54 research outputs found
Hydrometeor classification from dual-polarized weather radar: extending fuzzy logic from S-band to C-band data
International audienceA model-based fuzzy classification method for C-band polarimetric radar data, named Fuzzy Radar Algorithm for Hydrometeor Classification at C-band (FRAHCC), is presented. Membership functions are designed for best fitting simulation data at C-band, and they are derived for ten different hydrometeor classes by means of a scattering model, based on T-Matrix numerical method. The fuzzy logic classification technique uses a reduced set of polarimetric observables, i.e. copolar reflectivity and differential reflectivity, and it is finally applied to data coming from radar sites located in Gattatico and S. Pietro Capofiume in North Italy. The final purpose is to show qualitative accuracy improvements with respect to the use of a set of ten bidimensional MBFs, previously adopted and well suited to S-band data but not to C-band data
Platelet lysate maintains chondrogenic potential and promotes cartilage regeneration
cartilage.
We
report
the
biological
effect
of
the
platelet
lysate
(PL),
a
PRP
derivative,
on
primary
human
articular
chondrocytes
(HAC)
cultured
under
both
physiological
and
inflammatory
condition.
Added
to
the
culture
medium,
PL
induced
a
strong
mitogenic
response
in
the
chondrocytes.
The
in
vitro
expanded
cell
population
maintained
a
chondrogenic
re-‐differentiation
potential
as
revealed
by
micromass
culture
in
vitro
as
well
as
in
vivo
as
demonstrated
by
ectopic
cartilage
formation
in
nude
mice.
Furthermore,
in
chondrocytes
cultured
in
the
presence
of
the
pro-‐inflammatory
cytokine
IL-‐1α,
the
PL
induced
a
drastic
enhancement
of
the
synthesis
of
the
cytokines
IL-‐6
and
IL-‐8
and
of
NGAL,
a
lipocalin
expressed
in
cells
of
the
chondrogenic
lineage.
These
events
were
controlled
by
the
p38
MAP
kinase
and
NF-‐κΒ
pathways.
The
pro-‐inflammatory
effect
of
the
PL
was
a
transient
phenomenon.
In
fact,
after
an
initial
up
regulation,
we
observed
a
significant
reduction
of
the
NF-‐κΒ
activity
together
with
the
repression
of
the
inflammatory
enzyme
ciclooxygenase-‐2
(COX-‐2).
Moreover,
the
medium
of
chondrocytes
cultured
in
the
contemporary
presence
of
PL
and
IL-‐1α,
showed
a
significant
enhancement
of
the
chemoattractant
activity
versus
untreated
chondrocytes.
On
the
whole,
our
findings
support
the
concept
that
the
platelet
products
have
a
direct
beneficial
effect
on
articular
chondrocytes
and
at
the
same
time
could
drive
in
sequence
a
trans
Beta-tricalcium phosphate ceramic triggers fast and robust bone formation by human mesenchymal stem cells
Due to their osteoconductive and inductive properties, a variety of calcium phosphate (CaP) scaffolds are commonly used in orthopaedics as graft material to heal bone defects. In this study, we have used two CaP scaffolds with different hydroxyapatite (HA) and \u3b2-tricalcium phosphate (\u3b2-TCP) ratios (MBCP\uae; 60/40 and MBCP+\uae; 20/80) to investigate their intrinsic capacity to favour human bone marrow stem cells (hBMSCs) osteogenic differentiation capacity. We report that MBCP+\uae showed in in vitro culture model a higher rate of calcium ion release in comparison with MBCP\uae. In two defined coculture systems, the hBMSC seeded onto MBCP+\uae presented an increased amount of VEGF secretion, resulting in an enhanced endothelial cell proliferation and capillary formation compared with hBMSC seeded onto MBCP\uae. When both ceramics combined with hBMSC were implanted in a nude mouse model, we observed a faster osteogenic differentiation and enhancement mature bone deposition sustained by the presence of a vast host vasculature within the MBCP+\uae ceramics. Bone formation was observed in samples highly positive to the activation of calcium sensing receptor protein (CaSr) on the surface of seeded hBMSC that also shown higher BMP-2 protein expression. With these data we provide valuable insights in the possible mechanisms of ossification and angiogenesis by hBMSC that we believe to be primed by calcium ions released from CaP scaffolds. Evidences could lead to an optimization of ceramic scaffolds to prime bone repair
Novel injectable gel encapsulating human articular chondrocytes for cartilage tissue repair and regeneration
[Excerpt] Cartilage tissue loss, as a result of trauma, congenital disorders and diseases of joints, involving structural damage of articular cartilage surface, is a substantial clinical problem representing a major
challenge for cartilage tissue engineering. The aim of our study was to evaluate the in vitro and in vivo behavior of human articular chondrocytes encapsulated within a novel carrageenan in situ injectable
hydrogel for cartilage tissue engineering and regeneration. Human articular chondrocytes (Hac) were expanded using a well defined serum free medium able to support cell proliferation and
differentiation with high cell chondrogenicity. [...]info:eu-repo/semantics/publishedVersio
Novel injectable gel (system) as a vehicle for human articular chondrocytes in cartilage tissue regeneration
We developed a novel injectable carrageenan/fibrin/hyaluronic acid-based hydrogel with in situ
gelling properties to be seeded with chondrogenic cells and used for cartilage tissue engineering
applications. We first analysed the distribution within the hydrogel construct and the phenotype of
human articular chondrocytes (HACs) cultured for 3 weeks in vitro. We observed a statistically
significant increase in the cell number during the first 2 weeks and maintenance of cell
viability throughout the cell culture, together with the deposition/formation of a cartilage-specific
extracellular matrix (ECM). Taking advantage of a new in vivo model that allows the integration
between newly formed and preexisting cartilage in immunodeficient mice to be investigated, we
showed that injectable hydrogel seeded with human articular chondrocytes was able to regenerate
and repair an experimentally made lesion in bovine articular cartilage, thus demonstrating the
potential of this novel cell delivery system for cartilage tissue engineering.The authors are grateful to Recco orthopaedic staff members for the collaboration and patients for bioptic material donation as well as to Mrs Daniela Marubbi for histological assistance. This work was supported by funds from the Italian MUR (FIRB-Tissuenet project), the European Union-funded STREP project, HIPPOCRATES (Grant No. NMP3-CT-2003-505758) and the European NoE EXPERTISSUES project (Grant No. NMP3-CT-2004-500283)
BRS Jaspe: a processing peach cultivar for low chill areas.
