Lead-antimony sulfosalts from Tuscany (Italy). XXIII. Andreadiniite, CuAg7HgPb7Sb24S48, a new oversubstituted (Cu,Hg)-rich member of the andorite homeotypic series from the Monte Arsiccio mine, Apuan Alps

The new mineral species andreadiniite, CuAg7HgPb7Sb24S48, was discovered in a quartz vein embedded in metadolostone from the Sant'Olga tunnel, Monte Arsiccio mine, Stazzema, Apuan Alps, Tuscany, Italy. It occurs as black anhedral grains, up to some mm in size, with a metallic luster, associated with sphalerite and stibnite. Under the ore microscope, andreadiniite is white, with a slightly yellow-bronze tint. Pleochroism was not observed. Anisotropism is weak, in shades of gray to bluish-gray. Reflectance percentages for the four COM wavelengths are [R-min, R-max (%), (lambda)]: 34.8, 36.4 (470 nm); 33.5, 35.1 (546 nm); 32.9, 35.0 (589 nm); and 31.8, 32.4 (650 nm). Electron-microprobe analysis gave (in wt% - average of seven spot analyses): Cu 1.06(2), Ag 11.25(18), Tl 0.45(9), Hg 2.76 (14), Pb 19.95(16), As 1.55(5), Sb 40.45(21), S 22.23(11), total 99.70(42). On the basis of Sigma Me= 40 atoms per formula unit, the chemical formula is Cu1.14Ag7.12Tl0.15Hg0.94Pb6.57(Sb22.68As1.41) S24.09S47.33, ideally CuAg7HgPb7Sb24S48. The main diffraction lines, corresponding to multiple hkl indices, are [d in angstrom (relative visual intensity)]: 3.719 (ms), 3.406 (s), 3.277 (s), 2.885 (s), 2.740 (ms), 2.131 (ms), 2.055 (s), and 1.788(s). The crystal structure study gave a monoclinic pseudo-orthorhombic unit cell, space group P2(1)/c, with a = 19.0982(14), b = 17.0093(11), c = 13.0008(10) angstrom, beta = 90.083(4)degrees, V = 4223.3(5) angstrom(3), Z = 2. The crystal structure was solved and refined to R-1 = 0.067 on the basis of 9756 reflections with F-o> 4 sigma(F-o) and 424 refined parameters. Andreadiniite is a new L-4,L-4 homologue belonging to the andorite sub-series of Sb-rich members within the lillianite homologous series. Antimony substituting Pb gives an ideal substitution percentage n = 106.25%. Distribution of minor cations (Hg, Cu, As) is detailed. Mercury may play a critical role for the stabilization of andreadiniite, through a complex substitution rule implying three cation sites: Pb2++Sb3++Ag+ -> Sb3++Ag++Hg2+. Copper is subordinate to the twoHg-rich sites. The name honors Andrea Dini (b. 1966) for his contribution to the knowledge of ore deposits from Tuscany and, in particular, the ore geology and mineralogy of Hg ores from Apuan Alps

Generalized Fourier Integral Operators on spaces of Colombeau type

Generalized Fourier integral operators (FIOs) acting on Colombeau algebras are defined. This is based on a theory of generalized oscillatory integrals (OIs) whose phase functions as well as amplitudes may be generalized functions of Colombeau type. The mapping properties of these FIOs are studied as the composition with a generalized pseudodifferential operator. Finally, the microlocal Colombeau regularity for OIs and the influence of the FIO action on generalized wave front sets are investigated. This theory of generalized FIOs is motivated by the need of a general framework for partial differential operators with non-smooth coefficients and distributional data

Dutrowite, Na(Fe2.52+Ti0.5)Al6(Si6O18)(BO3)3(OH)3O, a new mineral from the Apuan Alps (Tuscany, Italy). The first member of the tourmaline supergroup with Ti as a species-forming chemical constituent

The new tourmaline supergroup mineral dutrowite, Na(Fe2.52+Ti0.5)Al6(Si6O18)(BO3)3(OH)3O, has been discovered in an outcrop of a Permian metarhyolite near the hamlet of Fornovolasco, Apuan Alps, Tuscany, Italy. It occurs as chemically homogeneous domains, up to 0.5 mm, brown in colour, with a light-brown streak and a vitreous lustre, within anhedral to subhedral prismatic crystals, up to 1 mm in size, closely associated with Fe-rich oxy-dravite. Dutrowite is trigonal, space group R3m, with aCombining double low line15.9864(8), cCombining double low line7.2187(4) Å, VCombining double low line1597.68(18) Å3, and ZCombining double low line3. The crystal structure was refined to R1Combining double low line0.0257 for 1095 unique reflections with Fo>4σ (Fo) and 94 refined parameters. Electron microprobe analysis, coupled with Mössbauer spectroscopy, resulted in the empirical structural formula X(Na0.81Ca0.20K0.01)ς1.02 Y(Fe1.252+Mg0.76Ti0.56Al0.42)ς3.00 Z(Al4.71Fe0.273+V0.023+Mg0.82Fe0.182+)ς6.00 T[(Si5.82Al0.18)ς6.00O18] (BO3)3O(3)(OH)3O(1)[O0.59(OH)0.41]ς1.00, which was recast in the empirical ordered formula, required for classification purposes: X(Na0.81Ca0.20K0.01)ς1.02 Y(Fe1.432+Mg1.00Ti0.56)ς3.00 Z(Al5.13Fe0.273+V0.023+Mg0.58)ς6.00 T[(Si5.82Al0.18)ς6.00O18] (BO3)3V(OH)3 W[O0.59(OH)0.41]ς1.00. Dutrowite is an oxy-species belonging to the alkali group of the tourmaline supergroup. Titanium is hosted in octahedral coordination, and its incorporation is probably due to the substitution 2Al3+ Combining double low line Ti4+ + (Fe,Mg)2+. Its occurrence seems to be related to late-stage high-T/low-P replacement of "biotite"during the late-magmatic/hydrothermal evolution of the Permian metarhyolite

Nickel-and Fe3+-rich oxy-dravite from the Artana Mn prospect, Apuan Alps (Tuscany, Italy)

Nickel-and Fe3+-rich oxy-dravite was identified on a specimen collected in the Artana Mn prospect, Carrara, Apuan Alps, Tuscany, Italy. Oxy-dravite occurs as brownish-orange prismatic crystals, up to 0.3 mm in length, associated with quartz, carbonates, and hematite. Electron microprobe analysis gave (in wt. % – average of 7 spot analyses): SiO2 35.81, TiO2 0.41, B2 O3(calc) 10.38, Al2 O3 29.36, V2 O3 0.78, Cr2 O3 0.09, Fe2 O3 3.32, FeO 0.33, MgO 8.04, CaO 0.39, MnO 0.34, NiO 3.46, ZnO 0.40, Na2 O 2.84, F 0.29, H2 O(calc) 3.00, O = F –0.12, total 99.12. The Fe3+/Fetot ratio was calculated based on optical absorption spectroscopy. The empirical ordered formula of the studied sample is (with rounding errors)X(Na0.92 Ca0.07 □0.01)Σ1.00 Y (Mg2.01 Ni2+0.47Fe3+ Ti0.33 0.05Mn2+0.05Fe2+ Zn)Z (Al 0.05 0.05 Σ3.005.80 V0.10 Cr0.01 Fe3+) Si O (BO)V (OH) 0.09 Σ6.00 6 18 3 33W [O0.50 (OH)0.35 F0.15 ]Σ1.00 . This is an intermediate member of the dravite–oxy-dravite series. In naming it, the prefix oxy-was preferred sinceWO is very close to being larger than 0.5 atoms per formula unit. Infrared spectroscopy revealed the occurrence of significant amounts ofW(OH), and allowed to propose a specific short-range arrangements around the O(1) and O(3) sites. Unit-cell parameters are a = 15.9349(11), c = 7.2038(5) Å, V = 1584.1(2) Å3, space group R3m. The crystal structure was refined by single-crystal X-ray diffraction data to R1 = 0.0146 on the basis of 1138 unique reflections with Fo > 4σ(Fo) and 94 refined parameters. The optimized crystal-chemical formula isX(Na0.92 Ca0.07 □0.01)Σ1.00Y (Mg1.21 Al0.80 Ni2+0.47Fe3+0.26 Ti0.05 Mn2+ Zn V Cr)Z (Al 0.05 0.05 0.10 0.01 Σ3.005.00 Mg0.80 Fe3+ 0.16Fe2+) Si O (BO) O(3) O(1) (OH) 0.05 Σ6.00 6 18 3 33 [O0.50 (OH)0.35 F0.15 ]Σ1.00 . Nickel is ordered at the Y site, in agreement with results obtained on synthetic tourmalines. Oxy-dravite is likely the result of the metamorphic recrystallization of Mn-rich layers at the top of the Liassic carbonates belonging to the Marble Formation of the Apuan Alps Metamorphic Complex

