The Dynamic Formation of Prominence Condensations

We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

Post Operative Fungal Endopthalmitis Due to \u3cem\u3eGeotrichum candidum\u3c/em\u3e

Geotrichum species have been rarely reported as the cause of sepsis, disseminated infection in immunosuppressed patients. The patient we describe developed indolent endophthalmitis four months after her routine right eye cataract surgery. The intraoperative sample from right vitreous fluid grew Geotrichum candidum. The patient underwent vitrectomy, artificial lens explantation and intravitreal injection of amphotericin B followed by oral voriconazole. Despite these interventions, she underwent enucleation. This is the first published case of Geotrichum candidum endophthalmitis

Degradation of Plasticised Poly(lactide) Composites with Nanofibrillated Cellulose in Different Hydrothermal Environments

In this study, bionanocomposite films based on poly(lactide) (PLA) plasticised with poly(ethylene glycol) (PEG) (7.5 wt%) and reinforced with various contents of nanofibrillated cellulose (NFC) (1, 3, 5 wt%) were prepared. The hydrothermal degradation was investigated through immersion in several aqueous environments at temperatures of 8, 23, 58, and 70 °C as a function of time (7, 15, 30, 60, 90 days). The effect of water immersion on the physicochemical properties of the materials was assessed by monitoring the changes in the morphology, thermo-oxidative stability, thermal properties, and molar mass through field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). The hydrothermal degradation behaviour was not critically affected regardless of the nanofibrillated cellulose content. All the materials revealed certain integrity towards water immersion and hydrolysis effects at low temperatures (8 and 23 °C). The low hydrothermal degradation may be an advantage for using these PLA biocomposites in contact with water at ambient temperatures and limited exposure times. On the other hand, immersion in water at higher temperatures above the glass transition (58 and 70 °C), leads to a drastic deterioration of the properties of these PLA-based materials, in particular to the reduction of the molar mass and the disintegration into small pieces. This hydrothermal degradation behaviour can be considered a feasible option for the waste management of PLA/PEG/NFC bionanocomposites by deposition in hot aqueous environments

Effect of Dendritic Side Groups on the Mobility of Modified Poly(epichlorohydrin) Copolymers

[EN] The macromolecular dynamics of dendronized copolymer membranes (PECHs), obtained by chemical modification of poly(epichlorohydrin) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy] benzoate, was investigated. In response to a thermal treatment during membrane preparation, these copolymers show an ability to change their shape, achieve orientation, and slightly crystallize, which was also observed by CP-MAS NMR, XRD, and DSC. The phenomenon was deeply analyzed by dielectric thermal analysis. The dielectric spectra show the influence of several factors such as the number of dendritic side groups, the orientation, their self-assembling dendrons, and the molecular mobility. The dielectric spectra present a sub-Tg dielectric relaxation, labelled as gamma, associated with the mobility of the benzyloxy substituent of the dendritic group. This mobility is not related to the percentage of these lateral chains but is somewhat hindered by the orientation of the dendritic groups. Unlike other less complex polymers, the crystallization was dismantled before the appearance of the glass transition (alpha(Tg)). Only after that, clearing transition (alpha(Clear)) can be observed. The PECHs were flexible and offered a high free volume, despite presenting a high degree of modifications. However, the molecular mobility is not independent in each phase and the self-assembling dendrons can be eventually fine-tuned according to the percentage of grafted groups.This research was funded by the Spanish Ministry of Science, Innovation and Universities, grant POLYDECARBOCELL (ENE2017-86711-C3-1-R, ENE2017-86711-C3-3-R).Teruel Juanes, R.; Pascual-Jose, B.; Graf, R.; Reina, JA.; Giamberini, M.; Ribes-Greus, A. (2021). Effect of Dendritic Side Groups on the Mobility of Modified Poly(epichlorohydrin) Copolymers. Polymers. 13(12):1-19. https://doi.org/10.3390/polym13121961119131

Agelastatin A, a new skeleton cytotoxic alkaloid of the oroidin family : isolation from the Axinellid sponge Agelas dendromorpha of the Coral Sea

Agelastatin A, isolated from the axinellid sponge #Agelas dendromorpha$ of the Coral Sea, is a new skeleton alkaloid with, unusually for the oroidin family to which it belongs, marked cytototoxicity toward tumour cells in culture. (Résumé d'auteur

Anatomic and computed tomographic atlas of the head of the newborn bottlenose dolphin (Tursiops truncatus)

