Melt block copolymerization of ε-caprolactone and L-lactide

AB block copolymers of ε-caprolactone and (L)-lactide could be prepared by ring-opening polymerization in the melt at 110°C using stannous octoate as a catalyst and ethanol as an initiator provided ε-caprolactone was polymerized first. Ethanol initiated the polymerization of ε-caprolactone producing a polymer with ε-caprolactone derived hydroxyl end groups which after addition of L-lactide in the second step of the polymerization initiated the ring-opening copolymerization of L-lactide. The number-average molecular weights of the poly(ε-caprolactone) blocks varied from 1.5 to 5.2 × 103, while those of the poly(L-lactide) blocks ranged from 17.4 to 49.7 × 103. The polydispersities of the block copolymers varied from 1.16 to 1.27. The number-average molecular weights of the polymers were controlled by the monomer/hydroxyl group ratio, and were independent on the monomer/stannous octoate ratio within the range of experimental conditions studied. When L-lactide was polymerized first, followed by copolymerization of ε-caprolactone, random copolymers were obtained. The formation of random copolymers was attributed to the occurrence of transesterification reactions. These side reactions were caused by the ε-caprolactone derived hydroxyl end groups generated during the copolymerization of ε-caprolactone with pre-polymers of L-lactide. The polymerization proceeds through an ester alcoholysis reaction mechanism, in which the stannous octoate activated ester groups of the monomers react with hydroxyl groups

How nursing home residents with dementia respond to the interactive art installation ‘VENSTER’: a pilot study

The goal of this study was (1) to determine whether and how nursing home residents with dementia respond to the interactive art installation in general and (2) to identify whether responses change when the content type and, therefore, the nature of the interaction with the artwork changes. The interactive art installation ‘VENSTER’ evokes responses in nursing home residents with dementia, illustrating the potential of interactive artworks in the nursing home environment. Frequently observed responses were naming, recognizing or asking questions about depicted content and how the installation worked, physically gesturing towards or tapping on the screen and tapping or singing along to the music. It seemed content matters a lot. When VENSTER is to be used in routine care, the choice of a type of content is critical to the intended experience/usage in practice. In this study, recognition seemed to trigger memory and (in most cases) a verbal reaction, while indistinctness led to asking for more information. When (initially) coached by a care provider, residents actively engaged physically with the screen. Responses differed between content types, which makes it important to further explore different types of content and content as an interface to provide meaningful experiences for nursing home residents. Implications for rehabilitation: - VENSTER can facilitate different types of responses ranging from verbal reactions to active physical engagement. The choice of a type of content is critical to the intended experience/usage in practice. - Activating content seems suitable for use as a meaningful experience during the spare time in between existing activities or therapy. - Sessions with interactive content are short (avg. 30 mins) and intense and can therefore potentially be used as an activating therapy, activity or exercise. - In order to actively engage residents with dementia, the role of the care provider seems very important

Ethane-beta-Sultam Modifies the Activation of the Innate Immune System Induced by Intermittent Ethanol Administration in Female Adolescent Rats

Intermittent ethanol abuse or ‘binge drinking’ during adolescence induces neuronal damage, which may be associated with cognitive dysfunction. To investigate the neurochemical processes involved, rats were administered either 1 g/kg or 2 g/kg ethanol in a ‘binge drinking’ regime. After only 3 weeks, significant activation of phagocytic cells in the peripheral (alveolar macrophages) and the hippocampal brain region (microglia cells) was present,as exemplified by increases in the release of pro-inflammatory cytokines in the macrophages and of iNOS in the microglia. This was associated with neuronal loss in the hippocampus CA1 region. Daily supplementation with a taurine prodrug, ethane-β-sultam, 0.028 g/kg, during the intermittent ethanol loading regime, supressed the release of the pro-inflammatory cytokines and of reactive nitrogen species, as well as neuronal loss, particularly in the rats administered the lower dose of ethanol, 1 g/kg. Plasma, macrophage and hippocampal taurine levels increased marginally after ethane-β-sultam supplementation. The ‘binge drinking’ ethanol rats administered 1 g/kg ethanol showed increased latencies to those of the control rats in their acquisition of spacial navigation in the Morris Water Maze, which was normalised to that of the controls values after ethane-β-sultam administration. Such results confirm that the administration of ethane-β-sultam to binge drinking rats reduces neuroinflammation in both the periphery and the brain, suppresses neuronal loss, and improved working memory of rats in a water maze study

