Calculation Strategies of Molar Ratio Based Homeopathic Dilutions and the need for Pharmaceutical Scientists' Engagement

Cellular membranes are often composed of phospholipid mixtures in which one or more components have a tendency to adopt a type II non-bilayer lipid structure such as the inverted hexagonal (H||) phase. The formation of a type II non-bilayer intermediate, the inverted lipid micel is proposed as the initial step in membrane fusion (Verkleij 1984, Siegel, 1986). In the various forms of cellular transport mediated by carrier vesicles (e.g. exocytosis, endocytosis) the regulation of membrane fusion, and hence of inverted lipid micel formation, is of vital importance.We studied the phase behaviour of simple and complex lipid mixtures by cryo-electron microscopy to gain more insight in the ultrastructure of different lipid phases (e.g. Pβ’, Lα, H||) and in the complex membrane structures arising after Lα < - > H|| phase changes (e.g. isotropic, cubic). To prepare hydrated thin films a 700 mesh hexagonal grid (without supporting film) was dipped into and withdrawn from a liposome suspension. The excess fluid was blotted against filter paper and the thin films that form between the bars of the specimen grid were immediately (within 1 second) vitrified by plunging of the carrier grids into ethane cooled to its melting point by liquid nitrogen (Dubochet et al., 1982). Surface active molecules such as phospholipids play an important role in the formation and thinning of these aqueous thin films (Frederik et al., 1989). The formation of two interfacial layers at the air-water interfaces requires transport of surface molecules from the suspension as well as the orientation of these molecules at the interfaces. During the spontaneous thinning of the film the interfaces approach each other, initially driven by capillary forces later by Van der Waals attraction. The process of thinning results in the sorting by size of the suspended material and is also accompanied by a loss of water from the thinner parts of the film. This loss of water may result in the concentration and eventually in partial dehydration of suspended material even if thin films are vitrified within 1 sec after their formation. Film formation and vitrification were initiated at temperatures between 20-60°C by placing die equipment in an incubator provided widi port holes for the necessary manipulations. Unilamellar vesicles were made from dipalmitoyl phosphatidyl choline (DPPC) by an extrusion method and showed a smooth (Lα) or a rippled (PB’.) structure depending on the temperature of the suspensions and the temperature of film formation (50°C resp. 39°C) prior to vitrification. The thermotropic phases of hydrated phospholipids are thus faithfully preserved in vitrified thin films (fig. a,b). Complex structures arose when mixtures of dioleoylphosphatidylethanol-amine (DOPE), dioleoylphosphatidylcholine (DOPC) and cholesterol (molar ratio 3/1/2) are heated and used for thin film formation. The tendency of DOPE to adopt the H|| phase is responsible for the formation of complex structures in this lipid mixture. Isotropic and cubic areas (fig. c,d) having a bilayer structure are found in coexistence with H|| cylinders (fig. e). The formation of interlamellar attachments (ILA’s) as observed in isotropic and cubic structures is also thought to be of importance in biological fusion events. Therefore the study of the fusion activity of influenza B virus with liposomes (DOPE/DOPC/cholesterol/ganglioside in a molar ratio 1/1/2/0.2) was initiated. At neutral pH only adsorption of virus to liposomes was observed whereas 2 minutes after a drop in pH (7.4 - > 5.4) fusion between virus and liposome membranes was demonstrated (fig. f). The micrographs illustrate the exciting potential of cryo-electron microscopy to study lipid-lipid and lipid-protein interactions in hydrated specimens.

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Changes in Fe 2+ /Fe 3+ molar ratio for the formation of spinel CoFe 2 O 4 layered double hydroxide nanoparticles

Micro & Nano Letters ◽

10.1049/mnl.2018.5611 ◽

2019 ◽

Vol 14 (9) ◽

pp. 937-940

Author(s):

Hesham Hamad ◽

Amal Ibrahim ◽

Mona Abd El‐latif

Keyword(s):

Layered Double Hydroxide ◽

Molar Ratio ◽

Double Hydroxide ◽

Layered Double Hydroxide Nanoparticles

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A New Method for Plasminogen Standardization

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651297 ◽

1968 ◽

Vol 20 (03/04) ◽

pp. 548-554

Author(s):

J Gajewski ◽

G Markus

Keyword(s):

Proteolytic Activity ◽

Specific Activity ◽

Molar Ratio ◽

Sharp Transition ◽

Equivalence Point ◽

Constant Amount ◽

Residual Level ◽

Activity Measurements ◽

Complete Saturation ◽

Human Plasminogen

SummaryA method for the standardization of human plasminogen is proposed, based on the stoichiometric interaction between plasminogen and streptokinase, resulting in inhibition of proteolytic activity. Activation of a constant amount of plasminogen with increasing amounts of streptokinase yields linearly decreasing activities, as a function of streptokinase, with a sharp transition to a constant residual level. The point of transition corresponds to complete saturation of plasmin with streptokinase in a 1:1 molar ratio, and is therefore a measure of the amount of plasminogen present initially, in terms of streptokinase equivalents. The equivalence point is independent of the kind of protein substrate used, buffer, pH, length of digestion and, within limits, temperature. The method, therefore, is not subject to the variations commonly encountered in the usual determination based on specific activity measurements.

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Fungicidal and Bactericidal Activity of the Alkyl-Substituted Guanidine-Containing Oligomers

Mikrobiolohichnyi Zhurnal ◽

10.15407/microbiolj82.06.054 ◽

2020 ◽

Vol 82 (6) ◽

pp. 54-63

Author(s):

M.Ya. Vortman ◽

◽

Yu.B. Pysmenna ◽

A.I. Chuenko ◽

D.R. Abdulina ◽

...

Keyword(s):

Heterotrophic Bacteria ◽

Trichoderma Viride ◽

Rhodococcus Erythropolis ◽

Biological Action ◽

Molar Ratio ◽

Diffusion Method ◽

Klebsiella Pneumonia ◽

Alkyl Bromides ◽

Base Form ◽

Two Stages

Biocides are widely used in medicine and various industries to protect against a number of harmful microorganisms. Organic quaternary ammonium and guanidine-containing compounds, the biological action of which is based on membrane-toxic properties, are used as bactericidal preparations. The aim of this work was to study the bactericidal and fungicidal activities of the synthesized oligomeric alkylsubstituted guanidinium bromides with different radicals -C3H7, -C7H15, -C10H21, against different isolates of heterotrophic bacteria and microscopic fungi. Methods. The synthesis of alkyl-substituted guanidiniumcontaining oligomers was performed in two stages. In the first stage, alkyl-substituted guanidine was obtained by the reaction of guanidine, previously converted by alkali from the salt form to the base form by the base and alkyl bromides (Alk=-C3H7 (propyl), -C7H15 (heptyl), -C10H21 (decyl)) in methanol at a temperature of 50°C and a molar ratio of 1:1. The second carried out the reaction between aromatic oligoepoxide DER-331 and alkyl-substituted guanidine in methanol at a temperature of 50°C for 2–3 hours and a molar ratio of 1:2. Bacteria were grown on meat-peptone agar for 48 hours at a temperature of 28±2°С. Test cultures of micromycetes were cultured on agar beer wort (6°B), incubated for 14 days in a thermostat at a temperature of 28±2°C. Antimicrobial activity of newly synthesized alkyl-substituted guanidinium-containing oligomers was determined by standard disco-diffusion method (method of disks on agar) and fungicidal activity was determined by the method of holes in agar. Results. Oligomeric alkylsubstituted guanidinium bromides with different radicals composed -C3H7, -C7H15, -C10H21- synthesized by the reaction of guanidine alkyl bromides with aromatic oligoepoxydes. It was found that alkyl-substituted guanidinium-containing oligomers at a concentration of 1–3% inhibited the growth of Escherichia coli 475, Pseudomonas aeruginosa 465, Klebsiella pneumonia 479, Pseudomonas pseudoalcaligenes 109, Staphylococcus aureus 451, E. faecalis 422, Rhodococcus erythropolis 102, Bacillus subtilis 138 and most of the studied micromycetes – Aureobasidium pullulans F-41430, Paecilomyces variotii F-41432, Penicillium funiculosum F-41435, Penicillium ochrochloron F-41431, Scopulariopsis brevicaulis F-41434, Trichoderma viride F-41437, Candida albicans F-41441, Aspergillus flavus F-41442, Aspergillus niger F-41448, Penicillium sp. F-41447. Conclusions. Antimicrobial and fungicidal properties significantly depend on the length of the alkyl radical, with increasing of its length the diameter of the zone of bacterial and micromycetes growth retardation increases.10.15407/microbiolj82.06.054

