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1.
Gynecol Endocrinol ; 36(12): 1047-1050, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32960105

RESUMO

Polycystic Ovary Syndrome (PCOS) is a complex endocrine disorder, which affects 5-17% of reproductive age women and is often associated with obesity and metabolic impairment. Common treatment strategies are based on exercise, diet and nutrient supplementation since PCOS is often linked with obesity and metabolic impairment. Studies have recommended that nutrition is a key factor in the health maintenance of women with PCOS, however, little is known about the subject in the context of such a disease. This narrative review aims to identify dietary and nutritional aspects of PCOS and discuss the role of nutrients in management of polycystic ovary syndrome in view of clinical trials.


Assuntos
Restrição Calórica , Dieta com Restrição de Carboidratos , Dieta Cetogênica , Suplementos Nutricionais , Síndrome do Ovário Policístico/dietoterapia , Dieta , Feminino , Preferências Alimentares , Humanos , Resistência à Insulina , Obesidade/dietoterapia , Obesidade/metabolismo , Síndrome do Ovário Policístico/metabolismo
2.
Int J Mol Sci ; 21(8)2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32331206

RESUMO

The unprecedently high CO2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g-1) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.


Assuntos
Dióxido de Carbono/química , Anidrases Carbônicas/química , Biocatálise , Engenharia Química/métodos , Estabilidade Enzimática , Gases de Efeito Estufa/química , Concentração de Íons de Hidrogênio , Relação Estrutura-Atividade , Temperatura
3.
Int J Adolesc Med Health ; 25(1): 55-63, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23334054

RESUMO

AIM: It has been suggested that the decline in menarcheal age is associated with the increase of obesity prevalence. OBJECTIVE: To examine the association between age at menarche and adiposity development from age 7 to 15 years. SUBJECTS: A cohort of 109 schoolgirls from Viana do Castelo (Northern Portugal). METHODS: Anthropometric measurements (height, weight, and triceps and subscapular skinfold thicknesses) were longitudinally obtained at 7, 8, 9, and 15 years. Waist circumference and self-reported age at menarche were obtained at age 15. Obesity was defined by the cut-off value of 30% body fat. Ages of <12 years, 12-13 years, and >13 years were classified as early menarche (EM), average menarche (AM) and late menarche (LM), respectively. RESULTS: Median menarcheal age was 12.0 years (range, 8-15 years), with 26.6% of girls classified as EM. Compared with their LM peers, EM girls were always fatter (p=0.001) and had higher waist circumference at age 15 (p=0.009). All variables showed significant negative associations with age at menarche, except subscapular to triceps skinfold ratio at all ages and height at age 15. At both ages 9 and 15 years, LM girls had the lowest prevalence of obesity (4.5% and 9.1%, respectively). The 8-year incidence of obesity in EM girls was 24.1%, while that in the AM plus LM group was 13.8% (p=0.005). CONCLUSION: EM seems to be a risk factor for the development of obesity during adolescence. However, this vulnerability may start to be programmed before menarche as girls with precocious menarche were already fatter than their late-maturing peers at age 7 years.


Assuntos
Adiposidade , Menarca , Obesidade/epidemiologia , Adolescente , Fatores Etários , Estatura , Peso Corporal , Distribuição de Qui-Quadrado , Criança , Feminino , Seguimentos , Humanos , Incidência , Portugal/epidemiologia , Prevalência , Fatores de Risco , Dobras Cutâneas , Estatísticas não Paramétricas , Circunferência da Cintura
4.
Environ Sci Technol ; 46(1): 462-8, 2012 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-22087544

RESUMO

Dioxins and dioxin-like chemicals are predominantly produced by thermal processes such as incineration and combustion at concentrations in the range of 10-100 ng of I-TEQ/kg (I-TEQ = international toxic equivalents). In this work, a new approach for the removal of dioxins from high-temperature vapor streams using facilitated supported ionic liquid membranes (SILMs) is proposed. The use of ceramic membranes containing specific ionic liquids, with extremely low volatility, for dioxin removal from incineration sources is proposed owing to their stability at very high temperatures. Supported liquid membranes were prepared by successfully immobilizing the ionic liquids tri-C(8)-C(10)-alkylmethylammonium dicyanamide ([Aliquat][DCA]) and 1-n-octyl-3-methylimidazolium dicyanamide ([Omim][DCA]) inside the porous structure of ceramic membranes. The porous inorganic membranes tested were made of titanium oxide (TiO(2)), with a nominal pore size of 30 nm, and aluminum oxide (Al(2)O(3)), with a nominal pore size of 100 nm. The ionic liquids were characterized, and the membrane performance was assessed for the removal of dioxins. Different materials (membrane pore size, type of ionic liquid, and dioxin) and different operating conditions (temperature and flow rate) were tested to evaluate the efficiency of SILMs for dioxin removal. All membranes prepared were stable at temperatures up to 200 °C. Experiments with model incineration gas were also carried out, and the results obtained validate the potential of using ceramic membranes with immobilized ionic liquids for the removal of dioxins from high-temperature vapor sources.


Assuntos
Dioxinas/isolamento & purificação , Temperatura Alta , Líquidos Iônicos/química , Membranas Artificiais , Vapor/análise , Boratos/química , Cerâmica/química , Dioxinas/química , Gases/química , Imidazóis/química , Incineração , Permeabilidade , Porosidade , Reologia , Viscosidade
5.
Membranes (Basel) ; 12(1)2022 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-35054624

RESUMO

Spent caustic effluents are very challenging due to their very hazardous nature in terms of toxicity as well as their extreme pH (approximately 12-14). Spent caustic has presented a challenge for wastewater treatment in refineries, due to its composition rich in mercaptans, sulfides and other aromatic compounds. To address such problems, membrane filtration was studied using real effluents from Sines Refinery, in Portugal. The present study attempts to assess the potential for spent caustic treatment with nanofiltration (NF) polymeric and ceramic membranes, assessing membrane life expectancy. For that, membrane aging studies in static mode were performed with the polymeric membrane before attempting NF treatment (dynamic studies). A ceramic membrane was also tested for the first time with this type of effluents, though only in dynamic mode. Although the polymeric membrane performance was very good and in accordance with previous studies, its lifespan was very reduced after 6 weeks of contact with spent caustic, compromising its use in an industrial unit. Contrarily to expectations, the ceramic membrane tested was not chemically more resistant than the polymeric one upon direct contact with spent caustic (loss of retention capacity in less than 1 h in contact with the spent caustic). The results obtained suggest that a pH of 13.9 is very aggressive, even for ceramic membranes.

6.
Polymers (Basel) ; 14(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36298020

RESUMO

This work assessed the film-forming capacity of exopolysaccharides (EPS) produced by six Alteromonas strains recently isolated from different marine environments in French Polynesia atolls. The films were transparent and resulted in small colour alterations when applied over a coloured surface (ΔEab below 12.6 in the five different colours tested). Moreover, scanning electron microscopy showed that the EPS films were dense and compact, with a smooth surface. High water vapour permeabilities were observed (2.7-6.1 × 10-11 mol m-1 s-1 Pa-1), which are characteristic of hydrophilic polysaccharide films. The films were also characterised in terms of barrier properties to oxygen and carbon dioxide. Interestingly, different behaviours in terms of their mechanical properties under tensile tests were observed: three of the EPS films were ductile with high elongation at break (ε) (35.6-47.0%), low tensile strength at break (Ꞇ) (4.55-11.7 MPa) and low Young's modulus (εm) (10-93 MPa), whereas the other three were stiffer and more resistant with a higher Ꞇ (16.6-23.6 MPa), lower ε (2.80-5.58%), and higher εm (597-1100 MPa). These properties demonstrate the potential of Alteromonas sp. EPS films to be applied in different areas such as biomedicine, pharmaceuticals, or food packaging.

