Recurrent aggressive chondrosarcoma of the middle phalanx of the index finger: excision and reconstruction with an osteocartilaginous allograft

Introduction: Chondrosarcomas are malignant tumours and need to be treated aggressively including ablative surgery. Bovée et al. and Mankin have recently drawn attention to a less aggressive behaviour of chondrosarcomas of the phalanges compared with those of other localizations including the metacarpals. Materials and methods: An 12year follow-up of a patient with a chondrosarcoma of the middle phalanx of the index finger is presented. The lesion was curetted initially, and a repeat curettage was performed 4years later. Finally, 8years later the phalanx was excised and reconstructed with an osteocartilaginous allograft. Histologically, the lesion changed from a chondrosarcoma grade I to grade II. Result: The patient continues to be free of recurrence and metastases 4years after the final resection. Conclusion: The potential for systemic disease of chondrosarcomas of the phalanges is probably much lower than in chondrosarcomas of other localizations, and therefore digit-sparing techniques may be considered rather than ablative procedure

Coulomb blockade and transport in a chain of one-dimensional quantum dots

A long one-dimensional wire with a finite density of strong random impurities is modelled as a chain of weakly coupled quantum dots. At low temperature T and applied voltage V its resistance is limited by "breaks": randomly occuring clusters of quantum dots with a special length distribution pattern that inhibits the transport. Due to the interplay of interaction and disorder effects the resistance can exhibit T and V dependences that can be approximated by power laws. The corresponding two exponents differ greatly from each other and depend not only on the intrinsic electronic parameters but also on the impurity distribution statistics.Comment: 4 pages, 1 figure. Changes from v2: Dropped discussion of the high-field regime. Added discussion of mesoscopic fluctuations and multiple channels in the quasi-1D case. Improved presentation styl

Two-dimensional electron gas formation in undoped In[0.75]Ga[0.25]As/In[0.75]Al[0.25]As quantum wells

We report on the achievement of a two-dimensional electron gas in completely undoped In[0.75]Al[0.25]As/In[0.75]Ga[0.25]As metamorphic quantum wells. Using these structures we were able to reduce the carrier density, with respect to reported values in similar modulation-doped structures. We found experimentally that the electronic charge in the quantum well is likely due to a deep-level donor state in the In[0.75]Al[0.25]As barrier band gap, whose energy lies within the In[0.75]Ga[0.25]As/In[0.75]Al[0.25]As conduction band discontinuity. This result is further confirmed through a Poisson-Schroedinger simulation of the two-dimensional electron gas structure.Comment: 17 pages, 6 figures, to be published in J. Vac. Sci. Technol.

The AMS-RICH velocity and charge reconstruction

The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.Comment: Contribution to the ICRC07, Merida, Mexico (2007); Presenter: F. Bara

Quantum creep and variable range hopping of one-dimensional interacting electrons

The variable range hopping results for noninteracting electrons of Mott and Shklovskii are generalized to 1D disordered charge density waves and Luttinger liquids using an instanton approach. Following a recent paper by Nattermann, Giamarchi and Le Doussal [Phys. Rev. Lett. {\bf 91}, 56603 (2003)] we calculate the quantum creep of charges at zero temperature and the linear conductivity at finite temperatures for these systems. The hopping conductivity for the short range interacting electrons acquires the same form as for noninteracting particles if the one-particle density of states is replaced by the compressibility. In the present paper we extend the calculation to dissipative systems and give a discussion of the physics after the particles materialize behind the tunneling barrier. It turns out that dissipation is crucial for tunneling to happen. Contrary to pure systems the new metastable state does not propagate through the system but is restricted to a region of the size of the tunneling region. This corresponds to the hopping of an integer number of charges over a finite distance. A global current results only if tunneling events fill the whole sample. We argue that rare events of extra low tunneling probability are not relevant for realistic systems of finite length. Finally we show that an additional Coulomb interaction only leads to small logarithmic corrections.Comment: 15 pages, 3 figures; references adde

Dynamic Fluctuation Phenomena in Double Membrane Films

Dynamics of double membrane films is investigated in the long-wavelength limit including the overdamped squeezing mode. We demonstrate that thermal fluctuations essentially modify the character of the mode due to its nonlinear coupling to the transversal shear hydrodynamic mode. The corresponding Green function acquires as a function of the frequency a cut along the imaginary semi-axis. Fluctuations lead to increasing the attenuation of the squeezing mode it becomes larger than the `bare' value.Comment: 7 pages, Revte

The RICH detector of the AMS-02 experiment: status and physics prospects

The Alpha Magnetic Spectrometer (AMS), whose final version AMS-02 is to be installed on the International Space Station (ISS) for at least 3 years, is a detector designed to measure charged cosmic ray spectra with energies up to the TeV region and with high energy photon detection capability up to a few hundred GeV. It is equipped with several subsystems, one of which is a proximity focusing RICH detector with a dual radiator (aerogel+NaF) that provides reliable measurements for particle velocity and charge. The assembly and testing of the AMS RICH is currently being finished and the full AMS detector is expected to be ready by the end of 2008. The RICH detector of AMS-02 is presented. Physics prospects are briefly discussed.Comment: 5 pages. Contribution to the 10th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications (Como 2007). Presenter: Rui Pereir

Экстрафасциальная гемитиреоидэктомия

The aim of the study was to improve surgical results of patients having thyroid gland pathology by the development of the surgery method directed to increasing possibility of injury and maintenance of the upper laryngeal nerve integrity. Method of performing extrafascial hemithyreoidectomy with visualization of recurrent nerve, parathyroid gland and upper thyroid artery is presented which is directed to decrease specific complications (vocal fold paresis, hypoparathyreosis) and complications associated with the upper laryngeal nerve injury. Using this method, 166 patients having node pathology of thyroid gland were operated on. This method resulted in decreased number of complications (from 15,0 to 2,6%).Цель исследования - улучшение результатов оперативного лечения больных с патологией щитовидной железы путем разработки методики оперативного вмешательства, направленной на снижение вероятности повреждения и сохранение целостности верхнего гортанного нерва. Предложена методика выполнения экстрафасциальной гемитиреоидэктомии с визуализацией возвратного нерва, паращитовидных желез и верхней щитовидной артерии, способствующая снижению специфических осложнений - пареза голосовых складок, гипопаратиреоза и осложнений, связанных с травмой верхнего гортанного нерва. По данной методике прооперировано 116 пациентов с узловой патологией щитовидной железы. Благодаря применению данной методики удалось снизить количество осложнений с 15,0 до 2,6%

Отдаленные результаты оперативного лечения узлового зоба

Long-term results of surgical treatment of 649 patients with different morphological forms of nodular goiter in terms of 15 to 3 years are analyzed. Postsurgical recurrent goiter was diagnosed in 26.8% (174 people). The most part of relapses falls on operations characterized by the large part of TG tissue rest (resection of TG lobe and node enucleation): 69.1% (139 patients of 201). No one relapse was diagnosed after thyreoidectomy. After extremely subtotal resection, relapses were observed in 2.2% (7 people of 312) and after hemithyroidectomy in 20.6% (26 people of 136). This study indicates inadequacy of operations such as node enucleation and resection of the lobe with a node, especially, if the node belongs to nodular colloid goiter, because in such operations the pathologically changed TG tissue is often rest and there is high probability of relapse.Прослежены отдаленные результаты оперативного лечения 649 пациентов с различными морфологическими формами узлового зоба в сроки от 3 до 15 лет. Послеоперационный рецидив узлового зоба был диагностирован у 174 (26,8%) больных. Большая часть рецидивов приходится на оперативные вмешательства, характеризующиеся оставлением большей части ткани щитовидной железы, - резекции доли и энуклеации узлов - 69,1% (139 пациентов из 201). Минимальное число рецидивов возникло после операций, характеризующихся максимальным удалением ткани щитовидной железы: предельно-субтотальную резекцию - 2,2%, тиреоидэктомию - 0%. Данное исследование указывает на неадекватность проведения таких операций, как энуклеация узла и резекция доли с узлом, особенно при принадлежности узла к узловому коллоидному зобу, поскольку сопряжена с оставлением патологически измененной ткани железы и большой вероятностью возникновения рецидива заболевания