Regioselective Synthesis of Highly Substituted Imidazoles via the Sequential Reaction of Allenyl Sulfonamides and Amines

A novel synthesis of imidazoles from electron-withdrawing group-substituted allenyl sulfonamides with amines was developed. The 4- and 5-functionalized imidazoles were constructed regioselectively, which depended on the substituents on the nitrogen atoms

Hydroxyphosphinylation Reaction of 3‑Cyclopropylideneprop-2-en-1-ones via C–P σ‑Bond Cleavage

An unexpected hydroxyphosphinylation of 3-cyclopropylideneprop-2-en-1-ones with phosphines has been observed. This method provides a unique regio- and stereoselective synthesis of highly functionalized 1-dialkylphinyl-3-oxo-(1<i>Z</i>)-alkenyl cyclopropanols with important potentials. The reaction displays an unusual mechanistic featurea highly selective cleavage of C–P σ bonds in phosphines

Hydroxyphosphinylation Reaction of 3‑Cyclopropylideneprop-2-en-1-ones via C–P σ‑Bond Cleavage

An unexpected hydroxyphosphinylation of 3-cyclopropylideneprop-2-en-1-ones with phosphines has been observed. This method provides a unique regio- and stereoselective synthesis of highly functionalized 1-dialkylphinyl-3-oxo-(1<i>Z</i>)-alkenyl cyclopropanols with important potentials. The reaction displays an unusual mechanistic featurea highly selective cleavage of C–P σ bonds in phosphines

Bright and High-Color-Rendering White Light-Emitting Diode Using Color-Tunable Oxychloride and Oxyfluoride Phosphors

White lighting converted by tricolor phosphor and near-ultraviolet light-emitting diode demonstrates great potential in general lighting. However, a major problem with this approach is the lower luminous efficiency of the resulting white lighting by the reabsorption among tricolor phosphors. In this work, we propose a general but effective method for achieving high-efficacy white light-emitting diodes (WLEDs) by using two-color phosphors having the same host that can lower energy loss by reabsorption. Color-tunable Sr_7.95Si₄O₁₂Cl₈:0.05Eu²⁺ (SSO_Cl:0.05Eu²⁺) phosphors are synthesized by cationic substitution strategy, and the emission colors can be tuned from blue-greenish to blue/yellow by Sr → Mg/Ca substitution. The red-shifted emission is attributed to the increased Eu²⁺ d-orbital splitting owing to the smaller size of Ca²⁺, whereas blue-shifted Eu²⁺ emission is unusual in Mg-substitution for Sr²⁺. WLEDs with luminous efficacies (η_L) of 28.9–56 lm/W and CRIs of 79–90.2 are demonstrated using the two-color phosphors. By employing a narrow-line Mn⁴⁺ emission deep red oxyfluoride phosphor, a high CRI (Ra = 90.3, R9 = 94) WLED with η_L of 39.3 lm/W is obtained. These findings provide a possible way for developing high CRI WLED by using two-color phosphors

Rhodamine-actin (red) was injected into embryos expressing a distinct GFP fusion protein (green; specified in left column)

Puncta was scored as colocalized if two puncta moved in unison over a minimum of two consecutive time points (arrowheads). Time points (s) are indicated at the top right of panel. Percentage of colocalization is shown in the right column. (A–F) Live series shows that actin puncta colocalize with Rab7-GFP–labeled late endosomes (A), Dah-GFP–labeled vesicles (B), Syt-GFP–labeled vesicles (C), and Rab5-GFP–labeled early endosomes (D). Actin puncta did not show considerable colocalization with Grasp65-GFP–labeled Golgi (E) or Clathrin light chain–GFP–labeled membrane (F). Insets in C depict single channels for actin (left) and Syt-GFP (right). Error = SEM. Bar, 5 μm<p><b>Copyright information:</b></p><p>Taken from "Vesicles and actin are targeted to the cleavage furrow via furrow microtubules and the central spindle"</p><p></p><p>The Journal of Cell Biology 2008;181(5):777-790.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2396810.</p><p></p

(A) Phalloidin in fixed embryos shows F-actin puncta in cycle 14 interphase cells (arrow)

