Temperature-Induced Unfolding Pathway of Staphylococcal Enterotoxin B:Insights from Circular Dichroism and Molecular Dynamics Simulation

In this study,circular dichroism(CD)and molecular dynamics(MD)simulation were used to investigate the thermal unfolding pathway of staphylococcal enterotoxin B(SEB)at temperatures of 298–371 and 298–500 K,and the relationship between the experimental and simulation results were explored.Our computational findings on the secondary structure of SEB showed that at room temperature,the CD spectroscopic results were highly consistent with the MD results.Moreover,under heating conditions,the changing trends of helix,sheet and random coil obtained by CD spectral fitting were highly consistent with those obtained by MD.In order to gain a deeper understanding of the thermal stability mechanism of SEB,the MD trajectories were analyzed in terms of root mean square deviation(RMSD),secondary structure assignment(SSA),radius of gyration(R_(g)),free energy surfaces(FES),solvent-accessible surface area(SASA),hydrogen bonds and salt bridges.The results showed that at low heating temperature,domain Ⅰ without loops(omitting the mobile loop region)mainly relied on hydrophobic interaction to maintain its thermal stability,whereas the thermal stability of domain Ⅱ was mainly controlled by salt bridges and hydrogen bonds.Under high heating temperature conditions,the hydrophobic interactions in domain Ⅰ without loops were destroyed and the secondary structure was almost completely lost,while domain Ⅱ could still rely on salt bridges as molecular staples to barely maintain the stability of the secondary structure.These results help us to understand the thermodynamic and kinetic mechanisms that maintain the thermal stability of SEB at the molecular level,and provide a direction for establishing safer and more effective food sterilization processes.

一类非线性curl-curl问题柱对称基态解的存在性

本文研究一类非线性curl-curl问题,在对位势V(x)和Q(x)进行合适的假设下证明了柱对称基态解的存在性.

Temperature-induced effect on refractive index of graphene based on coated in-fiber Mach-Zehnder interferometer

The temperature-induced complex refractive index（CRI） effect of graphene is demonstrated theoretically and experimentally based on a graphene coated in-fiber MZI（Mach-Zehnder interferometer）. The relationships between real and imaginary parts of the graphene CRI and temperature are obtained through investigating the dip wavelength and intensity of the MZI interference spectrum changing with temperature, respectively. The temperature effect of CRI of the graphene is also analyzed theoretically. Both experimental and theoretical studies show that the real part and imaginary part of the CRI nonlinearly decrease and increase with temperature increasing, respectively. This graphene-coated in-fiber MZI structure also possesses the advantages of easy fabrication, miniaturization, low cost and robustness. It has potential applications in nanomaterial-based optic devices for communication and sensing.

Experimental studies on curling development of artificial soils

Soil curling is an important phenomenon associated with volume changes induced by increasing soil suction upon desiccation.The study of soil behaviors associated with drying in soils(e.g.soil shrinkage,desiccation cracks and curling)has received increasing attention over the last few years,which has been mainly driven by the forecast climate change that will warm up our planet.There are significant gaps in the current knowledge related to the factors that control the development of curling deformations in soils.For this,the curling phenomenon is investigated through laboratory desiccation tests on different mixtures of artificial soils.The effects of soil grain size distribution,mineralogy,soil microstructure,and soil water content on the curling deformation are analyzed.Digital photos were taken at regular time intervals during the tests to understand the volume changes in the soil samples during drying.It is found that soil fabric and soil water content have significant effects on curling scenario.It is observed that the percentage of sand particles and the initial water content play a critical role in the development of soil curling.Samples of pure clayey minerals experienced shrinkage without or with minor curling during drying.

