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  • Author: Bin Yu x
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Abstract

A ceria loaded carbon nanotubes (CeO2/CNTs) nanocomposites photocatalyst was prepared by chemical precipitation, and the preparation conditions were optimized using an orthogonal experiment method. HR-TEM, XRD, UV-Vis/DRS, TGA and XPS were used to characterize the photocatalyst. Nitrogen adsorption-desorption was employed to determine the BET specific surface area. The results indicated that the photocatalyst has no obvious impurities. CeO2 was dispersed on the carbon nanotubes with a good loading effect and high loading efficiency without agglomeration. The catalyst exhibits a strong ability to absorb light in the ultraviolet region and some ability to absorb light in the visible light region. The CeO2/CNTs nanocomposites photocatalyst was used to degrade azo dye Acid Orange 7 (40 mg/L). The optical decolorization rate was 66.58% after xenon lamp irradiation for 4 h, which is better than that of commercial CeO2 (43.13%). The results suggested that CeO2 loading on CNTs not only enhanced the optical decolorization rate but also accelerated the separation of CeO2/CNTs and water.

Abstract

The role of corticosteroids in the management of severely ill patients with influenza A (H1N1) viral infection is unclear and controversial. Two critically ill cases with influenza A (H1N1) infections complicated with organizing pneumonia (OP) in 2011 successfully treated with low dose corticosteroids were reported here. After initial clinical improvement, the condition of both patients aggravated 20-23 days after the onset of illness. Chest X-ray and computed tomographies (CT) showed an increment of lung infiltrates. Cultures of blood, pleural fluid and transbronchial aspirate were negative for bacteria and fungi. Organizing pneumonia was diagnosed clinically and both patients were successfully treated with low-dose corticosteroids. Low-dose corticosteroids initiated during convalescence may be beneficial for severe swine-origin influenza A H1N1 pandemic 2009 virus (S-OIV) infections.

Abstract

In this paper, an area and power efficient current mode frequency synthesizer for system-on-chip (SoC) is proposed. A current-mode transformer loop filter suitable for low supply voltage is implemented to remove the need of a large capacitor in the loop filter, and a current controlled oscillator with additional voltage based frequency tuning mechanism is designed with an active inductor. The proposed design is further integrated with a fully programmable frequency divider to maintain a good balance among output frequency operating range, power consumption as well as silicon area. A test chip is implemented in a standard 0.13 µm CMOS technology, measurement result demonstrates that the proposed design has a working range from 916 MHz to 1.1 l GHz and occupies a silicon area of 0.25 mm2 while consuming 8.4 mW from a 1.2 V supply.

Abstract

With aim to improve the mechanical and thermal properties of poly (lactic acid) (PLA) melt-blown nonwovens (MBs), polyamide 11 (PA11) was melt blended with PLA at the weight proportions of PLA/PA11 (95/5, 90/10, 85/15, 80/20), and the corresponding PLA/PA11 MBs were also manufactured. The crystallization, thermal and rheological behaviors of PLA/PA11 blends were investigated. PLA/PA11 MBs were also characterized by morphology and mechanical properties. The results indicated that PA11, as globular dispersed phases, formed confined crystals and could improve the thermal stability of PLA matrix. The viscosity of PLA/PA11 blends was slightly increased but the rheological behaviors of “shear-thinning” kept unchanged in comparison with PLA. The average diameter of PLA/PA11 MB fibers was slightly increased, whereas the toughness of PLA/PA11 MBs including the strength and elongation were efficiently enhanced compared with those of PLA MBs.

Abstract

Advantages of the supercritical fluid (SCF) process compared to the conventional solution stirring method (CSSM) in the preparation of daidzein-hydroxypropyl-β-cyclodextrin (HPβCD) complexes were investigated. Formation of daidzein/ HPβCD inclusion complexes was confirmed by Fourier transformed-infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Particle size, inclusion yield, drug solubility and dissolution of daidzein/HPβCD complexes were evaluated. Compared to CSSM, the SCF process resulted in higher inclusion yield and higher solubility. Also, extended dissolution of daidzein from the SCF processed HPβCD inclusion complexes was observed, with only 22.94 % released in 45 min, compared to its rapid release from those prepared by CSSM, with 98.25 % drug release in 15 min. This extended release of daidzein from SCF prepared inclusion complexes was necessary to avoid drug precipitation and improve drug solubilisation in the gastrointestinal tract. The results showed that the SCF process is a superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes.

