基于hACE2转导建立SARS-CoV-2 spike假病毒感染病证结合的小鼠病毒肺炎模型

目的建立与评价一种安全、经济、有效的病证结合小鼠新冠病毒感染肺炎模型。方法30只KM种小鼠随机分为空白组、对照组及实验1组、实验2组、实验3组,每组各6只。每天把KM小鼠置于模拟寒湿环境中4 h,将表达hACE2的重组腺相关病毒(pAAV-hACE2)采用改良悬挂法气管内给药转导至肺组织,继以新型冠状病毒(SARS-CoV-2)spike假病毒采用相同的气管内给药方式造模。观察各组小鼠一般情况,检测体重变化、肺指数、血清炎性因子及肺部病理变化。结果免疫组化法显示h ACE2在小鼠肺组织中有效表达;在寒湿环境中给予SARS-CoV-2 spike假病毒后,实验组小鼠表现出类似疫毒犯肺证候的体征;且同样喂养条件和时间下,与空白组和对照组小鼠比较,实验组小鼠出现体重下降;实验1、2、3组小鼠出现肺指数显著增大(P<0.05或P<0.01),血清炎性因子白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、白细胞介素-8(IL-8)、肿瘤坏死因子-α(TNF-α)显著升高(P<0.01),肺组织病理改变明显。结论本研究成功建立了一种安全、经济、有效的病证结合小鼠新冠病毒感染肺炎模型。

The first factor affecting dryland winter wheat grain yield under various mulching measures: Spike number

Water is the key factor limiting dryland wheat grain yield.Mulching affects crop yield and yield components by affecting soil moisture.Further research is needed to determine the relationships between yield components and soil moisture with yield,and to identify the most important factor affecting grain yield under various mulching measures.A long-term 9-yearifeld experiment in the Loess Plateau of Northwest China was carried out with three treatments:no mulch (CK),plastic mulch (M_(P)) and straw mulch (M_(S)).Yield factors and soil moisture were measured,and the relationships between them were explored by correlation analysis,structural equation modeling and significance analysis.The results showed that compared with CK,the average grain yields of M_(P) and M_(S) increased by 13.0and 10.6%,respectively.The average annual grain yield of the M_(P) treatment was 134 kg ha^(–1) higher than the M_(S) treatment.There were no significant differences in yield components among the three treatments (P<0.05).Soil water storage of the M_(S) treatment was greater than the M_(P) treatment,although the differences were not statistically signifiant.Soil water storage during the summer fallow period (SWSSF) and soil water storage before sowing (SWSS) of M_(S) were significantly higher than in CK,which increased by 38.5 and 13.6%,respectively.The relationship between M_(P) and CK was not statistically significant for SWSSF,but the SWSS in M_(P) was significantly higher than in CK.In terms of soil water storage after harvest (SWSH) and water consumption in the growth period(ET),there were no signi?cant differences among the three treatments.Based on the three analysis methods,we found that spike number and ET were positively correlated with grain yield.However,the relative importance of spike number to yield was the greatest in the M_(P )and M_(S) treatments,while that of ET was the greatest in CK.Suifcient SWSSF could indirectly increase spike number and ET in the three treatments.Based on these results,mulch can improve yield and soil water storage.The most important factor affecting the grain yield of dryland wheat was spike number under mulching,and ET with CK.These findings may help us to understand the main factors influencing dryland wheat grain yield under mulching conditions compared to CK.

