Investigation of the exact spin channels in laser-induced spin dynamics in two mononuclear Cu(II) complexes.

In the quest to harness the potential of nanospintronic applications, we analyze and investigate the spin channels for the ultrafast spin dynamics in mononuclear Cu2+(tdp)Cl2 (Cutdp) and Cu2+(tdp)Cl2·MeCN (Cutdp·MeCN) using a high-level ab initio many-body theory. In that spirit, we select two slightly different polymerizations arising from one parent complex. We establish the difference in magnetic behavior between the two complexes which arises solely from the geometrical differences. We calculate the static magnetic properties, such as the magnetic anisotropy of the complexes, which is analyzed by means of the magnetic moment of the ground state. The asymmetry of the core Cu-Cl-Cu-Cl axial plane unit is also reflected in the ground state absorption spectra of the two complexes. Comparisons with the experimental data are in good agreement with the exception of one peak in the theoretical calculations for each of the complexes, confirming the reliability of theoretical methods employed. A major finding in this work is the distinction between classical and coherent superpositions of Λ processes. We employ the selective blocking and retention (SBR) technique to find the unique path or paths for spin dynamic scenarios like spin flip and spin transfer. Additionally, we also present two different scenarios in which intermediate states are involved in spin dynamic processes, (i) classical superposition of Λ processes (i.e., there are many unique paths for transition, even with just one intermediate state the transition completes successfully), and (ii) collective coherent superposition of Λ processes (i.e., there is only one path for the transition, which requires more than one intermediate state to be in a specific coherent superposition). As a consequence, we gain insight into the type of correlations (static or dynamic) involved in a particular spin dynamic scenario.

Ginsenoside Rg1 and Re alleviates inflammatory responses and oxidative stress of broiler chicks challenged by lipopolysaccharide.

Previous study showed that ginsenoside Rg1 (Rg1) and ginsenoside Re (Re) alleviated growth inhibition of broiler chicks with immune stress. The aim of this study was to investigate the effect of Rg1 and Re on inflammatory responses, oxidative stress, and apoptosis in liver of broilers with immune stress induced by lipopolysaccharide (LPS). Forty broiler chicks were randomly divided into 4 groups, each group consisting of 10 chickens. The model group, Rg1 group, and Re group were received continuously interval injection of 250 µg/kg body weight LPS at the age of 12, 14, 33, and 35 days to induce immune stress. Control group was injected with an equivalent amount of sterile saline. Then broilers in Rg1 group and Re group were given 1mg/kg body weight Rg1 and Re intraperitoneally 2 h after the LPS challenge respectively. Blood samples were collected for the detection of hormone levels, inflammatory mediators, and antioxidant parameters. Hepatic tissues were taken for pathological observation. Total RNA was extracted from the liver for real-time quantitative polymerase chain reaction analysis. Our results showed that Rg1 or Re could alleviate histological changes of liver, reduce production of stress-related hormones, inhibit inflammatory responses, and enhance antioxidant capacity in broilers challenged by immune stress. In addition, Rg1 or Re treatment upregulated mRNA expression of antioxidant-related genes and downregulated mRNA expression of inflammation-related factors and apoptosis-related genes in the liver of immune-stressed broilers. The results suggest that the plant extracts containing Rg1 and Re can be used for ameliorating hepatic oxidative stress and inflammation and controlling immune stress in broiler chicks.

Slow magnetic relaxation in high-coordinate Co(II) and Fe(II) compounds bearing neutral tetradentate ligands.

