scholarly journals Possibilities of preparation and storage of standard histamine solutions

2016 ◽  
Vol 13 (1) ◽  
pp. 23-26
Author(s):  
A S Prylutskyi ◽  
K Ye Tkachenko ◽  
Yu D Rogovaia ◽  
N B Abylgazinova
Keyword(s):  
Biological Activity ◽  
Membrane Filtration ◽  
Skin Prick Testing ◽  
Histamine Dihydrochloride ◽  
Low Concentrations ◽  
Repeated Freezing ◽  
Skin Prick Tests ◽  
The Stability ◽  
Comparison Of The Results ◽  
And Storage

Background. To explore the stability of histamine solutions of low concentrations sterilized by autoclaving and filtration as well as the possibilities of storage and use of these solutions after 1-fold and 5-fold freezing and defrosting. Methods. Histamine dihydrochloride solutions at a concentration of 10 μg/ml were sterilized by the membrane filtration or the autoclaving at 121 °C for 30 minutes. The solutions were frozen in sterile insulin syringes, followed by 1- and 5-fold defrosting. Skin prick tests have been performed with the resulting solutions. Results. When comparing the results of skin prick testing performed with autoclaved and sterilized by the filtration histamine, no statistically significant differences were found (p>0,05). Comparison of the results of skin prick tests performed with histamine that hadn't been frozen before, after 1- and 5-fold freezing and defrosting showed no statistically significant differences (p>0,05). Conclusion. It has been shown that histamine solutions sterilized by autoclaving at 121 °C for 30 minutes followed by repeated freezing and defrosting don’t change their biological activity substantially.

Assessment of Staphylococcus Bacteria in Hawaii's Marine Recreational Waters

1993 ◽  
Vol 27 (3-4) ◽  
pp. 283-289 ◽  
Author(s):  
Naowarut Charoenca ◽  
Roger S. Fujioka
Keyword(s):  
Membrane Filtration ◽  
Antibiotic Sensitivity ◽  
Marine Waters ◽  
Recreational Waters ◽  
Filtration Method ◽  
Phage Types ◽  
Low Concentrations ◽  
Agar Media ◽  
Staphylococcal Skin Infections ◽  
The Stability

Several media to specifically recover staphylococcus from marine recreational waters in Hawaii were evaluated. The membrane filtration method using Vogel-Johnson and Tellurite Glycine Agar media supplemented with 0.005% sodium azide were shown to quantitatively recover total staphylococcus and S. aureus from marine recreational waters. Beaches in Hawaii were determined to contain high or low concentrations of staphylococci based on Favero's proposed standard of 100 staphylococci/100 ml as the maximum allowable concentration. Statistical analysis of the data showed that levels of total staphylococci were significantly correlated with that of S. aureus and with swimmer density. Staphylococci were recovered from beach waters throughout the day, including evening hours, indicating the stability of these bacteria in marine waters. Moreover, the antibiotic sensitivity patterns and phage types of S. aureus isolates from marine waters and from clinical human skin cultures were similar. These results support the hypothesis that recreational waters can serve as vehicles for the transmission of staphylococcal skin infections.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Preparation, Stabilization and Some Properties of Purified Human Plasmin*

1964 ◽  
Vol 11 (01) ◽  
pp. 075-084 ◽  
Author(s):  
Daniel L Kline ◽  
Jacob B Fishman ◽  
Keyword(s):  
Plasminogen Activator ◽  
Stable Form ◽  
Neutral Ph ◽  
The Stability ◽  
And Storage

Summary1. Lysine increased the solubility, decreased the SK requirement and increased the stability of plasmin prepared from purified plasminogen by SK activation.2. A procedure is presented for the rapid and quantitative conversion of plasminogen to plasmin and storage of the plasmin in stable form at neutral pH as a lyophilized powder.3. Approximately 10% for the plasminogen molecule was split off during its activation. No carbohydrate was lost.4. The plasmin isolated was homogeneous in the ultracentrifuge at pH 2.5 and was quantitatively convertible to plasminogen activator by the addition of SK.

