A two-color dual-comb system for time-resolved measurements of ultrafast magnetization dynamics using triggerless asynchronous optical sampling.

We report on an Er-doped fiber (EDF)-laser-based dual-comb system that allows us to perform triggerless asynchronous optical sampling pump-probe measurements of ultrafast demagnetization and spin precession in magnetic materials. Because the oscillation frequencies of the two frequency-comb light sources are highly stabilized, the pulse-to-pulse timing jitter is sufficiently suppressed, and data accumulation without any trigger signals is possible. To effectively induce spin precession in ferromagnetic thin films, the spectral bandwidth of the output of one of the EDF frequency comb sources is broadened by a highly nonlinear fiber and then amplified at a wavelength of about 1030 nm by a Yb-doped fiber amplifier. The output of the other frequency comb source is converted to about 775 nm by second harmonic generation. We used this system to observe ultrafast demagnetization and spin precession dynamics on the picosecond and nanosecond time scales in a permalloy thin film. This time-domain spectroscopy system is promising for the rapid characterization of spin-wave generation and propagation dynamics in magnetic materials.

Differences between primary care physicians and specialised neurotologists in the diagnosis of dizziness and vertigo in Japan.

OBJECTIVE: Vertigo and dizziness are frequent symptoms in patients at out-patient services. An accurate diagnosis for vertigo or dizziness is essential for symptom relief; however, it is often challenging. This study aimed to identify differences in diagnoses between primary-care physicians and specialised neurotologists. METHOD: In total, 217 patients were enrolled. To compare diagnoses, data was collected from the reference letters of primary-care physicians, medical questionnaires completed by patients and medical records. RESULTS: In total, 62.2 per cent and 29.5 per cent of the patients were referred by otorhinolaryngologists and internists, respectively. The cause of vertigo or dizziness and diagnosis was missing in 47.0 per cent of the reference letters. In addition, 67.3 per cent of the diagnoses by previous physicians differed from those reported by specialised neurotologists. CONCLUSION: To ensure patient satisfaction and high quality of life, an accurate diagnosis for vertigo or dizziness is required; therefore, methods or materials to improve the diagnostic accuracy are needed.

Ankle fusion percutaneous home run screw fixation: Technical aspects and soft tissue structures at risk.

INTRODUCTION: The objective of this cadaveric study was to identify the number of attempts necessary for a perfect positioning of the ankle fusion home run screw and the neurovascular and tendinous structures at risk. METHODS: Eleven cadaveric limbs were used. Guidewires were percutaneously placed into the distal posterolateral aspect of the leg, under fluoroscopic guidance, with the ankle held in neutral position. Malpositioned guidewires were not removed and served as guidance for the following wires. The number of guidewires needed to achieve an acceptable positioning of the implant was noted. Neurovascular and tendinous injuries were assessed, and the shortest distance between the closest guidewire and the soft tissue structures was measured using a precision digital caliper. RESULTS: Mean number of guidewires needed to achieve acceptable positioning of the implant was 2.34 (SD 0.81, range 2-4). The mean distances between the closest guide pin and the soft tissue structures of interest were: Achilles tendon 5.35 mm (SD 2.74 mm); peroneal tendons 9.65 mm (SD 5.19 mm); posteromedial neurovascular bundle 12.78 mm (SD 7.14 mm). The sural bundle was in contact with the guide pin in 5/11 specimens (45.5%) and impaled in 3/11 specimens (27.3%). The average distance from the sural nerve bundle was 3.58 mm (SD 2.16 mm). CONCLUSIONS: The placement of percutaneous ankle fusion home run screws is technically demanding requiring multiple attempts for acceptable placement. Important tendinous and neurovascular structures are in close proximity to the guidewires. The sural bundle was either injured or in direct contact with the guide wire in approximately 73% of the cases. When using a home run screw, a mini-open approach is recommended. LEVEL OF EVIDENCE: Level V, cadaveric study.

Avaliação da estabilidade de máscaras faciais peel-off contendo rutina / Stability assessment of peel-off face masks containing rutin

Máscaras faciais peel-off baseiam-se em resinas vinílicas formadoras de filme. O álcool polivinílico (PVOH) é amplamente utilizado neste produto cosmético e interfere nas propriedades da película formada. A rutina, flavonóide da classe dos flavonóis, é empregadacomo potente antioxidante. O presente estudo contemplou como objetivo a avaliação da estabilidade física, físico-química e química de máscaras faciais peel-off contendo rutina, adicionada ou não de agente quelante, EDTA dissódico. Máscaras faciais peel-off foram desenvolvidas com 12,0% p/p de PVOH e 0,05% p/p de rutina. As amostras em estudo foram avaliadas quanto ao valor de pH, viscosidade aparente (cP) e teor da rutina remanescente nas amostras quantificada por espectrofotometria na derivada de primeira ordem a 410,0 nm, previamente validada; durante 45 dias nas seguintes condições de armazenamento: (1) 40,0 mais 0,5 ºC; (2) exposição à luz solar indireta e direta, à temperatura ambiente (22 mais 2 ºC); e (3) 5,0 mais 0,5 ºC. Verificou-se que a presença do EDTA Na2 (0,1% p/p) na formulação contribuiu para elevar a estabilidade da rutina nas condições de 22 mais ou menos 2 ºC e 5,0 mais ou menos 0,5 ºC. Sem a presença do agente quelante, o princípio ativo sofreu degradação em todas as temperaturas de armazenamento. Observou-se que valor de pH para ambas as preparações apresentou tendência para redução quando estas foram armazenadas a 40,0 mais ou menos 0,5 ºC, porém, não interferiu na estabilidade da rutina. Os resultados permitem concluir que o EDTA Na2 contribuiu para elevar a estabilidade do flavonóide na máscara facial peel-off elaborada com PVOH em condições consideradas normais e de temperaturas reduzidas de armazenamento (22 mais ou menos 2 ºC e 5,0 mais ou menos 0,5 ºC).