A novel mouse model of calcific aortic valve stenosis

Background:Calcific aortic valve stenosis(CAVS)is one of the most challenging heart diseases in clinical with rapidly increasing prevalence.However,study of the mecha-nism and treatment of CAVS is hampered by the lack of suitable,robust and efficient models that develop hemodynamically significant stenosis and typical calcium deposi-tion.Here,we aim to establish a mouse model to mimic the development and features of CAVS.Methods:The model was established via aortic valve wire injury(AVWI)combined with vitamin D subcutaneous injected in wild type C57/BL6 mice.Serial transthoracic echocardiography was applied to evaluate aortic jet peak velocity and mean gradi-ent.Histopathological specimens were collected and examined in respect of valve thickening,calcium deposition,collagen accumulation,osteogenic differentiation and inflammation.Results:Serial transthoracic echocardiography revealed that aortic jet peak velocity and mean gradient increased from 7 days post model establishment in a time depend-ent manner and tended to be stable at 28 days.Compared with the sham group,sim-ple AVWI or the vitamin D group,the hybrid model group showed typical pathological features of CAVS,including hemodynamic alterations,increased aortic valve thicken-ing,calcium deposition,collagen accumulation at 28 days.In addition,osteogenic dif-ferentiation,fibrosis and inflammation,which play critical roles in the development of CAVS,were observed in the hybrid model.Conclusions:We established a novel mouse model of CAVS that could be induced efficiently,robustly and economically,and without genetic intervention.It provides a fast track to explore the underlying mechanisms of CAVS and to identify more effec-tive pharmacological targets.

初中物理“欧姆定律”生活化教学初探

“欧姆定律”是初中物理学习中的一个非常重要的知识点,是组成电学内容的骨干知识,也是今后学习电磁学的基础知识.通过对常用重量测量仪器“电子秤”进行拆解分析,从生活化的角度探讨了如何结合学生的生活经验开展“欧姆定律”的实验教学,探索出了一条能有效提高学生物理核心素养的生活化教学新途径.

Distribution of benthic macrofaunal communities in intertidal flat under hydrodynamic influence:a case study of Jiangsu coast,East China

To identify the distribution pattern of macrofaunal assemblages of the Dafeng intertidal flats in response to hydrodynamic and sediment dynamic processes in the northern Jiangsu coast,East China,macrofauna sampling and hydrodynamic observations were carried out simultaneously across the mud flat,mixed mud-sand flat,and silt-sand flat of the intertidal zone in June 2018.Results show that there was a clear zonal distribution pattern of the macrofaunal communities,as is controlled by local hydrological and sedimentary environments.Principal component analysis(PCA)revealed three types of intertidal area in terms of hydrological and surficial sediment parameters.Similarly,three distinct groups of the macrofaunal communities,i.e.,mud flat,mix mud-sand,and silt-sand groups,were recognized at similarity level of 24%based on the CLUSTER analysis in similarity profile(SIMPROF)test.Correlation analysis upon best variables stepwise search(BVSTEP)indicated the importance of the hydrodynamics(e.g.,water temperature and salinity,tidal duration,flow speed,suspended sediment concentration,and wave height)in the differentiation of macrofaunal communities with different taxonomic classes over the intertidal zone.Therefore,macrofaunal assemblages,similar to hydrology and surficial sediment,have a unique zonation pattern.Small-sized deposit feeders adapt better to low energy environments,thus dominated the upper part of the intertidal flat,whilst the heavy and large-sized filter feeders and deposit feeders were dominant over the middle and lower parts.The hydrodynamic and sediment processes cause biota-niche separation,which affected the biological processes across the intertidal flat.

