102,173 research outputs found
Resolution of the enantiomers of verapamil and gallopamil by chiral liquid chromatography mass spectrometry
No full textAn HPLC-CSP method has been developed for the separation of enantiomers of verapamil and gallopamil using the improved version of the alpha(1)-acid glycoprotein, chiral stationary phase as selector with a volatile mobile phase. The results of the investigation provide the conditions which allow direct coupling to a mass spectrometer. In addition, the simultaneous enantioseparation of both the enantiomeric pairs of verapamil and gallopamil was achieved
Dehydroepiandrosterone Sulfate, Dehydroepiandrosterone, 5α-Dihydroprogesterone and Pregnenolone: Serum Analysis and Correlation Between Migraine and Non-headache Control Females
No full textMigraine is a very painful and disabling disorder of the nervous system (NS) affecting about 10% of the world's adult population, especially women and it is associated with a variety of comorbidities [1, 2]. Neuroactive steroids have pleiotropic actions on the NS. Alterations in their peripheral and central levels could be involved in the pathogenesis, still not fully understood, of migraine and its comorbidities [3]. The purpose of our exploratory study (approved by Modena Ethical Committee) was to determine serum levels of dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 5α-dihydroprogesterone (DHP) and pregnenolone (PREGNE) in women suffering from migraine without aura (n=30) and age-matched non-headache control females (n=30). The patients were enrolled at the Headache Centre of Modena; controls were patients’ contacts. Calibrators and serum samples were spiked with the ISs solution and treated to deplete proteins and phospholipids. The obtained extracts were evaporated to dryness, derivatized and analysed by RP-LC-ESI-MS/MS in MRM mode. Analyte’s levels were determined by interpolation on the regression curves, generated from the analyte quantifier ion peak area to the corresponding IS. Migraine women presented significantly lower levels of DHEAS, DHEA and DHP compared to controls (P<0.05) and the found concentrations negatively correlated with migraine history, and migraine days in the last three months (P< 0.05). These results parallel to our previous studies showing reduced serum levels of allopregnanolone and pregnenolone sulfate in migraine women [4,5]. The low serum levels found for both inhibitory and excitatory neurosteroids indicate that migraine women may suffer from inadequate neuroprotection, anti-inflammation activity and pain modulation. These deficits could represent the link between migraine and its various comorbidities.
References
[1] Headache classification Committee of the International Headache Society (IHS). Cephalalgia 2018, 38,1–211.
[2] Yin JH., Lin YK., Yang CP., et al. Headache 2021. doi: 10.1111/head.14106. Online ahead of print.
[3] Yilmaz, C.; Karali, K.; Fodelianaki, G.; et al. Front Neuroendocrinol 2019, 55, 100788.
[4] Rustichelli, C.; Bellei, E.; Bergamini, S.; et al. Cephalalgia 2020, 40, 1355-1362.
[5] Rustichelli, C.; Bellei, E.; Bergamini, S.; et al. J Head Pain 2021, 22, 13
Neutron diffraction measurements of residual stresses in a thermoelastically coupled AL6082 alloy system.
No full textPubl. Netherlands Society for Materials Scienc
Reconfiguring the boundaries of a mesh-connected array of processors with run-time programmable logic
No full textFine grain mesh-connected arrays of processors with a SIMD architecture are considered an attractive solution for many important and emerging real-time data handling applications that require high speed processing of dynamic data sampled over a bidimensional region. Nevertheless, even if the interconnections between the arrays' adjacent nodes are well suited to those applications that may be handled by neighbour based algorithms, the SIMD computational model is, in general terms, still not flexible. Furthermore, the limited size of economically viable arrays calls for a severe overhead in data transfer and array boundary data handling that may impair the system's efficiency. Without modifying the arrays' internal structure, most algorithms could overcome some of their implementation drawbacks with a flexible, fast switching facility on the array boundary. This article presents a 'boundary processor' based on programmable gate arrays whose aim is to dynamically activate the required boundary interconnection pattern either under software control or through an on-line hardware reconfiguration facility. The device has been designed and implemented at the University of Bologna as part of a computer vision machine for robotic applications. © 1993
A study of the transitions smetic A - Hexatic B and Hexatic B - Crytal B by X-ray diffraction
No full textNew combined treatment of hypermelanosis: analytical studies on efficacy and stability improvement
No full textThe aim of this work was to evaluate the synergybetween di¡erent lightening agents when associated;depigmenting activity was tested in vitro bymonitoring the appearance of dopachrome, an intermediatein the melanogenesis process. The resultsobtained were compared with the depigmentingactivity of each single compound, keeping the sameglobal concentration of inhibitor.Our studies showed that the combinationof hydroquinoneand kojic acid had a synergistic e¡ect, andthat the maximum inhibiting action was achievedwith an equimolecular mixture. This result couldserve inthe cosmetics ¢eld to prepare skin-lighteningformulations that are less irritant.We also investigated the feasibility of complexinghydroquinone with cyclodextrin and evaluated thee¡ectiveness of the complex obtained in the treatmentof hyperpigmentation
Analysis of design methodology with logic cell arrays
No full textField Programmable Gale Arrays (FPGA) are becoming popular as an alternative to ASIC because of their good price/performance ratio in terms of speed and flexibility and ease of design implementation especially in the prototype phase. This paper analyses FPGA design both from the methodology and optimization techniques points of view. As an example the paper describes in detail the design optimization adopted for an array processor control unit which is characterized by a very large number of signals and repetitive architecture. The logic complexity and the corresponding simulation has led to choose an LCA (XIUNX) instead of a gate-array Ixised design. All design phases are discussed and a comparison with other design methodologies is presented
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