scholarly journals DABCO-Customized Nanoemulsions: Characterization, Cell Viability and Genotoxicity in Retinal Pigmented Epithelium and Microglia Cells

Pharmaceutics ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1652
Author(s):  
Ana R. Fernandes ◽  
Tiago dos Santos ◽  
Pedro L. Granja ◽  
Elena Sanchez-Lopez ◽  
Antonello Santini ◽  
...  
Keyword(s):  
Surface Tension ◽  
Cell Viability ◽  
Viscoelastic Properties ◽  
Site Specific ◽  
Ocular Structure ◽  
Oil In Water ◽  
Pigmented Epithelium ◽  
Derivatives Of ◽  
Anionic Surface

Quaternary derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO) and of quinuclidine surfactants were used to develop oil-in-water nanoemulsions with the purpose of selecting the best long-term stable nanoemulsion for the ocular administration of triamcinolone acetonide (TA). The combination of the best physicochemical properties (i.e., mean droplet size, polydispersity index, zeta potential, osmolality, viscoelastic properties, surface tension) was considered, together with the cell viability assays in ARPE-19 and HMC3 cell lines. Surfactants with cationic properties have been used to tailor the nanoemulsions’ surface for site-specific delivery of drugs to the ocular structure for the delivery of TA. They are tailored for the eye because they have cationic properties that interact with the anionic surface of the eye.

scholarly journals Mono- and Dicationic DABCO/Quinuclidine Composed Nanomaterials for the Loading of Steroidal Drug: 32 Factorial Design and Physicochemical Characterization

Nanomaterials ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2758
Author(s):  
Ana R. Fernandes ◽  
Elena Sanchez-Lopez ◽  
Antonello Santini ◽  
Tiago dos Santos ◽  
Maria L. Garcia ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
Tear Film ◽  
Age Related Macular Degeneration ◽  
Charged Droplets ◽  
Age Related ◽  
Oil In Water ◽  
32 Factorial Design ◽  
Derivatives Of ◽  
Positively Charged

Oil-in-water nanoemulsions (NEs) are considered a suitable nanotechnological approach to improve the eye-related bioavailability of lipophilic drugs. The potential of cationic NEs is prominent due to the electrostatic interaction that occurs between the positively charged droplets with the negatively charged mucins present in the tear film. This interaction offers prolonged NEs residence at the ocular surface, increasing the drug absorption. Triamcinolone acetonide (TA) is one of the first pharmacologic strategies applied as an intravitreal injection in the treatment of age-related macular degeneration (AMD). Newly synthesized quaternary derivatives of 1,4-diazabicyclo[2.2.2]octane (DABCO) and quinuclidine surfactants have been screened with the purpose to select the best compound to formulate long-term stable NEs that combine the best physicochemical properties for the loading of TA intended for ocular administration.

scholarly journals Long-term effectiveness of faecal immunochemical test screening for proximal and distal colorectal cancers

Gut ◽  
2021 ◽  
pp. gutjnl-2020-322545
Author(s):  
Han-Mo Chiu ◽  
Grace Hsiao-Hsuan Jen ◽  
Ying-Wei Wang ◽  
Jean Ching-Yuan Fann ◽  
Chen-Yang Hsu ◽  
...  
Keyword(s):  
Large Scale ◽  
Distal Colon ◽  
Population Based ◽  
Proximal Colon ◽  
Advanced Stage ◽  
Site Specific ◽  
Faecal Immunochemical Test ◽  
Immunochemical Test ◽  
Selection Factors

ObjectiveTo measure the effects of faecal immunochemical test (FIT) for colorectal cancer (CRC) screening on overall and site-specific long-term effectiveness of population-based organised service screening.DesignA prospective cohort study of Taiwanese nationwide biennial FIT screening was performed. A total of 5 417 699 eligible subjects were invited to attend screening from 2004 through 2009 and were followed up until 2014. We estimated the adjusted relative rates (aRRs) on the effectiveness of reducing advanced-stage CRC (stage II+) and CRC death by Bayesian Poisson regression models with the full adjustment for a cascade of self-selection factors (including the screening rate and the colonoscopy rate) and the completeness of colonoscopy together with demographic features.ResultsFIT screening (exposed vs unexposed) reduced the incidence of advanced-stage CRC (48.4 vs 75.7 per 100 000) and mortality (20.3 vs 41.3 per 100 000). Statistically significant reductions of both incidence of advanced-stage CRCs (aRR=0.66, 95% CI 0.63 to 0.70) and deaths from CRC (aRR=0.60, 95% CI 0.57 to 0.64) were noted. FIT screening was more effective in reducing distal advanced-stage CRCs (aRR=0.61, 95% CI 0.58 to 0.64) and CRC mortality (aRR=0.56, 95% CI 0.53 to 0.69) than proximal advanced CRCs (aRR=0.84, 95% CI 0.77 to 0.92) and CRC mortality (aRR=0.72, 95% CI 0.66 to 0.80).ConclusionA large-scale population-based biennial FIT screening demonstrates 34% significant reduction of advanced-stage CRCs and 40% reduction of death from CRC with larger long-term effectiveness in the distal colon than the proximal colon. Our findings provide a strong and consistent evidence-based policy for supporting a sustainable population-based FIT organised service screening worldwide. The disparity of site-specific long-term effectiveness also provides an insight into the remedy for lower effectiveness of FIT screening in the proximal colon.

