Selective serotonin reuptake inhibitor discontinuation syndrome: Understanding, recognition, and management for psychologists.

Psychologists increasingly provide psychotherapeutic services to patients receiving concomitant pharmacotherapy. Ongoing experience with the relatively new selective serotonin reuptake inhibitors and other atypical antidepressants has revealed a discontinuation syndrome that emerges following abrupt or tapered withdrawal from these agents. The syndrome has both somatic and psychological characteristics, which tend to be mild and transient but can also be more distressing and become temporarily debilitating. Psychologists need to be aware of the potential for these events, as they are in an optimal position to collaborate with physicians and other prescribing clinicians to prevent or manage this syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural characterization of grain pattern diversity in parametric space

Grain patterns are characterized by size and shape diversity as reflected by variations in the values of structural parameters ascribed to them. Analysis of the population of grains calls for a global analysis of all the pertinent structural parameters taken together. In this study, algorithms were developed for advanced grain image analysis, unbiased grain size-side measurement and full grain pattern recognition. The correlations of these normalized structural parameters were studied for each topological class and geometrical group, for the grain patterns formed under different nucleation-growth conditions. Relationships between the structural parameters and the grain spatial coordinates are given. This provides a useful approach to investigate the structural inhomogeneity in grain patterns. The results show strong interdependence between the topology, geometry and physical dynamics of the spherulitic grain size-shape arrangement in semi-crystalline polymeric films.     

Delaminated Zeolites: An Efficient Support for Enzymes

Delaminated zeolites (see, e.g., Figure) have been proposed as excellent supports for enzymes. This type of material presents suitable physicochemical properties such as a very high, hydroxylated, and ordered external surface, and good thermal stability. Here we describe the method of preparation of delaminated materials and surface immobilization of enzymes, as well as the remarkable activity and stability of the final products.     

Dietary vitamin A concentration alters fatty acid composition in pigs

This experiment was conducted to study the effect of vitamin A concentration in the diet on fatty acid composition in pigs. One-hundred and twenty eight Duroc × (Large White × Landrace) castrated male pigs were used. Pigs were randomly distributed and located in cages of four pigs each to the following treatment: vitamin A-enriched diet (100,000IU/kg) (n=16) and control diet with a basal level (7500IU/kg) (n=16). The pigs were slaughtered at an average weight of 125.9kg. No effect of diet vitamin A level on performance, carcass traits and intramuscular fat percentage was observed. The retinol concentration in subcutaneous backfat and retinol and retinol palmitate contents in liver were higher in the pigs that were given the vitamin A enriched diet than in those receiving the control diet. However the vitamin A supplementation did not increase the retinol content in the muscle. Pigs receiving the vitamin A enriched diet showed a higher C16:0 and ∑SFA proportions in the outer layer and C18:0 and ∑SFA proportions in the inner layer. Moreover, the diet rich in vitamin A led to a reduction of C18:1 n-9 and ∑MUFA proportions in subcutaneous backfat inner layer. Dietary vitamin A concentration had not influence on main fatty acids composition of intramuscular lipids. Dietary vitamin A enrichment lead to a higher C16:0, ∑SFA concentration in liver lipids.     

Interactions between genotype,dietary fat saturation and vitamin A concentration on intramuscular fat content and fatty acid composition in pigs

The effect of dietary fat saturation (dFat) and dietary vitamin A (dVitA) level (0 IU vs. 100,000 IU) on performance, carcass characteristics and fatty acid composition in the offspring of two terminal sires: Duroc (DU) and Landrace × Large White (LD × LW) was studied. In the inner backfat layer, the DU-sired pigs had higher C16:0 proportion (P < 0.05) and tended (P < 0.07) to have higher total saturated fatty acids (SFA) and lower C18:1 n-9 proportions than LD × LW-sired pigs. An interaction sire line × dVitA was observed for intramuscular fat (IMF) content (P < 0.005). The effect of supplementation with the high dVitA level in DU-sired pigs was associated with a 20% increase in IMF while no effect was observed in LD × LW pigs. Fatty acid pattern was affected by dFat and sire line. In the inner backfat layer, LD × LW-sired pigs receiving the low dVitA level increased C18:0 proportions by 8% in comparison to animals receiving the high dVitA, whereas in DU-sired pigs the effect of vitamin A was opposite. It is concluded that the effect of dFat and dVitA concentration on IMF content and fatty acid profile of subcutaneous backfat and IMF is variable according to pig genotype.     

Estrogenic activity of polychlorinated biphenyls present in human tissue and the environment

This study evaluated the estrogenicity of polychlorinated biphenyls (PCBs) present in environmental media and human tissue and assessed exposure pathways for PCB-derived estrogenic potency in air, soil, and dust from New Bedford, MA, an area with a PCB-contaminated Superfund site. Thirty-four PCB congeners were assayed for estrogenic potency using E-SCREEN, an assay based on the estrogen-dependent proliferation of MCF-7 cells in vitro. Childhood exposure to estradiol-equivalents via PCBs in environmental media was estimated byweighting previously reported New Bedford congener-specific concentrations by their relative estrogenic potency and published inhalation and soil ingestion rates. Thirteen congeners were weakly estrogenic in E-SCREEN: PCBs 17, 18, 30, 44, 49, 66, 74, 82, 99, 103, 110, 128, and 179. These PCBs were typically 6 orders of magnitude less potent than 17beta-estradiol, with proliferative potencies ranging from 0.0007% to 0.0040%. Of the environmental media assessed, air (inhalation) had the highest PCB-derived estradiol-equivalent exposure. PCB estrogenic potency information from this study provides an important resource both for preliminary estimation of routes of human exposure to xenoestrogens and for application to human health studies focused on estrogen-responsive health outcomes, such as reproductive development and related malignancies.     

First direct synthesis of highly ordered bifunctionalized mesoporous silica thin films

Optically transparent and highly ordered mesoporous organosilica thin films functionalized with two different organic groups in various proportions were synthesized by templated-directed cocondensation of tetraethylorthosilicate (TEOS) and a mixture of two distinct and functional organotriethoxysilanes [NC(CH2)3Si(OEt)3 and O=P(OEt)2(CH2)3Si(OEt)3]. The mesostructured films obtained by evaporation induced self-assembly (EISA) approach were deposited on glass or silicon substrates by dip-coating. They were characterized by Grazing Incidence Small Angle X-ray Scattering (GISAXS) and X-ray reflectivity. We showed that whatever the proportion in organic groups, only 2D hexagonal phase having p6m symmetry was observed for all the materials indicating a good compatibility between the organic groups. The bi-functionalization of the internal pores surface by the organotriethoxysilanes groups was clearly evidenced by using micro-Raman spectroscopy.     

Biomimetic apatite-based biomaterials: on the critical impact of synthesis and post-synthesis parameters

Nanocrystalline apatites are major constituents of hard tissues, and attempts are made worldwide to prepare synthetic analogs. However the impact of synthesis/postsynthesis parameters is often disregarded. Based on an updated knowledge on such compounds, we inspected the effects of synthesis parameters (maturation time, temperature, pH, nature of counter-ions) and post-treatments (re-immersion in aqueous media, thermal treatment) on physicochemical characteristics. Great modifications were noticed during the 3 first days of maturation, where a progressive evolution of the apatite phase (localized in the core of the nanocrystals) toward stoichiometry was observed at the expense of the non-apatitic surface layer which progressively disappears. Similar trends were also evidenced for maturation run under increasing temperatures, studied here in the range 20–100?°C. pH impacted more specifically the chemical composition. The nature of the counter-ion in the starting phosphate salt influenced composition and nonstoichiometry, depending on its (in)ability to be incorporated in the lattice. Freeze-drying allowed to preserve a high surface reactivity, although further evolutions were noticed after re-immersion. Effects of a thermal treatment of dried samples were unveiled, suggesting a denaturation of the hydrated layer on the nanocrystals. This work underlines the necessity of a good control of synthesis/postsynthesis parameters for the production of biomimetic apatites.     

Composition and properties of silver-containing calcium carbonate–calcium phosphate bone cement

The introduction of silver, either in the liquid phase (as silver nitrate solution: Ag(L)) or in the solid phase (as silver phosphate salt: Ag(S)) of calcium carbonate–calcium phosphate (CaCO₃–CaP) bone cement, its influence on the composition of the set cement (C-Ag(L) and C-Ag(S) cements with a Ca/Ag atomic ratio equal to 10.3) and its biological properties were investigated. The fine characterisation of the chemical setting of silver-doped and reference cements was performed using FTIR spectroscopy. We showed that the formation of apatite was enhanced from the first hours of maturation of C-Ag(L) cement in comparison with the reference cement, whereas a longer period of maturation (about 10 h) was required to observe this increase for C-Ag(S) cement, although in both cases, silver was present in the set cements mainly as silver phosphate. The role of silver nitrate on the setting chemical reaction is discussed and a chemical scheme is proposed. Antibacterial activity tests (S. aureus and S. epidermidis) and in vitro cytotoxicity tests (human bone marrow stromal cells (HBMSC)) showed that silver-loaded CaCO₃–CaP cements had antibacterial properties (anti-adhesion and anti-biofilm formation) without a toxic effect on HBMSC cells, making C-Ag(S) cement a promising candidate for the prevention of bone implant-associated infections.     

Finite-Element and Effective-Medium Calculations of the Electrical Behaviour Near the Vortex–Antivortex Binding Transition of Planar Superconductors with Critical Temperature Inhomogeneities

We present calculations of the electrical behaviour near the Berezinskii–Kosterlitz–Thouless (BKT) vortex–antivortex binding transition of planar type-II superconductors with critical temperatures varying in space according to a random Gaussian distribution. By using a finite-element mesh-circuit analysis we obtain as a function of temperature and intensity the spatial maps of local voltages. These calculations allow us to argument that in these inhomogeneous superconductors the occurrence of a global voltage-current curve V∝I ³ signals with good accuracy the average BKT temperature $\overline{T}_{\mathrm{BKT}}$ because of the appearance of percolation-like configurations when 50 % of the sample has experienced the vortex–antivortex binding transition. In addition, we also present an effective-medium calculation aimed to obtain the resistance V/I without any finite-element computation. It leads to results in agreement with the finite-element approach except in the close vicinity of $\overline{T}_{\mathrm{BKT}}$ . For instance, for the upper part of the transition both theoretical approaches coincide in all the ohmic region of temperatures, including also the average mean-field temperature $\overline{T}_{c0}$ .