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1.
Nanomaterials (Basel) ; 13(17)2023 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-37686938

RESUMEN

Cleaning represents an important and challenging operation in the conservation of cultural heritage, and at present, a key issue consists in the development of more sustainable, "green" materials and methods to perform it. In the present work, a novel xylene-in-water microemulsion based on nonionic surfactants with low toxicity was obtained, designed as low-impact cleaning agent for metallic historic objects. Phase diagram of the mixtures containing polyoxyethylene-polyoxypropilene triblock copolymer Pluronic P84 and D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS) as surfactants, water, ethanol and xylene was studied, and a microemulsion with low surfactant content was selected as suitable cleaning nanosystem. Essential oils (EOs) from thyme and cinnamon leaf were added to the selected microemulsion in order to include other beneficial properties such as anticorrosive and antifungal protection. The microemulsions with or without EOs were characterized by size, size distribution and zeta potential. The cleaning efficacy of the tested microemulsions was assessed based on their ability to remove two types of artificial dirt by using X-ray energy dispersion spectrometry (EDX), scanning electron microscopy (SEM), contact angle measurements and color analysis. Microemulsions exhibit high capacity to remove artificial dirt from model copper coupons in spite of very low content of the organic solvent. Both thyme and cinnamon oil loading microemulsions prove to significantly reduce the corrosion rate of treated metallic plates compared to those of bare copper. The antifungal activity of the novel type of microemulsion was evaluated against Aspergillus niger, reported as main treat in biocorrosion of historic copper artifacts. Application of microemulsion with small amounts of EOs on Cu plates inhibits the growth of fungi, providing a good fungicidal effect.

2.
Materials (Basel) ; 16(17)2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37687707

RESUMEN

This case study focuses on twelve compacted clay soil samples to understand their fundamental physical and thermal properties. For each sample, the density, thermal conductivity, thermal diffusivity, specific heat, and drying shrinkage were assessed. The identification and characterisation of the materials were also carried out by positioning them into the ternary diagram based on the percentage of sand, silt, and clay. These properties are definitive for the performance characteristics of materials used in rammed earth wall construction. The aim is to provide information for better knowledge and prediction regarding the dynamic heat flow in rammed earth walls. Experimental results show a relatively wide range of values for each property, reflecting the diverse properties of the sampled clays. The thermophysical characteristics of the 12 types of earth analysed showed correlations with reports in the literature in terms of density (1490-2150 kg/m3), porosity (23.22-39.99%), specific heat capacity (701-999 J/kgK), and thermal conductivity (0.523-1.209 W/mK), which indicates them as materials suitable for use in the construction of rammed earth walls. Using test data, a dynamic assessment of heat flow through simulated rammed earth walls was performed. For a better understanding of the results obtained, they were compared with results obtained for simulations where the building element would be made of concrete, i.e., a mineral wool core composite. Thus, heat flux at the wall surface and mass flux, respectively, during the 16 years of operation showed similar evolution for all 12 types of clay material analysed, with small variations explained by differences in thermophysical characteristics specific to each type of S1-S12 earth. In the case of walls made from clay material, there is a stabilisation in the evolution of the water content phenomenon by the 5th year of simulation. This contrasts with walls made of concrete, where the characteristic water content appears to evolve continuously over the 16-year period. Therefore, it can be said that in the case of the construction elements of existing buildings, which have already gone through a sufficient period for the maturation of the materials in their construction elements, the rammed earth wall quickly develops a moisture buffer function. In the case of simulating a mineral wool core composite wall, it cannot perform as a temperature or humidity buffer, exhibiting an enthalpy exchange with indoor air that is only 4% of that of the rammed earth walls; consequently, it does not play a significant role in regulating indoor comfort conditions. Overall, there is confirmation of the temperature and moisture buffering capabilities of rammed earth walls during both warm and cold periods of the year, which is consistent with other reports in the literature. The findings of this research provide a better insight into clay as a material for rammed earth walls for more efficient design and construction, offering potential improvements regarding indoor comfort, energy efficiency, and sustainability. The data also provides useful information in the fields of architecture and civil engineering regarding the use of clay as an eco-friendly building material. The results emphasise the importance of thoroughly understanding the thermophysical properties of clay to ensure the efficiency of rammed earth construction.

3.
Materials (Basel) ; 16(15)2023 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-37570162

RESUMEN

Worldwide, the need for thermal insulation materials used to increase the energy performance of buildings and ensure indoor thermal comfort is constantly growing. There are several traditional, well-known and frequently used thermal insulation materials on the building materials market, but there is a growing trend towards innovative materials based on agro-industrial waste. This paper analyses the performance of 10 such innovative thermal insulation materials obtained by recycling cellulosic and/or animal waste, using standardised testing methods. More precisely, thermal insulation materials based on the following raw materials were analysed: cellulose acetate, cigarette filter manufacturing waste; cellulose acetate, cigarette filter manufacturing waste and cigarette paper waste; cellulose acetate, waste from cigarette filter manufacturing, waste cigarette paper and waste aluminised paper; cellulose from waste paper (two types made by two independent manufacturers); wood fibres; cellulose from cardboard waste; cellulose from waste cardboard, poor processing, inhomogeneous product; rice husk waste and composite based on sheep wool, recycled PET fibres and cellulosic fibres for the textile industry. The analysis followed the performance in terms of thermal insulating quality, evidenced by the thermal conductivity coefficient (used as a measurable indicator) determined for both dry and conditioned material at 50% RH, in several density variants, simulating the subsidence under its own weight or under various possible stresses arising in use. The results showed in most cases that an increase in material density has beneficial effects by reducing the coefficient of thermal conductivity, but exceptions were also reported. In conjunction with this parameter, the analysis of the 10 types of materials also looked at their moisture sorption/desorption capacity (using as a measurable indicator the amount of water stored by the material), concluding that, although they have a capacity to regulate the humidity of the indoor air, under low RH conditions the water loss is not complete, leaving a residual quantity of material that could favour the development of mould. Therefore, the impact on indoor air quality was also analysed by assessing the risk of mould growth (using as a measurable indicator the class and performance category of the material in terms of nutrient content conducive to the growth of microorganisms) under high humidity conditions but also the resistance to the action of two commonly encountered moulds, Aspergillus niger and Penicillium notatum. The results showed a relative resistance to the action of microbiological factors, indicating however the need for intensified biocidal treatment.

4.
Materials (Basel) ; 16(14)2023 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-37512178

RESUMEN

This research investigates the feasibility of developing clay composites using natural materials and incorporating waste by-products suitable for plastering diverse support structures. The study identified a versatile composition suitable for a wide range of support materials and explored the potential of revaluing industrial waste and by-products by reintegrating them into the Circular Economy. The experimental investigation outlines the process of evaluating the influence of different raw materials on the performance of the clay composite. The findings confirm that using limestone sludge and fly ash as additives to clay contributes to reducing axial shrinkage and increasing mechanical strengths, respectively. The optimal percentage of additives for the clay used are identified and provided. Using hydraulic lime as a partial substitute for clay reduces the apparent density of dried clay composites, axial shrinkage, and fissures formation while improving adhesion to the substrate. Introducing dextrin into this mix increases the apparent density of the hardened plaster while keeping axial shrinkage below the maximum threshold indicated by the literature. Mechanical strengths improved, and better compatibility in terms of adhesion to the support was achieved, with composition S3 presenting the best results and a smooth, fissure-free plastered surface after drying.

5.
Polymers (Basel) ; 15(14)2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37514413

RESUMEN

This paper describes the preparation of new PEG6000-silica-MWCNTs composites as shape-stabilized phase change materials (ssPCMs) for application in latent heat storage. An innovative method was employed to obtain the new organic-inorganic hybrid materials, in which both a part of the PEG chains, used as the phase change material, and a part of the hydroxyl functionalized multiwall carbon nanotubes (MWCNTs-OH), used as thermo-conductive fillers, were covalently connected by newly formed urethane bonds to the in-situ-generated silica matrix. The study's main aim was to investigate the optimal amount of PEG6000 that can be added to the fixed sol-gel reaction mixture so that no leakage of PEG occurs after repeated heating-cooling cycles. The findings show that the optimum PEG6000/NCOTEOS molar ratio was 2/1 (~91.5% PEG6000), because both the connected and free PEG chains interacted strongly with the in-situ-generated silica matrix to form a shape-stabilized material while preserving high phase-transition enthalpies (~153 J/G). Morphological and structural findings obtained by SEM, X-ray and Raman techniques indicated a distribution of the silica component in the amorphous phase (~27% for the optimum composition) located among the crystalline lamellae built by the folded chains of the PEG component. This composite maintained good chemical stability after a 450-cycle thermal test and had a good storage efficiency (~84%).

