Electrospun polyvinyl alcohol/carbon dioxide modified polyethyleneimine composite nanofiber scaffolds

A novel biocompatible polyvinyl alcohol/carbon dioxide modified polyethyleneimine (PVA/PEI-CO2) composite nanofiber was fabricated by a green and facile protocol, which reduces the cytotoxicity of PEI through the surface modification of the PEI with CO2. The 13C NMR spectrum, elemental analysis, and TGA show that CO2 has been incorporated in the PEI surface resulting in a relatively stable structure. The resulting PVA/PEI-CO2 composite nanofibers have been characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), contact angle, and scanning electron microscopy (SEM). The results show that the average diameters of the nanofibers range from 265 ± 53 nm to 423 ± 80 nm. The cytotoxicity of PVA/PEI-CO2 composite nanofibers was assessed by cytotoxicity evaluation using the growth and cell proliferation of normal mice Schwann cells. SEM and the MTT assay demonstrated the promotion of cell growth and proliferation on the PVA/PEI-CO2 composite scaffold. It suggests that PEI-CO2 can have tremendous potential applications in biological material research

Influence of phacoemulsification on five sites of corneal endothelium of senile cataract after anti-glaucoma surgery

AIM: To study the influence of phacoemulsification on five sites of corneal endothelium of senile cataract in patients after anti-glaucoma surgery. METHODS: Patients with cataract after anti-glaucoma surgery were selected, and the surgery of phacoemulsification was performed by a same skilled surgeon, The superior, inferior, central, nasal, temporal endothelium cells were observed with a non-contact endothelium scope on pre-operation and seventh day, first month, third month and sixth month of post-operation. RESULTS: After operation, there were obvious differences of corneal endothelium of every sites between two groups(P<0.01). CONCLUSION: Endothelium cells of senile cataract in patients after anti-glaucoma surgery are easier to be damaged in the phacoemulsification, so preoperative evaluation, surgery manner and postoperative treatment are very important

Magnonic band structure of domain wall magnonic crystals

Magnonic crystals are prototype magnetic metamaterials designed for the control of spin wave propagation. Conventional magnonic crystals are composed of single domain elements. If magnetization textures, such as domain walls, vortices and skyrmions, are included in the building blocks of magnonic crystals, additional degrees of freedom over the control of the magnonic band structure can be achieved. We theoretically investigate the influence of domain walls on the spin wave propagation and the corresponding magnonic band structure. It is found that the rotation of magnetization inside a domain wall introduces a geometric vector potential for the spin wave excitation. The corresponding Berry phase has quantized value $4 n_w \pi$, where $n_w$ is the winding number of the domain wall. Due to the topological vector potential, the magnonic band structure of magnonic crystals with domain walls as comprising elements differs significantly from an identical magnonic crystal composed of only magnetic domains. This difference can be utilized to realize dynamic reconfiguration of magnonic band structure by a sole nucleation or annihilation of domain walls in magnonic crystals.Comment: 21 pages, 9 figure

Hexakis(1H-imidazole-κN 3)mangan­ese(II) triaqua­tris(1H-imidazole-κN 3)manganese(II) bis­(naphthalene-1,4-dicarboxyl­ate)

In the crystal structure of the title compound, [Mn(C3H4N2)6][Mn(C3H4N2)3(H2O)3](C12H6O4)2, there are uncoordinated naphthalene­dicarboxyl­ate dianions and two kinds of MnII complex cations, both assuming a distorted octa­hedral geometry. One MnII cation is located on an inversion center and is coordinated by six imidazole mol­ecules, while the other MnII cation is located on a twofold rotation axis and is coordinated by three water mol­ecules and three imidazole units. The naphthalene­dicarboxyl­ate dianions are linked to both MnII complex cations via O—H⋯O and N—H⋯O hydrogen bonding, but no π–π stacking is observed between aromatic rings in the crystal structure

