Enhanced water permeability and rejection of As(Ⅲ) in groundwater by nanochannels and active center formed in nanofibrillated celluloses UF membranes with ZIF-8

This study aimed to examine the impact of membrane properties on membrane fouling in membrane bioreactor (MBR). Membrane fouling was divided into two categories: physically reversible and irreversible fouling. Membrane properties related to each type of membrane fouling were investigated separately. Five microfiltration (MF) and one ultrafiltration (UF) membranes with different properties (pore size, contact angle, roughness, zeta potential, and pure water permeability) were examined with a laboratory-scale MBR, fed with synthetic wastewater. Two separate experiments were conducted: the first to examine physically reversible fouling, and the second to examine physically irreversible fouling. The correlation between the degree of each type of fouling and membrane properties was studied. High correlation was observed between the degree of physically reversible fouling and roughness (R2=0.96). In contrast, with regard to physically irreversible fouling, strong correlation between roughness and degree of membrane fouling can only be found in the case of MF membranes. Except for the membrane with the highest roughness, the degree of physically irreversible fouling can be well correlated with pure water permeability (lower pure water permeability results in higher degree of physically irreversible fouling) including UF membrane. On the basis of the results obtained in this study, it can be concluded that roughness is an important factor in determination of physically reversible fouling regardless of the types of membrane (i.e. MF or UF membranes) and evolutions of physically irreversible fouling can be mitigated when an MBR is operated with membranes with smooth surface and high pure water permeability.

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Kinetic Study of the Effect of Heparin on the Amidase Activity of Trypsin, Plasmin and Urokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657362 ◽

1983 ◽

Vol 49 (03) ◽

pp. 199-203 ◽

Cited By ~ 10

Author(s):

V M Yomtova ◽

N A Stambolieva ◽

B M Blagoev

Keyword(s):

Kinetic Study ◽

Active Center ◽

Simultaneous Presence ◽

Amidase Activity ◽

Competitive Inhibitors ◽

Uncompetitive Inhibitor

SummaryIt was found that the effect of heparin on the amidase activity of urokinase (E C 3.4.21.31), plasmin (E C 3.4.21.7) and trypsin (E C 3.4.21.4) depended on the substrate used. No effect of heparin on the amidase activity of urokinase and trypsin was observed when Pyro Glu-Gly-Arg-p-nitroanilide (S-2444) and α-N-acetyl-L-lysine-p-nitroanilide (ALNA) were used as substrates. Heparin acted as a uncompetitive inhibitor of trypsin (Ki = 1.2×10-6 M), plasmin (Ki = 4.9×10-6 M) and urokinase (Ki = l.0×10-7 M) when Bz-Phe-Val-Arg-p-nitroanilide (S-2160), H-D-Val-Leu-Lys-p-nitroanilide (S-2251) and plasminogen, respectively, were used as substrates. These results, as well as the data obtained by studying the effect of the simultaneous presence of heparin and competitive inhibitors suggest that although heparin is not bound at the active center of these enzymes, it may influence the effectivity of catalysis.

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Influence of Rock-Fracture and Water Permeability of Outburst-Prone Coal Bed on its Site Development through the Wells of Hydro-Separation from the Surface

Occupational Safety in Industry ◽

10.24000/0409-2961-2017-5-8-16 ◽

2017 ◽

pp. 8-16

Author(s):

Yu.M. Biryukov ◽

Keyword(s):

Water Permeability ◽

Rock Fracture ◽

Coal Bed ◽

Site Development

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Matrix metalloproteinases: structure, functions and genetic polymorphism

Nauchno-prakticheskii zhurnal «Patogenez» ◽

10.25557/gm.2017.2.7297 ◽

2017 ◽

pp. 14-23

Author(s):

А.С. Шадрина ◽

И.В. Терешкина ◽

Я.З. Плиева ◽

Д.Н. Кушлинский ◽

Д.О. Уткин ◽

...

Keyword(s):

Genetic Polymorphism ◽

Matrix Metalloproteinases ◽

Active Center ◽

Human Body ◽

Enzymatic Catalysis ◽

Structure Functions ◽

Zinc Ion ◽

Etiological Factors ◽

Mmp Genes

Матриксные металлопротеиназы (ММП) - ферменты класса гидролаз, осуществляющие ферментативный катализ с помощью связанного в активном центре иона цинка. Функции ММП разнообразны, и нарушение баланса их активности может быть одним из этиологических факторов различных заболеваний. В данном обзоре рассмотрена классификация ММП человека, особенности их структуры и регуляции, а также роль в физиологических и патологических процессах в организме человека. Приведен перечень наиболее изученных на настоящий момент полиморфных вариантов генов MMП, описаны их функциональные эффекты и представлены результаты ассоциативных исследований. Matrix metalloproteinases (MMPs) are enzymes of the hydrolase class that carry out enzymatic catalysis with the help of a zinc ion bound in the active center. MMP functions are diverse, and a disturbance in the balance of their activity may be one of the etiological factors of various diseases. In this review, the classification of human MMP, the features of their structure and regulation, as well as the role in physiological and pathological processes in the human body are considered. A list of the most studied polymorphic versions of MMP genes has been given, their functional effects have been described, and the results of associative studies have been presented.

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