Efficacy of intraarticular hyaluronic acid in patients with osteoarthritis—a prospective clinical trial

AbstractAim The goal of this study was to determine whether or not the intraarticular administration of hyaluronic acid can improve functional parameters, such as isokinetic muscle strength or total work and clinical test results in patients with osteoarthritis (OA) of the knee.Method As part of a prospective, controlled study 43 patients with osteoarthritic changes of both knees (radiographic Kellgren stage II–III) were followed in a right/left comparison. The influence of intraarticularly injected hyaluronic acid (20mg hyaluronic acid/2ml Hyalart®) on functional and clinical parameters was analysed. We used the isokinetic system Cybex 600 for measuring maximal isokinetic muscle strength and total work. A total of 20 males and 23 females fulfilled the inclusion criteria with an age between 55–78 years and underwent five injections of hyaluronic acid (one injection per week). The injected knee represented the treatment group, while the contralateral knee served as the control.Results The maximum peak torque of the knee extensors in the treatment group was measured between 57±26.15/32.33±19.63Nm prior to the injections and 77.17±32.54/47.83±21.43Nm following the hyaluronic acid therapy (P< 0.01). The analysis of the knee flexors at angular velocities of 60°/s and 180°/s revealed values of 40.44±21.58/22.89±16.64Nm and 53.55±24.26/34.05±17.37Nm (P< 0.01) respectively. The evaluation of the total work of the knee flexors and extensors revealed a significant difference (P< 0.01) between the treatment and control group. The Lequesne score was reduced from 13.57±1.88 prior to the injections to 7.94±2.53 after the treatment (P< 0.01). The pain score was documented with the help of a visual analog scale. The VAS values were reduced at rest from 3.83±1.72cm to 1.36±1.42cm and during weight bearing from 7.57±1.34cm to 3.75±1.32cm in the treatment group (P< 0.01).Conclusions This controlled prospective clinical trial confirmed that 5 weekly intraarticular injections of HA (Hyalart®) in patients with OA of the knee provide pain relief and functional improvements. Copyright 2002 OsteoArthritis Research Society International. Published by Elsevier Science Ltd. All rights reserved

Weak force detection with superposed coherent states

We investigate the utility of non classical states of simple harmonic oscillators, particularly a superposition of coherent states, for sensitive force detection. We find that like squeezed states a superposition of coherent states allows displacement measurements at the Heisenberg limit. Entangling many superpositions of coherent states offers a significant advantage over a single mode superposition states with the same mean photon number.Comment: 6 pages, no figures: New section added on entangled resources. Changes to discussions and conclusio

Bosonic lasers: The state of the art (Review Article)

Bosonic lasers represent a new generation of coherent light sources. In contrast to conventional, fermionic, lasers they do not require inversion of electronic population and do not rely on the stimulated emission of radiation. Bosonic lasers are based on the spontaneous emission of light by condensates of bosonic quasiparticles. The first realization of bosonic lasers has been reported in semiconductor microcavities where bosonic condensates of exciton-polaritons first studied several decades ago by K. B. Tolpygo can be formed under optical or electronic pumping. In this paper we overview the recent progress in the research area of polaritonics, address the perspective of realization of polariton devices: from bosonic cascade lasers to spin transistors and switches

Entanglement Dynamics in Two-Qubit Open System Interacting with a Squeezed Thermal Bath via Quantum Nondemolition interaction

We analyze the dynamics of entanglement in a two-qubit system interacting with an initially squeezed thermal environment via a quantum nondemolition system-reservoir interaction, with the system and reservoir assumed to be initially separable. We compare and contrast the decoherence of the two-qubit system in the case where the qubits are mutually close-by (`collective regime') or distant (`localized regime') with respect to the spatial variation of the environment. Sudden death of entanglement (as quantified by concurrence) is shown to occur in the localized case rather than in the collective case, where entanglement tends to `ring down'. A consequence of the QND character of the interaction is that the time-evolved fidelity of a Bell state never falls below $1/\sqrt{2}$, a fact that is useful for quantum communication applications like a quantum repeater. Using a novel quantification of mixed state entanglement, we show that there are noise regimes where even though entanglement vanishes, the state is still available for applications like NMR quantum computation, because of the presence of a pseudo-pure component.Comment: 17 pages, 9 figures, REVTeX