7.
Ann Hum Biol ; 38(4): 520-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21495896

RESUMO

BACKGROUND: Cross-sectional data show high prevalence of overweight in Portuguese children, but there are few longitudinal studies describing the patterns of obesity development in the young. AIM: To examine the trajectories of obesity from late childhood to adolescence. SUBJECTS AND METHODS: Triceps and subscapular skinfold thickness measurements were carried out in 288 children at age 9 (baseline) and later at age 15 (follow-up). Percentage body fat (%BF) was estimated according to Slaughter equations and the health-related definition of obesity ( ≥ 25%BF in boys and ≥ 30%BF in girls) was used. RESULTS: In boys, the prevalence of obesity decreased from 21.9% to 14.8% (p < 0.05) while in girls it increased from 14.3% to 19.5%. The incidence of obesity in the 6-year study period was 2.6% and 8.3% for boys and girls, respectively (p < 0.05). In comparison with girls, the percentage of boys that reversed obesity was more than 3-fold higher (3% vs 9.7%, p < 0.05). Obesity tracked moderately in both sexes (Kappa = 0.6, p < 0.001). CONCLUSION: The results indicate a marked sex difference in the incidence and reversal of obesity from late childhood to adolescence that is unfavourable to girls. Consideration of this difference might be important when designing programmes for the prevention and treatment of obesity focusing on this period.


Assuntos
Adiposidade/fisiologia , Adolescente , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Obesidade/fisiopatologia , Portugal/etnologia , Estatísticas não Paramétricas
8.
RSC Adv ; 11(62): 39278-39286, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-35492502

RESUMO

Carboxylate ionic liquids (ILs) combining benzethonium (BE) and didecyldimethylammonium (DDA) as cations have been explored to be used for the first time as dual functional solvents for microcrystalline cellulose (MCC) dissolution and, subsequently development of polymeric structures. Considering that some ILs can remain in the polymeric structures after phase inversion, these ILs can offer advantages such as antibacterial/antimicrobial response and ability to disrupt H-bonds. In this context, all tested ILs have been able to dissolve MCC up to a concentration of 4% (w/w), resulting in different polymeric structures, such as gel-like or films, depending on the type of IL and the ratio between MCC and IL. Furthermore, FTIR spectroscopy showed that some IL remains in the polymeric structures, which can enhance their application in the biomedical field.

9.
Membranes (Basel) ; 11(12)2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34940499

RESUMO

Despite the fact that iongels are very attractive materials for gas separation membranes, they often show mechanical stability issues mainly due to the high ionic liquid (IL) content (≥60 wt%) needed to achieve high gas separation performances. This work investigates a strategy to improve the mechanical properties of iongel membranes, which consists in the incorporation of montmorillonite (MMT) nanoclay, from 0.2 to 7.5 wt%, into a cross-linked poly(ethylene glycol) diacrylate (PEGDA) network containing 60 wt% of the IL 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][TFSI]). The iongels were prepared by a simple one-pot method using ultraviolet (UV) initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) and characterized by several techniques to assess their physico-chemical properties. The thermal stability of the iongels was influenced by the addition of higher MMT contents (>5 wt%). It was possible to improve both puncture strength and elongation at break with MMT contents up to 1 wt%. Furthermore, the highest ideal gas selectivities were achieved for iongels containing 0.5 wt% MMT, while the highest CO2 permeability was observed at 7.5 wt% MMT content, due to an increase in diffusivity. Remarkably, this strategy allowed for the preparation and gas permeation of self-standing iongel containing 80 wt% IL, which had not been possible up until now.

10.
Polymers (Basel) ; 13(5)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803474

RESUMO

This study seeks to render residues from banana plants into a useful byproduct with possible applications in wound dressings and food packaging. Films based on cellulose extracted from banana plant pseudostem and doped with phenolic compounds extracted from banana plant leaves were developed. The phenolic compounds were extracted using batch solid-liquid and Soxhlet methods, with different drying temperatures and periods of time. The total phenolic content and antioxidant activity were quantified. The optimum values were obtained using a three-day period batch-solid extraction at 40 °C (791.74 ± 43.75 mg/L). SEM analysis indicates that the pseudostem (PS) films have a porous structure, as opposed to hydroxyethyl cellulose (HEC) films which presented a homogeneous and dense surface. Mechanical properties confirmed the poor robustness of PS films. By contrast HEC films manifested improved tensile strength at low levels of water activity. FTIR spectroscopy reinforced the need to improve the cellulose extraction process, the success of lignin and hemicellulose removal, and the presence of phenolic compounds. XRD, TGA and contact angle analysis showed similar results for both films, with an amorphous structure, thermal stability and hydrophilic behavior.