Temperature-induced phase transition of two-dimensional semiconductor GaTe

GaTe is a two-dimensional Ⅲ-Ⅵ semiconductor with suitable direct bandgap of~1.65 eV and high photoresponsivity,which makes it a promising candidate for optoelectronic applications.GaTe exists in two crystalline phases:monoclinic(m-GaTe,with space group C2/m) and hexagonal(h-GaTe,with space group P63/mmc).The phase transition between the two phases was reported under temperature-varying conditions,such as annealing,laser irradiation,etc.The explicit phase transition temperature and energy barrier during the temperature-induced phase transition have not been explored.In this work,we present a comprehensive study of the phase transition process by using first-principles energetic and phonon calculations within the quasi-harmonic approximation framework.We predicted that the phase transition from h-GaTe to m-GaTe occurs at the temperature decreasing to 261 K.This is in qualitative agreement with the experimental observations.It is a two-step transition process with energy barriers 199 meV and 288 meV,respectively.The relatively high energy barriers demonstrate the irreversible nature of the phase transition.The electronic and phonon properties of the two phases were further investigated by comparison with available experimental and theoretical results.Our results provide insightful understanding on the process of temperature-induced phase transition of GaTe.

Curling ulcer in the setting of severe sunburn: A case report

BACKGROUND While sunburns are very common,especially in pediatrics,curling ulcers secondary to sunburns are a very rare entity that has not been noted in the literature in over fifty years.This case is the first addition to the literature since the originally documented case.CASE SUMMARY A previously healthy 17 year old male presents to the emergency room with lethargy,shortness of breath on exertion,dark stools and nausea.His fatigue started to become significantly worse four days prior to admission.Approximately two weeks prior to admission,the patient was on a beach vacation with his family at which time he suffered severe sunburns.He had developed crampy epigastric abdominal pain,which was followed by dark,loose stools.On exam,he is non-toxic appearing,but with pallor and peeling skin on his face and chest with epigastric tenderness.Infectious stool studies were all negative including Helicobacter pylori.He denies use of any non-steroidal anti-inflammatory drugs and also denies alcohol or recreational drug use.While admitted he is found to be significantly anemic with his hemoglobin as low as 6.3 requiring two units of packed red blood cells.Endoscopy revealed several severe and deep ulcerations in the antrum and body of the stomach indicative of stress or curling ulcers.CONCLUSION While the incidence of stress ulcers is not known,it is most common with severe acute illness,most commonly presenting as upper gastrointestinal(GI)bleeding.It is essential to be aware of the risk of curling ulcers secondary to severe sunburns as patients with stress ulcer GI bleeding have increased morbidity and mortality compared to those who do not have GI bleed.

Curling of New Concrete Pavement and Long-Term Performance

Curling results from the temperature differential across the concrete slab thickness and may induce undue stresses in newly placed slab. This study deals with the finite element （FE） analysis of curling, curling stresses, field measurement of curling on a newly built jointed plain concrete pavement, and comparison of its long-term performance using both Mechanistic-Empirical Pavement Design Guide （MEPDG） and HIPERPAVII software. The FE analysis was performed with a software program, ANSYS. The test section was modeled as a three-layer system with 300 mm concrete slab, 100 mm treated drainable base, and 150 mm lime-treated subgrade. All layers were assumed to be linear elastic. Temperature data was collected at five different depth locations across the concrete slab with digital data loggers. Curling was measured on five different days with a simple setup. The effect of temperature nonlinearities across the slab thickness was also examined. The results show that both upward and downward curling increase as the temperature differential increases. The maximum stress resulting from the combined effect of curling and traffic loading due to positive temperature differential is higher than that due to the negative temperature differential of the same magnitude. Since temperature differential has a significant influence on curling, both curling and curling stresses can be mitigated at an early age with temperature control, namely via enhanced curing. Both MEPDG and HIPERPAVII showed approximately the same performance for the PCC thickness ranging from 215 mm to 300 mm for this project. Performance prediction from HIPERPAVII is very sensitive to the change in PCC thickness less than 230 mm whereas MEPDG prediction is not as sensitive to the thickness change as with HIPERPAV 1I.

FORECAST OF BREAKING LENGTH OF SIDE CURLING SHORT SPIRAL CHIPS

The theoretical formula for estimating the side curling short spiral chips is simplified. On the basis of experiment, a practical formula for forecasting the chip breaking length is obtained. It is proved by experiment that the result from the practical formula fits well with that from the experiments.