Synthesis and Biological Evaluation of Various New Substituted 1,3,4-oxadiazole-2-thiols

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Gabriela Laura Almajan ◽  
Stefania Felicia Barbuceanu ◽  
Ioana Saramet ◽  
Mihaela Dinu ◽  
Cristian Vasile Doicin ◽  
...  
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Biological Evaluation ◽  
Ethyl Chloroacetate ◽  
Low Concentrations ◽  
Synthesis And Biological Evaluation

5-[4-(4X-phenylsulfonyl)phenyl]-1,3,4-oxadiazole-2-thiols, X=H, Cl, Br, reacted with ethyl chloroacetate to give S-alkylated compounds. Aminomethylation of the thione form of oxadiazoles yielded N(3)-derivatives. All the products have been characterized by elemental analysis, IR, 1H-NMR and 13C-NMR. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak stimulatory activities at low concentrations.

Effect of C6-Volatiles on Bioluminescent Plant Pathogens

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 557d-557
Author(s):  
Jennifer Warr ◽  
Fenny Dane ◽  
Bob Ebel
Keyword(s):  
Biological Activity ◽  
Bacterial Growth ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Genetically Engineered ◽  
The Other ◽  
Computer Assisted ◽  
Signal Molecules ◽  
Low Concentrations

C6 volatile compounds are known to be produced by the plant upon pathogen attack or other stress-related events. The biological activity of many of these substances is poorly understood, but some might produce signal molecules important in host–pathogen interactions. In this research we explored the possibility that lipid-derived C6 volatiles have a direct effect on bacterial plant pathogens. To this purpose we used a unique tool, a bacterium genetically engineered to bioluminesce. Light-producing genes from a fish-associated bacterium were introduced into Xanthomonas campestris pv. campestris, enabling nondestructive detection of bacteria in vitro and in the plant with special computer-assisted camera equipment. The effects of different C6 volatiles (trans-2 hexanal, trans-2 hexen-1-ol and cis-3 hexenol) on growth of bioluminescent Xanthomonas campestris were investigated. Different volatile concentrations were used. Treatment with trans-2 hexanal appeared bactericidal at low concentrations (1% and 10%), while treatments with the other volatiles were not inhibitive to bacterial growth. The implications of these results with respect to practical use of trans-2 hexanal in pathogen susceptible and resistant plants will be discussed.

Evaluation of the quality and the stability of human samples for analysis and storage in biorepository

2018 ◽  
Vol 50 (1) ◽  
Author(s):  
Leonardo André Lange ◽  
Caroline Galgowski ◽  
Anna Cecília Roncalio ◽  
Fabiana Sehnem ◽  
Grabriela Borgmann ◽  
...  
Keyword(s):  
Human Samples ◽  
The Stability ◽  
And Storage

Effect of pH and temperature on the infectivity of human coronavirus 229E

1989 ◽  
Vol 35 (10) ◽  
pp. 972-974 ◽  
Author(s):  
Alain Lamarre ◽  
Pierre J. Talbot
Keyword(s):  
Incubation Period ◽  
Storage Conditions ◽  
Viral Infectivity ◽  
Human Coronavirus ◽  
Virus Growth ◽  
The Stability ◽  
And Storage ◽  
Influence Of Ph ◽  
Human Coronavirus 229E

The stability of human coronavirus 229E infectivity was maximum at pH 6.0 when incubated at either 4 or 33 °C. However, the influence of pH was more pronounced at 33 °C. Viral infectivity was completely lost after a 14-day incubation period at 22, 33, or 37 °C but remained relatively constant at 4 °C for the same length of time. Finally, the infectious titer did not show any significant reduction when subjected to 25 cycles of thawing and freezing. These studies will contribute to optimize virus growth and storage conditions, which will facilitate the molecular characterization of this important pathogen.Key words: coronavirus, pH, temperature, infectivity, human coronavirus.

scholarly journals Optimal profile for concave slopes under static and seismic conditions

2016 ◽  
Vol 53 (9) ◽  
pp. 1522-1532 ◽  
Author(s):  
Farshid Vahedifard ◽  
Shahriar Shahrokhabadi ◽  
Dov Leshchinsky
Keyword(s):  
Limit Equilibrium ◽  
Stable Configuration ◽  
Preliminary Evaluation ◽  
Construction Technology ◽  
Stability Of Slopes ◽  
Optimal Profile ◽  
Stabilized Soil ◽  
The Stability ◽  
Comparison Of The Results ◽  
The Impact

