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As the high calibre candidate of lightweight and flexible solar cells, polymer solar cells (PSCs) have made tremendous progress in recent years. However, the active photovoltaic materials in PSCs are mainly synthesized by metal-mediated coupling reaction requiring harsh reaction conditions, multiple-step synthesis, and cumbersome purification, which is not cost-efficient and may bring toxicity concerns. It is not favorable to the production of photovoltaic polymers and PSC devices on a large scale, and therefore unsuitable for the PSCs industrialization. Direct arylation coupling reaction via aromatic C—H bonds activation enables the synthesis of conjugated polymers under mild conditions and simultaneously reduces synthetic steps, difficulty, and toxic reaction byproducts. This review provides an overview of the history of preparing representative photovoltaic polymers utilized in PSCs through direct arylation reactions and discusses the activity and selectivity of C—H bonds in typical building blocks under different reaction conditions. Especially, the impact of direct arylation condition on defect formation and photovoltaic performance of the photovoltaic polymers is addressed and compared with conventional Stille coupling methods. [ABSTRACT FROM AUTHOR]

Summary: Postmenopausal patients with osteoporosis who have a recent fracture are at very high risk of fracture, and this study finds that stratified treatment based on fracture risk would be a cost-effective treatment option for this population. Purpose: To evaluate the cost-effectiveness of four anti-osteoporosis medications (denosumab, zoledronate, teriparatide, and alendronate) for postmenopausal osteoporotic women in mainland China, using a stratified treatment strategy recommended by the American Association of Clinical Endocrinologists and the American College of Endocrinology (AACE/ACE). Methods: A microsimulation Markov model was used to compare the cost-effectiveness of the four treatments in postmenopausal osteoporotic patients of different ages (65, 70, 75, and 80 years), with a recent fracture from the Chinese healthcare perspective. The primary outcome was the incremental cost-effectiveness ratio (ICER), which represent the incremental cost per quality-adjusted life-year (QALY) obtained. One-way deterministic sensitivity analysis (DSA) and probabilistic sensitivity analysis (PSA) were performed to assess the robustness of model findings. Results: Alendronate was dominated by denosumab-to-alendronate and zoledronate at all ages examined, indicating that the costs of the two drugs were lower, but QALYs was greater. However, teriparatide-to-alendronate yielded an ICER of $76,432.07/ QALY, compared with alendronate at age 65, which exceeded the pre-determined willingness-to-pay threshold of $37,653/ QALY. The results were similar at other ages. The DSA showed that the most sensitive parameters were drug efficacy for vertebral and wrist fractures, the relative risk of vertebral fractures, and the persistence of the drugs. The PSA showed that zoledronate had a 100% probability of being the most cost-effective treatment, with a willingness-to-pay threshold of $37,653/ QALY. Conclusion: Stratified treatment based on very high fracture risk is more cost-effective than conventional pills in mainland China. Among the stratified treatments, zoledronate is the optimal option. [ABSTRACT FROM AUTHOR]

The active layer of all polymer solar cells (all-PSCs) is composed of a blend of a p-type conjugated polymer (p-CP) as donor and an n-type conjugated polymer (n-CP) as acceptor. All-PSCs possess the advantages of light weight, thin active layer, mechanical flexibility, low cost solution processing and high stability, but the power conversion efficiency (PCE) of the all-PSCs was limited by the poor photovoltaic performance of the n-CP acceptors before 2016. Since the report of the strategy of polymerized small molecule acceptors (PSMAs) in 2017, the photovoltaic performance of the PSMA-based n-CPs improved rapidly, benefitted from the development of the A-DA'D-A type small molecule acceptors (SMAs). PCE of the all-PSCs based on the PSMA acceptors reached 17%–18% recently. In this review article, we will introduce the development history of the n-CPs, especially the recent research progress of the PSMAs. Particularly, the structure-property relationship of the PSMAs is introduced and discussed. Finally, current challenges and prospects of the n-CP acceptors are analyzed and discussed. [ABSTRACT FROM AUTHOR]

