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This report is on the synthesis by electrospinning of multiferroic core-shell nanofibers of strontium hexaferrite and lead zirconate titanate or barium titanate and studies on magneto-electric (ME) coupling. Fibers with well-defined core–shell structures showed the order parameters in agreement with values for nanostructures. The strength of ME coupling measured by the magnetic field-induced polarization showed the fractional change in the remnant polarization as high as 21%. The ME voltage coefficient in H-assembled films showed the strong ME response for the zero magnetic bias field. Follow-up studies and potential avenues for enhancing the strength of ME coupling in the core–shell nanofibers are discussed.
Post-stroke depression (PSD) is the most common psychiatric complication facing stroke survivors and has been associated with increased distress, physical disability, poor rehabilitation, and suicidal ideation. However, the pathophysiological mechanisms underlying PSD remain unknown, and no objective laboratory-based test is available to aid PSD diagnosis or monitor progression.
Here, an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach was performed to identify differentially expressed proteins in plasma samples obtained from PSD, stroke, and healthy control subjects.
The significantly differentiated proteins were primarily involved in lipid metabolism and immunoregulation. Six proteins associated with these processes – apolipoprotein A-IV (ApoA-IV), apolipoprotein C-II (ApoC-II), C-reactive protein (CRP), gelsolin, haptoglobin, and leucine-rich alpha-2-glycoprotein (LRG) – were selected for Western blotting validation. ApoA-IV expression was significantly upregulated in PSD as compared to stroke subjects. ApoC-II, LRG, and CRP expression were significantly downregulated in both PSD and HC subjects relative to stroke subjects. Gelsolin and haptoglobin expression were significantly dysregulated across all three groups with the following expression profiles: gelsolin, healthy control > PSD > stroke subjects; haptoglobin, stroke > PSD > healthy control.
Early perturbation of lipid metabolism and immunoregulation may be involved in the pathophysiology of PSD. The combination of increased gelsolin levels accompanied by decreased haptoglobin levels shows promise as a plasma-based diagnostic biomarker panel for detecting increased PSD risk in post-stroke patients.
The seasonality of individual influenza subtypes/lineages and the association of influenza epidemics with meteorological factors in the tropics/subtropics have not been well understood. The impact of the 2009 H1N1 pandemic on the prevalence of seasonal influenza virus remains to be explored. Using wavelet analysis, the periodicities of A/H3N2, seasonal A/H1N1, A/H1N1pdm09, Victoria and Yamagata were identified, respectively, in Panzhihua during 2006–2015. As a subtropical city in southwestern China, Panzhihua is the first industrial city in the upper reaches of the Yangtze River. The relationship between influenza epidemics and local climatic variables was examined based on regression models. The temporal distribution of influenza subtypes/lineages during the pre-pandemic (2006–2009), pandemic (2009) and post-pandemic (2010–2015) years was described and compared. A total of 6892 respiratory specimens were collected and 737 influenza viruses were isolated. A/H3N2 showed an annual cycle with a peak in summer–autumn, while A/H1N1pdm09, Victoria and Yamagata exhibited an annual cycle with a peak in winter–spring. Regression analyses demonstrated that relative humidity was positively associated with A/H3N2 activity while negatively associated with Victoria activity. Higher prevalence of A/H1N1pdm09 and Yamagata was driven by lower absolute humidity. The role of weather conditions in regulating influenza epidemics could be complicated since the diverse viral transmission modes and mechanism. Differences in seasonality and different associations with meteorological factors by influenza subtypes/lineages should be considered in epidemiological studies in the tropics/subtropics. The development of subtype- and lineage-specific prevention and control measures is of significant importance.
