A Metal Coordination Number Determined Catalytic Performance in Manganese Borides for Ambient Electrolysis of Nitrogen to Ammonia.

A new strategy that can effectively increase the nitrogen reduction reaction performance of catalysts is proposed and verified by tuning the coordination number of metal atoms. It is found that the intrinsic activity of Mn atoms in the manganese borides (MnBx ) increases in tandem with their coordination number with B atoms. Electron-deficient boron atoms are capable of accepting electrons from Mn atoms, which enhances the adsorption of N2 on the Mn catalytic sites (*) and the hydrogenation of N2 to form *NNH intermediates. Furthermore, the increase in coordination number reduces the charge density of Mn atoms at the Fermi level, which facilitates the desorption of ammonia from the catalyst surface. Notably, the MnB4 compound with a Mn coordination number of up to 12 exhibits a high ammonia yield rate (74.9 ± 2.1 µg h-1 mgcat -1 ) and Faradaic efficiency (38.5 ± 2.7%) at -0.3 V versus reversible hydrogen electrode (RHE) in a 0.1 m Li2 SO4 electrolyte, exceeding those reported for other boron-related catalysts.

Ternary Lithium Nickel Boride with 1D Rapid-Ion-Diffusion Channels as an Anode for Use in Lithium-Ion Batteries.

Anode materials with high-rate performances and good electrochemical stabilities are urgently required for the grid-scale application of lithium-ion batteries (LIBs). Theoretically, transition metal borides are desirable candidates because of their appropriate working potentials and good conductivities. However, the reported metal borides exhibit poor performances owing to their lack of favorable Li+ storage sites and poor structural stabilities during long-term charging/discharging. In this work, a ternary alkali metal boride, Li1.2 Ni2.5 B2 , which displays a high Li+ storage capacity and remarkable electrochemical stability and an excellent rate performance is studied. In contrast to conventional transition metal borides, the introduction of Li atoms facilitates the formation of 1D Ni/B-based honeycomb channels during synthesis. This Ni/B framework successfully sustains the strain during Li+ intercalation and deintercalation, and thus, the optimized Li1.2 Ni2.5 B2 anode exhibits an excellent cycle stability over 500 charge/discharge cycles. This electrode also exhibits superior reversible capacities of 350, 183, and 80 mA h g-1 at 0.1, 1, and 5 A g-1 , respectively, indicating the considerable potential of the 1D Ni/B framework as a commercially available fast-charging LIB anode.

Poly(ether imide) Porous Membrane Developed by a Scalable Method for High-Performance Lithium-Sulfur Batteries: Combined Theoretical and Experimental Study.

Lithium-sulfur (Li-S) batteries are one of the emerging candidates for energy storage systems due to their high theoretical energy density and the abundance/nontoxicity/low cost of sulfur. Compared with conventional lithium-ion batteries, multiple new challenges have been brought into this advanced battery system, such as polysulfide shuttling in conventional polyolefin separators and undesired lithium dendrite formation of the Li metal anode. These issues severely affect the cell performance and impede their practical applications. Herein, we develop a poly(ether imide) (PEI)-based membrane with a sponge-like pore morphology as the separator for the Li-S battery by a simplified phase inversion method. This new separator can not only alleviate the new challenges in Li-S batteries but also exhibit excellent ion conductivity, better thermal stability, and higher mechanical strength compared to those of the conventional polypropylene (PP) separator. A combined experimental and theoretical study indicates that the sponge-like morphology of the PEI membrane and its good wettability toward the electrolyte can facilitate uniform ion transportation and suppress dendrite growth. Meanwhile, the PEI molecules exhibit a strong interaction with polysulfides and avoid their shuttling effectively. As a result, the PEI-based Li-S battery shows a much better performance from various aspects (capacity, rate capability, and cycling stability) than that of the PP-based Li-S battery, especially at high charge/discharge current densities and high sulfur loadings. Since the developed PEI membrane can be easily scaled up, this work may accelerate the practical applications of Li-S batteries from the point of separators.

Bridging 1D Inorganic and Organic Synthesis to Fabricate Ultrathin Bismuth-Based Nanotubes with Controllable Size as Anode Materials for Secondary Li Batteries.

The growth of ultrathin 1D inorganic nanomaterials with controlled diameters remains challenging by current synthetic approaches. A polymer chain templated method is developed to synthesize ultrathin Bi2 O2 CO3 nanotubes. This formation of nanotubes is a consequence of registry between the electrostatic absorption of functional groups on polymer template and the growth habit of Bi2 O2 CO3 . The bulk bismuth precursor is broken into nanoparticles and anchored onto the polymer chain periodically. These nanoparticles react with the functional groups and gradually evolve into Bi2 O2 CO3 nanotubes along the chain. 5.0 and 3.0 nm tubes with narrow diameter deviation are synthesized by using branched polyethyleneimine and polyvinylpyrrolidone as the templates, respectively. Such Bi2 O2 CO3 nanotubes show a decent lithium-ion storage capacity of around 600 mA h g-1 at 0.1 A g-1 after 500 cycles, higher than other reported bismuth oxide anode materials. More interestingly, the Bi materials developed herein still show decent capacity at very low temperatures, that is, around 330 mA h g-1 (-22 °C) and 170 mA h g-1 (-35 °C) after 75 cycles at 0.1 A g-1 , demonstrating their promising potential for practical application in extreme conditions.

Nano-Graphite Prepared by Rapid Pulverization as Anode for Lithium-Ion Batteries.

Reducing the particle size of active material is an effective solution to the poor rate performance of the lithium-ion battery. In this study, we proposed a facile strategy for the preparation of nano-graphite as an anode for a lithium-ion battery via the rapid mechanical pulverization method. It is the first time that diamond particle was selected as the medium to achieve high preparation efficiency and low energy consumption. The as-prepared nano-graphite with the size from 10 to 300 nm displays an intact structure and high specific surface area. The introduced oxygen atoms increased the wettability of nano-graphite electrode and lowered its polarization. The nano-graphite prepared from three hours of grinding shows an excellent reversible capacity of 191 mAh g-1, at a rate of 5 C, after 480 cycles, along with an increase of 86% in capacity, at 1 C, in comparison with pristine graphite. The highlight of this strategy is to optimize the current preparation method. The good electrochemical performance comes from the combined effect of nano-scale particle size, large specific surface area, and continuous mesopores.

Fasudil hydrochloride hydrate, a Rho-kinase inhibitor, ameliorates hepatic fibrosis in rats with type 2 diabetes.

BACKGROUND: Hyperglycemia may accelerate liver fibrosis. Currently, there is no effective treatment for liver fibrosis induced by type 2 diabetes. The study aim was to investigate whether RhoA/Rho kinase (ROCK) pathway is involved in liver fibrosis in the rats with type 2 diabetes and define the protective effects of fasudil on livers. METHODS: A rat model of type 2 diabetes was established by high fat diet combined with streptozotocin (30 mg/kg, intraperitoneal injection). Animals were randomly assigned to 3 groups: control rats, untreated diabetic rats that received vehicle and fasudil-treated diabetic rats that received ROCK inhibitor fasudil hydrochloride hydrate (10 mg/kg per day, intraperitoneal injection, for 14 weeks). The morphological features of liver were observed by HE staining. Accumulation of collagen in livers was determined by Masson staining and the measurement of hydroxyproline. The mRNA expression of transforming growth factor-ß1 (TGFß1), connective tissue growth factor (CTGF), type-I, and type-III procollagen was assessed with real-time polymerase chain reaction. The phosphorylation of myosin phosphatase target subunit-1 (MYPT1) and the protein levels of TGFß1 and α-smooth muscle actin (a-SMA) were evaluated by Western blotting. RESULTS: Compared with control rats, untreated diabetic rats showed higher values of collagen and hydroxyproline in livers (P < 0.01), the phosphorylation of MYPT1 and the protein levels of TGFß1 and α-SMA were increased (P < 0.01), and the mRNA expression of TGFß1, CTGF, type-I, and type-III procollagen was upregulated (P < 0.01); compared with untreated diabetic rats, treatment with fasudil signifcantly reduced values of collagen and hydroxyproline (P < 0.01), and decreased the phosphorylation of MYPT1 and the levels of TGFß1 and α-SMA (P < 0.01), concomitant with the downregulation of TGFß1/CTGF, type-I, and type-III procollagen mRNA expression (P < 0.01). CONCLUSIONS: Fasudil ameliorates liver fibrosis in rats with type 2 diabetes at least partly by inhibiting TGFß1/CTGF pathway and α-SMA expression. Inhibition of RhoA/ROCK may be a novel therapeutic target for liver fibrosis in diabetic non-alcoholic steatohepatitis.

Involvement of RhoA/ROCK in myocardial fibrosis in a rat model of type 2 diabetes.

AIM: To investigate whether activation of RhoA/Rho kinase (ROCK) is involved in myocardial fibrosis in diabetic hearts. METHODS: A rat model of type 2 diabetes was established using high fat diet combined with streptozotocin (30 mg/kg, ip). Animals were randomly divided into 3 groups: control rats, untreated diabetic rats that received vehicle and treated diabetic rats that received Rho-kinase inhibitor fasudil hydrochloride hydrate (10 mg·kg(-1)·d(-1), ip, for 14 weeks). Cardiac contractile function was evaluated in vivo. The morphological features of cardiac fibrosis were observed using immunohistochemistry and TEM. The mRNA expression of JNK, TGFß1, type-I, and type-III procollagen was assessed with RT-PCR. The phosphorylation of MYPT1, JNK and Smad2/3, as well as the protein levels of TGFß1 and c-Jun, were evaluated using Western blotting. RESULTS: In untreated diabetic rats, myocardial fibrosis was developed and the heart contractility was significantly reduced as compared to the control rats. In the hearts of untreated diabetic rats, the mRNA expression level and activity of JNK were upregulated; the expression of TGFß1 and phosphorylation of Smad2/3 were increased. In the hearts of treated diabetic rat, activation of JNK and TGFß/Smad was significantly decreased, myocardial fibrosis was reduced, and cardiac contractile function improved. CONCLUSION: The data suggest that fasudil hydrochloride hydrate ameliorates myocardial fibrosis in rats with type 2 diabetes at least in part through inhibiting the JNK and TGFß/Smad pathways. Inhibition of RhoA/ROCK may be a novel therapeutic target for prevention of diabetic cardiomyopathy.

Diabetes mellitus with hepatic infarction: a case report with literature review.

Hepatic infarction rarely occurs due to the double supply of arterial and portal inflow. A 53-year-old man with diabetes mellitus developed multiple hepatic infarctions after an episode of fever and diarrhea. The infarction was documented by pathology after partial liver resection. Several causes of hepatic infarction may present in this patient: dehydration and hypotension caused by fever and diarrhea, type 2 diabetes and administration of glibenclamide, diabetic ketoacidosis and widespread atherosclerosis. We suggest that diabetic patient with elevated liver enzyme should be considered the possibility of hepatic infarction.