Built‑In Electric Field‑Driven Ultrahigh‑Rate K‑Ion Storage via Heterostructure Engineering of Dual Tellurides Integrated with Ti_(3)C_(2)T_(x)MXene

Exploiting high-rate anode materials with fast K+diffusion is intriguing for the development of advanced potassium-ion batteries(KIBs)but remains unrealized.Here,heterostructure engineering is proposed to construct the dual transition metal tellurides(CoTe_(2)/ZnTe),which are anchored onto two-dimensional(2D)Ti_(3)C_(2)T_(x)MXene nanosheets.Various theoretical modeling and experimental findings reveal that heterostructure engineering can regulate the electronic structures of CoTe_(2)/ZnTe interfaces,improving K+diffusion and adsorption.In addition,the different work functions between CoTe_(2)/ZnTe induce a robust built-in electric field at the CoTe_(2)/ZnTe interface,providing a strong driving force to facilitate charge transport.Moreover,the conductive and elastic Ti_(3)C_(2)T_(x)can effectively promote electrode conductivity and alleviate the volume change of CoTe_(2)/ZnTe heterostructures upon cycling.Owing to these merits,the resulting CoTe_(2)/ZnTe/Ti_(3)C_(2)T_(x)(CZT)exhibit excellent rate capability(137.0 mAh g^(-1)at 10 A g^(-1))and cycling stability(175.3 mAh g^(-1)after 4000 cycles at 3.0 A g^(-1),with a high capacity retention of 89.4%).More impressively,the CZT-based full cells demonstrate high energy density(220.2 Wh kg^(-1))and power density(837.2 W kg^(-1)).This work provides a general and effective strategy by integrating heterostructure engineering and 2D material nanocompositing for designing advanced high-rate anode materials for next-generation KIBs.

Prediction of one-dimensional CrN nanostructure as a promising ferromagnetic half-metal

Searching for one-dimensional(1D)nanostructure with ferromagnetic(FM)half-metallicity is of significance for the development of miniature spintronic devices.Here,based on the first-principles calculations,we propose that the 1D CrN nanostructure is a FM half-metal,which can generate the fully spin-polarized current.The ab initio molecular dynamic simulation and the phonon spectrum calculation demonstrate that the 1D CrN nanostructure is thermodynamically stable.The partially occupied Cr-d orbitals endow the nanostructure with FM half-metallicity,in which the half-metallic gap(?s)reaches up to 1.58 eV.The ferromagnetism in the nanostructure is attributed to the superexchange interaction between the magnetic Cr atoms,and a sizable magnetocrystalline anisotropy energy(MAE)is obtained.Moreover,the transverse stretching of nanostructure can effectively modulate?s and MAE,accompanied by the preservation of half-metallicity.A nanocable is designed by encapsulating the CrN nanostructure with a BN nanotube,and the intriguing magnetic and electronic properties of the nanostructure are retained.These novel characteristics render the 1D CrN nanostructure as a compelling candidate for exploiting high-performance spintronic devices.

稀土-天然皮革可穿戴X射线防护材料的合成及性能

天然皮革(NL)具有质轻、无毒、柔软和可穿戴性好的特点。本文将稀土氧化物纳米粒子(RE)引入天然皮革中制备了稀土-天然皮革复合材料(RE-NL),并考察其X射线屏蔽性能。采用X射线衍射、扫描电子显微镜、透射电子显微镜等方法对所制备的材料进行表征,结果表明,通过制革的“复鞣”方法可成功制得稀土-天然皮革复合材料。对不同稀土天然皮革复合材料进行X射线屏蔽性能测定,发现纳米氧化镧-天然皮革(La-NL)有更优异的屏蔽性能,这是因为其K吸收边能量同X射线入射能量较近。当纳米La_(2)O_(3)在材料中的摩尔含量为7.80 mmol·cm^(−3)时,所制备的La_(7.80)-NL在40–80 keV有优异X射线屏蔽性能,比0.25 mm的铅板(摩尔含量为54.7 mmol·cm^(–3))具有更好的屏蔽性能,表明稀土在天然皮革中的高度均匀分布增强了其对X射线的屏蔽能力。力学性能测试表明稀土-天然皮革X射线屏蔽材料较高分子聚合物基稀土复合材料具有更好的力学性能和柔软性。

<i>In Vivo </i>Imaging of Biophoton Emission in the Whole Brain of Mice

In recent years, studies have demonstrated that biophoton is a medium for the transmission and processing of neural information. However, such studies were mainly carried out by using brain slices combined with biophoton imaging technology, while there are few reports on in vivo brain biophoton imaging. In this study, the ultraweak biophoton imaging system (UBIS) was employed to carry out an in vivo biophoton imaging for the whole brain of mice. It was found that the biophoton emission of whole brain in the slightly anesthetized mice was significantly higher than that of the background, suggesting that the brain of living mouse emits a certain intensity of stable biophotons. The biophoton imaging established in this study for the in vivo mouse whole brain may provide a new technical method for further study of the relationship between the biophoton and brain functions, and give new ideas for developing diagnostic method of neuropsychiatric diseases.