To solve the on-ground lateral direction control problem of the unswept flying-wing unmanned aerial vehicle (UAV) without rudder, steering system or breaking system, a control approach which uses differential propeller thrust to control the lateral direction is proposed. First, a mathematical model of the unswept flying-wing UAV on-ground moving is established. Second, based on the active disturbance rejection control (ADRC) theory, a yaw angle controller is designed by using the differential propeller thrust as the control output. Finally, a straight line trajectory tracking control law is designed by improving the vector field path following method. Experiment results show that the proposed control laws have a shorter response time, better robustness and better control precision compared with proportional integral derivative (PID) controller. The proposed controller has small computational complexity, simple parameter setting process, and uses practical measurable physical quantities, providing a reference solution for further engineering applications.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Galeruca daurica (Joannis) is a new outbreak pest in the Inner Mongolia grasslands in northern China. Heat shock protein 10 and 60 (Hsp10 and Hsp60) genes of G. daurica, designated as GdHsp10 and GdHsp60, were cloned by rapid amplification of cDNA ends techniques. Sequence analysis showed that GdHsp10 and GdHsp60 encoded polypeptides of 104 and 573 amino acids, respectively. Sequence alignment and phylogenetic analysis clearly revealed that the amino acids of GdHsp10 and GdHsp60 had high homology and were clustered with other Hsp10 and Hsp60 genes in insects which are highly relative with G. daurica based on morphologic taxonomy. The mRNA expression analysis by real-time PCR revealed that GdHsp10 and GdHsp60 were expressed at all development stages and in all tissues examined, but expressed highest in eggs and in adults’ abdomen; both heat and cold stresses could induce mRNA expression of GdHsp10 and GdHsp60 in the 2nd instar larvae; the two Hsp genes were expressed from high to low with the extension of treatment time in G. daurica eggs exposed to freezing point. Overall, our study provides useful information to understand temperature stress responses of Hsp60 and Hsp10 in G. daurica, and provides a basis to further study functions of Hsp60/Hsp10 relative to thermotolerance and cold hardiness mechanism.
Streptococcus pneumoniae is an important cause of community-acquired pneumonia and pneumococcal conjugate vaccines (PCVs) may reduce this burden. This study's goal was to analyse trends in lower respiratory tract infections (LRTI) hospitalisations before and during a routine vaccination programme targeting all newborns with PCV was started in the province of Quebec, Canada in December 2004. The study population included hospital admissions with a main diagnosis of LRTI among 6–59 month-old Quebec residents from April 2000 to December 2014. Trends in proportions and rates were analysed using Cochran-Armitage tests and Poisson regression models. We observed a general downward trend in all LTRI hospitalisations rate: from 11·55/1000 person-years in 2000–2001 to 9·59/1000 in 2013–2014, a 17·0% reduction, which started before the introduction of PCV vaccination. Downward trends in hospitalisation rates were more pronounced for all-cause of pneumonia (minus 17·8%) than for bronchiolitis (minus 15·4%). There was also a decrease in the mean duration of hospital stay. There was little evidence that all-cause pneumonia decreased over the study period due mainly to the introduction of PCVs. Trends may be related to changes in clinical practice. This study casts doubt on the interpretation of ecological analyses of the implementation of PCV vaccination programmes.
This paper presents an analytical study on the buckling of cylindrical shells with arbitrary circumferential thickness variations under external pressure. Firstly, based on the thin shell theory and separation of variables, corresponding ordinary differential equations of laterally pressured cylinders are obtained. Secondly, the general asymptotic formula of buckling load, which is in terms of thickness variation parameter up to arbitrary order, is derived by combining the perturbation method and Fourier series expansion. Thirdly, the effects of uniform and circumferential modal thickness variations on the buckling of cylindrical shells under external pressure are investigated, respectively, and the results agree well with those available in literature. Particularly, the buckling load reduction of cylinders with circumferential modal thickness variation obtained by the proposed method coincides with the numerical results presented by Gusic et al. This analytical method is applicable for evaluating the stability of laterally pressured cylindrical shells with arbitrary circumferential thickness variations, once the thickness variation is known.
