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This paper reports on an atomic-scale investigation into the β′ precipitates and the long-period stacking ordered phase (LPSO) in Mg–5Y–2.5Ni–0.5Zr (at.%) alloy, using Cs-corrected high angle annular dark field-scanning transmission electron microscopy (HAADF-STEM). The results displayed that the 18R-type and 14H-type LPSO phases coexisted in the as-cast and the solid solution states, and the 18R-type and 14H-type LPSO structures were thermal stable. After aging treatment, the aging peak hardness reached 138 HV at 225 °C for 48 h. The significant increase in hardness was attributed to the formation of the metastable β′ phase. The lattice parameters of a and b axes for β′ phases are a = 0.65 nm, b = 2.20 nm, and c = 0.52 nm by HAADF-STEM. The interaction between the LPSO phase and the β′ can be found. The atomic-scale interactions between the LPSO and β′ phases are divided into two parts: under-aging and peak-aging conditions between the building blocks.
Clozapine treatment increases the risk of agranulocytosis, but findings on the epidemiology of agranulocytosis have been inconsistent. This meta-analysis examined the prevalence of agranulocytosis and related death in clozapine-treated patients.
A literature search in the international (PubMed, PsycINFO, and EMBASE) and Chinese (WanFang, Chinese National Knowledge Infrastructure, and Sinomed) databases was conducted. Prevalence estimates of agranulocytosis and related death in clozapine-treated patients were synthesized with the Comprehensive Meta-Analysis program using the random-effects model.
Thirty-six studies with 260 948 clozapine-treated patients published between 1984 and 2018 were included in the meta-analysis. The overall prevalence of agranulocytosis and death caused by agranulocytosis were 0.4% (95% CI 0.3–0.6%) and 0.05% (95% CI 0.03–0.09%), respectively. The prevalence of agranulocytosis was moderated by sample size, study quality, year of publication, and that of data collection.
The prevalence of clozapine-associated agranulocytosis is low. Agranulocytosis-related death appears rare.
The paper presents an experimental investigation on the flow-induced vibrations of two tandem circular cylinders for spacing ratio
and reduced velocity
is the cylinder centre-to-centre spacing and
is the cylinder diameter. Both cylinders are allowed to vibrate only laterally. Extensive measurements are conducted to capture the cylinder vibration and frequency responses, surface pressures, shedding frequencies and flow fields using laser vibrometer, hotwire, pressure scanner and PIV techniques. Four vibration regimes are identified based on the characteristics and generation mechanisms of the cylinder galloping vibrations. Several findings are made on the mechanisms of vibration generation and sustainability. First, the initial states (vibrating or fixed) of a cylinder may have a pronounced impact on the vibration of the other. Second, alternating reattachment, detachment, rolling up and shedding of the upper and lower gap shear layers all contribute to the vibrations. Third, the gap vortices around the base surface of the upstream cylinder produce positive work on the cylinder, sustaining the upstream cylinder vibration. Fourth, reattachment, detachment and switching of the gap shear layers result in largely positive work on the downstream cylinder, playing an important role in sustaining its vibration.
The present study was undertaken to investigate the antiparasitic activity of extracellular products of Streptomyces albus. Bioactivity-guided isolation of chloroform extracts affording a compound showing potent activity. The structure of the compound was elucidated as salinomycin (SAL) by EI-MS, 1H NMR and 13C NMR. In vitro test showed that SAL has potent anti-parasitic efficacy against theronts of Ichthyophthirius multifiliis with 10 min, 1, 2, 3 and 4 h (effective concentration) EC50 (95% confidence intervals) of 2.12 (2.22–2.02), 1.93 (1.98–1.88), 1.42 (1.47–1.37), 1.35 (1.41–1.31) and 1.11 (1.21–1.01) mg L−1. In vitro antiparasitic assays revealed that SAL could be 100% effective against I. multifiliis encysted tomonts at a concentration of 8.0 mg L−1. In vivo test demonstrated that the number of I. multifiliis trophonts on Erythroculter ilishaeformis treated with SAL was markedly lower than that of control group at 10 days after exposed to theronts (P < 0.05). In the control group, 80% mortality was observed owing to heavy I. multifiliis infection at 10 days. On the other hand, only 30.0% mortality was recorded in the group treated with 8.0 mg L−1 SAL. The median lethal dose (LD50) of SAL for E. ilishaeformis was 32.9 mg L−1.
