The supramolecular self-assembly of diphenylalanine(FF)-based peptides have been the focus of considerable research in the field of supramolecular chemistry and biomaterials over the past few years. Due to the structural diversity, facile functionalization and excellent biocompatibility, the diphenylalanine-based assemblies are extremely attractive as building blocks for various applications such as nanofabrication and tissue engineering. This review aims to introduce the recent advances in the self-assembly of diphenylalanine-based peptides, from the molecular design, structural control and applications. Specifically, we summarize the diphenylalanine-based peptides with different chemical groups, such as acetyl, aromatic ring, amino acid, and short peptides. Meanwhile, we highlight the various strategies and methods for controlling the self-assembly behavior and structure of assemblies, including solvent, interface, vapor, co-assembly and enzymatic assembly. Moreover, we introduce the applications of the diphenylalanine-based nanomaterials, such as the templates for nanomaterials fabrication, elements in sensors, carriers for drug delivery and scaffolds for tissue engineering & regeneration. In addition, the problems existed in this field and the key issues for further research were also discussed in this review.

Contents
1 Introduction
2 Molecular design of FF-based peptides
3 Structural control of FF-based assemblies
3.1 pH and temperature
3.2 Solvents
3.3 Interfaces
3.4 Vapors
3.5 Co-assembly
3.6 Enzymatic self-assembly
4 Applications of FF-based nanomaterials
4.1 Nanofabrication
4.2 Sensors
4.3 Drug delivery
4.4 Tissue engineering and regeneration
4.5 Other applications
5 Conclusion and outlook

Photocatalytic reactions take place under much milder conditions compared to conventional catalytic systems, and can make full use of solar energy as the light source. Also, photocatalytic reactions avoids the use of powerful oxidants, hazardous reductants and toxic substances, which meet the demand of energy saving and environment protection. Photocatalysts are low-cost, nontoxic, possess stable physical and chemical properties and high activity on organic compounds synthesis even after used several times. The high selective activity to target product can be achieved by optimizing the photocatalytic reaction system, thus offering a green and energy-efficient route for organic compounds synthesis. The type of catalysts on photocatalytic selective synthesis of organic compounds, influencing factors of selectivity and the way to improve the selectivity in recent years are reviewed in this paper. The review especially focuses on crystal form of photocatalysts, synthesis and surface modification of catalysts, different tapes of solvents, conditions of photocatalytic reaction and other factors to the organic synthesis of photocatalytic selective, such as polymerization, hydroxylation of aromatic, oxidation of amine, epoxidation of olefins and carbonylation. Finally, the application and development of photocatalysis in selective organic synthesis are prospected.

Contents
1 Introduction
2 TiO₂ photocatalysis in organic selective synthesis
2.1 Polymerization
2.2 Hydroxylation of aromatic
2.3 Oxidation of amine
2.4 Epoxidation of olefins
2.5 Carbonylation
3 The other new catalyst in organic selective synthesis
3.1 Polyoxometalate
3.2 g-C₃N₄
3.3 V₂O₅
3.4 CdS
4 Conclusion and outlook

The Thorpe-Ingold effect and its advances in both theoretical and experimental studies are introduced briefly. Its recent applications in cyclizations for formations of three-, four-, five-, and six-membered ring products are reviewed. The Thorpe-Ingold effect can promote intra- and intermolecular cyclizations effectively, accelerating reaction rates and improving yields in cyclizations. The effect exerts its influence in reactions through steric hindrance and/or electronic effect and is impacted by catalysts and solvents in some cases. Application of the effect can help some difficult cyclization reactions to occur smoothly, affording the desired products in good yields.

