4,014 research outputs found
Test beam Characterizations of 3D Silicon Pixel detectors
3D silicon detectors are characterized by cylindrical electrodes
perpendicular to the surface and penetrating into the bulk material in contrast
to standard Si detectors with planar electrodes on its top and bottom. This
geometry renders them particularly interesting to be used in environments where
standard silicon detectors have limitations, such as for example the radiation
environment expected in an LHC upgrade. For the first time, several 3D sensors
were assembled as hybrid pixel detectors using the ATLAS-pixel front-end chip
and readout electronics. Devices with different electrode configurations have
been characterized in a 100 GeV pion beam at the CERN SPS. Here we report
results on unirradiated devices with three 3D electrodes per 50 x 400 um2 pixel
area. Full charge collection is obtained already with comparatively low bias
voltages around 10 V. Spatial resolution with binary readout is obtained as
expected from the cell dimensions. Efficiencies of 95.9% +- 0.1 % for tracks
parallel to the electrodes and of 99.9% +- 0.1 % at 15 degrees are measured.
The homogeneity of the efficiency over the pixel area and charge sharing are
characterized.Comment: 5 pages, 7 figure
COLOR III: a multicentre randomised clinical trial comparing transanal TME versus laparoscopic TME for mid and low rectal cancer
Total mesorectal excision (TME) is an essential component of surgical management of rectal cancer. Both open and laparoscopic TME have been proven to be oncologically safe. However, it remains a challenge to achieve complete TME with clear circumferential resections margin (CRM) with the conventional transabdominal approach, particularly in mid and low rectal tumours. Transanal TME (TaTME) was developed to improve oncological and functional outcomes of patients with mid and low rectal cancer.An international, multicentre, superiority, randomised trial was designed to compare TaTME and conventional laparoscopic TME as the surgical treatment of mid and low rectal carcinomas. The primary endpoint is involved CRM. Secondary endpoints include completeness of mesorectum, residual mesorectum, morbidity and mortality, local recurrence, disease-free and overall survival, percentage of sphincter-saving procedures, functional outcome and quality of life. A Quality Assurance Protocol including centralised MRI review, histopathology re-evaluation, standardisation of surgical techniques, and monitoring and assessment of surgical quality will be conducted.The difference in involvement of CRM between the two treatment strategies is thought to be in favour of the TaTME. TaTME is therefore expected to be superior to laparoscopic TME in terms of oncological outcomes in case of mid and low rectal carcinomas
Magnetic Structure in Fe/Sm-Co Exchange Spring Bilayers with Intermixed Interfaces
The depth profile of the intrinsic magnetic properties in an Fe/Sm-Co bilayer
fabricated under nearly optimal spring-magnet conditions was determined by
complementary studies of polarized neutron reflectometry and micromagnetic
simulations. We found that at the Fe/Sm-Co interface the magnetic properties
change gradually at the length scale of 8 nm. In this intermixed interfacial
region, the saturation magnetization and magnetic anisotropy are lower and the
exchange stiffness is higher than values estimated from the model based on a
mixture of Fe and Sm-Co phases. Therefore, the intermixed interface yields
superior exchange coupling between the Fe and Sm-Co layers, but at the cost of
average magnetization.Comment: 16 pages, 6 figures and 1 tabl
"My right-hand man" versus "We barely make use of them":change leaders talking about educational scientists in curriculum change processes-a Membership Categorization Analysis
Health professions education scholarship units (HPESUs) are increasingly becoming a standard for medical schools worldwide without having much information about their value and role in actual educational practices, particularly of those who work in these units, the educational scientists. We conducted a linguistic analysis, called Membership Categorization Analysis, of interviews with leaders of recent curriculum changes to explore how they talk about educational scientists in relation to these processes. The analysis was conducted on previously collected interview data with nine change leaders of major undergraduate medical curriculum change processes in the Netherlands. We analyzed how change leaders categorize HPESUs and educational scientists (use of category terms) and what they say about them (predicates). We noticed two ways of categorizing educational scientists, with observable different predicates. Educational scientists categorized by their first name were suggested to be closer to the change process, more involved in decisional practices and positively described, whereas those described in more generic terms were represented in terms of relatively passive and unspecified activities, were less explicit referenced for their knowledge and expertise and were predominantly factually or negatively described. This study shows an ambiguous portrayal of educational scientists by leaders of major curriculum change processes. Medical schools are challenged to establish medical curricula in consultation with a large, diverse and interdisciplinary stakeholder group. We suggest that it is important to invest in interpersonal relationships to strengthen the internal collaborations and make sure people are aware of each other's existence and roles in the process of curriculum development
Real-time analysis of single influenza virus replication complexes reveals large promoter-dependent differences in initiation dynamics
