Mechanisms of anticholinesterase-induced myopathy and its prevention

In the introduction a brief outline of the possible mechanisms involved in the process of cellular necrosis with particular emphasis on skeletal muscle necrosis after antiChE is discussed. Ecothiopate (ECO), an antiChE, was shown to produce dose-dependent inhibition of both AChE and BuChE in diaphragm and blood of mice. Inhibition of AChE resulted in dose-dependent influx of calcium at the junctional region with the consequent development of morphological and biochemical alterations. Non-necrotising doses of ECO caused hypercontractions of varying severity, distorted end plate and slight elevation of serum creatine kinase (CK). Necrotising doses of ECO further caused contraction clumps, loss of striations and procion staining with high serum CK. The extent of ECO-induced myopathy depended on entry of extracellular calcium rather than the degree of AChE inhibition. The essential Ca2+ mediated process(es) in ECO-induced myopathy was thought to be the generation of superoxide and superoxide-derived free radicals and/or lipid peroxidation. Mitochondria and xanthine oxidase may be the major contributors to the generation of superoxide. No evidence was found for the depletion of high energy phosphates. ECO-induced myopathy could be successfully prevented by prior administration of pyridostigmine or various antioxidants, the most effective being Vit E or Vit E + N-acetylcysteine. Allopurinol or N-acetylcysteine alone were also effective. However, the use of a wide range of membrane end plate channel blockers or non-quantal release blockers were unsuccessful in the prevention of ECO-induced myopathy

Asymmetrical Vortex over Slender Body A Computational Approach

Computational investigations were carried out on an ogive-cylinder configuration having a slenderness ratio of 7.5. The geometry of the nose tip was generated based on the physical geometry of the nose tip observed under a scanning electron microscope. Time-dependent simulations were performed on the slender body at a diameter Reynolds number of 3.0×104. Results indicated that the onset of vortex asymmetry was mainly due to the micro-tip imperfection existing at the tip. It was also observed that the variation in the roll angle of the model affected the flow physics largely which has been experimentally observed by several researchers in the past. The computed results were in better agreement with the referenced experimental data

Stability of nonlinear one-dimensional laser pulse solitons in a plasma

In a recent one-dimensional numerical fluid simulation study [Saxena et al., Phys. Plasmas 13,032309 (2006)], it was found that an instability is associated with a special class of one-dimensional nonlinear solutions for modulated light pulses coupled to electron plasma waves in a relativistic cold plasma model. It is shown here that the instability can be understood on the basis of the stimulated Raman scattering phenomenon and the occurrence of density bursts in the trailing edge of the modulated structures are a manifestation of an explosive instability arising from a nonlinear phase mixing mechanism.Comment: 17 pages, 7 figures, Published in Phys. Plasma

Faktor snage nanostrukturiranog bizmut telurida određen oblicima

Bismuth telluride is a thermoelectric material with high figure of merit, used for cooling applications at room temperature. To investigate the effect of morphology and grain size on transport parameters, nanostructured bismuth telluride has been synthesized under different reaction conditions and characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. From the measurement of electrical conductivity and thermoelectric power, power factor for different samples has been obtained. The results show that the transport parameters are critically influenced by the morphology and dimension of the samples that in turn depend on the condition of synthesis. The experimentally observed variation of electrical conductivity with the change of dimensionality of the samples from 2D to 0D, which is in line with the theoretical prediction made by other workers, is discussed. There is a variation of the power factor of the samples prepared under different conditions of synthesis.Bizmut telurid je termoelektrična tvar s visokom učinkovitošću koja se rabi za hlađenje na sobnim temperaturama. Radi istraživanja učinka oblika i veličine zrna na transportne parametre, sintetizirali smo nanostrukturirani bizmut telurid u različitim uvjetima i ispitivali rentgenskom difrakcijom, te propusnom i pretražnom elektronskom mikroskopijom. Mjerenjem električne vodljivosti i termoelektrične snage niza uzoraka odredili smo faktore snage. Ishodi analize pokazuju da transportni parametri jako ovise o obliku i veličini uzoraka, koji pak ovise o uvjetima njihove sinteze. Raspravljamo o opaženim promjenama električne vodljivosti ovisnim o dimenzionalnosti uzoraka od 2D do 0D i nalazimo sklad s teorijskim predviđanjima drugih autora. Nalazimo promjene faktora snage uzoraka pripremljenih uz različite uvjete sinteze

Faktor snage nanostrukturiranog bizmut telurida određen oblicima

Bismuth telluride is a thermoelectric material with high figure of merit, used for cooling applications at room temperature. To investigate the effect of morphology and grain size on transport parameters, nanostructured bismuth telluride has been synthesized under different reaction conditions and characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. From the measurement of electrical conductivity and thermoelectric power, power factor for different samples has been obtained. The results show that the transport parameters are critically influenced by the morphology and dimension of the samples that in turn depend on the condition of synthesis. The experimentally observed variation of electrical conductivity with the change of dimensionality of the samples from 2D to 0D, which is in line with the theoretical prediction made by other workers, is discussed. There is a variation of the power factor of the samples prepared under different conditions of synthesis.Bizmut telurid je termoelektrična tvar s visokom učinkovitošću koja se rabi za hlađenje na sobnim temperaturama. Radi istraživanja učinka oblika i veličine zrna na transportne parametre, sintetizirali smo nanostrukturirani bizmut telurid u različitim uvjetima i ispitivali rentgenskom difrakcijom, te propusnom i pretražnom elektronskom mikroskopijom. Mjerenjem električne vodljivosti i termoelektrične snage niza uzoraka odredili smo faktore snage. Ishodi analize pokazuju da transportni parametri jako ovise o obliku i veličini uzoraka, koji pak ovise o uvjetima njihove sinteze. Raspravljamo o opaženim promjenama električne vodljivosti ovisnim o dimenzionalnosti uzoraka od 2D do 0D i nalazimo sklad s teorijskim predviđanjima drugih autora. Nalazimo promjene faktora snage uzoraka pripremljenih uz različite uvjete sinteze

Aerosolized In Vivo 3D Localization of Nose-to-Brain Nanocarrier Delivery Using Multimodality Neuroimaging in a Rat Model—Protocol Development

The fate of intranasal aerosolized radiolabeled polymeric micellar nanoparticles (LPNPs) was tracked with positron emission tomography/computer tomography (PET/CT) imaging in a rat model to measure nose-to-brain delivery. A quantitative temporal and spatial testing protocol for new radio-nanotheranostic agents was sought in vivo. LPNPs labeled with a zirconium 89 (89Zr) PET tracer were administered via intranasal or intravenous delivery, followed by serial PET/CT imaging. After 2 h of continuous imaging, the animals were sacrificed, and the brain substructures (olfactory bulb, forebrain, and brainstem) were isolated. The activity in each brain region was measured for comparison with the corresponding PET/CT region of interest via activity measurements. Serial imaging of the LPNPs (100 nm PLA–PEG–DSPE+89Zr) delivered intranasally via nasal tubing demonstrated increased activity in the brain after 1 and 2 h following intranasal drug delivery (INDD) compared to intravenous administration, which correlated with ex vivo gamma counting and autoradiography. Although assessment of delivery from nose to brain is a promising approach, the technology has several limitations that require further development. An experimental protocol for aerosolized intranasal delivery is presented herein, which may provide a platform for better targeting the olfactory epithelium