Size-dependent patterned recognition and extraction of metal ions by a macrocyclic aromatic pyridone pentamer

2014 ◽  
Vol 50 (84) ◽  
pp. 12730-12733 ◽  
Author(s):  
Jie Shen ◽  
Wenliang Ma ◽  
Lin Yu ◽  
Jin-Bo Li ◽  
Hu-Chun Tao ◽  
...  
Keyword(s):  
Metal Ions ◽  
Aqueous Phase ◽  
The Other ◽  
Size Dependent ◽  
Chloroform Layer

A macrocyclic aromatic pyridine pentamer was found to exhibit patterned recognition of metal ions and efficiently extract larger ions, such as Cs+, Ba2+, Tl+, Au+, K+ and Rb+ preferentially over the other 18 smaller metal ions from the aqueous phase into the chloroform layer.

scholarly journals A rapid procedure for selectively isolating the major glycoprotein from purified rat brain myelin

1977 ◽  
Vol 163 (3) ◽  
pp. 635-637 ◽  
Author(s):  
R H Quarles ◽  
C F Pasnak
Keyword(s):  
Rat Brain ◽  
Aqueous Phase ◽  
The Other ◽  
Insoluble Residue ◽  
Rapid Procedure ◽  
Myelin Associated Glycoprotein ◽  
Chloroform Methanol

Treatment of the chloroform/methanol-insoluble residue of rat brain myelin with lithium 3,5-di-iodosalicylate solubilized the major myelin-associated glycoprotein along with most other proteins and glycoproteins. Equilibration of the extract with phenol resulted in the selective partitioning of the major glycoprotein into the aqueous phase, whereas nearly all of the other proteins and glycoproteins went into the phenol phase.

scholarly journals The role of transition metal ions on HO<sub>x</sub> radicals in clouds: a numerical evaluation of its impact on multiphase chemistry

2004 ◽  
Vol 4 (1) ◽  
pp. 95-110 ◽  
Author(s):  
L. Deguillaume ◽  
M. Leriche ◽  
A. Monod ◽  
N. Chaumerliac
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Aqueous Phase ◽  
Numerical Evaluation ◽  
Transition Metal Ions ◽  
Cloud Chemistry ◽  
Sensitivity Tests ◽  
Fe Speciation ◽  
Deposition Processes

Abstract. A new modelling study of the role of transition metal ions on cloud chemistry has been performed. Developments of the Model of Multiphase Cloud Chemistry (M2C2; Leriche et al., 2001) are described, including the transition metal ions reactivity emission/deposition processes and variable photolysis in the aqueous phase. The model is then applied to three summertime scenarios under urban, remote and marine conditions, described by Ervens et al. (2003). Chemical regimes in clouds are analyzed to understand the role of transition metal ions on cloud chemistry and especially, on HxOy chemistry, which consequently influences the sulphur and the VOCs chemistry in droplets. The ratio of Fe(II)/Fe(III) exhibits a diurnal variation with values in agreement with the available measurements of Fe speciation. In the urban case, sensitivity tests with and without TMI chemistry, show an enhancement of OH concentration in the aqueous phase when TMI chemistry is considered.

Donor-acceptor Stenhouse Adducts with Three Orthogonally Controlled Intrisic Stationary States

2020 ◽  
Author(s):  
Yongli Duan ◽  
Haiquan Zhao ◽  
GuoDong Xue ◽  
Ze Wang ◽  
Chaoyue Xiong ◽  
...  
Keyword(s):  
Crown Ether ◽  
Metal Ions ◽  
Smart Materials ◽  
Green Light ◽  
Supramolecular Structures ◽  
The Other ◽  
Van Der Waals Interactions ◽  
Stationary States ◽  
Complex Stimuli ◽  
Donor Acceptor

Abstract Photoresponsive molecules with more than two intrinsic stationary states are very Interesting. Here, we demonstrate a series of crown ether (CE) substituted donor-acceptor Stenhouse adducts (DASAs) that can be switched between three stationary states under orthogonal control of light and metal ions. DASA-CE molecules are self-assembled into 1:1 head-to-tail supramolecular structures to form di-linear states due to strong van der Waals interactions between electron-donating and -withdrawing moieties. Furthermore, treatment with metal ions (Na+ or K+) switches the di-linear back to the linear state, which is reversible after adding free crown ether. On the other hand, green light irradiation induces linear-to-cyclic isomerization of DASA-CE, while the photoisomerization from di-linear to cyclic state is inhibited. The reverse cyclic-to-linear isomerization can occur under heating in the dark. All in all, the orthogonal switching of DASA-CE between di-linear, linear and cyclic states enables the development of smart materials in environments with complex stimuli.