Effective degradation of organic pollutants in wastewater is of great importance to the environment and human society. TiO2-based electrospun nanofibrous materials combining the properties of the large specific surface area, high aspect ratio, tunable compositions and structures, as well as easy to recycle, show great promise for the efficient removal of organic pollutants. In this Prospective paper, the recent progress in the degradation of organic water contaminants over visible-light-responsive TiO2-based nanofibrous materials is summarized, with emphasis on the strategies for improving the visible-light photocatalytic activity of TiO2-based nanofibrous materials. Finally, the current challenges and future outlook in this field are discussed.
Nacre-mimetic (PE/TiO2)4 nanolayered composites (NLCs) with the nanocrystalline TiO2 layer thickness less than 30 nm and different thickness ratios of inorganic/organic layers were successfully prepared by using layer-by-layer self-assembly and chemical bath deposition method. Mechanical properties, especially fatigue properties of the NLCs with different thickness ratios were evaluated. The elastic modulus, hardness and fracture toughness, strain amplitude to fatigue limits of the NLCs reached 27.78 ± 5.69 GPa, 1.33 ± 0.31 GPa, and 4.16 ± 0.20 MPa m1/2, respectively. Fatigue performance of the NLCs in the high and low cycle fatigue regimes was optimized by tailoring the thickness ratio of the TiO2/PE layers. The PE/TiO2 NLCs with the larger thickness ratio of ∼3 has the high fatigue limit (the critical strain amplitude of 0.0853%) in the high-cycle fatigue regime, while that with the smaller thickness ratio of ∼1 and ∼0.5 are of the good fatigue strength in the low-cycle fatigue regime. The basic mechanism for the enhanced fatigue performance is elucidated.
Previous studies have indicated that some food items and nutrients are associated with uric acid metabolism in humans. However, little is known about the role of dietary patterns in hyperuricaemia. We designed this case–control study to evaluate the associations between dietary patterns and newly diagnosed hyperuricaemia in Chinese adults. A total of 1422 cases and 1422 controls were generated from 14 538 participants using the 1:1 ratio propensity score matching methods. Dietary intake was assessed using a validated self-administered FFQ. Dietary patterns were derived by factor analysis. Hyperuricaemia was defined as concentrations of serum uric acid higher than 7 mg/dl (416·5 μmol/l) for men and 6 mg/dl (357 μmol/l) for women. Three dietary patterns were derived by factor analysis: sweet pattern; vegetable pattern; animal foods pattern. The animal foods pattern characterised by higher intake of an animal organ, seafood and processed meat products was associated with higher prevalence of newly diagnosed hyperuricaemia (Pfor trend<0·01) after adjustment. Compared with the participants in the lowest quartile of the animal foods pattern, the OR of newly diagnosed hyperuricaemia in the highest quartile was 1·50 (95 % CI 1·20, 1·87). The other two dietary patterns were not associated with the prevalence of newly diagnosed hyperuricaemia after adjustment. In conclusion, a diet rich in animal organ, seafood and processed meat products is associated with higher prevalence of newly diagnosed hyperuricaemia in a Chinese population. Further cohort studies and randomised controlled trials are required to clarify these findings.
Several studies have suggested that higher carotenoid levels may be beneficial for atherosclerosis patients, but few studies have examined this relationship in the Chinese population. This cross-sectional study examined the association between the levels of carotenoids in diet and serum and carotid intima–media thickness (IMT) in Chinese adults aged 50–75 years in Guangzhou, China. Dietary intake was assessed using a FFQ. HPLC was used to assay the serum concentrations of α-carotene, β-carotene, lutein+zeaxanthin, β-cryptoxanthin and lycopene. The IMT at the common carotid artery (CCA) and bifurcation of the carotid artery was measured by B-mode ultrasound. A total of 3707 and 2947 participants were included in the analyses of dietary and serum carotenoids. After adjustment for demographic, socio-economic and lifestyle factors, all the serum carotenoids levels except lycopene were found to be inversely associated with the IMT at the CCA and bifurcation (Ptrend<0·001 to 0·013) in both men and women. The absolute mean differences in the IMT between the subjects in the extreme quartiles of serum carotenoid levels were 0·034 mm (α-carotene), 0·037 mm (β-carotene), 0·032 mm (lutein+zeaxanthin), 0·030 mm (β-cryptoxanthin), 0·015 mm (lycopene) and 0·035 mm (total carotenoids) at the CCA; the corresponding values were 0·025, 0·053 0·043, 0·050, 0·011 and 0·042 mm at the bifurcation. The favourable associations were also observed between dietary carotenoids (except lycopene) and the CCA IMT. In conclusion, elevated carotenoid levels in diet and serum are associated with lower carotid IMT values (particular at the CCA) in Chinese adults.
