Ultra-stable self-foaming oils

This paper is concerned with the foaming of a range of fats in the absence of added foaming agent/emulsifier. By controlling the temperature on warming from the solid or cooling from the melt, crystals of high melting triglycerides form in a continuous phase of low melting triglycerides. Such crystal dispersions in oil can be aerated to produce whipped oils of high foamability and extremely high stability. The foams do not exhibit drainage and bubbles neither coarsen nor coalesce as they become coated with solid crystals. The majority of the findings relate to coconut oil but the same phenomenon occurs in shea butter, cocoa butter and palm kernel stearin. For each fat, there exists an optimum temperature for foaming at which the solid fat content reaches up to around 30%. We demonstrate that the oil foams are temperature-responsive and foam collapse can be controllably triggered by warming the foam to around the melting point of the crystals. Our hypothesis is given credence in the case of the pure system of tristearin crystals in liquid tricaprylin

Photochemical and evaporation behaviour of sunscreen formulations

Sunscreens ensure protection of the human skin against the harmful effects of the UV radiation in the UVB (290 – 320 nm) and UVA (320 – 400 nm) wavelength ranges. They commonly contain one or more organic UV absorbers that absorb light in the wavelength range of interest and/or inorganic particles, such as metal oxide semiconductors that absorb, scatter and reflect light. The efficiency of these formulations is measured by introducing the Sun Protection Factor (SPF). Currently, SPF is estimated from in vivo measurements, which is a time-consuming and expensive process. For a validated method, however, SPF can also be determined in vitro by measuring the diffuse optical transmittance as a function of wavelength. In this study, we show how in vitro SPF changes as a function of time upon i) evaporation of volatile components and ii) exposure under UV irradiation.We start by investigating the evaporation of solution films containing a selection of UV absorbers. We show that during solvent evaporation, an initial film, which is deposited on a smooth quartz plate, progressively dewets. The solvent loss causes an increase in the solute concentration until its solubility limit is reached. From that point onwards, solute precipitation is expected to occur. Hence, the combined effect of dewetting and solute precipitation during evaporation leads to a decrease in the absorbance and thus to the in vitro SPF values. We model the evolution of film spectra and we compare it with experiment. Results confirm that both are in reasonable agreement.The addition of either inorganic particulates in the nm size or polymer was also pursued. Our data confirm that their use aid film pinning at its base edge and suppressed dewetting. However, it did not tackle the problem of precipitation during solvent evaporation. Throughout our experimental procedure, the solvent of choice was the slow evaporating propane-1,2-diol (PG). We show that the same behaviour is observed when a fast- evaporating solvent, such as n-decane is used. Dewetting is also suppressed when alternative substrates such as Vitro Skin and keratin-lipid film are used.We have extended our investigation to the evaporation of particle-stabilised emulsion films, consisting of equal volumes of involatile squalane (SQ) and slow-evaporating PG and stabilised by partially hydrophobised silica particles. We show for these emulsions that the loss in the absorbance is due to the loss of light scattering. The loss of the latter results from the collapse of the emulsion structure during evaporation.We also examine how the in vitro SPF of solutions containing UV absorbers varies with standard solar irradiation. With the use of chemical actinometry, we have determined the overall quantum yields of the photochemical processes of photolabile UV absorbers. Using the obtained parameters, we have developed models to calculate the evolution of the film spectra and derived SPF values for both non-scattering films consisting of solutions of multiple UV absorbers and for highly scattering emulsion films. Finally, we are able to predict the SPF changes as a result of the photochemical processes upon “standard” sunlight exposure

Spectrophotometry of thin films of light absorbing particles

Thin films of dispersions of light absorbing solid particles or emulsions containing a light absorbing solute all have a non-uniform distribution of light absorbing species throughout the sample volume. This results in non-uniform light absorption over the illuminated area which causes the optical absorbance, as measured using a conventional specular UV-vis spectrophotometer, to deviate from the Beer-Lambert relationship. We have developed a theoretical model to account for the absorbance properties of such films which are shown to depend on the size and volume fraction of the light absorbing particles plus other sample variables. We have compared model predictions with measured spectra for samples consisting of emulsions containing a dissolved light absorbing solute. Using no adjustable parameters, the model successfully predicts the behaviour of non-uniform, light absorbing emulsion films with varying values of droplet size, volume fraction and other parameters

