236 research outputs found

    YBa2_2Cu3_3O7_7/La0.7_{0.7}Ca0.3_{0.3}MnO3_3 bilayers: Interface coupling and electric transport properties

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    Heteroepitaxially grown bilayers of ferromagnetic La0.7_{0.7}Ca0.3_{0.3}MnO3_3 (LCMO) on top of superconducting YBa2_2Cu3_3O7_7 (YBCO) thin films were investigated by focusing on electric transport properties as well as on magnetism and orbital occupation at the interface. Transport measurements on YBCO single layers and on YBCO/LCMO bilayers, with different YBCO thickness dYd_Y and constant LCMO thickness dL=50d_L=50\,nm, show a significant reduction of the superconducting transition temperature TcT_c only for dY<10d_Y<10\,nm,with only a slightly stronger TcT_c suppression in the bilayers, as compared to the single layers. X-ray magnetic circular dichroism (XMCD) measurements confirm recently published data of an induced magnetic moment on the interfacial Cu by the ferromagnetically ordered Mn ions, with antiparallel alignment between Cu and Mn moments. However, we observe a significantely larger Cu moment than previously reported, indicating stronger coupling between Cu and Mn at the interface. This in turn could result in an interface with lower transparency, and hence smaller spin diffusion length, that would explain our electric transport data, i.e.smaller TcT_c suppression. Moreover, linear dichroism measurements did not show any evidence for orbital reconstruction at the interface, indicating that a large change in orbital occupancies through hybridization is not necessary to induce a measurable ferromagnetic moment on the Cu atoms.Comment: 8 Figure

    Importance of spinal deformity index in risk evaluation of VCF (vertebral compression fractures) in obese subjects: prospective study.

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    Introduction Obesity and osteoporosis share many features and recent studies have identified many similarities suggesting common pathophysiological mechanisms. Obesity is associated with a higher risk of non-traumatic fractures despite bone mineral density (BMD) being normal or even increased. Materials and methods 54 obese subjects were analyzed (51 ± 16 years, 10 males, 44 females). Spinal deformity index (SDI) is a semi-quantitative method that may be a surrogate index of bone microarchitecture. SDI index was higher in patients than in controls. In 87.5 % of patients and 10 % of controls we found morphometric vertebral fractures, despite a DEXA Tscore not diagnostic of osteoporosis. Conclusion The objective of this study was to assess in obese patients levels of 25OH vitamin D, parathyroid hormone, serum and urinary calcium (Ca) and phosphorus (P), BMD, and SDI. 87.5 % of the obese subjects present nontraumatic vertebral fractures and reduced bone quality as measured by SDI

    Assessment, pharmacological therapy and rehabilitation management of musculoskeletal pain in children with mucopolysaccharidoses: a scoping review

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    Pain of musculoskeletal origin is very common in young patients affected by Mucopolysaccharidoses. This scoping review evaluates the evidence for assessment, pharmacological treatment and rehabilitation management for musculoskeletal pain of the latter

    Unsulfated biotechnological chondroitin by itself as well as in combination with high molecular weight hyaluronan improves the inflammation profile in osteoarthritis in vitro model

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    Several studies suggest that inflammation has a pivotal role during the progression of osteoarthritis (OA) and cytokines have been identified as the main process mediators. This study aimed to explore the ability to modulate the main OA pro-inflammatory biomarkers of novel gels (H-HA/BC) based on high molecular weight hyaluronan (H-HA) and unsulfated biotechnological chondroitin (BC). For the first time, BC was tested also in combination with H-HA on human primary cells isolated from pathological knee joints. Specifically, the experiments were performed using an OA in vitro model based on human chondrocytes and synoviocytes. To evaluate the anti-inflammatory effects of H-HA/BC in comparison with H-HA and BC single gels, NF-kB, COMP-2, MyD88, MMP-13 and a wide range of cytokines, known to be specific biomarkers in OA (e.g., IL-6, IL-8, and TNF-α), were&nbsp;evaluated. In addition, cell morphology and proliferation occurring in the presence of either H-HA/BC or single components were assessed using time-lapse video microscopy. It was shown that synovial fluids and cells isolated from OA suffering patients, presented a cytokine&nbsp;pattern respondent to an ongoing inflammation status. H-HA and BC significantly reduced the levels of 23 biomarkers associated with cartilage damage. However, H-HA/BC decreased significantly 24 biological mediators and downregulated 19 of them more efficiently than the single components. In synoviocytes cultures, cytokine&nbsp;analyses proved that H-HA/BC gels re-established an extracellular environment more similar to a healthy condition reducing considerably the concentration of 11 analytes. Instead, H-HA and BC significantly modulated 7 (5 only with a longer treatment) and 8 biological cytokines, respectively. Our results suggest that H-HA/BC beyond the viscosupplementation effect typical for HA-based gels, can improve the inflammation status in joints and thus could be introduced as a valid protective and anti-inflammatory intraarticular device in the field of Class III medical devices for OA treatments

    Electron sampling depth and saturation effects in perovskite films investigated by soft x-ray absorption spectroscopy

