Retrospective analysis of the Beijing family of Mycobacterium tuberculosis in preserved lung tissues

Direct repeat spoligotyping of 85 paraffin-embedded lung biopsies was used to investigated the occurrence around Beijing of the Beijing family of Mycobacterium tuberculosis. Samples ranged in time from 1956 to 1990. Hybridization patterns were found with 49 (58%) samples, and 45 (92%) produced typical Beijing family patterns extending over the 34-year period.     

Synthesis and characterization of bifunctional β-MnO2-based Pt/C photoelectrochemical cell for hydrogen production

A manganese dioxide (β-MnO₂) photocatalyst for light-induced water splitting and hydrogen generation is studied via the impregnation and heat treatment method. The phase and fluorescence characterizations are examined by X-ray diffraction (XRD) and photoluminescence. A series of peaks for its (110) and (200) planes are identified as those for pure β-MnO₂ crystals with lattice spacings of 3.11 and 2.19 Å, respectively. The photoluminescence shows that the primary signals are located in the blue-violet spectral region, corresponding to the band-edge emission of β-MnO₂ (376 nm). Furthermore, two types of photoelectrochemical cell with added Pt are constructed to compare hydrogen production rates. A significant enhancement of light-induced hydrogen generation by water splitting is observed on Pt/β-MnO₂/C, with a hydrogen generation rate of 194.67 μmol cm⁻¹ h⁻¹, greater than that on a Pt/TiO₂/C photocatalyst, which can be attributed to the effective inhibiting of CO poisoning, thus maintaining the catalyst's surface area in methanol oxidation.     

Using ADABOOST and Rough Set Theory for Predicting Debris Flow Disaster

Debris flow resulting from typhoons, heavy rainfall, tsunamis or other natural disasters is a matter of particular importance to Taiwan owing to the country’s unique geographical environment and exacerbated by poor slope management and global warming. With regard to these types of natural occurrences, recent global events have attracted the attention of experts in various fields, such as civil engineering, environmental engineering and information management. These experts have developed several techniques to study the various factors of debris flow. The ADABOOST and rough set theory (RST) are two emerging methods with regard to classification and rule provision. The ADABOOST, an adaptive boosting machine learning algorithm, uses very little memory during computation and can obtain robust classification results. RST is able to deal with uncertainties and vague information in generating rules for decision makers. Thus, this study develops an ADARST model which uses the unique strengths of the ADABOOST and RST in classification and rule generation and applies the proposed ADARST to analyze debris flow. Specifically, data from previous studies were obtained and used for the purposes of this study. Experimental results have shown that the proposed ADARST model is able to generate better results than those in previous investigations in terms of prediction accuracy. In addition, the designed ADARST model can provide rules including forward and backward reasoning ways for decision makers. Therefore, the proposed ADARST model is shown to be an effective methodology with which to analyze debris flow.     

Demonstration of cellular aging and senescence in serially passaged long-term cultures of human trabecular osteoblasts

The proliferative capacity and cellular and biochemical characteristics of human trabecular bone osteoblasts were analysed throughout their replicative lifespan in vitro. Like several other cell types, human osteoblasts demonstrated a typical Hayflick phenomenon of cellular aging comprising a period of rapid proliferation until cumulative population doubling level (CPDL) 22 to 24, followed by a phase of slow growth and the final cessation of cell division at CPDL 32 to 34. Comparing young cells (less than 20% lifespan completed) and old cells (more than 90% lifespan completed) revealed a progressive increase in population doubling (PD) time, a decrease in attachment frequency, a decrease in the number of S-phase positive cells, a decrease in the rates of DNA, RNA and protein synthesis, an increase in the protein content per cell and an increased proportion of senescence-specific beta-galactosidase positive cells. While osteoblastic production of collagen type I decreased progressively during aging, alkaline phosphatase activity dropped rapidly after the first few passages and then remained constant during the rest of the proliferative lifespan, Significant morphological changes from thin and spindle-shaped early passage young cells to large, flattened and irregularly shaped late passage old cells full of intracellular debris were observed. In comparison, osteoblasts established from an osteoporotic bone sample showed a maximum CPDL of less than 5, had a longer PD time and exhibited abnormal senescent morphology. Thus, we have demonstrated for the first time that human osteoblasts, like several other diploid cell types, have a limited proliferative capacity in vitro and undergo aging and senescence as measured by various cellular and biochemical markers. In addition, preliminary studies show that cells from osteoporotic bone have a severely reduced proliferative capacity. This model of bone cell aging facilitates study of the molecular mechanisms of osteoblast senescence as well as factors related to osteoblast dysfunction in patients with osteoporosis.     

Treatment of severe acute exacerbation of asthma and chronic obstructive lung disease. An interview study

A telephone survey was conducted of all the 71 Danish hospitals with the capacity to receive acutely ill medical patients. The purpose was to register treatment regimes used in acute asthma and exacerbations in chronic obstructive pulmonary disease (COPD). The house officer on duty was interviewed and questioned about the use of nebulizers, oxygen therapy, bronchodilators, steroids, theophyllins and monitoring of the patient's condition. The physician survey was supplemented by a smaller survey among emergency room nurses about nebulizing systems. The answers showed inadequate knowledge of nebulizing systems. There was a noticeable variation in the dosing of oxygen and in the dosing of bronchodilators and steroids. beta 2-agonist treatment by nebulizer differed with a factor 14 in dose. The majority of the physicians had no specific parameters for monitoring severity of disease. CONCLUSION: There is a need for improvement of the knowledge of nebulizing systems, including specific knowledge of the appropriate use of propellant gasflow and time of nebulizing for optimum performance of the used nebulizer. Divergent answers from the nurses and the physicians show the need for interdisciplinary instruction. The noticeable variation in treatment in this Danish survey displays a need for quality control in terms of concise guidelines for medical therapy in acute exacerbations of asthma and COPD and guidelines for monitoring of the response to the treatment. A suggestion for a treatment regime is proposed.     

Application of the generalized method of cells principle to particulate-reinforced metal matrix composites

A three-dimensional model based on the generalized method of cells (GMC) principle has been used to predict the effective properties of particulate-reinforced metal matrix composites (PMMCs). The effects of constituent phases on the elastic properties of PMMCs are predicted using GMC. The predictions are compared with an assortment of finite-element predictions and experimental results available in the literature. The accuracy and the computational efficiency of the GMC model are also discussed. Moreover, the effect of particle shape and orientation on the elastic properties of PMMCs has been predicted and analyzed. Cubical and parallelepiped shaped particles having different orientations are considered for this study. Significant variations are noted on the elastic properties of the PMMC systems by altering the shape and orientation of the particles.     

Roughness-enhanced reliability of MOS tunneling diodes

Both electrical and optical reliabilities of PMOS and NMOS tunneling diodes are enhanced by oxide roughness, prepared by very high vacuum prebake technology. For rough PMOS devices, as compared to flat PMOS devices, the Weibull plot of T_BD shows a 2.5-fold enhancement at 63% failure rate, while both the D₂ and H₂-treated flat PMOS devices show similar inferior reliability. For rough NMOS devices, as compared to flat NMOS devices, the Weibull plot of T_BD shows a 4.9-fold enhancement at 63% failure rate. The time evolutions of the light emission from rough PMOS and NMOS diodes degrade much less than those of flat PMOS and NMOS diodes. The momentum reduction perpendicular to the Si/SiO₂ interface by roughness scattering could possibly make it difficult to form defects in the bulk oxide and at the Si/SiO₂ interface by the impact of the energetic electrons and holes