The Role of Leukotriene B4 in Cow Metritis.

Introduction: Metritis is a common postpartum disease in dairy cows. As a mast cell (MC) mediator, leukotriene B4 (LTB4) is the strongest phagocyte chemokine. It is important in inflammation for the recruitment of immune cells to resist infection. This study investigated the effect of LTB4 in metritis. Material and Methods: Twenty Holstein cows 3 to 6 years old and at 6 to 10 days postpartum were selected, ten of which with postpartum metritis were the experimental group, and the other ten of which as healthy cows were the control group. The levels of LTB4, substance P (SP) and vasoactive intestinal peptide (VIP) were measured by ELISA, the expression of LTB4 receptor 2 (BLT2), matrix metalloproteinase (MMP)-2 and MMP-9 mRNA was measured by qPCR, and collagens I and IV were detected by immunohistochemical staining. Results: Concentrations of SP and LTB4 were significantly higher, but those of VIP were significantly lower in the experimental group than those in the control group. The expression of BLT2, MMP-2 and MMP-9 mRNA was significantly higher in the experimental group than that in the control group. The expression of collagen Ⅰ and collagen Ⅳ was significantly lower in the experimental group than that in the control group. Conclusion: In metritis, SP promotes the activation of MC and the synthesis and release of LTB4. Leukotriene B4 chemotactic immune cells promote the high expression of collagenase, which accelerated the hydrolysis of collagen, while the inhibitory effect of VIP on MC was weakened. This may further aggravate the damage to uterine tissue.

Synthesis and X-Ray Crystal Structures of Trinuclear Nickel(II) Complexes Derived from Schiff Bases and Acetate Ligands with Biological Activity.

The reactions of Ni(OAc)2 2H2O with Schiff base ligands 5-bromo-2-((cyclopentylimino)methyl)phenol (HL1) and 5-bromo-2-(((2-(isopropylamino)ethyl)imino)methyl)phenol (HL2) in methanol afforded two discrete trinuclear com-plexes [Ni3(L1)2(?2-?1:?1-OAc)2(DMF)2(BrSal)2] (1) and [Ni3(L2)2(?2-?1:?1-OAc)2(?2-?2:?1-OAc)2] (2), where BrSal is the monoanionic form of 4-bromosalicylaldehyde. The complexes were characterized by elemental analysis, IR and UV-Vis spectroscopy. The crystal structures of the complexes have been determined by X-ray crystallography. In both com-plexes, the nickel atoms are in octahedral coordination geometries. The L1 ligand coordinates to the nickel atoms through the phenolate O and imino N atoms, and the L2 ligand coordinates to the nickel atoms through the phenolate O, imino N and amino N atoms. The antimicrobial activities of the complexes were assayed.

Method of electrochemical etching of tungsten tips with controllable profiles.

We demonstrate a new and simple process to fabricate tungsten tips with good control of the tip profile. In this process, we use a commercial function generator without any electronic cutoff circuit or complex mechanical setup. The tip length can be varied from 160 µm to 10 mm, corresponding to an aspect ratio of 1.6-100. The radius of curvature of the tip apex can be controlled to a size <10 nm. Surface roughness and the taper angle can be controlled independently. Through control of the etching parameters, the tip length, the radius of curvature, surface roughness, and the taper angle can be controlled to suit different requirements of various applications. The possible etching mechanisms are also discussed.

4-Meth-oxy-N'-(3-nitro-benzyl-idene)benzohydrazide.

In the title compound, C(15)H(13)N(3)O(4), the dihedral angle between the benzene rings is 3.1 (3)°. The mol-ecule displays an E conformation about the C=N bond. In the crystal, mol-ecules are linked via N-H⋯O hydrogen bonds, generating chains that propagate along the b-axis direction. There is also a C-H⋯O inter-action present.

4-Hy-droxy-N'-(3-nitro-benzyl-idene)benzohydrazide.

The title compound, C(14)H(11)N(3)O(4), was obtained by a condensation reaction between 3-nitro-benzaldehyde and 4-hy-droxy-benzohydrazide. The whole mol-ecule is approximately planar, with a dihedral angle of 9.2 (3)° between the benzene rings. The mol-ecule displays an E conformation about the C=N bond. In the crystal, mol-ecules are linked via N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, generating sheets parallel to the bc plane.

Fabrication of CoPt ultra-sharp single atom tips.

Two kinds of new nano tips with potential to magnetic application are fabricated. One is a PtCo alloy pyramidal tip formed by surface faceting, the other is a Pt based Co tip formed by the epitaxy with a proper growth mode. Ultra high vacuum-field ion microscopy with atomic resolution is used to investigate the atomic structures of the tip apex after various sharpen treatments.

A single-atom sharp iridium tip as an emitter of gas field ion sources.

We report a reliable method for preparing a pure Ir single-atom tip by thermal treatment in oxygen. The atomic structure of the tip apex and its ion emission characteristics are investigated with field ion microscopy. We have shown that the Ir single-atom tip can be a good field ion emitter, capable of emitting a variety of gas ion beams, such as He+, H2+, N2+, and O2+, with high brightness and stability. In addition, this tip can easily be maintained and regenerated in vacuum, ensuring it has sufficient lifetime for practical applications.

N'-(3-Bromo-5-chloro-2-hydroxy-benzyl-idene)-2-methoxy-benzohydrazide.

The title compound, C(15)H(12)BrClN(2)O(3), was obtained by the condensation reaction between 3-bromo-5-chloro-2-hydroxy-benzaldehyde and 2-methoxy-benzohydrazide. The mol-ecule is essentially planar, with a dihedral angle between the two benzene rings of 4.7 (2)°, and displays an E configuration about the C=N double bond. The mol-ecular conformation is stabilized by intramolecular O-H⋯N and N-H⋯O hydrogen bonds. In the crystal structure, mol-ecules are linked into zigzag chains running parallel to the c axis by inter-molecular C-H⋯O hydrogen bonds. The chains are further connected through aromatic π-π stacking inter-actions with centroid-centroid distances of 3.583 (4) Å.