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Moyamoya angiopathy (MMA) related cerebral perfusion deficits or infarctions might influence quality of life (QoL). This study examines preoperative QoL in adult patients with MMA and correlates these with findings obtained via diagnostic imaging. Sixty-seven adult Moyamoya patients underwent preoperative neuropsychological testing including questionnaires to determine QoL, as well as psychiatric and depressive symptoms. The results were checked for correlation with territorial hypoperfusions seen in H215O PET with acetazolamide (ACZ) challenge (cerebrovascular reserve) and infarction patterns observed in MRI. Each vascular territory was analyzed separately and correlated with QoL. Physical role function was restricted in 41.0% of cases and emotional role function in 34.4% of cases (SF-36). Obsessive–compulsive disorder (39.3%) (SCL-90-R), psychoticism (34.4%) (SCL-90-R), and depression (32.7%) (BDI-II) were also very common. Psychoticism was significantly more frequent in cases where perfusion deficits in PET CT were observed in both MCA territories (left p = 0.0124, right p = 0.0145) and infarctions in MRI were present in the right MCA territory (p = 0.0232). Depression was significantly associated with infarctions in the right MCA territory (SCL-90-R p = 0.0174, BDI-II p = 0.0246). Women were affected more frequently by depression (BDI-II, p = 0.0234). Physical role function impairment was significantly associated with perfusion deficits in the left MCA territory (p = 0.0178) and infarctions in the right MCA territory (p = 0.0428). MMA leads to impairments in different areas of QoL. Approximately one-third of all adult MMA patients suffered from depression, with women being most affected. In addition to depression, presence of executive dysfunctions and mental disorders such as psychoticism, obsessive–compulsive disorder, and impaired physical and emotional role function affected QoL. These patients showed significantly more often infarctions and perfusion deficits in the right MCA territory. Long-term studies with follow-up results are necessary to clarify a possible beneficial impact of early surgical revascularization on QoL and depression in adult MMA patients.

This study aims to describe the posterolateral epidural supra-C2-root approach (PESCA), which might be a good alternative to the transoral, anterolateral, and other posterolateral approaches for biopsy of lesions of the odontoid process (OP). The preoperative planning of PESCA included computerized tomography (CT), CT-angiography, and three-dimensional reconstruction (if possible, even with three-dimensional print) to analyze the angle of the trajectory and the anatomy of the vertebral artery (VA). For PESCA, the patient is positioned under general anesthesia in prone position. In case of an osteolytic lesion with fracture of the OP, an X-ray is performed after positioning to verify anatomic alignment. In the first step, in case of instability and compression of the spinal cord, a craniocervical fusion and decompression is performed (laminectomy of the middle part of the C1 arc and removal of the lower part of the lateral C1 arc). The trajectory is immediately above the C2 root (and under the upper rest of the lateral part of C1 arc). Even if the trajectory is narrowed, it is possible to perform PESCA without relevant traction of the spinal cord. The vertical segment of V3 of the VA at the level of C2 is protected by the vertebral foramen, and the horizontal part of V3 is protected by the remnant upper lateral part of the C1 arc (in case of normal variants). PESCA might be a good choice for biopsy of selected lesions of the OP in same sitting procedure after craniocervical stabilization and decompression.

The cutting tool is a key element in the milling process; it determines the process performance and the quality of the machined pieces. For best performance, cutting fluids are applied as close as possible to the area between the tool and the work piece. Its primary functions are chip evacuation, cooling of the tool and piece as well as lubrication. Recent developments allow the injection of the fluid through the spindle, the tool holder and finally through a central hole in the cutting tool. For tools with large diameters (> 6mm) one or several central straight channels are used. For tools with small diameter ( A 10 pico-second laser was used for drilling the holes in order to avoid thermal impact in the tungsten cobalt (Wc-Co) – hard metal that would occur using other methods like EDM-drilling. For the milling tool of O 1.0 mm, the lateral holes have a diameter of 0.12 mm and, for the milling tool of O 2.5 mm, the lateral holes are O 0.3 mm. The diameter of the central blind hole is identical for both tools, i.e. O 0.3 mm. The paper focuses on the hole trepanning technology, i.e. the parametrization of both the laser and the scanner. The tools developed were tested by processing stainless steel with injection of a water based emulsion as cutting fluid with 20 bars through the tiny channels. A significant increase in the tool lifetime as well as an improved surface quality have been observed.

