Fabrication of Si Nanoparticles Encapsulated into Porous N-Doped Carbon for Superior Lithium Storage Performances.

To improve lithium storage performances of Si anode for lithium-ion batteries, Si nanoparticles encapsulated into porous N-doped carbon (Si@PNC) was devised and prepared by metal nitrate accelerated polymer blowing process. The Si@PNC composites have large specific surface area of 221.7 m² g-1 and possess a great deal of mesopores and micropores, which are attributed to the carbonization of PVP and etching metallic nanoparticles. As anode for lithium ion battery, the initial discharge capacity of Si@PNC composites is high to 1626 mA h g-1, and the specific capacity still retains 1030 mA h g-1 after 200 cycles at 200 mA g-1. Meanwhile, remarkably improved rate capability is achieved with an excellent reversible specific capacity of 375 mA h g-1 at 5.0 A g-1. The excellent lithium storage performances benefit from the unique porous core-shell structure of Si@PNC composites, which improve electroconductivity, reduce volume dilatation and accelerate lithium ion transmission.

Slow magnetic relaxation influenced by change of symmetry from ideal Ci to D3d in cobalt(ii)-based single-ion magnets.

The coordination geometries of the Co(ii) site in the two complexes [Co(imidazole)6][BPh4]2·0.3CH3CN (1) and [Co(imidazole)6][NO3]2 (2) were observed to display the ideal symmetries Ci and D3d, respectively. Both complexes were shown to be field-induced single-ion magnets. The effective energy barrier was found to decrease as the local symmetry changed from low-symmetry Ci to high-symmetry D3d.

Modification of as Synthesized SBA-15 with Pt nanoparticles: Nanoconfinement Effects Give a Boost for Hydrogen Storage at Room Temperature.

In this work, Pt nanoparticles were incorporated into SBA-15 to prepare the materials for hydrogen spillover adsorption. We provide a direct modification (DM) strategy to improve the content of Pt nanoparticles inside the channels of SBA-15. In this strategy, the Pt precursor was directly incorporated into as synthesized SBA-15 by a solid-state grinding method. The subsequent calcination in air, then H2/Ar gases was conducted to obtain the resultant materials of PtAS. For the samples of PtAS, Pt nanoparticles up to 5.0 wt% have a high dispersion inside the channels of SBA-15. The size of nanoparticles is in control of 3.7 nm. Although much work so far has focused on modification of SBA-15 with Pt nanoparticles. Here, it is the first time the loading amount of Pt nanoparticles raises up to 5.0 wt%, and the location of the Pt nanoparticles is interior channels of SBA-15. We reveal that the high dispersion behaviors of Pt nanoparticles are ascribed to the nanoconfinement effects provided by as synthesized SBA-15. However, the samples derived from template free SBA-15 (PtCS) show sparsely dispersion of Pt nanoparticles with the size of 7.7 nm. We demonstrate that the PtAS samples show better hydrogen adsorption performance than PtCS.

Significance of the preoperative neutrophil-to-lymphocyte ratio in the prognosis of patients with gastric cancer.

AIM: To investigate the significance of the preoperative neutrophil-to-lymphocyte ratio (NLR) in the prognosis of patients with gastric cancer (GC). METHODS: The clinical data of 291 GC patients were analysed retrospectively; these patients were divided into two groups according to their preoperative NLR: a high-NLR group (NLR ≥ 3.5, 131 cases) and a low-NLR group (NLR < 3.5, 160 cases). The clinicopathological characteristics and five-year survival rates of the two groups were compared. The NLR and other clinicopathological factors were subjected to univariate and multivariate survival analysis to evaluate the effects of the NLR on the prognosis of GC patients. RESULTS: The lowest preoperative NLR among the 291 patients was 0.56, whereas the highest preoperative NLR was 74.5. The mean preoperative NLR was 5.99 ± 8.98. Age, tumour size, T staging, tumour-node-metastasis (TNM) staging and platelet count were significantly different between the high- and low-NLR groups (P < 0.05). The five-year survival rate of the high-NLR group was 17.0%, which was significantly lower than that of the low-NLR group (43.6%; 17.0% vs 43.6%, P < 0.05). The univariate analysis results showed that the five-year survival rate was related to age, tumour size, T staging, N staging, TNM staging, carcinoembryonic antigen value and NLR (P < 0.05). Multivariate analysis results showed that the NLR was an independent risk factor that likely affected the five-year survival rate of GC patients (P = 0.003, HR = 0.626, 95%CI: 0.460-0.852). CONCLUSION: The preoperative NLR could be used as a prognostic factor for GC patients; in particular, a high NLR corresponded to poor prognosis of GC patients.

