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Using unique real estate data that allow for accurately measured capital gains, we examine whether sell propensities depend on the magnitude of a seller’s capital gain. We find that short-term sell propensities are flat over losses and increasing in gains. Consistent with their higher sell propensities, selling prices are lower for properties with larger gains. Large-sized short-term stock investments also have sell propensities that are flat over losses and increasing in gains, although the sell propensities of typical-sized short-term stock investments are V-shaped. Our findings provide empirical support for theories of realization utility.
Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.
Tonsillectomy is one of the most common otolaryngological procedures. Nonetheless, there is still no universally approved ‘gold standard’ technique.
Objective
To compare the safety and efficacy of argon plasma coagulation and coblation techniques in tonsillectomy.
Methods
A multi-institutional, retrospective cohort study was conducted, comprising 283 patients who underwent bilateral tonsillectomies performed by a single surgeon between 2014 and 2017. The outcome measures included: operative time, intra-operative blood loss, post-operative pain and post-operative haemorrhage.
Results
In the argon plasma coagulation group, mean operative time and post-operative haemorrhage rate were significantly reduced, p = 0.0006 and p = 0.003 respectively. There was no statistically significant difference between the two groups in terms of post-operative pain and intra-operative blood loss.
Conclusion
The argon plasma coagulation technique is easy, safe and efficacious. Argon plasma coagulation tonsillectomy seems cost-effective compared to coblation tonsillectomy: the single-use disposable electrode tip and wand used in this study cost AUD$76.50 and AUD$380 respectively. Argon plasma coagulation appears to be a favourable alternative to current modalities such as coblation.
Acute mastoiditis remains the commonest intratemporal complication of otitis media in the paediatric population. There has been a lack of consensus regarding the diagnosis and management of acute mastoiditis, resulting in considerable disparity in conservative and surgical management.
Objectives:
To review the current literature, proposing recommendations for the management of paediatric acute mastoiditis and appraising the treatment outcomes.
Method:
A systematic review was conducted using PubMed, Web of Science and Cochrane Library databases.
Results:
Twenty-one studies were included, with a total of 564 patients. Cure rates of medical treatment, conservative surgery and mastoidectomy were 95.9 per cent, 96.3 per cent and 89.1 per cent, respectively.
Conclusion:
Mastoidectomy may be the most definitive treatment available; however, reviewed data suggest that conservative treatment alone has high efficacy as first-line treatment in uncomplicated cases of acute mastoiditis, and conservative therapy may be an appropriate first-line management when treating acute mastoiditis.
An association between metabolic syndrome (MetS) and disturbances in neurocognitive function has been identified in Caucasians but the nature and extent of impaired cognition in Asian MetS patients, who may be at greater risk of degenerative cognitive decline, remains unspecified.
Methods:
A cross-sectional study was conducted at the National University Hospital of Singapore. Participants were recruited from a diabetes clinic at the National University Hospital. Fifty-three patients who met MetS criteria and 44 clinical controls were recruited. All participants were 55 years and above and community ambulant. Neurocognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). CANTAB performances between MetS and control groups were examined with analysis of variance (ANOVA) and the relative contributions of vascular risk, and intrademographic factors on CANTAB scores were dilineated with stepwise regression analyses.
Results:
Participants with MetS consistently performed significantly worse than controls across all CANTAB subtests. Education and Chinese race were found to be potential protective factors.
Conclusions:
Executive and memory impairment is present in Asian patients with midlife MetS who may be particularly vulnerable to the detrimental impact of MetS in midlife.
Weekly (August 2003–December 2008) numbers of five common paediatric diseases and the incidence of respiratory viruses were obtained from a children's hospital in Singapore and correlated with climate data using multivariate time-series techniques. Upper respiratory tract infections were positively correlated with the incidences of influenza A, B, respiratory syncytial virus (RSV) and parainfluenza viruses (types 1–3 combined). Lower respiratory tract infections were positively correlated with only the incidence of RSV. Both upper and lower respiratory tract infections were negatively correlated with relative humidity. Asthma admissions were negatively correlated with maximum temperature and positively correlated with the incidence of influenza B and increasing hours of sunshine. Although sporadic cases of adenovirus infection were identified, not enough cases were available for a more detailed analysis. Gastroenteritis and urinary tract infections, included as control diseases, were not correlated significantly with any climate parameters. These correlations are compatible with current understanding of respiratory virus survival under certain climate conditions and may assist the prediction of disease burdens and hospital resource planning in such tropical environments.
