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Photoelectrochemical reaction is emerging as a powerful approach for biomass conversion. However, it has been rarely explored for glucose conversion into value-added chemicals. Here we develop a photoelectrochemical approach for selective oxidation of glucose to high value-added glucaric acid by using single-atom Pt anchored on defective TiO 2 nanorod arrays as photoanode. The defective structure induced by the oxygen vacancies can modulate the charge carrier dynamics and band structure, simultaneously. With optimized oxygen vacancies, the defective TiO 2 photoanode shows greatly improved charge separation and significantly enhanced selectivity and yield of C 6 products. By decorating single-atom Pt on the defective TiO 2 photoanode, selective oxidation of glucose to glucaric acid can be achieved. In this work, defective TiO 2 with single-atom Pt achieves a photocurrent density of 1.91 mA cm −2 for glucose oxidation at 0.6 V versus reversible hydrogen electrode, leading to an 84.3 % yield of glucaric acid under simulated sunlight irradiation. Photoelectrochemical oxidation provides a promising strategy for glucaric acid production. Here, selective oxidation of glucose to glucaric acid is realized on the photoanode of defective TiO2 decorated with single-atom Pt via a photoelectrochemical strategy.

Background Menaquinone-7 (MK-7) is a valuable vitamin K 2 produced by Bacillus subtilis. Although many strategies have been adopted to increase the yield of MK-7 in B. subtilis , the effectiveness of these common approaches is not high because long metabolic synthesis pathways and numerous bypass pathways competing for precursors with MK-7 synthesis. Regarding the modification of bypass pathways, studies of common static metabolic engineering method such as knocking out genes involved in side pathway have been reported previously. Since byproductsphenylalanine(Phe), tyrosine (Tyr), tryptophan (Trp), folic acid, dihydroxybenzoate, hydroxybutanone in the MK-7 synthesis pathway are indispensable for cell growth, the complete knockout of the bypass pathway restricts cell growth, resulting in limited increase in MK-7 synthesis. Dynamic regulation via quorum sensing (QS) provides a cost-effective strategy to harmonize cell growth and product synthesis, eliminating the need for pricey inducers. SinR, a transcriptional repressor, is crucial in suppressing biofilm formation, a process closely intertwined with MK-7 biosynthesis. Given this link, we targeted SinR to construct a dynamic regulatory system, aiming to modulate MK-7 production by leveraging SinR’s regulatory influence. Results A modular PhrC-RapC-SinR QS system is developed to dynamic regulate side pathway of MK-7. In this study, first, we analyzed the SinR-based gene expression regulation system in B. subtilis 168 (BS168). We constructed a promoter library of different abilities, selected suitable promoters from the library, and performed mutation screening on the selected promoters. Furthermore, we constructed a PhrC-RapC-SinR QS system to dynamically control the synthesis of Phe, Tyr, Trp, folic acid, dihydroxybenzoate, hydroxybutanone in MK-7 synthesis in BS168. Cell growth and efficient synthesis of the MK-7 production can be dynamically balanced by this QS system. Using this system to balance cell growth and product fermentation, the MK-7 yield was ultimately increased by 6.27-fold, from 13.95 mg/L to 87.52 mg/L. Conclusion In summary, the PhrC-RapC-SinR QS system has been successfully integrated with biocatalytic functions to achieve dynamic metabolic pathway control in BS168, which has potential applicability to a large number of microorganisms to fine-tune gene expression and enhance the production of metabolites.

As an important source of nutrients, meat can supply protein, fat, vitamins and minerals, which are crucial in people's diet worldwide [...].As an important source of nutrients, meat can supply protein, fat, vitamins and minerals, which are crucial in people's diet worldwide [...].

