scholarly journals Functionalization of orange waste with phosphoric group for Anion separation

2013 ◽  
Vol 29 ◽  
pp. 110-112
Author(s):  
Kedar Nath Ghimire

A novel adsorbent, Phosphorylated Orange Juice Residue, POJR, has been investigated. The extent of phosphorylation was measured with the aid of fluorescence X-ray crystallography, which indicates that the degree of phosphorylation is 1.2. The POJR has very high binding affinity for ferric ion. Also bound ferric ions selectively adsorb anions like arsenite, arsenate, selenite, selenate, antimonate and phosphate.DOI: http://dx.doi.org/10.3126/jncs.v29i0.9275Journal of Nepal Chemical Society Vol. 29, 2012 Page: 110-112 Uploaded date: 12/6/2013 

Soft Matter ◽  
2020 ◽  
Vol 16 (47) ◽  
pp. 10750-10758
Author(s):  
Yingchun Han ◽  
Xinyue Zhao ◽  
Yonggang Liu ◽  
Yunqi Li ◽  
Quan Chen

In this study, we investigate the conformational evolution and phase behavior of poly(acrylic acid) (PAA) solution upon the introduction of ferric ions through combining of small angle X-ray scattering (SAXS), turbidity, ζ-potential and pH measurements.


1989 ◽  
Vol 44 (9) ◽  
pp. 1093-1101 ◽  
Author(s):  
Karl Wieghardt ◽  
Stefan Drüeke ◽  
Phalguni Chaudhuri ◽  
Ulrich Flörke ◽  
Hans-Jürgen Haupt ◽  
...  

The reaction of LFeCl3 (L = N,N′,N″-trimethyl-1,4,7-triazacyclononane) with Na2SO4, Na2SO3/NaClO4, and Na2SeO3/NaClO4 in aqueous solution affords the binuclear oxo bridged complexes [L2Fe2(μ-Ο)(μ-SΟ4)2]·3Η2Ο (1), [L2Fe2(μ-O)(μ-SO3)2]·5/3NaClO4·(H2O)3.67 (2), [L2Fe2(μ-O)(μ-SeO3)2](NaClO4)2.75·5H2O (3). The reaction of LFeCl3 in dry methanol with Na2SO4 yields yellow crystals of [L2Fe2(μ-SO4)3] · 2 H2O (4). The crystal structures of 1 and 2 have been determined by X-ray crystallography. Crystals of 1, 2, and 3 consist of neutral, binuclear μ-oxo bridged diiron(III) complexes which contain two additional O,O′-coordinated sulfato, sulfito, and selenito bridging ligands, respectively. The high spin ferric ions in 1, 2, and 3 are strongly intramolecularly antiferromagnetically spin exchange coupled with J values of —97(1), -104(2), and —104(2) cm-1 (H = —2JŜ,·Ŝ2, S1 = S2 = 5/2), respectively. 4 contains three μ-sulfato bridges between two FeIII ions. Only a very weak antiferromagnetic coupling has been detected (J = —5.5(5) cm-1). Complex 1 serves as a model compound for the diiron(III) complex of the sulfate treated, oxidized form of the biomolecule uteroferrin.


Author(s):  
Ryuichi Kato ◽  
Masahiko Hiraki ◽  
Yusuke Yamada ◽  
Mikio Tanabe ◽  
Toshiya Senda