Exogenous Control over Intracellular Acidification: Enhancement via Proton Caged Compounds Coupled to Gold Nanoparticles

The pH regulation has a fundamental role in several intracellular processes and its variation via exogenous compounds is a potential tool for intervening in the intracellular processes. Proton Caged Compounds (PPCs) release protons upon UV irradiation and may efficiently provoke intracellular on-command acidification. Here, we explore the intracellular pH variation, when purposely synthesized PCCs are coupled to gold nanoparticles (AuNPs) and dosed to HEK-293 cells. We detected the acidification process caused by the UV irradiation by monitoring the intensity of the asymmetric stretching mode of the CO2 molecule at 2343 cm-1. The comparison between free and AuNPs functionalized proton caged compound demonstrates a highly enhanced CO2 yield, hence pH variation, in the latter case. Finally, PCC functionalized AuNPs were marked with a purposely synthesized fluorescent marker and dosed to HEK-293 cells. The corresponding fluorescence optical images show green grains throughout the whole cytoplasm

Crystal-chemistry of sulfates from the apuan alps (tuscany, italy). VI. Tl-bearing alum-(k) and voltaite from the fornovolasco mining complex

Thallium-bearing samples of alum-(K) and voltaite from the Fornovolasco mining complex (Apuan Alps, Tuscany, Italy) have been characterized through X‑ray diffraction, chemical analyses, micro-Raman, infrared (FTIR), Mössbauer, and X-ray absorption spectroscopy (XAS). Alum-(K) occurs as anhedral colorless grains or rarely as octahedral crystals, up to 5 mm. Electron-microprobe analysis points to the chemical formula (K0.74Tl0.10)ς0.84(Al0.84Fe0.14)ς0.98S2.03O8·12H2O. The occurrence of minor NH4+ $ext{NH}_{4}^{+}$ was detected through FTIR spectroscopy. Its unit-cell parameter is a = 12.2030(2) Å, V = 1817.19(9) Å3, space group Pa3¯. $Paar{3}.$Its crystal structure has been refined down to R1 = 0.0351 for 648 reflections with F o > 4σ(Fo) and 61 refined parameters. The crystal structure refinement agrees with the partial substitution of K by 12 mol% Tl. This substitution is confirmed by XAS data, showing the presence of Tl+ having a first coordination shell mainly formed by 6 O atoms at 2.84(2) Å. Voltaite occurs as dark green cubic crystals, up to 1 mm in size. Voltaite is chemically zoned, with distinct domains having chemical formula (K1.94Tl0.28)σ2.22(Fe2+3.57Mg0.94Mn0.55)σ5.06Fe3+3.06Al0.98S11.92O4818H2O and (K2.04Tl0.32)σ2.36(Fe2+3.83Mg0.91Mn0.29)σ5.03Fe3+3.05Al0.97S11.92O48 18H2O, respectively. Infrared spectroscopy confirmed the occurrence of minor NH4+ also in voltaite. Its unit-cell parameter is a = 27.2635 Å, V = 20265(4) Å3, space group Fd3c. The crystal structure was refined down to R1 = 0.0434 for 817 reflections with Fo > 4σ(Fo) and 87 refined parameters. The partial replacement of K by Tl is confirmed by the structural refinement. XAS spectroscopy showed that Tl+ is bonded to six O atoms, at 2.89(2) Å. The multi-technique characterization of thallium-bearing alum-(K) and voltaite improves our understanding of the role of K-bearing sulfates in immobilizing Tl in acid mine drainage systems, temporarily avoiding its dispersion in the environment

Hyperalgesic activity of kisspeptin in mice.

