具有异构发光变色的双核铜(I)配合物的合成、铜含量分析和发光性能研究——推荐一个综合化学实验

介绍了一个研究型综合化学实验——具有异构发光变色的双核铜(I)配合物的合成、铜含量分析和发光性能研究。本实验基于氧化还原反应和配位反应合成Cu(I)配合物,采用薄层色谱法判断合成反应进程,运用配位滴定法测定其铜含量,利用荧光光度法和荧光定量分析法测定固态荧光以及判断产品的纯度。本实验综合了无机化学、有机化学、分析化学的基础知识和实验技能以及大型仪器的学习和操作,同时体现了发光金属配合物这一科研热点,探究物质结构与性质的关系。通过本实验的实践,学生在巩固所学实验知识和实验技能的同时,训练了运用所学知识解决实际问题的综合能力,有利于学生初步建立科学的思维方式和研究能力。

A novel live attenuated vaccine candidate protects chickens against subtype B avian metapneumovirus

Avian metapneumovirus(aMPV) is a highly contagious pathogen that causes acute upper respiratory tract diseases in chickens and turkeys, resulting in serious economic losses. Subtype B aMPV has recently become the dominant epidemic strain in China. We developed an attenuated aMPV subtype B strain by serial passaging in Vero cells and evaluated its safety and efficacy as a vaccine candidate. The safety test showed that after the 30th passage, the LN16-A strain was fully attenuated, as clinical signs of infection and histological lesions were absent after inoculation.The LN16-A strain did not revert to a virulent strain after five serial passages in chickens. The genomic sequence of LN16-A differed from that of the parent wild-type LN16(wtLN16) strain and had nine amino acid mutations. In chickens, a single immunization with LN16-A induced robust humoral and cellular immune responses, including the abundant production of neutralizing antibodies, CD4^(+) T lymphocytes, and the Th1(IFN-γ) and Th2(IL-4 and IL-6)cytokines. We also confirmed that LN16-A provided 100% protection against subtype B aMPV and significantly reduced viral shedding and turbinate inflammation. Our findings suggest that the LN16-A strain is a promising live attenuated vaccine candidate that can prevent infection with subtype B aMPV.

UPLC-MS/MS法测定化妆品常用植物提取物中16种香豆素类化合物

建立了同时测定常用化妆品植物提取物原料中16种香豆素类化合物的UPLC-MS/MS法,为评估植物提取物作为化妆品原料的安全性和规范植物提取物在化妆品中的应用提供理论依据。采用液质联用法,应用Waters ACQUITY HPLC BEH C18柱,以乙腈-0.1%甲酸溶液为流动相,梯度洗脱分离,质谱采用正离子模式,多反应监测,流速为0.3 mL/min。16种香豆素类化合物在各自质量浓度范围内呈现良好的线性关系,相关系数均大于0.995。在低、中、高3个加标水平的平均回收率为85.7%~108.6%,相对标准偏差为1.5%~5.8%,16种香豆素类化合物检出限为0.3~28.0μg/kg,定量限为1.0~93.0μg/kg,收集的14批植物提取物中,4批检出香豆素类化合物。该方法准确、分析速度快、操作简便、灵敏度高,能满足化妆品植物提取物原料中16种香豆素类化合物的定性筛查和定量检测要求,为探究植物提取物致敏风险物质基础提供一种思路,建议关注化妆品植物提取物原料带入致敏成分的安全风险情况,建立化妆品植物提取物原料质量控制和使用规范。

The high-quality sequencing of the Brassica rapa‘XiangQingCai’genome and exploration of genome evolution and genes related to volatile aroma

