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Liquid-liquid extraction and separation of total rare earth(RE) metals from polymetallic manganese nodule leaching solution

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Journal of Rare Earths 2015年第2期33卷 207-213页

作者： P.K.Parhi K.H.Park c.W.Nam J.T.Park Mineral Resources Research Division Korea Institute of Geoscience & Mineral Resources (KIGAM)Daejeon 305-350 Republic of Korea School of Applied Science and center of Industrial Technology KIIT UniversityBhubaneswar 751024 Odisha India

The study on the solvent extraction for quantitative and selective separation of total rare earth metals from the polymetallic nodule leach liquor was investigated. The typical leach liquor bearing 0. 094 g/L total rare earth, 0. 23 g/L Mn, 0.697 g/L cu, 0.2 g/L Fe, 0.01 g/L co and 0.735 g/L Ni was subjected to the removal iron content by precipitation method using ca（OH）2 at pH 3.95, prior to solvent extraction of rare earth metals. Three different organo-phosphoric acid reagents（D2EHPA, Pc88 A, cyanex 272） were used to ascertain their performances and selectivity towards the loading of rare earth metals in presence of other base metals. Based on the results of eq. pH effect, the performances of above three extractants followed the order as： D2EHPA〉Pc88A〉cyanex 272. To ensure the absence of extraction of base metals（cu, co, Ni）, the eq. pH of the solution was optimized at the level of 2.21, though higher rare earth metal extraction efficiency was observed at higher eq. pH with either of the extractants. The complete process flow diagram for substantial recovery of total rare earth was developed using D2 EHPA. Extraction isotherm plot was constructed at A：O=12：1, 3-stages and phe=2.21, using 0.8 mol/L D2 EHPA and the predicted condition of this study was further confirmed by 6-cycles counter current Simulation（ccS） study. The stripping of total rare earth from loaded organic phase（LO） was conducted using Hcl solution. Mc-cabe Thiele diagram study carried out at A：O=1：5 using 4 mol/L Hcl showed that three theoretical stages were needed for quantitative stripping of total rare earth. The subsequent stripped solution resulted thus led to contain total rare earth of 5.6 g/L indicating a very high enrichment of total metals by solvent extraction（SX） process.

关键词： total rare earth (RE) metals SX D2EHPA Hcl deep sea nodule

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Blockade of Na^+/H^+ exchanger type 3 causes intracellular acidification and hyperexcitability via inhibition of pH-sensitive K^+ channels in chemosensitive respiratory neurons of the dorsal vagal nucleus in rats

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Neuroscience Bulletin 2014年第1期30卷 43-52页

作者： Jing Zhang Hui Peng Sigrid c.Veasey Jing Ma Guang-Fa Wang Ke-Wei Wang Department of Respiratory and critical care Medicine Peking University First Hospital Departments of Neurobiology and Molecular and cellular Pharmacology Peking University Health Science Center center for Sleep and circadian Neurobiology University of Pennsylvania School of Medicine Department of Medicine University of Pennsylvania School of Medicine

Extracellular pH （phe） and intracellular pH （pHi） are important factors for the excitability of chemosensitive central respiratory neurons that play an important role in respiration and obstructive sleep apnea. It has been proposed that inhibition of central Na^＋/ H^＋ exchanger 3 （NHE-3）, a key pHi regulator in the brainstem, decreases the pH, leading to membrane depolarization for the maintenance of respiration. However, how intracellular pH affects the neuronal excitability of respiratory neurons remains largely unknown. In this study, we showed that NHE-3 mRNA is widely distributed in respiration-related neurons of the rat brainstem, including the dorsal vagal nucleus （DVN）. Whole-cell patch clamp recordings from DVN neurons in brain slices revealed that the standing outward current （Iso） through pH-sensitive K^＋ channels was inhibited in the presence of the specific NHE-3 inhibitor AVE0657 that decreased the pHi. Exposure of DVN neurons to an acidified PIle and AVE0657 （5 μmol/L） resulted in a stronger effect on firing rate and Iso than acidified phe alone. Taken together, our results showed that intracellular acidification by blocking NHE-3 results in inhibition of a pH- sensitive K^＋ current, leading to synergistic excitation of chemosensitive DVN neurons for the regulation of respiration.

