DYNAMICS OF COPPER OXIDATION INVESTIGATED BY IN SITU UHV-TEM

To bridge the gap between information provided by surface science methods (adsorption of up to ~a few monolayers of oxygen) and that provided by bulk oxidation studies (typically, an oxide layer of a few microns or thicker), the initial stages of metal oxidation ¾ from nucleation to coalescence ¾ are being investigated by in situ ultra-high vacuum transmission electron microscopy (UHV-TEM). The aims of this thesis research are to gain basic insight into the complex kinetics and energetics of nano-oxide formation during the initial stages of oxidation, and fundamentally understand the distribution, stability, and morphological evolution of oxide islands since controlled oxidation is a processing tool for creating nanostructure patterns on surfaces. A systematic in situ study was carried out of the dynamic responses of Cu thin films to variations in thermodynamic variables such as temperature, oxygen pressure, strain, and crystallographic orientation. The main findings of the experiments include: 1) the universality of oxygen surface diffusion model, 2) formation of completely different oxide structure from oxide islands (disks, nanorods, dome, container pyramids) to disordered networks and almost uniform layer growth by altering the oxidation temperature and substrate orientation, 3) creation of nano-indentation arrays on metal surfaces by reducing the oxide arrays. The in situ UHV-TEM measurements of shape and size evolution of the oxides were used to gain fundamental insights into the complex kinetics and energetics of oxidation and reduction. Models based on the surfaces and strain during oxidation explained quantitatively the formation of some of the novel oxide nano-structures. A wealth of surface processes were discovered that reveal how each surface and thermodynamic condition needs to be considered for fundamentally understanding and controlling oxidation behavior

Molecular hot spots in surface-enhanced Raman scattering

The chemical and electromagnetic (EM) enhancements both contribute to surface-enhanced Raman scattering (SERS). It is well-known that the EM enhancement is induced by the intense local field of surface plasmon resonance (SPR). This report shows that the polarizability of the molecules adsorbed on the metal surface can lead to another channel for the EM field enhancement. When aromatic molecules are covalently bonded to the Au surface, they strongly interact with the plasmon, leading to a modification of the absorption spectrum and a strong SERS signal. The effect is seen in both 3 nm-Au nanoparticles with a weak SPR and 15 nm-Au nanoparticles with a strong SPR, suggesting that the coupling is through both EM field and chemical means. Linear-chain molecules on the 3 nm-Au nanoparticles do not have a SERS signal. However, when the aromatic and linear molecules are co-adsorbed, the strong SPR/molecular polarizability interaction spatially extends the local EM field, leading to a strong SERS signal from the linear-chain molecules. The results show that aromatic molecules immobilized on Au can create “hot spots” just like plasmonic nanostructures

BASIC STUDY FOR COAL MOISTURE CONTROL INTEGRATING PNEUMATIC CLASSIFICATION TECHNIQUE

A technique of coal moisture control integrating pneumatic classification with flue gas as heating medium was put forward. With this technique, refined coal moisture control can be realized accompanying classification in one process, and considerable high-quality energy can be saved in coking and milling procedure. In this paper, coal classification and moisture control behaviors was investigated at different conditions. Based on experimental results, the basic parameters for the technique were worked out accordingly

Temperature and pressure dependent Mott potentials and their influence on self-limiting oxide film growth

Classic Cabrera-Mott theory stipulates that the limited oxide-film growth results from electron tunneling from the metal through the oxide film to adsorbed oxygen. This leads to an electric field across the oxide film that assists ion migration for low-temperature oxide-film growth. Here, we show that the field-driven oxide-film growth can be manipulated via the temperature and pressure of oxidation. The magnitude of the self-generated electric field depends on the oxygen surface coverage that exhibits a Langmuir isotherm behavior with changes in temperature and oxygen pressure. These observations demonstrate the ability to tune an interfacial reaction via self-adaptation to its environment

PKD1 Phosphorylation-Dependent Degradation of SNAIL by SCF-FBXO11 Regulates Epithelial-Mesenchymal Transition and Metastasis

SummaryMetastatic dissemination is often initiated by the reactivation of an embryonic development program referred to as epithelial-mesenchymal transition (EMT). The transcription factor SNAIL promotes EMT and elicits associated pathological characteristics such as invasion, metastasis, and stemness. To better understand the posttranslational regulation of SNAIL, we performed a luciferase-based, genome-wide E3 ligase siRNA library screen and identified SCF-FBXO11 as an important E3 that targets SNAIL for ubiquitylation and degradation. Furthermore, we discovered that SNAIL degradation by FBXO11 is dependent on Ser-11 phosphorylation of SNAIL by protein kinase D1 (PKD1). FBXO11 blocks SNAIL-induced EMT, tumor initiation, and metastasis in multiple breast cancer models. These findings establish the PKD1-FBXO11-SNAIL axis as a mechanism of posttranslational regulation of EMT and cancer metastasis

SUPPLEMENTARY INFORMATION Dislocation nucleation facilitated by atomic segregation DOI: 10.1038/NMAT5034

This is a set of supplementary data and information supporting the Journal Publication 'Dislocation nucleation facilitated by atomic segregation', DOI: 10.1038/NMAT5034, and available at Journal article in Nature Materials

Mapping the scientific research on integrated care: a bibliometric and social network analysis

BackgroundIntegrated care (IC) is the cornerstone of the sustainable development of the medical and health system. A thorough examination of the existing scientific literature on IC is essential for assessing the present state of knowledge on this subject. This review seeks to offer an overview of evidence-based knowledge, pinpoint existing knowledge gaps related to IC, and identify areas requiring further research.MethodsData were retrieved from the Web of Science Core Collection, from 2010 to 2020. Bibliometrics and social network analysis were used to explore and map the knowledge structure, research hotspots, development status, academic groups and future development trends of IC.ResultsA total of 7,501 articles were obtained. The number of publications on IC was rising in general. Healthcare science services were the most common topics. The United States contributed the highest number of articles. The level of collaboration between countries and between authors was found to be relatively low. The keywords were stratified into four clusters: IC, depression, integrative medicine, and primary health care. In recent years, complementary medicine has become a hotspot and will continue to be a focus.ConclusionThe study provides a comprehensive analysis of global research hotspots and trends in IC, and highlights the characteristics, challenges, and potential solutions of IC. To address resource fragmentation, collaboration difficulties, insufficient financial incentives, and poor information sharing, international collaboration needs to be strengthened to promote value co-creation and model innovation in IC. The contribution of this study lies in enhancing people’s understanding of the current state of IC research, guiding scholars to discover new research perspectives, and providing valuable references for researchers and policymakers in designing and implementing effective IC strategies