基于Geomagic spark的手扶式插秧机变速箱箱体重构

变速箱是插秧机的核心部件之一。本文针对插秧机变速箱箱体改造,应用逆向工程软件Geomagic spark来重构变速箱箱体,并对其进行优化设计。首先,利用手持式激光扫描仪对变速箱箱体进行扫描,获取三维点云数据;再利用正逆向混合软件Geomagic spark对扫描得到的点云数据进行三角形网格模型重建;依据三角形网格数据重构变速箱箱体的三维几何模型。根据得到的三维几何模型对模型进行优化,最后在SolidWorks Simulation中进行有限元分析,为箱体的优化设计提供了理论基础。利用逆向工程技术对插秧机变速箱箱体进行优化,可以缩短设计周期,降低设计成本。

Baicalin influences the dendritic morphology of newborn neurons in the hippocampus of chronically stressed rats

Chronic stress models, established in adult Sprague-Dawley rats through a 14-day subcutaneous injection of 40 mg/kg corticosterone, once per day, were given a daily oral feeding of 50 mg/kg baicalin. The study was an attempt to observe the effect of baicalin on neurogenesis in chronically stressed rats. Results showed that subcutaneous injection of corticosterone significantly decreased the total number of doublecortin-positive neurons in the hippocampus. The reduced cell number caused by corticosterone was mainly due to the decrease of class II doublecortin-positive neurons, but the class I doublecortin-positive neurons were unaffected. Baicalin treatment increased the number of both class I and class II doublecortin-positive neurons. In addition, doublecortin-positive neurons showed less complexity in dendritic morphology after corticosterone injection, and this change was totally reversed by baicalin treatment. These findings suggest that baicalin exhibits a beneficial effect on adult neurogenesis.

Impact of Mid-and Upper-Level Dry Air on Tropical Cyclone Genesis and Intensification:A Modeling Study of Durian(2001)

The impact of mid-and upper-level dry air,represented by low relative humidity(RH)values,on the genesis of tropical cyclone(TC)Durian(2001)in the South China Sea was investigated by a series of numerical experiments using the Weather Research and Forecasting model.The mid-level RH was lowered in different regions relative to TC Durian(2001)’s genesis location.Results suggest that the location of dry air was important to Durian(2001)’s genesis and intensification.The rapid development of the TC was accompanied by sustained near-saturated mid-and upper-level air,whereas low humidity decelerated its development.Water vapor budget analysis showed that moisture at mid and upper levels was mainly supplied by the vertical convergence of moisture flux and the divergence terms,and consumed by the condensation process.The horizontal convergence of moisture flux term supplied moisture in the air moistening process but consumed moisture in the air drying process.With a dryer mid-and upper-level environment,convective and stratiform precipitation were both inhibited.The upward mass fluxes and the diabatic heating rates associated with these two precipitation types were also suppressed.Generally,convection played the dominant role,since the impact of the stratiform process on vertical mass transportation and diabatic heating was much weaker.The vorticity budget showed that the negative vorticity convergence term,which was closely related to the inhibited convection,caused the vorticity to decrease above the lower troposphere in a dryer environment.The negative vorticity tendency is suggested to slow down the vertical coherence and the development rate of TCs.