The head of a newborn dolphin (Tursiops truncatus), that died shortly after birth was imaged using computed tomography (CT). Gross cross-sectional slices of the head were compared with the CT images to identify normal structures of the cranium, brain, and respiratory and digestive pathways. Labelled transverse CT images of the dolphin head are presented sequentially as a reference for normal anatomy

Rotura del ligamento deltoideo del tobillo: evaluación clínico-quirúrgica

No existe un criterio uniforme sobre la conduct a a seguir en el tratamient o de la rotur a del ligamento deltoideo del tobillo. Se ha n revisado 36 paciente s diagnosticados y tra - tado s quirúrgicament e de rotur a de dicho ligamento, la mayorí a de la s veces est a lesión iba acompañad a de fractur a del maleolo peroneo. Se ha valorado la etiología, el mecanismo lesional y los resultados siguiendo la clasificación de Cedell, considerándos e estos últimos como buenos en la práctic a totalidad de los casos. En cuatro de los paciente s (11%), se presentó como únic a secuela la limitación de la movilidad en los últimos grados de flexo-extensiónUniform criteria about the actions to be taken in the tearing of the ankle deltoid ligament d o no t exist. Thirt y si x patients diagnose d an d surgicall y treate d becaus e o f th e tearin g o f th e abov e mentione d ligamen t hav e bee n reviewed . Most o f th e times, this lesio n wa s accompanie d b y a fractur e o f th e peronea l maleolus. Etiology , injur y mechanism s an d results followin g Cedell's clasificatio n hav e bee n evaluate d an d th e results hav e bee n considere d goo d i n practicall y all cases. I n fou r patients, th e onl y secuel a wa s a limitatio n o f th e most extrem e grade s o f flexo-extension

Structure–Properties Relationship of Reprocessed Bionanocomposites of Plasticized Polylactide Reinforced with Nanofibrillated Cellulose

Bionanocomposites of polylactide (PLA), plasticized with poly(ethylene glycol) (PEG) (7.5 wt%, 400 and 1500 g/mol) and reinforced with nanofibrillated cellulose (NFC) (1, 3, and 5 wt%) were sequentially compounded, and injection and compression molded. All of the stages caused structural and morphological consequences, more relevant in the plasticized PLA, especially with low molar PEG. Small percentages of NFC (1 and 3 wt%) acted as crystalline nucleating agents and improved thermo-oxidative stability. Given the substantial degradation caused by (re)processing, a downgrading validation strategy was applied, assessing the mechanical and water contact performance during fictional first and second service life applications. After the first processing, PEG increased the ductility and reduced the strength and elastic modulus, while NFC buffered the fall in stiffness and increased rigidity compared to their PLA-PEG counterparts. Once reprocessed, PEG increased the water affinity of the blend, especially for low molar mass PEG. Low percentages of NFC (1 and 3 wt%) modulated water diffusivity and permeability, regardless of the water temperature. Overall, although reprocessing caused significant degradation, the mechanical valorization possibilities of these green bionanocomposites were proven, and are pointed out as sustainable candidates for food packaging or agricultural applications where modulated mechanical or water contact behaviors are required

Performance of Sulfonated Poly(Vinyl Alcohol)/Graphene Oxide Polyelectrolytes for Direct Methanol Fuel Cells

The use of nanotechnology along with the consideration of a functionalization and stabilization approach to poly(vinyl alcohol) (PVA) is considered useful for the preparation of cost-effective polyelectrolyte membranes. A set of nanocomposite and crosslinked membranes based on PVA/sulfosuccinic acid (SSA)/graphene oxide (GO) are prepared and analyzed as polyelectrolytes in direct methanol fuel cells (DMFCs). The crosslinking and sulfonation by the use of SSA enhances the stability and increase the proton-conducting sites in the PVA structure. The presence of GO augments the stability, remarkably decreases the methanol crossover, and enhances power density curves. An optimum value for proton conductivity is found for the 0.50 wt% of GO proportion, which decreases with higher concentrations of GO. Given the power density curve dependency on both the proton conductivity and the crossover reduction, the performance of these membranes as polyelectrolytes in DMFCs is strictly related to the balance between both factors. Therefore, a proportion of GO of 0.75 wt% may assure suitable proton conductivity of 3 mS cm−1 and high resistance to methanol permeability, reaching promising power density of 16 mW cm−2 with lower hydration levels