Surface-Mounted Metal-Organic Frameworks as the Platform for Surface Science: Photoreactivity, Electroreactivity, and Thermal Reactivity

Bisher haben Forscher Modellsysteme wie Einkristallmetalle oder Metalloxide entwickelt, um reale Pulversysteme besser zu verstehen. Es bestehen jedoch immer noch Fragen hinsichtlich der Oberflächenstruktur und Reaktivität von MOFs (Metall-organische Gerüstverbindungen). Glücklicherweise bieten oberflächenorientierte SURMOFs (surface-oriented SURMOFs) einen alternativen Ansatz für den Aufbau von Modellplattformen zur Untersuchung dieser grundlegenden Aspekte von MOFs. Diese Arbeit konzentriert sich auf die organische Photochemie, Elektrokatalyse und thermische Pyrolyse von MOFs aus einer physikalisch-chemischen Perspektive unter Verwendung von Oberflächenwissenschaftstechniken und SURMOF-Plattformen. Das Ziel dieser Arbeit besteht nicht nur darin, das Wissen über MOFs und SURMOFs zu erweitern, sondern auch die Leistungsfähigkeit von Oberflächenwissenschaftstechniken und -methoden im Bereich chemischer Reaktionen zu demonstrieren. Zu diesem Zweck verwendet die Arbeit eine hochmoderne UHV-IRRAS-Apparatur (Ultra-High-Vacuum Infrared Reflection Absorption Spectroscopy). Ein auf der Oberfläche montiertes MOF (SURMOF) Modellsystem mit Azid-Seitenketten wurde erfolgreich hergestellt und genau überwacht, um chemische Veränderungen während des Betriebs zu erfassen. Die umfassenden Ergebnisse, die durch die Kombination von IRRAS mit in situ XRD, MS und XPS erzielt wurden, zeigen, dass die Photoreaktion von Azid durch die Bildung von hochaktiven Nitren-Gruppen initiiert wird, die anschließend mit benachbarten C=C-Bindungen des Gerüsts reagieren und Pyrrol-Derivate durch intramolekulare Aminierung erzeugen. Ein hochwertiges ZIF-67-SURMOF wurde in einem Flüssigphasen-Schicht-für-Schicht-Verfahren hergestellt und erstmals in der Sauerstoffentwicklungskatalyse (OER) eingesetzt. Die katalytisch aktiven Spezies, CoOOH, in den SURMOF-Derivaten wurden identifiziert, was Einblicke in die Mechanismen der strukturellen Transformation und die Struktur-Leistung-Beziehungen bietet. Durch Zugabe von Ni und B wurde die Überspannung auf 375 mV bei 10 mA/cm2 reduziert. Zusätzlich wurden in situ IRRAS und XPS verwendet, um die strukturellen Übergänge von ZIF-67 zu kohlenstoffhaltigen Materialien mit Stickstoffelementen zu enthüllen. NEXAFS-Daten zeigen eine abschließende graphitische Struktur der kohlenstoffhaltigen Materialien nach Pyrolyse bei 900 K. Hoffentlich kann diese Arbeit das grundlegende Verständnis und die Anwendungsfelder von auf MOF und SURMOF basierenden Materialien erweitern

Toward Collinearity-Avoidable Localization for Wireless Sensor Network

In accordance with the collinearity problem during computation caused by the beacon nodes used for location estimation which are close to be in the same line or same plane, two solutions are proposed in this paper: the geometric analytical localization algorithm based on positioning units and the localization algorithm based on the multivariate analysis method. The geometric analytical localization algorithm based on positioning units analyzes the topology quality of positioning units used to estimate location and provides quantitative criteria based on that; the localization algorithm based on the multivariate analysis method uses the multivariate analysis method to filter and integrate the beacon nodes coordinate matrixes during the process of location estimation. Both methods can avoid low estimation accuracy and instability caused by multicollinearity

Seroprevalence of Bartonella in Eastern China and analysis of risk factors

<p>Abstract</p> <p>Background</p> <p><it>Bartonella </it>infections are emerging in the Zhejiang Province of China. However, there has been no effort to date to explore the epidemiology of these infections in this region, nor to identify risk factors associated with exposure to <it>Bartonella</it>. The aim of this study was to investigate the seroprevalence of <it>Bartonella </it>in both patients bitten by dogs and blood donors (for control) in Eastern China, and to identify risk factors associated with exposure to <it>Bartonella</it>. As no previous data for this region have been published, this study will provide baseline data useful for <it>Bartonella </it>infection surveillance, control, and prevention.</p> <p>Methods</p> <p>Blood samples were collected from industrial rabies clinic attendees and blood donors living in eight areas of the Zhejiang Province of China, between December 2005 and November 2006. An indirect immunofluorescent antibody test was used to determine the presence of <it>Bartonella </it>in these samples. Risk factors associated with <it>Bartonella </it>exposure were explored using Chi-square tests and logistic regression analysis of epidemiological data relating to the study's participants.</p> <p>Results</p> <p><it>Bartonella </it>antibodies were detected in 19.60% (109/556) of blood samples. Seroprevalence varied among the eight areas surveys, ranging from over 32% in Hangzhou to only 2% in Jiangshan (X²= 28.22, P < 0.001). We detected a significantly higher prevalence of <it>Bartonella </it>antibodies in people who had been bitten by dogs than in blood donors (X²= 13.86, P < 0.001). Seroprevalence of <it>Bartonella </it>was similar among males (18.61%, n = 317) and females (20.92%, n = 239).</p> <p>Conclusions</p> <p><it>Bartonella </it>antibodies were encountered in people living across Zhejiang Province and the seropositivity rate among those exposed to dog bites was significantly higher than that among blood donors, indicating that dog bites may be a risk factor for <it>Bartonella </it>infection.</p

L’impact des TICE sur la formation des enseignants en Corée

Depuis la fin des années 90, la Corée a entrepris d’améliorer la qualité de l’enseignement en promouvant l’utilisation des TICE, vues comme donnant aux enseignants la possibilité d’améliorer leur maîtrise de l’information. À mesure que les technologies progressaient, la formation des enseignants s’est transformée pour adapter les nouvelles technologies à la situation de classe et pour développer les aptitudes des enseignants. Le « Plan TICE », depuis 2002, s’adresse à plus de 30 % des enseignants, ainsi qu’aux chefs d’établissements et autres personnels d’éducation. Les nouveaux programmes de formation aux TICE prennent en compte toute la durée de la carrière des enseignants et les nouvelles technologies.Since the end of the 1990s, Korea has been striving to improve teaching quality by promoting the use of educational ICT (EICT), seen as offering teachers the possibility to improve their mastery of their subjects. As technology has progressed, teacher training has been transformed in order to adapt such new technologies to classroom situations and to develop teachers’ skills. The “EICT Plan”, operational since 2002, concerns over 30% of teachers, heads of institutions and other education personnel. The new EICT training programmes take the teachers’ length of experience and the new technologies into account.Desde finales de los años 90, Corea se ha propuesto mejorar la calidad de la enseñanza promoviendo el uso de las TICE, considerando que ofrecen a los profesores la posibilidad de mejorar su dominio de la información. A medida que iban progresando las tecnologías, la formación de los profesores se ha ido transformando para adaptar las nuevas tecnologías a la situación de las clases y para desarrollar las aptitudes de los profesores. El “Plan TICE”, lanzado desde 2002, se dirige a más del 30% de los profesores, así como a los directores de establecimientos y a otros personales de la educación. Los nuevos programas de formación sobre las TICE tienen en cuenta todo el periodo de la carrera de los profesores y las nuevas tecnologías

Metal‐Organic Framework Thin Films as Ideal Matrices for Azide Photolysis in Vacuum

Studies on reactions in solutions are often hampered by solvent effects. In addition, detailed investigation on kinetics is limited to the small temperature regime where the solvent is liquid. Here, we report the in situ spectroscopic observation of UV-induced photochemical reactions of aryl azides within a crystalline matrix in vacuum. The matrices are formed by attaching the reactive moieties to ditopic linkers, which are then assembled to yield metal–organic frameworks (MOFs) and surface-mounted MOFs (SURMOFs). These porous, crystalline frameworks are then used as model systems to study azide-related chemical processes under ultrahigh vacuum (UHV) conditions, where solvent effects can be safely excluded and in a large temperature regime. Infrared reflection absorption spectroscopy (IRRAS) allowed us to monitor the photoreaction of azide in SURMOFs precisely. The in situ IRRAS data, in conjunction with XRD, MS, and XPS, reveal that illumination with UV light first leads to forming a nitrene intermediate. In the second step, an intramolecular rearrangement occurs, yielding an indoloindole derivative. These findings unveil a novel pathway for precisely studying azide-related chemical transformations. Reference experiments carried out for solvent-loaded SURMOFs reveal a huge diversity of other reaction schemes, thus highlighting the need for model systems studied under UHV conditions

PREVENTING EFFECT ON DIET-INDUCED OBESITY OFWATER-EXTRACT FROM MASSON PINE POLLEN ON MICE

Background: In order to investigate the preventing effect of water-extract from masson pine pollen (PWE) on obesity in mice. Materials and Methods: Sixty male KM mice (bodyweight was 19±1g) were divided randomly into six groups: normal control group (NC), high fat group (FC), positive control group (Orlistat, 0.05g/kg bw·d, PC), low-dose PWE group (0.0625g/kg bw·d, PWEL), medium-dose group (0.125g/kg bw·d, PWEM) and high-dose group (0.25g/kg bw·d, PWEH). Mice were treated by intragastric administration daily for 6 weeks. Results: The body weight changes of three PWE groups decreased obviously. In serum, TC of PWEH group reduced remarkably (

A Case of Familial Comedonal Darier's Disease

Darier's disease is a genetic disorder of keratinization with autosomal dominant inheritance. Its appearance is usually in the form of greasy, crusted, keratotic yellow-brown papules and plaques found particularly on seborrheic areas of the body. However, there are some clinical variants showing atypical skin lesions. Here we report an unusual case of Darier's disease, which mainly showed prominent comedonal papules over the face