219 research outputs found
Suspended-core fibers for sensing applications
A brief review on suspended-core fibers for sensing applications is presented. A historical overview over the previous ten years about this special designed microstructure optical fiber is described. This fiber presents attractive optical properties for chemical/biological or gas measurement, but it can be further explored for alternative sensing solutions, namely, in-fiber interferometers based on the suspended-core or suspended-multi-core fiber, for physical parameter monitoring.info:eu-repo/semantics/publishedVersio
Optical Current Sensors for High Power Systems: A Review
The intrinsic advantages of optical sensor technology are very appealing for high voltage applications and can become a valuable asset in a new generation of smart grids. In this paper the authors present a review of optical sensors technologies for electrical current metering in high voltage applications. A brief historical overview is given together with a more detailed focus on recent developments. Technologies addressed include all fiber sensors, bulk magneto-optical sensors, piezoelectric transducers, magnetic force sensors and hybrid sensors. The physical principles and main advantages and disadvantages are discussed. Configurations and strategies to overcome common problems, such as interference from external currents and magnetic fields induced linear birefringence and others are discussed. The state-of-the-art is presented including commercial available systems.info:eu-repo/semantics/publishedVersio
Chemical features and bioactivities of cornflower (Centaurea cyanus L.) capitula: The blue flowers and the unexplored non-edible part
Cornflower is a flowering weed and ornamental plant whose blue flowers have been used for food, decorative and colouring purposes. In this study, the upper (edible flowers) and lower (non-edible receptacle and involucre) parts of the capitulum were studied and compared for their chemical composition and bioactive properties. The flowers were richer in tocopherols, organic acids, and apigenin derivatives (mainly apigenin-7-O-glucuronide-4′-O-(6-O-malonylglucoside)) than the non-edible bristly part (where syringic acid predominated). Four cyanidin derivatives were identified in the flowers. The extract of the non-edible part was more efficient in inhibiting the formation of thiobarbituric acid reactive substances (TBARS), the bleaching of β-carotene, and the haemolysis of the erythrocytes membrane. In general, the extracts were more active against Gram-positive bacteria and had no cytotoxicity against non-tumour liver PLP2 cells. Therefore, while flowers are a potential source of natural cyanidin-based colorants, the lower part of the capitulum has bioactive properties to be exploited in different food or pharmaceutical formulations.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO ( UID/AGR/00690/2013 ); to FCT for the grants of C.L. Roriz ( SFRH/BD/129551/2017 ) and C. Pereira ( SFRH/BPD/122650/2016 ) (awarded under the Programa Operacional Capital Humano (POCH) supported by the European Social Fund and National Funds of MCTES (Ministério da Ciência, Tecnologia e Ensino Superior) , and the research contracts of J. Pinela (Project AllNatt , POCI-01-0145-FEDER-030463 ) and L. Barros. This work is also funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®; and FEDER-Interreg España-Portugal through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio
Synthesis, antimalarial activity, structure–activity relationship analysis of thieno-[3,2-b]benzothiazine S,S-dioxide analogs
An improved procedure for the synthesis of 3-amino-9-arylsubstituted-thieno[3,2-b]benzothiazine S,S-dioxide 2-decarboxylated is reported. Thieno-[3,2-b]benzothiazine S,S-dioxide derivatives were investigated for their abilities to inhibit β-hematin formation, hemoglobin hydrolysis and in vivo for their efficacy in rodent Plasmodium berghei. Compounds 5j-o were the most promising as inhibitors of hemoglobin hydrolysis, however, the compounds are not as efficient as chloroquine. A structure-activity relationship (SAR) study was carried out in this series. Our results allow us to determine the minimal structural requirements to produce the biological response.Fil: Barazarte, Arthur. Universidad Central de Venezuela; VenezuelaFil: Camacho, José. Universidad Central de Venezuela; VenezuelaFil: Domínguez, José. Universidad Central de Venezuela; VenezuelaFil: Lobo, Gricela. Universidad Central de Venezuela; VenezuelaFil: Gamboa, Neira. Universidad Central de Venezuela; VenezuelaFil: Rodrigues, Juan. Universidad Central de Venezuela; VenezuelaFil: Capparelli, Mario V.. Universidad Central de Venezuela; VenezuelaFil: Álvarez Larena, Ángel. Universitat Autònoma de Barcelona; EspañaFil: Andujar, Sebastian Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; ArgentinaFil: Charris, Jaime. Universidad Central de Venezuela; Venezuel
Red pitaya (Hylocereus costaricensis) peel as a source of valuable molecules: extraction optimization to recover natural colouring agents
Hylocereus costaricensis peel contains large amounts of betacyanins and can be exploited as a source of natural
colorants. This work aimed the chemical characterization and evaluation of bioactive properties of this byproduct
and the optimization of the ultrasound-assisted extraction (UAE) of betacyanins using the response
surface methodology (RSM). Oxalic and malic acids and traces of fumaric acid were detected, as well as the four
tocopherol isoforms, predominantly γ-tocopherol. Four betacyanins were identified and used as response criteria
for UAE optimization, namely phyllocactin, isobetanin, isophyllocactin, and betanin. Sample processing at 487 W for 38 min result in the maximum betacyanin content (36 ± 1 mg/g dw). The peel extract inhibit the oxidative
haemolysis, with IC50 values of 255 and 381 μg/mL for Δt of 60 and 120 min, respectively, and the growth of
pathogenic bacteria, with minimum inhibitory concentrations ranging from 5 to 20 mg/mL. Furthermore, no
toxicity was observed for normal cells.The authors are grateful to the Foundation for Science and Technology
(FCT, Portugal) for financial support by national funds FCT/
MCTES to CIMO (UIDB/00690/2020); C. L. Roriz PhD’s grant (SFRH/
BD/117995/2016), L. Barros and C. Calhelha also thank the national
funding by FCT, P.I., through the institutional scientific employment
program-contract for their contracts, and S.A. Heleno (CEECIND/
03040/2017) and J. Pinela (CEECIND/01011/2018) through the individual
scientific employment program-contract. The authors are also
grateful to the European Regional Development Fund (ERDF) through
the Regional Operational Program North 2020, within the scope of
project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural® and
GreenHealth (Norte-01-0145-FEDER-000042. Finally, P. Morales is also
grateful to UCM ALIMNOVA Research Group (GR105/18).info:eu-repo/semantics/publishedVersio
Does Gestrinone Antagonize the Effects of Estrogen on Endometrial Implants Upon the Peritoneum of Rats?