Synthesis of mono and multidomain YIG particles by chemical coprecipitation or ceramic procedure

4 páginas, 3 figuras.Yttrium iron garnet powders have been synthesized by chemical coprecipitation using two different precursors, nitrates and chlorides, and by an oxides mixture route. It is shown that depending on the precursors and synthesis conditions used pure yttrium iron garnet powders can be obtained with a mono or multidomain magnetic behaviour. The yttrium iron garnet crystalline structure, as studied by Raman spectroscopy, was already formed after calcination at temperatures as low as 800 °C when the nitrate precursors were used. However, calcination temperatures of up to 1100 °C were required to obtain yttrium iron garnet powders when the precursors were chlorides or when the oxides mixture route was chosen. The saturation magnetization of the powders correlates well with the structural characterization: when nitrate precursors were used, the saturation magnetization was already close to the bulk value, 26.8 emu/cm3, after calcination at 800 °C. However, the saturation magnetization of the powders obtained by the chlorides and oxides mixture routes was close to zero up to calcination temperatures of 1100 °C. Finally, both the chlorides and the oxides mixture routes yield multidomain micron sized yttrium iron garnet powders, whereas the nitrates route led to monodomain submicron sized powders.The authors want to acknowledge the Spanish Ministry of Education and Science and UE for funding through project MAT2009-14534-C03-03. One of us, L. Fernandez-Garcia, wants to acknowledge JAE program for PhD grant.Peer reviewe

Identification of the most suitable app to support the self-management of hypertension : systematic selection approach and qualitative study

Background: Smartphone apps are increasingly being used to aid in hypertension self-management, and a large and ever-growing number of self-management apps have been commercially released. However, very few of these are potentially effective and secure, and researchers have yet to establish the suitability of specific hypertension apps to particular contexts. Objective: The aim of this study is to identify the most suitable hypertension app in the context of Saudi Arabia and its health system. Methods: This study used a 2-stage approach to selecting the most suitable app for hypertension self-management. First, a systematic selection approach was followed to identify a shortlist of the most suitable apps according to the criteria of potential effectiveness, theoretical underpinning, and privacy and security. Second, an exploratory qualitative study was conducted to select the most suitable from the shortlist: 12 doctors were interviewed, and 22 patients participated in 4 focus groups. These explored participants’ attitudes towards self-management apps in general, and their views towards the apps identified via the systematic selection process. The qualitative data were analyzed using framework analysis. Results: In the first stage, only 5 apps were found to be potentially effective while also having a theoretical underpinning and protecting users’ data. In the second stage, both doctors and patients were generally interested in using hypertension apps, but most had no experience with these apps due to a lack of awareness of their availability and suitability. Patients and doctors liked apps that combine intuitive interfaces with a pleasant and clear visual design, in-depth features (eg, color-coded feedback accompanied with textual explanations), activity-specific reminders, and educational content regarding hypertension and potential complications. When the pros and cons of the 5 apps were discussed, 3 apps were identified as being more suitable, with Cora Health rated the highest by the participants. Conclusions: Only 5 apps were deemed potentially effective and secure. Patients’ and doctors’ discussions of the pros and cons of these 5 apps revealed that 3 out of the 5 are clearly more suitable, with the Cora Health app being judged most suitable overall

In-gas-cell laser ionization spectroscopy in the vicinity of 100Sn: Magnetic moments and mean-square charge radii of N=50-54 Ag

In-gas-cell laser ionization spectroscopy studies on the neutron deficient 97-101Ag isotopes have been performed with the LISOL setup. Magnetic dipole moments and mean-square charge radii have been determined for the first time with the exception of 101Ag, which was found in good agreement with previous experimental values. The reported results allow tentatively assigning the spin of 97,99Ag to 9/2 and confirming the presence of an isomeric state in these two isotopes, whose collapsed hyperfine structure suggests a spin of 1/2 . The effect of the N=50 shell closure is not only manifested in the magnetic moments but also in the evolution of the mean-square charge radii of the isotopes investigated, in accordance with the spherical droplet model predictions