The first-row transition metal compounds, [MII(L1)2](ClO4)2 (M = Ni (1); Co (2)), have been prepared by treatment of a neutral tetradentate ligand (L1 = N2,N9-dibutyl-1,10-phenanthroline-2,9-dicarboxamide) with metal perchlorate salts in MeOH. Both compounds have been structurally characterized by X-ray crystallography and it was found that the coordination numbers are 6 and 7, respectively. The reaction of 6,6'-bis(2-tbutyl-tetrazol-5-yl)-2,2'-bipyridine (L2) with hydrated FeII(ClO4)2 afforded a 8-coordinate Fe(II) compound, [FeII(L2)2](ClO4)2 (3); however its reaction with hydrated CoII(ClO4)2 resulted in 6-coordinate [CoII(L2)2](ClO4)2. It is interesting to observe field-induced slow magnetic relaxation in the 7-coordinate Co(II) compound 2 and 8-coordinate Fe(II) compound 3, which further supports the validity of designing high coordination number compounds as single-molecule magnets. Direct current magnetic studies demonstrate that 2 has a very large positive D value (56.2 cm-1) and a small E value (0.66 cm-1), indicating easy plane magnetic anisotropy. Consistent with the larger D value, an effective spin-reversal barrier of Ueff = 100 K (71.4 cm-1) is obtained, which is the highest value reported for 7-coordinate Co(II) complexes with a pentagonal bipyramidal geometry. In contrast, 8-coordinate Fe(II) compound 3 exhibits uniaxial magnetic anisotropy.

Duck Complement Factor H Binds to Outer Membrane Protein Omp24 of Riemerella anatipestifer.

The resistance to serum complement-mediated killing is a vital virulence property of microbial pathogens. Complement factor H (FH) is a key negative regulator of the complement alternative pathway (AP) that prevents formation and accelerates the decay of AP C3 convertase and acts as a cofactor in the inactivation of C3b. Pathogens can recruit host FH through their surface proteins to escape the clearance of the complement system. Riemerella anatipestifer could also evade the complement system attack to achieve host infection, but the mechanism is still unclear. In this study, the R. anatipestifer proteins that could interact with FH in host serum were screened and analyzed, and the functions were determined. Affinity chromatography with a Ni-nitrilotriacetic acid Sefinose column and mass spectrometry identified three outer membrane proteins (Omp) of R. anatipestifer, Omp54, Omp53, and Omp24, as potential FH-binding proteins. We then successfully conducted the prokaryotic expression and polyclonal antibody preparation of three candidate proteins. Indirect immunofluorescence assay showed that three candidate proteins were all present in R. anatipestifer. The affinity blotting assay, anti-serum-inhibiting assay, and serum bactericidal assay presented evidence that Omp24 could bind FH. Moreover, FH bound to Omp24 was associated with resistance to the alternative pathway and functional for R. anatipestifer survival in the normal duck serum. These results suggested that R. anatipestifer Omp24 was a FH-binding protein and the interaction with FH blocked the alternative pathway. Recruitment of complement regulatory proteins may facilitate better R. anatipestifer resistance to this vital line of host defense.

Artículo regular­El factor H del complemento de pato se une a la proteína de la membrana externa Omp24 de Riemerella anatipestifer La resistencia a la destrucción mediada por el complemento sérico es una propiedad vital para la virulencia de los patógenos microbianos. El factor de complemento H (FH) es un regulador negativo clave de la vía alterna del complemento (AP) que previene la formación y acelera la descomposición de la C3 convertasa de la vía alterna y actúa como cofactor en la inactivación de C3b. Los patógenos pueden reclutar factor H del huésped a través de sus proteínas de superficie para escapar de la destrucción por el sistema del complemento. Riemerella anatipestifer también pudo evadir el ataque del sistema del complemento para lograr la infección del huésped, pero el mecanismo aún no está claro. En este estudio, se seleccionaron y analizaron las proteínas de R. anatipestifer que podrían interactuar con el factor H en el suero del huésped y se determinaron las funciones. La cromatografía de afinidad con una columna de sefinosa de Ni-NTA y la espectrometría de masas identificaron tres proteínas de la membrana externa de R. anatipestifer, Omp54, Omp53 y Omp24, como posibles proteínas que se unen al factor H. Posteriormente, se llevó a cabo con éxito la expresión procariota y la preparación de anticuerpos policlonales de las tres proteínas candidatas. El ensayo de inmunofluorescencia indirecta mostró que las tres proteínas candidatas estaban presentes en R. anatipestifer. El ensayo de transferencia para afinidad, el ensayo anti-inhibidor del suero y el ensayo bactericida sérico presentaron evidencia de que la proteína Omp24 podría unirse al factor H. Además, el factor H unido a la proteína Omp24 se asoció con resistencia a la vía alterna y funcional para la supervivencia de R. anatipestifer en el suero de pato normal. Estos resultados sugirieron que la proteína Omp24 de R. anatipestifer era una proteína de unión al factor H y que la interacción con este factor bloqueaba la vía alterna del complemento. El reclutamiento de proteínas reguladoras del complemento puede facilitar una mejor resistencia de R. anatipestifer a esta línea vital de defensa del huésped.