A DNA aptamer with high affinity and specificity for molecular recognition and targeting therapy of gastric cancer.

BACKGROUND: Aptamers have emerged as excellent molecular probes for cancer diagnosis and therapy. The aim of the current study was to determine the feasibility of using DNA aptamer cy-apt 20 developed by live cell-SELEX for detecting and targeting gastric cancer. METHODS: The specificity, sensitivity and biostability of cy-apt 20 in detecting gastric cancer were assessed by binding assay, cell fluorescence imaging, and in vivo tumor imaging in animal model in comparison with non-gastric cancers. RESULTS: Flow cytometric analysis showed that cy-apt 20 had higher than 78% of maximal binding rate to gastric cancer cells, much higher than that of non-gastric cancer cells. Cell fluorescence imaging and in vivo tumor imaging showed that the targeting recognition could be visualized by using minimal dose of fluorochrome labeled cy-apt 20. Meanwhile, strong fluorescence signals were detected and lasted for a period of time longer than 50 min in vitro and 240 min in vivo. The fluorescence intensities of gastric cancer were about seven folds in vitro and five folds of that of non-gastric cancers in vivo. CONCLUSION: Our study demonstrated that cy-apt 20 was an excellent molecular probe with high specificity and sensitivity and a certain degree of biostability for molecular recognition and targeting therapy of gastric cancer.

Evolution of a gastric carcinoma cell-specific DNA aptamer by live cell-SELEX.

Aptamers have emerged as promising molecular probes for disease diagnosis and therapy. In the present study, the entire live cell-SELEX method was used to generate gastric cancer cell­specific aptamers. Human gastric carcinoma AGS cells were used as target cells for positive selections and human normal gastric epithelial GES-1 cells as the negative cells for counter selections. The selection procedure was monitored by gel electrophoresis and flow cytometric analysis. By successive in vitro evolutions and subsequent cloning and sequencing, a gastric carcinoma cell­specific DNA aptamer termed cy-apt 20 with minimal recognition to the controls was identified from the final enriched ssDNA pool. Flow cytometry binding assays revealed that cy-apt 20 had a >70% binding rate to AGS cells and <30% binding affinity to non-gastric cancer cells. Furthermore, the targeting recognition of AGS cells was established by using minimal doses of FITC-cy-apt 20 that continued for a long period of time. As visualized by fluorescence imaging, the majority of AGS cells were stained by FITC-cy-apt 20. The fluorescence intensity of AGS cells was ~6-fold over that of non-AGS cells. The present study demonstrated that the entire live cell-SELEX was simple, but effective in generating gastric cancer cell­specific aptamers, and that the aptamer cy-apt 20 has great potential to be used for the study and diagnosis of gastric cancer.

4,4'-(Ethene-1,2-di-yl)dipyridinium 4-[2-(pyridin-4-yl)ethen-yl]pyridinium octa-cyanidomolybdate(V) tetra-hydrate.

The crystal structure of the title compound, (C12H12N2)(C12H11N2)[Mo(CN)8]·4H2O, consists of 4,4'-(ethene-1,2-di-yl)dipyridinium and 4-[2-(pyridin-4-yl)ethen-yl]pyridinium cations disordered over the same site, an [Mo(CN)8](3-) anion and four water mol-ecules of crystallization. The eight-coordinate [Mo(CN)8](3-) unit exhibits a slightly distorted square-anti-prismatic geometry. In the structure, the cations (crystallographic symmetry, 2) and anions (crystallographic symmetry, 222) are arranged alternately by N-H⋯O and O-H⋯N hydrogen bonds, forming layers parallel to the bc plane. These layers are further linked through O-H⋯N hydrogen bonds, generating a three-dimensional supra-molecular network.

Tris(3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium) hexa-cyanidocobaltate(III) penta-hydrate.

