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The study of the mechanical properties of polycrystalline alloy materials under dynamic impact, namely, the prediction of mechanical behavior after yield stress and the establishment of a constitutive model, has attracted much attention in the field of engineering. The stress-strain curves of 5083 aluminum alloy were obtained under strain rates varying from 0.0002 s-1 to 7130 s-1 through uniaxial compression experiments. The equipment used included a CRIMS RPL100 tester, Instron tester, and split Hopkinson test system. In addition, based on dislocation dynamics and the strengthening mechanism of metals, the plastic flow of the 5083 aluminum alloy was systematically analyzed under a wide range of strain rates. It was found that the abnormal yield behavior of the 5083 aluminum alloy under a wide range of strain rates increased, and the experimental phenomenon of hardening rate decreased with an increase in strain rate. This study also revealed that the abnormal yield behavior is caused by the different dislocation mechanisms of two-phase alloy elements under different strain rates. Based on the thermal activation theory and the experimental data, a constitutive model was developed. A comparison showed good agreement between the experimental and model curves. This indicates that this model has good plastic flow stress prediction ability for such types of materials.
The origins and phylogeny of different sheep breeds has been widely studied using polymorphisms within the mitochondrial hypervariable region. However, little is known about the mitochondrial DNA (mtDNA) content and phylogeny based on mtDNA protein-coding genes. In this study, we assessed the phylogeny and copy number of the mtDNA in eight indigenous (population size, n=184) and three introduced (n=66) sheep breeds in China based on five mitochondrial coding genes (COX1, COX2, ATP8, ATP6 and COX3). The mean haplotype and nucleotide diversities were 0.944 and 0.00322, respectively. We identified a correlation between the lineages distribution and the genetic distance, whereby Valley-type Tibetan sheep had a closer genetic relationship with introduced breeds (Dorper, Poll Dorset and Suffolk) than with other indigenous breeds. Similarly, the Median-joining profile of haplotypes revealed the distribution of clusters according to genetic differences. Moreover, copy number analysis based on the five mitochondrial coding genes was affected by the genetic distance combining with genetic phylogeny; we also identified obvious non-synonymous mutations in ATP6 between the different levels of copy number expressions. These results imply that differences in mitogenomic compositions resulting from geographical separation lead to differences in mitochondrial function.
Hand, foot, and mouth disease (HFMD) is highly prevalent in China, and more efficient methods of epidemic detection and early warning need to be developed to augment traditional surveillance systems. In this paper, a method that uses Baidu search queries to track and predict HFMD epidemics is presented, and the outbreaks of HFMD in China during the 60-month period from January 2011 to December 2015 are predicted. The Pearson correlation coefficient (R) of the predictive model and the mean absolute percentage errors between observed HFMD case counts and the predicted number show that our predictive model gives excellent fit to the data. This implies that Baidu search queries can be used in China to track and reliably predict HFMD epidemics, and can serve as a supplement to official systems for HFMD epidemic surveillance.
Pudong White (PW) pigs are distributed in the Taihu region of China and are characterized by their completely white coats. A heated debate concerning this genetic resource and its relationship to Taihu and western pig breeds has arisen, due to the white coat of the animals. To determine whether PW is a unique genetic resource, we performed a detailed assessment of the genetic relationships among PW, six breeds from the Taihu population and three western pig breeds, based on whole-genome single nucleotide polymorphism (SNP) data. A total of 68 102 SNPs were identified in the genomes of the tested populations by next-generation sequencing technology, of which, 64 were determined as the potentially specific to PW breed. The genetic distance between PW pigs and the Taihu population was shorter than that between PW and western breeds. The genetic distance within the PW population was small and neighbour-joining tree analysis revealed that all PW individuals clustered into a separated group, indicating a close genetic relationship among PW individuals which may result from a small effective population size (Ne) and inbreeding. The results of both principal component analysis and evaluation using fastSTRUCTURE demonstrated that PW was clearly differentiated from other breeds. Together, these results indicate that PW is a distinctive genetic resource with a unique genetic structure separate from other Taihu and western pig breeds. Furthermore, this genome-wide comprehensive survey of the relationships among PW, Taihu and western pig breeds, demonstrates the rationality of the current breed classification of PW. The results also provide evidence about the unique genetic resource of PW, based on genome-wide genetic markers. These data will improve our understanding of the genetic structure and current state of PW breed, and facilitate the development of a national project for the conservation and utilization of these pigs.