Vanadium-based oxides are considered to be a type of promising electrode materials for Li-ion batteries due to their low cost and high theoretical capacity. However, the dissolution of vanadium (V3+), low electron conductivity and volume change during charge and discharge processes hamper their application. A novel porous structure was synthesized by hydrothermal method in this study. The hierarchical porous structure is assembled with nanoflake and coated with carbon. The hierarchical porous structure provides multitudinous reaction sites, shortens the Li-ion transfer distance and buffers the volume variety. The carbon improves the conductivity of the composite. It is also found that the tetravalent and trivalence vanadium coexists in the prepared composite. V4+ can prevent V3+ from dissolution. The synergistic effects of hierarchical porous structure, carbon coating and the coexistence of V3+ and V4+ endow the composite with excellent performance as an anode material. The composite exhibits a low resistance and sizeable capacitive effects during the charge and discharge process, which are beneficial to the energy storage performance. A discharge capacity of 439.6 mAh g−1 after 100 cycles at a current density of 0.1 A g−1 is delivered, which is 90.0% of its initial specific capacity (488.2 mAh g−1). The composite processes a decent prospect in high-performance Li-ion batteries.

Li-O2battery with high theoretical energy density can exceed the limits of Li-ion batteries and meet the demands of the future electrochemical power sources. However, superoxide radicals (O2-) from LiO2intermediate easily launch parasitic attack towards the electrolyte and/or electrode, then deteriorating the performance of Li-O2battery. In this thesis, we propose a few strategies to stabilize O2- in Li-O2batteries to achieve high-performance of Li-O2 battery.In Chapter 3, we propose that lithium acetylacetonate (LiA) can stabilize O2- via forming LiA-O2complex, which can reduce the amount of free O2- in the electrolyte and then effectively suppress the degradation of the electrolyte and the Li anode interface. Therefore, the Li | Li symmetric batteries using 0.4 M LiA/1 M bis(trifluoromethane)sulfonimide lithium salt (LiTFSI)/DMSO (0.4A1FD) not only exhibit smaller interfacial resistance less than half of that using 1 M LiTFSI/DMSO (1FD) after 17 days, but also display longer-term cycling stability up to 500 hours (vs. ~100 hours using 1FD). Furthermore, the presence of LiA leads to the preferential growth of film-like Li2O2. Finally, Li-O2batteries using 0.4A1FD acquire almost twice longer lifetime and the reduced charging overpotential (i.e., 0.53 V vs. Li+ / Li).In Chapter 4, we found that manganese(III) acetylacetonate (MnA3) can stabilize O2- in 1 M LiTFSI/ tetraethylene glycol dimethyl ether (TEGDME) by forming MnA3O2to ameliorate the stability of the 1 M LiTFSI/TEGDME (1FT) electrolyte. Meanwhile, the multivalent redox pairs of Mn cation can play a bifunctional role in the ORR and OER process. Ultimately, and the lifetime of Li-O2battery with MnA3is enhanced, which is around four-times longer than that without MnA3. In addition, the approximate performance of Li-O2battery using 30 mM LiA/1FT and 1FT implied that the MnIII, rather than acetylacetonate (acac) ligand, contributed to the enhanced performance of Li-O2battery when using MnA3/1FT. The large electrolyte resistance of LiA in DMSO also exclude the possible influence of acac ligand in the enhanced performance of Li-O2batteries using MnA3, though LiA can reduce the charge overpotential of Li-O2batteries by 0.5 V vs. Li+/Li and assist in lowering the interface resistance of the Li | Li symmetric batteries around one eleventh of that with 1FD under oxygen atmosphere.In Chapter 5, by combining the function of LiA complexing with O2- (Chapter 3) and the insoluble property of LiA in TEGDME (Chapter 4), we propose a sol containing acac ligand, TiO2-acac sol, which can not only act as a new binder, but also anchor and stabilize O2- on the cathode surface after drying process. Finally, the Li-O2batteries using the TiO2-acac sol binder display enhanced cycling performance from 100 cycles (poly(vinylidenefluoride) (PVDF) binder) to 260 cycles. Moreover, compared to the irreversible rate capability of the Li-O2battery with PVDF binder, the Li-O2battery using TiO2acac sol binder displays reversible rate capability when current density changing between 250 mA g-1 and 1000 mA g-1, demonstrating the efficiency of TiO2-acac sol binder in improving the performance of Li-O2batteries.