The structure of the title compound, (C16H17N2)3[Co(CN)6]·5H2O, consists of three 3,4,7,8-tetra-methyl-1,10-phenanthrolin-1-ium cations, a [Co(CN)6](3-) anion and five water mol-ecules of crystallization, one of which is disordered over two sets of sites in a 0.587 (15):0.413 (15) ratio. The [Co(CN)6](3-) anion exhibits an octa-hedral geometry. In the structure, cations and anions are linked alternatively through O-H⋯O, O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds, π-π inter-actions [centroid-centroid distances = 3.523 (2)-4.099 (2) Å] and van der Waals forces, forming a three-dimensional supra-molecular network.

Lanthanide-ion-tuned magnetic properties in a series of three-dimensional cyano-bridged Ln(III)W(V) assemblies.

The reaction of [W(CN)(8)](3-) with Ln(3+) and pyrazine in acetonitrile yielded a series of isostructural compounds formulated as Ln(H(2)O)(4)(pyrazine)(0.5)W(CN)(8) (Ln = La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7)). The Ln(III) and W(V) centers in the structure are linked through cyanide groups to form two-dimensional (2D) layers, which are further pillared by pyrazine, generating 3D frameworks. The magnetic behavior for compounds 1-7 were driven by the lanthanide ions involved. The Ln(III) and W(V) ions in compounds 2 and 5 are ferromagnetically coupled with magnetic ordering occurring at 2.8 K, comparable with magnetic ordering with the critical temperature of 1.9 K for compound 4. In addition, the antiferromagnetic interactions were observed in compounds 3 and 7, while no significant magnetic couplings were found in compounds 1 and 6.

Poly[[diaqua-hexa-µ-cyanido-cerium(III)ferrate(III)] dihydrate].

In the structure of the title complex, {[CeFe(CN)(6)(H(2)O)(2)]·2H(2)O}(n), the Ce(III) and Fe(III) atoms exhibit square anti-prismatic [CeN(6)(H(2)O)(2)] (site symmetry m2m) and octahedral [FeC(6)] (site symmetry 2/m) coordination geometries, respectively. The metal atoms are linked alternately through the cyanide groups, forming a three-dimensional framework in which the {Ce(2)Fe(2)(CN)(4)} puckered square unit is the basic building block. The crystal packing is enforced by O-H⋯O and O-H⋯N hydrogen bonds, including the uncoordinated water molecule which is located on a mirror plane.

Tris(1,10-phenanthrolin-1-ium) hexa-cyanidoferrate(III) ethanol monosolvate trihydrate.

The asymmetric unit of the title complex, (C(12)H(9)N(2))(3)[Fe(CN)(6)]·C(2)H(5)OH·3H(2)O, consists of two half [Fe(CN)(6)](3-) anions located on inversion centers, three 1,10-phenanthrolin-1-ium cations, [Hphen](+), an ethanol and three water solvent mol-ecules. The average Fe-C and C-N bond lengths are 1.942 (6) and 1.154 (3) Å, respectively, while the Fe-C-N angles deviate slightly from linearity with values ranging from 177.8 (2) to 179.7 (2)°. The Fe(III) atoms adopt a distorted octa-hedral geometry. All the species are linked through O-H⋯N, N-H⋯O and O-H⋯O hydrogen-bonding inter-actions, resulting in a three-dimensional supra-molecular network.

Tetra-aqua-tetra-kis-(4,4'-bipyridine dioxide-κO)terbium(III) octa-cyanidotungstate(V).

In the title compound, [Tb(C(10)H(8)N(2)O(2))(4)(H(2)O)(4)][W(CN)(8)], both metal atoms are eight-coordinated. The Tb(III) ion displays a dodeca-hedral geometry, while the W(v) ion exhibits a distorted square-anti-prismatic geometry. The Tb atoms are located on a special position of site symmetry -4, whereas the W atoms are located on a twofold rotation axis. The cations are linked by O-H⋯O hydrogen bonds. The title compound is isotypic with the corresponding and previously described Mo compound [Qian & Yuan (2011 ▶). Acta Cryst. E67, m845].

Tetra-aqua-tetra-kis-(4,4'-bipyridine dioxide-κO)terbium(III) octa-cyanido-molybdate(V).

