Circularly Polarized Organic Ultralong Room-Temperature Phosphorescence with A High Dissymmetry Factor in Chiral Helical Superstructures.

Long-lived room-temperature phosphorescence (RTP) of organic materials holds a significant potential for optical information. Circularly polarized organic ultralong room-temperature phosphorescence (CP-OURTP) with extremely high dissymmetry factor (glum ) values is even highly demanded and considerably challenging. Here, an effective strategy is introduced to realize CP-OURTP with an emission decay time of 735 ms and a glum value up to 1.49, which exceeds two orders of magnitude larger than previous records, through a system composed of RTP polymers and chiral helical superstructures. The system exhibits excellent stability under multiple cycles of photoirradiation and thermal treatment, and is further employed for information encryption based on optical multiplexing. The results are anticipated to lay the foundation for the development of CP-OURTP materials in advanced photonic applications.

Promoting photocatalytic hydrogen evolution over the perovskite oxide Pr0.5(Ba0.5Sr0.5)0.5Co0.8Fe0.2O3 by plasmon-induced hot electron injection.

Exploration of highly efficient and stable photocatalysts for water splitting has attracted much attention. However, developing a facile and effective approach to enhance the photocatalytic activity for practical applications is still highly challenging. Herein, we report a newly-fabricated perovskite oxide (Pr0.5(Ba0.5Sr0.5)0.5Co0.8Fe0.2O3) decorated with Au ultrafine nanoparticles for photocatalytic water splitting. An exceptionally high hydrogen evolution rate of 1618 µmol g-1 h-1 was achieved (under 2 h illumination) when the Au mass loading was optimized to 9.3 wt%, which is 540 times higher than that of the pristine one. The splendid photocatalytic activity of the sample was attributed to plasmon-excited hot electron injection from Au to Pr0.5(Ba0.5Sr0.5)0.5Co0.8Fe0.2O3 (PBSCF) under illumination. The finite-difference time-domain simulations (FDTD) demonstrated that the localized strong electric field formed at the interface between Au and PBSCF under illumination, enables the hot electrons to be energetic and make the injection possible.

Cation and Anion Co-doped Perovskite Nanofibers for Highly Efficient Electrocatalytic Oxygen Evolution.

Perovskite oxides have been recognized as one of the most attractive oxygen evolution reaction (OER) catalysts because of their low cost, earth abundance, and robust nature. Herein, one-dimensional porous LaFe1-xNixO3 (LFNO) perovskite oxide nanofibers (LFNO NFs) are fabricated with a feasible electrospinning route and its further post-calcination treatment. By tailoring the atomic percent of Fe and Ni in the perovskite oxide, we determined that LaFe0.25Ni0.75O3 (LFNO-III) NFs afford the best OER activity among all the prepared perovskite oxides. Especially remarkable is that the further selenide-doped LaFe0.25Ni0.75O3 (LFNOSe-III) NFs exhibit outstanding OER activity with a low overpotential of 287 mV at 10 mA cm-2 and a small Tafel slope of 87 mV dec-1 in 1 M KOH solution, markedly exceeding that of the parent perovskite oxide and the commercial RuO2. It also delivers decent durability with no significant degradation after 22 h of stability test. In the meanwhile, density functional theory calculations are also conducted to justify the optimized adsorption features of *OH, *O, and *OOH intermediates and unveil that the electrocatalytic active sites are the Ni atoms adjacent to Fe in the Ni- and Se codoped perovskite. This work provides an effective method for the development of highly efficient perovskite oxide catalysts.

[A new antimicrobial isobenzoisofuran compound from Cassia pumila].

A new isobenzoisofuran(1) has been isolated from the whole plant of Cassia pumila using various chromatographic techniques, including silica gel, Sephadex, MCI-gel resin, and RP-HPLC, and its structure was determined as 9-(2-hydroxyethyl)-2,2-dimethyl-2H-furo[3,4-g]chromen-6(8H)-one. This compound was also evaluated for its antibacterial activity. The results showed that it had prominent antibacterial activity with MIC_(90) value of(45.2±4.2) µg·mL~(-1) for methicillin resistant Staphylococcus aureus(MRSA) strain. This value was closed to that of levofloxacin [with MIC_(90) value(48.5±4.3) µg·mL~(-1)].

Dilation of the cystic duct confluence in laparoscopic common bile duct exploration and stone extraction in patients with secondary choledocholithiasis.