‘Vanilla’(XQC,brassica variety chinensis)is an important vegetable crop in the Brassica family,named for its strong volatile fragrance.In this study,we report the high-quality chromosome-level genome sequence of XQC.The assembled genome length was determined as 466.11 Mb,with an N50 scaffold of 46.20 Mb.A total of 59.50%repetitive sequences were detected in the XQC genome,including 47570 genes.Among all examined Brassicaceae species,XQC had the closest relationship with B.rapa QGC(‘QingGengCai’)and B.rapa Pakchoi.Two whole-genome duplication(WGD)events and one recent whole-genome triplication(WGT)event occurred in the XQC genome in addition to an ancient WGT event.The recent WGT was observed to occur during 21.59-24.40 Mya(after evolution rate corrections).Our findings indicate that XQC experienced gene losses and chromosome rearrangements during the genome evolution of XQC.The results of the integrated genomic and transcriptomic analyses revealed critical genes involved in the terpenoid biosynthesis pathway and terpene synthase(TPS)family genes.In summary,we determined a chromosome-level genome of B.rapa XQC and identified the key candidate genes involved in volatile fragrance synthesis.This work can act as a basis for the comparative and functional genomic analysis and molecular breeding of B.rapa in the future.

Mercury Speciation of Flue Gas Desulphurization By-Products in Coal-Fired Power Plants in China

The aim of this study was to develop and examine the morphology and distribution of mercury (Hg) in flue gas desulfurization (FGD) by-product. Mercury in the coal of coal-fired power plants is concentrated in the by-products of desulfurization process, and it is widely used as an additive in cement, building materials and other industries. Due to the different stability of various forms of mercury in the environment, subsequent use of products containing desulfurization by-product additives will continue to be released into the environment, endangering human health. Therefore, it is very necessary to study the form and distribution of mercury in the by-products of desulfurization in coal-fired power plants to provide a theoretical basis for subsequent harmless treatment. For content and morphology of mercury analysis, 1 sample of dry FGD ash and 6 samples of wet FGD gypsum were analyzed. The total 7 samples were extracted using a modification of sequential chemical extractions (SCE) method, which was employed for the partitioning Hg into four fractions: water soluble, acid soluble, H2O2 soluble, and residual. The Hg analysis was done with United States Environmental Protection Agency (USEPA) method 7471B. Comparing with the wet FGD gypsums of coal-fired boilers, the total Hg content in the dry FGD by-product was as high as 1.22 mg/kg, while the total Hg content in the FGD gypsum is 0.23 - 0.74 mg/kg, which was 2 times over the wet FGD gypsum. The concentration of water soluble Hg in the dry FGD by-product was the highest amount (0.72 mg/kg), accounting for 59.02% of the total mercury. While residual Hg content was 0.16 mg/kg, only about 13.11% of the total mercury. Mercury content in FGD gypsum was expressed in the form of ρ (residual Hg) > ρ (H2O2 soluble Hg) > ρ (water soluble Hg) > ρ (acid soluble Hg). The morphology and distribution of mercury in FGD by-products is supposed to be analyzed before utilization, and the impact of mercury on the environment should be considered.

血清胆红素和糖化血红蛋白及血脂联合检验在诊断T2DM合并冠心病中的应用研究

目的探究分析血清胆红素和糖化血红蛋白及血脂联合检验在诊断T2DM合并冠心病中的应用价值。方法从我院收治的T2DM合并冠心病患者中抽选44例,列为实验组,同期选择单纯T2DM患者43例,列为对照组。两组均接受血清胆红素和糖化血红蛋白及血脂联合检验,对比其检验结果。结果实验组血清总胆红素水平明显低于对照组,糖化血红蛋白含量、TG、LDL-C、TC等水平均明显高于对照组,差异具有统计学意义(P<0.05)。结论在T2DM合并冠心病诊断中采取血清胆红素和糖化血红蛋白及血脂联合检验能够有效确诊疾病,为患者后续治疗提供准确的依据,值得临床推广应用。

Neurological function following intra-neural injection of fluorescent neuronal tracers in rats