In the title compound, [Tb(C(10)H(8)N(2)O(2))(4)(H(2)O)(4)][Mo(CN)(8)], both metal atoms are eight-coordinated. The Tb(III) atom displays a dodecahedral geometry, while the Mo(V) ion exhibits a distorted square-anti-prismatic geometry. The Tb atoms are located on a special position of site symmetry [Formula: see text], whereas the Mo atoms are located on a twofold rotation axis. The cations are linked by O-H⋯O hydrogen bonds.

Two octacyanometallate-based Ni(II)W(V) bimetallic assemblies with metamagnetism.

Reactions of the precursors [Ni(macrocyclic ligand)](2+) with [W(CN)(8)](3-) afford two octacyanotungstate-based assemblies, (H(2)L(1))(0.5)[Ni(L(1))][W(CN)(8)]·2DMF·H(2)O (L(1) = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) (1) and [Ni(L(2))](3)[W(CN)(8)](2)·4H(2)O (L(2) = 3,10-dipropyl-1,3,5,8,10,12-hexaazacyclotetradecane) (2). Single crystal X-ray diffraction shows that 1 consists of anionic one-dimensional (1D) linear chains, while 2 is built of 2D graphite-like layers with (6, 3) topology. Magnetic studies reveal that both complexes exhibit metamagnetic behavior from the spin-canted antiferromagnet to the ferromagnet induced by field.

Efficient synthetic strategy to construct three-dimensional 4f-5d networks using neutral two-dimensional layers as building blocks.

The reaction of neutral two-dimensional (2D) layer Tb(H(2)O)(5)W(CN)(8) with pyrazine in the acetonitrile solution has led to a 3D bimetallic complex, Tb(H(2)O)(4)(pyrazine)(0.5)W(CN)(8) (1). In the structure of 1, the eight-coordinated W center adopts a slightly distorted dodecahedron, while the Tb center exhibits a nine-coordinated slightly distorted tricapped trigonal prism. The Tb(3+) atoms and the [W(CN)(8)](3-) units are linked in alternating fashion in the ab crystallographic plane, resulting in an infinite 2D corrugated layers. The linear bis-monodentate pyrazine ligands acting as pillars link adjacent layers along the c axis to form an extended 3D open framework. The possible formation mechanism is proposed, and the temperature has played a crucial role for the formation of 1. Magnetic measurements revealed the presence of ferromagnetic interaction between Tb(III) and W(V) centers. 1 marks the first structural pattern using the neutral 2D layer as building block and the first 3D complex with Ln(III)-[W(V)(CN)](8) found in octacyanometallate-based system. Such a novel and effective building-block methodology will provide a new attractive path forward in developing functionalities of 3D 4f-5d system and may provide an opportunity to obtain 3D magnet in 4f-5d assembly.

A cyanide-bridged Fe(II)-Nd(III) bimetallic assembly with a one-dimensional ladder-like chain structure.

The title complex, catena-poly[[[(2,2'-bipyridine-1kappa(2)N,N')tris(methanol-2kappaO)(nitrato-2kappa(2)O,O')-mu-cyanido-1:2C:N-cyanido-1kappaC-iron(II)neodymium(III)]-di-mu-cyanido-1:2'C:N;2:1'N:C] methanol solvate], {[Fe(II)Nd(III)(CN)(4)(NO(3))(C(10)H(8)N(2))(CH(3)OH)(3)].CH(3)OH}(n), is made up of ladder-like one-dimensional chains oriented along the c axis. Each ladder consists of two strands based on alternating Fe(II) and Nd(III) centers connected by cyanide bridges. Furthermore, two such parallel chains are connected by additional cyanide cross-pieces (the ;rungs' of the ladder), which likewise connect Fe(II) and Nd(III) centers, such that each [Fe(CN)(4)(bipy)](2-) unit (bipy is 2,2'-bipyridine) coordinates with three Nd(III) centers and each Nd(III) center connects with three different [Fe(CN)(4)(bipy)](2-) units. In the complex, the iron(II) cation is six-coordinated with a distorted octahedral geometry and the neodymium(III) cation is eight-coordinated with a distorted dodecahedral environment.

