361 research outputs found
Improving Clinical Diagnosis of Melanocytic Skin Lesions by Raman Spectroscopy
High-quality Raman signals from melanocytic lesions compatible with a possible clinical application have not been demonstrated yet. The objectives of the work described in this thesis were:
I: The development of a Raman spectroscopic prototype for objective and fast assessment of melanocytic skin lesions clinically suspicious for melanoma;
II: Identification of the main spectroscopic features of melanoma and benign melanocytic lesions suspicious for melanoma;
III: Assessment of the feasibility of Raman spectroscopy as an adjunct technique to improve clinical diagnosis of melanocytic skin lesions
Griscelli syndrome-type 2 in twin siblings: case report and update on RAB27A human mutations and gene structure
Griscelli syndrome (GS) is a rare autosomal recessive disorder caused by mutation in the MYO5A (GS1, Elejalde), RAB27A (GS2) or MLPH (GS3) genes. Typical features of all three subtypes of this disease include pigmentary dilution of the hair and skin and silvery-gray hair. Whereas the GS3 phenotype is restricted to the pigmentation dysfunction, GS1 patients also show primary neurological impairment and GS2 patients have severe immunological deficiencies that lead to recurrent infections and hemophagocytic syndrome. We report here the diagnosis of GS2 in 3-year-old twin siblings, with silvery-gray hair, immunodeficiency, hepatosplenomegaly and secondary severe neurological symptoms that culminated in multiple organ failure and death. Light microscopy examination of the hair showed large, irregular clumps of pigments characteristic of GS. A homozygous nonsense mutation, C-T transition (c.550C>T), in the coding region of the RAB27A gene, which leads to a premature stop codon and prediction of a truncated protein (R184X), was found. In patient mononuclear cells, RAB27A mRNA levels were the same as in cells from the parents, but no protein was detected. In addition to the case report, we also present an updated summary on the exon/intron organization of the human RAB27A gene, a literature review of GS2 cases, and a complete list of the human mutations currently reported in this gene. Finally, we propose a flow chart to guide the early diagnosis of the GS subtypes and Chédiak-Higashi syndrome.FAPESPCNPq(FAEPA) Fundação de Apoio ao Ensino, Pesquisa e Assistência do Hospital das Clínicas da Faculdade de Medicina de Ribeirão PretoCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
Extratos fenólicos de flores de Rubus ulmifolius Schoot: caracterização química, microencapsulação e incorporação em iogurtes para benefícios antioxidants
Rubus ulmifolius Schoot (Rosaceae), conhecida como amora silvestre, é um arbusto perene
encontrado em habitats silvestres e cultivados da Europa, Ásia e África do Norte.
Tradicionalmente é conhecido pelas suas propriedades medicinais, incluindo atividade
antioxidante. Neste trabalho caracterizaram-se quimicamente dois extratos fenólicos obtidos a
partir de botões florais de R. ulmifolius, decocção e extrato hidroalcoólico, tendo sido
identificados vários compostos fenólicos, maioritariamente derivados de elagitaninos
nomeadamente, os isómeros sanguiin H-10 e lambertianina.
Comparativamente à decocção, o extrato hidroalcoólico apresentou um conteúdo em
compostos fenólicos superior e uma maior atividade antioxidante. A sua forma liofilizada foi a
escolhida para microencapsular pela técnica de spray seguida de coagulação tendo-se
produzido microesferas de alginato que foram posteriormente incorporadas num iogurte
natural. Os resultados obtidos mostraram que o extrato microencapsulado originou produtos
com atividade antioxidante superior e com melhor preservação desta ao longo do tempo.
Ambas as formas (extrato direto e microencapsulado) mostraram maior atividade que o
controlo. Em síntese, os resultados obtidos demonstraram o potencial antioxidante do extrato
hidroalcoólico R. ulmifolius e a eficiência da microencapsulação para a sua preservação,
abrindo assim possibilidades para a sua exploração em aplicações na indústria alimentar.Fundação para a Ciência e a Tecnologia (FCT, Portugal) pelo apoio financeiro ao CIMO
(projeto estratégico PEst-OE/AGR/UI0690/2011) e ao LSRE (projeto estratégico PEst-
C/EQB/LA0020/2011). L. Barros agradece ao FCT, POPH-QREN e FSE pelo seu contrato de
investigação no âmbito do “Programa Compromisso com Ciência-2008”.O GIP-USAL é financeiramente suportado pelo governo espanhol através do Programa Consolider-Ingenio 2010 (FUN-C-FOOD, CSD2007-00063)
Phenolic extracts of Rubus ulmifolius Schoot flowers: characterization, microencapsulation and incorporation into yogurts as nutraceutical sources
Rubus ulmifolius Schott (Rosaceae), known as wild blackberry, is a perennial shrub found in wild and
cultivated habitats in Europe, Asia and North Africa. Traditionally, it is used for homemade remedies
because of its medicinal properties, including antioxidant activity. In the present work, phenolic extracts
of R. ulmifolius flower buds obtained by decoction and hydroalcoholic extraction were chemically and
biologically characterized. Several phenolic compounds were identified in both decoction and
hydroalcoholic extracts of flowers, ellagitannin derivatives being the most abundant ones, namely the
sanguiin H-10 isomer and lambertianin. Additionally, comparing with the decoction form, the
hydroalcoholic extract presented both higher phenolic content and antioxidant activity.