P - Phenyl-bridged bis-salicylaldiminato binuclear titanium complexes Ti 2 L 1 , Ti 2 L 2 and the corresponding momonuclear counterpart TiL 4 were synthesized and characterized by 1 H NMR, 13 C NMR, FT-IR, and elemental analysis. The binuclear titanium complex Ti 2 L 1 showed good catalytic performances for ethylene polymerization and copolymerization with norbornene or 1,5-hexadiene. For ethylene polymerization, the binuclear titanium complex Ti 2 L 1 exhibited highest activity of 8.70 × 10 5  g/mol(Ti) . h . atm at 70 °C and retained an activity of 3.00 × 10 5  g/mol(Ti) . h . atm at 90 °C, which showed much higher thermal stability compared with its bi- and mono-nuclear derivatives Ti 2 L 3 and TiL 4 , due probably to the rigid phenyl-bridged structure offering more stable state of active metal centers. The binuclear complex Ti 2 L 1 could catalyze ethylene copolymerization with norbornene (NB) or 1,5-hexadiene (1,5-HD) to produce copolymer bearing cyclic groups. Compared with mononuclear complex TiL 4 , the binuclear Ti 2 L 1 showed higher catalytic activity and incorporation rate of comonomer for ethylene/NB copolymerization. The mononuclear complex TiL 4 could barely catalyze the copolymerization of ethylene and 1,5-HD, however, the binuclear analogue Ti 2 L 1 exhibited an activity of 1.67 × 10 5  g/mol(Ti)·h·atm with 4.74% of incorporation rate of 1,5-HD for ethylene/1,5-HD copolymerization, implying that the bimetallic synergistic effect could greatly improve the catalytic performance of the bis-salicylaldiminato binuclear titanium complexes.

Menaquinone-7 (MK-7) is a valuable vitamin K.sub.2 produced by Bacillus subtilis. Although many strategies have been adopted to increase the yield of MK-7 in B. subtilis, the effectiveness of these common approaches is not high because long metabolic synthesis pathways and numerous bypass pathways competing for precursors with MK-7 synthesis. Regarding the modification of bypass pathways, studies of common static metabolic engineering method such as knocking out genes involved in side pathway have been reported previously. Since byproductsphenylalanine(Phe), tyrosine (Tyr), tryptophan (Trp), folic acid, dihydroxybenzoate, hydroxybutanone in the MK-7 synthesis pathway are indispensable for cell growth, the complete knockout of the bypass pathway restricts cell growth, resulting in limited increase in MK-7 synthesis. Dynamic regulation via quorum sensing (QS) provides a cost-effective strategy to harmonize cell growth and product synthesis, eliminating the need for pricey inducers. SinR, a transcriptional repressor, is crucial in suppressing biofilm formation, a process closely intertwined with MK-7 biosynthesis. Given this link, we targeted SinR to construct a dynamic regulatory system, aiming to modulate MK-7 production by leveraging SinR's regulatory influence. A modular PhrC-RapC-SinR QS system is developed to dynamic regulate side pathway of MK-7. In this study, first, we analyzed the SinR-based gene expression regulation system in B. subtilis 168 (BS168). We constructed a promoter library of different abilities, selected suitable promoters from the library, and performed mutation screening on the selected promoters. Furthermore, we constructed a PhrC-RapC-SinR QS system to dynamically control the synthesis of Phe, Tyr, Trp, folic acid, dihydroxybenzoate, hydroxybutanone in MK-7 synthesis in BS168. Cell growth and efficient synthesis of the MK-7 production can be dynamically balanced by this QS system. Using this system to balance cell growth and product fermentation, the MK-7 yield was ultimately increased by 6.27-fold, from 13.95 mg/L to 87.52 mg/L. In summary, the PhrC-RapC-SinR QS system has been successfully integrated with biocatalytic functions to achieve dynamic metabolic pathway control in BS168, which has potential applicability to a large number of microorganisms to fine-tune gene expression and enhance the production of metabolites.

