Absolute electron density fluctuation reconstruction for two-dimensional hydrogen beam emission spectroscopy

Scrape-off layer (SOL) and edge plasma turbulence significantly contribute to the radial particle and heat transport, lowering the plasma confinement and increasing the heat load on the plasma facing components. SOL turbulence is predominantly intermittent, which manifests in the occurrence of isolated density filaments or blobs. Filaments propagate radially outward toward plasma facing components, limiting their lifetime by erosion and sputtering. To characterize this phenomenon in detail, few diagnostic techniques are available. Beam emission spectroscopy is a diagnostic capable of measuring plasma turbulence in both SOL and edge plasmas. Due to the finite lifetime of the excitation states during the beam-plasma interaction and the misalignment between the optics and the magnetic field, spatial smearing is introduced in the measurement. In this paper, a novel method is introduced to overcome this hindering effect by inverting the fluctuation response matrix on an optimally smoothed signal. We show that this method is fast and provides significantly more accurate absolute density fluctuation reconstruction than the direct inversion technique. The presented method is usable for all types of beam emission diagnostics where the spatial resolution is higher than the combined smearing of the atomic physics and the observation.

Novel angular velocity estimation technique for plasma filaments

Magnetic field aligned filaments such as blobs and edge localized mode filaments carry significant amounts of heat and particles to the plasma facing components and they decrease their lifetime. The dynamics of these filaments determine at least a part of the heat and particle loads. These dynamics can be characterized by their translation and rotation. In this paper, we present an analysis method novel for fusion plasmas, which can estimate the angular velocity of the filaments on frame-by-frame time resolution. After pre-processing, the frames are two-dimensional (2D) Fourier-transformed, then the resulting 2D Fourier magnitude spectra are transformed to log-polar coordinates, and finally the 2D cross-correlation coefficient function (CCCF) is calculated between the consecutive frames. The displacement of the CCCF's peak along the angular coordinate estimates the angle of rotation of the most intense structure in the frame. The proposed angular velocity estimation method is tested and validated for its accuracy and robustness by applying it to rotating Gaussian-structures. The method is also applied to gas-puff imaging measurements of filaments in National Spherical Torus Experiment plasmas.

Novel 2D velocity estimation method for large transient events in plasmas

Dynamics of fast transient events are challenging to be analyzed with high time resolution. Such events can occur in fusion plasmas such as the filaments during edge-localized modes (ELMs). In this paper, we present a robust method-the spatial displacement estimation-for estimating the displacements of structures with fast dynamics from high spatial and time resolution imaging diagnostics [e.g., gas-puff imaging (GPI)] with sampling time temporal resolution. First, a background suppression method is shown, which suppresses the slowly time-evolving and spatially non-uniform background in the signal. In the second step, a two-dimensional polynomial trend subtraction method is presented to tackle the remaining polynomial order trend in the signal. After performing these pre-processing steps, the spatial displacement of the propagating structure is estimated from the two-dimensional spatial cross-correlation coefficient function calculated between consecutive frames. The method is tested for its robustness and accuracy by simulated Gaussian events and spatially displaced random noise. An example application of the method is presented on propagating ELM filaments measured by the GPI system on the National Spherical Torus Experiment spherical tokamak.

Micro-Faraday cup matrix detector for ion beam measurements in fusion plasmas

Atomic beam probe is an extension of the routinely used beam emission spectroscopy diagnostic for the plasma edge current fluctuation measurement at magnetically confined plasmas. Beam atoms ionized by the plasma are directed to a curved trajectory by the magnetic field and may be detected close to the wall of the device. The arrival location and current distribution of the ions carry information about the plasma current distribution, the density profile, and the electric potential in the plasma edge. This paper describes a micro-Faraday cup matrix detector for the measurement of the few microampere ion current distribution close to the plasma edge. The device implements a shallow Faraday cup matrix, produced by printed-circuit board technology. Secondary electrons induced by the plasma radiation and the ion bombardment are basically confined into the cups by the tokamak magnetic field. Additionally, a double mask is installed in the front face to limit the ion influx into the cups and supplement secondary electron suppression. The setup was tested in detail using a lithium ion beam in the laboratory. Switching time, cross talk, and fluctuation sensitivity test results in the lab setup are presented along with the detector setup to be installed at the COMPASS tokamak.

