scholarly journals Application of Depletion Attraction in Mineral Flotation: I. Theory

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 451 ◽  
Author(s):  
Junhyun Choi ◽  
Gahee Kim ◽  
Sowon Choi ◽  
KyuHan Kim ◽  
Yosep Han ◽  
...  

We investigate the role of depletion interactions in the particle–bubble interactions that determine the attachment capability of particles on the bubble surface in flotation. In this article, we propose a theoretical model that explains how this attractive interaction could enhance flotation efficiency. Two optimum conditions are determined for the concentration and molecular weight of the depletion agent. The optimum concentration can be determined through the extent of surface activity of the depletion agents. The magnitude of the depletion attraction increases as the concentration increases; however, an increase in the concentration simultaneously enhances its surface concentration. The bubble surface adsorption of the depletion agent results in polymer brushes on the bubble surface that produce a large repulsive interaction. In contrast, the optimal molecular weight of the depletion agents is given by the interaction between the depletion agent sizes, which is determined by its molecular weight and Debye length which is determined by the solution ionic strength. We demonstrate that exploiting this depletion interaction could significantly enhance the flotation efficiency and in principal could be used for any particle system.

1979 ◽  
Author(s):  
P. A. Bolhuis ◽  
K. S. Sakariassen ◽  
J. J. Sixma

Platelet adhesion to human subendothelium was determined by perfusions with albumin solutions containing 51Cr-labeled, aspirin-treated platelets and washed red cells (hematocrit 40%) at 37° and a flow rate of 135 ml/min. Adherence was similar with Von Willebrand plasma instead of albumin solution and addition of purified FVIII-VWF caused adhesion similar to that from normal plasma. Incubation of subendotheliurn with FVIII-VWF resulted of binding of FVIII-VWF at the surface and in subsequent perfusions a surface concentration of, FVII-VWF/cm2 was shown to correct the platelet adhesion in albumin solutions towards normal. The kinetics of binding of FVIII-VWF and platelets to the subendothelium confirm the role of bound FVIII-VWF in adhesion. Binding of FVII-VWF occurs rapidly in the first minute of perfusion to about 4 x 10-4U/cm2 and then increases further to about 10-3 u/cm2 in 5 min. Platelet adhesion is similar for perfusates with and without FVIII-WF in the first minute; then the presence of FVIII-VWF results in a two-fold increase of adhesion at 5 min. Reduced adhesion was found with the high-molecular weight component of FVIII-VWF obtained by high iconic strength dissociation. Also, the activity of glycin precipitated FVIII-VWF (e.g. Hemofil FVIII-concentrate) is impaired, cross-electrophoresis of FVIII-VWF from cryoprecipitate and FVIII-VWF after glycin precipitation showed an increased mobility or the latter, indicating a reduced molecular siie. From these experiments we conclude tnat platelet adhesion is mediated by subendothelium-bound FVIII-WWF. The degree of adhesion may depend on the molecular weight of the FVIII-VWF.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1180
Author(s):  
Kayvan Khoramipour ◽  
Karim Chamari ◽  
Amirhosein Ahmadi Hekmatikar ◽  
Amirhosein Ziyaiyan ◽  
Shima Taherkhani ◽  
...  

Adiponectin (a protein consisting of 244 amino acids and characterized by a molecular weight of 28 kDa) is a cytokine that is secreted from adipose tissues (adipokine). Available evidence suggests that adiponectin is involved in a variety of physiological functions, molecular and cellular events, including lipid metabolism, energy regulation, immune response and inflammation, and insulin sensitivity. It has a protective effect on neurons and neural stem cells. Adiponectin levels have been reported to be negatively correlated with cancer, cardiovascular disease, and diabetes, and shown to be affected (i.e., significantly increased) by proper healthy nutrition. The present review comprehensively overviews the role of adiponectin in a range of diseases, showing that it can be used as a biomarker for diagnosing these disorders as well as a target for monitoring the effectiveness of preventive and treatment interventions.


Biosensors ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Agnes Purwidyantri ◽  
Telma Domingues ◽  
Jérôme Borme ◽  
Joana Rafaela Guerreiro ◽  
Andrey Ipatov ◽  
...  