A novel tandem catalysis system consisted of salicylaldiminato binuclear/mononuclear titanium and 2,6-bis(imino)pyridyl iron complexes was developed to catalyze ethylene in-situ copolymerization. Linear low-density polyethylene (LLDPE) with varying molecular weight and branching degree was successfully prepared with ethylene as the sole monomer feed. The polymerization conditions, including the reaction temperature, the Fi/Ti molar ratio, and the structures of bi- or mononuclear Ti complexes were found to greatly influence the catalytic performances and the properties of obtained polymers. The polymers were characterized by differential scanning calorimetry (DSC), high temperature gel permeation chromatography (GPC) and high temperature 13C NMR spectroscopy, and found to contain ethyl, butyl, as well as some longer branches. The binuclear titanium complexes demonstrated excellent catalytic activity (up to 8.95 × 106 g/molTi·h·atm) and showed a strong positive comonomer effect when combined with the bisiminopyridyl Fe complex. The branching degree can be tuned from 2.53 to 22.89/1000C by changing the reaction conditions or using different copolymerization pre-catalysts. The melting points, crystallinity and molecular weights of the products can also be modified accordingly. The binuclear complex Ti2L1 with methylthio sidearm showed higher capability for comonomer incorporation and produced polymers with higher branching degree and much higher molecular weight compared with the mononuclear analogue.

MnO 2 -modified Li 3 V 2 (PO 4 ) 3 /C (LVP/C) composites with plate-like structure were prepared via an improved sol–gel method followed by PVA-assisted suspension coating. The plate-like structure provides an enlarged contact area between the electrolyte and electrode, alleviating the Li + diffusion and e − transport during the reaction process. The formed hybrid coating layer consisted of C and MnO 2 has the double effects, that is, the formation of a complete continuous protective layer on the surface of LVP particles and the simultaneous improvement of electronic and ionic conductivities. This coating layer not only prevents the V 3+ dissolution into the electrolyte, but also achieves the simultaneous Li + /e − diffusion at charge–discharge process. Benefiting from the unique structure and the synergistic effect of C and MnO 2 , the 3 wt% MnO 2 -modified LVP/C material (M-3) exhibits the most excellent electrochemical performance among all the samples. At a high current rate of 5 C, the M-3 electrode delivers a discharge capacity of 113.2 mAh g −1 and corresponds to capacity retention almost 100% after 100 cycles. Even at low temperatures of 0 and − 20 °C, the discharge capacities of M-3 are 102.4 mAh g −1 at 2 C and 81.6 mAh g −1 at 1 C, with capacity retention of 98.8 and 97.3%, respectively. The enhanced electrochemical performance of M-3 is mainly attributed to the cooperation of C and MnO 2 , which provides large specific surface area and complete conductive network. As a result, the MnO 2 -modified LVP/C composites with the plate-like structure can be a promising candidate as cathode materials for LIBs.

Airway remodeling is a significant pathological change of asthma. This study aimed to detect differentially expressed microRNAs in the serum of asthma patients and airway smooth muscle cells (ASMCs) of asthmatic mice, exploring their role in the airway remodeling of asthma. The differentially expressed microRNAs in the serum of mild and moderate-severe asthma patients compared to healthy subjects were revealed using the \"limma\" package. Gene Ontology (GO) analysis was used to annotate the functions of microRNA target genes. The relative expressions of miR-107 (miR-107-3p in mice sharing the same sequence) in the primary airway smooth muscle cells (ASMCs) of the asthma mice model were tested by RT-qPCR. Cyclin-dependent kinases 6 (Cdk6), a target gene of miR-107, was predicted by algorithms and validated by dual-luciferase reporter assay and Western blot. The roles of miR-107, Cdk6, and protein Retinoblastoma (Rb) in ASMCs were examined by transwell assay and EDU KIT in vitro. The expression of miR-107 was down-regulated in both mild and moderate-severe asthma patients. Intriguingly, the level of miR-107 was also decreased in ASMCs of the asthma mice model. Up-regulating miR-107 suppressed ASMCs' proliferation by targeting Cdk6 and the phosphorylation level of Rb. Increasing the expression of Cdk6 or suppressing Rb activity abrogated the proliferation inhibition effect of ASMCs induced by miR-107. In addition, miR-107 also inhibits ASMC migration by targeting Cdk6. The expression of miR-107 is down-regulated in serums of asthma patients and ASMCs of asthmatic mice. It plays a critical role in regulating the proliferation and migration of ASMCs via targeting Cdk6.