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ABSTRACT: We propose a new way to temperature compensate solidly mounted bulk acoustic wave resonators (SMRs). With the proposed process high Q, high electromechanical coupling coefficient, fully temperature compensated resonators have been successfully fabricated with TCF less than 1 ppm/°C and total thermal drift of less than 35 ppm across the temperature range from 0-100°C.
Electron Devices Meeting (IEDM), 2009 IEEE International; 01/2010
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ABSTRACT: After optimizing for electromechanical coupling coefficient K(2), the main performance improvement in the thin film bulk acoustic wave resonators and filters can be achieved by improving the Q value, i.e., minimizing the losses. In Bragg-reflector-based solidly mounted resonator technology, a significant improvement of Q has been achieved by optimizing the reflector not only for longitudinal wave, the intended operation mode, but also for shear waves. We have investigated the remaining acoustic radiation losses to the substrate in so-optimized 1850-MHz AlN resonators by removing the substrate underneath the resonators and comparing the devices with and without substrate by electrical characterization before and after the substrate removal. Several methods to extract Q-values of the resonators are compared. Changes caused by substrate removal are observed in resonator behavior, but no significant improvement in Q-values can be confirmed. Loss mechanisms other than substrate leakage are concluded to dominate the resonator Q-value. Difficulties of detecting small changes in the Q-values of the resonators are also discussed.
IEEE transactions on ultrasonics, ferroelectrics, and frequency control 11/2009; 56(11):2544-52. · 1.80 Impact Factor
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K J Aichberger,
S Herndlhofer,
H Agis,
W R Sperr,
H Esterbauer,
W Rabitsch,
P Knöbl,
O A Haas, R Thalhammer,
I Schwarzinger,
C Sillaber,
U Jäger,
P Valent
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ABSTRACT: Central nervous system (CNS) relapse in chronic myeloid leukaemia (CML) is rare and if recorded is usually found to occur in patients with lymphoblastic transformation. The BCR/ABL tyrosine kinase inhibitor imatinib is highly effective in patients with CML, but hardly crosses the blood-brain barrier.
We report on two CML patients who developed a myeloid CNS relapse during treatment with imatinib. One patient was in major cytogenetic response at the time of CNS relapse. In both cases, the myeloid origin of neoplastic cells in the cerebrospinal fluid (CSF) was demonstrable by immunophenotyping, and their leukaemic origin by detection of the BCR/ABL oncoprotein. No BCR/ABL kinase domain mutations were found. Both patients received intrathecal liposomal cytarabine (50 mg each cycle; 6 cycles). In one patient, additional CNS radiation was performed, whereas in the other, consecutive treatment with dasatinib (70 mg per os twice daily) was started.
In response to therapy, the clinical symptoms resolved, and the leukaemic cells in the CSF disappeared in both cases. After three months of observation, both patients are in complete cytogenetic and major molecular response, without evidence for a systemic or a CNS relapse.
'Anatomic' resistance against imatinib in the CNS can lead to a myeloid CNS relapse. Liposomal cytarabine with or without radiation is effective as local therapy in these patients. For systemic treatment and prophylaxis, BCR/ABL kinase inhibitors crossing the blood-brain barrier such as dasatinib should be considered in patients with CNS relapse.
European Journal of Clinical Investigation 11/2007; 37(10):808-13. · 3.02 Impact Factor
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ABSTRACT: Bulk acoustic wave (BAW) filters owe their performance advantages particularly to the excellent Q-values of the acoustic resonators. As these devices achieve very low impedances in the series resonance condition, the ohmic conductivity of the electrodes is expected to affect the device performance significantly. This paper presents a comprehensive analysis of ohmic effects including a discussion of the associated power dissipation as well as the interaction of ohmic and acoustic effects. The analysis is based on two combined techniques: first, the potential and current distribution on the electrodes and the resulting ohmic power dissipation are derived from surface vibration measured by laser interferometry and an inverse calculation of local charge distribution. The second technique is finite element modeling that has been extended by including ohmic conductivity, thus enabling a consistent electro-acoustic analysis
Microwave Symposium Digest, 2006. IEEE MTT-S International; 07/2006
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Leukemia 12/2005; 19(11):2005-8. · 9.56 Impact Factor
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ABSTRACT: Bulk acoustic wave (BAW) filters owe their performance advantages particularly to the excellent Q-values of the acoustic resonators. Solidly mounted resonator (SMR) type BAW devices achieve Q-values greater than 1500 when acoustic mirror layers with a large impedance ratio and, hence, a high reflectivity are used. Tungsten and silicon oxide are the materials of choice for low loss BAW resonators. This paper describes the loss mechanism still present in low loss BAW resonators and presents comprehensive methods to acquire quantitative data about energy losses. These methods are based on electrical measurements, 1D transmission line models and higher dimensional FEM simulations, and laser interferometer measurements. The lateral currents across the electrodes and the resulting ohmic power dissipation are derived from surface vibration measurements and an inverse calculation of local charge distribution. It is demonstrated that combining these methods allows to detect acoustic leaks and to analyze resistive losses and, thus, the major energy losses in the respective operating conditions can be identified.
Microwave Symposium Digest, 2005 IEEE MTT-S International; 07/2005
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ABSTRACT: Filters based upon bulk-acoustic-wave (BAW) resonators are attractive for a variety of RF applications. To satisfy the ambitious specifications and to facilitate a fast and cost economic design, we present an efficient simulation strategy combining different modeling approaches. First, a 1D transmission line model (Mason model) is used to construct the layer stack to meet the desired resonance frequencies and bandwidth. Second, the system of Newton's equation of motion and Maxwell's equations coupled by the piezoelectric effect is solved by FEM simulations. Thus, the lateral structure, e.g., a specific border region, can be designed to maximize the Q-value and to minimize the excitation of spurious modes. The theoretical predictions are excellently confirmed by electrical measurements and laser interferometry. Typical technological features, such as processing-related non-uniform thicknesses, and their impact on the resonance characteristics are analyzed by numerical simulations.
Ultrasonics Symposium, 2004 IEEE; 09/2004
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IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems 05/2004; · 1.27 Impact Factor
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ABSTRACT: The paper describes a novel quartz crystal sensor for the measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two circular quartz crystal plates with an air-gap in between and the liquid sample in contact with the outer plate surfaces. Plano-convex AT-cut quartz crystals arranged in mirror symmetric crystallographic orientation and vibrating in an even-symmetric thickness-shear fundamental mode at 2.77 MHz are utilized. The two outer plane sides of the crystals are fully covered by gold electrodes, which are both connected to ground potential. This special mirror symmetric set-up allows the compensation of spurious displacements in the circular clamping zones of the two crystals. The measurement values of the sensor are the fundamental resonance frequency f and the associated resonance Q-value, which are analytically dependent on the density-viscosity product of the liquid in contact with the sensing surfaces. In contrast to an earlier report about a sandwich resonator sensor, which entrapped the liquid sample between two quartz plates, the immersible sensor presented here is not restricted to low viscosity samples. The sensor covers a viscosity range from almost zero (air!) up to 2000 Pa.s, and is not restricted to electrically insulating liquids.
Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003 IEEE International; 06/2003
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ABSTRACT: Ex vivo expansion strategies with different cytokine combinations are currently used by several groups as a means of increasing the number of HPCs for a variety of special clinical applications. Because there is little information on the potential role of IL-10 in such ex vivo expansion models, the effect of this cytokine on the generation of myeloid progenitor cells in suspension cultures was investigated.
On the basis of data from the literature and from new experiments, the combination of SCF and IL-3 at concentrations of 100 ng per mL and 100 U per mL, respectively, was chosen as the standard cocktail. The addition of IL-10 to such cultures resulted in a marked and dose-dependent potentiation of myeloid progenitor cell production.
Using unmanipulated leukapheresis components from 13 individuals (including lymphoma and cancer patients and normal donors), the expansion multiple of CFU-GM after 14 days as compared with pre-expansion values was 9.54 +/- 2.31 times by SCF/IL-3 and 46.38 +/- 7.37 times by the combination of SCF/IL-3 and 100 ng per mL of IL-10 (p<0.001). IL-10 also potentiated CFU-GM generation from selected CD34 PBMNCs (n = 9) with an expansion of 17.22 +/- 7.04 times versus 45.67 +/- 16.78 times using the SCF/IL-3 and SCF/IL-3/IL-10 combination, respectively (p<0.05). Moreover, expansion-promoting effects of IL-10 were observed in liquid cultures containing MNCs from bone marrow (n = 4) and cord blood (n = 3), but did not reach statistical significance because of the small number of samples.
These results suggest IL-10 as a useful cytokine to optimize progenitor cell-expansion strategies for clinical application.
Transfusion 05/2001; 41(5):659-66. · 3.22 Impact Factor
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ABSTRACT: The immunophenotypes of 12 acute promyelocytic leukemias (APL-M3; eight hypergranular, four microgranular) with documented PML-RAR-alpha fusion gene are presented. Bone marrow mononuclear cells were immunophenotyped using a panel of 20 monoclonal antibodies. The hypergranular APLs exhibited a mature myeloid phenotype as it has been described to be typical for M3. No lineage infidelity was detectable in classic M3 cases. In contrast, among the four cases of M3 variant, all leukemias showed marked expression of CD34 and two of four cases expressed the HLA-DR antigen. The CD2 antigen was expressed in three of four cases. Furthermore, one case showed expression of the CD56 antigen, and one case was positive for the blood group H antigen. The data suggest that microgranular APL is a heterogeneous entity with regard to the immunologic phenotype.
Cytometry 05/2000; 42(2):106-9.
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ABSTRACT: The carrier distribution in the interior of power devices can be
determined from free carrier absorption measurements. In this work, a
physically rigorous simulation of the entire measurement process is
performed to investigate the effects which arise from the wave
propagation of the probing beam and the sample preparation. Quantitative
results for optimization of the optical set-up and the sample geometries
which minimize the unavoidable experimental errors are presented
Simulation of Semiconductor Processes and Devices, 2000. SISPAD 2000. 2000 International Conference on; 02/2000
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ABSTRACT: Current treatment of patients with myelodysplastic syndrome (MDS) is unsatisfactory. Very recently, immunosuppressive treatment strategies have been gaining interest. We report a patient with transfusion-dependent MDS who achieved significant hematopoietic improvement following cyclosporine (CsA) therapy and who is now transfusion independent for more than 5 years. This single observation supports the view that CsA, among other immunosuppressive agents, could play an important role in future treatment concepts in MDS and may lead to clinically relevant and sustained improvement of hematopoiesis in a subset of patients.
Wiener klinische Wochenschrift 11/1999; 111(19):815-8. · 0.81 Impact Factor
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ABSTRACT: Arsenic trioxide has recently been introduced as a promising new agent to treat refractory acute promyelocytic leukemia (APL). In the present study, arsenic trioxide was given intravenously for 42 days to a 56-year-old female patient suffering from chemotherapy/ATRA-resistant APL, with 43% APL blasts in the bone marrow and elevated D-dimers. During the first days of arsenic trioxide treatment a rapid decrease in the D-dimers was seen (normal values reached until day 7), together with a slight decrease in peripheral blood leukocytes. This initial coagulation response was followed by a second phase of hematological response (starting on days 15-20) characterized by leukocytosis, occurrence of myeloid progenitor cells in the peripheral blood, and a decrease in bone marrow blasts (<1% on days 28 and 36). Finally, the patient entered complete hematological and cytogenetic remission, although the PML-RAR alpha fusion product was still detectable by PCR. These data confirm the therapeutic value of arsenic trioxide in relapsed/resistant APL.
Annals of Hematology 07/1999; 78(7):329-32. · 2.62 Impact Factor
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ABSTRACT: We present a differential backside laser probing technique for the
investigation of lateral temperature variations in power devices. The
method is applied to analyze the temperature evolution in IGBTs operated
under short circuit conditions. The extraction of the temperature from
optical modulation signals is supported by electro-thermal device
simulations, taking into account sample preparation effects
Power Semiconductor Devices and ICs, 1999. ISPSD '99. Proceedings., The 11th International Symposium on; 02/1999
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ABSTRACT: Recently, it has been demonstrated that internal carrier
concentration and temperature profiles in semiconductor devices are
accessible to accurate measurement by various infrared laser probing
techniques (Deboy et al., Microelectronic Eng. vol 31, p. 299, 1996, and
Seliger et al., ibid., vol. 31, p. 87, 1996). This work presents an
additional technique, namely the time-resolved characterization of IGBTs
by backside laser probing. Calibrated numerical device simulation is
employed for investigation of the relevance of effects introduced by the
sample preparation on the interpretation of the measurement
results
Power Semiconductor Devices and ICs, 1998. ISPSD 98. Proceedings of the 10th International Symposium on; 07/1998
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ABSTRACT: The principles of characterization techniques for semiconductor devices based on infrared laser interferometry are reviewed.
Transient optical signals due to plasma-and thermo-optical effects are studied by experiment and numerical modeling, providing
information on carrier concentration and lattice temperature in the device. The applicability of the techniques is demonstrated
on smart power devices, VDMOSFETs, IGBTs and on sub-micron technology MOS- and bipolar transistors.
