地塞米松对脓毒血症鼠Peyer小结Tfh细胞的影响

目的：测定脓毒血症鼠Peyer小结内滤泡辅助性T细胞（T follicular helper,Tfh）的变化,分析地塞米松（dexamethasone,Dex）对脓毒血症Tfh细胞的可能作用。方法：昆明小鼠诱导脓毒血症模型,模型诱导成功后随机分2组,脓毒血症组（SE组,n=12）、脓毒血症＋Dex处理组（DE组,n=12）。另设对照组（NC组,n=12）。测定血清白介素-6（interleukin-6,IL-6）、降钙素原（procalcitonin,PCT）、中性粒细胞明胶酶相关载脂蛋白（neutrophil gelatinase-associated lipocalin,NGAL）水平。Peyer小结Ⅰ型1-磷酸鞘氨醇（Sphingosine 1-Phosphate 1,S1P1）、CXC趋化因子配体13（CXC chemokine ligand 13,CXCL13）免疫组化染色。Western blot分别检测Peyer小结IL-21、程序性死亡分子-1（programmed death 1,PD-1）、胞嘧啶脱氨酶（enzyme activation-induced cytidine deaminase,AID）蛋白的表达。流式细胞仪测定3组Peyer小结Tfh细胞占T淋巴细胞的百分率。结果：与NC组相比,SE组血清IL-6（19.7±5.20 vs 10.7±3.60 ng·L~（-1））、PCT（1.56±0.92 vs 0.31±0.09μg·L~（-1））、NGAL（0.44±0.11 vs 0.35±0.09 mg·L（-1））升高（P〈0.05或0.01）,Peyer小结S1P1（0.22±0.06 vs 0.14±0.04）、CXCL13（0.25±0.07 vs 0.15±0.04）的表达增加（P〈0.01）,IL-21（0.60±0.08 vs 0.35±0.08）、PD-1（0.30±0.04 vs 0.20±0.05）、AID（0.23±0.05 vs 0.18±0.03）蛋白的表达亦升高（P〈0.05或0.01）,Tfh细胞占T淋巴细胞（8.30±2.00 vs 5.69 vs 1.64%）的百分率升高（P〈0.01）。Dex治疗可降低SE鼠血清IL-6（19.7±5.20 vs 12.8±3.40 ng·L~（-1））、PCT（1.56±0.92 vs 0.71±0.44μg·L~（-1））水平（P〈0.05或0.01）,降低Peyer小结S1P1（0.22±0.06 vs 0.17±0.05）、CXCL13（0.25±0.07 vs 0.19±0.06）的表达（P〈0.05或0.01）,下调Peyer小结IL-21（0.60±0.08 vs 0.48±0.09）、PD-1（0.30±0.04 vs 0.26±0.06）、AID（0.23±0.05 vs0.19±0.04）蛋白的表达（P〈0.05）,降低Tfh细胞占T淋巴细胞（8.30±2.00 vs 6.56±1.59%）的百分率（P〈0.05）。结论：Peyer小结Tfh细胞可能参与脓毒血症的发病机制,Dex抑制Peyer小结Tfh的活化,对Peyer小结微环境起保护作用。     

Analysis of The Working Performance of Large Curvature Prestressed Concrete Box Girder Bridges

Based on numerical shape functions and the structural stressing state theory, the mechanical properties of the curved prestressed concrete box girder (CPCBG) bridge model under different loading cases are presented. First, the generalized strain energy density (GSED) obtained from the measured strain data is used to represent the stressing state pattern of the structure; then, the stressing state of the concrete section is analyzed by plotting the strain and stress fields of the bridge model. The stressing state pattern and strain fields of the CPCBG are shown to reveal its mechanical properties. In addition, the measured concrete strain data are interpolated by the non-sample point interpolation (NPI) method. The strain and stress fields of the bridge model have been plotted to analyze the stressing state of the concrete cross-section. The internal forces in the concrete sections are calculated by using interpolated strains. Finally, the torsional effects are simulated by measuring the displacements to show the torsional behavior of the cross-section. The analysis and comparison of the internal force and strain fields reveal the common and different mechanical properties of the bridge model. The results of the analysis of the curved bridge model provide a reference for the future rational design of bridge projects.     

A Coupled CFD-DEM Study on the Effect of Basset Force Aimed at the Motion of a Single Bubble

The physical meaning of Basset force is first studied via polynomial approximation and the Fourier series representation method. After compiling the Basset force into the coupling interface with Visual C, a dynamic mathematical model is set up to describe the upward motion behavior of a single bubble by adopting the CFD-DEM method. Afterwards, the coupling interface with Basset force proposed in this study is verified experimentally and shows very good agreements. The initial velocity, releasing depth, bubble size, density ratio and viscosity ratio are studied qualitatively due to their great importance to Basset force. The ratio of Basset force to the sum of Basset force and drag force and to buoyancy, F→Ba/(F→D+F→Ba) and |F→Ba/F→B|, are employed to quantify the contribution of Basset force quantitatively. In addition, some instructive outlooks and recommendations on a further development of appropriate and justifiable use of Basset force are highlighted at last.     

Constructing Heterogeneous Photocatalysts Based on Carbon Nitride Nanosheets and Graphene Quantum Dots for Highly Efficient Photocatalytic Hydrogen Generation

Although graphitic carbon nitride nanosheets (CNs) with atomic thickness are considered as promising materials for hydrogen production, the wide band gap (3.06 eV) and rapid recombination of the photogenerated electron–hole pairs impede their applications. To address the above challenges, we synergized atomically thin CNs and graphene quantum dots (GQDs), which were fabricated as 2D/0D Van der Waals heterojunctions, for H₂ generation in this study. The experimental characterizations indicated that the addition of GQDs to the π-conjugated system of CNs can expand the visible light absorption band. Additionally, the surface photovoltage spectroscopy (SPV) confirmed that introducing GQDs into CNs can facilitate the transport of photoinduced carriers in the melon chain, thus suppressing the recombination of charge carriers in body. As a result, the H₂ production activity of the Van der Waals heterojunctions was 9.62 times higher than CNs. This study provides an effective strategy for designing metal-free Van der Waals hetero-structured photocatalysts with high photocatalytic activity.     

Morphology,Microstructure, and Mechanical Properties of S32101 Duplex Stainless-Steel Joints in K-TIG Welding

In this paper, the {"type":"entrez-protein","attrs":{"text":"S32101","term_id":"422005","term_text":"pir||S32101"}}S32101 duplex stainless steel welded joints were produced by a K-TIG welding system. The weld geometry parameters under different welding speeds were analyzed by combining the morphological characteristics of the keyhole. The microstructure and impact toughness of the base metal and weld metal zone under different welding speeds were studied. The experiment results show that the welding speed has quite an effect on the geometry profile of the weld. In addition, the characteristic parameters of the keyhole can effectively predict the geometry profile of the weld. The test results prove that the microstructure, Σ3 coincidence site lattice grain boundary, and phase boundary of ferrite and austenite have an effect on the impact property of the weld metal zone. When the proportion of the austenite, Σ3 coincidence site lattice grain boundary and random phase boundary increased, the impact property of the weld metal zone also increased.     

Superhydrophobic Anticorrosive Phosphonate–Siloxane Films Formed on Zinc with Different Surface Morphology

The composition, structure, and protective and hydrophobic properties of nanoscale films formed layer-by-layer in solutions of sodium dodecylphosphonate (SDDP) and vinyltrimethoxysilane or n-octyltriethoxysilane (OTES) on the zinc surface with different morphologies were studied by SEM, XPS, water contact angle measurements, and electrochemical and corrosion tests. The protective, hydrophobic properties of phosphonate–siloxane films on zinc and their stability in a corrosive media are determined both by the initial surface morphology and composition of the surface oxide layer, and by the nature of inhibitors. It was shown that preliminary laser texturing of the zinc surface is preferable than chemical etching to enhance the anticorrosive properties of the resulting thin films. The most stable films with excellent superhydrophobic and protective properties in atmospheres of high humidity and salt spray are formed on the zinc surface with fractal morphology during layer-by-layer passivation with SDDP and OTES.     