The hydroalcoholic extract was thereafter microencapsulated in an alginate-based matrix and
incorporated into a yogurt to achieve antioxidant benefits. In what concerns the performed
incorporation tests, the obtained results pointed out that, among the tested samples, the yoghurt
containing the microencapsulated extract presented a slightly higher antioxidant activity, and that both
forms (free and microencapsulated extracts) gave rise to products with higher activity than the control.
In conclusion, this study demonstrated the antioxidant potential of the R. ulmifolius hydroalcoholic
extract and the effectiveness of the microencapsulation technique used for its preservation, thus
opening new prospects for the exploitation of these natural phenolic extracts in food application
Ceratonia siliqua L. hydroethanolic extract obtained by ultrasonication: antioxidant activity, phenolic compounds profile and effects in yogurts functionalized with their free and microencapsulated forms
Bioactive extracts were obtained from powdered carob pulp through an ultrasound extraction process and then evaluated in terms of antioxidant activity. Ten minutes of ultrasonication at 375 Hz were the optimal conditions leading to an extract with the highest antioxidant effects. After its chemical characterization, which revealed the preponderance of gallotannins, the extract (free and microencapsulated) was incorporated in yogurts. The microspheres were prepared using an extract/sodium alginate ratio of 100/400 (mg mg(-1)) selected after testing different ratios. The yogurts with the free extract exhibited higher antioxidant activity than the samples added with the encapsulated extracts, showing the preserving role of alginate as a coating material. None of the forms significantly altered the yogurt's nutritional value. This study confirmed the efficiency of microencapsulation to stabilize functional ingredients in food matrices maintaining almost the structural integrity of polyphenols extracted from carob pulp and furthermore improving the antioxidant potency of the final product.The authors acknowledge FCT (Portugal) for financial support to CIMO (PEst-OE/AGUI0690/2014) and L. Barros (SFRH/BPD/107855/2015) research grants, to FCT/MEC and FEDER under Programme PT2020 for financial support to LSRE (Project UID/EQU/50020/2013), and to QREN, ON2 and FEDER (Projects NORTE-07-0124-FEDER-000014 and NORTE-07-0162-FEDER-000050)
Normal solution and transport coefficients to the Enskog-Landau kinetic equation for a two-component system of charged hard spheres. The Chapman-Enskog method
An Enskog-Landau kinetic equation for a many-component system of charged hard
spheres is proposed. It has been obtained from the Liouville equation with
modified boundary conditions by the method of nonequilibrium statistical
operator. On the basis of this equation the normal solutions and transport
coefficients such as bulk kappa and shear eta viscosities, thermal conductivity
lambda, mutual diffusion D^{\alpha\beta} and thermal diffusion D_T^\alpha have
been obtained for a binary mixture in the first approximation using the
Chapman-Enskog method. Numerical calculations of all transport coefficients for
mixtures Ar-Kr, Ar-Xe, Kr-Xe with different concentrations of compounds have
been evaluated for the cases of absence and presence of long-range Coulomb
interactions. The results are compared with those obtained from other theories
and experiment.Comment: 24 LaTeX209 pages, 3 EPS figures (4 files). To be published in
Physica
On the free field realization of the osp(1|2) current algebra
The free field representation of the osp(1|2) current algebra is analyzed.
The four point conformal blocks of the theory are studied. The structure
constants for the product of an arbitrary primary operator and a primary field
that transforms according to the fundamental representation of osp(1|2) are
explicitly calculated.Comment: 11 pages, phyzz
Potencial antioxidante dos compostos fenólicos de Helichrysum stoechas (L.) Moench para aplicações cosméticas: caracterização química, microencapsulação e incorporação num hidratante
As propriedades bioativas de várias plantas têm sido atribuídas à presença de compostos
fenólicos, especialmente flavonoides (Mishra et al., 2008). As propriedades biológicas,
farmacológicas e medicinais deste grupo de compostos têm também sido exaustivamente
estudadas (Marchand, 2002). Estudos etnobotânicos realizados no Nordeste de Portugal registam
o uso da decocção de Helichrysum stoechas (L.) Moench (perpétua-das-areias ou douradinha)
pelas suas propriedades medicinais nomeadamente no controlo da febre, sintomas gripais e
bronquite (Carvalho, 2010). O presente trabalho teve como objetivo explorar o potencial
antioxidante dos compostos fenólicos das sumidades floridas (capítulos e brácteas e os 15 cm
terminais dos caules com folhas que suportam as inflorescências) de H. stoechas para aplicações
cosméticas e envolveu as seguintes etapas: caracterização química, microencapsulação e
incorporação num hidratante.
