Schule zwischen Harmonie und Aufstand. SchülerInnenmitbestimmung an den Zürcher LehrerInnenseminaren um 1918

Im Beitrag geht es um die Mitbestimmung von Schülerinnen und Schülern an drei Zürcher Lehrpersonenseminaren um 1918. Der Text untersucht, inwiefern sich die Etablierung von institutionalisierten Mitbestimmungsformen an den Seminaren in ein Narrativ von emanzipatorischem Aufbegehren und kriegsbedingten sozialen Unruhen um 1918 einschreiben lassen. Anhand der Chiffre 1918 loten die Autoren Kontinuitäten und Brüche aus, legen Verflechtungen mit reformpädagogischen Diskursen und den zeitgenössischen Jugendbewegungen frei, um Krieg und Revolution nicht a priori als Erklärungen für die Konflikte um Mitbestimmung der Schülerinnen und Schüler festzulegen. Mit derart geweitetem Blick und theoretischen Bezügen zu Luc Boltanski und Laurent Thévenot setzen sie bei der Kritik der Akteurinnen und Akteure an und gelangen durch diese Perspektivierung zu neuen Bewertungen teilweise bereits bekannter Handlungen. Der Beitrag zeichnet mit dem über drei verschiedene Zürcher Ausbildungsorte gespannten Vergleich unter Einbezug und Diskussion ähnlicher Formierungen wie etwa Schülerinnen- und Schülervereine oder Elternmitbestimmung ein tiefenscharfes Bild der unterschiedlichen Facetten von Mitbestimmung. Auf einer Metaebene werden angesichts der spärlichen und meist retrospektiven Quellen von beteiligten Seminaristinnen und Seminaristen zudem Verhältnis und Aussagewert von Erinnerung und in der Erinnerung überliefertem Ereignis ausgelotet und allfällige Verzerrungen quellenkritisch reflektiert. (DIPF/Orig.

Schule zwischen Harmonie und Aufstand. SchülerInnenmitbestimmung an den Zürcher LehrerInnenseminaren um 1918

Im Beitrag geht es um die Mitbestimmung von Schülerinnen und Schülern an drei Zürcher Lehrpersonenseminaren um 1918. Der Text untersucht, inwiefern sich die Etablierung von institutionalisierten Mitbestimmungsformen an den Seminaren in ein Narrativ von emanzipatorischem Aufbegehren und kriegsbedingten sozialen Unruhen um 1918 einschreiben lassen. Anhand der Chiffre 1918 loten die Autoren Kontinuitäten und Brüche aus, legen Verflechtungen mit reformpädagogischen Diskursen und den zeitgenössischen Jugendbewegungen frei, um Krieg und Revolution nicht a priori als Erklärungen für die Konflikte um Mitbestimmung der Schülerinnen und Schüler festzulegen. Mit derart geweitetem Blick und theoretischen Bezügen zu Luc Boltanski und Laurent Thévenot setzen sie bei der Kritik der Akteurinnen und Akteure an und gelangen durch diese Perspektivierung zu neuen Bewertungen teilweise bereits bekannter Handlungen. Der Beitrag zeichnet mit dem über drei verschiedene Zürcher Ausbildungsorte gespannten Vergleich unter Einbezug und Diskussion ähnlicher Formierungen wie etwa Schülerinnen- und Schülervereine oder Elternmitbestimmung ein tiefenscharfes Bild der unterschiedlichen Facetten von Mitbestimmung. Auf einer Metaebene werden angesichts der spärlichen und meist retrospektiven Quellen von beteiligten Seminaristinnen und Seminaristen zudem Verhältnis und Aussagewert von Erinnerung und in der Erinnerung überliefertem Ereignis ausgelotet und allfällige Verzerrungen quellenkritisch reflektiert. (DIPF/Orig.

Optical Coherence Tomography Navigated Laser Retinopexy for Retinal Breaks

The prevalent cause of retinal detachment is a full-thickness retinal break, which allows fluid to enter the subretinal space from the vitreous cavity. To prevent progression of the detachment, laser photocoagulation (LPC) lesions are placed around the break in clinical practice to seal the tissue. The treatment is usually performed under indirect ophthalmoscopy. Therefore, the subretinal damage can be difficult to delineate and an experienced operator is required for a successful outcome. In this work, optical coherence tomography (OCT) is used for optimal treatment planning, and LPC is subsequently applied in a navigated and user-friendly procedure. The novel method was integrated in a modified OCT diagnostic system (SPECTRALIS OCT, Heidelberg Engineering, Heidelberg, Germany) with integrated treatment laser (Merilas 532 shortpulse, Meridian, Thun, Switzerland). To reliably seal the break, LPC lesions must be applied in regions of still attached retina. Therefore, OCT B-scans were used to manually mark the boundary of the surrounding detachment, which allowed to compute an optimally placed elliptical treatment area. To evaluate the method, artificially provoked retinal breaks were treated accordingly in 10 ex-vivo porcine eyes and the outcome was assessed by fundus photography and OCT imaging. Ex-vivo experiments showed that OCT-based laser treatment is feasible and the visibility of the subretinal space allows precise treatment planning. A total of 99 to 227 automatically applied lesions per eye at 200 ms and 200 mW were evident as coagulation in color fundus photography. Furthermore, OCT cross-sectional scans showed the required ruptures of the retina at the LPC application sites (Figure 1). The results indicate the potential of OCT navigated laser retinopexy to achieve high treatment accuracy, efficiency, and safety. Future studies should address treatment of peripheral breaks and the integration of the existing tracking and follow-up functionalities to further enhance and facilitate the treatment. This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually. Retinal break treatment outcome in an ex-vivo porcine eye. Fundus photographs before (A) and after (B) treatment, infrared scanning laser ophthalmoscope images before (C) and after (E) treatment with the corresponding OCT B-scans (D)(F). The effect of LPC treatment is visible in (B)(E) as spots of whitened tissue and in (F) as ruptures in the retina at the treatment sites (marked in red)

BICAR : urban light electric vehicle

This paper describes the technical features of the light electric vehicle (L2e-category) named BICAR. This specially designed vehicle is an all-in-one emissions-free micro-mobility solution providing a cost-effective and sustainable mobility system while supporting the transition towards a low carbon society (smart and sustainable city concept). The BICAR represents part of a multimodal system, complementing public transport with comfort and safety, relieving inner-city congestion and solving the “first and last mile” issue. The BICAR is the lightest and smallest three-wheel vehicle with weather protection. Due to the space-saving design, six to nine BICARS will fit into a single standard parking space. Safety is increased by an elevated driving position and a tilting mechanism when cornering. The BICAR achieves a range of 40–60 km depending on the battery package configuration in urban transport at a speed of 45 km/h. It features a luggage storage place and exchangeable, rechargeable batteries. The BICAR can be driven without a helmet thanks to the safety belt system, which is engineered for street approved tests. The BICAR has an integrated telematic box connected to the vehicle electronics and communicating with the dedicated mobile application, through which the BICAR can be geo-localised, reserved, locked/unlocked and remotely maintained

Dynamic OCT Signal Loss for Determining RPE Radiant Exposure Damage Thresholds in Microsecond Laser Microsurgery

Optical microsurgery of the retinal pigment epithelium (RPE) requires reliable real-time dosimetry to prevent unwanted overexposure of the neuroretina. The system used in this experiment implements optical coherence tomography (OCT) to detect the intentional elimination of RPE cells. We evaluated the performance of OCT dosimetry in terms of its ability to detect RPE cell damage caused by microsecond laser pulses of varying duration. Therefore, ex-vivo porcine RPE choroid sclera explants were embedded in an artificial eye and exposed to single laser pulses of 2–20 µs duration (wavelength: 532 nm, exposure area: 120 × 120 µm2, intensity modulation factor: 1.3). Simultaneously, time-resolved OCT M-scans were recorded (central wavelength: 870 nm, scan rate: 33 kHz). Post-irradiation, RPE cell damage was quantified using a calcein-AM viability assay and compared with an OCT-dosimetry algorithm. The results of our experiments show that the OCT-based analysis successfully predicts RPE cell damage. At its optimal operating point, the algorithm achieved a sensitivity of 89% and specificity of 94% for pulses of 6 µs duration and demonstrated the ability to precisely control radiant exposure of a wide range of pulse durations towards selective real-time laser microsurgery

Selective Large-Area Retinal Pigment Epithelial Removal by Microsecond Laser in Preparation for Cell Therapy

Purpose: Cell therapy is a promising treatment for retinal pigment epithelium (RPE)- associated eye diseases such as age-related macular degeneration. Herein, selective microsecond laser irradiation targeting RPE cells was used for minimally invasive, large- area RPE removal in preparation for delivery of retinal cell therapeutics. Methods: Ten rabbit eyes were exposed to laser pulses 8, 12, 16, and 20 μs in duration (wavelength, 532 nm; top-hat beam profile, 223 × 223 μm2). Post-irradiation retinal changes were assessed with fluorescein angiography (FA), indocyanine green angiogra- phy (ICGA), and optical coherence tomography (OCT). RPE viability was evaluated with an angiographic probit model. Following vitrectomy, a subretinal injection of balanced salt solution was performed over a lasered (maximum 13.6 mm2) and untreated control area. Bleb retinal detachment (bRD) morphology was then evaluated by intraoperative OCT. Results: Within 1 hour after irradiation, laser lesions showed FA and ICGA leakage. OCT revealed that large-area laser damagewas limited to the RPE. The angiographic median effective dose irradiation thresholds (ED50)were45μJ(90 mJ/cm2)at8μs,52μJ(104 mJ/cm2) at 12 μs, 59 μJ (118 mJ/cm2)at16μs,and71μJ(142mJ/cm2) at 20 μs. Subretinal injection over the lasered area resulted in a controlled, shallowbRD rise, whereas control blebs were convex in shape, with less predictable spread. Conclusions: Large-area, laser-based removal ofhost RPEwithout visible photoreceptor damage is possible and facilitates surgical retinal detachment. Translational Relevance: Selective microsecond laser-based, large-area RPE removal prior to retinal cell therapy may reduce iatrogenic trauma. Introductio

Real-Time Optical Coherence Tomography Controlled Microsecond Laser Retinal Microsurgery: First In-vivo Results

Reliable mild photocoagulation and selective retina therapy (SRT) selectively damaging the retinal pigment epithelium (RPE) while sparing the neuroretina, the photoreceptors as well as the choroid are highly demanded. However, due to the inter- and intraindividual variability of RPE and choroidal absorption, optical microsurgery requires reliable real-time laser dosing to prevent unwanted overexposure and extended damage of the neuroretina. In this experiment optical coherence tomography (OCT) was implemented to detect minimal damage, and a laser feedback control algorithm was used for real-time dosing. For the first time in-vivo experiments on rabbits were performed with microsecond laser pulses of varying duration. Pigment rabbit eyes (n=6) were exposed to laser pulses of 4, 8, 12, and 20 μs in duration (wavelength, 532 nm; ramp-mode, maximum 15 pulses; repetition rate, 100 Hz). Therefore, a system with a scanning laser ophthalmoscope and spectral-domain OCT (Heidelberg Engineering) extended with a prototype laser (Meridian Medical) was used. For each laser lesion, the increasing ramp’s end energy was individually controlled in real-time using OCT dosimetry (central wavelength, 870 nm; scan rate, 80 kHz). Within 1 hour after irradiation, retinal changes were assessed with fluorescein angiography (FA), indocyanine green angiography (ICGA), color fundus photography (CFP) and OCT. OCT dosimetry utilizing the control algorithm can interrupt the ramp-mode in real-time for each lesion individually. The preconditioned algorithm enabled treatment with a clearly visible breakdown of the blood-retinal barrier (BRB) according to FA and ICGA imaging and barely visible treatment lesions according to CFP. OCT B-scans through the treated areas provided a first indication of the morphological tissue impact. Preliminary evaluation shows that the algorithm stopped the laser at 4 μs at a ramp end energy of 53 μJ (corresponds to 13/15 pulses), at 8 μs at 68 μJ (5/15 pulses), at 12 μs at 74 μJ (7/15 pulses), and at 20 μs at 100 μJ (1/15 pulses). The novel system with OCT based laser dosing proved to induce minimal visible damage and BRB breakdown in a wide range of pulse durations. The new irradiation scheme and algorithm are being optimized and tested in multiple subjects to further limit unwanted damage and enable pure RPE selective laser microsurgery in real-time. This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually

Short-term follow up after Large-Area RPE Removal by Microsecond Laser followed by hiPS-RPE suspension transplantation in rabbits

Cell therapy is a promising treatment for retinal pigment epithelium (RPE)-associated eye diseases. Herein, microsecond laser irradiation targeting RPE cells was used for large-area RPE removal followed by subretinal injection of human induced pluripotent stem cell derived RPE (hiPS-RPE). 19 immunosuppressed pigmented rabbits (Chinchilla bastard hybrid) underwent a large area RPE removal using an infrared reflectance (IR) confocal scanning laser ophthalmoscope (cSLO) with spectral-domain optical coherence tomography (SD-OCT) system (Heidelberg Engineering ) extended with a prototype laser (modified Merilas 532 shortpulse ophthalmic laser photocoagulator, Meridian Medical) (wavelength, 532 nm; pulse duration, 8 µs), followed by a 25G vitrectomy. Subsequently, a suspension of hiPS-RPE (1000 cells/ µl) was grafted subretinally into the RPE laser lesion under real-time intraoperative OCT imaging (RESCAN 700, Zeiss) by manual injection via a 25/38G cannula connected to a 100µl Hamilton syringe. 5 rabbits served as a control with hiPS-RPE injected subretinally over healthy RPE. The rabbits were followed with in vivo multimodal retinal imaging at baseline after laser and then for 7 days including fluorescein (FA) and indocyanine angiography (ICGA), aw well as SD-OCT (Spectralis ®, Heidelberg Engineering). Baseline imaging of RPE laser wounds showed mild late phase FA/ICGA leakage, with normal outer retinal and choroidal reflectivity on OCT, without signs of coagulation. The size of the RPE wounds was typically 10-12mm2. Real time iOCT showed a directed spread of the bleb retinal detachment (bRD) within the lasered zone, in contrast to a circular spread in controls. Subretinal injection ranged from 5-20µl, with lesser volumes/ larger bRD areas over lasered regions. At 7 days, implanted regions showed FA/ICGA leakage, blockage due to hyperpigmentation was observed mostly at the edges of the lasered zone; OCT showed hyperreflectivity of the outer retina with RPE irregularities. Control implantation sites showed hyperreflectivity in all retinal layers and a variably thickened RPE band suggesting clumping. Microsecond laser irradiation to the RPE seems to accelerate the subretinal integration of hiPS-RPE, when compared to subretinal injection over intact RPE. Future work will address correlation of multimodal imaging and histology. This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually

Stimulatory MAIT cell antigens reach the circulation and are efficiently metabolised and presented by human liver cells.

OBJECTIVE Mucosal-associated invariant T (MAIT) cells are the most abundant T cells in human liver. They respond to bacterial metabolites presented by major histocompatibility complex-like molecule MR1. MAIT cells exert regulatory and antimicrobial functions and are implicated in liver fibrogenesis. It is not well understood which liver cells function as antigen (Ag)-presenting cells for MAIT cells, and under which conditions stimulatory Ags reach the circulation. DESIGN We used different types of primary human liver cells in Ag-presentation assays to blood-derived and liver-derived MAIT cells. We assessed MAIT cell stimulatory potential of serum from healthy subjects and patients with portal hypertension undergoing transjugular intrahepatic portosystemic shunt stent, and patients with inflammatory bowel disease (IBD). RESULTS MAIT cells were dispersed throughout healthy human liver and all tested liver cell types stimulated MAIT cells, hepatocytes being most efficient. MAIT cell activation by liver cells occurred in response to bacterial lysate and pure Ag, and was prevented by non-activating MR1 ligands. Serum derived from peripheral and portal blood, and from patients with IBD stimulated MAIT cells in MR1-dependent manner. CONCLUSION Our findings reveal previously unrecognised roles of liver cells in Ag metabolism and activation of MAIT cells, repression of which creates an opportunity to design antifibrotic therapies. The presence of MAIT cell stimulatory Ags in serum rationalises the observed activated MAIT cell phenotype in liver. Increased serum levels of gut-derived MAIT cell stimulatory ligands in patients with impaired intestinal barrier function indicate that intrahepatic Ag-presentation may represent an important step in the development of liver disease

Consensus guidelines for the use and interpretation of angiogenesis assays

The formation of new blood vessels, or angiogenesis, is a complex process that plays important roles in growth and development, tissue and organ regeneration, as well as numerous pathological conditions. Angiogenesis undergoes multiple discrete steps that can be individually evaluated and quantified by a large number of bioassays. These independent assessments hold advantages but also have limitations. This article describes in vivo, ex vivo, and in vitro bioassays that are available for the evaluation of angiogenesis and highlights critical aspects that are relevant for their execution and proper interpretation. As such, this collaborative work is the first edition of consensus guidelines on angiogenesis bioassays to serve for current and future reference