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Abstract: Treatment of (SiH2)(SiMe2 t Bu)2 (1), (SiH3)SiH(SiMe2 t Bu)2 (2) with Pt(dcpe)(PEt3)2 (dcpe = Cy2PCH2CH2PCy2) in the ratio of 2:1:1 in one pot leads to a novel complex {(SiH)(SiMe2 t Bu)2}(SiH3)PtII(dcpe) (3), which is the first example of bis(silyl) platinum(II) complex bearing a SiH3 ligand structurally characterized by single crystal X-ray analysis and multinuclear NMR spectroscopic studies. H2Si(SiMe2 t Bu)2 for 1, HSi(SiH3)(SiMe2 t Bu)2 for 2, Pt(dcpe)(SiH3)[SiH(SiMe2 t Bu)2] for 3 throughout the manuscript. [Copyright &y& Elsevier]

Highlights: [•] N2 gas flux affects the microstructure, surface morphology and optical properties. [•] The films have better crystallization quality after incorporating properly. [•] The photoluminescence spectra include ultraviolet and green emission parts. [•] The optical band gap decreases with increasing the N2 gas flux. [ABSTRACT FROM AUTHOR]

Introduction Previous influenza pandemics had second and on occasion third waves in many countries that were at times more severe than the initial pandemic waves. Objective This study aims to determine the seroepidemiology of successive waves of H1N1pdm09 infections in Singapore and the overall risks of infection. Methods We performed a cohort study amongst 838 adults, with blood samples provided upon recruitment and at 5 points from 2009 to 2011 and tested by haemagglutination inhibition ( HI) with A/California/7/2009 (H1N1pdm09). Surveys on key demographic and clinical information were conducted at regular intervals, and associations between seroconversion and these variables were investigated. Results After the initial wave from June to September 2009, second and third waves occurred from November 2009 to February 2010 and April to June 2010, respectively. Seroconversion was 13·5% during the first wave and decreased to 6·2% and 6·8% in subsequent waves. Across the three waves, the elderly and those with higher starting HI titres were at lower risk of seroconversion, while those with larger households were at greater risk. Those with higher starting HI titres were also less likely to have an acute respiratory infection. Conclusions The second and third waves in Singapore had lower serological attack rates than the first wave. The elderly and those with higher HI titres had lower risk, while those in larger households had higher risk of seroconversion. [ABSTRACT FROM AUTHOR]

Three new solvent-directed three-dimensional (3D) lead(ii) coordination polymers, [Pb2(L)2]n (1), [Pb3(L)3]n (2) and [Pb(L)]·H2O (3) [H3L = 2-(pyridine-2-yl)-1H-imidazole-4,5-dicarboxylic acid], have been synthesized solvothermally. As influenced by different solvent systems, compounds 1 and 3 exhibit varying architectures from a multi-nodal 3,3,4,4-connected to a uninodal 3-connected net, while 2 with helices represents a binodal 3,4-connected topological net. Moreover, 3 possesses a micropore which is decorated with pyridyl systems and uncoordinated carboxylate oxygen atoms. In addition, the small-sized and highly polar pores enable 3 to attract CO2 strongly, leading to a high sorption heat for CO2 and significant selectivity for CO2 over H2 and N2 at 293 K. The luminescent behaviors and emissive lifetimes of 1–3 are also discussed. [ABSTRACT FROM AUTHOR]

Abstract: GsZFP1 encodes a Cys2/His2-type zinc-finger protein. In our previous study, when GsZFP1 was heterologously expressed in Arabidopsis, the transgenic Arabidopsis plants exhibited enhanced drought and cold tolerance. However, it is still unknown whether GsZFP1 is also involved in salt stress. GsZFP1 is from the wild legume Glycine soja. Therefore, the aims of this study were to further elucidate the functions of the GsZFP1 gene under salt and drought stress in the forage legume alfalfa and to investigate its biochemical and physiological functions under these stress conditions. Our data showed that overexpression of GsZFP1 in alfalfa resulted in enhanced salt tolerance. Under high salinity stress, greater relative membrane permeability and malondialdehyde (MDA) content were observed and more free proline and soluble sugars accumulated in transgenic alfalfa than in the wild-type (WT) plants; in addition, the transgenic lines accumulated less Na+ and more K+ in both the shoots and roots. Overexpression of GsZFP1 also enhanced the drought tolerance of alfalfa. The fold-inductions of stress-responsive marker gene expression, including MtCOR47, MtRAB18, MtP5CS, and MtRD2, were greater in transgenic alfalfa than those of WT under drought stress conditions. In conclusion, the transgenic alfalfa plants generated in this study could be used for farming in salt-affected as well as arid and semi-arid areas. [Copyright &y& Elsevier]

A new one-dimensional (1D) 4d–4f heterometallic coordination polymer [ErAg(Himdc)2(H2O)3] (1) (H3imdc=4,5-imidazoledicarboxylic acid) is synthesized under hydrothermal condition and characterized by elemental analysis, IR, PXRD and single crystal X-ray diffraction. Complex 1 crystallizes in the triclinic space group P-1, showing a 1D metal–organic pseudo-nanotube with a 4.014×12.027Å2 cross-section. Furthermore, it assembles into a 3D supramolecular architecture via hydrogen bonds between pseudo-nanotubes. The complex 1 exhibits solid-state photoluminescence and high thermal stability. [ABSTRACT FROM AUTHOR]

A novel silicon-based compound, 10-phenyl-2′-(triphenylsilyl)-10 H-spiro[acridine-9,9′-fluorene] (SSTF), with spiro structure has been designed, synthesized, and characterized. Its thermal, electronic absorption, and photoluminescence properties were studied. Its energy levels make it suitable as a host material or exciton-blocking material in blue phosphorescent organic light-emitting diodes (PhOLEDs). Accordingly, blue-emitting devices with iridium(III) bis[(4,6-difluorophenyl)-pyridinato- N, C2′]picolinate (FIrpic) as phosphorescent dopant have been fabricated and show high efficiency with low roll-off. In particular, 44.0 cd A−1 (41.3 lm W−1) at 100 cd m−2 and 41.9 cd A−1 (32.9 lm W−1) at 1000 cd m−2 were achieved when SSTF was used as host material; 28.1 lm W−1 at 100 cd m−2 and 20.6 lm W−1 at 1000 cd m−2 were achieved when SSTF was used as exciton-blocking layer. All of the results are superior to those of the reference devices and show the potential applicability and versatility of SSTF in blue PhOLEDs. [ABSTRACT FROM AUTHOR]

Highlights: [•] N-doped Ga2O3 films were deposited on sapphire substrates by radio frequency magnetron sputtering. [•] The samples were annealed in N2, O2, air, respectively. [•] The influence of annealing atmosphere on the structure, morphology and transmittance was investigated. [•] Annealing in nitrogen showed smooth surface and higher transmission in visible range. [•] The red shift of the optical band gap was observed after annealing. [ABSTRACT FROM AUTHOR]