BACKGROUND: Many options exist for the management of cholelithiasis and secondary choledocholithiasis. Among them, laparoscopic common bile duct exploration (LCBDE) with choledocotomy followed by laparoscopic cholecystectomy has gained popularity. However, efforts should be made to ensure minimally invasive or noninvasive management of the common bile duct (CBD). The purpose of this study was to explore the clinical experience of non-invasive surgical modality, i.e., laparoscopic transcystic dilation of the cystic duct confluence in CBD exploration (LTD-CBDE), including feasibility, safety, adverse events, and incidence. METHODS: In this retrospective analysis, 68 patients were offered the LTD-CBDE technique from December 2015 to April 2018 based on patient's own intention. During the surgery, the cystic duct confluence was dilated with separation forceps and/or a columnar dilation balloon. Subsequently, CBD exploration and stone extraction were performed with a choledochoscope. The entrance of the CBD was covered with a cystic duct stump wall and was subjected to primary closure at the end of surgery. RESULTS: Forty-nine females and 19 males with cholelithiasis and secondary choledocholithiasis were included. The mean age was 53 years old (18 to 72 year). Of these patients, 62 (91.2%) were successfully treated with the LTD-CBDE technique, and bile leakage was observed in 3 patients (4.4%). The mean operation time was 106 min, and the mean hospital stay was 5.9 days. Among the other 6 patients, 3 were converted to open cholecystectomy due to severe fibrosis, unclear anatomical structure at Calot's triangle (n = 2) or Mirizze syndrome (n = 1); LCBDE was performed in 3 patients due to cystic duct atresia (n = 2) and low level of flow from the gallbladder duct into the CBD (n = 1). These patients had a smooth postoperative course. In total, 43/68 of the patients presented no radiological evidence of retained CBD stones at the postoperative follow-up (40 patients treated with LTD-CBDE) 1 year later. CONCLUSIONS: The current work suggests that LTD-CBDE for the management of cholelithiasis and secondary choledocholithiasis is a feasible, safe and effective technique with a low complication rate. LTD-CBDE offers another alternative for surgeons to treat patients in similar scenarios. However, additional randomized, controlled studies are needed to demonstrate its efficacy, safety, and impact on CBD stenosis.

[A new cytotoxic flavone from Cassia nomame].

A new flavone( 1) has been isolated from the whole plant of Cassia nomame by using various chromatographic techniques,including silica gel,Sephadex,MCI-gel resin,and RP-HPLC,and its structure was determined as 8,4'-dimethoxy-7-( 2-oxopropyl)-flavone based on spectroscopic data. The biological activity test showed that this compound displayed potent cytotoxicity against NB4,SH-SY5 Y,PC3,A549 and MCF-7 cell lines with IC50 values 2. 2,1. 8,3. 4,4. 5 and 1. 6 µmol·L-1,respectively.

Engineering the coupling interface of rhombic dodecahedral NiCoP/C@FeOOH nanocages toward enhanced water oxidation.

Hydrogen, regarded as one of the most promising green and sustainable energy resources, could be generated by splitting water with electrochemical methods. The challenge for efficient hydrogen generation is the sluggish kinetics at the anodes for the oxygen evolution reaction (OER). Here, a novel catalyst with remarkably enhanced OER activity was prepared by coupling FeOOH and NiCoP/C. The enhanced OER activity of the hybrid catalyst should be ascribed to the synergistic effect of the individual components. First, NiCoP/C derived from ZIF-67 with a hollow rhombic dodecahedral architecture not only allows exposure of numerous active sites but also provides high conductivity. Second, the re-localization of electrons at the coupling interface optimizes the adsorption/desorption nature of intermediate oxygenated species and imparts a high OER activity. The hybrid NiCoP/C@FeOOH catalyst exhibits very high OER activity with a low overpotential of 271 mV for producing a current density of 10 mA cm-2 in 1 M KOH aqueous solution, markedly surpassing the individual counterparts of pure NiCoP/C nanocages and bare FeOOH. This work represents a universal strategy for boosting the OER kinetics of catalysts and pushing boundaries for high-efficiency water oxidation.

[A new isobenzofuranone derivative from Chaenomeles sinensis and its antibacterial activity].

