C-reactive protein a better indicator of inflammation after third molar extraction

Purpose: The purpose of this study was to evaluate the relation between pre-operative pain and pre-operative levels of C-reactive and post-operative pain and swelling in impacted third molar surgery.Materials and Methods: In this prospective study subjects were patients indicated for mandibular third molar extraction. Patients were assessed for certain inclusion and exclusion criteria’s. A standard surgical extraction procedure was followed to reduce the bias. Hematological investigation of C-reactive protein levels were recorded pre-operatively and post-operatively. Pain, swelling and trismus in patients were assessed pre-operatively and post-operatively in an interval of 24 hours, 48 hours and 7 days. Pain and swelling were measured using verbal analogue scale and thread length measurement respectively. The mouth opening was recorded, too.Results: Post-operative C-reactive protein levels were seen consistency raised in those cases which showed high pre-operative levels. Peak levels of C-reactive protein were seen at 48 hours post operatively. It was observed that preoperative pain swelling and mouth opening were seen to be variable in all the cases having high C-reactive protein levels.Conclusion: C-reactive protein was found to be a better indicator of inflammation than pre-operative pain, swelling and mouth opening for post-operative discomfort.Key words: C-reactive protein, inflammation, third molar extraction

Microstructural evolution and characterisation of interfacial phases in Al<inf>2</inf>O<inf>3</inf>/Ag-Cu-Ti/Al<inf>2</inf>O<inf>3</inf> braze joints

Alumina ceramics with different levels of purity have been joined to themselves using an active braze alloy (ABA) Ag–35.3Cu–1.8Ti wt.% and brazing cycles that peak at temperatures between 815 °C and 875 °C for 2 to 300 min. The microstructures of the joints have been studied using scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy. A limited number of joints prepared with the ABA Ag–26.7Cu–4.5Ti wt.% have also been studied. In terms of characterising the interfacial phases, efforts were made to understand the interfacial reactions, and to determine the influence of various brazing parameters, such as the peak temperature (Tp) and time at Tp (τ), on the microstructure. In addition, the extent to which impurities in the alumina affect the interfacial microstructure has been determined. Ti3Cu3O has been identified as the main product of the reactions at the ABA/alumina interfaces. At the shortest joining time used, this phase was observed in the form of a micron-size continuous layer in contact with the ABA, alongside a nanometre-size layer on the alumina that was mostly composed of γ-TiO grains. Occasionally, single grains of Ti3O2 were observed in the thin layer on alumina. In the joints prepared with Ag–35.3Cu–1.8Ti wt.%, the interfacial structure evolved considerably with joining time, eventually leading to a high degree of inhomogeneity across the length of the joint at the highest Tp. The level of purity of alumina was not found to affect the overall interfacial microstructure, which is attributed to the formation of various solid solutions. It is suggested that Ti3Cu3O forms initially on the alumina. Diffusion of Ti occurs subsequently to form titanium oxide at the Ti3Cu3O/alumina interface.The authors acknowledge the financial support for this study provided by AWE.This is the author accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S1359645415003791

Interfacial reactions between sapphire and Ag-Cu-Ti-based active braze alloys

The interfacial reactions between two commercially available Ag–Cu–Ti-based active braze alloys and sapphire have been studied. In separate experiments, Ag– 35.3Cu–1.8Ti wt.% and Ag–26.7Cu–4.5Ti wt.% alloys have been sandwiched between pieces of R-plane orientated sapphire and heated in argon to temperatures between 750 and 900 °C for 1 min. The phases at the Ag–Cu– Ti/sapphire interfaces have been studied using selected area electron diffraction, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. Gradual and subtle changes at the Ag–Cu–Ti/sapphire interfaces were observed as a function of temperature, along with the formation of a transient phase that permitted wetting of the sapphire. Unequivocal evidence is shown that when the active braze alloys melt, titanium first migrates to the sapphire and reacts to dissolve up to ~33 at.% oxygen, forming a nanometre-size polycrystalline layer with a chemical composition of Ti₂O₁₋ₓ (x<<1). Ti₃Cu₃O particles subsequently nucleate behind the Ti₂O₁₋ₓ layer and grow to become a continuous micrometre-size layer, replacing the Ti₂O₁₋ₓ layer. Finally at 845 °C, a nanometre-size γ-TiO layer forms on the sapphire to leave a typical interfacial structure of Ag–Cu/Ti₃Cu₃O/γ-TiO/sapphire consistent with that seen in samples of polycrystalline alumina joined to itself with these active braze alloys. These experimental observations have been used to establish a definitive bonding mechanism for the joining of sapphire with Ag–Cu alloys activated by small amounts of titaniumWe are grateful for the financial support for this study provided by AWE.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.actamat.2015.11.01

