Protocol for quantitative evaluation of misfolded protein degradation using Agrobacterium-mediated expression system in Nicotiana benthamiana.

Cellular protein homeostasis is maintained by the disposal of aggregated misfolded proteins. Here, we present a protocol for investigating the involvement of the proteins of interest in misfolded protein degradation via Agrobacterium-mediated transient expression in Nicotiana benthamiana. We describe in detail the steps of misfolded protein design, transient protein expression in N. benthamiana, subsequent total protein extraction, and quantification of misfolded proteins through western blotting. This generalizable system can be used for misfolded proteins derived from various plants or microbes. For complete details on the use and execution of this protocol, please refer to Ai et al.1.

Noble Metal Phosphides Supported on CoNi Metaphosphate for Efficient Overall Water Splitting.

Transition metal metaphosphates and noble metal phosphides prepared under similar conditions are potential hybrid catalysts for electrocatalytic water splitting, which is of great significance for H2 production. Herein, the structure and electrocatalytic activity of different noble metal species (i.e., Rh, Pd, Ir) on CoNiP4O12 nanoarrays have been systematically studied. Due to the different formation energies of noble metal phosphides, the phosphides of Rh (RhPx) and Pd (PdPx) as well as the noble metal Ir are obtained under the same phosphorylation conditions perspectively. RhPx/CoNiP4O12 and PdPx/CoNiP4O12 exhibit much better HER activity than Ir/CoNiP4O12 due to the advantages of phosphides. Density functional theory (DFT) calculations reveal that the extraordinary activity of RhPx/CoNiP4O12 originated from the strong affinity to H2O and optimal adsorption for H*. The best RhPx/CoNiP4O12 only requires a low overpotential of 30 and 234 mV to deliver 10 mA cm-2 for HER and OER, respectively, and therefore is effective for overall water splitting (requiring 1.57 V to achieve a current density of 10 mA cm-2). This work not only develops a novel RhPx/CoNiP4O12 electrocatalyst for overall water splitting but also provides deep insight into the formation mechanism of noble metal phosphides.

Noble Metal Phosphides: Robust Electrocatalysts toward Hydrogen Evolution Reaction.

Facing with serious carbon emission issues, the production of green H2 from electrocatalytic hydrogen evolution reaction (HER) has received extensive research interest. Almost all kinds of noble metal phosphides (NMPs) consisting of Pt-group elements (i.e., Ru, Rh, Pd, Os, Ir and Pt) are all highly active and pH-universal electrocatalysts toward HER. In this review, the recent progress of NMP-based HER electrocatalysts is summarized. It is further take typical examples for discussing important impact factors on the HER performance of NMPs, including crystalline phase, morphology, noble metal element and doping. Moreover, the synthesis and HER application of hybrid catalysts consisting of NMPs and other materials such as transition metal phosphides, oxides, sulfides and phosphates, carbon materials and noble metals is also reviewed. Reducing the use of noble metal is the key idea for NMP-based hybrid electrocatalysts, while the expanded functionality and structure-performance relationship are also noticed in this part. At last, the potential opportunities and challenges for this kind of highly active catalyst is discussed.

Heterostructures of Cut Carbon Nanotube-Filled Array of TiO2 Nanotubes for New Module of Photovoltaic Devices.

In this work, a new photovoltaic device was prepared. The device uses titanium (Ti) foil/TiO2 nanotubes as the photoanode and multi-walled carbon nanotubes (MWCNTs) as a photosensitizer. Titanium dioxide nanotube arrays (TiO2-NTs) were prepared by one-step anodic oxidation. Cut-MWCNTs with a length of less than 100 nm were obtained by the mixed-acid oxidation of MWCNTs. The two materials were combined to form a TiO2-NTs@cut-MWCNT heterostructure by electrophoresis. TiO2-NTs@cut-MWCNTs were characterized by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), which showed that the two materials were effectively combined. We fabricated the heterostructure into a photovoltaic device, showing an enhanced photocurrent response and an efficiency of 0.0138%, and explained this phenomenon by performing UV-vis absorption spectroscopy and electrochemical tests. It is hoped that this work can provide a reference value for the application of carbon nanotubes in photovoltaic devices.

Magnetic Field Enhanced Electrocatalytic Oxygen Evolution of NiFe-LDH/Co3 O4 p-n Heterojunction Supported on Nickel Foam.

