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Chlamydia trachomatis (CT) infection has been a major public health threat globally. Monitoring and prediction of CT epidemic status and trends are important for programme planning, allocating resources and assessing impact; however, such activities are limited in China. In this study, we aimed to apply a seasonal autoregressive integrated moving average (SARIMA) model to predict the incidence of CT infection in Shenzhen city, China. The monthly incidence of CT between January 2008 and June 2019 in Shenzhen was used to fit and validate the SARIMA model. A seasonal fluctuation and a slightly increasing pattern of a long-term trend were revealed in the time series of CT incidence. The monthly CT incidence ranged from 4.80/100 000 to 21.56/100 000. The mean absolute percentage error value of the optimal model was 8.08%. The SARIMA model could be applied to effectively predict the short-term CT incidence in Shenzhen and provide support for the development of interventions for disease control and prevention.
Losing one's only child is a major traumatic life event that may lead to post-traumatic stress disorder (PTSD); however, the underlying mechanisms of its psychological consequences remain poorly understood. Here, we investigated subregional hippocampal functional connectivity (FC) networks based on resting-state functional magnetic resonance imaging and the deoxyribonucleic acid methylation of the human glucocorticoid receptor gene (NR3C1) in adults who had lost their only child.
A total of 144 Han Chinese adults who had lost their only child (51 adults with PTSD and 93 non-PTSD adults [trauma-exposed controls]) and 50 controls without trauma exposure were included in this fMRI study (age: 40–67 years). FCs between hippocampal subdivisions (four regions in each hemisphere: cornu ammonis1 [CA1], CA2, CA3, and dentate gyrus [DG]) and methylation levels of the NR3C1 gene were compared among the three groups.
Trauma-exposed adults, regardless of PTSD diagnosis, had weaker positive FC between the left hippocampal CA1, left DG, and the posterior cingulate cortex, and weaker negative FC between the right CA1, right DG, and several frontal gyri, relative to healthy controls. Compared to non-PTSD adults, PTSD adults showed decreased negative FC between the right CA1 region and the right middle/inferior frontal gyri (MFG/IFG), and decreased negative FC between the right DG and the right superior frontal gyrus and left MFG. Both trauma-exposed groups showed lower methylation levels of the NR3C1 gene.
Adults who had lost their only child may experience disrupted hippocampal network connectivity and NR3C1 methylation status, regardless of whether they have developed PTSD.
In this article, we study the problem of optimal index insurance design under an expected utility maximization framework. For general utility functions, we formally prove the existence and uniqueness of optimal contract and develop an effective numerical procedure to derive the optimal solution. For exponential utility and quadratic utility functions, we obtain analytical expression of the optimal indemnity function. Our results show that the indemnity can be a highly nonlinear and even non-monotonic function of the index variable in order to align with the actual loss variable so as to achieve the best reduction in basis risk. Due to the generality of model setup, our proposed method is readily applicable to a variety of insurance applications including index-linked mortality securities, weather index agriculture insurance, and index-based catastrophe insurance. Our method is illustrated by numerical examples where weather index insurance is designed for protection against the adverse rice yield using temperature and precipitation as the underlying indices. Numerical results show that our optimal index insurance significantly outperforms linear-type index insurance contracts in terms of basis risk reduction.
Although it is crucial to improve the treatment status of people with severe mental illness (SMI), it is still unknown whether and how socioeconomic development influences their treatment status.
To explore the change in treatment status in people with SMI from 1994 to 2015 in rural China and to examine the factors influencing treatment status in those with SMI.
Two mental health surveys using identical methods and ICD-10 were conducted in 1994 and 2015 (population ≥15 years old, n = 152 776) in the same six townships of Xinjin County, Chengdu, China.
Compared with 1994, individuals with SMI in 2015 had significantly higher rates of poor family economic status, fewer family caregivers, longer duration of illness, later age at first onset and poor mental status. Participants in 2015 had significantly higher rates of never being treated, taking antipsychotic drugs and ever being admitted to hospital, and lower rates of using traditional Chinese medicine or being treated by traditional/spiritual healers. The factors strongly associated with never being treated included worse mental status (symptoms/social functioning), older age, having no family caregivers and poor family economic status.