Objective: Image quality in high-field intraoperative MRI (iMRI) is often influenced negatively by susceptibility artifacts. While routine sequences are rather robust, advanced imaging such as diffusion-weighted imaging (DWI) is very sensitive to susceptibility resulting in insufficient imaging data. This study aims to analyze intraoperatively acquired DWI to identify the main factors for susceptibility, to compare results with postoperative images and to identify technical aspects for improvement of intraoperative DWI. Methods: 100 patients with intraaxial lesions operated in a high-field iMRI were analyzed retrospectively for the quality of intraoperative DWI in comparison to the postoperative scan. General quality of the MR scan, individual diffusion restrictions, artifacts, and their causes were analyzed. Results: Inclusion criteria were met in 78 patients, 124 diffusion restrictions were included in the comparative analysis. PPV and NPV for the detection of DWI changes intraoperatively were 0.94 and 0.56, respectively (SEN 0.94; SPE 0.56). Image quality was rated significantly (p < 0.0001) worse intraoperatively compared to the postoperative MRI. The main reasons for reduced image quality intraoperatively were air (64%) and artificial material (e.g., compress) (38%) in the resection cavity, as well as positioning of patient’s head outside the MR’s isocenter 37%. Analysis of surgical approaches showed that frontal craniotomies have the highest risk of limited image quality (40%), whereat better results (15% limited image quality) were seen for all other approaches (p = 0.059). Conclusion: Intraoperative DWI showed reliable results in this analysis. However, image-quality was limited severely in many cases leading to uncertainty in the interpretation. Susceptibility-causing factors might be prevented in many cases, if the surgical team is aware of them. The most important factors are good filling of the resection cavity with irrigation fluid, not placing artificial materials in the resection cavity and adequate positioning of patient’s head according to the MR isocenter.

Patients with moyamoya angiopathy (MMA) are known to have an increased risk of impaired executive function (dysexecutive cognitive syndrome (DCS)). Numbers of moyamoya patients with DCS vary strongly in the literature; evidence of a correlation to affected vascular territories is low. This study aims to identify cognitive impairment in adult moyamoya patients and to correlate findings with imaging results. In addition, the predictive value of individual tests for the identification of DCS was analyzed. Neuropsychological test data of 41 adult moyamoya patients was analyzed for a possible correlation with territorial hypoperfusion on H215O PET with acetazolamide (ACZ) challenge (cerebrovascular reserve-CVR) and infarction patterns observed in MRI. Each vascular territory was analyzed separately and correlated to neuropsychological test results and to the presence of DCS. In total, 41.5% of patients presented with DCS. Significant association of DCS and affection of the right middle cerebral artery (MCA) territory was seen for insufficient CVR in PET (p = 0.030) and for patients with infarctions seen in MRI (p = 0.014). Analysis of individual neuropsychological test results confirmed the main association with the right MCA territory, as well as some association with the right anterior cerebral artery (ACA) territory. Analysis of a subgroup of patients with chronic disease on MRI (presence of large post-infarction gliosis and brain atrophy in affected territories) revealed a significantly higher risk for DCS (85% affected) than non-chronic patients (21% affected) (p < 0.001). Analysis of neuropsychological test data in this moyamoya cohort reveals DCS in 41.5% of all patients. Correlation between DCS and an impairment of CVR seen in PET and/or infarctions seen in MRI was significant for the right MCA territory. Patients with chronic disease had a significantly higher risk for DCS than non-chronic patients (p < 0.001).

