Stress Relaxation Behaviors of Monocrystalline Silicon Coated with Amorphous SiO2 Film:A Molecular Dynamics Study

Long-lasting constant loading commonly exists in silicon-based microelectronic con-tact,as well as the chemical mechanical polishing area.In this work,the stres...     

Efficient conversion of fructose to 5-hydroxymethylfurfural over sulfated porous carbon catalyst

Sulfated porous carbon (PC-SO3H) catalyst was successfully synthesized from one-pot treatment of porous polydivinylbenzene in H2SO4 at 250 C, which exhibited very good catalytic performances in the production of 5-hydroxymethylfurfural from fructose.     

煤浆浓度和颗粒分布对煤浆黏度预测的影响

采用神华煤制备煤浆,分析了颗粒粒径比λ和小颗粒体积分数ξ对双峰分布浆体黏度的影响,根据浆体黏度的关联式预测了煤浆的黏度并且与实验结果进行了比较。结果表明,采用双峰分布的颗粒制浆可以有效地降低浆体的黏度,同时可以获得较大的浆体体积分数 。在相同体积分数下,随着颗粒粒径比λ的增加,浆体的黏度迅速下降。当小颗粒体积分数ξ_dp1为35%时,浆体的黏度最小。采用Ouchiyama模型计算浆体的最大体积分数Φ_m与实验值较为吻合,而浆体的本质黏度[μ]基本保持不变。考虑λ和小颗粒体积分数ξ对双峰分布浆体的最大体积分数Φ_m的影响,可以采用单峰分布浆体的黏度关联式预测双峰分布浆体的黏度。     

Synthesis of fluorinated hyperbranched polymers capable as highly hydrophobic and oleophobic coating materials

A series of coating materials were prepared from two classes of hyperbranched polymers containing short fluorocarbon chains (HPEFs/HPUFs). The obtained hyperbranched polymers were characterized by FT-IR, ¹H NMR, ¹³C NMR, ¹⁹F NMR, GPC and TG analyses. HPEFs/HPUFs exhibited very low surface free energies (13.67-24.49 mJ/m²) which almost are independent of their internal backbone but dependent on the terminal fluorocarbon chains. Highly hydrophobic and/or oleophobic surfaces of cotton woven fabric can be achieved from these polymers by solution-immersion coating method. The static and dynamic wettabilities of the HPEFs/HPUFs treated fabrics have been investigated. The static contact angles reached to 146°, 122° and 102° for water, hexadecane and decane, respectively. The lowest contact angle hysteresis reached to 5.9°.     

Morphine-induced conditioned place preference in mice: Metabolomic profiling of brain tissue to find “molecular switch” of drug abuse by gas chromatography/mass spectrometry

Conditioned place preference (CPP) is a widely used model to explore the mechanism of context-dependent learning. In this work, we developed a GC–MS method to investigate the metabolites in mice brain which was used to study the mechanism of context-dependent learning associated with rewarding effect of morphine. Metabolites were extracted from brain tissues and derivatized followed by analysis by gas chromatography/mass spectrometry (GC–MS). In total, 69 peaks were identified as known compounds. By a Wilcoxon ran sum test with p value ≤0.05, 21 metabolites were selected and considered as the potential biomarkers of morphine in mice brain. Using principal component analysis (PCA) and receiver-operator characteristic (ROC) curves, a model was constructed with a combination of these 21 metabolic markers. Multivariate statistics of the model yielded separation between the two groups with an area under the curve value of 0.947. Some metabolites were further discussed in detail about their pathway. Results showed that our technique can be successfully applied to profile for biomarkers and in understanding molecular mechanisms of drug abuse.     

Ultrathin Alternating Copolymer Nanotubes with Readily Tunable Surface Functionalities

Well‐defined ultrathin nanotubes (30 nm in diameter and of micrometer‐scale length) were generated through the self‐assembly of a novel alternative copolymer synthesized using an epoxy–thiol click‐chemistry reaction. The self‐assembly mechanism was investigated both by experiments and using dissipative particle dynamics (DPD) simulations. The obtained nanotubes can be readily functionalized with carboxy groups, amino groups, peptides, or other groups by simple modular click copolymerization.     