6.
Exp Ther Med ; 26(1): 329, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37346404

RESUMEN

Bioceramic-based fillers have been evaluated in several in vitro studies but in vivo studies are still limited. The present study examined 36 postoperative radiographic analyses that were divided into four groups, of which three used bioceramic-based fillers, namely Total Fill, BioRoot RCS and Biodentine, while the fourth group was used as control and implemented the resin-based AH Plus Jet sealer. The present results did not indicate significant differences in radiopacity between sealers at a certain level of obturation. Biodentine-based fillers have a radiodensity close to that of dentin, which makes it difficult for the physician to radiologically assess the correctness of the canal filling.

7.
Gels ; 9(5)2023 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-37233016

RESUMEN

Natural polysaccharides are highly attractive biopolymers recommended for medical applications due to their low cytotoxicity and hydrophilicity. Polysaccharides and their derivatives are also suitable for additive manufacturing, a process in which various customized geometries of 3D structures/scaffolds can be achieved. Polysaccharide-based hydrogel materials are widely used in 3D hydrogel printing of tissue substitutes. In this context, our goal was to obtain printable hydrogel nanocomposites by adding silica nanoparticles to a microbial polysaccharide's polymer network. Several amounts of silica nanoparticles were added to the biopolymer, and their effects on the morpho-structural characteristics of the resulting nanocomposite hydrogel inks and subsequent 3D printed constructs were studied. FTIR, TGA, and microscopy analysis were used to investigate the resulting crosslinked structures. Assessment of the swelling characteristics and mechanical stability of the nanocomposite materials in a wet state was also conducted. The salecan-based hydrogels displayed excellent biocompatibility and could be employed for biomedical purposes, according to the results of the MTT, LDH, and Live/Dead tests. The innovative, crosslinked, nanocomposite materials are recommended for use in regenerative medicine.

8.
Pharmaceutics ; 15(5)2023 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-37242662

RESUMEN

The skin is a complex and selective system from the perspective of permeability to substances from the external environment. Microemulsion systems have demonstrated a high performance in encapsulating, protecting and transporting active substances through the skin. Due to the low viscosity of microemulsion systems and the importance of a texture that is easy to apply in the cosmetic and pharmaceutical fields, gel microemulsions are increasingly gaining more interest. The aim of this study was to develop new microemulsion systems for topical use; to identify a suitable water-soluble polymer in order to obtain gel microemulsions; and to study the efficacy of the developed microemulsion and gel microemulsion systems in the delivery of a model active ingredient, namely curcumin, into the skin. A pseudo-ternary phase diagram was developed using AKYPO® SOFT 100 BVC, PLANTACARE® 2000 UP Solution and ethanol as a surfactant mix; caprylic/capric triglycerides, obtained from coconut oil, as the oily phase; and distilled water. To obtain gel microemulsions, sodium hyaluronate salt was used. All these ingredients are safe for the skin and are biodegradable. The selected microemulsions and gel microemulsions were physicochemically characterized by means of dynamic light scattering, electrical conductivity, polarized microscopy and rheometric measurements. To evaluate the efficiency of the selected microemulsion and gel microemulsion to deliver the encapsulated curcumin, an in vitro permeation study was performed.

9.
Materials (Basel) ; 16(7)2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-37049167

RESUMEN

The continuous degradation of cultural heritage artifacts (due to different factors, including the rising air pollution, climate change or excessive biological activity, among others) requires the continuous development of protection strategies, technologies and materials. In this regard, polyelectrolytes have offered effective ways to fight against degradation but also to conserve the cultural heritage objects. In this review, we highlight the key developments in the creation and use of polyelectrolytes for the preservation, consolidation and cleaning of the cultural heritage artifacts (with particular focus on stone, metal and artifacts of organic nature, such as paper, leather, wood or textile). The state of the art in this area is presented, as well as future development perspectives.

