295 research outputs found
(4-Cyanophenolato)(subphthalocyaninato)boron1
The crystal structure of the title compound, C31H16BN7O, (CNPhO-BsubPc) is characterized by pairs of π–π stacking interactions between the concave faces of inversion-related BsubPc fragments with a centroid–centroid distance of 3.600 (1) Å. In addition, these pairs of molecules are linked into chains along [101] through further weak π–π stacking interactions with a centroid–centroid distance of 3.8587 (9) Å. There are also weak C—H⋯π(arene) interactions within the chains
(4-Acetylphenolato)(subphthalocyaninato)boron(III)
In the title compound, C32H19BN6O2, the B atom adopts a BON3 tetrahedral coordination geometry. In the crystal, pairs of molecules are associated through aromatic π–π stacking interactions between the concave faces of the boronsubphthalocyanine fragments at a centroid–centroid distance of 3.4951 (19) Å and a weaker interaction of the same type between the convex faces of the same group [centroid–centroid separation = 3.5669 (18) Å] also occurs
Regulation of GATA-3 Expression during CD4 Lineage Differentiation
GATA-3 is necessary for the development of MHC class II-restricted CD4 T cells, and its expression is increased during positive selection of these cells. TCR signals drive this upregulation, but the signaling pathways that control this process are not well understood. Using genetic and pharmacological approaches, we show that GATA-3 upregulation during thymocyte-positive selection is the result of additive inputs from the Ras/MAPK and calcineurin pathways. This upregulation requires the presence of the transcription factor c-Myb. Furthermore, we show that TH-POK can also upregulate GATA-3 in double-positive thymocytes, suggesting the existence of a positive feedback loop that contributes to lock in the initial commitment to the CD4 lineage during differentiation
(4-Nitrophenolato)(subphthalocyaninato)boron(III)1
The main feature of the structure of the title compound, C30H16BN7O3 or NO2PhO-BsubPc, are pairs of molecules linked through π-interactions between the concave faces of the BsubPc fragments at a distance of 3.5430 (11) Å across an inversion centre. However, the angle between the planes of the five- and six-menbered rings involved in this interaction is 1.44 (10)°, causing the interacting BsubPcs units to be slightly askew rather than parallel as is typical for π-stacking interactions
Early-type galaxies in the SDSS. I. The sample
A sample of nearly 9000 early-type galaxies, in the redshift range 0.01 < z <
0.3, was selected from the Sloan Digital Sky Survey using morphological and
spectral criteria. This paper describes how the sample was selected, presents
examples of images and seeing corrected fits to the observed surface brightness
profiles, describes our method for estimating K-corrections, and shows that the
SDSS spectra are of sufficiently high quality to measure velocity dispersions
accurately. It also provides catalogs of the measured photometric and
spectroscopic parameters. In related papers, these data are used to study how
early-type galaxy observables, including luminosity, effective radius, surface
brightness, color, and velocity dispersion, are correlated with one another.Comment: 63 pages, 21 figures. Accepted by AJ (scheduled for April 2003). This
paper is part I of a revised version of astro-ph/0110344. The full version of
Tables 2 and 3, i.e. the tables listing the photometric and spectroscopic
parameters of ~ 9000 galaxies, are available at
http://astrophysics.phys.cmu.edu/~bernardi/SDSS/Etypes/TABLE
(Dodecafluorosubphthalocyaninato)(4-methylphenolato)boron(III)
In the title compound, C31H7BF12N6O, molecules are arranged into one-dimensional columns with an intermolecular B⋯B distance of 5.3176 (8) Å. Bowl-shaped molecules are arranged within the columns in a concave bowl-to-ligand arrangement separated by a ring centroid distance of 3.532 (2) Å between the benzene ring of the 4-methylphenoxy ligand and one of the three five-membered rings of a symmetry-related molecule
Bromido(dodecafluorosubphthalocyaninato)boron(III)
The title compound, C24BBrF12N6 or Br-F12BsubPc (BsubPc is boronsubphtalocyanine), has a bowl-shaped structure with an approximate molecular C
3v symmetry characteristic of boronsubphthalocyanine compounds. In the crystal, molecules are arranged in one-dimensional columns and the boron–subphthalocyanine units within each column are offset and angled in a bowl-to-ligand packing arrangement such that the axial Br atom rests in the aromatic concaved bowl of the neighboring subphthalocyanine with an intermolecular Br⋯B distance of 3.721 (3) Å
