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In this study, we investigate a new simple scheme using a planar undulator (PU) together with a properly dispersed electron beam (
beam) with a large energy spread (
) to enhance the free-electron laser (FEL) gain. For a dispersed
beam in a PU, the resonant condition is satisfied for the center electrons, while the frequency detuning increases for the off-center electrons, inhibiting the growth of the radiation. The PU can act as a filter for selecting the electrons near the beam center to achieve the radiation. Although only the center electrons contribute, the radiation can be enhanced significantly owing to the high-peak current of the beam. Theoretical analysis and simulation results indicate that this method can be used for the improvement of the radiation performance, which has great significance for short-wavelength FEL applications.
Evidence on the association between maternal Hb concentration and preterm birth (PTB) risk is inconclusive. This paper aimed to explore whether women with anaemia or high Hb level before pregnancy would be at higher risk of PTB. We conducted a population-based cohort study with 2 722 274 women aged 20–49 years, who participated in National Free Pre-Pregnancy Checkups Project between 2013 and 2015 and delivered a singleton before 2016 in rural China. Logistic models were used to estimate OR and 95 % CI after adjusting for confounding variables. Restricted cubic spline models were applied to evaluate the dose–response relationships. A total of 192 819 (7·08 %) women had preterm deliveries. Compared with women with Hb of 110–149 g/l, the multivariable-adjusted OR for PTB was 1·19 (95 % CI 0·98, 1·44) for women with Hb<70 g/l, 1·01 (95 % CI 0·97, 1·03) for 70–99 g/l, 0·96 (95 % CI 0·95, 0·98) for 100–109 g/l, 1·04 (95 % CI 1·01, 1·06) for 150–159 g/l, 1·11 (95 % CI 1·05, 1·17) for 160–169 g/l and 1·19 (95 % CI 1·11, 1·27) for ≥170 g/l, respectively. The multivariable-adjusted OR for very PTB (VPTB) was 1·07 (95 % CI 1·03, 1·12) and 1·06 (95 % CI 1·01, 1·12) for women with Hb <110 and ≥150 g/l, compared with those with Hb of 110–149 g/l, respectively. Our study identified a U-shaped relationship between maternal preconception Hb concentration and PTB risk. Both preconception anaemia and high Hb level can significantly increase VPTB risk. Appropriate intervention for women with abnormal Hb levels before pregnancy is very necessary.
Coal has fueled China's rapid growth in recent decades, but it also severely pollutes the air and causes many health issues. The magnitude of the health damage caused by air pollution depends on the location of emission sources. In this paper, we look into the spatial distribution of coal-fired power plants, which are the major emission sources in China, and investigate the determining factors behind the distribution. We find that the driving factors are economic development and expansion of electricity grid coverage; the latter factor plays a key role in provinces that are less developed but have abundant coal resources. This suggests a way to reduce health damages caused by air pollution without harming the economy: attracting coal-fired plants to less populated areas by developing trans-province electricity trade and grid coverage.
Although many studies worldwide have focused on the relationship between vitamin D and insulin resistance, results remain controversial. Furthermore, concentrations of serum 25-hydroxyvitamin D (25(OH)D) in the Chinese population are unclear. We aimed to investigate vitamin D status and its correlation with insulin resistance among a Chinese adult population.
Serum 25(OH)D, fasting blood glucose, fasting insulin, glycated Hb (HbA1c) and other metabolic parameters were assessed. Neck circumference, waist circumference, hip circumference, weight and height were also measured. Lifestyle factors including smoking and drinking status were obtained. Diabetes mellitus was diagnosed by HbA1c according to the 2010 American Diabetes Association criteria.
Of 7200 residents included, 6597 individuals were ultimately analysed.
