1,498 research outputs found

    Pattern Selection in the Complex Ginzburg-Landau Equation with Multi-Resonant Forcing

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    We study the excitation of spatial patterns by resonant, multi-frequency forcing in systems undergoing a Hopf bifurcation to spatially homogeneous oscillations. Using weakly nonlinear analysis we show that for small amplitudes only stripe or hexagon patterns are linearly stable, whereas square patterns and patterns involving more than three modes are unstable. In the case of hexagon patterns up- and down-hexagons can be simultaneously stable. The third-order, weakly nonlinear analysis predicts stable square patterns and super-hexagons for larger amplitudes. Direct simulations show, however, that in this regime the third-order weakly nonlinear analysis is insufficient, and these patterns are, in fact unstable

    A model of maxilla resection to test new hybrid implants:macroporous titanium and tissue engineering elements

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    Maxillary bone loss in commonly found in humans, due to bone ageing, tooth loos, periodontal disease and, more severely, to trauma, radiotherapy and tumor resection. Masillofacial reconstructive surgery is a still unmet clinical demand, available therapies include grafting of autologous or heterologous bone tissue and/or the implantation of metallic plates, buy these treatments are still unable to resume form and function. The emrgence of 3D-printing technology applied to metal alloys now allows the manufacturing of customized, patient-tailored prosthetic implants. However, poor bone quiality at the implant site due to ageing or disease still hamper proper osseointegration. By combining Electron Beam Melting metal sintering and tissue engineering, we are developing hybrid maxillofacial implants, wher a metal framework of Ti6Al4V alloy confers both and appropiaate shape and mechanical stabilty, while stem cells and osteogenic molecules stimulate bone growth into the metal framework, thus pormoting osseointegration. We hereby present the in vitro work driving to the development of our hybrid maxillofacial prostheses, as well as the setting up of an in vivo model of complete maxilla full resection, created in order to test the prostheses in a preclinical studyUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Experimental study of Taylor's hypothesis in a turbulent soap film

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    An experimental study of Taylor's hypothesis in a quasi-two-dimensional turbulent soap film is presented. A two probe laser Doppler velocimeter enables a non-intrusive simultaneous measurement of the velocity at spatially separated points. The breakdown of Taylor's hypothesis is quantified using the cross correlation between two points displaced in both space and time; correlation is better than 90% for scales less than the integral scale. A quantitative study of the decorrelation beyond the integral scale is presented, including an analysis of the failure of Taylor's hypothesis using techniques from predictability studies of turbulent flows. Our results are compared with similar studies of 3D turbulence.Comment: 27 pages, + 19 figure

    Rituximab plus chemotherapy provides no clinical benefit in a peripheral T-cell lymphoma not otherwise specified with aberrant expression of CD20 and CD79a. A case report and review of the literature

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    Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is the most common entity of mature T-cell neoplasms. PTCL-NOS generally has an aggressive behavior and is often refractory to standard therapy. Only a few cases of PTCL with aberrant expression of B-cell antigens have been reported so far. This phenotypic aberrancy may lead to misdiagnosis as B-cell non- Hodgkin lymphomas and eventual inappropriate patient management, whereas in an accurately diagnosed PTCL, the presence of CD20 may appear as an appealing therapeutic target. In this setting, response to anti-CD20 monoclonal antibody in combination with chemotherapy has been poorly explored. We describe the case of a 59-year-old male diagnosed by a pathological and molecular approach as PTCL-NOS with aberrant co-expression of the B-cell antigens CD20 and CD79a, which proved non-responsive to the addition of rituximab to standard polychemotherapy. This case highlights that the presence of CD20 in PTCL may be misleading in the diagnosis and also act as a lure for the clinician to adopt a rituximab-based treatment, the effectiveness of which is undefined as the molecular mechanisms underlying B-cell marker expression in PTCL

