Fluorinated MOF platform for selective removal and sensing of SO2 from flue gas and air.

Conventional SO2 scrubbing agents, namely calcium oxide and zeolites, are often used to remove SO2 using a strong or irreversible adsorption-based process. However, adsorbents capable of sensing and selectively capturing this toxic molecule in a reversible manner, with in-depth understanding of structure-property relationships, have been rarely explored. Here we report the selective removal and sensing of SO2 using recently unveiled fluorinated metal-organic frameworks (MOFs). Mixed gas adsorption experiments were performed at low concentrations ranging from 250 p.p.m. to 7% of SO2. Direct mixed gas column breakthrough and/or column desorption experiments revealed an unprecedented SO2 affinity for KAUST-7 (NbOFFIVE-1-Ni) and KAUST-8 (AlFFIVE-1-Ni) MOFs. Furthermore, MOF-coated quartz crystal microbalance transducers were used to develop sensors with the ability to detect SO2 at low concentrations ranging from 25 to 500 p.p.m.

Cloaking through cancellation of diffusive wave scattering.

A new cloaking mechanism, which makes enclosed objects invisible to diffusive photon density waves, is proposed. First, diffusive scattering from a basic core-shell geometry, which represents the cloaked structure, is studied. The conditions of scattering cancellation in a quasi-static scattering regime are derived. These allow for tailoring the diffusivity constant of the shell enclosing the object so that the fields scattered from the shell and the object cancel each other. This means that the photon flow outside the cloak behaves as if the cloaked object were not present. Diffusive light invisibility may have potential applications in hiding hot spots in infrared thermography or tissue imaging.

Single-Readout High-Density Memristor Crossbar.

High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

Control and switching synchronization of fractional order chaotic systems using active control technique.

This paper discusses the continuous effect of the fractional order parameter of the Lü system where the system response starts stable, passing by chaotic behavior then reaching periodic response as the fractional-order increases. In addition, this paper presents the concept of synchronization of different fractional order chaotic systems using active control technique. Four different synchronization cases are introduced based on the switching parameters. Also, the static and dynamic synchronizations can be obtained when the switching parameters are functions of time. The nonstandard finite difference method is used for the numerical solution of the fractional order master and slave systems. Many numeric simulations are presented to validate the concept for different fractional order parameters.

Hepatitis C virus infection in Egyptian children: single centre experience.

The outcome of hepatitis C virus (HCV) infection acquired in childhood is uncertain because of the diversity of the epidemiological and clinical features of infection and disease. The aim of this study was to determine the outcome of HCV infection in 105 Egyptian children who tested positive for HCV antibody (anti-HCV). The data of 105 anti-HCV-positive children presenting to the Pediatric Hepatology Unit, Cairo University Children's Hospital, between 1995 and 2002, were retrospectively analysed for risk factors. Seventy-four children with available polymerase chain reaction results were further analysed clinically, serologically and histologically. The age range was 1.3-22 years, with a mean of 11.2 +/- 4.9 years. History of blood transfusion was found in 81 children (77%). HCV RNA was detected in 58.1% of 74 children. Persistently elevated alanine aminotransferase (ALT) levels were present in 40 patients (54.1%). Hepatitis B virus markers (HBsAg and/or anti-HBc) were detected in 18 patients (24.3%). Twenty-six of the 43 HCV RNA-positive children underwent a diagnostic liver biopsy that showed chronic hepatitis in 19 patients (73.1%), cirrhosis in one case only (3.8%), and normal biopsy findings in seven children (26.9%). Blood transfusion remains a major risk of HCV transmission among Egyptian children. HCV infection is not always benign in the childhood period. ALT levels remain elevated in half of the children and histological abnormalities are detected in three quarters of HCV RNA-positive cases.

Gamma interferon (IFN-?) y factor transormador de crecimiento beta 1 (TGF-ß1) en niños egipcios con anemia aplástica adquirida / Interferon gamma (IFN-?) and transforming growth factor beta one (TGF-ß1) in Egyptian children with acquired aplastic anemia

Introducción: Observaciones clínicas y estudios analíticos han indicado la existencia de una base inmunológica para la patogénesis de anemia aplástica adquirida (AAA), con la mayoría de los pacientes respondiendo a terapia inmunosupresora. El factor transformador de crecimiento beta 1 (TGF-ß1) y gamma interferón (IFN-?) son dos de las citocinas implicadas en la regulación de células madre hematopoyéticas y células estromales de la médula ósea. Objetivo: La evaluación de los efectos del TGF-ß1 e IFN-? sobre la patogénesis de AAA en niños, la valoración de su relevancia clinica y relación con la terapia. Escenario: La Clínica Hematológica Pediátrica del New Children's Hospital de la Universidad de Cairo (Egipto).Pacientes y métodos: Sesenta y tres pacientes con AAA seleccionados de forma aleatoria y 31 controles similares. Medimos el nivel de IFN-? en suero por medio de ELISA en 33 pacientes (Grupo 1) y controles similares (n= 11), y valoramos el efecto del suero en estos pacientes sobre médula ósea normal según la formación de agregaciones y crecimiento de colonias. También medimos el nivel de TGF-ß1 en suero en 30 pacientes (Grupo 2) y controles similares (n= 20) por ELISA. Resultados: El Grupo 1 (n= 33) mostró un incremento significativo en IFN-? en suero y exhibió una inhibición muy significativa del crecimiento de colonias y la formación de agregaciones en médula ósea normal. El Grupo 2 (n= 30) presentó una disminución significativa de TGF-ß1 en comparación con controles. Estos resultados se relacionaron directamente con el estado de tratamiento. Conclusión: IFN-? y TGF-ß1 son factores patogénicos importantes en AAA que se relacionan con la gravedad de la enfermedad y la respuesta a la terapia inmunosupresora. TGF-ß1 tiene valor pronóstico predictivo que puede servir en el seguimiento de enfermos (AU)