10.
Pharmaceutics ; 15(2)2023 Jan 21.
Artículo en Inglés | MEDLINE | ID: mdl-36839693

RESUMEN

Salecan, a kind of polysaccharide, is produced by the Agrobacterium ZX09 salt tolerant strain. In this study, green crosslinked citric acid-salecan hydrogels are explored as novel materials with a high potential for use in regenerative medicine. The impact of salecan and citric acid on the final crosslinked hydrogels was intensively studied and estimated in terms of the whole physicochemical properties and antimicrobial activity. FTIR spectra demonstrated the successful green crosslinking of salecan through its esterification with citric acid where the formation of strong covalent bonds collaboratively helped to stabilize the entire hydrogel systems in a wet state. Hydrogels presented a microporous morphology, good swelling capacity, pH responsiveness, great mechanical stability under stress conditions and good antibacterial activity, all related to the concentration of the biopolymers used in the synthesis step. Additionally, salecan hydrogels were preliminary investigated as printing inks. Thanks to their excellent rheological behavior, we optimized the citrate-salecan hydrogel inks and printing parameters to render 3D constructs with great printing fidelity and integrity. The novel synthesized salecan green crosslinked hydrogels enriches the family of salecan-derived hydrogels. Moreover, this work not only expands the application of salecan hydrogels in various fields, but also provides a new potential option of designing salecan-based 3D printed scaffolds for customized regenerative medicine.

11.
Diagnostics (Basel) ; 13(3)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36766533

RESUMEN

Corticoids are largely used for fetal interest in expected preterm deliveries. This study went further, evaluating the effect of maternal administration of dexamethasone (Dex) on the umbilical artery (UA), middle cerebral artery (MCA), and ductus venous (DV) spectrum, in growth-restricted fetuses, with the absent end-diastolic flow (AEDF) in UA, from singleton early-onset severe preeclamptic pregnancies. Supplementary, the impact on both uterine arteries (UTAs) flow was also evaluated. In 68.7% of cases, the EDF was transiently restored (trAEDF group), in the rest of 31.2% remained persistent absent (prAEDF group). UA-PI significantly decreased in the first day after Dex (day 1/0; p < 0.05), reaching its minimum during day 2 (day 2/1; p > 0.05), revealing a significant recovery to day 4 (day 4/2; p < 0.05), in both groups. The MCA-PI decreased from day 1 until day 3 in both groups, but significantly only in the trAEDF group (p = 0.030 vs. p = 0.227. The DV-PI's decrease (during day 1) and the CPR's increase (between days 0 and 2) were not significant in both groups. UTAs-PIs did not vary. The prAEDF group had a significantly increased rate of antenatal worsening Doppler and a poorer perinatal outcome compared with the trAEDF group. In conclusion, Dex transiently restored the AEDF in UA in the majority of cases, a "positive" effect being a useful marker for better perinatal prognosis. UA-PI significantly decreased in all cases. The improvement in umbilical circulation probably was responsible for the short but not significant DV-PI reduction. MCA-PI decreased only in sensitive cases, probably due to an already cerebral "full" vasodilation in the prAEDF group. Furthermore, the CPR's nonsignificant improvement was the result of a stronger effect of Dex on UA-PI than on MCA-PI. Finally, despite the same etiology, it was only a weak correlation between the severity of the umbilical and uterine abnormal spectrum.

12.
Materials (Basel) ; 15(22)2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36431651

RESUMEN

In recent decades, there has been an increased interest in azo compounds with special optical and biological properties. In this work, we report the preparation of novel azo-compounds with two and three -N=N- double bonds, using the classical method of synthesis, diazotization and coupling. The compounds were characterized by 1H-NMR, 13C-NMR, FTIR, UV-VIS and fluorescence spectra. DFT calculations were employed for determining the optical parameters, polarizability α, the total static dipole moment µtot, the quadrupole moment Q and the mean first polarizability ßtot. All azo derivatives show strong fluorescence emission in solutions. The antioxidant and antifungal activities were determined and the influence of the number of azo bonds was discussed. The synthesized compounds exhibit remarkable efficiency in the growth reduction of standard and clinical isolated Candida strains, suggesting future applications as novel antifungal.

