482 research outputs found
Development of an efficient method for isolation and purification of bioactive Compounds from panax ginseng and rhodiola rosea using high performance counter current chromatography
No full textThis Thesis was submitted for the degree of Master of Philosophy and awarded by Brunel University.Traditional Chinese medicine has developed for several thousands of years and accumulated an abundant amount of human pharmacological information and experience as a large potential resource in drug discovery and development. Panax ginseng C. A. Meyer and Rhodiola rosea are both popular herbs worldwide and have many potential pharmacological effects including adaptogenic, antistress, and vasodilating, anticancer and anti-inflammatory. To improve the isolation and separation effect of the two traditional Chinese herbs for quantity and quality control herbal products in general, Separation and purification techniques using high performance counter-current chromatography (HPCCC) are widely applied for this purpose. High performance counter-current chromatography (HPCCC) is a form of liquid liquid chromatography with the higher “g” ” field, which the Brunel Institute for Bioengineering (BIB) team have developed to process scale. It would provide not only more rapid and high throughout isolation and purification process of crude sample, but also relatively simply volumetric and linear scale-up between all scales instruments. A rapid and convenient method for the separation and purification of five ginsenosides from crude sample of Panax ginseng by high-performance counter-current chromatography was successfully developed. One gradient method in normal phase mode was applied for the first separation step for the isolation of ginsenosides using a Spectrum CCC (73 ml coil volume, 1.6 mm bore) with an EtOAc/BuOH/aqueous 5mM ammonium acetate solvent system. The composition ratio of mobile phase changed from 3.5:0.5:4 (v/v) to 2.5:1.5:4 (v/v). Ginsenosides Rd, Rg1 and Rb1 were separated in less than 120 minutes with purities of 96.3% and 98.6% yield, 88.5% and 95.8% yield, 93.7% and 97.4% yield respectively and ginsenosides Rb2 and Rb3, Re and Rc were co-eluted. The final retention of stationary phase was 77.6%. Methylene chloride/methanol/aqueous 5mM ammonium acetate/isopropanol (6:3:4:3, v/v/v) solvent system was used for the isocratic separation of ginsenosides Re and Rc in the second separation step. The ginsenosides Rb2 and Rb3 have similar structures and properties as they are isomers and their aglycone moieties both belong to the same 20 (S) – protopanaxadiol. They were difficult to isolate using this solvent system. The purity of ginsenosides Re and Rc was assessed by HPLC–DAD to be 97.5% with 98.2% recovery and 92.6% with 96.3% recovery. These purified ginsenosides was identified using commercial reference standard on the HPLC and MS.A simple and efficient high-performance counter-current chromatography method for the simultaneous separation and purification for quantity and quality of the two biological compounds salidroside and tyrosol from Rhodiola rosea extract has been developed and scale up for the first time. The experiment were conducted initially by sample concentration, sample loading volume and flow rate study at analytical scale using a Mini HPCCC (17.7 ml coil, 0.8 mm bore) with a new MTBE/butanol /ACN/water (4:2:4:10 v/v/v) solvent system. Then linearly scaled up to the Midi-HPCCC (923 ml coil volume, 4.0 mm bore). Midi-HPCCC runs produced 28.2mg (purity 93%) of salidroside and 13.1mg (purity 96.5%) of tyrosol from the 1000mg crude Rhodiola rosea extract. with the throughput scaled up 50 times. The results demonstrate that HPCCC operating at the high flow and high “g” field is a reliable strategy for linear scale-up from analytical-scale high-throughput screening to preparative-scale
A tücsök meg a hangyák
No full textThis children's book is composed of seven thick boards bound together. On the cover a grasshopper with moustache sits on a mushroom playing his fiddle as a row of ants marches by carrying or rolling food and an ant-baby. The next pages expand on their labors. They include a cut-out portion that looks past their hill to the flowers. On the following pages ants continue their workline while, I believe, young grasshoppers dance about and the older grasshopper continues to fiddle. Succeeding pages show more ant work, including carrying off a dead or exhausted ant on a stretcher. And we see lots of grasshopper fiddlers while other ants push carts full of food, both by day and by night. Soon there are rains and snows, and an ant finds the grasshopper lying next to his fiddle on the ground. The ants take him in, feed him, and dance to his music. I believe it is typical of the East Block countries that a Hungarian book was executed in Czechoslovakia. Might there have been a Czech original?Language note: Hungaria
It is not magic, it is smith: Comparison in a study of Jewish theology
No full textIn a search for a theoretical framework that would structure and orient a comparative analysis of diverse Jewish theological responses to the Holocaust, the author reached for J.Z. Smith’s discussions of comparative enterprise. The questions of similarity, difference and of the putative goal of comparison loomed large over her project. In J.Z. Smith’s work, the author found helpful clues, illuminating insights as well as somewhat confusing and counterintuitive examples