The gut microbiota has been implicated in host nutrient absorption and energy homeostasis. We studied the influence of different diets on body composition in germ-free (GF) and conventional (CV) mice. GF and CV male adult C3H mice were fed ad libitum a semi-synthetic low-fat diet (LFD; carbohydrate–protein–fat ratio: 41:42:17; 19·8 kJ/g), a high-fat diet (HFD; 41:16:43; 21·4 kJ/g) or a commercial Western diet (WD; 41:19:41; 21·5 kJ/g). There was no difference in body weight gain between GF and CV mice on the LFD. On the HFD, GF mice gained more body weight and body fat than CV mice, and had lower energy expenditure. GF mice on the WD gained significantly less body fat than GF mice on the HFD. GF mice on both HFD and WD showed increased intestinal mRNA expression of fasting-induced adipose factor/angiopoietin-like protein 4 (Fiaf/Angptl4), but they showed no major changes in circulating Fiaf/Angptl4 compared with CV mice. The faecal microbiota composition of the CV mice differed between diets: the proportion of Firmicutes increased on both HFD and WD at the expense of the Bacteroidetes. This increase in the Firmicutes was mainly due to the proliferation of one family within this phylum: the Erysipelotrichaceae. We conclude that the absence of gut microbiota does not provide a general protection from diet-induced obesity, that intestinal production of Fiaf/Angptl4 does not play a causal role in gut microbiota-mediated effects on fat storage and that diet composition affects gut microbial composition to larger extent than previously thought.
To determine the prevalence and profile of patients who use complementary and alternative medicine, within a cohort of head and neck cancer patients.
Study design:
Cross-sectional survey.
Subjects and methods:
Ninety-three consecutive head and neck cancer patients being followed up at the department of otolaryngology head and neck surgery were surveyed using an interviewer-administered questionnaire.
Results:
The prevalence of complementary and alternative medicine use was 67.8 per cent. Patients who used complementary and alternative medicine were more likely to be female, better educated and younger, compared with non-users. A total of 82.5 per cent (52/63) perceived complementary and alternative medicine to be effective, even though they were aware of the lack of research and endorsement by their physician regarding such medicine.
Conclusion:
The use of complementary and alternative medicine by head and neck cancer patients is common, regardless of efficacy or cost. Clinicians should routinely ask patients about their use of complementary and alternative medicine, to facilitate communication and enable appropriate use of such medicine.
Multilocus enzyme electrophoretic analysis was employed to assess the genetic relatedness of Neisseria gonorrhoeae. Based on the diversity of electromorphs at 9 enzyme loci, 16 electrophoretic types (ETs) were estabilished amongst the 65 isolates. The average number of alleles per enzyme locus was 1·7 and the mean genetic diversity per locus was 0·212. The majority of isolates belonged to either ET1 (32·3%) or ET2 (16·9%). No specific correlation of ETs was seen with serovars as the major types, ETs 1 and 2, were found distributed amongst the various serovars. Major serovars such as Bacjk (IB-1/2) and Bajk (IB-3/6) were each represented by 6 or 8 ETs respectively. Analysis of the genetic relationships of ETs to each other showed some clustering of subgroups that were more closely related than others.
Acoustic streaming patterns, velocity fields, which is induced by a
cylindrical ultrasonic exciter vibrating at 28.4 kHz in an open physical
boundaries, is analytically and experimentally investigated using Particle
Imaging Velocimetry (PIV). Induced acoustic streaming patterns and velocity
fields for the gaps of 18 mm at which the irrotational tangential velocity
becomes a maximum, resulting in a substantial increase in the acoustic
streaming velocity and pronounced visualization of streaming patterns
between the vibrator and quiescent glass plate are presented. The overall
air flow patterns at the gaps of 24, 30, 36 mm are similar to the gap of 18
mm but as the gap increases the frequency of occurrence and irregularity of
vortices in the gap appear to increase. The symmetric definite steady
circular flow with local vortices is observed. The maximum streaming
velocity measured stands at 0.16 cm/s with a vibration amplitude of 50
micrometers. Theoretical analysis indicates that the pattern of air flow in
the gap is determined by the top and bottom limiting velocities induced by
acoustic streaming within the Stokes boundary layer and that the streaming
pattern is symmetrical with respect to the center axis of the vibrator by
reason of symmetry. The comparison between the experimental data and the
theoretical estimation based on Nyborg and Jackson is performed.
To rapidly establish a temporary isolation ward to handle an unexpected sudden outbreak of severe acute respiratory syndrome (SARS) and to evaluate the implementation of exposure control measures by healthcare workers (HCWs) for SARS patients.
Design:
Rapid creation of 60 relatively negative pressure isolation rooms for 196 suspected SARS patients transferred from 19 hospitals and daily temperature recordings of 180 volunteer HCWs from 6 medical centers.
Setting:
A military hospital.
Results:
Of the 196 patients, 34 (17.3%) met the World Health Organization criteria for probable SARS with positive results of serologic testing for SARS-associated coronavirus (SARS-CoV), reverse transcriptase polymerase chain reaction (RT-PCR) from nasopharyngeal or throat swabs for SARS-CoV, or both. Seventy-four patients had suspected SARS based on unprotected exposure to SARS patients; three of them had positive results on RT-PCR but negative serologic results. The remaining 88 patients did not meet the criteria for a probable or suspected SARS diagnosis. Of the 34 patients with probable SARS, 13 were transferred to medical centers to receive mechanical ventilation due to rapid deterioration of chest x-ray results, and three patients died of SARS despite intensive therapy in medical centers. During the study period, one nurse developed probable SARS due to violation of infection control measures, but there was no evidence of cross-transmission to other HCWs.
Conclusions:
Despite the use of full personal protection equipment, the facility failed to totally prevent exposures of HCWs to SARS but minimized the risk of nosocomial transmission. Better training and improvements in infection control infrastructure may limit the impact of SARS.
Ultra low dielectric constant (κ) material is needed as the inter-metal
dielectrics to reduce RC delay when device dimension is scaled to sub-100nm.
Porous dielectric films have been considered as good candidates for the
application as inter-metal dielectrics due to their ultra low-k properties.
Identifying proper dielectric copper diffusion barrier on the porous low-k
films is critical for the low-k/Cu damascene fabrication process. In this
study, we have evaluated the compatibility of plasma-deposited amorphous
Boron Nitride film as a dielectrics copper diffusion barrier on a MSQ-based
porous low-k LKD5109 film (from JSR). Both microwave plasma enhanced CVD
(2.45 GHz) and radio-frequency plasma enhanced CVD (13.56 MHz) were applied
for the BN deposition in order to evaluate the compatibility of the two
plasma processes with the porous film. Growth parameters were optimized to
minimize the boron diffusion and carbon depletion in the porous low-k films,
which were found to have deleterious effects on the dielectric properties of
the low-k films. FTIR and micro-Raman were employed for analyzing the
changes in chemical structure of the low-k films after BN growth.
Capacitance-voltage measurement was used to characterize the dielectric
constants of BN film on Si and the BN-deposited porous low-k film. SIMS
characterization was carried out to evaluate the performance of the BN film
against copper diffusion.
This paper describes the research into the flight dynamics modelling and flight control of a flapping wing micro aerial vehicle (MAV). The equations of motion based on a multi-body representation of the vehicle and the flapping wings were derived and form the basis for the simulation program, which was developed using MATLAB and SIMULINK. The aerodynamic forces were obtained through experimental methods and form the basis for the aerodynamic model.