Abstract

Accurate measurements of cigarette coal temperature are essential to understand the thermophysical and thermo-chemical processes in a burning cigarette. The last system-atic studies of cigarette burning temperature measurements were conducted in the mid-1970s. Contemporary cigarettes have evolved in design features and multiple standard machine-smoking regimes have also become available, hence there is a need to re-examine cigarette combustion. In this work, we performed systematic measurements on gas-phase temperature of burning cigarettes using an improved fine thermocouple technique. The effects of machine-smoking parameters (puff volume and puff duration) and filter ventilation levels were studied with high spatial and time resolutions during single puffs. The experimental results were presented in a number of differ-ent ways to highlight the dynamic and complex thermal processes inside a burning coal. A mathematical distribution equation was used to fit the experimental temperature data. Extracting and plotting the distribution parameters against puffing time revealed complex temperature profiles under different coal volume as a function of puffing intensities or filter ventilation levels. By dividing the coal volume prior to puffing into three temperature ranges (low-temperature from 200 to 400 °C, medium-temperature from 400 to 600 °C, and high-temperature volume above 600 °C) by following their development at different smoking regimes, useful mechanistic details were obtained. Finally, direct visualisation of the gas-phase temperature through detailed temperature and temperature gradient contour maps provided further insights into the complex thermo-physics of the burning coal. [Beitr. Tabakforsch. Int. 26 (2014) 191-203]

Abstract

Objective To construct prokaryotic expression vector of CFP-10 gene, and obtain recombinant protein, and the recombinant CFP-10 protein was taken as stimulus to detect specific T cell responses, to set up a method to faciliate to detect potential TB infection in China.

Methods CFP-10 was cloned into inducible prokaryotic expression vector pET-32a (+) and transfected into E. coli BL21 (DE3). After IPTG induction, the product were verified with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot hybridization were carried out to verify the antigenicity; the recombinant CFP-10 protein was taken as stimulus to detect specific T cell responses in HIV (+) persons with or without clinical manifestation of TB diseases, and HIV (-) controls with or without TB diseases.

Results The CFP-10 recombinant protein exsited in the form of inclusion body and accounted for 94% in total bacterial protein of E. coli and the molecular weight is 31 kD; Western blot confirmed the recombinant proteins had high antigenicity; our in-house ELISpot-IFN-γ assay with recombinant antigen derived from CFP-10 proteins showed significant higher frequencies in TB patients with or without HIV infection than that in the healthy controls and only HIV (+) group.

Conclusions The recombinant CFP-10 genes can be expressed successfully in prokaryotic expression system of E. coli and recombinant proteins with high antigenicity were obtained, which will set foundation for further study on their immunogenicity and bioinformatics. Our results proved that it is indeed true that some HIV positive patient have high frequencies of TB specific T cell responses, which maybe a clue to find latent TB infection in this population.

Abstract

The nucleotide binding site (NBS) domain sequences were iso­lated from genomic DNA in black bamboo, using the degenerate primer designed according to the conserved motifs of the NBS resistance gene. The expected size of the PCR product was about 700 bp. Among 55 positive clones, the amino acid sequence alignment identified 33 black bamboo resistance gene analogs (RGAs) that contain the NBS conserved motifs. All of the 33 RGAs ORFs were constructed in an NJ (Neighbor-joi­ning) tree, and divided into 10 groups. This analysis demonstrated the diversity of the NBS class RGA in black bamboo. The maximum likelihood estimates of various evolutionary models were analyzed; the result showed that 2 groups with a total of 10 sequences and 12 sites demonstrated statistically significant positive selection. Most of the positive selected sites were not located in the NBS conserved motifs. Two groups of gene conversion events had been discovered, which provide a mate­rial basis and research direction in isolating black bamboo R genes.

CYP2E1 mRNA Expression, Genetic Polymorphisms in Peripheral Blood Lymphocytes and Liver Abnormalities in Chinese VCM-Exposed Workers

Objective: To study the relationship between expression of cytochrome P4502E1 (CYP2E1) in human lymphocytes, variant CYP2E1 genotype, exposure to vinyl chloride monomer (VCM), and liver abnormalities in VCM-exposed workers. Methods: A case-control study was performed on 90 male occupationally exposed workers and 42 matched male nonexposed controls. Data were collected based on health surveillance, workplace investigation and questionnaire Survey. Total RNA and DNA were isolated from peripheral blood lymphocytes, and CYP2E1 mRNA expression was determined using RT-PCR, and the presence of CYP2E1 polymorphisms was identified based on PCR-RFLP. Results: The mRNA expression of CYP2E1 in exposed workers (0.89±0.46) was significantly higher than in nonexposed controls (0.61±0.35) (P < 0.01). Logistic regression analysis demonstrated a statistically significant association between CYP2E1 mRNA expression levels and liver abnormalities in the VCM-exposed workers (OR = 3.66, P < 0.05). The genotype frequency for CYP2E1 variants among VCM-exposed workers was not significantly different between workers with liver abnormalities and those without. Conclusions: Liver abnormalities in subjects exposed to VCM are positively associated with expression of peripheral blood lymphocyte mRNA, which is significantly increased in exposed workers compared to nonexposed controls. Therefore, CYP2E1 mRNA levels may be useful for health surveillance and protection of VCM-exposed workers.

Abstract

This article revealed two valuable case reports about two young females suffered tuberculous meningitis after cesarean section. After antituberculous therapy, the condition of one patient improved and the other one became deteriorated.