Synchronous Presentation of Ampullary Adenocarcinoma and Common Bile Duct Cancer: Report of a Case and Review of Literature

Context Ampullary adenocarcinomas and bile duct cancers represent a very small minority of all gastrointestinal malignancies. Synchronous presentation of both malignancies is extremely rare. Case report We report a case of a 76-year-old male who presented with painless jaundice. His work-up showed an ampullary mass and a separate common bile duct stricture. Attempted endoscopic resection established the diagnosis of ampullary adenocarcinoma. Pathologic examination of the Whipple specimen identified a separate focus of bile duct cancer. Conclusion Synchronous presentation of an ampullary mass and separate distal bile duct stricture, especially in elderly patients, should raise concern for both lesions representing malignancies. In the absence of conclusive evidence for survival advantage in resected early stage ampullary and biliary cancers, close observation should be considered a valid alternative to adjuvant chemotherapy and radiation.Image: EUS showing a hypoechoic oval mass in the ampulla

Thermal Plasma of Electric Arc Discharge Between Composite Cu-Cr Electrsodes: Optical Emission and Electrode Surface Interaction

This work deals with investigations of thermal plasma of electric arc discharge between sintered composite Cu-Cr electrodes, which can be used in electrical contacts of vacuum circuit breakers. Breaking arcs between composite Cu-Cr as well as single-component copper electrodes were used to study the electrical properties, plasma optical emission and electrodes surface modification behavior. In particular, the temporal evolution of plasma emission spectra of electric breaking arcs in air atmosphere was investigated by Optical Emission Spectroscopy (OES). Scanning Electron Microscopy (SEM) with Energy-dispersive X-ray Spectroscopy (EDXS) were applied to analyze the cross-section of working layer of electrodes surface modified by the heat flux from the discharge

Does social context impact metacognition? Evidence from stereotype threat in a visual search task

While recent studies have emphasized the role of metacognitive judgments in social interactions, whether social context might reciprocally impact individuals’ metacognition remains an open question. It has been proposed that such might be the case in situations involving stereotype threat. Here, we provide the first empirical test of this hypothesis. Using a visual search task, we asked participants, on a trial-by-trial basis, to monitor the unfolding and accuracy of their search processes, and we developed a computational model to measure the accuracy of their metacognition. Results indicated that stereotype threat enhanced metacognitive monitoring of both outcomes and processes. Our study thus shows that social context can actually affect metacognition

Plasma-surface interaction of electric arc discharge between composite Cu-Cr electrodes

In this work the plasma of electric arc discharges between Cu-Cr composite electrodes, which material were pressured and sintered at different temperatures 750 or 1050°C, are investigated by Optical Emission Spectroscopy (OES). The Scanning Electron Microscopy (SEM) with Energy-Dispersive X-ray Spectroscopy (EDXS) are used to study the working surface of electrodes, modified by thermal effect of breaking electrical arc in the air atmosphere. The erosion intensity of electrodes’ material due to plasma-surface interaction is estimated in indirect way by determination of metal vapours content in the discharge gap in an assumption of local thermodynamic equilibrium (LTE). The plasma composition is calculated in this case on the base of experimentally determined plasma parameters: temperature and electron density.Методами оптичної емісійної спектроскопії досліджується плазма електродугових розрядів між композитними Cu-Cr-електродами, матеріал яких y процесі виготовлення піддавався пресуванню та спіканню при різних температурах: 750 або 1050°C. Для дослідження робочої поверхні електродів, які зазнали впливу термічної дії розривної електричної дуги в атмосфері повітря, використовується скануюча електронна мікроскопія (СЕМ), доповнена енергодисперсійною рентгенівською спектроскопією (ЕДРС). Інтенсивність ерозії матеріалу електродів внаслідок взаємодії плазма-поверхня оцінювалась у непрямий спосіб шляхом визначення вмісту парів металів у розрядному проміжку в припущенні локальної термодинамічної рівноваги (ЛТР). Склад плазми в даному випадку розрахований з експериментально отриманих параметрів плазми: температури та електронної концентрації.Методами оптической эмиссионной спектроскопии (ОЭС) исследуется плазма электродуговых разрядов между композитными Cu-Cr- электродами, материал которых в процессе изготовления подвергался прессованию и спеканию при разных температурах: 750 или 1050°C. Для изучения рабочей поверхности электродов, подвергающейся термическому воздействию разрывной электрической дуги в атмосфере воздуха, использована сканирующая электронная микроскопия (СЭМ), дополненная энергодисперсионной рентгеновской спектроскопией (ЭДРС). Интенсивность эрозии материала электродов вследствие взаимодействия плазма-поверхность оценивалась косвенным методом путем определения содержания паров металлов в разрядном промежутке в предположении локального термодинамического равновесия (ЛТР). Состав плазмы в этом случае рассчитан из экспериментально полученных параметров: температуры и электронной концентрации

