For individual cultures, findings on regulating embryo density by changing the microdrop volume are contradictory. The aim of this study was to investigate the relationship between embryo density and the developmental outcome of day 3 embryos after adjusting covariates. In total, 1196 embryos from 206 couples who had undergone in vitro fertilization treatment were analyzed retrospectively. Three embryo densities were used routinely, i.e. one embryo in a drop (30 μl/embryo), two embryos in a drop (15 μl/embryo) and three embryos in a drop (10 μl/embryo). Embryo quality on day 3 was evaluated, both the cell number of day 3 embryos and the proportion of successful implantations served as endpoints. Maternal age, paternal age, antral follicles and level of anti-Müllerian hormone, type of infertility, controlled ovarian stimulation protocol, length of stimulation, number of retrieved oocytes, number of zygotes (two pronuclei) and insemination type were covariates and adjusted. After adjusting fully for all covariates, the cell number of day 3 embryos was significantly increased by 0.40 (95% CI 0.00, 0.79; P = 0.048) and 0.78 (95% CI 0.02, 1.54; P = 0.044) in the 15 μl/embryo and 10 μl/embryo group separately, compared with the 30 μl/embryo group. The proportions of implanted embryos were 42.1%, 48.7% and 0.0% in the 30 μl/embryo, 15 μl/embryo and 10 μl/embryo groups respectively. There was no statistical significance (P = 0.22) between the 30 μl/embryo group and the 15 μl/embryo group. After adjusting for confounders that were significant in univariate analysis, embryo density was still not associated with day 3 embryo implantation potential (P > 0.05). In a 30-μl microdrop, culturing embryos with an embryo density of both 15 and 10 μl/embryo increased the cell number of day 3 embryos, which did not benefit embryo implanting potential, compared with individual culture of 30 μl/embryo.

The wheat aphid Sitobion miscanthi (CWA) is an important harmful pest in wheat fields. Insecticide application is the main method to effectively control wheat aphids. However, CWA has developed resistance to some insecticides due to its extensive application, and understanding resistance mechanisms is crucial for the management of CWA. In our study, a new P450 gene, CYP4CJ6, was identified from CWA and showed a positive response to imidacloprid and thiamethoxam. Transcription of CYP4CJ6 was significantly induced by both imidacloprid and thiamethoxam, and overexpression of CYP4CJ6 in the imidacloprid-resistant strain was also observed. The sensitivity of CWA to these two insecticides was increased after the knockdown of CYP4CJ6. These results indicated that CYP4CJ6 could be associated with CWA resistance to imidacloprid and thiamethoxam. Subsequently, the posttranscriptional regulatory mechanism was assessed, and miR-316 was confirmed to participate in the posttranscriptional regulation of CYP4CJ6. These results are crucial for clarifying the roles of P450 in the resistance of CWA to insecticides.

Seasonal climate variability is an important component of Earth's climate system, and has a significant impact on ecosystems and social systems. However, the temporal resolution of most proxy-based paleoclimate records is limiting to fully understand the past seasonal changes. Here, we used high-precision monthly resolution Sr/Ca records of three Tridacna squamosa specimens from the northern South China Sea (SCS) to reconstruct the sea surface temperature (SST) seasonality during three time periods from the middle Holocene. The results suggested that SST seasonality in the northern SCS during the middle Holocene (3.21 ± 0.98°C) was smaller than that for recent decades (AD 1994–2004, 4.32 ± 0.59°C). Analysis of modern instrumental data showed that the SST seasonality in the northern SCS was dominated by the winter SST, which was deeply influenced by the intensity of East Asian winter monsoon (EAWM). A strong EAWM usually resulted in cooler winter SST and a larger SST seasonality in the northern SCS. The reconstructed Holocene EAWM records showed that the EAWM strengthened from the middle to late Holocene, which was seen in our reconstruction of less SST seasonality changes during the middle Holocene in the northern SCS. This study highlighted that the Sr/Ca ratios from Tridacna shells can be used as a potential high-resolution indicator of past seasonal climate changes.

