scholarly journals Nanomotion Spectroscopy as a New Approach to Characterize Bacterial Virulence

2021 ◽  
Vol 9 (8) ◽  
pp. 1545
Author(s):  
Maria I. Villalba ◽  
Leonardo Venturelli ◽  
Ronnie Willaert ◽  
Maria E. Vela ◽  
Osvaldo Yantorno ◽  
...  
Keyword(s):  
Medical Information ◽  
Whooping Cough ◽  
Model Organism ◽  
Chemical Properties ◽  
Movement Pattern ◽  
Time Frame ◽  
Label Free ◽  
Physical Chemical ◽  
Afm Cantilever ◽  
Living Organisms

Atomic force microscopy (AFM)-based nanomotion detection is a label-free technique that has been used to monitor the response of microorganisms to antibiotics in a time frame of minutes. The method consists of attaching living organisms onto an AFM cantilever and in monitoring its nanometric scale oscillations as a function of different physical-chemical stimuli. Up to now, we only used the cantilever oscillations variance signal to assess the viability of the attached organisms. In this contribution, we demonstrate that a more precise analysis of the motion pattern of the cantilever can unveil relevant medical information about bacterial phenotype. We used B. pertussis as the model organism, it is a slowly growing Gram-negative bacteria which is the agent of whooping cough. It was previously demonstrated that B. pertussis can expresses different phenotypes as a function of the physical-chemical properties of the environment. In this contribution, we highlight that B. pertussis generates a cantilever movement pattern that depends on its phenotype. More precisely, we noticed that nanometric scale oscillations of B. pertussis can be correlated with the virulence state of the bacteria. The results indicate a correlation between metabolic/virulent bacterial states and bacterial nanomotion pattern and paves the way to novel rapid and label-free pathogenic microorganism detection assays.

The physical-chemical environment of microbes

2018 ◽  
Author(s):  
David L. Kirchman
Keyword(s):  
Reynolds Number ◽  
Low Reynolds Number ◽  
Chemical Properties ◽  
Physical World ◽  
Chemical Environment ◽  
Viscous Forces ◽  
Physical Chemical ◽  
Terrestrial Habitats ◽  
Low Reynolds ◽  
Living Organisms

Many physical-chemical properties affecting microbes are familiar to ecologists examining large organisms in our visible world. This chapter starts by reviewing the basics of these properties, such as the importance of water for microbes in soils and temperature in all environments. Another important property, pH, has direct effects on organisms and indirect effects via how hydrogen ions determine the chemical form of key molecules and compounds in nature. Oxygen content is also critical, as it is essential to the survival of all but a few eukaryotes. Light is used as an energy source by phototrophs, but it can have deleterious effects on microbes. In addition to these familiar factors, the small size of microbes sets limits on their physical world. Microbes are said to live in a “low Reynolds number environment”. When the Reynolds number is smaller than about one, viscous forces dominate over inertial forces. For a macroscopic organism like us, moving in a low Reynolds number environment would seem like swimming in molasses. Microbes in both aquatic and terrestrial habitats live in a low Reynolds number world, one of many similarities between the two environments at the microbial scale. Most notably, even soil microbes live in an aqueous world, albeit a thin film of water on soil particles. But the soil environment is much more heterogeneous than water, with profound consequences for biogeochemical processes and interactions among microbes. The chapter ends with a discussion of how the physical-chemical environment of microbes in biofilms is quite different from that of free-living organisms.