13.
Pharmaceutics ; 14(10)2022 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-36297572

RESUMEN

Apart from its well-known activity as an antimicrobial agent, Curcumin (CURC) has recently started to arouse interest as a photosensitizer in the photodynamic therapy of bacterial infections. The aim of the present study was to evidence the influence of the encapsulation of Curcumin into polymeric micelles on the efficiency of photoinduced microbial inhibition. The influence of the hydrophobicity of the selected Pluronics (P84, P123, and F127) on the encapsulation, stability, and antimicrobial efficiency of CURC-loaded micelles was investigated. In addition, the size, morphology, and drug-loading capacity of the micellar drug delivery systems have been characterized. The influence of the presence of micellar aggregates and unassociated molecules of various Pluronics on the membrane permeability was investigated on both normal and resistant microbial strains of E. coli, S. aureus, and C. albicans. The antimicrobial efficiency on the common pathogens was assessed for CURC-loaded polymeric micelles in dark conditions and activated by blue laser light (470 nm). Significant results in the reduction of the microorganism's growth were found in cultures of C. albicans, even at very low concentrations of surfactants and Curcumin. Unlike the membrane permeabilization effect of the monomeric solution of Pluronics, reported in the case of tumoral cells, a limited permeabilization effect was found on the studied microorganisms. Encapsulation of the Curcumin in Pluronic P84 and P123 at very low, nontoxic concentrations for photosensitizer and drug-carrier, produced CURC-loaded micelles that prove to be effective in the light-activated inhibition of resistant species of Gram-positive bacteria and fungi.

14.
Diagnostics (Basel) ; 12(9)2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36140569

RESUMEN

We aim to review data on 3beta-hydroxysteroid dehydrogenase type II (3ßHSD2) deficiency. We identified 30 studies within the last decade on PubMed: 1 longitudinal study (N = 14), 2 cross-sectional studies, 1 retrospective study (N = 16), and 26 case reports (total: 98 individuals). Regarding geographic area: Algeria (N = 14), Turkey (N = 31), China (2 case reports), Morocco (2 sisters), Anatolia (6 cases), and Italy (N = 1). Patients' age varied from first days of life to puberty; the oldest was of 34 y. Majority forms displayed were salt-wasting (SW); some associated disorders of sexual development (DSD) were attendant also-mostly 46,XY males and mild virilisation in some 46,XX females. SW pushed forward an early diagnosis due to severity of SW crisis. The clinical spectrum goes to: premature puberty (80%); 9 with testicular adrenal rest tumours (TARTs); one female with ovarian adrenal rest tumours (OARTs), and some cases with adrenal hyperplasia; cardio-metabolic complications, including iatrogenic Cushing' syndrome. More incidental (unusual) associations include: 1 subject with Barter syndrome, 1 Addison's disease, 2 subjects of Klinefelter syndrome (47,XXY/46,XX, respective 47,XXY). Neonatal screening for 21OHD was the scenario of detection in some cases; 17OHP might be elevated due to peripheral production (pitfall for misdiagnosis of 21OHD). An ACTH stimulation test was used in 2 studies. Liquid chromatography tandem-mass spectrometry unequivocally sustains the diagnostic by expressing high baseline 17OH-pregnenolone to cortisol ratio as well as 11-oxyandrogen levels. HSD3B2 gene sequencing was provided in 26 articles; around 20 mutations were described as "novel pathogenic mutation" (frameshift, missense or nonsense); many subjects had a consanguineous background. The current COVID-19 pandemic showed that CAH-associated chronic adrenal insufficiency is at higher risk. Non-adherence to hormonal replacement contributed to TARTs growth, thus making them surgery candidates. To our knowledge, this is the largest study on published cases strictly concerning 3ßHSD2 deficiency according to our methodology. Adequate case management underlines the recent shift from evidence-based medicine to individualized (patient-oriented) medicine, this approach being particularly applicable in this exceptional and challenging disorder.

