This paper presents a study of the reaction of thin film niobium/selenium multilayers as a function of layer thickness. Diffraction and calorimetry data show a distinct difference in reactions between films with layer thicknesses above and below 60 A. The thicker films are shown to nucleate NbsSe4 heterogeneously at the niobium-selenium interfaces. Thinner films form kinetically stable amorphou...

Peptide bond formation on the ribosome takes place in an active site composed of RNA. Recent progress of structural, biochemical, and computational approaches has provided a fairly detailed picture of the catalytic mechanism of the reaction. The ribosome accelerates peptide bond formation by lowering the activation entropy of the reaction due to positioning the two substrates, ordering water in...

IT is clear that, for the determination of enzymic reaction-velocity under readily definable conditions, the states near the initiation of the reaction are decidedly the best. Usually however this part of the progress has been left unexplored and delineation of it has been based merely upon empirical expressions of doubtful value. In the present paper data have been directly collected within a ...

Asymmetric ring-opening of 3-substituted oxetanes provides rapid access to highly functionalized chiral building blocks. However, progress in this field is limited. Recently we developed a new catalytic system based on chiral Brønsted acids for this type of reaction and demonstrated the synthesis of a range of useful molecules under mild and operationally simple conditions. In this perspective,...

Chloroplast structure and function is known to alter during foliar senescence. Besides, the alterations in the structural organisation of thylakoid membranes changes in the steady state levels of thylakoid membrane proteins occur due to leaf ageing. We monitored temporal changes in some of the specific proteins of thylakoid membrane protein complexes by western blotting in the Cucumis sativus c...

Erythema ab igne (EAI) is a cutaneous reaction in response to prolonged exposure infrared heat sources at temperatures insufficient induce burn. Although considered chronic pigmentary disorder, EAI rarely can progress malignant transformation, including squamous cell carcinoma.

This perspective discusses progress in the theory of bimolecular reaction dynamics in the gas phase. The examples selected show that definitive quantum dynamical computations are providing insights into the detailed mechanisms of chemical reactions.

A molecular gate attached on the pore outlet of a mesoporous material, which is opened and closed by redox system of thiol groups, effectively switched the progress of a catalytic reaction promoted by the acidic site in the pore void.

introduction: despite wide use of hyoscine by midwives and doctors as an adjunct to labor, the obstetrics literature contains few references to the effect of this drug. this study was a double blinded, randomized controlled trial of primigravidas in iran to determine the effects of hyoscine intravenous injection on parturition (labor). methods:one hundred primigravidas in uncomplicated spontane...