Triplet Lifetimes, Solvent, and Intramolecular Capture of Isoxazolones

2004 ◽  
Vol 57 (1) ◽  
pp. 101 ◽  
Author(s):  
Kiah H. Ang ◽  
Matthew Cox ◽  
Warren D. Lawrance ◽  
Rolf Prager ◽  
Jason A. Smith ◽  
...  
Keyword(s):  
Triplet State ◽  
Laser Photolysis ◽  
Present Evidence ◽  
Intramolecular Cycloaddition ◽  
First Time

The first step in the photochemical decarboxylation of isoxazolones is the formation of the triplet state of the isoxazolone. We present evidence for the first time from flash laser photolysis of the lifetime of such species, and examples of their capture by solvent and by intramolecular cycloaddition.

slimb coordinates wg and dpp expression in the dorsal-ventral and anterior-posterior axes during limb development

Development ◽  
1998 ◽  
Vol 125 (17) ◽  
pp. 3411-3416 ◽  
Author(s):  
N.A. Theodosiou ◽  
S. Zhang ◽  
W.Y. Wang ◽  
T. Xu
Keyword(s):  
Genetic Analysis ◽  
Limb Development ◽  
Imaginal Disc ◽  
Essential Role ◽  
Present Evidence ◽  
First Time ◽  
Anterior Posterior

In the Drosophila leg disc, wingless (wg) and decapentaplegic (dpp) are expressed in a ventral-anterior and dorsal-anterior stripe of cells, respectively. This pattern of expression is essential for proper limb development. While the Hedgehog (Hh) pathway regulates dpp and wg expression in the anterior-posterior (A/P) axis, mechanisms specifying their expression in the dorsal-ventral (D/V) axis are not well understood. We present evidence that slimb mutant clones in the disc deregulate wg and dpp expression in the D/V axis. This suggests for the first time that their expression in the D/V axis is actively regulated during imaginal disc development. Furthermore, slimb is unique in that it also deregulates wg and dpp in the A/P axis. The misexpression phenotypes of slimb- clones indicate that the regulation of wg and dpp expression is coordinated in both axes, and that slimb plays an essential role in integrating A/P and D/V signals for proper patterning during development. Our genetic analysis further reveals that slimb intersects the A/P pathway upstream of smoothened (smo).

scholarly journals Cleavage of membrane-associated pref-1 generates a soluble inhibitor of adipocyte differentiation.

1997 ◽  
Vol 17 (2) ◽  
pp. 977-988 ◽  
Author(s):  
C M Smas ◽  
L Chen ◽  
H S Sul
Keyword(s):  
Adipocyte Differentiation ◽  
Constitutive Expression ◽  
Soluble Form ◽  
Inhibitory Effects ◽  
Alternate Splicing ◽  
Produce Cell ◽  
Present Evidence ◽  
Juxtamembrane Region ◽  
Epidermal Growth ◽  
First Time

pref-1 is an epidermal growth factor-like repeat protein present on the surface of preadipocytes that functions in the maintenance of the preadipose state. pref-1 expression is completely abolished during 3T3-L1 adipocyte differentiation. Bypassing this downregulation by constitutive expression of full-length transmembrane pref-1 in preadipocytes drastically inhibits differentiation. For the first time, we show processing of cell-associated pref-1 to generate both a soluble pref-1 protein of approximately 50 kDa that corresponds to the ectodomain and also smaller products of 24 to 25 kDa and 31 kDa. Furthermore, while all four of the alternately spliced forms of pref-1 produce cell-associated protein, only the two largest of the four alternately spliced isoforms undergo cleavage in the juxtamembrane region to release the soluble 50-kDa ectodomain. We demonstrate that addition of Escherichia coli-expressed pref-1 ectodomain to 3T3-L1 preadipocytes blocks differentiation, thus overriding the adipogenic actions of dexamethasone and methylisobutylxanthine. The inhibitory effects of the pref-1 ectodomain are blocked by preincubation of the protein with pref-1 antibody. That the ectodomain alone is sufficient for inhibition demonstrates that transmembrane pref-1 can be processed to generate an inhibitory soluble form, thereby greatly extending its range of action. Furthermore, we present evidence that alternate splicing is the mechanism that governs the production of transmembrane versus soluble pref-1, thereby determining the mode of action, juxtacrine or paracrine, of the pref-1 protein.

