Phosphine-Triggered Structural Defects in Au44 Homologues Boost Electrocatalytic CO2 Reduction.

The systematic induction of structural defects at the atomic level is crucial to metal nanocluster research because it endows cluster-based catalysts with highly reactive centers and allows for a comprehensive investigation of viable reaction pathways. Herein, by substituting neutral phosphine ligands for surface anionic thiolate ligands, we establish that one or two Au3 triangular units can be successfully introduced into the double-stranded helical kernel of Au44 (TBBT)28 , where TBBT=4-tert-butylbenzenethiolate, resulting in the formation of two atomically precise defective Au44 nanoclusters. Along with the regular face-centered-cubic (fcc) nanocluster, the first series of mixed-ligand cluster homologues is identified, with a unified formula of Au44 (PPh3 )n (TBBT)28-2n (n=0-2). The Au44 (PPh3 )(TBBT)26 nanocluster having major structural defects at the bottom of the fcc lattice demonstrates superior electrocatalytic performance in the CO2 reduction to CO. Density functional theory calculations indicate that the active site near the defects significantly lowers the free energy for the *COOH formation, the rate-determining step in the whole catalytic process.

Highly Boosting Circularly Polarized Luminescence of Chiral Metal-Imidazolate Frameworks.

To develop a simple and general method for improving the circularly polarized luminescence (CPL) performances of materials is of great significance. In this work, two pairs of CPL-active homochiral metal-organic frameworks (MOFs) P/M-Et and P/M-Et(Cd) with eta topology are reported. In comparison to the reported isomorphic Zn-imidazolate MOFs P-Me and M-Me, both luminescence dissymmetry factor (glum ) and photoluminescence quantum yields (ΦPL ) of P-Et and M-Et are largely improved by simply changing the methyl group to an ethyl group of ligands in P-Et and M-Et. Furthermore, the |glum | values are significantly amplified up to 0.015 from 0.0057 by introducing the non-luminescent halogenated aromatics, while an enhanced fluorescence efficiency is observed simultaneously (from 27.2% to 47.3%). The figure of merit value is about 40 times larger than that of P-Me and M-Me. Similarly, the CPL performances of P/M-Et(Cd) are improved by about five times after encapsulating fluorobenzene molecules. This work represents a new and simple method for developing CPL-active MOF materials.

Metal-Organic Framework Supported Copper Photoredox Catalysts for Iminyl Radical-Mediated Reactions.

Visible-light copper photocatalysis has recently emerged as a viable technology for building sustainable synthetic processes. To broaden the applications of phosphine-ligated copper(I) complexes, we describe herein an effective metal-organic framework (MOF)-supported copper(I) photocatalyst for multiple iminyl radical-mediated reactions. Due to site isolation, the heterogenized copper photosensitizer has a significantly higher catalytic activity than its homogeneous counterpart. Using a hydroxamic acid linker to immobilize copper species on MOF supports affords the heterogeneous catalysts with high recyclability. The post-synthetic modification sequence on MOF surfaces allows for the preparation of previously unavailable monomeric copper species. Our findings highlight the potential of using MOF-based heterogeneous catalytic systems to address fundamental challenges in the development of synthetic methodologies and mechanistic investigations of transition-metal photoredox catalysis.

Phosphinous Acid-Phosphinito Tetra-Icosahedral Au52 Nanoclusters for Electrocatalytic Oxygen Reduction.

While the formation of superatomic nanoclusters by the three-dimensional assembly of icosahedral units was predicted in 1987, the synthesis and structural determination of such clusters have proven to be incredibly challenging. Herein, we employ a mixed-ligand strategy to prepare phosphinous acid-phosphinito gold nanocluster Au52(HOPPh2)8(OPPh2)4(TBBT)16 with a tetra-icosahedral kernel. Unlike expected, each icosahedral Au13 unit shares one vertex gold atom with two adjacent units, resulting in a "puckered" ring shape with a nuclearity of 48 in the kernel. The phosphinous acid-phosphinito ligand set, which consists of two phosphinous acids and one phosphinito motif, has strong intramolecular hydrogen bonds; the π-π stacking interactions between the phosphorus- and sulfur-based ligands provide additional stabilization to the kernel. Highly stable Au52(HOPPh2)8(OPPh2)4(TBBT)16 serves as an effective electrocatalyst in the oxygen reduction reaction. Density functional theory calculations suggest that the phosphinous acid-phosphinito ligands provide the most active sites in the electrochemical catalysis, with O* formation being the rate-determining step.

