1,249 research outputs found
Public knowledge of how to use an automatic external defibrillator in out-of-hospital cardiac arrest in Hong Kong
published_or_final_versio
Detection and characterisation of defects in directed energy deposited multi-material components using full waveform inversion and reverse time migration
Directed energy deposition (DED) is capable in producing complex or high-value components with good mechanical properties. Despite these potential advantages, the quality and integrity of multi-material DED parts, remains a challenging issue that limits its wide applications. Material porosity in multi-material components is detrimental since it may lead to premature structural failure. This paper proposes a two-stage ultrasonic method to characterise the internal structure to enhance the understanding of the process parameters on material porosity. In this method, the low-frequency model building aims at reconstructing background structure and the high-frequency imaging targets at small defects. The first stage is based on the gradient sampling full-waveform inversion for the estimation of the velocity model, which is then used as the initial model for the reverse time migration for reflectivity. The experimental results show that accurate reconstructions of the interface between two materials and defects in multi-material DED components can be achieved
Paediatric Epilepsy Surgery Programme in Hong Kong: experience in Queen Mary Hospital / Duchess of Kent Children's Hospital
Poster: no. P6BACKGROUND: Surgery is a well-established treatment for adults with intractable seizures. Increasingly, infants and children are being considered for epilepsy surgery. In a growing child, epilepsy surgery has the additional benefit of aborting cognitive decline and improving development and behaviour ...published_or_final_versio
Paediatric Epilepsy Surgery Programme in Hong Kong: experience in Queen Mary Hospital/Duchess of Kent Children's Hospital
Poster: no. P6BACKGROUND: Surgery is a well-established treatment for adults with intractable seizures. Increasingly, infants and children are being considered for epilepsy surgery. In a growing child, epilepsy surgery has the additional benefit of aborting cognitive decline and improving development and behaviour. METHODS: The paediatric epilepsy surgery programme ...published_or_final_versio
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Association of proinflammatory cytokines and chemotherapy-associated cognitive impairment in breast cancer patients: a multi-centered, prospective, cohort study.
BackgroundExisting evidence suggests that proinflammatory cytokines play an intermediary role in postchemotherapy cognitive impairment. This is one of the largest multicentered, cohort studies conducted in Singapore to evaluate the prevalence and proinflammatory biomarkers associated with cognitive impairment in breast cancer patients.Patients and methodsChemotherapy-receiving breast cancer patients (stages I-III) were recruited. Proinflammatory plasma cytokines concentrations [interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, interferon-γ and tumor necrosis factor-α] were evaluated at 3 time points (before chemotherapy, 6 and 12 weeks after chemotherapy initiation). The FACT-Cog (version 3) was utilized to evaluate patients' self-perceived cognitive disturbances and a computerized neuropsychological assessment (Headminder) was administered to evaluate patients' memory, attention, response speed and processing speed. Changes of cognition throughout chemotherapy treatment were compared against the baseline. Linear mixed-effects models were applied to test the relationships of clinical variables and cytokine concentrations on self-perceived cognitive disturbances and each objective cognitive domain.ResultsNinety-nine patients were included (age 50.5 ± 8.4 years; 81.8% Chinese; mean duration of education = 10.8 ± 3.3 years). Higher plasma IL-1β was associated with poorer response speed performance (estimate: -0.78; 95% confidence interval (CI) -1.34 to -0.03; P = 0.023), and a higher concentration of IL-4 was associated with better response speed performance (P = 0.022). Higher concentrations of IL-1β and IL-6 were associated with more severe self-perceived cognitive disturbances (P = 0.018 and 0.001, respectively). Patients with higher concentrations of IL-4 also reported less severe cognitive disturbances (P = 0.022).ConclusionsWhile elevated concentrations of IL-6 and IL-1β were observed in patients with poorer response speed performance and perceived cognitive disturbances, IL-4 may be protective against chemotherapy-associated cognitive impairment. This study is important because cytokines would potentially be mechanistic mediators of chemotherapy-associated cognitive changes
Partial purification of alpha-amylase from culture supernatant of Bacillus subtilis in aqueous two-phase systems
The original publication can be found at www.springerlink.comA study was made of the partition and purification of -amylase from a culture supernatant of Bacillus subtilis in the polyethylene glycol (PEG)—citrate aqueous two-phase system (ATPS). Factors that influenced the partition of the protein in this system, including the molecular weight of the PEG, the tie line length of ATPS, the pH value and the sodium chloride concentration, were investigated. Purification of -amylase was attained with a purification factor (PF) of 1.8 and 90% yield at pH 6.0 in a PEG1000-citrate ATPS with short tie line length. By utilizing the salt-out effect of neutral salt, the purification of -amylase was further improved to 2.0 of PF and 80% yield in a PEG3350-citrate ATPS with 4% sodium chloride.Wenbo Zhi, Jiangnan Song, Jingxiu Bi and Fan Ouyan
On the Morphology, Structure and Field Emission Properties of Silver-Tetracyanoquinodimethane Nanostructures
Silver-tetracyanoquinodimethane(Ag-TCNQ) nanostructured arrays with different morphologies were grown by an organic vapor-transport reaction under different conditions. The field emission properties of nanostructured arrays were studied systematically. Their morphology and crystal structure were characterized by SEM and XRD, respectively. It was found that the field emission properties were strongly dependent on the reaction temperature and the initial Ag film thickness. The lowest turn-on field with 10-nm-thick silver film is about 2.0 V/μm, comparable to that of carbon nanotubes. The film crystal structure and the morphology are contributed to the final emission performance
Data-Driven Optimization of Public Transit Schedule
Bus transit systems are the backbone of public transportation in the United
States. An important indicator of the quality of service in such
infrastructures is on-time performance at stops, with published transit
schedules playing an integral role governing the level of success of the
service. However there are relatively few optimization architectures leveraging
stochastic search that focus on optimizing bus timetables with the objective of
maximizing probability of bus arrivals at timepoints with delays within desired
on-time ranges. In addition to this, there is a lack of substantial research
considering monthly and seasonal variations of delay patterns integrated with
such optimization strategies. To address these,this paper makes the following
contributions to the corpus of studies on transit on-time performance
optimization: (a) an unsupervised clustering mechanism is presented which
groups months with similar seasonal delay patterns, (b) the problem is
formulated as a single-objective optimization task and a greedy algorithm, a
genetic algorithm (GA) as well as a particle swarm optimization (PSO) algorithm
are employed to solve it, (c) a detailed discussion on empirical results
comparing the algorithms are provided and sensitivity analysis on
hyper-parameters of the heuristics are presented along with execution times,
which will help practitioners looking at similar problems. The analyses
conducted are insightful in the local context of improving public transit
scheduling in the Nashville metro region as well as informative from a global
perspective as an elaborate case study which builds upon the growing corpus of
empirical studies using nature-inspired approaches to transit schedule
optimization.Comment: 20 pages, 6 figures, 2 table
Are Hylobates lar Extirpated from China?
The Nangunhe Nature Reserve in Southwest Yunnan (PRC) has long been presumed to be the last stronghold of lar (or white-handed) gibbons (Hylobates lar) in China and the likely last place of occurrence of Hylobates lar yunnanensis. We conducted a comprehensive survey to assess the status of lar gibbons at Nangunhe. We found no visual or auditory evidence of them still residing at the reserve and therefore tentatively conclude that lar gibbons have become extinct in China. It appears that large-scale destruction of primary forests in the 1960s and 1970s brought about an initial decline in their numbers, and subsequent uncontrolled hunting has resulted in their extirpation. The situation for the six Chinese ape taxa is nothing less than disastrous, with 1 taxon assumed to have become extinct during the last few years, 1 taxon not having been confirmed since the 1980s, and 2 species at the very brink of extinction with only tens of individuals remaining in China
Quantitative Proteomics Identifies the Myb-Binding Protein p160 as a Novel Target of the von Hippel-Lindau Tumor Suppressor
Background: The von Hippel-Lindau (VHL) tumor suppressor gene encodes a component of a ubiquitin ligase complex, which is best understood as a negative regulator of hypoxia inducible factor (HIF). VHL ubiquitinates and degrades the a subunits of HIF, and this is proposed to suppress tumorigenesis and tumor angiogenesis. However, several lines of evidence suggest that there are unidentified substrates or targets for VHL that play important roles in tumor suppression. Methodology/Principal Findings: Employing quantitative proteomics, we developed an approach to systematically identify the substrates of ubiquitin ligases and using this method, we identified the Myb-binding protein p160 as a novel substrate of VHL. Conclusions/Significance: A major barrier to understanding the functions of ubiquitin ligases has been the difficulty in pinpointing their ubiquitination substrates. The quantitative proteomics approach we devised for the identification of VHL substrates will be widely applicable to other ubiquitin ligases
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