Nefedovite, Na
5
Ca
4
(PO
4
)
4
F, has been investigated by in situ high-temperature powder (30–690 °C) and single crystal (27–827 °C) X-ray diffraction and Raman spectroscopy. Nefedovite is ...tetragonal, space group
I
-4,
a
= 11.6560(2),
c
= 5.4062(2) Å,
V
= 734.50(2) Å
3
(
R
1
= 0.0149). Nefedovite is a 1
D
antiperovskite, since its crystal structure contains chains of corner-sharing anion-centered FCa
4
Na
2
9+
octahedra. The chains are parallel to the
c
direction. Nefedovite is stable up to 727 °C and undergoes a displacive phase transition in the temperature range 277–327
°
C. With increasing temperature, the PO
4
tetrahedra in the crystal structure of nefedovite gradually rotate around the imaginary fourfold inversion axes aligning the O2
…
O3 edge parallel to 110, which ultimately leads to the appearance of the mirror plane perpendicular to the
c
direction and the change of space group from
I
-4 (82) to
I
4/
m
(87). The crystal structure of nefedovite expands strongly anisotropically with the direction of the maximum thermal expansion oriented perpendicular to the chains of anion-centered octahedra. The information-based structural complexity analysis demonstrates that both low- and high-temperature modifications of nefedovite are structurally simple with the
I
G,total
value less than 100 bits per unit cell. The structural complexity decreases along the phase transition, which is typical for displacive phase transitions.
Zuktamrurite, FeP
2
, is a new mineral, a natural iron diphosphide found in the pyrometamorphic rocks of the Hatrurim Formation, in the southern part of the Negev Desert, Israel and on the ...Transjordan Plateau, Jordan. The mineral occurs as irregular grains up to 50 µm in size associated with murashkoite, FeP, and barringerite, (Fe,Ni)
2
P. In reflected light, zuktamrurite is white with a distinct bluish tint. It is non-pleochroic but exhibits distinct anisotropy in bluish colours. Reflectance values for the IMA COM recommended wavelengths are
R
max
/
R
min
, % (
λ
, nm): 50.40/47.20 (470); 49.16/46.23 (546); 48.97/46.16 (589); 49.40/46.40 (650). It is brittle. Electron microprobe analysis of the holotype specimen gave the following chemical composition (wt%, average of 5 points): Fe 40.23; Ni 7.97; P 51.70; total 99.90. The empirical formula calculated on the basis of 3 apfu is (Fe
0.86
Ni
0.16
)
1.02
P
1.98
corresponding to FeP
2
. Zuktamrurite is orthorhombic, space group
Pnnm
, unit cell parameters refined from the single-crystal data:
a
4.9276(6),
b
5.6460(7),
c
2.8174(4) Å,
V
78.38(1) Å
3
,
Z
= 2.
D
x
= 5.003 g cm
−3
. The crystal structure was solved and refined to
R
1
= 0.0121 on the basis of 109 unique reflections with
I
> 2
σ
(
I
). The strongest lines of the powder X-ray diffraction pattern (
d
, Å) (
I
, %) (
hkl
): 3.714 (54) (110); 2.820 (31) (020); 2.451 (100) (120, 101); 2.242 (55) (111); 1.760 (37) (211). The mineral is named for the Zuk-Tamrur cliff (Dead Sea) located nearby the type locality, the Halamish Wadi, southern Negev Desert, Israel. Zuktamrurite is the phosphide analogue of löllingite (loellingite), FeAs
2
. It is the most phosphorus-rich phosphide ever found in nature.
A decrease of nonspecific body resistance, an imbalance of local and systemic immunity and a free-radical oxidation abnormality substantially contribute to the pathogenesis of community-acquired ...pneumonia (CAP). Purpose: To study the efficiency of including immunomodulators into the comprehensive treatment of nonsevere community-acquired pneumonia and assess the long-term effects of the treatment conducted. Patients (n = 55) with non-severe CAP (41 (31-48) years old, with CRB-65 score of 0.15 (0-1)) are included in the study. Group 1 (control) received only standard CAP therapy; the other two groups received immunomodulators concurrently with the standard therapy: bacterial lysate (BL) for group 2 and azoximer bromide (AzB) for group 3. TNFα and IL-6 concentration was determined on the day of visit, on day 13 and day 60 of follow-up. During 2 years, the incidence of low respiratory tract infections (LRTI) was studied in the same patients with CAP in past (n = 55). All patients (n = 55) had clinical signs of non-severe community-acquired pneumonia. The overall duration of all symptoms was lower in immunomodulators groups as compared to the control group: 12 (11-13) days in BL group (p < 0.001) and 12 (11-12) days in AzB group (p < 0.001) with no statistically significant difference between intervention groups (p = 0.36). During treatment, TNFα and IL-6 concentration decreased on day 13 and day 60 in all patients; in patients who received immunomodulators, TNFα and IL-6 were reliably lower as compared to the control. Changes of TNFα and IL-6 concentration in the groups on day 60 of the study as compared to the baseline showed a decrease in BL group by 85 (-89 – -82) % and 86 (-90 – -85) % (p < 0.001; p = 0.001 and control); in AzB group by 82 (-86 – -80) % and 86 (-88 – -84) % (p = 0.002; p = 0.007 and control). Intensity of IL-6 concentration decrease on day 60 in BL and AzB groups did not differ (p = 0.72). Gender- and age-adjusted odds ratio for the development of low respiratory tract diseases (during 2 years after CAP) in AzB group was 0.15 (0.02-0.93) (p = 0.04) suggesting its protective effect. Inclusion of immunomodulators in basic treatment of non-severe community-acquired pneumonia reduces duration of symptoms and is associated with improvement of the proinflammatory cytokine profile. In 2 years of follow-up, long-term effects of the immunomodulatory therapy showed statistically significant lower incidence of low respiratory tract infections in AzB group only.
Three series of Sr3–1.5xEuxB2+ySi1–yO8–y/2 (xEu3+ = 0.01–0.51; y = 0, 0.28, 0.53) solid solutions were prepared by crystallization of the melt. The crystal structures of solid solutions with x = 0.2, ...y = 0; x = 0.06, y = 0.28; x = 0.23, y = 0.28; x = 0.46, y = 0.28; x = 0.06, y = 0.53 and x = 0.51, y = 0.53 were determined on the basis of single-crystal X-ray diffraction data (XRD) and refined in the orthorhombic space group Pnma to Robs = 0.029, 0.054, 0.030, 0.029, 0.042 and 0.025, respectively. Heterovalent substitution scheme 3Sr2+ → 2Eu3+ + □ is assumed from the single-crystal XRD data. In the phases with xEu3+≥ 0.2 the substitution leads to a split of the Sr/Eu positions. According to the results of powder and single crystal study, the critical concentration of europium in the structure reaches about 17 at. %. The Eu-doped borosilicates are thermally stable upon heating in air up to at least 800 °C, but decompose at above 900 °C forming a mixture of borates and silicates of Sr and Eu. Ceteris paribus, fluorescence intensity of the borosilicates with y = 0 and 0.28 shows a similar high level of fluorescence while that of the series enriched in boron (y = 0.53) is reduced. The measured quantum yield of the promising red phosphors (xEu3+ ≥ 0.4) demonstrates high values from 44 up to 79% depending on Sr/B/Si ratio.
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•Sr3B2+ySi1–yO8–y/2 (xEu3+ ≤ 0.51, y = 0, 0.28, 0.53) solutions were synthesized from the melt.•The crystal structures are characterized by single crystal and powder XRD.•The position Sr/Eu is split in the structures with high Eu3+ content.•For xEu3+ ≥ 0.4 the measured quantum yield is between 44 and 79% depending on Sr/B/Si ratio.•Homogeneous solutions crystallise up to xEu = 0.4; they are stable on heating to at least 800 °C.
Five samples of voltaite-group minerals from post-volcanic occurrences (geothermal fields and solfatara at pyroclastic flow) and from pseudofumaroles born by coal fires are characterized by ...single-crystal X-ray diffraction, scanning electron microscopy and electron microprobe analysis. The studied minerals include ammoniomagnesiovoltaite, ammoniovoltaite, voltaite and magnesiovoltaite. The quadrilateral of chemical compositions is determined by monovalent cations such as (NH4)+ and K+ and divalent cations such as Fe2+ and Mg2+. Minor Al can occur in the Fe3+ site. Minor amounts of P, V can occur in the S site. Ammonium members are described from geothermal fields, expanding the mineral potential of this type of geological environment. All minerals are cubic, space group Fd-3c, a = 27.18–27.29 Å, V = 20079–20331 Å3, Z = 16. No clear evidence of symmetry lowering (suggested for synthetic voltaites) is observed despite the chemical variation in the studied samples. Ammonium species tend to have a larger a lattice parameter than potassium ones due to longer <A–O> distances (A = N or K). The systematically shorter <Me2+–ϕ>obs (Me2+ = Fe, Mg; ϕ = O, H2O) in comparison to <Me2+–ϕ>calc bond lengths can be explained as a consequence of mean bond length variation due to significant bond length distortion in Me2+ϕ6 octahedra Me2–O2—2.039–2.055 Å; Me2–O4—2.085–2.115 Å; and Me2–Ow5—2.046–2.061 Å, with bond length distortion estimated as from 0.008 to 0.014 for different samples.