It is not magic, it is smith: Comparison in a study of Jewish theology
No full textIn a search for a theoretical framework that would structure and orient a comparative analysis of diverse Jewish theological responses to the Holocaust, the author reached for J.Z. Smith’s discussions of comparative enterprise. The questions of similarity, difference and of the putative goal of comparison loomed large over her project. In J.Z. Smith’s work, the author found helpful clues, illuminating insights as well as somewhat confusing and counterintuitive examples.acceptedVersion© 2019. This is the authors' accepted and refereed manuscript. Locked until 12 February 2021 due to copyright restrictions. The final authenticated version is available online at: https://doi.org/10.1163/15700682-12341460
Direct coherent multi-ink printing of fabric supercapacitors
No full textCoaxial fiber-shaped supercapacitors with short charge carrier diffusion paths are highly desirable as high-performance energy storage devices for wearable electronics. However, the traditional approaches based on the multistep fabrication processes for constructing the fiber-shaped energy device still encounter persistent restrictions in fabrication procedure, scalability, and mechanical durability. To overcome this critical challenge, an all-in-one coaxial fiber-shaped asymmetric supercapacitor (FASC) device is realized by a direct coherent multi-ink writing three-dimensional printing technology via designing the internal structure of the coaxial needles and regulating the rheological property and the feed rates of the multi-ink. Benefitting from the compact coaxial structure, the FASC device delivers a superior areal energy/power density at a high mass loading, and outstanding mechanical stability. As a conceptual exhibition for system integration, the FASC device is integrated with mechanical units and pressure sensor to realize high-performance self-powered mechanical devices and monitoring systems, respectively.Published versionThis work was funded by the Science and Technology Development Fund, Macau SAR (file nos. 0057/2019/A1 and 0092/2019/A2), the startup grant from Fuzhou University, and the National Nature Science Foundation of China (grant no. 21875040). Author contributions: Y.T., X.C., and J.P. proposed and supervised this project. J.Z., H.L., Yan Zhang, and S.Y. designed the experiments and wrote the manuscript. O.I.M. and X.Z. contributed to the writing of the manuscript. L.W., H.W., X.L., Yanyan Zhang, S.C., and H.P. participated in analyzing and G.X. and C.L. in discussing the experimental results
Embedding of rank two supercharges in the superconformal algebra
No full textFunding Information: P.D.A. acknowledges MINEDUC-UA Project ANT 1755 and Semillero de Investigacion Project SEM18-02 from Universidad de Antofagasta, Chile. J.Z. was partially supported by Fondecyt/ANID-Chile through Grant No. 1180368. Publisher Copyright: © 2022 Author(s).We discuss an embedding of su(n) rank two antisymmetric supercharges in the su(2, 2|dn) superalgebra, where dn = n(n - 1)/2. We describe an algorithm to construct the explicit form of the generators of the superalgebra
Schaeffer est mort! Long live Schaeffer!
No full textThis paper examines two groups of composers and discusses the commonality in their approach to using concrete sound materials and rhythm in their works. As a result of this commonality an examination of the ways in which these composers have expanded the electroacoustic language through the hybridisation of electronica and musique concrete techniques is undertaken. It will then be demonstrated how these works, whilst pushing at the boundaries of electroacoustic music can nevertheless be discussed and analysed with reference to Emmerson’s language grid as originally proposed in The Relation of Language to Materials (1986: 17-39). It will be demonstrated how, with the advent of the sampler and proliferation of works utilizing concrete materials, Emmerson’s language grid can be used as the basis for a wider discussion of electronic works
Nanometer-Scale Lateral p–n Junctions in Graphene/α-RuCl3 Heterostructures
No full text[EN] The ability to create nanometer-scale lateral p-n junctions is essential for the next generation of two-dimensional (2D) devices. Using the charge-transfer heterostructure graphene/alpha-RuCl3, we realize nanoscale lateral p-n junctions in the vicinity of graphene nanobubbles. Our multipronged experimental approach incorporates scanning tunneling microscopy (STM) and spectroscopy (STS) and scattering-type scanning near-field optical microscopy (s-SNOM) to simultaneously probe the electronic and optical responses of nanobubble p-n junctions. Our STM/STS results reveal that p-n junctions with a band offset of 0.6 eV can be achieved with widths of 3 nm, giving rise to electric fields of order 108 V/m. Concurrent s-SNOM measurements validate a point-scatterer formalism for modeling the interaction of surface plasmon polaritons (SPPs) with