3,530 research outputs found
Circuit breaker utilizing magnetic latching relays Patent
Relay circuit breaker with magnetic latching to provide conductive and nonconductive paths for current device
Advanced head and neck cancer: Long-term results of chemo-radiotherapy, complications and induction of second malignancies
Background: Chemo-radiotherapy is superior to radiotherapy alone in the treatment of advanced, inoperable head and neck cancer. The long-term treatment results, the induction of second malignant tumors, and other long-term toxicities are not well defined. Patients and Methods: 100 consecutive patients with advanced head and neck cancer who were treated at our center were studied. Treatment results, survival, the occurrence of late complications, and second malignant tumors (SMT) were investigated. 78 patients were treated with a protocol combining cisplatinum, 5-fluorouracil, folinic acid and hyper-fractionated irradiation. 22 patients were treated with other chemo-radiotherapy protocols. The relative risk of developing an SMT was compared with that within the normal population. Results: The cumulative total probability of survival was 51.1% at 2 years and 38.7% at 4 years. The probability of relapse-free survival was 39.9% at 2 years and 36.7% at 4 years. A total of 7 patients developed SMT (4 cases of lung cancer, 2 colon cancers, 1 skin cancer). After 6 years, a cumulative risk of SMT of 8.7% was observed. The relative risk of developing an SMT was significantly increased (4.45-fold in males) compared with a normal population. 13 of 38 evaluable patients (34.2%) had severe late complications like fibrosis of soft tissues, nerve lesions, or were dependent on tracheal cannulas. Conclusions: The treatment results and long-term prognoses in our population of unselected high-risk patients are unsatisfactory, but comparable to those from multicenter studies. About 35% of patients become long-term (> 4 years) survivors. SMT generally occur early, have a poor prognosis and, most likely, are not treatment-related. Approximately 30% of long-term survivors have severe, often incapacitating late effects. The treatment and - if possible - prevention of these late effects is important for the quality of life of patients who survived advanced head and neck cancer
Spontaneous bleeding in a patient with malignant lymphoma: A case of acquired hemophilia
Background: Acquired hemophilia is a rare condition which can be associated with lymphoproliferative disease. Case Report: Eleven yea rs after the diagnosis of immunocytoma had been made, a 72-year-old man developed a high-titer factor VIII inhibitor. At this time, the lymphoma was without significant progress and there was no paraprotein in the serum. Partial thromboplastin time (PTT) was 83 a, factor-VIII clotting activity was <1%, and inhibitor level was 50.4 Bethesda units. The patient presented with spontaneous hematomas in the skin and musculature of the extremities. Following combination chemotherapy with cyclophosphamide, vincristine and prednisolone (COP), there was a prompt disappearance of the inhibitor and normalization of coagulation; however, the patient developed serious infectious complications. When the inhibitor recurred he was treated with low-dose cyclophosphamide and prednisolone. This time there was a more delayed response, but the inhibitor disappeared again completely. Two months after cessation of therapy, there was again relapse. Conclusion: Causal relationship between lymphoma and acquired hemophilia remains speculative. At least in some cases of factor VIII inhibitors associated with malignant disease, immunosuppressive therapy may be sufficient to suppress the inhibitor
Coulomb Charging at Large Conduction
We discuss the suppression of Coulomb charging effects on a small metallic
island coupled to an electrode by a tunnel junction. At high temperatures the
quantum corrections to the classical charging energy , where is
the island capacitance, are evaluated. At low temperatures the large quantum
fluctuations of the island charge cause a strong reduction of the effective
which is determined explicitly in the limit of a large tunneling
conductance.Comment: 4 page
Energy spectrum and broken spin-surface locking in topological insulator quantum dots
We consider the energy spectrum and the spin-parity structure of the
eigenstates for a quantum dot made of a strong topological insulator. Using the
effective low-energy theory in a finite-length cylinder geometry, numerical
calculations show that even at the lowest energy scales, the spin direction in
a topologically protected surface mode is not locked to the surface. We find
"zero-momentum" modes, and subgap states localized near the "caps" of the dot.
Both the energy spectrum and the spin texture of the eigenstates are basically
reproduced from an analytical surface Dirac fermion description. Our results
are compared to microscopic calculations using a tight-binding model for a
strong topological insulator in a finite-length nanowire geometry.Comment: 11 pages, 12 figures, to appear in Physical Review B (2011
Collisions of Slow Highly Charged Ions with Surfaces
Progress in the study of collisions of multiply charged ions with surfaces is
reviewed with the help of a few recent examples. They range from fundamental
quasi-one electron processes to highly complex ablation and material
modification processes. Open questions and possible future directions will be
discussed.Comment: 13 pages, 16 figures, review pape
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