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    Knowledge of the electron sampling depth and related saturation effects is important for quantitative analysis of X-ray absorption spectroscopy data, yet for oxides with the perovskite structure no quantitative values are so far available. Here we study absorption saturation in films of two of the most-studied perovskites, LCMO and YBCO, at the L2,3 edge of Mn and Cu, respectively. By measuring the electron-yield intensity as a function of photon incidence angle and film thickness, the sampling depth d, photon attenuation length, lambda, and the ratio lambda/d have been independently determined between 50 and 300 K. The extracted sampling depth dLCMO=3 nm for LCMO at high temperatures in its polaronic insulator state (150-300K) is not much larger than values reported for pure transition metals (d Co or Ni=2-2.5nm) at room temperature, but it is smaller than dYBCO=3.9 nm for metallic YBCO that is in turn smaller than the value reported for Fe3O4 (d=4.5 nm) The measured dLCMO increases to 4.5 nm when LCMO is in the metallic state at low temperatures. These results indicate that a universal rule of thumb for the sampling depth in oxides cannot be assumed, and that it can be measurably influenced by electronic phase transitions that derive from strong correlations.Comment: 19 pages, 7 figure

    Control de Cydia molesta (Busck.) (Lepidoptera: Olethreutidae) por el método de confusión sexual en Córdoba (Argentina)

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    Durante los años 1995/96 y 1997/98 se llevaron a cabo en Córdoba (Argentina)experiencias para evaluar el control de Cydia molesta mediante el método de confusión sexual. El ensayo se realizó sobre un lote plantado con duraznero variedad Novedad de Córdoba de maduración semitardía. Se colocaron 300 emisores de feromona sintética por hectárea. Se observó una reducción drástica de captura de machos adultos en ambos años en el área de confusión (1,8% y 0,7% respectivamente, de insectos capturados con respecto al testigo). El daño en frutos también se redujo significativamente, ya que en el área de confusión se obtuvieron 0,9% de frutos atacados contra 11,7% en el testigo, lo que significa un 92,3% de control en el primer año. En el segundo año el ataque a frutos se elevó a 1,2% con 88% de control. El ataque en brotes se redujo a valores de 3,1 % dentro del área de confusión y de 8,9% en el testigo, es decir 64,6% de control en 1995, y 2,6% con 71,2% de control en 1997. Estos resultados indican que el método de confusión sexual es eficiente en el control de C. molesta en Córdoba, en variedades de maduración semitardía

    A single polyploidization event at the origin of the tetraploid genome of Coffea arabica is responsible for the extremely low genetic variation in wild and cultivated germplasm

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    The genome of the allotetraploid species Coffea arabica L. was sequenced to assemble independently the two component subgenomes (putatively deriving from C. canephora and C. eugenioides) and to perform a genome-wide analysis of the genetic diversity in cultivated coffee germplasm and in wild populations growing in the center of origin of the species. We assembled a total length of 1.536 Gbp, 444 Mb and 527 Mb of which were assigned to the canephora and eugenioides subgenomes, respectively, and predicted 46,562 gene models, 21,254 and 22,888 of which were assigned to the canephora and to the eugeniodes subgenome, respectively. Through a genome-wide SNP genotyping of 736 C. arabica accessions, we analyzed the genetic diversity in the species and its relationship with geographic distribution and historical records. We observed a weak population structure due to low-frequency derived alleles and highly negative values of Taijma's D, suggesting a recent and severe bottleneck, most likely resulting from a single event of polyploidization, not only for the cultivated germplasm but also for the entire species. This conclusion is strongly supported by forward simulations of mutation accumulation. However, PCA revealed a cline of genetic diversity reflecting a west-to-east geographical distribution from the center of origin in East Africa to the Arabian Peninsula. The extremely low levels of variation observed in the species, as a consequence of the polyploidization event, make the exploitation of diversity within the species for breeding purposes less interesting than in most crop species and stress the need for introgression of new variability from the diploid progenitors

    Biophysical stimulation of bone and cartilage : state of the art and future perspectives

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    Introduction: Biophysical stimulation is a non-invasive therapy used in orthopaedic practice to increase and enhance reparative and anabolic activities of tissue. Methods: A sistematic web-based search for papers was conducted using the following titles: (1) pulsed electromagnetic field (PEMF), capacitively coupled electrical field (CCEF), low intensity pulsed ultrasound system (LIPUS) and biophysical stimulation; (2) bone cells, bone tissue, fracture, non-union, prosthesis and vertebral fracture; and (3) chondrocyte, synoviocytes, joint chondroprotection, arthroscopy and knee arthroplasty. Results: Pre-clinical studies have shown that the site of interaction of biophysical stimuli is the cell membrane. Its effect on bone tissue is to increase proliferation, synthesis and release of growth factors. On articular cells, it creates a strong A2A and A3 adenosine-agonist effect inducing an anti-inflammatory and chondroprotective result. In treated animals, it has been shown that the mineralisation rate of newly formed bone is almost doubled, the progression of the osteoarthritic cartilage degeneration is inhibited and quality of cartilage is preserved. Biophysical stimulation has been used in the clinical setting to promote the healing of fractures and non-unions. It has been successfully used on joint pathologies for its beneficial effect on improving function in early OA and after knee surgery to limit the inflammation of periarticular tissues. Discussion: The pooled result of the studies in this review revealed the efficacy of biophysical stimulation for bone healing and joint chondroprotection based on proven methodological quality. Conclusion: The orthopaedic community has played a central role in the development and understanding of the importance of the physical stimuli. Biophysical stimulation requires care and precision in use if it is to ensure the success expected of it by physicians and patients
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