Technical-functional and surface properties of white common bean proteins (Phaseolus vulgaris L.): Effect of pH, protein concentration, and guar gum presence.

Legumes are abundant sources of proteins, and white common bean proteins play an important role in air-water interface properties. This study aims to investigate the technical-functional properties of white common bean protein isolate (BPI) as a function of pH, protein concentration, and guar gum (GG) presence. BPI physicochemical properties were analyzed in terms of solubility, zeta potential, and mean particle diameter at pH ranging from 2 to 9, in addition to water-holding capacity (WHC), oil-holding capacity (OHC), and thermogravimetric analysis. Protein dispersions were evaluated in terms of dynamic, interfacial, and foam-forming properties. BPI showed higher solubility (>80 %) at pH 2 and above 7. Zeta potential and mean diameter ranged from 15.43 to -34.08 mV and from 129.55 to 139.90 nm, respectively. BPI exhibited WHC and OHC of 1.37 and 4.97 g/g, respectively. Thermograms indicated decomposition temperature (295.81 °C) and mass loss (64.73 %). Flow curves indicated pseudoplastic behavior, with higher η100 values observed in treatments containing guar gum. The behavior was predominantly viscous (tg δ > 1) at lower frequencies, at all pH levels, shifting to predominantly elastic at higher frequencies. Equilibrium surface tension (γeq) ranged from 43.87 to 41.95 mN.m-1 and did not decrease with increasing protein concentration under all pH conditions. All treatments exhibited ϕ < 15°, indicating predominantly elastic surface films. Foaming properties were influenced by higher protein concentration and guar gum addition, and the potential formation of protein-polysaccharide complexes favored the kinetic stability of the system.

Foaming of 3D-Printed PLA/CaCO3 Composites by Supercritical CO2 Process for Sustainable Food Contact Materials.

In the last decade, among the emerging technologies in the area of bioplastics, additive manufacturing (AM), commonly referred to as 3D printing, stands out. This technology has gained great interest in the development of new products, mainly due to its capability to easily produce customized and low-cost plastic products. This work aims to evaluate the effect of supercritical foaming of 3D-printed parts based on a commercial PLA matrix loaded with calcium carbonate, for single-use sustainable food contact materials. 3D-printed PLA/CaCO3 parts were obtained by 3D printing with a 20% and 80% infill, and two infill patterns, rectilinear and triangular, were set for each of the infill percentages selected. Supercritical fluid foaming of PLA/CaCO3 composite printed parts was performed using a pressure of 25 MPa, a temperature of 130 °C for 23 min, with a fast depressurization rate (1 s). Closed-cell foams were achieved and the presence of CaCO3 did not influence the surface of the foams or the cell walls, and no agglomerations were observed. Foam samples with 80% infill showed subtle temperature fluctuations, and thermogravimetric analysis showed that samples were thermally stable up to ~300 °C, while the maximum degradation temperature was around 365 °C. Finally, tensile test analysis showed that for lower infill contents, the foams showed lower mechanical performance, while the 80% infill and triangular pattern produced foams with good mechanical performance. These results emphasize the interest in using the supercritical CO2 process to easily produce foams from 3D-printed parts. These materials represent a sustainable alternative for replacing non-biodegradable materials such as Expanded Polystyrene, and they are a promising option for use in many industrial applications, such as contact materials.

Bio-based polyester-polyurethane foams: synthesis and degradability by Aspergillus niger and Aspergillus clavatus.

In this article, the degradability by Aspergillus niger and Aspergillus clavatus of three bio-based polyurethane (PU) foams is compared to previous degradability studies involving a Pseudomonas sp. bacterium and similar initial materials (Spontón et al. in Int. Biodet. Biodeg. 85:85-94, 2013, https://doi.org/10.1016/j.ibiod.2013.05.019 ). First, three new polyester-polyurethane foams were prepared from mixtures of castor oil (CO), maleated castor oil (MACO), toluene diisocyanate (TDI), and water. Then, their degradation tests were carried out in an aqueous medium, and employing the two mentioned fungi, after their isolation from the environment. From the degradation tests, the following was observed: (a) the insoluble (and slightly collapsed) foams exhibited free hydroxyl, carboxyl, and amine moieties; and (b) the water soluble (and low molar mass) compounds contained amines, carboxylic acids, and glycerol. The most degraded foam contained the highest amount of MACO, and therefore the highest concentration of hydrolytic bonds. A basic biodegradation mechanism was proposed that involves hydrolysis and oxidation reactions.

Terapia de estrógenos vaginales y riesgo de recurrencia en mujeres con antecedente de cáncer de mama

El cáncer de mama sigue siendo la neoplasia maligna más frecuente y una de las mortales en mujeres, considerándose un importante objetivo de la salud global y prioridad en salud pública. Con el uso de terapias innovadoras, ha mejorado la supervivencia, apareciendo condiciones asociadas, como el síndrome genitourinario menopaúsico. La terapia hormonal, se utiliza para el manejo de esta condición, mejorando sustancialmente la sintomatología, e incluso, siendo en algunos casos la única solución. La más utilizada, es la terapia de estrógenos vaginales. Sin embargo, se ha descrito un posible riesgo de recurrencia de cáncer de mama con su uso. En habla hispana, no existe evidencia que haya discutido este tópico. Se llevó a cabo una búsqueda en las bases PubMed, ScienceDirect y MEDLINE, utilizando los términos "Terapia de estrógenos vaginales", "Recurrencia" y "Cáncer de mama". Se encontró, que, de forma global, la terapia de estrógenos vaginales es una opción terapéutica eficaz y segura en el manejo del síndrome genitourinario menopaúsico en mujeres con antecedente de cáncer de mama, sin incrementar el riesgo de recurrencia, a excepción de aquellas tratadas con inhibidores de la aromatasa, en quienes se recomienda el uso de otras terapias para evitar acarrear este riesgo.

Breast cancer remains the most common malignant neoplasm and one of the leading causes of mortality in women, making it a significant target for global health efforts and a public health priority. Through the use of innovative therapies, survival rates have improved, leading to the emergence of associated conditions such as genitourinary menopausal syndrome. Hormonal therapy is employed for managing this condition, significantly alleviating its symptoms and, in some cases, serving as the sole solution. The most commonly utilized approach is vaginal estrogen therapy. Nevertheless, there have been reports of a potential risk of breast cancer recurrence associated with its use. In the Spanish-speaking context, there is limited evidence discussing this topic. A search was conducted across PubMed, ScienceDirect, and MEDLINE databases, using the terms "Vaginal Estrogen Therapy", "Recurrence" and "Breast Cancer." It was determined that, on a global scale, vaginal estrogen therapy is an effective and safe therapeutic option for managing genitourinary menopausal syndrome in women with a history of breast cancer. This therapy does not appear to increase the risk of recurrence, with the exception of those undergoing treatment with aromatase inhibitors. For these individuals, alternative therapies are recommended to mitigate this potential risk.

Computational Study of the Influence of α/ß-Phase Ratio and Porosity on the Elastic Modulus of Ti-Based Alloy Foams.

This work aims to perform a computational analysis on the influence that microstructure and porosity have on the elastic modulus of Ti-6Al-4V foams used in biomedical applications with different α/ß-phase ratios. The work is divided into two analyses, first the influence that the α/ß-phase ratio has and second the effects that porosity and α/ß-phase ratio have on the elastic modulus. Two microstructures were analyzed: equiaxial α-phase grains + intergranular ß-phase (microstructure A) and equiaxial ß-phase grains + intergranular α-phase (microstructure B). The α/ß-phase ratio was variated from 10 to 90% and the porosity from 29 to 56%. The simulations of the elastic modulus were carried out using finite element analysis (FEA) using ANSYS software v19.3. The results were compared with experimental data reported by our group and those found in the literature. The ß-phase amount and porosity have a synergic effect on the elastic modulus, for example, when the foam has a porosity of 29 with 0% ß-phase, and it has an elastic modulus of ≈55 GPa, but when the ß-phase amount increases to 91%, the elastic modulus decreases as low as 38 GPa. The foams with 54% porosity have values smaller than 30 GPa for all the ß-phase amounts.

Rigid Polyurethane Biofoams Filled with Pine Seed Shell and Yerba Mate Wastes.

Pine seed shells and yerba mate are common wastes leftover from the food and beverage industry. This study presents the development of rigid polyurethane foams (RPUFs) filled with pine seed shells and yerba mate at 5, 10 and 15 wt%. The fillers were characterized for chemical properties using bench chemistry analyses, and the RPUFs were investigated in terms of chemical, morphological, mechanical, thermal and colorimetric characteristics. The main results indicated that yerba mate showed good compatibility with the polyurethane system, probably because its available hydroxyl groups reacted with isocyanate groups to form urethane bonds, producing increases in mechanical and thermal properties. However, pine seed shell did not appear to be compatible. Anisotropy increased slightly, as there was an increase in the percentage of reinforcement. The mechanical properties of the yerba mate reinforced foams proved stable, while there was a loss of overall up to ~50% for all mechanical properties in those reinforced with pine seed shell. Thermal properties were improved up to ~40% for the yerba mate reinforced foams, while those reinforced with pine nuts were stable. It was possible to observe a decrease in the glass transition temperature (Tg) of ~-5 °C for the yerba mate reinforced foams and ~-14 °C for the pine seed shell reinforced ones.

PFAS in fish from AFFF-impacted environments: Analytical method development and field application at a Canadian international civilian airport.

Methods targeting anionic per- and polyfluoroalkyl substances (PFAS) in aquatic biota are well established, but commonly overlook many PFAS classes present in aqueous film-forming foams (AFFFs). Here, we developed an analytical method for the expanded analysis of negative and positive ion mode PFAS in fish tissues. Eight variations of extraction solvents and clean-up protocols were first tested to recover 70 AFFF-derived PFAS from the fish matrix. Anionic, zwitterionic, and cationic PFAS displayed the best responses with methanol-based ultrasonication methods. The response of long-chain PFAS was improved for extracts submitted to graphite filtration alone compared with those involving solid-phase extraction. The validation included an assessment of linearity, absolute recovery, matrix effects, accuracy, intraday/interday precision, and trueness. The method was applied to a set of freshwater fish samples collected in 2020 in the immediate vicinity (creek, n = 15) and downstream (river, n = 15) of an active fire-training area at an international civilian airport in Ontario, Canada. While zwitterionic fluorotelomer betaines were major components of the subsurface AFFF source zone, they were rarely detected in fish, suggesting limited bioaccumulation potential. PFOS largely dominated the PFAS profile, with record-high concentrations in brook sticklebacks (Culaea inconstans) from the creek (16000-110,000 ng/g wet weight whole-body). These levels exceeded the Canadian Federal Environmental Quality Guidelines (FEQG) for PFOS pertaining to the Federal Fish Tissue Guideline (FFTG) for fish protection and Federal Wildlife Diet Guidelines (FWiDG) for the protection of mammalian and avian consumers of aquatic biota. Perfluorohexane sulfonamide and 6:2 fluorotelomer sulfonate were among the precursors detected at the highest levels (maximum of ∼340 ng/g and ∼1100 ng/g, respectively), likely reflecting extensive degradation and/or biotransformation of C6 precursors originally present in AFFF formulations.

Foaming properties are improved by interactions between brewer's spent grain proteins and carrageenans in aqueous solution.

BACKGROUND: Foaming properties and macromolecular interactions in solution among brewer's spent grain proteins (CP) and iota and lambda carrageenans (i-CG and l-CG, respectively) as a function of aqueous medium pH (2-6) and protein-polysaccharide ratio, RCP:CG (1:1, 2:1 and 4:1), were studied. At these conditions, the CP colloidal stability was favored by the formation of soluble electrostatic complexes with CG. Fluorescence (intrinsic and extrinsic) spectroscopy and dynamic light scattering techniques, including particle size and ζ-potential analysis, were applied to know the phase behavior of the biopolymer systems. The bubbling method was used to produce foams, and the foam expansion (%) and half-life time (t1/2 ) were determined. RESULTS: Both CG promoted an increased Trp fluorescence emission depending on the pH, suggesting conformational changes in CP. The CG in mixed systems produced a significant decrease in the extrinsic fluorescence intensity, mainly at low pH values, highlighting a reduction in CP surface hydrophobicity. At the examined pH range, the ζ-potential values for mixed-systems were negative, and their magnitudes were intermediate between CP and CG, revealing the associative electrostatic nature of biopolymer interactions, which were dependent on the RCP:CG . The particle size analysis confirmed the formation of soluble electrostatic complexes in solution. Finally, using i-CG at pH 2 or 3 and 2:1 RCP:CG , the best foaming properties for mixed systems were observed. CONCLUSION: The formation of electrostatic complexes with a compact assembly among biopolymers, high negative net charge, and colloidal stability convert the CP-CG mixed solutions into promising biopolymer systems for food foams production. © 2022 Society of Chemical Industry.

Density Gradients, Cellular Structure and Thermal Conductivity of High-Density Polyethylene Foams by Different Amounts of Chemical Blowing Agent.

LDPE (low-density polyethylene) foams were prepared using the improved compression moulding technique (ICM) with relative densities ranging from 0.3 to 0.7 and with different levels of chemical blowing agents (from 1% to 20%). The density gradients, cellular structure and thermal conductivity of the foams were characterized. The density and amount of CBA used were found to have a significant effect on the cellular structure both at the mesoscale (density gradients) and at the microscale (different cell sizes and cell densities). In addition, the thermal conductivity of the samples is very sensitive to the local structure where the heat flux is located. The technique used to measure this property, the Transient Plane Source method (TPS), makes it possible to detect the presence of density gradients. A simple method for determining these gradients based on thermal conductivity data was developed.

Thermally Resistant, Self-Extinguishing Thermoplastic Composites Enabled by Tannin-Based Carbonaceous Particulate.

Flame-resistant materials are key components in buildings and several other engineering applications. In this study, flame retardancy and thermal stability were conferred to a highly flammable technical thermoplastic-polypropylene (PP)-upon compositing with a carbonaceous tannin-based particulate (CTP). Herein, we report on a straightforward, facile, and green approach to prepare self-extinguishing thermoplastic composites by thermoblending highly recalcitrant particulate. The thermal stability and mechanical properties of the composites are tethered to the CTP content. We demonstrate that the addition of up to 65 wt% of CTP improved the viscoelastic properties and hydrophobicity of the PP, whereas having marginal effects on bulk water interactions. Most importantly, compositing with CTP remarkably improved the thermal stability of the composites, especially over 300 °C, which is an important threshold associated with the combustion of volatiles. PP-CTP composites demonstrated great capacity to limit and stop fire propagation. Therefore, we offer an innovative route towards thermally resistant and self-extinguishing PP composites, which is enabled by sustainable tannin-based flame retardants capable of further broadening the technical range of commodity polyolefins to high temperature scenarios.

Polyurethane/Vermiculite Foam Composite as Sustainable Material for Vertical Flame Retardant.

Rigid polyurethane foams were prepared by the one-step expandable foam method using casting molding followed by forming clay-based composites. Polyurethane/vermiculite foam composites (PU/VMT) were controlled based on adding the percentage of clay in the formulation. The effects of composite modifications were evaluated by X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), and scanning electron microscopy (SEM/EDS) applied to the flame retardancy explored by the vertical burn test. The results indicated that adding clay controlled the particle size concerning polyurethane (PU) foams. However, they exhibited spherical structures with closed cells with relatively uniform distribution. XRD analysis showed the peaks defined at 2θ = 18° and 2θ = 73° relative to the crystallinity in formation and interaction of rigid segments were identified, as well as the influence of crystallinity reduction in composites. In the flame test, the flame retardant surface was successful in all composites, given the success of the dispersibility and planar orientation of the clay layers and the existence of an ideal content of vermiculite (VMT) incorporated in the foam matrix.

Nitric Oxide-Releasing Supramolecular Cellulose Nanocrystal/Silsesquioxane Foams.

Cellulose nanocrystals (CNC)-based foams are promising tissue engineering materials that may facilitate implant-tissue integration and allow localized and controlled drug delivery. Herein, hybrid CNC-based foams, which are ultralightweight (30-100 mg cm-3 ), highly porous (>95%), ominiphilic and superabsorbent (1500-3000 wt% of water and/or toluene uptake) are obtained by the in situ condensation of poly(ethylene glycol) ditriethoxysilyl (TES-PEG-TES) into a 3D network, where silsesquioxane nanoparticles (SS-NP) are the crosslinking nodes, and CNC are entrapped forming ionic interactions, in a supramolecular structure. In a new approach, using 3-mercaptopropyltrimethoxysilane, sulfhydryl groups are inserted on the SS-NP periphery and S-nitrosated to enable the functionalization of SS-NP with S-nitrosothiol groups, which can nitric oxide (NO), in a process triggered by the hydration of the foams and modulated by their supramolecular structure. CNC-SS-PEG foams exhibit elevated thermal and structural stability, compressive strength compatible with various soft human tissues, and NO release rates (1-18 pmol mg-1 min-1 ) within the range of the beneficial NO actions. Thus, the CNC-SS-PEG foams herein described represent a new platform of supramolecular hybrid materials for localized delivery of NO, with potential uses in tissue engineering and other biomedical applications.

Innovation in Aircraft Cabin Interior Panels Part I: Technical Assessment on Replacing the Honeycomb with Structural Foams and Evaluation of Optimal Curing of Prepreg Fiberglass.

Sandwich composites are widely used in the manufacture of aircraft cabin interior panels for commercial aircraft, mainly due to the light weight of the composites and their high strength-to-weight ratio. Panels are used for floors, ceilings, kitchen walls, cabinets, seats, and cabin dividers. The honeycomb core of the panels is a very light structure that provides high rigidity, which is considerably increased with fiberglass face sheets. The panels are manufactured using the compression molding process, where the honeycomb core is crushed up to the desired thickness. The crushed core breaks fiberglass face sheets and causes other damage, so the panel must be reworked. Some damage is associated with excessive build-up of resin in localized areas, incomplete curing of the pre-impregnated fiberglass during the manufacturing process, and excessive temperature or residence time during the compression molding. This work evaluates the feasibility of using rigid polyurethane foams as a substitute for the honeycomb core. The thermal and viscoelastic behavior of the cured prepreg fiberglass under different manufacturing conditions is studied. The first part of this work presents the influence of the manufacturing parameters and the feasibility of using rigid foams in manufacturing flat panels oriented to non-structural applications. The conclusion of the article describes the focus of future research.

Bio-Based Rigid Polyurethane Foam Composites Reinforced with Bleached Curauá Fiber.

This study aims to evaluate the influence of using a bleached Curauá fiber (CF) as filler in a novel rigid polyurethane foam (RPUF) composite. The influence of 0.1, 0.5 and 1 wt.% of the reinforcements on the processing characteristics, cellular structure, mechanical, dynamic-mechanical, thermal, and flame behaviors were assessed and discussed for RPUF freely expanded. The results showed that the use of 0.5 wt.% of CF resulted in RPUF with smoother cell structure with low differences on the processing times and viscosity for the filled pre-polyol. These morphological features were responsible for the gains in mechanical properties, in both parallel and perpendicular rise directions, and better viscoelastic characteristics. Despite the gains, higher thermal conductivity and lower flammability were reported for the developed RPUF composites, related to the high content of cellulose and hemicellulose on the bleached CF chemical composition. This work shows the possibility of using a Brazilian vegetable fiber, with low exploration for the manufacturing of composite materials with improved properties. The developed RPUF presents high applicability as enhanced cores for the manufacturing of structural sandwich panels, mainly used in civil, aircraft, and marine industries.

Effect of the Processing Parameters on the Fabrication of MgAl2O4 Foams.

Stable MgAl2O4 foams (7-21 vol.%) were manufactured using a natural extract from the pericarp of the soap-nut fruit, saponin being the main component, as the foaming agent. The soap-nut extract is soluble in water, biodegradable, non-toxic, and has similar properties to commercial tensoactives. The stability and characteristics of the porous structure of the ceramic foams were evaluated in terms of the amount of foaming agent, content of MgAl2O4 particles, time and speed of stirring of the slurry, type of agitator, and drying temperature. It was found that the foaming capacity decreased with the percent of foaming agent and ceramic, whereas the time and speed of stirring enhanced the foamability. Foaming trials showed that stirring aqueous slurries with 3 wt.% of soap-nut extract for 2 min at 1070 or 2120 rpm, depending on the type of agitator, produced stable MgAl2O4 foams when drying at 60 °C. The mechanism of foaming is discussed. The foams were sintered at 1400 °C for 1 h under an Ar atmosphere. Observation of the sintered foam structures in the scanning electron microscope revealed nearly spherical cells with very good interconnectivity and strength to be manipulated, making them suitable as preforms for manufacturing Al-based composites by pressureless infiltration.

Numerical Study Using Microstructure Based Finite Element Modeling of the Onset of Convective Heat Transfer in Closed-Cell Polymeric Foam.

The thermal performance of closed-cell foams as an insulation device depends on the thermal conductivity. In these systems, the heat transfer mode associated with the convective contribution is generally ignored, and studies are based on the thermo-physical properties that emerge from the conductive contribution, while others include a term for radiative transport. The criterion found in the literature for disregarding convective heat flux is the cell diameter; however, the cell size for which convection is effectively suppressed has not been clearly disclosed, and it is variously quoted in the range 3-10 mm. In practice, changes in thermal conductivity are also attributed to the convection heat transfer mode; hence, natural convection in porous materials is worthy of research. This work extends the field of study of conjugate heat transfer (convection and conduction) in cellular materials using microstructure-based finite element analysis. For air-based insulating materials, the criteria to consider natural convection (Ra=103) is met by cavities with sizes of 9.06 mm; however, convection is developed into several cavities despite their sizes being lower than 9.06 mm, hence, the average pore size that can effectively suppress the convective heat transfer is 6.0 mm. The amount of heat transported by convection is about 20% of the heat transported by conduction within the foam in a Ra=103, which, in turn, produces an increasing average of the conductivity of about 4.5%, with respect to a constant value.

Tailoring strength of nanocellulose foams by electrostatic complexation.

Supramolecular assembly of biobased components in water is a promising strategy to construct advanced materials. Herein, electrostatic complexation was used to prepare wet-resilient foams with improved mechanical property. Small-angle X-ray scattering and cryo-transmission electron microscopy experiments showed that suspensions with oppositely charged cellulose nanofibers are a mixture of clusters and networks of entangled fibers. The balance between these structures governs the colloidal stability and the rheological behavior of CNFs in water. Foams prepared from suspensions exhibited maximum compressive modulus at the mass composition of 1:1 (ca 0.12 MPa), suggesting that meaningful attractive interactions happen at this point and act as stiffening structure in the material. Besides the electrostatic attraction, hydrogen bonds and hydrophobic contacts may also occur within the clustering, improving the water stability of cationic foams. These results may provide a basis for the development of robust all- cellulose materials prepared in water, with nontoxic chemicals.

Evaluation of rubber powder waste as reinforcement of the polyurethane derived from castor oil.

Waste tire rubber is produced on a large scale in the automotive industry and is considered difficult to recycle because they have iron, nylon, polyester, and chemical structure formed by cross-links. In this way, the waste is almost always deposited in inappropriate places or incorrectly burned, causing a series of environmental problems. The objective of this work was to analyze the viability of the use of waste tire rubber (5, 10, and 20% m/m) reinforced in polyurethane foam (PU) derived from castor oil to obtain composites, as an alternative for raw materials petrochemical industrial. The materials were characterized by scanning electron microscopy (SEM), optical microscopy (OM), apparent density, contact angle, water absorption, X-ray diffractometry (XRD), spectroscopy infrared (FTIR), thermogravimetry (TGA) techniques, and mechanical tests. The results showed that the residue of the rubber powder reinforced with polyurethane caused an increase in the density of the composites when compared to pure PU, which directly influenced the morphological, physical, thermal, and mechanical properties. This fact occurred because with the insertion of rubber powder in the PU there was a decrease in cell size and increase of pore volume. The TG and DTG analyzes showed that the insertion of the rubber powder improved the thermal stability of the composite when compared to pure PU, as well as impact tests and contact angle.