Meson Thermalization in Various Dimensions

In gauge/gravity duality framework the thermalization of mesons in strongly coupled (p+1)-dimensional gauge theories is studied for a general Dp-Dq system, q>=p, using the flavour Dq-brane as a probe. Thermalization corresponds to the horizon formation on the flavour Dq-brane. We calculate the thermalization time-scale due to a time-dependent change in the baryon number chemical potential, baryon injection in the field theory. We observe that for such a general system it has a universal behaviour depending only on the t'Hooft coupling constant and the two parameters which describe how we inject baryons into the system. We show that this universal behaviour is independent of the details of the theory whether it is conformal and/or supersymmetric.Comment: 26 pages, 2 figure

Evolution of the interfacial phases in Al2_{2}O3_{3}–Kovar joints®^{®} brazed using a Ag–Cu–Ti-based alloy

A systematic investigation of the brazing of Al$_{2}$O$_{3}$ to Kovar$^{®}$ (Fe–29Ni–17Co wt.%) using the active braze alloy (ABA) Ag–35.25Cu–1.75Ti wt.% has been undertaken to study the chemical reactions at the interfaces of the joints. The extent to which silica-based secondary phases in the Al$_{2}$O$_{3}$ participate in the reactions at the ABA/Al$_{2}$O$_{3}$ interface has been clarified. Another aspect of this work has been to determine the influence of various brazing parameters, such as the peak temperature, $\textit{T}$$_{p}$, and time at $\textit{T}$$_{p}$, $\tau$, on the resultant microstructure. As a consequence, the microstructural evolution of the joints as a function of $\textit{T}$$_{p}$ and $\tau$ is discussed in some detail. The formation of a Fe$_{2}$Ti layer on the Kovar$^{®}$ and its growth, along with adjacent Ni$_{3}$Ti particles in the ABA, dominate the microstructural developments at the ABA/Kovar$^{®}$ interface. The presence of Kovar$^{®}$ next to the ABA does not change the intrinsic chemical reactions occurring at the ABA/Al$_{2}$O$_{3}$ interface. However, the extent of these reactions is limited if the purity of the Al$_{2}$O$_{3}$ is high, and so it is necessary to have some silica-rich secondary phase in the Al$_{2}$O$_{3}$ to facilitate the formation of a Ti$_{3}$Cu$_{3}$O layer on the Al$_{2}$O$_{3}$. Breakdown of the Ti$_{3}$Cu$_{3}$O layer, together with fracture of the Fe$_{2}$Ti layer and separation of this layer from the Kovar$^{®}$, has been avoided by brazing at temperatures close to the liquidus temperature of the ABA for short periods of time, e.g. for $\textit{T}$$_{p}$ between 820 and 830 °C and $\tau$ between 2 and 8 min.We are grateful for the contribution and support for this study by AWE plc

Evolution of the interfacial phases in Al2_{2}O3_{3}–Kovar joints®^{®} brazed using a Ag–Cu–Ti-based alloy

A systematic investigation of the brazing of Al$_{2}$O$_{3}$ to Kovar$^{®}$ (Fe–29Ni–17Co wt.%) using the active braze alloy (ABA) Ag–35.25Cu–1.75Ti wt.% has been undertaken to study the chemical reactions at the interfaces of the joints. The extent to which silica-based secondary phases in the Al$_{2}$O$_{3}$ participate in the reactions at the ABA/Al$_{2}$O$_{3}$ interface has been clarified. Another aspect of this work has been to determine the influence of various brazing parameters, such as the peak temperature, $\textit{T}$$_{p}$, and time at $\textit{T}$$_{p}$, $\tau$, on the resultant microstructure. As a consequence, the microstructural evolution of the joints as a function of $\textit{T}$$_{p}$ and $\tau$ is discussed in some detail. The formation of a Fe$_{2}$Ti layer on the Kovar$^{®}$ and its growth, along with adjacent Ni$_{3}$Ti particles in the ABA, dominate the microstructural developments at the ABA/Kovar$^{®}$ interface. The presence of Kovar$^{®}$ next to the ABA does not change the intrinsic chemical reactions occurring at the ABA/Al$_{2}$O$_{3}$ interface. However, the extent of these reactions is limited if the purity of the Al$_{2}$O$_{3}$ is high, and so it is necessary to have some silica-rich secondary phase in the Al$_{2}$O$_{3}$ to facilitate the formation of a Ti$_{3}$Cu$_{3}$O layer on the Al$_{2}$O$_{3}$. Breakdown of the Ti$_{3}$Cu$_{3}$O layer, together with fracture of the Fe$_{2}$Ti layer and separation of this layer from the Kovar$^{®}$, has been avoided by brazing at temperatures close to the liquidus temperature of the ABA for short periods of time, e.g. for $\textit{T}$$_{p}$ between 820 and 830 °C and $\tau$ between 2 and 8 min.We are grateful for the contribution and support for this study by AWE plc