Moyamoya angiopathy (MMA) related cerebral perfusion deficits or infarctions might influence quality of life (QoL). This study examines preoperative QoL in adult patients with MMA and correlates these with findings obtained via diagnostic imaging. Sixty-seven adult Moyamoya patients underwent preoperative neuropsychological testing including questionnaires to determine QoL, as well as psychiatric and depressive symptoms. The results were checked for correlation with territorial hypoperfusions seen in H

In the rehabilitation of postoperative facial palsy, physical therapy is of paramount importance. However, in the early rehabilitation phase, voluntary movements are often limited, and thus, the motivation of patients is impacted. In these situations, biofeedback of facial electromyographic (EMG) signals enables the visual representation of the rehabilitation progress, even without apparent facial movements. In the present study, we designed and evaluated a custom-made EMG biofeedback system enabling cost-effective facial rehabilitation.This prospective study describes a custom-made EMG system, consisting of a microcontroller board and muscle sensors, which was used to record the EMG ofIn healthy subjects, a good correlation was measured between the mean EMG amplitudes of the custom-made and commercial EMG device for bothThe present study demonstrates a good application potential of our custom-made EMG biofeedback device to detect facial EMG activity in healthy subjects as well as patients with facial palsies. There is a correlation between the electrophysiological measurements and the clinical outcome. Such a device might enable cost-efficient home-based facial EMG biofeedback. However, movement detection accuracy should be improved in future studies to reach ranges of commercial devices.

Background Medical students show varying clinical practical skills when entering their final year clinical clerkship, which is the final period to acquire and improve practical skills prior to their residency. We developed a one-on-one mentoring program to allow individually tailored teaching of clinical practical skills to support final year students with varying skill sets during their neurosurgical clinical clerkship. Methods Each participating student (n = 23) was paired with a mentor. At the beginning students were asked about their expectations, teaching preferences and surgical interest. Regular meetings and evaluations of clinical practical skills were scheduled every 2 weeks together with fixed rotations that could be individually adjusted. The one-on-one meetings and evaluations with the mentor gave each student the chance for individually tailored teaching. After completion of the program each student evaluated their experience. Results The mentoring program was well received by participating students and acquisition or improvement of clinical practical skills was achieved by most students. A varying practical skill level and interest in the field of surgery was seen. Conclusions A neurosurgical one-on-one mentoring program is well received by final year medical students and allows for individually tailored learning of clinical practical skills. Supplementary Information The online version contains supplementary material available at 10.1186/s12909-021-02657-0.

Patients with moyamoya angiopathy (MMA) are known to have an increased risk of impaired executive function (dysexecutive cognitive syndrome (DCS)). Numbers of moyamoya patients with DCS vary strongly in the literature; evidence of a correlation to affected vascular territories is low. This study aims to identify cognitive impairment in adult moyamoya patients and to correlate findings with imaging results. In addition, the predictive value of individual tests for the identification of DCS was analyzed. Neuropsychological test data of 41 adult moyamoya patients was analyzed for a possible correlation with territorial hypoperfusion on H

In recent years, analytics became increasingly important in sports. Newly developed, wearable tracking devices allow football players to log position and motion data during a game. These data can be exploited for enhancing the performance of individual players and entire teams. We present different machine learning approaches to predict spatial football player positions, which serve for advanced tactical analyses.

In large cities, pollution composed of many different chemical components and small particles is an important public health problem that affects especially children and people presenting breathing difficulties.

Persulfide dioxygenases (PDOs) are abundant in Bacteria and also crucial for H2S detoxification in mitochondria. One of the two pdo-genes of the acidophilic bacterium Acidithiobacillus caldus was expressed in Escherichia coli. The protein (AcPDO) had 0.77 ± 0.1 Fe/subunit and an average specific sulfite formation activity of 111.5 U/mg protein (Vmax) at 40°C and pH 7.5 with sulfur and GSH following Michaelis–Menten kinetics. KM for GSH and Kcat were 0.5 mM and 181 s−1, respectively. Glutathione persulfide (GSSH) as substrate gave a sigmoidal curve with a Vmax of 122.3 U/mg protein, a Kcat of 198 s−1 and a Hill coefficient of 2.3 ± 0.22 suggesting positive cooperativity. Gel permeation chromatography and non-denaturing gels showed mostly tetramers. The temperature optimum was 40–45°C, the melting point 63 ± 1.3°C in thermal unfolding experiments, whereas low activity was measurable up to 95°C. Site-directed mutagenesis showed that residues located in the predicted GSH/GSSH binding site and in the central hydrogen bond networks including the iron ligands are essential for activity. Among these, the R139A, D141A, and H171A variants were inactive concomitant to a decrease of their melting points by 3–8 K. Other variants were inactivated without significant melting point change. Two out of five cysteines are likewise essential, both of which lie presumably in close proximity at the surface of the protein (C87 and C224). MalPEG labeling experiments suggests that they form a disulfide bridge. The reducing agent Tris(2-carboxyethyl)phosphine was inhibitory besides N-ethylmaleimide and iodoacetamide suggesting an involvement of cysteines and the disulfide in catalysis and/or protein stabilization. Mass spectrometry revealed modification of C87, C137, and C224 by 305 mass units equivalent to GSH after incubation with GSSH and with GSH in case of the C87A and C224A variants. The results of this study suggest that disulfide formation between the two essential surface-exposed cysteines and Cys-S-glutathionylation serve as a protective mechanism against uncontrolled thiol oxidation and the associated loss of enzyme activity.