OBJECTIVE: To evaluate the effects of estrogen treatment in combination with gestrinone on an experimental rat model of endometriosis. METHODS: Uterine transplants were attached to the peritoneum of female Wistar rats via a surgical autotransplantation technique. The implanted area was measured during the proestrus phase and after hormonal treatment. We performed morphometric analysis and examined the macroscopic and morphometric alterations of endometrial implants after hormonal treatment in ovariectomized rats. RESULTS: The high dose of estrogen caused macroscopic increases in the endometrial implant group compared with other groups, which were similar to increases in the proestrus phase. The low dose showed morphometric development of implants, such as an increase in number of endometrial glands, leukocyte infiltration and mitosis. Gestrinone antagonized both doses of estrogen. CONCLUSION: Our findings suggest that gestrinone antagonizes estrogen's effects on rat peritoneal endometrial implants
Estudio de la actividad de los fotocatalizadores Pt and Au-TiO2 en la degradación de contaminantes orgánicos bajo luz visible
Pt-TiO and Au-TiO photocatalysts were prepared by noble metal photodeposition on sulfated TiO. It was observed that optical absorption, oxidation state and particle size of the metallic species (Pt or Au) play an important role in the TiO photocatalytic activity under visible-light irradiation. Photocatalytic activity of the bare TiO powder in the phenol and methyl orange degradation increased with the sulfation and metal addition. The highest degradation rate under UV-Visible and visible light irradiation was obtained on Pt-S-TiO photocatalyst; this is mainly due to the optical properties of TiO induced by platinization and also to the good distribution and low Pt particles size. It was also found that this catalyst has a good stability after two cycles of reaction in the phenol photodegradation under UV-Visible light irradiation. The Pt-S-TiO photocatalyst was also active under solar light and under the environmental conditions of the city of Tunja (Boyacá), Colombia.Los fotocatalizadores Pt-TiO2 y Au-TiO2 se prepararon por fotodeposición del metal noble sobre el TiO2 sulfatado. Se encontró que las propiedades ópticas, el estado de oxidación y el tamaño de partícula de las especies metálicas (Pt o Au) juegan un papel fundamental en la actividad fotocatalítica del TiO2 bajo luz visible. La actividad fotocatalítica del TiO2 en la degradación de fenol y naranja de metilo aumentó significativamente a través de los tratamientos de sulfatación y metalización de este óxido. La más alta velocidad de degradación bajo luz UV-Visible y visible, se alcanzó usando el fotocatalizador Pt-S-TiO2 ; esto se debe principalmente a la modificación de las propiedades ópticas del TiO2 inducidas por la platinización, también a la buena distribución y al pequeño tamaño de las partículas de Pt. Se encontró, además, que este catalizador presenta una buena estabilidad después de dos ciclos de reacción en la degradación de fenol bajo luz UV-Visible. El fotocatalizador Pt-S-TiO2 fue activo también bajo luz solar directa y bajo las condiciones medioambientales de la ciudad de Tunja (Boyacá), Colombia.Fondo Nacional de Financiamiento para la Ciencia, la Tecnología y la Innovación Fransisco José de Caldas – Colciencias 279-2016MINECO/FEDER, UE CTQ2015-64664-C2-2-
POWERbreathe® Inspiratory Muscle Training in Amyotrophic Lateral Sclerosis.