Transcriptome analysis reveals key differentially expressed genes involved in wheat grain development

Wheat seed development is an important physiological process of seed maturation and directly affects wheat yield and quality. In this study, we performed dynamic transcriptome microarray analysis of an elite Chinese bread wheat cultivar(Jimai 20) during grain development using the Gene Chip Wheat Genome Array. Grain morphology and scanning electron microscope observations showed that the period of 11–15 days post-anthesis(DPA) was a key stage for the synthesis and accumulation of seed starch. Genome-wide transcriptional profiling and significance analysis of microarrays revealed that the period from 11 to 15 DPA was more important than the 15–20 DPA stage for the synthesis and accumulation of nutritive reserves.Series test of cluster analysis of differential genes revealed five statistically significant gene expression profiles. Gene ontology annotation and enrichment analysis gave further information about differentially expressed genes, and Map Man analysis revealed expression changes within functional groups during seed development. Metabolic pathway network analysis showed that major and minor metabolic pathways regulate one another to ensure regular seed development and nutritive reserve accumulation. We performed gene co-expression network analysis to identify genes that play vital roles in seed development and identified several key genes involved in important metabolic pathways. The transcriptional expression of eight key genes involved in starch and protein synthesis and stress defense was further validated by q RT-PCR. Our results provide new insight into the molecular mechanisms of wheat seed development and the determinants of yield and quality.

Differences between Convective and Stratiform Precipitation Budgets in a Torrential Rainfall Event

Differences in rainfall budgets between convective and stratiform regions of a torrential rainfall event were investigated using high-resolution simulation data produced by the Weather Research and Forecasting(WRF) model. The convective and stratiform regions were reasonably separated by the radar-based convective–stratiform partitioning method, and the threedimensional WRF-based precipitation equation combining water vapor and hydrometeor budgets was further used to analyze the rainfall budgets. The results showed that the magnitude of precipitation budget processes in the convective region was one order larger than that in the stratiform region. In convective/stratiform updraft regions, precipitation was mainly from the contribution of moisture-related processes, with a small negative contribution from cloud-related processes. In convective/stratiform downdraft regions, cloud-related processes played positive roles in precipitation, while moisture-related processes made a negative contribution. Moisture flux convergence played a dominant role in the moisture-related processes in convective or stratiform updraft regions, which was closely related to large-scale dynamics. Differences in cloud-related processes between convective and stratiform regions were more complex compared with those in moisture-related processes.Both liquid-and ice-phase microphysical processes were strong in convective/stratiform updraft regions, and ice-phase processes were dominant in convective/stratiform downdraft regions. There was strong net latent heating within almost the whole troposphere in updraft regions, especially in the convective updraft region, while the net latent heating(cooling) mainly existed above(below) the zero-layer in convective/stratiform downdraft regions.

Genetic, hormonal, and environmental control of tillering in wheat

Tillering contributes greatly to grain yield in wheat.Investigating the mechanisms of tillering provides a theoretical foundation and genetic resources for the molecular breeding of wheat.The regulation of tillering is a complex molecular process that involves a multitude of factors.Little is known about the molecular mechanisms in the wheat genome,although progress has been made in rice.Here we review the developmental characteristics of tillers and summarize current knowledge of the roles of endogenous and environmental factors in wheat tillering.We propose directions for future studies and advanced technologies to be used for gene identification and functional studies.

Surface Rainfall Processes during the Genesis Period of Tropical Cyclone Durian(2001)

The rainfall processes during the formation of tropical cyclone(TC) Durian(2001) were investigated quantitatively using the three-dimensional(3 D) WRF-based precipitation equation. The rain rate(PS) decreased slightly as the TC approached to formation, and then increased as Durian began to intensify. The rate of moisture-related processes(QWV) in the equation contributed around 80% to PSbefore TC genesis, and made more contribution during and after TC genesis. The rate of hydrometeor-related processes(QCM) contributed about 20% before TC formation, followed by less contribution during and after TC formation. QWVwere dominated by the 3 D moisture flux advection rate(QWVA), while the surface evaporation rate(QWVE) also played an important role. Just before TC genesis, moisture from QWVAand QWVEhelped the local atmosphere moisten(negative QWVL). QCMwere determined by the 3 D hydrometeor advection rates(QCLAand QCIA) and the local change rates of hydrometeors(QCLLand QCIL). During TC formation, QCMlargely decreased and then reactivated as Durian began to intensify, accompanied by the development of TC cloud. Both the height and the strength of the net latent heating center associated with microphysical processes generally lowered before and during TC genesis, resulting mainly from lessening deposition and condensation. The downward shift of the net latent heating center induced a more bottom-heavy upward mass flux profile, suggesting to promote lower-tropospheric convergence in a shallower layer, vorticity amplification and TC spin-up.