Fluorescent neuronal tracers should not be toxic to the nervous system when used in long-term labeling. Previous studies have addressed tracer toxicity, but whether tracers injected into an intact nerve result in functional impairment remains to be elucidated. In the present study, we examined the functions of motor, sensory and autonomic nerves following the application of 5% Fluoro-Gold, 4% True Blue and 10% Fluoro-Ruby （5 pL） to rat tibial nerves via pressure injection. A set of evaluation methods including walking track analysis, plantar test and laser Doppler perfusion imaging was used to determine the action of the fluorescent neuronal tracers. Additionally, nerve pathology and ratio of muscle wet weight were also observed. Results showed that injection of Fluoro-Gold significantly resulted in loss of motor nerve function, lower plantar sensibility, increasing blood flow volume and higher neurogenic vasodilatation. Myelinated nerve fiber degeneration, unclear boundaries in nerve fibers and high retrograde labeling efficacy were observed in the Fluoro-Gold group. The True Blue group also showed obvious neurogenic vasodilatation, but less severe loss of motor function and degeneration, and fewer labeled motor neurons were found compared with the Fluoro-Gold group. No anomalies of motor and sensory nerve function and no myelinated nerve fiber degeneration were observed in the Fluoro-Ruby group. Experimental findings indicate that Fluoro-Gold tracing could lead to significant functional impairment of motor, sensory and autonomic nerves, while functional impairment was less severe following True Blue tracing. Fluoro-Ruby injection appears to have no effect on neurological function.

Nanoimprint Lithography:A Processing Technique for Nanofabrication Advancement

Nanoimprint lithography(NIL) is an emerging micro/nano-patterning technique,which is a high-resolution,high-throughput and yet simple fabrication process.According to International Technology Roadmap for Semiconductor(ITRS),NIL has emerged as the next generation lithography candidate for the22 nm and 16 nm technological nodes.In this paper,we present an overview of nanoimprint lithography.The classfication,research focus,critical issues,and the future of nanoimprint lithography are intensively elaborated.A pattern as small as 2.4 nm has been demonstrated.Full-wafer nanoimprint lithography has been completed on a 12-inch wafer.Recently,12.5 nm pattern resolution through soft molecular scale nanoimprint lithography has been achieved by EV Group,a leading nanoimprint lithography technology supplier.

Research on Embedding Capacity and Efficiency of Information Hiding Based on Digital Images

Generally speaking, being an efficient information hiding scheme, what we want to achieve is high embedding capacity of the cover image and high visual quality of the stego image, high visual quality is also called embedding efficiency. This paper mainly studies on the information hiding technology based on gray-scale digital images and especially considers the improvement of embedding capacity and embedding efficiency. For the purpose of that, two algorithms for information hiding were proposed, one is called high capacity of information hiding algorithm (HCIH for short), which achieves high embedding rate, and the other is called high quality of information hiding algorithm (HQIH for short), which realizes high embedding efficiency. The simulation experiments show that our proposed algorithms achieve better performance.

MFCIS: an automatic leaf-based identification pipeline for plant cultivars using deep learning and persistent homology

Recognizing plant cultivars reliably and efficiently can benefit plant breeders in terms of property rights protection and innovation of germplasm resources.Although leaf image-based methods have been widely adopted in plant species identification,they seldom have been applied in cultivar identification due to the high similarity of leaves among cultivars.Here,we propose an automatic leaf image-based cultivar identification pipeline called MFCIS(Multi-feature Combined Cultivar Identification System),which combines multiple leaf morphological features collected by persistent homology and a convolutional neural network(CNN).Persistent homology,a multiscale and robust method,was employed to extract the topological signatures of leaf shape,texture,and venation details.A CNN-based algorithm,the Xception network,was fine-tuned for extracting high-level leaf image features.For fruit species,we benchmarked the MFCIS pipeline on a sweet cherry(Prunus avium L.)leaf dataset with>5000 leaf images from 88 varieties or unreleased selections and achieved a mean accuracy of 83.52%.For annual crop species,we applied the MFCIS pipeline to a soybean(Glycine max L.Merr.)leaf dataset with 5000 leaf images of 100 cultivars or elite breeding lines collected at five growth periods.The identification models for each growth period were trained independently,and their results were combined using a score-level fusion strategy.The classification accuracy after score-level fusion was 91.4%,which is much higher than the accuracy when utilizing each growth period independently or mixing all growth periods.To facilitate the adoption of the proposed pipelines,we constructed a user-friendly web service,which is freely available at http://www.mfcis.online.

