168 research outputs found
Fisiopatología de los Cuerpos Libres Intraarticulares : estudio Experimental
La cubierta cartilaginosa de los cuerpos libres intraarticulares tiene un origen
no bien conocido. Se ha realizado un estudio experimental en conejos, liberando fragmentos osteocondrales
en la cavidad articular de la rodilla, estudiando sus cambios histológicos desde la
primera semana hasta el año. En todos los casos los fragmentos osteocondrales se observaron
adheridos a la membrana sinovial. Hubo una remodelación progresiva del componente óseo y
cartilaginoso, cubriéndose todo el fragmento de una cubierta fibrocartilaginosa, reabsorbiéndose
el hueso central y formándose nuevo hueso en la porción periférica debajo del fibrocartí-
lago. Todos los cambios tisulares dependieron de la actividad de la membrana sinovial. No pudo
demostrarse crecimiento del cartílago articular.It is not well known the origin of the cartilaginous outer layer of the
intrarticular loose bodies. An experimental study has been carried out on rabbits
loosening out osteochondral fragments into the articular cavity of the kne e joint and
studying their histological changes between the first week and the first year. The osteochondral
fragments wer e found adhered to the synovial membrane in all cases.
A proggressive remodeling tood place within the osseous and cartilaginous components,
the whole fragment became covered by a fibrocartilaginous covering, the
central bone was reabsorbed and new bone was formed at the peripheral portion
unde r fibrocartilage. All tissue change s wer e dependent on synovial membrane
activity. Growth of articular cartilage could not be demonstrated
Cicatrización del fibrocartílago meniscal de la Rodilla : estudio Experimental
Para estudiar la cicatrización de las lesiones meniscales se ha realizado un estudio
experimental en conejos. Se han practicado tres tipos de lesiones en el menisco, transversal,
longitudinal parameniscal y longitudinal interna alejeda del paramenisco. Posteriormente
el defecto creado era reparado mediante puntos sueltos con material reabsorvible.
Se ha estudiado el fenómeno de cicatrización desde el punto de vista histológico desde la
semana a los tres meses. Los resultados muestran que la cicatrización es fundamentalmente
extrínseca a partir de la capacidad plástica de la membrana sinovial. Las heridas longitudinales
parameniscales cicatrizaron sin dificultad, las transversales casi en toda su anchura y las
longitudinales en zona avascular cicatrizaron principalmente en su porción anterior gracias a
la invasión de sinovial hiperplásica desde la inserción tibial del ligamento cruzado anterior.To study the healing of meniscal tears, the authors hav e carried out
an experimental work in rabbits. They performed three types of tears in the internal
menisci, radial, peripheral longitudinal (in the parameniscal zone) and longitudinal
within of the parameniscus. The menisci were reparated by suture with
absorbible material.
The healing phenomenon has been histologically studied from the first wee k to
three months after. The results showed that the cicatrization is mainly extrinsic by
the plastic capacity of sinovial membrane. The longitudinal tears in the parameniscus
heal without difficulty, the transversal tears almost in their whol e width and the
longitudinal tears at the avascular zone healed principally in the anterior portion
by the invasion of hyperplasic sinovial from the tibial insertion of the anterior cruciate
ligament
Fibrocartílago meniscal como biomaterial de sustitución en los Defectos Osteocondrales. Estudio experimental en el conejo con injertos homólogos
Los autores presentan un estudio experimental en el cual han empleado homoinjertos
de fibrocartílago meniscal, para reparar defectos osteocondrales localizados
en zona de carga, del cóndilo medial de la rodilla del conejo.
Han sido estudiados 33 animales, realizando un estudio histológico, con periodos
de evolución comprendidos entre una semana y 22 meses.
Los homoinjertos meniscales parecen ser capaces de restaurar una superficie
articular funcional. Conservan su estructura y celularidad a lo largo de toda la
experiencia consiguiendo un perfecto anclaje al lecho óseo, adaptándose a la carga
y sin producir cambios en el cartílago articular vecino.
No se han producido rechazos.The authors report on an experimental study, employing meniscal fibrocartilage
homo grafts to repair osteochondral defects in the weightbearing
area of medial condile of rabbit knee.
Thirty-three animals were studied by histological means for periods of
one week to 22 months.
