The Nobel Prize in Chemistry for 2002 is to be shared between scientists working on two very important methods of chemical analysis applied to biological macromolecules: mass spectrometry (MS) and nuclear magnetic resonance (NMR). Laureates John B. Fenn, Koichi Tanaka (MS) and Kurt Wüthrich (NMR) have pioneered the successful application of their techniques to biological macromolecules. Biologi...

We calculate the shape of the ππ and ¯ K N invariant mass distributions in the b → J/ψ π and b → J/ψ ¯ K N decays that are dominated by the (1405) resonance. The weak interaction part is the same for both processes and the hadronization into the different meson–baryon channels in the final state is given by symmetry arguments. The most important feature is the implementation of the meson–baryon...

Two of the key spectroscopic techniques used to accomplish this task are mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (NMR). These methods provide a wealth of complementary structural information. Mass spectrometry is used to determine the molecular formula for a given compound and can provide structural information through MSn analysis. Nuclear magnetic resonance spectros...

In this article, by using Moser's twist theorem, we prove that all solutions of the equation $x'' + ax^{+} - bx^{-} \varphi(x) = p(t)$ are bounded in critical situation, where $p$ is a smooth periodic function, and $\varphi$ one.