Slow magnetic relaxation in structurally similar mononuclear 8-coordinate Fe(II) and Fe(III) compounds.

A pair of structurally-similar and stable 8-coordinate high-spin Fe(ii) and Fe(iii) compounds have been obtained. Both compounds exhibit field-induced slow magnetic relaxation behaviour. The Fe(iii) compound represents the first example of 8-coordinate Fe(iii) single-molecule magnets (SMM).

[Cloning and expression of duck C4BPα and verification of its interaction with Riemerella anatipestifer].

To study the interaction between C4b-binding protein (C4BP) and Riemerella anatipestifer (RA), we cloned duck C4BPα, conducted prokaryotic expression and prepared the polyclonal antibody by immunizing mice. Then indirect immunofluorescence assay and dot blotting hybridization assay were used to verify the interaction between C4BP and RA. The full length of duck C4BPα nucleotide sequence was 1 230 bp, with the highest similarity to chicken C4BPα (82.1%). Phylogenetic tree analysis showed that duck C4BPα and chicken C4BPα were on the same phylogenetic tree branch and the genetic evolution relationship between them was the closest. C4BPα was efficiently expressed in Escherichia coli BL21 (DE3). The recombinant proteins existed in intracellular soluble form. The titer of polyclonal antibody was more than 1:10 000 and polyclonal antibodies could specifically recognize the recombinant proteins. The results of indirect immunofluorescence assay and dot blot hybridization assay showed that RA could interact with duck C4BP. The results provide a basis to further reveal the pathogenesis of RA.

Molybdate-Tellurite Compounds with Capped-Kagomé Spin-Lattices.

Three new molybdate-tellurites, K2M9(TeO3)4(MoO4)4(OH)4 (M = NiII and CoII) and (NH4)2Cu9II(TeO3)4(MoO4)4(OH)4, have been successfully synthesized by conventional hydrothermal method. Due to the influence of the Jahn-Teller effect, these compounds crystallize in different space groups of rhombohedral R3̅m, monoclinic P21/c and triclinic P1̅ for Ni-, Co-, and Cu-analogues, respectively. The topological arrangements of magnetic ions in these compounds show that deficient capped-kagomé spin-lattices with kagomé positions exhibit different 1/6 depletion. Magnetic and specific heat measurements confirm that K2Ni9(TeO3)4(MoO4)4(OH)4 exhibits a spin-glass behavior at low temperature, while (NH4)2Cu9(TeO3)4(MoO4)4(OH)4 possesses a long-range canted antiferromagnetic ordering with TN ∼ 10.8 K and further shows a 3/5 magnetization plateau in the magnetization curve at low temperature.

Detection and Molecular Characterization of Two Genotypes of Goose Parvoviruses Isolated from Growing Period Geese and Cherry Valley Ducks in China.

Goose parvovirus (GPV) is the etiologic pathogen of Derzsy's disease, causing great economic losses in the waterfowl industry. A novel GPV-related virus (NGPV), which caused short beak and dwarfism syndrome, has occurred in China since 2015. In this study, two GPV strains (RC45 and RC70) were isolated from diseased growing period geese (45 days old and 70 days old), and one NGPV strain GXN45 was isolated from a 45-day-old Cherry Valley duck in China. To better understand the genetic diversity between GPVs isolated from growing period waterfowls and other classical waterfowl parvoviruses, the complete genomes and main genes were sequenced and analyzed. Full-length genomic sequence alignments demonstrated that both RC45 and RC70 showed the highest identity with classical GPVs YZ99-6 and SHFX1201, whereas GXN45 shared the highest identity with NGPV SDLC01. Sequence alignment of the inverted terminal repeat region showed that GXN45, RC45, and RC70 had two 14-nucleotide (nt) deletions compared with the classical GPV virulent B strain and one 14-nt deletion compared with mule duck-origin NGPV M15 strain. Phylogenetic tree analysis of nonstructural and VP1 genes showed that GXN45 was clustered into a branch with NGPV QH15 strain except for the VP1 amino acid tree. Although both RC45 and RC70 formed one separate branch distinct from classic GPV isolates, they were in one large phylogenetic tree branch. This study will contribute to a better understanding of the genetic diversity and molecular characterization of three isolated parvoviruses and lay the foundation to further study the relationship between mutations of virus genome and viral pathogenicity.

Detección y caracterización molecular de dos genotipos del parvovirus del ganso aislados de gansos en período de crecimiento y de patos Cherry Valley en China. El parvovirus del ganso (GPV) es el patógeno etiológico de la enfermedad de Derzsy, que causa grandes pérdidas económicas en la industria de las aves acuáticas. Un nuevo virus relacionado con el parvovirus del ganso (NGPV), que causó el síndrome de pico corto y enanismo, se ha presentado en China desde el año 2015. En este estudio, se aislaron dos cepas de parvovirus del ganso (RC45 y RC70) a partir de gansos enfermos en período de crecimiento (45 días de edad y 70 días) y se aisló una cepa del nuevo virus relacionado con el parvovirus del ganso, cepa GXN45 a partir de un pato Cherry Valley de 45 días de edad en China. Para comprender mejor la diversidad genética entre los aislamientos del parvovirus del ganso de aves acuáticas en período de crecimiento y de otros parvovirus clásicos de aves acuáticas, se secuenciaron y analizaron los genomas completos y los genes principales. Las alineaciones de secuencias genómicas completas demostraron que tanto RC45 como RC70 mostraron la identidad más alta con los parvovirus de ganso clásicos cepas YZ99-6 y SHFX1201, mientras que la cepa GXN45 compartió la identidad más alta con nuevo virus relacionado con el parvovirus del ganso cepa SDLC01. La alineación de la secuencia de la región repetida invertida terminal mostró que las cepas GXN45, RC45 y RC70 tenían dos deleciones de 14 nucleótidos (nt) en comparación con la cepa B clásica virulenta del parvovirus del ganso y una deleción de 14 nucleótidos en comparación con la cepa M15 de un virus nuevo relacionado con el parvovirus del ganso originado en patos mula. El análisis del árbol filogenético de los genes no estructurales y VP1 mostró que la cepa GXN45 se agrupó en una rama con la cepa QH15 del nuevo virus relacionado con el parvovirus del ganso, excepto en el árbol de aminoácidos de VP1. Aunque tanto RC45 como RC70 formaron una rama separada distinta de los aislados de parvovirus de ganso clásicos, estaban en una rama de árbol filogenética grande. Este estudio contribuirá a una mejor comprensión de la diversidad genética y en la caracterización molecular de tres aislamientos de parvovirus aislados y contribuirá con las bases para seguir estudiando la relación entre las mutaciones del genoma del virus y la patogenicidad viral.

Targeted replacement: systematic studies of dodecanuclear {MLn} coordination clusters (M = Cr, Co; Ln = Dy, Y).