This study presents a methodology to determine the stability and optimal profile for slopes with concave cross section under static and seismic conditions. Concave profiles are observed in some natural slopes suggesting that such geometry is a more stable configuration. In this study, the profile of a concave slope was idealized by a circular arc defined by a single variable, the mid-chord offset (MCO). The proposed concave profile formulation was incorporated into a limit equilibrium–based log spiral slope stability method. Stability charts are presented to show the stability number, MCO, and mode of failure for homogeneous slopes corresponding to the most stable configuration under static and pseudostatic conditions. It is shown that concave profiles can significantly improve the stability of slopes. Under seismic conditions, the impact of concavity is most pronounced. Good agreement was demonstrated upon comparison of the results from the proposed method against those attended from a rigorous upper bound limit analysis. The proposed methodology, along with recent advances in construction technology, can be employed to use concave profiles in trenches, open mine excavations, earth retaining systems, and naturally cemented and stabilized soil slopes. The results presented provide a useful tool for preliminary evaluation for adopting such concave profiles in practice.

scholarly journals Pre-Drawn Syringes of Comirnaty for an Efficient COVID-19 Mass Vaccination: Demonstration of Stability

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1029
Author(s):  
Francesca Selmin ◽  
Umberto M. Musazzi ◽  
Silvia Franzè ◽  
Edoardo Scarpa ◽  
Loris Rizzello ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Real Life ◽  
Storage Conditions ◽  
Lipid Nanoparticles ◽  
Mass Vaccination ◽  
Hydrodynamic Diameter ◽  
The Us ◽  
Real Mass ◽  
The Stability ◽  
And Storage

Moving towards a real mass vaccination in the context of COVID-19, healthcare professionals are required to face some criticisms due to limited data on the stability of a mRNA-based vaccine (Pfizer-BioNTech COVID-19 Vaccine in the US or Comirnaty in EU) as a dose in a 1 mL-syringe. The stability of the lipid nanoparticles and the encapsulated mRNA was evaluated in a “real-life” scenario. Specifically, we investigated the effects of different storing materials (e.g., syringes vs. glass vials), as well as of temperature and mechanical stress on nucleic acid integrity, number, and particle size distribution of lipid nanoparticles. After 5 h in the syringe, lipid nanoparticles maintained the regular round shape, and the hydrodynamic diameter ranged between 80 and 100 nm with a relatively narrow polydispersity (<0.2). Samples were stable independently of syringe materials and storage conditions. Only strong mechanical stress (e.g., shaking) caused massive aggregation of lipid nanoparticles and mRNA degradation. These proof-of-concept experiments support the hypothesis that vaccine doses can be safely prepared in a dedicated area using an aseptic technique and transferred without affecting their stability.

AN ADVANCED ADAPTIVE FINITE ELEMENT CODE APPLIED FOR COATING-SUBSTRATE SIMULATION

2011 ◽  
Vol 03 (01n02) ◽  
pp. 91-107 ◽  
Author(s):  
JÜRGEN LEOPOLD ◽  
KATRIN HELLER ◽  
ARNDT MEYER ◽  
REINER WOHLGEMUTH
Keyword(s):  
Finite Element ◽  
Fe Simulation ◽  
Scale Up ◽  
Computational Time ◽  
Adaptive Finite Element ◽  
Workpiece Surface ◽  
Coated Tools ◽  
Geometrical Simulation ◽  
The Stability ◽  
And Storage

The stability of coating-substrate systems influences the chip formation and the surface integrity of the new generated workpiece surface, too. Using finite element (FE) simulation, deformations, strains and stresses in coated tools, caused by external and internal loads, can be computed on a microscopic scale. Since both, the whole macroscopic tool (in mm-scale) and the microscopic coating layers (in μm-scale up to nm-scale) must be included in the same geometrical simulation model, graded high-resolution FE meshes must be used. Nevertheless, the number of nodes in the 3D computational FE grid reaches some millions, leading to large computational time and storage requirements. For this reason, an advanced adaptive finite element (AAFEM) software has been developed and used for the simulation.

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