Crystal structures of the solid solutions Na3Zn0.912Cd0.088B5O10 and Na3Zn0.845Mg0.155B5O10.

Two new penta-borates, tris-odium zinc cadmium penta-borate, Na3Zn0.912Cd0.088B5O10, and tris-odium zinc magnesium penta-borate, Na3Zn0.845Mg0.155B5O10, have been synthesized by high-temperature solution reactions at 1023 K. Their crystal structures were determined by single-crystal X-ray diffraction. Both solid solutions crystallize in the ortho-rhom-bic form of the parent compound Na3ZnB5O10 (space group type Pbca, Z = 8) and contain the double ring [B5O10]5- anion composed of one BO4 tetra-hedron and four BO3 triangles as the basic structural motif. The anions are bridged by tetra-hedrally coordinated and occupationally disordered M2+ (M = Zn/Cd, Zn/Mg) cations via common O atoms to form [MB5O10] n3n- layers. The intra-layer inter-secting channels and the inter-layer voids are occupied by Na+ cations to balance the charge.

Protective effect of lycium barbarum polysaccharides against heat stress-induced germ cell apoptosis in rats and its mechanism / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of lycium barbarum polysaccharides (LBP) against heat stress-induced apoptosis of germ cells in rats and its action mechanism.</p><p><b>METHODS</b>Ninety male Sprague-Dawley rats were randomly divided into five groups of 18 each: control, heat stress (HS), high-dose LBP, median-dose LBP and low-dose LBP. The rats of the three LBP groups were given LBP by intragastric administration at 100 mg/(kg x d), 50 mg/(kg x d) and 10 mg/(kg x d) respectively for 14 days, and on the 15th day they, together with those of the HS group, were exposed to a heat of 43 degrees C for 30 minutes. At 24 h, 48 h and 7 d after heat stress, the animals were killed by cervical dislocation, followed by observation of the apoptotic germ cells by TUNEL, determination of the expression of Caspase-3 by immunohistochemistry and detection of cytochrome C in the cytosol by ELISA.</p><p><b>RESULTS</b>Compared with the HS group, the three LBP groups showed statistically significant decreases in the apoptosis index (P<0.05), the expression level of Caspase-3 in germ cells (P<0.05) and the concentration of cytochrome C in the cytosol (P<0.05).</p><p><b>CONCLUSION</b>LBP can inhibit cytochrome C release from mitochondria, decrease the expression of Caspase-3 and hence reduce the apoptosis of germ cells. It thus can be deduced that LBP can protect germ cells against apoptosis via the mitochondrial pathway.</p>

[THz-ultraviolet spectra of KDP crystal].

THz time domain spectrum of KH2PO4 crystal in the range from 0.2 to 1.6 THz, the far-infrared spectrum in the range from 50-4000 cm(-1), and ultraviolet-visible-infrared spectrum in the range from 200-2000 nm were measured at the room temperature. The energy band gap Eg of KH2PO4 Crystal is 5.91 eV. There is a wide band of the phonon absorption in the KDP crystal. The values of the absorption coefficient are 35-80 cm(-1) in the range from 0.2 to 205.5 THz. The end of the low frequency of the optical phonon model is smaller than 0.2 THz. The highest frequency upsilonLO of the longitudinal optical phonon model LO is about 205.5 THz, and the force constant K of H-O ionic chemical bond stretch vibration from the omegaLO was calculated to be 13.13 N x cm(-1).

A new polymorph of magnesium oxalate dihydrate.

In the asymmetric unit of the title compound, catena-poly[[diaqua-magnesium(II)]-µ-oxalato], [Mg(C(2)O(4))(H(2)O)(2)](n), there is one Mg atom in an octa-hedral coordination with site symmetry 222, a unique C atom of the oxalate anion lying on a twofold axis, an O atom of the anion in a general position and a water O atom at a site with imposed twofold rotation symmetry. The Mg(2+) ions are ligated by water mol-ecules and bridged by the anions to form chains that are held together by O-H⋯O hydrogen bonds. The structure of the title compound has already been reported in a different space group [Lagier, Pezerat & Dubernat (1969 ▶). Rev. Chim. Miner.6, 1081-1093; Levy, Perrotey & Visser (1971 ▶). Bull. Soc. Chim. Fr. pp. 757-761].

Poly[disodium [diaqua-tri-µ(2)-oxalato-dimagnesium(II)]].

The title compound, {Na(2)[Mg(2)(C(2)O(4))(3)(H(2)O)(2)]}(n), is isotypic with its Co analogue. There are two crystallographically independent oxalate groups in the asymmetric unit, one lying on an inversion center and the other on a general position. Mg(2+) ions are ligated by H(2)O mol-ecules and bridged by tri- and tetra-dentate oxalate ligands, forming ladder-like double chains that are held together via O-H⋯O hydrogen bonds, with Na(+) cations located between the chains to balance the charge.

Lithium dioxobis[trioxoiodato(V)]vanadate, Li[VO2(IO3)2].

The title compound represents a new structure type, in which distorted VO6 octahedra are bridged by iodate groups to form infinite two-dimensional [VO2(IO3)2]- layers that are separated by octahedrally coordinated Li+ cations.

Lead zinc borate, PbZn2(BO3)2.

PbZn2(BO3)2 crystallizes in the space group Pccn, with the Pb cation at a site with imposed twofold symmetry. The compound represents a new structure type in which ZnBO3 layers are bridged by Pb2+ cations, giving rise to a three-dimensional framework. Channels parallel to the [010] direction accommodate the stereochemically active lone pairs of the Pb2+ cations.

Gallium tris(iodate), Ga(IO3)3.

Ga(IO(3))(3) crystallizes in the space group P6(3), with the Ga atom at a site with imposed threefold symmetry. The crystal structure consists of slightly distorted GaO(6) octahedra that are bridged by I atoms of IO(3)(-) groups, giving rise to a three-dimensional polar network. The framework contains unoccupied hexagonal channels running parallel to the hexagonal [001] direction. The iodate groups have their stereochemically active non-bonded electron pairs pointing in the same direction along [001], which creates the polarity in the structure. The I-O bond distances and O-I-O angles are normal, being in the ranges 1.783 (3)-1.847 (2) A and 94.68 (11)-99.61 (12) degrees , respectively.

Cerium triiodate, Ce(IO(3))(3).

The crystal structure of Ce(IO3)3 consists of one-dimensional chains of edge-sharing CeO9 polyhedra which are crosslinked into two-dimensional layers through bridging IO3- groups. The layers are held together via long I...O contacts, resulting in an extended three-dimensional network. The I-O bond distances and O-I-O angles are normal, lying in the ranges 1.806 (4)-1.846 (4) A and 89.9 (2)-100.9 (2) degrees, respectively. The three crystallographically independent iodate groups all show different coordination modes.