关键词： Na^+/H^+ exchange potassium channel dorsal vagal nucleus in situ hybridization respiration

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The changes of oligodendrocytes induced by anesthesia during brain development

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Neural Regeneration Research 2015年第9期10卷 1386-1387页

作者： Danye Jiang Sanghee Lim Minhye Kwak Yun Kyoung Ryu c.David Mintz Department of Anesthesiology and critical care Medicine Johns Hopkins Medical Institutes

With the advent of modern techniques, drugs, and monitoring, general anesthesia has come to be considered an unlikely cause of harm, particularly for healthy patients. While this is largely true, newly emerging clinical and laboratory studies have sug- gested that exposure to anesthetic agents during early childhood may have long-lasting adverse effects on cognitive function. This concern has been the focus of intense study in the field of anesthesia research. A recent high-profile review by Rappaport et al. （2015） concluded that while many questions remain un- answered, there is strong evidence from laboratory studies that commonly used anesthetics interfere with brain development and that clinical studies suggest a correlation between early childhood exposure to these agents and subsequent effects on learning and cognition. The issue is of sufficient public health importance that a public-private partnership known as Smar- Tots （Strategies for Mitigating Anesthesia-Related Neurotoxicity in Tots） was developed by the FDA to study pediatric anesthetic neurotoxicity. The mechanism of injury underlying this phe- nomenon has yet to be fully elucidated, and there is evidence to suggest that anesthetics may have direct cytotoxic effects on neurons leading to cell death or suppressed neurogenesis （Strat- mann et al., 2010） and that they may interfere with key pro- cesses in neuronal growth and development that underlie brain circuit development （Wagner et al., 2014）.

关键词： The changes of oligodendrocytes induced by anesthesia during brain development

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Searching systematics for nonfactorizable contributions to B^(-)and B^(0) hadronic decays

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chinese Physics c 2022年第7期46卷 47-55页

作者： Maninder Kaur Supreet Pal Singh R.c.Verma Department of Physics Punjabi UniversityPatiala-147002India

The two-body weak decays B→πD/B→ρD and B→πD are examined using isospin analysis to study nonfactorizable *** determining strong interaction phases and obtaining factorizable contributions from spectator-quark diagrams for Nc=3,we determine nonfactorizable isospin amplitudes from the experimental data for these *** results support the universality of the ratio of nonfactorizable isospin reduced amplitudes for these decays within experimental *** demonstrate that these systematics are not coincidental,we also plot our results *** ratio.

关键词： nonfactorization weak hadronic decays HEP-phe

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Microbial stabilisation and kinetic enhancement of marine methane hydrates in both deionised-and sea-water

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Petroleum 2021年第4期7卷 402-406页

作者： Mohammad Reza Ghaani Jonathan M.Young Prithwish K.Nandi Shamsudeen Dandare c.rist.pher c.RAllen Niall J.English School of chemical and Bioprocess Engineering University College DublinBelfieldDublin 4Ireland School of Biological Sciences Queen's University BelfastUniversity RoadBelfastBT71NNNorthern IrelandUK

The large quantity of marine methane hydrates has driven substantial interest in methane-gas-fuel potential,especially with the qualified success of Shensu(2017)and Nankai-Trough(2014&17)production trials via depressurisation(blighted ultimately by sanding out),building on an earlier Malik-2008 trial for permafrost-bound *** particular,obviating deep-water-drilling approaches,such as the MeBO production rig(without such a drill bit),together with blowout preventers,constitutes a tantalising cost-saving *** means of addressing sand production by customised gravel packs,wellbore screens and slotted liners with from-seafloor drilling will be expected to lead to future production-trial ***,despite these exciting engineering advances and a few marinemimicking laboratory studies of methane-hydrate kinetics and stabilisation from microbial perspectives,relatively little is known about the thermogenic or microbial origin of marine hydrates,nor their possible formation kinetics or potential stabilisation by microbial sources as an exponent of Gaia's hypothesis,or within the context of“Gaia's breath”as regards global methane‘exhalations’.Here,for the first time,we elucidate the methylotrophic-microbial basis for kinetic enhancement and stabilisation of marine-hydrate formation in both deionised-and sea-water,identifying the key protein at play,which has some similarity to porins in other methylotrophic *** so doing,we suggest such phenomena in marine hydrates as evidence of Gaia's hypothesis.

关键词： Gas hydrate Microbes Methylotrophs

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耐化学腐蚀和疏水性的食品包装用含SnO_(2)生物纳米复合材料

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Transactions of Nonferrous Metals Society of china 2023年第7期33卷 2136-2154页

作者： Joseph Raj XAVIER cDHANALAKSHMI Shanmuga Sundari cHANDRARAJ SPVINODHINI Department of chemistry Saveetha School of EngineeringSaveetha Institute of Medical and Technical SciencesChennai-602105Tamil NaduIndia Department of chemistry Vel Tech Rangarajan Dr.Sagunthala R&D Institute of Science and TechnologyChennai-600062Tamil NaduIndia

研究了聚(天冬酰胺-共苯丙氨酸)(P(Asn-co-phe)/SnO_(2))对环氧树脂(EP)涂层防护性能的影响。电化学阻抗谱分析表明,与纯环氧树脂涂层相比,马口铁表面EP-P(Asn-co-phe)/SnO_(2)纳米复合材料涂层具有更好的防护作用。EP-P(Asn-co-phe)/Sn... 详细信息