Chlorinated Organics in Nearshore Waters and Tributaries of the St. Clair River

1986 ◽  
Vol 21 (3) ◽  
pp. 344-350 ◽  
Author(s):  
Barry G. Oliver ◽  
Klaus L.E. Kaiser
Keyword(s):  
United States ◽  
Suspended Sediment ◽  
Waste Disposal ◽  
Large Volume ◽  
Water Samples ◽  
Chemical Properties ◽  
Low Level ◽  
Chemical Company ◽  
Physical Chemical ◽  
The Individual

Abstract The concent rat ions of hexachloroethane (HCE), hexachlorobutadiene (HCBD), pentachlorobenzene (QCB), hexachlorobenzene (HCB) and octachlorostyrene (OCS) in large volume water samples show that the major sources of these chemicals to the St. Clair River are Dow Chemical Company effluents and, to a lesser degree, Sarnia’s Township ditch which drains one of Dow’s waste disposal sites. Tributaries entering the river on both sides of the Canada/United States border contain measurable concentrations of these chemicals indicating low level contamination throughout the area. The degree of water/suspended sediment partitioning of the chemicals (Kp) was studied. Kp values for the individual chemicals changed in a manner consistent with changes in their physical-chemical properties.

Polymer-Graphene Nanoassemblies and their Applications in Cancer Theranostics

2020 ◽  
Vol 20 (11) ◽  
pp. 1340-1351 ◽  
Author(s):  
Ponnurengam M. Sivakumar ◽  
Matin Islami ◽  
Ali Zarrabi ◽  
Arezoo Khosravi ◽  
Shohreh Peimanfard
Keyword(s):  
Mechanical Stability ◽  
Chemical Properties ◽  
The Other ◽  
Hydrophilic Polymer ◽  
Two Dimensional ◽  
Normal Tissues ◽  
Physical Chemical ◽  
Anti Cancer ◽  
Good Biocompatibility ◽  
Cancer Theranostics

Background and objective: Graphene-based nanomaterials have received increasing attention due to their unique physical-chemical properties including two-dimensional planar structure, large surface area, chemical and mechanical stability, superconductivity and good biocompatibility. On the other hand, graphene-based nanomaterials have been explored as theranostics agents, the combination of therapeutics and diagnostics. In recent years, grafting hydrophilic polymer moieties have been introduced as an efficient approach to improve the properties of graphene-based nanomaterials and obtain new nanoassemblies for cancer therapy. Methods and results: This review would illustrate biodistribution, cellular uptake and toxicity of polymergraphene nanoassemblies and summarize part of successes achieved in cancer treatment using such nanoassemblies. Conclusion: The observations showed successful targeting functionality of the polymer-GO conjugations and demonstrated a reduction of the side effects of anti-cancer drugs for normal tissues.

scholarly journals Metal Binding Proteins

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 261-292
Author(s):  
Eugene A. Permyakov
Keyword(s):  
Metal Ions ◽  
Metal Binding ◽  
Transition Metal Ions ◽  
Short Review ◽  
Sodium Potassium ◽  
Physical Chemical ◽  
Physiological Properties ◽  
Cell Processes ◽  
Living Organisms ◽  
Potassium Magnesium

Metal ions play several major roles in proteins: structural, regulatory, and enzymatic. The binding of some metal ions increase stability of proteins or protein domains. Some metal ions can regulate various cell processes being first, second, or third messengers. Some metal ions, especially transition metal ions, take part in catalysis in many enzymes. From ten to twelve metals are vitally important for activity of living organisms: sodium, potassium, magnesium, calcium, manganese, iron, cobalt, zinc, nickel, vanadium, molybdenum, and tungsten. This short review is devoted to structural, physical, chemical, and physiological properties of proteins, which specifically bind these metal cations.

scholarly journals Shellfish Chitosan Potential in Wine Clarification

2021 ◽  
Vol 11 (10) ◽  
pp. 4417
Author(s):  
Veronica Vendramin ◽  
Gaia Spinato ◽  
Simone Vincenzi
Keyword(s):  
Molecular Structure ◽  
Chemical Properties ◽  
Allergic Reactions ◽  
Chitin Content ◽  
Deacetylation Degree ◽  
Physical Chemical ◽  
Similar Chemical ◽  
Fungal Chitosan ◽  
Significant Difference ◽  
Fish Industry