[Display omitted] • The evaporation technology of charged desulfurization wastewater droplets was proposed. • Main influence factors and internal mechanisms were fully analyzed. • The charge transfer characteristic between charged droplets and fine particles were analyzed. • Higher agglomeration efficiency of fine particles can be obtained after charged DW droplet evaporation. The evaporation of desulfurization wastewater (DW) using hot flue gas is an effective treatment method for DW. However, its application is limited owing to a slow evaporation rate and formation of fine crystalline particles. To increase the evaporation rate of DW and the agglomeration efficiency of fine particles, a technology for the evaporation of charged DW droplets was proposed and investigated. The influence of factors such as induction electrode voltage, atomization pressure, and Cl¯ concentration on the agglomeration of fine particles and the charge transfer characteristics between droplets and particles was studied. The results showed that increasing the induction electrode voltage and atomization pressure and reducing Cl¯ concentration improved the agglomeration efficiency of fine particles. Compared to the uncharged droplet conditions, the agglomeration efficiency of fine particles increased by 57.12% under conditions of 12 kV induction electrode voltage, 0.3 MPa atomization pressure, and 20 g/L Cl¯ concentration. The relative agglomeration efficiency of the ultra-fine particles and particles in the 0.1–1 μm size range also increased. After evaporation of the charged DW droplets, most of the electric charge of the droplets remained on the dry agglomerated particles. Agglomerated particles exhibited characteristics of chains and irregular clusters, and were tightly connected by solid bridges. The study results confirmed the feasibility of using the atomization of charged droplets to treat DW more effectively and improve the agglomeration efficiency of fine particles.. [ABSTRACT FROM AUTHOR]

Nanozymes have been widely used in biosensors instead of natural enzymes because of low cost, high stability and ease of storage. However, few works use oxidase-like nanozymes to fabricate electrochemical biosensors. Herein, we proposed a sensitive electrochemical biosensor to detect uracil-DNA glycosylase (UDG) based on the hollow Mn/Ni layered doubled hydroxides (h-Mn/Ni LDHs) as oxidase-like nanozyme. Briefly, the h-Mn/Ni LDHs, which was prepared by a facile hydrothermal method, exhibited excellent oxidase-like activity because the hollow structure provided rich active sites and high specific surface area. Then, the signal probes were constructed by assembling the hairpin DNA (hDNA), single DNA1 and DNA2 on the h-Mn/Ni LDHs, respectively. In the presence of UDG, the uracil bases in the stem of hDNA were specifically excised, generating apyrimidinic (AP) sites and inducing the unwinding of the hDNA. Afterwards, the h-Mn/Ni LDHs@Au-hDNA/DNA1 was connected on the electrode via hybridization between unwinded hDNA and capture DNA (cDNA). Subsequently, the self-linking process allowed the retention of numerous h-Mn/Ni LDHs through simple DNA hybridization to amplify the signal of o -phenylenediamine (o -PD). Unlike many peroxidase-like nanozyme-based electrochemical biosensors, there is no need to add H 2 O 2 during the experimental process, which effectively reduced the background signal as well as improved the stability of the biosensor. As expected, the biosensor exhibited excellent performance with a wide linear range and a low detection limit. This work highlights an appealing opportunity to develop a no H 2 O 2 platform based on h-Mn/Ni LDHs for future application in biological analysis and clinical diagnosis. • An electrochemical biosensor was developed for UDG detection with high sensitivity. • The h-Mn/Ni LDHs shows excellent oxidase-like activity due to the hollow structure. • The background signal effectively reduced by the absence of unstable H 2 O 2. • Self-linking process enhanced the signal, and improved the sensitivity. [ABSTRACT FROM AUTHOR]

• One new cevanine isosteroidal alkaloid named 5,6-anhydrohupehenine with strong inhibitory activity against HepG2 and MCF-7 cells was isolated from Fritillaria hupehensis Hsiao et K.C.Hsia. • 5,6-anhydrohupehenine derivatives were synthesized and evaluated for their cytotoxicity. • Compound 9 s exhibited the most cytotoxic activity against HepG2 cells. • Compound 9 s inhibited the proliferation and induced the apoptosis of HepG2 cells, and it showed strong antimetastatic potential on cancer cells. One new cevanine isosteroidal alkaloid named 5,6-anhydrohupehenine (1), together with five known alkaloids (2–6) were isolated from Fritillaria hupehensis Hsiao et K.C.Hsia, among which 5,6-anhydrohupehenine (1) exhibited strong inhibitory activity against HepG2 (IC 50 = 12.21 μM) and MCF-7 (IC 50 = 22.05 μM) cancer cells. Therefore, a total of 33 5,6-anhydrohupehenine derivatives (9a-9s, 10a-10f, 11a-11b, and 12a-12f) were synthesized and evaluated for their cytotoxic activity. The cytotoxicity evaluation of all 5,6-anhydrohupehenine derivatives against HepG2 and MCF-7 human cancer cells revealed that 9s displayed best activity against HepG2 cells with IC 50 at 1.27 μM. Further biological evaluations on 9s showed that it inhibited the proliferation of HepG2 cells and induced apoptosis of the HepG2 cells by activating cleaved caspase-3. Moreover, 9s exhibited strong antimetastatic potential. These results suggest that 5,6-anhydrohupehenine is a promising compound to be designed as novel cytotoxic agents. [ABSTRACT FROM AUTHOR]

A new Co-based 3D framework has been constructed from an unprecedented 1D alternate Co5 chain and discrete linear Co3 unit as two distinct secondary building units, which exhibits slow magnetic relaxation behavior. [ABSTRACT FROM AUTHOR]

Under solvothermalconditions, six new Zn(II) coordination polymers,[(CH3)2NH2]2[Zn(L)]·2H2O (1), [Zn2(L)(py)2] (2), [Zn2(L)(bpe)2]·bpe·6H2O (3), [Zn2(L)(bpe)(DMA)(H2O)]·5H2O (4), [Zn2(L)(bpy)0.5(H2O)2]·2.5H2O (5), and [Zn2(L)(bpe)(H2O)]·3H2O (6) [H4L = 5,5′-(p-xylylenediamino)-1,1′,3,3′-(benzenetetra-carboxylicacid), py = pyridine, bpy = 4,4′-dipyridine and bpe = 1,2-bis(4-pyridyl)ethane],have been synthesized by employing a flexible tetracarboxylic acidH4L and different auxiliary pyridine-based ligands. In 1–6, all L4–ligandsare 4-connected nodes; however, the diverse configurations of thetwo terminal isophthalate units of L4–around thecentral −NHCH2PhCH2NH– spacerlead to various topological nets. 1shows a three-dimensional(3D) 2-fold interpenetrated 4-connected dianetwork resultingfrom the vertical configuration of the two isophthalate units of L4–. 2displays a 3D (4,4)-connected ptsnet in which the two isophthalate units of L4–adopt a parallel configuration. The two isophthalate units of L4–in 3are also almost parallel, resultingin an intriguing 3D 2-fold interpenetrated network with the (4,4)-connected bbfnet. 4is a two-dimensional bilayer structure,extending into a 3D supramolecular framework through interlayer hydrogen-bondinginteractions. 5and 6disclose similar 3Dstructural architectures, in which the two isophthalate units of L4–are almost vertical and exhibit tetrahedral topologicalnodes, inducing a rare (4,5)-connected xwwnet and anunprecedented (4,6)-connected network, respectively. The thermal stabilitiesand luminescent properties of 1–6have also been studied in detail. The complexes exhibit intensesolid-state fluorescent emissions at room temperature. [ABSTRACT FROM AUTHOR]

