Nuclear recent progress

Kliewer, S.A., Lehmann, J.M., Milburn, M.V. and Willson, T.M. (1999) The PPARs and PXRs nuclear xenobiotic receptors that define novel hormone signaling pathways. Recent Progress in Hormone Research, 54, 345-367. 

Nuclear magnetic resonance (NMR) has proved to be a very useful tool for structural elucidation of natural products. Recent progress in the development of two-dimensional 1H- and 13C-NMR techniques has contributed to the unambiguously assignment of proton and carbon chemical shifts, in particular in complex molecules. The more used techniques include direct correlations through homonuclear (COSY, TOCSY, ROESY, NOESY) [62-65] and heteronuclear (HMQC, HMBC) [66. 67] couplings. 

It is my pleasure to introduce Volume 73 of Annual Reports on NMR. In common with previous volumes, it contains reports from a few of the many areas of NMR active research. The first contribution is by T. W. T. Tsai and J. C. C. Chan on Recent Progress in the Solid-State NMR Studies of Biomineralization the topic Recent Advances in the NMR Spectroscopy of Chlorine, Bromine and Iodine is covered by B. J. Butler, J. M. Hook and J. B. Harper M. D. Lingwood and S. Han report on Solution-State Dynamic Nuclear Polarization the topic of Solid-State NMR of Membrane Proteins Moving Towards Greater Complexity is covered by L. K. Thompson Chromatographic NMR is the topic chosen by S. Caldarelli the final contribution on Kinetic Monte Carlo Simulation of DNMR Spectra is by Z. Szalay and J. Rohonczy. My grateful thanks are due to all of these reporters for their interesting and timely contributions. 

Recent progress in laser technology has led to the widespread use of ultrafast lasers with pulse widths shorter than the vibrational periods of most chemical bonds. A localized state, called a nuclear wave packet, is created on a potential surface by exciting a molecule with ultrashort pulses of radiation. The time-evolution of such wave packets can be directly utilized to observe the transition states of chemical reactions. This development is one of the major accomplishments of femtosecond chemistry. 

From its very beginning nuclear magnetic resonance (NMR) was used to unravel dynamic processes in amorphous matter, where the high selectivity of this technique was exploited. Recent progress has largely benefited from the development of multidimensional NMR spectroscopy, significantly extending the traditional techniques such as spin-lattice relaxation and line-shape analyses. Modern NMR techniques helped a lot to understand the molecular dynamics in disordered systems such as the a-process. 

J. Davidovits, Recent progress in concretes for nuclear waste and uranium waste containment, J. Concr. Int., 16 [12] (1994) 53-58. 

Recent Progress in Nuclear Receptor Drug Discovery 9... 

Recent developments in Mossbauer spectroscopy may also lead to interesting high-pressure applications. Many years ago it was proposed that the special properties of synchrotron radiation could be used to provide nuclear excitation without the use of radioactive sources, and recently progress with modern synchrotron-radiation sources could mean that such experiments could be feasible for Fe. Due to the natural high collimation of the most favourable undulator radiation from synchrotron insertion devices, one can expect that high-pressure measurements will be one of the first applications of this technique, which will eventually be applied to isotopes for which no suitable radioactive sources exist. " ... 

In the case of small molecules, attempts have been made to calculate the force constants by quantum mechanical methods. The principle of the method is to express the total electronic energy of a molecule as a function of nuclear displacements near the equilibrium position and to calculate its second derivatives, d V/0 , and so on for each displacement coordinate qt. In the past, ab initio calculations of force constants were made for small molecules such as HF, H2O, and NH3. The force constants thus obtained are in good agreement with those calculated from the analysis of vibrational spectra. More recent progress in computer technology has made it possible to extend this approach to more complex molecules (Sec. 1.24). 

This paper briefly reviews the recent progress in design and R D status of SiC/SiC composites for fusion reactor applications in the initial section. It also overviews the remaining critical issues related to nuclear applications of SiC/SiC composites, such as transmutation gases, thermal properties, Pb-17Li compatibility, hermeticity, joining techniques and protective coatings. Finally, emphases of future work on SiC/SiC composites for fusion applications are prospected. 

M. This partition was originally proposed by Sakurai s group and exploited in a semiempirical version of PCM [28]. We have adapted it to make more effective the calculation of ab initio analytical derivatives of G with respect to nuclear coordinates [29, 30, 31], a subject on which there are recent progresses from our group. 

Volume 83 of Annual Reports on NMR Spectroscopy commences with an interesting account of Dynamic Pictures of Proteins by NMR from H. Saito this is followed by a report on Recent Progress in the Solid-State NMR Studies of Short Peptides—Techniques, Structure and Dynamics by A. Jezioma, S. Kazmierski, P. Paluch, E. Skorupska and M. J. Potrzebowski an account of Solid-State NMR Studies of Biomolecules is presented by A. Wong and F. PoU G. A. Monti, A. K. Chattah and Y. G. Linck report on Solid-State Nuclear Magnetic Resonance in Pharmaceutical Compounds the final report by M. Jaeger andR. L. E. G. Aspers is on Covariance NMR and Small-Molecule Applications . 

Abstract This chapter reviews the historical perspective of transuranium elements and the recent progress in the production and study of nuclear properties of transuranium nuclei. Exotic decay properties of heavy nuclei are also introduced. Chemical properties of transuranium elements in aqueous and solid states are summarized based on the actinide concept. For new application of studying transuranium elements, an X-ray absorption fine structure (XAFS) method and computational chemistry are surveyed. 

In the following, exotic nuclear decay modes of heavy nuclei, cluster radioactivities, delayed fission, and spontaneous fission (SF) together with the recent progress on deformation paths toward fission are briefly introduced. 

Abstract The use of synchrotron radiation has opened up new areas in nuclear resonant scattering studies. It has permitted measurements that are difficult with conventional radioactive sources, such as the measurement of element-specific dynamics. Recent progress in studies using nuclear resonant scattering of synchrotron radiation is reviewed in this chapter. 

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