Exercise and footwear in medial knee osteoarthritis: a randomized controlled trial comparing flat flexible footwear to stable supportive shoes.

Objective: This randomized controlled trial (RCT) investigated whether adding daily use of flat flexible footwear (FFF) to a strengthening and aerobic exercise program improved short- and longer-term outcomes compared with adding stable supportive shoes (SSS) in people with medial tibiofemoral OA.

Methods: Participants ( = 97) with medial tibiofemoral OA were randomly assigned (1:1) to the FFF ( = 50) or SSS ( = 47) group. Participants in both groups received a 9-month intervention (3 months supervised followed by 6 months unsupervised exercise).

Flat Optics: feature issue introduction.

This feature issue of Optics Express was created in conjunction with a topical meeting that took place during the 2023 Optica Imaging Congress and includes 17 state-of-the art articles. This introduction provides a summary of these articles that cover various aspects of metasurfaces from fundamental mechanisms, design methods, novel materials and processes to applications.

Shape optimization for high efficiency metasurfaces: theory and implementation.

Complex non-local behavior makes designing high efficiency and multifunctional metasurfaces a significant challenge. While using libraries of meta-atoms provide a simple and fast implementation methodology, pillar to pillar interaction often imposes performance limitations. On the other extreme, inverse design based on topology optimization leverages non-local coupling to achieve high efficiency, but leads to complex and difficult to fabricate structures.

Do dielectric bilayer metasurfaces behave as a stack of decoupled single-layer metasurfaces?

Flat optics or metasurfaces have opened new frontiers in wavefront shaping and its applications. Polarization optics is one prominent area which has greatly benefited from the shape-birefringence of metasurfaces. However, flat optics comprising a single layer of meta-atoms can only perform a subset of polarization transformations, constrained by a symmetric Jones matrix.

Neuropathic-like pain in knee osteoarthritis: exploring differences in knee loading and inflammation. A cross-sectional study.

Background: A subgroup of patients with knee osteoarthritis (OA) reports symptoms attributable to a neuropathic cause. Little to no attention has been invested on investigating differences in knee loading and inflammation in these patients.

Aim: To explore differences in inflammation and knee loading in patients with knee OA categorized based on the presence of neuropathic-like pain.

Associations between markers of inflammation and altered pain perception mechanisms in people with knee osteoarthritis: a systematic review.

To provide an extensive review on the associations between knee inflammation and altered pain perception mechanisms in people with knee osteoarthritis (OA). MEDLINE, Web of Science, EMBASE and Scopus were searched up to 13 December 2022. We included articles reporting associations between knee inflammation (measured by effusion, synovitis, bone marrow lesions (BMLs) and cytokines) and signs of altered pain processing (assessed by quantitative sensory testing and/or questionnaire for neuropathic-like pain) in people with knee OA.

Movement retraining programme in young soccer and rugby football players: A feasibility and proof of concept study.

Introduction: Movement screening to identify abnormal movement patterns can inform development of effective interventions. The primary objective of this study was to evaluate the feasibility of using a movement screening tool in combination with a tailored movement control retraining programme in young soccer and rugby football players. A secondary objective was to investigate changes in movement control patterns post-intervention, to provide proof of concept (PoC) for movement retraining.

Adjoint-optimized metasurfaces for compact mode-division multiplexing.

Optical fiber communications rely on multiplexing techniques that encode information onto various degrees of freedom of light to increase the transmission capacity of a fiber. However, the rising demand for larger data capacity is driving the need for a multiplexer for the spatial dimension of light. We introduce a mode-division multiplexer and demultiplexer design based on a metasurface cavity.

Efficient integrated tri-modal coupler for few-mode fibers.

This paper demonstrates a high-efficiency vertical grating coupler for the LP, LP, and LP modes of a graded-index few-mode fiber. The coupler is composed of a non-uniform straight bidirectional grating that was inverse-designed to address the desired fiber modes, combined with two mode-selective directional couplers and two tapers. The device was fabricated by e-beam lithography with a minimum feature size of 100 nm and presented coupling efficiencies of -3.

Association between knee inflammation and knee pain in patients with knee osteoarthritis: a systematic review.

Objective: To systematically review the literature on the relationship between markers of inflammation and pain in patients with knee osteoarthritis (OA).

Methods: We searched MEDLINE, Web of Science and EMBASE databases from inception until June 2021. Eligible articles had to report on the association between inflammation (as measured by effusion, synovitis, baker's cysts, cytokines and C-reactive protein) and pain in patients with radiographic knee OA.

Compact dual-polarization silicon integrated couplers for multicore fibers.

Compact fiber-to-chip couplers play an important role in optical interconnections, especially in data centers. However, the development of couplers has been mostly limited to standard single-mode fibers, with few devices compatible with multicore and multimode fibers. Through the use of state-of-the-art optimization algorithms, we designed a compact dual-polarization coupler to interface chips and dense multicore fibers, demonstrating, for the first time, coupling to both polarizations of all the cores, with measured coupling efficiency of -4.

Ultra-low-power four-wave mixing wavelength conversion in high-Q chalcogenide microring resonators.

A compact chalcogenide microring resonator is fabricated with an intrinsic quality factor of 3.0×10 in the telecom band. By taking advantage of the strong nonlinearity and cavity enhancement, highly efficient wavelength conversion via four-wave mixing is demonstrated using a microring resonator.

Characterization of surface-states in a hollow core photonic crystal fiber.

Surface or edge states represent an important class of modes in various photonic crystal systems such as in dielectric topological insulators and in photonic crystal fibers. In the later, strong attenuation peaks in the transmission spectrum are attributed to coupling between surface and core-guided modes. Here, we explore a modified implementation of the spatial and spectral interference method to experimentally characterize surface modes in photonic crystal fibers.

Accuracy of movement quality screening to document effects of neuromuscular control retraining exercises in a young ex-footballer with hip and groin symptoms: A proof of concept case study.

Hip and groin pain is common in footballers and altering movement patterns can reduce symptoms. Observational tests of movement control are thought to identify abnormal movement patterns, but their accuracy needs yet to be confirmed by comparison with an objective measure. To assess the accuracy, using 3D motion analysis, of observational movement control tests and their ability to detect changes, and document changes in symptoms following a neuromuscular control exercise programme in an ex-footballer with hip and groin pain.

Fiber taper diameter characterization using forward Brillouin scattering.

We propose a fast and non-destructive method to characterize the absolute diameter and uniformity of micrometer-scale fiber tapers using a pump and probe forward Brillouin scattering setup. The fundamental torsional-radial acoustic mode supported by the wire is excited using a pulsed pump laser and oscillates at a frequency that is inversely proportional to the taper waist diameter. This standing time-varying torsional-radial wave induces polarization modulation on a probe signal, whose spectrum structure reveals the sample diameter and its non-uniformity.

Design of a compact CMOS-compatible photonic antenna by topological optimization.

Photonic antennas are critical in applications such as spectroscopy, photovoltaics, optical communications, holography, and sensors. In most of those applications, metallic antennas have been employed due to their reduced sizes. Nevertheless, compact metallic antennas suffer from high dissipative loss, wavelength-dependent radiation pattern, and they are difficult to integrate with CMOS technology.

Side-lobe level reduction in bio-inspired optical phased-array antennas.

Phased arrays are expected to play a critical role in visible and infrared wireless systems. Their improved performance compared to single element antennas finds uses in communications, imaging, and sensing. However, fabrication of photonic antennas and their feeding network require long element separation, leading to the appearance of secondary radiation lobes and, consequently, crosstalk and interference.

Brillouin scattering self-cancellation.

The interaction between light and acoustic phonons is strongly modified in sub-wavelength confinement, and has led to the demonstration and control of Brillouin scattering in photonic structures such as nano-scale optical waveguides and cavities. Besides the small optical mode volume, two physical mechanisms come into play simultaneously: a volume effect caused by the strain-induced refractive index perturbation (known as photo-elasticity), and a surface effect caused by the shift of the optical boundaries due to mechanical vibrations. As a result, proper material and structure engineering allows one to control each contribution individually.

