549 research outputs found
Intra and inter-rater reliability study of pelvic floor muscle dynamometric measurements
The aim of this study was to evaluate the intra and inter-rater reliability of pelvic floor muscle (PFM) dynamometric measurements for maximum and average strengths, as well as endurance. A convenience sample of 18 nulliparous women, without any urogynecological complaints, aged between 19 and 31 (mean age of 25.4±3.9) participated in this study. They were evaluated using a pelvic floor dynamometer based on load cell technology. The dynamometric evaluations were repeated in three successive sessions: two on the same day with a rest period of 30 minutes between them, and the third on the following day. All participants were evaluated twice in each session; first by examiner 1 followed by examiner 2. The vaginal dynamometry data were analyzed using three parameters: maximum strength, average strength, and endurance. The Intraclass Correlation Coefficient (ICC) was applied to estimate the PFM dynamometric measurement reliability, considering a good level as being above 0.75. The intra and inter-raters' analyses showed good reliability for maximum strength (ICCintra-rater1=0.96, ICCintra-rater2=0.95, and ICCinter-rater=0.96), average strength (ICCintra-rater1=0.96, ICCintra-rater2=0.94, and ICCinter-rater=0.97), and endurance (ICCintra-rater1=0.88, ICCintra-rater2=0.86, and ICCinter-rater=0.92) dynamometric measurements. The PFM dynamometric measurements showed good intra- and inter-rater reliability for maximum strength, average strength and endurance, which demonstrates that this is a reliable device that can be used in clinical practice.1929710
Superpartner spectrum of minimal gaugino-gauge mediation
We evaluate the sparticle mass spectrum in the minimal four-dimensional
construction that interpolates between gaugino and ordinary gauge mediation at
the weak scale. We find that even in the hybrid case -- when the messenger
scale is comparable to the mass of the additional gauge particles -- both the
right-handed as well as the left-handed sleptons are lighter than the bino in
the low-scale mediation regime. This implies a chain of lepton production and,
consequently, striking signatures that may be probed at the LHC already in the
near future.Comment: 8 pages, 3 figures; V2: refs and a few comments added; V3 title
change
In vitro evaluation of the behaviour of human polymorphonuclear neutrophils in direct contact with chitosan-based membranes
Several novel biodegradable materials have been proposed for wound healing applications in the past few years. Taking into consideration the
biocompatibility of chitosan-based biomaterials, and that they promote adequate cell adhesion, this work aims at investigating the effect of chitosanbased
membranes, over the activation of human polymorphonuclear neutrophils (PMNs). The recruitment and activation of polymorphonuclear
neutrophils (PMNs) reflects a primary reaction to foreign bodies. Activation of neutrophils results in the production of reactive oxygen species
(ROS) such as O2
− and HO− and the release of hydrolytic enzymes which are determinant factors in the inflammatory process, playing an essential
role in the healing mechanisms.
PMNs isolated from human peripheral blood of healthy volunteers were cultured in the presence of chitosan or chitosan/soy newly developed
membranes. The effect of the biomaterials on the activation of PMNs was assessed by the quantification of lysozyme and ROS.
The results showed that PMNs, in the presence of the chitosan-based membranes secrete similar lysozyme amounts, as compared to controls
(PMNs without materials) and also showed that the materials do not stimulate the production of either O2
− or HO−. Moreover, PMNs incubated
with the biomaterials when stimulated with phorbol 12-myristate 13-acetate (PMA) or formyl-methionyl-leucyl-phenylalanine (fMLP) showed a
chemiluminescence profile with a slightly lower intensity, to that observed for positive controls (cells without materials and stimulated with PMA),
which reflects the maintenance of their stimulation capacity.
Our data suggests that the new biomaterials studied herein do not elicit activation of PMNs, as assessed by the low lysozyme activity and by the
minor detection of ROS by chemiluminescence. These findings reinforce previous statements supporting the suitability of chitosan-based materials
for wound healing applications
Chitosan improves the biological performance of soy-based biomaterials
Soybean protein has been proposed for distinct applications within nutritional, pharmaceutical, and cosmetic industries
among others. More recently, soy-based biomaterials have also demonstrated promising properties for
biomedical applications.However, althoughmany reports within other fields exist, the inflammatory/immunogenic
potential of those materials is still poorly understood and therefore can hardly be controlled. On the contrary,
chitosan (Cht) has been well explored in the biomedical field, either by itself or combined with synthetic or other
natural-based polymers. Therefore, the combination of chitosan with soybean protein is foreseen as a suitable
approach to control the biological behavior of soy-based biomaterials. Under this context this work was designed to
try to understand the influence of chitosan in the host response elicited by soy-based biomaterials. Soybean protein
isolate powder (SI-P) and Cht powder (Cht-P) were injected as suspension into the intraperitoneal cavity of rats. SI-P
induced the recruitment of higher numbers of leukocytes compared to the Cht-P during the entire observation
period. In this sense, SI-P elicited a considerable reaction from the host comparing to the Cht-P, which elicited
leukocyte recruitment similar to the negative control.After subcutaneous implantation of the soybean and denatured
membranes, (SI-M and dSI-M) a severe host inflammatory reaction was observed. Conversely, Cht/soy-based
membranes (Cht/soy-based membranes) showed the induction of a normal host response after subcutaneous implantation
in rats, which allowed concluding that the addition of chitosan to the soy-based membranes improved
their in vivo performance. Thus, the presented results assert the improvement of the host response, considering
inflammatory cells recruitment, and overall inflammatory reaction,when chitosan is combined to soybean. Together
