Cadmium-containing windmill-like heteropolyoxoniobate macrocycle with high yield for catalyzing Knoevenagel condensation.

A rare cadmium-containing windmill-like heteropolyoxoniobate macrocycle has been successfully synthesized with stable 1-D cyclic cluster aggregates. The compound exhibited promising basic catalytic ability for Knoevenagel condensation with a high yield under mild reaction conditions and high cycling stability. The theoretical calculation showed that the promising basic catalytic ability is due to the dense and stronger basic sites of the surface terminal O atoms.

Electrophotocatalytic oxygenation of multiple adjacent C-H bonds.

Oxygen-containing functional groups are nearly ubiquitous in complex small molecules. The installation of multiple C-O bonds by the concurrent oxygenation of contiguous C-H bonds in a selective fashion would be highly desirable but has largely been the purview of biosynthesis. Multiple, concurrent C-H bond oxygenation reactions by synthetic means presents a challenge1-6, particularly because of the risk of overoxidation. Here we report the selective oxygenation of two or three contiguous C-H bonds by dehydrogenation and oxygenation, enabling the conversion of simple alkylarenes or trifluoroacetamides to their corresponding di- or triacetoxylates. The method achieves such transformations by the repeated operation of a potent oxidative catalyst, but under conditions that are sufficiently selective to avoid destructive overoxidation. These reactions are achieved using electrophotocatalysis7, a process that harnesses the energy of both light and electricity to promote chemical reactions. Notably, the judicious choice of acid allows for the selective synthesis of either di- or trioxygenated products.

Electrochemical vicinal oxyazidation of α-arylvinyl acetates.

α-Azidoketones are valuable and versatile building blocks in the synthesis of various bioactive small molecules. Herein, we describe an environmentally friendly and efficient electrochemical vicinal oxyazidation protocol of α-arylvinyl acetates to afford diverse α-azidoketones in good yields without the use of a stoichiometric amount of chemical oxidant. A range of functionality is shown to be compatible with this transformation, and further applications are demonstrated.

Melatonin protects oocytes from MEHP exposure-induced meiosis defects in porcine.

In 2011, DEHP (plasticizer) was reported to illegally be added in food and beverage products in Taiwan, which caused great concerns about food safety worldwide. DHEP has multiple toxic effects to human and animals such as endocrine disruption, cardiotoxicity, reproductive function, and development defects. However, the toxic effects of DEHP on mammalian oocyte quality are still unclear. Since MEHP is the active metabolite of DEHP in vivo, in this study we used porcine oocyte as model to explore the effects of MEHP on oocyte maturation and we also studied the effects of melatonin administration on MEHP exposure-induced meiosis defects. Our results showed that exposure to MEHP significantly decreased the polar body extrusion rate in porcine oocytes. Further study showed that cell cycle progression, meiotic spindle organization, and actin assembly were all disturbed after MEHP exposure. Moreover, the DNA and histone methylation levels were also affected, showing with altered 5mC and H3K4me2 levels. These results indicated that MEHP affected porcine oocyte maturation, while MEHP exposure-induced meiotic defects were all remarkably ameliorated by the administration of melatonin in porcine oocytes. We further tried to explore the causes of MEHP toxicity on oocytes, and we found that MEHP exposure resulted in significant elevations of oxidative stress and induced early apoptosis as well as elevated autophagy, while melatonin administration could reduce these. Taken together, our results indicated that MEHP exposure induced deterioration of oocyte quality, whereas melatonin supplement showed amelioration on oocyte maturation through its rescue effects on oocyte oxidative stress-mediated apoptosis and autophagy.

Single junction inverted polymer solar cell reaching power conversion efficiency 10.31% by employing dual-doped zinc oxide nano-film as cathode interlayer.

We present high efficiency and stable inverted PSCs (i-PSC) by employing sol-gel processed simultaneously doped ZnO by Indium and fullerene derivative (BisNPC60-OH) (denoted as InZnO-BisC60) film as cathode interlayer and PTB7-Th:PC71BM as the active layer (where PTB7-Th is a low bandgap polymer we proposed previously). This dual-doped ZnO, InZnO-BisC60, film shows dual and opposite gradient dopant concentration profiles, being rich in fullerene derivative at the cathode surface in contact with active layer and rich in In at the cathode surface in contact with the ITO surface. Such doping in ZnO not only gives improved surface conductivity by a factor of 270 (from 0.015 to 4.06 S cm(-1)) but also provides enhanced electron mobility by a factor of 132 (from 8.25*10(-5) to 1.09*10(-2) cm(2) V(-1) s(-1)). The resulting i-PSC exhibits the improved PCE 10.31% relative to that with ZnO without doping 8.25%. This PCE 10.31% is the best result among the reported values so far for single junction PSC.

Physically adsorbed fullerene layer on positively charged sites on zinc oxide cathode affords efficiency enhancement in inverted polymer solar cell.