Here, a strategy to regulate the electron density distribution by integrating NiFe layered double hydroxides (NiFe-LDH) nanosheets with Co3 O4 nanowires to construct the NiFe-LDH/Co3 O4 p-n heterojunction supported on nickel foam (NiFe-LDH/Co3 O4 /NF) for electrocatalytic oxygen evolution reaction (OER) is proposed. The p-n heterojunction can induce the charge redistribution in the heterogeneous interface to reach Fermi level alignment, thus modifying the adsorption free energy of *OOH and improving the intrinsic activity of the catalyst. As a result, NiFe-LDH/Co3 O4 /NF exhibits outstanding OER performance with a low overpotential of 274 mV at a current density of 50 mA cm-2 and long-time stability over 90 h. Moreover, NF can serve as a magnetic core that induces the exchange bias effect between the magnetic substrate and the active species under the action of the magnetic field, resulting in decreased magnetoresistance and weakened scattering of spin electrons, which further lowers the OER overpotential by 25 mV @ 50 mA cm-2 under a 10 000 G magnetic field. This work provides a new perspective on the design of p-n heterojunction catalysts and a deeper understanding of the magnetic field-enhanced electrocatalytic reactions.

Crystalline-Amorphous Ni2 P4 O12 /NiMoOx Nanoarrays for Alkaline Water Electrolysis: Enhanced Catalytic Activity via In Situ Surface Reconstruction.

Water electrolysis affords a promising approach to large-scale hydrogen yield, but its efficiency is restrained by the sluggish water dissociation kinetics. Here, an efficient bifunctional electrocatalyst of in situ formed crystalline nickel metaphosphate on amorphous NiMoOx nanoarrays supported on nickel foam (c-Ni2 P4 O12 /a-NiMoOx /NF) for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solution is reported. The c-Ni2 P4 O12 /a-NiMoOx /NF can deliver a current density of 10 mA cm-2 at a low potential of 78 mV for HER, and a current density of 20 mA cm-2 at an overpotential of 250 mV for OER. Moreover, it only requires a small cell voltage of 1.55 V at 10 mA cm-2 for robust water splitting with outstanding long-term durability over 84 h. Various spectroscopic studies reveal that in situ surface reconstruction is crucial for the enhanced catalytic activity, where c-Ni2 P4 O12 /a-NiMoOx is transformed into c-Ni2 P4 O12 /a-NiMoO4 during the HER process, and into c-Ni2 P4 O12 /a-NiOOH in the OER process. This work may provide a new strategy for uncovering the catalytic mechanism of crystalline-amorphous catalysts.

Smart Mn7+ Sensing via Quenching on Dual Fluorescence of Eu3+ Complex-Modified TiO2 Nanoparticles.

In this work, titania (TiO2) nanoparticles modified by Eu(TTA)3Phen complexes (ETP) were prepared by a simple solvothermal method developing a fluorescence Mn7+ pollutant sensing system. The characterization results indicate that the ETP cause structural deformation and redshifts of the UV-visible light absorptions of host TiO2 nanoparticles. The ETP also reduce the crystallinity and crystallite size of TiO2 nanoparticles. Compared with TiO2 nanoparticles modified with Eu3+ (TiO2-Eu3+), TiO2 nanoparticles modified with ETP (TiO2-ETP) exhibit significantly stronger photoluminescence under the excitation of 394 nm. Under UV excitation, TiO2-ETP nanoparticles showed blue and red emission corresponding to TiO2 and Eu3+. In addition, as the concentration of ETP in TiO2 nanoparticles increases, the PL intensity at 612 nm also increases. When ETP-modified TiO2 nanoparticles are added to an aqueous solution containing Mn7+, the fluorescence intensity of both TiO2 and ETP decreases. The evolution of the fluorescence intensity ratio (I1/I2) of TiO2 and ETP is linearly related to the concentration of Mn7+. The sensitivity of fluorescence intensity to Mn7+ concentration enables the design of dual fluorescence ratio solid particle sensors. The method proposed here is simple, accurate, efficient, and not affected by the environmental conditions.

Understanding the Effect of Second Metal on CoM (M = Ni, Cu, Zn) Metal-Organic Frameworks for Electrocatalytic Oxygen Evolution Reaction.