Advanced neutral alkali beam diagnostics for applications in fusion research (invited)

Diagnosing the density profile at the edge of high temperature fusion plasmas by an accelerated lithium beam is a known technique since decades. By knowledge of the relevant atomic physics rate coefficients, the plasma electron density profile can be calculated from the relatively calibrated light profile along the beam. Several additional possibilities have already been demonstrated: Charge Exchange Resonance Spectroscopy (CXRS) for ion temperature/flow and Zeeman polarimetry for edge plasma current; therefore the Li-beam diagnostic offers a wealth of information at the plasma edge. The weaknesses of the method are the relatively faint light signal, background light, and technical difficulties of the beam injector which usually seriously limit the applicability. In this talk, we present systematic developments in alkali-beam diagnostics (Li, Na) for the injector and the observation system and detectors which resulted in strongly increased capabilities. Advanced systems have been built, and microsecond scale density profile, turbulence, and zonal flow measurement have been demonstrated. A novel edge current measurement technique has also been designed, and components have been tested with potential microsecond-scale time resolution. Additional possibilities of these advanced systems for spectral measurements (CXRS and various Zeeman schemes) are also discussed.

Development of a high current 60 keV neutral lithium beam injector for beam emission spectroscopy measurements on fusion experiments

A 60 keV neutral lithium beam system was designed and built up for beam emission spectroscopy measurement of edge plasma on the KSTAR and EAST tokamaks. The electron density profile and its fluctuation can be measured using the accelerated lithium beam-based emission spectroscopy system. A thermionic ion source was developed with a SiC heater to emit around 4-5 mA ion current from a 14 mm diameter surface. The ion optic is following the 2 step design used on other devices with small modifications to reach about 2-3 cm beam diameter in the plasma at about 4 m from the ion source. A newly developed recirculating sodium vapour neutralizer neutralizes the accelerated ion beam at around 260-280 °C even during long (<20 s) discharges. A set of new beam diagnostic and manipulation techniques are applied to allow optimization, aiming, cleaning, and beam modulation. The maximum 60 keV beam energy with 4 mA ion current was successfully reached at KSTAR and at EAST. Combined with an efficient observation system, the Li-beam diagnostic enables the measurement of the density profile and fluctuations on the plasma turbulence time scale.

Combined hydrogen and lithium beam emission spectroscopy observation system for Korea Superconducting Tokamak Advanced Research

A novel beam emission spectroscopy observation system was designed, built, and installed onto the Korea Superconducting Tokamak Advanced Research tokamak. The system is designed in a way to be capable of measuring beam emission either from a heating deuterium or from a diagnostic lithium beam. The two beams have somewhat complementary capabilities: edge density profile and turbulence measurement with the lithium beam and two dimensional turbulence measurement with the heating beam. Two detectors can be used in parallel: a CMOS camera provides overview of the scene and lithium beam light intensity distribution at maximum few hundred Hz frame rate, while a 4 × 16 pixel avalanche photo-diode (APD) camera gives 500 kHz bandwidth data from a 4 cm × 16 cm region. The optics use direct imaging through lenses and mirrors from the observation window to the detectors, thus avoid the use of costly and inflexible fiber guides. Remotely controlled mechanisms allow adjustment of the APD camera's measurement location on a shot-to-shot basis, while temperature stabilized filter holders provide selection of either the Doppler shifted deuterium alpha or lithium resonance line. The capabilities of the system are illustrated by measurements of basic plasma turbulence properties.

CACNA1D de novo mutations in autism spectrum disorders activate Cav1.3 L-type calcium channels

BACKGROUND

Cav1.3 voltage-gated L-type calcium channels (LTCCs) are part of postsynaptic neuronal signaling networks. They play a key role in brain function, including fear memory and emotional and drug-taking behaviors. A whole-exome sequencing study identified a de novo mutation, p.A749G, in Cav1.3 α1-subunits (CACNA1D), the second main LTCC in the brain, as 1 of 62 high risk-conferring mutations in a cohort of patients with autism and intellectual disability. We screened all published genetic information available from whole-exome sequencing studies and identified a second de novo CACNA1D mutation, p.G407R. Both mutations are present only in the probands and not in their unaffected parents or siblings.

