695 research outputs found
Step by step optimization of a sperm cryopreservation protocol for spotted wolffish (Anarhichas minor Olafsen, 1772)
Spotted wolffish Anarhichas minor reproduction in captivity is dependent on in vitro fertilization. However, low sperm volume with relatively low cell concentration and the lack of gametes synchronization (simultaneous availability of mature eggs and sperm) represent a challenge for the industry. Thus, the development of protocols for sperm storage are crucial. Four sequential experiments were conducted to optimize a sperm cryopreservation protocol for this species. First, three different cryoprotectants (DMSO; 1, 2-propanediol; and methanol) at different concentrations (5, 10, and 20%) were tested for their toxicity. No significant differences (p > 0.05) were detected between the control samples and cryoprotectants at concentration up to 10% DMSO, 10% propanediol, and 20% methanol in terms of motility parameters. Second, using the highest non-toxic concentrations of cryoprotectants, sperm was cryopreserved in 0.5 mL straws, at different distances from the liquid nitrogen (1.5, 2.5, 4.5, and 7.5 cm) that correspond to different freezing rates. Motility parameters after freezing/thawing decreased for all the cryoprotectants (p 0.05) between the two thawing rates. The best results were obtained using 10% DMSO. Finally, the fertilization capacity of cryopreserved sperm (10% DMSO and thawed at 5 °C for 1 min) was tested against fresh sperm using two spermatozoa:egg ratios and 4 h gametes contact time. The ratio of eggs with normal cell cleavage, abnormal cleavage or undeveloped were counted at the 2-4 cell stage. Cryopreserved sperm showed lower fertilization capacity at a concentration of 5 × 104 spermatozoa:egg compared with fresh sperm (p 0.05). To cryopreserve spotted wolffish sperm it is recommended to use 10% DMSO, loaded in 0.5 mL straws, freeze at a height between 4.5 (-14.05 °C/min) and 7.5 cm (-5.9 °C/min) from liquid nitrogen for 10 min and thaw for 1 min at 5 °C (177.9 °C/min). In vitro fertilization with cryopreserved sperm should be performed with a concentration of at least 5 × 105 spermatozoa per egg.WOLFSTORE project (AF0078) supported by the MABIT program from Norway. JS was supported by a Cost action FA1205 AQUAGAMETE and an ERASMUS grant.info:eu-repo/semantics/publishedVersio
Dor em portadores de próteses totais primárias da anca: causas e avaliação clínica
Apesar da prótese total primária da anca ser referenciada como uma das endopróteses com maior sucesso em Ortopedia, uma pequena percentagem de doentes desenvolve um quadro doloroso localizado na anca num curto, médio ou a longo prazo, que pode ou não ser provocado pelo implante.
A razão da persistência da dor após a implantação de uma prótese da anca pode ser sustentada por fatores intrínsecos, por fatores extrínsecos loco-regionais ou por outros fatores extrínsecos. O estudo das próteses da anca não pode ser feito isoladamente, deve estar integrado no complexo funcional vertebro-pélvico-femoral.
Assim, tendinopatias dos músculos glúteos, do psoas-ilíaco, dos adutores, dos isquiotíbiais ou as afeções da coluna lombar, da articulação sacroilíaca ou do joelho homolateral e, ainda, afeções vasculares, nervosas e fatores psicológicos podem justificar a presença da dor.
Neste contexto, o desprendimento assético e a infeção periprotética são dois importantes fatores que poderão estar na origem da dor na anca após uma prótese total da anca e devem, desde logo, ser excluídos antes de se considerarem outras causas menos comuns. Se não existir, aparentemente, uma razão que justifique a dor, o doente deve ser considerado como tendo uma infeção periprotética até prova do contrário.
A anamnese e o exame físico, complementados por provas laboratoriais sanguíneas e do aspirado articular ou periarticular e, ainda, pelos exames imagiológicos, constituem os pilares sobre os quais assenta o diagnóstico das diferentes afeções que podem estar na génese da dor. Com efeito, o hemograma com fórmula leucocitária, a velocidade de sedimentação, a proteína C reativa, os exames radiográficos em diferentes incidências, a ecografia, a artrocentese com estudo citológico, microbiológico, cultura e antibiograma do aspirado articular, a tomografia axial computorizada quando indicada, são instrumentos valiosos para se conseguir alcançar um diagnóstico definitivo.
Identificada a etiologia da dor, torna-se possível definir a estratégia terapêutica mais indicada, que é necessariamente diferente de um caso para outro.
