A series of naphthalenyl-substituted arenediynes were prepared to examine photochemical reactivity. For naphthalen-1-ylethynyl arenediyne, 350 nm photolysis resulted in a tandem [2 + 2] photocycloaddition to afford cyclobutene adducts. For naphthalen-2-ylethynyl derivatives, electron-donating methoxy substituents were found to facilitate C(1)-C(6) Bergman cyclization at 300 nm. Theoretical calc...

introduction: the aim of this experimental laboratory study was to evaluate the effect of different mixing and placement techniques on compressive strength (cs) of calcium-enriched mixture (cem) cement. methods and materials: cem powder was mixed with its liquid either by hand mixing or amalgamator mixing. the mixture was loaded to cylindrical acrylic molds with 6.0±0.1 mm height and 4.0±1 mm d...

INTRODUCTION Effective irrigant delivery and agitation are prerequisites for successful endodontic treatment. Ultrasonic irrigation can be performed with or without simultaneous ultrasonic instrumentation. Existing literature reveals that ultrasonic irrigation may have a very positive effect on chemical, biological and physical debridement of the root canal system as investigated in many in vit...

1. The determination of the influence of temperature on the velocity of a photochemical reaction is always of importance. This is particularly true when the mechanism of the reaction is unknown, as in the present instance of the bleaching of visual purple. The usefulness of determining the temperature coefficient lles in this. Photochemical reactions have low temperature coefficients.near unity...

1. The determination of the influence of temperature on the velocity of a photochemical reaction is always of importance. This is particularly true when the mechanism of the reaction is unknown, as in the present instance of the bleaching of visual purple. The usefulness of determining the temperature coefficient lles in this. Photochemical reactions have low temperature coefficients.near unity...

A general concept for parallel near-field photochemical and radiation-induced chemical processes for the fabrication of nanopatterns of a self-assembled monolayer (SAM) of (3-aminopropyl)triethoxysilane (APTES) is explored with three different processes: 1) a near-field photochemical process by photochemical bleaching of a monomolecular layer of dye molecules chemically bound to an APTES SAM, 2...

We investigated changes in photochemical activity and cold hardiness of detached needles of three clones of Picea abies (L.) Karst. by measuring variable chlorophyll fluorescence (F(v)/F(m)), before and after artificial freezing, from September to June. Photochemical activity varied considerably during the study, but only minor differences in photochemical activity among the clones were observe...