O programa de melhoramento da Embrapa fornece um processamento de pêssego cultivar, 'BRS Jaspe'. Ao longo dos anos, o rendimento desta cultivar foi estável e seus frutos podem ser colhidos em meados de novembro, com bom tamanho e sabor. Pode representar uma alternativa à cultivar Granada, com um período de maturação semelhante
'BRS Mandinho': the first platycarpa peach cultivar released in Brazil.
Pêssegos tipo platicarpa têm alcançado ótimos preços devido à boa aceitação no mercado. entretanto, a quase totalidade das cultivares lançadas são bastante exigentes em frio hibernal e não se adaptam às condições brasileiras, exceção representada por pequenas áreas de microclimas, com elevada altitude. a cultivar BRS Mandinho é a primeira cultivar da variedade botânica platicarpa lançada no Brasil e adapta-se a condições subtropicais. Suas plantas são vigorosas e a floração, no Rio Grande do Sul, ocorre na segunda quinzena de Julho. As frutas são doces e amadurecem em novembro e apresentam massa média de 55,3 g.Scientific Communication
BRS Cainguá, a blackberry fresh-market cultivar.
Uma das razões para a baixa demanda de amoras do mercado no Brasil é o sabor ácido da fruta fresca. Os frutos da cultivar BRS Cainguá, recém-lançada, têm um sabor melhor e uma forma muito atraente
Estudo de simulações de microclimas em casas de vegetação visando à aclimatação de mudas micropropagadas de bananeira cv Grande Naine.
Em processos de aclimatação, o controle ambiental assume papel de vital importância, pois, ainda que na condição in vitro, as plantas não operam eficientemente a absorção de luz, água e nutrientes. Devem, portanto, ser submetidas a ambientes controlados sob condições favoráveis de luminosidade, temperatura (ao redor de 28oC, com mínimas de 18o.C e máximas a 34oC) e umidade relativa (acima de 75%). Para tanto, foram construídos 5 mini-túneis com temperatura e umidade controladas. No controle da temperatura, usaram-se resfriadores evaporativos do tipo ventilador-meio poroso, 28/25oC. No controle da umidade relativa, usou-se nebulização durante o dia a 75% sob intermitência de 6s a cada 40s. Para o monitoramento da temperatura e umidade relativa, foram instalados 3 psicrômetros aspirados em cada casa de vegetação, ligados a sistema programado para leituras diárias com partição de 60s. Os resultados indicam controle satisfatório nos ambientes, oferecendo condições favoráveis para as plantas de bananeira sob o 2o estágio de aclimatação, embora tenham sido observadas diferenças significativas entre eles. Para o estudo da luminosidade, sob filme plástico transparente PEBD de 100um, foram utilizadas telas com média de sombreamento na faixa RFA (400 a 700nm) de 69,92%, 50,73%, 29,73% e 57,77%, sendo as 3 primeiras de cor vermelha (com picos na faixa de 580nm e redução abrupta a partir daí), e a última de cor preta (comportamento linear), respectivamente. O 5o ambiente contou apenas com o filme, apresentando 12,74% de interceptação da radiação solar. Esses valores foram obtidos a partir de amostras pareadas, tela e filme para os 4 primeiros ambientes e apenas o filme para o último, utilizando-se de espectro-radiômetro programado para a faixa de 400 a 1.100nm, com resolução espectral de 2nm. Dentro e fora de cada ambiente, obtiveram-se dados de irradiâncias RFA e global, por meio de sensores fotovoltaicos de silício, por volta das 9h, 12h e 15h, sob condições de céu claro e encoberto, durante o verão de 2004/5 e inverno de 2005. As malhas vermelhas apresentam transmitâncias diferenciadas ao longo do espectro da radiação fotossinteticamente ativa, construindo-se assim em interessantes materiais para os pretendidos estudos sobre aclimatação. Resultados mostram maiores reduções na faixa RFA para as telas vermelhas, independentes do horário, insolação e estação do ano, concordantes com aqueles obtidos por espectro-radiômetro
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