Ab initio study of the giant ferroelectric distortion and pressure induced spin-state transition in BiCoO3

Using configuration-state-constrained electronic structure calculations based on the generalized gradient approximation plus Hubbard U method, we sought the origin of the giant tetragonal ferroelectric distortion in the ambient phase of the potentially multiferroic material BiCoO3 and identified the nature of the pressure induced spin-state transition. Our results show that a strong Bi-O covalency drives the giant ferroelectric distortion, which is further stabilized by an xy-type orbital ordering of the high-spin (HS) Co3+ ions. For the orthorhombic phase under 5.8 GPa, we find that a mixed HS and low-spin (LS) state is more stable than both LS and intermediate-spin (IS) states, and that the former well accounts for the available experimental results. Thus, we identify that the pressure induced spin-state transition is via a mixed HS+LS state, and we predict that the HS-to-LS transition would be complete upon a large volume decrease of about 20%.Comment: 6 pages, 6 figures, 2 table

Tetra­aqua­bis­(2-{[5-(pyridin-4-yl)-1,3,4-oxadiazol-2-yl]sulfan­yl}acetato)­iron(II)

In the title compound, [Fe(C9H6N3O3S)2(H2O)4] or [Fe(POA)2(H2O)4], the FeII atom is located on an inversion center and is ligated by four O atoms of coordinated water mol­ecules in the equatorial plane while two POA ligands acting as monodentate ligands occupy the axial positions through their pyridyl N atoms, completing a slightly distorted octa­hedral coordination geometry. A three-dimensional supra­molecular network is formed by multiple O—H⋯O hydrogen-bonding inter­actions between the coordinated water donors and the uncoordinated carboxyl acceptors

catena-Poly[[(2,2′-bipyridine-κ2 N,N′)cadmium]-μ3-4-nitro­phthalato-κ4 O:O′,O′′:O′′′]

In the title polymeric compound, [Cd(C8H3NO6)(C10H8N2)]n, two O atoms from both carboxyl­ate groups of a nitro­phthalate anion coordinate to the CdII cation, forming a seven-membered chelate ring and two carboxyl­ate O atoms from another two nitro­phthalate anions and a 2,2′-bipyridine ligand coordinate to the Cd cation to complete the distorted octa­hedral coordination geometry. The carboxyl­ate groups of the nitro­phthalate anion adopt a syn–anti bridging mode, linking adjacent CdII cations and forming a polymeric chain running along the a axis. Weak intra- and inter­molecular C—H⋯O hydrogen bonding is present in the crystal structure

Tetra­aqua­bis­[3-(pyridin-4-yl)benzoato-κN]cobalt(II)

In the title compound, [Co(C12H8NO2)2(H2O)4], the Co atom lies on a twofold rotation axis and has an N2O4 octa­hedral coordination environment formed by four O atoms of water mol­ecules in the equatorial plane and two apical N atoms of pyridine groups. An intricate three-dimensional supra­molecular network is formed by multiple O—H⋯O hydrogen bonds between the coordinated water mol­ecules and the uncoordinated carboxyl­ate groups

Mediastinal Lymph Node Metastases in Thyroid Cancer: Characteristics, Predictive Factors, and Prognosis

Background. Mediastinal lymph node metastases (MLNM) have not been extensively studied. The aim of this study is to investigate the characteristics, predictive factors, and prognosis of MLNM in thyroid cancer. Methods. This is a retrospective study based on the thyroid cancer patients with MLNM at our institution from 2008 to 2015. Results. In total, 73 thyroid cancer patients with positive MLNM were included in this study. It contained sixty patients (82.2%) with papillary thyroid carcinoma (PTC), twelve (16.4%) with medullary thyroid carcinoma, and one (1.4%) with anaplastic thyroid carcinoma. Forty-eight patients had the surgery as initial treatment. Fifty-three (72.6%) patients remained disease-free, and fifteen (20.5%) developed a regional recurrence. Distant metastases occurred in four (5.5%) patients and five (6.8%) patients died. Five-year overall survival rate and disease-free survival (DFS) rate of the PTC patients for initial treatment are 95.4% and 77.2%, respectively. Extrathyroidal extension and multiple lymph nodes involved were associated with DFS in PTC patients. Conclusions. Initial therapeutic control is very important for the thyroid cancer patients. Extrathyroidal extension and multiple mediastinal lymph nodes involved were the influence factors of prognosis in the thyroid cancer patients with MLNM

(Methanol-κO)bis­{2-meth­oxy-6-[(4-methyl­phen­yl)iminiometh­yl]phenolato-κ2 O,O′}tris­(nitrato-κ2 O,O′)lanthanum(III)

The asymmetric unit of title compound, [La(NO3)3(C15H15NO2)2(CH3OH)], consists of two Schiff base 2-meth­oxy-6-[(4-methyl­phen­yl)iminiometh­yl]phenolato (HL) ligands, three independent nitrate anions and one methanol mol­ecule coordinated to LaIII. The coordination environment of the LaIII ion is formed by eleven O atoms. Three bidentate nitrate anions coordinate to the LaIII ion, while two HL ligands chelate the metal center with O atoms from the phenolate and meth­oxy groups. The HL ligands are zwitterionic, with protonated imine N atoms. The coordination sphere is completed by one methanol mol­ecule. The protonated imine N atoms are involved in intra­molecular N—H⋯O hydrogen bonds with the phen­oxy groups and nitrate ligands. One O atom of one nitrate group is disordered over two sites of equal occupancy

In situ epicatechin-loaded hydrogel implants for local drug delivery to spinal column for effective management of post-traumatic spinal injuries

Purpose: To prepare hydrogels loaded with epicatechin, a strong antioxidant,  anti-inflammatory, and neuroprotective tea flavonoid, and characterise them in situ as a vehicle for prolonged and safer drug delivery in patients with post-traumatic spinal cord injury.Methods: Five in situ gel formulations were prepared using chitosan and evaluated in terms of their visual appearance, clarity, pH, viscosity, and in vitro drug release. In vivo anti-inflammatory activity was determined and compared with 2 % piroxicam gel as standard. Motor function activity in a rat model of spinal injury was examined comparatively with i.v. methylprednisolone as standard.Results: The N-methyl pyrrolidone solution (containing 1 % w/w epicatechin with 2 to 10 % w/w chitosan) of the in situ gel formulation had a uniform pH in the range of 4.01 ± 0.12 to 4.27 ± 0.02. High and uniform drug loading, ranging from 94.48 ± 1.28 to 98.08 ± 1.24 %, and good in vitro drug release (79.48 ± 2.84 to 96.48 ± 1.02 % after 7 days) were achieved. The in situ gel prepared from 1 % epicatechin and 2 % chitosan (E5) showed the greatest in vivo anti-inflammatory activity  (60.58 % inhibition of paw oedema in standard carrageenan-induced hind rat paw oedema model, compared with 48.08 % for the standard). The gels showed  significant therapeutic effectiveness against post-traumainduced spinal injury in rats. E5 elicited maximum motor activity (horizontal bar test) in the spinal injuryrat model; the rats that received E5 treatment produced an activity score of 3.62 ± 0.02 at the end of 7 days, compared with 5.0 ± 0.20 following treatment with the standard.Conclusion: In situ epicatechin-loaded gel exhibits significant neuroprotective and anti-inflammatory effects, and therefore can potentially be used for prolonged and safe drug delivery in patients with traumatic spinal cord injury.Keywords: Epicatechin, In situ gel, Chitosan, Spinal injury, Post-traumatic, Motor activity, Antiinflammator