Telmisartan prevents high-fat diet-induced hypertension and decreases perirenal fat in rats

We sought to investigate the effects of telmisartan on high-fat diet-induced hypertension and to explore the possible underlying mechanisms. Rats receiving high-fat diet were randomly divided into two groups, the tel- misartan group （n = 9） and the high-fat diet group （n = 10）. The control group consisted of age-matched rats on a regular diet （n = 10）. At the end of the treatment, the body weight, blood pressure, insulin sensitivity and serum adiponectin levels of all rats were examined, and their visceral fat was extracted and weighed. Our results showed that telmisartan improved insulin resistance and dyslipidemia and increased serum adiponectin levels. Telmisar- tan also lowered both systolic blood pressure and diastolic blood pressure, and decreased the accumulation of perirenal fat associated with high-fat diet. Furthermore, telmisartan increased adiponectin mRNA expression in the perirenal fat. Correlation analysis showed that both systolic blood pressure and diastolic blood pressure were positively correlated with perirenal fat. These effects of telmisartan may be mediated through decreases in perirenal fat and contributed to the improvement of perirenal fat function. Our findings suggested a strong link between perirenal fat and high-fat diet-induced hypertension, and identified telmisartan as a potential drug for the treatment of obesity-related hypertension.

A collagen-based electrolyte-locked separator enables capacitor to have high safety and ionic conductivity

The conventional liquid electrolytes(LEs) have a high level of ionic conductivity;however, they often suffer from the poor processability and safety risks of potential leakage. Although solid-state electrolytes(SSEs) can solve these inherent problems of LEs, the ionic conductivity of most SSEs is several magnitudes lower than these of LEs. Herein, we report a novel strategy by building liquid ion-transport channels in a solid framework and prepared an electrolyte-locked separator(ELS) using a collagen fiber membrane(CFm). The liquid electrolyte was primarily infiltrated in the smaller voids of CFm, and its ionic conductivity could attain to 9.0×10-3 S cm-1 when the electrolyte absorption(EA) reached up to 112.0%. After centrifuging treatment, the electrolyte retentions(ER) and ionic conductivities of ELS were 108.93% and 8.37×10-3 S cm-1, respectively, which were much higher than those of commercial cellulose separator(CS), exerting excellent liquid-locking performances. In particular, the electrical double-layer capacitors(EDLC) assembled by ELS or CS were characterized and exhibited similar electrochemical performance,demonstrating the satisfactory ability and applicability of ELS for commercial use. In addition, the ELSbased EDLC exhibited favorable flexibility with relative lower loss of capacitance under different angles of bending.

Characterization of longshore currents in southern East China Sea during summer and autumn

Current characteristics and vertical variations during summer and autumn in the southern East China Sea were investigated by measuring current profile, tide, wind, and wave data for 90 d from July 28 to October 25, 2015. Our results are:(1) The current was mainly a(clockwise) rotating flow, displaying reciprocating flow characteristics,and vertically the current directions were the same throughout the vertical profile.(2) The horizontal current speed was strongest during August(summer) with an average speed of 51.8 cm/s. The average current speeds during spring tides were highest in August and weakest in September, with speeds of 59.9 and 42.8 cm/s,respectively.(3) Considerable differences exist in average current speeds in different layers and seasons. The highest average current speeds were found in the middle–upper layers in August and in the middle–lower layers in September and October.(4) The residual current speed was highest in August, when the speed was 12.5–47.1 cm/s,whereas the vertical average current speed was 34.3 cm/s. The depth-averaged residual current speeds in September and October were only 50% of that in August, and the residual current direction gradually rotated in a counter-clockwise direction from the lower to surface layers.(5) Typhoon waves had a significant influence on the currents, and even affected the middle and lower water layers at depths of >70.0 m. Our results showed that the currents are controlled by the dynamic interplay of the Taiwan Warm Current, incursion of the Kuroshio Current onto the continental shelf, and monsoonal changes.

Influences of Rifle Weight,Weight Distribution and Layout on Aiming Comfort

A rifle in a soldier’s system is often equipped with a grenade launcher,aiming device,etc.,which increases the weight of the rifle and changes its center of gravity.This study explores how the rifle weight,weight distribution and layout(e.g.stock length,position of grip and forestock)affect aiming comfort.In the paper,the upper extremity muscle activity was used to characterize the aiming comfort.A human-rifle musculoskeletal model was developed,which was validated by the surface electromyography(EMG)data.The results showed that the design parameters of rifle(weight,distance of gravity center to body and layout)had a significant influence on aiming comfort.The greater the weight was,the stronger the muscle activity was.With the distance increasing,first the muscle activity decreased,and then increased when the distance is exceeding a certain value.In addition,the combined influences of weight and distance illustrated that there was an optimal distance to make the slightest muscle movements for certain weight.For designing a rifle’s layout,more muscular exertions were required to maintain the holding posture with the stock length increasing,which was suggested to be in the range of 0.1 8 m to 0.2 7 m.Results can be used to optimize the ergonomics design of rifle,improving the comfort of the rifle aiming process and the shooting accuracy.

A self-guidance biological hybrid drug delivery system driven by anaerobes to inhibit the proliferation and metastasis of colon cancer

Colorectal cancer is often accompanied by multiple organ metastasis.Anaerobic Bifidobacterium Infantis(BI)bacterial can selectively grow in hypoxic colorectal tumor microenvironment(TME),to own the natural advantage of preferentially colorectal tumor targeting.Herein,a self-guidance biological hybrid drug delivery system(BI-ES-Fe Alg/DOX)based on BI was constructed to inhibit the proliferation and metastasis of colon cancer.Results demonstrated that BI-ES-Fe Alg/DOX could overcome physical barriers to target and accumulate in colon tumor tissues.Then DOX was released to kill tumor cells along with the phase transition(solid to liquid)of Fe Alg hydrogel,due to Fe3+was reduced to Fe^(2+)by intracellular GSH.Meanwhile,BI-ES selectively colonized into tumors and expressed endostatin(ES)protein to down-regulate VEGF and b FGF expression,exerting anti-angiogenic effect.Moreover,Fe Alg catalyzed H_(2)O_(2)in the local tumor to generate cytotoxic·OH,further enhancing the antitumor effect.The pharmacodynamic result in AOM/DSS model proved that BI-ES-Fe Alg/DOX had the best therapeutic effect,with the final V/V0of 2.19±0.57,which was significantly lower than the other groups.Meanwhile,on CT-26tumor-bearing model,it also showed an outstanding anti-tumor effect with inhibition rate of 82.12%±3.08%.In addition,lung metastases decreased significantly in tumor metastasis model after BI-ES-Fe Alg/DOX treatment.

Identification of liver metastasis-associated genes in human colon carcinoma by mRNA profiling

Objective: Liver metastasis,which contributes substantially to high mortality,is the most common recurrent mode of colon carcinoma.Thus,it is necessary to identify genes implicated in metastatic colonization of the liver in colon carcinoma.Methods: We compared mRNA profiling in 18 normal colon mucosa(N),20 primary tumors(T) and 19 liver metastases(M) samples from the dataset GSE49355 and GSE62321 of Gene Expression Omnibus(GEO) database.Gene ontology(GO) and pathways of the identified genes were analyzed.Co-expression network and proteinprotein interaction(PPI) network were employed to identify the interaction relationship.Survival analyses based on The Cancer Genome Atlas(TCGA) database were used to further screening.Then,the candidate genes were validated by our data.Results: We identified 22 specific genes related to liver metastasis and they were strongly associated with cell migration,adhesion,proliferation and immune response.Simultaneously,the results showed that C-X-C motif chemokine ligand 14(CXCL14) might be a favorable prediction factor for survival of patients with colon carcinoma.Importantly,our validated data further suggested that lower CXCL14 represented poorer outcome and contributed to metastasis.Gene set enrichment analysis(GSEA) showed that CXCL14 was negatively related to the regulation of stem cell proliferation and epithelial to mesenchymal transition(EMT).Conclusions: CXCL14 was identified as a crucial anti-metastasis regulator of colon carcinoma for the first time,and might provide novel therapeutic strategies for colon carcinoma patients to improve prognosis and prevent metastasis.