Stopping of relativistic ions in multicomponent plasmas

Investigation of the processes of stopping of charged particles moving in different media is of significant interest for many realms of Physics, such that Nuclear Physics, Condensed Matter Physics, Plasma Physics, etc. The problem of evaluation of energy losses of relativistic protons has acquired special importance recently [1] and, due to the experimental conditions, it is necessary to estimate relativistic corrections to the asymptotic form of energy losses in non-ideal multicomponent plasmas..

Stopping of relativistic ions in multicomponent plasmas

Investigation of the processes of stopping of charged particles moving in different media is of significant interest for many realms of Physics, such that Nuclear Physics, Condensed Matter Physics, Plasma Physics, etc. The problem of evaluation of energy losses of relativistic protons has acquired special importance recently [1] and, due to the experimental conditions, it is necessary to estimate relativistic corrections to the asymptotic form of energy losses in non-ideal multicomponent plasmas..

The stopping power and straggling of strongly coupled electron fluids revisited

Measuring energy losses of beams of charged particles is an important diagnostic tool in both modern condensed matter and plasma physics..

Random to chaotic temperature transition in low-field Fano-Feshbach resonances of cold thulium atoms

Here, we report on the observation of a random to chaotic temperature transition in the spacing of Fano-Feshbach resonances in the ultracold polarized gas of thulium atoms. This transition is due to the appearance of so-called d-resonances, which are not accessible at low temperatures, in the spectra at high temperatures, which drastically changes thulium's overall resonance statistic. In addition to this statistical change, it has been observed that s- and d-resonances experience quite different temperature shifts: s-resonances experience almost no shift with the temperature, while d-resonances experience an obvious positive shift. In addition, careful analysis of the broad Fano-Feshbach resonances enabled the determination of the sign of thulium's background scattering length. A rethermalization experiment made it possible to estimate a length value of a=144+-38a.u.. This proves that thulium atoms are suitable for achieving Bose-Einstein Condensation

Collective and static properties of model two-component plasmas

Classical MD data on the charge-charge dynamic structure factor of two-component plasmas (TCP) modeled in Phys. Rev. A 23, 2041 (1981) are analyzed using the sum rules and other exact relations. The convergent power moments of the imaginary part of the model system dielectric function are expressed in terms of its partial static structure factors, which are computed by the method of hypernetted chains using the Deutsch effective potential. High-frequency asymptotic behavior of the dielectric function is specified to include the effects of inverse bremsstrahlung. The agreement with the MD data is improved, and important statistical characteristics of the model TCP, such as the probability to find both electron and ion at one point, are determined.Comment: 25 pages, 6 figures, 5 tables. Published in Physical Review E http://link.aps.org/abstract/PRE/v76/e02640

Assembly of Protein Building Blocks Using a Short Synthetic Peptide

Combining proteins or their defined domains offers new enhanced functions. Conventionally, two proteins are either fused into a single polypeptide chain by recombinant means or chemically cross-linked. However, these strategies can have drawbacks such as poor expression (recombinant fusions) or aggregation and inactivation (chemical cross-linking), especially in the case of large multifunctional proteins. We developed a new linking method which allows site-oriented, noncovalent, yet irreversible stapling of modified proteins at neutral pH and ambient temperature. This method is based on two distinct polypeptide linkers which self-assemble in the presence of a specific peptide staple allowing on-demand and irreversible combination of protein domains. Here we show that linkers can either be expressed or be chemically conjugated to proteins of interest, depending on the source of the proteins. We also show that the peptide staple can be shortened to 24 amino acids still permitting an irreversible combination of functional proteins. The versatility of this modular technique is demonstrated by stapling a variety of proteins either in solution or to surfaces