Multipartite Classical and Quantum Secrecy Monotones

In order to study multipartite quantum cryptography, we introduce quantities which vanish on product probability distributions, and which can only decrease if the parties carry out local operations or carry out public classical communication. These ``secrecy monotones'' therefore measure how much secret correlations are shared by the parties. In the bipartite case we show that the mutual information is a secrecy monotone. In the multipartite case we describe two different generalisations of the mutual information, both of which are secrecy monotones. The existence of two distinct secrecy monotones allows us to show that in multipartite quantum cryptography the parties must make irreversible choices about which multipartite correlations they want to obtain. Secrecy monotones can be extended to the quantum domain and are then defined on density matrices. We illustrate this generalisation by considering tri-partite quantum cryptography based on the Greenberger-Horne-Zeilinger (GHZ) state. We show that before carrying out measurements on the state, the parties must make an irreversible decision about what probability distribution they want to obtain

Inhibiting decoherence via ancilla processes

General conditions are derived for preventing the decoherence of a single two-state quantum system (qubit) in a thermal bath. The employed auxiliary systems required for this purpose are merely assumed to be weak for the general condition while various examples such as extra qubits and extra classical fields are studied for applications in quantum information processing. The general condition is confirmed with well known approaches towards inhibiting decoherence. A novel approach for decoherence-free quantum memories and quantum operations is presented by placing the qubit into the center of a sphere with extra qubits on its surface.Comment: pages 8, Revtex

Solving the Shortest Vector Problem in Lattices Faster Using Quantum Search

By applying Grover's quantum search algorithm to the lattice algorithms of Micciancio and Voulgaris, Nguyen and Vidick, Wang et al., and Pujol and Stehl\'{e}, we obtain improved asymptotic quantum results for solving the shortest vector problem. With quantum computers we can provably find a shortest vector in time $2^{1.799n + o(n)}$, improving upon the classical time complexity of $2^{2.465n + o(n)}$ of Pujol and Stehl\'{e} and the $2^{2n + o(n)}$ of Micciancio and Voulgaris, while heuristically we expect to find a shortest vector in time $2^{0.312n + o(n)}$, improving upon the classical time complexity of $2^{0.384n + o(n)}$ of Wang et al. These quantum complexities will be an important guide for the selection of parameters for post-quantum cryptosystems based on the hardness of the shortest vector problem.Comment: 19 page

Possible charge inhomogeneities in the CuO2 planes of YBa2Cu3O6+x (x=0.25, 0.45, 0.65, 0.94) from pulsed neutron diffraction

The atomic pair distribution functions (PDF) of four powder samples of YBa2Cu3O6+x (x=0.25, 0.45, 0.65, 0.94) at 15 K have been measured by means of pulsed neutron diffraction. The PDF is modelled using a full-profile fitting approach to yield structural parameters. In contrast to earlier XAFS work we find no evidence of a split apical oxygen site. However, a slightly improved fit over the average crystallographic model results when the planar Cu(2) site is split along the z-direction. This is interpreted in terms of charge inhomogeneities in the CuO2 planes.Comment: 8 pages, 3 figure

Innovations in air sampling to detect plant pathogens

Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics

Quasars and their host galaxies

This review attempts to describe developments in the fields of quasar and quasar host galaxies in the past five. In this time period, the Sloan and 2dF quasar surveys have added several tens of thousands of quasars, with Sloan quasars being found to z>6. Obscured, or partially obscured quasars have begun to be found in significant numbers. Black hole mass estimates for quasars, and our confidence in them, have improved significantly, allowing a start on relating quasar properties such as radio jet power to fundamental parameters of the quasar such as black hole mass and accretion rate. Quasar host galaxy studies have allowed us to find and characterize the host galaxies of quasars to z>2. Despite these developments, many questions remain unresolved, in particular the origin of the close relationship between black hole mass and galaxy bulge mass/velocity dispersion seen in local galaxies.Comment: Review article, to appear in Astrophysics Update