A new isobenzofuranone derivative was isolated from Chaenomeles sinensis by using various chromatographic techniques,including silica gel,Sephadex LH-20,MCI-gel resin and RP-HPLC. This compound was determined as 2,2-dimethyl-5-( 2-oxopropyl)-2 H-furo[3,4-h]chromen-7( 9 H)-one( 1) by NMR,MS,IR and UV spectra,and was also evaluated for its antibacterial activity. The results showed that it showed prominent antibacterial activity with MIC90 value of( 53. 7±4. 5) mg·L-1 for methicillin resistant Staphylococcus aureus( MRSA) strain. This value is close to that of levofloxacin [with MIC90 value( 50. 2± 4. 2) mg·L-1].

Template-Directed Bifunctional Dodecahedral CoP/CN@MoS2 Electrocatalyst for High Efficient Water Splitting.

Designing high efficient and noble metal-free bifunctional electrocatalysts for both hydrogen and oxygen generation is still critical and challenged. In this study, hierarchical dodecahedral-structured CoP/CN@MoS2 is prepared through a two-step calcination treatment and a solvothermal approach. The metal-organic framework of ZIF-67 is chosen to serve as the template and for providing Co sources, in which ZIF-67 is first transformed to Co nanoparticles embedded in nitrogen-doped carbon polyhedrons and then transformed to CoP/CN. MoS2 nanosheets are further grown on the surface of dodecahedral-structured CoP/CN with a solvothermal method. Benefiting from the synergistic coupling effect of CoP and MoS2 and the nitrogen-doped carbon matrix, advanced hydrogen evolution reaction (HER) both in acid and alkaline solution as well as splendid oxygen evolution reaction (OER) performance in alkaline aqueous were achieved. Moreover, the coupling effect of CoP/CN and MoS2 is disclosed theoretically by density functional theory calculations to validate the increased HER activity. The as-prepared hybrid CoP/CN@MoS2 not only exhibits decent HER activity in acidic (η10 = 144 mV) and alkaline solutions (η10 = 149 mV), but also exhibits splendid OER activity (η10 = 289 mV) in 1.0 M KOH. This work represents a solid step toward boosting the electrocatalytic kinetics of nonprecious catalysts.

Markedly Enhanced Oxygen Reduction Activity of Single-Atom Fe Catalysts via Integration with Fe Nanoclusters.

Single-atom catalysts (SACs) have emerged as one of the most promising alternatives to noble metal-based catalysts for highly efficient oxygen reduction reaction (ORR). While SACs can offer notable benefits in terms of lowering overall catalyst cost, there is still room for improvement regarding catalyst activity. To this end, we designed and successfully fabricated an ORR electrocatalyst in which atomic clusters are embedded in an atomically dispersed Fe-N-C matrix (FeAC@FeSA-N-C), as shown by comprehensive measurements using aberration-corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption spectroscopy (XAS). The half-wave potential of FeAC@FeSA-N-C is 0.912 V (versus reversible hydrogen electrode (RHE)), exceeding that of commercial Pt/C (0.897 V), FeSA-N-C (0.844 V), as well as the half-wave potentials of most reported non-platinum-group metal catalysts. The ORR activity of the designed catalyst stems from single-atom active centers but is markedly enhanced by the presence of Fe nanoclusters, as confirmed by both experimental measurements and theoretical calculations.

Metal-Organic Framework-Derived Hierarchical (Co,Ni)Se2@NiFe LDH Hollow Nanocages for Enhanced Oxygen Evolution.

High-efficient electrocatalysts are crucial for fuel cell applications; however, the whole cell performance is generally restricted by the anodic part because of the sluggish kinetics involved in the oxygen evolution reaction (OER) process. Herein, a hierarchical hollow (Co,Ni)Se2@NiFe layered double hydroxide (LDH) nanocage was synthesized by deriving from the metal-organic framework (MOF) of ZIF-67. Concretely, it involves first fabrication of hollow rhombic (Co,Ni)Se2 nanocages and then deposition of NiFe LDH nanosheets on the surface of nanocages. Notably, the incorporation of Ni into Co-based ZIF-67 (via ion-exchange) could tail the atomic arrangement of the MOF, exposing more additional active sites in the following selenization treatment. The as-synthesized (Co,Ni)Se2@NiFe LDH demonstrates splendid OER performance with a small overpotential of 277 mV (to launch a current density of 10 mA cm-2), a small Tafel slope of 75 mV dec-1, and robust durability (a slight stability decay of 5.1% after 17 h of continuous test), not only surpassing the commercial RuO2 but also being comparable/superior to most reported nonprevious metal-based catalysts. Upon analysis, the outstanding OER performance is attributed to the optimized adsorption/desorption nature of iron and nickel/cobalt toward the oxygenated species and partial delocalization of spin status at the interface via the bridging O2-. This work represents a solid step toward exploration of advanced catalysts with deliberate experimental design and/or atom tailoring.

Effect of different levels of nitrogen on rhizosphere bacterial community structure in intensive monoculture of greenhouse lettuce.

Pyrosequencing-based analyses revealed significant effects among low (N50), medium (N80), and high (N100) fertilization on community composition involving a long-term monoculture of lettuce in a greenhouse in both summer and winter. The non-fertilized control (CK) treatment was characterized by a higher relative abundance of Actinobacteria, Acidobacteria, and Chloroflexi; however, the average abundance of Firmicutes typically increased in summer, and the relative abundance of Bacteroidetes increased in winter in the N-fertilized treatments. Principle component analysis showed that the distribution of the microbial community was separated by a N gradient with N80 and N100 in the same group in the summer samples, while CK and N50 were in the same group in the winter samples, with the other N-level treatments existing independently. Redundancy analysis revealed that available N, NO3(-)-N, and NH4(+)-N, were the main environmental factors affecting the distribution of the bacterial community. Correlation analysis showed that nitrogen affected the shifts of microbial communities by strongly driving the shifts of Firmicutes, Bacteroidetes, and Proteobacteria in summer samples, and Bacteroidetes, Actinobacteria, and Acidobacteria in winter samples. The study demonstrates a novel example of rhizosphere bacterial diversity and the main factors influencing rizosphere microbial community in continuous vegetable cropping within an intensive greenhouse ecosystem.

A two-dimensional zincII coordination polymer created via in situ ligand synthesis involving C-N bond formation.

The novel Zn(II) coordination polymer poly[{µ4-2-[3-(pyridin-2-yl)-1H-pyrazol-3-yl]butanedioato}zinc(II)], [Zn(C12H9N3O4)]n, has been synthesized hydrothermally and structurally characterized. The results demonstrate that the complex shows two-dimensional neutral wave-like layers. The complex was prepared by the conjugate addition reaction of 2-(1H-pyrazol-3-yl)pyridine to cis-fumaric acid in the presence of Zn(OAc)2·2H2O (OAc is acetate) at 413 K.

Changes in platelet function following cold storage of RBC suspensions.

OBJECTIVE: To provide a basis for the cold-storage of human platelets as a way to assess changes in platelet function. METHODS: Red blood cell suspensions (11 U and 50 U) were randomly selected at different storage times (3-28 days) and evidence of platelet activation (CD62P) and thromboelastography (TEG) reaction times were investigated. RESULTS: After 21 days of storage at 4°C, a large number of activated platelets (PAC1+62P+, PAC1-62P+) within the red blood cell suspension (RBCs) retained their function and had TEG-maximum amplitude (TEG-MA) indices in the normal range. CONCLUSION: We report that platelets in RBC suspensions retain high activity when stored at 4°C for 21 days. The results provide important information for studies that involve storing platelets under cold conditions.

Controllable assembly of a three-dimensional metal-organic supramolecular framework displaying hydrogen-bonding and π-π stacking interactions.

The complex poly[[aqua(µ2-phthalato-κ(2)O(1):O(2)){µ3-2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]acetato-κ(4)N(2),N(3):O:O'}{µ2-2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]acetato-κ(3)N(2),N(3):O}dizinc(II)] dihydrate], {[Zn2(C10H8N3O2)2(C8H4O4)(H2O)]·2H2O}n, has been prepared by solvothermal reaction of 2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]acetonitrile (PPAN) with zinc(II). Under hydrothermal conditions, PPAN is hydrolyzed to 2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]acetate (PPAA(-)). The structure determination reveals that the complex is a one-dimensional double chain containing cationic [Zn4(PPAA)4](4+) structural units, which are further extended by bridging phthalate ligands. The one-dimensional chains are extended into a three-dimensional supramolecular architecture via hydrogen-bonding and π-π stacking interactions.

A one-dimensional coordination polymer created via in situ ligand synthesis involving C-N bond formation.

