Insight into the Impact of Oxidative Stress on the Barrier Properties of Lipid Bilayer Models

As a new field of oxidative stress-based therapy, cold physical plasma is a promising tool for several biomedical applications due to its potential to create a broad diversity of reactive oxygen and nitrogen species (RONS). Although proposed, the impact of plasma-derived RONS on the cell membrane lipids and properties is not fully understood. For this purpose, the changes in the lipid bilayer functionality under oxidative stress generated by an argon plasma jet (kINPen) were investigated by electrochemical techniques. In addition, liquid chromatography-tandem mass spectrometry was employed to analyze the plasma-induced modifications on the model lipids. Various asymmetric bilayers mimicking the structure and properties of the erythrocyte cell membrane were transferred onto a gold electrode surface by Langmuir-Blodgett/Langmuir-Schaefer deposition techniques. A strong impact of cholesterol on membrane permeabilization by plasma-derived species was revealed. Moreover, the maintenance of the barrier properties is influenced by the chemical composition of the head group. Mainly the head group size and its hydrogen bonding capacities are relevant, and phosphatidylcholines are significantly more susceptible than phosphatidylserines and other lipid classes, underlining the high relevance of this lipid class in membrane dynamics and cell physiology.     

Determination of IgG1 and IgG3 SARS-CoV-2 Spike Protein and Nucleocapsid Binding—Who Is Binding Who and Why?

The involvement of immunoglobulin (Ig) G3 in the humoral immune response to SARS-CoV-2 infection has been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) in COVID-19. The exact molecular mechanism is unknown, but it is thought to involve this IgG subtype’s differential ability to fix, complement and stimulate cytokine release. We examined the binding of convalescent patient antibodies to immobilized nucleocapsids and spike proteins by matrix-assisted laser desorption/ionization–time of flight (MALDI-ToF) mass spectrometry. IgG3 was a major immunoglobulin found in all samples. Differential analysis of the spectral signatures found for the nucleocapsid versus the spike protein demonstrated that the predominant humoral immune response to the nucleocapsid was IgG3, whilst for the spike protein it was IgG1. However, the spike protein displayed a strong affinity for IgG3 itself, as it would bind from control plasma samples, as well as from those previously infected with SARS-CoV-2, similar to the way protein G binds IgG1. Furthermore, detailed spectral analysis indicated that a mass shift consistent with hyper-glycosylation or glycation was a characteristic of the IgG3 captured by the spike protein.     

双色激光产生太赫兹辐射的调控机理研究

采用双色激光在气体介质中诱导产生太赫兹波的数值模拟方法,深入分析了各种激光参数对双色激光场产生太赫兹波的影响,目的是优化参数以实现太赫兹波辐射能量的最大化。模拟计算表明,双色激光的波长、相对相位、激光脉冲宽度等对瞬态电流和太赫兹能量都有调控作用,并且具有不同的规律性。此外,还通过分析激光电场、电子密度、光电流等相关因素,对双色激光场产生太赫兹波的物理机理进行了解释。该研究为在不同激光激发条件下提高太赫兹波辐射强度,提供了详尽的参数优化分析和理论支持,对后续大幅增强太赫兹辐射效率具有重要意义。     

煅烧温度对环保型莫来石多孔陶瓷结构和性能的影响

莫来石多孔陶瓷因其高强度和耐腐蚀等性能得到广泛地应用。然而,由于合成莫来石的原料高岭土的不可再生性及持续上涨的价格,寻找廉价易得的替代原料对于合成莫来石多孔陶瓷迫在眉睫。建筑废弃物的成分与高岭土相似,可作为高岭土的可行替代品之一。以建筑废弃物和Al₂O₃为主要原料,AlF₃为晶须催化剂,B₂O₃为烧结助剂,成功制备了环保型莫来石多孔陶瓷。通过阿基米德排水法、XRD和SEM等表征手段,深入探究了多孔陶瓷的晶相、微观形貌和物理化学特性。同时,研究了煅烧温度对莫来石多孔陶瓷结构和性能的影响规律及作用机制。结果表明,适当提升煅烧温度有助于莫来石晶须的生成,但过高的温度会导致晶须粗化和晶粒增大。当煅烧温度为1 200 ℃时,莫来石晶须的生长形貌最佳,晶须直径约为0.05—0.1 μm、长度为0.5—1 μm、长径比在15—20之间。随着煅烧温度增加,莫来石多孔陶瓷的开口孔隙率不断降低,抗折强度不断增强。当煅烧温度为1 200 ℃时,样品的开口孔隙率达到（61.78±0.72 ）%,抗折强度达到（3.74±0.46） MPa。因此,以建筑废弃物为主要原料可成功制备具有高气孔率的莫来石多孔陶瓷。本研究为建筑废弃物合成莫来石多孔陶瓷提供了可靠的理论支持,对降低生产成本及推动建筑废弃物资源化再利用等有重要理论价值和实际意义。     