Three new complexes, {[Mn(dtb)(bpe)·2H2O]·H2O}n(1), {[Mn(dtb)(bpa)·2H2O]·H2O}n(2), and {[Mn(dtb)(phen)]}n(3) [H2dtb = 5,5′-dithiobis(2-nitrobenzoic acid), bpe = 1,2-bis(4-pyridyl)ethene, bpa = 1,2-bi(4-pyridyl)ethane, phen = 1,10-phenanthroline], have been synthesized under hydrothermal conditions with Mn(OAc)2·4H2O, dtb, and differentN-donor ligands. X-ray structure analyses of1and2reveal analogous structures with 1D helical chains and 2D 44chiral layers. The structure of3shows a 1D chain which is outwardly decorated with phen ligands. These neutral polymeric complexes exhibit structural diversity due to the different coordination modes of the flexible dtb ligand and the N-donor ligands. The thermogravimetric analyses and X-ray powder diffractions of1–3are also presented. [ABSTRACT FROM AUTHOR]

Abstract: Background: Pancreatic cancer (PC), a hypovascular tumor, thrives under hypoxic conditions. Pancreatic stellate cells (PSCs) promote PC progression by secreting soluble factors, but their functions in hypoxia are poorly understood. This study aimed to clarify the effects of hypoxic conditions on the interaction between PC cells and PSCs. Methods: We isolated human PSCs from fresh pancreatic ductal adenocarcinomas and analyzed functional differences in PSCs between normoxia (21% O2) and hypoxia (1% O2), including expression of various factors related to tumor–stromal interactions. We particularly analyzed effects on PC invasiveness of an overexpressed molecule—connective tissue growth factor (CTGF)—in PSCs under hypoxic conditions, using RNA interference techniques. Results: Conditioned media from hypoxic PSCs enhanced PC cell invasiveness more intensely than that from normoxic PSCs (P < 0.01). When co-cultured with PSCs, PC cell invasion was more enhanced under hypoxia than under normoxia (P < 0.05). Among various soluble factors, which were related to invasiveness, CTGF was one of the overexpressed molecules in hypoxic PSCs. A higher level of CTGF expression was also found in supernatant of hypoxic PSCs than in supernatant of normoxic PSCs. PC cell invasiveness was reduced by CTGF knockdown in hypoxic PSCs co-cultured with PC cells (P < 0.05). Conclusion: Hypoxia induces PSCs'' secretion of CTGF, leading to enhancement of PC invasiveness. CTGF derived from hypoxia-stimulated PSCs may be a new therapeutic target for pancreatic cancer. [Copyright &y& Elsevier]

Abstract: Two host materials, DBTSF2 and DBTSF4, were designed and synthesized, incorporating dibenzothiophene (DBT) and spirobifluorene (SF) blocks. Their thermal, electrochemical and photo-physical properties were fully characterized. DBTSF4, which adopted an ortho-linkage between DBT and SF moieties, showed a significantly higher T 1 energy of 2.82eV as compared to its para-linkage analogue DBTSF2 (2.49eV). Their applications as host for green, blue and white phosphorescent organic light-emitting diodes (PHOLEDs) were explored. The DBTSF4 based blue PHOLED has a highest current efficiency of 23.5cdA−1. And using DBTSF4 as a single host, two-color based white PHOLEDs were achieved from cold white emission with CIE coordinate of (0.31, 0.43) to yellowish warm white emission (0.44, 0.49) with maximum current efficiencies varying from 35.8 to 52.3cdA−1 and maximum external quantum efficiencies from 13.1% to 16.9% respectively. The white PHOLED devices also showed a low efficiency roll-off even at 10,000cdm−2. [Copyright &y& Elsevier]

Chronic inflammation-promoted metastasis has been considered as a major challenge in cancer therapy. Pro-inflammatory cytokine TNFα can induce cancer invasion and metastasis associated with epithelial–mesenchymal transition (EMT). However, the underlying mechanisms are not entirely clear. In this study, we showed that TNFα induces EMT in human HCT116 cells and thereby promotes colorectal cancer (CRC) invasion and metastasis. TNFα-induced EMT was characterized by acquiring mesenchymal spindle-like morphology and increasing the expression of N-cadherin and fibronectin with a concomitant decrease of E-cadherin and Zona occludin-1(ZO-1). TNFα treatment also increased the expression of transcription factor Snail, but not Slug, ZEB1 and Twist. Overexpression of Snail induced a switch from E-cadherin to N-cadherin expression in HCT116 cells, which is a characteristic of EMT. Conversely, knockdown of Snail significantly attenuated TNFα-induced EMT in HCT116 cells, suggesting that Snail plays a crucial role in TNFα-induced EMT. Interestingly, exposure to TNFα rapidly increased Snail protein expression and Snail nuclear localization but not mRNA level upregulation. Finally, we demonstrated that TNFα elevated Snail stability by activating AKT pathway and subsequently repressing GSK-3β activity and decreasing the association of Snail with GSK-3β. Knockdown of GSK-3β further verified our finding. Taken together, these results revealed that AKT/GSK-3β-mediated stabilization of Snail is required for TNFα-induced EMT in CRC cells. Our study provides a better understanding of inflammation-induced CRC metastasis. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we studied the growth of AlN films on 6H–SiC substrates under various sputtering pressures by RF reactive magnetron sputtering at low deposition temperature (300°C). The composition, chemical structure and oxygen impurity of the deposited films were investigated by X-ray photoelectron spectroscopy (XPS). It is suggested that the Al/N ratio of the high purity film is 1.13:1 which is very close to the stoichiometric value (1:1), and a few oxygen impurities exist in the grain boundaries in the form of Al. The two-dimensional X-ray diffraction (2D-XRD) was used to study the crystal structure of the deposited films. 2D-XRD patterns indicate that a low sputtering pressure favor the growth of AlN film with c-axis oriented, and a highly c-axis oriented AlN film resemble single crystal structure was prepared at the sputtering pressure of 0.3Pa. Surface morphology of the deposited films were investigated by SEM and AFM. The images show that the surface morphology of the films with (0002) preferred orientation present a pebble-like structure, and the grain size and surface roughness of the films decrease with increasing the sputtering pressure. [Copyright &y& Elsevier]