Novel optical fiber design for low-cost optical interconnects in consumer applications.

We propose a novel fiber design optimized for short-reach interconnects in consumer applications. A detailed analysis of the optical and mechanical properties of this fiber design is presented. Results are presented demonstrating (i) low bend loss and enhanced mechanical reliability in bends as small as 3 mm diameter; (ii) high power budget margin to enable relaxed mechanical tolerances on transmitter, receiver, and expanded-beam connectors for low-cost connectivity; and (iii) high bandwidth capability and system testing results at 10 Gb/s.

Raman-like light scattering from acoustic phonons in photonic crystal fiber.

Raman and Brillouin scattering are normally quite distinct processes that take place when light is resonantly scattered by, respectively, optical and acoustic phonons. We show how few-GHz acoustic phonons acquire many of the same characteristics as optical phonons when they are tightly trapped, transversely and close to modal cut-off, inside the wavelength-scale core of an air-glass photonic crystal fiber (PCF). The result is an optical scattering effect that closely resembles Raman scattering, though at much lower frequencies.

Cold-Resistant and Cold-Sensitive Maize Lines Differ in the Phosphorylation of the Photosystem II Subunit, CP29.

The effects of low temperature on the relative contributions of the reaction center and the antenna activities to photosystem II (PSII) electron transport were estimated by chlorophyll fluorescence. The inhibition of PSII photochemistry resulted from photo-damage to the reaction center and/or a reduced probability of excitation energy trapping by the reaction center. Although chill treatment did not modify the proportion of the dimeric to monomeric PSII, it destabilized its main light-harvesting complex.

Breakdown of cytoskeletal proteins during meiosis of starfish oocytes and proteolysis induced by calpain.

Meiosis reinitiation in starfish oocytes is characterized by Ca(2+) transients in the cytosol and in the nucleus and is accompanied by the disassembly of the nuclear envelope, a process which is likely to be mediated by the cleavage of selected proteins. We have used mass spectrometry analysis (mass profile fingerprinting) on 2D polyacrylamide gels of extracts of oocytes in which meiosis resumption was induced by 1-methyladenine and have identified five proteins that were specifically degraded: alpha-tubulin, lamin B, dynamin, and two kinds of actin. They are all components of the cytoskeleton or associated with it.

Proteome analysis of heat shock protein expression in Bradyrhizobium japonicum.

A set of 19 heat shock proteins (Hsp) was observed - by subtractive two-dimensional gel electrophoresis - to be induced when Bradyrhizobium japonicum, the nitrogen-fixing root-nodule symbiont of soybean, was temperature up-shifted from 28 degrees C to 43 degrees C. Up-regulated protein spots were excised from multiple two-dimensional gels. The proteins were concentrated using a funnel-gel device before being blotted onto poly(vinylidene difluoride) membranes for digestion with trypsin before MS and tandem MS analysis or for Edman sequence determination.

An algorithm for the identification of proteins using peptides with ragged N- or C-termini generated by sequential endo- and exopeptidase digestions.

We have developed an algorithm (MassDynSearch) for identifying proteins using a combination of peptide masses with small associated sequences (tags). Unlike the approach developed by Matthias Mann, 'Tag searching', in which the sequence tags are generated by gas phase fragmentation of peptides in a mass spectrometer, 'Rag Tag' searching uses peptide tags which are generated enzymatically or chemically. The protein is digested either chemically or with an endopeptidase and the resultant mixture is then subjected to partial exopeptidase degradation.

Functional conservation of calreticulin in Euglena gracilis.

Calreticulin is the major high capacity, low affinity Ca2+ binding protein localized within the endoplasmic reticulum. It functions as a reservoir for triggered release of Ca2+ by the endoplasmic reticulum and is thus integral to eukaryotic signal transduction pathways involving Ca2+ as a second messenger. The early branching photosynthetic protist Euglena gracilis is shown to possess calreticulin as its major high capacity Ca2+ binding protein.