Three dodecanuclear 3d-4f coordination clusters, [CrIII6LnIII6(µ3-OH)8(tbdea)6(C6H5COO)16]·2H2O (Ln = Dy (1), Y (2)) and [CoIII6DyIII6(µ3-OH)8(nbdea)6(m-CH3C6H4COO)16]·2H2O·2CH3CN (3), have been synthesized under solvothermal conditions and characterized. Single-crystal X-ray diffraction analysis revealed that all three compounds possess an analogous {MIII6LnIII6} core (M = Cr, Co; Ln = Dy, Y) and dc magnetic susceptibility studies indicated that the magnetic exchange couplings between DyIII ions are dominant antiferromagnetic, while the CrIII-DyIII interactions are weakly ferromagnetic. Furthermore, the ac magnetic susceptibility measurements showed that both CrIII6DyIII6 compound 1 and CoIIi6DyIII6 compound 3 containing highly anisotropic DyIII ions displayed single-molecule magnetic (SMM) behavior with the energy barrier Ueff increasing from 12.8 K (for 1) to 20.8 K (for 3), indicating that weak 3d-4f exchange couplings enhance the QTM and reduce the energy barrier.

Synthesis and magnetic properties of two isostructural fluorophosphates BaMPO4F (M = Cu, Co) with a tunnel structure.

Two fluorophosphates, BaMPO4F (M = Cu, Co), have been synthesized by a conventional hydrothermal method, and they crystallize in the orthorhombic system with the space group P212121, exhibiting a tunnel structure built by distorted MO4F square-pyramids and PO4 tetrahedra. The magnetic behaviors of the two compounds are investigated by means of magnetic susceptibility, magnetization, and heat capacity measurements. The results indicate that BaCuPO4F exhibits a paramagnetic behavior down to 2 K, while BaCoPO4F undergoes long-range antiferromagnetic ordering at 11.3 K and short-range magnetic ordering at ∼22 K.

Riemerella anatipestifer extracellular protease S blocks complement activation via the classical and lectin pathways.

Riemerella anatipestifer (RA) is the causative agent of infectious serositis in ducklings and other avian species. It is difficult to control the disease due to its 21 serotypes, poor cross-protection, and bacterial resistance to antimicrobial agents. The complement system is an important component of the innate immune system. However, bacterial pathogens exploit several strategies to evade detection by the complement system. Here, we purified and identified a 59-kDa RA extracellular protease S (EcpS) consisting of a gelatinase. In this study, we aimed to determine how EcpS interferes with complement activation and whether it could block complement-dependent neutrophil function. We found that EcpS potently blocked RA phagocytosis and killing by duck neutrophils. Furthermore, EcpS inhibited the opsonization of bacteria by complement 3b. EcpS specifically blocked complement 3b and complement 4b deposition via the classical and lectin pathways, whereas the alternative pathway was not affected. In summary, we show that RA can survive the bactericidal activity of the duck complement system. These results indicate that RA has evolved mechanisms to evade the duck complement system that may increase the efficiency by which this pathogen can gain access and colonize the inner tissues where it may cause severe infections.

Synthesis, structure, and magnetic properties of new layered phosphate halides Sr2Cu5(PO4)4X2·8H2O (X = Cl, Br) with a crown-like building unit.

Two new compounds Sr2Cu5(PO4)4X2·8H2O (X = Cl and Br) are synthesized by a conventional hydrothermal method. Sr2Cu5(PO4)4Cl2·8H2O crystallizes in the tetragonal system with a space group of P4212, while Sr2Cu5(PO4)4Br2·8H2O crystallizes in the space group P4/nmm, which are found to have a similar framework of layered structure, in which the crown-like {Cu5(PO4)4X2} building units connect to each other forming a 2D corrugated sheet with vacancies, while the Sr2+ cations are located along the vacancies. The spin lattice of two compounds built by Cu2+ ions shows a new type of corrugated square. Magnetic measurements confirmed that both Sr2Cu5(PO4)4X2·8H2O (X = Cl and Br) exhibit antiferromagnetic ordering at low temperatures. A fit of theoretical model shows exchange interaction J = -25.62 K for the Cl-analogue and J/kB = -26.47 K for the Br-analogue.

BaCo4(OH)2(H2PO4)(HPO4)2(PO4): Archimedean lattice T11 in distorted layers built from Co4O12(OH)4 squares.

The family of Archimedean lattices has eleven numbers, yet several of these lattices have not been reported for transition metal oxides. Here, the last number of Archimedean lattice was firstly realized in a layered phosphate.

First heterometallic Ga(III)-Dy(III) single-molecule magnets: implication of Ga(III) in extracting Fe-Dy interaction.

The compounds of the system [M4M'2(µ3-OH)2(nbdea)4(C6H5CO2)8]·MeCN, where M = Ga(III), M' = Dy(III) (), M = Fe(III), M' = Y(III) () are isostructural to the known [Fe4Dy2] compound (). Those of the system [M4M'4(µ3-OH)4(nbdea)4(m-CH3C6H4CO2)12]·nMeCN, where M = Ga(III), M' = Dy(III), n = 4 (), M = Fe(III), M' = Y(III), n = 1 () are isostructural to the [Fe4Dy4] compound (). This allows for comparisons between single ion effects of the paramagnetic ions. The structures were determined using single crystal analysis. Magnetic susceptibility measurements reveal that the Ga(III)-Dy(III) compounds and are SMMs. The energy barrier for is close to that for the known isostructural Fe4Dy2 compound (), but with a significantly increased relaxation time.

A single molecule magnet to single molecule magnet transformation via a solvothermal process: Fe4Dy2 → Fe6Dy3.

Two series of heterometallic Fe(III)-Ln(III) compounds, [FeLn(µ3-OH)2(mdea)4(m-NO2C6H4COO)8]·3MeCN where Ln = Y (1) and Dy (2) and [FeLn(µ4-O)3(µ3-O)(mdea)5(m-NO2C6H4COO)9]·3MeCN where Ln = Y (3) and Dy (4), were synthesized. Compounds 1 and 2 were obtained under ambient conditions, whereas 3 and 4 were obtained via a solvothermal transformation process by heating 1 or 2 at 120 °C in MeCN. The magnetic properties of all four compounds have been measured and show that compounds 2 and 4 containing Dy(III) ions exhibit slow relaxation of magnetization characteristic of Single Molecule Magnetic (SMM) behaviour.

Developing a "highway code" to steer the structural and electronic properties of Fe(III)/Dy(III) coordination clusters.

In the recently established field of 3d/4f coordination cluster (CC) chemistry several burning questions still need to be addressed. It is clear that combining 3d and 4f metal ions within a coordination cluster core has the potential to lead to electronic structures that will be very difficult to describe but can also be extremely interesting. Furthermore, understanding why certain core topologies seem to be favored is difficult to predict. Here we show that the secondary coordination sphere provided by the ligands influences the favored product, as demonstrated for the compound [Fe4Dy2(µ3-OH)2(n-bdea)4(C6H5CO2)8]·MeCN (1), which has a 2Fe:2Dy:2Fe core and was made using [Fe(III)3O(C6H5)CO2)(L)3](+) as starting material plus Dy(NO3)3 and N-n-butyl-diethanolamine (n-bdeaH2), compared with the compound made using a methyl meta-substituent (R) on the phenyl ring of the benzoate, [Fe(III)3O(C6H4Me)CO2)(L)3](+) as starting material, which resulted in the "square-in-square" compound [Fe4Dy4(µ3-OH)4(n-bdea)4(O2CC6H4CH3)12]·MeCN (2) when using ambient conditions. Changing reaction conditions from ambient to solvothermal leads to "double-propeller" compounds [Fe4Dy4(µ4-O)3(n-bdea)3(C6H5CO2)12]·13MeCN (3) and [Fe4Dy4(µ4-O)3(n-bdea)3(O2CC6H4CH3)12]·MeCN (4) forming with this core, resulting irrespective of the substitution on the iron benzoate starting material. Furthermore, compounds 1 and 2 can be transformed into compounds 3 and 4, respectively, using a solvothermal method. Thus, compounds 3 and 4 appear to be the thermodynamically most stable species. The factors steering the reactions toward these products are discussed. The electronic structures have been investigated using magnetic and Mössbauer studies. All compounds are cooperatively coupled 3d/4f systems, with compound 1 showing single-molecule magnet behavior.