Extracellular vesicles are a heterogeneous group of cell-derived membranous structures comprising exosomes and microvesicles, which originate from the endosomal system or which are shed from the plasma membrane, respectively They are present in biological fluids and are involved in multiple physiological and pathological processes Extracellular vesicles are now considered as an additional mechanism for intercellular communication, allowing cells to exchange proteins, lipids and genetic material Knowledge of the cellular processes that govern extracellular vesicle biology is essential to shed light on the physiological and pathological functions of these vesicles as well as on clinical applications involving their use and/or analysis However, in this expanding field, much remains unknown regarding the origin, biogenesis, secretion, targeting and fate of these vesicles

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Shedding light on the cell biology of extracellular vesicles.

The lithium metal battery is strongly considered to be one of the most promising candidates for high-energy-density energy storage devices in our modern and technology-based society. However, uncontrollable lithium dendrite growth induces poor cycling efficiency and severe safety concerns, dragging lithium metal batteries out of practical applications. This review presents a comprehensive overview of the lithium metal anode and its dendritic lithium growth. First, the working principles and technical challenges of a lithium metal anode are underscored. Specific attention is paid to the mechanistic understandings and quantitative models for solid electrolyte interphase (SEI) formation, lithium dendrite nucleation, and growth. On the basis of previous theoretical understanding and analysis, recently proposed strategies to suppress dendrite growth of lithium metal anode and some other metal anodes are reviewed. A section dedicated to the potential of full-cell lithium metal batteries for practical applicatio...

Toward Safe Lithium Metal Anode in Rechargeable Batteries: A Review.

Since the discovery of mechanically exfoliated graphene in 2004, research on ultrathin two-dimensional (2D) nanomaterials has grown exponentially in the fields of condensed matter physics, material science, chemistry, and nanotechnology. Highlighting their compelling physical, chemical, electronic, and optical properties, as well as their various potential applications, in this Review, we summarize the state-of-art progress on the ultrathin 2D nanomaterials with a particular emphasis on their recent advances. First, we introduce the unique advances on ultrathin 2D nanomaterials, followed by the description of their composition and crystal structures. The assortments of their synthetic methods are then summarized, including insights on their advantages and limitations, alongside some recommendations on suitable characterization techniques. We also discuss in detail the utilization of these ultrathin 2D nanomaterials for wide ranges of potential applications among the electronics/optoelectronics, electrocat...

Recent Advances in Ultrathin Two-Dimensional Nanomaterials

Nitrogen (N)-doped carbon materials exhibit high electrocatalytic activity for the oxygen reduction reaction (ORR), which is essential for several renewable energy systems. However, the ORR active site (or sites) is unclear, which retards further developments of high-performance catalysts. Here, we characterized the ORR active site by using newly designed graphite (highly oriented pyrolitic graphite) model catalysts with well-defined π conjugation and well-controlled doping of N species. The ORR active site is created by pyridinic N. Carbon dioxide adsorption experiments indicated that pyridinic N also creates Lewis basic sites. The specific activities per pyridinic N in the HOPG model catalysts are comparable with those of N-doped graphene powder catalysts. Thus, the ORR active sites in N-doped carbon materials are carbon atoms with Lewis basicity next to pyridinic N.

Active sites of nitrogen-doped carbon materials for oxygen reduction reaction clarified using model catalysts

The recent advances in electrocatalysis for oxygen reduction reaction (ORR) for proton exchange membrane fuel cells (PEMFCs) are thoroughly reviewed. This comprehensive Review focuses on the low- and non-platinum electrocatalysts including advanced platinum alloys, core–shell structures, palladium-based catalysts, metal oxides and chalcogenides, carbon-based non-noble metal catalysts, and metal-free catalysts. The recent development of ORR electrocatalysts with novel structures and compositions is highlighted. The understandings of the correlation between the activity and the shape, size, composition, and synthesis method are summarized. For the carbon-based materials, their performance and stability in fuel cells and comparisons with those of platinum are documented. The research directions as well as perspectives on the further development of more active and less expensive electrocatalysts are provided.

http://repository.ust.hk/ir/bitstream/1783.1-77094/1/acs.chemrev.5b00462_withlink.pdf