with previous results that reported their promising physicochemical characteristics and their inability to activate
human polymorphonuclear neutrophils in vitro, the herein presented conclusions reinforce the usefulness of theCht/
soy-based membranes and justify the pursue for a specific application within the biomedical field.The author Tircia C. Santos acknowledges the Marie Curie European Program for a short-term scholarship in the Alea Jacta EST project (MEST-CT-2004-008104). This work was developed under the scope of the European Network of Excellence EXPERTISSUES (NMP3-CT-2004-5000283)
Particle-associated polycyclic aromatic hydrocarbons in a suburban region of Rio de Janeiro, Brazil, with industrial and traffic emissions
From April 206 to March 2007, total suspended particles (TSP) and PM10 samples were collected at the Campus of FIOCRUZ, situated in a suburban region with intense industrial and commercial activities in Rio de Janeiro (Brazil). The concentrations of 16 selected polycyclic aromatic hydrocarbons (PAHs) were determined by gas chromatography with mass selective detection. Individual concentrations were between the detection limit (acenaphtylene, acenaphthene, anthracene and fluorene) and 6.16 ng m-3 for benzo[b]fluoranthene. The five most abundant PAHs, in TSP, samples were B[b]F, Ipy, Py, Chry and DB[ah]An, and the mean sum of 16 PAHs was 15.53 ng m-3. The same most abundant compounds were obtained in PM10 samples and a total mean mass of 8.99 ng m-3 was determined. Diagnostic ratios were calculated and vehicular emissions were determined as the potential sources for PAHs in particulate matter. The contribution of both light duty and diesel engines is significant, but the cluster and factorial analysis failed to classify clearly in gasoline or diesel emissions
In vivo performance of chitosan/soy-based membranes as wound dressing devices for acute skin wounds
Wound management represents a major clinical challenge on what concerns healing enhancement and pain control. The selection of an appropriate dressing plays an important role in both recovery and esthetic ap- pearance of the regenerated tissue. Despite the wide range of available dressings, the progress in the wound care market relies on the increasing interest in using natural-based biomedical products. Herein, a rat wound- dressing model of partial-thickness skin wounds was used to study newly developed chitosan/soy (cht/soy)- based membranes as wound-dressing materials. Healing and repair of nondressed, cht/soy membrane-dressed, and Epigard -dressed wounds were followed macroscopically and histologically for 1 and 2 weeks. cht/soy membranes performed better than the controls, promoting a faster wound repair. Re-epithelialization, ob- served 1 week after wounding, was followed by cornification of the outermost epidermal layer at the second week of dressing, indicating repair of the wounded tissue. The use of this rodent model, although in impaired healing conditions, may enclose some drawbacks regarding the inevitable wound contraction. Moreover, being the main purpose the evaluation of cht/soy-based membranes’ performance in the absence of growth factors, the choice of a clinically relevant positive control was limited to a polymeric mesh, without any growth factor influencing skin healing/repair, Epigard. These new cht/soy membranes possess the desired features regarding healing/repair stimulation, ease of handling, and final esthetic appearance-thus, valuable prop- erties for wound dressings.The author Tircia C. Santos acknowledges the Portuguese Foundation for Science and Technology (FCT) for her PhD grant (SFRH/BD/40861/2007). This work was developed under the scope of the European Network of Excellence EXPERTISSUES (NMP3-CT-2004-5000283)
The use of ionic liquids in the processing of chitosan/silk hydrogels for biomedical applications
Natural polymers are adequate renewable resources for the processability of well-defined architectures for
several applications. Combinations of polysaccharides and proteins may mimic the naturally occurring
environment of certain tissues. The main goal of this work renders the application of green chemistry
principles, namely the use of ionic liquids (ILs) and biorenewable sources, such as chitosan (CHT) and
silkfibroin (SF), to process new hydrogel-based constructs. Although the solubilization of both materials
in ILs has been studied individually, this work reports, for the first time, the role of ILs as solvent, for the
production of hydrogels from blends of chitosan and silkfibroin (CSF). These systems offer the
advantage of being homogeneous and presenting easy and short dissolution time of both
biomacromolecules. Moreover, the use of chitosan obtained fromα- andβ-chitin allowed the production
of blended hydrogels with distinct physical–chemical properties.In vitroassays demonstrated that these
hydrogels supported the adhesion and growth of primary human dermalfibroblasts. Taken these
properties together, the CSF hydrogels might be promising biomaterials to be explored for skin tissue
engineering approaches.Fundação para a Ciência e a Tecnologia FCT - SFRH/BPD/45307/2008, SFRH/BPD/
34704/2007, SFRH/BD/64601/2009, PTDC/QUI/68804/2006FEDER - POCTEP 0330_IBEROMARE_1_P
Rational Design and Synthesis of Large Stokes Shift 2,6-Sulphur-Disubstituted BODIPYs for Cell Imaging
Five new disubstituted 2,6-thioaryl-BODIPY dyes were synthesized via selective aromatic electrophilic substitution from commercially available thiophenols. The analysis of the photophysical properties via absorption and emission spectroscopy showed unusually large Stokes shifts for BODIPY fluorophores (70–100 nm), which makes them suitable probes for bioimaging. Selected compounds were evaluated for labelling primary immune cells as well as different cancer cell lines using confocal fluorescence microscopy
On the Spectrum of Direct Gaugino Mediation
In direct gauge mediation, the gaugino masses are anomalously small, giving
rise to a split SUSY spectrum. Here we investigate the superpartner spectrum in
a minimal version of "direct gaugino mediation." We find that the sfermion
masses are comparable to those of the gauginos - even in the hybrid
gaugino-gauge mediation regime - if the messenger scale is sufficiently small.Comment: 21 pages, 4 figures; V2: refs. adde
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