It remains unclear whether the topological deficits of the white matter network documented in cross-sectional studies of chronic schizophrenia patients are due to chronic illness or to other factors such as antipsychotic treatment effects. To answer this question, we evaluated the white matter network in medication-naive first-episode schizophrenia patients (FESP) before and after a course of treatment.
We performed a longitudinal diffusion tensor imaging study in 42 drug-naive FESP at baseline and then after 8 weeks of risperidone monotherapy, and compared them with 38 healthy volunteers. Graph theory was utilized to calculate the topological characteristics of brain anatomical network. Patients’ clinical state was evaluated using the Positive and Negative Syndrome Scale (PANSS) before and after treatment.
Pretreatment, patients had relatively intact overall topological organizations, and deficient nodal topological properties primarily in prefrontal gyrus and limbic system components such as the bilateral anterior and posterior cingulate. Treatment with risperidone normalized topological parameters in the limbic system, and the enhancement positively correlated with the reduction in PANSS-positive symptoms. Prefrontal topological impairments persisted following treatment and negative symptoms did not improve.
During the early phase of antipsychotic medication treatment there are region-specific alterations in white matter topological measures. Limbic white matter topological dysfunction improves with positive symptom reduction. Prefrontal deficits and negative symptoms are unresponsive to medication intervention, and prefrontal deficits are potential trait biomarkers and targets for negative symptom treatment development.
At the end of 2013, China reported a countrywide outbreak of measles. From January to May 2014, we investigated the clinical and immunological features of the cases of the outbreak admitted to our hospital. In this study, all 112 inpatients with clinically diagnosed measles were recruited from the 302 Military Hospital of China. The virus was isolated from throat swabs from these patients, and cytokine profiles were examined. By detecting the measles virus of 30 of the 112 patients, we found that this measles outbreak was of the H1 genotype, which is the major strain in China. The rates of complications, specifically pneumonia and liver injury, differed significantly in patients aged <8 months, 8 months to 18 years, and >18 years: pneumonia was more common in children, while liver injury was more common in adults. Pneumonia was a significant independent risk factor affecting measles duration. Compared to healthy subjects, measles patients had fewer CD4+IL-17+, CD4+IFN-γ+, and CD8+IFN-γ+ cells in both the acute and recovery phases. In contrast, measles patients in the acute phase had more CD8+IL-22+ cells than those in recovery or healthy subjects. We recommend that future studies focus on the age-related distribution of pneumonia and liver injury as measles-related complications as well as the association between immunological markers and measles prognosis.
In late 2014, a gastroenteritis outbreak occurred in a school in Shandong Province, eastern China. Hundreds of individuals developed the symptoms of diarrhoea and vomiting. Epidemiological investigation showed that food consumption was not linked to this outbreak, and unboiled direct drinking water was identified as the independent risk factor with a relative risk of 1·37 (95% confidence interval 1·03–1·83). Furthermore, examination of common bacterial and viral gastroenteritis pathogens was conducted on different specimens. Norovirus GI.1, GI.2, GI.6, GII.4, GII.6 and GII.13 were detected in clinical specimens and a water sample. GII.4 sequences between clinical specimens and the water sample displayed a close relationship and belonged to GII.4 variant Sydney 2012. These results indicate that direct drinking water contaminated by norovirus was responsible for this gastroenteritis outbreak. This study enriches our knowledge of waterborne norovirus outbreaks in China, and presents valuable prevention and control practices for policy-makers. In future, strengthened surveillance and supervision of direct drinking-water systems is needed.