Polymerizing the narrow bandgap small-molecule architecture with a conjugated linking unit (or called the polymerized small molecule acceptors (PSMAs)) is a promising strategy to design polymer acceptors for efficient all polymer solar cells (all-PSCs). Currently, the fused-ring-based small molecule acceptors (SMAs) are preferred monomers to design efficient PSMAs, leaving the challenge of reducing the materials cost. In this work, we firstly employ nonfused-core SMA with simple synthetic procedures to design PSMAs (namely PBTI-H, PBTI-F and PBTI-Cl) to address this issue. Relative to the fused-ring based counterparts, these three PSMAs exhibit much higher figure-of-merit value. Additionally, a power-conversion efficiency of 8.80% is achieved in the PBTI-Cl-based all-PSC. The results offer an attractive approach to design low-cost PSMAs for efficient all-PSCs. [ABSTRACT FROM AUTHOR]

Sorghum is largely grown for food, fodder and for biofuel production in semi-arid regions where the drought or high temperature or their combination co-occur. Plant microRNAs (miRNAs) are integral to the gene regulatory networks that control almost all biological processes including adaptation to stress conditions. Thus far, plant miRNA profiles under separate drought or heat stresses have been reported but not under combined drought and heat. In this study, we report miRNA profiles in leaves of sorghum exposed to individual drought or heat or their combination. Approximately 29 conserved miRNA families represented by 80 individual miRNAs, 26 families represented by 47 members of less conserved or sorghum-specific miRNA families as well as 8 novel miRNA families have been identified. Of these, 25 miRNAs were found to be differentially regulated in response to stress treatments. The comparative profiling revealed that the miRNA regulation was stronger under heat or combination of heat and drought compared to the drought alone. Furthermore, using degradome sequencing, 48 genes were confirmed as targets for the miRNAs in sorghum. Overall, this study provides a framework for understanding of the miRNA-guided gene regulations under combined stresses. [ABSTRACT FROM AUTHOR]

Azide-alkyne click polymerization has become a powerful tool for polymer synthesis. However, the click polymerization between internal alkynes and azides is rarely utilized to prepare functional polymers. In this work, the polymerization reactions of activated internal alkyne monomers of tris(2-butynoate)s (1) with tetraphenylethene-containing diazides (2) were performed in dimethylformamide (DMF) under simple heating, affording four hyperbranched poly(methyltriazolylcarboxylate)s (hb-PMTCs) with high molecular weights (Mw up to 2.4 × 104) and regioregularities (up to 83.9%) in good yields. The hb-PMTCs are soluble in common organic solvents, and thermally stable with 5% weight loss temperatures up to 400 °C. They are non-emissive in dilute solution, but become highly emissive in aggregated state, exhibiting aggregation-induced emission characteristics. The polymers can generate fluorescent photopatterns with high resolution, and can work as fluorescent sensors to detect nitroaromatic explosive with high sensitivity. [ABSTRACT FROM AUTHOR]

The copper-catalyzed and metal-free azide-alkyne click polymerizations have become efficient tools for polymer synthesis. However, the 1,3-dipolar polycycloadditions between internal alkynes and azides are rarely employed to construct functional polymers. Herein, the polycycloadditions of dibutynoate (1) and tetraphenylethene-containing diazides (2) were carried out at 100 °C for 12 h under solvent- and catalyst-free conditions, producing soluble poly(methyltriazolylcarboxylate)s (PMTCs) with high molecular weights in high yields. The resultant polymers were thermally stable with 5% weight loss temperatures up to 377 °C. The PMTCs showed aggregation-induced emission (AIE) properties. They could work as fluorescent sensors for detecting explosive with high sensitivity, and generate two-dimensional fluorescent photopatterns with high resolution. Furthermore, their triazolium salts could be utilized for cell-imaging applications. [ABSTRACT FROM AUTHOR]

Donor-acceptor (D-A) type fully conjugated block copolymer systems have been rarely reported due to the challenges in synthetic approaches to prepare well-defined low-polydispersity products. In this work, fully conjugated block copolymers are synthesized in a one-pot reaction through Stille coupling polycondensation, by utilizing the end-functional polymer copolymerization method. End-functional P3HT are copolymerized with AA (2,7-dibromo-9-(heptadecan-9-yl)-9 H-carbazole) and BB (4,7-bis(5-(trimethylstannyl)thiophen-2-yl)benzo[c][1,2,5]thiadiazole, TBT) type monomers, respectively. The orthogonal solubility between the very soluble P3HT donor and the insoluble PCDTBT acceptor block improves the purity of block copolymers as well as distinct nano-scale phase-separation compared with other reports on miscibility of donor and acceptor polymer block. Further purification via preparative GPC is carried out to remove the excess of unreacted P3HT and free PCDTBT as well as to achieve low polydispersity of block copolymers. The chemical structure of the P3HT- b-PCDTBT block copolymers are verified via H-NMR, and further confirmed by FTIR spectra. The block copolymer shows broad absorption and moderate optical band gap of 1.8 eV. Furthermore, the fully conjugated block copolymer films exhibit significant fine structures, much smoother film morphology compared to P3HT/PCDTBT polymer blends. By adding a small amount of block copolymer P3HT- b-PCDTBT as a compatibilizer into the bulk-heterojunction of P3HT:PCBM blends, polymer solar cells with an 8% increase of short circuit current ( J and 10% increase of power conversion efficiency (PCE) are achieved owing to the improvement of the active-layer film morphology. To the best of our knowledge, this is the first report on donor-acceptor type fully conjugated block copolymer as an effective ternary additive in polymer: fullerene bulk heterojunction solar cells. [ABSTRACT FROM AUTHOR]

