Self-Healing Conjugated Microporous Polyanilines for Effective and Continuous Catalytic Detoxification of 4-Nitrophenol to 4-Aminophenol.

Detoxification of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) with high efficiency and dynamic performance is challenging for a polymeric catalyst. Herein, a series of conjugated microporous polyanilines (CMPAs), capable of efficiently catalytically reducing 4-NP, were synthesized based on the Buchwald-Hartwig cross-coupling reaction mechanism. By adjusting the types of linkers and the molar ratios of linker to core, CMPAs with different Brunauer-Emmett-Teller (BET) specific surface areas and reduction degrees were obtained and used as the catalysts in reducing 4-NP. The ultrahigh catalytic reduction efficiency (K = 141.32 s-1 g-1, kapp = 0.00353 s-1) was achieved when using CMPA-3-0.7 as the catalyst (prepared with 4,4'-diaminodiphenylamine as the linker and a 0.7:1 molar ratio of linker to core). The catalytic reduction performance exhibited a strong correlation with the reduction degree and BET specific surface area of CMPAs. Furthermore, they also exhibit excellent cycling stability and dynamic performance. The coexistence of a microporous structure and high BET specific surface area endowed CMPAs with an increased number of catalytic active centers. The reversible redox transformation of CMPAs in the presence of NaBH4 and air enabled self-healing (the oxidation units in CMPAs were reduced to reduction units by NaBH4, and the newly generated reduction unit in CMPAs was subsequently oxidized to its original state by the O2 in the air), leading to the reduction reaction of 4-NP proceeded continuously and stably. The aforementioned factors resulted in the high efficiency of CMPAs for reducing 4-NP to 4-AP, enhancing the practical application prospects of CMPAs in the detoxification of 4-NP wastewater.

CommPath: An R package for inference and analysis of pathway-mediated cell-cell communication chain from single-cell transcriptomics.

Single-cell transcriptomics offers opportunities to investigate ligand-receptor (LR) interactions between heterogeneous cell populations within tissues. However, most existing tools for the inference of intercellular communication do not allow prioritization of functional LR associations that provoke certain biological responses in the receiver cells. In addition, current tools do not enable the identification of the impact on the downstream cell types of the receiver cells. We present CommPath, an open-source R package and webserver, to analyze and visualize the LR interactions and pathway-mediated intercellular communication chain with single-cell transcriptomic data. CommPath curates a comprehensive signaling pathway database to interpret the consequences of LR associations and therefore infers functional LR interactions. Furthermore, CommPath determines cell-cell communication chain by considering both the upstream and downstream cells of user-defined cell populations. Applying CommPath to human hepatocellular carcinoma dataset shows its ability to decipher complex LR interaction patterns and the associated intercellular communication chain, as well as their changes in disease versus homeostasis.

Sulfonated polydivinylbenzene bamboo-like nanotube stabilized Pickering emulsion for effective oxidation of olefins to 1,2-diol.

Sulfonated polydivinylbenzene bamboo-like nanotube (SPDVB) with effective olefins oxidation activity is prepared by combining cationic polymerization and sulfonation. By merely adjusting sulfonation time, SPDVB with different sulfonic acid group (-SO3H) contents is achieved. SPDVB is used as both a solid emulsifier and catalyst to fabricate Pickering emulsion interface catalytic system for oxidizing olefins with 30% H2O2 acting as oxidant/water phase and olefins acting as reactants/oil phase. It is shown that Pickering emulsion interface catalytic system stabilized by SPDVB exhibits enhanced olefins oxidation efficiency than the conventional ones. At the optimum catalyst and reaction condition, the conversion of olefins by Pickering emulsion interface catalytic system stabilized by SPDVB for cyclohexene, 1-methylcyclohexene, cyclooctene, 2,3-dimethyl-2-butene oxidation is higher than 90.00% and the corresponding 1,2-diol selectivity exceeds 93.00% except the selectivity to 1-methyl-1,2-cyclohexanediol. The catalytic system also exhibits excellent cycling performance (>95.00% olefins conversion and >89.00% 1,2-diol selectivity for cyclohexene/2,3-dimethyl-2-butene oxidation after four cycles). A possible mechanism for oxidation of olefins to 1,2-diol by SPDVB stabilized Pickering emulsion is proposed: the high catalytic interface area between sulfonic acid group and H2O2 in water phase enhances the sulfonic acid group of SPDVB to convert into peroxysulfonic acid (catalytic activity centre) firstly; then the formed peroxysulfonic acid attacks the double bond of olefins to form epoxide intermediates, which will be hydrolyzed to 1,2-diol.

