1,312 research outputs found
Shoulder Torque Production and Muscular Balance after Long and Short Tennis Points
Tennis is an asymmetric sport characterized by a systematic repetition of specific movements that may cause disturbances in muscular strength, power, and torque. Thus, we assessed (i) the torque, power, ratio production, and bilateral asymmetries in the shoulder’s external and internal rotations at 90 and 180°/s angular velocities, and (ii) the point duration influence of the above-mentioned variables. Twenty competitive tennis players performed external and internal shoulder rotations; an isokinetic evaluation was conducted of the dominant and non-dominant upper limbs before and after five and ten forehands. A higher torque production in the shoulder’s internal rotations at 90 and 180°/s was observed for the dominant vs. non-dominant sides (e.g., 63.1 ± 15.6 vs. 45.9 ± 9.8% and 62.5 ± 17.3 vs. 44.0 ± 12.6% of peak torque/body mass, p < 0.05). The peak torque decreased only after ten forehands (38.3 ± 15.8 vs. 38.2 ± 15.8 and 39.3 ± 16.1 vs. 38.1 ± 15.6 Nm, respectively, p < 0.05), but without impacting speed or accuracy. Unilateral systematic actions of tennis players caused contralateral asymmetries, evidencing the importance of implementing compensatory training. The forehand kinematic assessment suggests that racket and wrist amplitude, as well as speed, are important success determinants in tennis.SIThis research received no external funding
Capture-recapture: a method for determining the prevalence of vision impairment in the population
Targeting cancer resistance via multifunctional gold nanoparticles
POCI-01-0145-FEDER-007728
SFRH/BD/120030/2016
PD/BD/105734/2014
Pest-OE/UID/DTP/04138/2013Resistance to chemotherapy is a major problem facing current cancer therapy, which is continuously aiming at the development of new compounds that are capable of tackling tumors that developed resistance toward common chemotherapeutic agents, such as doxorubicin (DOX). Alongside the development of new generations of compounds, nanotechnology-based delivery strategies can significantly improve the in vivo drug stability and target specificity for overcoming drug resistance. In this study, multifunctional gold nanoparticles (AuNP) have been used as a nanoplatform for the targeted delivery of an original anticancer agent, a Zn(II) coordination compound [Zn(DION)2]Cl2 (ZnD), toward better efficacy against DOX-resistant colorectal carcinoma cells (HCT116 DR). Selective delivery of the ZnD nanosystem to cancer cells was achieved by active targeting via cetuximab, NanoZnD, which significantly inhibited cell proliferation and triggered the death of resistant tumor cells, thus improving efficacy. In vivo studies in a colorectal DOX-resistant model corroborated the capability of NanoZnD for the selective targeting of cancer cells, leading to a reduction of tumor growth without systemic toxicity. This approach highlights the potential of gold nanoformulations for the targeting of drug-resistant cancer cells.publishersversionpublishe
Catalytic performance of bulk and colloidal Co/Al layered double hydroxide with Au nanoparticles in aerobic olefin oxidation
A Co/Al layered double hydroxide material was synthesized in both bulk and exfoliated (colloidal) forms. Anion exchange with methionine allowed immobilization of Au nanoparticles previously prepared by a biomimetic method using an anti-oxidant tea aqueous extract to reduce the Au salt solution. The catalytic performance of bulk and exfoliated clays Au-hybrid materials was assessed in aerobic olefin epoxidation. Both catalysts were very active towards the epoxide products and with very interesting substrate conversion levels after 80 h reaction time. The Au-exfoliated material, where the nanosheets work as large ligands, yielded higher product stereoselectivity in the case of limonene epoxidation. This arises from a confined environment around the Au nanoparticles wrapped by the clay nanosheets modulating access to the catalytic active centres by reagents. Mechanistic assessment was also accomplished for styrene oxidation by DFT methodspublishe
Training zones in competitive swimming: a biophysical approach
Since swimming performance depends on both physical conditioning and technical proficiency, training zones should be built based on physiology and biomechanics inputs to dispose of structured and effective training programs. This paper presents a zone-based swimming training, supported by the oxygen uptake (V˙O2) kinetics at low, moderate, heavy, severe and extreme intensities concurrently with lactate and heart rate values. Since technique is vital for efficiently moving through the water, upper limbs frequency and length should also be targeted during the workouts. The index of coordination was also added to our proposal since upper limbs synchronization is a key technical factor. To better establish and characterize a wide range of swimming intensities, the training methods and corresponding contents that better fit each training zone will be suggested. It will be shown that when under/at the anaerobic threshold (at low-to-moderate intensities), swimmers are at homeostasis and can maintain stable internal and external load indicators. However, above that boundary (at heavy and severe intensities), the physiological stable state is no longer observed and the anaerobic metabolism starts contributing significantly, with a technical degradation being more evident when performing near/at the V˙O2max intensity. Then, when performing above aerobic power, on typical anaerobic intensities, V˙O2 kinetics presents a very evident fast rise, ending abruptly due to exhaustion caused by muscle acidosis. This overall knowledge allows advancing toward more objective training programs and highlights the importance of systematic training control and swimmers' evaluation and advice
Psicologia política em Portugal: a importância de cruzar fronteiras
