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Since the beginning of 2020, the COVID-19 pandemic has dramatically influenced almost every aspect of human life. Activities requiring human gatherings have either been postponed, cancelled, or held completely virtually. To supplement lack of in-person contact, people have increasingly turned to virtual settings on-line, advantages of which include increased inclusivity and accessibility and reduction of carbon footprint. However, emerging online technologies cannot fully replace, in-person scientific events. In-person meetings are not susceptible to poor internet connectivity problems, and they provide novel opportunities for socialization, creating new collaborations, and sharing ideas. To continue such activities, a hybrid model for scientific events could be a solution offering both in-person and virtual components. While participants can freely choose the mode of their participation, virtual meetings would most benefit those who cannot attend in-person due to the limitations. In-person portions of meetings should be organized with full consideration of prevention and safety strategies including risk assessment and mitigation, venue and environmental sanitation, participant protection and disease prevention, and promoting the hybrid model. This new way of interaction between scholars can be considered as a part of a resilience system which was neglected previously and should become a part of routine practice in scientific community.
Universal masking for healthcare workers and patients in hospitals was adopted to combat coronavirus disease 2019 (COVID-19), with compliance rates of 100% and 75.9%, respectively. Zero rates of nosocomial influenza A, influenza B, and respiratory syncytial virus infection were achieved from February to April 2020, which was significantly lower than the corresponding months in 2017–2019.
The relationship between the subtypes of psychotic experiences (PEs) and common mental health symptoms remains unclear. The current study aims to establish the 12-month prevalence of PEs in a representative sample of community-dwelling Chinese population in Hong Kong and explore the relationship of types of PEs and common mental health symptoms.
This is a population-based two-phase household survey of Chinese population in Hong Kong aged 16–75 (N = 5719) conducted between 2010 and 2013 and a 2-year follow-up study of PEs positive subjects (N = 152). PEs were measured with Psychosis Screening Questionnaire (PSQ) and subjects who endorsed any item on the PSQ without a clinical diagnosis of psychotic disorder were considered as PE-positive. Types of PEs were characterized using a number of PEs (single v. multiple) and latent class analysis. All PE-positive subjects were assessed with common mental health symptoms and suicidal ideations at baseline and 2-year follow-up. PE status was also assessed at 2-year follow-up.
The 12-month prevalence of PEs in Hong Kong was 2.7% with 21.1% had multiple PEs. Three latent classes of PEs were identified: hallucination, paranoia and mixed. Multiple PEs and hallucination latent class of PEs were associated with higher levels of common mental health symptoms. PE persistent rate at 2-year follow-up was 15.1%. Multiple PEs was associated with poorer mental health at 2-year follow-up.
Results highlighted the transient and heterogeneous nature of PEs, and that multiple PEs and hallucination subtype of PEs may be specific indices of poorer common mental health.
Large discrepancies have been observed between satellite-derived sea-ice concentrations(IC) from passive microwave remote sensing and those derived from optical images at several locations in the East Antarctic, between February and April 2014. These artefacts, that resemble polynyas in the IC maps, appear in areas where optical satellite data show that there is landfast sea ice. The IC datasets and the corresponding retrieval algorithms are investigated together with microwave brightness temperature, air temperature, snowfall and bathymetry to understand the failure of the IC retrieval. The artefacts are the result of the application of weather filters in retrieval algorithms. These filters use the 37 and 19 GHz channels to correct for atmospheric effects on the retrieval. These channels show significant departures from typical ranges when the artefacts occur. A melt–refreeze cycle with associated snow metamorphism is proposed as the most likely cause. Together, the areas of the artefacts account for up to 0.5% of the Antarctic sea-ice area and thus cause a bias in sea-IC time series. In addition, erroneous sea ICs can adversely affect shipping operations.
Anxiety disorders are prevalent yet under-recognized in late life. We examined the prevalence of anxiety disorders in a representative sample of community dwelling older adults in Hong Kong.
Data on 1,158 non-demented respondents aged 60–75 years were extracted from the Hong Kong Mental Morbidity survey (HKMMS). Anxiety was assessed with the revised Clinical Interview Schedule (CIS-R).