Daily genital cares of female gynecologists: a descriptive study

SUMMARY INTRODUCTION: Genital hygiene can play an essential role in avoiding vulvovaginal discomfort and preventing infections. The scientific evidence on best practices on genital hygiene is scarce, and without doubt, gynecologists should be the best person to discuss and guide the subject. OBJECTIVE: Evaluate the general genital female gynecologist hygiene. METHODS: This descriptive analytic study identified genital hygiene and sexual practices of 220 female gynecologists, through a questionnaire with 60 self-answered questions. The data were analyzed and presented using frequency, percentage, mean and standard deviation. RESULTS: The studied population was constituted by middle age (37.3 years) and white (71.3%) female gynecologists. More than a half (53.6%) declared spending over 10 hours a day away from home and complained of vaginal discharge in 48.1% of the cases. Regular vulvovaginal hygiene: 17.8% reported washing genitals once a day and 52% twice a day. The use of dry paper alone was reported in 66.4% post urination and 78.5% post-evacuation. Using running water and soap was practiced by 25.9% and 21.5% respectively. Vulvovaginal hygiene related to sex: More than half of them had intercourse 1-3 times a week, and 37.4% and 24.1% had frequent oral sex and eventually anal sexof the participants, respectively. Genital hygiene before sex was positive in 52.7% of the subjects and, post-sex hygiene in 78.5% of them. Conclusion: Genital hygiene habits of female gynecologists can be improved, despite the high grade of scientific knowledge they hold.

RESUMO INTRODUÇÃO: A higiene genital pode desempenhar um papel importante na prevenção de desconfortos vulvovaginais e infecções. Evidências científicas sobre as melhores práticas em higiene genital são escassas, e o ginecologista, sem dúvida, é a melhor pessoa para discutir e orientar o assunto. OBJETIVO: Avaliar a higiene genital feminina usual de médicas ginecologistas. MÉTODOS: Estudo analítico descritivo que identificou higiene genital e práticas sexuais de 220 ginecologistas por meio de um questionário com 60 perguntas autorrespondidas. Os dados foram analisados e apresentados por frequência, porcentagem, média e desvio padrão. Resultados: A população estudada consistiu de médicas ginecologistas femininas brancas (71,3%) com idade média de 37,3 anos. Mais da metade (53,6%) relatou ficar fora de suas casas por períodos superiores a 10 horas por dia e queixaram-se de descarga vaginal em 48,1% dos casos. Higiene vulvovaginal regular: 17,8% relataram lavar os genitais uma vez por dia e 52%, duas vezes por dia. O uso apenas de papel (seco) foi relatado em 66,4% dos casos após micção e em 78,5% após a evacuação. A higiene ideal com água corrente e sabão foi praticada apenas em 25,9% e 21,5%, respectivamente. Higiene vulvovaginal relacionada ao sexo: mais da metade delas relatou relações sexuais 1-3 vezes por semana, sexo oral frequente e anal eventual em 37,4% e 24,1%, respectivamente. A higiene genital pré-sexo foi relatada por 52,7% das pessoas e em 78,5% após o coito. Conclusão: Os hábitos de higiene genital dos ginecologistas femininos estão sujeitos a melhorias, mesmo considerando o alto grau de conhecimento científico que possuem.

Effect of surfactant concentration on the responsiveness of a thermoresponsive copolymer/surfactant mixture with potential application on "Smart" foams formulations.

HYPOTHESIS: Previous efforts to formulate smart foams composed of mixtures of PNIPAAm, a thermoresponsive uncharged polymer, and surfactants have failed because the surfactant displaces the PNIPAAm from the liquid-air interface, removing the thermal responsiveness. We hypothesized that thermoresponsive foams could be formulated with such a mixture if a charged surfactant were used in order to anchor an oppositely charged brush-type polyelectrolyte, for which PNIPAAm could be incorporated as side chains, to the interface. EXPERIMENTS: A brush-type negatively charged co-polyelectrolyte (Cop-L) with PNIPAAm as side chains was synthetized. Its mixtures with DTAB, a cationic surfactant, in aqueous solution were characterized by dynamic light scattering, surface tension and surface compression viscoelasticity measurements, as a function of both surfactant concentration and temperature. The foam stability and its responsiveness to temperature changes were studied with a homemade apparatus. FINDINGS: The Cop-L/DTAB mixtures were capable of producing thermoresponsive foams but only in a very narrow surfactant concentration (cs) range, 0.3 < cs< 1.6 mM. The responsiveness is due to a modification of the interfacial compression elasticity induced by conformational changes of the Polyeletrolyte/surfactant aggregates at the interface. This is possible only for cs < 1.6 because higher surfactant concentrations induce the polymer collapse at all temperatures, eliminating the thermal responsiveness.