We present herein the synthesis, and the structural and spectroscopic analysis of a non-planar tripod-shaped p -( N , N ′-dimethylamino)benzyliden-1,3-indandione (DMABI) chromophore. This novel ...molecule is composed of a Si core with three incorporated arms, each of them contains a 1,3-indandione derivative with an electron donating (−NMe 2 ) group, thus providing fluorescence capabilities. We prepared a DMABI arm by coupling a p -( N , N ′-dimethylamino)benzaldehyde (DMAB) tripod substituted molecule with 1,3-indandione via aldol condensation. The structures of DMAB-tripods were confirmed by spectroscopic data and studied by quantum chemical calculations. Fluorescence spectroscopy was used for optical characterization. Quantum yields and the corresponding lifetimes reveal typical characteristics of conjugated derivatives. Finally, we monitored the enhancement in fluorescence intensity of compound 1 in the presence of 4-chloro-2,6-dinitroaniline (4CDNA) in the range between 0 and 20 mg L −1 . We justify this enhancement by calculated energies and the distribution of the HOMO and the LUMO for DMABI-tripod and 4CDNA.
Up until now there has been limited, contradictive data on the high energy range of the cosmic ray electron-positron, proton and helium spectra. Due to the limitations of the use of a magnetic ...spectrometer, over 8 years experimental data was processed using information from a sampling electro-magnetic calorimeter, a neutron detector and scintillator detectors. The use of these devices allowed us to successfully obtain the high energy cosmic ray particle spectra measurements. The results of this study clarify previous findings and greaten our understanding of the origin of cosmic rays.
A new extraction phase based on hydrogel disks of polyvinyl alcohol (PVOH) and pectin was proposed, characterized and evaluated for the extraction of six steroidal hormones (estriol, estrone, ...17β-estradiol, 17α-ethinylestradiol, progesterone, and testosterone) in aqueous samples with subsequent determination by gas chromatography-tandem mass spectrometry (GC-MS/MS) after the derivatization procedure. The developed extraction procedure was based on the solid phase extraction (SPE) technique, but employed hydrogel as the sorbent phase. The effects of several parameters, including the amount and composition of the sorbent phase, pH, sample volume, flow rate, and gel swelling over the extraction efficiency, were evaluated. Gels with lower swelling indexes and larger amounts of sorbent ensured higher extraction yields of analytes. The main benefits of using the PVOH/pectin-based hydrogel as the extraction phase are the ease of synthesis, low-cost preparation, and the possibility of reusing the extraction disks. Limits of quantification of 0.5 μg L
for estrone and 17β-estradiol, and 1 μg L
for testosterone, 17α-ethinylestradiol, progesterone, and estriol were obtained. Accuracy values ranged from 80% to 110%, while the inter-assay precision ranged from 0.23% to 22.2% and the intra-assay from 0.55% to 12.3%. Since the sorbent phase has an amphiphilic character, the use of hydrogels is promising for the extraction of medium-to-high polarity compounds.
The
22
Ne(p,
γ
)
23
Na reaction takes part in the neon-sodium cycle of hydrogen burning. This cycle is active in asymptotic giant branch stars as well as in novae and contributes to the ...nucleosythesis of neon and sodium isotopes. In order to reduce the uncertainties in the predicted nucleosynthesis yields, new experimental efforts to measure the
22
Ne(p,
γ
)
23
Na cross section directly at the astrophysically relevant energies are needed. In the present work, a feasibility study for a
22
Ne(p,
γ
)
23
Na experiment at the Laboratory for Underground Nuclear Astrophysics (LUNA) 400 kV accelerator deep underground in the Gran Sasso laboratory, Italy, is reported. The ion-beam-induced
γ
-ray background has been studied. The feasibility study led to the first observation of the
E
p
=186 keV resonance in a direct experiment. An experimental lower limit of 0.12 × 10
−6
eV has been obtained for the resonance strength. Informed by the feasibility study, a dedicated experimental setup for the
22
Ne(p,
γ
)
23
Na experiment has been developed. The new setup has been characterized by a study of the temperature and pressure profiles. The beam heating effect that reduces the effective neon gas density due to the heating by the incident proton beam has been studied using the resonance scan technique, and the size of this effect has been determined for a neon gas target.
Results of galactic deuteron spectrum measurement by means of PAMELA apparatus are described. PAMELA is an international experiment developed for antimatter search and measurement of p,He, electron ...and positron spectra in wide energy range. In addition, PAMELA allows to identify and measure deuteron spectrum at low energies. In this paper deuteron-to-proton ratio and deuteron spectrum are presented.
The concentration of some anions (Cl, F, NO
3, and SO
4), cations (Na, K, Ca, and Mg), pH and conductivity was determined in seven sampling points in the Serra da Estrela Mountains (Portugal) to ...verify if the application of road deicing with salt provokes impact in the water quality. Multivariate chemometric data analysis techniques of clustering and factor analysis were used. Preliminary analysis shows an overall conductivity increase in late spring and a decrease in late summer. A strong association between sodium chloride and the conductivity was observed by cluster analysis. Factor analysis supports the previous results and shows that the variation of the concentration of sodium chloride is the main source of the variance of the data along the year. In conclusion, the spreading of salt during the winter creates a local and seasonal impact on the water quality.
Background/Aims
: Hepatobiliary transporters are down-regulated in cholestasis, but their expression in acute, non-cholestatic, cytokine-mediated liver injury is unknown. Thus we studied the ...molecular mechanisms, by which sodium taurocholate cotransporting polypeptide (Ntcp), organic anion transporting polypeptide 1 (Oatp1), Oatp2, Oatp4, multidrug-resistance protein 2 (Mrp2) and bile salt export pump (Bsep) are regulated in liver injury induced by carbon tetrachloride (CCl
4).
Methods
: mRNA and protein levels were determined in rats 24 and 72
h after CCl
4 injection. Transporter gene transcription and binding activities of
Ntcp and
Mrp2 transactivators were assessed by nuclear runoff and electrophoretic mobility shift assays.
Results
: mRNA levels significantly declined to 41±44% for Ntcp, 65±41% for Oatp1 and 64±28% for Oatp2, but remained unchanged for Oatp4, canalicular Mrp2 and Bsep. Protein levels declined only for Oatp4 (−50±17%) and Ntcp (−23±13%) at 24
h. Reduced mRNA levels (Ntcp, Oatp1, Oatp2) were associated with decreased transcriptional activities. Binding activity of
Ntcp transactivators (hepatocyte nuclear factor 1 α (HNF1α) and CAAT enhancer binding protein α (C/EBPα) were reduced by 24
h, whereas retinoid X receptor α (RXRα):retinoid acid receptor α (RARα) as transactivator of both
Ntcp and
Mrp2 remained unaltered. Recovery of acute hepatitis and changes in gene expression occurred after 72
h.
Conclusions
: Acute liver injury results in down-regulation of basolateral organic anion transporters similar to liver regeneration after partial hepatectomy, but in contrast to endotoxin-induced cholestasis. Maintained binding activity of RXRα:RARα may explain differences in
Mrp2 expression.
Quantum walks have been shown to have a wide range of applications, from artificial intelligence, to photosynthesis, and quantum transport. Quantum stochastic walks (QSWs) generalize this concept to ...additional non-unitary evolution. In this paper, we propose a trajectory-based quantum simulation protocol to effectively implement a family of discrete-time QSWs in a quantum device. After deriving the protocol for a 2-vertex graph with a single edge, we show how our protocol generalizes to a graph with arbitrary topology and connectivity. The straight-forward generalization leads to simple scaling of the protocol to complex graphs. Finally, we show how to simulate a restricted class of continuous-time QSWs by a discrete-time QSW, and how this is amenable to our simulation protocol for discrete-time QSWs.
Using data taken by the Pamela experiment during 5 years of operation we studied the anisotropy in the arrival direction of cosmic ray electrons and positrons with energy above 40 GeV. We report on a ...study of anisotropy in the e± flux at different angular scales extending from 30° up to 90°, furthermore a directional analysis has been performed around the Sun direction. The observed distribution of arrival directions is consistent with the isotropic expectation at any angular scale used in this study and no significant evidence of strong anisotropies has been observed, also the analysis around the Sun direction did not show any significant excess.
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