Liquid-gated Graphene Field-Effect Transistors (GFET) are ultrasensitive bio-detection platforms carrying out the graphene’s exceptional intrinsic functionalities. Buffer and dilution factor are prevalent strategies towards the optimum performance of the GFETs. However, beyond the Debye length (λD), the role of the graphene-electrolytes’ ionic species interactions on the DNA behavior at the nanoscale interface is complicated. We studied the characteristics of the GFETs under different ionic strength, pH, and electrolyte type, e.g., phosphate buffer (PB), and phosphate buffer saline (PBS), in an automatic portable built-in system. The electrostatic gating and charge transfer phenomena were inferred from the field-effect measurements of the Dirac point position in single-layer graphene (SLG) transistors transfer curves. Results denote that λD is not the main factor governing the effective nanoscale screening environment. We observed that the longer λD was not the determining characteristic for sensitivity increment and limit of detection (LoD) as demonstrated by different types and ionic strengths of measuring buffers. In the DNA hybridization study, our findings show the role of the additional salts present in PBS, as compared to PB, in increasing graphene electron mobility, electrostatic shielding, intermolecular forces and DNA adsorption kinetics leading to an improved sensitivity.


1995 ◽  
Vol 73 (9-10) ◽  
pp. 575-592 ◽  
Author(s):  
Harish C. Pant ◽  
Veeranna

Neurofilament proteins (NFPs) are highly phosphorylated molecules in the axonal compartment of the adult nervous system. The phosphorylation of NFP is considered an important determinant of filament caliber, plasticity, and stability. This process reflects the function of NFs during the lifetime of a neuron from differentiation in the embryo through long-term activity in the adult until aging and environmental insult leads to pathology and ultimately death. NF function is modulated by phosphorylation–dephosphorylation in each of these diverse neuronal states. In this review, we have summarized some of these properties of NFP in adult nervous tissue, mostly from work in our own laboratory. Identification of sites phosphorylated in vivo in high molecular weight NFP (NF-H) and properties of NF-associated and neural-specific kinases phosphorylating specific sites in NFP are described. A model to explain the role of NF phosphorylation in determining filament caliber, plasticity, and stability is proposed.Key words: neurofilament proteins, phosphorylation, kinases, phosphatases, regulators, inhibitors, multimesic complex, domains.


2004 ◽  
Vol 78 (1) ◽  
pp. 47-50 ◽  
Author(s):  
X.-C. Long ◽  
M. Bahgat ◽  
K. Chlichlia ◽  
A. Ruppel ◽  
Y.-L. Li

AbstractSchistosoma japonicumandS. mansoniwere tested for reactivity with an anti-inducible nitric oxide (iNOS) antibody and the distribution of iNOS was studied by immunofluorescent tests in different stages of the parasites. Reactivity was associated with the tegument in both larval schistosomes (sporocysts and cercariae) and eggs. With adult worms, the majority of the immunofluorescence was predominantly subtegumental inS. japonicumand parenchymal inS. mansoni. Fluorescence was also observed in host tissues (snails and mouse liver). In Western blots, the enzyme ofS. japonicumhad an apparent molecular weight of about 210 kDa. The possible role of worm and host iNOS in the parasite–host interrelation remains to be clarified.


2010 ◽  
Vol 24 (5) ◽  
pp. 1373-1378 ◽  
Author(s):  
Juan Sun ◽  
Yan Wu ◽  
Zhuang Su ◽  
Zhifang Liu ◽  
Bingzhong Su ◽  
...  

1988 ◽  
Vol 134 ◽  
Author(s):  
Eric J. Roche

ABSTRACTRow-nucleated structures in PPTA and PBZT thin films are compared and their dependence upon quench rate and molecular weight illustrated. It is proposed that the lamellar appearance of the morphology is due to a coherent periodic twisting of fibrillar ribbons. The role of crystallosolvate phases is discussed.


2000 ◽  
Vol 275 (33) ◽  
pp. 25139-25145 ◽  
Author(s):  
David H. Ho ◽  
Karen Badellino ◽  
Frank A. Baglia ◽  
Mao-Fu Sun ◽  
Ming-Ming Zhao ◽  
...  

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