In this paper we assume a broad conception of political psychological that recognizes its disciplinary, theoretical and methodological pluralism. As a result, we review research from diverse disciplines in the social sciences that either focus on the relationship between psychology and politics or emphasize the role of power, participation and oppression in the production of marginalization, empowerment and social change. The studies presented here are organized into four main topics: (i) ideology, values e attitudes; (ii) civic culture, social capital and electoral behavior; (iii) power, social relationships and deviant territories; and (iv) civic and political participation, empowerment and social change. Even if the institutionalization and dissemination of political psychology in Portugal is recent, research appears to recognize the need for a deeper understanding of the relationship between psychology and politics, including the factors that predict and mediate the impact of civic and political participation.Neste artigo assumimos uma conceção ampla da psicologia política que reconhece o seu pluralismo disciplinar, teórico e metodológico. Os contributos analisados provêm de diversas áreas das ciências sociais, ora porque assumem a interface entre a psicologia e a política, ora porque reconhecem o papel do poder, da participação e da opressão nos processos de produção de marginalização, empoderamento e transformação social. As investigações são apresentadas em torno de quatro temas principais: (i) ideologia, valores e atitudes; (ii) cultura cívica, capital social e comportamento eleitoral; (iii) o poder como produtor de realidades sociais e espaços de marginalidade, e (iv) participação cívica e política, empoderamento e transformação social. Apesar de a institucionalização e disseminação da Psicologia Política em Portugal ser ainda moderada, são várias as investigações que enfatizam a saliência da relação entre a psicologia e a política, incluindo os fatores que predizem e medeiam o impacto a/da participação cívica e política.En este artículo asumimos una compreensión amplia de psicología política que reconocce su pluralismo disciplinar, teórico y metodológico. Los contributos analizados provienen de diversas áreas de las ciencias sociales, ora porque asumen la interface entre la psicología y la política, ora porque reconocen el papel del poder, de la participación y de la opresión en los procesos de producción de marginalización, empoderamiento y transformación social. Las investigaciones son presentadas en torno de cuatro temas principales: (i) ideología, valores y atitudes; (ii) cultura cívica, capital social y comportamiento electoral; (iii) el poder como productor de realidades sociales y espacios de marginalidad, y (iv) participación cívica y política, empoderamiento y transformación social. Aunque la institucionalización y diseminación de la Psicología Política en Portugal sea todavía moderada, son varias las investigaciones que enfatizan la saliencia de la relación entre la psicología y la política, incluyendo los factores que predicen y median el impacto a la/de la participación cívica y política
Influence of chemical reaction conditions in P(St-MMA-AA) synthesis: variation in nanoparticle size, color and deposition methods
info:eu-repo/semantics/publishedVersio
Nutrição mineral de plantas ornamentais: V. estudos de adubação nitrogenada de Gladiolus grandiflorus L. cv. 'Perusi'
The present work tried to determine the effects of three sites of application of nitrogenous fertilizers as well as the effects of two differents sources of nitrogen on the flowers, conns and cormels productions o Gladiolus grandiflorus L., cv. 'Perusi' cultivated in podzolic soil. All the necessary cultural treatments were given to the plants. Nitrogen applied at planting time has no effect on the plant growth. Its localization in furrows near the root system helps in increasing corn and cormels production. The ammoniacal form permits a better use of nitrogen, influencing the production of floral stems, number of floral buds per stem, higher number and weight of corais. The sodium nitrate causes a despersion in the harvest of the floral stems, while the ammonium sulphate tends to concentrate it.O presente trabalho teve como objetivo estudar os efeitos de três épocas de aplicação de fertilizantes nitrogenados, três localizações e duas fontes de nitrogênio, no que concerne à produção de flores, bulbos e bulbilhos de Gladiolus grandiflorus cv. 'Perusi' cultivado em condições de solo podzolizado. Todos os tratos culturais necessários foram dispensados às plantas. Não há influência do nitrogênio aplicado por ocasião do plantio. A sua localização em sulcos próximos ao sistema radicular favorece a maior produção de bulbos e de bulbilhos. A fonte amonical proporciona um melhor aproveitamento do nitrogênio, influindo em produção de hastes florais, número de botões florais por haste, maior número e peso de bulbos. O nitrato de sódio acarreta uma maior dispersão de colheita de hastes florais, enquanto o sulfato de amônio tende a concentrá-la
Pathway for cyanotoxin valorization: microscystin as case study
Book of Abstracts of CEB Annual Meeting 2017info:eu-repo/semantics/publishedVersio
Combined effect of light intensity and CO2 concentration on Microcystis aeruginosa growth
[Excerpt] Worldwide occurrence of hepatotoxic cyanobacterium Microcystis aeruginosa and the accumulation of its toxin (microcystin), have been responsible for several human deaths and animal intoxication incidents. In recognition to its toxicity, the WHO and national governments established recommendation values for this toxin in water, which gave rise to an increasing demand for microcystin's analytical standards. These standards might be used either as laboratory standards in human and environmental risk assessment or as tools for molecular and cell biology studies. However, their availability is limited due to constraints found in production and purification processes, which inflate the final price to values as high as 28000€/mg. [...
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