The effect of perceived social support during early pregnancy on depressive symptoms at 6 weeks postpartum: a prospective study.

BACKGROUND: Postpartum depression was associated with maternal suffering and diminished functioning, increased risk of marital conflict as well as adverse child outcomes. Perceived social support during pregnancy was associated with postpartum depression among women. However, its causal relationship remains unclear. Therefore, we prospectively evaluate the association between perceived social support during early pregnancy and postpartum depressive symptoms. METHODS: We prospectively examined whether perceived social support during early pregnancy affected depressive symptoms at 6 weeks postpartum in a cohort of 3310 women. Perceived social support and postpartum depression were assessed by ENRICHD Social Support Instrument (ESSI) and the postpartum Edinburgh Postpartum Depression Scale (EPDS), respectively. Prevalence of postpartum depressive symptoms was 11.4% (EPDS cutoff≥10). As a test of heterogeneity of association in subpopulations, logistic regression models were performed to analyze the association between social support and postpartum depressive symptoms in strata which were defined by the potential confounder candidates. After multiple imputation, multivariable logistic regression was performed to assess the effect of social support on postpartum symptoms in individual items and total score. Two models were built. Model I adjusted for the variables associated with social support or postpartum depression and changed the association estimates by ≥10%. Model II adjusted for all variables that may be related to social support or postpartum depression. RESULTS: Significant associations between low perceived social support and postpartum depressive symptoms was found(Model I odds ratio: 1.63, 95% confidence interval: 1.15, 2.30; Model II odds ratio: 1.77, 95% confidence interval: 1.24-2.52). Stratified analyses showed that there was little evidence of heterogeneity of association in subpopulations by basic characteristics of participants. CONCLUSIONS: These findings suggest that early intervention may be able to help protect against depression symptoms at 6 weeks postpartum.

miR-181b-5p promotes proliferation and inhibits apoptosis of hypertrophic scar fibroblasts through regulating the MEK/ERK/p21 pathway.

Hypertrophic scar (HS) is a common skin disorder occurring during the wound healing process, and the pathogenesis of HS remains unclear. Previous studies indicated that miRNAs may be involved in the onset and progression of HS. In the present study, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blotting were used to investigate the expression of miR-181b-5p and decorin in HS tissues. Direct interaction between miR-181b-5p and decorin was confirmed using a dual-luciferase assay. Human HS fibroblasts (HSFbs) were cultured and transfected with miR-181b-5p mimics, and MTT assay and Annexin V fluorescein isothiocyanate/propidium iodide staining were performed to investigate the role of miR-181b-5p in the proliferation and apoptosis of HSFbs. Subsequently, the expression levels of mitogen-activated protein kinase kinase (MEK), phospho (p)-extracellular signal-regulated kinase (ERK) and p21 were determined in HSFbs transfected with miR-181b-5p mimics and untransfected cells using RT-qPCR and western blotting. The results indicated upregulation of miR-181b-5p and downregulation of decorin expression in HS tissues compared with normal skin samples. miR-181b-5p may regulate the expression of decorin through direct binding to the 3'-untranslated region, as demonstrated by the results of the dual-luciferase assay. Transfection with miR-181b-5p mimics in HSFbs enhanced cell proliferation, reduced apoptosis and increased the expression of MEK, p-ERK and p21. Furthermore, treatment with MEK inhibitor in HSFbs transfected with miR-181b-5p mimics partially inhibited miR-181b-5p-induced antiapoptotic effects. Taken together, increased expression of miR-181b-5p may serve important roles in the pathogenesis of HS through regulating the MEK/ERK/p21 pathway, suggesting that miR-181b-5p may be a therapeutic target for the treatment of HS.

Effects of grape seed proanthocyanidin on Alzheimer's disease in vitro and in vivo.

