15 research outputs found
Systematical, experimental investigations on LiMgZ (Z= P, As, Sb) wide band gap semiconductors
This work reports on the experimental investigation of the wide band gap
compounds LiMgZ (Z = P, As, Sb), which are promising candidates for
opto-electronics and anode materials for Lithium batteries. The compounds
crystallize in the cubic (C1_b) MgAgAs structure (space group F-43m). The
polycrystalline samples were synthesized by solid state reaction methods. X-ray
and neutron diffraction measurements show a homogeneous, single-phased samples.
The electronic properties were studied using the direct current (DC) method.
Additionally UV-VIS diffuse reflectance spectra were recorded in order to
investigate the band gap nature. The measurements show that all compounds
exhibit semiconducting behavior with direct band gaps of 1.0 eV to 2.3 eV
depending on the Z element. A decrease of the peak widths in the static 7Li
nuclear magnetic resonance (NMR) spectra with increasing temperature was
observed, which can directly be related to an increase of Li ion mobility.Comment: 8 page
Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility
Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes
Propuesta para estructurar puntos de lactancia en centros comerciales en Bogotá, que desarrollen una experiencia única para usuarios y visitantes
Hoy en día, las expectativas sociales de las mujeres van mucho más allá de ejercer su papel como madres y cuándo ese rol es ejercido, buscan las mejores condiciones posibles. Es por ello que vale la pena preguntarse, cuando estas mujeres están en estado de lactancia: ¿cuáles son los factores que más dificultan o favorecen su experiencia como consumidoras en sitios públicos específicamente en centros comerciales? Este trabajo de investigación tiene como fin entender estas necesidades insatisfechas y poder llegar a una solución, para aliviarlas de la mejor manera posible, mejorando así la experiencia de estas madres como usuarias.Resumen Ejecutivo. Marco teórico. Marco conceptual. Metodología. Actitudes de las madres lactantes sobre la lactancia, preferencias para su realización y temores asociados a ella en centros comerciales. Aceptación / rechazo de visitantes y compradores diferentes a madres lactantes de su realización en centros comerciales. Opinión de gerentes de centros comerciales sobre la práctica de la lactancia y posibilidad de contar con lugares específicos en ellos. Propuesta de valor para ejecutar la lactancia en centros comerciales. Conclusiones y Recomendaciones. Bibliografía. Anexos.Administrador de EmpresasPregrad
Gerencia de proyecto para el diseño e implementación de un sistema de automatización de la fuerza de ventas de Schering Plough S.A
El éxito del negocio farmacéutico reside en su mayoría en el tema de la innovación. La tecnología es el camino para llegar a los productos innovadores y es por ello que los laboratorios, no solo deben estar a la vanguardia, si no ser pioneros para tener ventajas xvi competitivas sobre sus competidores. Así mismo el rol de la mercadotecnia se ha vuelto más estratégico y más cercanamente alineado con el de Investigación y Desarrollo para poder mantener una considerable participación de mercado duradera. En un amplio sentido, las compañías farmacéuticas producen y mercadean dos tipos de productos. Un tipo es el producto de prescripción que, debido a su potencial de causar efectos dañinos, debe venderse sólo bajo la supervisión de un médico. El otro tipo son los que se conocen en inglés como productos “over-the-counter” (OTC) que no necesitan prescripción y se venden directamente al público para que éste las use sin supervisión médica. Sin embargo, el negocio fundamental de las compañías farmacéuticas sigue siendo la producción y mercadotecnia de medicamentos de prescripció
Brain gray matter morphometry relates to onset age of bilingualism and theory of mind in young and older adults
Abstract Lifelong bilingualism may result in neural reserve against decline not only in the general cognitive domain, but also in social cognitive functioning. In this study, we show the brain structural correlates that are associated with second language age of acquisition (L2AoA) and theory of mind (the ability to reason about mental states) in normal aging. Participants were bilingual adults (46 young, 50 older) who completed a theory-of-mind task battery, a language background questionnaire, and an anatomical MRI scan to obtain cortical morphometric features (i.e., gray matter volume, thickness, and surface area). Findings indicated a theory-of-mind decline in older adults compared to young adults, controlling for education and general cognition. Importantly, earlier L2AoA and better theory-of-mind performance were associated with larger volume, higher thickness, and larger surface area in the bilateral temporal, medial temporal, superior parietal, and prefrontal brain regions. These regions are likely to be involved in mental representations, language, and cognitive control. The morphometric association with L2AoA in young and older adults were comparable, but its association with theory of mind was stronger in older adults than young adults. The results demonstrate that early bilingual acquisition may provide protective benefits to intact theory-of-mind abilities against normal age-related declines
Beyond Boycotts. Sport during the Cold War in Europe
This book explores original studies on sport during the Cold War in Europe. Three perspectives have been developed. First, the book gives new insight into the use of sport by European states as a tool of diplomacy. Second, the researchers show how sport institutions could counterbalance Cold War divisions throughout the period. Finally, the book demostrates how sport on the continent acted globally, enlarging the framework of the narrative and considering Europe in its worldwide context
Influence of the particle size on the microstructure and mechanical properties of grains containing mixtures of nanoparticles and microparticles: Levitator tests and pilot-scaled validation
Signalling or binding:the role of the platelet-activating factor receptor in invasive pneumococcal disease
<p>Streptococcus pneumoniae (the pneumococcus) is an opportunistic human pathogen, which causes serious invasive disease such as pneumonia, bacteraemia and meningitis. The interaction of the bacteria with host receptors precedes the development of invasive disease. One host receptor implicated in pneumococcal adhesion to, invasion of and ultimately translocation of cell layers is the platelet-activating factor receptor (PAFR). PAFR is a G-protein coupled receptor which binds PAF, a potent phospholipid activator involved in many leucocyte functions, platelet aggregation and inflammation. PAFR has been proposed to bind S.pneumoniae and as such facilitate adhesion to, uptake by and transcytosis of endothelial cells leading to invasive disease. However, there is a shortage of biochemical data supporting direct interaction between PAFR and the bacteria, in addition to conflicting data on its role in development of invasive pneumococcal disease (IPD). In this review, we will discuss current literature on PAFR and S.pneumoniae and other pathogens,including data concerning human PAFR genetic variation related to IPD clinical aspects, to shed light on the importance of PAFR in IPD. Clarification of the role of this receptor in IPD development has the potential to enable the development of novel therapeutic strategies for treating pneumococcal disease by interfering with the PAFR.</p>