Solvay

About: Solvay is a company organization based out in Brussels, Belgium. It is known for research contribution in the topics: Catalysis & Polymer. The organization has 6083 authors who have published 7004 publications receiving 105745 citations.

Structure and Ferroelectric Properties of Nanoimprinted Poly(vinylidene fluoride-ran-trifluoroethylene)

Abstract: Nanoimprint lithography (NIL) was used to shape thin films of a ferroelectric copolymer of vinylidene fluoride and trifluoroethylene (PVDF-TRFE), using a variety of molding shapes and imprinting conditions. The morphology of the layers was characterized by atomic force microscopy (AFM), and preferential orientation of the crystallographic axes was monitored by infrared microspectroscopy; in addition, the local ferroelectric properties were obtained by piezoresponse force microscopy (PFM). When the sample is imprinted in its paraelectric phase in conditions leading to complete confinement, in cavities of size lower than the natural lamellar length observed in a continuous thin film, the crystallographic a axis aligns preferentially parallel to the substrate, and the crystalline lamellae are of significantly reduced length. These characteristics translate in a strongly decreased coercive field and accelerated ferroelectric switching, which is in part ascribed to the improved coupling between the electric field and the properly oriented dipole moments. When decreasing the confinement either by leaving a residual film connecting the nanopillars, or by increasing the lateral size of the nanopillars above the natural lamellar length, or by using line molds where confinement only exists in one direction, or by using continuous films, the preferential orientation becomes less visible and the lamellar length increases, resulting in increased coercive and switching fields. Interestingly, the average length of the crystalline lamellae tends to correlate with the value of the coercive field. Finally, if the sample is imprinted in the melt, a flat-on setting of the crystalline lamellae ensues, with a vertical chain axis which is unfavorable for ferroelectric properties probed with a vertical electric field.

Review of fluvoxamine safety database.

Abstract: A review of the safety and tolerability of fluvoxamine in worldwide marketing studies involving 24 624 patients, predominantly receiving fluvoxamine treatment in uncontrolled studies in depression, has been conducted. There was a marked preponderance of female patients and patients aged between 30 and 50 years. The majority of patients were treated for 6 weeks, with the most frequent modal total daily dose being 100mg. The greatest proportion of adverse experiences occurring, by COSTART body system, affected the digestive system (24.1%), the nervous system (23.7%), and the body as a whole (15.3%). The only adverse experience with an incidence greater than 10% was nausea (15.7%), with somnolence (6.9%) and asthenia (6.2%) as the next most frequent experiences. Notably, the rates of agitation and anxiety were only 1.4 and 1.3%, respectively. The incidences of adverse experiences increased with age, and were slightly higher in females than males. 15.1% of patients discontinued treatment prematurely as a result of adverse experiences, principally nausea, dizziness, vomiting, somnolence, abdominal pain, and headache. The overall incidence of serious adverse events associated with fluvoxamine treatment was 2.5%, and the incidence of overall suicidality, including suicidal ideation, overdose, and intentional overdose as well as attempted and completed acts of suicide, was remarkably low at 0.8%.

The efficacy of fluvoxamine in patients with severe depression

Abstract: 1. Intent-to-treat analysis of a parallel, double-blind comparative study of fluvoxamine, imipramine and placebo in patients with major depressive episode (DSM III). 2. A posteriori the patients have been stratified in three severity groups on basis of their initial HAMD-score: Mild depression (15-20), Moderate depression (21-25) and Severe depression (> or = 26). 3. At endpoint both the decrease in HAMD-scores and the percentage responders (CGI 1-2) differed significantly comparing fluvoxamine with placebo and tended to differ significantly comparing with imipramine in the severely depressed patients. 4. The results with fluvoxamine in severely depressed patients were better than in moderately depressed patients, which in turn were better than in mildly depressed patients. 5. Despite a lower daily fluvoxamine dosage in the mild group, the premature terminator rate in this group (47%) was higher than in the moderate group (27%) or in the severe group (24%). With placebo the situation was opposite. More patients (47%) terminated before day 28 in the severe group, compared to the moderate (32%) and the mild group (24%), while on placebo. 6. The majority of responders to fluvoxamine at endpoint, showed already improvement at week 1 (82.5%).

Selective synthesis of ethylene oxide through liquid-phase epoxidation of ethylene with titanosilicate/H2O2 catalytic systems

Abstract: Liquid-phase epoxidation of ethylene to ethylene oxide (EO) with H 2 O 2 over various titanosilicate catalysts like Ti-MWW, TS-1, Ti-MOR and Ti-Beta has been investigated. The effects of solvent, catalyst amount, reaction pressure, temperature and time on the catalytic performance of Ti-MWW have been studied in detail. Ti-MWW preferred acetonitrile as a solvent and showed the highest reactivity and EO selectivity among the titanosilicate catalysts investigated. Under optimized reaction conditions, Ti-MWW gave a EO selectivity high as 97.9% as well as a reasonable utilization efficiency of H 2 O 2 of 77.7%. Ti-MWW was gradually deactivated after repeated use in ethylene epoxidation. High-temperature calcination easily recovered the catalytic activity of deactivated Ti-MWW after removing ethylene glycol (EG) and other heavy byproducts with high boiling points that were deposited inside micropores. The issues of molecular dimension and reactivity have also been considered by comparing the epoxidation of linear alkenes with different lengths (C 2 to C 6 ) between two representative titanosilicates Ti-MWW and TS-1. Ethylene, with the smallest dynamic diameter but containing electron-deficient C C double bonds, was more difficult to be epoxidized than other alkenes with higher intrinsic activities.