This experiment was designed to investigate the effect of supplementing conjugated linoleic acid (CLA) in breeder hens diet on development and hepatic lipid metabolism of chick offspring. Hy-Line Brown breeder hens were allocated into two groups, supplemented with 0 (control (CT)) or 0·5 % CLA for 8 weeks. Offspring chicks were grouped according to the mother generation and fed for 7 d. CLA treatment had no significant influence on development, egg quality and fertility of breeder hens but darkened the egg yolks in shade and increased yolk sac mass compared with the CT group. Addition of CLA resulted in increased body mass and liver mass and decreased deposition of subcutaneous adipose tissue in chick offspring. The serum TAG and total cholesterol levels of chick offspring were decreased in CLA group. CLA treatment increased the incorporation of both CLA isomers (c9t11 and t10c12) in the liver of chick offspring, accompanied by the decreased hepatic TAG levels, related to the significant reduction of fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC) enzyme activities and the increased carnitine palmitoyltransferase-1 (CPT1) enzyme activity. Meanwhile, CLA treatment reduced the mRNA expression of genes related to fatty acid biosynthesis (FAS, ACC and sterol regulatory element-binding protein-1c) and induced the expression of genes related to β-oxidative (CPT1, AMP-activated protein kinase and PPARα) in chick offspring liver. In summary, the addition of CLA in breeder hens diet significantly increased the incorporation of CLA in the liver of chick offspring, which further regulate hepatic lipid metabolism.

In December 2019, the first confirmed case of pneumonia caused by a novel coronavirus was reported. Coronavirus disease 2019 (COVID-19) is currently spreading around the world. The relationships among the pandemic and its associated travel restrictions, social distancing measures, contact tracing, mask-wearing habits and medical consultation efficiency have not yet been extensively assessed. Based on the epidemic data reported by the Health Commission of Wenzhou, we analysed the developmental characteristics of the epidemic and modified the Susceptible-Exposed-Infectious-Removed (SEIR) model in three discrete ways. (1) According to the implemented preventive measures, the epidemic was divided into three stages: initial, outbreak and controlled. (2) We added many factors, such as health protections, travel restrictions and social distancing, close-contact tracing and the time from symptom onset to hospitalisation (TSOH), to the model. (3) Exposed and infected people were subdivided into isolated and free-moving populations. For the parameter estimation of the model, the average TSOH and daily cured cases, deaths and imported cases can be obtained through individual data from epidemiological investigations. The changes in daily contacts are simulated using the intracity travel intensity (ICTI) from the Baidu Migration Big Data platform. The optimal values of the remaining parameters are calculated by the grid search method. With this model, we calculated the sensitivity of the control measures with regard to the prevention of the spread of the epidemic by simulating the number of infected people in various hypothetical situations. Simultaneously, through a simulation of a second epidemic, the challenges from the rebound of the epidemic were analysed, and prevention and control recommendations were made. The results show that the modified SEIR model can effectively simulate the spread of COVID-19 in Wenzhou. The policy of the lockdown of Wuhan, the launch of the first-level Public Health Emergency Preparedness measures on 23 January 2020 and the implementation of resident travel control measures on 31 January 2020 were crucial to COVID-19 control.

Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.

We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band ( ${\sim}60\%$ ), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.

In the search for chemically stable two-dimensional (2D) materials with high in-plane mobility, proper bandgap, and compatibility with vapor-based fabrication, van der Waals semiconductor SiP has become a potential candidate as a robust variation of black phosphorous. While bulk SiP crystals were synthesized in the 1970s, the vapor-based synthesis of SiP nanostructures or thin films is still absent. We here report the first chemical vapor growth of SiP nanostructures on SiO2/Si substrate. SiP islands with lateral size up to 20 μm and showing well-defined Raman signals were grown on SiO2/Si substrate or on SiP-containing concentric rings. The presence of SiP phase is confirmed by XRD. The formation of rings and islands is explained by a multiple coffee ring growth model where a dynamic fluctuation of droplet growth front induces the topography of concentric ring surfaces. This new growth method might shed light on the controlled growth of group IV-III high-mobility 2D semiconductors.

Improving the production traits and resistance against mastitis in dairy cattle is a challenge for animal scientists across the globe. The present study was designed to investigate the genetic effects of single nucleotide polymorphisms (SNPs) in Janus kinase 2 (JAK2) and diacylglycerol acyltransferase (DGAT1) genes with production and mastitis-related traits. Four SNPs in JAK2 and one in DGAT1 were analyzed through Chinese Cow's SNPs Chip-I (CCSC-I) and genotyped in a population of 312 Chinese Holsteins. Our findings demonstrated that milk fat percentage, somatic cell count (SCC), somatic cell score (SCS), serum cytokines interleukin 6 (IL-6) and interferon gamma (IFN-γ) showed significant associations (P < 0.05) with at least one or more identified SNPs. Consequently, the analysis based on haplotypes amongst the SNPs in JAK2 revealed noteworthy (P < 0.05) association with SCC and IL-6. Collectively, our results verified the pleiotropic ability of detected SNPs in bovine JAK2 and DGAT1 for milk fat percentage as well as mastitis-related traits. The significant SNPs in both the genes could serve as powerful genetic markers to minimize mastitis risk. In addition, besides SCC and SCS, the IFN-γ and IL-6 could also be used as indicators of improved genetic resistance against mastitis.