Shape and size control of gold (Au) nanocrystals plays important roles in their catalytic and optical properties. Hierarchical Au nanodendrites were directly electrodeposited on a glassy carbon electrode (GCE) using l-arginine as a growth-directing agent, while there is no seed, template, or surfactant involved. It was found that the experimental conditions such as the applied potentials, concentrations of HAuCl and l-arginine, and deposition time were essential to the final morphology of the Au deposits. The as-synthesized Au nanocrystals displayed enhanced electrocatalytic activity and improved stability for ethylene glycol (EG) oxidation in acidic media as compared to Au nanoparticles. [ABSTRACT FROM AUTHOR]

Reaction of 2-phenyl-1,3-dibromopropane with in situ generated NaSe gave 4-phenyl-1,2-diselenolancyclopentane, which subsequently underwent the oxidative addition with Fe(CO) yielding the diiron diselenolato complex [( μ-SeCH)CHCH]Fe(CO) ( 1). Substitution of one or two carbonyls of complex 1 for triphenylphosphine (PPh) or cis-1,2-bis(diphenylphosphine)ethylene ( cis-dppv) in the presence of decarbonylating agent MeNO·2HO afforded the PPh-monosubstituted complex [( μ-SeCH)CHCH]Fe(CO)(PPh) ( 2) or the dppv-disubstituted complex [( μ-SeCH)CHCH]Fe(CO)( κ-dppv) ( 3). The structures of the four compounds were fully characterized by elemental analysis and various spectroscopic methods and for complexes 2 and 3 by X-ray crystallography. The cycle voltammetry under different conditions, such as CFCOOH, MeCN or CHCl, potential scan rate and temperature, was investigated. [ABSTRACT FROM AUTHOR]

Treatment of 2-phenyl-1,3-bis(selenocyanate)propane with Fe(CO) yielded the expected diiron diselenolato complex [( μ-SeCH)CHCH]Fe(CO) ( 1). Reaction of complex 1 with bis(diphenylphosphine)methane (dppm) in refluxing xylene gave an intra-molecular phosphine bridging complex [( μ-SeCH)CHCH]Fe(CO)( μ-dppm) ( 2), while reaction of complex 1 with 1,1′-bis(diphenylphosphino)ferrocene (dppf) in the presence of the decarbonylating agent MeNO afforded an inter-molecular phosphine bridging tetrairon complex {[( μ-SeCH)CHCH]Fe(CO)}( μ, κ, κ-dppf) ( 3). All three complexes were characterized by physical-chemical and spectroscopic methods and for complexes 2 and 3 by X-ray crystallography. Their electrochemical behaviors, especially in the presence of HBF for 2, were investigated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

In this report, a simple and facile method was developed for preparation of MnO nanowires by calcinations of MnOOH nanowires previously synthesized under hydrothermal conditions, using hexamethylenetetramine as a reducing agent, without any template. The as-prepared MnO nanowires displayed an enhanced specific capacitance (262.7 F g) and good cycling stability (e.g., no loss within 1,500 cycles), showing good electrochemical performances as electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

