1,305 research outputs found
Fast plasma sintering delivers functional graded materials components with macroporous structures and osseointegration properties
We explored the osseointegration potential of two macroporous titanium surfaces obtained using fast plasma sintering (FPS): Ti macroporous structures with 400-600 ”mà pores (TiMac400) and 850-1000 ”mà pores (TiMac850). They were compared against two surfaces currently in clinical use: Ti-GrowthŸ and air plasma spray (Ti-Y367). Each surface was tested, once placed over a Ti-alloy and once onto a CoCr bulk substrate. Implants were placed in medial femoral condyles in 24 sheep. Samples were explanted at four and eight weeks after surgery. Push-out loads were measured using a material-testing system. Bone contact and ingrowth were assessed by histomorphometry and SEM and EDX analyses. Histology showed early osseointegration for all the surfaces tested. At 8 weeks, TiMac400, TiMac850 and Ti-GrowthŸ showed deep bone ingrowth and extended colonisation with newly formed bone. The mechanical push-out force was equal in all tested surfaces. Plasma spray surfaces showed greater bone-implant contact and higher level of pores colonisation with new bone than FPS produced surfaces. However, the void pore area in FPS specimens was significantly higher, yet the FPS porous surfaces allowed a deeper osseointegration of bone to implant. FPS manufactured specimens showed similar osseointegration potential to the plasma spray surfaces for orthopaedic implants. FPS is a useful technology for manufacturing macroporous titanium surfaces. Furthermore, its capability to combine two implantable materials, using bulk CoCr with macroporous titanium surfaces, could be of interest as it enables designers to conceive and manufacture innovative components. FPS delivers functional graded materials components with macroporous structures optimised for osseointegration
Norbornene-chitosan spray-dried microspheres for peptide conjugation using thiol-ene âphotoclickâ chemistry
This work was financed by Portuguese funds through FCT/MCTES (Fundação para a CiĂȘncia e a Tecnologia/MinistĂ©rio da CiĂȘncia, Tecnologia e Inovação) in the framework of the projects 2022.06048.PTDC (i3S), UIDB/50006/2020 (LAQV-REQUIMTE), LA/P/0045/2020 (ALiCE) and UIDB/00511/2020 (LEPABE). P.A. (SFRH/BD/145471/2019) and D.F. (SFRH/ BD/146890/2019) doctoral grants, were financially supported by national (FCT/Norte 2020 Framework) and European Union (ESF â European Social Fund) funds. B.E. acknowledges FCT for the contract based on the âLei do Emprego CientĂficoâ (DL 57/2016). Maria Cristina L. Martins also acknowledges FCT (LA/P/0070/2020), project Bio2Skin Advanced (2021-24):NORTE-01-0247-FEDER-047225; and MOBILIsE Project, which has received funding from the European Unionâs Horizon 2020 research and innovation program under grant agreement no. 951723.The action of bioactive peptides, such as antimicrobial peptides (AMP), in the human body
is often compromised by limited residence time and stability in the target site. Bioconjugation of
peptides to biomaterial surfaces is one of the strategies that may overcome these limitations. Herein,
norbornene-chitosan (NorChit) microspheres were engineered to react with thiolated peptides by thiolene âphotoclickâ chemistry. NorChit microspheres were produced by spray drying and crosslinked
with dithiothreitol (DTT) to prevent their solubilization. Microspheres with a diameter of 5 ± 2 ”m
showed round and smooth morphology with pockets over the surface that could be related with
hydrophobic interactions between internal norbornene groups. Thiol-ene bioconjugation carried
out using a fluorescent model peptide, showed a yield of 45%, whereas using the peptide but without
UV exposure indicated a maximum of peptide adsorption of 30%. Altogether, NorChit microspheres
show the potential for carrying bioactive peptides, which may open avenues for AMP activity onto
harsh environments in the bod
Water-gated organic transistors on polyethylene naphthalate films
Water-gated organic transistors have been successfully exploited as potentiometric transducers in a variety of sensing applications. The device response does not depend exclusively on the intrinsic properties of the active materials, as the substrate and the device interfaces play a central role. It is therefore important to fine-tune the choice of materials and layout in order to optimize the final device performance. Here, polyethylene naphthalate (PEN) has been chosen as the reference substrate to fabricate and test flexible transistors as bioelectronic transducers in liquid. PEN is a biocompatible substrate that fulfills the requirements for both bio-applications and micro-fabrication technology.Three different semiconducting or conducting polymer thin films employing pentacene, poly(3-hexylthiophene) or poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) were compared in terms of transconductance, potentiometric sensitivity and response time. The different results allow us to identify material properties crucial for the optimization of organic transistor-based transducers operating in water