Inspiratory muscle training may benefit respiratory function, cardiocirculatory parameters, quality of life and functionality in neuromuscular diseases. This pilot study aimed to demonstrate the POWERbreathe® inspiratory muscle training effects on maximum inspiratory pressure (PImax), heart rate (HR) and HR variability, as well as the quality of life impairment and functionality in patients with Amyotrophic Lateral Sclerosis (ALS). A pilot single-blinded, non-randomized controlled clinical trial was carried out. A total of 20T ALS patients were enrolled and divided into experimental (n = 10) and control (n = 10) groups. The experimental group received POWERbreathe® inspiratory muscle training in conjunction with usual care, and the control group received only usual care for 8 weeks. PImax (measured by POWERbreathe® KH1), HR and HR variability (evaluated by Polar H7), quality of life impairment [measured by the Amyotrophic Lateral Sclerosis Assessment Questionnaire—40 items (ALSAQ-40)] and functionality [assessed by the ALS Functional Rating Scale Revised (ALSFRS-R)] were collected at baseline and after 8 weeks of intervention. We detected statistically significant differences (p < 0.05) with an effect size ranging from medium to large (Cohen’s d = 0.72–1.37); relative to the control group, the experimental group had an increased PImax (mean difference = 10.80 cm H2O; 95% CI = 3.42–18.17) and ALSFRS-R score (mean difference = 5.30 points; 95% CI = −0.03–10.63) and reduced HR (mean difference = −8.80 beats-per-minute; 95% CI = −20.27–2.67) and R-R interval (mean difference = 78.30 ms; 95% CI = 2.89–153.70). POWERbreathe® inspiratory muscle training, in addition to usual care, may improve inspiratory strength and heart rate in patients with ALS. These results encourage larger and longer trials investigating potential clinically relevant benefits of inspiratory muscle training to these patients over the disease course.post-print6421 K
Exercise Physiology at “Conversational Level” Is Not Impaired in Healthy Young Subjects Wearing Masks or Respirators.
Objective: The aim of this study was to evaluate the effects of the use of both surgical masks and FFP2 respirators on the inspiratory muscle strength, metabolic parameters, heart rate, subjective perceived exertion, and dyspnea perception, before and during 30 min stable load exercise at “conversational level”. Methods: A randomized cross-over study was carried out. Nineteen healthy adults completed 3 conditions (without a mask, with a surgical mask or an FFP2 respirator) during a 30-min steady-state test at the lactate threshold intensity. Inspiratory muscle strength was measured before and after the test, and metabolic parameters, heart rate, subjective perceived exertion, and dyspnea perception were collected at baseline, during, and after the test. Results: There was a significant reduction in inspiratory muscle strength after the 30-min test in all conditions (control: 6.26 mm Hg, p < 0.5; surgical mask: 8.55 mm Hg, p < 0.01; FFP2 respirator: 12.42 mm Hg, p < 0.001), but without significant differences between them (p = 0.283). Data showed a statistically significant effect for time, but did not show a statistically significant interaction between condition and time for heart rate (p = 0.674), oxygen saturation (p = 0.297), blood lactate level (p = 0.991), rating perceived exertion (p = 0.734) and dyspnea (p = 0.532) comparisons. Conclusions: The present study findings suggested that inspiratory muscle strength and physiological parameters during “conversational level” exercise were not impaired under wearing masks in healthy, nonsmoking young adults.pre-print319 K
Valorisation of black mulberry and grape seeds: Chemical characterization and bioactive potential
Grape (Vitis vinifera L. var. Albariño) and mulberry (Morus nigra L.) seeds pomace were characterized in terms of tocopherols, organic acids, phenolic compounds and bioactive properties. Higher contents of tocopherols (28 ± 1 mg/100 g fw) were obtained in mulberry, whilst grape seeds were richer in organic acids (79 ± 4 mg/100 g fw). The phenolic analysis of hydroethanolic extracts characterised grape seeds by catechin oligomers (36.0 ± 0.3 mg/g) and mulberry seeds by ellagic acid derivatives (3.14 ± 0.02 mg/g). Both exhibited high antimicrobial activity against multiresistant Staphylococcus aureus MIC = 5 mg/mL) and no cytotoxicity against carcinogenic and non-tumour primary liver (PLP) cells. Mulberry seeds revealed the strongest inhibition (p lt 0.05) against thiobarbituric reactive substances (IC50 = 23 ± 2 µg/mL) and oxidative haemolysis (IC50 at 60 min = 46.0 ± 0.8 µg/mL). Both seed by-products could be exploited for the developing of antioxidant-rich ingredients with health benefits for industrial application.The authors are grateful to the Foundation for Science and
Technology (FCT, Portugal) for financial support by national funds
FCT/MCTES to CIMO (UIDB/00690/2020); C. L. Roriz PhD’s grant
(SFRH/BD/117995/2016), L. Barros to FCT, P.I., through the institutional
scientific employment program-contract for their contract and
the individual scientific employment program-contract for S.A.
Heleno’s contract. To Eramus + grant (P BRAGAC01) and the
Complutense University of Madrid, Spain for the preodoctoral grant
[CT17/17-CT18/17] of E. Gómez-Mejía. In addition, to the
Complutense University of Madrid, Spain for the preodoctoral grant
[CT17/17-CT18/17] of E. Gómez-Mejía. In addition, to the companies
Ponto Agricola Lda. (Portugal) and Terras Gaudas (Spain) for providing
the sample by-products. The authors are grateful to FEDER-Interreg
España-Portugal programme for financial support through the project
0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio
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