Abstract: The design and synthesis of cyanide-bridged heterometallic molecular assemblies via self-assembly of capped tetracyanometalate [MA(L)(CN)4] n− (MA =FeIII/II, CrIII, L=bidentate ligand, n =1, 2) and metal ions in the presence or absence of blocking ligands lead to a wide diversity of structures, ranging from di-, tri-, tetra-, hexanuclear compounds, to various one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) metal-cyanide architectures. Intensive research in this field resulted in the crystallographic and magnetochemical characterization of these metal-cyanide assemblies. The magnetic properties will be discussed in terms of the magnetic exchange coupling between MA and metal ions. Among these assemblies, ferromagnetically coupled 2,4-ribbon like chains which exhibit slow magnetic relaxation and hysteresis effects are the most appealing single-chain magnets (SCMs). [Copyright &y& Elsevier]

The traditional method of gas chromatography-mass spectrometry for monosaccharide component analysis with pretreatment of acetylation is described with slight modifications and verified in detail in this paper. It was then successfully applied to the quantitative analysis of component monosaccharides in polysaccharides extracted from the pine cones. The results demonstrated that the three pine cone polysaccharides all consisted of ribose, rhamnose, arabinose, xylose, mannose, glucose and galactose in different molar ratios. According to the recovery experiment, the described method was proved accurate and practical for the analysis of pine cone polysaccharides, meeting the need in the field of chemical analysis of Pinus plants. Furthermore; the chemical characteristics, such as neutral sugar, uronic acids, amino acids, molecular weights, and antioxidant activities of the polysaccharides were investigated by chemical and instrumental methods. The results showed that the chemical compositions of the polysaccharides differed from each other, especially in the content of neutral sugar and uronic acid. In the antioxidant assays, the polysaccharide fractions exhibited effective scavenging activities on ABTS radical and hydroxyl radical, with their antioxidant capabilities decreasing in the order of PKP > PAP > PSP. Therefore, although the polysaccharide fractions had little effect on superoxide radical scavenging, they still have potential to be developed as natural antioxidant agents in functional foods or medicine. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, c-axis oriented AlN films were prepared on sapphire substrate by RF reactive magnetron sputtering at various deposition temperatures (30–700°C). The influences of deposition temperature on the chemical composition, crystalline structure and surface morphology of the AlN films were systematically investigated. The as-deposited films were characterized by X-ray photoelectron spectroscopy (XPS), two-dimensional X-ray diffraction (2D-XRD) and atomic force microscopy (AFM). The experimental results show that it can be successfully grown for high-purity and near-stoichiometric (Al/N=1.12:1) AlN films except for the segregation of a few oxygen impurities exist in the form of Al–O bonding. The chemical composition of as-deposited films is almost independent of substrate temperature in the range of 30–700°C. However, the crystalline structure and surface morphology of the deposited AlN films are strongly influenced by the deposition temperature. The optimum deposition temperature is 300°C, giving a good compromise between crystalline structure and surface morphology to grow AlN films. [Copyright &y& Elsevier]

Abstract: A new coordination compound [Ag(Hcpob)(bpy)]n (1) was assembled by 4-(3′-carboxylphenoxy)benzoic acid (H2cpob), 4,4′-bipyridine (bpy) and AgNO3 under the hydrothermal synthesis. Especially, H2cpob came from the in situ decarboxylation of 4-(2′,3′-dicarboxylphenoxy)benzoic acid (H3dpob) in the hydrothermal reaction. Single-crystal X-ray diffraction reveals that 1 crystallizes in a monoclinic P21/c space group. 1 displays a one-dimensional (1D) fishbone-like double chain structure constructed from Ag(I) ions, bpy ligands and partly deprotonated H2dpob ligands, which further form a three-dimensional (3D) supramolecular architecture via π–π stacking and hydrogen-bonding interactions. In addition, the photoluminescence of 1 has been investigated in detail. [Copyright &y& Elsevier]

A new coordination polymer, {[Ag(H3bptc)(bpe)] · 2H2O} n (1) (H4bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, bpe = 1,2-bis(4-pyridyl)ethene), has been synthesized through a hydrothermal technique and structurally characterized. The crystal structure of 1 exhibits a 2-D hydrogen-bonding sheet between H3bptc− and two free water molecules. Fluorescent property, TG analysis, and X-ray powder diffraction for 1 were also measured and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Based on 1H-imidazo[4,5-f][1,10]-phenanthroline (IP), 4,4′-oxybis(benzoic acid) (H2oba), and two different metal salts, two novel complexes were hydrothermally constructed, {[Cd2(oba)2(IP)2(H2O)]·H2O} n (1) and {[Mn2(IP)4(oba)2]·(oba)(H2O)2} n (2). Complex 1 exhibits a rare 2D→2D parallel interpenetration layer , which contains two same-hand chiral sheets with the space group. Complex 2 contains 1D left-hand helical chain with the C2 space group. Meanwhile, the dissociate oba and water molecules are connected to be a right-hand helical chain via hydrogen bonds, and form a twofold-interpenetrating structure. In addition, the two compounds also exhibit good thermal stability. [Copyright &y& Elsevier]

Background: Schools are important foci of influenza transmission and potential targets for surveillance and interventions. We compared several school-based influenza monitoring systems with clinic-based influenza-like illness (ILI) surveillance, and assessed the variation in illness rates between and within schools. Methods: During the initial wave of pandemic H1N1 (pdmH1N1) infections from June to Sept 2009 in Singapore, we collected data on nation-wide laboratory confirmed cases (Sch-LCC) and daily temperature monitoring (Sch-DTM), and teacher-led febrile respiratory illness reporting in 6 sentinel schools (Sch-FRI). Comparisons were made against age-stratified clinic-based influenza-like illness (ILI) data from 23 primary care clinics (GP-ILI) and proportions of ILI testing positive for pdmH1N1 (Lab-ILI) by computing the fraction of cumulative incidence occurring by epidemiological week 30 (when GP-ILI incidence peaked); and cumulative incidence rates between school-based indicators and sero-epidemiological pdmH1N1 incidence (estimated from changes in prevalence of A/California/7/2009 H1N1 hemagglutination inhibition titers ≥ 40 between pre-epidemic and post-epidemic sera). Variation in Sch-FRI rates in the 6 schools was also investigated through a Bayesian hierarchical model. Results: By week 30, for primary and secondary school children respectively, 63% and 79% of incidence for Sch-LCC had occurred, compared with 50% and 52% for GP-ILI data, and 48% and 53% for Sch-FRI. There were 1,187 notified cases and 7,588 episodes in the Sch-LCC and Sch-DTM systems; given school enrollment of 485,723 children, this represented 0.24 cases and 1.6 episodes per 100 children respectively. Mean Sch-FRI rate was 28.8 per 100 children (95% CI: 27.7 to 29.9) in the 6 schools. We estimate from serology that 41.8% (95% CI: 30.2% to 55.9%) of primary and 43.2% (95% CI: 28.2% to 60.8%) of secondary school-aged children were infected. Sch-FRI rates were similar across the 6 schools (23 to 34 episodes per 100 children), but there was widespread variation by classrooms; in the hierarchical model, omitting age and school effects was inconsequential but neglecting classroom level effects led to highly significant reductions in goodness of fit. Conclusions: Epidemic curves from Sch-FRI were comparable to GP-ILI data, and Sch-FRI detected substantially more infections than Sch-LCC and Sch-DTM. Variability in classroom attack rates suggests localized class-room transmission. [ABSTRACT FROM AUTHOR]

Abstract: A novel amperometric biosensor based on immobilizing acetylcholinesterase on 3-carboxyphenylboronic/reduced graphene oxide–gold nanocomposites modified electrode was developed for the detection of organophosphorus and carbamate pesticides. Acetylcholinesterase was successfully immobilized on the electrode with relatively high activity by the specific binding between the boronic acid group of 3-carboxyphenylboronic and the glycosyl of acetylcholinesterase. The biosensor enjoyed good sensitivity owing to the excellent properties of gold nanoparticles and reduced graphene oxide, which promoted electron transfer reaction and enhanced the electrochemical response. Parameters affecting the biosensor response such as pH, applied potential, enzyme loading and inhibition time were optimized. Based on the inhibition of an organophosphorus insecticide on the enzymatic activity of AChE, organophosphorus and carbamate pesticides were determined with satisfactory results in the presence of acetylthiocholine chloride as a substrate. Moreover, the fabricated biosensor had good repeatability and high stability. [Copyright &y& Elsevier]

Chikungunya virus (CHIKV) is an alphavirus responsible for numerous epidemics throughout Africa and Asia, causing infectious arthritis and reportedly linked with fatal infections in newborns and elderly. Previous studies in animal models indicate that humoral immunity can protect against CHIKV infection, but despite the potential efficacy of B-cell-driven intervention strategies, there are no virus-specific vaccines or therapies currently available. In addition, CHIKV has been reported to elicit long-lasting virus-specific IgM in humans, and to establish long-term persistence in non-human primates, suggesting that the virus might evade immune defenses to establish chronic infections in man. However, the mechanisms of immune evasion potentially employed by CHIKV remain uncharacterized. We previously described two human monoclonal antibodies that potently neutralize CHIKV infection. In the current report, we have characterized CHIKV mutants that escape antibody-dependent neutralization to identify the CHIKV E2 domain B and fusion loop "groove" as the primary determinants of CHIKV interaction with these antibodies. Furthermore, for the first time, we have also demonstrated direct CHIKV cell-to-cell transmission, as a mechanism that involves the E2 domain A and that is associated with viral resistance to antibody-dependent neutralization. Identification of CHIKV sub-domains that are associated with human protective immunity, will pave the way for the development of CHIKV-specific sub-domain vaccination strategies. Moreover, the clear demonstration of CHIKV cell-to-cell transmission and its possible role in the establishment of CHIKV persistence, will also inform the development of future anti-viral interventions. These data shed new light on CHIKV-host interactions that will help to combat human CHIKV infection and inform future studies of CHIKV pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract: The interaction between flower-like CdSe nanostructure particles (CdSe NP) and bovine serum albumin (BSA) was investigated from a spectroscopic angle under simulative physiological conditions. Under pH 7.4, CdSe NP could effectively quench the intrinsic fluorescence of BSA via static quenching. The binding constant (K A) was 6.38, 3.27, and 1.90×104 M−1 at 298, 304, and 310K, respectively and the number of binding sites was 1.20. According to the Van''t Hoff equation, the thermodynamic parameters (ΔH°=−77.48kJmol−1, ΔS°=−168.17Jmol−1 K−1) indicated that hydrogen bonds and van der Waals forces played a major role in stabilizing the BSA−CdSe complex. Besides, UV–vis and circular dichroism (CD) results showed that the addition of CdSe NP changed the secondary structure of BSA and led to a decrease in α-helix. These results suggested that BSA underwent substantial conformational changes induced by flower-like CdSe nanostructure particles. [Copyright &y& Elsevier]

A total of 828 community-dwelling adults were studied during the course of the pandemic (H1N1) 2009 outbreak in Singapore during June-September 2009. Baseline blood samples were obtained before the outbreak, and 2 additional samples were obtained during follow-up. Seroconversion was defined as a >4-fold increase in antibody titers to pandemic (H1N1) 2009, determined by using hemagglutination inhibition. Men were more likely than women to seroconvert (mean adjusted hazards ratio [HR] 2.23, mean 95% confidence interval [CI] 1.26-3.93); Malays were more likely than Chinese to seroconvert (HR 2.67, 95% CI 1.04-6.91). Travel outside Singapore during the study period was associated with seroconversion (HR 1.76, 95% CI 1.11-2.78) as was use of public transport (HR 1.81, 95% CI 1.05-3.09). High baseline antibody titers were associated with reduced seroconversion. This study suggests possible areas for intervention to reduce transmission during future influenza outbreaks. [ABSTRACT FROM AUTHOR]

Abstract: Determination of perfluorinated compounds (PFCs) is very important because of their potential hazards to the environment and human health. In present work, 1,8-bis (tetramethylguanidino)-naphthalene (TMGN), a superbasic proton sponge, was firstly employed as the matrix for quantitative detection of acidic PFCs in environmental water samples by Matrix-assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF-MS). Several acidic PFCs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), were selected as model analytes for demonstrating the feasibility of the detection method. The results showed that deprotonated ions of these PFCs were detected without any other matrix ions interference. The achieved sensitivity with TMGN for PFOS detection was ten-fold higher than that with 1,8-bis (dimethyl-amino)-naphthalene (DMAN) which was used for the detection of fatty acid by MALDI-TOF-MS. The high sensitivity of this method made it feasible to monitor and quantify acidic PFCs in complicated environmental water samples. Furthermore, a novel combined strategy of solid phase extraction (SPE) followed by MALDI-TOF-MS detection was developed for quantifying PFCs in environmental water samples. The calibration curves with a wide linear dynamic range (0.1–10ngL−1 for PFOS, PFHxS, and PFBS, and 0.5–50ngL−1 for PFOA, PFNA, and PFDA.) were obtained. The limit of detection (LOD) for PFOS of this method was 0.015ngL−1 (a signal-to-noise ratio of 3), which was lower than the LOD (0.036ngL−1) obtained by high-pressure liquid chromatography/tandem mass spectrometry (LC–MS/MS) method. Moreover, the strategy was used to detect the selected PFCs in water samples collected from Xiaoqinghe river and Gaobeidian wastewater. The achieved concentrations of PFCs were closed to those obtained by LC–MS/MS method. It is indicated that the proposed MALDI-TOF-MS method with TMGN as the matrix is much reliable and can be used as an alternative method to detect trace PFCs in environmental water samples. [Copyright &y& Elsevier]

Abstract: Two new metal-organic frameworks, [M2(CTA)(bipy)1.5(H2O)2] n ·3n(H2O) (M=Cd for 1 and Mn for 2, H4CTA=cyclohexane-1,2,4,5-tetracarboxylic acid, bipy=4,4′-bipyridine) have been successfully synthesized and characterized. Complexes 1 and 2 are isostructural, which display unusual three-dimensional (3D) self-penetrating coordination frameworks with 3-nodal (3,5,5)-connectivity and the Schläfli symbol of (4,6,8)(42,67,8)(43,63,83,9). Moreover, in solid state, complex 1 exhibits blue emission at ambient temperature. Magnetic measurement shows that there exist weak antiferromagnetic interactions in 2. [Copyright &y& Elsevier]