scholarly journals Nanoemulsions for the Encapsulation of Hydrophobic Actives

Cosmetics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 45
Author(s):  
Eduardo Guzmán ◽  
Laura Fernández-Peña ◽  
Lorenzo Rossi ◽  
Mathieu Bouvier ◽  
Francisco Ortega ◽  
...  
Keyword(s):  
Surface Charge ◽  
Long Term Stability ◽  
Promising Tool ◽  
Oil In Water ◽  
Nanometric Range ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Highly Hydrophobic ◽  
Technological Interest

This work analyzes the dispersion of two highly hydrophobic actives, (9Z)-N-(1,3-dihydroxyoctadecan-2-yl)octadec-9-enamide (ceramidelike molecule) and 2,6-diamino-4-(piperidin-1-yl)pyrimidine 1-oxide (minoxidil), using oil-in-water nanoemulsions with the aim of preparing stable and safe aqueous-based formulations that can be exploited for enhancing the penetration of active compounds through cosmetic substrates. Stable nanoemulsions with a droplet size in the nanometric range (around 200 nm) and a negative surface charge were prepared. It was possible to prepare formulations containing up to 2 w/w% of ceramide-like molecules and more than 10 w/w% of minoxidil incorporated within the oil droplets. This emulsions evidenced a good long-term stability, without any apparent modification for several weeks. Despite the fact that this work is limited to optimize the incorporation of the actives within the nanoemulsion-like formulations, it demonstrated that nanoemulsions should be considered as a very promising tool for enhancing the distribution and availability of hydrophobic molecules with technological interest.

Site-Specific Photomodification of Single-Stranded DNA Targets by Arylazide and Perfluoroarylazide Derivatives of Oligonucleotides

1996 ◽  
Vol 6 (2) ◽  
pp. 119-126 ◽  
Author(s):  
ASYA S. LEVINA ◽  
DAVID R. TABATADZE ◽  
MIKHAIL I. DOBRIKOV ◽  
GENNADII V. SHISHKIN ◽  
LUDMILA M. KHALIMSKAYA ◽  
...  
Keyword(s):  
Single Stranded Dna ◽  
Site Specific ◽  
Derivatives Of

Testing Long-Term Predictions from Hydro-Geochemical Models

1993 ◽  
Vol 333 ◽  
Author(s):  
William E. Glassley ◽  
Carol J. Bruton ◽  
William L. Bourcier
Keyword(s):  
Yucca Mountain ◽  
Taupo Volcanic Zone ◽  
Ambient Conditions ◽  
Volcanic Zone ◽  
Site Specific ◽  
Thermally Induced ◽  
Induced Flow ◽  
Geochemical Models ◽  
Kinetics And Thermodynamic

ABSTRACTThermally induced flow of liquid water and water vapor at the potential repository site at Yucca Mountain, Nevada, will extend hundreds of meters away from the repository edge. The resultant transfer of heat and mass will sufficiently perturb the ambient conditions such that a variety of mineralogical and chemical reactions will occur that may modify hydrological properties. The consequences of this “coupling” of geochemical and hydrological processes will vary through time, and will occur to different degrees in four regimes (T < Tboiling; T = Tboiling; T > T boiling; cooling) that will develop within the repository block. The dominant processes in the regimes differ, and reflect the local balance between: 1) kinetics and equilibrium; 2) dissolution and precipitation; 3) evaporation and boiling; and 4) fluid flow in matrix and fractures. Simulations were conducted of the evolution of these regimes, using laboratory derived kinetics and thermodynamic data, and site specific mineralogical and hydrological properties. These simulations identify regions where chemical and mineralogical equilibrium is likely to be achieved, and where net changes in hydrological properties will be concentrated. Tests of the results of these simulations have been initiated using field data from the Taupo Volcanic Zone, New Zealand. A preliminary series of calculations suggest that relative changes in porosity of as much as ± 20% to 30% may be possible for rocks with an initial porosity of 10%.

Plateau–Rayleigh instability in a soft viscoelastic material

Soft Matter ◽  
2021 ◽  
Author(s):  
S. I. Tamim ◽  
J. B. Bostwick
Keyword(s):  
Surface Tension ◽  
Stability Analysis ◽  
Dynamic Stability ◽  
Viscoelastic Material ◽  
Viscoelastic Properties ◽  
Rayleigh Instability ◽  
Cylindrical Interface

A soft cylindrical interface endowed with surface tension can be unstable to wavy undulations. The most unstable wavelength depends upon the viscoelastic properties of the material and is determined by a dynamic stability analysis.

scholarly journals A method for reconstructing past lake water phosphorus concentrations using sediment geochemical records

2021 ◽  
Author(s):  
Madeleine Moyle ◽  
John F. Boyle
Keyword(s):  
Lake Water ◽  
Water Quality Monitoring ◽  
Specific Reference ◽  
Site Specific ◽  
Burial Rate ◽  
Steady State Model ◽  
Sediment Records ◽  
Current Water ◽  
Study Sites

AbstractAn existing steady state model of lake phosphorus (P) budgets has been adapted to allow reconstruction of long-term average historic lake water total phosphorus (TP) concentrations using lake sediment records of P burial. This model can be applied without site-specific parameterisation, thus potentially having universal application. In principle, it is applicable at any site where there is both a sediment P burial record and knowledge of the current water budget, although we advise caution applying it to problematic sediment records. Tested at six published case study sites, modelled lake water TP concentrations agree well with water-quality monitoring data, and limited testing finds good agreement with wholly independent diatom inferred lake water TP. Our findings, together with a review of the literature, suggest that well preserved lake sediments can usefully record a long-term average P burial rate from which the long-term mean lake water TP can be reliably estimated. These lake water TP reconstructions can provide meaningful site-specific reference values to support decision making in lake eutrophication management, including establishing targets for lake restoration.

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