Abstract-Recent studies have shown that the heme oxygenase (HO) product, carbon monoxide (CO), induces vasodilation and that inhibition of HO produces a sustained hypertension in rats. Given the importance of renal medullary blood flow (MBF) in the long-term control of arterial blood pressure, we hypothesized that the HO/CO system may play an important role in maintaining the constancy of blood flow to the renal medulla, which in turn contributes to the antihypertensive effects of the renal medulla. To test this hypothesis, we first determined the expression of 2 isoforms of HO (HO-1 and HO-2) in the different kidney regions. By Northern blot analyses, the abundance of both isozyme mRNAs was found highest in the renal inner medulla and lowest in the renal cortex. The transcripts for HO-1 in the renal outer medulla and inner medulla were 2.5 and 3.7 times that expressed in the renal cortex and those for HO-2 in the outer medulla and inner medulla were 1.3 and 1.6 times that expressed in the renal cortex, respectively. Western blot analyses of both enzymes showed the same expression pattern in these kidney regions as the mRNAs. To determine the role that HO plays in the control of renal MBF, we examined the effect of the HO inhibitor zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG) on cortical blood flow and MBF in anesthetized rats. ZnDPBG was given by renal medullary interstitial infusion, and cortical blood flow and MBF were measured by laser Doppler flowmetry. Renal medullary interstitial infusion of ZnDPBG at a dose of 60 nmol/kg per minute produced a 31% decrease in MBF over a period of 60 minutes as measured by laser Doppler flow signal (0.62Ϯ0.02 vs 0.43Ϯ0.04 V in control vs ZnDPBG). With the use of an in vivo microdialysis technique, ZnDPBG was found to significantly reduce renal medullary cGMP concentrations when infused into the renal medullary interstitial space. These results suggest that both HO-1 and HO-2 are highly expressed in the renal medulla, that HO and its products play an important role in maintaining the constancy of blood flow to the renal medulla, and that cGMP may mediate the vasodilator effect of HO products in the renal medullary circulation.

There is an increasing need for new strategies to improve the heating efficiency or the specific absorption rate (SAR) of magnetite (Fe O ), which is the only FDA approved magnetic material. We propose a facile approach to obtain well-dispersed highly crystalline Fe O nanorods (NRs) by the reduction of β-FeOOH in an organic solvent and demonstrate that the SAR of Fe O NRs can be enhanced by tuning their aspect ratios. Fe O NRs with an aspect ratio of 4.5 have a much higher SAR as compared with 15 nm Fe O nanoparticles and Fe O NRs counterparts with an aspect ratio of 10. The highest SAR is greatly increased up to 1072 W g for an ac field of 33 kA m and a concentration of 5 mg mL , which is mostly attributed to hysteresis losses. These findings pave a new pathway for the design and synthesis of novel anisotropic iron oxide nanostructures with an optimal heating efficiency for advanced hyperthermia.

Pulsatilla (Ranunculaceae) consists of about 40 species, and many of them have horticultural and/or medicinal value. However, it is difficult to recognize and identify wild Pulsatilla species. Universal molecular markers have been used to identify these species, but insufficient phylogenetic signal was available. Here, we compared the complete chloroplast genomes of seven Pulsatilla species. The chloroplast genomes of Pulsatilla were very similar and their length ranges from 161,501 to 162,669 bp. Eight highly variable regions and potential sources of molecular markers such as simple sequence repeats, large repeat sequences, and single nucleotide polymorphisms were identified, which are valuable for studies of infra- and inter-specific genetic diversity. The SNP number differentiating any two Pulsatilla chloroplast genomes ranged from 112 to 1214, and provided sufficient data for species delimitation. Phylogenetic trees based on different data sets were consistent with one another, with the IR, SSC regions and the barcode combination rbcL + matK + trnH-psbA produced slightly different results. Phylogenetic relationships within Pulsatilla were certainly resolved using the complete cp genome sequences. Overall, this study provides plentiful chloroplast genomic resources, which will be helpful to identify members of this taxonomically challenging group in further investigation.

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Pulsatilla (Ranunculaceae) comprises about 40 species, many of which have horticultural and/or medicinal importance. However, the recognition and identification of wild Pulsatilla species is difficult due to the presence of complex morphological characters. DNA barcoding is a powerful molecular tool capable of rapidly and accurately distinguishing between species. Here, we assessed the effectiveness of four commonly used DNA barcoding loci—rbcL (R), trnH-psbA ( T ), matK (M), and ITS (I)—to identify species of Pulsatilla from a comprehensive sampling group. Among the four barcoding single loci, the nuclear ITS marker showed the highest interspecific distances and the highest rate of correct identification. Among the eleven combinations, the chloroplast multi-locus R+T and R+M+T combinations were found to have the best species discrimination rate, followed by R+M. Overall, we propose that the R+M+T combination and the ITS marker on its own are, respectively, the best multi- and single-locus barcodes for discriminating among species of Pulsatilla. The phylogenetic analysis was able to distinguish species of Pulsatilla to the subgenus level, but the analysis also showed relatively low species resolution. This may be caused by incomplete lineage sorting and/or hybridization events in the evolutionary history of the genus, or by the resolution limit of the candidate barcodes. We also investigated the leaf epidermis of eight representative species using scanning electronic microscopy. The resulting micro-morphological characters were valuable for identification of related species. Using additional genome fragments, or even whole chloroplast genomes combined with micro-morphological data may permit even higher resolution of species in Pulsatilla.

Fe 4 Nb 2 O 9 was recently reported to be a new magnetoelectric material with two distinct dielectric anomalies located at T N ≈ 90 K for an antiferromagnetic transition and T str ≈ 77 K of unknown origin, respectively. By analyzing low-temperature neutron-powder-diffraction data, here we determined its magnetic structure below T N and uncovered the origin of the second dielectric anomaly as a structural phase transition across T str . In the antiferromagnetically ordered state below T N , both Fe1 and Fe2 magnetic moments lying within the weakly and strongly buckled honeycomb layers are arranged in a fashion that the three nearest neighbors are directed oppositely. Upon cooling below T str , the symmetry of crystal structure is lowered from trigonal P-3c1 to monoclinic C2/c, in which a weak sliding of the metal octahedral planes introduces a monoclinic distortion of ∼1.7 • . The magnetic structure is preserved in the low-temperature monoclinic phase, and the Fe magnetic moment increases from 2.1(1)μ B at 95 K to 3.83(4)μ B at 10 K assuming an equal moment configuration at Fe1 and Fe2 sites. The magnetic point group and linear magnetoelectric tensor at each temperature region are determined. From a symmetry-related tensor analysis, the microscopic origins of the magnetoelectric effects between T N and T str are proved to be spin-current and d-p hybridization mechanisms.

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