One hundred and thirty-seven respondents (11.9%, 95% CI = 10–13.7%) had common mental disorders with a CIS-R score of 12 or above. 8% (95% CI = 6.5–9.6%) had anxiety, 2.2% (95% CI = 1.3–3%) had an anxiety disorder comorbid with depressive disorder, and 1.7% (95% CI = 1–2.5%) had depression. Anxious individuals were more likely to be females (χ2 = 25.3, p < 0.001), had higher chronic physical burden (t = −9.3, p < 0.001), lower SF-12 physical functioning score (t = 9.2, p < 0.001), and poorer delayed recall (t = 2.3, p = 0.022). The risk of anxiety was higher for females (OR 2.8, 95% C.I. 1.7–4.6, p < 0.001) and those with physical illnesses (OR 1.4, 95% C.I. 1.3–1.6, p < 0.001). The risk of anxiety disorders increased in those with disorders of cardiovascular (OR 1.9, 95% C.I. 1.2–2.9, p = 0.003), musculoskeletal (OR 2.0, 95% C.I. 1.5–2.7, p < 0.001), and genitourinary system (OR 2.0, 95% C.I. 1.3–3.2, p = 0.002).
The prevalence of anxiety disorders in Hong Kong older population was 8%. Female gender and those with poor physical health were at a greater risk of developing anxiety disorders. Our findings also suggested potential risk for early sign of memory impairment in cognitively healthy individuals with anxiety disorders.
The LAMOST Complete Spectroscopic Survey of Pointing Area (LCSSPA) at Southern Galactic Cap (SGC), is one of the LAMOST Key Project, designed to complete the spectroscopic observations of all Galactic and extra-galactic sources in two selected fields of 20 degrees2 at SGC, with the limiting magnitude of r = 18.1 mag. The main purposes of the project are focused on the completeness of the LAMOST ExtraGAlactic Surveys (LEGAS), testing the selection methods of galaxies and stars, and obtaining the basic performance parameters of the LAMOST telescope. Meanwhile the scientific studies include galaxies, clusters of galaxies, variable sources (quasars and variable stars), infrared excess stars and luminous infrared galaxies. The project has considerable scientific value since it is the most complete spectral data in LEGAS up to now. The project completed its observation in the early of 2014, and obtained at least 5000 spectra of galaxies and 25000 spectra of stars.
A simple method is proposed for the chemical modification of carbon nanotubes (CNT) thin film counter electrodes (CE) for the replacement of fluorine-doped tin oxide (FTO) and platinum catalyst (Pt) while retaining light transparency. In order to decrease the sheet resistance, CNT thin films underwent various concentrations (≤10 M) and durations of HNO3 treatment prior to cell fabrication, and the effect on thin film properties was analyzed. P-doping was observed, and the maximum change in work function was found to be +0.35 eV with 4 M HNO3. Optimum sheet resistance reduction (50%) and work function increment were achieved after 1 h treatment with 4 M HNO3. Changes in optical transmittances for all samples were negligible (± 5%). Pristine and HNO3 treated films on plastic substrates were tested as CE in flexible bifacial dye sensitized solar cells (DSSC). Most significant improvements in conversion efficiencies were obtained when CNT on plastic substrates were pretreated with 8 M HNO3 (from 1.18% to 1.40% under roomlight, from 0.19% to 0.26% under 1 Sun).
This study examined the effect of a pre-exercise meal with different glycaemic index (GI) and glycaemic load (GL) on immune responses to an endurance performance run. Eight men completed a preloaded 1 h run at 70 % VO2max on a level treadmill followed by a 10 km performance run on three occasions. In each trial, one of the three prescribed isoenergetic meals, i.e. high GI and high GL (H-H), high GI and low GL (H-L), or low GI and low GL (L-L) was consumed by the subjects 2 h before exercise. Carbohydrate intake (% of energy intake), GI, and GL were 65 %, 79·5, and 82·4 for H-H; 36 %, 78·5, and 44·1 for H-L; 65 %, 40·2, and 42·1 for L-L, respectively. The running time for the three trials was approximately 112 min at 70 % VO2max for the first hour and 76 % VO2max for the last 52 min. Consumption of pre-exercise high-carbohydrate meals (H-H and L-L) resulted in less perturbation of the circulating numbers of leucocytes, neutrophils and T lymphocyte subsets, and in decreased elevation of the plasma IL-6 concentrations immediately after exercise and during the 2 h recovery period compared with the H-L trial. These responses were accompanied by an attenuated increase in plasma IL-10 concentrations at the the end of the 2 h recovery period. The amount of carbohydrate consumed in the pre-exercise meal may be the most important influencing factor rather than the type of carbohydrate in modifying the immunoendocrine response to prolonged exercise.
To compare the public's knowledge and perception of SARS and the extent to which various precautionary measures were adopted in Hong Kong and Singapore.
Cross-sectional telephone survey of 705 Hong Kong and 1,201 Singapore adults selected by random-digit dialing.