Novel NiMoO4-integrated electrode materials were successfully prepared by solvothermal method using Na2MoO4·2H2O and NiSO4·6H2O as main raw materials, water, and ethanol as solvents. The morphology, phase, and structure of the as-prepared materials were characterized by SEM, XRD, Raman, and FT-IR. The electrochemical properties of the materials in supercapacitors were investigated by cyclic voltammetry, constant current charge–discharge, and electrochemical impedance spectroscopy techniques. The effects of volume ratio of water to ethanol (W/E) in solvent on the properties of the product were studied. The results show that the pure phase monoclinic crystal NiMoO4 product can be obtained when the W/E is 2:1. The diameter and length are 0.1–0.3 µm and approximately 3 µm, respectively. As an active material for supercapacitor, the NiMoO4 nanorods material delivered a discharge specific capacitance of 672, 498, and 396 F/g at a current density of 4, 7, and 10 A/g, respectively. The discharge specific capacitance slightly decreased from 815 to 588 F/g with a retention of 72% after 1000 cycles at a current density of 1 A/g. With these superior capacitance properties, the novel NiMoO4 integrated electrode materials could be considered as promising material for supercapacitors.

Objective: Deficits in the semantic learning strategy were observed in subjects with amnestic mild cognitive impairment (aMCI) in our previous study. In the present study, we explored the contributions of executive function and brain structure changes to the decline in the semantic learning strategy in aMCI. Methods: A neuropsychological battery was used to test memory and executive function in 96 aMCI subjects and 90 age- and gender-matched healthy controls (HCs). The semantic clustering ratio on the verbal learning test was calculated to evaluate learning strategy. Medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) were measured on MRI with the MTA and Fazekas visual rating scales, respectively. Results: Compared to HCs, aMCI subjects had poorer performance in terms of memory, executive function, and the semantic clustering ratio (P < .001). In aMCI subjects, no significant correlation between learning strategy and executive function was observed. aMCI subjects with obvious MTA demonstrated a lower semantic clustering ratio than those without MTA (P < .001). There was no significant difference in the learning strategies between subjects with high-grade WMH and subjects with low-grade WMH. Conclusion: aMCI subjects showed obvious impairment in the semantic learning strategy, which was attributable to MTA but independent of executive dysfunction and subcortical WMH. These findings need to be further validated in large cohorts with biomarkers identified using volumetric brain measurements. (JINS, 2019, 25, 706–717)

Cu0.62Zn0.38 foil was subjected to surface mechanical attrition treatment (SMAT) processing first. Growth behavior of ZnO nanostructure on the SMAT Cu0.62Zn0.38 surface during thermal oxidation was investigated in this paper. The original and SMAT Cu0.62Zn0.38 foils were thermally oxidized at 400 ~ 700 °C under various gaseous environments, including nitrogen and mixture of N2-O2 at a pressure of 1 atm. for 3 h. The oxidized specimens were characterized with a scanning electron microscope, an X-ray diffractometer and a transmission electron microscope. It is found that nanosheets are easily formed on the SMAT specimen surface. The favorable formation of nanosheets relates to twin lamellae structure of Cu0.62Zn0.38 formed during SMAT processing.

Depression is one of the most pervasive and debilitating psychiatric diseases, and the molecular mechanisms underlying the pathophysiology of depression have not been elucidated. Cyclin-dependent kinase 5 (Cdk5) has been implicated in synaptic plasticity underlying learning, memory, and neuropsychiatric disorders. However, whether Cdk5 participates in the development of depressive diseases has not been examined. Using the chronic mild stress (CMS) procedure, we examined the effects of Cdk5/p35 activity in the hippocampus on depressive-like behaviour in rats. We found that CMS increased Cdk5 activity in the hippocampus, accompanied by translocation of neuronal-specific activator p35 from the cytosol to the membrane in the dentate gyrus (DG) subregion. Inhibition of Cdk5 in DG but not in the cornu ammonis 1 (CA1) or CA3 hippocampal subregions inhibited the development of depressive-like symptoms. Overexpression of p35 in DG blocked the antidepressant-like effect of venlafaxine in the CMS model. Moreover, the antidepressants venlafaxine and mirtazapine, but not the antipsychotic aripiprazole, reduced Cdk5 activity through the redistribution of p35 from the membrane to the cytosol in DG. Our results showed that the development of depressive-like behaviour is associated with increased Cdk5 activity in the hippocampus and that the Cdk5/p35 complex plays a key role in the regulation of depressive-like behaviour and antidepressant actions.

The formation enthalpy, electronic structures, and elastic moduli of the intermetallic compound Ti5Si3 with substitutions Zr, V, Nb, and Cr are investigated by using first-principles methods based on the density-functional theory. Our calculation shows that the site occupancy behaviors of alloying elements in Ti5Si3, determined by their atom radius, are consistent with the available experimental observations. Furthermore, using the Voigt–Reuss–Hill (VRH) approximation method, we obtained the bulk modulus B, shear modulus G, and the Young’s modulus E. Among these four substitutions, the V, Nb, and Cr substitutions can improve the ductility of Ti5Si3 effectively, while Zr substitution has little effect on the elastic properties of Ti5Si3. The elastic property variations of Ti5Si3 due to different substitutions are found to be correlated with the Me4d–Me4d antibonding and the strengthened Me4d–Si bonding in the solids.

This study used three winter wheat (Triticum aestivum L.) genotypes (H6756, H311 and SP8581) to compare the effects of sampling time, callus induction media, differentiation media and rooting media on in vitro culture of young spikes in wheat. In all these three genotypes, the frequencies of green plantlet differentiation were high when their young spikes were cultured between the stages of protective glume primordium formation and pistil and stamen primordium formation, but low at other stages. The optimum medium for callus induction was Murashige and Skoog (MS) medium+2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The optimum green plantlet differentiation medium was MS medium. Some abnormal plantlets regenerated from calli. When these plantlets were transferred to another differentiation medium [MS+1.0 mg/l 1-naphthaleneacetic acid (NAA)+0.2 mg/l 6-benzylaminopurine (6-BA)], shoot formation and elongation were induced. This allowed 90.91% of them to develop into normal green plantlets. The optimum rooting medium was 1/2MS+0.2 mg/l 3-Indolylacetonitrile (IAA)+80 g/l sucrose. An efficient regeneration system for young spike culture of wheat was set up based on such methods. Using this wheat-regeneration system, young spikes and immature embryos of 17 genotypes of wheat were in vitro cultured to study and compare the callus induction frequencies and green plantlet differentiation frequencies. The results of two successive years showed that in 15 out of the 17 genotypes (88.24%) the green plantlet differentiation frequencies were higher than those of immature embryos by 6.2–65.1%. These results showed that the regeneration system established in this trial for young spike culture of wheat was effective.

Biomaterials such as DNA are currently being explored as potential application in nanotechnology. DNA templates were immobilized on crystal-violet-treated mica by spin coating as a grid-like network. The DNA templates were then activated with PdCl2, followed by reduction with dimethylamine borane (DMAB) to form seeding nanoclusters on the DNA chain. Afterward the DNA chain with deposition of zero-valence Pd nanoclusters was grew in a Co electroless plating bath. SEM/EDS analysis revealed that Co nanoparticles could be assembled on the DNA template to form magnetic nanowires with a diameter of 25nm to 250nm by a conventional electroless plating. Vibrating Sample Magnetometer analysis indicated that Co-DNA nanowires showed a paramagnetic characteristic. Grid-like networks of DNA template were effectively preserved after Co electroless plating. These characteristics indicated that DNA is an ideal template for the production of magnetic nanowires, which could be useful in the development of high-density memory storage or magnetic field sensors.

The distribution of genetic diversity between Oryza sativa L. ssp. indica and O. sativa L. ssp. japonica covering different ecological zones in Yunnan was studied, and specific markers of indica/japonica subspecies, paddy/upland rice and different ecological zones were screened, using 36 microsatellite primers and 113 accessions in the Yunnan landrace rice core collection. The genetic diversity of japonica was higher than that of indica, and the ecological zone with the highest and smallest genetic diversity lay in south-east and north-east Yunnan, respectively. This distribution was consistent at morphological and isozyme levels with studies on the entire Yunnan rice resources and core collection. In addition, the results showed that, among 416 markers, there were six indica/japonica-specific markers, 15 specific markers for paddy/upland rice and three specific markers in different ecological zones. The main conclusions are that the landrace rice core collection in Yunnan genetically represents the entire landrace rice resources in Yunnan, the centre of genetic diversity at DNA level lies in south-east Yunnan, and the DNA differentiation between indica and japonica is small. Furthermore, microsatellite markers were useful for studying the genetic diversity, classification and ecotype of germplasm resources and their core collection.