Construction and demolition waste management in Hong Kong

Author name used in this publication: J Jian-li HaoAuthor name used in this publication: C N L Fan2005-2006 > Academic research: refereed > Chapter in an edited book (author)Version of RecordPublishe

Management of tracheobronchial obstruction in infants using metallic stents: long-term outcome

© 2015, Springer-Verlag Berlin Heidelberg. Results: Twelve balloon-expandable metallic stents were placed in the trachea (n = 10) and/or bronchi (n = 2) of 5 patients with a median age of 13 months (range 5–30 months). Etiology of the airway obstruction included congenital tracheal stenosis (n = 4), giant cervical and superior mediastinal lymphatic malformation with tracheobronchomalacia (n = 1). Seven complications were reported (3 patients developed granulation tissue, 2 patients had re-stenosis, 1 stent migrated, 1 stent fractured). All patients survived and were in good condition with a median follow-up of 16 years (range 11–18 years). Three patients weaned off ventilator and oxygen. Conclusions: Endoscopic stenting with metallic stent has satisfactory long-term outcome in treating infants with tracheobronchial obstruction. Introduction: Tracheobronchial obstruction, although uncommon in the pediatric age group, remains a challenging problem. We review the long-term outcome of endoscopic metallic stenting in infants with tracheobronchial obstruction. Materials and methods: Medical records of all pediatric surgical patients who underwent tracheobronchial metallic stenting in our center were reviewed retrospectively from 1996 to 2014. Patients’ demographic data, including etiology, associated anomalies and nature of obstruction were reviewed. Outcome measures include complications such as re-stenosis, granulation tissue, stent migration, fractured stent, maximal tracheal diameter achieved, weaning of ventilator and growth at interval follow-up.postprin

Effects of shelf age based on types of approval marking on passenger car tyres' safety performance

Issues surrounding the use of aged tyres are one of the major concerns with regard to vehicle safety. The changes in rubber components due to the ageing process may cause changes in a tyre's mechanical and chemical properties which may lead to road crashes attributed to tyre failure. The main objective of this study is to discover the effects of tyre shelf age and approval markings on the performance of aftermarket passenger car tyres. This study involved conducting accelerated ageing on the randomly purchased tyres. By utilizing the Design of Experiment method, 48 passenger car tyres from four tyre manufacturers were used as test samples representing 'Marked' and 'Non-marked' tyres. Half of the samples were subjected to accelerated ageing process using an accelerated ageing chamber to simulate the desired age, to the maximum of 5-year old shelf aged. All new and aged tyres comprising both 'Marked' and 'Non- marked' groups were then tested under the Tyre Performance Test protocols stipulated in the Malaysian Standard (MS) 149:2008. All of the samples were tested in accordance with MS 149:2008 and the results were compared thoroughly by markings, age and type of failure. The study implied that age did have effects on safety performance of the tyres and significant difference in terms of safety performance was observed between 'Marked' and 'Non-marked' tyres. In overall 'Marked' tyres showed superior performance as compared to 'Non-marked' tyres for all of the tests conducted. The results had also provided crucial reference in terms of suggested age of tyre life span for proactive tyre replacement. The suggested tire life span for proactive tire replacement is 7.2 years-old for 'Marked' tyres and 2.3 years old for 'Non-marked' tyres. Since the Malaysian government has already gazetted the mandatory standard on tyre markings for the local market, relevant authorities need to take responsibility for the effective and efficient enforcement of compliance with the standard

Fine Mapping of the NRG1 Hirschsprung's Disease Locus

The primary pathology of Hirschsprung's disease (HSCR, colon aganglionosis) is the absence of ganglia in variable lengths of the hindgut, resulting in functional obstruction. HSCR is attributed to a failure of migration of the enteric ganglion precursors along the developing gut. RET is a key regulator of the development of the enteric nervous system (ENS) and the major HSCR-causing gene. Yet the reduced penetrance of RET DNA HSCR-associated variants together with the phenotypic variability suggest the involvement of additional genes in the disease. Through a genome-wide association study, we uncovered a ∼350 kb HSCR-associated region encompassing part of the neuregulin-1 gene (NRG1). To identify the causal NRG1 variants contributing to HSCR, we genotyped 243 SNPs variants on 343 ethnic Chinese HSCR patients and 359 controls. Genotype analysis coupled with imputation narrowed down the HSCR-associated region to 21 kb, with four of the most associated SNPs (rs10088313, rs10094655, rs4624987, and rs3884552) mapping to the NRG1 promoter. We investigated whether there was correlation between the genotype at the rs10088313 locus and the amount of NRG1 expressed in human gut tissues (40 patients and 21 controls) and found differences in expression as a function of genotype. We also found significant differences in NRG1 expression levels between diseased and control individuals bearing the same rs10088313 risk genotype. This indicates that the effects of NRG1 common variants are likely to depend on other alleles or epigenetic factors present in the patients and would account for the variability in the genetic predisposition to HSCR

RET Mutational Spectrum in Hirschsprung Disease: Evaluation of 601 Chinese Patients

Rare (RVs) and common variants of the RET gene contribute to Hirschsprung disease (HSCR; congenital aganglionosis). While RET common variants are strongly associated with the commonest manifestation of the disease (males; short-segment aganglionosis; sporadic), rare coding sequence (CDS) variants are more frequently found in the lesser common and more severe forms of the disease (females; long/total colonic aganglionosis; familial)

Evaluation of the effects of implementing an electronic early warning score system: protocol for a stepped wedge study

Background: An Early Warning Score is a clinical risk score based upon vital signs intended to aid recognition of patients in need of urgent medical attention. The use of an escalation of care policy based upon an Early Warning Score is mandated as the standard of practice in British hospitals. Electronic systems for recording vital sign observations and Early Warning Score calculation offer theoretical benefits over paper-based systems. However, the evidence for their clinical benefit is limited. Previous studies have shown inconsistent results. The majority have employed a “before and after” study design, which may be strongly confounded by simultaneously occurring events. This study aims to examine how the implementation of an electronic early warning score system, System for Notification and Documentation (SEND), affects the recognition of clinical deterioration occurring in hospitalised adult patients. Methods: This study is a non-randomised stepped wedge evaluation carried out across the four hospitals of the Oxford University Hospitals NHS Trust, comparing charting on paper and charting using SEND. We assume that more frequent monitoring of acutely ill patients is associated with better recognition of patient deterioration. The primary outcome measure is the time between a patient’s first observations set with an Early Warning Score above the alerting threshold and their subsequent set of observations. Secondary outcome measures are in-hospital mortality, cardiac arrest and Intensive Care admission rates, hospital length of stay and system usability measured using the System Usability Scale. We will also measure Intensive Care length of stay, Intensive Care mortality, Acute Physiology and Chronic Health Evaluation (APACHE) II acute physiology score on admission, to examine whether the introduction of SEND has any effect on Intensive Care-related outcomes. Discussion: The development of this protocol has been informed by guidance from the Agency for Healthcare Research and Quality (AHRQ) Health Information Technology Evaluation Toolkit and Delone and McLeans’s Model of Information System Success. Our chosen trial design, a stepped wedge study, is well suited to the study of a phased roll out. The choice of primary endpoint is challenging. We have selected the time from the first triggering observation set to the subsequent observation set. This has the benefit of being easy to measure on both paper and electronic charting and having a straightforward interpretation. We have collected qualitative measures of system quality via a user questionnaire and organisational descriptors to help readers understand the context in which SEND has been implemented

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe