Treatment using 448 kHz capacitive resistive monopolar radiofrequency improves pain and function in patients with osteoarthritis of the knee joint: A randomised controlled trial

Objective: This study investigated whether capacitive resistive monopolar radiofrequency (CRMRF)-based treatment improves pain and function among patients with osteoarthritis of the knee. Design and setting: Three-group randomised controlled trial with concealed allocation, participant blinding and intention-to-treat analysis. Forty-five patients diagnosed with osteoarthritis, from the waiting list for physiotherapy at a local hospital were enrolled. Intervention: Participants in the active and sham groups received eight sessions of CRMRF and sham-CRMRF respectively over four weeks, along with standard care. The control group received standard care only. Assessment: Pain and function were measured at four time points: week zero (baseline), week four (post intervention), week eight and week 16 (two follow-ups) using visual analogue scale (VAS), Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index, timed up and go (TUG) test and knee range of motion (ROM). Results: For pain (VAS), there were clinically significant changes in the active group at post treatment compared to sham (Mean difference: 0.79 (95% CI: 0.29 to 1.3), effect size: 1.3) and control (Mean difference: 0.82 (95% CI: 0.32 to 1.3), effect size: 1.5), and at one-month follow-up compared to control (Mean difference: 0.68 (95% CI: 0.10 to 1.3), effect size: 1.1). For function (WOMAC), there was clinically significant change in the active group at post treatment compared to control (Mean difference: 1.3 (95% CI: 0.02 to 2.6), effect size: 0.94), but not compared to sham. No meaningful differences were noted for TUG or knee ROM. No differences were noted at three-month follow-up for any outcomes. Conclusion: CRMRF treatment can improve pain and function in patients with knee osteoarthritis in the short term. Trial registration: NIHR-CRN study ID: 20264.Peer reviewedFinal Accepted Versio

Skin thermophysiological effects of 448 kHz capacitive resistive monopolar radiofrequency in healthy adults : A randomised crossover study and comparison with Pulsed Shortwave Therapy

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Electromagnetic Biology and Medicine on 8 January 2018, available online: https://doi.org/10.1080/15368378.2017.1422260. Under embargo until 8 January 2019.Radiofrequency-based electrophysical agents (EPA) have been used in therapy practice over several decades (e.g., shortwave therapies). Currently, there is insufficient evidence supporting such devices operating below shortwave frequencies. This laboratory-based study investigated the skin physiological effects of 448 kHz capacitive resistive monopolar radiofrequency (CRMRF) and compared them to pulsed shortwave therapy (PSWT). In a randomised crossover study, seventeen healthy volunteers received four treatment conditions–High, Low and Placebo dose conditions receiving 15-min CRMRF treatment and a Control condition receiving no intervention. Fifteen participants also received high dose PSWT for comparison. Treatment was applied to the right lower medial thigh. Pre, post and 20-min follow-up measurements of skin temperature (SKT), skin blood flow (SBF) and nerve conduction velocity (NCV) were obtained using Biopac MP150 system. Group data were compared using the ANOVA model. Statistical significance was set at p ≤ 0.05 (0.8P, 95%CI). Significant increase and sustenance of SKT with both high and low dose CRMRF was demonstrated over the other groups (p < 0.001). PSWT increased SKT significantly (p < 0.001) but failed to sustain it over the follow-up. However, among the five conditions, only high dose CRMRF significantly increased and sustained SBF (p < 0.001). Overall, the CRMRF physiological responses were significantly more pronounced than that of PSWT. No significant changes in NCV were noted for any condition. Physiological changes associated with CRMRF were more pronounced when compared to PSWT, placebo or control. Any potential stronger therapeutic benefits of CRMRF need to be confirmed by comparative clinical studies.Peer reviewedFinal Accepted Versio