2-(4′-Bromopyrazolyl-1′)-3-tosylaminopyridine (HL
3
) and its complex ZnL
2
(
I
) are synthesized, and their structures are studied by IR, UV, and
1
H NMR spectroscopy. The molecular structure of ...complex ZnL
2
is determined by X-ray diffraction analysis. The atomic structure of ZnL
2
is confirmed by the optimization of the molecular geometry using quantum-chemical calculations in the density functional theory approximation. The experimental bands in the absorption spectrum of complex
I
are interpreted on the basis of the calculations, and its photoluminescence properties are studied.
In this article, we present the new product and its description developed by the CoLiTec (Collection Light Technology) project (Khlamov & Savanevych 2020), called CoLiTecVS (CoLiTec Variable Stars) ...software as a set of tools for the automated light curve creation of variable stars using the sensor data received from the different sensors.
CoLiTecVS allows performing the photometry and light curve creation with minimal user interaction in two different modes. The first one is an observation mode when the data are received online from the sensors directly and immediately processed by the OnLine Data Analysis System (OLDAS). This mode is called “OLDAS-Night” mode. The second one is processing the existing observations when sensor data are already received and saved. This mode is called ”CoLiTec-Day” mode.
Nowadays, the modern sensors (robotic ground-based telescopes equipped with different cameras with charge-coupled device (CCD)) still have a lack of capabilities, like non-uniform sensitivity of the matrix pixels, non-linearity of the pixel response to the number of photons that have fallen, oversaturation of bright objects leads to charge transfer to neighboring pixels and the presence of cold or hot pixels. All these shortcomings of modern sensors complicate the process of obtaining the accurate photometric measurements. Such lack of capabilities of modern sensors also makes the plotting of light curves a difficult and routine task. The latter shifts astronomer’s main attention from research to the very time-consuming tasks of processing sensor data and light curve creation. To solve this problem, we developed a new tool for the automated reduction of photometric observations, which includes the computational method for the brightness assessment of the investigated and comparison stars; brightness equalization of astronomical images using an inverse median filter; and light curve plotting and its processing using different tools.
This new CoLiTecVS software provides a tool for high accurate stellar brightness measuring and automated light curve creation with aperture photometry uncertainties less than 0.04 magnitude, the value of which generally depends on various imaging characteristics of telescopes, detectors, and sensors.
CoLiTecVS has been tested on many different time series of 20-600 CCD-frames with variable stars and has produced high-quality photometric light curves in a fraction of the usual processing time.
The
lateral septum
(LS) is an important part of the limbic and reward brain systems; its activity has been associated with the development of different aspects of addiction. Using a stereotaxically ...inserted semi-microelectrode, we recorded local field potentials (LFPs) from the rat LS under background conditions and after i.p. injection of 2.0 g/kg body mass 15% ethanol (Ethl) solution. The recorded LFPs showed typical 1/f behavior. Acute Ethl intoxication resulted in increases in the spectral power of nearly all frequency LFP ranges, except the beta-1 sub-band. A prominent peak has been detected in the beta-1 sub-band centered at 14.77 Hz. Ethanol intoxication resulted in a shift of this peak toward 13.70 Hz with simultaneous decrease in the power of the above sub-band. Powers of most LFP ranges/subranges under conditions of the above intoxications demonstrated increments, most intense for delta, beta-2, gamma-high, and epsilon (ultrafast, >90 Hz) oscillations. Changes in the relatively highfrequency LFP components are assumed to reflect Ethl-induced modifications of the activity of local LS neuronal ensembles, while those of low-frequency (delta) oscillations are probably related to global modulation of the activity of the entire brain. It is supposed that the observed changes caused by acute Ethl intoxication may reflect mainly intensification of GABA-mediated signaling.
Abstract
The study presents the results of an analysis of possible mechanisms of antibacterial activity of nanocarbon compounds. It was found that the contact of carbon-based nanomaterials with ...bacterial cells is not accompanied by a violation of their structural integrity and the development of various types of stress (oxidative stress, reaction of the protein-chaperone system, SOS response). The result of this interaction is a change in the magnitude of the surface zeta potential of cells and the permeability of their membrane, which negatively affects the energy processes occurring in target cells. The direct manifestation of this condition is a decrease in the level of luminescence of luminescent strains and a loss of viability.
We report on the earliest detection of the optical transient MASTER OT J123248.62-012924.5 coincident within the error box with the optical and X-ray transient AT2021lfa/ZTF21aayokph. In our images ...the brightness of the object rises monotonically with
confidence. We interpret this transient as a gamma-ray burst (GRB) characterized by smooth optical self-similar (SOSS) emission, while the nondetection of gamma-ray emission at space observatories is interpreted in terms of the hypothesis of a ‘‘failed’’ GRB. Thus, this is the first detection of a nonmonotonic orphan burst.
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