11.
Membranes (Basel) ; 12(1)2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-35054541

RESUMO

Carbon dioxide (CO2) capture has become of great importance for industrial processes due to the adverse environmental effects of gas emissions. Mixed matrix membranes (MMMs) have been studied as an alternative to traditional technologies, especially due to their potential to overcome the practical limitations of conventional polymeric and inorganic membranes. In this work, the effect of using different ionic liquids (ILs) with the stable metal-organic framework (MOF) ZIF-8 was evaluated. Several IL@ZIF-8 composites and IL@ZIF-8 MMMs were prepared to improve the selective CO2 sorption and permeation over other gases such as methane (CH4) and nitrogen (N2). Different ILs and two distinct loadings were prepared to study not only the effect of IL concentration, but also the impact of the IL structure and affinity towards a specific gas mixture separation. Single gas sorption studies showed an improvement in CO2/CH4 and CO2/N2 selectivities, compared with the ones for the pristine ZIF-8, increasing with IL loading. In addition, the prepared IL@ZIF-8 MMMs showed improved CO2 selective behavior and mechanical strength with respect to ZIF-8 MMMs, with a strong dependence on the intrinsic IL CO2 selectivity. Therefore, the selection of high affinity ILs can lead to the improvement of CO2 selective separation for IL@ZIF-8 MMMs.

12.
Nanoscale Adv ; 2(7): 2885-2896, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-36132391

RESUMO

Currently, the fabrication of scaffolds for engineered skeletal muscle tissues is unable to reach the millimeter size. The main drawbacks are the poor nutrient diffusion, lack of an internal structure to align the precursor cells, and poor mechanical and electric properties. Herein, we present a combination of gelatin-carboxymethyl cellulose materials polymerised by a cryogelation process that allowed us to reach scaffold fabrication up to millimeter size and solve the main problems related to the large size muscle tissue constructs. (1) By incorporating carbon nanotubes (CNT), we can improve the electrical properties of the scaffold, thereby enhancing tissue maturation when applying an electric pulse stimulus (EPS). (2) We have fabricated an anisotropic internal three-dimensional microarchitecture with good pore distribution and highly aligned morphology to enhance the cell alignment, cell fusion and myotube formation. With this set up, we were able to generate a fully functional skeletal muscle tissue using a combination of EPS and our doped-biocomposite scaffold and obtain a mature tissue on the millimeter scale. We also characterized the pore distribution, swelling, stiffness and conductivity of the scaffold. Moreover, we proved that the cells were viable and could fuse in three-dimensional (3D) functional myotubes throughout the scaffold. In conclusion, we fabricated a biocompatible and customizable scaffold for 3D cell culture suitable for a wide range of applications such as organ-on-a-chip, drug screening, transplantation and disease modelling.

13.
Membranes (Basel) ; 10(3)2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32192181

RESUMO

Iongel-based CO2 separation membranes were prepared by fast (< 1 min) UV-initiated polymerization of poly(ethylene glycol) diacrylate (PEGDA) in the presence of different ionic liquids (ILs) with the [C2mim]+ cation and anions such as [TFSI]-, [FSI]-, [C(CN)3]- and [B(CN)4]-. The four ILs were completely miscible with the non-ionic PEGDA network. Transparent and free-standing iongels containing between 60 and 90 %wt of IL were obtained and characterized by diverse techniques (FTIR, TGA, DSC, DMTA, SEM, CO2 solubility and pure gas permeability). The thermal and mechanical stability of the iongels, as well as CO2 solubility, were found to be strictly dependent on the IL content and the anion's nature. The TGA results indicated that the iongels mostly follow the thermal profile of the respective neat ILs. The DMTA analysis revealed that the iongels based on fluorinated anions have higher storage modulus than those of cyano-functionalized anions. Conversely, the PEGDA-C(CN)3 iongels presented the highest CO2 solubility values ranging from 72 to 80 mmol/g. Single CO2 permeabilities of 583 ± 29 Barrer and ideal CO2/N2 selectivities of 66 ± 3 were obtained with the PEGDA-70 C(CN)3 iongel membrane. This work demonstrates that the combination of PEGDA with high contents of the best performing ILs is a promising and simple strategy, opening up new possibilities in the design of high-performance iongel membranes for CO2 separation.

