The instantaneous helical axis of the subtalar and talocrural joints: a non-invasive in vivo dynamic study

<p>Abstract</p> <p>Background</p> <p>An understanding of rear-foot (talocrural and subtalar joints) kinematics is critical for diagnosing foot pathologies, designing total ankle implants, treating rear-foot injuries and quantifying gait abnormalities. The majority of kinematic data available have been acquired through static cadaver work or passive <it>in vivo </it>studies. The applicability of these data to dynamic <it>in vivo </it>situations remains unknown. Thus, the purpose of this study was to fully quantify subtalar, talocrural and calcaneal-tibial <it>in vivo </it>kinematics in terms of the instantaneous helical axis (IHA) in twenty-five healthy ankles during a volitional activity that simulated single-leg toe-raises with partial-weight support, requiring active muscle control.</p> <p>Methods</p> <p>Subjects were each placed supine in a 1.5 T MRI and asked to repeat this simulated toe-raise while a full sagittal-cine-phase contrast (dynamic) MRI dataset was acquired. From the cine-phase contrast velocity a full kinematic description for each joint was derived.</p> <p>Results</p> <p>Nearly all motion quantified at the calcaneal-tibial joint was attributable to the talocrural joint. The subtalar IHA orientation and position were highly variable; whereas, the talocrural IHA orientation and position were extremely consistent.</p> <p>Conclusion</p> <p>The talocrural was well described by the IHA and could be modeled as a fixed-hinge joint, whereas the subtalar could not be.</p

A novel approach to sonographic examination in a patient with a calf muscle tear: a case report

© 2009 Chen et al; licensee Cases Network Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Leaf-applied sodium chloride promotes cadmium accumulation in durum wheat grain

Cadmium (Cd) accumulation in durum wheat grain is a growing concern. Among the factors affecting Cd accumulation in plants, soil chloride (Cl) concentration plays a critical role. The effect of leaf NaCl application on grain Cd was studied in greenhouse-grown durum wheat (Triticum turgidum L. durum, cv. Balcali-2000) by immersing (10 s) intact flag leaves into Cd and/or NaCl-containing solutions for 14 times during heading and dough stages. Immersing flag leaves in solutions containing increasing amount of Cd resulted in substantial increases in grain Cd concentration. Adding NaCl alone or in combination with the Cd-containing immersion solution promoted accumulation of Cd in the grains, by up to 41%. In contrast, Zn concentrations of grains were not affected or even decreased by the NaCl treatments. This is likely due to the effect of Cl complexing Cd and reducing positive charge on the metal ion, an effect that is much smaller for Zn. Charge reduction or removal (CdCl2 0 species) would increase the diffusivity/lipophilicity of Cd and enhance its capability to penetrate the leaf epidermis and across membranes. Of even more significance to human health was the ability of Cl alone to penetrate leaf tissue and mobilize and enhance shoot Cd transfer to grains, yet reducing or not affecting Zn transfer

NADPH oxidase and reactive oxygen species contribute to alcohol-induced microglial activation and neurodegeneration

<p>Abstract</p> <p>Background</p> <p>Activation of microglia causes the production of proinflammatory factors and upregulation of NADPH oxidase (NOX) that form reactive oxygen species (ROS) that lead to neurodegeneration. Previously, we reported that 10 daily doses of ethanol treatment induced innate immune genes in brain. In the present study, we investigate the effects of chronic ethanol on activation of NOX and release of ROS, and their contribution to ethanol neurotoxicity.</p> <p>Methods</p> <p>Male C57BL/6 and NF-κB enhanced GFP mice were treated intragastrically with water or ethanol (5 g/kg, i.g., 25% ethanol w/v) daily for 10 days. The effects of chronic ethanol on cell death markers (activated caspase-3 and Fluoro-Jade B), microglial morphology, NOX, ROS and NF-κB were examined using real-time PCR, immunohistochemistry and hydroethidine histochemistry. Also, Fluoro-Jade B staining and NOX gp91^phoximmunohistochemistry were performed in the orbitofrontal cortex (OFC) of human postmortem alcoholic brain and human moderate drinking control brain.</p> <p>Results</p> <p>Ethanol treatment of C57BL/6 mice showed increased markers of neuronal death: activated caspase-3 and Fluoro-Jade B positive staining with Neu-N (a neuronal marker) labeling in cortex and dentate gyrus. The OFC of human post-mortem alcoholic brain also showed significantly more Fluoro-Jade B positive cells colocalized with Neu-N, a neuronal marker, compared to the OFC of human moderate drinking control brain, suggesting increased neuronal death in the OFC of human alcoholic brain. Iba1 and GFAP immunohistochemistry showed activated morphology of microglia and astrocytes in ethanol-treated mouse brain. Ethanol treatment increased NF-κB transcription and increased NOX gp91^phoxat 24 hr after the last ethanol treatment that remained elevated at 1 week. The OFC of human postmortem alcoholic brain also had significant increases in the number of gp91^phox+ immunoreactive (IR) cells that are colocalized with neuronal, microglial and astrocyte markers. In mouse brain ethanol increased gp91^phoxexpression coincided with increased production of O₂^-and O₂^-- derived oxidants. Diphenyleneiodonium (DPI), a NOX inhibitor, reduced markers of neurodegeneration, ROS and microglial activation.</p> <p>Conclusions</p> <p>Ethanol activation of microglia and astrocytes, induction of NOX and production of ROS contribute to chronic ethanol-induced neurotoxicity. NOX-ROS and NF-κB signaling pathways play important roles in chronic ethanol-induced neuroinflammation and neurodegeneration.</p