Dinoflagellate cyst distribution around the British Isles

1972 ◽  
Vol 52 (4) ◽  
pp. 939-944 ◽  
Author(s):  
Philip C. Reid
Keyword(s):  
Red Tide ◽  
Irish Sea ◽  
Intertidal Sediment ◽  
British Isles ◽  
Present Evidence ◽  
Gonyaulax Polyedra ◽  
Large Numbers ◽  
First Time ◽  
Potential Conditions ◽  
Motile Stage

Rich assemblages of acid-resistant microfossils occur in intertidal sediment from the British Isles and are here reported, for the first time, to contain large numbers of dino-flagellate cysts. These cysts provide evidence to show that the distribution of certain dino-flagellate cysts is different from that of the motile stage, that the coastal distribution of cysts appears to be controlled by currents and that their occurrence within bays is possibly related to localized temperature and salinity conditions. Further, they present evidence that potential conditions for a red tide of Gonyaulax polyedra Stein may be present in the east Irish Sea.

scholarly journals Photoinduced triplet-state electron transfer of platinum porphyrin: a one-step direct method for sensing iodide with an unprecedented detection limit

2015 ◽  
Vol 3 (13) ◽  
pp. 6733-6738 ◽  
Author(s):  
Dilshad Masih ◽  
Shawkat M. Aly ◽  
Erkki Alarousu ◽  
Omar F. Mohammed
Keyword(s):  
Electron Transfer ◽  
Detection Limit ◽  
Triplet State ◽  
Direct Method ◽  
Economical Method ◽  
State Electron ◽  
One Step ◽  
Platinum Porphyrin ◽  
First Time

Herein, we report for the first time the photoinduced triplet-state electron transfer of Pt(ii)TMPyP as an easy, rapid, environmentally friendly, ultra-sensitive and economical method for the determination of iodide in the aqueous phase.

scholarly journals A longslit spectroscopic survey of bulges in disc galaxies

2012 ◽  
Vol 10 (H16) ◽  
pp. 345-345
Author(s):  
Maximilian Fabricius ◽  
Roberto Saglia ◽  
David Fisher ◽  
Niv Drory ◽  
Ralf Bender ◽  
...  
Keyword(s):  
High Resolution ◽  
Velocity Dispersion ◽  
Low Resolution ◽  
Present Evidence ◽  
Counter Rotation ◽  
Two Systems ◽  
Velocity Dispersions ◽  
First Time ◽  
Disc Galaxies

AbstractWe use the Marcario Low Resolution Spectrograph (LRS) at the Hobby-Eberly-Telescope (HET) to study the kinematics of pseudobulges and classical bulges in 45 S0-Sc type galaxies in the nearby universe. Our high-resolution (instrumental σ ≈ 39 km s−1) spectra allo only to resolve the typical velocity dispersions of our targets but also to derive the h3 and h4 Gauss-Hermite moments. We demonstrate for the first time that purely kinematic diagnostics of the bulge dichotomy agree systematically with those based on Sérsic index. Low Sérsic index bulges have both increased rotational support (higher v/σ values) and on average lower central velocity dispersions. Pseudobulges have systematically shallower velocity dispersion profiles. The same correlation also holds when visual morphologies are used to diagnose bulge type. Finally, we present evidence for formerly undetected counter rotation in the two systems NGC 3945 and NGC 4736. With these, a total of 16% of the systems in or sample show signs for stellar counter rotation.

Morphometric analysis of mice uteri treated with the preservatives methyl, ethyl, propyl, and butylparaben

2004 ◽  
Vol 20 (6-10) ◽  
pp. 123-132 ◽  
Author(s):  
C Lemini ◽  
A Hernández ◽  
R Jaimez ◽  
Y Franco ◽  
ME Avila ◽  
...  
Keyword(s):  
Morphometric Analysis ◽  
Luminal Epithelium ◽  
Methyl Ethyl ◽  
Alkyl Esters ◽  
Histological Changes ◽  
Present Evidence ◽  
Cd1 Mice ◽  
First Time

The alkyl esters of p-hydroxybenzoic acid (PHBA) known as parabens (Pbens) are widely used as preservatives in food, pharmaceuticals, and cosmetics. Several in vivo and in vitro studies have shown these compounds to be estrogenic. Here, for the first time, we present evidence of their estrogenicity using a morphometric analysis of uteri from mice treated with the preservatives methylparaben (MePben), ethylparaben (EtPben), propylparaben (PrPben), and butylparaben (BuPben) compared with estradiol (E2). Different groups of adult ovariectomized (Ovx) CD1 mice were subcutaneously (sc) treated daily for three days with two different equimolar doses (362 and 1086 mmol/kg) of the Pbens: MePben (55 and 165 mg/kg), EtPben (60 and 180 mg/kg), PrPben (65 and 195 mg/kg), BuPben (70 and 210 mg/kg), E2 (10 mg/kg; 0.036 mmol/kg), and vehicle (propyleneglycol; V, 10 mL/kg). On the fourth day, uteri were dissected, blotted, weighed, and placed in a fixative solution for 24 h. The paraffin embeded uteri were cut to obtain 7 mm thick transversal sections. Luminal epithelium heights (LEH), glandular epithelium heights (GEH), and myometrium widths (MW) were measured. The highest Pbens dose was able to produce uterotrophic effects (38 to 76%) compared to E2 efects (100%). The relative uterotrophic potency to E2 (100) was from 0.02 to 0.009. Significant increases ( P <0.05) in LEH, GEH, and MW as compared with V were obtained: LEH from 87 to 113% (E2 153%), GEH from 10 to 40% (E2 60%), and MW from 35 to 43% (E2 88%). These results confirm that Pbens at the doses assayed here induce estrogenic histological changes in the uteri of Ovx mice.

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