Cooling the ischemic heart by just a few degrees protects it from infarction without affecting its mechanical function, but the mechanism of this protection is unknown. We investigated whether signal transduction pathways might be involved in the anti-infarct effect of mild hypothermia (35°C). Isolated rabbit hearts underwent 30 min of coronary artery occlusion/2 h of reperfusion. They were either maintained at 38.5°C or cooled to 35°C just before and only during ischemia. Infarct size was measured. The effects of the protein kinase C inhibitor chelerythrine, the nitric oxide synthase inhibitor N-nitro- l-arginine methyl ester ( l-NAME), the phosphatidylinositol 3-kinase antagonist wortmannin, or either of the mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitors PD98059 or U0126 on cooling's protection were examined. Myocardial ATP assays were performed and the level of phosphorylation of extracellular signal-regulated kinase (ERK) and MEK was examined by western blotting. To investigate an effect of cooling on protein phosphatase (PPase), a PPase inhibitor cantharidin was tested in the infarct model and the effect of mild hypothermia on PP2A activity in vitro was measured. Infarct size was 34.4 ± 2.2% of the ischemic zone in normothermic (38.5°C) hearts, but only 15.6 ± 8.7% in hearts cooled to 35°C during ischemia. Mechanical function was unaffected. Neither chelerythrine, l-NAME, nor wortmannin had any effect, but both PD98059 and U0126 completely eliminated protection. Ischemia rather than reperfusion was the critical time when ERK had to be active to realize protection. Phosphorylation of ERK and MEK fell during normothermic ischemia, but during hypothermic ischemia phosphorylation of ERK remained high while that of MEK was increased. Cooling only slightly delayed the rate at which ATP fell during ischemia, and ERK inhibition did not affect that attenuation suggesting ATP preservation was unrelated to protection. Cantharidin, like cooling, also protected during ischemia but not at reperfusion, and its protection was dependent on ERK phosphorylation. However, mild hypothermia had a negligible effect on PP2A activity in an in vitro assay. Hence, mild hypothermia preserves ERK and MEK activity during ischemia which somehow protects the heart. While a PPase inhibitor mimicked cooling's protection, a direct effect of cooling on PP2A could not be demonstrated. [ABSTRACT FROM AUTHOR]

Triphenylsulfonium chloride (TPSC) was employed as a bifunctional agent for the selective enrichment of perfluoroalkyl sulfonates by triphenylsulfonium perfluorosulfonic acid (TPA, a photoacid generator) precipitation, and for the direct detection of perfluorosulfonic acid by MALDI-TOF-MS, using the triphensylsulfonium group of TPA as a matrix. [ABSTRACT FROM AUTHOR]

Abstract: In this study, a series of graded multilayer ta-C films were investigated by varying their sublayer thickness ratios, in which each film sublayer was prepared at different substrate bias by filtered cathode vacuum arc (FCVA) method. The experimental results show that the graded multilayer film structure can effectively decrease the internal stress level of deposited ta-C film, and meanwhile the graded multilayer ta-C films still have high sp3 fractions. The applied substrate bias voltage and sublayer thickness ratio can apparently influence the microstructure characteristics and internal stress of the graded multilayer ta-C films. The graded multilayer ta-C film has larger sp3 fraction when applying a larger negative substrate bias voltage and having a thicker outer sublayer during the film deposition process. However, the internal stress in the as-deposited film also increases with larger thickness of the outer sublayer, and the optimal ratio of sublayer thicknesses is 1:1:1:1 for graded ta-C film with four sublayers. [Copyright &y& Elsevier]

Abstract: Background: In June 2009, we conducted a prospective study in Singapore on 51 individuals to determine their serologic responses before and following receipt of the 2009 Southern Hemisphere seasonal influenza vaccine. Materials and methods: Paired serum samples were obtained before and 3–4 weeks after vaccination. Virus microneutralization assays were performed to quantify antibodies against A/Brisbane/59/2007 vaccine, pandemic H1N1-2009 and A/Puerto Rico/08/34 H1N1 strains. Results: Post-vaccination, 43%, 12% and 24% of subjects displayed a 4-fold or greater rise in neutralizing antibody titers against the three strains, respectively. There was a positive correlation among individuals who showed increased titers to both pandemic H1N1-2009 and A/Puerto Rico/08/34 (p <0.001). However, this correlation was not observed for A/Brisbane/59/2007 with either strain. The relative conservation and accessibility of predicted B-cell epitopes may explain the limited cross-reactivity of the antibodies directed against common H1N1 epitopes. Conclusions: These results suggest that seasonal influenza vaccination confers a certain degree of cross-protection to other H1N1 strains. The correlation in cross-reactive antibody titers to A/Puerto Rico/08/34 and pandemic H1N1-2009 implies that previous exposure to pre-1957 H1N1 strains may confer some protection against the 2009 pandemic strain. [ABSTRACT FROM AUTHOR]

An oseltamivir-resistant influenza A pandemic (H1N1) 2009 virus evolved and emerged from zero to 52% of detectable virus within 48 hours of a patient's exposure to oseltamivir. Phylogenetic analysis and data gathered by pyrosequencing and cloning directly on clinical samples suggest that the mutant emerged de novo. [ABSTRACT FROM AUTHOR]

We describe incidence and risk factors for pandemic (H1N1) 2009 virus infection in healthcare personnel during the June-September 2009 epidemic in Singapore. Personnel contributed 3 serologic samples during June-October 2009, with seroconversion defined as a ≥4-fold increase in hemagglutination inhibition titers to pandemic (H1N1) 2009. Of 531 participants, 35 showed evidence of seroconversion. Seroconversion rates were highest in nurses (28/290) and lowest in allied health staff (2/116). Significant risk factors on multivariate analysis were being a nurse (adjusted odds ratio [aOR] 4.5, 95% confidence interval [CI] 1.0-19.6) and working in pandemic (H1N1) 2009 isolation wards (aOR 4.5, 95% CI 1.3-15.6). Contact with pandemic (H1N1) 2009-infected colleagues (aOR 2.5, 95% CI 0.9-6.6) and larger household size (aOR 1.2, 95% CI 1.0-1.4) were of borderline significance. Our study suggests that seroconversion was associated with occupational and nonoccupational risk factors. [ABSTRACT FROM AUTHOR]

This work investigated the cytotoxicities of three silver nanoparticles (SNPs) SNP-5, SNP-20 and SNP-50 with different sizes (∼ 5 nm, ∼ 20 nm and ∼ 50 nm) using four human cell models (A549, SGC-7901, HepG2 and MCF-7). Endpoints included cell morphology, cell viability, cellular membrane integrity, oxidative stress and cell cycle progression. Observable deleterious effects on the cell morphologies and membrane integrity were induced by SNP-5 and SNP-20. SNPs elevated the ROS levels in cells and arrested the cells at S phase. Apoptosis occurred for 4–9% of the exposed cells. All these cellular responses as well as EC50 values were found to be size-dependent for the tested SNPs. Ultrastructural observations confirmed the presence of SNPs inside cells. Elemental analysis of silver in cells by ICP-MS showed that smaller nanoparticles enter cells more easily than larger ones, which may be the cause of higher toxic effects. The findings may assist in the design of SNP applications and provide insights into their toxicity. [ABSTRACT FROM AUTHOR]