METHODS

We functionally expressed both mutations in tsA-201 cells to study their functional consequences using whole-cell patch-clamp.

RESULTS

The mutations p.A749G and p.G407R caused dramatic changes in channel gating by shifting (~15 mV) the voltage dependence for steady-state activation and inactivation to more negative voltages (p.A749G) or by pronounced slowing of current inactivation during depolarizing stimuli (p.G407R). In both cases, these changes are compatible with a gain-of-function phenotype.

CONCLUSIONS

Our data, together with the discovery that Cav1.3 gain-of-function causes primary aldosteronism with seizures, neurologic abnormalities, and intellectual disability, suggest that Cav1.3 gain-of-function mutations confer a major part of the risk for autism in the two probands and may even cause the disease. Our findings have immediate clinical relevance because blockers of LTCCs are available for therapeutic attempts in affected individuals. Patients should also be explored for other symptoms likely resulting from Cav1.3 hyperactivity, in particular, primary aldosteronism.

Edge electron density profiles and fluctuations measured by two-dimensional beam emission spectroscopy in the KSTAR

Beam emission spectroscopy (BES) system in Korea Superconducting Tokamak Advanced Research (KSTAR) has recently been upgraded. The background intensity was reduced from 30% to 2% by suppressing the stray lights. This allows acquisition of the relative electron density profiles on the plasma edge without background subtraction from the beam power modulation signals. The KSTAR BES system has its spatial resolution of 1 cm, the temporal resolution of 2 MHz, and a total 32 channel (8 radial × 4 poloidal) avalanche photo diode array. Most measurements were done on the plasma edge, r/a ∼ 0.9, with 8 cm radial measurement width that covers the pedestal range. High speed density profile measurements reveal temporal behaviors of fast transient events, such as the precursors of edge localized modes and the transitions between confinement modes. Low background level also allows analysis of the edge density fluctuation patterns with reduced background fluctuations. Propagation of the density structures can be investigated by comparing the phase delays between the spatially distributed channels.

Analysis of edge density fluctuation measured by trial KSTAR beam emission spectroscopy system

A beam emission spectroscopy (BES) system based on direct imaging avalanche photodiode (APD) camera has been designed for Korea Superconducting Tokamak Advanced Research (KSTAR) and a trial system has been constructed and installed for evaluating feasibility of the design. The system contains two cameras, one is an APD camera for BES measurement and another is a fast visible camera for position calibration. Two pneumatically actuated mirrors were positioned at front and rear of lens optics. The front mirror can switch the measurement between edge and core region of plasma and the rear mirror can switch between the APD and the visible camera. All systems worked properly and the measured photon flux was reasonable as expected from the simulation. While the measurement data from the trial system were limited, it revealed some interesting characteristics of KSTAR plasma suggesting future research works with fully installed BES system. The analysis result and the development plan will be presented in this paper.

[Agranulocytosis in a patient treated with metamizole and clopidogrel]

Wir berichten über einen 75-jährigen Patienten, der drei Wochen nach einem ischämischen zerebrovaskulären Insult eine Agranulozytose entwickelte und anschliessend an einer Pneumonie erkrankte. Als mögliche Ursachen für die Agranulozytose konnten am ehesten Metamizol oder Clopidogrel identifiziert werden. Die Agranulozytose ist eine seltene, aber ernst zu nehmende unerwünschte Arzneimittelwirkung. Seit 1997 wurden den Schweizer Arzneimittelbehörden sechs Fälle von Agranulozytose unter Metamizol und zwei unter Clopidogrel gemeldet. Die Therapie besteht in der Injektion von hämatopoietischem Wachstumsfaktor (G-CSF, granulocyte colony stimulating factor) sowie der Gabe von breit wirksamen Antibiotika im Falle einer bakteriellen Infektion. Bei adäquater Therapie ist die Prognose gut. Wir diskutieren den Einsatz des Analgetikums und Antipyretikums Metamizol in der Akut- und Langzeittherapie.