nanobubbles. Ab initio density functional theory (DFT) calculations corroborate our experimental data and reveal the dependence of charge transfer on layer separation. Our study provides experimental and conceptual foundations for generating p-n nanojunctions in 2D materials.Research at Columbia University was supported as part of the Energy Frontier Research Center on Programmable Quantum Materials funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0019443. Plasmonic nano-imaging at Columbia University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), under Award No DE-SC0018426. J.Z. and A.R. were supported by the European Research Council (ERC-2015-AdG694097), the Cluster of Excellence “Advanced Imaging of Matter” (AIM) EXC 2056-390715994, funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under RTG 2247, Grupos Consolidados (IT1249-19), and SFB925 “Light induced dynamics and control of correlated quantum systems”. J.Z. and A.R. would like to acknowledge Nicolas Tancogne-Dejean and Lede Xian for fruitful discussions and also acknowledge support by the Max Planck Institute-New York City Center for Non-Equilibrium Quantum Phenomena. The Flatiron Institute is a division of the Simons Foundation. J.Z. acknowledges funding received from the European Union Horizon 2020 research and innovation programme under Marie Skłodowska-Curie Grant Agreement 886291 (PeSD-NeSL). STM support was provided by the National Science Foundation via Grant DMR-2004691. C.R.-V. acknowledges funding from the European Union Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement 844271. D.G.M. acknowledges support from the Gordon and Betty Moore Foundation’s EPiQS Initiative, Grant GBMF9069. J.Q.Y. was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. S.E.N. acknowledges support from the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Division of Scientific User Facilities. Work at University of Tennessee was supported by NSF Grant 180896
Zimmerman - Leander M. Zimmerman
No full textA.B.; A.M., 1887; Phi Beta Kappa; Philomathaean. Entered Preparatory, 1878. Grad. Gettysburg Seminary, 1887; D.D., Susquehanna U., 1901. Born Aug. 29, 1860, or August 22, 1861, Manchester, Md. Parents, Henry and Leah. Brother of J.Z., class of 1873. Lutheran clergyman: Baltimore, Md., 1887-1925; pastor-emeritus, Christ Church, Baltimore, Md., 1925- . Member, Home Miss. Bd., 1899-1908; pres. of Deaconess Bd.; past pres. of Md. Synod; director, Gettysburg Seminary, 1909- ; past pres., Baltimore Min. Assoc. Author: Paths That Cross; Yvonne; Sparks; Cordelia; Dot; Echoes from Battlefield; For Love's Sake; Reminiscences; The Gospel Minister; and many booklets on social and religious subjects. Address: Burlington Hotel, Washington D.C
Crystalline Whispering Gallery Mode Resonators for Quantum and Nonlinear Optics
No full textThis work describes a series of projects and technology developments aimed at the realization of a solid-state photonic-ionic trap for quantum optics experiments. The projects however, are not constrained to this goal and explore the fields of nonlinear optics and fabrication techniques.
Fabri-Perot resonators have transformed the optical technology and can be found in many devices that utilize laser radiation. Whispering gallery mode resonators (WGMR) are relatively new elements and have such advantages as compactness, highest optical quality factors, and relative ease of fabrication. Small optical mode volume and long storage times allow record low thresholds of various nonlinear processes. Raman and Brillouin lasing, second and third harmonic generation, parametric oscillations and four wave mixing have all been enhanced in WGM resonators. Compared to glass microspheres, crystalline WGM resonators have higher nonlinear coefficients, may not be sensitive to water vapor, and have generally higher purity leading to record optical quality (Q) factors. Zero phonon lines of ions in crystals enable applications in cavity QED with single ions.
A novel application of diamond turning to fabrication of axially symmetric crystalline optical resonators is described. This technique enabled crystalline WGM microresonators, multiple resonators coupled via the evanescent field, and a single mode resonator. Crystalline resonators having a record high optical Q of 1011 were demonstrated. Fundamental limits of the Q factor were investigated and Q=1015 was predicted at cryogenic temperatures. Record low threshold and high efficiency of stimulated Raman and Brillouin scattering led to the first observations of these effects in crystalline cavities. Brillouin and Raman lasers based on WGM resonators are expected to have very narrow linewidth. A cryogenic setup was developed that allowed observation of WG modes at low temperatures. Crystalline cavity was used as a reference for narrowing a linewidth of a commercial diode laser with a Pound-Drever-Hall technique for the first time. A device based on a fused silica WGMR was used to generate beams with large angular momenta. In addition, a Fabri-Perot cavity was used to sense thermal expansion of mirrors to derive thermal expansion and temperature conductivity of thin optical coatings.</p
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