Spike蛋白介导细胞融合程度定量方法的建立及其在药物筛选中的应用

新型冠状病毒Spike蛋白(S蛋白)与受体ACE2结合介导细胞融合的发生,为进一步探究新冠感染合胞体发生、发展的规律及致病机制,明确关键蛋白靶点,筛选干预合胞体形成的药物,笔者拟构建新冠S蛋白介导的细胞融合程度的定量方法.利用pCDH-CMV-MCS-EF1-Puro、pLV-CMV-MCS-3FLAG-IRES-Bla、S蛋白基因序列、ACE2基因序列、LacZ基因序列、EcoRⅠ限制性内切酶及同源重组酶构建慢病毒穿梭质粒pCDH-S,pCDH-ACE2,pLV-α与pLV-ω,利用该慢病毒质粒分别构建稳定表达S蛋白与ACE2蛋白的293FT和A549细胞系,随后利用pLV-α与pLV-ω慢病毒质粒分别感染上述稳定细胞系,构建出可以定量细胞融合程度的细胞系293FT-S_(1-56),A549-S_(1-56),293FT-ACE2△_(11-41),A549-ACE2△_(11-41).最后采用Western Blot蛋白免疫印迹技术鉴定上述融合定量细胞系中S蛋白与ACE2蛋白的过表达效果,并通过细胞共培养确定融合效果,用β-半乳糖苷酶报告基因检测试剂盒定量细胞融合程度.结果显示,慢病毒载体和稳定细胞系构建成功,时间梯度、转染梯度实验显示该系统具有良好的定量灵敏度,并能用于卡莫司他(Camostat mesylate)和氯硝柳胺(Niclosamide)等药物抗融合效果的定量评价.成功构建的新冠病毒Spike蛋白介导细胞融合程度定量系统,可用于不同S蛋白突变体致融合能力评价和抗融合药物筛选评价,可为进一步的研究奠定技术基础.

The wheat sucrose synthase gene TaSus1 is a determinant of grain number per spike

Some haplotypes of the sucrose synthase gene TaSus1 are associated with thousand-grain weight(TGW)in wheat(Triticum aestivum L.).However,no mutations have been identified within the gene to test this association.The effects of TaSus1 on grain number per spike(GNS)also are largely unknown.Our previous genome-wide association study identified TaSus-A1 as a candidate gene controlling fertile spikelet number per spike(FSN).In the present study,we generated two independent mutants for the three TaSus1 homoeologs by CRISPR/Cas9-mediated genome editing.The triple mutants displayed lower FSN,GNS,grain number per spikelet(GNST),and TGW than wild-type plants.In 306 hexaploid wheat accessions,two single-nucleotide polymorphisms in TaSus-A1 contributed differently to GNS.Introgression of the two alleles into a wheat genetic background confirmed their effects.The alleles differed in geographical distribution among the accessions.

Estimating wheat spike-leaf composite indicator(SLI)dynamics by coupling spectral indices and machine learning

The contribution of spike photosynthesis to grain yield(GY)has been overlooked in the accurate spectral prediction of yield.Thus,it’s essential to construct and estimate a yield-related phenotypic trait considering spike photosynthesis.Based on field and spectral reflectance data from 19 wheat cultivars under two nitrogen fertilization conditions in two years,our objectives were to(i)construct a yield-related phenotypic trait(spike–leaf composite indicator,SLI)accounting for the contribution of the spike to photosynthesis,(ii)develop a novel spectral index(enhanced triangle vegetation index,ETVI3)sensitive to SLI,and(iii)establish and evaluate SLI estimation models by integrating spectral indices and machine learning algorithms.The results showed that SLI was sensitive to nitrogen fertilizer and wheat cultivar variation as well as a better predictor of yield than the leaf area index.ETVI3 maintained a strong correlation with SLI throughout the growth stage,whereas the correlations of other spectral indices with SLI were poor after spike emergence.Integrating spectral indices and machine learning algorithms improved the estimation accuracy of SLI,with the most accurate estimates of SLI showing coefficient of determination,root mean square error(RMSE),and relative RMSE values of 0.71,0.047,and 26.93%,respectively.These results provide new insights into the role of fruiting organs for the accurate spectral prediction of GY.This high-throughput SLI estimation approach can be applied for wheat yield prediction at whole growth stages and may be assisted with agronomical practices and variety selection.

Translocation of a fish spike from the pharynx to the thyroid gland:A case report

BACKGROUND A fish spike stuck in the throat is a common ear,nose,and throat(ENT)emergency.However,it is very rare for a fish spike to reach the thyroid tissue through the throat,which is very dangerous and can lead to pharyngeal fistula,cervical abscess,mediastinal abscess,and thyroid abscess.Proper and timely management can help reduce complications,especially in elderly patients.CASE SUMMARY In the case presented here,the causative factor was dentures,but improper management aggravated the condition.In the case presented here,an elderly woman with a history of accidentally swallowing fish bones for 20 d had a sensation of foreign bodies in her throat.Eventually,computed tomography(CT)of the neck showed that the left side of the thyroid gland had a dense shadow in the form of a stripe.CONCLUSION If a fishbone foreign body is not visible during endoscopic examination but the patient has significant symptoms,the surgeon should be aware that the fishbone may be lodged in the thyroid.To avoid a misdiagnosis,ultrasound,CT,and other tests can be used to clarify the diagnosis.T The first step in treating a fish bone in the thyroid gland is to determine the position of the foreign body and the extent of the infection,and to develop a personalized surgical plan for its removal.At the same time,scientific information should be made available to the general public so that people know that if a fish bone is accidentally lodged,they should not force it to be swallowed or be spit out by inducing vomiting,which are incorrect methods and may aggravate the condition or even cause it to migrate outside the cavity,leading to serious complications,as in this reported case.

Innovative COVID-19 Screening: RT-LAMP Assay for Spike and NSP1 Proteins

Coronavirus disease(COVID-19)is a serious respiratory disease that spreads through the coronavirus globally.It soon became a pandemic after its appearance in 2019 and demanded new techniques for its identification and detection.Owing to this situation,RT-LAMP appears to be a novel method for the identification of COVID-19 because of its vast applications,including cost-effectiveness and time-saving.This research highlights the use of RT-LAMP,a more sensitive test than RT-PCR,for the assessment of SARS-CoV-2,the severe acute respiratory illness.To identify the spike(S)and NSP1 protein using RT-LAMP,170 total samples of coronavirus-suspected patients were served in this research.Health certifications and bioethical considerations were taken into consideration.After the sample was extracted from the patient's swabs,RNA was isolated,extracted,and purified.The response was then run on the RT-LAMP at the ideal temperature,and the outcomes could be observed with the unaided eye as they changed from pink to yellow.It is a simple method of determining if the test is positive or negative.For this purpose,both RT-LAMP and RT-PCR tests are used during these procedures.Genes linked with COVID-19 testing including S,nspl,and ORF are suited to coronavirus testing;they have 100%specificity and low sensitivity,but S has more specificity and sensitivity than nspl and ORF,respectively.Out of the 95 positive samples,89(93.68%)samples yielded favorable outcomes utilizing RT-LAMP,while 55 negative samples yielded 100%positive results.The present research demonstrates that RT-LAMP is less sensitive yet more selective for coronavirus detection.

基于RISC-V架构的Spike缓存模型的设计和实现

使用基于精简指令集原则的指令架构(RISC-V)的指令集,针对现有Spike验证模型中的缓存写回功能的缺失问题,设计一种基于RISC-V指令集的现代超标量处理器缓存模型。基于现代高速缓存的基本原理,结合Spike验证模型,实现现代高速缓存的基本读写操作,并进行系统级芯片(SoC)环境下的仿真和验证,可作为微型电子芯片(IC)前端逻辑设计中的验证模型使用。该方案能够以较快的时间完成基于RISC-V指令集的大型SoC的设计与验证。

Twice-split phosphorus application alleviates low-temperature impacts on wheat by improved spikelet development and setting

Extreme low-temperature incidents have become more frequent and severe as climate change intensifies.In HuangHuai-Hai wheat growing area of China,the late spring coldness occurring at the jointing-booting stage(the anther interval stage)has resulted in significant yield losses of winter wheat.This study attempts to develop an economical,feasible,and efficient cultivation technique for improving the low-temperature(LT)resistance of wheat by exploring the effects of twice-split phosphorus application(TSPA)on wheat antioxidant characteristics and carbon and nitrogen metabolism physiology under LT treatment at the anther interval stage using Yannong 19 as the experimental material.The treatments consisted of traditional phosphorus application and TSPA,followed by a-4℃ LT treatment and natural temperature(NT)control at the anther interval stage.Our analyses showed that,compared with the traditional application,the TSPA increased the net photosynthetic rate(P_(n)),stomatal conductance(Gs),and transpiration rate(T_(r))of leaves and reduced the intercellular carbon dioxide concentration(C_(i)).The activity of carbon and nitrogen metabolism enzymes in the young wheat spikes was also increased by the TSPA,which promoted the accumulation of soluble sugar(SS),sucrose(SUC),soluble protein(SP),and proline(Pro)in young wheat spike and reduced the toxicity of malondialdehyde(MDA).Due to the improved organic nutrition for reproductive development,the young wheat spikes exhibited enhanced LT resistance,which reduced the sterile spikelet number(SSN)per spike by 11.8%and increased the spikelet setting rate(SSR)and final yield by 6.0 and 8.4%,respectively,compared to the traditional application.The positive effects of split phosphorus application became more pronounced when the LT treatment was prolonged.

Highly Sensitive Poly-N-isopropylacrylamide Microgel-based Electrochemical Biosensor for the Detection of SARS-COV-2 Spike Protein

Objective Late 2019 witnessed the outbreak and widespread transmission of coronavirus disease 2019(COVID-19),a new,highly contagious disease caused by novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Consequently,considerable attention has been paid to the development of new diagnostic tools for the early detection of SARS-CoV-2.Methods In this study,a new poly-N-isopropylacrylamide microgel-based electrochemical sensor was explored to detect the SARS-CoV-2 spike protein(S protein)in human saliva.The microgel was composed of a copolymer of N-isopropylacrylamide and acrylic acid,and gold nanoparticles were encapsulated within the microgel through facile and economical fabrication.The electrochemical performance of the sensor was evaluated through differential pulse voltammetry.Results Under optimal experimental conditions,the linear range of the sensor was 10-13-10-9 mg/m L,whereas the detection limit was 9.55 fg/mL.Furthermore,the S protein was instilled in artificial saliva as the infected human saliva model,and the sensing platform showed satisfactory detection capability.Conclusion The sensing platform exhibited excellent specificity and sensitivity in detecting spike protein,indicating its potential application for the time-saving and inexpensive detection of SARS-CoV-2.

Natural variants and editing events provide insights into routes for spike architecture modification in common wheat

Spike architecture is an indicative trait of grain yield in common wheat(Triticum aestivum).A segregating population was generated for mapping genes contributing to spike morphometric traits by crossing the two common wheat cultivars'CItr 17600'with branching spikes and'Yangmai 18'with normal spikes.A major quantitative trait locus for spike length was mapped to the Q5A region of chromosome 5A.Yangmai18 carried a Q5Ab allele for short spikes,which harbored one SNP in the last intron,and a 1-bp InDel in the 720-bp fragment from the start codon,compared to Q5Aa in Chinese Spring.CItr 17600 harbored a q5Ab allele for long spikes,which has a 6-bp deletion compared to the reported q5Aa allele that was involved in the binding site of microRNA 172(miR172).This 6-bp deletion in immediately upstream of this binding site was involved in changes of four amino acids.The natural q5A allele appeared to be rare in common wheat but frequent in tetraploid T.turgidum accessions with branching spikes.The CRISPR/Cas9 technology was used to edit the upstream region involving in the miR172 binding site in Yangmai 18 and identified two independent editing events,one with a 1-bp insertion in Q5A and the other with a 2-bp deletion in Q5D,resulting in several shapes of spikes in the transgenic progeny.In addition to the effects of natural q5A allele and the edited Q5A genes,this study indicated the regeneratability and transformability of Yangmai 18 as an elite cultivar.Altogether,this study provides insight into future modification and engineering of spike architecture in common wheat.

Bifurcations for counterintuitive post-inhibitory rebound spike related to absence epilepsy and Parkinson disease

Seizures are caused by increased neuronal firing activity resulting from reduced inhibitory effect and enhancement of inhibitory modulation to suppress this activity is used as a therapeutic tool.However,recent experiments have shown a counterintuitive phenomenon that inhibitory modulation does not suppress but elicit post-inhibitory rebound(PIR)spike along with seizure to challenge the therapeutic tool.The nonlinear mechanism to avoid the PIR spike can present theoretical guidance to seizure treatment.This paper focuses on identifying credible bifurcations that underlie PIR spike by modulating multiple parameters in multiple theoretical models.The study identifies a codimension-2 bifurcation called saddle-node homoclinic orbit(SNHOB),which is an intersection between saddle node bifurcation on invariant cycle(SNIC)and other two bifurcations.PIR spike cannot be evoked for the SNIC far from the SNHOBbut induced for the SNIC close to the SNHOB,which extends the bifurcation condition for PIR spike from the well-known Hopf to SNIC.Especially,in a thalamic neuron model,increases of conductance of T-type Ca^(2+)(TC a)channel induce SNIC bifurcation approaching to the SNHOB to elicit PIR spikes,closely matching experimental results of the absence seizure or Parkinson diseases.Such results imply that,when inhibition is employed to relieve absence seizure and Parkinson diseases related to PIR spike,modulating SNIC to get far from the SNHOBto avoid PIR spike is the principle.The study also addresses the complex roles of TCacurrent and comprehensive relationships between PIR spike and nonlinear conceptions such as bifurcation types and shapes of threshold curve.