FREEZING DAMAGE TO BOVINE CREAM INDICATED BY RELEASE OF ENZYMES

1959 ◽  
Vol 37 (7) ◽  
pp. 821-827 ◽  
Author(s):  
L. J. N. Cole ◽  
D. Kluepfel ◽  
C. V. Lusena
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Xanthine Oxidase ◽  
Aqueous Phase ◽  
The Other ◽  
Rapid Freezing ◽  
Freezing Damage ◽  
Membrane Material ◽  
Fat Globules ◽  
Main Effect

When washed cream was frozen slowly and thawed, some breaking of the emulsion occurred and on centrifugation a pellet, mostly membrane material, was obtained. Xanthine oxidase and alkaline phosphatase were present in this pellet, but little enzyme activity was found in the aqueous phase. The main effect of slow freezing was to force the fat globules together so that alteration and redistribution of the membranes could occur, and, on thawing, fat could coalesce. Rapid freezing on the other hand distributed fat globules more evenly so that less coalescence could occur on thawing.

scholarly journals Perch Selection by Three Cooccurring Species ofCelithemis(Odonata: Libellulidae): Testing for a Competitive Hierarchy among Similar Species

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wade B. Worthen ◽  
Parker H. Morrow
Keyword(s):  
Body Size ◽  
Niche Partitioning ◽  
Open Water ◽  
The Other ◽  
Similar Species ◽  
Male Body ◽  
Size Dependent ◽  
Anatomical Characters ◽  
Relative Abundances ◽  
Imagej Software

In many communities of perching dragonflies (Odonata: Libellulidae), a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species:Celithemis elisa,C. fasciata, andC. ornata.Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing.Celithemis fasciatawas significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the largeC. fasciatawas attacked less frequently, and the smallC. ornatamore frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.

FREEZING DAMAGE TO BOVINE CREAM INDICATED BY RELEASE OF ENZYMES

1959 ◽  
Vol 37 (1) ◽  
pp. 821-827 ◽  
Author(s):  
L. J. N. Cole ◽  
D. Kluepfel ◽  
C. V. Lusena
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Xanthine Oxidase ◽  
Aqueous Phase ◽  
The Other ◽  
Rapid Freezing ◽  
Freezing Damage ◽  
Membrane Material ◽  
Fat Globules ◽  
Main Effect

When washed cream was frozen slowly and thawed, some breaking of the emulsion occurred and on centrifugation a pellet, mostly membrane material, was obtained. Xanthine oxidase and alkaline phosphatase were present in this pellet, but little enzyme activity was found in the aqueous phase. The main effect of slow freezing was to force the fat globules together so that alteration and redistribution of the membranes could occur, and, on thawing, fat could coalesce. Rapid freezing on the other hand distributed fat globules more evenly so that less coalescence could occur on thawing.

LINGCOD MUSCLE PHOSPHOMONOESTERASES: I. ACID PHOSPHATASES THAT HYDROLYZEp-NITROPHENYL PHOSPHATE

1960 ◽  
Vol 38 (1) ◽  
pp. 605-612 ◽  
Author(s):  
Neil Tomlinson ◽  
R. A. J. Warren
Keyword(s):  
Metal Ions ◽  
The Other ◽  
Acid Phosphatases ◽  
Free Base ◽  
Ph Optimum ◽  
Ophiodon Elongatus ◽  
Nitrophenyl Phosphate ◽  
Diethylaminoethyl Cellulose ◽  
Ph Range ◽  
Acid Phosphomonoesterase

