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The development of powerful and general methods to acquire ubiquitin (Ub) chains has prompted the deciphering of Ub-mediated processes. Herein, the cysteine-aminoethylation assisted chemical ubiquitination (CAACU) strategy is extended and improved to enable the efficient semi-synthesis of atypical Ub chain analogues and Ub-based probes. Combining the Cys aminoethylation and the auxiliary-mediated protein ligation, several linkage- and length-defined atypical Ub chains including di-Ubs, K27C-linked tri-Ub, K11/K48C-branched tri-Ub, and even the SUMOlated Ub are successfully prepared from recombinantly expressed starting materials at about a 9-20 mg L-1 expression level. In addition, the utility of this strategy is demonstrated with the synthesis of a novel non-hydrolyzable di-Ub PA probe, which may provide a new useful tool for the mechanistic studies of deubiquitinase (DUB) recognition.

Li4Ti5O12 nanosheets (LTONS) embedded in three-dimensional amorphous carbon (3DAC) are fabricated by a facile hydrothermal method. Structure and morphology analyses confirm that the Li2TiO3 impurity phase is effectively suppressed in LTONS@3DAC and that the stacking of LTONS is also significantly inhibited in the porous matrix of the 3DAC, helpfully increasing the lithium ion diffusion coefficient. Compared to LTONS, LTONS@3DAC has a greatly enhanced electrochemical performance, including superior rate capabilities of 146, 142, and 140 mAh g−1 at the current rates of 32, 48, and 64 C, respectively, and an excellent cycling stability of 140 mAh g−1 after 700 cycles at 8 C. Therefore, the LTONS@3DAC composite is promising for applications in superior-rate lithium-ion batteries.

A novel structure of bondwire and microstrip lines for Chip-to-Chip inter-connection up to 130GHz is firstly pre-sented in this paper. Its realization is based on PCB heterogeneous integration process. In order to reduce its high inserted loss which mainly caused of high inductance of the bondwire, the microstrip line of the structure is then optimized. Simulated results show that the minimum insertion loss of 1.0 dB for the structure can be achieved, with the bandwidth more than 35 GHz in bands of 100-135 GHz.

Guanylate cyclase C (GC-C) is an important receptor protein expressed by intestinal epithelial cells, and its dysregulation leads to severe intestinal diseases. Linaclotide is a 14-amino acid peptide approved by the FDA for the treatment of irritable bowel syndrome with constipation (IBS-C), which activates guanylate cyclase C to accelerate intestinal transit. Drug molecule design based on structural information plays a crucial role and the activity of linaclotide still need to improve, while the structure of linaclotide remains unknown. In this work, linaclotide and its d -enantiomer were obtained through Fmoc solid phase peptide synthesis method and co-crystalized through racemic crystallization. The crystal structure showed that linaclotide has a tight, three-beta turns structure immobilized by three pairs of disulfide bonds.

Snake toxin Calciseptine as a natural antagonist of L-type calcium channel has potential drug values, but its structural information remains unknown. Here, we report the total chemical synthesis of Calciseptine by using hydrazide based native chemical ligation. The crystal structure of Calciseptine was determined by racemic protein crystallography technique. Compared to the structure of its homologous family protein, we found that Calciseptine is adopting a typical three-finger structure.

Graphene materials have recently experienced rapid developments, but large-scale production of high-quality graphene is still desired. Electrochemical exfoliation method is considered as a promising approach to meet this requirement. Here we demonstrate a non-electrified electrochemical exfoliation method to produce high-quality graphene (NEEG) sheets. By direct electrochemical reaction between graphite powders and metallic Li in 1 M LiPF6/propylene carbonate electrolyte, continuous graphite exfoliation is achieved with a high yield of excess 80% without any consumption of electric energy. The as-prepared NEEG has high quality with few defects (ID/IG = 0.45), a high C/O ratio of 27.74 and excellent electronic conductivity of 102.5 S cm−1. As conductive additives in Li4Ti5O12 electrode for lithium ion batteries, NEEG contributes to higher capacity and initial coulombic efficiency than common thermally reduced graphene oxide. Given the advantages of NEEG, the non-electrified electrochemical exfoliation method is promising for the large-scale preparation of high-quality graphene sheets.