Role of the Endogenous Antioxidant System in the Protection of Schistosoma mansoni Primary Sporocysts against Exogenous Oxidative Stress
Antioxidants produced by the parasite Schistosoma mansoni are believed to be involved in the maintenance of cellular redox balance, thus contributing to larval survival in their intermediate snail host, Biomphalaria glabrata. Here, we focused on specific antioxidant enzymes, including glutathione-S-transferases 26 and 28 (GST26 and 28), glutathione peroxidase (GPx), peroxiredoxin 1 and 2 (Prx1 and 2) and Cu/Zn superoxide dismutase (SOD), known to be involved in cellular redox reactions, in an attempt to evaluate their endogenous antioxidant function in the early-developing primary sporocyst stage of S. mansoni. Previously we demonstrated a specific and consistent RNA interference (RNAi)-mediated knockdown of GST26 and 28, Prx1 and 2, and GPx transcripts, and an unexpected elevation of SOD transcripts in sporocysts treated with gene-specific double-stranded (ds)RNA. In the present followup study, in vitro transforming sporocysts were exposed to dsRNAs for GST26 and 28, combined Prx1/2, GPx, SOD or green-fluorescent protein (GFP, control) for 7 days in culture, followed by assessment of the effects of specific dsRNA treatments on protein levels using semi-quantitative Western blot analysis (GST26, Prx1/2 only), and larval susceptibility to exogenous oxidative stress in in vitro killing assays. Significant decreases (80% and 50%) in immunoreactive GST26 and Prx1/2, respectively, were observed in sporocysts treated with specific dsRNA, compared to control larvae treated with GFP dsRNA. Sporocysts cultured with dsRNAs for GST26, GST28, Prx1/2 and GPx, but not SOD dsRNA, were significantly increased in their susceptibility to H2O2 oxidative stress (60–80% mortalities at 48 hr) compared to GFP dsRNA controls (∼18% mortality). H2O2-mediated killing was abrogated by bovine catalase, further supporting a protective role for endogenous sporocyst antioxidants. Finally, in vitro killing of S. mansoni sporocysts by hemocytes of susceptible NMRI B. glabrata snails was increased in larvae treated with Prx1/2, GST26 and GST28 dsRNA, compared to those treated with GFP or SOD dsRNAs. Results of these experiments strongly support the hypothesis that endogenous expression and regulation of larval antioxidant enzymes serve a direct role in protection against external oxidative stress, including immune-mediated cytotoxic reactions. Moreover, these findings illustrate the efficacy of a RNAi-type approach in investigating gene function in larval schistosomes
A meta-analysis of the associations between common variation in the PDE8B gene and thyroid hormone parameters, including assessment of longitudinal stability of associations over time and effect of thyroid hormone replacement
Objective Common variants in PDE8B are associated with TSH but apparently without any effect on thyroid hormone levels that is difficult to explain. Furthermore, the stability of the association has not been examined in longitudinal studies or in patients on levothyroxine (l-T4).
Design Totally, four cohorts were used (n=2557): the Busselton Health Study (thyroid function measured on two occasions), DEPTH, EFSOCH (selective cohorts), and WATTS (individuals on l-T4).
Methods Meta-analysis to clarify associations between the rs4704397 single nucleotide polymorphism in PDE8B on TSH, tri-iodothyronine (T3), and T4 levels.
Results Meta-analysis confirmed that genetic variation in PDE8B was associated with TSH (P=1.64×10−10 0.20 s.d./allele, 95% confidence interval (CI) 0.142, 0.267) and identified a possible new association with free T4 (P=0.023, −0.07 s.d./allele, 95% CI −0.137, −0.01), no association was seen with free T3 (P=0.218). The association between PDE8B and TSH was similar in 1981 (0.14 s.d./allele, 95% CI 0.04, 0.238) and 1994 (0.20 s.d./allele, 95% CI 0.102, 0.300) and even more consistent between PDE8B and free T4 in 1981 (−0.068 s.d./allele, 95% CI −0.167, 0.031) and 1994 (−0.07 s.d./allele, 95% CI −0.170, 0.030). No associations were seen between PDE8B and thyroid hormone parameters in individuals on l-T4.
Conclusion Common genetic variation in PDE8B is associated with reciprocal changes in TSH and free T4 levels that are consistent over time and lost in individuals on l-T4. These findings identify a possible genetic marker reflecting variation in thyroid hormone output that will be of value in epidemiological studies and provides additional evidence that PDE8B is involved in TSH signaling in the thyroid
- …