We carried out a pivot experiment to select distant luminous late-type stars on the basis on their 2MASS and GLIMPSE photometry. Low-resolution infrared spectra enabled us to measure the equivalent widths (EWs) of their CO band-heads at 2.293 μm, and to confirm an extraordinarily high detection rate of red supergiants (RSGs), i.e. 61% (Messineo et al. (2016)).
We compute the thermal X-ray emission from hydrodynamic simulations of the 30 Wolf-Rayet (WR) stars orbiting within a parsec of Sgr A*, with the aim of interpreting the Chandra X-ray observations of this region. The model well reproduces the spectral shape of the observations, indicating that the shocked WR winds are the dominant source of this thermal emission. The model X-ray flux is tied to the strength of the Sgr A* outflow, which clears out hot gas from the vicinity of Sgr A*. A moderate outflow best fits the present-day observations, even though this supermassive black hole (SMBH) outflow ended ~100 yr ago.
Studies of schizophrenia at drug-naive state and on antipsychotic medication have reported a number of regions of gray-matter (GM) abnormalities but the reports have been inconsistent. The aim of this study was to conduct multimodal meta-analysis to compare the cross-sectional voxel-based morphometry studies of brain GM in antipsychotic-naive first-episode schizophrenia (AN-FES) and those with antipsychotic treatment within 1 year (AT-FES) to determine the similarities and differences in these groups. We conducted two separate meta-analyses containing 24 studies with a sample size of 801 patients and 957 healthy controls. A multimodal meta-analysis method was used to compare the findings between AN-FES and AT-FES. Meta-regression analyses were done to determine the influence of different variables including age, duration of illness, and positive and negative symptom scores. Finally, jack-knife analyses were done to test the robustness of the results. AN-FES and AT-FES showed common patterns of GM abnormalities in frontal (gyrus rectus), superior temporal, left hippocampal and insular cortex. GM in the left supramarginal gyrus and left middle temporal gyrus were found to be increased in AN-FES but decreased in AT-FES, whereas left median cingulate/paracingulate gyri and right hippocampus GM was decreased in AN-FES but increased in AT-FES. Findings suggest that both AN-FES and AT-FES share frontal, temporal and insular regions as common anatomical regions to be affected indicating these to be the primary regions of GM abnormalities in both groups.
Ectropis grisescens Warren and Ectropis obliqua (Prout) are two morphologically similar sibling species with overlapping ranges. In this study, manipulative laboratory experiments were conducted to examine the possibility of reproductive interference in sympatric populations of E. grisescens and E. obliqua and the potential consequences of the mating interaction. Our results showed that the presence of males or females of different species could incur mating interference and significant reduction of F1 offspring. The reduction was not significant relevant to the initial relative abundance of E. grisescens and E. obliqua. Detailed observations of mating opportunity showed that female mating frequencies of both species were not significantly affected by the absolute species density, but the mating success of E. obliqua females with conspecific males depended on species ratio. In addition, adding males to the other species resulted in lower number of offspring suggesting that the males’ behaviour might be linked with mating interference. Males of both E. grisescens and E. obliqua could interfere the intraspecific mating of the other species, but the impact of the mating interference differed. These combined data indicated that asymmetric reproductive interference existed in E. grisescens and E. obliqua under laboratory conditions, and the offspring of the mixed species were significantly reduced. The long term outcome of this effect is yet to be determined since additional reproductive factors such as oviposition rate and progeny survival to adulthood may reduce the probability of demographic displacement of one species by the other in overlapping niches.
Chinese psychiatrists have gradually started to focus on those who are deemed to be at ‘clinical high-risk (CHR)’ for psychosis; however, it is still unknown how often those individuals identified as CHR from a different country background than previously studied would transition to psychosis. The objectives of this study are to examine baseline characteristics and the timing of symptom onset, help-seeking, or transition to psychosis over a 2-year period in China.
The presence of CHR was determined with the Structured Interview for Prodromal Syndromes (SIPS) at the participants' first visit to the mental health services. A total of 86 (of 117) CHR participants completed the clinical follow-up of at least 2 years (73.5%). Conversion was determined using the criteria of presence of psychotic symptoms (in SIPS). Analyses examined baseline demographic and clinical predictors of psychosis and trajectory of symptoms over time. Survival analysis (Kaplan–Meier) methods along with Log-rank tests were performed to illustrate the relationship of baseline data to either conversion or non-conversion over time. Cox regression was performed to identify baseline predictors of conversion by the 2-year follow-up.