Cytogenetic analysis of five Hypostomus species (Siluriformes, Loricariidae)
In this work, we analyzed the karyotypes of five Hypostomus species. Hypostomus cf. heraldoi, from the Mogi-Guaçu River, had 2n = 72 chromosomes, with a nucleolar organizer region (NOR) in one chromosomal pair. Hypostomus regani, from the Mogi-Guaçu River had 2n = 72 chromosomes with NORs in two chromosomal pairs. Hypostomus sp., from the Mogi-Guaçu River basin, had 2n = 68 chromosomes, with NORs in two chromosomal pairs. Hypostomus aff. agna, from Cavalo Stream, had 2n = 74 chromosomes with NORs in two chromosomal pairs. Hypostomus cf. topavae, from Carrapato Stream, had 2n = 80 chromosomes, with NORs in two chromosomal pairs. Hypostomus species showed marked diversity in the karyotypic formula, which suggested the occurrence of several Robertsonian rearrangements and pericentric inversions during the evolutionary history of this genus. This hypothesis was supported by the occurrence of a large number of uniarmed chromosomes and multiple NORs in a terminal position in most species and may be a derived condition in the Loricariidae
Lima beans production and economic revenue as function of organic and mineral fertilization
Preparation and characterisation of high refractive index PhO-TiO2-TeO2 glass systems
We describe the predaration and characterisation of high refractive index PbO-TiO2-TeO2 glass systems. Highly homogeneous glasses were obtained by agitating the oxide mixture during the melting process in an alumina crucible. The characterisation was performed by X-ray diffraction, density, dilatometry, Raman scattering, light absorption and linear refractive index measurements. The results show a change in the glass structure as the PbO content increases: the TeO4 trigonal bipyramids characteristic of TeO4 glasses transform into TeO, trigonal pyramids. However, the measured refractive indices are almost independent of the glass composition. We show that third-order non-linear optical susceptibilities calculated from the measured refractive indices using Lines' theoretical model are also independent of the glass composition.6111811181
High speed railway ground dynamics: a multi-model analysis
High speed railway track and earthwork structures experience varied levels of displacement amplification depending upon train speed. Protecting against amplified track deflections is challenging due to the complexity of deep wave propagation within both the track and supporting soil structures. Therefore it is challenging to derive design guidelines that encompass the full range of influential variables. As a solution, this paper uses a novel multi-model framework where 4 complimentary modelling strategies are combined, and thus able to generate new insights into railway ground dynamics and âcritical velocityâ. The four types of model are: 1) analytical, 2) hybrid analytical-numerical, 3) 2.5D numerical, 4) 3D numerical. They are used to explore subgrade layering, track type, train type, soil non-linearity, shakedown and ground improvement. The findings provide new insights into railway track-ground geodynamics and are useful when considering the design or upgrade of railroad lines
History of adversity, health and psychopathology among prisoners: comparison between men and women
Adversity in childhood, risk behaviors
and psychopathology are highly prevalent phenomena
in inmate populations and have a strong
impact on health. Knowing the differences in these
variables between the sexes is most important in
order to develop appropriate intervention strategies
in a prison context. By administering the
Socio-demographic and Life History Questionnaire
and the Brief Symptoms Inventory, we
sought to characterize adverse childhood experiences
and relate them to risk behaviors and to
psychopathological symptoms, and study the differences
between the 65 male and 42 female detainees
in Portuguese prison establishments. Men
and women report a complex web of adversity in
childhood. In a range of ten possible categories, a
medium value of 5.05 (DP = 2.63) in total adversity
for women and 2.63 (DP = 2.18) for men was
encountered, with the prevalence being significantly
higher within the female population (Z =
-4.33; p = .000). A high prevalence of risk behaviors
and psychopathological symptoms was found
in both groups, the latter being higher among females.
