3.6kg-N/m3/d的氮负荷和2h的HRT下,UBF的脱氮效率最高,为93.19±3.39%。作为EPS中关键成分的色氨酸样蛋白对于颗粒形成至关重要。进一步的16srRNA分析表明,相对丰度为40.5%的SBR1031在细胞聚集中起重要作用。因此,成功开发了具有两层空间结构的厌氧氨氧化颗粒,其中外层是氨氧化细菌,内核是厌氧氨氧化细菌。一起,引入多孔固定圆筒载体是避免生物量损失和浮选的有效方法。
    Granule formation, microstructure and microbial spatial distribution are crucial to granule stability and nitrogen removal. Here, an upflow blanket filter (UBF) reactor with porous fixed cylinder carriers was fabricated and operated for 234 days to investigate overall performance and the formation mechanism of anammox granules. Results showed that the UBF performed the highest nitrogen removal efficiency of 93.19 ± 3.39% under nitrogen loading rate of 3.6 kg-N/m3/d and HRT of 2 h. The tryptophan-like proteins as the key component in EPS were vital for granules formation. Further 16 s rRNA analysis indicated that SBR1031 with a relative abundance of 40.5% played an important role in cell aggregation. Thus, anammox granules were developed successfully with a two-layered spatial structure where outer-layer was ammonia oxidizing bacteria and inner-core was anaerobic ammonia oxidizing bacteria. Together, introduction of porous fixed cylinder carriers is a valid method to avoid biomass loss and floatation.
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  • 文章类型: Journal Article
    UNASSIGNED: Eimeria spp. are gastrointestinal protozoans that affect animal productivity, thereby causing symptoms that range from bloody diarrhea to death. These symptoms cause economic losses to farmers. The distribution of Eimeria spp. in cattle has, therefore, been reported to have spread widely, especially in the tropics and subtropics. Indonesia is a tropical country at high risk of Eimeria infections. This study aimed to identify the prevalence and risk factors related to the levels of eimeriosis in beef cattle originating from different geographic areas in Indonesia.
    UNASSIGNED: Here, 817 fecal samples were collected from beef cattle in Indonesia, including 282 calves, 535 adults, 530 males, and 287 females. In addition, 156 semi-intensively and 661 intensively managed cattle were randomly collected. Then, fecal samples were analyzed by parasitology examinations.
    UNASSIGNED: Screening examination using the sugar flotation modification method showed that Eimeria spp. were prevalent in Indonesia, as 65.4% of the bacterial strain was detected. The prevalence of identified Eimeria spp. in Indonesia was highest in North Maluku (Maluku Island) (94.1%), whereas the lowest levels were observed in West Java (24.0%) (Java Island). The prevalence was also found to be higher in males (79.3%) than females (51.9%). Similarly, levels in semi-intensively managed cattle (66.7%) were higher than those subjected to intensive management (65.9%). However, its prevalence in calf and adult cattle was similar.
    UNASSIGNED: Bovine eimeriosis spp. were detected at high prevalence in Indonesia, and high-level risks were observed in infected males, including those under the semi-intensive management. In addition, although the results from oocyst examinations were based on qualitative analysis, the endemicity levels of Eimeria spp. among farms in Indonesia should be considered because Eimeria spp. were distributed in most parts of Indonesia. Based on the results of this study, we provide the first information about the prevalence of bovine eimeriosis from different geographical locations in Indonesia, which have differing climates associated with the level of the existing risk factors. Hence, farmers are advised to pay more attention to strict biosecurity techniques on their farms, thereby favoring the early control of bovine eimeriosis.
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  • 文章类型: Journal Article
    Support films are commonly used during cryo-EM specimen preparation to both immobilise the sample and minimise the exposure of particles at the air-water interface. Here we report preparation protocols for carbon and graphene supported single particle electron microscopy samples using a novel 3D-printed sample transfer block to facilitate the direct, wetted, movement of both carbon and graphene supports from the substrate on which they were generated to small volumes (10 μL) of sample. These approaches are simple and inexpensive to implement, minimise hydrophobic contamination of the support films, and are widely applicable to single particle studies. Our approach also allows the direct exchange of the sample buffer on the support film in cases in which it is unsuitable for vitrification, e.g. for samples from centrifugal density gradients that help to preserve sample integrity.
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  • 文章类型: Journal Article
    BACKGROUND: Gastric residence time is the key factor affecting the bioavailability of active pharmaceutical ingredients absorbed mainly through the gastric mucous membrane and influencing the local activity of some drugs.
    OBJECTIVE: The aim of this study was the development of a new composition of non-effervescent floating tablets and the evaluation of the effect of an anionic polymer and compressive force on the floating properties and release characteristics of tablets containing a model alkaline drug, chlorhexidine (CHX).
    METHODS: Direct compression was applied to a polyacrylic acid derivative and sorbitol to fabricate the tablets. Drug release was analyzed using several kinetic models. The formulations floated on the surface of the fluid for 24 h. The values of the rate constants, statistical parameters, and half-release time (t0.5) were calculated.
    RESULTS: The diffusion coefficient n falls between 0.54 ±0.02 and 0.81 ±0.03 for most formulations. The floating time (FT) and floating lag time (FLT) were found to depend on the amount of polymer incorporated in the formulations. A high compressive force sustained the release of the drug but reduced the FT and FLT. Based on the FT and t0.5, it was determined that the C1 composition is the optimal formulation with FT >24 h and t0.5 between 113 ±2 and 144 ±13 min, depending on the drug release model.
    CONCLUSIONS: The application of an anionic polymer results in a prolonged release of the drug from the tablets and allows them to float on fluid surfaces.
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