We present a novel idea for overcoming the drawback of poor contact between the ZnO cathode and active layer interface in an inverted polymer solar cell (i-PSC), simply by incorporating an electron-acceptor self-assembled monolayer (SAM)--tetrafluoroterephthalic acid (TFTPA)--on the ZnO cathode surface to create an electron-poor surface of TFTPA on ZnO. The TFTPA molecules on ZnO are anchored on the ZnO surface by reacting its carboxyl groups with hydroxyl groups on the ZnO surface, such that the tetrafluoroterephthalate moieties lay on the surface with plane-on electron-poor benzene rings acting as positive charge centers. Upon coating a layer of fullerenes on top of it, the fullerene molecules can be physically adsorbed by Coulombic interaction and facilitate a promoted electron collection from the bulk. The active layer is composed of the mid bandgap polymer poly(3-hexylthiophene) (P3HT) or low bandgap polymer, poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7), as the donor and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) or [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as the acceptor. Significant enhancement in power conversion efficiency (PCE) was observed for the devices with the active layer P3HT:PC61BM (or PC71BM) by promoting from 3.20 to 4.03% (or from 3.27 to 4.04%) and with the active layer PTB7:PC71BM from 6.03 to 6.90%. This method should be also applicable to other types of active layer.

Dual involvements of cyclooxygenase and nitric oxide synthase expressions in ketamine-induced ulcerative cystitis in rat bladder.

AIMS: The aims of the present study were to investigate voiding patterns, tissue constituents and the expressions of cyclooxygenase-2 (COX-2) and nitric oxide synthase (NOS) involved in ketamine-induced ulcerative cystitis in rat urinary bladder. METHODS: Thirty Sprague-Dawley rats were distributed into three groups which received saline or ketamine (25 mg/kg/day) for a period of 14 and 28 days. In each group, cystometry was performed weekly and the concentration of ketamine and its metabolites (norketamine) was assayed. Paraffin-embedded sections were stained with Masson's trichrome stain, and ketamine-induced morphological changes were examined. Western blot analyses were carried out to examine the expressions of COX-2 and different NOS isoforms in bladder tissues. Immunofluorescence study was done to evaluate the expressions of COX-2 and macrophage infiltration (stained with ED-1 macrophage cell surface antigen) within the bladder. RESULTS: Ketamine treatment resulted in bladder hyperactivity and the non-voiding contractions were significantly increased. The urine concentrations of ketamine and norketamine were much higher in ketamine-treated group. Moreover, ulcerated urothelium and mononuclear cell infiltration were noted in ketamine-treated group. These alterations in urodynamic functions and tissue constituents were accompanied by increases in the expression of COX-2. Two NOS isoforms (iNOS and eNOS) were also overexpressed, but no significant change was observed for nNOS. COX-2 positive stained cells were significantly increased. Meanwhile, increased amounts of ED-1 positive stained macrophages were present and most of COX-2 expressed cells were co-stained with ED-1 in the early stage of ketamine treatment. CONCLUSIONS: Ketamine treatment affected bladder tissues by enhancing interstitial fibrosis and accelerating macrophages infiltration. Ketamine also initiated the up-regulations of COX-2 and iNOS and eNOS expressions. These up-regulated enzymes might play an important role in contributing to ketamine-induced alterations in micturition patterns and ulcerative cystitis.

Multiple functionalities of polyfluorene grafted with metal ion-intercalated crown ether as an electron transport layer for bulk-heterojunction polymer solar cells: optical interference, hole blocking, interfacial dipole, and electron conduction.

We present a novel electron transport (ET) polymer composed of polyfluorene grafted with a K(+)-intercalated crown ether involving six oxygen atoms (PFCn6:K(+)) for bulk-heterojunction polymer solar cells (PSCs) with regioregular poly(3-hexylthiophene) (P3HT) as the donor and indene-C(60) bisadduct (ICBA) or indene-[6,6]-phenyl-C(61)-butyric acid methyl ester (IPCBM) as the acceptor in the active layer and with Al or Ca/Al as the cathode. A remarkable improvement in the power conversion efficiency (PCE) (measured in air) was observed upon insertion of this ET layer, which increased the PCE from 5.78 to 7.5% for a PSC with ICBA and Ca/Al (5.53 to 6.63% with IPCBM) and from 3.87 to 6.88% for a PSC with ICBA and Al (3.06 to 6.21% with IPCBM). This ET layer provides multiple functionalities: (1) it generates an optical interference effect for redistribution of light intensity as an optical spacer; (2) it blocks electron-hole recombination at the interface with the cathode; (3) it forms an interfacial dipole that promotes the vacuum level of the cathode metal; and (4) it enhances electron conduction, as evidenced by (1) the increase in total absorption of 1:1 w/w P3HT:ICBA by a factor of 1.3; (2) the reduction in the hole-only current density profile by a factor of 3.3 at 2.0 × 10(5) V/cm; (3) the decrease of 0.81 eV in the work function of Al from 4.28 to 3.47 eV, as determined by UV photoelectron spectroscopy; and (4) the decrease in the series resistance of PSCs with ICBA and Al by a factor of 4.5, as determined by the current-voltage characteristic under dark conditions; respectively. The PSC of 7.5% is the highest among the reported values for PSC systems with the simplest donor polymer, P3HT.