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Background: Procedural analgesia is essential for burn-injured patients. Ketamine is the cornerstone of many procedural analgesia protocols for children as it is safe and effective. However, it requires monitoring and the child may remain sedated for a number of hours. We sought an alternative analgesic option. Methoxyflurane is an inhalational analgesic with rapid onset of action for short term analgesia. There is little literature on the use of this drug in children in South Africa, particularly in burns patients. This paper describes our introduction of methoxyflurane into our procedural analgesia protocols for pain associated with dressing changes for paediatric burns. Methods: We performed a retrospective review of data from the burns database for a two-month period after the addition of methoxyflurane to the paediatric burn outpatient procedural analgesia protocol as the first line analgesia option. Results: Ninety-five children were reviewed in the clinic over the two-month period. Thirty patients did not require analgesia for their dressing changes. Methoxyflurane provided effective analgesia in 49/65 (75%) patients. Conclusion: This study has shown that methoxyflurane is a viable option for analgesia for burns dressing changes in a busy outpatient setting. It is an effective and safe alternative to ketamine. Further research is required into the use of methoxyflurane in other burns settings to clarify predictors of failure, ease of use and possible side effect profiles. The full articles is available at https://doi.org/10.36303/SAJAA.2020.26.5.2311

Stony coral tissue loss disease (SCTLD) is decimating Caribbean corals. Here, through the metatranscriptomic assembly and annotation of two alphaflexivirus-like strains, we provide genomic evidence of filamentous viruses in SCTLD-affected, -exposed, and -unexposed coral colonies. These data will assist in clarifying the roles of viruses in SCTLD.

Erbium-doped gallium nitride (Er:GaN) is a promising gain material for solid-state high-energy lasers operating in the 1.5 μm wavelength window due to the superior optical properties and extremely high thermal conductivity of a GaN host crystal that permit high-power and high-temperature applications. We report the realization of all-crystalline GaN/Er:GaN/GaN embedded waveguide fiber structures using the hydride vapor phase epitaxy growth and re-growth technique, along with chemical–mechanical polishing processes. The Er:GaN core layer possesses an Er doping concentration of [Formula: see text] atoms/cm3, confirmed by secondary ion mass spectrometry measurements. X-ray diffraction measurements confirm, respectively, c-, a-, and m-plane orientations for top/bottom, side, and front/back cross-sectional cladding layers of the fiber structure with good single-crystalline quality. The 1.5 μm Er3+ emission was detected from each surface of the fiber structures via 980 nm resonant excitation. The effect of 1.54 μm light guiding by the fiber structure has been demonstrated. This work laid the foundation toward achieving all-crystalline core-cladding fibers based on GaN wide bandgap semiconductor with potential applications in the harsh environments of high powers, power densities, and temperatures.

Erbium doped GaN (Er:GaN) is a promising candidate as a novel gain medium for solid-state high energy lasers (HELs) due to its superior physical properties over a synthetic garnet such as Nd:YAG. Er:GaN emits in the 1.5 µm region, which is retina-safe and has a high transmission in the air. We report photoluminescence (PL) studies performed on Er:GaN epilayers synthesized by the hydride vapor phase epitaxy (HVPE) technique. The room temperature PL spectra of HVPE grown Er:GaN epilayers resolved as many as 11 and seven emission lines in the 1.5 µm and 1.0 µm wavelength regions, respectively, corresponding to the intra-4f shell transitions between Stark levels from the first (4I13/2) and the second (4I11/2) excited states to the ground state (4I15/2) of Er3+ in GaN. The observed peak positions of these transitions enabled the construction of the detailed energy levels in Er:GaN. The results agree well with those of the calculation based on a crystal field analysis. Precise determination of the detailed energy levels of the Stark levels in the 4I11/2, 4I13/2, and 4I15/5 states is critically important for the realization of HELs based on Er:GaN.