Site-specific in vivo targeting of magnetoliposomes using externally applied magnetic field

Human serum albumin labeled with technetium-99m was encapsulated together with magnetite particles into phosphatidylcholine/cholesterol liposomes. In order to investigate the stability of this complex and its ability to be used for magnetic drug targeting, the in-vivo distribution after intravenous administration in rats was estimated. For in-vivo targeting an SmCo permanent magnet with intensity approximately 0.35 T was attached near the right kidney. Difference between the relative radioactivity in the magnetically targeted right kidney (25.92+/-5.84%) and non-targeted left kidney (0.93+/-0.05%) is sufficiently high for relevant clinical applications.

[Concurrent cavernous and venous cerebral angiomas]

Presence of venous angioma (VA) in a close vicinity of cavernous angioma (CA) of the brain enhances the risk of bleeding from CA. However, VA drains the venous blood from surrounding brain tissue and should be left in place during surgical removal of CA. Coincidence of CA and VA was found in 6 of 44 patients operated on for 45 CA during a six years period (1993-1998). Coincidental VA were found more often with the CA located in the deep structures of the brain, in the thalamus and the brainstem (5 of 15 cases) than with the superficial CA (1 of 30 cases). The most valuable diagnostic method was T1 weighted MR imaging with contrast enhancement, less reliable was nonenhanced T1 or proton density weighted imaging. Finding of the VA may positively influence the decision making concerning the indication for surgery and the selection of the most appropriate surgical tactics. (Tab. 1, Fig. 2, Ref. 15.)

Comparison of pain, motion, and edema after modified radical mastectomy vs. local excision with axillary dissection and radiation

Recent data suggest that prognosis is similar for women with primary breast cancer whether they receive modified radical mastectomy (MRM) or local excision and axillary dissection with radiation (XRT). The effects of either of these treatments on arm mobility, pain, or edema have not been compared. To assess the impact of MRM or XRT on mobility, pain, or edema, we evaluated patients treated in a prospective randomized trial designed to assess prognosis following MRM or XRT. All were provided a standardized physical therapy program including arm mobilization, shoulder strengthening, prevention and treatment of upper extremity edema, and education about arm function. Patients were evaluated for chest wall pain, arm motion, muscle strength, and edema as determined by circumferential measurements at the wrist, forearm, and arm. Evaluations were performed preoperatively and at yearly anniversaries of their surgery. Women receiving XRT had more chest wall tenderness at 1 and 2 years after surgery than those receiving MRM (p2 less than 0.0001 and p2 = 0.0007 respectively). Those receiving MRM were slower to reach their preoperative range of motion (ROM) (p2 = 0.043). Incidence of muscle weakness was similar in both groups. The few patients with local recurrence of tumor had more upper extremity edema than those who did not recur (p2 = 0.085) at 1 year and (p2 = 0.02) at 2 years. In patients who did not develop local recurrence, those who had received XRT had greater but nonsignificant increases in upper extremity circumferential measures compared with those receiving MRM at any anniversary evaluation. Patients receiving MRM and XRT are likely to have some differences in functional outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of preoperative chemotherapy on mastectomy for locally advanced breast cancer