Contents
1 Thorpe-Ingold effect
2 Application in cyclizations involving formations of three-membered ring products
2.1 Cyclopropane derivatives
2.2 Ethylene oxide derivatives
3 Application in cyclizations involving formations of four-membered ring products
3.1 Cyclobutane deivatives
3.2 Oxacyclobutane derivatives
4 Application in cyclizations involving formations of five-membered ring products
4.1 Cyclopentane derivatives
4.2 Azacyclopentane derivatives
4.3 Oxacyclopentane derivatives
4.4 Thiazolidine derivatives
4.5 Phosphacyclopentane derivatives
4.6 Silicacyclopentane derivatives
5 Application in cyclizations involving formations of six-membered ring products
5.1 Cyclohexane derivatives
5.2 Azacyclohexane derivatives
5.3 Oxacyclohexane derivatives
5.4 Silicacyclohexane derivatives
6 Miscellaneous
7 Summary and prospects

Chiral homoallylic alcohols are important drug intermediates for synthesis of pharmaceutical molecules and nature products. Asymmetric carbonyl-ene reaction is a powerful tool for the preparation of them. The chiral catalysts reported include chiral organometallic complexs and chiral organic molecules, which have achieved good catalytic activity and enantioselectivity. This paper reviews the application of various types of chiral catalysts in asymmetric carbonyl-ene reactions, the reaction mechanism of asymmetric induction, the effect of the structure of the catalysts and reaction conditions on the catalytic activity and enantioselectivity.

Contents
1 Introduction
2 Application of chiral organometallic catalysts in carbonyl-ene reaction
2.1 Chiral alkaline earth metal catalyst
2.2 Chiral transition metal catalyst
2.3 Chiral indium catalyst
3 Chiral organocatalyst
3.1 Chiral phosphorus amide
3.2 Chiral binaphthol and its derivatives
4 Conclusion and outlook

Carbene polymerization of α-diazocarbonyl compounds is a new type reaction which has been developed in recent years for the synthesis of functional polymers with an ester group at every backbone carbon atom. Carbene polymerization which differs from traditional and classic vinyl polymerizations offers a convenient and useful method to obtain polyolefins, leading to a wide range of applications in various fields. This review describes the carbene polymerization of diazo compounds (diazoacetate, diazoacetamide, α-diazoketone) in the presence of transition metals (such as copper, palladium and rhodium) and the relevant mechanisms. Besides, the copolymerizations of α-diazo compound with each other, as well as other kinds of reagents, are indicated in detail. Moreover, the carbene (co)polymerization of bisdiazo compounds are introduced. Finally, the future outlook of carbene polymerization is suggested.

Contents
1 Introduction
2 Carbene polymerizations of diazo compounds
2.1 Palladium-mediated carbene polymerizations of diazo compounds
2.2 Rhodium-mediated polymerizations of diazo compounds
2.3 Copolymerizations of diazo compounds
2.4 Carbene polymerizations of bisdiazo compounds
3 Copolymerizations of carbene polymerization with other kinds of monomers
3.1 Copolymerization of carbene with alkene
3.2 Copolymerization of carbene with alkyne
3.3 Copolymerization of carbene polymerization with cyclic monomer
4 Conclusion and outlook

Surface-enhanced Raman scattering (SERS) technology has revealed considerably potential application in the field of life science due to its ultrasensitive detectability and non-destructivity, which is considered as a powerful tool for detection of nucleic acid. The article reviews recent advances in SERS-based detection of nucleic acids, including labeled and label-free detections as well as other methods. The principles and detection strategies of these different methods are introduced, especially the labeled detection using SERS tags via sandwich structure and hairpin structure. We also made a detailed explanation of the basic structure of SERS tags and their recent developments. By analyzing the detection strategies and summarizing recent achievements, some issues related to SERS-based nucleic acid detection techniques are also discussed.

Contents
1 Introduction
2 Principle of SERS enhancement
3 Nucleic acid detection based on SERS
3.1 Label-free detection
3.2 Labeled detection
3.3 SERS-based other methods
4 Conclusion and outlook

Histone deacetylase inhibitor is a novel class of histone deacetylase targeted anti-cancer drug, which takes excellent effects on anti-proliferation, pro-apoptosis, pro-differentiation, cell cycle arrest, anti-angiogenesis and so on. Histone deacetylase inhibitor plays an important role in the development of anticancer drug with its unique anti-tumor mechanism. Among the histone deacetylase inhibitors, the cyclopeptide histone deacetylase inhibitor with the most complicated structure has good antagonism on various types of solid tumors and hematologic cancer. In this review, the structural features of the metal binding region, the surface recognition region and the linker region of natural and synthetic cyclic peptide histone deacetylase inhibitors are summarized, and the inhibitory activity and anti-tumor proliferative activity of various inhibitors are described. Modification of different structure domains can make inhibitors with high efficiency and specificity on different tumor cells. We expect to find the structure rule of the high efficient and low toxic targeted peptide inhibitors through structure-activity relationships, providing new sights for investigation of anti-cancer drugs.

Contents
1 Introduction
2 Histone deacetylase inhibitors and classification
3 Cyclopeptide histone deacetylase inhibitors
3.1 Cyclopeptide histone deacetylase inhibitors containing ketone
3.2 Cyclopeptide histone deacetylase inhibitors containing hydroxamic acid
3.3 Cyclopeptide histone deacetylase inhibitors containing sulfur
3.4 Cyclopeptide histone deacetylase inhibitors containing carboxylic acid or amide
3.5 Other histone deacetylase inhibitors
4 Conclusion

The conformational variability of linear peptides affects the strength and selectivity of receptor binding. In contrast, cyclopeptides adopt more rigid and conformationally constrained structures than their linear analogues, as the cyclization could lead to a restricted mobility of the peptide skeleton. Therefore, the cyclization is one of the important ways to improve the biological stability and physiological activity of the peptides. Furthermore, cyclopeptides are important building blocks in molecular material chemistry and life science, working in diverse areas such as physiological processes, nanoscale materials, and supramolecular chemistry. They are used to study the physiological process, construct transmembrane nanotube channels in order to transport molecules and ions, recognize molecules, anions, and cations. In recent years, the researchers pay more attention to the interaction of biological molecules and metal ions, especially with cyclopeptides as the models. In this paper, we review the research progress of the metal ion recognition functions of cyclopeptides. Alkali and alkaline earth metals, transition metals (such as Cu, Zn and Ni), heavy metals, and lanthanides are discussed. A major focus has been on the influencing factors to the metal ion affinity and selectivity. The challenges and prospects of the metal ion recognition are also discussed concisely.

Contents
1 Introduction
2 The research progress of the metal ion recognition functions of cyclopeptides
2.1 Alkali and alkaline earth metals
2.2 Transition metals
2.3 Heavy metals
2.4 Lanthanides
3 Outlook

Arsenic pollution has posed increasingly severe threat to human health, therefore, dealing with the problem of arsenic contamination in water bodies is extremely urgent. Iron and manganese oxides/carbon composite materials, characterized in superior adsorption properties, strong performance of separation and regeneration potentials, have received more and more concern in recent years. Especially, novel carbon-based nano materials such as carbon nanotubes and graphene have high specific surface area and possess a wealth of surface functional groups, providing good conditions for the loading of iron/manganese oxides. Moreover, finer particle size of iron/manganese oxides can be formed on the surface of carbon-based materials, offering more adsorption sites for the adsorption of arsenic. In this paper, we have purposively focused on the synthesis methods of Fe-Mn oxides/carbon composite materials from the domestic and foreign research programs. The advantages and disadvantages of the synthesis of this material were compared, and the removal effects and adsorption mechanisms of arsenic by this adsorbent were elucidated. Furthermore, the regeneration potential of iron and manganese oxides/carbon composite materials was analyzed and the existing deficiencies of this material in practical application were proposed. Finally, the development trend of arsenic removal in water bodies by this new composite material was forecasted.

Contents
1 Introduction
2 Preparation of iron and manganese oxides/carbon composite materials
2.1 Iron/manganese oxides
2.2 Iron and manganese oxides/ activated carbon
2.3 Iron and manganese oxides/carbon nanotubes
2.4 Iron and manganese oxides/ graphene
3 Influencing factors of arsenic removal from water by iron and manganese oxides/carbon composite materials
3.1 Properties of composite materials
3.2 Environmental conditions
4 Adsorption mechanisms of arsenic by iron and manganese oxides/ carbon composite materials
5 Regenerability
6 Conclusion and outlook

In this paper, we review the preparation methods of carbon nanotube (CNT)/graphene composite materials for the electrode of supercapacitors, and introduce the developments of CNT/graphene/pseudo-capacitive material ternary composite materials with highly electrochemical performance. The rational designed CNT/graphene composite nanostructures could largely utilize the characteristics of carbon nanomaterials for electrochemical double-large supercapacitors, such as large specific area, high conductivity and befitting porous structure, and also achieve large mass loading of pseudo-capacitive materials with high dispersion for pseudo-capacitors. As a result, these composite materials are promising candidates for the electrode materials of high-performance supercapacitors with high capacitance, excellent rate performance and long lifetime.

