Cytocompatible cellulose nanofibers from invasive plant species Agave americana L. and Ricinus communis L.: a renewable green source of highly crystalline nanocellulose     

Evdokimova  Olga L.  Alves  Carla S.  Krsmanović Whiffen  Radenka M.  Ortega  Zaida  Tomás  Helena  Rodrigues  João 《Journal of Zhejiang University. Science. B》2021,22(6):450-461

In this study, the fibers of invasive species Agave americana L. and Ricinus communis L. were successfully used for the first time as new sources to produce cytocompatible and highly crystalline cellulose nanofibers. Cellulose nanofibers were obtained by two methods, based on either alkaline or acid hydrolysis. The morphology, chemical composition, and crystallinity of the obtained materials were characterized by scanning electron microscopy(SEM) together with energy-dispersive X-ray spectroscopy(EDX), dynamic light scattering(DLS), X-ray diffraction(XRD), and Fourier transform infrared(FTIR)spectroscopy. The crystallinity indexes(CIs) of the cellulose nanofibers extracted from A. americana and R. communis were very high(94.1% and 92.7%, respectively). Biological studies evaluating the cytotoxic effects of the prepared cellulose nanofibers on human embryonic kidney 293 T(HEK293 T) cells were also performed. The nanofibers obtained using the two different extraction methods were all shown to be cytocompatible in the concentration range assayed(i.e., 0-500 μg/mL). Our results showed that the nanocellulose extracted from A. americana and R. communis fibers has high potential as a new renewable green source of highly crystalline cellulose-based cytocompatible nanomaterials for biomedical applications.  相似文献   

The Use of Different Translation Devices to Analyze Knowledge-Building in a University Chemistry Classroom     

Barreto  Lucas Passos  Rodrigues  Adriana Araújo Dutra  de Oliveira  Giordanna Camilla Bié  de Almeida  Laila Thayanne Gomes  Felix  Matheus Augusto Campelo  Silva  Penha de Souza  Quadros  Ana Luiza  Macedo  Andrea Mara  Mortimer  Eduardo Fleury 《Research in Science Education》2021,51(1):135-152

Research in Science Education - This research draws on Legitimation Code Theory (LCT) to understand the epistemic dimension of the higher education classroom discourse of a professor who is well...  相似文献   

Risk Society and Science Education     

Pietrocola  Maurício  Rodrigues  Ernani  Bercot  Filipe  Schnorr  Samuel 《Science & Education》2021,30(2):209-233

Science & Education - The current COVID-19 pandemic raises reflection on the new roles of science education in citizen education in a world characterized by civilization risks, derived from the...  相似文献   

Lifelong learning policies supporting young adults in two Portuguese regions     

Mariana Rodrigues  Rita Queiroga  Ana Bela Ribeiro  Natália Alves  Tiago Neves 《International Journal of Lifelong Education》2020,39(1):61-74

ABSTRACT

Precarious jobs and unemployment have become common issues for many young adults due to the unfavourable labour market situation in Portugal. Against this background, lifelong learning (LLL) policies have been called in to play a role in creating economic growth and supporting the social inclusion of young adults in vulnerable educational and economic circumstances. These policies are defined at the national level; however, their implementation depends on the action of local actors who face specific challenges. This paper explores disparities in the definition and implementation of LLL policies targeting young adults in two Portuguese regions. Specifically, we analyse professional courses in Vale do Ave (North) and adult education and training courses in Alentejo Litoral (South). These regions were selected due to their dissimilar economic structure. This study adopted a qualitative approach through interviews with LLL experts and policy roundtables with local stakeholders and decision-makers in both regions. Data were transcribed and analysed using NVivo 10. The study shows that the two regions have different cooperation networks between local stakeholders, and that these impact the opportunities to influence the regional skills formation system differently. Also, the study shows that LLL policies are not designed to address destandardised life courses.  相似文献   

Higher education and its contribution to a diverse regional supply of human capital: does the binary/unitary divide matters?     

Artur Santoalha  Ricardo Biscaia  Pedro Teixeira 《Higher Education》2018,75(2):209-230

Diversity has been an important topic of research for some time in higher education, though the purposes underlying this attention have varied across national and regional contexts. In many parts of the world, the term diversity has been emphasized with regard to variety among the programs or services provided by academic institutions, and differences among the types of institutions themselves. It is particularly important to discuss whether different dimensions of diversity may influence the degree of effectiveness of higher education (HE) in fulfilling its contribution and relevance to economic and social development. We are particularly interested in analyzing whether unitary or binary systems present significant differences in different dimensions of diversity that may be relevant to enhance higher education institutions’ (HEIs) contribution to territorial cohesion, notably by enhancing the local stock of human capital and contributing to the social and cultural development of their regions. Therefore, we propose the following research questions: *Are there relevant patterns regarding different dimensions of diversity between unitary and binary HE systems? *In the case of binary systems, is it possible to find relevant differences in different dimensions of diversity between universities and more vocational HEIs? By looking at these questions, we aim at contributing both to the literature on HE institutional diversity and to the study of the role played by HEIs on regional development.  相似文献   

