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Aim: This study aimed to compare several specific staining protocols recommended for paraffin sections and toluidine blue and light green double staining combination to be tried for the first time with routine toluidine blue staining on semithin epon sections. Material and Methods: Samples of 1x1x1 mm were taken from the liver, skin, and aorta tissues of Wistar albino adult rats. Tissue samples were fixed with 5% glutaraldehyde at +4º C overnight, postfixed with 1% osmium tetroxide for one hour, and then, blocked with Epon 812 after processing. Semithin sections of 1 μm thickness were obtained from the epon blocks. Sections were stained with Altmann’s method (for mitochondria), Verhoeff’s method (for elastic fibers), Gordon&Sweets’ silver impregnation method (for type III collagen), toluidine blue and light green double staining combination (for type I collagen) and routine toluidine blue method. Results: In liver sections, mitochondria in hepatocytes were differentiated by the Altmann method, and stromal type III collagen fibers were distinguished with Gordon&Sweets’ method. Elastic lamellar structures were easily observed in black in the aortic sections stained with the Verhoeff method. Successful results were obtained in the staining of dermal type I collagen with toluidine blue and light green double staining in skin sections. Conclusion: Since the specific staining tried for the first time gave positive results in epon sections, it was concluded that these methods can be used to determine the localization of cellular and intercellular components that are aimed to be examined at the ultrastructural level.

A passive optical network (PON) is an auspicious access technology that keeps track of emerging application diversity. When it comes to the point of handling multiple service types together in the same network with resource limitation, there comes the important term of prioritization as all of the services do not need the same quality of service. In this paper, an efficient resource allocation scheme based on service prioritization is proposed for 100 Gb/s next-generation Ethernet passive optical network (NG-EPON) upstream. Higher-priority service quality is ensured despite load fluctuation. The proposed prioritization scheme by accessing the multiple wavelengths for higher-priority service classes also enhances bandwidth utilization. Higher-priority classes can work suitably using excess bandwidth occupied by the low-priority services during increasing demand. Further increment can preempt low-priority bandwidth for higher-priority services. We performed extensive simulation and got that at 11 % overloaded network case, the highest priority service delay of 379 msec decreased to 5 msec from the non-priority scheme to the priority scheme. The jitter of 1.06 μsec decreased to 0.035 μsec. This prioritization does not decrease the bandwidth utilization which was found near 99.26 % excluding the overhead. The proposed scheme achieves stable performance of the higher-priority service classes.

To guarantee the reliability of Tactile Internet (TI) applications such as telesurgery, which demand extremely high reliability and are experiencing rapid expansion, we propose a novel smart resilience mechanism for Next-Generation Ethernet Passive Optical Networks (NG-EPONs). Our architecture integrates Artificial Intelligence (AI) and Software-Defined Networking (SDN)-Enabled Broadband Access (SEBA) platform to proactively enhance network reliability and performance. By harnessing the AI’s capabilities, our system automatically detects and localizes fiber faults, establishing backup communication links using Radio Frequency over Glass (RFoG) to prevent service disruptions. This empowers NG-EPONs to maintain uninterrupted, high-quality network service even in the face of unexpected failures, meeting the stringent Quality-of-Service (QoS) requirements of critical TI applications. Our AI model, rigorously validated through 5-fold cross-validation, boasts an average accuracy of 81.49%, with a precision of 84.33%, recall of 78.18%, and F1-score of 81.00%, demonstrating its robust performance in fault detection and prediction. The AI model triggers immediate corrective actions through the SDN controller. Simulation results confirm the efficacy of our proposed mechanism in terms of delay, system throughputs and packet drop rate, and bandwidth waste, ultimately ensuring the delivery of high-quality network services.