Contents
1 Introduction
2 The preparation strategies of carbon nanotube/graphene composites
2.1 The assembling based on π-π interaction
2.2 The assembling based on electrostatic attraction
2.3 In-situ growth
2.4 Other methods
3 Ternary composite electrodes based on graphene, carbon nanotube and pseudo-capacitive materials
3.1 Carbon nanotube/graphene/conductive polymer
3.2 Carbon nanotube/graphene/metallic oxides (hydroxides)
4 Conclusion

As a new generation of energy conversion devices, solid oxide fuel cells (SOFC) and solid oxide electrolysis cells (SOEC) are of great importance with the advantage of highly efficient energy conversion in a clean way. For the commercialization of SOFC and SOEC technologies, operation at the intermediate-low temperature (IT) is the current major research direction all over the world, which are beneficial for the operation of SOFC and SOEC more durably and economically. The key point is how to improve the oxygen reduction reaction (ORR) or oxygen evolution reaction (OER) activity of oxygen electrodes. In this review, the important roles of atomic-scale molecular simulation and in-situ experimental characterization are mainly illustrated to provide insight and understanding on the oxygen transport mechanism analysis. These fundamental studies could put forward the progress from traditional materials and structures to novel designs and concepts. The recent R&D oxygen electrodes of mixed ionic electronic conducting (MIEC) materials, the corresponding ion migration paths, anisotropic structures and lattice dynamics are summarized in detail. The current advanced research methods and characterizations are introduced focusing on the in-situ X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) for probing the surface chemical composition and structure of materials. With in-situ methods, a several nanometers to tens of nanometers structure of the dense film could be visualized that made the study of the formation and migration of charged defects of oxygen electrode material feasible. Oxygen transport mechanisms in the traditional materials and novel materials at atomic scale are analyzed by the results of density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Furthermore, the research progress of oxygen electrodes at INET in Tsinghua University is briefly introduced.

Contents
1 Introduction
2 Oxygen electrode materials
2.1 Mixed ionic electronic conductor (MIEC) oxygen electrode
2.2 Perovskite oxides
2.3 Ruddlesden-popper series of layered oxides
2.4 Layered double perovskites oxides
3 The current research methods
3.1 Pulsed laser deposition (PLD)
3.2 Thin film characterization
3.3 Computational methods
4 Oxygen transport mechanisms in oxygen electrode
4.1 Oxygen bulk diffusion in oxygen electrode
4.2 Oxygen surface exchange in oxygen electrode
5 The research progress of INET in Tsinghua University on the oxygen electrode of the solid oxide cells
6 Conclusions

With the expanding of lithium-ion battery applications, novel cathode/anode materials with high capacity, long cycle life and excellent rate capability are in great demand. SnS₂ is deemed to be one of potential alternative anode materials for its unique layer structure and high theoretical capacity. However, it suffers from large initial irreversible capacity, low electrical conductivity and huge volume change during charge/discharge process, which limit its practical application. In the present paper, the development history and latest progress of SnS₂ anode material are reviewed. The basic properties of SnS₂ are described. The approaches for improving the electrochemical performance of SnS₂ are summarized, including micromorphology control of nanoparticles, preparation of SnS₂/C and SnS₂/oxide composites, bulk-doping, making integrative electrode, optimizing binder, etc. The influences of processing parameters (raw material, concentration, ratio, pH value, hydrothermal temperature and time) of hydrothermal (solovthermal) methods on the structure and electrochemical performance of the prepared SnS₂ and SnS₂/C composites are expounded. Besides, the problems associated with SnS₂ anode materials are also discussed. Nanostructured SnS₂ with high specific area, such as sheet- and flowerlike-shaped particles, is proved to be beneficial for cycle performance. Compositing SnS₂ with different kinds of carbon can enhance the structure stability as well as electrical conductivity, and hence improve the cycle performance and rate capability of electrode. The optimized SnS₂/graphene composite exhibits high specific capacity (over 1000 mAh/g), stable cycling performance and excellent rate capability, which make it a promising high capacity anode material for lithium-ion batteries.