Water and Oil Resistance of Special Paperboard for Petroleum Packaging

The influence of different coating formulas and times on the water and oil resistance of paperboard was studied. The water and oil resistance of paperboard coated with a modified butadiene-styrene copolymer latex and fluorinated anion grease-proof agent was better than that coated with modified butadiene-styrene copolymer latex,where the modified butadiene-styrene copolymer latex was used as the pre-coating substrate and the F1516 fluorinated grease-proof agent was used as the top coating material. By coating modified butadiene-styrene copolymer latex with 30% solid content and F1516 fluorinated grease-proof agent with 24% solid content,the oil resistance of paperboard could reach anti-oil grade 12 and the water resistance could increased by98. 64%( compared with the base paperboard without any coating treatment).

Generating routes for autonomous driving in vehicle-to-infrastructure communications

The study of vehicular networks has attracted considerable interest in academia and the industry.In the broad area,connected vehicles and autonomous driving are technologies based on wireless data communication between vehicles or between vehicles and infrastructures.A Vehicle-to-Infrastructure(V2I)system consists of communications and computing over vehicles and related infrastructures.In such a system,wireless sensors are installed in some selected points along roads or driving areas.In autonomous driving,it is crucial for a vehicle to figure out the ideal routes by the communications between its equipped sensors and infrastructures then the vehicle is automatically moving along the routes.In this paper,we propose a Bezier curve based recursive algorithm,which effectively creates routes for vehicles through the communication between the On-Board Unit(OBU)and the Road-Side Units(RSUs).In addition,this approach generates a very low overhead.We conduct simulations to test the proposed algorithm in various situations.The experiment results demonstrate that our algorithm creates almost ideal routes.

β-FeOOH Modified Sludge Biochar as Efficient Adsorbent for Phosphate Removal

β⁃FeOOH modified sludge biochar(FSBC)was prepared and investigated in this work to remove phosphate from water via adsorption.FSBC exhibited superior adsorption performance for phosphate with the maximum adsorption amount of 27.17 mg/g at 25℃.The specific adsorption capacity of FSBC was 57.8%higher than that of commercial activated carbon at pH 5 with the initial phosphate concentration of 10 mg/L.Coexisting anions can inhibit the adsorption of phosphate,but cations(Cr(VI)and Cd^(2+))exhibited some promotion effect.The results of kinetic and isotherm models and characterization analysis in combination indicated chemical adsorption,as electrostatic interaction,metal phosphate precipitation and hydrogen bonding may be the dominant process.The adsorption of phosphate onto FSBC was a monolayer adsorption,and the process was endothermic.After four adsorption/desorption cycles,the adsorption capacity of FSBC for phosphate decreased by 36.4%,which was in a distinct comparison with the 57.5%of SBC.

QTL mapping by whole genome re-sequencing and analysis of candidate genes for salt tolerance in linseed(Linum usitatissmum L.)