14.
Bioengineering (Basel) ; 7(2)2020 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-32260526

RESUMO

The co-culture of Cupriavidus necator DSM 428 and Pseudomonas citronellolis NRRL B-2504 was performed using apple pulp waste from the fruit processing industry as the sole carbon source to produce poly(3-hydroxybutyrate), P(3HB) and medium-chain length PHA, mcl-PHA, respectively. The polymers accumulated by both strains were extracted from the co-culture's biomass, resulting in a natural blend that was composed of around 48 wt% P(3HB) and 52 wt% mcl-PHA, with an average molecular weight of 4.3 × 105 Da and a polydispersity index of 2.2. Two melting temperatures (Tm) were observed for the blend, 52 and 174 °C, which correspond to the Tm of the mcl-PHA and P(3HB), respectively. P(3HB)/mcl-PHA blend films prepared by the solvent evaporation method had permeabilities to oxygen and carbon dioxide of 2.6 and 32 Barrer, respectively. The films were flexible and easily deformed, as demonstrated by their tensile strength at break of 1.47 ± 0.07 MPa, with a deformation of 338 ± 19% until breaking, associated with a Young modulus of 5.42 ± 1.02 MPa. This study demonstrates for the first time the feasibility of using the co-culture of C. necator and P. citronellolis strains to obtain a natural blend of P(3HB)/mcl-PHA that can be processed into films suitable for applications ranging from commodity packaging products to high-value biomaterials.

15.
Carbohydr Polym ; 247: 116679, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829807

RESUMO

This work explores the novelty of dissolving chitin-glucan complex (CGC), from two fungal strains, Komagataella pastoris (CGCP) and Aspergillus niger (CGCKZ) (KiOnutrime-CG™), using biocompatible ionic liquids (ILs). Three cholinium-based ILs were tested, choline acetate, choline propionate and choline hexanoate. Although all tested ILs resulted in the dissolution of the co-polymer at a concentration of 5 % (w/w), distinct polymeric structures, films or gels, were obtained from CGCP and CGCKZ, respectively. CGCP films were dense, flexible and elastic, with high swelling capacity (> 200 %). The IL anion alkyl chain length influenced the polymeric structures' properties, namely, the CGCP films elongation at break and swelling degree. CGCKZ resulted in weak gels. For both polymeric structures, exposure to the ILs under the dissolution conditions caused significant changes in the co-polymers' chemical structure, namely, reduction of their glucan moiety and reduction of the degree of acetylation, thus yielding chitosan-glucan complexes (ChGC) enriched in glucosamine (53.4 ± 0.3-60.8 ± 0.3 %).


Assuntos
Biopolímeros/química , Quitina/química , Quitina/isolamento & purificação , Glucanos/química , Glucanos/isolamento & purificação , Líquidos Iônicos/química , Acetilação , Aspergillus niger/química , Colina/análogos & derivados , Colina/química , Géis/química , Glucosamina/química , Microscopia Eletrônica de Varredura , Oscilometria , Reologia , Saccharomycetales/química , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Água/química
16.
Int J Biol Macromol ; 163: 1707-1718, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32961186