We enrolled 2813 males (mean age 52·7 (sd 13·5) years) and 3784 females (52·3 (sd 13·5) years); mean serum 25(OH)D concentration was 43·1 (sd 11·6) and 39·6 (sd 9·8) nmol/l, respectively. Additionally, 83·3 % of participants were 25(OH)D deficient. A significant difference in 25(OH)D was observed between males and females in winter and spring (P<0·001). Furthermore, 25(OH)D concentrations were inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR) in the overweight and pre-diabetic populations. After adjusting for several variables, 25(OH)D was significantly associated with HOMA-IR in winter. When 25(OH)D values were categorized into quartiles, HOMA-IR was significantly associated with decreasing 25(OH)D.
The majority of the Chinese population was vitamin D deficient and this deficiency was negatively associated with insulin resistance, particularly in the overweight and pre-diabetic populations. Moreover, these associations might be more evident in the winter.
Design rationale (DR) is an important category within design knowledge, and effective reuse of it depends on its successful retrieval. In this paper, an ontology-based DR retrieval approach is presented, which allows users to search by entering normal queries such as questions in natural language. First, an ontology-based semantic model of DR is developed based on the extended issue-based information system-based DR representation in order to effectively utilize the semantics embedded in DR, and a database of ontology-based DR is constructed, which supports SPARQL queries. Second, two SPARQL query generation methods are proposed. The first method generates initial SPARQL queries from natural language queries automatically using template matching, and the other generates initial SPARQL queries automatically from DR record-based queries. In addition, keyword extension and optimization is conducted to enhance the SPARQL-based retrieval. Third, a design rationale retrieval prototype system is implemented. The experimental results show the advantages of the proposed approach.
Recent studies have suggested an association between vitamin D and non-alcoholic fatty liver disease (NAFLD); however, some results are subject to debate. This study was carried out to evaluate the correlation between NAFLD and vitamin D in men and women in East China. The data were obtained from a cross-sectional study that focused on the health and metabolic status of adults in sixteen areas of East China. According to ultrasonic assessments, the patients were divided into normal and NAFLD groups. Demographic characteristics and biochemical measurements were obtained. Binary logistic regression analysis was used to explore the association. In total, 5066 subjects were enrolled, and 2193 (43·3 %) were diagnosed with NAFLD; 84·56 % of the subjects showed vitamin D deficiency. Subjects with high vitamin D levels had a lower prevalence of NAFLD, particularly male subjects. Within the highest quartile of vitamin D levels, the prevalence of NAFLD was 40·8 %, whereas the lowest quartile of vitamin D levels showed a prevalence of 62·2 %, which was unchanged in women across the vitamin D levels. Binary logistic analysis showed that decreased vitamin D levels were associated with an increased risk of NAFLD (OR 1·54; 95 % CI 1·26, 1·88). This study suggests that vitamin D levels are significantly associated with NAFLD and that vitamin D acts as an independent factor for NAFLD prevalence, particularly in males in East China. Vitamin D interventional treatment might be a new target for controlling NAFLD; elucidating the mechanism requires further research.
Most long QT syndrome patients are associated with genetic mutations. We aimed to investigate the clinical and biochemical characteristics and look for genotype-based preventive implications in Chinese long QT syndrome patients.
Methods and results
We identified two missense mutations of the KCNQ1 gene in two independent Chinese families, including a previously reported mutation R380S in the C-terminus and a novel mutation W305L in the P-loop domain of the Kv7.1 channel, respectively. The proband with R380S was an 11-year-old girl who suffered a prolonged corrected QT interval of 660 ms, recurrent syncope, and sudden cardiac death, whose father was an asymptomatic carrier. The mutation W305L was detected in a 36-year-old woman with long QT syndrome and her immediate family members including the proband’s younger sister with an unexplained syncope, her son, and her elder daughter without symptoms. Metoprolol appeared to be effective in preventing arrhythmias and syncope in long QT syndrome patients with mutation W305L. Both R380S and W305L mutations led to “loss-of-function” of the Kv7.1 channel accounting for the clinical phenotypes.