In total 25 (29.1%) of 86 completers transitioned to a psychotic disorder over the course of follow-up. Among the CHR sample, the mean time between attenuated symptom onset and professional help-seeking was about 4 months on average, and converters developed fully psychotic symptoms about 12 months after symptom onset. Compared with those CHR participants whose risk syndromes remitted over the course of the study, converters had significantly longer delays (p = 0.029) for their first visit to a professional in search of help. At baseline assessment, the conversion subgroup was younger, had poorer functioning, higher total SIPS positive symptom scores, longer duration of untreated prodromal symptoms, and were more often given psychosis-related diagnoses and subsequently prescribed antipsychotics in the clinic.
Chinese CHR identified primarily by a novel clinical screening approach had a 2-year transition rate comparable with those of specialised help-seeking samples world-wide. Early clinical intervention with this functionally deteriorating clinical population who are suffering from attenuated psychotic symptoms, is a next step in applying the CHR construct in China.
A new type of steel-concrete composite beam with double-box cross-section is proposed in this paper. In order to investigate stress behaviors and deflection characteristics of such composite beam with wide flange considering the shear lag effect, theoretical analysis and experimental study are launched simultaneously. Based on the minimum potential energy principle, governing differential equations in view of the shear lag effect are deduced by energy variational method, and analytical solutions of it's stress and deflection under the effect of symmetrical loading are calculated. The preceding analyses show that relative error is less than 14.71%, with a good agreement, and farther show that this method of theoretical derivation, which is used for analyzing shear lag effect of composite beam with wide flange, has certain reference and guidance.
Escherichia albertii is a newly emerging enteric pathogen that has been associated with gastroenteritis in humans. Recently, E. albertii has also been detected in healthy and sick birds, animals, chicken meat and water. In the present study, the prevalence and characteristics of the eae-positive, lactose non-fermenting E. albertii strains in retail raw meat in China were evaluated. Thirty isolates of such strains of E. albertii were identified from 446 (6·73%) samples, including duck intestines (21·43%, 6/28), duck meat (9·52%, 2/21), chicken intestines (8·99%, 17/189), chicken meat (5·66%, 3/53), mutton meat (4·55%, 1/22) and pork meat (2·44%, 1/41). None was isolated from 92 samples of raw beef meat. Strains were identified as E. albertii by phenotypic properties, diagnostic PCR, sequence analysis of the 16S rRNA gene, and housekeeping genes. Five intimin subtypes were harboured by these strains. All strains possessed the II/III/V subtype group of the cdtB gene, with two strains carrying another copy of the I/IV subtype group. Pulsed-field gel electrophoresis showed high genetic diversity of E. albertii in raw meats. Our findings indicate that E. albertii can contaminate various raw meats, posing a potential threat to public health.
Dopamine D2 receptors (D2R) are the primary target of antipsychotic drugs and have been shown to regulate Akt/glycogen synthase kinase-3b (GSK-3b) signaling through scaffolding protein b-arrestin 2.
In the present study, we researched the effects of saikosaponin B1 on the b-arrestin 2-mediated Akt/GSK-3b pathway in human neuroblastoma cell lineSH-SY5Y cells.
To determine whether saikosaponin B1 affected neuronal morphology in human neuroblastoma cell line SH-SY5Y cells.
We investigated the effects of saikosaponin B1 on neurite outgrowth using immunostaining. We examined the effects of saikosaponin B1 on Akt and GSK-3b and its well-known downstream regulators, cAMP response element-binding protein (CREB), brain-derived neurotrophic factor (BDNF), and Bcl-2 levels using Western blot analysis.
Saikosaponin B1 was found to enhance neurite outgrowth. Small interfering RNA (siRNA) for b-arrestin 2 knockdown blocked the increase in saikosaponin B1-induced neurite outgrowth. Furthermore, saikosaponin B1 increased the levels of Akt and GSK-3b phosphorylation. The elevation of Akt phosphorylation induced by saikosaponin B1 was reduced by b-arrestin 2 siRNA. Moreover, saikosaponin B1 effectively increased the levels of phospho-CREB, BDNF, and Bcl-2.
Together, these results suggest that regulation of the b-arrestin 2-dependent pathway via blockade of the D2R in SH-SY5Y cells is one mechanism underlying the neuroprotective effect of saikosaponin B1.