Multilayer composites are effective to improve the toughness of Tungsten (W). To demonstrate the toughing mechanism, a series of W/Ti multilayer composites are prepared by diffusion bonding at different temperatures in a spark plasma sintering system. It shows that the mechanical properties of the composites vary with the change of bonding temperature, which is closely related with the microstructures developed at different bonding temperatures. The bending strength of the composites bonding at 1100 °C is highest, which reaches 1847 MPa. However, the composites bonding at 1200 °C has absorbed the highest fracture energy during three-point bending tests. The different microstructures developed at different bonding temperatures are mainly due to the different diffusion behaviors of W and Ti elements. The activation energy of W diffusion into Ti and Ti diffusion into W is 87.69 KJ/mol and 152.20 KJ/mol, respectively. And the diffusion coefficient of W into Ti is two orders of magnitude higher than that of Ti into W. Thus, β-Ti has formed in the Ti layer due to W diffusion into Ti. Although α-Ti is precipitated in the β-Ti, solid solution strengthening is the main strengthening mechanism in the Ti layer. The toughening mechanism of the W/Ti multilayer composites is mainly crack deflection, and the plastic deformation of the Ti layer. Meanwhile, the fracture modes of these composites are proposed.

An efficient method for the assembly of polyUb chains using auxiliary-modified Ub isomers is reported. This strategy takes advantages of auxiliary-mediated native chemical ligation between the distal Ub C-terminal hydrazide and the auxiliary of proximal Ub. Using removable protecting groups, Lys48-linked and Lys6-linked tri-Ub and even a mixed-linkage Lys6, Lys48-linked triUb in multimilligram quantities was made. These results demonstrate that this strategy yields natural polyubiquitin chains of desired length and linkage by using Ub isomer.

MoO2 nanoparticle-modified Li4Ti5O12 materials were prepared via a facile solution-based method. X-ray diffraction patterns (XRD) and high resolution transmission electron microscopy (HRTEM) analyses revealed that the MoO2 nanoparticles were anchored on the surface of spinel Li4Ti5O12, and energy dispersive X-ray spectroscopy (EDX) mapping indicated the MoO2 nanoparticles distributed uniformly. Compared with the pristine Li4Ti5O12, the appropriate amount of MoO2 on the surface of the Li4Ti5O12 could not only effectively reduce the electrochemical polarization of Li4Ti5O12, but also contribute to specific capacity for lithium storage. The 3% MoO2 modified Li4Ti5O12 exhibited excellent rate capability of 116 mA h g−1 at 10 C, and superior cycling performance of 124 mA h g−1 after 450 cycles at 5 C. Since the MoO2 modification process was easy to handle and the source of Mo has affordable costs, MoO2-modified Li4Ti5O12 would be promising for industrial application.

Mechanical properties of tungsten (W) multilayer composites can be modified by the toughening layers and interfacial microstructure between W layer and toughening layer. The W/Ta multilayer composite usually shows low tensile strength and toughness because of the low strength of Ta layers and large bonding strength between W layer and Ta layer. In order to improve the strength and toughness of the W/Ta multilayer composite, Ti intermediate layers with different thickness ranging from 30 µm to 100 µm have been added between W layer and Ta layer to get a kind of W/Ti/Ta/Ti multilayer composites. It can be found that the thickness of the Ti layer has a large effect on the microstructure and mechanical properties of the W/Ta multilayer composites. The solid solution with pure β-Ti and β-Ta are formed in the Ti layer when the thickness of Ti layer is lower than 50 µm. Ti layer composed of β-Ti, β-Ta and α precipitates is developed when the thickness of Ti layer is larger than 80 µm. The comprehensive mechanical properties of the W/Ta multilayer composites increase as the thickness of Ti intermediate layer increases. The tensile strength of the W/Ti/Ta/Ti multilayer composites is up to 642 MPa, which is much higher than that of the W/Ta multilayer composites (274 MPa). The tensile strength of these multilayer composites can be evaluated by a modified mix model considering the interfacial stress concentration factor. As the fracture mechanism of the W/Ta multilayer composites is also modified by addition of the Ti layer, the toughness of the W/Ti/Ta/Ti multilayer composites is improved because of the delamination along with the W/Ti interface and plastic deformation of the Ti/Ta/Ti layer in plane stress condition.

The effect of propylene carbonate (PC)-Li + solvation structures on graphite exfoliation was investigated over a range of concentrations of PC-based electrolytes. At low concentrations of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) in PC (1.3 M and 2.1 M), the graphite anode was exfoliated. However, the graphite exfoliation could be effectively suppressed when the concentrations of dissolved LiTFSI were increased to 2.5 M and 3.3 M. The results of spectroscopic analyses and density functional theory (DFT) calculations revealed that electrochemical exfoliation of the graphite anode is closely associated with a special spatial configuration of Li + -(PC) n (1 ≤ n ≤ 4) solvation structures at various Li-salt concentrations and corresponding solid electrolyte interface (SEI) film formation mechanisms. When the concentration of LiTFSI increased from 1.3 to 3.3 M, the spatial configuration of Li + -(PC) n (1 ≤ n ≤ 4) solvation gradually changed from a tetrahedron (occupied space of 10.19 A) to planar (occupied space of 3.05 A), which reduced the structure change for co-intercalation into the graphite interlayers of Li + -(PC) n (1 ≤ n ≤ 4) solvates. Meanwhile, the affinity between Li + -(PC) n (1 ≤ n ≤ 4) solvation cations and TFSI − anions was increased, leading to the significant contribution of TFSI − anions to SEI formation on the surface of graphite. Additionally, Al corrosion was not of concern in concentrated LiTFSI electrolyte. The 3.3 M LiTFSI/PC concentrated electrolyte exhibits promising electrochemical performance in graphite||LiNi 1/3 Co 1/3 Mn 1/3 O 2 full cells.

The cubic Ca/Ta-substituted Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 (LLCZTO) electrolytes were synthesized at 800 °C with Li3BO3 as additives. The optimal amount of Li3BO3 and its influences on the microstructure, crystal structures, Li+ conductivity and the stability of the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 were studied by SEM, XRD and EIS. Among all the samples, when the molar ratio of Li3BO3 to the Li6.55(La2.95Ca0.05)(Zr1.5Ta0.5)O12 is 4:5, the highest Li+ conductivity of 1.33 × 10−4 S cm−1 at 30 °C is obtained. When the LLCZTO samples are exposed in air, the Li+ conductivity is deteriorated possibly owing to the side reactions between the LLCZTO and the H2O or CO2 in the air. The Li3BO3 addition can alleviate such deterioration of the Li+ conductivity.

Li3.9Cr0.3Ti4.8O12 nanofibers with one-dimensional (1D) morphology and excellent electrical conductivity are prepared via a facile electrospinning technique. The as-prepared Li3.9Cr0.3Ti4.8O12 nanofibers exhibit excellent lithium storage performance with superior rate capability and low-temperature performance: 140 mAh g−1 at 10 C and 91 mAh g−1 at 50 C rates at room temperature, 100 mAh g−1 at 1 C rate at −20 °C. The superior electrochemical performance of Li3.9Cr0.3Ti4.8O12 nanofibers is attributed to the 1D nano-architectures composed of nanocrystals and the reduced grain size in Li3.9Cr0.3Ti4.8O12, both of which facilitate the Li+ ion transport. The Li3.9Cr0.3Ti4.8O12 nanofibers also have a high Ti3+ concentration and an in-situ surface coating layer of Li2CrO4, which could enhance intraparticle and interparticle electronic conductivities of Li3.9Cr0.3Ti4.8O12 grains, respectively.