We first show two missense KCNQ1 mutations – R380S and W305L – in Chinese long QT syndrome patients, resulting in the loss of protein function. Mutation W305L in the P-loop domain of the Kv7.1 may derive a pronounced benefit from β-blocker therapy in symptomatic long QT syndrome patients, whereas mutation R380S located in the C-terminus may be associated with a high risk of sudden cardiac death.
Introduction: The mortality of Parkinson’s disease (PD) and its associated risk factors among clinically definite PD patients in China has been rarely investigated. Our study aimed to identify the mortality rates and predictors of death in PD patients in China. Methods: 157 consecutive, clinically definite PD patients from the urban area of Shanghai were recruited from a central hospital based movement disorder clinic in 2006. All patients were regularly followed up at the clinic until December 31, 2011, or death. Mortality and associations with baseline demographics, health and medical factors were then determined within the cohort. Results: After 5 years, 11(7%) patients had died. The standardised mortality ratio was 0.62 (95% CI 0.32 to 1.07, P=0.104). The main causes of death were pneumonia (54.5%, 6/11) and digestive disorders (18.2%, 2/11), respectively. Age at onset, independent living, the mini mental state examination score, the Parkinson’s disease sleep scale score and the Epworth sleepiness scale score at baseline were statistically significantly different between the survival group and the deceased group (P<0.05). Across all participants, risk factors for death included low mini mental state examination score, and high Epworth sleepiness scale score according to a binary variable logistic regression analysis. Conclusions: This study confirms the similar survival of patients with PD to the control population up to a follow-up of 5 years. Interventions tailored to potential risk factors associated with death may offer further benefits.
Thermal stress can induce birefringence in a laser medium, which can cause depolarization of the laser. The depolarization effect will be very severe in a high-average-power laser. Because the depolarization will make the frequency doubling efficiency decline, it should be compensated. In this paper, the thermal characteristics of two kinds of materials are analyzed in respect of temperature, thermal deformation and thermal stress. The depolarization result from thermal stress was simulated. Depolarization on non-uniform pumping was also simulated, and the compensation method is discussed.
A self-decoupled inelastic style piezoelectric three-degrees-of-freedom (three-DOF) accelerometer is put forward for the solution of cross coupling interference without decoupling easily in the field of three-DOF acceleration sensing. Meanwhile, the proposed piezoelectric three-DOF accelerometer has simple structure and solves the contradictions between high stiffness and high sensitivity. The operating principle of the presented piezoelectric three-DOF accelerometer is analyzed, and its structure model is constructed. The numerical simulation model (finite element model) of the three-axis accelerometer is established. Piezoelectric quartz is chosen for the acceleration sensing element and conversion element, and its output sensitivity, static characteristics, dynamic natural frequency, etc. are analyzed by FEM tool (ANSYS software). Research results show that the proposed piezoelectric three-DOF accelerometer has advantages of simple and rational structure, correct sensing principle and mathematic model, good linearity, high rigidity, and theoretical natural frequency is more than 16 kHz, self-decoupled without complex decoupling work.
The high repetition rate 10 J/10 ns Yb:YAG laser system and its key techniques are reported. The amplifiers in this system have a multi-pass V-shape structure and the heat in the amplifiers is removed by means of laminar water flow. In the main amplifier, the laser is four-pass, and an approximately 8.5 J/1 Hz/10 ns output is achieved in the primary test. The far-field of the output beam is approximately 10 times the diffraction limit. Because of the higher levels of amplified spontaneous emission (ASE) in the main amplifier, the output energy is lower than expected. At the end we discuss some measures that can improve the properties of the laser system.
To promote understandings about the pathogenesis of ischemic stroke (IS) through mining key genes, functions and pathways with microarray technology.
Differentially expressed genes (DEGs) in blood between patients with IS and healthy people were screened out through comparing microarray data obtained from Gene Expression Omnibus. Overrepresented functions in DEGs were revealed by Gene Ontology (GO) enrichment analysis. Interaction network was constructed for the top 24 DEGs with information from Human Protein Reference Database (HPRD). Relevant microRNAs (miRNAs) were retrieved from three databases: TargetScan, miRBase and miRanda.