A coaxial-output rolled strip pulse-forming line (RSPFL) with a dry structure is researched for the purpose of miniaturization and all-solid state of pulse-forming lines (PFL). The coaxial-output RSPFL consists of a coaxial-output electrode (COE) and a rolled strip line (RSL). The COE is characterized by quasi-coaxial structure, making the output pulse propagate along the axial direction with a small output inductance. The RSL is rolled on the COE, whose transmission characteristics are analyzed theoretically. It shows that the RSL can be regarded as a planar strip line when the rolling radius of the strip line is larger than 60 times of the thickness of the insulation dielectric layer of RSL. CST modeling was carried out to simulate the discharging characteristic of the coaxial-output RSPFL. It shows that the coaxial-output RSPFL can deliver a discharging pulse with a rise time <6 ns when the impedance of the RSL matches that of the COE, which confirms the theoretical analysis. A prototype of the coaxial-output RSPFL was developed. A 49-kV discharging pulse on a matched load was achieved when it was charged to 100 kV. The discharging waveform has a pulse width of 32 ns, with a rise time of 6 ns, which is consistent with the simulation waveform. An energy-storage density of 1.9 J/L was realized in the coaxial-output RSPFL. By the method of multi-stage connection in series, a much higher output voltage is convenient to be obtained.
Previous studies have demonstrated adverse mental health effects of Pb exposure. The purpose of this study is to investigate the relationship between consumption of preserved egg (PE), a high-Pb-containing food and depressive symptoms among adults in China. A sample of 25 213 adults (mean age 41·4 (sd 11·8) years; males, 53·9 %) in Tianjin, China, was studied in a cross-sectional analysis. Dietary intake including PE was assessed using a valid self-administered FFQ. Depressive symptoms were assessed using the Self-Rating Depression Scale (SDS). The association was estimated by OR using logistic regression models adjusted for multiple confounders. The prevalence of elevated depressive symptoms was 6·6 % (SDS≥50). Compared with the least frequent PE consumption (<once/week), multivariable adjusted OR for elevated depressive symptoms were 1·52 (95 % CI 1·28, 1·81), 2·24 (95 % CI 1·76, 2·81) and 3·31 (95 % CI 2·52, 4·30) for consumption of once, 2–3 times and ≥4 times/week, respectively (Pfor trend<0·0001), indicating a clear dose–response relationship. The results suggested that higher consumption of PE was strongly associated with depressive symptoms among adults in China. These findings underscore the need to consider dietary Pb exposure as a risk factor for psychological distress.
This paper presents a systematic study of the cross-flow-induced vibration on a spring-supported circular cylinder of diameter
placed in the wake of a fixed cylinder of smaller diameter
. The ratios
are varied from 0.2 to 1.0 and from 1.0 to 5.5, respectively, where
is the distance between the centre of the upstream cylinder to the forward stagnation point of the downstream cylinder. Extensive measurements are conducted to capture the cylinder vibration and frequency responses, surface pressure, shedding frequencies and flow fields using laser vibrometer, hot-wire, pressure scanner and particle image velocimetry techniques. Six distinct flow regimes are identified. It has been found that a violent vibration may erupt for the spring-supported cylinder, and its dependence on
is documented. A careful examination and analysis of the flow structure, along with the simultaneously captured pressure distribution around and vibration of the downstream cylinder, cast light upon the mechanisms behind this vibration and its sustainability. The roles of added mass, flow-induced damping and physical aspects in the process of initiating the vibration are discussed in detail.