The novel cadmium complex catena-poly[cadmium(II)-µ3-{2-[3-(pyridin-2-yl)-1H-pyrazol-1-yl]butanedioato}], [Cd(C12H9N3O4)]n, has been prepared by the conjugate addition reaction of 2-(1H-pyrazol-3-yl)pyridine to fumaric acid in the presence of Cd(OAc)2·3H2O (OAc is acetate) at 413 K. Single-crystal X-ray diffraction analysis reveals that the complex consists of one-dimensional ladders constructed from [Cd2(COO)2] dimeric subunits. A combination of hydrogen bonding and π-π stacking interactions extend the one-dimensional ladders into a three-dimensional supramolecular architecture.

Controllable assembly of a three-dimensional metal-organic supramolecular framework including π-π stacking interactions.

The mixed-ligand metal-organic complex poly[(µ(3)-phthalato)[µ(2)-3-(pyridin-2-yl)-1H-pyrazol-1-ido]dicopper(II)], [Cu(2)(C(8)H(4)O(4))(C(8)H(6)N(3))(2)](n), has been synthesized by the reaction of copper(II) acetate with 2-(1H-pyrazol-3-yl)pyridine (HL) and phthalic acid. The binuclear chelating-bridging L units are further linked by bridging phthalate ligands into a two-dimensional network parallel to the (010) plane. The two-dimensional networks are extended into a three-dimensional supramolecular architecture via π-π stacking interactions.

Effect of a rock dust amendment on disease severity of tomato bacterial wilt.

Nutrients are important for growth and development of plants and microbes, and they are also important factors in plant disease control. The objective of this study was to evaluate the effect of a rock dust used as a fertilizer in maintaining health of soil and tomato plants under greenhouse conditions. Four treatments-including M (commercial organic fertilizer), A (rock dust soil amendment), M + A (commercial organic fertilizer + rock dust soil amendment) and CK (blank control)--were examined for their effect on soil properties, soil enzymatic activity, plant growth and control efficacy against tomato bacterial wilt. Treatments A and M + A were significantly better than other treatments in changing soil pH, increasing it from acidic (pH 5.13) to nearly neutral (pH 6.81 and 6.70, respectively). Enzymatic activities in soil were notably influenced by the different treatments--particularly treatment M + A, which increased the activities of alkaline phosphatase, urease, catalase and sucrase to a greater extent in soil. There was no significant difference (P < 0.05) in the effects of treatments A and M + A on tomato plant height, stem diameter and biomass. The effect of the four treatments on the chlorophyll content and photosynthetic rate (in decreasing order) were M + A, A, M and CK. The replicate greenhouse experiments showed that the control efficacies of treatments M + A, A, and M against bacterial wilt were respectively 89.99, 81.11 and 8.89 % in first experiment and with the efficacies of 84.55, 74.36, and 13.49 % in the replicate; indicating that rock dust played a key role in the plant-soil interaction. The raised soil pH and Ca content were the key factors for the rock dust amendment controlling bacterial wilt under greenhouse conditions.

Bis[1-phenyl-3-(1H-1,2,4-triazol-1-yl-κN(4))propan-1-one]bis-(thio-cyanato-κN)copper(II).

The title compound, [Cu(NCS)(2)(C(11)H(11)N(3)O)(2)], contains two independent Cu(II) atoms. Each Cu(II) atom, lying on an inversion center, is coordinated by two N atoms from two NCS(-) anions and two N atoms from two monodentate 1-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-1-one ligands in a distorted square-planar geometry. Two S atoms from adjacent mol-ecules occupy the axial positions with long Cu⋯S distances [3.0495 (10) and 3.1045 (9) Å] and complete the overall distorted octahedral coordination sphere. Weak inter-molecular C-H⋯O hydrogen bonds are present.

Bis(nitrato-κO)tetra-kis-[1-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-1-one]copper(II).

In the title complex, [Cu(NO(3))(2)(C(11)H(11)N(3)O)(4)], the Cu(II) atom is situated on a centre of inversion and is coordinated by two O atoms from two nitrate anions and four N atoms from four monodentate 1-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-1-one ligands in a distorted octa-hedral geometry. Weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds result in a supra-molecular layer parallel to (101). These layers are connected by π-π inter-actions between the benzene rings [centroid-centroid distance = 3.891 (2) Å].