Soil salinization is detrimental to the growth and development of flax and ultimately leads to a decrease in yield.However,the molecular mechanism of linseed response to salt stress is still unclear.In this study,a salt-tolerant(ST)linseed variety STS and a salt-sensitive(SS)variety DYM were selected as experiment materials.Bulk segregation analysis and whole-genome resequencing technologies were performed to map salt tolerance quantitative trait loci(QTL).A total of 38,625 QTL loci were identified.Fifteen genes(which were not annotated in the reference genome)were identified within a 2.597 Mb region in chromosome 1.Two salt tolerance candidate genes Lus.o.m.scaffold91.141 and Lus.o.m.Scaffold1.14 encoding WD40 and cytochrome P450 were identified by predicting protein functions.Previous studies showed that WD40 and cytochrome P450 could significantly improve plant salt stress tolerance.In this paper,results showed that Lus.o.m.scaffold91.141 and Lus.o.m.Scaffold1.14 might be involved in response to salt stress in lineseed.The fine mapping and functional analysis of these genes provide a molecular breeding basis for the genetic improvement of high salt-tolerant linseed varieties.

维生素及类维生素对猪肉品质的影响

我国是世界上养猪生产大国,也是猪肉消费大国,随着人们经济生活水平的不断提高,对猪肉品质的要求也越高,安全的、无抗的、口感鲜美的猪肉成为消费者青睐的重点。因此如何生产出安全的,鲜美的猪肉成为现代养猪业的焦点问题之一。文章就维生素及类维生素对猪肉品质的影响进行了综述。

维生素及类维生素对母猪繁殖性能的影响

当前非洲猪瘟给我国养猪业造成很大的损失,繁殖母猪的存栏量急剧减少,造成猪肉供需平衡失调。那么,如何提高母猪的繁殖性能,提供更多的商品猪,成为养殖场管理者关注的焦点。文章就提高母猪繁殖性能的关键环节和维生素及类维生素对母猪繁殖性能影响进行综述。

有限生成无挠幂零群的有限扩张的4阶自同构

设G是有限生成无挠幂零群的有限扩张,α是G的4阶自同构且φ:是满射,则G的二阶导群G''包含在G的中心Z(G)里且CG(α2)是Abel群。

Cloning and functional analysis of the calreticulin gene from the scleractinian coral Galaxea astreata

Calreticulin(CRT)is a highly conserved Ca2+-binding protein and chaperone in the endoplasmic reticulum,which mainly participates in adjusting calcium level and directing proper conformation of proteins.Here,we cloned the crt gene of the scleractinian coral Galaxea astreata,named Gacrt,and analysed its ability to drive bacterial agglutination.The full-length Gacrt cDNA consisted of 1792 nucleotides and contained a 77 bp 5’untranslated region(UTR),a 380 bp 3’UTR and a 1335 bp open reading frame(ORF)that encoded a 444 amino acid protein.The deduced peptide possessed a signal peptide domain,an endoplasmic reticulum retrieval signal sequence(KDEL),two potential calreticulin family signature motifs and a set of triplicate repeats.We also found that the recombinant GaCRT protein could promote agglutination of both the Gram-positive bacterium Micrococcus luteus and the Gram-negative bacterium Escherichia coli.These results show that the GaCRT protein can enhance bacterial agglutination,hinting that GaCRT is an immune-relevant molecule involved in host defense against bacterium.

A stochastic model of bubble distribution in gas–solid fluidized beds

On the basis of the Langevin equation and the Fokker-Planck equation, a stochastic model of bubble distribution in a gas-solid fluidized bed was developed. A fluidized bed with a cross section of 0.3 m×0.02 m and a height of 0.8 m was used to investigate the bubble distribution with the photographic method. Two distributors were used with orifice diameters of 3 and 6 mm and opening ratios of 6.4% and 6.8%, respectively. The particles were color glass beads with diameters of O.3, 0.5 and 0.8 mm （Geldart group B particles）. The model predictions are reasonable in accordance with the experiment data. The research results indicated that the distribution of bubble concentration was affected by the particle diameter, the fluidizing velocity, and the distributor style. The fluctuation extension of the distribution of bubble concentration narrowed as the particle diameter, fluidizing velocity and opening ratio of the distributor increased. For a given distributor and given particles the distribution was relatively steady along the bed height as the fluidizing velocity changed.