In this paper the asymmetric shock reflection configurations in two-dimensional steady flows have been studied theoretically. For an overall Mach reflection, it is found that the horizontal distance between both triple points in the Mach stem is related to the angles of two slip streams. Based on the features of the converging stream tube, several assumptions are put forward to perform better the wave configurations near the slip streams. Therefore, we present an analytical model here to describe the asymmetric overall Mach reflection configurations which agrees well with the computational and experimental results.
In this work, the reduction mechanism of potassium chromate (K2CrO4) was investigated via in situ high-temperature X-ray diffraction coupled with Fourier transform infrared spectroscopy. During the hydrogen reduction of K2CrO4, the formation of K3CrO4, KCrO2, and KxCrO2 were detected for the first time. The study discovered that K2CrO4 was firstly reduced to K3CrO4 and an amorphous Cr(III) intermediate product at low temperature (400–500 °C). Moreover, the K3CrO4 was the only crystalline material at this stage. As the temperature increased, a stabilized amorphous CrOOH was formed. At a high temperature (550–700 °C), KCrO2 was generated. Interestingly, a portion of KCrO2 was spontaneously decomposed during the hydrogen reduction, accompanying by the formation of K0.7CrO2. Finally, the results clearly illustrated the reduction mechanism of K2CrO4: K2CrO4 → K3CrO4 → amorphous intermediate → KCrO2.
Previous studies have investigated the association between dietary inflammatory potential and the development of cancer. For breast cancer the results have been equivocal. The present study aimed to investigate whether higher Dietary Inflammatory IndexTM (DII) scores were associated with increased risk of breast cancer among Chinese women. A total of 867 cases and 824 controls were recruited into the present case–control study from September 2011 to February 2016. DII scores were computed based on baseline dietary intake assessed by a validated 81-item FFQ. The OR and 95 % CI were assessed by multivariable logistic regression after adjusting for various potential confounders. DII scores in this study ranged from −5·87 (most anti-inflammatory score) to +5·71 (most proinflammatory score). A higher DII score was associated with a higher breast cancer risk (adjusted ORquartile 4 v. 1 2·28; 95 % CI 1·71, 3·03; adjusted ORcontinuous 1·40; 95 %CI 1·25, 1·39). In stratified analyses, positive associations also were observed except for underweight women or women with either oestrogen receptor+ or progesterone receptor+ status (but not both). Results from this study indicated that higher DII scores, corresponding to more proinflammatory diets, were positively associated with breast cancer risk among Chinese women.
The main purpose of this paper is to study north–south Smale solenoid diffeomorphisms on
-manifolds by using affine Hirsch foliations. A north–south Smale solenoid diffeomorphism
on a closed
is a diffeomorphism whose non-wandering set is composed of a Smale solenoid attractor
and a Smale solenoid repeller
. The key observation is that a north–south Smale solenoid diffeomorphism
automatically induces two non-isotopically leaf-conjugate affine Hirsch foliations
on the orbit space of the wandering set of
(abbreviated to the wandering orbit space of
) by the stable and unstable manifolds of
, respectively. Under this viewpoint, we build some close relationships between north–south Smale solenoid diffeomorphisms and Hirsch manifolds (the closed
-manifolds admitting two non-isotopically leaf-conjugate affine Hirsch foliations).
∙On the one hand, the union of the wandering orbit spaces is nearly in one-to-one correspondence with the union of Hirsch manifolds.
∙On the other hand, surprisingly, the topology of the wandering orbit space (Hirsch manifold) is nearly a complete invariant of north–south Smale solenoid diffeomorphisms up to semi-global conjugacy.
Moreover, as applications, we consider several more concrete questions. For instance, we prove that every diffeomorphism in many semi-global conjugacy classes of north–south Smale solenoid diffeomorphisms are not structurally stable.
Incorrect propagation speed of discontinuities may occur by straightforward application of standard dissipative schemes for problems that contain stiff source terms for underresolved grids even for time steps within the CFL condition. By examining the dissipative discretized counterpart of the Euler equations for a detonation problem that consists of a single reaction, detailed analysis on the spurious wave pattern is presented employing the fractional step method, which utilizes the Strang splitting. With the help of physical arguments, a threshold values method (TVM), which can be extended to more complicated stiff problems, is developed to eliminate the wrong shock speed phenomena. Several single reaction detonations as well as multispecies and multi-reaction detonation test cases with strong stiffness are examined to illustrate the performance of the TVM approach.