A total of 503 DEGs were obtained. Functional enrichment analysis showed that immune response, signaling pathways and apoptosis were significantly over-represented. Six key genes with big degree, betweenness and clustering coefficient were then revealed, which might play important roles in the development of IS. In addition, 57 differentially expressed miRNAs targeting the 6 genes were retrieved.
Our study provides insights into the pathogenesis of IS and potential targets to treat the disease.
Numerical simulation of two-phase flow in fractured karst reservoirs is still a challenging issue. The triple-porosity model is the major approach up to now. However, the triple-continuum assumption in this model is unacceptable for many cases. In the present work, an efficient numerical model has been developed for immiscible two-phase flow in fractured karst reservoirs based on the idea of equivalent continuum representation. First, based on the discrete fracture-vug model and homogenization theory, the effective absolute permeability tensors for each grid blocks are calculated. And then an analytical procedure to obtain a pseudo relative permeability curves for a grid block containing fractures and cavities has been successfully implemented. Next, a full-tensor simulator has been designed based on a hybrid numerical method (combining mixed finite element method and finite volume method). A simple fracture system has been used to demonstrate the validity of our method. At last, we have used the fracture and cavity statistics data from TAHE outcrops in west China, effective permeability values and other parameters from our code, and an equivalent continuum simulator to calculate the water flooding profiles for more realistic systems.
A one-dimensional (1D) position sensitive detector (PSD) with the active layer imbedded in resonant cavity is proposed. The lateral photovoltaic effect (LPE) on the surface of active layer is related to the lifetime of photo-generated carriers-electrons and holes pairs. Theoretically, by improving the transmittance of multiple layered systems, the lifetime of carriers can be lengthened. For a photodetector in near infrared, we design the multiple layered system stacked by alternating layers with MgF2 and InP. The calculated result of electric field distribution in the proposed PSD is maximized in active layer with appropriate thickness. By this means, our aim is theoretically accomplished to enhance LPE in PSD based on resonant cavity structure.
Vinpocetine has long been used for cerebrovascular disorders and cognitive impairment. Based on the evidence that the translocator protein (TSPO, 18 kDa) was expressed in activated microglia, while Vinpocetine was able to bind TSPO, we explored the role of Vinpocetine on microglia treated with lipopolysaccharide (LPS) and oxygen–glucose deprivation (OGD) in vitro. Our results show that both LPS and OGD induced the up-regulation of TSPO expression on BV-2 microglia by RT-PCR, western blot and immunocytochemistry. Vinpocetine inhibited the production of nitrite oxide and inflammatory factors such as interleukin-1β (IL-1β), IL-6 and tumour necrosis factor-α (TNF-α) in BV-2 microglia, in which cells were treated with LPS or exposed to OGD, regardless of the time Vinpocetine was added. Next, we measured cell death-related molecules Akt, Junk and p38 as well as inflammation-related molecules nuclear factor-κB (NF-κB) and activator protein-1 (AP-1). Vinpocetine did not change cell death-related molecules, but inhibited the expression of NF-κB and AP-1 in LPS-stimulated microglia, indicating that Vinpocetine has an anti-inflammatory effect by partly targeting NF-κB/AP-1. Next, conditioned medium from Vinpocetine-treated microglia protected from primary neurons. As compared with in vitro, the administration of Vinpocetine in hypoxic mice also inhibited inflammatory molecules, indicating that Vinpocetine as a unique anti-inflammatory agent may be beneficial for the treatment of neuroinflammatory diseases.
