A novel two-step recombinogenic engineering method for bacterial artificial chromosome manipulation

published_or_final_versio

Membrane fouling in a submerged membrane bioreactor (SMBR): Characterisation of the sludge cake and its high filtration resistance

The attachment of sludge cake to the membrane surface is the main cause of the fouling problem in the submerged membrane bioreactors (SMBR) used in biological wastewater treatment. In this laboratory study, the sludge cake deposited on the membrane was found to have a specific filtration resistance of the order of 1014 m/kg, which is much greater than expected for sludge cake formed during the dewatering of activated sludge. The filterability tests showed that the cake sludge removed from the fouled membrane of the SMBR had an average specific filtration resistance of 4.9 × 1013 m/kg, whereas the sludge cake of the SMBR bulk sludge had an average filtration resistance of only 1.9 × 1011 m/kg. Detailed chemical analysis showed there was a pool of biopolymer clusters (BPC) that was trapped within the sludge cake on the membrane. These clusters could be readily separated from the cake sludge by stirring it into a suspension. The abundance of non-filterable BPC as measured by the total organic carbon (TOC) in the suspended solids (SS) was about 10.3 mg/g SS for the cake sludge, in comparison to 0.4 mg/g SS for the bulk sludge. When the BPC were removed from the cake sludge, the filtration resistance of the cake sludge could be reduced considerably from 4.9 × 1013 to 8.4 × 1012 m/kg. It is argued that the BPC are a special form of organic matter formed by affinity clustering of the free extracellular polymeric substances (EPS) and soluble microbial products (SMP) in the sludge cake deposited on the membrane surface. The accumulation of BPC within the pores of the sludge cake is mostly responsible for the unusually high filtration resistance of the cake sludge during the SMBR operation. © 2006 Elsevier B.V. All rights reserved.postprin

PIKfyve, a class III lipid kinase, is required for TLR-induced type I IFN production via modulation of ATF3

Type I IFN plays a key role in antiviral responses. It also has been shown that deregulation of type I IFN expression following abnormal activation of TLRs contributes to the pathogenesis of systemic lupus erythematosus. In this study, we find that PIKfyve, a class III lipid kinase, is required for endolysosomal TLR-induced expression of type I IFN in mouse and human cells. PIKfyve binds to phosphatidylinositol 3-phosphate and synthesizes phosphatidylinositol 3,5-bisphosphate, and plays a critical role in endolysosomal trafficking. However, PIKfyve modulates type I IFN production via mechanisms independent of receptor and ligand trafficking in endolysosomes. Instead, pharmacological or genetic inactivation of PIKfyve rapidly induces expression of the transcription repressor ATF3, which is necessary and sufficient for suppression of type I IFN expression by bin'ding to its promoter and blocking its transcription. Thus, we have uncovered a novel phosphoinositide-mediated regulatory mechanism that controls TLR-mediated induction of type I IFN, which may provide a new therapeutic indication for the PIKfyve inhibitor.X111313Ysciescopu

Smad3 promotes cancer progression by inhibiting E4BP4-mediated NK cell development

published_or_final_versio

Spiritual needs of the Chinese stroke survivors in holistic care

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

Interrogating Institutionalized Establishments: Urban-Rural Inequalities in China’s Higher Education

postprin

Planar and van der Waals heterostructures for vertical tunnelling single electron transistors

Despite a rich choice of two-dimensional materials, which exists these days, heterostructures, both vertical (van der Waals) and in-plane, offer an unprecedented control over the properties and functionalities of the resulted structures. Thus, planar heterostructures allow p-n junctions between different two-dimensional semiconductors and graphene nanoribbons with well-defined edges; and vertical heterostructures resulted in the observation of superconductivity in purely carbon-based systems and realisation of vertical tunnelling transistors. Here we demonstrate simultaneous use of in-plane and van der Waals heterostructures to build vertical single electron tunnelling transistors. We grow graphene quantum dots inside the matrix of hexagonal boron nitride, which allows a dramatic reduction of the number of localised states along the perimeter of the quantum dots. The use of hexagonal boron nitride tunnel barriers as contacts to the graphene quantum dots make our transistors reproducible and not dependent on the localised states, opening even larger flexibility when designing future devices

Citywide Trauma Experience in Mwanza, Tanzania: A Need for Urgent Intervention.

Trauma remains a leading cause of morbidity and mortality in resource limited countries. There is paucity of published reports on trauma care in Tanzania, particularly the study area. This study was carried out to describe our experiences in trauma management outlining the etiological spectrum, injury characteristics and treatment outcome of trauma patients at our local setting and compare our results with those from other centers in the world. A descriptive prospective study of trauma patients was conducted at Bugando Medical Centre from April 2010 to March 2012. Statistical data analysis was done using SPSS software version 17.0. A total of 5672 trauma patients were enrolled in the study. The male to female ratio was 2.3: 1. The majority of patients were in the 2nd decade of life. Road traffic accident was the most common cause of trauma accounting for 60.7% of cases. The majority of patients (76.6%) sustained blunt injuries. Musculoskeletal (68.5%) and head/neck (52.6%) were the most frequent body region injured. Soft tissue injuries (open wounds) and fractures were the most common injuries accounting for 82.8% and 76.8% respectively. Majority of patients (74.4%) were treated surgically with wound debridement (94.0%) being the most frequently performed procedure. Postoperative complications were recorded in 31.5% of cases.The overall median duration of hospitalization was 26 days (range 1 day to 144 days). Mortality rate was 16.7%. Patients who had polytrauma, burn injuries and those who had tetanus and long bone fractures stayed longer in the hospital and this was statistically significant (P < 0.001), whereas the age > 65 years, severe trauma, admission Systolic Blood Pressure < 90 mmHg, presence of tetanus, severe head injury, the duration of loss of consciousness, the need for intensive care unit admission and finding of space occupying lesion on CT scan of the brain significantly influenced mortality (P < 0.001). Trauma resulting from road traffic accidents remains a major public health problem in this part of Tanzania. Urgent preventive measures targeting at reducing the occurrence of road traffic accidents is necessary to reduce the incidence of trauma in this region

Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification was produced by heating the ground of the street canyon. Using the Boussinesq approximation, thermal buoyancy forces were taken into account in both the Navier–Stokes equations and the transport equation for subgrid-scale turbulent kinetic energy (TKE). The LESs were validated against experimental data obtained in wind-tunnel studies before the model was applied to study the detailed turbulence, temperature, and pollutant dispersion characteristics in the street canyon of aspect ratio 1. The effects of different Richardson numbers (Ri) were investigated. The ground heating significantly enhanced mean flow, turbulence, and pollutant flux inside the street canyon, but weakened the shear at the roof level. The mean flow was observed to be no longer isolated from the free stream and fresh air could be entrained into the street canyon at the roof-level leeward corner. Weighed against higher temperature, the ground heating facilitated pollutant removal from the street canyon.Singapore-MIT Alliance for Research and Technology. Center for Environmental Sensing and Monitorin