This article outlines the evolution of a rescue team in responding to adenovirus prevention with a deployable field hospital. The local governments mobilized a shelter hospital and a rescue team consisting of 59 members to assist with rescue and response efforts after an epidemic outbreak of adenovirus. We describe and evaluate the challenges of preparing for deployment, field hospital maintenance, treatment mode, and primary treatment methods. The field hospital established at the rescue scene consisted of a medical command vehicle, a computed tomography shelter, an X-ray shelter, a special laboratory shelter, an oxygen and electricity supply vehicle, and epidemic prevention and protection equipment. The rescue team comprised paramedics, physicians, X-ray technicians, respiratory therapists, and logistical personnel. In 22 days, more than 3000 patients with suspected adenovirus infection underwent initial examinations. All patients were properly treated, and no deaths occurred. After emergency measures were implemented, the spread of adenovirus was eventually controlled. An emergency involving infectious diseases in less-developed regions demands the rapid development of a field facility with specialized medical personnel when local hospital facilities are either unavailable or unusable. An appropriate and detailed prearranged action plan is important for infectious diseases prevention. (Disaster Med Public Health Preparedness. 2018;12:109–114)
Disaster can strike people in any community at any time anywhere in the world. Disasters occur with high frequency, take on multiple forms, and exert wide influence, typically causing property damage, injuries, and death. As the world’s largest developing country, China incurs great costs when a disaster hits. After the Wenchuan earthquake in 2008, the Chinese government focused its attention on the construction of an emergency response system, the creation of disaster prevention and mitigation systems, and the development of a disaster medicine program. Here, we describe the current status of disaster medicine in China, focusing on the following four aspects: the Emergency Management System, Education & Training, Rescue Practices, and Research. We also discuss the future of disaster medicine in China. (Disaster Med Public Health Preparedness. 2018;12:157–165)
Landfast sea ice forms and remains fixed along the coast for most of its life time. In Prydz Bay, landfast ice is seasonal due to melting, mechanical breakage and drift of ice in summer. Its annual cycle of thickness and temperature was examined using a one-dimensional thermodynamic model. Model calibration was made for March 2006 to March 2007 with forcing based on the Chinese National Antarctic Research Expedition data, which consisted of in situ ice and snow observations and meteorological records at the Zhongshan Station. The observed maximum annual ice thickness was 1.74 m. The ice broke and drifted out in summer when its thickness was 0.5–1.0 m. Oceanic heat flux was estimated by tuning the model with observed ice thickness. In the growth season, it decreased from 25 W m-2 to 5 W m-2, and in summer it recovered back to 25 W m-2. Albedo was important in summer; by model tuning the estimated value was 0.6, consistent with the ice surface being bare all summer. Snow cover was thin, having a minor role. The results can be used to further our understanding of the importance of landfast ice in Antarctica for climate research and high-resolution ice–ocean modelling.
Most species of the genus Eulecanium Cockerell (Hemiptera: Coccidae) are important economic pests for ornamental plants and fruit trees. Two morphologically similar species, Eulecanium giganteum Shinji and E. kuwanai Kanda, are distributed mainly in China and are quite difficult to identify because of the paucity of distinguishing characteristics, which can only be observed in slide-mounted young, adult females. Furthermore, we demonstrate here that the species occur in sympatry and on many of the same host plants. Mitochondrial cytochrome c oxidase I (COI) and the D2–D3 expansion segments of 28S rDNA were used for accurate identification of these two Eulecanium species from 19 different locations in China. The average K2P distances of COI sequences were 0.47% in E. kuwanai and 0.32% in E. giganteum, and the interspecific divergences varied from 7.23% to 8.34%. Neighbour-joining (NJ) trees of COI and 28S rDNA revealed two distinct non-overlapping clusters, respectively. Meanwhile, “best close match” analysis also showed that 100% of individuals were classified successfully using COI and 28 S sequences. Differentiating between E. giganteum and E. kuwanai is challenging when using ecological and morphological traits. In contrast, identification using DNA diagnostics appears to be very effective, especially when slide-mounted specimens are difficult to obtain.