Active metal brazing of Al2_{2}O3_{3} to Kovar® (Fe–29Ni–17Co wt.%) using Copper ABA® (Cu–3.0Si–2.3Ti–2.0Al wt.%)

The application of an active braze alloy (ABA) known as Copper ABA® (Cu–3.0Si–2.3Ti–2.0Al wt.%) to join Al$_{2}$O$_{3}$ to Kovar® (Fe–29Ni–17Co wt.%) has been investigated. This ABA was selected to increase the operating temperature of the joint beyond the capabilities of typically used ABAs such as Ag–Cu–Ti-based alloys. Silica present as a secondary phase in the Al$_{2}$O$_{3}$ at a level of ~5 wt.% enabled the ceramic component to bond to the ABA chemically by forming a layer of Si$_{3}$Ti$_{5}$ at the ABA/Al$_{2}$O$_{3}$ interface. Appropriate brazing conditions to preserve a near-continuous Si$_{3}$Ti$_{5}$ layer on the Al$_{2}$O$_{3}$ and a continuous Fe$_{3}$Si layer on the Kovar® were found to be a brazing time of ≤15 min at 1025 °C or ≤2 min at 1050 °C. These conditions produced joints that did not break on handling and could be prepared easily for microscopy. Brazing for longer periods of time, up to 45 min, at these temperatures broke down the Si$_{3}$Ti$_{5}$ layer on the Al$_{2}$O$_{3}$, while brazing at ≥1075 °C for 2–45 min broke down the Fe$_{3}$Si layer on the Kovar® significantly. Further complications of brazing at ≥1075 °C included leakage of the ABA out of the joint and the formation of a new brittle silicide, Ni$_{16}$Si$_{7}$Ti$_{6}$, at the ABA/Al$_{2}$O$_{3}$ interface. This investigation demonstrates that it is not straightforward to join Al$_{2}$O$_{3}$ to Kovar® using Copper ABA®, partly because the ranges of suitable values for the brazing temperature and time are quite limited. Other approaches to increase the operating temperature of the joint are discussed.We are grateful for the financial support for this study provided by AWE

Spin-valve Josephson junctions with perpendicular magnetic anisotropy for cryogenic memory

We demonstrate a Josephson junction with a weak link containing two ferromagnets with perpendicular magnetic anisotropy and independent switching fields in which the critical current can be set by the mutual orientation of the two layers. Such pseudospin-valve Josephson junctions are a candidate cryogenic memory in an all superconducting computational scheme. Here, we use Pt/Co/Pt/CoB/Pt as the weak link of the junction with dCo=0.6 nm, dCoB=0.3 nm, and dPt=5 nm and obtain a 60% change in the critical current for the two magnetization configurations of the pseudospin-valve. Ferromagnets with perpendicular magnetic anisotropy have advantages over magnetization in-plane systems, which have been exclusively considered at this point, as, in principle, the magnetization and magnetic switching of layers in the junction should not affect the in-plane magnetic flux

Energy loss in a strongly coupled anisotropic plasma

We study the energy loss of a rotating infinitely massive quark moving, at constant velocity, through an anisotropic strongly-coupled N=4 plasma from holography. It is shown that, similar to the isotropic plasma, the energy loss of the rotating quark is due to either the drag force or radiation with a continuous crossover from drag-dominated regime to the radiation dominated regime. We find that the anisotropy has a significant effect on the energy loss of the heavy quark, specially in the crossover regime. We argue that the energy loss due to radiation in anisotropic media is less than the isotropic case. Interestingly this is similar to analogous calculations for the energy loss in weakly coupled anisotropic plasma.Comment: 26+1 pages, 10 figures, typos fixe

On the Beaming of Gluonic Fields at Strong Coupling

We examine the conditions for beaming of the gluonic field sourced by a heavy quark in strongly-coupled conformal field theories, using the AdS/CFT correspondence. Previous works have found that, contrary to naive expectations, it is possible to set up collimated beams of gluonic radiation despite the strong coupling. We show that, on the gravity side of the correspondence, this follows directly (for arbitrary quark motion, and independently of any approximations) from the fact that the string dual to the quark remains unexpectedly close to the AdS boundary whenever the quark moves ultra-relativistically. We also work out the validity conditions for a related approximation scheme that proposed to explain the beaming effect though the formation of shock waves in the bulk fields emitted by the string. We find that these conditions are fulfilled in the case of ultra-relativistic uniform circular motion that motivated the proposal, but unfortunately do not hold for much more general quark trajectories.Comment: 1+33 pages, 2 figure