scholarly journals Response of Freshwater Biofilms to Antibiotic Florfenicol and Ofloxacin Stress: Role of Extracellular Polymeric Substances

2019 ◽  
Vol 16 (5) ◽  
pp. 715 ◽  
Author(s):  
Chaoqian Wang ◽  
Deming Dong ◽  
Liwen Zhang ◽  
Ziwei Song ◽  
Xiuyi Hua ◽  
...  
Keyword(s):  
Natural Waters ◽  
Extracellular Polymeric Substances ◽  
Life Forms ◽  
Biological Properties ◽  
Distribution Coefficients ◽  
Antibiotic Residues ◽  
Low Concentrations ◽  
Veterinary Antibiotic ◽  
Freshwater Biofilms

Antibiotic residues have been detected in aquatic environments worldwide. Biofilms are one of the most successful life forms, and as a result are ubiquitous in natural waters. However, the response mechanism of freshwater biofilms to the stress of various antibiotic residues is still unclear. Here, the stress of veterinary antibiotic florfenicol (FF) and fluoroquinolone antibiotic ofloxacin (OFL) on freshwater biofilms were investigated by determining the changes in the key physicochemical and biological properties of the biofilms. The results showed that the chlorophyll a content in biofilms firstly decreased to 46–71% and then recovered to original content under the stress of FF and OFL with high, mid, and low concentrations. Meanwhile, the activities of antioxidant enzymes, including superoxide dismutase and catalase, increased between 1.3–6.7 times their initial values. FF was more toxic to the biofilms than OFL. The distribution coefficients of FF and OFL binding in extracellular polymeric substances (EPS)-free biofilms were 3.2 and 6.5 times higher than those in intact biofilms, respectively. It indicated that EPS could inhibit the FF and OFL accumulation in biofilm cells. The present study shows that the EPS matrix, as the house of freshwater biofilms, is the primary barrier that resists the stress from antibiotic residues.

Testosterone Potentiation of Ionophore and ADP Induced Platelet Aggregation : Relationship to Arachidonic Acid Metabolism

1981 ◽  
Vol 46 (02) ◽  
pp. 538-542 ◽  
Author(s):  
R Pilo ◽  
D Aharony ◽  
A Raz
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Unsaturated Fatty Acids ◽  
Human Platelet ◽  
Platelet Rich Plasma ◽  
Arachidonic Acid Metabolism ◽  
Ionophore A23187 ◽  
Low Concentrations ◽  
Induced Aggregation

SummaryThe role of arachidonic acid oxygenated products in human platelet aggregation induced by the ionophore A23187 was investigated. The ionophore produced an increased release of both saturated and unsaturated fatty acids and a concomitant increased formation of TxA2 and other arachidonate products. TxA2 (and possibly other cyclo oxygenase products) appears to have a significant role in ionophore-induced aggregation only when low concentrations (<1 μM) of the ionophore are employed.Testosterone added to rat or human platelet-rich plasma (PRP) was shown previously to potentiate platelet aggregation induced by ADP, adrenaline, collagen and arachidonic acid (1, 2). We show that testosterone also potentiates ionophore induced aggregation in washed platelets and in PRP. This potentiation was dose and time dependent and resulted from increased lipolysis and concomitant generation of TxA2 and other prostaglandin products. The testosterone potentiating effect was abolished by preincubation of the platelets with indomethacin.

Integrated interrelationship of sewage sludges with absorbing complex of river Miass drainage area

2014 ◽  
Vol 9 (4) ◽  
pp. 441-444
Author(s):  
Y. A. Dzhenis ◽  
I. I. Tuber
Keyword(s):  
Heavy Metals ◽  
Natural Waters ◽  
Drainage Area ◽  
Sewage Sludges

Soil is a powerful and active absorber of many substances, assumes the pressure of industrial and municipal emissions and waste, and performs the important role of a buffer and a detoxicant. It accumulates heavy metals, pesticides, hydrocarbons and other chemical polluting substances and due to the soil absorbing complex (SAC) strongly captures and protects natural waters and the atmosphere from harm. Applying sewage sludges in our research will enable us to strengthen the capacity of SAC and to reduce the toxicity of heavy metals when they enter a reservoir via a drain from anthropogenically polluted territory.

Green synthesis of silver nanoparticles using sustainable resources and their use as antibacterial agents: A review

2020 ◽  
Vol 13 ◽  
Author(s):  
Kumari Jyoti ◽  
Punyasloka Pattnaik ◽  
Tej Singh
Keyword(s):  
Silver Nanoparticles ◽  
Plant Extracts ◽  
Metallic Nanoparticles ◽  
Cost Effective ◽  
Biological Properties ◽  
Metal Species ◽  
Sustainable Resources ◽  
Research Areas ◽  
Low Toxicity

Background:: Synthesis of metallic nanoparticles has attracted extensive vitality in numerous research areas such as drug delivery, biomedicine, catalysis etc. where continuous efforts are being made by scientists and engineers to investigate new dimensions for both technological and industrial advancements. Amongst numerous metallic nanoparticles, silver nanoparticle (AgNPs) is a novel metal species with low toxicity, higher stability and significant chemical, physical and biological properties. Methods:: In this, various methods for the fabrication of AgNPs are summarized. Importantly, we concentrated on the role of reducing agents of different plants parts, various working conditions such as AgNO3 concentration; ratio of AgNO3/extract; incubation time; centrifugal conditions, size and shapes. Results:: This study suggested that eco-friendly and non toxic biomolecules present in the extracts (e.g. leaf, stem and root) of plants are used as reducing and capping agents for silver nanoparticles fabrication. This method of fabrication of silver nanoparticles using plants extracts is comparatively cost-effective and simple. A silver salt is simply reduced by biomolecules present in the extracts of these plants. In this review, we have emphasized the synthesis and antibacterial potential of silver nanoparticles using various plant extracts. Conclusion:: Fabrication of silver nanoparticles using plant extracts have advantage over the other physical methods, as it is safe, eco-friendly and simple to use. Plants have huge potential for the fabrication of silver nanoparticles of wide potential of applications with desired shape and size.

Physical and Biological Properties and Principles

2018 ◽  
Keyword(s):  
Biological Properties ◽  
Animal Locomotion ◽  
The Media ◽  
Key Dimensions ◽  
Scaling Analyses ◽  
Physical Principles

Studies of animal locomotion are grounded in an understanding of the physical principles that govern how animals move and properties of the media through which they move. These studies, in turn, explain why certain biological devices, such as a wing or a fin, share features that have evolved for movement within their particular fluid environments. In this chapter, we examine the role of the environment and the fundamentals of loading and forces in animal mechanics. We offer a quick review of scaling analyses as well as the key dimensions and units used in this book to assist with your appreciation of the information.

scholarly journals Tocopherols and Tocotrienols—Bioactive Dietary Compounds; What Is Certain, What Is Doubt?

2021 ◽  
Vol 22 (12) ◽  
pp. 6222
Author(s):  
Kacper Szewczyk ◽  
Aleksandra Chojnacka ◽  
Magdalena Górnicka
Keyword(s):  
Vitamin E ◽  
Metabolic Disorders ◽  
Tissue Concentration ◽  
Biological Properties ◽  
Biological Role ◽  
Future Research ◽  
The Past ◽  
The Subject ◽  
The Relationship

Tocopherols and tocotrienols are natural compounds of plant origin, available in the nature. They are supplied in various amounts in a diet, mainly from vegetable oils, some oilseeds, and nuts. The main forms in the diet are α- and γ-tocopherol, due to the highest content in food products. Nevertheless, α-tocopherol is the main form of vitamin E with the highest tissue concentration. The α- forms of both tocopherols and tocotrienols are considered as the most metabolically active. Currently, research results indicate also a greater antioxidant potential of tocotrienols than tocopherols. Moreover, the biological role of vitamin E metabolites have received increasing interest. The aim of this review is to update the knowledge of tocopherol and tocotrienol bioactivity, with a particular focus on their bioavailability, distribution, and metabolism determinants in humans. Almost one hundred years after the start of research on α-tocopherol, its biological properties are still under investigation. For several decades, researchers’ interest in the biological importance of other forms of vitamin E has also been growing. Some of the functions, for instance the antioxidant functions of α- and γ-tocopherols, have been confirmed in humans, while others, such as the relationship with metabolic disorders, are still under investigation. Some studies, which analyzed the biological role and mechanisms of tocopherols and tocotrienols over the past few years described new and even unexpected cellular and molecular properties that will be the subject of future research.

