Characteristics and community diversity of a wheat straw-colonizing microbial community

A microbial community named WSD-5 was successfully selected from plant litter and soil after longterm directed acclimation at normal temperature. After 15 days of cultivation at 30°C, the degradation rate of wheat straw by WSD-5 was 75.6%. For cellulose, hemicellulose and lignin, the degradation rates were 94.2, 81.9 and 21.3%, respectively. The optimal pH for filter paper, CMCase, avicelase, β- glucosidase and xylanse activities was 6.24, 6.24, 5.91, 5.91 and 6.24, respectively. The optimal reaction temperature for all enzyme activity was 55°C. Filter paper enzyme, cellulase and xylanase were secreted from the degradation of wheat straw by WSD-5. The highest filter paper, cellulose endonuclease (CMCase), cellulose exonuclease (avicelase), β-glucosidase and xylanase activities were 1.30, 4.35, 0.60, 0.43 and 15.16 U/ml, respectively. A library of bacterial and fungal ribosomal gene sequences obtained from the community showed the presence of Ochrobactrum sp, Coprinus cinereus and Pseudallescheria boydii. To our knowledge, this was the first report of a microbial community which consisted of bacteria and fungi and was selected in the presence of wheat straw to produce extracellular filter paper enzyme, cellulase and xylanase.Key words: Microbial community, lignocellulose degradation, filter paper activity, CMCase, avicelase, β- glucosidase, xylanase

Enhanced performance of Si MOS capacitors with HfTaOxNy gate dielectric by using AlOxNy or TaOxNy interlayer

Si MOS capacitors with HfTa oxide and oxynitride as gate dielectric were fabricated. Moreover, AlOxNy or TaOxN y was used as the interlayer between HfTa oxynitride and Si substrate to improve the electrical quality of the capacitors. Experimental results showed that the HfTaOxNy capacitor with TaO xNy interlayer achieved better performance with larger capacitance and smaller leakage current than its counterpart with AlO xNy interlayer. © 2008 IEEE.published_or_final_versio

Synoptic-scale precursors of extreme UK summer 3-hourly rainfall

This is the final version. Available on open access from AGU via the DOI in this recordThe synoptic-scale meteorological conditions leading up to the 30 most extreme sub-daily summer rain events for two regions of the UK (north-west and south-east) were examined for the period 1979-2013. Using a recently available, quality controlled, national hourly rain gauge dataset, we were able to identify extreme 3-hour rainfall accumulations that may be indicative of flash flooding. Composites of the state of the atmosphere leading up to these dates were produced to investigate synoptic-scale processes, thus potentially allowing for them to be identified in coarse resolution re-analyses and in climate models. The results show that the two regions have different dominant synoptic-scale conditions leading to extreme 3-hour rainfall, which is thought to be related to the type of rainfall typically experienced in each region. In particular, positive anomalies in mean sea level pressure and the geopotential height at 200hPa over the UK are associated with extreme rainfall in the north-west, where the position of the westerly jet is also important. For the south-east, no clear anomalous synoptic-scale conditions could be identified, however localised moisture sources and unstable air masses were observed in association with extremes. These results indicate the importance of better understanding of both synoptic-scale and thermodynamic drivers of short-duration extreme rainfall, with potential implications in forecasting and flood warning, as well as for understanding the representation of key processes by regional climate models.Natural Environment Research Council (NERC)European Research CouncilWolfson FoundationRoyal Societ

Improved electrical properties of Ge p-MOSFET with HfO 2 gate dielectric by using TaO xN y interlayer

The electrical characteristics of germanium p-metal-oxide-semiconductor (p-MOS) capacitor and p-MOS field-effect transistor (FET) with a stack gate dielectric of HfO 2TaO xN y are investigated. Experimental results show that MOS devices exhibit much lower gate leakage current than MOS devices with only HfO 2 as gate dielectric, good interface properties, good transistor characteristics, and about 1.7-fold hole-mobility enhancement as compared with conventional Si p-MOSFETs. These demonstrate that forming an ultrathin passivation layer of TaO xN y on germanium surface prior to deposition of high- k dielectrics can effectively suppress the growth of unstable GeO x, thus reducing interface states and increasing carrier mobility in the inversion channel of Ge-based transistors. © 2008 IEEE.published_or_final_versio

Comparative study of HfTa-based gate-dielectric Ge metal-oxide- semiconductor capacitors with and without AlON interlayer

The electrical properties and high-field reliability of HfTa-based gate-dielectric metal-oxide-semiconductor (MOS) devices with and without AlON interlayer on Ge substrate are investigated. Experimental results show that theMOS capacitor with HfTaON/AlON stack gate dielectric exhibits low interface-state/oxide-charge densities, low gate leakage, small capacitance equivalent thickness (∼1.1 nm), and high dielectric constant (∼20). All of these should be attributed to the blocking role of the ultrathin AlON interlayer against interdiffusions of Ge, Hf, and Ta and penetration of O into the Ge substrate, with the latter effectively suppressing the unintentional formation of unstable poorquality low-k GeO x and giving a superior AlON/Ge interface. Moreover, incorporation of N into both the interlayer and high-k dielectric further improves the device reliability under high-field stress through the formation of strong Nrelated bonds. © Springer-Verlag 2009.published_or_final_versionSpringer Open Choice, 01 Dec 201

Cervical lymph node metastatic patterns of squamous carcinomas in the upper aerodigestive tract

The radical neck dissection specimens of 384 ethnically Chinese patients with different primary squamous carcinomas in the head and neck region were studied. Over 50 per cent of the specimens showed metastatic disease at one level in the neck. For oral cavity carcinoma, the levels of metastasis frequently involved were I, II and III while for carcinoma of the oropharynx, hypopharynx and larynx, the levels were II, III and IV. Extracapsular spread was present in 112/384 of patients (29 per cent) and this increased with advancing N-stages. Based on these findings, different selective neck dissections could be used for patients harbouring different primary head and neck carcinomas with limited neck disease.published_or_final_versio

Design of low-threshold compact Au-nanoparticle lasers

2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Investigation on the Dispersal Characteristics of Liquid Breakup in Vacuum

This work presents an experimental study on the dispersal characteristics of a liquid jet ejecting into vacuum. The liquid breaking experiments of several kinds of liquid under different pressure and temperature conditions are carried out in a flash chamber. The stability of the jet and the sizes of the droplets or the icing particles formed during liquid flashing dispersing are analyzed. The influences of the superheat degree, spray velocity, and the mass of the volatile liquid mixing in the nonvolatile liquid on these characteristics are discussed. Moreover, the applicability of the two definitions of superheat degree is discussed. The results show that the superheat degree is an important parameter influencing the pattern of the breaking liquid, and the jet velocity has a large influence on the distribution of particle sizes. In addition, mixing some volatile liquid with nonvolatile liquid can enhance the dispersion of the latter

Treatment time for non-surgical endodontic therapy with or without a magnifying loupe

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