研究了聚(天冬酰胺-共苯丙氨酸)(P(Asn-co-phe)/SnO_(2))对环氧树脂(EP)涂层防护性能的影响。电化学阻抗谱分析表明,与纯环氧树脂涂层相比,马口铁表面EP-P(Asn-co-phe)/SnO_(2)纳米复合材料涂层具有更好的防护作用。EP-P(Asn-co-phe)/SnO_(2)纳米复合材料涂层的电阻(Rcoat)为3854.70 kΩ·cm^(2),比环氧树脂涂层的大38倍。扫描电化学显微镜分析表明,EP-P(Asn-co-phe)/SnO_(2)的电流分布更小。通过XRD和SEM/EDX对降解产物进行分析,证实了功能化SnO_(2)颗粒对环氧树脂涂层防护能力的影响。EP-P(Asn-co-phe)/SnO_(2)纳米复合材料涂层的水接触角为133°,证实了其疏水性。此外,与纯环氧树脂涂层相比,EP-P(Asn-co-phe)/SnO_(2)纳米材料复合涂层具有更高的力学性能和抗菌活性。综上,由于在环氧树脂基体中添加了P(Asn-co-phe)/SnO_(2)纳米颗粒,EP-P(Asn-co-phe)/SnO_(2)纳米复合材料提供了出色的屏障和力学性能,从而阻碍了材料的降解,有助于延长涂层钢的寿命。

关键词：马口铁环氧树脂 SnO_(2) 纳米材料复合涂层共聚物热稳定性硬度

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Prediction of a neutralizing epitope of a H5N1 virus hemagglutinin complexed with an antibody variable fragment using molecular dynamics simulation

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Journal of Biophysical chemistry 2011年第3期2卷 258-267页

作者： cenmidtal c. Mulyanto Rosari Saleh Departemen Fisika Fakultas MIPA Kampus Universitas Indonesia Depok Indonesia 16424

In this present study, we predicted the neutralizing epitope of a modeled H5N1 hemagglutinin 1046T when interacted with a modeled monoclonal antibody variable fragment 8H5Fv using molecular dynamics simulation. Following the production run of the molecular dynamics simulation, we observed the average change of solvent accessible surface of the antigen alongside the formation of hydrogen bonds between the two structures during the simulation. Based on the acquired data, we predicted the neutralizing epitope of the 1046T antigen to be consisted of residues Asp 84, Glu85, phe86, Ile87, Asn88, Val89, Pro90, Ile132, Ser136, Val147, Pro152, Tyr153, Leu154, Arg161, and Tyr268. By calculating the RMSD of the cα backbone chain of the complex during the simulation we found the structure to be generally stable suggesting a well maintained steric hindrance, while RMSD calculation of the predicted neutralizing epitope backbone suggests the stability of the neutralizing epitope itself.

关键词： Molecular Dynamics Simulation Neutralizing Epitope Antibody H5N1 Hemagglutinin Molecular Docking

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In vitro and in silico studies on fibrinolytic activity of nattokinase： A clot buster from Bacillus sp.

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Frontiers in Biology 2017年第3期12卷 219-225页

作者： V. Mohanasrinivasan. A. Mohanapriya Swaroop Potdar Sourav chatterji Srinath Konne Sweta Kumari S. Merlyn Keziah. c. Subathra Devi School of Biosciences and Technology VIT University Vellore-632014 Tamil Nadu India

BAcKGROUND： Nattokinase （NK） is a serine protease enzyme of the subtilisin family. It exhibits a strong fibrinolytic activity. The fibrinolytic enzymes from Bacillus sp. have attracted interest as thrombolytic agents because of their efficiency in the fibrinolytic process including plasmin activation. METHODS： In the present study, VIT garden soil was collected and subjected to isolation process in order to screen for the NK production. Screening for NK enzyme was performed by radial caseinolytic assay. The production of NK enzyme was done in two different production medium for comparative studies. The NK enzyme was purified by gel permeation chromatography. The activity of the purified NK was checked by clot lysis and casein digestion assay. To investigate the structural basis of NK and fibrinogen interaction and also to identify the best binding mode, molecular dynamics and docking studies were performed. RESULTS： Based on the morphological and biochemical characterization, the isolate was identified as Bacillus sp. The overall purification fold of NK was about 3 with the specific activity of 664U/mg and 9.9% yield. Homogeneity of the purified enzyme was analyzed and confirmed by the single band obtained in SDS-PAGE. Molecular weight of the purified protease was estimated as 25 kDa. Purified NK enzyme exhibited 97% of effective clot lysis activity. The NK was docked in to the knob region of the fibrinogen at its binding site using Dock server. A total of 26 residues of fibrinogen and 29 residues of NK constitute the interface region. However, 9 residues offibrinogen （THR238, MET264, LYS266, ARG275, THR277, ALA279, ASN308, MET310, and LYS321） and 8 residues ofNK （GLY61, SER63, THR99, phe189, LEU209, TYR217, ASN218, and MET222） are involved in intact binding. cONcLUSIONS： A significant amount of NK enzyme was obtained from Bacillus sp. The docking analysis revealed that the NK and fibrinogen adopt an extended binding pattern and interacts with the crucial residues t

