Protective capping of topological surface states of intrinsically insulating Bi2_2Te3_3

We have identified epitaxially grown elemental Te as a capping material that is suited to protect the topological surface states of intrinsically insulating Bi$_2$Te$_3$. By using angle-resolved photoemission, we were able to show that the Te overlayer leaves the dispersive bands of the surface states intact and that it does not alter the chemical potential of the Bi$_2$Te$_3$ thin film. From in-situ four-point contact measurements, we observed that the conductivity of the capped film is still mainly determined by the metallic surface states and that the contribution of the capping layer is minor. Moreover, the Te overlayer can be annealed away in vacuum to produce a clean Bi$_2$Te$_3$ surface in its pristine state even after the exposure of the capped film to air. Our findings will facilitate well-defined and reliable ex-situ experiments on the properties of Bi$_2$Te$_3$ surface states with nontrivial topology.Comment: 5 pages, 5 figures, 2 pages supplemental material accepted for publication in AIP Advance

In vivo manipulation of interleukin-2 expression by a retroviral tetracycline (tet)-regulated system

We have used the tetracycline (tet)-regulated system as described previously to evaluate the applicability of controlled gene expression in cancer gene therapy. As a model gene, we used the human interleukin-2 (IL-2) gene, which has been placed under the transcriptional control of the tetO/promoter. Human melanoma cells were transduced by two modified retroviral tet vectors containing the transactivator regulatory unit and the IL-2 gene driven by the tetO/promoter, respectively. In the absence of tet, IL-2 expression in the target cells was stable over several months. IL-2 production was in the range of 40 U/106 cells/24 hours. A fine tuning of IL-2 expression could be achieved by culturing the transduced cells with increasing doses of tet, whereby a concentration of 500 ng/mL tet in the culture medium abrogated IL-2 expression. Most importantly for clinical application, IL-2 expression by the transduced melanoma cells could also be regulated in vivo. When nu/nu mice were inoculated with the transduced tumor cells, they failed to develop tumors. Instead, the inhibition of IL-2 expression in the transduced tumor cells by oral administration of tet led to subcutaneous tumor growth; this growth rate was comparable with the growth rate of subcutaneously inoculated untransduced parental cells. The finding demonstrates the applicability of the tet-regulated system in cancer gene therapy

Acute Muscle Trauma due to Overexercise in an Otherwise Healthy Patient with Cystic Fibrosis

Cystic fibrosis (CF) is one of the most common inherited diseases and is caused by mutations in the CFTR gene. Although the pulmonary and gastrointestinal manifestations of the disease remain in the focus of treatment, recent studies have shown expression of the CFTR gene product in skeletal muscle cells and observed altered intramuscular Ca2+ release dynamics in CFTR-deficient animal models. Physical exercise is beneficial for maintaining fitness and well-being in CF patients and constitutes one aspect of modern multimodal treatment, which has considerably increased life span and reduced morbidity. We report on a case of acute muscle trauma resulting from excessive dumbbell exercise in a young adult with cystic fibrosis and describe clinical, laboratory and imaging characteristics of acute exercise-induced muscle injury

The ifo Education Survey 2014-2021

The ifo Education Survey is a representative opinion survey of the German voting-age population on education topics that has been conducted annually since 2014. It covers public preferences on a wide range of education policy issues ranging from early childhood education, schools, and apprenticeships to university education and life-long learning. The dataset comprises several survey experiments that facilitate investigating the causal effects of information provision, framing, and question design on answering behavior. This paper gives an overview of the survey content and methodology, describes the data, and explains how researchers can access the dataset of over 4000 participants per wave

Meniscus body position and its change over four years in asymptomatic adults: a cohort study using data from the Osteoarthritis Initiative (OAI).

A high degree of meniscal body extrusion on knee magnetic resonance imaging has been shown to be strongly associated with development of knee osteoarthritis. However, very little is known about meniscal position in the asymptomatic knee and its natural history. Hence our objective was to study meniscal body position and its change over 4 years in asymptomatic adults

Spatial distribution and optical properties of Saharan dust observed by airborne high spectral resolution lidar during SAMUM 2006

Airborne measurements of pure Saharan dust extinction and backscatter coefficients, the corresponding lidar ratio and the aerosol optical thickness (AOT) have been performed during the Saharan Mineral Dust Experiment 2006, with a high spectral resolution lidar. Dust layers were found to range from ground up to 4–6 km above sea level (asl). Maximum AOT values at 532 nm, encountered within these layers during the DLR Falcon research flights were 0.50–0.55. A significant horizontal variability of the AOT south of the High Atlas mountain range was observed even in cases of a well-mixed dust layer. High vertical variations of the dust lidar ratio of 38–50 sr were observed in cases of stratified dust layers. The variability of the lidar ratio was attributed to dust advection from different source regions. The aerosol depolarization ratio was about 30% at 532 nm during all measurements and showed only marginal vertical variations

Restoration of the patient-specific anatomy of the distal fibula based on a novel three-dimensional contralateral registration method

PURPOSE: Posttraumatic fibular malunion alters ankle joint biomechanics and may lead to pain, stiffness, and premature osteoarthritis. The accurate restoration is key for success of reconstructive surgeries. The aim of this study was to analyze the accuracy of a novel three-dimensional (3D) registration algorithm using different segments of the contralateral anatomy to restore the distal fibula. METHODS: Triangular 3D surface models were reconstructed from computed tomographic data of 96 paired lower legs. Four segments were defined: 25% tibia, 50% tibia, 75% fibula, and 75% fibula and tibia. A surface registration algorithm was used to superimpose the mirrored contralateral model on the original model. The accuracy of distal fibula restoration was measured. RESULTS: The median rotation error, 3D distance (Euclidean distance), and 3D angle (Euler's angle) using the distal 25% tibia segment for the registration were 0.8° (- 1.7-4.8), 2.1 mm (1.4-2.9), and 2.9° (1.9-5.4), respectively. The restoration showed the highest errors using the 75% fibula segment (rotation error 3.2° (0.1-8.3); Euclidean distance 4.2 mm (3.1-5.8); Euler's angle 5.8° (3.4-9.2)). The translation error did not differ significantly between segments. CONCLUSION: 3D registration of the contralateral tibia and fibula reliably approximated the premorbid anatomy of the distal fibula. Registration of the 25% distal tibia, including distinct anatomical landmarks of the fibular notch and malleolar colliculi, restored the anatomy with increasing accuracy, minimizing both rotational and translational errors. This new method of evaluating malreductions could reduce morbidity in patients with ankle fractures. LEVEL OF EVIDENCE: IV

Taking shortcuts: Cognitive conflict during motivated rule-breaking

Deliberate rule violations have typically been addressed from a motivational perspective that asked whether or not agents decide to violate rules based on contextual factors and moral considerations. Here we complement motivational approaches by providing a cognitive perspective on the processes that operate during the act of committing an unsolicited rule violation. Participants were tested in a task that allowed for violating traffic rules by exploiting forbidden shortcuts in a virtual city maze. Results yielded evidence for sustained cognitive conflict that affected performance from right before a violation throughout actually committing the violation. These findings open up a new theoretical perspective on violation behavior that focuses on processes occurring right at the moment a rule violation takes place

Taking shortcuts: Cognitive conflict during motivated rule-breaking

Deliberate rule violations have typically been addressed from a motivational perspective that asked whether or not agents decide to violate rules based on contextual factors and moral considerations. Here we complement motivational approaches by providing a cognitive perspective on the processes that operate during the act of committing an unsolicited rule violation. Participants were tested in a task that allowed for violating traffic rules by exploiting forbidden shortcuts in a virtual city maze. Results yielded evidence for sustained cognitive conflict that affected performance from right before a violation throughout actually committing the violation. These findings open up a new theoretical perspective on violation behavior that focuses on processes occurring right at the moment a rule violation takes place