Wuzi Yanzong Pill relieves CPZ-induced demyelination by improving the microenvironment in the brain.

Ethnopharmacology relevance: Wuzi Yanzong Pill (WYP), a well-known prescription for invigorating the kidney and essence, which is widely used to treat infertility such as oligoasthenospermia. Studies have shown that WYP can be used to treat neurological diseases, but its therapeutic effects and mechanisms for multiple sclerosis (MS) remain unclear. Aim of the study: Based on the establishment of Cuprizone (CPZ)-induced demyelination model, this study determined the effect of WYP on remyelination by detecting changes in the microenvironment of the central nervous system. Materials and methods: C57BL/6 mice were divided into three groups. The CPZ group and CPZ + WYP group were fed with 0.2% CPZ feed, and the control group was fed normal feed, for 6 weeks. At the end of the second week, the CPZ + WYP group was gavaged with WYP solution (16 g/kg/d), and the other two groups were gavaged with normal saline twice a day with an interval of 12 h each time, for 4 weeks. Forced swimming and elevated plus maze were used to detect changes in anxiety and depression before and after treatment. Luxol fast blue staining and the expression of MBP were used to evaluate the demyelination of the brain. Western blot was used to detect the expression of microglia and their subtype markers Iba-1, Arg-1, iNOS, the expression of neurotrophic factors BDNF, GDNF, CNTF, and the expression of oligodendrocyte precursor cells NG2. ELISA detected the content of IL-6, IL-1ß, IL-10, TGF-ß, BDNF, GDNF, CNTF in the brain. The distribution of Iba-1 in the corpus callosum was observed by immunofluorescence. Results: The results showed that on the basis of improving mood abnormalities and demyelination, WYP reduced the protein content of Iba-1 and iNOS, increased the protein content of Arg-1, and reduce accumulation of microglia in the corpus callosum. In addition, WYP reduced the secretion of IL-6 and IL-1ß while promoting the secretion of IL-10 and TGF-ß. After WYP intervention treatment, the levels of neurotrophic factors BDNF, GDNF, CNTF increased. Due to the improvement of inflammatory and nutritional environment in the CNS, promoting the proliferation of NG2 oligodendrocyte, increased the expression of MBP, and repairing myelin sheath. Conclusion: Our results indicated that WYP promoted the proliferation and development of oligodendrocytes by improving the CNS microenvironment, effectively alleviating demyelination.

Pseudomonas putida Represses JA- and SA-Mediated Defense Pathways in Rice and Promotes an Alternative Defense Mechanism Possibly through ABA Signaling.

The signaling pathways induced by Pseudomonas putida in rice plants at the early plant-rhizobacteria interaction stages, with and without inoculation of Xanthomonas oryzae pv. oryzae, were studied. In the absence of pathogen, P. putida reduced ethylene (ET) production, and promoted root and stem elongation. Interestingly, gene OsHDA702, which plays an important role in root formation, was found significantly up-regulated in the presence of the rhizobacterium. Although X. oryzae pv. oryzae inoculation enhanced ET production in rice plants, P. putida treatment repressed ET-, jasmonic acid (JA)- and salicylic acid (SA)-mediated defense pathways, and induced the biosynthesis of abscisic acid (ABA), and the overexpression of OsHDA705 and some pathogenesis-related proteins (PRs), which in turn increased the susceptibility of the rice plants against the pathogen. Collectively, this is the first work on the defense signaling induced by plant growth-promoting rhizobacteria in plants at the early interaction stages, and suggests that rhizobacteria stimulate an alternative defense mechanism in plants based on ABA accumulation and OsHDA705 signaling.

Coordination-driven self-assembly of M10L8 metal-organic bi-capped square antiprisms with adaptable cavities.

A family of polyhedral metal-imidazolate cages based on the flexible bi-imidazole ligand L and Cu2+ ions have been synthesized and characterized, featuring an unusual Cu10L8 bicapped square antiprism structure (or Johnson solids, J17) with an adaptable cavity. These metal-organic cages encapsulate anions, and they will expand or compress after they are filled with different-sized anions.

Assembly of Metal-Organic Frameworks of SiF62- in Situ Formed from Borosilicate Glass.

The SiF62- anions are in situ formed in the reactions of MF2 (M = Cu2+, Zn2+, Ni2+, and Co2+) salts and nitrogen-containing ligands in borosilicate glass tubes under solvothermal conditions and then used to further construct a family of metal-organic frameworks (MOFs). This in situ reaction demonstrates a new and facile strategy for the fabrication of MOFs based on SiF62-.

Comparison of the crystal structures of the potent anticancer and anti-angiogenic agent regorafenib and its monohydrate.

Regorafenib {systematic name: 4-[4-({[4-chloro-3-(trifluoromethy)phenyl]carbamoyl}amino)-3-fluorophenoxy]-1-methylpyridine-2-carboxamide}, C21H15ClF4N4O3, is a potent anticancer and anti-angiogenic agent that possesses various activities on the VEGFR, PDGFR, raf and/or flt-3 kinase signaling molecules. The compound has been crystallized as polymorphic form I and as the monohydrate, C21H15ClF4N4O3·H2O. The regorafenib molecule consists of biarylurea and pyridine-2-carboxamide units linked by an ether group. A comparison of both forms shows that they differ in the relative orientation of the biarylurea and pyridine-2-carboxamide units, due to different rotations around the ether group, as measured by the C-O-C bond angles [119.5 (3)° in regorafenib and 116.10 (15)° in the monohydrate]. Meanwhile, the conformational differences are reflected in different hydrogen-bond networks. Polymorphic form I contains two intermolecular N-H...O hydrogen bonds, which link the regorafenib molecules into an infinite molecular chain along the b axis. In the monohydrate, the presence of the solvent water molecule results in more abundant hydrogen bonds. The water molecules act as donors and acceptors, forming N-H...O and O-H...O hydrogen-bond interactions. Thus, R4(2)(28) ring motifs are formed, which are fused to form continuous spiral ring motifs along the a axis. The (trifluoromethyl)phenyl rings protrude on the outside of these motifs and interdigitate with those of adjacent ring motifs, thereby forming columns populated by halogen atoms.

[Crystal structure and crystal form stability of trelagliptin succinate].

In order to investigate trelagliptin succinate's stability in solution, recrystallization and suspension methods in polar solvent (mainly in water and 95% alcohol) were used to study the crystal form transformation of trelagliptin succinate. Single crystal X-ray diffraction, powder X-ray diffraction and thermalgravimetric analysis, and differential scanning calorimetry were used to characterize the structure of the solid state form before and after transformation. The results showed that trelagliptin succinate can easily convert to trelagliptin hemi-succinate mediated by solvent, especially by polar solvent, namely trelagliptin hemi-succinate is more stable than trelagliptin succinate in solution.

Crystal structures of vortioxetine and its methanol monosolvate.

Vortioxetine, C18H22N2S, (1), systematic name 1-{2-[(2,4-di-methyl-phen-yl)sulfan-yl]phen-yl}piperazine, a new drug used to treat patients with major depressive disorder, has been crystallized as the free base and its methanol monosolvate, C18H22N2S·CH3OH, (2). In both structures, the vortioxetine mol-ecules have similar conformations: in (1), the dihedral angle between the aromatic rings is 80.04 (16)° and in (2) it is 84.94 (13)°. The C-S-C bond angle in (1) is 102.76 (14)° and the corresponding angle in (2) is 103.41 (11)°. The piperazine ring adopts a chair conformation with the exocyclic N-C bond in a pseudo-equatorial orientation in both structures. No directional inter-actions beyond normal van der Waals contacts could be identified in the crystal of (1), whereas in (2), the vortioxetine and methanol mol-ecules are linked by N-H⋯O and O-H⋯N hydrogen bonds, generating [001] chains.

Energetic aqueous rechargeable sodium-ion battery based on Na2 CuFe(CN)6 -NaTi2 (PO4 )3 intercalation chemistry.