(B) F-actin puncta localize to the cell equator near furrow MTs (arrowheads) and the central spindle at cytokinesis (arrows). Merged images of F-actin (phalloidin; red) and MTs (α-Tub; green) are shown in the bottom panels. (C–J) Live series of cycle 14 telophase. Rhodamine-actin, red; Tub-GFP, green. Actin puncta accumulate near the central spindle (D, bracket). Arrowheads in C–F show an individual actin puncta moving alongside an MT bundle at the central spindle. Furrow MTs (G, arrowed bracket) align perpendicular to the cleavage plane. Its midpoint contacts the furrow tip (G, arrowhead). Actin puncta are visible near ends of furrow MTs (I, blue arrowhead) and accumulate at the contact point between the leading furrow edge and furrow MTs (G and I, white arrowheads). Arrow in I shows an actin puncta colocalized with the central spindle. Time points (s) are shown at the top right of each panel. For full video, see Video 2, available at . Bars, 5 μm.<p><b>Copyright information:</b></p><p>Taken from "Vesicles and actin are targeted to the cleavage furrow via furrow microtubules and the central spindle"</p><p></p><p>The Journal of Cell Biology 2008;181(5):777-790.</p><p>Published online 2 Jun 2008</p><p>PMCID:PMC2396810.</p><p></p

Free vibration analysis of composite cylindrical shells with non-uniform thickness walls

The paper proposes to characterize the free vibration behaviour of non-uniform cylindrical shells using spline approximation under first order shear deformation theory. The system of coupled differential equations in terms of displacement and rotational functions are obtained. These functions are approximated by cubic splines. A generalized eigenvalue problem is obtained and solved numerically for an eigenfrequency parameter and an associated eigenvector which are spline coefficients. Four and two layered cylindrical shells consisting of two different lamination materials and plies comprising of same as well as different materials under two different boundary conditions are analyzed. The effect of length parameter, circumferential node number, material properties, ply orientation, number of lay ups, and coefficients of thickness variations on the frequency parameter is investigated

Interaction of a Hydrophobic-Functionalized PAMAM Dendrimer with Bovine Serum Albumin: Thermodynamic and Structural Changes

The interaction between a hydrophobic-functionalized PAMAM dendrimer (PAMAM-NH₂-C12, 25%, G4) and bovine serum albumin (BSA) has been investigated by circular dichroism (CD), UV–vis, and fluorescence spectroscopic methods and molecular modeling. The analysis of the effects of dendrimer complexation on the stability and conformation of BSA indicated that the binding process of the hydrophobic-functionalized dendrimer with BSA induced the relatively large changes in secondary structure of protein. Thermal denaturation of BSA, when carried out in the presence of dendrimer, also indicated that this hydrophobic-functionalized dendrimer acted as a structure destabilizer for BSA. The hydrophobic, electrostatic, and hydrogen bonding forces played important roles in the complex formation. The putative binding site of PAMAM-NH₂-C12 (25%) dendrimer on BSA was near to domain I and domain II. The effect of hydrophobic modification on the stability and structure of BSA would find useful information on the cytotoxicity of PAMAM dendrimer

Polyacrylonitrile Fiber Supported <i>N</i>‑Heterocyclic Carbene Ag(I) As Efficient Catalysts for Three-Component Coupling and Intramolecular 1,3-Dipolar Cycloaddition Reactions under Flow Conditions

A series of recoverable and reusable <i>N</i>-heterocyclic carbene silver complexes supported on polyacrylonitrile fiber were prepared and characterized. Their catalytic performances in three-component coupling reactions of aldehydes, amines, and alkynes (A3 coupling) to synthesize propargylamines were evaluated. The catalysts were also used to prepare fused triazoles in one-pot reactions with excellent yields and diastereoselectivities. In these reactions, the substrates underwent A3 coupling followed by intramolecular 1,3-dipolar cycloaddition. The above reactions were also successfully performed in a continuous-flow process, and sustainable, modular, and efficient syntheses of propargylamines and fused triazoles were achieved

Cardiolipin Effects on PLA₂ Activity toward PAPC.

<p>The <i>in vitro</i> mixed micelle assay was utilized to determine if cardiolipin affects the enzymatic activities of A. GVIA iPLA₂, B. GIA sPLA₂, C. GV sPLA₂, and D. GIVA cPLA₂ toward PAPC. Mixed micelles composed of 100 µM phospholipid and 400 µM Triton X-100 was employed as substrate containing the mole % of cardiolipin to PAPC indicated.</p