Constitui um princípio crucial só iniciar a terapêutica após o conhecimento do diagnóstico, quer se trate de uma abordagem conservadora ou, sobretudo, de uma intervenção cirúrgica. As dores inexplicáveis, de causa desconhecida, não encontram indicação para uma intervenção cirúrgica, assim como não é de aceitar a origem periarticular da dor sem terem sido eliminadas todas as causas de dor relacionadas com a prótese.
A intervenção cirúrgica com a finalidade de se proceder a uma eventual recolocação artroplástica, sem prévio esclarecimento da etiologia da dor, não é uma boa prática produz, muitas vezes, um pobre resultado clínico
Processing and classification of biological images: Application to histology
This article deals with a histological problem by using image processing and feature extraction in images of renal tissues of rats and their classification through various methods such as: Bayesian inference, decision trees and support vector machines
Synthesis of titanate nanofibers co-sensitized with ZnS and Bi2S3 nanocrystallites and their application on pollutants removal
The synthesis of nanocomposite materials combining titanate nanofibers (TNF)
with nanocrystalline ZnS and Bi2S3 semiconductors is described in this work.
The TNF were produced via hydrothermal synthesis and sensitized with the
semiconductor nanoparticles, through a single-source precursor decomposition
method. ZnS and Bi2S3 nanoparticles were successfully grown onto the TNF's
surface and Bi2S3-ZnS/TNF nanocomposite materials with different layouts were
obtained using either a layer-by-layer or a co-sensitization approach. The
samples' photocatalytic performance was first evaluated through the production
of the hydroxyl radical using terephthalic acid as probe molecule. All the
tested samples show photocatalytic ability for the production of this oxidizing
species. Afterwards, the samples were investigated for the removal of methylene
blue. The nanocomposite materials with best adsorption ability for the organic
dye were the ZnS/TNF and Bi2S3ZnS/TNF. The removal of the methylene blue was
systematically studied, and the most promising results were obtained
considering a sequential combination of an adsorption-photocatalytic
degradation process using the Bi2S3ZnS/TNF powder as a highly adsorbent and
photocatalyst material.Comment: 26 pages, 10 figure
Adaptação de esqueletos metálicos de próteses parciais removíveis produzidos por CAD-CAM – estudo clínico
Objectives: To assess the effect of a CAD-CAM protocol fabrication on the clinical fit accuracy of removable partial denture metal frameworks to abutment teeth. Methods: Fifteen patients with partial edentulism were selected to participate in this clinical study, and twenty dental arch rehabilitations were planned. For each dental arch (n=20), two cobalt-chromium frameworks were produced through two protocols: CAD-CAM production (experimental group); and conventional lost-wax casting technique (control group). Clinical fit accuracy was assessed using an indirect quantitative method to evaluate the gap between the framework occlusal rest and the corresponding rest seat. A silicone mold of that gap was obtained, digitized, and analyzed by micro-computed tomography. The two silicone molds obtained for each occlusal rest were overlapped and evaluated for thickness and volume. Data were analyzed with the paired t test for silicone thickness results and the Wilcoxon test for silicone volume results (α= 0.05). Results: Considering the two dependent variables under study, no statistically significant (p=0.441 for silicone thickness and p=0.204 for silicone volume) differences were found between groups. Conclusions: The results of this study suggest that the CAD-CAM protocol applied is a viable method for the production of removable partial denture metal frameworks.info:eu-repo/semantics/publishedVersio
Dismetrias dos membros inferiores após artroplastias totais primárias da anca: medidas preventivas
Apesar de ser reconhecida como uma das intervenções de maior sucesso em cirurgia reconstrutiva ortopédica, a artroplastia total primária da anca não está isenta de complicações. Desigualdades no comprimento dos membros inferiores até 1 cm são comuns e, de uma forma geral, bem toleradas. Todavia, dismetrias maiores podem estar associadas a dor e a lesões nervosas e serem, por isso, motivo de insatisfação do doente e de litigância.
Embora não se possa eliminar, de todo, as dismetrias após uma artroplastia total da anca, estas podem ser minimizadas através de uma série de procedimentos antes e durante a intervenção cirúrgica. Neste sentido, são de realçar o valor da anamnese e do exame físico com determinação do comprimento real e aparente dos membros inferiores, a avaliação e planificação radiográficas, uma diversidade de provas e medições efetuadas durante a operação e a cirurgia assistida por computador.
