Experimental observation of the hot electron equilibrium in a minimum-B mirror plasma

(12.06. – 18.06.2017

Prospective Registry Trial Assessing the Use of Magnetic Seeds to Locate Clipped Nodes After Neoadjuvant Chemotherapy for Breast Cancer Patients

Background Targeted axillary dissection (TAD) involves locating and removing both clipped nodes and sentinel nodes for assessment of the axillary response to neoadjuvant chemotherapy (NAC) by clinically node-positive breast cancer patients. Initial reports described radioactive seeds used for localization, which makes the technique difficult to implement in some settings. This trial was performed to determine whether magnetic seeds can be used to locate clipped axillary lymph nodes for removal. Methods This prospective registry trial enrolled patients who had biopsy-proven node-positive disease with a clip placed in the node and treatment with NAC. A magnetic seed was placed under ultrasound guidance in the clipped node after NAC. All the patients underwent TAD. Results Magnetic seeds were placed in 50 patients by 17 breast radiologists. All the patients had successful seed placement at the first attempt (mean time for localization was 6.1 min; range 1-30 min). The final position of the magnetic seed was within the node (n = 44, 88%), in the cortex (n = 3, 6%), less than 3 mm from the node (n = 2, 4%), or by the clip when the node could not be adequately visualized (n = 1, 2%). The magnetic seed was retrieved at surgery from all the patients. In 49 (98%) of the 50 cases, the clip and magnetic seed were retrieved from the same node. Surgeons rated the transcutaneous and intraoperative localization as easy for 43 (86%) of the 50 cases. No device-related adverse events occurred. Conclusions Localization and selective removal of clipped nodes can be accomplished safely and effectively using magnetic seeds

Nuclear Alpha-Particle Condensates

The $\alpha$-particle condensate in nuclei is a novel state described by a product state of $\alpha$'s, all with their c.o.m. in the lowest 0S orbit. We demonstrate that a typical $\alpha$-particle condensate is the Hoyle state ($E_{x}=7.65$ MeV, $0^+_2$ state in $^{12}$C), which plays a crucial role for the synthesis of $^{12}$C in the universe. The influence of antisymmentrization in the Hoyle state on the bosonic character of the $\alpha$ particle is discussed in detail. It is shown to be weak. The bosonic aspects in the Hoyle state, therefore, are predominant. It is conjectured that $\alpha$-particle condensate states also exist in heavier $n\alpha$ nuclei, like $^{16}$O, $^{20}$Ne, etc. For instance the $0^+_6$ state of $^{16}$O at $E_{x}=15.1$ MeV is identified from a theoretical analysis as being a strong candidate of a $4\alpha$ condensate. The calculated small width (34 keV) of $0^+_6$, consistent with data, lends credit to the existence of heavier Hoyle-analogue states. In non-self-conjugated nuclei such as $^{11}$B and $^{13}$C, we discuss candidates for the product states of clusters, composed of $\alpha$'s, triton's, and neutrons etc. The relationship of $\alpha$-particle condensation in finite nuclei to quartetting in symmetric nuclear matter is investigated with the help of an in-medium modified four-nucleon equation. A nonlinear order parameter equation for quartet condensation is derived and solved for $\alpha$ particle condensation in infinite nuclear matter. The strong qualitative difference with the pairing case is pointed out.Comment: 71 pages, 41 figures, review article, to be published in "Cluster in Nuclei (Lecture Notes in Physics) - Vol.2 -", ed. by C. Beck, (Springer-Verlag, Berlin, 2011

Comparison of soft and hard tissue ablation with sub-ps and ns pulse lasers

Tissue ablation with ultrashort laser pulses offers several unique advantages. The nonlinear energy deposition is insensitive to tissue type, allowing this tool to be used for soft and hard tissue ablation. The localized energy deposition lead to precise ablation depth and minimal collateral damage. This paper reports on efforts to study and demonstrate tissue ablation using an ultrashort pulse laser. Ablation efficiency and extent of collateral damage for 0.3 ps and 1000 ps duration laser pulses are compared. Temperature measurements of the rear surface of a tooth section is also presented

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters