Scoring molecular wires subject to an ultrafast laser pulse for molecular electronic devices.

A nonionizing ultrafast laser pulse of 20-fs duration with a peak amplitude electric-field ±E = 200 × 10-4 a.u. was simulated. It was applied to the ethene molecule to consider its effect on the electron dynamics, both during the application of the laser pulse and for up to 100 fs after the pulse was switched off. Four laser pulse frequencies ω = 0.2692, 0.2808, 0.2830, and 0.2900 a.u. were chosen to correspond to excitation energies mid-way between the (S1 ,S2 ), (S2 ,S3 ), (S3 ,S4 ) and (S4 ,S5 ) electronic states, respectively. Scalar quantum theory of atoms in molecules (QTAIM) was used to quantify the shifts of the C1C2 bond critical points (BCPs). Depending on the frequencies ω selected, the C1C2 BCP shifts were up to 5.8 times higher after the pulse was switched off compared with a static E-field with the same magnitude. Next generation QTAIM (NG-QTAIM) was used to visualize and quantify the directional chemical character. In particular, polarization effects and bond strengths, in the form of bond-rigidity vs. bond-flexibility, were found, for some laser pulse frequencies, to increase after the laser pulse was switched off. Our analysis demonstrates that NG-QTAIM, in partnership with ultrafast laser irradiation, is useful as a tool in the emerging field of ultrafast electron dynamics, which will be essential for the design, and control of molecular electronic devices.

Self-Assembled Nanoparticles with E Protein Domains I and II of Duck Tembusu Virus Can Induce a More Comprehensive Immune Response Against the Duck Tembusu Virus Challenge.

Duck Tembusu virus (DTMUV) is a pathogenic flavivirus that causes a substantial drop in egg production and severe neurological disorders in domestic waterfowl. Self-assembled ferritin nanoparticles with E protein domains I and II (EDI-II) of DTMUV (EDI-II-RFNp) were prepared, and its morphology was observed. Two independent experiments were conducted. First, Cherry Valley ducks aged 14 days were vaccinated with EDI-II-RFNp, EDI-II, and phosphate buffered solution (PBS, pH 7.4), and special and virus neutralization (VN) antibodies, interleukin 4 (IL-4) and interferon gamma (IFN-γ) in serum, and lymphocyte proliferation were detected. Second, the vaccinated ducks with EDI-II-RFNp, EDI-II, and PBS were injected with virulent DTMUV, clinical signs at 7 days postinfection (dpi) were observed, and mRNA levels of DTMUV in the lungs, liver, and brain at 7 and 14 dpi were detected. The results showed near-spherical nanoparticles EDI-II-RFNp with a 16.46 ± 4.70 nm diameters. The levels of specific and VN antibodies, IL-4 and IFN-γ, and lymphocyte proliferation in the EDI-II-RFNp group were significantly higher than those in the EDI-II and PBS groups. In the DTMUV challenge test, clinical signs and mRNA levels in tissue were used to evaluate protection of EDI-II-RFNp. EDI-II-RFNp-vaccinated ducks showed milder clinical signs and lower levels of DTMUV RNA in the lungs, liver, and brain. These results indicate that EDI-II-RFNp effectively protects ducks against the DTMUV challenge and could be a vaccine candidate to provide an effective and safe method for preventing and controlling DTMUV infection.