In dieser Arbeit werden die Grundlagen der Infrarot-Laserinterferometrie beschrieben und deren Anwendung zur Charakterisierung
von Halbleiterbauelementen vorgestellt. Zeitabhängige optische Signale, die durch den plasmaoptischen und thermooptischen
Effekt hervorgerufen werden, geben mit Unterstützung numerischer Modellierung Information über Ladungsträgerdichten und Temperatur
in den Bauelementen. Die Anwendbarkeit der Technik wird beispielhaft an VDMOSFETs, IGBTs, Smart Power-Bauelementen und an
submicron MOS- und Bipolartransistoren demonstriert.
e & i Elektrotechnik und Informationstechnik 04/1998; 115(7):403-410.
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ABSTRACT: This paper describes a novel quartz crystal sensor for measurement of the density-viscosity product of Newtonian liquids. The sensor element consists of two piano-convex AT-cut quartz crystals vibrating in a thickness-shear mode with the liquid sample in between. This special set-up allows suppression of disturbing resonances in the liquid layer. Such resonances are generated in the common single-plate arrangements due to compressional waves caused by spurious out-of-plane displacements of the shear vibrating finite plate. The primary measurands of the sensor are the fundamental resonance frequency and the associated resonance Q-value, which are influenced by the viscously entrained liquid contacting the quartz surface. The sensor allows the measurement of samples with viscosities from almost zero (air!) up to 200 cP with a sample volume of 130 microl.
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control 02/1998; 45(5):1331-40. · 1.69 Impact Factor
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K Geissler,
E Koller,
E Hubmann,
D Niederwieser,
W Hinterberger,
D Geissler,
P Kyrle,
P Knöbl,
I Pabinger, R Thalhammer,
I Schwarzinger,
C Mannhalter,
U Jaeger,
R Heinz,
W Linkesch,
K Lechner
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ABSTRACT: Because of the recommendation to avoid the concomitant administration of growth factors and chemotherapy, there is only limited information on colony-stimulating factor (CSF) therapy in acute lymphoblastic leukemia (ALL) induction protocols, in which cytotoxic drugs are administered in divided doses over a prolonged period of time, thus requiring a simultaneous administration of growth factors and chemotherapy. We conducted a prospective, randomized, controlled study to determine the safety and efficacy of granulocyte colony-stimulating factor (G-CSF; filgrastim) as an adjunct to phase I of induction chemotherapy for adult ALL. Patients (n = 53) were randomized to receive no growth factor or G-CSF (5 microg/kg/d subcutaneously) starting on day 2 of chemotherapy consisting of daunorubicin (45 mg/m2) and vincristine (1.5 mg/m2) on days 1, 8, 15, and 22; L-asparaginase (2500 U/m2) on days 1 through 14; and prednisone (60 mg/m2) on days 1 through 28. A total of 25 patients in the G-CSF group and 26 patients in the control arm fulfilled the inclusion criteria of the study. G-CSF markedly ameliorated neutropenia because the median proportion of days with neutropenia less than 1,000/microL was 29% in the G-CSF group as compared with 84% in the control arm (P < .00005). The median time to reach absolute neutrophil counts (ANC) > or = 1,000/microL was 16 days in G-CSF patients and 26 days in controls (P < .001). More importantly, G-CSF significantly reduced the incidence of febrile neutropenia (12% v 42% in controls, P < .05) and documented infections (40% v 77%, P < .05). No significant differences were found with regard to requirements for red blood cell transfusions and platelet concentrates. A total of 24 of 25 (96%) patients in the G-CSF group and 20 of 25 (80%) evaluable control patients had complete remission after phase I of induction therapy. We conclude that G-CSF can be safely administered as an adjunct to induction therapy of ALL and is clinically beneficial by ameliorating neutropenia and reducing infectious complications.
Blood 07/1997; 90(2):590-6. · 9.90 Impact Factor
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[show abstract]
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ABSTRACT: The paper describes a novel quartz crystal sensor for measurement
of the density-viscosity product of Newtonian liquids. The sensor
element consists of two piano-convex AT-cut quartz crystals vibrating in
a thickness-shear mode with the liquid sample in between. This special
set-up allows suppression of disturbing resonances in the liquid layer.
Such resonances are generated in the common single-plate arrangements
due to compressional waves caused by spurious out-of-plane displacements
of the shear vibrating finite plate. The primary measurands of the
sensor are the fundamental resonance frequency and the associated
resonance Q-value, which are influenced by the viscously entrained
liquid contacting the quartz surface. The sensor allows the measurement
of samples with viscosities from almost zero (air!) up to 200 cP with a
sample volume of 130 μl
Frequency Control Symposium, 1997., Proceedings of the 1997 IEEE International; 06/1997