Graphene Photonics and Optoelectronics

The richness of optical and electronic properties of graphene attracts enormous interest. Graphene has high mobility and optical transparency, in addition to flexibility, robustness and environmental stability. So far, the main focus has been on fundamental physics and electronic devices. However, we believe its true potential to be in photonics and optoelectronics, where the combination of its unique optical and electronic properties can be fully exploited, even in the absence of a bandgap, and the linear dispersion of the Dirac electrons enables ultra-wide-band tunability. The rise of graphene in photonics and optoelectronics is shown by several recent results, ranging from solar cells and light emitting devices, to touch screens, photodetectors and ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres

Characterisation of a novel ACE2-based therapeutic with enhanced rather than reduced activity against SARS-CoV-2 variants

The human angiotensin-converting enzyme 2 acts as the host cell receptor for SARS-CoV-2 and the other members of the Coronaviridae family SARS-CoV-1 and HCoV-NL63. Here we report the biophysical properties of the SARS-CoV-2 spike variants D614G, B.1.1.7, B.1.351 and P.1 with affinities to the ACE2 receptor and infectivity capacity, revealing weaknesses in the developed neutralising antibody approaches. Furthermore, we report a pre-clinical characterisation package for a soluble receptor decoy engineered to be catalytically inactive and immunologically inert, with broad neutralisation capacity, that represents an attractive therapeutic alternative in light of the mutational landscape of COVID-19. This construct efficiently neutralised four SARS-CoV-2 variants of concern. The decoy also displays antibody-like biophysical properties and manufacturability, strengthening its suitability as a first-line treatment option in prophylaxis or therapeutic regimens for COVID-19 and related viral infections. IMPORTANCE Mutational drift of SARS-CoV-2 risks rendering both therapeutics and vaccines less effective. Receptor decoy strategies utilising soluble human ACE2 may overcome the risk of viral mutational escape since mutations disrupting viral interaction with the ACE2 decoy will by necessity decrease virulence thereby preventing meaningful escape. The solution described here of a soluble ACE2 receptor decoy is significant for the following reasons: While previous ACE2-based therapeutics have been described, ours has novel features including (1) mutations within ACE2 to remove catalytical activity and systemic interference with the renin/angiotensin system; (2) abrogated FcγR engagement, reduced risk of antibody-dependent enhancement of infection and reduced risk of hyperinflammation, and (3) streamlined antibody-like purification process and scale-up manufacturability indicating that this receptor decoy could be produced quickly and easily at scale. Finally, we demonstrate that ACE2-based therapeutics confer a broad-spectrum neutralisation potency for ACE2-tropic viruses, including SARS-CoV-2 variants of concern in contrast to therapeutic mAb

Nanostructured 3D Constructs Based on Chitosan and Chondroitin Sulphate Multilayers for Cartilage Tissue Engineering

Nanostructured three-dimensional constructs combining layer-by-layer technology (LbL) and template leaching were processed and evaluated as possible support structures for cartilage tissue engineering. Multilayered constructs were formed by depositing the polyelectrolytes chitosan (CHT) and chondroitin sulphate (CS) on either bidimensional glass surfaces or 3D packet of paraffin spheres. 2D CHT/CS multi-layered constructs proved to support the attachment and proliferation of bovine chondrocytes (BCH). The technology was transposed to 3D level and CHT/CS multi-layered hierarchical scaffolds were retrieved after paraffin leaching. The obtained nanostructured 3D constructs had a high porosity and water uptake capacity of about 300%. Dynamical mechanical analysis (DMA) showed the viscoelastic nature of the scaffolds. Cellular tests were performed with the culture of BCH and multipotent bone marrow derived stromal cells (hMSCs) up to 21 days in chondrogenic differentiation media. Together with scanning electronic microscopy analysis, viability tests and DNA quantification, our results clearly showed that cells attached, proliferated and were metabolically active over the entire scaffold. Cartilaginous extracellular matrix (ECM) formation was further assessed and results showed that GAG secretion occurred indicating the maintenance of the chondrogenic phenotype and the chondrogenic differentiation of hMSCs

Neutrinoless double beta decay in seesaw models

We study the general phenomenology of neutrinoless double beta decay in seesaw models. In particular, we focus on the dependence of the neutrinoless double beta decay rate on the mass of the extra states introduced to account for the Majorana masses of light neutrinos. For this purpose, we compute the nuclear matrix elements as functions of the mass of the mediating fermions and estimate the associated uncertainties. We then discuss what can be inferred on the seesaw model parameters in the different mass regimes and clarify how the contribution of the light neutrinos should always be taken into account when deriving bounds on the extra parameters. Conversely, the extra states can also have a significant impact, cancelling the Standard Model neutrino contribution for masses lighter than the nuclear scale and leading to vanishing neutrinoless double beta decay amplitudes even if neutrinos are Majorana particles. We also discuss how seesaw models could reconcile large rates of neutrinoless double beta decay with more stringent cosmological bounds on neutrino masses.Comment: 34 pages, 5 eps figures and 1 axodraw figure. Final version published in JHEP. NME results available in Appendi

Physics and Applications of Laser Diode Chaos

An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic