后生元调节肠道微生态及减少脑内β-淀粉样蛋白沉积改善阿尔茨海默病大鼠的认知障碍

为探究3种不同剂量的后生元对D-半乳糖联合AlCl_(3)诱导的阿尔茨海默病(Alzheimer’s disease,AD)大鼠记忆认知能力的影响,以SPF级Wistar大鼠为实验对象,随机分为空白对照组,AD模型组,阳性药物盐酸多奈哌齐对照组,后生元动物双歧杆菌乳亚种IOBL07低、高剂量组(10^(8)、10^(9) CFU/kg),后生元植物乳植杆菌IOB602低、高剂量组(10^(8)、10^(9) CFU/kg)和后生元副干酪乳酪杆菌IOB413低、高剂量组(10^(8)、10^(9) CFU/kg)。除空白组腹腔注射生理盐水、灌胃生理盐水外,其余各组均腹腔注射D-半乳糖,同时灌胃AlCl_(3),连续造模13周,在造模药物注射并灌胃结束1 h后,干预组分别灌胃盐酸多奈哌齐和3种不同剂量的后生元,空白组和模型组灌胃等量的生理盐水。采用Morris水迷宫测试各组大鼠学习记忆能力,并测定大鼠海马中β-淀粉样蛋白(amyloid β-protein,Aβ)的含量及其荧光强度,小肠组织病理形态和肠道菌群的变化,粪便、血清及海马中脂多糖(lipopolysaccharide,LPS)水平和炎症因子信号通路Toll样受体4(Toll-like receptor 4,TLR4)/NOD样受体热蛋白结构域相关蛋白3(NOD-like receptor thermal protein domain associated protein 3,NLRP3)/髓样分化因子88(myeloid differentiation factor 88,MyD88)相对表达量。结果表明,3种不同剂量的后生元均能够显著提升AD大鼠的学习记忆能力,并显著降低海马中Aβ的含量,降低粪便、血清及海马中LPS水平和炎症因子信号通路TLR4/NLRP3/MyD88的相对表达量。肠道菌群分析结果显示,后生元的干预可以调节AD大鼠肠道微生物群的结构和组成,与AD组大鼠相比,各后生元干预组肠道优势菌Firmicutes和肠道有益菌Ruminococcaceae相对丰度增加,肠道有害菌Muribaculaceae相对丰度降低。因此,后生元具有明显改善AD大鼠记忆认知障碍的作用,且后生元植物乳植杆菌IOB602高剂量组的干预效果最佳,其机制可能与改善肠道微生物群的结构组成和降低脑组织炎症因子信号通路的相对表达量有关。

Superhydrophobic and corrosion-resistant siloxane-modified MgAl-LDHs coatings on magnesium alloy prepared under mild conditions

We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg alloy.This composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperature(relative to hydrothermal reaction conditions)under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane(PFDTMS)using a simple immersion method.The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS).The corrosion resistance of the LDH-W film,both before and after the PFDTMS modification,was evaluated using electrochemical impedance spectroscopy(EIS),Tafel curves,and immersion experiments.The results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDHW film,with no apparent signs of corrosion after exposure to 3.5wt%NaCl solution for 15 d.Furthermore,the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages,as confirmed by static contact angle and water-repellency tests.These results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.

GH4169惯性摩擦焊界面摩擦及瞬态热过程数值模拟研究

针对GH4169高温合金惯性摩擦焊过程,基于有限元方法研究了界面摩擦机制的转变、摩擦产热和温度场等热过程参量的分布特征及瞬态演化规律。利用试验数据对有限元模型的准确性进行了对比验证。结果表明,焊接初始整个界面均为库仑摩擦区,从0.54 s开始库仑摩擦区逐渐缩小并在9.60 s完全消失,剪切摩擦区从0.31R0(R0为工件半径)处开始形成并逐渐扩展至整个界面。根据模拟结果,提出了描述库仑摩擦区演化过程的解析公式。分析了摩擦机制转变引起的界面热流密度、摩擦应力和温度的耦合关系及变化规律。研究表明,界面上库仑摩擦机制向剪切摩擦机制的转变有利于焊接界面附近温度场的均匀化。

卫宁北山金矿关键控矿因素分析

本文通过分析研究区关键控矿因素、矿床成因、找矿前景。认为研究区具有两期主要控矿构造,要重视NE向断裂对金成矿的控制作用。金的成矿经历了初始富集、早期硫化成矿、硫化物的次生氧化与金的富集三个阶段的地质过程,成矿物质来源以地层为主。寻找工业矿体应该以中浅部氧化矿体为主。

惯性摩擦焊高温区温度特征仿真与实验研究

目的定量分析影响惯性摩擦焊接头质量的关键因素——焊接过程高温区的温度特征。方法选取TC4钛合金为研究对象,综合运用有限元仿真及界面组织观察的研究方法,分析确定惯性摩擦焊过程中高温区的温度特征。针对初始转速分别为1000 r/min及1200 r/min的2种惯性摩擦焊工况开展实验,并建立了热-力耦合有限元仿真模型对惯性摩擦焊过程进行仿真分析。结果仿真得到的温度分布与焊接过程摩擦界面附近的测温结果吻合良好,仿真模型与实验分析结果均表明,与初始转速为1000 r/min相比,初始转速为1200 r/min时的接头的飞边更大,2种焊接工况下仿真得到的轴向缩短量均与实验结果吻合良好,表明了仿真模型对TC4钛合金惯性摩擦焊热-力过程分析的准确性。结论在TC4钛合金圆棒样品惯性摩擦焊过程中,摩擦界面附近存在高温区,高温区内的温度呈现出芯部低、外围高的特点,最高温度约出现在沿半径方向1/2半径处。在初速转速为1000 r/min及1200 r/min的焊接工况下,芯部温度约为720℃与780℃,外围的最高温度分别约为850℃与920℃。接头组织观察结果进一步证实了仿真得到的高温区的温度数值的准确性。

Well-oriented magnesium hydroxide nanoplatelets coating with high corrosion resistance and osteogenesis on magnesium alloy

Magnesium alloys are nontoxic and promising as orthopedic metallic implants,but preparing a biocompatible Mg(OH)_(2)layer with high corrosion protection ability remains challenging.It is generally believed that the Mg(OH)_(2)layer,especially that formed in a natural condition,cannot provide desirable corrosion resistance in the community of corrosion and protection.Here,several Mg(OH)_(2)coatings were prepared by changing the pH values of sodium hydroxide solutions.These coatings were composed of innumerable nanoplatelets with different orientations and showed distinguished capability in corrosion resistance.The nanoplatelets were well-oriented with their ab-planes parallel to,instead of perpendicular to,the magnesium alloy surface by raising the pH value to 14.0.This specific orientation resulted in the optimal coating showing long-term corrosion protection in both in vitro and in vivo environments and good osteogenic capability.These finds manifest that the environment-friendly Mg(OH)_(2)coating can also provide comparable and better corrosion protection than many traditional chemical conversion films(such as phosphate,and fluoride).

Proteomics for early prenatal screening of gestational diabetes mellitus

In this editorial,we comment on the article by Cao et al.Through applying isobaric tags for relative and absolute quantification technology coupled with liquid chromatography-tandem mass spectrometry,the researchers observed significant differential expression of 47 proteins when comparing serum samples from pregnant women with gestational diabetes mellitus(GDM)to the healthy ones.GDM symptoms may involve abnormalities in inflammatory response,complement system,coagulation cascade activation,and lipid metabolism.Retinol binding protein 4 and angiopoietin like 8 are potential early indicators of GDM.GDM stands out as one of the most prevalent metabolic complications during pregnancy and is linked to severe maternal and fetal outcomes like pre-eclampsia and stillbirth.Nevertheless,none of the biomarkers discovered so far have demonstrated effectiveness in predicting GDM.Our topic was designed to foster insights into advances in the application of proteomics for early prenatal screening of GDM.

检警协作视域下的帮助信息网络犯罪活动罪治理

基于诉讼理论与帮信罪案件的办案需要,帮信罪治理中有必要建立检警协作机制。然而,检警协作治理帮信罪存在帮信罪口袋罪特征导致检警协作难以有效开展,检警在行刑衔接实现帮信罪出罪方面存在一定缺位、检警证据指控的协作不足、检警对行业主体监督不力等困境。为更好地对帮信罪进行生态化系统化治理,强化检警协作可作为提升帮信罪治理质效的路径选择,主要有明确帮信罪的司法适用标准,为检警协作提供更明确指引;充分发挥检警协作在行刑衔接中的作用;加强检警证据指控的协作配合,完善信息共享机制;检警加强对行业主体的监督,推动多元共治。

法学课程校企合作的创新教学探究——以行政法与行政诉讼法课程为例

在地方应用型高校教育实践中,校企合作是提高法学课程教学质量、达成课程目标的重要途径。地方应用型高校法学类专业强调“应用型”教学,法学课程校企合作尤为重要,如何进行校企合作教学,需要不断地实践与探索。以行政法与行政诉讼法课程为例,构建法学课程校企合作的教学体系,提出法学课程校企合作教学实施落地建议。

Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells.The modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/C.Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct pathway.Density functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic performance.This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

The microbial community,nutrient supply and crop yields differ along a potassium fertilizer gradient under wheat-maize double-cropping systems

Soil microorganisms play critical roles in ecosystem function.However,the relative impact of the potassium(K)fertilizer gradient on the microbial community in wheat-maize double-cropping systems remains unclear.In this long-term field experiment(2008-2019),we researched bacterial and fungal diversity,composition,and community assemblage in the soil along a K fertilizer gradient in the wheat season(K0,no K fertilizer;K1,45 kg ha^(-1) K_(2)O;K_(2),90 kg ha^(-1)K_(2)O;K3,135 kg ha^(-1)K_(2)O)and in the maize season(K0,no K fertilizer;K_(1),150 kg ha^(-1) K_(2)O;K_(2),300 kg ha^(-1)K_(2)O;K_(3),450 kg ha^(-1)K_(2)O)using bacterial 16S rRNA and fungal internally transcribed spacer(ITS)data.We observed that environmental variables,such as mean annual soil temperature(MAT)and precipitation,available K,ammonium,nitrate,and organic matter,impacted the soil bacterial and fungal communities,and their impacts varied with fertilizer treatments and crop species.Furthermore,the relative abundance of bacteria involved in soil nutrient transformation(phylum Actinobacteria and class Alphaproteobacteria)in the wheat season was significantly increased compared to the maize season,and the optimal K fertilizer dosage(K2 treatment)boosted the relative bacterial abundance of soil nutrient transformation(genus Lactobacillus)and soil denitrification(phylum Proteobacteria)bacteria in the wheat season.The abundance of the soil bacterial community promoting root growth and nutrient absorption(genus Herbaspirillum)in the maize season was improved compared to the wheat season,and the K2 treatment enhanced the bacterial abundance of soil nutrient transformation(genus MND1)and soil nitrogen cycling(genus Nitrospira)genera in the maize season.The results indicated that the bacterial and fungal communities in the double-cropping system exhibited variable sensitivities and assembly mechanisms along a K fertilizer gradient,and microhabitats explained the largest amount of the variation in crop yields,and improved wheat?maize yields by 11.2-22.6 and 9.2-23.8%with K addition,respectively.These modes are shaped contemporaneously by the different meteorological factors and soil nutrient changes in the K fertilizer gradients.

Versatile and controlled quantum teleportation network

A quantum teleportation network involving multiple users is essential for future quantum internet.So far,controlled quantum teleportation has been demonstrated in a three-user network.However,versatile and controlled quantum teleportation network involving more users is in demand,which satisfies different combinations of users for practical requirements.Here we propose a highly versatile and controlled teleportation network that can switch among various combinations of different users.We use a single continuous-variable six-partite Greenberger-Horne-Zeilinger(GHZ)state to realize such a task by choosing the different measurement and feedback operations.The controlled teleportation network,which includes one sub-network,two sub-networks and three sub-networks,can be realized for different application of user combinations.Furthermore,the coherent feedback control(CFC)can manipulate and improve the teleportation performance.Our approach is flexible and scalable,and would provide a versatile platform for demonstrations of complex quantum communication and quantum computing protocols.

Re-evaluating the necessity of routine laboratory monitoring during isotretinoin therapy for acne

In this letter,we discuss the topic of necessity of routine laboratory monitoring during isotretinoin treatment for acne.According to Park and colleagues,it is advisable to monitor the levels of triglycerides,alanine aminotransferase,and aspartate aminotransferase every 5 to 6 months.Additionally,the levels of total cholesterol and low-density lipoprotein should be checked within the first two months of treatment.Isotretinoin is a commonly prescribed agent mainly used to treat acne.Despite its high effectiveness,it necessitates regular monitoring of laboratory parameters due to its side effect profile.Currently,there remains a lack of consensus on the appropriate frequency for monitoring these parameters during treatment with isotretinoin.This letter will provide insight into this complex and controversial topic.Based on existing literature,we concluded that the incidence of changes in lipid and liver aminotransferase levels during isotretinoin treatment for acne was low and likely clinically insignificant.For generally healthy people,we recommend testing lipid and liver profiles once at baseline and a second time at the peak dosage.However,frequent testing might still be beneficial in certain populations of patients.

含血管内皮生长因子缓释微粒显微缝线促进大鼠小血管吻合后的内皮再生

背景:血管内皮生长因子具有成血管作用,目前国内构建血管内皮生长因子缓释微粒缝线预防血管吻合术后并发症方面的报道较少。目的:合成含血管内皮生长因子的缓释微粒缝线,评估其对大鼠小血管吻合后血管再生的作用。方法:采用乳化分散法制备包裹血管内皮生长因子的可生物降解高分子聚乳酸/乙醇酸共聚物微粒,将其负载于显微缝线中,制备含血管内皮生长因子缓释微粒显微缝线。取90只SD大鼠,制作尾动脉血管吻合模型,随机分2组,实验组采用含血管内皮生长因子缓释微粒显微缝线进行吻合,对照组采用普通显微缝线进行吻合,吻合后2 h、12 h、1 d、3 d、7 d,观察两组并发症发生情况、外周血血管内皮生长因子水平及血管吻合处苏木精-伊红染色结果。结果与结论:(1)并发症情况:实验组术后皮肤坏死发生率明显小于对照组(P<0.05);(2)血管内皮生长因子水平:实验组术后不同时间点的外周血血管内皮生长因子水平均高于对照组(P<0.05);(3)苏木精-伊红染色:实验组血管吻合后1 d,吻合口缝线附近可见增生的内皮细胞;吻合后3 d,小血管吻合口两端缝线附近可见大量增生的内皮细胞和内皮下组织,完成覆盖缝线;吻合后1周,内皮细胞及内弹性膜修复完全,平滑肌细胞进一步增生,外膜恢复正常。对照组血管吻合后1 d,吻合口缝线附近表现为创伤后细胞变性坏死,仅外膜层细胞浸润并呈创伤性增生反应;吻合后3 d,内皮细胞脱落区出现新生内皮细胞,并出现生长移行,吻合口开始有少量内皮细胞覆盖;吻合后5-7 d,新生的内皮细胞爬过吻合口裂隙并覆盖缝线;(4)结果表明:含血管内皮生长因子缓释微粒显微缝线可促进大鼠小血管吻合内皮的再生。

PK-15细胞微载体悬浮培养及PCV2增殖工艺研究

研究表明,PCV2仅在PK15等少数哺乳动物细胞上增殖,但由于PCV2毒力弱,且不产生细胞病变,获得高滴度病毒难度较大[1]。因此,PCV2的培养滴度高低已成为制约现有疫苗质量的关键瓶颈之一。为建立在生物反应器内微载体逐级放大培养PK-15细胞和增殖PCV2技术,本研究以德国Sartorius14L生物反应器微载体悬浮培养PK-15细胞,对PK-15细胞初始接种密度、搅拌转速、微载体浓度、PCV2接毒时间、接毒剂量、收毒时间等工艺参数进行了摸索和优化[2-3]。结果表明:3g/L的微载体和60r/min的搅拌转速下,采用0.5×106cells/mL的初始接种密度操作工艺可获得最佳PK-15细胞生长效能。细胞生长后6h接毒,采用感染复数(MOI)为0.5的接毒比例,细胞接毒后在微载体上生长96h可获得最高的PCV2增殖滴度108.5TCID50/mL,利用该工艺,经过消化转移将PK-15细胞从14L反应器放大至42L反应器,微载体上细胞贴附均匀、生长旺盛,42L反应器中培养72h细胞密度可达39.0×105cells/mL,病毒滴度108.3TCID50/mL,应用生物反应器培养PCV2滴度较常规转瓶培养工艺提高了近10倍。进一步表明PCV2悬浮培养放大与接毒工艺稳定,为下一步实现工业级规模化生产奠定基础。

Experimental observation of topological large-area pseudo-spin-momentum-locking waveguide states with exceptional robustness

Unlike conventional topological edge states confined at a domain wall between two topologically distinct media,the recently proposed large-area topological waveguide states in three-layer heterostructures,which consist of a domain featuring Dirac points sandwiched between two domains of different topologies,have introduced the mode width degree of freedom for more flexible manipulation of electromagnetic waves.Until now,the experimental realizations of photonic large-area topological waveguide states have been exclusively based on quantum Hall and quantum valley-Hall systems.We propose a new way to create large-area topological waveguide states based on the photonic quantum spin-Hall system and observe their unique feature of pseudo-spin-momentum-locking unidirectional propagation for the first time in experiments.Moreover,due to the new effect provided by the mode width degree of freedom,the propagation of these large-area quantum spin-Hall waveguide states exhibits unusually strong robustness against defects,e.g.,large voids with size reaching several unit cells,which has not been reported previously.Finally,practical applications,such as topological channel intersection and topological energy concentrator,are further demonstrated based on these novel states.Our work not only completes the last member of such states in the photonic quantum Hall,quantum valley-Hall,and quantum spin-Hall family,but also provides further opportunities for high-capacity energy transport with tunable mode width and exceptional robustness in integrated photonic devices and on-chip communications.

热处理工艺对FGH96合金惯性摩擦焊组织与显微硬度的影响

采用惯性摩擦焊接方法进行了FGH96高温合金焊接,借助光学显微镜、扫描电子显微镜、显微硬度仪对焊态和热处理态FGH96惯性摩擦焊接头组织和显微硬度进行了研究.结果表明,焊缝中心区内发生完全动态再结晶,再结晶晶粒细小,晶粒尺寸为4.6μm±0.3μm,且二次γ′相完全溶解,导致硬度低于母材组织.随着远离焊缝,二次γ′相含量逐渐增加,距焊缝1.5 mm后γ′相体积分数基本保持不变,但γ′相形貌由球形逐渐向立方体转变,导致硬度逐渐增加.经热处理后,焊缝区域内二次γ′相的含量与形貌变化规律与焊态相似,但热处理后基材晶粒尺寸从11.4μm±0.3μm增大至13.5μm±1.0μm,是导致热处理后基材硬度较焊态较低的原因;另外热处理后三次γ′相的析出是导致热处理态焊缝硬度高于焊态的原因.

一种新的基于类内不平衡数据学习支持向量机算法

本文以不平衡支持向量机算法为基础,有效应用以往样本集中类内结构信息数据,重点对不平衡数据集进行研究和分析,并提出新的不平衡支持向量机算法,新的算法以类内离散度为基础,仿真实验数据结果证明,经过改进的算法非常有效,可进一步提升G-means值和SE值。

膜分离特色化工实验项目和教学资源的建设及应用

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