Chitosan is a chitin-derived fiber, extracted from the shellfish shells, a by-product of the fish industry, or from fungi grown in bioreactors. In oenology, it is used for the control of Brettanomyces spp., for the prevention of ferric, copper, and protein casse and for clarification. The International Organisation of Vine and Wine established the exclusive utilization of fungal chitosan to avoid the eventuality of allergic reactions. This work focuses on the differences between two chitosan categories, fungal and animal chitosan, characterizing several samples in terms of chitin content and degree of deacetylation. In addition, different acids were used to dissolve chitosans, and their effect on viscosity and on the efficacy in wine clarification were observed. The results demonstrated that even if fungal and animal chitosans shared similar chemical properties (deacetylation degree and chitin content), they showed different viscosity depending on their molecular weight but also on the acid used to dissolve them. A significant difference was discovered on their fining properties, as animal chitosans showed a faster and greater sedimentation compared to the fungal ones, independently from the acid used for their dissolution. This suggests that physical–chemical differences in the molecular structure occur between the two chitosan categories and that this significantly affects their technologic (oenological) properties.

scholarly journals Electrospinning: A promising technique for drug delivery systems

2020 ◽  
Vol 59 (1) ◽  
pp. 441-454
Author(s):  
Carlos A. Martínez-Pérez
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Chemical Properties ◽  
Delivery Systems ◽  
Extrinsic Factor ◽  
Promising Technique ◽  
Physical Chemical ◽  
Set Up ◽  
Final System ◽  
Intense Research

AbstractIn the last years, electrospinning has become a technique of intense research to design and fabricate drug delivery systems (DDS), during this time a vast variety of DDS with mainly electrospun polymers and many different active ingredient(s) have been developed, many intrinsic and extrinsic factor have influence in the final system, there are those that can be attributed to the equipment set up and that to the physical-chemical properties of the used materials in the fabrication of DDS. After all, this intense research has generated a great amount of DDS loaded with one or more drugs. In this manuscript a review with the highlights of different kind of systems for drug delivery systems is presented, it includes the basic concepts of electrospinning, types of equipment set up, polymer/drug systems, limitations and challenges that need to be overcome for clinical applications.

Variability in soil physical–chemical properties along the root-explored profile in deep Oxisols of commercial eucalypt plantations

2021 ◽  
Vol 494 ◽  
pp. 119334
Author(s):  
Vinicius Evangelista Silva ◽  
Thiago Assis Rodrigues Nogueira ◽  
Cassio Hamilton Abreu-Junior ◽  
Arun Dilipkumar Jani ◽  
Salatier Buzetti ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Physical Chemical ◽  
Eucalypt Plantations

scholarly journals Insights in Behavior of Variably Formulated Alginate-Based Microcapsules for Cell Transplantation

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Pia Montanucci ◽  
Silvia Terenzi ◽  
Claudio Santi ◽  
Ilaria Pennoni ◽  
Vittorio Bini ◽  
...  
Keyword(s):  
Divalent Cations ◽  
Chemical Properties ◽  
Live Cells ◽  
High Performing ◽  
Physical Chemical ◽  
Degenerative Disorders ◽  
Selection Of ◽  
Better Than

Alginate-based microencapsulation of live cells may offer the opportunity to treat chronic and degenerative disorders. So far, a thorough assessment of physical-chemical behavior of alginate-based microbeads remains cloudy. A disputed issue is which divalent cation to choose for a high performing alginate gelling process. Having selected, in our system, high mannuronic (M) enriched alginates, we studied different gelling cations and their combinations to determine their eventual influence on physical-chemical properties of the final microcapsules preparation,in vitroandin vivo. We have shown that used of ultrapure alginate allows for high biocompatibility of the formed microcapsules, regardless of gelation agents, while use of different gelling cations is associated with corresponding variable effects on the capsules’ basic architecture, as originally reported in this work. However, only the final application which the capsules are destined to will ultimately guide the selection of the ideal, specific gelling divalent cations, since in principle there are no capsules that are better than others.

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