Ambient particulate matter (PM) is a worldwide health issue of concern. However, limited information is available regarding the toxic contributions of the nitro-derivatives of polycyclic aromatic hydrocarbons (nitro-PAHs). This study intend to examine whether 1-nitropyrene (1-NP) and 3-nitrofluoranthene (3-NF) could activate the nuclear factor-erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) antioxidant defense system, and whether the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway participates in regulating pro-inflammatory responses in A549 cells. Firstly, 1-NP and 3-NF concentration-dependently induced cellular apoptosis, reactive oxygen species (ROS) generation, DNA damage, S phase cell cycle arrest and differential expression of related cytokine genes. Secondly, 1-NP and 3-NF activated the Nrf2/ARE defense system, as evidenced by increased protein expression levels and nuclear translocation of transcription factor Nrf2, elevated Nrf2/ARE binding activity, up-regulated expression of the target gene heme oxygenase-1 (HO-1). Significantly increased protein expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and phosphorylation level of Akt indicated that the PI3K/Akt pathway was activated during pro-inflammatory process. Further, both PI3K inhibitor (LY294002) and Akt inhibitor (MK-2206) reversed the elevated TNF-alpha expression to control level. Our results suggested that Nrf2/ARE pathway activation might cause an initiation step in cellular protection against oxidative stress caused by nitro-PAHs, and the PI3K/Akt pathway participated in regulating inflammatory responses.
Four polymers based on perylenediimide co-polymerized with thiophene, bithiophene, selenophone and thieno[3,2-b]thiophene were investigated as the acceptor materials in all-polymer solar cells. Two different donor polymers, poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexyl)-3-fluorothieno[3,4-b]thiophene)-2-carboxylate-2,6-diyl] (PTB7-Th) and poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3aEuro '-di(2-dodecyltetradecyl)-2,2';5',2aEuro(3);5aEuro(3),2aEuro '-quaterthiophen-5,5aEuro '-diyl)] (PffBT4T-2DT), with suitably complementary absorption spectra and energy levels were applied and examined. Among all different donor-acceptor pairs studied here, the combination of PTB7-Th:poly[N,N'-bis(1-hexylheptyl)-3,4,9,10-perylenediimide-1,6/1,7-diyl-alt-2,5-thiophene] (PDI-Th) exhibited the best power conversion efficiency (PCE) of 5.13%, with open-circuit voltage (Voc) = 0.79 V, short-circuit current density (J (sc) = 12.35 mA center dot cm(-2) and fill-factor (FF) = 0.52. The polymer of PDI-Th acceptor used here had a regio-irregular backbone, conveniently prepared from a mixture of 1,6- and 1,7-dibromo-PDI. It is also noteworthy that neither additive nor post-treatment is required for obtaining such a cell performance.
This paper studies the high priests found in inscriptions from Amastris concerning the Koinon of the Cities in Pontus (henceforth “the Koinon”), commonly recognized as an assembly of cities in coastal Paphlagonia (Marek 2003, Vitale 2012; contra Loriot 2006).
The Amastrian high priests (7 in total) comprise of three types: 1) ἀρχιερεὺς τοῦ Πόντοῦ, which can be securely associated with the Koinon; 2) ἀρχιερεύς, without specific designation as to what sort of imperial or local cult it was in charge; 3) ὁ τοῦ ἐπουρανίου Θεοῦ Σεβαστοῦ ἀρχ[ιερεὺς διὰ βίου, which also has the Latin equivalent Divi Aug. perpetuus sacerdos inscribed together as a bilingual text.
Should all three types titles be interpreted as the same office? Christian Marek (2003) assumed that they were: he included 2) and 3) under 1), without clarification. Xavier Loriot (2006) assumed differently: in his tabulation of dignitaries of Pontus, he omitted the office holders of 2) and 3), and he also did not state his rationale.
The discrepancy is significant because of dating. Time-reckoning markers on inscriptions of 2) and 3) help date the former to 62 CE, and the latter c. 50 CE, all considerably earlier than the earliest inscription in 1), which is Trajanic. The problem, on the other hand, is that Marek’s inclusion of 2) and 3) may be wrong: Frija (2012) demonstrated that when a high priesthood was not specified, they could be instead high priests of the municipal imperial cult.
This paper considers the possibility that 2) and 3) may have been local/municipal office(s), and could have been the precursor to the High Priesthood of Pontus. Particular emphasis will be on the bilingual text of 3), which contain the surprising attribution ἐπουρανίος, commonly associated with Zeus or Theos Hypsistos and without a Latin equivalent.