Five fractions (A to E), each possessing acid phosphomonoesterase activity, were separated from an aqueous extract of the muscle of lingcod (Ophiodon elongatus) by stepwise chromatography on diethylaminoethyl cellulose in the free-base form.Fraction A required Zn++or Mn++for activity, was inhibited by heparin, and had its pH optimum at 6.0. Fraction E required Zn++for activity, was not inhibited by heparin, and had its pH optimum at 5.5. Fractions B, C, and D did not require metal ions for activity, and were distinguished from each other by differences in response to pH, cysteine, ethylenediaminetetraacetate, fluoride, and tartrate.The pH range over which fraction A was active was shifted to slightly higher values when Mn++was the activator rather than Zn++. Also, A was inhibited strongly by cysteine when activated by Zn++, but not when activated by Mn++. Data are presented that indicate these differences were due to different properties of the activating ions, rather than to the presence in fraction A of two enzymes, one activated by Zn++and the other by Mn++.

scholarly journals A Process for the Separation of Noble Metals from HCl Liquor Containing Gold(III), Palladium(II), Platinum(IV), Rhodium(III), and Iridium(IV) by Solvent Extraction

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 243 ◽  
Author(s):  
Wei Dong Xing ◽  
Man Seung Lee
Keyword(s):  
Solvent Extraction ◽  
Metal Ions ◽  
Noble Metals ◽  
The Other ◽  
Secondary Resources ◽  
Cyanex 272 ◽  
Leaching Solution ◽  
Hcl Concentration ◽  
Hcl Solution ◽  
Excellent Chemical

The demand for noble metals is increasing, owing to their excellent chemical and physical properties. In order to meet the demand, the recovery of noble metals with high purity from diverse secondary resources, which contain small amounts of noble metals, is of immense value. In this work, the possibility of the separation of Au(III), Pd(II), Pt(IV), Rh(III), and Ir(IV) by solvent extraction from a synthetic HCl solution is investigated. Only Au(III) was selectively extracted by Cyanex 272 in the HCl concentration range from 0.5 M to 9 M, leaving the other metal ions in the raffinate. The loaded Au(III) in Cyanex 272 was efficiently stripped by (NH2)2CS. The other four noble metals were sequentially separated on the basis of the procedures reported in the previous work. The mass balance showed that about 98% of each metal, except Pt(IV), was recovered by the proposed process. An efficient process for the recovery of the five noble metal ions from the HCl leaching solution of secondary resources containing these metals can be developed.

scholarly journals Metal Ions in Activated Carbon Improve the Detection Efficiency of Aflatoxin-Producing Fungi

Toxins ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 140 ◽  
Author(s):  
Tadahiro Suzuki ◽  
Masatoshi Toyoda
Keyword(s):  
Activated Carbon ◽  
Metal Ions ◽  
Detection Efficiency ◽  
Trace Element Analysis ◽  
The Other ◽  
Dependent Manner ◽  
Element Analysis ◽  
Concentration Dependent Manner ◽  
Key Factor ◽  
Co Addition

Aflatoxins (AF), produced by several Aspergillus species, are visible under ultraviolet light if present in high amounts. AF detection can be improved by adding activated carbon, which enhances the observation efficiency of weakly AF-producing fungi. However, commercial activated carbon products differ in their characteristics, making it necessary to investigate which characteristics affect method reproducibility. Herein, the addition of 10 activated carbon products resulted in different AF production rates in each case. The differences in the production of aflatoxin G1 (AFG1) were roughly correlated to the observation efficiency in the plate culture. Trace element analysis showed that the concentrations of several metal ions differed by factors of >100, and the carbons that most effectively increased AFG1 production contained higher amounts of metal ions. Adding 5 mg L−1 Fe or Mg ions increased AFG1 production even without activated carbon. Furthermore, co-addition of both ions increased AFG1 production stably with the addition of carbon. When varying the concentration of additives, only AFG1 production increased in a concentration-dependent manner, while the production of all the other AFs decreased or remained unchanged. These findings suggest that a key factor influencing AF production is the concentration of several metal ions in activated carbon and that increasing AFG1 production improves AF detectability.

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