Abstract: To overcome the limited clinical efficacy of conditionally replicative adenoviruses (CRAds), we investigated the effects of combination therapy with gemcitabine (GEM) and the hTERT-promoter-dependent CRAd (hTERT-CRAd), Ad5/3hTERTE1. This combination therapy exhibited enhanced cytotoxic effects on pancreatic cancer both in vitro and in vivo. Furthermore, we revealed that this enhancement effect was due to the multiple bidirectional interactions between hTERT-CRAd and GEM. The GEM-sensitizing effect of E1 expression derived from hTERT-CRAd, and the enhancement effect by GEM on hTERT promoter activity which led to the increase of adenovirus E1 and viral infectivity. This combination therapy may be a promising therapeutic approach for pancreatic cancer. [Copyright &y& Elsevier]

Two isomorphous three-dimensional metal−organic frameworks, [M(dtb)(4,4′-bipyridine)1.5(H2O)]n (1, M = Ni; 2, M = Co) [dtb = 5,5′-dithiobis(2-nitrobenzoic acid), 4,4′-bipy = 4,4′-bipyridine], have been synthesized by ligating metal ions with V-shaped H2dtb and linear 4,4′-bipy ligands, and they have been characterized structurally by single crystal X-ray diffraction studies and FT-IR and TGA analysis. Complexes 1 and 2 exhibit fascinating interweaved meso-helices and represent the first examples of metal−organic frameworks with four spiral shafts in one helical chain, named a tetraflexural helix. The pitch of the single helical chain is up to 27.741 Å, which is out of the normal scope of helical pitch. Two isomorphous MOFs [M(dtb)(4'4-bipy)1.5(H2O)]n (M = Ni/Co) exhibit fascinating interweaved meso-helices, containing four spiral shafts in a single helix, which is named a tetraflexural helix. Viewing along the ab plane, the helical chain twists like a four-leaf clover which shares a and c shafts with the right helical chain and co-uses the b and d shafts with the left helical chain. [ABSTRACT FROM AUTHOR]

Abstract: The wide application of engineered nanomaterials, such as fullerene (C60), will inevitably lead to their release into the aqueous environment, which may alter the bioavailability of organic compounds to aquatic organisms. Negligible depletion solid-phase microextraction (nd-SPME) together with medaka (Oryzias latipes) bioaccumulation were used to study the effects of aqueous suspensions of fullerene (nC60) on the bioavailability of eight organochlorine compounds (OCCs) (log K OW 3.76–6.96). Freely dissolved concentrations of OCCs decreased by 11.5–88.4% at addition of 5mgL−1 nC60 as indicated by reduced equilibrium concentrations in the SPME fiber coating, the highest reduction being observed for the most hydrophobic OCCs. Medaka bioaccumulation study demonstrated that at the kinetic uptake regime, nC60 significantly decreased the bioaccumulation of the high hydrophobic OCCs (log K OW >6), but slightly enhanced the bioaccumulation of the less hydrophobic OCCs (log K OW <6). The OCC concentrations in medaka (C fish) at the kinetic uptake regime linearly correlated with that in nd-SPME fiber (C fiber) without nC60 (p =0.007–0.013, R 2 =0.666–0.723), but this correlation deteriorated with the presence of nC60 (p =0.073–0.081, R 2 =0.423–0.440). These results suggest that in nC60 the uptake mechanism of OCCs to medaka is different from that to nd-SPME fiber. While only the freely dissolved OCCs are available to nd-SPME fiber, both the freely dissolved and the nC60 associated OCCs contributed to the accumulation of OCCs to medaka. [ABSTRACT FROM AUTHOR]

Background: Recently, cancer stem cells have been reported as a new therapeutic target in pancreatic cancer as well as other cancers, but the specific role of these cells is unknown. Methods: The authors investigated the functional roles of CD133+ cells, 1 of the putative cancer stem cell candidates in pancreatic cancer. CD133 expression was assessed in human pancreatic cancer and cancer cell lines by quantitative real-time reverse transcriptase polymerase chain reaction and flow cytometry. Next, they compared the ability of CD133+ and CD133- cells to proliferate, migrate, and invade using 2 pancreatic cancer cell lines. In particular, they evaluated the relationship between CD133+ cells and primary pancreatic stromal cells. Results: CD133 was expressed in primary human pancreatic cancer tissues and some cancer cell lines, whereas there was little expression in primary normal pancreatic epithelial cells and primary pancreatic stromal cells. CD133+ cells, isolated by flow cytometry, showed increased cell proliferation under anchorage-independent conditions (P<.01), and enhanced migration and invasion, particularly when cocultured with primary pancreatic stromal cells (P<.001). Chemokine-related receptor-4 (CXCR4), markedly overexpressed in CD133+ cells, may be responsible for the increased invasive ability of the cells cocultured with pancreatic stromal cells, which express stromal derived factor-1, the ligand to CXCR4. Conclusions: These data suggest that CD133+ cells exhibit more aggressive behavior, such as increased cell proliferation, migration, and invasion, especially in the presence of pancreatic stromal cells. The targeting therapy for the interaction between CD133+ cancer cells and stromal cells may be a new approach for the treatment of pancreatic cancer. [ABSTRACT FROM AUTHOR]

Abstract: An amperometric bisphenol A (BPA) biosensor was fabricated by immobilizing tyrosinase on multiwalled carbon nanotubes (MWNTs)-cobalt phthalocyanine (CoPc)-silk fibroin (SF) composite modified glassy carbon electrode (GCE). In MWNTs-CoPc-SF composite film, SF provided a biocompatible microenvironment for the tyrosinase to retain its bioactivity, MWNTs possessed excellent inherent conductivity to enhance the electron transfer rate and CoPc showed good electrocatalytic activity to electrooxidation of BPA. The cyclic voltammogram of BPA at this biosensor exhibited a well defined anodic peak at 0.625V. Compared with bare GCE, the oxidation signal of BPA significantly increased; therefore, this oxidation signal was used to determine BPA. The effect factors were optimized and the electrochemical parameters were calculated. The possible oxidation mechanism was also discussed. Under optimum conditions, the oxidation current was proportional to BPA concentration in the range from 5.0×10−8 to 3.0×10−6 M with correlation coefficient of 0.9979 and detection limit of 3.0×10−8 M (S/N=3). The proposed method was successfully applied to determine BPA in plastic products and the recovery was in the range from 95.36% to 104.39%. [Copyright &y& Elsevier]