The meniscal fibrocartilage homograft appeared capable of restoring
a functional articular surface, maintaining its entire histological structure
and celularity throughout the experiment, obtaining a perfect union
with the bone tissue, adapting to the weightbearing and not modifying the
neighboring articular surface. No evidence of rejection was observed
El registro más antiguo de Loxodontomys micropus (Waterhouse) (Rodentia, Cricetidae) del Pleistoceno tardío del sur de Chile
Los roedores sigmodontinos constituyen un grupo endémico del Nuevo Mundo. Los registros más antiguos de América del Sur datan del Plioceno y en la actualidad incluyen alrededor de 71 géneros vivientes. Su historia evolutiva es aún poco comprendida, en parte por escasos hallazgos de fósiles y falta de consenso en su taxonomía. El presente resumen informa el descubrimiento de un cráneo fósil parcial atribuible a un roedor sigmodontino (MHMOP/ PI/39), procedente del sitio paleontológico Pilauco en la ciudad de Osorno, Región de Los Lagos, sur de Chile (40º 39'S-73º07'O). El espécimen fue extraído de la capa portadora PB-7 fechada en 12.540 ±90 años C14 AP (14.649±382 años cal. AP). Mediante el uso de claves y la comparación directa con cráneos de la Colección de Mamíferos del Instituto de Ecología y Evolución de la Universidad Austral de Chile (IEEUACH), se realizó una determinación taxonómica del mismo. La morfología dental (i.e., largo de la fila de molares y ausencia de surco en los incisivos superiores) y craneal (i.e., región interorbital estrecha, sutura premaxilar-maxilar recta) permiten asignar este fragmento al ratón de pie chico o pericote patagónico Loxodontomys micropus (Waterhouse). La fisura tripartita de la dentina de los incisivos superiores y la procumbencia de los mismos permiten diferenciarlo de L. pikumche (Spotorno, Cofre, Vilina, Marquet y Walker). En la actualidad las poblaciones de esta especie se encuentran asociadas a las áreas andinas y ecotonos de la Patagonia chilena y argentina. Es una especie plástica en sus requerimientos ecológicos, encontrándose en diversos ambientes con suelos cubiertos (e.g., estepas patagónicas, bosques y praderas con exuberante vegetación, hojarasca suelta y abundante y ambientes mésicos, con malezas). Estas características coinciden con los ambientes sugeridos para el sitio Pilauco durante la formación del mismo. El presente registro constituye el más antiguo para la especie y confirma su presencia durante el Pleistoceno tardío del sur de Chile.Sesiones libresFacultad de Ciencias Naturales y Muse
Dns of supersonic turbulent boundary layers over weakly and strongly adiabatic walls
We present spatially developing direct numerical simulations (DNS) of turbulent boundary layers at Mach 3 and Mach 7 with Reτ ≈ 600. In this work we make an explicit distinction in the wall thermal boundary condition, which, to our knowledge, has not been addressed in the literature. Namely, we deem "weakly adiabatic" walls as those whose temperature is fixed at the recovery temperature, and "strongly adiabatic" walls as those that enforce null heat transfer in the local and instantaneous sense. These two boundary conditions are bracketing cases for real materials that have finite, non-zero thermal diffusivities. Using scaling arguments, we propose a dimensionless quantity, the "fluctuation Nusselt number," as the relevant similarity parameter describing the thermal damping at the wall. Furthermore, we demonstrate that this parameter can vary by many orders of magnitude due to different thermal diffusivities of relevant wall materials and different edge Mach numbers. By design, the "weakly adiabatic" boundary condition damps near wall temperature fluctuations, which helps to enforce the assumption of weak total temperature fluctuations built into much of the theory for compressible boundary layers. Adopting a "strongly adiabatic" wall will place greater strain on these assumptions and may be more relevant to flight conditions of interest. Here we present data at Mach 3 for both boundary conditions, and at Mach 7 for the "strongly adiabatic" case. The simulations are spatially developing and have large domains to prevent unphysical forcing due to the inflow and spanwise boundary conditions, as discussed in Beekman, Priebe, Kan & Martin. 1 For all three data sets we present basic turbulence statistics and note that a non negligible effect is observed due to the differences in wall boundary condition
Plus ça change : pots, crucibles and the development of metallurgy in Chalcolithic Las Pilas (Mojácar, Spain)
This paper considers the structure of production, distribution and consumption of ceramics within Chalcolithic communities of SE Iberia, an important region for modelling social and technological change in the recent prehistory of Eurasia. Our research provides new data through the comparative analysis of domestic and metallurgical ceramics, as well as building and other clay-rich materials from the archaeological site of Las Pilas (2875–2620 cal. BC 2σ to 2460–2205 cal. BC 2σ) (Mojácar, Almería). In total, 56 samples are characterised by optical petrography, with SEM analysis of 22 of those individuals, in order to assess firing conditions. Results point to the existence of a local tradition in which domestic and metallurgical wares exhibit important similarities in their production processes. In terms of technology, the assemblage shows a relative homogeneity, although firing conditions, surface treatment and decoration seem to have played an important role in the differentiation of highly symbolic wares from other ceramics. We conclude that raw material procurement and processing at Las Pilas differ from those at other Copper Age sites already studied in SE and SW Iberia. This is in agreement with earlier archaeometallurgical studies on Las Pilas, suggesting the development of local and community-based technological traditions. As such, the paper attempts to bridge the recent divide between re-emergent top-down models and our detailed understandings of technological practice
Spatial distribution of Cydia fagiglandana (Zeller) in an exploited holm oak (Quercus ilex L.) forest.