Evaporation of particle-stabilised emulsion sunscreen films

We recently showed (Binks et al., ACS Appl. Mater. Interfaces, 2016, DOI: 10.1021/acsami.6b02696) how evaporation of sunscreen films consisting of solutions of molecular UV filters leads to loss of UV light absorption and derived sun protection factor (SPF). In the present work, we investigate evaporation-induced effects for sunscreen films consisting of particle-stabilized emulsions containing a dissolved UV filter. The emulsions contained either droplets of propylene glycol (PG) in squalane (SQ), droplets of SQ in PG or droplets of decane in PG. In these different emulsion types, the SQ is involatile and shows no evaporation, the PG is volatile and evaporates relatively slowly, whereas the decane is relatively very volatile and evaporates quickly. We have measured the film mass and area, optical micrographs of the film structure, and the UV absorbance spectra during evaporation. For emulsion films containing the involatile SQ, evaporation of the PG causes collapse of the emulsion structure with some loss of specular UV absorbance due to light scattering. However, for these emulsions with droplets much larger than the wavelength of light, the light is scattered only at small forward angles so does not contribute to the diffuse absorbance and the film SPF. The UV filter remains soluble throughout the evaporation and thus the UV absorption by the filter and the SPF remain approximately constant. Both PG-in-SQ and SQ-in-PG films behave similarly and do not show area shrinkage by dewetting. In contrast, the decane-in-PG film shows rapid evaporative loss of the decane, followed by slower loss of the PG resulting in precipitation of the UV filter and film area shrinkage by dewetting which cause the UV absorbance and derived SPF to decrease. Measured UV spectra during evaporation are in reasonable agreement with spectra calculated using models discussed here

How the sun protection factor (SPF) of sunscreen films change during solar irradiation

We have investigated how the sun protection factor (SPF) of different types of sunscreen film varies with “standard” solar irradiation due to photochemical processes. We have used a combination of chemical actinometry, measurement and modelling to estimate the overall quantum yields for the photoprocesses occurring for avobenzone (AVB) and isopentyl p-methoxycinnamate (MC) in either propane-1,2-diol (PG) or squalane (SQ) as solvent. Using the obtained parameters, we have developed models to calculate the evolution of the film spectra and derived SPF values for both non-scattering sunscreen films consisting of solutions of multiple UV filters and for highly scattering Pickering emulsion based sunscreen films. Model calculations for all films are in excellent agreement with film spectra measured as a function of irradiation time using different laboratory light sources. Finally, using the estimated parameters and experimentally validated models, we are able to quantitatively predict how the in vitro SPF values for different film types containing any set combination of UV filter concentrations will vary with time due to photochemical processes induced by irradiation with “standard” sunlight. This provides a useful tool for the rational design and optimisation of new sunscreen formulations

Evaporation of Sunscreen Films: How the UV Protection Properties Change

© 2016 American Chemical Society. We have investigated the evaporation of thin sunscreen films and how the light absorption and the derived sun protection factor (SPF) change. For films consisting of solutions of common UV filters in propylene glycol (PG) as solvent, we show how evaporation generally causes three effects. First, the film area can decrease by dewetting leading to a transient increase in the average film thickness. Second, the film thins by evaporative loss of the solvent. Third, precipitation of the UV filter occurs when solvent loss causes the solubility limit to be reached. These evaporation-induced changes cause the UV absorbance of the film to decrease with resultant loss of SPF over the time scale of the evaporation. We derive an approximate model which accounts semiquantitatively for the variation of SPF with evaporation. Experimental results for solutions of different UV filters on quartz, different skin mimicking substrates, films with added nanoparticles, films with an added polymer and films with fast-evaporating decane as solvent (instead of slow evaporating PG) are discussed and compared with model calculations. Addition of either nanoparticles or polymer suppress film dewetting. Overall, it is hoped that the understanding gained about the mechanisms whereby film evaporation affects the SPF will provide useful guidance for the formulation of more effective sunscreens