Socioeconomic development influences the treatment status of people with SMI in contemporary rural China. Relative poverty, having no family caregivers and older age are important factors associated with a worse treatment status. Culture-specific, community-based interventions and targeted poverty-alleviation programmes should be developed to improve the early identification, treatment and recovery of individuals with SMI in rural China.
This study was performed to explore the clinical features of Kawasaki disease shock syndrome and analyse the association between the left ventricular ejection fraction and Kawasaki disease shock syndrome.
We retrospectively reviewed the medical records of all consecutive inpatients with Kawasaki disease at Wenzhou Medical University Second Affiliated Hospital and Yuying Children’s Hospital in Wenzhou, China from January 2009 to December 2016. We compared the clinical characteristics, laboratory data, and left ventricular ejection fraction between patients with and without Kawasaki disease shock syndrome and analysed the effect of the left ventricular ejection fraction on Kawasaki disease shock syndrome under different clinical conditions of Kawasaki disease.
In total, 1147 patients were diagnosed with Kawasaki disease. Of these 1147 patients, 17 were diagnosed with Kawasaki disease shock syndrome; 68 patients admitted to the hospital at the same time, ±2 weeks, with Kawasaki disease but without Kawasaki disease shock syndrome served as the control group. Compared with the control group, the Kawasaki disease shock syndrome group had a significantly higher incidence of coronary artery lesions, cardiac troponin I concentration, N-terminal prohormone of brain natriuretic peptide concentration, neutrophil count and ratio, alanine aminotransferase concentration, aspartate aminotransferase concentration, and C-reactive protein concentration and a significantly lower platelet count, serum albumin concentration, and left ventricular ejection fraction. A low left ventricular ejection fraction was associated with Kawasaki disease shock syndrome under different conditions of Kawasaki disease.
Among patients with Kawasaki disease, cardiac injury is more likely in those with Kawasaki disease shock syndrome than without, and a low left ventricular ejection fraction may be associated with the development of Kawasaki disease shock syndrome.
Dilatometric studies of C–Mn hypoeutectoid steel with an as-cast structure were carried out to study the effects of the heating or cooling rate, heating and cooling process on phase transformation, and the thermal expansion coefficient. As the heating or cooling rate (Vc) increased, the characteristic temperatures of Ac1, Acp, and Ac3 also rose, while Ar3, Ar1, and Arp fell. In addition, the phase transformation temperature range (Ac3–Ac1) rose, while (Ar3–Arp) fell as the heating or cooling rate increased. At the same time, the maximum thermal expansion coefficients│αT│ between the heating and cooling processes during phase transformation showed significant differences, and the difference (│ΔαT│) in the maximum │αT│ between these processes increased along with the heating or cooling rate, and this is because of the different phase transformation rates, with regard to the change from austenite to ferrite on cooling and ferrite to austenite on heating. During the heating process, the phase transformation rate of ferrite to austenite first decreases and then increases as the temperature rises, and the phase transformation rate of austenite to ferrite first increases and then decreases during the cooling process. The evolution of carbon and substitutional alloying elements (Si and Mn) in austenite during heating and cooling is also analyzed in this work.
Due to its excellent physical properties, graphene acting as reinforcing fillers has attracted intense interests. To achieve a controlled distribution, the formation of a conductive network composed of graphene sheets within polymer matrix is of critical importance. In this work, polystyrene (PS) microspheres wrapped by graphene oxide (GO) sheets were prepared via layer-by-layer (LBL) assembly of oppositely charged GO sheets onto PS microspheres. The deposited GO was then reduced, and the composite films with a graphene conductive network were prepared by hot pressing. The morphology of graphene conductive network was studied, and the thermal and electrical properties of the composite films were measured. The as-prepared composites showed an improved thermal stability as well as electrical conductivity with a percolation threshold as low as 0.2 vol%. The combination of latex technology and LBL self-assembly method thus demonstrated an efficient and facile approach to fabricate electrically conductive graphene/polymer composites.