Peroxyacyl nitrates (PANs) are photochemical secondary pollutants that play a key role in the atmospheric chemistry of the troposphere. However, there have been few studies on the long-term variation and inter-regional transport of PANs. In this study, summertime ambient PAN concentrations were monitored at urban and rural sites in Beijing and Hebei, China, between 2006 and 2014. In Beijing, the peak concentrations of PAN and PPN were in the range of 6–17 ppbv and 0.6–2.2 ppbv, respectively, higher than concentrations in other provinces. The nitrogen oxide (NOx) concentration decreased at a rate of 1.7 ppbv/yr (∼4% yr−1), and the PAN concentration decreased at a rate of 0.03 ppbv/yr (∼3% yr−1), while the ozone (O3) concentration increased at a rate of 1.5 ppbv/yr (∼4% yr−1). Trajectory clustering analyses showed that high concentrations of PAN were mainly affected by low air masses transported medium/short distances from South Beijing, and the potential source contribution function maps showed that the likely pollution source area was concentrated in the southern region of Beijing. These findings provide a theoretical basis for pollution control in this region.
Poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) is one of the most widely used hole transport layers (HTL) in inverted perovskite solar cells (PSCs) due to its simple solution-processed ability, high transparency, and conductivity. However, PEDOT: PSS-based devices suffer a lower open-circuit voltage (V-oc) than devices with the conventional structure. To address this issue, we fabricated ammonia-modified PEDOT: PSS films by simply doping PEDOT: PSS solution with different ratio of ammonia. The acidity of PEDOT: PSS can be neutralized by the doped ammonia, which inhibits the ion-exchange reaction between PSS-H and CH3NH3I, thus retarding the reduction of the work function for PEDOT: PSS to some extent. As a result, a superior power conversion efficiency (PCE) of 15.5% was obtained for the device based on the ammonia-doped PEDOT: PSS HTL than that of the pristine PEDOT: PSS-based device. We ascribe the PCE enhancement to the increased Voc and fill factor (FF), which is attributed not only to the better energy-level alignment between the ammonia-modified PEDOT: PSS film and perovskite layer but also to the increased grain size and crystallinity of perovskite film. (C) 2017 Published by Elsevier B.V.
Lanthanide-doped glasses and crystals are attractive for laser applications because the metastable energy levels of the trivalent lanthanide ions facilitate the establishment of population inversion and amplified stimulated emission at relatively low pump power(1-3). At the nanometre scale, lanthanide-doped upconversion nanoparticles (UCNPs) can now be made with precisely controlled phase, dimension and doping level(4,5). When excited in the near-infrared, these UCNPs emit stable, bright visible luminescence at a variety of selectable wavelengths(6-9), with single-nanoparticle sensitivity(10-13), which makes them suitable for advanced luminescence microscopy applications. Here we show that UCNPs doped with high concentrations of thulium ions (Tm3+), excited at a wavelength of 980 nanometres, can readily establish a population inversion on their intermediate metastable H-3(4) level: the reduced inter-emitter distance at high Tm3+ doping concentration leads to intense cross-relaxation, inducing a photon-avalanche-like effect that rapidly populates the metastable H-3(4) level, resulting in population inversion relative to the H-3(6) ground level within a single nanoparticle. As a result, illumination by a laser at 808 nanometres, matching the upconversion band of the H-3(4)-> H-3(6) transition, can trigger amplified stimulated emission to discharge the H-3(4) intermediate level, so that the upconversion pathway to generate blue luminescence can be optically inhibited. We harness these properties to realize low-power super-resolution stimulated emission depletion (STED) microscopy and achieve nanometre-scale optical resolution (nanoscopy), imaging single UCNPs; the resolution is 28 nanometres, that is, 1/36th of the wavelength. These engineered nanocrystals offer saturation intensity two orders of magnitude lower than those of fluorescent probes currently employed in stimulated emission depletion microscopy, suggesting a new way of alleviating the square-root law that typically limits the resolution that can be practically achieved by such techniques.
With the development of laser technology, laser-driven proton acceleration provides a new method for proton tumor therapy. However, it has not been applied in practice because of the wide and decreasing energy spectrum of laser-accelerated proton beams. In this paper, we propose an analytical model to reconstruct the spread-out Bragg peak (SOBP) using laser-accelerated proton beams. Firstly, we present a modified weighting formula for protons of different energies. Secondly, a theoretical model for the reconstruction of SOBPs with laser-accelerated proton beams has been built. It can quickly calculate the number of laser shots needed for each energy interval of the laser-accelerated protons. Finally, we show the 2D reconstruction results of SOBPs for laser-accelerated proton beams and the ideal situation. The final results show that our analytical model can give an SOBP reconstruction scheme that can be used for actual tumor therapy.