A simple method was developed for synthesis of network-like gold nanochains and gold nanoflowers in the presence of cytosine by reduction of tetrachloroauric acid with sodium borohydride and ascorbic acid, respectively. The resulting gold nanocrystals were coated with microperoxidase-11 via electrostatic interactions. Electrodes modified with protein-coated gold nanochains or nanoflowers display well-defined and quasireversible redox peaks and enhanced high electrocatalytic activity toward the reduction of HO that is due to direct electron transfer to the protein. The effects were exploited for the amperometric detection of HO with a linear response from 0.5 μM to 0.13 mM (for the gold nanochains) and from1.0 μM to 0.11 mM (for the gold nanoflowers), respectively. The sensor shows lower detection limit and faster response time than sensors based on the use of spherical gold nanoparticles. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Arabidopsis nudix hydrolase 7 ( Atnudt7) mutants exhibit reduced seed germination phenotype following after-ripening. The role of AtNUDT7 in seeds and during early stages of imbibition was examined. Seeds of Atnudt7- 1 and Col-0 following 3 days of imbibition were used to profile changes in NADH- and ADP-ribose pyrophosphohydrolase enzyme activities, expression of nudix family genes closely related to AtNudt7, and AtNUDT7 protein levels. Changes in pyridine nucleotides, phytohormones, reactive oxygen species and poly(ADP-ribose) levels in after-ripened seeds and 1 day after imbibition were also analyzed. Changes in AtNUDT7 gene expression, protein levels and enzyme activities in WT seeds and during early stages of imbibition were correlated. Atnudt7- 1 seeds lacked NADH pyrophosphohydrolase activity that led to very high catabolic redox charge. Abscisic acid (ABA) levels were higher in Atnudt7- 1 mutant while salicylic acid, gibberellic acid, and reactive oxygen species (ROS) levels were higher in WT seeds. In Atnudt7- 1, there was excess ROS accumulation 1 day after imbibition. PAR levels were significantly higher in Atnudt7- 1 mutant when compared to WT during imbibition. Based on these observations, we conclude NADH pyrophosphohydrolase activity conferred by AtNUDT7 is important for NAD:NADH homeostasis in seeds. Perturbations to this key redox couple alter ABA and ROS levels in the seeds that in turn lowers germination. [ABSTRACT FROM AUTHOR]

Carbonyl substitution reactions of [ μ-(SCH)CHCH]Fe(CO) with bidentate phosphine ligands, cis-1,2-bis(diphenylphosphine)ethylene ( cis-dppv) and N, N-bis(diphenylphosphine)propylamine [(PhP)N-Pr- n], yielded an asymmetrically substituted chelated complex [( μ-SCH)CHCH]Fe(CO)( k-dppv) and a symmetrically substituted bridging complex [( μ-SCH)CHCH]Fe(CO)[ μ-(PPh)N-Pr- n] under different reaction conditions. Both complexes were fully characterized by spectroscopic methods and by X-ray crystallography. Their electrochemical behaviors were observed by cyclic voltammetry, and the catalytic electrochemical reduction of protons from acetic or trifluoroacetic acid to give dihydrogen mediated by complex [( μ-SCH)CHCH]Fe(CO)( k-dppv) was investigated. [ABSTRACT FROM AUTHOR]

Five higher chlorinated benzenes (including hexachlorobenzene (HCB), pentachlorobenzene (PeCB) and three isomers of tetrachlorobenzens) were measured in the livers of grass carp and common carp collected from five markets in Xinxiang city, China. HCB and PeCB were detected in all samples. The major component of the higher CBs residue was HCB and significant correlations existed between HCB and PeCB in both grass carp and common carp livers. The ratio range of HCB/PeCB in grass carp and common carp were 3.4-6.2 and 4.9-7.7, respectively, which implied the sources of higher CBs originate mainly from the revolatilization of industrial HCB with a minor impact from PeCB. [ABSTRACT FROM AUTHOR]

Single crystalline vertical nanorod arrays and nanoflowers of ZnO have been grown in situ on cheap zinc foils under hydrothermal conditions, by means of hexamethylenetetramine and ethanolamine, respectively. Their morphologies and crystal structures are characterized by X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. The nanorods and flowers of ZnO grew along the $$ \{ 10\bar{1}1\} $$ and $$ \{ 0001\} $$ planes, respectively. Both types of ZnO display high photocatalytic ability toward the degradation of methylene orange under UV irradiation. The ZnO nanorods show better performance than that of the ZnO nanoflowers, and the $$ \{ 10\bar{1}1\} $$ facets of the ZnO nanorods have higher photoactivity than that of the $$ \{ 000\bar{1}\} $$ or $$ \{ 10\bar{1}0\} $$ crystal planes. This is because the weaker coordinated O atoms on the surface are more likely to be saturated by H atoms in aqueous solution, thereby releasing more free OH radicals. Graphical Abstract: A facile method was developed for selective control synthesis of ZnO nanoflowers and nanorod arrays on Zinc foil, with the assistance of ethanolamine and the hexamethylenetetramine, respectively. The illustration shows the time evolution of the two ZnO structures.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

