Insertion of heterometals into the NifEN-associated iron–molybdenum cofactor precursor

The cofactors of Mo-, V-, Fe-dependent nitrogenases are believed to be highly homologous in structure despite the different types of heterometals (Mo, V, and Fe) they contain. Previously, a precursor form of the FeMo cofactor (FeMoco) was captured on NifEN, a scaffold protein for FeMoco biosynthesis. This all-Fe precursor closely resembles the Fe/S core structure of the FeMoco and, therefore, could reasonably serve as a precursor for all nitrogenase cofactors. Here, we report the heterologous incorporation of V and Fe into the NifEN-associated FeMoco precursor. EPR and activity analyses indicate that V and Fe can be inserted at much reduced efficiencies compared with Mo, and incorporation of both V and Fe is enhanced in the presence of homocitrate. Further, native polyacrylamide gel electrophoresis experiments suggest that NifEN undergoes a significant conformational rearrangement upon metal insertion, which allows the subsequent NifEN–MoFe protein interactions and the transfer of the cofactor between the two proteins. The combined outcome of these in vitro studies leads to the proposal of a selective mechanism that is utilized in vivo to maintain the specificity of heterometals in nitrogenase cofactors, which is likely accomplished through the redox regulation of metal mobilization by different Fe proteins (encoded by nifH, vnfH, and anfH, respectively), as well as the differential interactions between these Fe proteins and their respective scaffold proteins (NifEN and VnfEN) in the Mo-, V-, and Fe-dependent nitrogenase systems

An Assessment Of Traditional Uighur Medicine In Current Xinjiang Region (China)

Background: The main objectives of this study were to assess the current research and development of traditional Uighur medicine in Xinjiang (China), and to evaluate the promising pharmacological products of traditional Uighur medicine for further studies.Materials and Methods: Traditional Uighur medicine data of medicine registry, patent, and academic publications was collected and analyzed.Results: Data showed that, among the registered and studied traditional Uighur medicine, the main therapeutic areas of traditional Uighur medicine focused on skin disease, urogenital disease, rheumatism and digestive system disease. The representative traditional Uighur patent medicine included the following: BaixuanXiatare Tablets, Kaliziran Tincture and Vernoniaanthelmintica Injection (Psoriasis and vitiligo); Xi-payimazibiziLiquid (prostatitis); KursiKaknaq (urinary tract infection); Tongzhisurunjiang Capsules (anti-rheumatism medicine); HuganBuzure Granules (digestive system disease). Moreover, ten Uighur herbs were widely used, including: ResinaScammoniae, Folium FumicisDentati, HerbaDracocephali, Semen AmygdaliDulcis, HerbaChamomillae, FructusPimpinellaeanisi, Cortex Foeniculi, FructusVernoniae, FructusApii, and Radix AnacycliPyrethri.Conclusion: This study concluded by indicating that traditional Uighur medicine with excellent curative effect should be screened in details for their phytochemical properties and pharmacological activity to discover new bioactive constituents.Key words: Traditional Uighur medicine, Traditional Uighur patent medicine, Uighur her

Characteristic free volumes of bulk metallic glasses : measurement and their correlation with glass-forming ability

2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Characteristic free volume change of bulk metallic glasses

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Finite temperature phase diagram of a polarised Fermi condensate

The two-component Fermi gas is the simplest fermion system displaying superfluidity, and as such finds applications ranging from the theory of superconductivity to QCD. Ultracold atomic gases provide an exceptionally clean realization of this system, where the interatomic interaction and the atom species population are both independent, tuneable parameters. This allows one to investigate the Fermi gas with imbalanced spin populations, which had previously been experimentally elusive, and this prospect has stimulated much theoretical activity. Here we show that the finite temperature phase diagram contains a region of phase separation between the superfluid and normal states that touches the boundary of second-order superfluid transitions at a tricritical point, reminiscent of the phase diagram of $^3$He-$^4$He mixtures. A variation of interaction strength then results in a line of tricritical points that terminates at zero temperature on the molecular Bose-Einstein condensate (BEC) side. On this basis, we argue that tricritical points will play an important role in the recent experiments on polarised atomic Fermi gases.Comment: 6 pages, 4 figures. Manuscript extended and figures modified. For final version, see Nature Physic