Cydia fagiglandana (Zeller) (Lepidoptera: Tortricidae) is a carpophagous insect which affects the quality andviability of the fruits of beech, oak and chestnut trees. The majority of the works on this species in holm oak woodsdealt with assessing its damages. No investigations have yet been performed on the spatial distribution of this pest,although this element is one of the key features to take in account in order to develop proper integrated managementprograms. The present study, performed during a four years period in an exploited holm oak forest area in SouthernSpain, investigated the spatial distribution of C. fagiglandana integrating classic methods based on dispersion ratesand distribution fitting together with the elaboration of population density maps based on GIS. Our results showedthat the infestation rate progressively decreased from 0.339 in 2001 to 0.102 in 2004. Density maps for C. fagiglandanaalso show an heterogeneous and aggregated distribution of this insect and a spatio-temporal stability in this area. It isconcluded that during the four years of the study inter-specific competition with the weevil Curculio elephas was thefactor that most affected the spatial distribution of C. fagiglandana in the experimental plot
Effectiveness of interventions to improve medication adherence in adults with depressive disorders: a meta-analysis
Trastorno depresivo mayor; Metanálisis; Adherencia al tratamientoTrastorn depressiu major; Metaanàlisi; Adherència al tractamentMajor depressive disorder; Meta-analysis; Treatment adherenceBackground
Non-adherence to medication is a major obstacle in the treatment of depressive disorders. We systematically reviewed the literature to evaluate the effectiveness of interventions aimed at improving adherence to medication among adults with depressive disorders with emphasis on initiation and implementation phase.
Methods
We searched Medline, EMBASE, The Cochrane Central Register of Controlled Trials (CENTRAL), PsycINFO, Social Science Citation Index and Science Citation Index for randomized or non-randomized controlled trials up to January 2022. Risk of bias was assessed using the criteria of the Cochrane Collaboration. Meta-analyses, cumulative and meta-regression analyses for adherence were conducted.
Results
Forty-six trials (n = 24,324) were included. Pooled estimate indicates an increase in the probability of adherence to antidepressants at 6 months with the different types of interventions (OR 1.33; 95% CI: 1.09 to 1.62). The improvement in adherence is obtained from 3 months (OR 1.62, 95% CI: 1.25 to 2.10) but it is attenuated at 12 months (OR 1.25, 95% CI: 1.02 to 1.53). Selected articles show methodological differences, mainly the diversity of both the severity of the depressive disorder and intervention procedures. In the samples of these studies, patients with depression and anxiety seem to benefit most from intervention (OR 2.77, 95% CI: 1.74 to 4.42) and collaborative care is the most effective intervention to improve adherence (OR 1.88, 95% CI: 1.40 to 2.54).
Conclusions
Our findings indicate that interventions aimed at improving adherence to medication among adults with depressive disorders are effective up to six months. However, the evidence on the effectiveness of long-term adherence is insufficient and supports the need for further research efforts.This study has been funded by Instituto de Salud Carlos III through the project "PI18/00767" (Co-funded by European Regional Development Fund/European Social Fund "A way to make Europe"/"Investing in your future")
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