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On the Properties of an Ion Conductive System Incorporated in Hybrid Films

MRS Proceedings ◽

10.1557/proc-628-cc6.19 ◽

2000 ◽

Vol 628 ◽

Author(s):

G. González ◽

P. J. Retuert ◽

S. Fuentes

Keyword(s):

Electrochemical Impedance ◽

Ternary Phase Diagram ◽

Lithium Perchlorate ◽

Molar Ratio ◽

Ionic Conductors ◽

X Ray Diffraction ◽

Poly Ethylene Oxide ◽

Ion Conducting ◽

Poly Ethylene ◽

High Degree

ABSTRACTBlending the biopolymer chitosan (CHI) with poly (aminopropilsiloxane) oligomers (pAPS), and poly (ethylene oxide) (PEO) in the presence of lithium perchlorate lead to ion conducting products whose conductivity depends on the composition of the mixture. A ternary phase diagram for mixtures containing 0.2 M LiClO4 shows a zone in which the physical properties of the products - transparent, flexible, mechanically robust films - indicate a high degree of molecular compatibilization of the components. Comparison of these films with binary CHI-pAPS nanocomposites as well as the microscopic aspect, thermal behavior, and X-ray diffraction pattern of the product with the composition PEO/CHI/pAPS/LiClO4 1:0.5:0.6:0.2 molar ratio indicates that these films may be described as a layered nanocomposite. In this composite, lithium species coordinated by PEO and pAPS should be inserted into chitosan layers. Electrochemical impedance spectroscopy measurements indicate the films are pure ionic conductors with a maximal bulk conductivity of 1.7*10-5 Scm-1 at 40 °C and a sample-electrode interface capacitance of about 1.2*10-9 F.

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Quantum Dot Bioconjugates as Energy Donors in Fluorescence Resonance Energy Transfer Assays

MRS Proceedings ◽

10.1557/proc-773-n7.9 ◽

2003 ◽

Vol 773 ◽

Author(s):

Aaron R. Clapp ◽

Igor L. Medintz ◽

J. Matthew Mauro ◽

Hedi Mattoussi

Keyword(s):

Energy Transfer ◽

Quantum Dot ◽

Organic Dyes ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Genetically Engineered ◽

Molar Ratio ◽

Binding Assays ◽

Specific Sequence ◽

Donor Acceptor

AbstractLuminescent CdSe-ZnS core-shell quantum dot (QD) bioconjugates were used as energy donors in fluorescent resonance energy transfer (FRET) binding assays. The QDs were coated with saturating amounts of genetically engineered maltose binding protein (MBP) using a noncovalent immobilization process, and Cy3 organic dyes covalently attached at a specific sequence to MBP were used as energy acceptor molecules. Energy transfer efficiency was measured as a function of the MBP-Cy3/QD molar ratio for two different donor fluorescence emissions (different QD core sizes). Apparent donor-acceptor distances were determined from these FRET studies, and the measured distances are consistent with QD-protein conjugate dimensions previously determined from structural studies.

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Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

10.26434/chemrxiv.5851701 ◽

2018 ◽

Author(s):

Tasneem Siddiquee ◽

Abdul Goni

Keyword(s):

Metal Salts ◽

Molar Ratio ◽

Pincer Complexes ◽

Asymmetric Unit ◽

X Ray Diffraction ◽

Pincer Ligand ◽

Tetrahedral Geometry ◽

X Ray ◽

Distorted Tetrahedral Geometry ◽

Cobalt Center

Chemical treatment of CoX2. 6H2O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-tert-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

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Controlled Growth of the Non-centrosymmetric Zn(3-ptz)2 and Zn(Oh)(3-ptz) Metal-organic Frameworks

10.26434/chemrxiv.7588640.v1 ◽

2019 ◽

Author(s):

javier enriquez ◽

Ignacio Chi-Duran ◽

Carolina Manquian ◽

Felipe Herrera ◽

Ruben Fritz ◽

...