Pseudomamma of the inguinal region in a female patient: A case report

Introduction: Supernumerary breasts are relative common benign congenital anomalies. General population occurrence rates vary up to 6% according to ethnicity and gender. Higher incidence is recorded in Asian individuals, especially Japanese. Embryonic breast development of the mammary ridge (milk line) is explained and supernumerary breast tissue resulting from involution failure of any portion of the embryonic mammary folds is described. Presentation of case: We report a case of supernumerary breast (pseudomamma) in a female occupying her right inguinal region that was treated in the breast unit of our hospital. Differential diagnosis, imaging methods, operative approach, surgical treatment and histological verification are specified. Discussion: Classification system for supernumerary breast tissue is presented, high risk population is identified and congenital malformations linked to it are outlined. Evaluation of diagnostic workup and limitations are stated. Cancerous degeneration and justification for surgical removal of the accessory gland is discussed. Conclusion: Differential diagnosis of lesions along the milk line should always be inclusive of developmental abnormalities such as any type of supernumerary breast, often overlooked due to small size, although carrying a malignant potential equal to normally positioned breasts. Surgical correction is a sensible approach, often encouraged by the patients. Additional evaluation is recommended due to the frequent accompanying urinary tract and cardiac anomalies

Cost analysis with respect to driver's licence training

Περίληψη: Πόσο κοστίζει η εκμάθηση ενός υποψήφιου οδηγού από μια σχολή οδηγών, ώστε να εκπαιδευτεί σωστά και σύμφωνα με τις διατάξεις των νόμων περί διδασκαλίας και εκπαίδευσης (θεωρητική και πρακτική εκπαίδευση) υποψηφίων οδηγών; Σύμφωνα με το νόμο 4599/2019 ( ΑΡΘΡΟ 4 ΠΑΡ. 11) θεσπίζετε κατώτερη τιμή για την έκδοση αδειών οδήγησης από τις σχολές οδηγών. Στην παρούσα διπλωματική εξετάζουμε και αναλύουμε όλα τα δεδομένα που επηρεάζουν την τελική τιμή ενός διπλώματος οδήγησης και πρέπει να ληφθούν υπόψη από την πολιτεία ώστε το κατώτατο ποσό που θα ορισθεί να είναι οικονομικά ορθό για να εξασφαλίζει την βιωσιμότητα όλων των σχολών οδήγησης, αποτρέποντας τες, από οποιαδήποτε υποβάθμιση στην ποιότητα των υπηρεσιών που παρέχουν στους υποψήφιους οδηγούς καθώς επίσης και να εξαλείψει τα φαινόμενα του αθέμιτου ανταγωνισμού μεταξύ αυτών

Germline mutations in a clinic-based series of pregnancy associated breast cancer patients

Background: Pregnancy-associated breast cancer (PABC) defined as breast cancer diagnosed during gestation, lactation or within 1 year after delivery, represents a truly challenging situation with significantly increasing incidence rate. The genomic background of PABC has only recently been addressed while the underlying mechanisms of the disease still remain unknown. This analysis aims to further elucidate the frequency of PABC cases attributable to genetic predisposition and identify specific cancer susceptibility genes characterizing PABC. Methods: A comprehensive 94-cancer gene panel was implemented in a cohort of 20 PABC patients treated in our clinic and descriptive correlation was performed among the results and the patients’ clinicopathological data. Results: In the present study, 35% of PABC patients tested carried pathogenic mutations in two known cancer predisposition genes (BRCA1 and CHEK2). In total, 30% of the patients carried BRCA1 pathogenic variants. An additional 5% carried pathogenic variants in the CHEK2 gene. Variants of unknown/uncertain significance (VUS) in breast cancer susceptibility genes BRCA2, CHEK2 and BRIP1 were also identified in three different PABC patients (15%). Not all patients carrying germline mutations reported known family history of cancer. Conclusions: Genetic testing should be considered as an option for PABC patients since the disease is highly associated with genetic susceptibility among other predisposing factors. Germline mutation identification may further modify PABC management approach and improve the prognostic outcome. © 2021, The Author(s)