Welding dynamics in an atomistic model of an amorphous polymer blend with polymer-polymer interface

We consider an atomistic model of thermal welding at the polymer-polymer interface of a polyetherimide/polycarbonate blend, motivated by applications to 3D manufacturing in space. We follow diffusion of semiflexible chains at the interface and analyze strengthening of the samples as a function of the welding time tw by simulating the strain-stress and shear viscosity curves. The time scales for initial wetting, and for fast and slow diffusion, are revealed. It is shown that each component of the polymer blend has its own characteristic time of slow diffusion at the interface. Analysis of strainstress demonstrates saturation of the Young’s modulus at tw = 240 ns, while the tensile strength continues to increase. The shear viscosity is found to have a very weak dependence on the welding time for tw > 60 ns. It is shown that both strain-stress and shear viscosity curves agree with experimental data

COVID-19 pandemic: Impact caused by school closure and national lockdown on pediatric visits and admissions for viral and non-viral infections, a time series analysis.

A time series analysis of 871,543 pediatric emergency visits revealed that the COVID-19 lockdown and school closure were associated with a significant decrease in infectious diseases disseminated through airborne or fecal-oral transmissions: common cold, gastro-enteritis, bronchiolitis, acute otitis. No change was found for urinary tract infections

Effectiveness of Chest Physiotherapy in Infants Hospitalized with Acute Bronchiolitis: A Multicenter, Randomized, Controlled Trial

Vincent Gajdos and colleagues report results of a randomized trial conducted among hospitalized infants with bronchiolitis. They show that a physiotherapy technique (increased exhalation and assisted cough) commonly used in France does not reduce time to recovery in this population

Myasthenia gravis

Myasthenia gravis (MG) is a rare, autoimmune neuromuscular junction disorder. Contemporary prevalence rates approach 1/5,000. MG presents with painless, fluctuating, fatigable weakness involving specific muscle groups. Ocular weakness with asymmetric ptosis and binocular diplopia is the most typical initial presentation, while early or isolated oropharyngeal or limb weakness is less common. The course is variable, and most patients with initial ocular weakness develop bulbar or limb weakness within three years of initial symptom onset. MG results from antibody-mediated, T cell-dependent immunologic attack on the endplate region of the postsynaptic membrane. In patients with fatigable muscle weakness, the diagnosis of MG is supported by: 1. pharmacologic testing with edrophonium chloride that elicits unequivocal improvement in strength; 2. electrophysiologic testing with repetitive nerve stimulation (RNS) studies and/or single-fiber electromyography (SFEMG) that demonstrates a primary postsynaptic neuromuscular junctional disorder; and 3. serologic demonstration of acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK) antibodies. Differential diagnosis includes congenital myasthenic syndromes, Lambert Eaton syndrome, botulism, organophosphate intoxication, mitochondrial disorders involving progressive external ophthalmoplegia, acute inflammatory demyelinating polyradiculoneuropathy (AIDP), motor neuron disease, and brainstem ischemia. Treatment must be individualized, and may include symptomatic treatment with cholinesterase inhibitors and immune modulation with corticosteroids, azathioprine, cyclosporine, and mycophenolate mofetil. Rapid, temporary improvement may be achieved for myasthenic crises and exacerbations with plasma exchange (PEX) or intravenous immunoglobulin (IVIg). Owing to improved diagnostic testing, immunotherapy, and intensive care, the contemporary prognosis is favorable with less than five percent mortality and nearly normal life expectancy