关键词： nattokinase (NK) Bacillus sp. clot busters docking

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Do key innovations unlock diversification?A case-study on the morphological and ecological impact of pharyngognathy in acanthomorph fishes

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current Zoology 2020年第5期66卷 575-588页

作者： Olivier Larouche Jennifer R.Hodge Laura R.V.Alencar Benjamin camper Danielle S.Adams Katerina Zapfe Sarah T.Friedman Peter c.Wainwright Samantha A.Price Department of Biological Sciences Clemson UniversityClemsonSC29634USA Department of Evolution&Ecology University of California DavisDavisCA95616USA

Key inn ovations may allow lin eages access to new resources and facilitate the invasi on of new adaptive zon es,potentially influencing diversificati on patter *** studies have focused on the impact of key inno vations on speciation rates,but far less is known about how they influe nee phe notypic rates and patterns of ecomorphological *** use the repeated evolution of pharyngognathy within acanthomorph fishes,a commonly cited key innovation,as a case study to explore the predicti ons of key inn ovation ***,we in vestigate whether transiti ons to phary ngognathy led to shifts in the rate of phenotypic evolution,as well as shifts and/or expansion in the occupation of morphological and dietary space,using a dataset of 8 morphological traits measured across 3,853 species of *** the 6 evolutionarily independent pharyngognathous clades together,we found no evidence to support pharyngognathy as a key innovation;however,comparisons between individual pharyngognathous lineages and their sister clades did reveal some consistent *** morphospace,most pharyngognathous clades cluster in areas that correspond to deeper-bodied morphologies relative to their sister clades,whereas occupying greater areas in dietary space that reflects a more diversified diet Additi on ally,both cichlidae and Labridae exhibited higher univariate rates of phenotypic evolution compared with their closest ***,few of these results were exceptional relative to our null *** results suggest that transitions to pharyngognathy may only be advantageous when combined with additional ecological or intrinsic factors,illustrating the importance of account!ng for lineage-specific effects when testing key innovation ***,the challenges we experienced formulating informative comparisons,despite the ideal evolutionary scenario of multiple independent evolutionary origins of pharyngognathous clades,illustrates the comple

关键词： Acanthomorpha comparative methods ecomorphological diversification evolutionary innovations phenotypic rates

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Substituent effects on novel lanthanide(Ⅲ) hydrazides complexes

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Journal of Rare Earths 2020年第6期38卷 642-648页

作者： Samira G.Brandao Marcos A.Ribeiro Rafael V.Perrella Paulo c.de Sousa Filho Priscilla P.Luz Department of chemistry Federal University of Espirito Santo29075-910VitoriaESBrazil Institute of chemistry University of CampinasPO Box 615413083-970CampinasSPBrazil

New lanthanide(Eu3+ and Gd3+) complexes were successfully synthesized and the effect of the p-phe nyl substituent on the Eu3+luminescent properties was *** this sense,benzhydrazide,p-toluic hydrazide,4-hydroxybenzhydrazide and 4-aminobenzoic hydrazide were used as ligands and the complexes were obtained by mixing the lanthanide salts with hydrazides in ethanol at room temperature and keeping the reaction for 2 h under mechanical *** of Gd-amino was obtained and its structure was elucidated by single-crystal X-ray diffraction,revealing that Gd3+centered in a distorted tricapped trigonal-prismatic molecular *** spectroscopy and the elucidated structure confirm hydrazides acting as bidentate ligands binding to Ln3+ions through the oxygen of carbonyl group and the nitrogen of terminal amine,forming a five-membered ring,cHN analyses confirm the molecular formulas [Gd(amino)4(H2 O)](NO3)3·(c2 H5 OH) and [Eu(toluic)3(H2 O)3](NO3)*** T1 state energies are observed for ligands p-substituted with higher electron donating capacity groups,such as p-NH2 and *** contrast,higher lifetimes and quantum efficiencies are obtained for Eu3+complexes with ligands p-H and p-cH3 substituted,which are not deactivator groups.

关键词： Lanthanide Hydrazide Substituent effect Photoluminescence Europium Gadolinium

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