The objective of this work is to investigate the dynamics of the dielectric fluid in the die sinking electrical discharge machining (EDM) process. Different methods were developed to investigate the fluid dynamics of the dielectric and particles. Both computational fluid dynamics (CFD) and experimental tests were performed. The most important achievement of this project is the improvement of the evacuation of the waste particles within the gap workpiece-electrode. An exhaustive understanding of the processes was crucial to obtain a uniform particles distribution which leads to a more efficient discharging and particle evacuation. A CFD analysis was used to figure out the characteristics for the electrode, such as its shape and dimensions and its kinematic properties. In particular, different combinations of axis Jerk, acceleration, speed and movement of the electrode were studied in detail. Different dielectric liquids were also considered. The experimental tests on full scale and increased scale models were performed at the AgieCharmilles laboratory and at the CMEFE laboratory in Geneva, in order to validate the CFD results. A test rig was built to perform study at a scale of 50:1 has been built, and a particle image velocimetry (PIV) was developed in order to study the effect of the fluid flow. The analysis of the trajectories of the waste particles inside the dielectric was performed for several configurations. The effect of the gas bubbles generated during the process is also under investigation.

During these last years, the evolution of the machining speed of the EDM processes has become a key challenge for this technology. The recent progress made on the spark generators leads to a higher production speed in all processes such wire EDM, die-sinking, drilling, milling, etc. Nevertheless, if the electrical process is developing fast, many limiting factors still remain under investigations. In this context, our group started 7 years ago a research program to increase the understanding of the EDM particle hydrodynamics. We describe in this paper some results obtained and discuss the physical aspects related to the evacuation of the machining debris. During the EDM process, if the cleaning of the dielectric is not effective and some debris remain in the gap, the electrical resistance is locally reduced and the spark occurs at the same place. The process cannot go farther. In this situation, i.e. when the spark frequency and power are high enough, the machining speed is governed mainly by hydrodynamics. In this paper we will present efficient strategies to clean the gap in the wire EDM (part 1) and die sinking processes (part 2). For the wire EDM process (part 1), we have designed and analysed dielectric injection nozzles with the aim of improving the cleaning processes in the gap. Three main tools have been used to achieve this goal. The first is a fluid flow simulation model using CFD solvers. Then, the results have been validated using experimental techniques at full scale on EDM machines. Finally, a test rig has been developed and experimental analyses have been done.