Aqueous rechargeable sodium-ion batteries have the potential to meet growing demand for grid-scale electric energy storage because of the widespread availability and low cost of sodium resources. In this study, we synthesized a Na-rich copper hexacyanoferrate(II) Na2 CuFe(CN)6 as a high potential cathode and used NaTi2 (PO4 )3 as a Na-deficient anode to assemble an aqueous sodium ion battery. This battery works very well with a high average discharge voltage of 1.4 V, a specific energy of 48 Wh kg(-1) , and an excellent high-rate cycle stability with approximately 90 % capacity retention over 1000 cycles, achieving a new record in the electrochemical performance of aqueous Na-ion batteries. Moreover, all the anode, cathode, and electrolyte materials are low cost and naturally abundant and are affordable for widespread applications.

[Modulation of RhoA/Rho kinase on migration, invasion and proliferation of fibroblast like synoviocytes from patients with rheumatoid arthritis].

OBJECTIVE: To evaluate the modulation of RhoA/Rho kinase (ROCK), a small Rho GTPase, on migration, invasion and proliferation of fibroblast like synoviocytes (FLS) from rheumatoid arthritis (RA) patients. METHODS: RA FLS were collected from active RA patients. And 10% fetal bovine serum (FBS) and interleukin-1ß (IL-1ß) were used as stimuli in migration and proliferation experiments respectively. RhoA activity was measured by pull down assay while ROCK activity by Western blot. FLS migration and invasion in vitro were measured by the Transwell chamber method. And thiazolyl blue tetrazolium bromide (MTT) test was used to detect cell proliferation. RESULTS: There were increased activities of RhoA and ROCK in ex vivo FLS from RA versus OA patients and healthy control. The migrated cell number of FBS-induced, C3-treated and Y27632-treated groups was 85 ± 14, 51 ± 15 and 42 ± 11 respectively. The Matrigel invading cell number of 3 groups was 64 ± 13, 39 ± 12 and 26 ± 9 respectively. Statistical differences existed in cell number between FBS-induced, C3-treated or Y27632-treated group (P < 0.05) in above migration and invasion experiments. Inhibition of RhoA and ROCK activity also suppressed the cytoskeletal reorganization and proliferation of RA FLS. CONCLUSION: Increased RhoA/ROCK activity may contribute to abnormal migration, invasion and proliferation of RA FLS. Thus inhibition of ROCK activity may be a new therapeutic target for RA.

[The inversion processing of vegetation biomass along Yongding River based on multispectral information].

Researching on vegetation biomass using the traditional measurement method is time-consuming and hard sledding, and prediction precision of biomass is always not good because of uncertain influencing factors. The present article aims at the current situation of Hebei-Beijing reach along Yongding River, using the Thematic Mapper data in this place on 20th July 2009 as source data, with the 30 meters Digital Elevation Model data in Beijing and other auxiliary information, meanwhile through field observation data, to find out the possible functional relationship along vegetation biomass and remote sensing image factor. The authros sorted out the vegetation biomass and remote sensing image factor on the sample plot, then set up an inverse model through multiple linear regression analysis, and analyzed the precision of inverse model. After calculating the measured value and predicted value, the authors got the global relative error is -0.025%, the average relative error is -0.016%, and the general predictive precision is 84.56%. The establishment of this model is able to investigate eco-environmental factors on large range timely, quickly and accurately, also can provide the experimental base for the eco-environmental survey on river basin, and make the foundation for the problem diagnosis of ecological environment and the research on ecosystem degradation mechanism of Yongding River.

[Studies on the chemical constituents from stems and leaves of Lonicera macranthoides].

OBJECTIVE: To research the chemical constituents from stems and leaves of Lonicera macranthoides. METHODS: Various column chromatographies were employed to isolate and purify the constituents. Their structures were elucidated by spectral analysis (IR, MS, 1H-NMR, 13 C-NMR) and chemical evidence. RESULTS: Nine constituents were obtained and identified as loganin (I), loganic acid (II), morroniside (III),7-O-ethyl-morroniside (IV), scopoletin (V), caffeic acid (VI), chlorogenic acid (VII), beta-sitosterol (VIII), daucosterol (IX). CONCLUSION: Compounds I-VI are isolated from the plant for the first time. All the compounds are found for the first time from the stems and leaves of Lonicera macranthoides.