Hexakis(1H-imidazole-κN 3)cobalt(II) triaqua­tris(1H-imidazole-κN 3)cobalt(II) bis­(naphthalene-1,4-dicarboxyl­ate)

The asymmetric unit of the title compound, [Co(C3H4N2)6][Co(C3H4N2)3(H2O)3](C12H6O4)2, contains two halves of crystallographically independent CoII complex cations, each assuming a distorted octa­hedral geometry, and one uncoordinated naphthalene-1,4-dicarboxyl­ate dianion. One CoII cation is located on an inversion center and is coordinated by six imidazole mol­ecules, while the other CoII cation is located on a twofold rotation axis and is coordinated by three water and three imidazole mol­ecules. The uncoordinated naphthalene-1,4-dicarboxyl­ate dianion links both CoII complex cations via O—H⋯O and N—H⋯O hydrogen bonding. One imidazole ligand is equally disordered over two sites about a twofold rotation axis, while the coordinated N atom of the imidazole is located on the twofold rotation axis. One water O atom has site symmetry 2

Bis(μ-4-chloro-2-oxidobenzoato)bis­[(1,10-phenanthroline)copper(II)] dihydrate

The structure of the the title compound, [Cu2(C7H3ClO3)2(C12H8N2)2]·2H2O, consists of a dimeric unit involving a planar Cu2O2 group arranged around an inversion center. The coordination sphere of the CuII atom can be described as an elongated distorted square pyramid where the basal plane is formed by the two N atoms of the 1,10-phenanthroline mol­ecule and the two O atoms of the hydroxy­chloro­benzoate (hcbe) anion. The long apical Cu—O distance of 2.569 (2) Å involves the O atom of a symmetry-related hcbe anion, building up the dinuclear unit. Each dinuclear unit is connected through O—H⋯O hydrogen bonds involving two water mol­ecules, resulting in an R 4 2(8) graph-set motif and building up an infinite chain parallel to (10). C—H⋯O inter­actions further stabilize the chain

cyclo-Tetra-μ-malato-κ16 O,O′,O′′:O′′′-tetra­kis[bis­(1H-benzimidazole-κN 3)cobalt(II)] eicosa­hydrate

The title compound, [Co4(C4H4O5)4(C7H6N2)8]·20H2O, consists of tetra­nuclear CoII complexes and disordered uncoordinated water mol­ecules. The tetra­meric complex mol­ecule has symmetry. While two benzimidazole mol­ecules and a tridentate malate dianion coordinate a CoII ion, the carboxylate O atom from an adjacent malate dianion bridges the CoII ions to complete a distorted octa­hedral coordination geometry. The tridentate malate dianion chelates the CoII ion, and the chelate six- and five-membered rings show half-chair and envelope configurations, respectively. A face-to-face separation of 3.494 (9) Å between parallel benzimidazole ligands indicates the existence of π–π stacking between adjacent complexes. The crystal structure also involves N—H⋯O and O—H⋯O hydrogen bonds

Aqua­(3-hydroxy­benzoato-κO)bis­(1,10-phenanthroline-κ2 N,N′)cobalt(II) 3-hydroxy­benzoate penta­hydrate

The crystal structure of the title compound, [Co(C7H5O3)(C12H8N2)2(H2O)](C7H5O3)·5H2O, consists of CoII complex cations, uncoordinated hydroxy­benzoate anions and uncoord­inated water mol­ecules. The CoII ion is coordinated by two phenanthroline ligands, a water mol­ecule and a 3-hydroxy­benzoate anion, and displays a distorted octa­hedral geometry. π–π stacking is observed between parallel phenanthroline ligands, the face-to-face separations being 3.454 (19) and 3.435 (7) Å. An extensive hydrogen-bonding network helps to stabilize the crystal structure. The hydroxybenzoate ligand is disordered over two positions, with site occupancy factors 0.6 and 0.4. One solvent water molecule is also disordered over two positions, with site occupancy factors 0.6 and 0.4