基于spike-and-slab先验的贝叶斯时间序列模型

贝叶斯方法通过引入先验信息并结合似然的方法进行参数估计和变量选择,使模型估计和预测结果更为精确。在贝叶斯框架下考虑时间序列之间的相关性,将偏自相关系数融合先验信息,提出基于spike-and-slab先验的贝叶斯层次时间序列模型(Spike-and-slab Prior with Partial Autocorrelation Coefficients,SS-PAC)。SS-PAC模型采用spike-and-slab先验并结合偏自相关系数,实现时间序列滞后阶数的选择、参数估计和预测。基于模拟数据和真实数据的实证研究表明,该模型相较于以往模型在变量选择和预测结果上表现更优。

基于预测校正算法的Spike and Slab Lasso逻辑回归模型

尽管Spike and Slab方法广泛应用于贝叶斯变量选择,但其惩罚似然估计的潜力在很大程度上被忽视了。通过在贝叶斯模态中引入惩罚化似然观点,本文提出了新的Spike and Slab Lasso逻辑回归模型,将两个拉普拉斯密度的混合先验置于单个坐标上,可以自适应地收缩系数,即弱收缩重要预测量,强收缩不相关预测量,从而可以得到准确的估计和预测。同时,我们使用了预测–校正算法来求解Spike and Slab Lasso逻辑回归模型,并将该算法扩展到不可分离惩罚的情况。该算法利用凸优化的预测校正算法,沿着整个正则化路径有效的计算解,方便了模型选择,避免了正则化参数值不同时的独立优化。最后,模拟学习和实证结果表明本文所提模型比Lasso逻辑回归模型具有更优的性能。

Waning of Anti-Spike IgG Antibody Titer after COVID-19 Vaccination: Myth or Reality?

This observational prospective study was conducted on 25 patients who had received a full 3-dose COVID-19 vaccination scheme with a follow-up ranging from 12 to 19 months after the last injection. The aim of the study was focused on a single biological indicator the anti-spike IgG antibody titer. The age of the patients ranged from 51 to 85 years old. 15 out 25 patients (60%) presented a comorbidity. Our data showed a persistent positive anti-spike IgG antibodies titer ranging from 105 to 5680 BAU/mL (mean: 2661 BAU/mL) in all patients. In view of these results, systematic administration of a SARS-CoV-2 vaccine booster is questionable and should be individually tailored according to the patient medical condition and the anti-spike IgG antibody level.

新型“spike 99”香料的GC/MS检验

目的:对缴获的新型"sp ike 99"香料进行主要有机成分检验。方法:采用GC/MS定性方法对缴获"sp ike 99"香料进行定性分析。结果:"sp ike 99"香料中检出JWH-018,JWH-073等合成大麻素成分。结论:含有这些合成大麻素的"sp ike 99"香料样本,应该被认定为是一种新的"策划药"产品。

皮秒脉冲电场调控大鼠运动皮层神经元spike发放的初步研究

近年来,皮秒脉冲电场诱导的生物电效应逐渐引起了国内外研究学者的关注。现有细胞实验已经初步证实,皮秒脉冲电场对神经元细胞及其动作电位有一定影响。然而,目前国内外尚未见皮秒脉冲对神经元spike发放影响的相关研究报道,皮秒脉冲对动物神经元spike发放的调控效果仍为一个未知数。为此,基于可调式皮秒脉冲发生器（最大峰值电压–1 000 V,半高宽550 ps,上升时间150 ps,重复频率0~10 k Hz可调）,以大鼠运动皮层神经元为实验对象,有效开展了皮秒脉冲对大鼠运动皮层电生理活动影响的研究,初步探讨了皮秒脉冲幅值、重复频率及作用时间等对大鼠运动皮层神经元spike发放的影响。实验发现：大鼠运动皮层神经元spike发放的改变与皮秒脉冲幅值、重复频率及作用时间密切相关。当皮秒脉冲电压幅值绝对值大于1 k V时,神经元spike发放开始出现变化。随着皮秒脉冲重复频率的增大,神经元spike发放有先增强后抑制的趋势。随着皮秒脉冲作用时间的增加,神经元spike发放出现增强或抑制效果的频率响应窗口均提前。

