The therapeutic effectiveness of chemotherapy is optimal only when tumor cells are subjected to a maximum drug exposure. To increase the intratumoral concentration and thus efficacy chemotherapy, thermoresponsive bubble-generating liposomal system proposed for triggering localized extracellular delivery. key component this formulation encapsulated ammonium bicarbonate (ABC), which used create transmembrane gradient needed highly efficient encapsulation doxorubicin (DOX). At an elevated...

To solve the toxic issue for new-generation photovoltaic applications, tin-based perovskite solar cells are a promising alternative to their lead counterparts, but they suffer from poor stability because of tendency exhibit tin oxidation. Herein we report new sequential method deposition based on solution processing using hexafluoro-2-propanol as solvent deposit eight bulky ammonium cations top 3D layer form 3D/quasi-2D protect grains penetration by moisture. The formation 2D was confirmed...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharge-transfer photochemistry in ion-molecule cluster complexes of silverK. F. Willey, P. Y. Cheng, M. B. Bishop, and A. DuncanCite this: J. Am. Chem. Soc. 1991, 113, 13, 4721–4728Publication Date (Print):June 1, 1991Publication History Published online1 May 2002Published inissue 1 June 1991https://pubs.acs.org/doi/10.1021/ja00013a001https://doi.org/10.1021/ja00013a001research-articleACS PublicationsRequest reuse permissionsArticle...

We describe a new reflectron time-of-flight mass spectrometer configuration for laser photodissociation of mass-selected ions and the initial performance characteristics observed this instrument. Ions are produced by photoionization within acceleration region instrument or vaporization in an external pulsed-nozzle cluster ion source. Mass selection is accomplished with pulsed deflection plates at end drift section. Laser selected takes place turning point trajectory reflectron. The transit...

Vasoactive intestinal polypeptide (VIP) stimulated cyclic AMP formation in rat pineal gland with dose-dependency vitro, though this effect was much less than that of norepinephrine.Bilateral ganglionectomy the superior cervical ganglion did not inhibit stimulatory VIP gland.In cultured gland, VIP, like norepinephrine, markedly increased activity serotonin N-acetyltransferase, an-enzyme for melatonin synthesis.A dose propranolol above lO""5 M inhibited action, but a lower (lO"5 M) stimulation...

Gas-phase ultrafast excited-state dynamics of cytosine, 1-methylcytosine, and 5-fluorocytosine were investigated in molecular beams using femtosecond pump-probe photoionization spectroscopy to identify the intrinsic major cytosine tautomers. The results indicate that, upon photoexcitation first absorption band, enol tautomer exhibits a significantly longer lifetime than its keto imino counterparts. initially excited states tautomers decay with sub-picosecond for excitation wavelengths...

This paper in the series gives our full account of preliminary results reported a communication [Cheng, Zhong, and Zewail, J. Chem. Phys. 103, 5153 (1995)] on real-time femtosecond (fs) studies transition state charge-transfer (CT) reactions, generally described as harpooning reactions. Here, experimental molecular beam, with help dynamics, we elucidate microscopic elementary dynamics structure states for isolated, bimolecular reaction benzenes (electron donor) iodine acceptor). The is...

With fs radical detachment and kinetic energy-resolved time-of-flight (KETOF) mass spectrometry, we are able to study the transition state dynamics of bimolecular reaction CH3I+I, inelastic reactive channels; collision complex is coherently formed (1.4 ps) long lived (1.7 ps). We also report studies I2 formation. Direct clocking CH3I dissociation, hitherto unobserved, gives 150 for C–I bond breakage time 0.8 Å repulsion length scale.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotodissociation in a reflectron time-of-flight mass spectrometer: novel spectrometry/mass spectrometry configuration for high-mass systemsK. LaiHing, P. Y. Cheng, T. G. Taylor, K. F. Willey, M. Peschke, and A. DuncanCite this: Anal. Chem. 1989, 61, 13, 1458–1460Publication Date (Print):July 1, 1989Publication History Published online1 May 2002Published inissue 1 July...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoionization and mass-selected photodissociation of tellurium clustersK. F. Willey, P. Y. Cheng, T. G. Taylor, M. B. Bishop, A. DuncanCite this: J. Phys. Chem. 1990, 94, 4, 1544–1549Publication Date (Print):February 1, 1990Publication History Published online1 May 2002Published inissue 1 February 1990https://pubs.acs.org/doi/10.1021/j100367a061https://doi.org/10.1021/j100367a061research-articleACS PublicationsRequest reuse permissionsArticle...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoinitiated charge transfer and dissociation in mass-selected metalloorganic complexesK. F. Willey, P. Y. Cheng, K. D. Pearce, M. A. DuncanCite this: J. Phys. Chem. 1990, 94, 12, 4769–4772Publication Date (Print):June 1, 1990Publication History Published online1 May 2002Published inissue 1 June 1990https://pubs.acs.org/doi/10.1021/j100375a005https://doi.org/10.1021/j100375a005research-articleACS PublicationsRequest reuse permissionsArticle...

We describe an approach for real-time studies of the transition-state dynamics charge-transfer reactions. An application to bimolecular reaction benzene with iodine is reported. The measured 750±50 fs transient growth free I atom product elucidates nature transition state and mechanism dissociative reaction. formulated in relation impact geometry dative bonding, which are crucial condense-phase surface reactions, supported by molecular dynamics.

We report studies of ultrafast dynamics azobenzene cation using femtosecond photoionization-photofragmentation spectroscopy. In our experiments, a pump pulse first produces an ensemble cations via photoionization the neutrals. A delayed probe then brings evolving ionic system to excited states that ultimately undergo ion fragmentation. The is followed by monitoring either parent-ion depletion or fragment-ion formation as function pump-probe delay time. observed transients for are...

Recent research has highlighted the importance of agricultural cooperatives on farm production. Although consensus from literature suggests that participating in these organizations significantly affects production, there is inconclusive evidence whether this effect positive or negative. Moreover, previous studies solely focus magnitude and fail to explain mechanism behind it. This study contributes knowledge gap by estimating impact profits. To do this, we apply causal mediation analysis...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUltraviolet photolysis in a laser vaporization cluster source: synthesis of novel mixed-metal clustersK. Lai Hing, P. Y. Cheng, and M. A. DuncanCite this: J. Phys. Chem. 1987, 91, 26, 6521–6525Publication Date (Print):December 1, 1987Publication History Published online1 May 2002Published inissue 1 December 1987https://pubs.acs.org/doi/10.1021/j100310a020https://doi.org/10.1021/j100310a020research-articleACS PublicationsRequest reuse...

The photodissociation dynamics of the acetone S2 (n, 3s) Rydberg state excited at 195 nm has been studied by using femtosecond pump-probe mass-selected multiphoton ionization spectroscopy. For first time, temporal evolutions initial state, intermediates, and methyl products were simultaneously measured analyzed for this reaction to elucidate complex dynamics. Two mechanisms considered: (1) commonly accepted mechanism in which primary dissociation occurs on triplet-state surface, (2) recently...