RESUMO

The development of natural based, effective and protective wound dressings associated to local treatment applied on chronic wounds, represents a major challenge nowadays. In this work chitosan-based films were prepared with different concentrations of ethanolic ultrasound assisted extracts from Cynara cardunculus leaves (EtPUAE). The physico-chemical film properties revealed that extract incorporation influences the volumetric swelling capacity and mechanical properties of the films, leading to materials with a lower fluid absorption capacity and more fragile. However, no impact was detected on the thermal properties of the films, as well as on their dense structure characterized by Scanning Electronic Microscopy (SEM) analysis. Biological screening of chitosan-based films show that chitosan with a 1% (w/w) and a 5% (w/w) EtPUAE loading did not induce cytotoxicity on normal human skin fibroblasts (Bj5-ta cell line), mainly attributed to cynaropicrin (extract key active compound) present in the film below its IC50 value. Nevertheless, chitosan-based films with 5% (w/w) EtPUAE presented an interesting anti-inflammatory activity. Bj5-ta cells stimulated with liposaccharides (LPS), presented a reduction of 86% on IL-6 cytokine levels, after exposure to chitosan with 5% EtPUAE film extract. The results obtained in this study open up the possibility of successfully using chitosan films doped with EtPUAE for development of chronic wound dressings, with the advantage of using naturally-sourced materials with anti-inflammatory activity.


Assuntos
Quitosana/química , Cynara/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Cicatrização/efeitos dos fármacos , Bandagens , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Lactonas/química , Microscopia Eletrônica de Varredura/métodos , Sesquiterpenos/química , Pele/efeitos dos fármacos
17.
Int J Biol Macromol ; 122: 1144-1151, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30219510

RESUMO

Pseudomonas chlororaphis subsp. aurantiaca (DSM 19603) was grown on crude glycerol from biodiesel production to produce a medium-chain-length polyhydroxyalkanoate (mcl-PHA), composed of 3-hydroxydodecanoate (43 ±â€¯1.8 mol%), 3-hydroxydecanoate (29 ±â€¯3.1 mol%), 3-hydroxytetradecanoate (12 ±â€¯0.4 mol%), 3-hydroxyoctanoate (10 ±â€¯1.5 mol%) and 3-hydroxyhexanoate (6 ±â€¯0.3 mol%). The biopolymer had an average molecular weight of 1.1 × 105 Da, with a polydispersity index of 1.5, and was semi-crystalline, as shown by its crystallinity index of 37 ±â€¯0.2%. It had low melting (44 °C) and glass transition (-48 °C) temperatures, and was thermally stable up to 285 °C. The biopolymer films were elastic and translucid, were hydrophobic and presented relatively high permeability to oxygen and carbon dioxide. The films demonstrated to have good adhesion properties towards porcine skin and human skin. The tension (61.1 ±â€¯20.6 kPa) and shear (12.7 ±â€¯2.14 kPa) bond strength of the mcl-PHA for porcine skin suggest its potential as a biomaterial for the development of novel natural adhesives for wound closure or wound dressings.


Assuntos
Glicerol/química , Poli-Hidroxialcanoatos/química , Pseudomonas chlororaphis/química , Adesividade , Animais , Humanos , Teste de Materiais , Peso Molecular , Estresse Mecânico , Suínos , Temperatura
18.
Mol Biol Cell ; 16(4): 2068-76, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15703210

RESUMO

Glycerol and other polyols are used as osmoprotectants by many organisms. Several yeasts and other fungi can take up glycerol by proton symport. To identify genes involved in active glycerol uptake in Saccharomyces cerevisiae we screened a deletion mutant collection comprising 321 genes encoding proteins with 6 or more predicted transmembrane domains for impaired growth on glycerol medium. Deletion of STL1, which encodes a member of the sugar transporter family, eliminates active glycerol transport. Stl1p is present in the plasma membrane in S. cerevisiae during conditions where glycerol symport is functional. Both the Stl1 protein and the active glycerol transport are subject to glucose-induced inactivation, following identical patterns. Furthermore, the Stl1 protein and the glycerol symporter activity are strongly but transiently induced when cells are subjected to osmotic shock. STL1 was heterologously expressed in Schizosaccharomyces pombe, a yeast that does not contain its own active glycerol transport system. In S. pombe, STL1 conferred the ability to take up glycerol against a concentration gradient in a proton motive force-dependent manner. We conclude that the glycerol proton symporter in S. cerevisiae is encoded by STL1.