To evauluate our novel ultrasound model for measurement of optic nerve sheath diameter (ONSD) and determine the intra- and inter-operator variability associated with this technique.
We conducted ten measurements of ONSD per model amongst eight different models with a single experienced operator to examine intra-operator variability. Similarly, we had seven different operators measure the OSND twice in eight different models, in order to determine inter-operator variability analyzed with a three level linear statistical model.
For intra-operator variability, the intra-cluster correlation coefficients for the experienced and novice operators were 0.643 and 0.453 respectively. This displayed improvement in intra-operator variability with experience. The inter-cluster correlation coefficient was 0 for the group of novice operators, indicating negligible difference amongst multiple operators in measuring any given model of ONSD. A strong, statistically significant, linear relationship between the actual model disc size and the ultrasound ONSD measures was identified, implying the reliability of the images produced by our novel model.
Utilizing a novel model for ONSD ultrasonography, we have determined the intraoperator reliability of ONSD measurement to be moderate, with no appreciable difference amongst multiple operators. Improvement in measurement reliability has been demonstrated between expert and novice operators with our model, indicating the potential benefit of simulation platforms for teaching the technique of ONSD ultrasound.
Schizophrenia (SCZ) and psychotic bipolar disorder (PBD) share considerable overlap in clinical features, genetic risk factors and co-occurrence among relatives. The common and unique functional cerebral deficits in these disorders, and in unaffected relatives, remain to be identified.
A total of 59 healthy controls, 37 SCZ and 57 PBD probands and their unaffected first-degree relatives (38 and 28, respectively) were studied using resting-state functional magnetic resonance imaging (rfMRI). Regional cerebral function was evaluated by measuring the amplitude of low-frequency fluctuations (ALFF). Areas with ALFF alterations were used as seeds in whole-brain functional connectivity analysis. We then tested whether abnormalities identified in probands were present in unaffected relatives.
SCZ and PBD probands both demonstrated regional hypoactivity in the orbital frontal cortex and cingulate gyrus, as well as abnormal connectivity within striatal-thalamo-cortical networks. SCZ probands showed greater and more widely distributed ALFF alterations including the thalamus and bilateral parahippocampal gyri. Increased parahippocampal ALFF was related to positive symptoms and cognitive deficit. PBD patients showed uniquely increased functional connectivity between the thalamus and bilateral insula. Only PBD relatives showed abnormal connectivity within striatal-thalamo-cortical networks seen in both proband groups.
The present findings reveal a common pattern of deficits in frontostriatal circuitry across SCZ and PBD, and unique regional and functional connectivity abnormalities that distinguish them. The abnormal network connectivity in PBD relatives that was present in both proband groups may reflect genetic susceptibility associated with risk for psychosis, but within-family associations of this measure were not high.
In the eastern Tibetan plateau both human cystic and alveolar echinococcosis (AE) caused by infection with Echincoccus granulosus or Echinococcus multilocularis, respectively are highly endemic. The domestic dog plays a key role in zoonotic transmission in this region. Our primary objective was to investigate the role of domestic dogs in maintaining transmission of E. multilocularis in Shiqu county, Sichuan. A cohort of 281 dogs was followed up over one year after a single treatment with praziquantel followed by re-infection surveillance at 2, 5 and 12 months post-treatment. Faecal samples were tested by an Echinococcus genus-specific coproantigen ELISA and two species-specific copro-PCR tests. Total Echinococcus coproantigen prevalence in Shiqu at baseline was 21% and 9·6% after 2 months. E. multilocularis copro-PCR was positive in 11·2% of dogs before treatment (vs 3·6% with E. granulosus copro-DNA), 2·9% at 2 months post-treatment, and 0% at 5 month and 12 months. The results suggest that dogs may have the potential to maintain E. multilocularis transmission within local pastoral communities, and thus dog dosing could be an effective strategy to reduce transmission of E. multilocularis as well as E. granulosus in these co-endemic Tibetan communities.
The false thyroid capsule is an important anatomical structure involved in thyroidectomy, yet it is rarely studied. This study aimed to define the anatomy of the false thyroid capsule, and its clinical significance.
A prospective study was performed involving 151 patients with goitre who underwent thyroid lobectomy. The anatomy of the false thyroid capsule was carefully documented intra-operatively.
The false thyroid capsule enclosed the inferior and middle thyroid veins and the superior thyroid vessels, forming a mesentery-like structure by attaching to the gland. Once the unilateral lobe had been removed, the thyroid mesentery could be seen to have a C-shaped edge. The recurrent laryngeal nerve, inferior thyroid artery and parathyroid glands were located beneath the C-shaped edge of the thyroid mesentery.
The thyroid mesentery is a distinctive structure that can be used as a guide for surgical dissection.
Many infectious diseases exhibit repetitive or regular behaviour over time. Time-domain approaches, such as the seasonal autoregressive integrated moving average model, are often utilized to examine the cyclical behaviour of such diseases. The limitations for time-domain approaches include over-differencing and over-fitting; furthermore, the use of these approaches is inappropriate when the assumption of linearity may not hold. In this study, we implemented a simple and efficient procedure based on the fast Fourier transformation (FFT) approach to evaluate the epidemic dynamic of scarlet fever incidence (2004–2010) in China. This method demonstrated good internal and external validities and overcame some shortcomings of time-domain approaches. The procedure also elucidated the cycling behaviour in terms of environmental factors. We concluded that, under appropriate circumstances of data structure, spectral analysis based on the FFT approach may be applicable for the study of oscillating diseases.
Coproantigen test kits for Echinococcus spp. worms in dogs, designed for commercial use, were obtained from three different Chinese producers, and were compared with a laboratory kit using reagents from New Zealand. None of the three producers would provide details of their test validation. From a known set of dog faeces obtained at necropsy from infected and uninfected dogs, and from faeces collected from dogs necropsied in the field, results differed between the kits. For field material, the Tiankang kit showed the best specificity but lacked sensitivity. The Combined kit showed best sensitivity but lacked specificity. Results for the Haitai kit were intermediate. With samples from experimentally infected dogs, both the Haitai and Combined kits lacked sensitivity. Kits will need to be validated by the user before they can be relied on to predict progress in Echinococcus spp. control in China or in other countries.
Large electrocaloric (EC) effects in ferroelectric polymers and in ferroelectric ceramics have attracted great attention for new refrigeration development which is more environmental friendly and more efficient and thus could be an alternative to the existing vapor-compression refrigerators which consume large energy and release large amount of green house gas. However in the past, all EC effects investigations have been focused on solid state dielectrics. It is interesting to ask whether a large EC effect can also be realized in dielectric fluids. A dielectric fluid with large EC effect could lead to new design of cooling devices with simpler structures than these based on solid state EC materials, for example, they can be utilized as both the refrigerant and heat exchange fluid. Here we present that a large EC effect can be realized in the liquid crystal (LC) 5CB near it's nematic-isotropic (N-I) phase transition. The LC 5CB possesses a large dielectric anisotropy which can induce large polarization change from the isotropic phase to the nematic phase near the N-I transition. An isothermal entropy change of more than 23 Jkg-1K-1 was observed near 39 oC that is just above the N-I transition.
Studying the distribution of anatomical abnormalities over the entire cortical surface can help to identify key neural circuits implicated in generating symptoms of neuropsychiatric disorders. There is a significant inconsistency among studies investigating the neuroanatomy of obsessive–compulsive disorder (OCD) because of the confounding influence of co-morbid depression and medication use and the lack of unbiased estimation of whole-brain morphometric changes. It is also unknown whether the distinct surface anatomical properties of thickness, surface area and gyrification, which collectively contribute to grey matter volume (GMV), are independently affected in OCD.
The cortical maps of thickness, gyrification and surface areal change were acquired from 23 unmedicated OCD patients and 20 healthy controls using an unbiased whole-brain surface-based morphometric (SBM) method to detect regional changes in OCD. Subcortical structures were not assessed in this study.
Patients showed a significant increase in the right inferior parietal cortical thickness. Significant increases in gyrification were also noted in the left insula, left middle frontal and left lateral occipital regions extending to the precuneus and right supramarginal gyrus in OCD. Areal contraction/expansion maps revealed no significant regional differences between the patients and controls. In patients, gyrification of the insula significantly predicted the symptom severity measured using Yale–Brown Obsessive–Compulsive Scale (YBOCS).
An alteration in the cortical surface anatomy is an important feature of OCD seen in unmedicated samples that relates to the severity of the illness. The results underscore the presence of a neurodevelopmental aberration underlying the pathophysiology of OCD.