scholarly journals The high dilution phenomenon, yours to discover!

Author(s):  
Carlos Renato Zacharias
Keyword(s):  
Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 293
Author(s):  
Agustín Blazquez-Martín ◽  
Ester Verde-Sesto ◽  
Angel J. Moreno ◽  
Arantxa Arbe ◽  
Juan Colmenero ◽  
...  

The folding of certain proteins (e.g., enzymes) into perfectly defined 3D conformations via multi-orthogonal interactions is critical to their function. Concerning synthetic polymers chains, the “folding” of individual polymer chains at high dilution via intra-chain interactions leads to so-called single-chain nanoparticles (SCNPs). This review article describes the advances carried out in recent years in the folding of single polymer chains into discrete SCNPs via multi-orthogonal interactions using different reactive chemical species where intra-chain bonding only occurs between groups of the same species. First, we summarize results from computer simulations of multi-orthogonally folded SCNPs. Next, we comprehensively review multi-orthogonally folded SCNPs synthesized via either non-covalent bonds or covalent interactions. Finally, we conclude by summarizing recent research about multi-orthogonally folded SCNPs prepared through both reversible (dynamic) and permanent bonds.


1970 ◽  
Vol 48 (16) ◽  
pp. 2509-2511 ◽  
Author(s):  
Brian J. Johnson ◽  
Donna S. Rea

The synthesis of the tetrapeptide, N-t-butoxycarbonyl-ε-N-carbobenzoxy-L-lysylglycyl-ε-N-carbobenzoxy-L-lysylglycine 4-(methylthio)phenyl ester is described. The utility of this protective ester is shown by its easy conversion to the protected tetrapeptide 4-(methylsulfonyl)phenyl activated ester without decomposition. Removal of the N-butoxycarbonyl protecting group afforded the polymerizing unit, ε-N-carbobenzoxy-L-lysylglycyl-ε-N-carbobenzoxy-L-lysylglycine 4-(methylsulfonyl)phenyl ester. Polymerization of this material on the partially blocked monomer glycine-1-C14 ethyl ester hydrochloride, at a relatively high dilution, gave poly-(ε-N-carbobenzoxyl-L-lysylglycyl)glycine-1-C14 ethyl ester. The carbobenzoxy protective groups were removed to give the title compound.


1985 ◽  
Vol 63 (7) ◽  
pp. 1568-1571 ◽  
Author(s):  
Hubert Daoust ◽  
Hoa Le Thanh ◽  
Pierre Ferland ◽  
Daniel St-Cyr

Heat capacities of polyelectrolytes in aqueous solutions have been measured at 25 °C using a Picker-type dynamic micro-calorimeter. The precision of the apparatus is such that it is possible to calculate the apparent molar heat capacity [Formula: see text] of the solute, even at high dilution. The polymers that were studied include polymethacrylic acid (PMAH) and polyacrylic acid (PAH), as well as its sodium salt and the sodium salt of the polystyrènesulfonate. For the salts, the results show that the value of [Formula: see text] decreases rapidly with dilution to low concentrations; this result is in perfect concordance with a relation derived from the theory of Lifson and Katchalsky. A study of the variation of [Formula: see text] at a constant concentration, with the extent of the neutralization of the acids PMAH and PAH has also been conducted. As has been shown previously, the chain of the PMAH undergoes a conformational transformation when the level of neutralization gets close to 25%. This transformation implies an increase of the value of [Formula: see text] [Journal translation]


2021 ◽  
Vol 10 (36) ◽  
pp. 215-217
Author(s):  
Eduardo Costa Gaia Nazareth ◽  
Francisco José De Freitas

Introduction: The knowledge and use of the venom of Bothrops jararaca in high dilutions is still quite limited. One of the important properties is the use of one of its components, bradykinin, for the development of antihypertensive medication known as captopril. Other situations, such as clinical, local and systemic should receive more depth to the composition of Materia Medica related to various medical actions on the man and mammals in general. The systemic action of the bite of this snake, includes hemostasis disorders, culminating as bleeding gums, in addition to sweating, hypertension, and hypothermia. The action includes local pain and swelling with bruising, bleeding and often blistering and tissue necrosis. The action on the immune system, through action on the complement C3 and other complement components may show its possible use in cases of bacterial infections, including mycobacteria, as presented in the study of 1970 Vanessa Birdsey, "Interactions of poisons toxic with the addition, "the journal of Immunology 1971. Today, this poison has a toxicology published by Anibal Melgarejo, "Venomous Animals of Brazil", 2003, which subsidizes the development of study for its use in high dilutions, and a comprehensive study of the biology of the animal itself. Published studies on biomolecular analysis add more details about the relations of the poison and mammals. All these characteristics suggest the use of poison as a homeopathic remedy. Objective: To investigate the therapeutic possibilities in high dilutions of the venom of the snake Bothrops jararaca, expanding its clinical use. Methodology: Methodological description of this poison in contemporary bases including: Origin, physical description chemistry, toxicology, pharmacology and medicine in preparation of high dilution, general action, specific actions on systems or organs, sensations, modalities, concomitants, etiological indications relations main clinics. Results: Defining the therapeutic indications such as modulation of the complement system, action on the cardiovascular system, among other uses, by Bothrops jararaca in high dilution. Conclusion: This evaluation can be used for different sources of products and allows the rational use of Bothrops jararaca in high dilution. The results can and should be complemented by clinical studies and pathogenetic. Bacterial infectious diseases such as tuberculosis and leprosy, and autoimmune disease LES and may receive treatment studies with the drug based on Bothrops jararaca snake venom because they are indirectly associated with them via similarity of the failure of complement, an important marker for bacterial the defense of mammals. Action on clinical aspects like hypertension, sweating, hypothermia and necrosis shall be seen. Perhaps the search for the stimulation of complement show a new pathway for the harmonization, long-predicted by Hahnemann, Hering and searched for among the many that followed the creator of this therapy.


2007 ◽  
Vol 14 (5) ◽  
pp. 301-305 ◽  
Author(s):  
Daniele Nani ◽  
Maurizio Brizzi ◽  
Lisa Lazzarato ◽  
Lucietta Betti

1918 ◽  
Vol 27 (3) ◽  
pp. 443-447 ◽  
Author(s):  
Harold L. Amoss

Suspensions of the central nervous tissues of monkeys, containing the active filterable virus of poliomyelitis, may be injected into the brain of rabbits without setting up symptoms, provided the volume of injection does not cause dangerous increased intracranial pressure. Aside from the pressure effects which develop quickly, no other symptoms or pathological lesions are produced by the suspensions. The active virus of poliomyelitis survives in the brain of rabbits for 4 days, as determined by tests in the monkey, into which the excised site of injection in the rabbit brain is reinoculated. It cannot be detected by this test after the expiration of 7 days. The virus of poliomyelitis is unadapted to the rabbit, and neither induces lesions nor survives long in the central nervous organs of that animal. In this respect it differs from certain streptococci cultivated from poliomyelitic tissues. A monkey immunized to streptococcus cultivated from human poliomyelitic nervous tissues yielded a serum which agglutinated the streptococcus in high dilution, but was without neutralizing action on the filtered virus; and the streptococcus-immune monkey was not protected against the effects of an intracerebral inoculation of the filtered virus. The experiments recorded provide additional reasons for concluding that the streptococcus cultivated from cases of poliomyelitis differs essentially from the filterable virus and is not the microbic cause of epidemic poliomyelitis.


Author(s):  
Matthew James ◽  
Teresa Melfi ◽  
Rajeev Katiyar

Current requirements for high strength pipelines are placing extreme demands on welding consumables. These applications include strain based pipelines using X80 as well as traditionally designed pipelines using X100 and even X120 base materials. Traditional procedures used in the pipemills for both the seam weld and the jointer weld utilize a SAW process with very high dilution and high heat inputs. Existing consumables are not able to meet the minimum strength requirements under these conditions. A project was undertaken to develop an alloy system that could meet these requirements while still allowing the use of traditional welding processes. Testing results with this new consumable are presented and future work is described. This alloy system may also prove useful in other high dilution applications where high strength is required.


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