Quenching parameter in a holographic thermal QCD

We have calculated the quenching parameter, $\hat{q}$ in a model-independent way using the gauge-gravity duality. In earlier calculations, the geometry in the gravity side at finite temperature was usually taken as the pure AdS blackhole metric for which the dual gauge theory becomes conformally invariant unlike QCD. Therefore we use a metric which incorporates the fundamental quarks by embedding the coincident D7 branes in the Klebanov-Tseytlin background and a finite temperature is switched on by inserting a black hole into the background, known as OKS-BH metric. Further inclusion of an additional UV cap to the metric prepares the dual gauge theory to run similar to thermal QCD. Moreover $\hat{q}$ is usually defined in the literature from the Glauber-model perturbative QCD evaluation of the Wilson loop, which has no reasons to hold if the coupling is large and is thus against the main idea of gauge-gravity duality. Thus we use an appropriate definition of $\hat{q}$: $\hat{q} L^- = 1/L^2$, where $L$ is the separation for which the Wilson loop is equal to some specific value. The above two refinements cause $\hat{q}$ to vary with the temperature as $T^4$ always and to depend linearly on the light-cone time $L^-$ with an additional ($1/L^-$) correction term in the short-distance limit whereas in the long-distance limit, it depends only linearly on $L^-$ with no correction term. These observations agree with other holographic calculations directly or indirectly.Comment: 16 page

Thermomagnetic properties and Bjorken expansion of hot QCD matter in a strong magnetic field

In this work we have studied the effects of an external strong magnetic field on the thermodynamic and magnetic properties of a hot QCD matter and then explored these effects on the subsequent hydrodynamic expansion of the said matter once produced in the ultrarelativistic heavy ion collisions. For that purpose, we have computed the quark and gluon self-energies up to one loop in the strong magnetic field, using the HTL approximation with two hard scales - temperature and magnetic field, which in turn compute the effective propagators for quarks and gluons, respectively. Hence the quark and gluon contributions to the free energy are obtained from the respective propagators and finally derive the equation of state (EOS) by calculating the pressure and energy density. We have found that the speed of sound is enhanced due to the presence of strong magnetic field and this effect will be later exploited in the hydrodynamics. Thereafter the magnetic properties are studied from the free energy of the matter, where the magnetization is found to increase linearly with the magnetic field, thus hints the paramagnetic behavior. The temperature dependence of the magnetization is also studied, where the magnetization is found to increase slowly with the temperature. Finally, to see how a strong magnetic field could affect the hydrodynamic evolution, we have revisited the Bjorken boost-invariant picture with our paramagnetic EOS as an input in the equation of motion for the energy-momentum conservation. We have noticed that the energy density evolves faster than in the absence of strong magnetic field, i.e. cooling becomes faster, which could have implications on the heavy-ion phenomenology. As mentioned earlier, this observation can be understood by the enhancement of the speed of sound.Comment: 37 pages with 5 figure

Effect of magnetic field on the charge and thermal transport properties of hot and dense QCD matter

We have studied the effect of strong magnetic field on the charge and thermal transport properties of hot QCD matter at finite chemical potential. For this purpose, we have calculated the electrical ($\sigma_{\rm el}$) and thermal ($\kappa$) conductivities using kinetic theory in the relaxation time approximation, where the interactions are subsumed through the distribution functions within the quasiparticle model at finite temperature, strong magnetic field and finite chemical potential. This study helps to understand the impacts of strong magnetic field and chemical potential on the local equilibrium by the Knudsen number ($\Omega$) through $\kappa$ and on the relative behavior between thermal conductivity and electrical conductivity through the Lorenz number ($L$) in the Wiedemann-Franz law. We have observed that, both $\sigma_{\rm el}$ and $\kappa$ get increased in the presence of strong magnetic field, and the additional presence of chemical potential further increases their magnitudes, where $\sigma_{\rm el}$ shows decreasing trend with the temperature, opposite to its increasing behavior in the isotropic medium, whereas $\kappa$ increases slowly with the temperature, contrary to its fast increase in the isotropic medium. The variation in $\kappa$ explains the decrease of the Knudsen number with the increase of the temperature. However, in the presence of strong magnetic field and finite chemical potential, $\Omega$ gets enhanced and approaches unity, thus, the system may move slightly away from the equilibrium state. The Lorenz number ($\kappa/(\sigma_{\rm el} T))$ in the abovementioned regime of strong magnetic field and finite chemical potential shows linear enhancement with the temperature and has smaller magnitude than the isotropic one, thus, it describes the violation of the Wiedemann-Franz law for the hot and dense QCD matter in the presence of a strong magnetic field.Comment: 29 pages, 6 figure