In order to show the formation mechanism of {001}〈210〉 orientation, a Ta-2.5W alloy was cold rolled to a large strain when many microbands are aligned with rolling direction. The {001}〈210〉 orientation is usually developed in a deformation band with normal direction//〈001〉 next to {111}〈110〉 orientation. The {001}〈210〉 and {111}〈110〉 orientations share a common rotation axis of 〈111〉 and a highly stressed slip system of {110}〈111〉. The orientation relationship between {001}〈210〉 and {111}〈110〉 orientations could be a twin relationship (60°/〈111〉). The {001}〈210〉 orientation is probably developed by the rotation of intra-grain deformation bands, which is related with the shear banding and rigid body rotation. When the strain reaches 90%, deformation bands are crossed by shear bands and the orientations are changed. However, the {001}〈210〉 orientation can still be seen. The {001}〈210〉 oriented grains grow larger during subsequent annealing at 1223 K to 1323 K attribute to the coincident site lattice interfaces.

Native chemical ligation combined with desulfurization has become a powerful strategy for the chemical synthesis of proteins. Here we describe the use of a new thiol additive, methyl thioglycolate, to accomplish one-pot native chemical ligation and metal-free desulfurization for chemical protein synthesis. This one-pot strategy was used to prepare ubiquitin from two or three peptide segments. Circular dichroism spectroscopy and racemic protein X-ray crystallography confirmed the correct folding of ubiquitin. Our results demonstrate that proteins synthesized chemically by streamlined 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis coupled with a one-pot ligation-desulfurization strategy can supply useful molecules with sufficient purity for crystallographic studies.

Tungsten (W) laminate materials are very promising to improve the fracture toughness of tungsten. In this study, four kinds of tungsten laminated composites with different interlayers, including Ta, Ti, Ti/Ta/Ti, and W layers, are fabricated by spark plasma sintering (SPS). Compared with the W/W, W/Ti and W/Ta multilayer composites, the W/Ti/Ta composites exhibit the highest tensile strength (581 MPa) and elongation (7.9%). It shows that a gradual decrease of strength and a gradual increase of ductility from the W layer to the Ta layer can be obtained in the W/Ti/Ta multilayer composites. The tensile strength of these multilayer composites can be approximately predicted by the modified rule of mix. The toughening mechanism can be attributed to the energy dissipation caused by interfacial debonding, plastic deformation of interlayers, and crack bridging of the intermediate layer. The results show that the mechanical properties of the different tungsten-based multilayers are closely related to the toughening interlayers, which is beneficial to design tungsten laminates with high strength and toughness.

The effect of tungsten content on deformation texture and microstructure of Ta-W alloy is studied. It is found that the increase of tungsten content results in the strengthening of α-fiber and the weakening of γ-fiber in Ta-W alloys. The volume fraction of γ-fiber developed in Ta-10W alloy is lower than that in Ta-2.5W alloys. Meanwhile, a more significant through-thickness texture gradient is formed in Ta-10W alloy. The addition of tungsten has an important effect on the ability cross-slip of dislocations. Therefore, more dislocation loops and activated slip systems can be seen in Ta-2.5W alloy. The size of the dislocation cells in Ta-2.5W alloy is larger than that in Ta-10W alloy. As shear bands tends to appear in γ-fiber, the density of shear bands in the Ta-2.5W alloy is much higher than that of Ta-10W alloy at the same reduction strain. Meanwhile, the wavelength of the wavy shear bands in Ta-10W alloy is smaller than that in Ta-2.5W alloy. In Ta-10W alloy, new grains with Goss orientation can be seen in periodic shear bands developed in {111} orientations, which is different from that in Ta-2.5W alloy.