Teamwork and Entrepreneurial Behavior among K-12 Teachers in the United States     

Roque do Carmo Amorim Neto  Vinícius Picanço Rodrigues  Kathryn Campbell  Meaghan Polega  Torrie Ochsankehl 《The Educational forum》2020,84(2):179-193

Abstract

This study attempted to identify the predictors of entrepreneurial behavior by assessing a series of variables that included teamwork skills and demographic variables, and to explore teachers’ experiences with teamwork. A sample of 367?K-12 public school teachers completed the survey. The findings indicated that teamwork predicts entrepreneurial behavior. Most participants received teamwork training through their school districts. Barriers to teamwork included time constraints, individual differences, and inability to collaborate.  相似文献   

What types of functions may be the lower Bohl function of a diagonal discrete linear time-varying systems?     

Artur Babiarz  Adam Czornik  Alexander Konyukh  Michał Niezabitowski 《Journal of The Franklin Institute》2017,354(13):5131-5144

In this paper, we give the necessary and sufficient conditions for a function f to be a lower Bohl function of a diagonal discrete linear time-varying systems.  相似文献   

Balance and proprioception responses to FIFA 11+ in amateur futsal players: Short and long-term effects     

Mário Lopes  Susana Lopes  Telma Patinha  Fábio Araújo  Mário Rodrigues  Rui Costa 《Journal of sports sciences》2013,31(20):2300-2308

ABSTRACT

Background: The FIFA 11+ has shown positive effects on balance and proprioception parameters in football players. As there have been very few research studies involving futsal, we examined the short and long term effects of the FIFA 11+ on static and dynamic balance, as well as proprioception in male amateur futsal players.

Methods: Seventy-one male futsal players were randomized to two groups (FIFA 11+: n = 37, age: 27.33 ± 4.33 years; Control: n = 34, age: 25.55 ± 4.65 years). Intervention lasted 10 weeks, 2 sessions per week, succeeded by a 10-week follow-up period. For balance testing, we assessed the single-legged postural sway with a force platform (static balance) and the Y balance test (dynamic balance). Proprioception was assessed with active joint position sense testing.

Results: Complete pre-post intervention and follow-up tests were available for 61 players. The FIFA 11+ group showed higher training exposure and lower body mass index and body weight. After adjustment for baseline differences, no significant differences between groups were observed in the pre-post changes for centre of pressure measures, Y-balance and proprioception parameters both at short and long-term.

Conclusions: Performing FIFA 11+ for 10 weeks did not improve static and dynamic balance as well as proprioception in amateur futsal players.  相似文献   

Delivering Information Literacy Instruction for a Joint International Program: An Innovative Collaboration Between Two Libraries     

Jiselle Maria Alleyne  Denyse Rodrigues 《College & Undergraduate Libraries》2013,20(2-3):261-271

This article focuses on a collaborative project between Mount Saint Vincent University Library and Bermuda College Library to introduce students to services and resources at the libraries of the partner institutions. Using Web conferencing software that allowed for voice, instant messaging chat, and live Web demonstration, a series of workshops was developed to introduce students to the concepts of information and literacy and reinforce for the students that they were able to access librarians and library services at both institutions. Issues relating to both the students’ home library at Bermuda College in Hamilton, Bermuda and their remote library at Mount Saint Vincent University in Nova Scotia, Canada are examined, including the obstacles that have been surmounted as well as recommendations for other libraries considering this type of partnership. Strategies, activities, and tools used to implement the initiative are discussed.  相似文献   

Effects of blood flow restriction without additional exercise on strength reductions and muscular atrophy following immobilization:A systematic review     

Mikhail Santos Cerqueira  Jose Diego Sales Do Nascimento  Daniel Germano Maciel  Jean Artur Mendonca Barboza  Wouber Herickson De Brito Vieira 《运动与健康科学(英文)》2020,9(2):152-159

Purpose:To investigate whether blood flow restriction(BFR) without concomitant exercise mitigated strength reduction and atrophy of thigh muscles in subjects under immobilization for lower limbs.Methods:The following databases were searched:PubMed,CINAHL,PEDro,Web of Science,Central,and Scopus.Results:The search identified 3 eligible studies,and the total sample in the identified studies consisted of 38 participants.Isokinetic and isometric torque of the knee flexors and extensors was examined in 2 studies.Cross-sectional area of thigh muscles was evaluated in 1 study,and thigh girth was measured in 2 studies.The BFR protocol was 5 sets of 5 min of occlusion and 3 min of free flow,twice daily for approximately 2 weeks.As a whole,the included studies indicate that BFR without exercise is able to minimize strength reduction and muscular atrophy after immobilization.It is crucial to emphasize,however,that the included studies showed a high risk of bias,especially regarding allocation concealment,blinding of outcome assessment,intention-to-treat analyses,and group similarity at baseline.Conclusion:Although potentially useful,the high risk of bias presented by original stodies limits the indication of BFR without concomitant exercise as an effective countermeasure against strength reduction and atrophy mediated by immobilization.  相似文献