A novel sensor for hydrogen peroxide (HO) was fabricated using β-MnO nanorods on a glassy carbon electrode (GCE). The nanorods were obtained by a hydrothermal method and characterized by scanning electron microscopy and X-ray diffraction. Cyclic voltammetry was used to evaluate the electrochemical performance of the modified GCE. The sensor exhibits excellent catalytic activity toward the oxidation of HO and displays a rather wide linear range (from 2.5 μM to 42.9 mM), high sensitivity (21.74 μA·mM), a low detection limit (2.45 μM at an S/N of 3), and a response time of <5 s. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The rural village, Taizhou of Zhejiang Province, had been exposed to e-waste recycling for years, the polybrominated diphenyl ether (PBDE) levels in hens and ducks were high. The concentration of ∑PBDEs in the brain was the lowest among tissues of individual hens and ducks after correction for the respective lipid content. Also, the concentration ratio of BDE-153 versus BDE-154 (153/154) of brain was the highest among tissues of individual hens and ducks. Our results indicate that the hindrance of blood-brain barrier to compounds, such as high molecular weight and non-planar conformation (steric hindrance), contributed to the low concentration of PBDEs in the brain tissue of hens and ducks, especially in cases exposed to high levels of PBDE. [ABSTRACT FROM AUTHOR]

Five higher Chlorinated Benzenes (CBs), include Hexachlorobenzene (HCB), pentachlorobenzene (PeCB) and three isomers of tetrachlorobenzens, were analyzed in 20 outdoor dust samples collected from a fast developing city, Xinxiang. Only HCB was detected in all outdoor dust samples. The dominate part of the CBs residue in most samples was HCB and the mean HCB concentration (4.13 ng/g dry weight) in this study was in the range of global background soil HCB levels (ranging from 0.010 to 5.20 ng/g dry weight). The higher ratios of HCB/PeCB in the outdoor dust samples in the present study indicate that pesticide application may be an important source of HCB in China. [ABSTRACT FROM AUTHOR]

Two soluble copolymers of fluorenone and dioctoxylbenzene (PFN) or anthracene (PFNAn) were synthesized through Heck polymerization, and were characterized by gel permeation chromatography (GPC), FT-IR, 1H-NMR, elemental analysis and thermogravimetric analysis. The polymers possess good solubility in common organic solvents and high thermal stability with the onset decomposition temperature at higher than 410 °C. The photophysical properties of the polymers were investigated in both solutions and spin-coated films. Cyclic voltammetry results revealed that the copolymers possess higher electron affinity and reversible reduction/re-oxidation processes. Their electroluminescent properties were further investigated. PFN and PFNAn show stable and saturated red light emission with high thermal stability and high electron injection ability. This type of conjugated polymers may be promising for the applications as electron acceptors in polymer photovoltaic cells and electron transporting materials. [ABSTRACT FROM AUTHOR]

The effects of amino acids (aa) and N-(diisopropyloxyphosphoryl)-amino acids (DIPP-aa) on cell membranes were investigated by evaluating water and methyl urea permeability. Permeability coefficients Pf and Ps were determined by standard osmotic methods for cells of Pisum sativum stem base epidermis after 20 min exposure to a 5 mM solution of each aa and DIPP-aa. The Pf value of P. sativum epidermal cells (untreated controls) was 1.3 ± 0.4 × 10-3 μm s-1. Treat ments with the diisopropyl-oxyphosphoryl derivatives of three one charged and three polar amino acids (serine, threonine, asparagine, and aspartic acid) and unsubstituted (free) serine and threonine increased water permeability up to about two fold of the control value. Serine and threonine and their DIPP-derivatives increased methyl urea permeability (controls 1.03 ± 0.09 × 10-3 μm s-1) 30 to 80 percent Other amino acids and their DIPP-derivatives caused small or insignificant changes of water permeability. Only certain polar amino acids and their DIPP-derivatives increased the osmotic water and methyl urea permeation through the plasma membrane. The specificity of these molecules on plasma membranes suggests that the active amino acids (serine and threonine) and their DIPP-derivatives interact with charged membrane molecules. The relatively small changes in water and methyl urea permeability may indicate that the effective aa’s and their DIPP-derivatives interact with phospholipids rather than aquaporin. A concurring alteration of water channel proteins, however, cannot excluded. [ABSTRACT FROM AUTHOR]