A planificação radiográfica pré-operatória integra uma das etapas mais importantes no processo da implantação de uma prótese total da anca, de sorte a restabelecer a biomecânica da anca e preservar ou restituir a isometria dos membros inferiores, sem comprometer a estabilidade da prótese
Effects of Glyphosate-Based Herbicide on Primary Production and Physiological Fitness of the Macroalgae Ulva lactuca
The use of glyphosate-based herbicides (GBHs) worldwide has increased exponentially over
the last two decades increasing the environmental risk to marine and coastal habitats. The present
study investigated the effects of GBHs at environmentally relevant concentrations (0, 10, 50, 100, 250,
and 500 g L1) on the physiology and biochemistry (photosynthesis, pigment, and lipid composition,
antioxidative systems and energy balance) of Ulva lactuca, a cosmopolitan marine macroalgae species.
Although GBHs cause deleterious effects such as the inhibition of photosynthetic activity, particularly
at 250 g L1, due to the impairment of the electron transport in the chloroplasts, these changes are
almost completely reverted at the highest concentration (500 g L1). This could be related to the
induction of tolerance mechanisms at a certain threshold or tipping point. While no changes occurred
in the energy balance, an increase in the pigment antheraxanthin is observed jointly with an increase
in ascorbate peroxidase activity. These mechanisms might have contributed to protecting thylakoids
against excess radiation and the increase in reactive oxygen species, associated with stress conditions,
as no increase in lipid peroxidation products was observed. Furthermore, changes in the fatty acids
profile, usually attributed to the induction of plant stress response mechanisms, demonstrated the
high resilience of this macroalgae. Notably, the application of bio-optical tools in ecotoxicology, such
as pulse amplitude modulated (PAM) fluorometry and laser-induced fluorescence (LIF), allowed
separation of the control samples and those treated by GBHs in different concentrations with a high
degree of accuracy, with PAM more accurate in identifying the different treatmentsinfo:eu-repo/semantics/publishedVersio
Techniques of intestinal transplantation in rat
Two surgical models of intestinal transplantation in the rat are described. One is the implantation of fetal and newborn intestine as free grafts into the omentum of adult recipients, the other the adult intestine transplantation as an accessory graft using vascular anastomoses. A hundred and sixteen small-bowel transplantations were done; 36 of which were fetal intestine (group I), 40 of newborn intestine (group II), and 40 of adult intestine (group III). In the fetal and newborn intestinal transplantation, we emphasize the practices that allowed us to avoid ischemic and traumatic injury to the graft. In the adult intestine transplantation with vascular anastomoses, we heighten the modifications in the surgical technique that made the operation easier and the strategies used to prevent hypothermia and hypovolemic shock. Once experienced with the two chosen surgical techniques, transplantation using an avascular segment became much easier and quicker than transplantation with vascular anastomoses. © 1998 Wiley-Liss, Inc. MICROSURGERY 18:424-429, 199
Gas Chromatography in the Analysis of Compounds Released from Wood into Wine
Wood has been used in alcoholic beverages for centuries, mainly as material for containers
used for alcoholic beverages aging. Recently OIV (Organisation International de la Vigne et
du Vin) approved the use of chips (Resolution oeno 3/2005) and staves as alternatives for
barrels. These practices are being rapidly spread among winemakers. The increased used of
these alternatives are mainly related to low investments, similar sensorial results obtained in
shorter time, simplicity of use and the possibility of avoiding contamination and offflavours,
too-often related to aged or contaminated barrels.
Besides oak, other woods are being looked at for enological purposes, such as acacia, cherry,
chestnut and mulberry. Their characteristics are commonly compared to oak. In the past,
chestnut (Castanea sativa) was widely used in the Mediterranean area, because of its
availability and its cheap price. Chestnut wood has higher porosity than oak. Cherry wood
(Prunus avium) has high porosity and oxygen permeation, and is usually used for short
aging times. Acacia wood (Robinia pseudoacacia) is hard, with low porosity. Mulberry wood
(Morus alba and Morus nigra) is tender and elastic, with medium porosity, and is
characterized by a low release of compounds. The lack of properties for cooperage is now
overcome by their possible use as staves or chips.
The aim of this work is to present an overview on volatile and semi-volatile composition of
different kind of wood with oenological interest. Within this purpose, this work will be
focused on a bibliographic review of the most used chromatographic methods for
characterization of volatile and semi-volatile compounds, including also a brief description
of the most common reported sample preparation methods for chromatographic analysis
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