Larger Cell Volume Research Articles

Structure, Electrode Voltage and Activation Energy of LiMnxCoyNi1-x-yO2 Solid Solutions as Cathode Materials for Li Batteries from First-Principles

Layered transition-metal oxides, LiMnxCoyNi1-x-yO2, have been considered as potential cathode materials for lithium batteries with high energy density. The crystal structures, reversible potentials and activation energies of LiMnxCoyNi1−x−yO2 are studied by means of density functional theory (DFT) calculations within generalized gradient approximation (GGA) and projector-augmented-wave (PAW) method. The larger cell volume with increasing Ni content benefits the capacity of the cathode materials. Sufficient amount of Ni content in the LiMnxCoyNi1-x-yO2 is beneficial for stabilizing the electrode voltage. Ni substitution is always beneficial to Li diffusion, whereas existence of Mn ions may hinder Li motion by increasing the activation energy. All these first-principles results reveal some general trends for the synergistic effects of TM ions and may guide finding optimal compositions in future experiments.

Intrathecal Catheterization Influences Tolerance to Chronic Morphine in Rats

We evaluated the antinociceptive effects of acute and chronic morphine administered spinally via lumbar puncture in intrathecally catheterized and sham-surgery rats. The effects of acute morphine did not differ between groups. Catheterized rats developed tolerance to chronic morphine more rapidly, compared with sham and naive rats. Therefore, catheter presence facilitated development of opioid antinociceptive tolerance. Spinal astrogliosis, determined by measurement of 3-dimensional cell volumes, was observed in catheterized rats as indicated by significantly larger cell volumes compared with surgery-naive controls. Gliosis induced by chronic intrathecal morphine administered to surgery-naive animals was comparable to that observed in saline-treated catheterized rats.

Phase formation in Li2MoO4-Rb2MoO4-MMoO4 (M = Ca, Sr, Ba, Pb) systems and the crystal structure of α-Rb2Pb(MoO4)2

A subsolidus triangulation of Li2MoO4-Rb2MoO4-MMoO4 (M = Ca, Sr, Pb, Ba) systems is performed. The RbLiMoO4-Rb2M(MoO4)2 (M = Pb, Ba) joins, where 11 mol.% long Rb2M(MoO4)2-based solid solutions are found, are studied in most detail. Ternary molybdates do not form in the systems, which is confirmed by spontaneous flux crystallization. The α-Rb2Pb(MoO4)2 crystals are obtained and their crystal structure is solved (a = 20.9724(15) A, b = 12.1261(8) A, c = 16.1171(10) A, β = 115.728(13)°, C2/m space group, R = 0.0695, Z = 16), which is a monoclinic superstructure of the palmierite type and has the largest cell volume and the most complex structure among lead-containing palmierites. One of the MoO6 tetrahedra is orientationally disordered over two sites; lead atoms are shifted from the centers of their coordination polyhedra to one of their faces and have cn = 6–8; for rubidium cations cn = 10–12.

Role of van der Waals interaction in crystalline ammonia borane

The structural property of crystalline ammonia borane NH3BH3 is studied by means of density-functional theory calculations. The prototypical inter-molecular N-H⋯H-B dihydrogen bonds are found to be weak so as to make the crystal structure flexible and sensitive to the calculational methods. We found that although conventional generalized gradient approximation describes the intra-molecular bonding in ammonia borane reasonably well, it predicts too large unit cell volume and wrong lattice parameters. Inclusion of the van der Waals forces through the semi-empirical correction improves the cell parameters and inter-molecular geometry significantly, suggesting the important role of van der Waals forces in the bonding between ammonia borane molecules.

Ni(1,10-phenanthroline)2(H2O)2](NO3)2: A Simple Coordination Complex with a Remarkably Complicated Structure that Simplifies on Heating

Despite the simple chemical formula, [Ni(1,10-phenanthroline)2(H2O)2](NO3)2, crystallizes with a remarkably complicated 3-D hydrogen bonding supramolecular assembly. The title compound crystallizes in the monoclinic space group P21/c, with an unusually long b axis and a large cell volume. A huge asymmetric unit has been identified, containing six discrete [Ni(1,10-phen)2(H2O)2]2+ cations and twelve nitrate anions. Detailed analyses of the crystal structure and O-H×××O and C-H×××O hydrogen bonding interactions are reported and discussed. In this way the anion-directed assembly of the 3-D structure is illustrated. The thermal and spectroscopic properties of the compound are described. Upon heating to 308 K, the crystal undergoes a phase change to a much simpler structure with a single [Ni(1,10-phen)2(H2O)2]2+ cation within the asymmetric unit and unit cell volume one sixth of that at low temperature. Although the crystal decomposed during data collection, it was possible to establish the molecular packing in the high temperature form and relate it to that at low temperature.

