Luis Almeida

Prof. Luis Almeida

University of Minho, Braga, Portugal
orcid

Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 March 2010 in Textile Research Journal
Verified
Journal Article
Closed access
PDF file
SGSorna Gowri
Sorna Gowri
LALuis Almeida
Luis Almeida
TATeresa Amorim
Teresa Amorim
NCNoémia Carneiro
Noémia Carneiro
ASAntónio Pedro Souto
António Pedro Souto
MEMaria Fátima Esteves
Maria Fátima Esteves
Improvement of existing properties and the creation of new material properties are the most important reasons for the functionalization of textiles. Polymer nanocomposites offer the possibility of developing a new class of nanofinishing materials for textiles with their own manifold of structure property relationship only indirectly related to their components and their micron and macro-scale composite counterparts. Though polymer nanocomposites with inorganic filler of different dimensionality and chemistry are possible, efforts have only begun to uncover the wealth of possibilities of these new materials. Approaches to modify the polymer nanocomposite system by various inorganic or organic substances can lead to a huge number of additional functionalities which are increasingly demanded by the textile industries. In this review, we have compiled the current research in polymer nanocomposite-based nanofinishes for multifunctional textiles which provides a snapshot of the current experimental and theoretical tools being used to advance our understanding of polymer nanocomposites and their applications in textiles.

17 June 2015 in ACS Applied Materials & Interfaces
Verified
Journal Article
Open access
Andrea ZilleAndrea Zille
Andrea Zille
Margarida M. FernandesMargarida M. Fernandes
Margarida M. Fernandes
AFAntonio Francesko
Antonio Francesko
TTTzanko Tzanov
Tzanko Tzanov
MFMarta Fernandes
Marta Fernandes
ASAntónio P. Souto
António P. Souto
This work studies the surface characteristics, antimicrobial activity, and aging effect of plasma-pretreated polyamide 6,6 (PA66) fabrics coated with silver nanoparticles (AgNPs), aiming to identify the optimum size of nanosilver exhibiting antibacterial properties suitable for the manufacture of hospital textiles. The release of bactericidal Ag(+) ions from a 10, 20, 40, 60, and 100 nm AgNPs-coated PA66 surface was a function of the particles' size, number, and aging. Plasma pretreatment promoted both ionic and covalent interactions between AgNPs and the formed oxygen species on the fibers, favoring the deposition of smaller-diameter AgNPs that consequently showed better immediate and durable antimicrobial effects against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Surprisingly, after 30 days of aging, a comparable bacterial growth inhibition was achieved for all of the fibers treated with AgNPs <100 nm in size. The Ag(+) in the coatings also favored the electrostatic stabilization of the plasma-induced functional groups on the PA66 surface, thereby retarding the aging process. At the same time, the size-related ratio (Ag(+)/Ag(0)) of the AgNPs between 40 and 60 nm allowed for the controlled release of Ag(+) rather than bulk silver. Overall, the results suggest that instead of reducing the size of the AgNPs, which is associated with higher toxicity, similar long-term effects can be achieved with larger NPs (40-60 nm), even in lower concentrations. Because the antimicrobial efficiency of AgNPs larger than 30 nm is mainly ruled by the release of Ag(+) over time and not by the size and number of the AgNPs, this parameter is crucial for the development of efficient antimicrobial coatings on plasma-treated surfaces and contributes to the safety and durability of clothing used in clinical settings.

16 March 2017 in Progress in Biomaterials
Verified
Journal Article
Open access
PDF file
LNLucas B. Naves
Lucas B. Naves
CDChetna Dhand
Chetna Dhand
JVJayarama Reddy Venugopal
Jayarama Reddy Venugopal
LRLakshminarayanan Rajamani
Lakshminarayanan Rajamani
SRSeeram Ramakrishna
Seeram Ramakrishna
LALuis Almeida
Luis Almeida
Melanoma is the most aggressive type of skin cancer and has very high rates of mortality. An early stage melanoma can be surgically removed, with a survival rate of 99%. This literature review intends to elucidate the possibilities to treat melanoma skin cancer using hybrid nanofibers developed by advanced electrospinning process. In this review we have shown that the enhanced permeability and retention is the basis for using nanotechnology, aiming topical drug delivery. The importance of the detection of skin cancer in the early stages is directly related to non-metastatic effects and survival rates of melanoma cells. Inhibitors of protein kinase are already available in the market for melanoma treatment and are approved by the FDA; these agents are cobimetinib, dabrafenib, ipilimumab, nivolumab, trametinib, and vemurafenib. We also report a case study involving two different approaches for targeting melanoma skin cancer therapy, namely, magnetic-based core–shell particles and electrospun mats.

1 May 1996 in Textile Research Journal
Verified
Journal Article
Closed access
PDF file
Artur Cavaco-PauloArtur Cavaco-Paulo
Artur Cavaco-Paulo
LALuis Almeida
Luis Almeida
DBDavid Bishop
David Bishop
We have attempted to clarify the effects of low and high levels of mechanical agitation on the cellulolytic activity of a pure endoglucanase ( EG ) and a total cellulase mixture (TC) on scoured and bleached cotton fabric, along with the effect of EG pretreatment on subsequent treatments with TC. Methods used to follow the progress of fabric treatments include weight loss, breaking load loss, bending hysteresis, and the pro duction of soluble reducing sugars and reducing end groups in the fibers. The results show that agitation rate affects the mechanism of cellulolytic attack, and that this has implications for delivering desired finishing effects.

1 September 2014 in Materials Research Express
Verified
Journal Article
Closed access
Andrea ZilleAndrea Zille
Andrea Zille
LALuis Almeida
Luis Almeida
TATeresa Amorim
Teresa Amorim
NCNoémia Carneiro
Noémia Carneiro
MEMaria Fátima Esteves
Maria Fátima Esteves
ASAntónio Pedro Souto
António Pedro Souto

1 June 1998 in Textile Research Journal
Verified
Journal Article
Closed access
PDF file
Artur Cavaco-PauloArtur Cavaco-Paulo
Artur Cavaco-Paulo
JMJose Morgado
Jose Morgado
LALuis Almeida
Luis Almeida
DKDouglas Kilburn
Douglas Kilburn
We have attempted to understand the mechanisms of indigo backstaining during enzyme stone washing by separately analyzing dye staining levels on different cotton surfaces during the process. The high ability of the cellulase enzyme protein to bind to cotton cellulose is the major cause of backstaining. Further studies of commercial cellulases show that the pH of maximum cellulase activity may not be the same pH of maximum of cellulase binding capacity to the substrate, and also that indigo dyes have completely different affinities for cellulase proteins from different fungal origins.