一种新型结构碳材料——碳管套碳纳米丝

以氢气和甲烷为气源,利用钟罩式微波等离子体化学气相沉积(MW PCVD)系统制备了一种新型结构碳材料——碳管套碳纳米丝,用扫描电子显微镜和拉曼光谱仪对它的形态结构和成份进行了分析。这种新型结构碳材料,具有与碳纳米管、碳纳米丝相似的性质,并在某些领域(如电子源探针、纳米电子器件等)具有很好的应用前景。     

PROPERTIES OF W/Cu FGMS CONTAINING 1%TiC OR 1%La2O3 PREPARED USING GSUHP

W / Cu functionally gradient materials (FGMs) containing 1%La_2O_3 and 1%TiC were prepared using graded sintering under ultra-high pressure (GSUHP). The specimens have been found to exhibit low porosity (11.57% and 11.35%, respectively). Shearing strength of the specimens between layers is good. Moreover, the specimens have still demonstrated good performance in testing thermal-shock resistance. When power density of laser is 200MWm~(-2), the specimens have been tested for thermal-shock resistance (1000 times); the specimens that contained 1%La_2O_3 were not subjected to damage, whereas those that contained 1%TiC began to crack. Finally, effect of additives on thermal-shock resistance was also preliminarily discussed.     

The Predictive Role of Plasma Biomarkers in the Evolution of Aortopathies Associated with Congenital Heart Malformations

Dilatation of the aorta is a constantly evolving condition that can lead to the ultimate life-threatening event, acute aortic dissection. Recent research has tried to identify quantifiable biomarkers, with both diagnostic and prognostic roles in different aortopathies. Most studies have focused on the bicuspid aortic valve, the most frequent congenital heart disease (CHD), and majorly evolved around matrix metalloproteinases (MMPs). Other candidate biomarkers, such as asymmetric dimethylarginine, soluble receptor for advanced glycation end-products or transforming growth factor beta have also gained a lot of attention recently. Most of the aortic anomalies and dilatation-related studies have reported expression variation of tissular biomarkers. The ultimate goal remains, though, the identification of biomarkers among the serum plasma, with the upregulation of circulating MMP-1, MMP-2, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1), asymmetric dimethylarginine (ADMA), soluble receptor for advanced glycation end-products (sRAGE) and transforming growth factor beta (TGF-β) being reported in association to several aortopathies and related complications in recent research. These molecules are apparently quantifiable from the early ages and have been linked to several CHDs and hereditary aortopathies. Pediatric data on the matter is still limited, and further studies are warranted to elucidate the role of plasmatic biomarkers in the long term follow-up of potentially evolving congenital aortopathies.     

Biocompatibility and Mechanical Stability of Nanopatterned Titanium Films on Stainless Steel Vascular Stents

Nanoporous ceramic coatings such as titania are promoted to produce drug-free cardiovascular stents with a low risk of in-stent restenosis (ISR) because of their selectivity towards vascular cell proliferation. The brittle coatings applied on stents are prone to cracking because they are subjected to plastic deformation during implantation. This study aims to overcome this problem by using a unique process without refraining from biocompatibility. Accordingly, a titanium film with 1 µm thickness was deposited on 316 LVM stainless-steel sheets using magnetron sputtering. Then, the samples were anodized to produce nanoporous oxide. The nanoporous oxide was removed by ultrasonication, leaving an approximately 500 nm metallic titanium layer with a nanopatterned surface. XPS studies revealed the presence of a 5 nm-thick TiO₂ surface layer with a trace amount of fluorinated titanium on nanopatterned surfaces. Oxygen plasma treatment of the nanopatterned surface produced an additional 5 nm-thick fluoride-free oxide layer. The samples did not exhibit any cracking or spallation during plastic deformation. Cell viability studies showed that nanopatterned surfaces stimulate endothelial cell proliferation while reducing the proliferation of smooth muscle cells. Plasma treatment further accelerated the proliferation of endothelial cells. Activation of blood platelets did not occur on oxygen plasma-treated, fluoride-free nanopatterned surfaces. The presented surface treatment method can also be applied to other stent materials such as CoCr, nitinol, and orthopedic implants.     

铁矿石的烧结基础特性之新概念

长期以来,人们对烧结用铁矿石的评价主要集中在化学成分、粒度组成、矿物特征等常温性能方面,而对铁矿石在烧结过程中的高温行为和作用知之甚少.根据对这一问题的深入思考和实验室的基础研究,提出了\     

Ambient flash sintering of reduced graphene oxide/zirconia composites:Role of reduced graphene oxide

Fabrication of graphene/ceramic composites commonly requires a high-temperature sintering step with long times as well as a vacuum or inert atmosphere,which not only results in property degradation but also significant equipment complexity and manufacturing costs.In this work,the ambient flash sintering behavior of reduced graphene oxide/3 mol% yttria-stabilized ZrO₂(rGO/3 YSZ) composites utilizing rGO as both a composite component and a conductive additive is reported.When the sintering condition is carefully optimized,a dense and conductive composite can be achieved at room temperature and in the air within 20 s.The role of the rGO in the FS of the rGO/3 YSZ composites is elucidated,especially with the assistance of a separate investigation on the thermal runaway behavior of the rGO.The work suggests a promising fabrication route for rGO/ceramic composites where the vacuum and furnace are not needed,which is of interest in terms of simplifying the fabrication equipment for energy and cost savings.