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)

High-Precision Optical Coherence Tomography Navigated Laser Retinopexy for Retinal Breaks

The prevalent cause of retinal detachment is a full-thickness retinal break and the ingress of fluid into the subretinal space. To prevent progression of the detachment, laser photocoagulation (LPC) lesions are placed around the break in clinical practice to seal the tissue. Unlike the usual application under indirect ophthalmoscopy, we developed a semi-automatic treatment planning software based on a sequence of optical coherence tomography (OCT) scans to perform navigated LPC treatment. The depth information allows demarcation of the border where the neurosensory retina is still attached to the retinal pigment epithelium (RPE), which is critical for prevention of detachment progression. To evaluate the method, artificially provoked retinal breaks were treated in seven ex-vivo porcine eyes. Treatment outcome was assessed by fundus photography and OCT imaging. The automatically applied lesions surrounding each detachment (4.4–39.6 mm2) could be identified as highly scattering coagulation regions in color fundus photography and OCT. Between the planned and applied pattern, a mean offset of 68 µm (SD ± 16.5 µm) and a mean lesion spacing error of 5 µm (SD ± 10 µm) was achieved. The results demonstrate the potential of navigated OCT-guided laser retinopexy to improve overall treatment accuracy, efficiency, and safety

Renal Allograft Survival in Transplant Recipients with Focal Segmental Glomerulosclerosis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73852/1/j.1600-6143.2003.30111.x.pd

The potential of collaborative drawing for literacy engagement and identity affirmation in multilingual settings: Guidance for practice and research

This is the final version. Available from Tilburg University via the link in this recordIn this article we explore multimodal communication, specifically drawing in a team, as a tool for literacy engagement and identity affirmation. For this, we developed and trialled collaborative drawing (CD) activities to engage 9 children and 8 adults in non-verbal and verbal communication. We collected photographic, video and audio data which we analysed using an exploratory approach, incorporating thematic analysis. Current research on collaborative drawing does not consider literacy engagement, identity affirmation or how teachers could use this communication method to engage diverse learners, and our study contributes to this gap. Our findings suggest that the CD approach has potential to facilitate literacy engagement and identity affirmation in multilingual settings, but its application in classrooms also has its challenges. This article, thus provides guidance for teachers with an interest in exploring collaborative drawing in practice, and it prepares the ground for further research in this this underresearched field

Observation of a kilogram-scale oscillator near its quantum ground state

We introduce a novel cooling technique capable of approaching the quantum ground state of a kilogram-scale system-an interferometric gravitational wave detector. The detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) operate within a factor of 10 of the standard quantum limit (SQL), providing a displacement sensitivity of 10(-18) m in a 100 Hz band centered on 150 Hz. With a new feedback strategy, we dynamically shift the resonant frequency of a 2.7 kg pendulum mode to lie within this optimal band, where its effective temperature falls as low as 1.4 mu K, and its occupation number reaches about 200 quanta. This work shows how the exquisite sensitivity necessary to detect gravitational waves can be made available to probe the validity of quantum mechanics on an enormous mass scale.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of NiedersachsenAustralian Research CouncilCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Educacion y CienciaConselleria d’Economia Hisenda i Innovacio of the Govern de les Illes BalearsScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan Foundatio

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

Rescue-Prime Optimized

This note specifies two instances of a hash function obtained from applying the Marvellous design strategy to a specific context. The context in question is native hashing in a STARKVirtual Machine such as Miden

Investigation of material deformation mechanism in double side incremental sheet forming

Double side incremental forming (DSIF) is an emerging technology in incremental sheet forming (ISF) in recent years. By employing two forming tools at each side of the sheet, the DSIF process can provide additional process flexibility, comparing to the conventional single point incremental forming (SPIF) process, therefore to produce complex geometries without the need of using a backing plate or supporting die. Although this process has been proposed for years, there is only limited research on this process and there are still many unanswered open questions about this process. Using a newly developed ISF machine, the DSIF process is investigated in this work. Focusing on the fundamental aspects of material deformation and fracture mechanism, this paper aims to improve the understanding of the DSIF process. Two key process parameters considered in this study include the supporting force and relative position between master and slave tools. The material deformation, the final thickness distribution as well as the formability under varying conditions of these two process variables are investigated. An analytical model was developed to evaluate the stress state in the deformation zone. Using the developed model, an explicit relationship between the stress state and key process parameters was established and a drop of stress triaxiality was observed in the double contact zone, which explains the enhanced formability in the DSIF process. Based on the analytical and experimental investigation, the advancements and challenges of the DSIF process are discussed with a few conclusions drawn for future research

PVDF and P(VDF-TrFE) Electrospun Scaffolds for Nerve Graft Engineering: A Comparative Study on Piezoelectric and Structural Properties, and In Vitro Biocompatibility

Polyvinylidene fluoride (PVDF) and its copolymer with trifluoroethylene (P(VDF-TrFE)) are considered as promising biomaterials for supporting nerve regeneration because of their proven biocompatibility and piezoelectric properties that could stimulate cell ingrowth due to their electrical activity upon mechanical deformation. For the first time, this study reports on the comparative analysis of PVDF and P(VDF-TrFE) electrospun scaffolds in terms of structural and piezoelectric properties as well as their in vitro performance. A dynamic impact test machine was developed, validated, and utilised, to evaluate the generation of an electrical voltage upon the application of an impact load (varying load magnitude and frequency) onto the electrospun PVDF (15–20 wt%) and P(VDF-TrFE) (10–20 wt%) scaffolds. The cytotoxicity and in vitro performance of the scaffolds was evaluated with neonatal rat (nrSCs) and adult human Schwann cells (ahSCs). The neurite outgrowth behaviour from sensory rat dorsal root ganglion neurons cultured on the scaffolds was analysed qualitatively. The results showed (i) a significant increase of the β-phase content in the PVDF after electrospinning as well as a zeta potential similar to P(VDF-TrFE), (ii) a non-constant behaviour of the longitudinal piezoelectric strain constant d33, depending on the load and the load frequency, and (iii) biocompatibility with cultured Schwann cells and guiding properties for sensory neurite outgrowth. In summary, the electrospun PVDF-based scaffolds, representing piezoelectric activity, can be considered as promising materials for the development of artificial nerve conduits for the peripheral nerve injury repair