15.
Int J Mol Sci ; 23(18)2022 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-36142243

RESUMEN

The present work aims to show how the main properties of poly(methacrylic acid) (PMAA) hydrogels can be engineered by means of several silicon-based fillers (Laponite XLS/XLG, montmorillonite (Mt), pyrogenic silica (PS)) employed at 10 wt% concentration based on MAA. Various techniques (FT-IR, XRD, TGA, SEM, TEM, DLS, rheological measurements, UV-VIS) were used to comparatively study the effect of these fillers, in correlation with their characteristics, upon the structure and swelling, viscoelastic, and water decontamination properties of (nano)composite hydrogels. The experiments demonstrated that the nanocomposite hydrogel morphology was dictated by the way the filler particles dispersed in water. The equilibrium swelling degree (SDe) depended on both the pH of the environment and the filler nature. At pH 1.2, a slight crosslinking effect of the fillers was evidenced, increasing in the order Mt < Laponite < PS. At pH > pKaMAA (pH 5.4; 7.4; 9.5), the Laponite/Mt-containing hydrogels displayed a higher SDe as compared to the neat one, while at pH 7.4/9.5 the PS-filled hydrogels surprisingly displayed the highest SDe. Rheological measurements on as-prepared hydrogels showed that the filler addition improved the mechanical properties. After equilibrium swelling at pH 5.4, G' and G" depended on the filler, the Laponite-reinforced hydrogels proving to be the strongest. The (nano)composite hydrogels synthesized displayed filler-dependent absorption properties of two cationic dyes used as model water pollutants, Laponite XLS-reinforced hydrogel demonstrating both the highest absorption rate and absorption capacity. Besides wastewater purification, the (nano)composite hydrogels described here may also find applications in the pharmaceutical field as devices for the controlled release of drugs.


Asunto(s)
Nanocompuestos , Contaminantes del Agua , Bentonita , Colorantes , Preparaciones de Acción Retardada , Hidrogeles/química , Metacrilatos , Nanocompuestos/química , Nanogeles , Silicatos , Silicio , Dióxido de Silicio , Espectroscopía Infrarroja por Transformada de Fourier , Agua
16.
Artículo en Inglés | MEDLINE | ID: mdl-35897304

RESUMEN

The purpose of this study was to show the improved outcomes of restoring endodontically treated teeth with fiberglass posts compared to restorations using metal posts. In our study, we used the Finite Element Method (FEM), which is based on the principle that a physical model that supports a given load distributes the stress throughout its volume. We sought to assess what stress results in a tooth when it is restored using a fiberglass post compared to restoration using a metal post. The finite element analysis showed that a system consisting of a tooth with a fiberglass post is more stable in terms of the maximum stress than a system consisting of a tooth with a metal post. The maximum displacements and deformations were obtained in the case of a canine restored with a fiberglass post, which showed that this system had a high elasticity, therefore, higher strength than a canine restored with a metal post, which had high rigidity.


Asunto(s)
Técnica de Perno Muñón , Diente no Vital , Resinas Compuestas , Análisis de Elementos Finitos , Vidrio , Humanos , Diente no Vital/terapia
17.
Antioxidants (Basel) ; 11(5)2022 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-35624718

RESUMEN

Curcumin, due to its antioxidant, antibacterial, anti-inflammatory, and antitumoral activity, has attracted huge attention in applications in many fields such as pharmacy, medicine, nutrition, cosmetics, and biotechnology. The stability of curcumin-based products and preservation of antioxidant properties are still challenges in practical applications. Stability and antioxidant properties were studied for curcumin encapsulated in O/W microemulsion systems and three related gel microemulsions. Only biodegradable and biocompatible ingredients were used for carriers: grape seed oil as oily phase, Tween 80, and Plurol® Diisostearique CG as a surfactant mix, and ethanol as a co-solvent. For the gel microemulsions, water-soluble polymers, namely Carbopol® 980 NF, chitosan, and sodium hyaluronate were used. The influence of UVC irradiation and heat treatment on the degradation kinetics of curcumin in the formulations was studied. Because of the antioxidant character of the microemulsion oily phase, the possibility of a synergistic effect between grape seed oil and curcumin was explored. In this study, the high efficiency of the studied drug delivery systems to ensure protection from external degradative factors was confirmed. Also, the influence of the encapsulation in microemulsion and derived gel microemulsion systems on the antioxidant capacity curcumin was studied, and a synergistic effect with vegetal oil was demonstrated.