Keyword(s):

Single Crystal ◽

Nonlinear Optical ◽

Metal Organic Frameworks ◽

Molar Ratio ◽

Thermal Synthesis ◽

Small Crystals ◽

Alkaline Environments ◽

Potential Applications ◽

Metal Organic ◽

Long Rod

Non-centrosymmetric single-crystal metal-organic frameworks (MOF) are promising candidates for phase-matched nonlinear optical communication, but typical hydrothermal synthesis produces small crystals with relatively low transmittance and poor phase matching. We study the effect of the metal-to-ligand molar ratio and reaction pH on the hydro-thermal synthesis of the non-centrosymmetric Zn(3-ptz)2 and Zn(OH)(3-ptz) MOFs with in-situ ligand formation. In acidic environments, we find that decreasing the amount of ligand below the stoichiometric molar ratio 1:2 also produces highly transparent single-crystal octahedrons of Zn(3-ptz)2. In alkaline environments, we obtain long rod-like Zn(OH)(3-ptz) crystals whose length exceeds previous reports by up to four orders of magnitude. Potential applications of these results in the development of MOF-based nonlinear optical devices are discussed.

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Calcium pyrophosphate powder synthesized from phosphoric acid and calcium carbonate

Materials Science ◽

10.31044/1684-579x-2020-0-11-42-48 ◽

2020 ◽

pp. 42-48

Author(s):

Tatiana Safronova ◽

◽

Tatiana Shatalova ◽

Snezhana Tikhonova ◽

Yaroslav Filippov ◽

...

Keyword(s):

Calcium Carbonate ◽

Phosphoric Acid ◽

Functional Materials ◽

Bone Defects ◽

Thermal Conversion ◽

Calcium Pyrophosphate ◽

Molar Ratio

Powders of calcium pyrophosphate Ca2P2O7 in the form of γ- и β-modifications have been produced as a result of thermal conversion of brushite CaHPO4∙2H2O synthesized from phosphoric acid H3PO4 and calcium carbonate CaCO3 at the molar ratio P / Ca = 1.1. The resulting powders can be used for production of various functional materials including biocompatible and bioresorbable ones for the treatment of bone defects.

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Mango (Magnifera indica) seed oil grown in Dilla town as potential raw material for biodiesel production using NaOH- a homogeneous catalyst

10.31221/osf.io/xsq5y ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Diesel Engine ◽

Physicochemical Properties ◽

Seed Oil ◽

Methyl Esters ◽

Pollution Prevention ◽

Raw Material ◽

Biodiesel Production ◽

Molar Ratio ◽

Homogeneous Catalyst ◽

Minimal Amount

Biodiesel produced by transesterification process from vegetable oils or animal fats is viewed as a promising renewable energy source. Now a day’s diminishing of petroleum reserves in the ground and increasing environmental pollution prevention and regulations have made searching for renewable oxygenated energy sources from biomasses. Biodiesel is non-toxic, renewable, biodegradable, environmentally benign, energy efficient and diesel substituent fuel used in diesel engine which contributes minimal amount of global warming gases such as CO, CO2, SO2, NOX, unburned hydrocarbons, and particulate matters. The chemical composition of the biodiesel was examined by help of GC-MS and five fatty acid methyl esters such as methyl palmitate, methyl stearate, methyl oleate, methyl linoleate and methyl linoleneate were identified. The variables that affect the amount of biodiesel such as methanol/oil molar ratio, mass weight of catalyst and temperature were studied. In addition to this the physicochemical properties of the biodiesel such as (density, kinematic viscosity, iodine value high heating value, flash point, acidic value, saponification value, carbon residue, peroxide value and ester content) were determined and its corresponding values were 87 Kg/m3, 5.63 Mm2/s, 39.56 g I/100g oil, 42.22 MJ/Kg, 132oC, 0.12 mgKOH/g, 209.72 mgKOH/g, 0.04%wt, 12.63 meq/kg, and 92.67 wt% respectively. The results of the present study showed that all physicochemical properties lie within the ASTM and EN biodiesel standards. Therefore, mango seed oil methyl ester could be used as an alternative to diesel engine.

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