Grape seed proanthocyanidin (GSPA) consists of catechin, epicatechin and epicatechin gallate, which are strong antioxidants that are beneficial to health and may attenuate or prevent Alzheimer's disease (AD). In the present study, the effects of GSPA on pheochromocytoma (PC12) cell viability were determined using cell counting kit-8 and lactate dehydrogenase (LDH) assays, whereas apoptosis and mitochondrial membrane potential (Ψm) were measured via flow cytometry analysis. The effect of GSPA administration on the behavior and memory of amyloid precursor protein (APP)/presenilin-1 (PS-1) double transgenic mice was assessed using a Morris water maze. APP Aß peptides and tau hyperphosphorylation were examined by western blotting; whereas the expression levels of PS-1 were evaluated by reverse transcription-quantitative polymerase chain reaction and compared with pathological sections stained with hematoxylin-eosin and Congo red. Data from the in vitro experiments demonstrated that GSPA significantly alleviated Aß25-35 cytotoxicity and LDH leakage ratio, inhibited apoptosis and increased Ψm. The findings from the in vivo experiments showed a significant enhancement in cognition and spatial memory ability, an improvement in the pathology of APP and tau protein and a decrease in PS-1 mRNA expression levels. Therefore, the results of the present study indicated that GSPA may be a novel therapeutic strategy for the treatment of AD or may, at the very least, improve the quality of life of patients with AD.

[Study on the Technology of the 4.4 µm Mid-Infrared Laser Heterodyne Spectrum].

In this paper, first time as our knowledge, we describe the development and performance evaluation of a 4.4 µm external cavity quantum cascade laser based laser heterodyne radiometer. Laser heterodyne spectroscopy is a high sensitive laser spectroscopy technique which offers the potential to develop a compact ground or satellite based radiometer for Earth observation and astronomy. An external cavity quantum cascade laser operating at 4. 4 µm, with output power up to 180 mW and narrow line width was used as a local oscillation. The external cavity quantum cascade laser offers wide spectral tuning range, it is tunable from 4.38 to 4.52 µm with model hop free and can be used for simultaneous detections of CO2, CO and N2 O. A blackbody was used as a signal radiation source. Development and fundamental theory of Laser heterodyne spectroscopy was described. The performance of the developed Laser heterodyne radiometer was evaluated by measuring of CO2 spectral at different pressures. Analyses results showed that a signal-to-noise ratio of 86 was achieved which was less than the theoretical value of 287. The spectral resolution of the developed Laser heterodyne spectroscopy is about 0.007 8 cm(-1) which could meet the requirement of high resolution spectroscopy measurement in the case of Doppler linewidth. The experiment showed that middle Infrared laser heterodyne spectroscopy system had high signal-to-noise ratio and spectral resolution, and had broad application prospect in high precision measurement of atmospheric greenhouse gas concentration and vertical profile.

Nanoparticle Capture During Directional Solidification of Nano-Sized SiC Particle-Reinforced AZ91D Composites.

The capture/push behavior of a particle in front of a solidification interface was analyzed theoretically and experimentally in this work. Van der Waals force, viscous force, and force due to interfacial energy played important roles in the particle capture/push process. Directional solidification experiments were conducted with nano-sized SiC particle-reinforced AZ91D composites to observe the distribution of nanoparticles in different solidification morphologies under varied cooling rates. When the composite solidified with plane manner, the nanoparticles could be captured by the solidification front and distributed uniformly in the matrix. When solidified with columnar or equiaxial manners, the nanoparticles could be captured by the solidification front but distributed uniformly only in the grain boundary as a result of the difference in interfacial energy and wettability between SiC/α-Mg and SiC/eutectic phase. Theoretical prediction of particle capture was in agreement with the experiment results.

Catalytic asymmetric sulfenylation to structurally diverse dithioketals.

We report the first example of the highly enantioselective synthesis of structurally diverse chiral dithioketals via asymmetric sulfenylation of various types of S-based nucleophiles, catalyzed by a cheap cinchona alkaloid derivative, dihydroquinine.

Preparation of Monoclonal Antibodies Against Bovine Progesterone.

Female, 8-week-old BALB/c mice were immunized with the progesterone complete antigen (P4-BSA). Two monoclonal antibodies (MAbs) against P4, named 8G6 and 11A11, were obtained by the lymphocyte hybridoma technique. The titers of the cell culture supernatant and ascitic fluid of MAb 8G6 were 1: 16,000 and 1:512,000, respectively, and the titers of the cell culture supernatant and ascitic fluid of MAb 11A11 were 1: 8000 and 1:256,000, respectively. The subtypes of the MAbs 8G6 and 11A11 were IgMκ. In specific analysis, both of the two MAbs did not react with estradiol. These data demonstrated that the MAbs 8G6 and 11A11 have a potential use for developing diagnostic reagents of progesterone.

[Yearly Changes of Phytoplankton Community in the Ecology-monitoring Area of Changli, Hebei in Summer].