Computational Drug Repurposing Based on a Recommendation System and Drug–Drug Functional Pathway Similarity

Drug repurposing identifies new clinical indications for existing drugs. It can be used to overcome common problems associated with cancers, such as heterogeneity and resistance to established therapies, by rapidly adapting known drugs for new treatment. In this study, we utilized a recommendation system learning model to prioritize candidate cancer drugs. We designed a drug–drug pathway functional similarity by integrating multiple genetic and epigenetic alterations such as gene expression, copy number variation (CNV), and DNA methylation. When compared with other similarities, such as SMILES chemical structures and drug targets based on the protein–protein interaction network, our approach provided better interpretable models capturing drug response mechanisms. Furthermore, our approach can achieve comparable accuracy when evaluated with other learning models based on large public datasets (CCLE and GDSC). A case study about the Erlotinib and OSI-906 (Linsitinib) indicated that they have a synergistic effect to reduce the growth rate of tumors, which is an alternative targeted therapy option for patients. Taken together, our computational method characterized drug response from the viewpoint of a multi-omics pathway and systematically predicted candidate cancer drugs with similar therapeutic effects.     

TRIM45 causes neuronal damage by aggravating microglia-mediated neuroinflammation upon cerebral ischemia and reperfusion injury

Excessive and unresolved neuroinflammation is a key component of the pathological cascade in brain injuries such as ischemic stroke. Tripartite motif-containing 45 (TRIM45) is a ubiquitin E3 ligase involved in various critical biological processes. However, the role of TRIM45 in cerebral ischemia remains unknown. Here, we found that the TRIM45 protein was highly expressed in the peri-infarct areas of mice subjected to cerebral ischemia and reperfusion injury induced by middle cerebral artery occlusion. This study systemically evaluated the putative role of TRIM45 in the regulation of neuroinflammation during ischemic injury and the potential underlying mechanisms. We found that TRIM45 knockdown significantly decreased proinflammatory cytokine and chemokine production in primary cultured microglia challenged with oxygen-glucose deprivation and reoxygenation (OGD/R) treatment. Mechanistically, we demonstrated that TRIM45 constitutively interacted with TAB2 and consequently facilitated the Lys-63-linked polyubiquitination of TAB2, leading to the formation of the TAB1–TAK1–TAB2 complex and activation of TAK1, which was ultimately followed by activation of the nuclear factor-kappa B (NF-κB) signaling pathway. In an in vitro coculture Transwell system, downregulation of TRIM45 expression also inhibited the OGD/R-induced activation of microglia and alleviated neuronal apoptosis. More importantly, microglia-specific knockdown of TRIM45 in mice significantly reduced the infarct size, mitigated neurological deficit scores, and improved cognitive function after ischemic stroke. Taken together, our study reveals that the TRIM45–TAB2 axis is a crucial checkpoint that controls NF-κB signaling in microglia during cerebral ischemia and reperfusion injury. Therefore, targeting TRIM45 may be an attractive therapeutic strategy.Subject terms: Cell death in the nervous system, Stroke     

Zinc-Guided 3D Graphene for Thermally Chargeable Supercapacitors to Harvest Low-Grade Heat

Low-grade heat energy recycling is the key technology of waste-heat utilization, which needs to be improved. Here, we use a zinc-assisted solid-state pyrolysis route to prepare zinc-guided 3D graphene (ZnG), a 3D porous graphene with the interconnected structure. The obtained ZnG, with a high specific surface area of 1817 m²·g⁻¹ and abundant micropores and mesopores, gives a specific capacitance of 139 F·g⁻¹ in a neutral electrolyte when used as electrode material for supercapacitors. At a high current density of 8 A·g⁻¹, the capacitance retention is 93% after 10,000 cycles. When ZnG is used for thermally chargeable supercapacitors, the thermoelectric conversion of the low-grade heat energy is successfully realized. This work thus provides a demonstration for low-grade heat energy conversion.     

交叉克尔非线性对二阶非线性诱导透明的影响

考虑耦合介质存在交叉克尔非线性的情形下,研究了交叉克尔效应对耦合双谐振腔中二阶非线性诱导透明的影响.首先给出了描述体系理论模型的哈密顿量,再通过对海森堡-朗之万方程进行线性化,得到了探测场的透射率,进而得出系统的吸收和色散关系.研究结果表明,在交叉克尔非线性强度较小时,可忽略其对诱导透明的影响;随着交叉克尔非线性强度的增大,诱导透明窗口宽度随之快速变窄.此外,吸收曲线中还出现了双吸收峰.进一步增强交叉克尔非线性,导致原本出现的诱导透明消失,并在新吸收峰处产生了新的诱导透明,新的诱导透明的吸收零点位置随着交叉克尔非线性增加而向左偏移.这些结果可能在不透明介质的窄窗口光传输和提高光学腔的性能方面提供一些参考.