Can PRP effectively treat injured tendons?

PRP is widely used to treat tendon and other tissue injuries in orthopaedics and sports medicine; however, the efficacy of PRP treatment on injured tendons is highly controversial. In this commentary, I reason that there are many PRP- and patient-related factors that influence the outcomes of PRP treatment on injured tendons. Therefore, more basic science studies are needed to understand the mechanism of PRP on injured tendons. Finally, I suggest that better understanding of the PRP action mechanism will lead to better use of PRP for the effective treatment of tendon injuries in clinic

A library of infectious hepatitis C viruses with engineered mutations in the E2 gene reveals growth-adaptive mutations that modulate interactions with scavenger receptor class B type I

While natural hepatitis C virus (HCV) infection results in highly diverse quasispecies of related viruses over time, mutations accumulate more slowly in tissue culture, in part because of the inefficiency of replication in cells. To create a highly diverse population of HCV particles in cell culture and identify novel growth-enhancing mutations, we engineered a library of infectious HCV with all codons represented at most positions in the ectodomain of the E2 gene. We identified many putative growth-adaptive mutations and selected nine highly represented E2 mutants for further study: Q412R, T416R, S449P, T563V, A579R, L619T, V626S, K632T, and L644I. We evaluated these mutants for changes in particle-to-infectious-unit ratio, sensitivity to neutralizing antibody or CD81 large extracellular loop (CD81-LEL) inhibition, entry factor usage, and buoyant density profiles. Q412R, T416R, S449P, T563V, and L619T were neutralized more efficiently by anti-E2 antibodies and T416R, T563V, and L619T by CD81-LEL. Remarkably, all nine variants showed reduced dependence on scavenger receptor class B type I (SR-BI) for infection. This shift from SR-BI usage did not correlate with a change in the buoyant density profiles of the variants, suggesting an altered E2-SR-BI interaction rather than changes in the virus-associated lipoprotein-E2 interaction. Our results demonstrate that residues influencing SR-BI usage are distributed across E2 and support the development of large-scale mutagenesis studies to identify viral variants with unique functional properties. IMPORTANCE Characterizing variant viruses can reveal new information about the life cycle of HCV and the roles played by different viral genes. However, it is difficult to recapitulate high levels of diversity in the laboratory because of limitations in the HCV culture system. To overcome this limitation, we engineered a library of mutations into the E2 gene in the context of an infectious clone of the virus. We used this library of viruses to identify nine mutations that enhance the growth rate of HCV. These growth-enhancing mutations reduced the dependence on a key entry receptor, SR-BI. By generating a highly diverse library of infectious HCV, we mapped regions of the E2 protein that influence a key virus-host interaction and provide proof of principle for the generation of large-scale mutant libraries for the study of pathogens with great sequence variability

A satellite image-based analysis of factors contributing to the green-space cool island intensity on a city scale

Urban green spaces provide cooler microclimates and create localized urban cool islands and, as part of an adaption strategy to cope with future urban climate change, have been proposed as a means to mitigate the urban heat island effect. Numerous previous research papers have discussed green-space size, type, and vegetation density, as well as many other factors that might influence green-space cooling effects. However, little has been done with regard to exploring and quantifying the characteristics of the green-space cool island (UCI). It is also largely unknown whether or how the patterns of green space and land use, as well as the adjacent urban thermal environment, affect UCIs. In this paper, based on the satellite image, the land surface temperature (LST) was retrieved and the UCI was first identified, then the UCI intensity, one of the UCI characteristics, is defined and at last multiple linear regression models used to explore and quantify the combined effects of factors related to UCI intensity. The results show that the intensity differed between UCIs, and that it was correlated significantly with the extent of and mean temperature reduction associated with a UCI. Multiple linear regression analysis shows that UCI intensity was affected by areas of forest vegetation and its spatial arrangements, as well as by the composition of the cool island and its neighboring thermal environment. The study validated the suitability of using intensity as an indicator of the UCI. Identifying the UCI as a result of the green-space cooling effect, will help in the management and planning of the spatial arrangement of green spaces in cities to mitigate the effects of the urban heat environment and help cities adapt to the climate change

High-velocity Limits for the Ratio of Double to Single Ionisation of Helium by Projectiles with Electrons

The ratio of total double to total single ionisation cross sections, R, by high velocity projectiles containing electrons is examined in the first Born approximation. For ionisation of helium by H+, H0 and He0 impact, it is found that t filt H+ \u3c filt Ho \u3c filt Heo . Connection with Bohr\u27s free-collision model for collisions with projectile electrons is given

Poincar\'e gauge theory with even and odd parity dynamic connection modes: isotropic Bianchi cosmological models

The Poincar\'e gauge theory of gravity has a metric compatible connection with independent dynamics that is reflected in the torsion and curvature. The theory allows two good propagating spin-0 modes. Dynamical investigations using a simple expanding cosmological model found that the oscillation of the 0$^+$ mode could account for an accelerating expansion similar to that presently observed. The model has been extended to include a $0^{-}$ mode and more recently cross parity couplings. We investigate the dynamics of this model in a situation which is simple, non-trivial, and yet may give physically interesting results that might be observable. We consider homogeneous cosmologies, more specifically, isotropic Bianchi class A models. We find an effective Lagrangian for our dynamical system, a system of first order equations, and present some typical dynamical evolution.Comment: 8 pages, 1 figures, submitted to IARD 2010 Conference Proceedings in {\em Journal of Physics: Conference Series}, eds. L. Horwitz and M. Land (2011

Critical success criteria for B2B E-commerce systems in Chinese medical supply chain.

The paper presents an exploratory investigation to determine and prioritise the critical success criteria, which can measure and guide the successful application and performance improvement of business to business e-commerce system (BBECS) in a medical supply chain's selling and buying functions, in the context of global business expansion. The research reveals that the buying and the selling functions have different prioritisations on the majority of the determined critical success measuring criteria. These criteria are categorised into three Critical Success Measuring Criteria Groups, for the selling and the buying functions, respectively, guiding medical supply chain members in harnessing the full advantage of a BBECS. For the selling function, the top critical success measuring criteria are as follows: integrating information searching/transmission and application processes, ensuring the reliability and timeliness of technical support, ensuring recognition and acceptance of e-commerce processes, displaying the organisation's business focus and product/service provisions online, securing a large scale/amount of business transactions, adjusting production outputs and inventory levels and having more registered users than competitors do. The top critical success measuring criteria for the buying function are as follows: securing the establishment of business relationships between businesses, displaying the measures ensuring mutual trust and cooperation online, ensuring employees' recognition of the benefit of e-commerce in increasing revenue, ensuring the contribution to the development and realisation of corporate strategy, achieving cost reduction for the organisation, making the purchase of famous brand products available/doable, securing a large scale/amount of business transactions, and ensuring the attainability of products/services at a lower price

Application of Higher-Order FEM Elements to the Analysis of Microstrip Structures

Microstrip structures, formed by metal traces printed on a dielectric substrate above a reference plane, are frequently the object of electromagnetic modeling. In this paper, hybrid FEM/MoM formulations employing conventional Whitney elements and newly developed linear-tangent/linear-normal (LT/LN) tangential vector finite elements (TVFEs) are applied to the analysis of microstrip structures with thin traces. This paper shows that the variation of the electric field below the trace is a significant issue to be addressed in microstrip structure modeling. Different mesh methods are investigated and the advantages of the LT/LN TVFEs are discussed

The Los Alamos Trapped Ion Quantum Computer Experiment

The development and theory of an experiment to investigate quantum computation with trapped calcium ions is described. The ion trap, laser and ion requirements are determined, and the parameters required for quantum logic operations as well as simple quantum factoring are described.Comment: 41 pages, 16 figures, submitted to Fortschritte der Physi