Directional motion of forced polymer chains with hydrodynamic interaction

We study the propulsion of a one-dimensional (1D) polymer chain under sinusoidal external forces in the overdamped (low Reynolds number) regime. We show that, when hydrodynamical interactions are included, the polymer presents directional motion which depends on the phase differences of the external force applied along the chain. Moreover, the velocity shows a maximum as a function of the frequency. We discuss the relevance of all these results in light of recent nanotechnology experiments.Comment: 5 pages, 6 figure

Revision and conservation status of the bryological flora from Sierra de Peña Sagra (Cordillera Cantábrica, Spain)

Se analiza el porcentaje de especies de briófitos amenazados del catálogo de la Sierra de Peña Sagra (Cantabria). Se aportan 4 nuevos taxones a la Lista Roja de Briófitos de la Península Ibérica: Anastrepta orcadensis, Plagiochila spinulosa, Orthotrichum consimile y Sphagnum brevifolium. Se plantea el cambio de categoría de amenaza de Bazzania tricrenata. Se propone la inclusión de esta zona en la lista de Humedales de Importancia Internacional como sitio Ramsar.The percentage of threatened taxa in the list of bryophytes of Sierra de Peña Sagra (Cantabria) is analysed. 4 new taxa are added to the Red List of Bryophytes of the Iberian Peninsula: Anastrepta orcadensis, Plagiochila spinulosa, Orthotrichum consimile and Sphagnum brevifolium. A change in the threat category of Bazzania tricrenata is suggested. We propose the inclusion of this locality in the Ramsar List of Wetlands of International Importance

A General Rhodium Catalyst for the Deuteration of Boranes and Hydrides of the Group 14 Elements

Pinacolborane, catecholborane, triethylsilane, triphenylsilane, dimethylphenylsilane, 1, 1, 1, 3, 5, 5, 5-heptamethyltrisiloxane, triethylgermane, triphenylgermane, and triphenylstannane deuterated at the heteroatom position have been catalytically prepared in 50-70% isolated yield, through H/D exchange between the D2 molecule and the respective boranes and hydrides of the group 14 elements, in the presence of the rhodium(I)-monohydride catalyst precursor RhH{¿3-P, O, P-[xant(PiPr2)2]} (xant(PiPr2)2 = 9, 9-dimethyl-4, 5-bis(diisopropylphosphino)xanthene)

Satisfacción vital, síntomas depresivos y apoyo social percibido en pacientes con insuficiencia cardiaca

This research examined life satisfaction, depressive symptoms and perceived social support in two groups of adults (N = 120; age 40-89 years). The first was formed by stable heart failure (HF) outpatients and the second was a control group of similar age. Perceived social support was the only significant predictor of life satisfaction in the control group but, in the HF group, life satisfaction was associated with more social support and less depressive symptoms. Gender (men > women) was also an important predictor of life satisfaction in both groups, but more significantly in the HF one. All womenreported more depressive symptoms and less life satisfaction than men. Female HR patients also perceived more social support than male patients did. Finally, a partial mediation of depressive symptoms in the association between social support and life satisfaction was found in the HF group.En esta investigación se analizaron la satisfacción vital, los síntomas depresivos y el apoyo social percibido en dos grupos de adultos (N =120; rango = 40-89 años), uno formado por pacientes no hospitalizados con insuficiencia cardiaca (IC) estable y otro control con personas de similar edad. El apoyo social percibido fue el único predictor significativo de la satisfacción vital en el grupo control, mientras que en el grupo con IC, se asociaba con más apoyo social y menos síntomas depresivos. El género fue también un predictor importante de la satisfacción vital (hombres > mujeres), aunque de forma más significativa en el grupo con IC. Todas las mujeres informaban más síntomas depresivos y menos satisfacción vital que los hombres. En el grupo IC, las mujeres también percibían más apoyo social que los varones. Finalmente, se encontró en este grupo que la asociación entre apoyo social y satisfacción vital estaba parcialmente mediada por los síntomas depresivos

Kinetic Analysis and Sequencing of Si-H and C-H Bond Activation Reactions: Direct Silylation of Arenes Catalyzed by an Iridium-Polyhydride

The saturated trihydride IrH3{¿3-P, O, P-[xant(PiPr2)2]} (1; xant(PiPr2)2 = 9, 9-dimethyl-4, 5-bis(diisopropylphosphino)xanthene) coordinates the Si-H bond of triethylsilane, 1, 1, 1, 3, 5, 5, 5-heptamethyltrisiloxane, and triphenylsilane to give the s-complexes IrH3(¿2-H-SiR3){¿2-cis-P, P-[xant(PiPr2)2]}, which evolve to the dihydride-silyl derivatives IrH2(SiR3){¿3-P, O, P-[xant(PiPr2)2]} (SiR3 = SiEt3 (2), SiMe(OSiMe3)2 (3), SiPh3 (4)) by means of the oxidative addition of the coordinated bond and the subsequent reductive elimination of H2. Complexes 2-4 activate a C-H bond of symmetrically and asymmetrically substituted arenes to form silylated arenes and to regenerate 1. This sequence of reactions defines a cycle for the catalytic direct C-H silylation of arenes. Stoichiometric isotopic experiments and the kinetic analysis of the transformations demonstrate that the C-H bond rupture is the rate-determining step of the catalysis. As a consequence, the selectivity of the silylation of substituted arenes is generally governed by ligand-substrate steric interactions

Acquisition of competencies of nurses: improving the performance of the healthcare system

Perspectives of the core competencies of nurses are varied among postgraduate-year nurses, which makes it challenging to establish training programs and develop evaluation instruments. Particularly critical for nurses is the ongoing acquisition of competencies throughout life. Sometimes this acquisition is funded by the healthcare system, but the key question is how the system leverages this acquisition and ultimately how it translates into patient care. This study seeks to explore nurses’ key competencies acquired through continuing education from the perspective of two groups of postgraduate nurses with different levels of experience and with different objectives to be assessed. An NGT procedure was applied to the group discussion. The participants were recruited according to basic factors such as the number of years of professional experience, their level of education, and their preferred professional status. Thus, seventeen professionals participated in the study, representing two public hospitals in the city. Following the NGT procedure, the competencies identified from the thematic analysis were scored and ranked to achieve a consensus. Eight core issues were derived in the novel group concerning transferring the competencies to patient care quality: holism, care work, organizational barriers, specialization, no transfer, confidence, knowledge, and instrumental tools. Four core issues were derived when asked about the relationship between the resources invested and the organizational and professional development of the nursing staff: professional development, positive learning, negative learning, and recognition. In the more experienced group, seven issues were derived from the first issue raised: continuous learning, quality, confidence, holism, safe care, autonomy, and technical issues. Additionally, six issues arose from the second question: satisfaction, autonomy, creativity, productivity, professional development, and recognition. In conclusion, the perceptions of the two selected groups are negative when it comes to assessing the extent to which the competencies acquired in lifelong learning are transferred to the patient and the system evaluates and recognizes these competencies for improvement