Co-based bimetallic metal-organic frameworks (MOFs) have emerged as a kind of promising electrocatalyst for oxygen evolution reaction (OER). However, most of present works for Co-based bimetallic MOFs are still in try-and-wrong stage, while the OER performance trend and the underlying structure-function relationship remain unclear. To address this challenge, Co-based MOFs on carbon cloth (CC) (CoM MOFs/CC, M = Zn, Ni, and Cu) are prepared through a room-temperature method, and their structure and OER performance are compared systematically. Based on the results of overpotential and Tafel slope, the order of OER activity is ordered in the decreasing sequence: CoZn MOF > CoNi MOF > CoCu MOF > Co MOF. Spectroscopic studies clearly show that the better OER performance of CoM MOFs results from the higher oxidation state of Co, which is related to the choice of second metal. Theoretical calculations indicate that CoZn MOFs possess strengthened adsorption for O-containing intermediate, and lower energy barrier towards OER. This study figures out the effect of second metal on the OER performance of Co-based bimetallic MOFs and suggests that tuning the electronic structure of the metal site can be an effective strategy for other MOFs-based OER catalysts.

FeMoO4 nanorods for efficient ambient electrochemical nitrogen reduction.

Herein, FeMoO4 nanorods are explored as an efficient electrocatalyst for nitrogen reduction reaction (NRR) in 0.1 M Na2SO4 solution, with an NH3 yield rate of 17.51 µg h-1 mg-1 and a high faradaic efficiency (FE) of 10.53%. Density functional theory (DFT) calculations reveal that surface Fe atoms are the active centers for NRR via an alternating mechanism.

[Composition analysis,antioxidative and antibacterial activities comparison of agarwood oils extracted by supercritical and steam distillation].

Agarwood is a traditional and precious medicinal material and natural spice in China and other southeast Asian countries.As the head of all spices,agarwood has many pharmacological activities such as analgesia,antidiarrheal,anti-inflammatory and antibacterial effects. Due to its high price and scarce resources,there were just a few previous studies on it,mainly focusing on the chemical compositions of the agarwood essential oil and solvent extract mixture. The components of agarwood oils obtained by supercritical extraction and steam distillation were analyzed by using Gas Chromatography-Mass Spectrometer( GC-MS),and then the agarwood oils compositions and contents were compared between the traditional extraction method and the recently emerging supercritical extraction method. Antioxidant experiments of scavenging DPPH,ABTS,hydroxyl radical,total reducing power and MIC experiments of five kinds of tester strains such as staphylococcus aureus were combined to illustrate the differences between these two kinds of agarwood oils in terms of antioxidant and bacteriostatic activities. The results showed that the main components of agarwood oil were sesquiterpenoids( 68. 68%) in steam distillation extraction method,but sesquiterpenoids( 23. 78%) and chromones( 29. 42%) in supercritical extraction method. Fourteen common components included benzyl acetone,α-santalol,γ-eudesmol,agarospirol and guaiol etc. The antioxidant activity and inhibitory MIC of agarwood oils in supercritical extraction method were better than those in steam distillation method,and the inhibitory effect of agarwood oil on the growth of bacillus subtilis was found for the first time.

Fabrication of uniform Ru-doped NiFe2O4 nanosheets as an efficient hydrogen evolution electrocatalyst.

Here we demonstrate the synthesis of uniform Ru-doped NiFe2O4 nanosheets with robust hydrogen evolution reaction (HER) activity in alkaline solution, with an extremely low overpotential of 18 mV versus a reversible hydrogen electrode (RHE) at a current density of 10 mA cm-2 and a Tafel slope of 27 mV dec-1.

Metal organic framework-derived CoPS/N-doped carbon for efficient electrocatalytic hydrogen evolution.

Electrocatalytic hydrogen evolution has attracted a great deal of attention due to the urgent need for clean energy. Herein, we demonstrate the synthesis of ternary pyrite-type cobalt phosphosulphide (CoPS) nanoparticles supported on a nitrogen-doped carbon matrix, CoPS/N-C, through carbonization and subsequent phosphosulfurization of Co-based zeolitic imidazolate frameworks (ZIF-67), as promising hydrogen evolution reaction (HER) electrocatalysts in both acidic and alkaline solutions. The polyhedral structure of ZIF-67 can be well maintained in the as-prepared CoPS/N-C nanocomposites. In particular, CoPS/N-C provides a geometric catalytic current density of -10 mA cm-2 at overpotentials of -80 and -148 mV vs. a reversible hydrogen electrode (RHE) and a Tafel slope of 68 and 78 mV dec-1 in 0.5 M H2SO4 and 1 M KOH, respectively, which is superior to most of the transition metal phosphosulfide materials. This MOF-derived synthesis of a transition metal phosphosulfide supported heteroatom-doped carbon matrix provides a promising opportunity for the development of highly efficient electrocatalysts for renewable energy devices.