Collagen Meniscal Implantation Outcomes Following Partial and Full Meniscectomies

Meniscal injuries are a common result of trauma to the knee. The main two surgical treatments available are partial meniscectomy or full meniscectomy due to the lack of blood flow in that region. These two treatments cause long-term complications such as pain, lack of mobility, and/or osteoarthritis. To avoid these complications, researchers have looked at placing collagen meniscal implantations (CMI) into the knee. The collagen implantation is composed of type I collagen from bovine Achilles tendon and was infused with glycosaminoglycans (GAGs) to trigger cellular growth. Patients were grouped into cohorts based on tears in the lateral or medial meniscus that underwent a partial or full meniscectomy. Following the procedure, patients were evaluated based on Tegner scale, Lysholm Score, IKDC, and MRI outcomes. These patients were then reevaluated at two years, five years, and ten years. The implantation had a 90% survival rate at ten years. CMI has proved to be a practical possibility for patients who have had a partial or full meniscectomy due to the regenerative qualities and reduced deterioration of the knee itself. The research showed that there were significant improvements in quality of life and long-term outcomes. This is a practical option for patients that live an active lifestyle or occupations that require adequate range of motion

Internally driven inertial waves in geodynamo simulations

Inertial waves are oscillations in a rotating fluid, such as the Earth’s outer core, which result from the restoring action of the Coriolis force. In an earlier work, it was argued by Davidson that inertial waves launched near the equatorial regions could be important for the α2 dynamo mechanism, as they can maintain a helicity distribution which is negative (positive) in the north (south). Here we identify such internally-driven inertial waves, triggered by buoyant anomalies in the equatorial regions in a strongly-forced geo-dynamo simulation. Using the time-derivative of vertical velocity, ∂uz /∂t, as a diagnostic for travelling wave-fronts, we find that the horizontal movement in the buoyancy field near the equator is well-correlated with a corresponding movement of the fluid far from the equator. Moreover, the azimuthally-averaged spectrum of ∂uz /∂t lies in the inertial wave frequency range. We also test the dispersion properties of the waves by computing the spectral energy as a function of frequency, π, and the dispersion angle, θ. Our results suggest that the columnar flow in the rotation-dominated core, which is an important ingredient for the maintenance of a dipolar magnetic field, is maintained despite the chaotic evolution of the buoyancy field on a fast-time scale by internally-driven inertial waves

Identification of the Mechanism of Electrocatalytic Ozone Generation on Ni/Sb-SnO2

This paper reports a systematic study of the codoping of SnO2with Sb and Ni to identify the mechanism responsible for the electrocatalytic generation of ozone on Ni/Sb-SnO2. On the basis of interpretation of a combination of X-ray diffraction, BET surface area measurements (N2), and thermal analysis, the formation of ozone appears to take place on particle surfaces of composite Sb-SnO2grains and is controlled by diffusion of OH along internal crystallite surfaces within the grain. Sb-doped SnO2is inactive with respect to ozone evolution in the absence of Ni, demonstrating a synergic interaction between nickel and antimony. From X-ray photoelectron spectroscopy (XPS) investigations, Sb(V) ions substitute for Sn(IV) in the lattice with a preference for centrosymmetric coordination sites, while the Sb(III) ions occur at grain surfaces or boundaries. Ni was not detected by XPS, being located in the subsurface region at concentrations below the detection limit of the instrument. In addition to identification of a possible mechanism for ozone formation, the study resulted in the production of active nanopowders which will allow the fabrication of high-surface-area anodes with the potential to exceed the space-time yields of β-PbO2anodes, permitting the application the Ni/Sb-SnO2anodes in the treatment of real waters

Hour-glass magnetic spectrum in an insulating, hole-doped antiferromagnet

Superconductivity in layered copper-oxide compounds emerges when charge carriers are added to antiferromagnetically-ordered CuO2 layers. The carriers destroy the antiferromagnetic order, but strong spin fluctuations persist throughout the superconducting phase and are intimately linked to super-conductivity. Neutron scattering measurements of spin fluctuations in hole-doped copper oxides have revealed an unusual `hour-glass' feature in the momentum-resolved magnetic spectrum, present in a wide range of superconducting and non-superconducting materials. There is no widely-accepted explanation for this feature. One possibility is that it derives from a pattern of alternating spin and charge stripes, an idea supported by measurements on stripe-ordered La1.875Ba0.125CuO4. However, many copper oxides without stripe order also exhibit an hour-glass spectrum$. Here we report the observation of an hour-glass magnetic spectrum in a hole-doped antiferromagnet from outside the family of superconducting copper oxides. Our system has stripe correlations and is an insulator, which means its magnetic dynamics can conclusively be ascribed to stripes. The results provide compelling evidence that the hour-glass spectrum in the copper-oxide superconductors arises from fluctuating stripes.Comment: 13 pages, 4 figures, to appear in Natur