Effect of Deformation Condition on Axial Compressive Precision Forming Process of Tube with Curling Die

The effect of the deformation condition on the axial compressive precision forming process of tube with curling die was investigated by using a rigid-plastic FEM. The results show that the forming accuracy depends mainly on geometric condition rp/d0, little on tube material properties and friction condition; the relative gap △/2rp of double-walled tubes obtained decreases with Increasing rp/d0, and there is a parameter k for a given to/do or rp/t0, when rp/d0 >k, △/2rp< 1, otherwise △/2rp>1.

Kenya's Curling Moment

The East African country is a sports powerhouse, especially in athletics. It is now trying to develop curling An athlete moves forward, focused on his aim, and slides a stone across the ice. The curl is in place. Two other athletes use brooms to furiously wipe the ice against the advancing piece of granite to keep it on course, without touching it, so that it comes to a stop close to the center of the “house,” as the target on the track is called. Curling is a high-intensity sport that needs strategy and focus.

严重烧伤并发Curling溃疡1例

患儿石某，男性，1岁8个月，邯郸县人。主诉全身多处热液烧伤4天，伴高热、黑便、严重腹胀1天于2003-8月3日22点30分入院。缘于4天前，不慎坐于热米汤中，烧伤全身多处，在当地诊所治疗2天后，出现高热、黑便和严重腹胀对症处理效果不佳，前来我院，以“特重烧伤脓毒性休克，Curling溃疡”收入院。自入院以来，精神淡漠。

Diverse Regulations of Viral and Host Genes in Tomato Germplasms Responding to Tomato Yellow Leaf Curl Virus Inoculation

Tomato yellow leaf curl virus(TYLCV)is the dominating pathogen of tomato yellow leaf curl disease that caused severe loss to tomato production in China.In this study,we found that a TYLCV-resistant tomato line drastically reduced the accumulation of viral complementary-sense strand mRNAs but just moderately inhibited that of viral DNA and virion-sense strand mRNAs.However,two other resistant lines did not have such virus inhibition pattern.Analysis of differential expressed genes showed that the potential host defense-relevant processes varied in different resistant tomatoes,as compared to the susceptible line,suggesting a diversity of tomato TYLCV-resistance mechanisms.

Changes of carbohydrate and protein metabolism in seedling leaves of a temperature-induced greenable albino mutant line W25 of rice

W25 is a low-temperature-sensitive albino mu-tant line. Temperature not only controls thealbino phenotype expression of W25, but alsodetermines whether it could survive. When thetemperature is lower than 25℃, the leaves ofW25 shows complete albino, but they exhibitsnormal green when temperature is higher than30℃. Meanwhile, at 25℃, it can be greenable

复合侵染云南西番莲的两种菜豆金色花叶病毒属病毒的分子鉴定及序列分析

西番莲Passiflora caerulea是我国南部省区广泛种植的一种热带果树。本研究于2020年6月从云南省德宏州西番莲种植区采集到4份疑似感染菜豆金色花叶病毒属病毒的西番莲样品,利用PCR扩增、克隆、测序以及生物信息学分析等方法,明确了西番莲样品受菜豆金色花叶病毒属病毒侵染。对4份西番莲样品进行菜豆金色花叶病毒属病毒全基因组扩增,从中共获得5条菜豆金色花叶病毒属病毒全基因组序列,分别命名为YN7292-6、YN7293-12、YN7293-4、YN7294-16和YN7295-25,均具有菜豆金色花叶病毒属单组分病毒的典型结构,编码7个开放阅读框(open reading frame,ORF);其中YN7292-6、YN7293-12、YN7294-16及YN7295-25与一品红曲叶病毒(Euphorbia leaf curl virus,EuLCuV)的不同分离物的核苷酸相似性均高于99.05%,为EuLCuV的不同分离物;而YN7293-4则与分离自江西西番莲样品的广东番木瓜曲叶病毒(papaya leaf curl Guangdong virus,PaLCuGdV)分离物GNPF1(GenBank登录号:MK673114.1)的核苷酸相似性最高,为99.70%,为PaLCuGdV的一个分离物;重组分析发现,2个分离物EuLCuV-YN7293-12和PaLCuGdV-YN7293-4均为重组病毒。本研究首次在云南省发现EuLCuV和PaLCuGdV这2种菜豆金色花叶病毒属病毒复合侵染西番莲,为有效预防和控制西番莲病毒病害的发生和传播提供理论依据。

果型和抗性基因协同对番茄黄化曲叶病毒带毒量的影响

以12份番茄种质为试材,其具有2类果实大小和3种不同抗性基因,通过检测番茄黄化曲叶病毒病田间抗性和带毒量指标,探索果实大小、抗病基因与田间抗性、带毒量之间的关系。结果显示,在自然传毒情况下,所有番茄材料都能检测到病毒感染。在番茄定植后28 d,小果型番茄M8(I)、M5(I)、M3(I)、M7(I)、M9(I)和M11(HR)带毒量均较低,大果型番茄M6(S)、M10(S)、M4(S)和M2(S)带毒量均较高,且小果型番茄田间发病率明显低于大果型番茄。除了Ty-1/ty-1单基因抗性不受番茄果实大小影响外,携带其他单基因或聚合基因抗性的番茄种质均与果实大小有关。在此节点上,带毒量越高抗性越弱,带毒量越低抗性越强。总体来说,在遭受番茄黄化曲叶病毒侵染时,小果型番茄田间抗性强于大果型番茄。

改进YOLOv5su模型检测桃树缩叶病

为实现自然环境下桃树缩叶病的检测,该研究提出了一种基于YOLOv5su的桃树缩叶病识别改进模型DLLYOLOv5su。首先,针对桃树缩叶病目标特征变化较大的问题,在骨干网络最后一层C3模块中加入可变形自注意力模块(deformable attention,DA),使模型更加关注目标区域,降低背景对模型的影响,提高模型在复杂背景下的拟合能力。其次在SPPF(fast spatial pyramid pooling)模块中引入LSKA(large separable kernel attention)结构,大核卷积增大了模型的感受野,使模型能够关注更多信息。最后,提出了LAWD(lightweight adaptive weighted downsampling)模块,使用轻量化的下采样结构替换卷积模块,减少计算开销。在桃树缩叶病数据集上进行试验,结果显示,DLL-YOLOv5su模型权重大小为17.6 MB,检测速度为83帧/s。识别准确率P、召回率R和平均精度均值mAP_(50)分别达到了80.7%、73.1%和80.4%,相较于原始YOLOv5su分别提高了4.2、2.4和4.3个百分点。与YOLOv3-tiny、Faster R-CNN、YOLOv7和YOLOv8相比mAP_(50)分别高出了28.5、11.8、2.1和4.1个百分点。改进模型识别精度高,误检、漏检率低,检测速度满足实时检测的要求,可以为桃树缩叶病的实时监测和预警提供参考。

冠心病患者血清VCAM-1、miR-145、Gal-3、SFRP5水平变化

目的探讨冠心病患者血清血管细胞黏附分子-1(VCAM-1)、miR-145、半乳糖凝集素-3(Gal-3)、分泌型卷曲蛋白5(SFRP5)水平变化及意义。方法选取冠心病患者80例为冠心病组,另收集健康志愿者40名为健康对照组。采集清晨空腹肘静脉血,酶联免疫吸附法测定血清VCAM-1、Gal-3、SFRP5浓度;RT-PCR检测血清miR-145表达水平。根据冠脉造影检查诊断的病变支数分为单支病变、双支病变、多支病变。收集两组受试者人口学特征及冠心病患者实验室指标;进行1 a随访,记录不良预后发生情况(病情加重再入院、死亡)。结果冠心病组患者血清VCAM-1、Gal-3水平明显高于健康对照组,miR-145、SFRP5水平明显低于健康对照组(均P<0.01)。急性心肌梗死组患者血清VCAM-1、Gal-3水平明显高于不稳定型心绞痛组、稳定型心绞痛组患者,血清miR-145、SFRP5水平明显低于不稳定型心绞痛组、稳定型心绞痛组患者(均P<0.05)。多支病变患者血清VCAM-1、Gal-3水平明显高于双支病变和单支病变患者,血清miR-145、SFRP5水平明显低于双支病变和单支病变患者(均P<0.05)。预后不良组患者血清VCAM-1、Gal-3水平明显高于预后良好组患者,miR-145、SFRP5水平明显低于预后良好组患者(均P<0.01)。VCAM-1、miR-145、Gal-3、SFRP5水平是冠心病患者预后的独立影响因素;ROC曲线分析显示,血清VCAM-1、miR-145、Gal-3、SFRP5水平联合检测对冠心病患者预后具有较高的预测价值(AUC=0.928)。结论冠心病患者血清VCAM-1、Gal-3水平高表达,miR-145、SFRP5水平低表达,且与冠心病分类、冠脉病变支数密切相关,联合检测对预后具有较高的预测价值。