Der Einfluss einer moglichen Klimaanderung auf das Abflussgeschehen wurde anhand von vier osterreichischen Testeinzugsgebieten – der Bregenzer Ache (Pegel Mellau), der Lavant (Pegel Fischering), der Traisen (Pegel Lilienfeld) und der Oberen Salzach (Pegel Mittersill) erforscht. Fur diese Untersuchung wurden Ergebnisse (Niederschlag, Lufttemperatur) des regionalen Klimamodells REMO-UBA des deutschen Max Planck Instituts Hamburg verwendet und die Klimaanderungssignale bestimmt. Dabei fanden die Entwicklungsszenarien A1B und B1 Anwendung. Mit Hilfe eines stochastischen Wettergenerators wurden Tageswerte der Lufttemperatur und des Niederschlags generiert, wobei die Klimanormalperiode 1961–1990 als Referenzperiode und 2071–2100 als zukunftige Vergleichsperiode gewahlt wurden. Anhand monatsweiser Analysen wurden Anderungstendenzen festgestellt und dokumentiert, wobei regional unterschiedliche Ergebnisse erzielt wurden. Generell wurden eine Niederschlagszunahme in den Wintermonaten und eine Reduktion in den Sommermonaten festgestellt. Gemeinsam mit zunehmenden Winterniederschlagen werden die Abflusse im Winter erhoht, die Sommerabflusse werden tendenziell geringer. An der Bregenzer Ache reduzieren sich die Hochwasserabflusse um ca. 10 %, ebenso and der Oberen Salzach bei Szenario A1B. An der Lavant werden gleichbleibende bis gering ansteigende Hochwasser prognostiziert. An der Traisen wird ein deutlicher Anstieg, insbesondere bei Szenario B1 vorhergesagt. Das ereignisbezogene saisonale Auftreten von Hochwassern zeigt eine Verschiebung in Richtung kurz andauernder intensiver Regenereignisse.

This study assesses the impact of a changing climate on fish fauna by comparing the past mean state of fish assemblage to a possible future mean state. It is based on (1) local scale observations along an Inner-Alpine river called Mur, (2) an IPCC emission scenario (IS92a), implemented by atmosphere-ocean global circulation model (AOGCM) ECHAM4/OPYC3, and (3) a model-chain that links climate research to hydrobiology. The Mur River is still in a near-natural condition and water temperature in summer is the most important aquatic ecological constraint for fish distribution. The methodological strategy is (1) to use downscaled air temperature and precipitation scenarios for the first half of the twenty-first century, (2) to establish a model that simulates water temperature by means of air temperature and flow rate in order to generate water temperature scenarios, and (3) to evaluate the impact on fish communities using an ecological model that is driven by water temperature. This methodology links the response of fish fauna to an IPCC emission scenario and is to our knowledge an unprecedented approach. The downscaled IS92a scenarios show increased mean air temperatures during the whole year and increased precipitation totals during summer, but reduced totals for the rest of the annual cycle. These changes result in scenarios of increased water temperatures, an altered annual cycle of flow rate, and, in turn, a 70 m displacement in elevation of fish communities towards the river's head. This would enhance stress on species that rely on low water temperatures and coerce cyprinid species into advancing against retreating salmonids. Hyporhithral river sectors would turn into epipotamal sectors. Grayling (Thymallus thymallus) and Danube salmon (Hucho hucho), presently characteristic for the Mur River, would be superceded by other species. Native brown trout (Salmo trutta), already now under pressure of competition, may be at risk of losing its habitat in favour of invaders like the exotic rainbow trout (Oncorhynchus mykiss), which are better adapted to higher water temperatures. Projected changes in fish communities suggest an adverse influence on salmonid sport fishing and a loss in its high economic value.

This study takes place within the framework of the Optipris project whose goal is to develop high-performance air intakes. Most of the time, air intakes are located in regions of negative pressure coefficients. In these cases, a flow regulation is necessary for any application for which the mass flow is prevalent. For example in the case of air conditioning systems. An intake offering a constant pressure at the inlet offers a great advantage: the fresh air mass flow is not influenced by the vehicule speed. In this project, a fully immerged intake yielding a constant mass flow is developed and validated for the incompressible domain. The development process is based on CFD simulations. Physical models are also built and tested in a subsonic wind tunnel to validate the simulation models. The intake design parameters are evaluated for several applications and pressure coefficients. Similarity criteria are developed. Then, the sensitive design parameters are determined. A design law is obtained from which it is possible to define a constant pressure air intake for given flow rates and pressure coefficients. These data are validated for a range of pressure coefficients from 0 to -0.3 and for the incompressible flow regime.

A dedicated 4 m high vertical wind tunnel has been designed and constructed at the University of Geneva in collaboration with the Groupe de compétence en mécanique des fluides et procédés énergétiques. With its diverging test section the tunnel is designed to study the aero dynamical behavior of non spherical particles with terminal velocities between 5 and 27 ms 1. A particle tracking velocimetry (PTV) code is developed to calculate drag coefficient of particles in standard conditions based on the real projected area of the particles. Results of our wind tunnel and PTV code are validated by comparing drag coefficient of smooth spherical particles and cylindrical particles to existing literature. Experiments are repeatable with average relative standard deviation of 1.7. Our preliminary experiments on the effect of particle to fluid density ratio on drag coefficient of cylindrical particles show that the drag coefficient of freely suspended particles in air is lower than those measured in water or in horizontal wind tunnels. It is found that increasing aspect ratio of cylindrical particles reduces their secondary motions and they tend to be suspended with their maximum area normal to the airflow. The use of the vertical wind tunnel in combination with the PTV code provides a reliable and precise instrument for measuring drag coefficient of freely moving particles of various shapes. Our ultimate goal is the study of sedimentation and aggregation of volcanic particles (density between 500 and 2700 kgm 3) but the wind tunnel can be used in a wide range of applications. © 2013 AIP Publishing LLC.

Goddard's Laboratory for Astronomy and Solar Physics has developed a CCD camera design for space flight use with multi-mission capability as part of its design philosophy. The first application of this camera is being demonstrated as part of the Coronal Diagnostic Spectrometer onboard the Solar and Heliospheric Observatory launched on December 2, 1995. The multi-mission design philosophy allows for the architecture of the camera electronics to be largely independent of the actual CCD selected for use as the detector. It is the CCD device itself that is typically the mission dependent part of the instrument. This is of great importance to the overall camera design since CCD topologies can vary widely from one manufacturer to another. Such factors as aspect ratio, number of pixels, readout mechanisms, clock phasing and clocking levels are all variables that must be incorporated into the hardware design of the camera. Among the advantages of this approach are the reduction of dedicated hardware and CCD development time. Also, since the camera can be reprogrammed from the ground, it is possible to continually optimize CCD performance in orbit. This may prove useful in offsetting degradation of the device due to factors such as radiation damage.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The Laboratory for Astronomy and Solar Physics at Goddard Space Flight Center uses a variety of CCD's and other solid state imaging sensors for its instrumentation programs. Traditionally, custom camera systems are built around the imaging device to optimize the circuitry for the particular sensor. This usually produces a camera that is small, uses little power and is elegant. Although these are desirable characteristics, this approach is also expensive and time consuming. An alternative approach is to design a `universal' camera that is easily customized to meet specific mission requirements. This is the approach our team used for SERTS. The camera design used to support the SERTS mission is a general purpose camera design that is derived from an existing camera on the SOHO spacecraft. This camera is designed to be rugged, modest in power requirements and flexible. The base design of the camera supports quadrant CCD devices with up to 4 phases. Imaging devices with simpler architectures are in general supportable. The basic camera is comprised of a main electronics box which performs all timing generation, voltage level control, data processing and compression. A second unit, placed close to the detector head, is responsible for driving the image device control electrodes and amplifying the multichannel detector video. Programmable high voltage units are used for the single stage MCP type intensifier. The detector head is customized for each sensor type supported. Auxiliary equipment includes a frame buffer that works either as a multi-frame storage unit or as a photon counting accumulation unit. This unit also performs interface buffering so that the camera may appear as a piece of GPIB instrumentation.

A photon-counting intensified charge injection device (CID) detector is currently in development at the Laboratory for Astronomy and Solar Physics at the Goddard Space Flight Center. Analogous microchannel-plate-intensified CCD detectors have achieved impressive spatial resolution performance in photon-counting operation. Such detectors suffer, however, from a severe limitation on local dynamic range; local event rates must be kept low in order to minimize event overlap at the frame rates achievable for reading out a full CCD. By utilizing a random access CID for the readout stage, we plan to avoid this severe local count rate limitation by virtue of the addressable (rather than serial) readout capability of such a device. Different portions of the detector field can be framed at different rates, as appropriate to the brightness distribution of the scene, maximizing the local count rate limit for a given pixel read rate and event processing capability. A high spatial resolution, high count rate photon counting detector of this type is of interest in a number of applications in space and ground- based astronomy. In this report, we present: (1) the advantages and applications of this kind of detector, (2) remarks on the suitability of different CID architectures, (3) our system design concept, and (4) the status and plans for our fabrication and testing efforts.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.