Erbium-doped GaN (Er:GaN) quasi-bulk crystals are emerging as a promising novel gain medium for high energy lasers emitting at the retina-safe wavelength window of 1.5 μm. We report the polarization-resolved photoluminescence (PL) emission spectroscopy studies, which revealed that the pumping efficiency with the excitation polarization parallel to the c-axis of GaN ( E ⇀ | | c ⇀ ) is significantly higher than that with the excitation polarization perpendicular to the c-axis of GaN ( E ⇀ ⊥ c ⇀ ). This phenomenon is a direct consequence of the inherent polar wurtzite GaN lattice, giving rise to a net local field, surrounding each Er ion, along the c-axis of GaN. The temperature dependent behaviors of the PL emission spectra were explained in terms of the Boltzmann population distributions among sublevels within the 4I15/2 ground state and the 4I13/2 first excited state of Er3+ in GaN, thereby providing an improved understanding regarding the origin of the dominant emission lines observed near 1.5 μm. The results suggested that the polarization field in GaN can be exploited to enhance the effective Er excitation cross section by manipulating the polarization of the excitation light source.

The onslaught of foreign antigens carried by spermatozoa into the epididymis, an organ that has not demonstrated immune privilege, a decade or more after the establishment of central immune tolerance presents a unique biological challenge. Historically, the physical confinement of spermatozoa to the epididymal tubule enforced by a tightly interwoven wall of epithelial cells was considered sufficient enough to prevent cross talk between gametes and the immune system and, ultimately, autoimmune destruction. The discovery of an intricate arrangement of mononuclear phagocytes (MPs) comprising dendritic cells and macrophages in the murine epididymis suggests that we may have underestimated the existence of a sophisticated mucosal immune system in the posttesticular environment. This review consolidates our current knowledge of the physiology of MPs in the steady state epididymis and speculates on possible interactions between auto-antigenic spermatozoa, pathogens and the immune system by drawing on what is known about the immune system in the intestinal mucosa. Ultimately, further investigation will provide valuable information regarding the origins of pathologies arising as a result of autoimmune or inflammatory responses in the epididymis, including epididymitis and infertility.

Erbium doped gallium nitride (Er:GaN) bulk crystals have emerged as a promising optical gain material for high energy lasers (HELs) operating at the 1.5 μm “retina-safe” spectral region. Among the many designs of HEL gain medium, the core-cladding planar waveguide (PWG) structure is highly desired due to its abilities to provide excellent optical confinement and heat dissipation. We report the realization of a GaN/Er:GaN/GaN core-cladding PWG structure synthesized by hydride vapor phase epitaxy and processed by mechanical and chemical-mechanical polishing. An Er doping concentration of [Er] = 3 × 1019 atoms/cm3 has been attained in the core layer, as confirmed by secondary ion mass spectrometry measurements. A strong 1.54 μm emission line was detected from the structure under 980 nm resonant excitation. It was shown that these PWGs can achieve a 96% optical confinement in the Er:GaN core layer having a thickness of 50 μm and [Er] = 3 × 1019 atoms/cm3. This work represents an important step toward the realization of practical Er:GaN gain medium for retina-safe HEL applications.Erbium doped gallium nitride (Er:GaN) bulk crystals have emerged as a promising optical gain material for high energy lasers (HELs) operating at the 1.5 μm “retina-safe” spectral region. Among the many designs of HEL gain medium, the core-cladding planar waveguide (PWG) structure is highly desired due to its abilities to provide excellent optical confinement and heat dissipation. We report the realization of a GaN/Er:GaN/GaN core-cladding PWG structure synthesized by hydride vapor phase epitaxy and processed by mechanical and chemical-mechanical polishing. An Er doping concentration of [Er] = 3 × 1019 atoms/cm3 has been attained in the core layer, as confirmed by secondary ion mass spectrometry measurements. A strong 1.54 μm emission line was detected from the structure under 980 nm resonant excitation. It was shown that these PWGs can achieve a 96% optical confinement in the Er:GaN core layer having a thickness of 50 μm and [Er] = 3 × 1019 atoms/cm3. This work represents an important step toward the real...

The NPDGamma experiment measures the parity-violating (PV) gamma asymmetry from polarized cold neutrons captured on protons at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The (PV) neutron spin asymmetry A γ of photons from polarized cold neutron capture on protons is proportional to the ΔI=1 long range weak meson coupling $h_{\pi }^{1}$ between nucleons in the hadronic weak interaction (HWI). Liquid para-hydrogen production data taking concluded in April 2014 and once the background aluminum asymmetry measurements are complete, the PV asymmetry A γ can be extracted. Preliminary results of the analysis of A γ are presented.