The hovering and low speed flight of the MAV was investigated using a SIMULINK simulation model. Various flight control concepts, inspired by observation of insect and bird flight, were investigated in some detail. The concepts include the control of flap frequency, flap and pitch phasing (wing beat kinematics) and shift in centre of gravity position. The paper concludes with a comparison of the control concepts and their feasibility for a practical vehicle application.
Background. The long-term use of methamphetamine (MAMP) can result in psychosis but it is not clear why some individuals develop psychotic symptoms, while others use MAMP regularly over long periods and remain unscathed. We set out to characterize MAMP users and to examine the relationship of pre-morbid personality, pre-morbid social function and other psychiatric disorders to MAMP psychosis.
Method. Four hundred and forty-five amphetamine users were recruited from a psychiatric hospital and a detention centre in Taipei, and were assessed with the Diagnostic Interview for Genetic Studies (DIGS). Their parents were interviewed with the Premorbid Schizoid and Schizotypal Traits (PSST) and the Premorbid Social Adjustment (PSA) schedules. Pre-morbid characteristics and psychiatric co-morbidity were compared between the MAMP users with a lifetime diagnosis of MAMP psychosis and those without.
Results. The MAMP users with psychosis presented a clinical picture which mimicked the positive symptoms of schizophrenia: 85% had auditory hallucinations; 71% persecutory delusions; 63% delusions of reference. Compared with their non-psychotic counterparts, these MAMP users were younger at first MAMP use, used larger amounts of MAMP, had a significantly higher mean PSST score, and higher rates of major depressive disorder, alcohol dependence and antisocial personality disorder.
Conclusions. Earlier and larger use of MAMP was associated with increased risk of psychosis. Our data are also compatible with the view that pre-morbid schizoid/schizotypal personality predisposes MAMP users to develop psychosis, and that the greater the personality vulnerability, the longer the psychosis will persist.
Experimental studies have shown that convergent–divergent nozzles, when run at low
pressure ratios, often undergo a flow resonance accompanied by emission of acoustic
tones. The phenomenon, different in characteristics from conventional ‘screech’ tones,
is addressed in this paper. Unlike screech, the resonant frequency (fN) increases
with increasing supply pressure. There is a ‘staging’ behaviour; odd-harmonic stages
resonate at lower pressures while the fundamental occurs in a wide range of higher
pressures corresponding to a ‘fully expanded Mach number’ (Mj) around unity. Within
a stage, fN varies approximately linearly with Mj; the slope of the variation steepens
when the angle of divergence of the nozzle is decreased. Based on the data, correlation
equations are provided for the prediction of fN. A companion computational study
captures the phenomenon and predicts the frequencies, including the stage jump,
quite well. While the underlying mechanisms are not completely understood yet, it is
clear that the unsteadiness of a shock occurring within the divergent section plays
a direct role. The shock drives the flow downstream like a vibrating diaphragm,
and resonance takes place similarly to the (no-flow) acoustic resonance of a conical
section having one end closed and the other end open. Thus, the fundamental is
accompanied by a standing one-quarter wave within the divergent section, the next
stage by a standing three-quarter wave, and so on. The distance from the foot of the
shock to the nozzle exit imposes the pertinent length scale. The principal trends in
the frequency variation are explained qualitatively from the characteristic variation of
that length scale. A striking feature is that tripping of the nozzle's internal boundary
layer tends to suppress the resonance. It is likely that the trip effect occurs due to a
break in the azimuthal coherence of the unsteady flow.
Background and objective The amount of procalcitonin eliminated in the urine and the plasma disappearance rate of procalcitonin were evaluated in patients with normal and impaired renal function, because patients with sepsis are a main target group for procalcitonin measurement, and these patients often develop renal dysfunction.
Methods Elimination of procalcitonin in the urine (μg 12 h−1) was measured in 76 patients. In another 67 patients, the 50% plasma disappearance rate (t½, h) was evaluated 48 h after peak concentrations (procalcitonin >2 μg L−1). Renal function was assessed by creatinine clearance.