scholarly journals Comparison of the Influence of 45S5 and Cu-Containing 45S5 Bioactive Glass (BG) on the Biological Properties of Novel Polyhydroxyalkanoate (PHA)/BG Composites

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2607 ◽  
Author(s):  
Katharina Schuhladen ◽  
Barbara Lukasiewicz ◽  
Pooja Basnett ◽  
Ipsita Roy ◽  
Aldo R. Boccaccini
Keyword(s):  
Tissue Engineering ◽  
Cell Biology ◽  
Inorganic Compounds ◽  
Release Kinetics ◽  
Biological Properties ◽  
Long Term Effects ◽  
Salt Leaching ◽  
Low Concentrations ◽  
A Minor ◽  
Hard Tissue Engineering

Polyhydroxyalkanoates (PHAs), due to their biodegradable and biocompatible nature and their ability to be formed in complex structures, are excellent candidates for fabricating scaffolds used in tissue engineering. By introducing inorganic compounds, such as bioactive glasses (BGs), the bioactive properties of PHAs can be further improved. In addition to their outstanding bioactivity, BGs can be additionally doped with biological ions, which in turn extend the functionality of the BG-PHA composite. Here, different PHAs were combined with 45S5 BG, which was additionally doped with copper in order to introduce antibacterial and angiogenic properties. The resulting composite was used to produce scaffolds by the salt leaching technique. By performing indirect cell biology tests using stromal cells, a dose-depending effect of the dissolution products released from the BG-PHA scaffolds could be found. In low concentrations, no toxic effect was found. Moreover, in higher concentrations, a minor reduction of cell viability combined with a major increase in VEGF release was measured. This result indicates that the fabricated composite scaffolds are suitable candidates for applications in soft and hard tissue engineering. However, more in-depth studies are necessary to fully understand the release kinetics and the resulting long-term effects of the BG-PHA composites.

The role of Fe(II) species on the oxidation of Fe(II) in natural waters in the presence of O2 and H2O2

2006 ◽  
Vol 99 (1-4) ◽  
pp. 70-82 ◽  
Author(s):  
J.M. Santana-Casiano ◽  
M. González-Dávila ◽  
F.J. Millero
Keyword(s):  
Natural Waters

scholarly journals Impaired platelet responses to thrombin and collagen in AKT-1–deficient mice

Blood ◽  
2004 ◽  
Vol 104 (6) ◽  
pp. 1703-1710 ◽  
Author(s):  
Juhua Chen ◽  
Sarmishtha De ◽  
Derek S. Damron ◽  
William S. Chen ◽  
Nissim Hay ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Dense Granules ◽  
Fibrinogen Binding ◽  
Downstream Effectors ◽  
Low Concentrations ◽  
Phosphoinositide 3 Kinase ◽  
Deficient Mice ◽  
Granule Release

Abstract We investigated the role of Akt-1, one of the major downstream effectors of phosphoinositide 3-kinase (PI3K), in platelet function using mice in which the gene for Akt-1 had been inactivated. Using ex vivo techniques, we showed that Akt-1-deficient mice exhibited impaired platelet aggregation and spreading in response to various agonists. These differences were most apparent in platelets activated with low concentrations of thrombin. Although Akt-1 is not the predominant Akt isoform in mouse platelets, its absence diminished the amount of total phospho-Akt and inhibited increases in intracellular Ca2+ concentration in response to thrombin. Moreover, thrombin-induced platelet α-granule release as well as release of adenosine triphosphate from dense granules was also defective in Akt-1-null platelets. Although the absence of Akt-1 did not influence expression of the major platelet receptors for thrombin and collagen, fibrinogen binding in response to these agonists was significantly reduced. As a consequence of impaired αIIbβ3 activation and platelet aggregation, Akt-1 null mice showed significantly longer bleeding times than wild-type mice. (Blood. 2004;104:1703-1710)

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