363 research outputs found
Double beta decay of : the deformed limit
The double beta decay of to the ground state and excited states of
is analysed in the context of the pseudo SU(3) scheme. The results
of this deformed limit are compared with the vibrational one based on the QRPA
formalism. Consistency between the deformed limit and the experimental
information is found for various transitions, although, in this
approximation some energies and B(E2) intensities cannot reproduced.Comment: 16 pages, revtex, no figures. Submmitted to Phys. Rev.
Relaxation and derelaxation of pure and hydrogenated amorphous silicon during thermal annealing experiments
The structural relaxation of pure amorphous silicon (a-Si) and hydrogenated
amorphous silicon (a-Si:H) materials, that occurs during thermal annealing
experiments, has been analysed by Raman spectroscopy and differential scanning
calorimetry. Unlike a-Si, the heat evolved from a-Si:H cannot be explained by
relaxation of the Si-Si network strain, but it reveals a derelaxation of the
bond angle strain. Since the state of relaxation after annealing is very
similar for pure and hydrogenated materials, our results give strong
experimental support to the predicted configurational gap between a-Si and
crystalline silicon.Comment: 15 pages, 3 figures, 1 table to be published in Applied Physics
Letter
Sentinel lymph node biopsy and axillary reverse mapping: a tailoring axillary staging in breast cancer
peer reviewedThe status of the axillary lymph nodes is one of the most important prognostic factors in women with early stage breast cancer. Histologic examination of removed lymph nodes is the most accurate method for assessing spread of disease to these nodes. Axillary lymph node dissection (ALND) remains the standard approach for women who have clinically palpable axillary nodes. The benefits of ALND include its impact on disease control (axillary recurrence and survival), its prognostic value, and its role in treatment selection. However, the anatomic disruption caused by ALND may result in lymphedema, nerve injury, and shoulder dysfunction, which compromise functionality and quality of life. For patients who have clinically negative axillary lymph nodes, sentinel lymph node (SLN) biopsy offers a less morbid method to determine if there are positive nodes, in which case axillary node dissection would be necessary. Patients who are SLN-positive should undergo complete ALND. Axillary reverse mapping (ARM) is a recent improvement of ALND which, like the biopsy of the GS, would reduce morbidity
The configurational energy gap between amorphous and crystalline silicon
The crystallization enthalpy of pure amorphous silicon (a-Si) and hydrogenated a-Si was measured by differential scanning calorimetry (DSC) for a large set of materials deposited from the vapour phase by different techniques. Although the values cover a wide range (200-480 J/g), the minimum value is common to all the deposition techniques used and close to the predicted minimum strain energy of relaxed a-Si (240 ± 25 J/g). This result gives a reliable value for the configurational energy gap between a-Si and crystalline silicon. An excess of enthalpy above this minimum value can be ascribed to coordination defects
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