Hong Kong respondents had significantly higher anxiety than Singapore respondents (State Trait Anxiety Inventory [STAI] score, 2.06 vs 1.77; P < .001). The former group also reported more frequent headaches, difficulty breathing, dizziness, rhinorrhea, and sore throat. More than 90% in both cities were willing to be quarantined if they had close contact with a SARS case, and 70% or more would be compliant for social contacts. Most respondents (86.7% in Hong Kong vs 71.4% in Singapore; P < .001) knew that SARS could be transmitted via respiratory droplets, although fewer (75.8% in Hong Kong vs 62.1% in Singapore; P < .001) knew that fomites were also a possible transmission source. Twenty-three percent of Hong Kong and 11.9% of Singapore respondents believed that they were “very likely” or “somewhat likely” to contract SARS during the current outbreak (P < .001). There were large differences between Hong Kong and Singapore in the adoption of personal precautionary measures. Respondents with higher levels of anxiety, better knowledge about SARS, and greater risk perceptions were more likely to take comprehensive precautionary measures against the infection, as were older, female, and more educated individuals.
Comparative psychobehavioral surveillance and analysis could yield important insights into generic versus population-specific issues that could be used to inform, design, and evaluate public health infection control policy measures.
PbS-coated CdS nanocomposite particles were synthesized by an ion displacement method in an inverse microemulsion. Their growth kinetics were studied with UV–vis spectroscopy. Transmission electron microscopic characterization shows that PbS-coated CdS particles are uniform in size with a mean diameter of 6 nm. The electron diffraction patterns demonstrate their crystalline nature. Third-order nonlinear optical properties in the samples were investigated using the Z-scan technique with femtosecond laser pulses at 780-nm wavelength. The nonlinear refractive index of PbS-coated CdS nanocomposite particles in microemulsion varied with the molar ratio of Cd/Pb ions and reached a maximum of 5.3 × 10−12 cm2/GW for the sample with a Cd/Pb ion ratio of 1 to 2. The observed large refractive nonlinearity in these nanocomposite particles may be attributed to the optical Stark effect and strong interfacial and inter-nanoparticle interactions.
Macroscopic poly(ether ether ketone) (PEEK) and polypropylene (PP) nanocomposites containing vapour-grown carbon nanofibres (CNF) were produced using standard polymer processing. Tensile tests revealed a linear increase in composite stiffness with nanofibre content. A detailed DSC study verified that under standard processing conditions the degree of crystallinity and the crystalline structure of these semicrystalline thermoplastics were not affected by the nanofibres. Nevertheless, we provide evidence that the nanoscale filler can alter the polymer morphology under certain conditions, an effect which needs to be considered when evaluating nanocomposite properties. Given the absence of morphological changes in the standard nanocomposites we were able to calculate the intrinsic nanofibre modulus using short fibre theory; both distinctively different matrix systems show a similar effective nanofibre modulus.
Diamondlike carbon (DLC) films have been prepared on radio-frequency (rf) biased substrates maintained at low temperature (∼60 °C) using electron cyclotron resonance CH4 –Ar plasma. The structures of the resultant films were characterized by Fourier transform infrared (FTIR), Raman, and ultraviolet/visible (UV/VIS) spectrometry. The studies revealed that the deposited structures were DLC films with sp3/sp2 bond hybridization, extremely high hardness (>3000 kgf/mm2), and high electrical resistivity (up to 1014 Ω cm). The DLC films deposited on colorless (transparent) polymer plastics were examined to determine visible light transparencies and optical bandgaps. The results indicate that electron cyclotron resonance (ECR) plasma processing with low negative rf bias, low deposition temperature, and suitable CH4/Ar gas composition can form optically visible light transparent and hard protective DLC films on polymer plastic surfaces.
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.
The pattern of recurrences after surgical treatment of 276 patients with stage T3 and T4 laryngeal carcinoma was reviewed. Nodal recurrence was the commonest site and occurred mainly in patients with supraglottic and transglottic carcinoma. Distant metastasis was the second commonest site of recurrence, and the most distant metastases developed without locoregional recurrence. Local recurrence alone was uncommon in patients treated with primary surgery.
We analyze certain self-organizing filing techniques when accesses are assumed to be dependent on each other. The stream of requests for accessing records in a file is modelled as a Markov chain. A general framework is introduced to obtain the asymptotic search cost of a memory-free self-organizing heuristic. The move-to-front heuristic is studied in detail. A formula for the asymptotic search cost, which generalizes that in the case of independent accesses, is obtained. Numerical examples on the performance of the transposition heuristic are provided, and compared with that of the move-to-front heuristic.
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