4,4'-Diazenediyldipyridinium 4-(4-pyridyldiazen-yl)pyridinium octa-cyanidotungstate(V) dihydrate.

The asymmetric unit of the title complex, (C(10)H(10)N(4))(C(10)H(9)N(4))[W(CN)(8)]·2H(2)O, contains two 4,4'-diazenediyldipyridinium, [H(2)(4,4'-azpy)](2+), two 4-(4-pyridyldiazen-yl)pyridinium, [H(4,4'-azpy)](+), cations, two [W(V)(CN)(8)](3-) anions, and four uncoordinated water mol-ecules. Each of the W centers is coordinated by eight CN groups in a slightly distorted square-anti-prismatic geometry. In the crystal structure, intra- and inter-molecular N-H⋯O, N-H⋯N and O-H⋯N hydrogen bonds link the cations and anions in an alternating fashion, forming a two-dimensional layered structure, in which they are further linked through the very weak π-π stacking inter-actions [shortest distance = 4.640 (2) Å] and van der Waals forces between adjacent layers, forming a three-dimensional supra-molecular network.

Di-µ-cyanido-1:2κC:N,2:3κN:C-hexa-cyanido-1κC,3κC-tetra-kis(1,10-phenanthroline)-1κN,N';2κN,N';3κN,N'-1,3-dicobalt(III)-2-iron(II) tetra-hydrate.

The hydro-thermal reaction of CoCl(2)·6H(2)O, 1,10-phenanthroline (phen) and K(3)[Fe(CN)(6)] in deionized water yielded the title cyanide-bridged trinuclear cluster, [Co(2)Fe(CN)(8)(C(12)H(8)N(2))(4)]·4H(2)O or [{Co(III)(phen)(CN)(4)}(2){Fe(II)(phen)(2)}]·4H(2)O, which contains two Co(III) centers and one Fe(II) center linked by cyanide bridges. The combination of coordinative bonds, O-H⋯N and O-H⋯O hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance = 3.630 (2) Å] results in the stabilization of a supra-molecular structure. All uncoordinated water molecules are disordered. Thermogravimetric analysis reveals that the title complex loses the four crystal water mol-ecules at about 333 K, then the anhydrous phase loses no further mass up to about 573 K, above which decomposition occurs.

Poly[[(µ(2)-benzene-1,4-dicarboxyl-ato-κO,O:O,O)(µ(2)-di-4-pyridyldiazene-κN:N)cobalt(II)] N,N-dimethyl-formamide disolvate hemihydrate].

In the title compound, {[Co(C(8)H(4)O(4))(C(10)H(8)N(4))]·2C(3)H(7)NO·0.5H(2)O}(n), the Co(II) atom is six-coordinated by four O atoms from two benzene-1,4-dicarboxyl-ate (H(2)bdc(2-)) groups and two N atoms from two 4,4'-azopyridine (4,4'-azpy, or di-4-pyridyldiazene) ligands, leading to a distorted octa-hedral geometry. The structure consists of two-dimensional corrugated sheets with a 4(4) topology in an …ABAB… packing pattern stacking along the a axis. The separation of the adjacent corrugated sheets is ca. 8.561 (2)  Š(Co⋯Co distance) along the a axis. The uncoordinated water molecule is half-occupied. The crystal structure is stabilized by O-H⋯N and C-H⋯O hydrogen-bonding inter-actions.

Poly[bis-(dimethyl-ammonium) [bis-(dimethyl-amine-κN)tris-(µ(2)-terephthalato-κO:O)dizinc(II)] N,N-dimethyl-formamide disolvate hexa-hydrate].

The title compound, {(C(2)H(8)N)(2)[Zn(2)(C(8)H(4)O(4))(3)(C(2)H(7)N)(2)]·2C(3)H(7)NO·6H(2)O}(n), consists of two-dimensional non-inter-penetrated sheets with 6(3) topology, which are stacked together in an …ABAB… packing mode along the c axis. The distance between adjacent A and B sheets is ca 7.3 Å. In the structure, the Zn(II) center is coordinated by three O atoms from three terephthalate groups and one N atom from one dimethyl-amine ligand, adopting a distorted tetra-hedral geometry. All solvent water mol-ecules are disordered. In the structure, N-H⋯O and O-H⋯O hydrogen bonds are observed.