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An analytical and a numerical study on coupling in microstrip transmission line (MTL) are reported for different split-gap orientations of a single gap square-shaped split-ring resonator (SRR). Taking both magnetic and electric couplings and adopting Lagrangian formulation for this coupled system, mathematical relations are found for each orientation of SRR to determine the connection between coupling co-efficient and resonant mode frequency. It is shown that coupling results in higher resonance frequency when the SRR, with parallel split-gap, has the gap far from the MTL. But, a lower resonance frequency is obtained when the SRR is placed at shorter distances with parallel split-gap near to the MTL. Again, for perpendicular split-gap orientation of SRR, the resonant frequency is found in terms of an effective coupling co-efficient; at shorter distances it is found to be lower than the fundamental resonance frequency of uncoupled SRR and an opposite effect is obtained at longer distances. Using CST Microwave Studio, the resonance frequency for each split-gap orientation of SRR is also studied as a function of separation between MTL and SRR. It is observed that this phenomenon strongly depends on SRR side-length, substrate height, and separation between MTL and SRR. [ABSTRACT FROM AUTHOR]

Introduction: This matched cohort study aims to determine whether the presence of a spinal arthrodesis (SA) compromises outcome of total hip arthroplasty (THA) and whether the outcome is better if THA is performed before- (THA-1st) or after- SA (THA-2nd). Methods: This is a single centre, multi-surgeon, review of prospective data. Thirty-seven patients (47 hips) that had SA and 1° THA(s), formed the cases (26 THA-1st; 21 THA-2nd). Most cases had 1-level SA (n = 24). Controls were patients without SA that had THA, over the same period matched for age, gender and prosthesis type. Outcome measures included complication-, revision- rates, Oxford-Hip- and Harris-Hip-Scores (OHS/HHS) (Δ: difference between pre- and post-operative scores). This is a single-centre, multi-surgeon, review of prospective data. Results: At a mean follow-up of 6 years, more complications were seen in cases of THA and SA compared with controls without SA (7 vs. 2) (p = 0.03). Consequently, more cases were revised (n = 4) compared with controls (n = 0) (p = 0.02). There were no differences in functional outcome between cases and controls (p = 0.1–0.6). No differences in complications- (4/26 vs. 3/21; p = 1.00) or revision- rates (2/26 vs. 2/21; p = 1.00) were seen between THA-1st and THA-2nd Groups. The THA-1st Group had higher pre- and post-operative OHS/HHS, compared to the THA-2nd Group. However, no significant difference in ΔOHS (24 vs. 17) and ΔHHS (39 vs. 26) were seen between the THA-1st and THA-2nd Groups (p = 0.1). Conclusions: Patients with THA and SA, had increased rates of revision; but no differences in patient-reported outcome measures (PROMs) were detected. Addressing the hip pathology first may be associated with improved functional outcome. [ABSTRACT FROM AUTHOR]

Purpose: Although previously frozen shoulder was thought to resolve by two to three years, recent studies demonstrated the symptoms can remain for much longer. Manipulation under anaesthetic (MUA) has been shown to be successful in relieving pain and restoring function. Yet, concerns have been raised regarding its safety and the risks of complications. We utilise Codman's paradox to manipulate the shoulder, avoiding rotational torque on the humerus. The aim of our study was to asses shoulder function in the early post MUA period.Methods: Two hundred twelve consecutive patients (224 shoulders) (mean age 52.4 years) underwent MUA using Codman's paradox for frozen shoulder as sole procedure between 2005 and 2013. All were evaluated clinically, preoperatively and postoperatively, at three weeks and three months, for Constant score (CS), pain, range of motion (ROM), patient satisfaction and subjective shoulder value (SSV).Results: At three weeks and three months, a significant improvement was found in CS from 30.7 to 66 and 70 respectively. Forward elevation improved from 91° to 154° and 160 °, abduction from 69° to 150° and 156 °, internal rotation from 12° to 62° and 66 °, and external rotation from 10° to 46° and 50 °. Pain score improved from 4.4/15 to 9.6/15 and 10.4/15, SSV improved from 1.5/10 to 6.5/10 and 6.7/10. (p<0.001).Conclusion: Use of Codman's paradox provides a safe and efficient way to perform MUA for frozen shoulder. It results in dramatic early improvement in ROM, functional outcomes and high satisfaction, as early as three weeks post-operatively. [ABSTRACT FROM AUTHOR]

A numerical model on reflective vertical cavity-based fast semiconductor (carrier recombination time in ps regime) saturable absorbers (VC-FSSA) is investigated for all-optical high-speed future applications, where the fluctuation of cavity optical length due to thermo-optic effects and cavity heating, and optically induced carrier density change are considered simultaneously with the increase of input signal intensity. The phase-shift due to thermal-optic effects and cavity heating is very important for high-speed device performances. At first, intensity and wavelength bi-stabilities are modelled with the different intensity time filling factor of RZ modulated pump signals and also, with the different input intensities, where the intensity tuning time is considered at few μs. Then the inverse saturation characteristics of reflectivity for the universal logic operations are shown for probe signal with the proper wavelength, which can control the negative effects of optically induced heating effects. These characteristics can be used for the high-speed thermally stable bi-stable optical switch and all-optical logic applications. [ABSTRACT FROM AUTHOR]