异种(牛)脱细胞真皮基质-游离空肠复合体构建实验研究

目的 研究异种(牛)脱细胞真皮基质-游离空肠复合体的构建技术,以期解决游离空肠移植重建长段气管术后肠腺分泌的问题。 方法 选择10只杂种犬,制备去上皮游离空肠段,将剪成合适大小的异种(牛)脱细胞真皮基质覆盖于游离空肠基底膜表面,并用覆膜镍钛合金支架支撑固定,将构建好的复合体移至腹膜外与腹部皮肤之间,分别于术后7 d、14 d、1个月、3个月和6个月后取出,查看复合体的生长情况。 结果 10只实验犬中,有1只因肠粘连和伤口感染死亡而未能完成实验,余9只实验犬术后存活良好。术后7 d、14 d肉眼观察和病理检查,在游离空肠内表面均见有异种(牛)脱细胞真皮基质成分,表面黏膜层可见部分鳞状上皮化生;术后1个月、3个月、6个月肉眼和病理检查均未再发现异种(牛)脱细胞真皮基质成分,游离空肠内表面几乎全部化生为复层鳞状上皮。 结论 合适大小的异种(牛)脱细胞真皮基质覆盖在去上皮游离空肠内表面,可以促进游离空肠内表面的鳞状上皮化生,抑制肠腺分泌。覆膜镍钛记忆合金支架有一定的弹性,可以很好的对异种(牛)脱细胞真皮基质-去上皮游离空肠复合体起到支撑固定作用。     

Investigation of Potential Use of Soybean Protein Isolate–Chinese Bayberry Tannin Extract Cross-Linked Films in Packaging Applications

The possibility of using commercial bayberry tannin (BT) from a Chinese source as a cross-linker and functional additive to develop soybean protein isolate (SPI)-based films was explored in this study by using the solvent casting method. In particular, the impacts of BT loading on the tensile strength, microstructure, thermal stability, water resistance and antioxidant capacity were fully investigated. The results reveal that SPI incorporated with BT yielded a phenolic–protein hybrid whose relevant films exhibited an improvement in tensile strength of around two times greater compared with native SPI as a result of the formed interactions and covalent cross-links, which could be proven using FTIR spectroscopy. The introduction of BT also led to the compact microstructure of SPI–BT films and enhanced the thermal stability, while the water vapor permeability was reduced compared with the control SPI film, especially at high loading content of tannin. Additionally, the use of BT significantly promoted the antioxidant capacity of the SPI-based films according to DPPH radical scavenging assay results. On this basis, Chinese bayberry tannin is considered a promising natural cross-linker and multifunctional additive that can be dedicated to developing protein-derived films with antioxidant activity for food packaging applications.     

279例耳闷胀感的病因分析

目的 探讨产生耳闷胀感的部位和原因。方法 收集耳闷胀感为主诉的279例362耳,对患耳的临床表现、鼓室导抗图、纯音测听和咽鼓管功能进行分析。结果 362耳中鼓室导抗图A型203耳、B型111耳、C型33耳以及鼓膜穿孔15耳。纯音测听表现为传导性聋、感音神经性聋、混合性聋以及正常者分别是83耳、8l耳、105耳和93耳。在362耳中,咽鼓管功能异常208耳,在A型鼓室导抗图203耳中,咽鼓管功能异常67耳。结论 产生耳闷胀感的病变部位包括外、中、内耳和面神经的病变,其中以分泌性中耳炎、各种原因引起的感音神经性聋和“咽鼓管狭窄症”为多。     

慢性鼻-鼻窦炎筛窦骨质病理形态学改变及其相关因素分析

目的:研究慢性鼻-鼻窦炎(CRS)筛窦骨质病理形态学改变的相关因素。方法:CRS患者180例,其中Ⅰ、Ⅱ和Ⅲ型各60例,鼻内镜手术中取带有筛窦黏膜的筛骨标本送病理苏木精-伊红染色,对其病理形态学改变严重程度进行分级。统计不同临床分型其病理分级的例数及所占比率。分析筛窦骨质病理改变严重程度与筛窦黏膜病理改变程度、筛窦CT分型、病程长短及是否有手术史的关系。结果:所有患者筛窦骨质发生不同程度的病理形态学改变。病理分级:Ⅰ级5例(2.78%),Ⅱ级38例(21.11%),Ⅲ级71例(39.44%),Ⅳ级66例(36.67%)。Ⅰ、Ⅱ和Ⅲ型的筛骨病理分级结果:Ⅰ型,Ⅰ级5例(8.33%),Ⅱ级33例(55.00%),Ⅲ级15例(25.00%),Ⅳ级7例(11.67%);Ⅱ型,Ⅱ级5例(8.33%),Ⅲ级37例(61.67%),Ⅳ级18例(30.00%);Ⅲ型,Ⅲ级19例(31.67%),Ⅳ级41例(68.33%)。180例CRS患者不同临床分型、筛窦黏膜病理改变严重程度、不同筛窦CT分型、病程长短及是否有手术史与筛窦骨质病理分级均差异有统计学意义(均P<0.01)。结论:CRS筛窦骨质发生不同程度的病理形态学改变,其...