Based on the investigation of phytoplankton and water body nutrient concentration in the ecology-monitoring area of Changli in summer from 2005 to 2013, the phytoplankton community structure was analyzed. The result showed that in recent 9 years, 3 phyla including 23 families, 39 genera and 105 species of phytoplankton were identified, in which 85.7% were diatoms and 13.3% were dinoflagellate. Only one species was found belonging to golden algae. There was great difference in dominant species among different years. According to the value of dominance, there were Coscinodiscus radiatus, Coscinodiscus debilis, Rhizosolenia styliformis, Cerataulina bergoni, Coscinodiscus wailesii, Thalassiosira sp., Ceratium tripos, Chaetoceros lorenzianus, Skeletonema costatum. The cell abundance was decreased yearly. The Shannon-Wiener index of phytoplankton community ranged from 0.015 to 3.889, and the evenness index ranged from 0.009 to 1, which showed little yearly change. And phytoplankton species were unevenly distributed among the 19 sites, there were relatively low amount of dominant species, but the dominance was relatively high. Canonical Correspondence Analysis (CCA) results of the phytoplankton community and its environmental factors showed that the environmental factors influencing the change of phytoplankton community structure in summer included water temperature, nutrients (TP, TN and NO3(-) -N, NH4(+)-N) and salinity, and the structural change was the result of the interactions of different environmental factors.

Michael Addition Catalyzed by Chiral Secondary Amine Phosphoramide Using Fluorinated Silyl Enol Ethers: Formation of Quaternary Carbon Stereocenters.

A chiral secondary amine phosphoramide was developed and identified as a powerful catalyst for the Mukaiyama-Michael addition of fluorinated enol silyl ethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternary carbon stereocenter bearing either a difluoroalkyl or monofluoroalkyl group.

Highly enantioselective Michael addition of 3-arylthio- and 3-alkylthiooxindoles to nitroolefins catalyzed by a simple cinchona alkaloid derived phosphoramide.

A new cinchona alkaloid derived bifunctional tertiary amine-phosphoramide is identified as a highly enantioselective catalyst for Michael addition of both unprotected 3-arylthio- and 3-alkylthiooxindoles to nitroolefins. The phosphoramide moiety of plays an indispensable role in this reaction.

Asymmetric copper(I)-catalyzed azide-alkyne cycloaddition to quaternary oxindoles.

We report a highly enantioselective Cu(I)-catalyzed azide-alkyne cycloaddition via asymmetric desymmetrization of oxindole-based 1,6-heptadiynes, which furnishes quaternary oxindoles bearing a 1,2,3-triazole-containing moiety with 84-98% ee.

Decacarbon-yl[µ(4)-(ethane-1,2-diyl-dinitrilo)-tetra-kis-(methane-thiol-ato)]bis(triphenyl-phosphane)tetra-iron(2 Fe-Fe).

In the title compound, [Fe(4)(C(6)H(12)N(2)S(4))(C(18)H(15)P)(2)(CO)(10)], the unit cell contains one mol-ecule, which exhibits a crystallographically imposed center of symmetry. The independent Fe(2)S(2) fragment [Fe-Fe = 2.527 (1) Å] is in a butterfly conformation, and each Fe atom displays a pseudo-square-pyramidal coordination geometry. The phosphane group occupies an apical position [Fe-P = 2.2670 (14) Å]. In the crystal, weak inter-molecular C-H⋯O hydrogen bonds link the mol-ecules into chains along [110].

A study on orthodontic bone-bonding anchorage.

OBJECTIVES: The study had two objectives: (1) to measure the maximum loading capacity of a new skeletal orthodontic anchorage, designated the "bone-bonding anchorage," and (2) to study its histological basis. MATERIALS AND METHODS: A total of 81 bone-bonding anchorages were fixed onto the surface of the tibia of 12 big-ear white rabbits with N-2-butyl cyanoacrylate. The 12 animals were divided into groups designated as the immediate, 2-week, 4-week, and 8-week after-surgery groups. The maximum loading capacity of each group was measured, and histological changes were observed. RESULTS: The results indicate a tendency toward an initial decrease and then an increase in the maximum loading capacity of the bone-bonding anchorage. The mean value of the 8-week group reached 45.69 N, which can satisfy orthodontic clinical needs. Histologically, new bone formation was found around the base of the bone-bonding anchorage, which wrapped the base until it was bone-buried, creating the histological basis of the maximum loading capacity. In the experiment, the total failure rate of the bone-bonding anchorage was 13.6%, and no failure occurred in the immediate and 8-week groups. CONCLUSION: The loading capacity of the bone-bonding anchorage is sufficient for orthodontic use, but whether or not it can be applied to clinical practice merits further study.