    Women's Cardiac Health in 2020: A Systematic Review

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    AbstractAlthough substantial progress has been made toward improving gender- and sex-specific cardiovascular disease (CVD) management and outcomes, contemporary reports indicate a persistent knowledge gap with regard to optimal risk-stratification and management in female cardiac heart disease (CHD) patients. Prominent patient and system delays in diagnosing CHD are, in part, due to the limited awareness for the latent CVD risk in women, a lack of sex-specific thresholds within clinical guidelines, and subsequent limited performance of contemporary diagnostic approaches in women. Several traditional risk factors for CHD affect both women and men. But other factors can play a bigger role in the development of heart disease in women. In addition, little is known about the influence of socioenvironmental and contextual factors on gender-specific disease manifestation and outcomes. It is imperative that we understand the mechanisms that contribute to worsening risk factors profiles in young women to reduce future atherosclerotic CVD morbidity and mortality. This comprehensive review focuses on the novel aspects of cardiovascular health in women and sex differences as they relate to clinical practice and prevention, diagnosis, and treatment of CVD. Increased recognition of the prevalence of traditional cardiovascular risk factors and their differential impact in women, as well as emerging nontraditional risk factors unique to or more common in women, contribute to new understanding mechanisms, leading to worsening outcome for women

    The Ferroxidase Hephaestin in Lung Cancer: Pathological Significance and Prognostic Value

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    Hephaestin (HEPH) belongs to a group of exocytoplasmic ferroxidases which contribute to cellular iron homeostasis by favouring its export. Down-regulation of HEPH expression, possibly by stimulating cell proliferation due to an increase in iron availability, has shown to correlate with poor survival in breast cancer. The lung is particularly sensitive to iron-induced oxidative stress, given the high oxygen tension present, however, HEPH distribution in lung cancer and its influence on prognosis have not been investigated yet. In this study we explored the prognostic value of HEPH and its expression pattern in the most prevalent histotypes of lung cancers, namely lung adenocarcinoma and lung squamous cell carcinoma. In silico analyses, based on UALCAN, Gene Expression Profiling Interactive Analysis (GEPIA) and Kaplan–Meier plotter bioinformatics, revealed a significant correlation between higher levels of HEPH expression and favorable prognosis, in both cancer histotypes. Moreover, TIMER web platform showed a statistically significant association between HEPH expression and cell elements belonging to the tumor microenvironment identified as endothelial cells and a subpopulation of cancer-associated fibroblasts, further confirmed by double immunohistochemical labeling with cell type specific markers. Taken together, these data shed a light on the complex mechanisms of local iron handling lung cancer can exploit to support tumorigenesis

    Effects of Heating and Cooling on Nerve Terminal Impulses Recorded from Cold-sensitive Receptors in the Guinea-pig Cornea

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    An in vitro preparation of the guinea-pig cornea was used to study the effects of changing temperature on nerve terminal impulses recorded extracellularly from cold-sensitive receptors. At a stable holding temperature (31–32.5°C), cold receptors had an ongoing periodic discharge of nerve terminal impulses. This activity decreased or ceased with heating and increased with cooling. Reducing the rate of temperature change reduced the respective effects of heating and cooling on nerve terminal impulse frequency. In addition to changes in the frequency of activity, nerve terminal impulse shape also changed with heating and cooling. At the same ambient temperature, nerve terminal impulses were larger in amplitude and faster in time course during heating than those recorded during cooling. The magnitude of these effects of heating and cooling on nerve terminal impulse shape was reduced if the rate of temperature change was slowed. At 29, 31.5, and 35°C, a train of 50 electrical stimuli delivered to the ciliary nerves at 10–40 Hz produced a progressive increase in the amplitude of successive nerve terminal impulses evoked during the train. Therefore, it is unlikely that the reduction in nerve terminal impulse amplitude observed during cooling is due to the activity-dependent changes in the nerve terminal produced by the concomitant increase in impulse frequency. Instead, the differences in nerve terminal impulse shape observed at the same ambient temperature during heating and cooling may reflect changes in the membrane potential of the nerve terminal associated with thermal transduction
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