The environmental concern about diffuse pollution from nitrogen (N) fertilizers has led to increased research on the diagnosis of crop N status. The SPAD chlorophyll (Chl) meter is the most commonly used tool for rice (Oryza sativa L.) N status diagnosis, but measurements are conducted at a specific point and readings are affected by different leaf positions. Many measurements per plant must be taken in order to increase the accuracy of N status diagnosis, which limits its application. The present paper attempts to determine rice N status at the canopy level using Multiplex®, a new hand-held optical fluorescence sensor. The fluorescence emission of rice leaves under light excitation was utilized by Multiplex® to non-destructively assess rice leaf Chl and phenolic compound content. A field experiment was conducted in 2011 using a completely randomized split-plot design, with main-plot treatments being six N fertilizer application rates and subplot treatments being different plant densities. Leaf Chl and phenolic compounds were evaluated using the ratio of far-red fluorescence (FRF) to red fluorescence (RF) emission under red light excitation (simple fluorescence ratio, SFR_R) (R2 = 0·35, P < 0·01) and the ratio of decadic logarithm of red to ultra-violet (UV) fluorescence emission (R2 = 0·30, P < 0·01), respectively. Both SPAD reading and fluorescence-based indices including flavonoids (FLAV), nitrogen balance index (NBI_R) and SFR_R could be used to predict rice leaf N contents. The canopy FLAV, SFR_R and NBI_R were all highly correlated to average SPAD readings (R2 > 0·70 in most cases, P < 0·01). Therefore, Multiplex® can be used as an alternative to SPAD to determine rice N status in paddy fields.
Imputation of high-density genotypes from low- or medium-density platforms is a promising way to enhance the efficiency of whole-genome selection programs at low cost. In this study, we compared the efficiency of three widely used imputation algorithms (fastPHASE, BEAGLE and findhap) using Chinese Holstein cattle with Illumina BovineSNP50 genotypes. A total of 2108 cattle were randomly divided into a reference population and a test population to evaluate the influence of the reference population size. Three bovine chromosomes, BTA1, 16 and 28, were used to represent large, medium and small chromosome size, respectively. We simulated different scenarios by randomly masking 20%, 40%, 80% and 95% single-nucleotide polymorphisms (SNPs) on each chromosome in the test population to mimic different SNP density panels. Illumina Bovine3K and Illumina BovineLD (6909 SNPs) information was also used. We found that the three methods showed comparable accuracy when the proportion of masked SNPs was low. However, the difference became larger when more SNPs were masked. BEAGLE performed the best and was most robust with imputation accuracies >90% in almost all situations. fastPHASE was affected by the proportion of masked SNPs, especially when the masked SNP rate was high. findhap ran the fastest, whereas its accuracies were lower than those of BEAGLE but higher than those of fastPHASE. In addition, enlarging the reference population improved the imputation accuracy for BEAGLE and findhap, but did not affect fastPHASE. Considering imputation accuracy and computational requirements, BEAGLE has been found to be more reliable for imputing genotypes from low- to high-density genotyping platforms.
A review is presented on our recent Vlasov-Fokker-Planck (VFP) simulation code development and applications for high-power laser-plasma interactions. Numerical schemes are described for solving the kinetic VFP equation with both electron-electron and electron-ion collisions in one-spatial and two-velocity (1D2V) coordinates. They are based on the positive and flux conservation method and the finite volume method, and these two methods can insure the particle number conservation. Our simulation code can deal with problems in high-power laser/beam-plasma interactions, where highly non-Maxwellian electron distribution functions usually develop and the widely-used perturbation theories with the weak anisotropy assumption of the electron distribution function are no longer in point. We present some new results on three typical problems: firstly the plasma current generation in strong direct current electric fields beyond Spitzer-Härm’s transport theory, secondly the inverse bremsstrahlung absorption at high laser intensity beyond Langdon’s theory, and thirdly the heat transport with steep temperature and/or density gradients in laser-produced plasma. Finally, numerical parameters, performance, the particle number conservation, and the energy conservation in these simulations are provided.