Contents
1 Introduction
2 Basic properties of SnS₂ anode materials
3 Approaches for improving the electrochemical performance of SnS₂ materials
3.1 Early studies
3.2 Micromorphology control of SnS₂ nanomaterials
3.3 SnS₂/C composite materials
3.4 Other methods
4 Conclusion and outlook

High energy density, high capacity, high work voltage, low cost, highly safe rechargeable battery is the future development directions of storage battery technology. High-energy density Mg ion battery (MIB) is rechargeable battery with Mg or Mg alloy as anode. Mg ion battery is the most promising and important new type of green storage battery applicable in electric vehicle. The slow diffusion of Mg ion in the cathode material is one reason for the slow development of Mg ion battery. Thus, in this paper, we review five types of crystal structured Mg-transition metal complex oxides with one-dimensional tunnel structure, two-dimensional layer structure, three-dimensional spinel structure, three-dimensional NASICON structure, three-dimensional olivine structure, the preparation method and the electrahemical properties. Further, we also illustrate the diffusion performance of Mg ion in the solid cathode and the measures to improve the slowness diffusion. Finally, we point out the possible research directions of Mg-transition metal complex as cathode materials for Mg ion batteries in the future. Searching for high-energy density, high-capacity, high-voltage cathode materials and the compatible electrolyte is the key to realizing the third breakthrough of the Mg ion battery. We hope that this paper is favorable for understanding the cathode materials of Mg ion battery, promoting the development of Mg ion battery.

Contents
1 Introduction
2 One-dimensional tunnel structure
3 Two-dimensional layer structure
3.1 Mg-Ni-O
3.2 Mg-Ti-O
3.3 Mg-V-O
4 Three-dimensional spinel structure
4.1 Mg-Mn-O
4.2 Mg-Co-O
4.3 Mg-Fe-O
5 Three-dimensional post-spinel structure
6 Three-dimensional NASICON structure
7 Three-dimensional olivine structure
7.1 Mg-Fe-P-O
7.2 Mg-V-P-O-F
7.3 Mg-Mn-Si-O
7.4 Mg-Fe-Si-O
7.5 Mg-Co-Si-O
7.6 Mg-Ni-Si-O
8 Mg diffusion in the solid cathode
9 Outlook

Redox cofactor plays an important role in maintaining cellular redox balance and driving catabolic or anabolic reactions. As the driving force of biochemical reactions and redox carriers, redox cofactor has received much attention for enhancing biotransformation process in recent years. The Gram-negative bacterium Escherichia coli (E. coli) has been studied extensively on a fundamental and applied level and has become a predominant host microorganism for industrial applications. Metabolic engineering of E. coli for the enhanced biochemical production such as bioethanol, organic acids, biopolymer, complex natural compounds and so on, has been significantly promoted by the redox cofactor engineering. This review introduced various strategies to improve productivity and product titers by engineered E. coli through metabolic engineering pathways and key enzymes involved redox cofactor. Advanced metabolic engineering strategies in redox cofactor include metabolic engineering of pathway involved in NAD(P)H biosynthesis, mutual transformation of redox cofactor, expression of heterogeneous redox cofactor dependent enzymes, manipulation of pyridine biosynthesis and NAD⁺ transportation. These strategies have been successfully implemented in recombinant E. coli to increase cellular availability of desired redox cofactor or change cofactor specificity of key enzymes. While current cofactor strategies just focus on natural metabolic pathways and enzymes, novel strategy needs to be developed for manipulating redox cofactor completely according to the will of the human.

Contents
1 Introduction
2 Metabolic engineering of pathways involved in NAD(P)H biosynthesis
2.1 Pentose phosphate pathway
2.2 Glyoxylate bypass
2.3 Pyruvate metabolic pathway
3 Mutual transformation of redox cofactor
3.1 Transhydrogenase system
3.2 NAD⁺ kinase and NADH kinase
4 Expression of Heterogeneous redox cofactor dependent enzymes
4.1 Heterogeneous NAD(P)⁺-dependent enzymes
4.2 Heterogeneous NAD(P)H-dependent enzymes
5 Manipulation of pyridine biosynthesis and NAD⁺ transportation
6 Perspectives