Controllable X-Ray Pulse Trains from Enhanced Self-Amplified Spontaneous Emission.

We report the demonstration of optical compression of an electron beam and the production of controllable trains of femtosecond, soft x-ray pulses with the Linac Coherent Light Source (LCLS) free-electron laser (FEL). This is achieved by enhanced self-amplified spontaneous emission with a 2 µm laser and a dechirper device. Optical compression was achieved by modulating the energy of an electron beam with the laser and then compressing with a chicane, resulting in high current spikes on the beam which we observe to lase. A dechirper was then used to selectively control the lasing region of the electron beam. Field autocorrelation measurements indicate a train of pulses, and we find that the number of pulses within the train can be controlled (from 1 to 5 pulses) by varying the dechirper position and undulator taper. These results are a step toward attosecond spectroscopy with x-ray FELs as well as future FEL schemes relying on optical compression of an electron beam.

A Potential Interaction Between Bisphosphonates and Osseointegration of Bone-Anchored Hearing Aid Implants Leading to Late Device Extrusion.

Bisphosphonate therapy is commonly used to treat patients suffering from osteoporosis due to its clinical effectiveness and its generally benign safety profile; however, osteonecrosis of the jaw is a rare side effect that can occur in some patients. A far less elucidated area of concern is the effect of these medications on osseointegrated implants, which require adequate bone formation to ensure long-term viability of the implant. To date, there are no reports in the otolaryngology literature examining the interplay between osteoporosis, bisphosphonate therapy, and osseointegrated bone-anchored hearing aids (BAHA). In this case report, we describe an osteoporotic patient on bisphosphonates experiencing late bilateral failure of her osseointegrated BAHA implants shortly after starting therapy. Certainly, direct causality cannot be determined from this single report, but the temporal relationship described in this case suggests a potential interaction between bisphosphonate use and delayed failure of the osseointegrated hearing devices. Consequently, otolaryngologists who implant osseointegrated hearing devices should consider offering preoperative counseling to patients receiving bisphosphonate therapy.

Excision of a sclerosing polycystic adenosis of the deep parotid gland.

A 15-year-old male presented to the hospital with a 2-month history of a right parotid mass. Magnetic resonance imaging revealed an encapsulated 3.7 cm mass. Fine-needle aspiration suggested a monomorphic adenoma (prior to utilization of the Milan Classification system). Total parotidectomy was performed with dissection and preservation of the facial nerve. Surgical pathology identified the lesion as sclerosing polycystic adenosis (SPA) after examining the histopathological and immunohistochemistry findings. SPA is a rare lesion which leads to inflammatory changes in the salivary gland. The most common site impacted is the parotid gland but also can affect other major or minor salivary glands. The fibrocystic changes are morphologically like the histological developments of sclerosing adenosis of breast tissue. Those changes consist of fibrosis, apocrine metaplasia, and different degrees of proliferation of ducts, acini, and myoepithelial cells. The pathogenesis of SPA is unknown but recent studies suggest that it could be a neoplasm. Treatment with surgical excision is effective and its' recurrence is rare. This case report details the cytomorphology, histology, and immunohistochemical profile of SPA.

Demographic Differences in Clinical Presentation of Pediatric Paradoxical Vocal Fold Motion (PVFM).

OBJECTIVES: Paradoxical vocal fold motion (PVFM) is involuntary closure of the vocal folds during inspiration, often presenting in children and young adults. Although common symptoms and triggers are known, differences in clinical presentation based on patient demographics are unknown. This study characterizes differences in clinical presentation of pediatric PVFM based on age, sex, and race/ethnicity. METHODS: We reviewed electronic medical records of patients 0-21 years old with PVFM based on ICD codes from 2009 to 2019 within a tertiary academic health system. Demographics, symptoms, triggers, concurrent diagnoses, and laryngoscopy findings were abstracted. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using logistic regression. RESULTS: Among 96 individuals the mean age was 10.6 years (standard deviation ±6.5) and 66 (69%) were female. In comparison to 13-21 year olds, those 0-2 years more often had PVFM observed on laryngoscopy (OR = 17.84, 95% CI: 3.14-101.51) and had less shortness of breath (OR = 0.01, 95% CI: 0.00-0.09). Those 3-12 years had more asthma (OR = 3.07, 95% CI: 1.07-8.81) and cough (OR = 6.12, 95% CI: 1.77-21.13). Both 0-2 (OR = 0.07, 95% CI: 0.02-0.24) and 3-12 year olds (OR = 0.13, 95% CI: 0.04-0.40) presented less with activity as a trigger. Racial/ethnic minorities were more likely to present with pharyngeal findings (eg mucosal inflammation, adenotonsillar hypertrophy) on laryngoscopy (OR = 4.58, 95% CI: 1.45-15.37) compared to non-Hispanic Whites. Differences in clinical presentation by sex were not observed. CONCLUSION: We identified several differences in symptoms, triggers, and laryngoscopy findings in pediatric PVFM based on age and race/ethnicity. Associations between sex and clinical presentation were not observed.

N-(5-chloro-2-(hydroxymethyl)-N-alkyl-arylsulfonamides as gamma-secretase inhibitors.

A series of N-alkylbenzenesulfonamides were developed from a high throughput screening hit. Classic and parallel synthesis strategies were employed to produce compounds with good in vitro and in vivo gamma-secretase activity.