密闭管道内瓦斯爆炸卷扬沉积煤尘爆炸传播特性

为了探究密闭管道内瓦斯爆炸卷扬沉积煤尘爆炸的传播特性,在自主研制的瓦斯爆炸卷扬沉积煤尘爆炸试验系统内,从爆炸压力、火焰以及压力-火焰的耦合关系等方面,研究了不同瓦斯体积分数及煤尘质量浓度下瓦斯爆炸卷扬沉积煤尘爆炸的爆炸压力传播特性及火焰传播特性,并利用Fluent数值模拟软件分析了煤尘的卷扬分散特征。结果表明:密闭管道内瓦斯体积分数为10%时的最大爆炸压力整体高于瓦斯体积分数为12%和8%时的最大爆炸压力。当瓦斯体积分数为10%,煤尘质量浓度为250 g/m^(3)时,最大爆炸压力传播规律表现为在瓦斯段先升后降再升,到达煤尘段后持续上升;随着煤尘质量浓度的增加,在瓦斯段则表现为先升后降,在煤尘段依旧持续上升。当瓦斯体积分数为8%和12%时,最大爆炸压力随煤尘质量浓度增加呈上升趋势,而瓦斯体积分数为10%时则呈现下降趋势。密闭管道内火焰锋面到达时间与传播距离呈正相关,瓦斯体积分数为10%时火焰锋面到达各测点的时间短于瓦斯体积分数为12%和8%的传播时间。火焰传播速度随传播距离呈先增大后减小的趋势,当瓦斯体积分数为10%时,火焰传播速度最快。密闭管道内瓦斯爆炸卷扬沉积煤尘爆炸的爆炸压力-时间曲线会出现2次峰值。第1次峰值是由瓦斯爆炸的前驱冲击波产生,当火焰传播至煤尘段后,压力同时开始上升,且压力峰值时刻和火焰峰值时刻耦合,达到第2次压力峰值,随着火焰信号的消失,压力逐渐减小直至反应停止。密闭管道内前驱冲击波与反射波使得煤尘卷扬分散,形成“漩涡状”煤尘云,促进煤粉与爆燃波接触。当煤尘质量浓度一定时,体积分数为10%瓦斯的卷扬程度优于体积分数12%和8%瓦斯;当瓦斯体积分数一定时,煤尘卷扬程度随煤尘质量浓度的增加而递减。

新德里番茄曲叶病毒的发生危害及阻截防控措施

新德里番茄曲叶病毒(Tomato leaf curl New Delhi virus,ToLCNDV)属双生病毒科,菜豆金色花叶病毒属,是近年来新发现的一种可侵染多种重要蔬菜、观赏植物、杂草和野生植物的病原物。1995年ToLCNDV首次在印度番茄上被报道,随后在巴基斯坦等亚洲国家发生危害,2012年以后传至西班牙等欧洲国家。我国首次于2010年在台湾地区报道了ToLCNDV。本文在收集相关资料的基础上,概述了该病毒的发生、分布与危害、分子特征、寄主范围、危害症状、传播方式和复合侵染现象,并提出了相应的阻截防控建议,以防范ToLCNDV在我国的传播扩散和危害。