Migration of Cells From the Yolk Sac to Hematopoietic Tissues After Transplantation of Early and Mid Gestation Canine Fetuses

Migration of Cells From the Yolk Sac to Hematopoietic Tissues After Transplantation of Early and Mid Gestation Canine Fetuses

Structural Studies of the Isomorphous MCl2(PMe3)4 (M = Mo, W) Complexes

The structure of WCl2(PMe3)4 has been determined in order to allow for a comparison with its molybdenum analogue. The complexes are isomorphous, and exhibit trans-pseudooctahedral coordination, with crystallographically imposed $$\overline{4}2m$$ (D2d) symmetry. A significant distortion occurs involving the PMe3 ligands, through which one opposing pair tilts upward toward one axial chloride ligand, while the other pair tilts in an opposite manner, by 9.33°. The complex crystallizes in the tetragonal space group $$I\overline{4}2m$$ , with a = b = 9.4987(4) A, c = 12.1058(5) A, V = 1092.25(8) A3, D calc = 1.700 at 150(1) K. For a better comparison, the structure of the molybdenum complex was redetermined, at a low temperature. Its space group is also $$I\overline{4}2m$$ with a = b = 9.5193(3) A, c = 12.1083(5) A, V = 1097.22 A3, D calc = 1.426 at 150(1) K. In accord with the larger cell volume, the molybdenum complex possesses slightly longer M–Cl and M–P bonds.

4,4′-Bis[2-(3,5-dimethoxyphenyl)ethenyl]biphenyl

The title compound, C32H30O4, crystallizes with three different conformers of the same mol­ecule in the asymmetric unit, which explains the unusually large unit cell volume. The supra­molecular structure is based on inter­actions involving the meth­oxy groups [C⋯O contacts between 3.090 (2) and 3.204 (2) Å, and C—H⋯O contacts between (normalized) 2.40 and 2.71 Å], π–π stacking of the electron-rich meth­oxy-substituted rings [centroid–centroid distances of 3.6454 (9)–3.738 (1) Å] and C—H⋯π contacts (normalized, 2.62–2.97Å).

Proliferation characteristics of CD133+ cell population in colorectal cancer

In this study, CD133+ subpopulations were isolated from 41 primary colorectal cancer tissues, the proliferation and cell cycle distribution of the cells were examined without in vitro expansion, and then compared to those of cell lines. The detection of CD133 in colorectal cancer tissues, isolation of CD133+ and CD133- epithelial subpopulations, Ki-67/DNA multiparameter assay and cell volume analysis were flow cytometrically conducted. The results showed that Ki-67 expression was correlated with CD133 level in primary cancer tissues, while cell cycle G2/M phase distribution or clinicopathological characteristics was not. In addition, the CD133+ cells showed larger cell volume and higher Ki-67 expression as compared with CD133- cells. But there was no statistically significant difference in G(2)/M phase distribution between the two subpopulations. Our results demonstrated that the CD133+ subpopulation in colorectal cancer tissue contained more actively cycling and proliferating cells, which was not correlated to clinicopathological factors but might contribute to tumor progression and poor clinical outcome.

Significant CO2 fixation by small prymnesiophytes in the subtropical and tropical northeast Atlantic Ocean

Global estimates indicate the oceans are responsible for approximately half of the carbon dioxide fixed on Earth. Organisms < or =5 microm in size dominate open ocean phytoplankton communities in terms of abundance and CO(2) fixation, with the cyanobacterial genera Prochlorococcus and Synechococcus numerically the most abundant and more extensively studied compared with small eukaryotes. However, the contribution of specific taxonomic groups to marine CO(2) fixation is still poorly known. In this study, we show that among the phytoplankton, small eukaryotes contribute significantly to CO(2) fixation (44%) because of their larger cell volume and thereby higher cell-specific CO(2) fixation rates. Within the eukaryotes, two groups, herein called Euk-A and Euk-B, were distinguished based on their flow cytometric signature. Euk-A, the most abundant group, contained cells 1.8+/-0.1 microm in size while Euk-B was the least abundant but cells were larger (2.8+/-0.2 microm). The Euk-B group comprising prymnesiophytes (73+/-13%) belonging largely to lineages with no close cultured counterparts accounted for up to 38% of the total primary production in the subtropical and tropical northeast Atlantic Ocean, suggesting a key role of this group in oceanic CO(2) fixation.

Crescimento e composição química de dez espécies de microalgas marinhas em cultivos estanques

Microalgas apresentam diversas aplicações econômicas consagradas, como usos na aquicultura e na indústria de alimentos, havendo buscas por novos usos, como a geração de biomassa para produção de biodiesel. As possíveis aplicações estão diretamente relacionadas à taxa de crescimento e ao perfil químico das espécies. Assim, a seleção de condições que promovam o aproveitamento da biomassa algácea é fundamental para sua utilização econômica. Neste estudo, 10 espécies de microalgas marinhas foram cultivadas e comparadas quanto ao crescimento e à composição química. Foram observadas diferenças na velocidade de crescimento, com espécies de células menores crescendo mais rapidamente que microalgas maiores. Teores de proteínas, carboidratos, lipídeos e pigmentos fotossintetizantes variaram amplamente entre as espécies, sendo as proteínas as substâncias mais abundantes. Todas as espécies apresentaram concentrações de ácidos aminados semelhantes, sendo os ácidos aspártico e glutâmico os mais abundantes. Algumas espécies apresentaram altas concentrações de ácidos graxos de importância econômica, como os ácidos eicosapentaenoico e linoleico. O balanço dos resultados indica que há poucas tendências gerais relacionadas a grandes grupos taxonômicos.

Spin-Crossover Behavior in Cyanide-Bridged Iron(II)−Copper(I) Bimetallic 1−3D Metal−Organic Frameworks

The synthesis and characterization of a series of 1-3D cyanide-bridged iron(II)-copper(I) bimetallic coordination polymers formulated as {Fe(3-Xpy)(2)[Cu(3-Xpy)(z)(CN)(2)](2)}, where 3-Xpy is a 3-halogenpyridine ligand with X = F (z = 1.5, 1), Cl (z = 1, 2 and 3), Br (z = 1, 4), and I (z = 1, 5), are reported. In all derivatives, the Fe(II) ion lies in pseudoctahedral [FeN(6)] sites defined by four in situ formed [Cu(3-Xpy)(z)(CN)(2)](-) bridging ligands and two 3-Xpy terminal ligands occupying the equatorial and axial positions, respectively. 1 consists of stacks of corrugated grids whose square windows are defined by pseudotrigonal and pseudotetrahedral [Cu(3-Fpy)(CN)(2)](-) and [Cu(3-Fpy)(2)(CN)(2)](-) units, respectively. 2 is a 3D coordination polymer with the topology of the open-framework CdSO(4). The [Cu(3-Clpy)(CN)(2)](-) rods connecting the pseudooctahedral Fe(II) sites are arranged in such a way that interpenetration is avoided. 3, an architectural isomer of 2, is defined by arrays of linear chains. 4 and 5 are isostructural to 3. Polymer 1 is essentially a low-spin (LS) compound with ca. 19% of residual Fe(II) ions in the high-spin (HS) state at 293 K. It undergoes an irreversible spin transition at T(c) = 356 K. Subsequent cooling-warming cycles give a new spin-crossover behavior characterized by T(c) = 187 K. The structural analysis at 130 and 293 K and at 293 K after irreversible transformation (293 K*) reveals a large unit cell volume variation of 67 A(3) per Fe atom. In addition to the volume change associated with the spin-state conversion, remarkable bond and angle modifications around the Cu(I) sites account for the high flexible nature of the crystal. 2 displays a complete not well-resolved two-step spin conversion, T(c1) = 169 K and T(c2) = 210 K, reflecting the occurrence of two distinct crystallographically Fe(II) sites. The large unit cell volume variation per Fe atom in 2, 59 A(3), has been rationalized in terms similar to those for 1. 1D polymers 3-5 are HS compounds.

Large pores generated by the combination of different inorganic units in a zinc hydroxide ethynylene diisophthalate MOF

An ethynylene diisophthalic acid linker molecule was synthesized and used to form a zinc carboxylate-based metal organic framework (MOF) with very large pores and unit cell volume resulting from the unusual combination of structurally different inorganic units forming the secondary building blocks (SBUs). The structure is the first zinc hydroxide carboxylate structure where the inorganic units do not form layers or ribbons but isolated islands. The structure forms true pores with a significantly narrowed pore entry similar to zeolites. The pores are, thus, not created simply by intersecting channels as in most other MOF structures. Although the pore shape is highly asymmetric the spherical free volume is with 10.8 A still large. The stability of the SBUs in respect to exchange and removal of coordinated solvent molecules is investigated.

Development of data processing software for a new TOF single crystal neutron diffractometer at J-PARC

We have developed new data processing software for a new time-of-flight (TOF) single crystal neutron diffractometer at the Materials and Life-science Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC); IBARAKI Biomolecular Crystal Diffractometer (iBIX). This software, named “STARGazer”, makes a HKLF list from three-dimensional ( x, y, TOF) raw data of the iBIX. The STARGazer has both a data processing part and a data visualization part. The former part is a main part to make a HKLF list. This part has fundamental data processing functions and additional functions, real-space indexing, refinement of detector positions simultaneously with an UB matrix, and finding overlapping Bragg reflections, to process diffraction data of bio-macromolecular crystal which has large unit cell volumes. The latter part displays the three-dimensional raw data with predicted positions of Bragg reflections to confirm how well an obtained UB matrix fits to the raw data. In the near future, a function to process overlapping Bragg reflections based on a profile fitting technique will be added to the STARGazer.

Exogenous nitric oxide regulates activity and synthesis of vascular endothelial nitric oxide synthase

Nitric oxide (NO) - a major signalling molecule of the vascular system - is constitutively produced in endothelial cells (EC) by the endothelial NO synthase (eNOS). Since a reduced NO synthesis is an early sign of endothelial dysfunction and NO delivering drugs are used to substitute the impaired endothelial NO production, we addressed the effect of exogenous NO on eNOS in human umbilical venous endothelial cell cultures. The synthetic NO donor DETA/NO (trade name, but in the following we refer to detNO), that releases NO in a strictly first order reaction with a half life of 20 h, was used in our experiments. Short-term (20-30 min) detNO treatment of EC increases the Ser(1177) phosphorylation of the constitutively expressed endothelial NOS and the production of endogenous NO generated by eNOS from [(3)H]arginine. The phosphorylation of eNOS is Akt-dependent and completely reverted by the phosphatidylinositol-3 kinase (PI-3K) inhibitor LY294002. A prolonged continuous exposure of EC to detNO 150 micromol L(-1) over a period of 24-48 h causes a reversible cell cycle arrest at G(1)-phase associated with a larger cell volume and increased cell protein content (hypertrophic phenotype of EC). The eNOS protein and mRNA of the hypertrophic cells and the generation of endogenous NO are reduced but eNOS phosphorylation could still be elevated by stimulation with vascular endothelial growth factor. Our data explain clinical studies describing a short-term but not a long-term benefit of NO treatment for patients with cardiovascular risk factors. The results could be a rational approach to develop a generation of NO donors accomplishing a retarded release from NO donors that mimic the low continuous pulsatile stress-induced release of endogenous NO.

Ionic conductivity in lanthanoid ion-doped BaCeLnO 3 electrolytes

Conductivity measurements at intermediate temperatures and phase studies were carried out in the compositions Ba x Ce 1 − y Gd y O 3 − δ (0.8≦ x≦ 1.1, 0 ≦ y ≦ 0.3) and Ba x Ce 0.8Ln 0.2O 3 − δ ( x = 0.975, 1.0; Ln = Nd,Sm,Gd,Dy,Yb). In Ba x Ce 0.8Ln 0.2O 3 − δ , the Ba-deficient compositions ( x = 0.975) showed higher conductivity than the stoichiometric ones ( x = 1.0) for all the Ln. The total (bulk) conductivities had a maximum (σ = 5.5 × 10 − 4 Scm − 1 at 250 °C) for Ln = Gd and x = 0.975. The σ value was nearly two times higher than that of the known stoichiometric BaCe 0.8Gd 0.2O 3 − δ electrolyte and the best of those of known oxide ion conductors at intermediate temperatures. The Ba-deficient Ba 0.975Ce 0.8Gd 0.2O 3 − δ composition was a single phase of the monoclinic perovskite-related phase ( I2/m). The high ionic conductivity is attributed to the fact that the Gd-doped composition had the largest cell volume in the Ln-doped Ba 0.975Ce 0.8Ln 0.2O 3 − δ series.

Abstract 1521: Platelet RNA Content is Increased in Patients with Acute Coronary Syndromes Compared to Patients with stable Coronary Artery Disease and Healthy Individuals