As propriedades antioxidantes do extrato hidroalcoólico e da decocção foram avaliadas por
métodos químicos (determinação do poder redutor e da capacidade captadora de radicais 2,2-
difenil-1-picril-hidrazilo (DPPH) e bioquímicos (inibição da descoloração do β-caroteno na
presença de radicais livres derivados do ácido linoleico e inibição da formação de espécies
reativas do ácido tiobarbitúrico (TBARS) em homogeneizados cerebrais). A composição fenólica
foi analisada por cromatografia líquida de alta eficiência de fase reversa acoplada a deteção de
díodos e espetrometria de massa com ionização por spray de eletrões (HPLC-DAD-ESI/MS).
Foram identificados dezoito compostos fenólicos diferentes, sendo o ácido 3,5-O-dicafeoilquínico e
a miricetina O-acetil-hexósido o ácido fenólico e o flavonoide mais abundante, respetivamente.
Comparativamente à decocção, o extrato hidroalcoólico apresentou maior atividade antioxidante e
conteúdo fenólico, tendo-se optado pela sua forma liofilizada para prosseguir os estudos de
microencapsulação. Para a microencapsulação utilizou-se a técnica da dupla emulsão/evaporação
de solvente, produzindo-se microesferas de base policaprolactona (PCL) com o respetivo
conteúdo (extrato hidroalcoólico de H. stoechas). Estas foram incorporadas com sucesso num
creme hidratante. Os resultados obtidos demonstraram o potencial antioxidante do extrato
hidroalcoólico de H. stoechas e a viabilidade da sua microencapsulação, abrindo novas
possibilidades de exploração e aplicação destes extratos fenólicos naturais, nomeadamente na
indústria de cosméticos.Fundação para a Ciência e a Tecnologia (FCT, Portugal) pelo apoio financeiro ao CIMO (projeto estratégico PEst-
OE/AGR/UI0690/2011) e ao LSRE (projeto estratégico PEst-C/EQB/LA0020/2011). L. Barros agradece ao FCT, POPHQREN
e FSE pelo seu contrato de investigação no âmbito do “Programa Compromisso com Ciência-2008”.O GIP-USAL é
financeiramente suportado pelo governo espanhol através do Programa Consolider-Ingenio 2010 (FUN-C-FOOD,
CSD2007-00063)
A bioactive formulation based on Fragaria vesca L. vegetative parts: chemical characterisation and application in κ-carrageenan gelatin
A bioactive formulation based on the vegetative parts of the wild strawberry, Fragaria vesca L., was developed by using a microencapsulated extract (lyophilized infusion form). For that purpose, a process based on an atomization/coagulation technique with alginate as the wall material was applied. Among the tested hydromethanolic and aqueous extracts, both obtained from wild and commercial samples, the infusion of a wild species emerged as the most antioxidative one. The higher amounts of flavonols and flavan-3-ols found in the aqueous extracts seem to be responsible for this greater antioxidant activity. Furthermore, the developed bioactive formulation was applied in k-carrageenan gelatin, being observed that the antioxidant properties of the extract were preserved, as compared with the free form. Thus, the antioxidant activity of the Fragaria vesca L. vegetative parts was demonstrated, as well as the advantages of using microencapsulation to produce effective bioactive formulations.Financial support was provided by FCT/MEC and FEDER under Programme PT2020 to LSRE (Project UID/EQU/50020/2013), CIMO (PEst-OE/AGR/UI0690/2014) and REQUIMTE (PEst-C/EQB/LA0006/2014), and QREN, ON2 and FEDER (Project NORTE-07-0162-FEDER-000050 and NORTE-07-0124-FEDER-000014). M.I. Dias and L. Barros thank FCT for SFRH/BD/84485/2012 grant and research contract (Compromisso para a Ciência 2008), respectively. G. Ruphuy thanks Universidad de Costa Rica (UCR) and Ministerio de Ciencia, Tecnología y Telecomunicaciones de Costa Rica (MICITT) for her scholarship. The GIP-USAL is financially supported by the Spanish Government through the project BFU2012-35228
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