Analysis of Unique Motility of the Unicellular Green Alga Chlamydomonas reinhardtii at Low Temperatures down to -8 °C.

Previous studies of motility at low temperatures in Chlamydomonas reinhardtii have been conducted at temperatures of up to 15 °C. In this study, we report that C. reinhardtii exhibits unique motility at a lower temperature range (-8.7 to 1.7 °C). Cell motility was recorded using four low-cost, easy-to-operate observation systems. Fast Fourier transform (FFT) analysis at room temperature (20-27 °C) showed that the main peak frequency of oscillations ranged from 44 to 61 Hz, which is consistent with the 60 Hz beat frequency of flagella. At lower temperatures, swimming velocity decreased with decreasing temperature. The results of the FFT analysis showed that the major peak shifted to the 5-18 Hz range, suggesting that the flagellar beat frequency was decreasing. The FFT spectra had distinct major peaks in both temperature ranges, indicating that the oscillations were regular. This was not affected by the wavelength of the observation light source (white, red, green or blue LED) or the environmental spatial scale of the cells. In contrast, cells in a highly viscous (3.5 mPa·s) culture at room temperature showed numerous peaks in the 0-200 Hz frequency band, indicating that the oscillations were irregular. These findings contribute to a better understanding of motility under lower-temperature conditions in C. reinhardtii.

Combination Therapy with Betamethasone and Josamycin Demonstrates Superior Therapeutic Efficacy in an NC/Nga Mouse Model of Atopic Dermatitis.

We have previously demonstrated the excellent bactericidal activity of josamycin against Staphylococcus aureus isolated from patients with atopic dermatitis (AD), with therapeutic efficacy equal to that of betamethasone. The present study was designed to evaluate the effectiveness of combination therapy with betamethasone and josamycin for AD. Betametasone (0.1%) and josamycin (0.1%) were topically administered to NC/Nga mice with severe AD-like skin lesions. Skin severity scores, histological changes in skin lesions, and serum immunoglobulin E (IgE) levels were assessed as indicators of therapeutic efficacy. Topical treatment with both drugs suppressed the skin severity score to a greater degree than betamethasone alone. This was associated with a reduction of epidermal thickening, a reduced density of dermal cellular infiltration, a decreased mast cell count in the dermis, and a reduced serum IgE level. In addition, both drugs in combination markedly reduced the expression of interferon (IFN)-γ and interleukin (IL)-4 in auricular lymph node cells, as well as the S. aureus count on the lesioned skin. These results show that simultaneous topical application of both drugs can ameliorate severe AD-like skin lesions in NC/Nga mice. It is suggested that combination therapy with betamethasone and josamycin would be beneficial for control of severe AD lesions colonized by S. aureus by inhibiting the development of both T helper (Th) type 1 (Th1) and Th2 cells and also through elimination of superficially located S. aureus.

A single tripodal ligand stabilizing three different oxidation states (II, III, and IV) of manganese.

A series of mononuclear Mn(II), Mn(III), and Mn(IV) complexes was prepared using a single tripodal ligand (H(3)L). Addition of a cation (NH(4)(+), K(+), Na(+)) to [Mn(III)L] showed a pronounced effect on the redox potentials. Different variants of Jahn-Teller distortion, axial elongation and compression, were observed in the Mn(III) complexes.

Face-sharing heterotrinuclear M(II)-Ln(III)-M(II) (M = Mn, Fe, Co, Zn; Ln = La, Gd, Tb, Dy) complexes: synthesis, structures, and magnetic properties.

Trinuclear linear 3d-4f-3d complexes (3d = Mn(II), Fe(II), Co(II), Zn(II) and 4f = La(III), Gd(III), Tb(III), Dy(III)) were prepared by using a tripodal nonadentate Schiff base ligand, N,N',N''-tris(2-hydroxy-3-methoxybenzilidene)-2-(aminomethyl)-2-methyl-1,3-propanediamine. The structural determinations showed that in these complexes two distorted trigonal prismatic transition metal complexes of identical chirality are assembled through 4f cations. The Mn and Fe entities crystallize in the chiral space group P2(1)2(1)2(1) as pure enantiomers; the cobalt complexes exhibit a less straightforward behavior. All Mn, Fe, and Co complexes experience M(II)-Ln(III) ferromagnetic interactions. The Mn-Gd interaction is weak (0.08 cm(-1)) in comparison to the Fe-Gd (0.69 cm(-1)) and Co-Gd (0.52 cm(-1)) ones while the single ion zero field splitting (ZFS) term D is larger for the Fe complexes (5.7 cm(-1)) than for the cobalt ones. The cobalt complexes behave as single-molecules magnets (SMMs) with large magnetization hysteresis loops, as a consequence of the particularly slow magnetic relaxation characterizing these trinuclear molecules. Such large hysteresis loops, which are observed for the first time in Co-Ln complexes, confirm that quantum tunnelling of the magnetization does not operate in the Co-Gd-Co complex.

Experimental evidence for the participation of 5d Gd(III) orbitals in the magnetic interaction in Ni-Gd complexes.

The syntheses, structural determinations, and magnetic studies of two trinuclear Ni-Gd-Ni complexes are described. The structural studies demonstrate that the two complexes present a linear arrangement of the Ni and Gd ions, with Ni ions in slightly distorted square-pyramidal or octahedral environments in complexes 1 and 2, respectively. The Ni and Gd ions are linked by two or three phenoxo bridges, so that complexes 1 and 2 present edge-sharing or face-sharing bridging cores. Ferromagnetic interactions operate in these complexes. While a unique J parameter is able to fit the magnetic data of complex 2, two very different J constants are needed for 1. This result is at first sight surprising, for the structural data of the two Ni-O(2)-Gd cores in complex 1 are quite similar (similar Ni-O and Gd-O bond lengths, similar angles, and dihedral angles), the only difference coming from the angle between the planes defined by the Gd ion and the two bridging phenoxo oxygen atoms of each Ni-O(2)-Gd half core. This latter magnetic behavior can be considered as a signature for the participation of 5d Gd(III) orbitals in the exchange interaction mechanism and can explain why edge-sharing complexes have larger J parameters than face-sharing complexes.

Synthesis, structures, and magnetic properties of face-sharing heterodinuclear Ni(II)-Ln(III) (Ln = Eu, Gd, Tb, Dy) complexes.

Heterodinuclear [(Ni (II)L)Ln (III)(hfac) 2(EtOH)] (H 3L = 1,1,1-tris[(salicylideneamino)methyl]ethane; Ln = Eu, Gd, Tb, and Dy; hfac = hexafluoroacetylacetonate) complexes ( 1.Ln) were prepared by treating [Ni(H 1.5L)]Cl 0.5 ( 1) with [Ln(hfac) 3(H 2O) 2] and triethylamine in ethanol (1:1:1). All 1.Ln complexes ( 1.Eu, 1.Gd, 1.Tb, and 1.Dy) crystallized in the triclinic space group P1 (No. 2) with Z = 2 with very similar structures. Each complex is a face-sharing dinuclear molecule. The Ni (II) ion is coordinated by the L (3-) ligand in a N 3O 3 coordination sphere, and the three phenolate oxygen atoms coordinate to an Ln (III) ion as bridging atoms. The Ln (III) ion is eight-coordinate, with four oxygen atoms of two hfac (-)'s, three phenolate oxygen atoms of L (3-), and one ethanol oxygen atom coordinated. Temperature-dependent magnetic susceptibility and field-dependent magnetization measurements showed a ferromagnetic interaction between Ni (II) and Gd (III) in 1.Gd. The Ni (II)-Ln (III) magnetic interactions in 1.Eu, 1.Tb, and 1.Dy were evaluated by comparing their magnetic susceptibilities with those of the isostructural Zn (II)-Ln (III) complexes, [(ZnL)Ln(hfac) 2(EtOH)] ( 2.Ln) containing a diamagnetic Zn (II) ion. A ferromagnetic interaction was indicated in 1.Tb and 1.Dy, while the interaction between Ni (II) and Eu (III) was negligible in 1.Eu. The magnetic behaviors of 1.Dy and 2.Dy were analyzed theoretically to give insight into the sublevel structures of the Dy (III) ion and its coupling with Ni (II). Frequency dependence in the ac susceptibility signals was observed in 1.Dy.

Mononuclear nickel(II) and zinc(II) complexes with deprotonated forms of the tripodal hexadentate ligand 1,3-bis(2-hydroxybenzylidene)-2-(2-hydroxybenzylideneaminomethyl)-2-methylpropane-1,3-diamine.

In the crystal structures of both title compounds, [1,3-bis(2-hydroxybenzylidene)-2-methyl-2-(2-oxidobenzylideneaminomethyl)propane-1,3-diamine]nickel(II) [2-(2-hydroxybenzylideneaminomethyl)-2-methyl-1,3-bis(2-oxidobenzylidene)propane-1,3-diamine]nickel(II) chloride methanol disolvate, [Ni(C(26)H(25.5)N(3)O(3))](2)Cl x 2 CH(4)O, and [1,3-bis(2-hydroxybenzylidene)-2-methyl-2-(2-oxidobenzylideneaminomethyl)propane-1,3-diamine]zinc(II) perchlorate [2-(2-hydroxybenzylideneaminomethyl)-2-methyl-1,3-bis(2-oxidobenzylidene)propane-1,3-diamine]zinc(II) methanol trisolvate, [Zn(C(26)H(25)N(3)O(3))]ClO(4) x [Zn(C(26)H(26)N(3)O(3))] x 3 CH(4)O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol-phenolate O-H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one-half of a chloride anion and a methanol solvent molecule. In the O-H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The Ni(II) compound is thus formulated as [Ni(H(1.5)L)](2)Cl x 2 CH(3)OH [H(3)L is 1,3-bis(2-hydroxybenzylidene)-2-(2-hydroxybenzylideneaminomethyl)-2-methylpropane-1,3-diamine]. In the analogous Zn(II) compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H(2)L)]ClO(4) x [Zn(HL)] x 3 CH(3)OH. In both compounds, each mononuclear unit is chiral with either a Delta or a Lambda configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Delta-Delta and Lambda-Lambda pairs co-exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M-O(phenol) and M-O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M-O and M-N bond distances decrease.

Ferro- and antiferromagnetic interactions in face-sharing trioctahedral Ni(II)Mn(II)Ni(II) and Ni(II)Fe(III)Ni(II) complexes with the same 1-5/2-1 spin system.

Two heterotrinuclear complexes, [Mn(II)(Ni(II)L)2].2CH3OH (where H3L = 1,1,1-tris(N-salicylideneaminomethyl)ethane) and [Fe(III)(Ni(II)L)2]NO3.C2H5OH, consisting of three face-sharing octahedra have been prepared; although these complexes have closely related structures and have the same 1-5/2-1 spin system, they show completely different magnetic interactions between the adjacent metal ions: ferromagnetic (Ni(II)-Mn(II)) and antiferromagnetic (Ni(II)-Fe(III)).

Ferromagnetic NiII-GdIII interactions in complexes with NiGd, NiGdNi, and NiGdGdNi cores supported by tripodal ligands.

Dinuclear [(NiL)Gd(hfac)(2)(EtOH)](H(3)L = 1,1,1-tris(N-salicylideneaminomethyl)ethane, Hhfac = hexafluoroacetylacetone), trinuclear [(NiL)(2)Gd(NO(3))], and tetranuclear [(NiL)Gd(CH(3)CO(2))(2)(MeOH)](2) complexes, were prepared by treating [Ni(HL)] with [Gd(hfac)(3)(H(2)O)(2)], Gd(NO(3))(3).6H(2)O, and Gd(CH(3)CO(2))(3).4H(2)O, respectively, in the presence of Et(3)N. All the complexes show that ferromagnetic interactions occur between the Ni(II) and Gd(III) ions.