Recent Advances in Electrocatalysts for Oxygen Reduction Reaction

The effect of rhenium on the microstructure stability and γ/γ′ interfacial characteristics of Ni-based single crystal superalloys during long-term aging

Composite efficient ceramic core demolding process and special equipment thereof

A new ternary system of tetradecyldimethylamine oxide (C(14)DMAO)/4-phenylazo benzoic acid (AzoH)/H(2)O was first investigated, and it was found that the self-assembly can be regulated via temperature and β-cyclodextrin (β-CD) recognition. In the temperature regulated self-assembly, the self-assembled phase structural transition between wormlike micelles and multilamellar vesicles (onions) were determined by cryogenic-transmission electron microscopy (cryo-TEM) images and (2)H nuclear magnetic resonance ((2)H NMR) spectra. The phase structural transition temperatures (PSTT) controlled by changing the amount of AzoH were measured by differential scanning calorimetry analysis. The self-assembled phase structural transition mechanism was discussed. It is argued that the self-assembled phase structural transition is the synergetic balance among the hydrophilic headgroup, steric structures of the hydrophobic chain, and membrane charge. β-CD molecules were used as controlling hands to modulate the phase structural transition of self-assembly of the C(14)DMAO/AzoH/H(2)O system in solution via snatching C(14)DMAO molecules. The phase structural transitions from the threadlike micellar phase to the lamellar phase and from the lamellar phase to the vesicular phase can each be controlled because of the β-CD molecular recognition. The phase structural transitions were confirmed by cryo-TEM observations and (2)H NMR measurements. The rheological properties were also investigated to display the importance in the phase structural transition. It was found that the dye molecule, AzoH, is harder to enclose by β-CD than by C(14)DMAO because of the lower complex stability constant (i.e., K(C(14)DMAO@β-CD) ≫ K(AzoH@β-CD). Therefore, the phase structural transition is mainly controlled by the inclusion of C(14)DMAO into the hydrophobic cavity of β-CD molecules. The phase structural transition controlled via temperature and β-CD may find potential applications such as in actuators, shape memories, drug delivery systems, and drag-reducing fluids, etc.

Self-assembly in the mixtures of surfactant and dye molecule controlled via temperature and β-cyclodextrin recognition.

An efficient allylic amination of Morita–Baylis–Hillman acetates with simple aromatic amines provided good yields with excellent α-regioselectivity (up to exclusive α-product) under the catalysis of Pd2(dba)3/ferrocene-type diphosphine ligand.

Palladium-catalyzed α-regioselective allylic amination of Morita–Baylis–Hillman acetates with simple aromatic amines

CH3NH3SnI3 crystals with largest size up to 10 mm × 6 mm × 6 mm were grown in aerobic environment using cooling crystallization method. XRD analysis of the crystal powder shows that the CH3NH3SnI3 crystal grown is of cubic phase with lattice constants a = b = c = 6.2480 A. XRD and EDX results show that the chemical properties of CH3NH3SnI3 crystal are unstable in air, and the oxidation mechanism of CH3NH3SnI3 was analyzed. HRTEM shows that the CH3NH3SnI3 crystal grown is of good crystallinity. FT-IR spectrum of CH3NH3SnI3 crystal was identified. The band gap Eg of the CH3NH3SnI3 crystal is estimated to be 1.33eV according to the absorption spectrum. First-principles calculation shows the band gap of cubic CH3NH3SnI3 crystal is 1.36 eV, which is consistent with the experimental results. The thermal property of CH3NH3SnI3 is analyzed by TG/DTG analysis. Our results show that CH3NH3SnI3 crystal has potential application prospects in the field of solar cells, however its poor chemical stability in air, leading to the formation of SnI4 and SnO would limit its application in photoelectric fields.

Dong Wang

Papers

The effect of rhenium on the microstructure stability and γ/γ′ interfacial characteristics of Ni-based single crystal superalloys during long-term aging

Composite efficient ceramic core demolding process and special equipment thereof

Self-assembly in the mixtures of surfactant and dye molecule controlled via temperature and β-cyclodextrin recognition.

Palladium-catalyzed α-regioselective allylic amination of Morita–Baylis–Hillman acetates with simple aromatic amines

Structure, optical and electrical properties of CH3NH3SnI3 single crystal