[Morphological characteristics of hyoid bone and its gender difference]

OBJECTIVE

To understand and analyze the morphological characteristics of hyoid bone and its gender difference in order to find out its forensic significance.

METHODS

The hyoid bones of 68 adult corpses were dissected from redundant soft tissues after heating. The connection status of body of hyoid, greater cornu and lesser cornu, the morphological characteristics of hyoid bone and the degree of ossification were observed by visual inspection. The height of hyoid bone and the arched height of hyoid bone were measured and compared the differences between male and female in order to deduce the analytic equation for gender estimation by hyoid bone.

RESULTS

Five connection conditions of hyoid bone were identified by the morphological characteristics, including complete ossification in both sides, no ossification in both sides, partial ossification in both sides, complete ossification in one side (partial ossification in the other side), and complete ossification in one side (no ossification in the other side). The values of the arched height of hyoid bone (x1) and the height of hyoid bone (x2) in male were both higher than that in female (P < 0.01). The analytic equation for gender estimation (y) was y = 0.438 x1 + 1.042x2-12.979. The discriminant value was -0.272 5 and the resolution was 88.2%.

CONCLUSION

According to the gender characteristics of hyoid bone, the data of hyoid bone can provide helps for forensic practices.

Probing the Low-Lying Electronic States of Cyclobutanetetraone (C4O4) and Its Radical Anion: A Low-Temperature Anion Photoelectron Spectroscopic Approach

Despite a seemingly simple appearance, cyclobutanetetraone (C4O4) has four low-lying electronic states. Determining the energetic ordering of these states and the ground state of C4O4(-) theoretically has been proven to be considerably challenging and remains largely unresolved to date. Here, we report a low-temperature negative ion photoelectron spectroscopic approach. Well-resolved spectra were obtained at both 193 and 266 nm. Combined with recent theoretical studies and our own Franck-Condon factors simulations, the ground state of C4O4(-) and the ground and two low-lying excited states of C4O4 are determined to be (2)A2u, (3)B2u, (1)A1g (8π), and (1)B2u, respectively. The frequency of the ring breathing mode (1810 ± 20 cm(-1)), the electron affinity (3.475 ± 0.005 eV), and the term values of (1)A1g (8π) (6.27 ± 0.5 kJ/mol) and (1)B2u (13.50 ± 0.5 kJ/mol) are also directly obtained from the experiments.

Bridging η2 -BO in B2(BO)3(-) and B3(BO)3(-) clusters: boronyl analogs of boranes

Anion photoelectron spectroscopy and theoretical calculations are combined to probe the structures and chemical bonding of two boron-rich oxide clusters, B(5)O(3)(-) and B(6)O(3)(-), which are shown to be appropriately formulated as B(2)(BO)(3)(-) and B(3)(BO)(3)(-), respectively. The anion clusters are found to each possess a bridging η(2)-BO group, as well as two terminal BO groups and are analogs of B(2)H(3)(-) and B(3)H(3)(-). This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes.

Transition metal–boron complexes BnM: From bowls (n = 8–14) to tires (n = 14)

Transition metal-boron complexes BnM have been predicted at density functional theory level to be molecular bowls (n = 8-14) hosting a transition metal atom (M) inside or molecular tires (n = 14) centered with a transition metal atom. Small Bn clusters prove to be effective inorganic ligands to all the VB-VIIIB transition metal elements in the periodic table. Density functional evidences obtained in this work strongly suggest that bowl-shaped fullerene analogues of Bn units exist in small BnM complexes and the bowl-to-tire structural transition occur to the first-row transition metal complexes BnM (M = Mn, Fe, Co) at n = 14, a size obviously smaller than n = 20 where the 2D-3D structural transition occurs to bare Bn. The half-sandwich-type B12Cr (C3v), full sandwich-type (B12)2Cr (D3d), bowl-shaped B14Fe (C2), and tire-shaped B14Fe (D7d) and B14Fe- (C7v) are the most interesting prototypes to be targeted in future experiments. These BnM complexes may serve as building blocks to form extended boron-rich BnMm tubes or cages (m > or = 2) or as structural units to be placed inside carbon nanotubes with suitable diameters.

C2h (BnEmSi)2H2 Molecules (E = B, C, Si; n = 3−6; m = 1, 2) Containing Double Planar Tetra-, Penta-, and Hexacoordinate Silicons

A density functional theory investigation on a series of S-shaped or cyclic (BnEmSi)2H2 molecules (E = B, C, Si; n = 3-6; m = 1, 2) containing double planar tetra-, penta-, and hexacoordinate silicons has been presented in this work. Further theoretical evidence is provided to support the previously proposed structural pattern to host planar hypercoordinate silicons in small aromatic molecules.

Carbon boronyls: Species with higher viable possibility than boron carbonyls at the density functional theory

Density functional theory investigations indicate that carbon boronyls (CBO)n (n = 3-7) are considerably more stable in thermodynamics than their boron carbonyl isomers (BCO)n and exhibit aromaticity throughout the whole series. The extra stabilities of (CBO)n originate from their frontier pi molecular orbitals delocalized over the Dnh Cn central rings which are absent in (BCO)n. It is expected that experimental characterization of these (CBO)n species may open a new branch of chemistry on carbon boronyls.

Planar Tetra-, Penta-, Hexa-, Hepta-, and Octacoordinate Silicons: A Universal Structural Pattern

A universal structural pattern has been presented at density function theory level to incorporate planar tetra-, penta-, hexa-, hepta-, and octacoordinate silicons in C2v B(n)E2Si series (E = CH, BH, or Si; n = 2-5) and D8h B8Si. The equivalence in valence electron counts and one-to-one correspondence of the delocalized pi and sigma valence orbitals with small boron clusters strongly support the optimized structures containing planar coordinate silicons. Planar B(n)E2Si series are predicted to be aromatic in nature, and the vertical detachment energies of their anions are presented to facilitate future photoelectron experiments. This structural pattern can be applied to form other planar coordinate nonmetals including Ge, P, As, Al, and Ga and needs to be confirmed in experiments to open a new branch of chemistry on planar coordinate main group elements.

Dual analyte flow injection fluorescence immunoassays using thiophilic gel reactors and synchronous scanning detection

Heterogeneous fluorescence immunoassays have been automated using flow injection manifolds incorporating thiophilic gel solid phase reactors to separate antibody-bound and unbound analyte molecules. Antibody elution is achieved by changes in ionic strength, thus allowing the use of pH sensitive fluorescent labels. This facilitates the development of dual analyte systems, in which two competitive immunoassays with separate labels are monitored in parallel. Detection of the fluorophores by high speed synchronous fluorescence scanning while the flow is briefly stopped utilises either one synchronous interval which detects both fluorophores, or two separate scans at different wavelength intervals, one for each fluorophore. Simultaneous analyses of serum albumin and transferrin exemplify these novel approaches. Spectroscopic interferences are very small, analyte recoveries are close to 100%, with a relative standard deviation of 5-6% and a sampling rate of 20 h-1.