Assuntos
Metabolismo dos Carboidratos , Glicerol/metabolismo , Hidrogênio/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Transporte Biológico/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Glucose/farmacologia , Proteínas de Membrana Transportadoras/genética , Mutação/genética , Pressão Osmótica , Prótons , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo
19.
Psico USF ; 28(3): 619-632, jul.-set. 2023. tab, graf
Artigo em Português | LILACS, INDEXPSI | ID: biblio-1521361

RESUMO

Este estudo busca identificar e analisar os estudos que associam a Psicologia Positiva e seus construtos com os transtornos relacionados ao uso de substâncias psicoativas. Foi feita uma revisão integrativa sobre o tema. De 64 resultados encontrados, 13 artigos foram selecionados para descrição e análise. Identificou-se baixa produção científica sobre o tema, ainda que esteja em expansão. Apenas sete estudos tinham como objetivo principal a relação entre a Psicologia Positiva e o uso de substâncias psicoativas, sendo apenas dois experimentais. Evidenciou-se também a concentração de publicações nos EUA e a falta de estudos brasileiros. Os construtos da Psicologia Positiva mais abordados são a felicidade e a espiritualidade, estando associados a um menor uso de substâncias psicoativas. Fica demonstrado o potencial desse campo de estudo para a prevenção e tratamento desses transtornos, sugerindo-se o aumento da produção cientifica. (AU)


This study aims to identify and analyze studies that associate Positive Psychology and its constructs with disorders related to the use of psychoactive substances. Method: An integrative review on the subject was conducted. Of the 64 results found, 13 articles were selected for description and analysis. Results: Although expanding, a low scientific production on the subject was identified. There were only seven studies focused on the relationship between Positive Psychology and the use of psychoactive substances, and only two were experimental. The concentration of publications in the USA and the lack of Brazilian studies were also evident. The most discussed constructs of Positive Psychology are happiness and spirituality, which are associated with a reduced use of psychoactive substances. Conclusions: This field of study has demonstrated potential for the prevention and treatment of these disorders, suggesting an increase in scientific production. (AU)


Este estudio busca identificar y analizar estudios que asocien la Psicología Positiva y sus constructos con trastornos relacionados con el uso de sustancias psicoactivas. Método: Se realizó una revisión integrativa sobre el tema. De 64 resultados encontrados, 13 artículos fueron seleccionados para su descripción y análisis. Resultados: Se identificó una baja producción científica sobre el tema, aunque se encuentra en expansión. Solo siete estudios tuvieron como objetivo principal la relación entre la Psicología Positiva y el uso de sustancias psicoactivas, de los cuales, solo dos fueron experimentales. También fue evidente la concentración de publicaciones en los EE. UU. y la falta de estudios brasileños. Los constructos más discutidos de la Psicología Positiva son la felicidad y la espiritualidad, asociándose a un menor consumo de sustancias psicoactivas. Conclusiones: Se demuestra el potencial de este campo de estudio para la prevención y tratamiento de estos trastornos, sugiriendo un incremento en la producción científica. (AU)


Assuntos
Humanos , Transtornos Relacionados ao Uso de Substâncias/psicologia , Literatura de Revisão como Assunto , Base de Dados , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle
20.
Membranes (Basel) ; 8(4)2018 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-30314326

RESUMO

The efficient separation of gases has industrial, economic, and environmental importance. Here, we report the improvement in gas separation performance of a polyimide-based matrix (Matrimid®5218) filled with a Cu-based metal organic framework [MOF, Cu3(BTC)2] with two different ionic liquids (ILs) confined within the pores. The chosen ILs are commonly used in gas solubilization, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([EMIM][OTf]), and the incorporation of the [EMIM][BF4]@Cu-BTC and [EMIM][OTf]@Cu-BTC composites in Matrimid®5218 proved to be an efficient strategy to improve the permeability and selectivity toward CO2/N2 and CO2/CH4 mixtures.

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