Mastectomy is frequently performed after intensive chemotherapy for locally advanced breast cancer. The effects of preoperative chemotherapy on the postoperative course and the timing of subsequent adjuvant therapy, however, have not been defined. We therefore reviewed the perioperative course of 54 patients undergoing mastectomy after combination (CAMFPT) chemotherapy for stage IIIA,B (IIIA - 25 pts; IIIB noninflammatory - 5 pts; IIIB inflammatory-24 patients) breast cancer. A median of 7 cycles (6 months) of chemotherapy was administered preoperatively. Mastectomy was performed a median of 20 days after last chemotherapy; white blood cell count (WBC) and platelet counts returned to normal limits preoperatively. Total mastectomy with or without axillary node dissection was performed in 53 patients, and a Halsted radical mastectomy in 1 patient. Negative margins on breast and/or axillary tissue were achieved in 47 patients (87.0%). Postoperative complications included skin flap necrosis in 8 patients (14.8%), seroma formation in 5 patients (9.3%), and wound infection in 1 patient (1.9%). Median operative blood loss (550 cc), hospital stay (8 days), and duration of wound catheter drainage (6 days) were comparable to published reports for modified radical mastectomy without preoperative chemotherapy. Systemic chemotherapy was resumed a median of 16 days after mastectomy, and radiotherapy started a median of 33 days after mastectomy. These findings indicate that intensive preoperative chemotherapy does not increase the hospital course or the postoperative complications of mastectomy for locally advanced breast cancer. In view of the current interest in treatment of stage I and II breast cancer with preoperative chemotherapy, this information may be useful in their management as well.

The Tikhoff-Linberg procedure: report of ten patients and presentation of a modified technique for tumors of the proximal humerus

The Tikhoff-Linberg resection is a limb-sparing surgical option to be considered for bony and soft-tissue tumors in and around the proximal humerus and shoulder girdle. Careful selection of patients whose tumor does not involve the neurovascular bundle in the axilla is required. The distal clavicle, upper humerus, and part or all of the scapula are resected. The tumor remains covered by the deltoid muscle plus portions of the muscles that arise from or insert into the resected specimen. In patients with tumors of the proximal humerus a custom prosthesis is used to maintain length and stabilize the distal humerus. Elbow flexion plus stability of the shoulder without the need of an orthosis may be achieved with muscle transfers. Function of the hand and forearm after Tikhoff-Linberg resection should be near normal. Review of results in 10 patients shows no local recurrences and excellent function. The major postoperative problem was nerve palsy. The Tikhoff-Linberg procedure should continue to be used for limb salvage in selected patients with tumors in or around the shoulder girdle.

Association of cellular 56,000- and 32,000-molecular-weight protein with BK virus and polyoma virus t-antigens

Two cellular proteins (molecular weights: 56,000 and 32,000) were specifically co-immunoprecipitated by simian virus 40 and BK virus t-antigens and by polyoma virus non-T early proteins.

Selection of somatic cell hybrids between BK virus transformed BHK-21 and human embryonic kidney cells to study viral gene expression

Somatic cell hybrids were constructed between the human papovavirus, BKV, transformed BHK-21 cells and human embryonic kidney cells, the permissive host for BKV using the polyethylene glycol-DMSO cell fusion method. Hybrids were selected to preserve the phenotype of transformation as anchorage independence to allow examination of the synthesis of BKV early gene products, the T proteins. Several hybrid clones which survived the selection procedure demonstrated an enhanced production of the small t or approximately 22 K protein while the viral large T or approximatley 94 K protein was not detectable. It was also determined in this study that BHK-21 cells which are thymidine kinase deficient (TK-) can be stably transformed by BKV and appear to remain enzyme deficient after transformation.

A prospective study of the rehabilitation of the above-knee amputee with rigid dressing. Comparison of immediate and delayed ambulation and the role of physical therapists and prosthetists

Twenty-four above-knee amputees (AKA) treated with rigid plaster dressings were randomized to receive ambulation on pylon within 24 hours of surgery or at time of suture removal. Casts were applied by physical therapists in half of each group, and by a prosthesist in the other half. There were no statistically significant differences among the groups with respect to age, sex, stump length, gait characteristics and wound healing. Time to prescription of final prosthetis was similar in all groups. Specifically, there was no delay in the group ambulated immediately. The immediate ambulators did have significantly greater stump pain requiring more analgesia than the group ambulated after suture removal. Patients with case applied by physical therapists used their prostheses more than patients with cases applied by prosthetists. There was no detectable difference among treatment groups with regard to participation in therapy, acceptance of prosthesis, and psychological status. Recommendation for management of AKA's include: use of rigid dressing; ambulation on pylon after suture removal; utilization of physical therapist for application of rigid dressings and alignment of pylon.