Anion-Directed Copper(II) Metallocages, Coordination Chain, and Complex Double Salt: Structures, Magnetic Properties, EPR Spectra, and Density Functional Study.

A series of Cu(II) metallo-assemblies showing anion-directed structural variations, including five metallocages [(G(n-) )⊂{Cu2 (Hdpma)4 }]((8-n)+) (A(-) )8-n (G(n-) =NO3 (-) , ClO4 (-) , SiF6 (2-) , BF4 (-) , SO4 (2-) ; A(-) =NO3 (-) , ClO4 (-) , BF4 (-) , CH3 SO4 (-) ; Hdpma=bis(3-pyridylmethyl)ammonium cation), a complex double salt, namely, (H3 dpma)4 (CuCl4 )5 Cl2 , and a coordination chain, namely, [Cu2 (dpma)(OAc)4 ], are reported. The influence of the anion can be explained by its coordinating ability, the affinity of which for the Cu(II) center interferes significantly with metallocage formation, and its shape, which offers host-guest recognition ability to engage in weak metal-anion coordination and hydrogen bonding to the organic ligand, which are responsible for metallocage templation. EPR studies of these metallocages in the powder phase at room temperature and 77 K showed a trend of the g values (g|| >2.10>g⊥ >2.00) indicating a dx2-y2 -based ground state with square-pyramidal geometry for the Cu(II) centers. The magnetism of these metallocages can be interpreted as the result of a combination of relatively small magnetic coupling integrals and a substantial contribution of temperature-independent paramagnetism (TIP). The weak magnetic interaction is corroborated by the results of DFT calculations and the EPR spectra. Availability of the low-lying state for spin population was confirmed by a magnetization study, which revealed a magnetic moment approaching 2Nß, which would explain the presence of the larger TIP term.

Linear oligoarylamines: electrochemical, EPR, and computational studies of their oxidative states.

A series of straight-chain oligoarylamines were synthesized and examined by electrochemical, spectroelectrochemical, electron paramagnetic resonance techniques, and density functional theory (DFT) calculation. Depending on their electrochemical characteristics, these oligoarylamines were classified into two groups: one containing an odd number and the other an even number of redox centers. In the systems with odd redox centers (N1, N3, and N5), each oxidation was associated with the loss of one electron. As for the systems with even redox centers (N2, N4, and N6), oxidation occurred by taking N2 as a unit. Absorption spectra of linear oligoarylamines at various oxidative states were obtained to investigate their charge transfer behaviors. Moreover, DFT-computed isotropic hyperfine coupling constants and spin density were in accordance with the EPR experiment, and gave a close examination of oligoarylamines at charged states.

Highly curved bowl-shaped fragments of fullerenes: synthesis, structural analysis, and physical properties.

Highly curved buckybowls 3, 4, and 5 were synthesized from planar precursors, fluoranthenes 8, benzo[k]fluoranthenes 10 and naphtho[1,2-k]-cyclopenta[cd]fluoranthenes 12, respectively, using straightforward palladium-catalyzed cyclization reactions. These fluoranthene-based starting materials were easily prepared from 1,8-bis(arylethynyl)naphthalenes 6. Both buckybowls 3 and 4 are fragments of C60 , whereas 5 is a unique subunit of C70 . The curved structures were identified by X-ray crystallography, and they are deep bowls. The maximum π-orbital axis vector (POAV) pyramidalization angle in both 3 and 4 is 12.8°. Such a high curvature is very rarely obtained. Buckybowls 5 are less curved than the others because they have a lower density of five-membered rings, analogous to the tube portion of C70 . Cyclopentaannulation increases the bowl depths of 3 and 4, but not the maximum POAV pyramidalization angle. Among the eight buckybowls studied herein, five form polar crystals. The bowl-to-bowl inversion dynamics of these buckybowls can be classified into two types; one has a planar transition structure, whereas the other has an S-shaped transition structure. A larger longitudinal length of these buckybowls corresponds to a stronger preference for the latter. The photophysical properties of these buckybowls were examined and compared with those of C60 and C70 . Buckybowls 5 have absorption bands at wavelengths greater than 450 nm, which are similar to those of C70 . The chiral resolution of the mono-substituted buckybowl 4 ac was also studied by using HPLC with a chiral column.

Studies on the structure of N-phenyl-substituted hexaaza[1(6)]paracyclophane: synthesis, electrochemical properties, and theoretical calculation.

The N-phenyl-substituted hexaaza[1(6)]paracyclophane (3, hexamer) has been synthesized successfully in two steps and the noncoplanar conformation was calculated by gaussian program. The electrochemical properties exhibited lots of interesting results and each overlapping oxidative wave contained two-electron transfer.

Higher harmonic generation microscopy of in vitro cultured mammal oocytes and embryos.

Oocyte and embryo selection governs the success of assisted reproductive technologies. The imaging tools applied for selecting embryos may need to contain several key properties: noninvasiveness, high 3D resolution, and the contrast capability to provide as much information about the embryos as possible, such as spindle fibers, zona pellucida, and organelles. Currently adopted imaging techniques can only provide one or two of these desired properties and are with limited contrast of the embryos. Some image techniques can even damage the embryos. Previous studies have shown that harmonic generation microscopy (HGM), a virtual-transition based technology, can provide noninvasive imaging in zebrafish embryos with a sub-cellular 3D resolution and a millimeter penetration depth, and thus could be a suitable tool for future oocyte and embryo selection of assisted reproductive technologies. However to evaluate HGM in clinical use, the intrinsic contrast origin of the second harmonic generation (SHG) and third harmonic generation (THG) inside the mammal embryos has to be studied. In this work we performed HGM studies on the in vitro cultured mouse oocytes and embryos by combining the SHG and THG modalities, with a focus on the contrast origin evaluation. Through the noninvasive HGM imaging, we can clearly identify various structures in the whole oocytes and embryos, including spindle fibers, zona pellucida, polar bodies, cell membranes, and the laminated organelles in the cells. The origin of the THG contrast was further confirmed through the standard staining studies. Through SHG signals, we could not only observe the spindle fibers when the oocytes were arrested at metaphase II or during the cleavage of the embryos, but can also distinguish and analyze the thickness of the three layers of the zona pellucida. Combining two different higher-harmonic generation modalities, SHG and THG, HGM successfully revealed the sub-cellular structures of the whole mouse embryos with a high 3D spatial resolution.

Imaging polyhedral inclusion bodies of nuclear polyhedrosis viruses with second harmonic generation microscopy.

We studied the polarization anisotropy of second harmonic generation (SHG) in polyhedral inclusion bodies (PIBs) of nuclear polyhedrosis viruses (NPV). Due to a body-centered-cubic arrangement of polyhedrin trimers, a characteristic SHG polarization property with a mixture of I23 and I3 symmetry was measured from PIBs. With this characteristic SHG anisotropy, it provides an intrinsic nonlinear signal for virus infection studies in living cells. With multimodal harmonic generation microscopy, we also demonstrated 3D imaging on PIBs of NPV in living cells. The distribution and the number of PIBs in intact infected cells can be revealed without the help of fluorescent labeling.

Cyclophilin A is associated with peripheral artery disease and chronic kidney disease in geriatrics: The Tianliao Old People (TOP) study.

Cyclophilin A (CyPA), secreted by vascular smooth muscle cells in response to oxidative stress, is important in the pathogenesis of progressive peripheral arterial occlusion disease (PAOD), which is common among chronic kidney disease. We explored the prevalence of PAOD in Taiwan's elderly (≥ 65 years old) population and its association with CyPA and renal function. Residents of Tianliao District, a rural community in southern Taiwan, were surveyed. An ankle-brachial index (ABI) < 0.91 was defined as PAOD. Chronic kidney disease (CKD) was defined based on eGFR levels < 60 mL/min/1.73 m(2). Serum CyPA was measured. Of the 473 participants, 68 (14.4%) had PAOD. Multiple logistic regression analysis showed PAOD was significantly associated with lower eGFR, lower BMI, higher glycated hemoglobin and higher pulse pressure. Serum CyPA levels in participants with PAOD were significantly higher than those with normal ABI values (47.3 ± 0.4 vs. 25.5 ± 0.2 ng/mL, p < 0.001). Moreover, eGFR inversely correlated with serum CyPA level (p < 0.05) in participants with CKD, but not in participants with normal renal function. In conclusion, with a prevalence of PAOD as high as 14.4% in an elderly community, CyPA might be the link between PAOD and advanced impaired renal function.

Fetuin-A as a predicator of sarcopenic left ventricular dysfunction.

Sarcopenia is an aging condition involving low muscle mass and function. Fetuin-A (FetA) appears to be a factor for body composition remodeling. We hypothesized that age increases FetA levels and deteriorates the myocardial function by affecting diastolic function, especially in people with sarcopenia. We enrolled 541 asymptomatic elderly (≥ 65 years) patients. Compared with non-sarcopenic population, FetA levels were significantly elevated in the ninety-two (17%) patients (79 ± 6 years; male: 34.7%) diagnosed with sarcopenia (621.1 ± 140.7 vs. 697.3 ± 179.6 µg/ml, < 0.001). Sarcopenic left ventricular dysfunction (S-LVD) was defined by the coexistence of sarcopenia and systolic impairment (LVEF < 50%) and 23 (4.3%) of them met the criteria. Patients with S-LVD showed relatively reduced systolic heart function, higher end-diastolic pressure and a higher FetA level (all p < 0.001) than did those with sarcopenia but without LV dysfunction (S-NLVD). Conversely, in the group without sarcopenia, FetA levels were similar regardless of systolic function. Multivariable logistic regression showed that older age, impaired diastolic function, and higher FetA levels were significantly associated with S-LVD. In conclusion, we found that FetA was significantly higher in elderly patients with sarcopenia, which was associated with impaired diastolic and systolic functions.