Synthesis and DFT investigation of new bismuth-containing MAX phases

The M(n + 1)AX(n) phases (M = early transition metal; A = group A element and X = C and N) are materials exhibiting many important metallic and ceramic properties. In the present study powder processing experiments and density functional theory calculations are employed in parallel to examine formation of Zr(2)(Al(1−x)Bi(x))C (0 ≤ x ≤ 1). Here we show that Zr(2)(Al(1−x)Bi(x))C, and particularly with x ≈ 0.58, can be formed from powders even though the end members Zr(2)BiC and Zr(2)AlC seemingly cannot. This represents a significant extension of the MAX phase family, as this is the first report of a bismuth-based MAX phase

TEMPRANILLO is a regulator of juvenility in plants

Many plants are incapable of flowering in inductive daylengths during the early juvenile vegetative phase (JVP). Arabidopsis mutants with reduced expression of TEMPRANILLO (TEM), a repressor of FLOWERING LOCUS T (FT) had a shorter JVP than wild-type plants. Reciprocal changes in mRNA expression of TEM and FT were observed in both Arabidopsis and antirrhinum, which correlated with the length of the JVP. FT expression was induced just prior to the end of the JVP and levels of TEM1 mRNA declined rapidly at the time when FT mRNA levels were shown to increase. TEM orthologs were isolated from antirrhinum (AmTEM) and olive (OeTEM) and were expressed most highly during their juvenile phase. AmTEM functionally complemented AtTEM1 in the tem1 mutant and over-expression of AmTEM prolonged the JVP through repression of FT and CONSTANS (CO). We propose that TEM may have a general role in regulating JVP in herbaceous and woody species

An association between unrecognized gastroesophageal reflux disease and excessive daytime sleepiness in Taiwanese subjects suspected to have liver disease: a pilot study

<p>Abstract</p> <p>Background</p> <p>In traditional Chinese culture, liver disease is believed to underlie excessive daytime sleepiness (EDS). Consequently, Chinese patients with complaints of EDS and physicians who treat them suspect that a liver abnormality is present. If liver disease is ruled out, these patients are often discharged without treatment. Gastroesophageal reflux disease (GERD) is a common disorder also associated with EDS. This pilot study was undertaken to determine the prevalence of GERD among Taiwanese patients with complaints of EDS suspected to be related to liver disease but in whom no evidence for the latter was found.</p> <p>Methods</p> <p>From July 2009 to December 2009, 121 outpatients who presented to or were referred to the Department of Gastroenterology and Hepatology of the Chiayi Gung Memorial Hospital for evaluation of a complaint of EDS thought to be due to liver disease were examined. Demographic data were collected, and physical examinations and liver function tests were performed. Forty-eight patients had liver disease and were excluded. The Chinese Epworth Sleepiness Scale questionnaire (Chinese ESS) and the Chinese Gastroesophageal Reflux Disease Questionnaire (CGERDQ) were then administered to 73 included patients.</p> <p>Results</p> <p>More than half (56.2%) of the included patients were found to suffer from GERD. Patients with symptoms of GERD had higher mean CGERDQ scores than patients without symptoms of the disorder (18.88 ± 5.49 and 5.56 ± 3.57, respectively; <it>P </it>< 0.001). Patients with symptoms of GERD also had higher mean Chinese ESS scores than patients without symptoms (8.80 ± 5.49 and 3.13 ± 3.50, respectively; <it>P </it>< 0.001). Chinese ESS scores indicative of EDS were observed in 48.8% of patients with symptoms of GERD and in 3.1% of those without symptoms (<it>P </it>< 0.001). Differences between the two groups retained their significance after controlling for potential confounders.</p> <p>Conclusions</p> <p>A significant percentage of Taiwanese patients who complained of EDS and were admitted to our Hepatology/Gastroenterology Department due to a suspicion of liver disease actually had symptoms of GERD. Further studies are needed to ascertain whether treatment of GERD will effectively resolve EDS in these patients.</p