Young age, adverse environmental conditions and infectious agents are established risk factors of lower respiratory tract infection (LRTI), whereas pneumococcal conjugate vaccines may be protective. To explore their relative role as predictors of hospitalizations under the continental climate prevailing in the province of Quebec, Canada, an ecological study was performed. Records with a main diagnosis of LRTI in children born during 2007–2010 and observed up to their second-year anniversary were extracted from the provincial hospital administrative database. Respiratory virus surveillance data and statistics on ambient air temperature were obtained. Vaccine use in different birth cohorts was derived from the Quebec City Immunization Registry. Additive and multiplicative Poisson regression models were applied to estimate attributable fractions. Age, month of birth, ambient temperature, and respiratory syncytial virus (RSV), human metapneumovirus (hMPV) and influenza-positive test proportions were significant predictors of LRTI hospitalizations. No substantial differences were observed in cohorts exposed to the 7-valent or 10-valent pneumococcal conjugate vaccines. In the additive model, the fraction of hospitalizations explained by temperature variation was 37%, whereas RSV circulation explained 28%, hMPV 4% and influenza 1%. Complex interplay between biological, environmental and social mechanisms may explain the important role of ambient air temperature in predicting LRTI hospitalization risk in young children.
The transmission of haemorrhagic fever with renal syndrome (HFRS) is deeply influenced by the reservoir and hantavirus prevalence rate. In this study, a surveillance on human HFRS cases, relative rodent abundance, and hantavirus infection prevalence was conducted in Shaanxi province, China, during 1984–2012. A generalized linear model with Poisson-distributed residuals and a log link was used to quantify the relationship between reservoir, virus and HFRS cases. The result indicated that there was a significant association of HFRS incidence with relative rodent density and the prevalence rate. This research provides evidence that the changes of infection prevalence in the reservoir could lead directly to the emergence of a new epidemic. It was concluded that the measurement of a number of these variables could be used in disease surveillance to give useful advance warning of potential disease epidemics.
Parrots are one of the most popular pet birds in China, and can harbour Chlamydia which has significance for human and animal health. We investigated, by indirect haemagglutination assay, the seroprevalence of Chlamydia infection in four species of parrots, namely budgerigars (Melopsittacus undulatus), lovebirds (Agapornis sp.), cockatiels (Nymphicus hollandicus) and Alexandrine parakeets (Psittacula eupatria) that were collected from Weifang and Beijing cities, North China and explored the association between potential risk factors and chlamydial seropositivity. We further determined the genotype of Chlamydia in 21 fresh faecal samples based on the ompA sequence by reconstruction of phylogenetic relationships. Of the 311 parrots examined, 35·37% (95% confidence interval 30·06–40·68) were seropositive, and species, gender, age, season and geographical location were identified as risk factors. Two PCR-positive samples represented Chlamydia psittaci genotype A. The occurrence of C. psittaci genotype A in the droppings of two pet parrots in China suggests potential environmental contamination with Chlamydiaceae and may raise a public health concern.
There have been a number of studies that have attempted to estimate the past radiocarbon reservoir effects in Qinghai Lake, China. This article reports on measurements on modern samples collected at the lake in October 2003 and October 2009, which allow us to better understand the systematics of the lake and shed new insights on the processes occurring in the lake. The results indicate that atmospheric exchange of 14C is the main process affecting surface dissolved inorganic carbon (DIC) in the lake, but dissolved organic carbon (DOC) can be explained as a combination of sources. We also conclude that sediment carbon can be explained by a model where input from the surrounding rivers and groundwater are important, in agreement with the model of Yu et al. (2007).
The ASTEP project aims at detecting and characterizing transiting planets from Dome C, Antarctica, and qualifying this site for photometry in the visible. The first phase of the project, ASTEP South, is a fixed 10 cm diameter instrument pointing continuously towards the celestial South Pole. Observations were made almost continuously during 4 winters, from 2008 to 2011. The point-to-point RMS of 1-day photometric lightcurves can be explained by a combination of expected statistical noises, dominated by the photon noise up to magnitude 14. This RMS is large, from 2.5 mmag at R = 8 to 6% at R = 14, because of the small size of ASTEP South and the short exposure time (30 s). Statistical noises should be considerably reduced using the large amount of collected data. A 9.9-day period eclipsing binary is detected, with a magnitude R = 9.85. The 2-season lightcurve folded in phase and binned into 1,000 points has a RMS of 1.09 mmag, for an expected photon noise of 0.29 mmag. The use of the 4 seasons of data with a better detrending algorithm should yield a sub-millimagnitude precision for this folded lightcurve. Radial velocity follow-up observations reveal a F-M binary system. The detection of this 9.9-day period system with a small instrument such as ASTEP South and the precision of the folded lightcurve show the quality of Dome C for continuous photometric observations, and its potential for the detection of planets with orbital periods longer than those usually detected from the ground.