CD4+ T cells play a key role in the immune response of pathogen-induced mastitis in dairy cattle. Mammary gland factor STAT5b is involved in the regulation of CD4+T cell differentiation during inflammatory response and milk production. Little is known about the genetic variation effects of bovine CD4 and STAT5b genes on somatic cell score (SCS) and milk production traits in dairy cattle. The aim of the study was to investigate the single nucleotide polymorphisms (SNPs) of bovine CD4 and STAT5b in Chinese Holsteins and to analyse their association with estimated breeding values (EBVs) for SCS and milk production traits. In the present study, SNPs of CD4 (NC_007303 g.13598C>T) and STAT5b (NC_007317 g.31562 T>C) were identified and genotyped in Chinese Holstein population. The results showed that both SNPs were significantly associated with the EBVs for milk yield and protein yield in Chinese Holstein cows, and the SNP in CD4 was associated with the EBV for SCS (P<0·01). The additive effect of CD4 SNP on protein yield was significant (P<0·05), and the dominant effect of STAT5b SNP was significant on milk yield and protein yield (P<0·01). Cows with combination genotype C7 (CCTT: CD4 g.13598C>T and STAT5b g.31562 T>C) had the highest SCS EBV but lower milk yield, while cows with C2 (TTTC) produced more milk, fat and protein than the other eight combination genotypes. These results suggested that the SNPs in CD4 and STAT5b may be potential genetic markers for SCS and milk/protein yields selecting and warrant further functional research.
Phase-pure nanostructured WB ceramics are hot pressed at ultrahigh pressures of 1.0 to 3.0 GPa and high temperatures of 700 to 1000 °C (UHPHT) for 60 min. The UHPHT samples are nanograin size from 15 to 40 nm. Our experimental observation shows that ultrahigh pressure could improve densification, and the density of WB samples could reach 99.4% of theoretical. The comparative experiments carried out at ambient pressure and temperatures of 550 to 1100 °C for 60 min indicate that the external pressure was favorable for phase-pure and highly dense WB formation. In addition, the UHPHT samples give a high hardness value of 28.9 ± 0.8 GPa.
Bacillus thuringiensis strain WZ-9, isolated from soil in Hebei province, China, was effective against Henosepilachna vigintioctomaculata larvae. The strain presented bipyramidal crystals with a protein band of 130 kDa in SDS–PAGE. The pH changes of the culture media showed important fluctuations during the 24 h growth cycle. The pH varied less in log and stationary phases than it did in the exponential phase. Bioassay results showed that the WZ-9 strain was only harmful to larvae of H. vigintioctomaculata and not to either adults of H. vigintioctomaculata or other several lepidopteran and coleopteran insects. LC50 to second-instar larvae of H. vigintioctomaculata was 2.95×107 cells/ml after 72 h. Genotypic investigations showed that this strain possessed the cry7 gene. Sequence analysis demonstrated that the encoding gene contained an open reading frame (ORF) of 3414 bp and encoded 1138 amino acid residues. The deduced amino acid sequence was 99.65% identical to that of the reported Cry7Ab2 sequences. This gene was designated by the Bt δ-endotoxin nomenclature committee as Cry7Ab3 with accession number BI 1015188 in the GenBank database.
Using hypocotyls as explants, the adventitious shoots of Euonymus fortunei var. radicans were differentiated directly from basal Murashige and Skoog (MS) medium supplemented with different plant growth regulators. The highest regeneration frequency was obtained with MS medium containing 0.5 mg/l 6-benzylaminopurine (BAP) and 0.01 mg/l α-naphthalene acetic acid (NAA). A regeneration frequency of 92% and 4.2 shoots per explant were obtained after 30 days of culture. The binary vector pBCGm, containing Galanthus nivalis agglutinin (GNA) gene, was introduced into Agrobacterium tumefaciens LBA4404. Hypocotyl segments of E. fortunei var. radicans were infected through A. tumefaciens-mediated transformation. Polymerase chain reaction (PCR) and PCR–Southern blot analysis results confirmed that the GNA gene was integrated into the genome of transgenic plants. The highest transformation frequency was obtained with un-precultured explants infected for 30 min with OD600=0.6 Agrobacterium tumefaciens, and co-cultivated for 3 days.