Animating the Carbon Cycle

This a post-print, author-produced version of an article accepted for publication in Ecosystems. Copyright © 2013 Springer Science+Business Media New York. The final publication is available at Springer via http://dx.doi.org/10.1007/s10021-013-9715-7Understanding the biogeochemical processes regulating carbon cycling is central to mitigating atmospheric CO2 emissions. The role of living organisms has been accounted for, but the focus has traditionally been on contributions of plants and microbes. We develop the case that fully “animating” the carbon cycle requires broader consideration of the functional role of animals in mediating biogeochemical processes and quantification of their effects on carbon storage and exchange among terrestrial and aquatic reservoirs and the atmosphere. To encourage more hypothesis-driven experimental research that quantifies animal effects we discuss the mechanisms by which animals may affect carbon exchanges and storage within and among ecosystems and the atmosphere. We illustrate how those mechanisms lead to multiplier effects whose magnitudes may rival those of more traditional carbon storage and exchange rate estimates currently used in the carbon budget. Many animal species are already directly managed. Thus improved quantitative understanding of their influence on carbon budgets may create opportunity for management and policy to identify and implement new options for mitigating CO2 release at regional scales.US National Science FoundationNERCBBSRCNippon Foundatio

Detection of small-molecule enzyme inhibitors with peptides isolated from phage-displayed combinatorial peptide libraries

AbstractBackground: The rapidly expanding list of pharmacologically important targets has highlighted the need for ways to discover new inhibitors that are independent of functional assays. We have utilized peptides to detect inhibitors of protein function. We hypothesized that most peptide ligands identified by phage display would bind to regions of biological interaction in target proteins and that these peptides could be used as sensitive probes for detecting low molecular weight inhibitors that bind to these sites.Results: We selected a broad range of enzymes as targets for phage display and isolated a series of peptides that bound specifically to each target. Peptide ligands for each target contained similar amino acid sequences and competition analysis indicated that they bound one or two sites per target. Of 17 peptides tested, 13 were found to be specific inhibitors of enzyme function. Finally, we used two peptides specific for Haemophilus influenzae tyrosyl-tRNA synthetase to show that a simple binding assay can be used to detect small-molecule inhibitors with potencies in the micromolar to nanomolar range.Conclusions: Peptidic surrogate ligands identified using phage display are preferentially targeted to a limited number of sites that inhibit enzyme function. These peptides can be utilized in a binding assay as a rapid and sensitive method to detect small-molecule inhibitors of target protein function. The binding assay can be used with a variety of detection systems and is readily adaptable to automation, making this platform ideal for high-throughput screening of compound libraries for drug discovery

Interaction Between Convection and Pulsation

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different formulations for how the convective turbulent velocity field couples with the global stellar oscillations. In this review we put emphasis on two, widely used, time-dependent convection formulations for estimating pulsation properties in one-dimensional stellar models. Applications to pulsating stars are presented with results for oscillation properties, such as the effects of convection dynamics on the oscillation frequencies, or the stability of pulsation modes, in classical pulsators and in stars supporting solar-type oscillations.Comment: Invited review article for Living Reviews in Solar Physics. 88 pages, 14 figure

Can postponement of an adverse outcome be used to present risk reductions to a lay audience? A population survey

BACKGROUND: For shared decision making doctors need to communicate the effectiveness of therapies such that patients can understand it and discriminate between small and large effects. Previous research indicates that patients have difficulties in understanding risk measures. This study aimed to test the hypothesis that lay people may be able to discriminate between therapies when their effectiveness is expressed in terms of postponement of an adverse disease event. METHODS: In 2004 a random sample of 1,367 non-institutionalized Danes aged 40+ was interviewed in person. The participants were asked for demographic information and asked to consider a hypothetical preventive drug treatment. The respondents were randomized to the magnitude of treatment effectiveness (heart attack postponement of 1 month, 6 months, 12 months, 2 years, 4 years and 8 years) and subsequently asked whether they would take such a therapy. They were also asked whether they had hypercholesterolemia or had experienced a heart attack. RESULTS: In total 58% of the respondents consented to the hypothetical treatment. The proportions accepting treatment were 39%, 52%, 56%, 64%, 67% and 73% when postponement was 1 month, 6 months, 12 months, 2 years, 4 years and 8 years respectively. Participants who thought that the effectiveness information was difficult to understand, were less likely to consent to therapy (p = 0.004). CONCLUSION: Lay people can discriminate between levels of treatment effectiveness when they are presented in terms of postponement of an adverse event. The results indicate that such postponement is a comprehensible measure of effectiveness

On the effects of surface morphology on the structure of wall-turbulence

Experiments were conducted in the fully-rough regime on surfaces with large relative roughness (h/δ ≈ 0.1) generated by regularly distributed LEGO™ bricks of uniform height, arranged in different configurations. Measurements were made with high resolution PIV on six different frontal solidities, λF, at fixed plan solidity, λP. Results indicate that the spatial underlying structure of the turbulence across the different surface morphologies is universal in both its shape and orientation in relation to the flow velocity. Harpin packets inclination with respect of the wall is also found to be consistent not only across the different wall surfaces but also when compared to previous studies on smooth walls. Slices of two-point correlations for both streamwise and wall-normal velocity fluctuations and Reynolds shear stresses present a good collapse across the entire y/δ range for all wall morphologies