2,409 research outputs found
Polar Kerr effect from a time-reversal symmetry breaking unidirectional charge density wave
We analyze the Hall conductivity of a charge ordered
state with momentum and calculate the intrinsic
contribution to the Kerr angle using the fully reconstructed
tight-binding band structure for layered cuprates beyond the low energy hot
spots model and particle hole symmetry. We show that such a unidirectional
charge density wave (CDW), which breaks time reversal symmetry as recently put
forward by Wang and Chubukov [Phys. Rev. B {\bf 90}, 035149 (2014)], leads to a
nonzero polar Kerr effect as observed experimentally. In addition, we model a
fluctuating CDW via a large quasiparticle damping of the order of the CDW gap
and discuss possible implications for the pseudogap phase. We can qualitatively
reproduce previous measurements of underdoped cuprates but making quantitative
connections to experiments is hampered by the sensitivity of the polar Kerr
effect with respect to the complex refractive index .Comment: 6 pages, 4 figure
Strategien des Kompetenzerwerbs von MusiklehrerInnen im Umgang mit Neuen Medien. Perspektiven musikpädagogischer Forschung im Umfeld von Lehrerfortbildung (am Beispiel des Me[i]Mus-Projekts)
FĂźr die berufsbegleitende Fortbildung werden auch im Bereich der Musik erhebliche finanzielle Mittel in der Hoffnung bereitgestellt, dass sich dadurch spĂźrbar die Qualität von Unterricht und damit letztlich auch das Schulsystem insgesamt verbessern. Ăber die Effektivität dieser MaĂnahmen ist bislang jedoch nur wenig bekannt. [...] Der Beitrag versteht sich als Impuls zur verstärkten Auseinandersetzung mit Aspekten der Fort- und Weiterbildung von Musiklehrerinnen. Es zeichnet sich ab, dass dieser Bereich in einer Zeit der Reorganisation des Bildungssystems weiter an Bedeutsamkeit gewinnen wird. Thematische AnschlĂźsse lassen sich u.a. zu einer sich erst langsam etablierenden Debatte zur Professionalisierung von MusiklehrerInnen herstellen. Diese Debatte hat sich bislang Ăźberwiegend mit der Problematik der Musiklehrerausbildung an Universitäten und Hochschulen beschäftigt [...]. Zunächst stellen die Autoren das Projekt Me[i]Mus, das den Ausgangs- und Bezugspunkt fĂźr die gewählte Thematik darstellt, kurz vor. Es handelt sich dabei um ein musikpädagogisches Lehrerfortbildungsangebot mit dem Schwerpunkt Neue Medien im Musikunterricht. AnschlieĂend wird ausgehend von dem Begriff âmedienpädagogische Kompetenzâ ein Konzept skizziert, das aus der Medienpädagogik stammt. Dieses theoretische Konzept konfrontieren die Autoren mit eigenen Erfahrungen aus der DurchfĂźhrung von Fortbildungsveranstaltungen im Rahmen des Projekts Me[i]Mus und formulieren anschlieĂend Perspektiven fĂźr zukĂźnftige musikpädagogische Forschungen in diesem Bereich. (DIPF/Orig.
VaĚter haben immer recht--- : eine heitere Selbstkritik
https://digitalrepository.trincoll.edu/eastbooks/1224/thumbnail.jp
MusiklehrerInnen als Lernende. Ăberlegungen zu Strategien der Fortbildung im Fach Musik
Die AusfĂźhrungen dieses Beitrags beruhen auf Forschungsergebnissen aus dem Modellvorhaben Me[i]Mus, das im Rahmen des BLK-Programms "Kulturelle Bildung im Medienzeitalter" (KUBIM) durchgefĂźhrt wurde. (DIPF/Orig.
Ambulatory Thoracoscopic Pleurodesis Combined With Indwelling Pleural Catheter in Malignant Pleural Effusion.
Background and Objective: Malignant pleural effusion (MPE) often results in debilitating symptoms. Relief of dyspnoea and improvement in quality of life can be achieved with either talc pleurodesis or insertion of an indwelling tunneled pleural catheter (IPC). The former requires a lengthy hospital stay and the latter is associated with lower pleurodesis rates. In response to limited hospital bed capacity, we developed a pragmatic approach in managing MPE by combining thoracoscopic talc poudrage and insertion of IPC into a single day case procedure. We present data on the safety and efficacy of this approach. Methods: Patients who had undergone the abovementioned procedure between 2017 and 2020 were analyzed. Demographic data, hospital length of stay (LOS), histological diagnosis, rates of pleurodesis success and procedural related complications were collated. Patients were followed-up for 6 months. Results: Forty-five patients underwent the procedure. Mean age was 68.5 Âą 10.4 years and 56% were male. Histological diagnosis was achieved in all cases. 86.7% of patients were discharged on the day of the procedure. Median LOS was 0 (IQR 0-0) days. Successful pleurodesis was attained in 77.8% at 6-month follow-up. No procedure related deaths or IPC related infections were recorded. Conclusion: Ambulatory thoracoscopic poudrage and IPC insertion is a safe and effective option in the management of MPE. All patients received a definitive pleural intervention with 77.8% pleurodesis success at 6-months and majority of them discharged on the same day. Future randomized trials are required to confirm these findings
MicroRNA-155 Protects Group 2 Innate Lymphoid Cells From Apoptosis to Promote Type-2 Immunity
Group-2 innate lymphoid cells (ILC2) play critical roles in the initiation and maintenance of type-2 immune responses, predominantly through their production of the type-2 cytokines IL-5, IL-9, and IL-13. ILC2 are essential for the efficient elimination of helminth parasites, but also contribute to the detrimental type-2 immune responses that underlie diseases such as asthma and allergy. While several transcription factors have been identified that regulate the development and function of ILC2, less is known about the post-transcriptional mechanisms that regulate these processes. We identified micro-RNAs (miRNAs) that are co-ordinately regulated in ILC2 from mice exposed to two different stimuli, namely IL-33 âalarminâ administration or Nippostrongylus brasiliensis parasitic worm infection. miR-155 is upregulated in ILC2 in response to both stimuli and miR-155â/â mice had impaired IL-33-driven ILC2 responses. Using mixed bone marrow chimeras, we demonstrate that this deficit is intrinsic to ILC2 and that miR-155 protects ILC2 from apoptosis, while having little impact on ILC2 proliferation or cytokine production. These data reveal a subset of miRNAs that are regulated upon ILC2 activation and establish a specific role for miR-155 in regulating ILC2 survival following activation
Radiation-Induced Graft Immobilization (RIGI): Covalent Binding of Non-Vinyl Compounds on Polymer Membranes
Radiation-induced graft immobilization (RIGI) is a novel method for the covalent binding of substances on polymeric materials without the use of additional chemicals. In contrast to the well-known radiation-induced graft polymerization (RIGP), RIGI can use non-vinyl compounds such as small and large functional molecules, hydrophilic polymers, or even enzymes. In a one-step electron-beam-based process, immobilization can be performed in a clean, fast, and continuous operation mode, as required for industrial applications. This study proposes a reaction mechanism using polyvinylidene fluoride (PVDF) and two small model molecules, glycine and taurine, in aqueous solution. Covalent coupling of single molecules is achieved by radical recombination and alkene addition reactions, with water radiolysis playing a crucial role in the formation of reactive solute species. Hydroxyl radicals contribute mainly to the immobilization, while solvated electrons and hydrogen radicals play a minor role. Release of fluoride is mainly induced by direct ionization of the polymer and supported by water. Hydrophobic chains attached to cations appear to enhance the covalent attachment of solutes to the polymer surface. Computational work is complemented by experimental studies, including X-ray photoelectron spectroscopy (XPS) and fluoride high-performance ion chromatography (HPIC)
Comparative Approach to Define Increased Regulatory T Cells in Different Cancer Subtypes by Combined Assessment of CD127 and FOXP3
In recent years an increase of functional CD4+CD25+ regulatory T cells (Treg cells) has been established for patients with
solid tumors, acute leukemias, and lymphomas. We have reported an expanded pool of CD4+CD25high Treg cells in patients
with chronic lymphatic leukemia (CLL), multiple myeloma (MM) as well as its premalignant precursor monoclonal gammopathy of undetermined significance (MGUS). In healthy individuals, low-level expression of
CD127 on T cells in addition to the expression of FOXP3 has been associated with Treg cells. Here, we demonstrate that the expanded FOXP3+ T-cell population in
patients with colorectal cancer, CLL, MGUS, MM, follicular lymphoma, and Hodgkin's disease are exclusively CD127low Treg cells and
were strongly suppressive. A significant portion of CD127lowFOXP3+ Treg cells expressed only low levels of CD25 suggesting
that the previously reported expansion of CD25+ Treg cells underestimates the true expansion. The assessment of CCR7 and CD45RA expression on
the expanded CD4+CD127lowFOXP3+ Treg cells revealed an increase of both naĂŻve as well as central
and effector memory Treg cells in peripheral blood. Our data strongly support superiority of combined CD127 and FOXP3 analysis in comparison to CD25 and FOXP3 assessment
for further quantification of Treg cells in malignant diseases
MicroRNA-155 Protects Group 2 Innate Lymphoid Cells From Apoptosis to Promote Type-2 Immunity.
Group-2 innate lymphoid cells (ILC2) play critical roles in the initiation and maintenance of type-2 immune responses, predominantly through their production of the type-2 cytokines IL-5, IL-9, and IL-13. ILC2 are essential for the efficient elimination of helminth parasites, but also contribute to the detrimental type-2 immune responses that underlie diseases such as asthma and allergy. While several transcription factors have been identified that regulate the development and function of ILC2, less is known about the post-transcriptional mechanisms that regulate these processes. We identified micro-RNAs (miRNAs) that are co-ordinately regulated in ILC2 from mice exposed to two different stimuli, namely IL-33 "alarmin" administration or Nippostrongylus brasiliensis parasitic worm infection. miR-155 is upregulated in ILC2 in response to both stimuli and miR-155-/- mice had impaired IL-33-driven ILC2 responses. Using mixed bone marrow chimeras, we demonstrate that this deficit is intrinsic to ILC2 and that miR-155 protects ILC2 from apoptosis, while having little impact on ILC2 proliferation or cytokine production. These data reveal a subset of miRNAs that are regulated upon ILC2 activation and establish a specific role for miR-155 in regulating ILC2 survival following activation
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