BACKGROUND: Kisspeptin is a neuropeptide known for its role in the hypothalamic regulation of the reproductive axis. Following the recent description of kisspeptin and its 7-TM receptor, GPR54, in the dorsal root ganglia and dorsal horns of the spinal cord, we examined the role of kisspeptin in the regulation of pain sensitivity in mice. RESULTS: Immunofluorescent staining in the mouse skin showed the presence of GPR54 receptors in PGP9.5-positive sensory fibers. Intraplantar injection of kisspeptin (1 or 3 nmol/5 μl) induced a small nocifensive response in naive mice, and lowered thermal pain threshold in the hot plate test. Both intraplantar and intrathecal (0.5 or 1 nmol/3 μl) injection of kisspeptin caused hyperalgesia in the first and second phases of the formalin test, whereas the GPR54 antagonist, p234 (0.1 or 1 nmol), caused a robust analgesia. Intraplantar injection of kisspeptin combined with formalin enhanced TRPV1 phosphorylation at Ser800 at the injection site, and increased ERK1/2 phosphorylation in the ipsilateral dorsal horn as compared to naive mice and mice treated with formalin alone. CONCLUSION: These data demonstrate for the first time that kisspeptin regulates pain sensitivity in rodents and suggest that peripheral GPR54 receptors could be targeted by novel drugs in the treatment of inflammatory pain.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Nanoantennas for visible and infrared radiation

Nanoantennas for visible and infrared radiation can strongly enhance the interaction of light with nanoscale matter by their ability to efficiently link propagating and spatially localized optical fields. This ability unlocks an enormous potential for applications ranging from nanoscale optical microscopy and spectroscopy over solar energy conversion, integrated optical nanocircuitry, opto-electronics and density-ofstates engineering to ultra-sensing as well as enhancement of optical nonlinearities. Here we review the current understanding of optical antennas based on the background of both well-developed radiowave antenna engineering and the emerging field of plasmonics. In particular, we address the plasmonic behavior that emerges due to the very high optical frequencies involved and the limitations in the choice of antenna materials and geometrical parameters imposed by nanofabrication. Finally, we give a brief account of the current status of the field and the major established and emerging lines of investigation in this vivid area of research.Comment: Review article with 76 pages, 21 figure

Atomic-scale confinement of optical fields

In the presence of matter there is no fundamental limit preventing confinement of visible light even down to atomic scales. Achieving such confinement and the corresponding intensity enhancement inevitably requires simultaneous control over atomic-scale details of material structures and over the optical modes that such structures support. By means of self-assembly we have obtained side-by-side aligned gold nanorod dimers with robust atomically-defined gaps reaching below 0.5 nm. The existence of atomically-confined light fields in these gaps is demonstrated by observing extreme Coulomb splitting of corresponding symmetric and anti-symmetric dimer eigenmodes of more than 800 meV in white-light scattering experiments. Our results open new perspectives for atomically-resolved spectroscopic imaging, deeply nonlinear optics, ultra-sensing, cavity optomechanics as well as for the realization of novel quantum-optical devices

Signatures of exciton coupling in paired nanoemitters

An exciton formed by the delocalized electronic excitation of paired nanoemitters is interpreted in terms of the electromagnetic emission of the pair and their mutual coupling with a photodetector. A formulation directly tailored for fluorescence detection is identified, giving results which are strongly dependent on geometry and selection rules. Signature symmetric and antisymmetric combinations are analyzed and their distinctive features identified