We concluded that the differences between
men and women calls for in depth studies in order
to provide guidelines for intervention projects
in specific populations.Adversidade na infĂąncia, comportamentos
de risco e psicopatologia sĂŁo fenĂłmenos muito
prevalentes na população reclusa e com forte impacto
na saĂșde. Conhecer as diferenças entre sexos,
no que diz respeito a tais variĂĄveis, Ă© de elevada
importùncia no sentido de adequar estraté-
gias de intervenção em contexto prisional. Utilizando
o QuestionĂĄrio SociodemogrĂĄfico e HistĂł-
ria de Vida, o QuestionĂĄrio de Adversidade na
InfĂąncia e o Brief Symptons Inventory, procuramos
caracterizar a adversidade na infĂąncia, os
comportamentos de risco e as dimensÔes psicopatológicas,
e averiguar as diferenças entre 65 homens
e 42 mulheres reclusos em estabelecimentos
prisionais Portugueses. Homens e mulheres relatam
um quadro complexo de adversidade na infĂąncia.
Num total possĂvel de dez categorias, verificamos
uma média de adversidade total de 5.05
(DP = 2.63) para as mulheres e de 2.63 (DP =
2.18) para os homens, sendo a prevalĂȘncia significativamente
mais elevada junto da população
feminina (Z = -4.33; p = .000). Foi ainda encontrada
uma elevada prevalĂȘncia de comportamentos
de risco e de sintomatologia psicopatolĂłgica
em ambos os grupos, sendo esta Ășltima superior
nas mulheres. ConcluĂmos que as diferenças entre
sexos devem ser estudadas para guiarem a adequação
dos projetos
Living with severe allergy: an Anaphylaxis Campaign national survey of young people
<p>Abstract</p> <p>Background</p> <p>The transition to adulthood can be particularly challenging for young people with severe allergies, who must learn to balance personal safety with independent living. Information and support for young people and their families are crucial to successfully managing this transition. We sought to: gather insights into the impact of severe allergies on the lives of young people; explore where young people go for information about anaphylaxis and what information they want and need; identify areas where further support is needed.</p> <p>Methods</p> <p>An online questionnaire survey of young people aged 15â25 years with severe allergies in the United Kingdom (UK) was conducted on behalf of the Anaphylaxis Campaign, the main patient support organisation. Participants were recruited mainly from the Anaphylaxis Campaign membership database and also via allergy clinics and social media. The study was funded by the Anaphylaxis Campaignâs In Memoriam Fund.</p> <p>Results</p> <p>A total of 520 young people responded to the survey. The majority had lived with severe allergies since they were young children; 59% reported having attended Accident and Emergency units as a consequence of their allergies. Only 66% of respondents reported always carrying their epinephrine auto-injectors; only 23% had ever used these. Few were currently receiving specialist allergy care; younger respondents were more likely to be under specialist care (34%) than those 18 years and above (23%). Respondents wanted more information about eating out (56%), travelling (54%) and food labelling (43%). Almost a quarter of respondents (23%) reported needing more information on managing their allergies independently without parental help. Managing allergies in the context of social relationships was a concern for 22% of respondents.</p> <p>Conclusions</p> <p>This survey has identified the information and support needs and gaps in service provision for young people with severe allergies. Healthcare professionals and patient support organisations, with the support of the food industry, can help to meet these needs.</p
DinĂąmica das relaçÔes familiares intergeracionais na Ăłtica de idosos residentes no MunicĂpio de JequiĂ© (Bahia), Brasil
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