18.
Materials (Basel) ; 15(4)2022 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-35207888

RESUMEN

The current context provides, worldwide, the need to identify solutions for the thermal efficiency of constructions, through sustainable and innovative methods and products. A viable solution is to produce thermal insulating products by carding-folding technology, using natural fibres and recycled polyethylene terephthalate (rPET) and polyester (rPES) waste, converted to fibres. This paper presents experimental results obtained after testing several thermal insulation composite products produced using a mix of sheep wool, cellulose, rPET and rPES fibres. The results of the research demonstrate the thermal insulation properties but, at the same time, identify the benefits of using such materials on the quality of the air in the interior space (the ability to adjust humidity and reduce the concentration of harmful substances). At the same time, the advantages of using sheep wool composite mattresses concerning their resistance to insect attack is demonstrated when compared with ordinary thermal insulation materials. Finally, sensitivity elements of these composites are observed in terms of sensitivity to mould, and to contact with water or soil, drawing future research directions in the development of this type of materials.

19.
Medicina (Kaunas) ; 58(2)2022 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-35208597

RESUMEN

Background and Objectives: The occurrence of human immunodeficiency virus (HIV) infection in children in Romania has been reported since 1989. This retrospective study was aimed at assessing clinical and biological risk factors for mother-to-child transmission (MTCT) of HIV in two HIV-acquired immune deficiency syndrome (AIDS) Regional Centers (RCs), Constanta and Craiova in Romania. Materials and Methods: During the study period (2008-2019), 408 HIV-positive pregnant women, 244 from Constanta RC and 164 from Craiova RC who attended antenatal visits, were included. All HIV-positive pregnant women were under combined antiretroviral therapy (cART) during pregnancy and childbirth, being followedup with their infants up to 18 months after delivery. We investigated the clinical as well as biological risk factorsassociated with increased MTCT of HIV. Results: Comparing different variables of HIV-positive pregnant women from the two HIV-AIDS CRs, we find that there are significant differences between the mean value of hemoglobin, CD4 level, environmental area, marital and amniotic membranes status, and HIV patient stage in the last trimester of pregnancy (p < 0.05), but without any differences in mother's mean age, education level, type of delivery, breastfeeding, the duration of cART administration, HIV viral load, and survival rate. Conclusions: In 408 HIV-positive pregnant women followed up at two HIV-AIDS RCs in Romania, the most important clinical and biological risk factors associated with increased MTCT of HIV are represented by anemia, CD4 level, and HIV patient stage.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , Infecciones por VIH , Complicaciones Infecciosas del Embarazo , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Lactante , Transmisión Vertical de Enfermedad Infecciosa , Embarazo , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Rumanía/epidemiología
20.
Nanomaterials (Basel) ; 11(10)2021 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-34685015

RESUMEN

ZnO nanoparticle-based multifunctional coatings were prepared by a simple, time-saving microwave method. Arginine and ammonia were used as precipitation agents, and zinc acetate dehydrate was used as a zinc precursor. Under the optimized conditions, flower-like morphologies of ZnO aggregates were obtained. The prepared nanopowders were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and UV/Visible spectroscopy. The developed in situ synthesis with microwave irradiation enabled significant ZnO nanoparticle deposition on cotton fabrics, without additional steps. The functionalized textiles were tested as a photocatalyst in methylene blue (MB) photodegradation and showed good self-cleaning and UV-blocking properties. The coated cotton fabrics exhibited good antibacterial properties against common microbial trains (Staphylococcus aureus, Escherichia coli, and Candida albicans), together with self-cleaning and photocatalytic efficiency in organic dye degradation. The proposed microwave-assisted in situ synthesis of ZnO nanocoatings on textiles shows high potential as a rapid, efficient, environmentally friendly, and scalable method to fabricate functional fabrics.

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