Fluorescent nanodiamonds (FNDs) with a size in the range of 10 – 100 nm have been produced by ion irradiation and annealing, and isolated by differential centrifugation. Single particle spectroscopic characterization with confocal fluorescence microscopy and fluorescence correlation spectroscopy indicates that they are photostable and useful as an alternative to far-red fluorescent proteins for bioimaging applications. We demonstrate the application by performing in vivo imaging of bare and bioconjugated FND particles (100 nm in diameter) in C. elegans and zebrafishes and exploring the interactions between this novel nanomaterial and the model organisms. Our results indicate that FNDs can be delivered to the embryos of both organisms by microinjection and eventually into the hatched larvae in the next generation. No deleterious effects have been observed for the carbon-based nanoparticles in vivo. The high fluorescence brightness, excellent photostability, and nontoxic nature of the nanomaterial have allowed long-term imaging and tracking of embryogenesis in the organisms.
Sui SG, Wu MX, King ME, Zhang Y, Ling L, Xu JM, Weng XC, Duan L, Shan BC, Li LJ. Abnormal grey matter in victims of rape with PTSD in Mainland China: a voxel-based morphometry study.
This study examined changes in brain grey matter in victims of rape (VoR) with and without post-traumatic stress disorder (PTSD). Previous research has focused on PTSD caused by various traumatic events, such as war and disaster, among others. Although considerable research has focused on rape-related PTSD, limited studies have been carried out in the context of Mainland China.
The study included 11 VoR with PTSD, 8 VoR without PTSD and 12 healthy comparison (HC) subjects. We used voxel-based morphometry to explore changes in brain grey-matter density (GMD) by applying statistical parametric mapping to high-resolution magnetic resonance images.
Compared with HC, VoR with PTSD showed significant GMD reductions in the bilateral medial frontal cortex, left middle frontal cortex, middle temporal gyrus and fusiform cortex and significant GMD increases in the right posterior cingulate cortex, postcentral cortex, bilateral precentral cortex and inferior parietal lobule. Compared to VoR without PTSD, VoR with PTSD showed significant GMD reductions in the right uncus, left middle temporal gyrus, and the fusiform cortex, and increases in the left precentral cortex, inferior parietal lobule and right post-central cortex.
The findings of abnormal GMD in VoR with PTSD support the hypothesis that PTSD is associated with widespread anatomical changes in the brain. The medial frontal cortex, precentral cortex, posterior cingulate cortex, post-central cortex and inferior parietal lobule may play important roles in the neuropathology of PTSD.
Under certain assumptions on the dependence structure of the residual lives of the insured (i.e. their independence, positive association, or negative association), in this paper we establish some laws of large numbers for the convex upper bounds, derived by the technique of comonotonicity, of the present value function of a homogeneous portfolio composed of the whole-life insurance policies.
The oxidation behavior of polymer-derived SiAlCN ceramic in a water vapor environment was studied at 1400 °C. The oxidation and corrosion rates of the SiAlCN are much lower than those of SiCN and pure silicon-based ceramics. The material retains about 75% of its original strength after exposure in water vapor for 300 h at 1400 °C. It is believed that the superior resistance of the SiAlCN to water vapor-related oxidation and corrosion is due to the formation of an aluminum-doped silica layer, in which the aluminum has reduced the activity of the silica.
The HA coatings were heated separately in vacuum, air and water vapor. The dissolution of the HA coatings was investigated by immersion in Tris buffer and SBF The dissolubility of HA coatings in the solutions decreased in this order: as-received, heated in vacuum, in air and in water vapor. The nucleation of bone-like apatite on the surfaces of HA coatings after immersing a period of 11 days in SBF was observed by SEM. The microenvironment with a sufficient supersaturation of Ca and P ions was crucial for the nucleation and growth of apatite in SBF. The dissolution of amorphous phase in coatings played an important part in establishing the supersaturation of Ca and P ions.
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