In 2003, a fully automated protein crystallization and monitoring system (PXS) was developed to support the structural genomics projects that were initiated in the early 2000s. In PXS, crystallization plates were automatically set up using the vapor-diffusion method, transferred to incubators and automatically observed according to a pre-set schedule. The captured images of each crystallization drop could be monitored through the internet using a web browser. While the screening throughput of PXS was very high, the demands of users have gradually changed over the ensuing years. To study difficult proteins, it has become important to screen crystallization conditions using small amounts of proteins. Moreover, membrane proteins have become one of the main targets for X-ray crystallography. Therefore, to meet the evolving demands of users, PXS was upgraded to PXS2. In PXS2, the minimum volume of the dispenser is reduced to 0.1 µl to minimize the amount of sample, and the resolution of the captured images is increased to five million pixels in order to observe small crystallization drops in detail. In addition to the 20°C incubators, a 4°C incubator was installed in PXS2 because crystallization results may vary with temperature. To support membrane-protein crystallization, PXS2 includes a procedure for the bicelle method. In addition, the system supports a lipidic cubic phase (LCP) method that uses a film sandwich plate and that was specifically designed for PXS2. These improvements expand the applicability of PXS2, reducing the bottleneck of X-ray protein crystallography.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 599
Author(s):  
Yanping Niu ◽  
Ya Li ◽  
Haoran Sun ◽  
Chuanyao Sun ◽  
Wanzhong Yin ◽  
...  

Ferric ions produced during grinding influence the flotation separation between kyanite and quartz adversely. In this study, citric acid was used as a regulator to eliminate the effect of ferric ions on the separation of kyanite from quartz with sodium oleate (NaOL) as a collector. The microflotation test results indicated that the quartz was selectively activated by FeCl3 and maintained significant quartz recovery. However, the citric acid could selectively eliminate the effect of ferric ions on the quartz and minimally influenced the kyanite. Contact angle tests demonstrated that FeCl3 significantly increased the interaction between NaOL and quartz, resulting in the high hydrophobicity of quartz, and the addition of citric acid made the quartz surface hydrophilic again but slightly influenced the kyanite. Fourier-transform infrared spectroscopy showed that FeCl3 facilitated NaOL adsorption onto the quartz surface, and the addition of citric acid eliminated the activation of FeCl3 on the quartz, resulting in the nonadsorption of NaOL onto the quartz surface. However, the FeCl3 and citric acid exhibited a negligible effect on NaOL adsorption onto the kyanite surface. X-ray photoelectron spectroscopy analysis indicated that the citric acid eliminated FeCl3 activation on the quartz.


Author(s):  
Jules S. Jaffe ◽  
Robert M. Glaeser

Although difference Fourier techniques are standard in X-ray crystallography it has only been very recently that electron crystallographers have been able to take advantage of this method. We have combined a high resolution data set for frozen glucose embedded Purple Membrane (PM) with a data set collected from PM prepared in the frozen hydrated state in order to visualize any differences in structure due to the different methods of preparation. The increased contrast between protein-ice versus protein-glucose may prove to be an advantage of the frozen hydrated technique for visualizing those parts of bacteriorhodopsin that are embedded in glucose. In addition, surface groups of the protein may be disordered in glucose and ordered in the frozen state. The sensitivity of the difference Fourier technique to small changes in structure provides an ideal method for testing this hypothesis.


Author(s):  
S. Cusack ◽  
J.-C. Jésior

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).


Author(s):  
Robert A. Grant ◽  
Laura L. Degn ◽  
Wah Chiu ◽  
John Robinson

Proteolytic digestion of the immunoglobulin IgG with papain cleaves the molecule into an antigen binding fragment, Fab, and a compliment binding fragment, Fc. Structures of intact immunoglobulin, Fab and Fc from various sources have been solved by X-ray crystallography. Rabbit Fc can be crystallized as thin platelets suitable for high resolution electron microscopy. The structure of rabbit Fc can be expected to be similar to the known structure of human Fc, making it an ideal specimen for comparing the X-ray and electron crystallographic techniques and for the application of the molecular replacement technique to electron crystallography. Thin protein crystals embedded in ice diffract to high resolution. A low resolution image of a frozen, hydrated crystal can be expected to have a better contrast than a glucose embedded crystal due to the larger density difference between protein and ice compared to protein and glucose. For these reasons we are using an ice embedding technique to prepare the rabbit Fc crystals for molecular structure analysis by electron microscopy.


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