The viral RNA (vRNA) genome of influenza viruses is replicated by the RNA-dependent RNA polymerase (RNAP) via a complementary RNA (cRNA) intermediate. The vRNA promoter can adopt multiple conformations when bound by the RNAP. However, the dynamics, determinants, and biological role of these conformations are unknown; further, little is known about cRNA promoter conformations. To probe the RNA conformations adopted during initial replication, we monitored single, surface-immobilized vRNA and cRNA initiation complexes in real-time. Our results show that, while the 3′ terminus of the vRNA promoter exists in dynamic equilibrium between pre-initiation and initiation conformations, the cRNA promoter exhibited very limited dynamics. Two residues in the proximal 3′ region of the cRNA promoter (residues absent in the vRNA promoter) allowed the cRNA template strand to reach further into the active site, limiting promoter dynamics. Our results highlight promoter-dependent differences in influenza initiation mechanisms, and advance our understanding of virus replication
Stronger than your voices:A cognitive behavioral therapy for youth suffering from auditory verbal hallucinations
Objective: Auditory verbal hallucinations (AVHs) are a common feature in youth and mostly transient. Nevertheless, while present, AVH can cause considerable distress. Children and adolescents seeking help for distressing AVH represent a heterogeneous group in terms of underlying factors, yet they consistently suffer from their AVH. Until now, a youth-specific psychotherapeutic intervention for AVH was lacking. Experts in the field of treating AVH in both adults and youngsters collaborated with service users to develop the cognitive behavioral therapy (CBT) "Stronger Than Your Voices" (STYV). We investigated feasibility and clinical outcomes of the STYV therapy. Methods: Patients were derived from children and adolescents seeking help for AVH at the UMC Utrecht outpatient clinic with an indication for STYV therapy. Therapists preferably originated from referring health care facilities and were required to have sufficient general knowledge and experience with CBT. They received a short individual training to apply STYV. After, patients and their therapists could participate this naturalistic pilot study, assessing feasibility, tolerability, and clinical change when applying the STYV therapy. Results: Six participants (10-16 years old), all suffering from comorbid psychopathology, provided pre and post measures, all completing STYV therapy without experiencing an aggravation of symptoms. AVH total impact decreased 40% with Cohen's d within-group effect size (1.28) also suggesting clinically meaningful change. Therapists were positive about STYV therapy and manual. Conclusion: The STYV therapy is feasible for youth with distressing AVH. First results indicate that STYV may be clinically effective. A trial to further test effectiveness in a larger sample is needed
Ferromagnetic Domain Distribution in Thin Films During Magnetization Reversal
We have shown that polarized neutron reflectometry can determine in a
model-free way not only the mean magnetization of a ferromagnetic thin film at
any point of a hysteresis cycle, but also the mean square dispersion of the
magnetization vectors of its lateral domains. This technique is applied to
elucidate the mechanism of the magnetization reversal of an exchange-biased
Co/CoO bilayer. The reversal process above the blocking temperature is governed
by uniaxial domain switching, while below the blocking temperature the reversal
of magnetization for the trained sample takes place with substantial domain
rotation
Reticulated livedoid skin patterns after soft-tissue filler–related vascular adverse events
Background: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. Objective: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. Methods: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. Results: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. Conclusion: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.</p
Reticulated livedoid skin patterns after soft-tissue filler–related vascular adverse events
Background: For the treatment of vascular adverse events caused by filler injections, duplex ultrasound imaging may be used. The findings of duplex ultrasound examination and the clinical features of reticulated livedoid skin patterns were compared with the hemifaces anatomy. Objective: The objective of this study was to link the reticulated livedoid skin patterns to the corresponding duplex ultrasound findings and the facial perforasomes. Methods: Duplex ultrasound imaging was used for the diagnosis and treatment of vascular adverse events. The clinical features and duplex ultrasound findings of 125 patients were investigated. Six cadaver hemifaces were examined to compare the typical livedo skin patterns with the vasculature of the face. Results: Clinically, the affected skin showed a similar reticulated pattern in each facial area corresponding with arterial anatomy and their perforators in the cadaver hemifaces. With duplex ultrasound, a disturbed microvascularization in the superficial fatty layer was visualized. After hyaluronidase injection, clinical improvement of the skin pattern was seen. Normalization of blood flow was noted accompanied by restoration of flow in the corresponding perforator artery. The skin patterns could be linked to the perforators of the superficial fat compartments. Conclusion: The livedo skin patterns seen in vascular adverse events may reflect the involvement of the perforators.</p
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