Genetic factors are known to be important in the development of esophageal squamous cell carcinoma (ESCC). Epidermal growth factor (EGF) can activate several signaling pathways leading to proliferation, differentiation, and tumorigenesis of epithelial tissues by binding with its receptor. Interindividual variations in EGF production were genetically contributed to EGF +61 G/A polymorphism. The purpose of this study is to investigate the potential association between EGF gene polymorphism and ESCC in a Chinese population. In this study, we analyzed single nucleotide polymorphism of EGF +61 G/A in 158 patients with ESCC and 212 age- and sex-matched controls in a Chinese population using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy and DNA sequencing. The variant genotypes of GA/AA were associated with a significantly decreased risk of ESCC compared with the wild-type homozygote GG (OR = 0.657, 95% CI: 0.434-0.996). However, no significant difference was observed between the EGF +61 G/A polymorphism and the risk of ESCC when the analyses were stratified in terms of age, gender, smoking status, different clinical stage, and lymph node status. The EGF +61 G/A polymorphism is associated with ESCC in a Chinese population. Our data suggests that the EGF gene may play a role in the development of ESCC. [ABSTRACT FROM AUTHOR]

A thermally activated delayed fluorescence material 2,6-bis(9,9-diphenylacridin-10(9H)-yl)pyrazine was designed and synthesized. The twisted configuration made it possesses very small singlet–triplet splitting. A red electroluminescent device based on this new host material is able to achieve ∼26% external quantum efficiency and relatively flat efficiency roll-off. [ABSTRACT FROM AUTHOR]

Abstract: A novel on-line coupled HPLC–hydride generation (HG)–ICP/MS system was developed for rapid, direct and sensitive speciation of methyltins in seawater without any pretreatment step. Methyltin compounds were separated by reversed phase HPLC, and then on-line reacted with potassium borohydride and acetic acid to generate volatile hydride products. The volatile derivatization products were separated in the spray chamber of ICP/MS and then introduced into ICP/MS by argon gas for detection. Monomethyltin (MMT), dimethyltin (DMT) and trimethyltin (TMT) were baseline separated in less than 15min by reversed phase HPLC. The influence of KBH4 concentration and type of acid on the system performance was investigated and optimized. Calibration curves, based on peak heights against concentration, were linear in the range of 0.5–50ng (Sn) mL−1 of methyltins with correlation coefficients of 0.9990, 0.9990 and 0.9996 for MMT, DMT and TMT, respectively. The relative standard deviations measured at 10ng (Sn) mL−1 for these three methyltins were in the range of 0.6–1.4% (n =5), and the calculated detection limits (S/N=3) for MMT, DMT and TMT were 0.266, 0.095 and 0.039ng (Sn) mL−1, respectively. This method was successfully applied to the speciation of methyltins in seawater with spiked recovery in the range of 95.4–106.9%. MMT and DMT were detected in all the seawater samples with concentrations in the range of 1.0–1.5 and 0.30–0.57ng (Sn) mL−1 for MMT and DMT, respectively. [Copyright &y& Elsevier]

• Provides a program for experimental investigation of floating point-absorber array. • The efficiency of the floating converter is better than a single floater at a low wave period. • The staggered arrangement of floaters is beneficial for power output. • Floaters' elimination effect can improve the platform's motion responses. The deep ocean contains abundant wave energy but the sea condition is complex for people to obtain ocean energy. Therefore, how to develop a floating wave energy converter that adapts to the severe environment of the deep ocean has become a hot research topic recently. In this paper, a point-absorber array is installed on a three-pontoon semi-submersible platform and a model experiment of such a system is conducted under regular and irregular waves. And, a simplified hydraulic power take-off (PTO) system is adopted to convert wave energy into potential energy of load inserts. Results show that such a combination increases pitch and heave, but the surge is suppressed under certain circumstances. The maximum hydraulic efficiency of the point-absorber array is 35.2%, and the max overall efficiency is 11.1%. Additionally, by comparing performance of each floater in the array, the staggered arrangement of floaters is more conducive to energy harvest. [ABSTRACT FROM AUTHOR]

Abstract: We previously reported that pharmacological preconditioning of rabbit hearts with acetylcholine involves activation of phosphatidylinositol 3-kinase (PI3-K) through transactivation of the epidermal growth factor receptor (EGFR). Transactivation is thought to be initiated by cleavage of membrane-bound pro-heparin-binding EGF-like growth factor (HB-EGF) by a membrane metalloproteinase thus releasing HB-EGF which binds to the EGFR. This pathway leads to redox signaling with the generation of reactive oxygen species (ROS) by mitochondria. We tested whether preconditioning''s physiological triggers, bradykinin and opioid, also signal through the EGFR. Both bradykinin and the synthetic δ-opioid agonist DADLE increased ROS production in isolated cardiomyocytes by approximately 50%. DADLE''s effect was abrogated by either metalloproteinase inhibitor III (MPI) or the diphtheria toxin mutant CRM-197 which blocks heparin-binding EGF shedding indicating that DADLE signals through EGFR transactivation. MPI also blocked DADLE''s infarct-sparing effect in whole hearts. Additionally, blocking Src kinase (a component of the EGFR''s signaling complex) with PP2 or PI3-K with wortmannin blocked DADLE''s effect on cardiomyocyte ROS production and PP2 blocked DADLE''s salvage of ischemic myocardium. Finally, DADLE increased phosphorylation of Akt and extracellular signal-regulated protein kinases (ERK) 1/2 in left ventricular myocardium, and this increase was blocked by the EGFR antagonist AG1478. On the other hand, neither MPI nor CRM-197 prevented bradykinin from increasing ROS production, and MPI did not affect bradykinin''s infarct-sparing effect in intact hearts. Conversely, both PP2 and wortmannin blocked bradykinin''s effect on ROS generation and also aborted bradykinin''s cardioprotective effect in intact hearts. While bradykinin also increased phosphorylation of Akt and ERK in myocardium, that increase was not affected by AG1478. Hence bradykinin, unlike acetylcholine or opioid, does not transactivate EGFR, although all 3 agonists do signal through Src and PI3-K. [Copyright &y& Elsevier]

The effects of phenylethyl isothiocyanate (PEITC) on urinary bladder and liver carcinogenesis were analyzed in a rat model. Diets containing 0.1%, 0.05%, or 0.01% PEITC were administered for 32 wk to male Fischer 344 rats with and without pretreatment with an injection of diethylnitrosamine (200 mg/kg body wt ip) and 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in the drinking water for 4 wk for initiation. In the initiated groups, PEITC administration significantly increased the incidences of papillary or nodular hyperplasia, dysplasia, and transitional cell carcinomas at higher doses of 0.01%, 0.01%, and 0.05%, respectively, compared with the control group, given initiation alone, in a dose-dependent manner. Without initiation, administration of 0.1% and 0.05% PEITC induced simple and papillary or nodular hyperplasia and dysplasia in the urinary bladder. In the liver, induction of glutathione S-transferase placental form-positive foci was dose dependently enhanced by PEITC administration, but the incidences of liver tumors were not different among the groups. From the present experiment, we can conclude that >0.01% PEITC enhances rat urinary bladder carcinogenesis, while weakly promoting hepatocarcinogenesis. In addition, it is suggested that >0.05% PEITC has tumorigenic potential. [ABSTRACT FROM AUTHOR]