Background: Platelets newly released from the bone marrow are characterized by large cell volumes and, contrary to mature platelets, contain RNA, which might reflect an increased capacity of producing proaggregatory proteins. We hypothesized that the fraction of RNA-containing, immature platelets (Immature Platelet Fraction = IPF) is a marker for acute coronary thrombus formation. Methods: Flow cytometric determination of immature platelets was conducted using a RNA fluorescent dye and an automated analyzer (Sysmex XE-2100). Measurements were performed in a total of 426 individuals (365 patients with acute coronary syndromes (ACS), 39 patients with stable coronary artery disease (CAD) and 22 healthy individuals). Results: Geometric mean IPF was 2.5 (CV = 0.37) in the control group, 2.9 (0.43) in patients with stable CAD, 3.0 (0.55) in the non-STEMI/Unstable Angina group and 3.7 (0.56) in patients with STEMI. IPF was significantly increased in STEMI patients compared to all other groups (t-test for log-transformed data: p &lt; 0.004), and the overall difference between groups was significant (ANOVA: p &lt; 0.0001). IPF was increased in active smokers among patients with ACS (3.2 vs 3.6, p=0.02), whereas no relation with age, sex, body mass index or CRP levels was observed. Conclusion: The fraction of RNA-containing platelets is increased in ACS, especially in the acute phase of STEMI. Immature platelets with an increased haemostatic potential may contribute to coronary thrombus formation and may partly explain previous findings of temporary resistance to anti-platelet therapy.

SINGLE CRYSTAL NEUTRON DIFFRACTION FOR THE INORGANIC CHEMIST – A PRACTICAL GUIDE

Advances and upgrades in neutron sources and instrumentation are poised to make neutron diffraction more accessible to inorganic chemists than ever before. These improvements will pave the way for single crystal investigations that currently may be difficult, for example due to small crystal size or large unit cell volume. This article aims to highlight what can presently be achieved in neutron diffraction and looks forward toward future applications of neutron scattering in inorganic chemistry.

Ionic Conductivity in Lanthanoid Ion-doped BaCeO3 Electrolytes

Oxide ion conductivity was examined in BaxCe0.8Ln0.2O3-δ (0.8{less than or equal to}x{less than or equal to}1.1; Ln=Lanthanoid). The slightly Ba-deficient compositions showed a higher conductivity than the nominal stoichiometric ones. A maximum total (bulk) conductivity (σ=5.5×10-4 Scm-1 at 250ºC, σ=9.6×10-3 Scm-1 at 500oC) was found in the Ba-deficient composition Ba0.975Ce0.8Gd0.2O3-δ. The σ value at 250oC was nearly two times higher than that of the known BaCe0.8Gd0.2O3-δ electrolyte. The conductivity is the best of those of known oxide ion conductors at intermediate temperatures. The non-stoichiometric Ba0.975Ce0.8Gd0.2O3-δ sample was a single phase of the monoclinic perovskite-related phase (I2/m). The high conductivity is attributed to the fact that the Gd-doped composition had the largest cell volume in the Ln-doped series. The unusual variation of the cell volume was due to a change in the portioning of the Ln ion between the B-site and the A(Ba)-site.

Mineralogical phase analysis of alkali and sulfate bearing belite rich laboratory clinkers

The activation of laboratory belite clinkers has been carried out by adding variable amounts of alkaline salts (K 2CO 3, Na 2CO 3), and/or SO 3 as gypsum in the raw materials but keeping almost constant the main elements ratios, Ca/Si/Al/Fe. Quantitative phase analyses by the Rietveld method using high resolution synchrotron and strictly monochromatic CuKα 1 laboratory X-ray powder diffraction data has been performed. Quantitative phase analysis results have been compared to validate the protocol using laboratory X-ray data. The agreement in the results is noteworthy, which indicates that good quantitative phase analyses can be obtained from laboratory X-ray powder data. Qualitative studies have confirmed that the addition of alkaline salts to raw mixtures promotes the stabilization, at room temperature, of the highest temperature polymorphs: α′ H-C 2S and α-C 2S. Quantitative studies gave the phase assemblage for ten different laboratory belite clinkers. As an example, an active belite clinker with 1.0 wt.% of K 2O and 1.0 wt.% of Na 2O (amounts added to the raw mixtures) contains 8.5(3) wt.% of β-C 2S, 21.2(3) wt.% of α' H-C 2S, 24.1(2) wt.% of α-C 2S, 18.9(3) wt.% of total C 3S, 17.3(2) wt.% of C 3A and 10.0(2) wt.% of C 4AF. A belite clinker with 0.8 wt.% SO 3 (nominal loading) contains 60.7(1) wt.% of β-C 2S, 6.7(2) wt.% of α′ H-C 2S, 12.3(7) wt.% of C 3S, 9.1(2) wt.% of C 3A and 11.2(2) wt.% of C 4AF. Overall, quantitative phase analyses have shown that alkaline oxides stabilize α′ H-C 2S and α-C 2S, sulfur stabilizes β-C 2S, with a large unit cell volume, and the joint presence of alkaline oxides and sulfur promotes mainly the stabilization of the α′ H-C 2S polymorph.