Las nanopartículas autoensambladas con los dominios de proteína E I y II del virus Tembusu del pato pueden inducir una respuesta inmunitaria más integral contra el desafío con el mismo virus. El virus Tembusu de los patos (DTMUV) es un flavivirus patógeno que causa una caída sustancial en la producción de huevos y graves trastornos neurológicos en las aves acuáticas domésticas. Se prepararon nanopartículas de ferritina autoensambladas con los dominios de la proteína E I y II (EDI-II) del virus Tembusu (EDI-II-RFNp) y se observó su morfología. Se realizaron dos experimentos independientes. En primer lugar, se vacunaron patos Cherry Valley de 14 días de edad con las partículas EDI-II-RFNp, con partículas EDI-II y con solución amortiguada de fosfato (PBS, pH 7,4), y se detectaron en suero anticuerpos especiales neutralizantes (VN), IL-4, IFN-γ y se detectó proliferación de linfocitos. En segundo lugar, a los patos vacunados con las partículas EDI-II-RFNp, EDI-II y PBS se les inyectó el virus Tembusu virulento, se observaron signos clínicos a los siete días posteriores a la infección (dpi) y se observaron los niveles de ARN mensajero del virus de Tembusu en el pulmón, el hígado y en el cerebro a los siete y 14 días después de la inoculación. Los resultados mostraron las nanopartículas casi esféricas ED?-II-RFNp con un diámetro de 16.46 ± 4.70 nm. Los niveles de anticuerpos específicos neutralizantes, IL-4, IFN-γ y la proliferación de linfocitos en el grupo inoculado con las partículas EDI-II-RFNp fueron significativamente más altos que en los de los grupos inoculados con las partículas EDI-II y con PBS. En la prueba de desafío con el virus Tembusu, se utilizaron los signos clínicos y los niveles de ARNm en tejidos para evaluar la protección inducida por las partículas EDI-II-RFNp. Los patos vacunados con las partículas EDI-II-RFNp mostraron signos clínicos más leves y niveles más bajos de ARN del virus Tembusu en los pulmones, el hígado y el cerebro. Estos resultados indican que las partículas EDI-II-RFNp protegen eficazmente a los patos contra el desafío con el virus Tembusu y podrían ser una vacuna candidata para proporcionar un método eficaz y seguro para prevenir y controlar la infección por dicho virus.

Wound Healing Potential of the Standardized Extract of Boswellia serrata on Experimental Diabetic Foot Ulcer via Inhibition of Inflammatory, Angiogenetic and Apoptotic Markers.

The aim of the present study was to evaluate the wound healing potential and possible mechanism of action of the standardized extract of Boswellia serrata against the experimental model of diabetic foot ulcer. α-Boswellic acid was isolated from the standardized extract of B. serrata and characterized (HPLC, 1H-NMR, 13C-NMR, ESI-MS). Diabetes was induced in Sprague-Dawley rats by streptozotocin (55 mg/kg, i. p.), and wounds were created on the dorsal surface of the hind paw. B. serrata (100, 200, and 400 mg/kg, p. o.) was administered to the rats for 16 days. The HPLC analysis showed a single peak with a retention time of 12.51 min. The compound was identified with ESI-MS [M + Na]+ = 455.37 as α-boswellic acid. Treatment with B. serrata (200 and 400 mg/kg) significantly increased the rate of wound contraction via modulation of oxido-nitrosative stress and elevated the hydroxyproline level at the wound area. reverse transcription-PCR analysis revealed that streptozotocin-induced increases in TNF-α, interleukin-1ß, interleukin-6, nuclear factor-kappa-light-chain-enhancer of activated B cells, and Bcl-2-associated X protein, and decreases in angiopoietin-1, Tie2, transforming growth factor beta 1, vascular endothelial growth factor, and collagen-1 mRNA expression were significantly inhibited by B. serrata. It also significantly reduced wound cellular necrosis as evaluated by flow cytometry using propidium iodide fluorescence intensity. Streptozotocin-induced histopathological alterations were also significantly ameliorated by B. serrata. In conclusion, standardized extracts of B. serrata exert its wound healing potential via orchestrating mechanisms, which include the inhibition of oxido-inflammatory markers (oxido-nitrosative stress, TNF-α, interleukins, and nuclear factor-kappa-light-chain-enhancer of activated B cells), increased collagen synthesis (hydroxyproline and collagen-1) and angiogenesis (Ang-1/Tie2), promoting growth factors (transforming growth factor beta 1 and vascular endothelial growth factor), and inhibition of apoptosis (Bcl-2-associated X protein) to accelerate wound healing in experimental delayed diabetic foot ulcer.