During the last decade, multilocus analysis has gradually become a powerful tool for the studies of population genetics and phylogeography. The double-striped cockroach, Blattella bisignata, is endemic to southeast Asia, and there is currently little genetic information available for the species. We chose it as the target species to investigate a biodiversity hotspot in southwest China. Here, we report the identification and characterization of 11 single-copy anonymous nuclear markers with an average length of 378bp. These loci, isolated from a genomic library of B. bisignata, can amplify in two additional Blattella species (B. germanica and B. lituricollis). While testing these markers in representative species of Blattellidae, Blattidae and Epilampridae, some of them can cross-amplify successfully. After sequencing 30 individuals collected from southern China per locus, we found relatively high variability (approximately 3.6 SNPs per 100bp). Finally, a small-scale study was also performed to show that these markers do indeed fulfill the expectations as phylogeographic markers.
The phylogenetic and epidemic relationships of 104 clinical isolates of Clostridium difficile from three hospitals of different geographical and population sources in China were investigated by multilocus sequence typing. Twenty-two sequence types (STs) were identified, four of which, ST117, ST118, ST119 and ST129, were novel. No geographically specific and host population-specific phylogenetic lineages were found and there was no correlation between geographical origin or host population and strain genotype. ST37 was the dominant type in our survey but the four novel STs underline the high genetic diversity and unique polymorphisms in C. difficile from China.
A cropping system is the consequence of environmental and socio-economic conditions that determine the intensity of agricultural land use. Accurate information on regional land use intensity and changes in land use intensity is important for food security and sustainable resource management in China. Therefore, a better understanding of the spatial and temporal changes in arable land use intensity (ALUI) based on the cropping system used is essential to comprehend the changes in land use and the sustainability of the food system. The purpose of the present study was to investigate the spatial difference in ALUI and how it has changed in China by comparing data on cropping systems from 1985 and 2005. The basic cropping system data were acquired from the 1985 reference book and the 2005 national land use investigation. The ALUI was defined by the application of inputs (irrigation water and fertilizer) to arable land and the duration of disturbances (the duration of cultivation and the frequency of cropping), and it was calculated using the information entropy approach at the cropping region scale (cropping region being defined by the geographical and climatic conditions at the beginning of the 1980s). Spatial and temporal changes in the ALUI in China over the past two decades were observed and analysed. The results indicated a clear pattern in ALUI, increasing from the north to the south in 2005. Furthermore, the ALUI significantly increased after the 1980s, but the rate of increase was lower in the south than in the north. The most intensive land use in 1985 was in the area of the lower reach of the Yangtze and Huai Rivers, and it expanded northwards towards the Huang-Huai-Hai plain in 2005. The large increase in intensity in the northern single-cropping regions was strongly associated with a rapid increase in inputs and longer duration of cultivation. Decreases in duration of cultivation and planting area helped slow the ALUI increase in multiple cropping regions, which were concentrated in coastal and economically developed regions where more fertile soil and suitable climates existed, allowing the growth of multiple crops. These results suggested that a decrease in the planting area and a slow increase in the ALUI in the lower reaches of the Yangtze River, South China, Southeast China and Northeast China should be of concern, but land use in some western regions should maintain the land production capacity to build sustainable cropping. In the future, it will be necessary to produce more food in a more sustainable way.