Attachment of a hydrogen-bonding carboxylate side chain to an [FeFe]-hydrogenase model complex: influence on the catalytic mechanism.

Azapropanedithiolate (adt)-bridged model complexes of [FeFe]-hydrogenase bearing a carboxylic acid functionality have been designed with the aim of decreasing the potential for reduction of protons to hydrogen. Protonation of the bisphosphine complexes 4-6 has been studied by in situ IR and NMR spectroscopy, which revealed that protonation with triflic acid most likely takes place first at the N-bridge for complex 4 but at the Fe-Fe bond for complexes 5 and 6. Using an excess of acid, the diprotonated species could also be observed, but none of the protonated species was sufficiently stable to be isolated in a pure state. Electrochemical studies have provided an insight into the catalytic mechanisms under strongly acidic conditions, and have also shown that complexes 3 and 6 are electro-active in aqueous solution even in the absence of acid, presumably due to hydrogen bonding. Hydrogen evolution, driven by visible light, has been observed for three-component systems consisting of [Ru(bpy)(3)](2+), complex 1, 2, or 3, and ascorbic acid in CH(3)CN/D(2)O solution by on-line mass spectrometry.

Binuclear iron-sulfur complexes with bidentate phosphine ligands as active site models of Fe-hydrogenase and their catalytic proton reduction.

The displacement of CO in a few simple Fe(I)-Fe(I) hydrogenase model complexes by bisphosphine ligands Ph2P-(CH2)n-PPh2 [with n = 1 (dppm) or n = 2 (dppe)] is described. The reaction of [{mu-(SCH2)2CH2}Fe2(CO)6] (1) and [{mu-(SCH2)2N(CH2CH2CH3)}Fe2(CO)6] (2) with dppe gave double butterfly complexes [{mu-(SCH2)2CH2}Fe2(CO)5(Ph2PCH2)]2 (3) and [{mu-(SCH2)2N(CH2CH2CH3)}Fe2(CO)5(Ph2PCH2)]2 (4), where two Fe2S2 units are linked by the bisphosphine. In addition, an unexpected byproduct, [{mu-(SCH2)2N(CH2CH2CH3)}Fe2(CO)5{Ph2PCH2CH2(Ph2PS)}] (5), was isolated when 2 was used as a substrate, where only one phosphorus atom of dppe is coordinated, while the other has been converted to P=S, presumably by nucleophilic attack on bridging sulfur. By contrast, the reaction of 1 and 2 with dppm under mild conditions gave only complexes [{mu-(SCH2)2CH2}Fe2(CO)5(Ph2PCH2PPh2)] (6) and [{mu-(SCH2)2N(CH2CH2CH3)}Fe2(CO)5(Ph2PCH2PPh2)] (8), where one ligand coordinated in a monodentate fashion to one Fe2S2 unit. Furthermore, under forcing conditions, the complexes [{mu-(SCH2)2CH2}Fe2(CO)4{mu-(Ph2P)2CH2}] (7) and [{mu-(SCH2)2N(CH2CH2CH3)}Fe2(CO)4{mu-(Ph2P)2CH2}] (9) were formed, where the phosphine acts as a bidentate ligand, binding to both the iron atoms in the same molecular unit. Electrochemical studies show that the complexes 3, 4, and 9 catalyze the reduction of protons to molecular hydrogen, with 4 electrolyzed already at -1.40 V versus Ag/AgNO3 (-1.0 V vs NHE).

Bidentate phosphine ligand based Fe2S2-containing macromolecules: synthesis, characterization, and catalytic electrochemical hydrogen production.

The reaction of [Fe2(CO)6(mu-SCH2)2NCH2CH2N(mu-SCH2)2Fe2(CO)6] (1) with 1,2-bis(diphenylphosphino)ethane in the presence of Me3NO.2H2O affords two structurally different metallomacromolecules: a dimer of the type [{Fe2(CO)5(mu-SCH2)2NCH2CH2N(mu-SCH2)2Fe2(CO)5}(Ph2PCH2)2] (2) and a tetramer species containing eight iron centers with an overall formula of [{Fe2(CO)6(mu-SCH2)2NCH2CH2N(mu-SCH2)2Fe2(CO)5}2(Ph2PCH2)2] (3). Their structures have been determined by X-ray crystallography, showing one macrocyclic complex (2) and one linear complex (3). Electrochemical hydrogen evolution catalyzed by these two complexes with ca. 80-90 single-run turnovers is observed, indicating good potential as catalysts for future applications.