Results Procalcitonin elimination in the urine was significantly reduced in patients with severe renal dysfunction. However, the plasma disappearance rate correlated only weakly with renal dysfunction (Spearman's rank correlation R = −0.36, P = 0.004, regression t½ = 49.87−0.15 creatinine clearance). The 25% quartile and median were 25.2 h and 30.0 h in patients with normal renal function, and 36.3 h and 44.7 h in patients with severely impaired renal function (creatinine clearance <30 mL min−1).
Conclusions Renal elimination of procalcitonin is not a major mechanism for procalcitonin removal from the plasma. Although the plasma disappearance rate may be prolonged up to 30–50% in some patients with renal dysfunction, clinical diagnostic decisions may not be severely influenced by this moderate prolongation of procalcitonin elimination. We conclude that procalcitonin can be used diagnostically in patients with renal failure as well as in those with normal renal function.
The elimination of procalcitonin and the course of plasma concentrations during continuous veno-venous haemodiafiltration were measured in patients with sepsis or multiple organ dysfunction syndrome, because these patients are a main target group for the measurement of procalcitonin and often require renal replacement therapy. Procalcitonin was measured in the prefilter plasma and the filtrate at 5 min, 15 min and 1, 2, 4, 6, 12, 24 h after set-up of continuous veno-venous haemodiafiltration. In a prospective study, 19 patients with plasma levels of procalcitonin >3ng mL−1 and acute oliguric renal failure treated with continuous veno-venous haemodiafiltration using a polysulphone membrane, were evaluated for the study of clearance. Twenty-one control patients (procalcitonin <2ng mL−1) were studied to determine whether filtration itself induced a procalcitonin response. No interventions were required. In patients with low procalcitonin concentrations (procalcitonin <2ng mL−1) continuous veno-venous haemodiafltration did not cause a rise in procalcitonin. In patients with increased procalcitonin plasma concentrations (>3ng mL−1), the protein was removed through the polysulphone membrane, with a final clearance of 4 mL min−1 after the initial adsorption period (clearance 0.4–0.9mL min−1 during the first hour of continuous veno-venous haemodiafiltration). Thus, on the average, approximately 10% of plasma concentrations were measurable in the filtrate ultimately. However, procalcitonin plasma levels were not significantly altered during continuous veno-venous haemodiafiltration (86% of the initial concentration after 24 h). Although procalcitonin is removed from the plasma during continuous veno-venous haemodiafiltration in measurable amounts plasma procalcitonin concentrations did not change significantly during haemodiafiltration. Procalcitonin thus can also be used as a diagnostic parameter in patients undergoing continuous veno-venous haemodiafiltration.
Low dielectric constant F-doped silicon oxide films (SiO:F) can be prepared by adding fluorine source, like as CF4 to the conventional PECVD processes. We could obtain SiO:F films with dielectric constant as low as 2.6 from the reaction mixture of SiH4/N2 O/CF4. The structural changes of the oxides were sensitively detected by Raman spectroscopy. The three-fold ring and network structure of the silicon oxides were selectively decreased by adding fluorine into the film. These structural changes contribute to the decrease ionic polarization of the film, but it was not the major factor for the low dielectric constant. The addition of fluorine was very effective to eliminate the Si-OH in the film and the disappearance of the Si-OH was the key factor to obtain low dielectric constant. A kinetic analysis of the process was also performed to investigate the reaction mechanism. We focused on the effect of gas flow rate, i.e. the residence time of the precursors in the reactor, on growth rate and step coverage of SiO:F films. It revealed that there exists two species to form SiO:F films. One is the reactive species which contributes to increase the growth rate and the other one is the less reactive species which contributes to have uniform step coverage. The same approach was made on the PECVD process to produce low-k C:F films from C2F4, and we found ionic species is the main precursor to form C:F films.
The aim of this article is to obtain an upper bound for the exponential sums $\sum{e(f(x)\,/\,q)}$, where the summation runs from $x=1$ to $x=q$ with $(x,q)=1$ and $e(\alpha )$ denotes $\exp (2\pi i\alpha )$.
We shall show that the upper bound depends only on the values of $q$ and $s$, where $s$ is the number of terms in the polynomial $f(x)$.