太阳spike辐射中的MHD振荡

我们在1981年5月16日所观测到的典型的微波大爆发的spike辐射中,发现存有～1.4—1.6秒的准周期振荡特征。本文依据MHD波理论,对观测进行了分析讨论,本文认为在日冕圈内外传播着的快磁声波(“腊肠”模)调制了源区的磁场以及电子束的投射角分布,从而影响了ECM不稳定性的增长率,因此而产生了spike辐射中的准周期振荡。另外,本文还对一些有关的物理参数作了定量的估算。

猪传染性胃肠炎病毒spike蛋白亲和肽的原核表达

【目的】原核表达猪传染性胃肠炎病毒(transmissible gastroenteritis virus of swine,TGEV)spike蛋白亲和肽(SQHT),检测其病毒亲和性,为建立TGEV诊断方法奠定理论和物质基础。【方法】人工合成TGEV spike蛋白亲和肽基因,亚克隆后将该基因分别插入至原核表达载体pET-32a和pGEX-6p-1中,构建重组质粒pET-32a-SQHT和pGEX-6p-SQHT,对重组质粒进行BamHⅠ单酶切和BamHⅠ/XhoⅠ双酶切及测序鉴定。将重组质粒分别转化至大肠杆菌Rosetta(DE3),用IPTG进行诱导表达,对其表达产物的生物学活性进行检测。【结果】亚克隆获得了150 bp的TGEV spike蛋白亲和肽基因。成功构建了重组质粒pET-32a-SQHT和pGEX-6p-SQHT,并诱导表达出重组蛋白TRX-SQHT和GST-SQHT,其分子质量分别为25和31 ku。Western blot分析表明,2种重组蛋白与TGEV病毒粒子具有良好的亲和性;Dot-ELISA分析表明,2种重组蛋白与TGEV病毒粒子的最低结合滴度TCID50为5×102 mL-1。特异性试验表明,重组蛋白TRX-SQHT和GST-SQHT均可与TGEV产生特异性结合,而不与猪流行性腹泻病毒(PEDV)和猪轮状病毒(PoRV)结合。【结论】使用原核细胞成功表达了TGEV spike蛋白亲和肽,表达的重组蛋白具有很好的TGEV特异亲和性。

严重急性呼吸综合征冠状病毒Spike蛋白诱发小鼠免疫损伤的实验研究

目的研究严重急性呼吸综合征冠状病毒(SARS-CoV)的Spike蛋白(S蛋白)引起免疫病理损伤的分子机制。方法采用信号转导通路发现者基因芯片筛选相关诱导免疫炎症的信号转导通路基因的表达,通过RT-PCR对基因芯片筛选基因进一步验证并观察信号分子阻断剂干预的影响;将SARS-CoV的S蛋白及信号分子阻断剂分别经气管滴注、尾静脉注射的途径感染BALB/c小鼠,通过免疫组织化学观察肺及免疫器官的病理变化。结果S蛋白诱导了与γ干扰素(IFN-γ)类似的JAK-STAT的信号通路相关基因的表达,RT-PCR证实S蛋白诱导了人支气管上皮细胞的γ干扰素诱导蛋白10(IP-10)基因表达,该作用能够被JAK3抑制剂完全阻断。经气管滴注或尾静脉注射S蛋白均可引起小鼠肺损伤和脾脏损伤。JAK3抑制剂能够抑制S蛋白诱导小鼠肺内IP-10表达,减轻病理损伤。结论JAK-STAT信号转导通路的激活可能在SARS-CoV的S蛋白诱导的以IP-10为代表的炎症级联中起重要作用,该发现可为发展抗SARS病毒诱导的免疫损伤治疗提供新的策略。