Background Post-induction anaesthesia often promotes intraoperative hypotension (IOH) that can worsen postoperative outcomes. This study aims to assess the benefit of norepinephrine versus ephedrine at the induction of anaesthesia to prevent postoperative complications following major abdominal surgery by preventing IOH.Methods and analysis The EPON STUDY is a prospective single-centre randomised controlled trial with the planned inclusion of 500 patients scheduled for major abdominal surgery at the Amiens University Hospital. The inclusion criteria are patients aged over 50 years weighing more than 50 kg with an American Society of Anesthesiologists physical status score of ≥2 undergoing major abdominal surgery under general anaesthesia. Patients are allocated either to the intervention group (n=250) or the standard group (n=250). In the intervention group, the prevention of post-induction IOH is performed with norepinephrine (dilution to 0.016 mg/mL) using an electric syringe pump at a rate of 0.48 mg/h (30 mL/h) from the start of anaesthesia and then titrated to achieve the haemodynamic target. In the control group, the prevention of post-induction IOH is performed with manual titration of ephedrine, with a maximal dose of 30 mg, followed by perfusion with norepinephrine. In both groups, the haemodynamic target to maintain is a mean arterial pressure (MAP) of 65 mm Hg or 70 mm Hg for patients with a medical history of hypertension. An intention-to-treat analysis will be performed. The primary outcome is the Clavien–Dindo score assessed up to 30 days postoperatively. The secondary endpoints are the length of hospital stay and length of stay in an intensive care unit/postoperative care unit; postoperative renal function; postoperative cardiovascular, respiratory, neurological, haematological and infectious complications at 1 month; and volume of intraoperative vascular filling and mortality at 1 month.Ethics and dissemination Ethical approval was obtained from the committee of protection of the persons of Ile de France in May 2021 (number 21 05 41). The authors will be involved in disseminating the research findings (through attending conferences and co-authoring papers). The results of the study will be disseminated via peer-reviewed publications and presentations at national and international conferences.Trial registration number NCT05276596.

Correlative light and electron microscopy (CLEM) combines light microscopy (LM) of fluorescent samples to ultrastructural analyses by electron microscopy (EM). Pre-embedding CLEM often suffers from inaccurate correlation between LM and EM modalities. Post-embedding CLEM enables precise registration of structures directly on EM sections, but requires fluorescent markers withstanding EM sample preparation, especially osmium tetroxide fixation, dehydration and EPON embedding. Most fluorescent proteins (FPs) lose their fluorescence during such conventional embedding (CE), but synthetic dyes represent promising alternatives as their stability exceeds those of FP. We analyzed various Janelia Fluor dyes and TMR conjugated to ligands for self-labeling enzymes, such as HaloTag, for fluorescence preservation after CE. We show that TMR, JF525, JF549, JFX549 and JFX554 retain fluorescence, with JFX549 and JFX554 yielding best results overall, also allowing integration of high-pressure freezing and freeze substitution. Furthermore, we found the recently published FP StayGold to resist CE, facilitating dual-fluorescence in-resin CLEM.

The IEEE 802.3ca Task Force group has recently approved the standardization of the next-generation Ethernet passive optical network (NG-EPON) to satisfy future bandwidth demands. NG-EPON architecture classifies the optical network unit (ONU) transmission to allow simultaneous Wavelength-Agile (WA-PON) transmission, which increases the network capacity (50 Gb/s) and flexibility. The recently launched 5G services and related functional standards, new capabilities, and quality of service (QoS) imposed on the optical transport network. The Peer-to-peer (P2P) based live streaming application is the most popular multimedia application in access networks, i.e., Facebook Live, YouTube Live, Twitch, and other streaming and video conferencing services are increasing, especially in global epidemics which requires a higher QoS. Hence, media-based applications require adequate infrastructure resources to meet customer demands such as high bandwidth, low latency, high quality audiovisual, live streaming, and services. Therefore, this paper proposes an SDN enhanced P2P virtual reality (VR) live video streaming application NG-EPON multicast architecture based on 5G-enabled Tactile Internet (TI) and aims to improve the QoS, QoE and provide flexible services to the end-users. Finally, we proposed an SDN-based TI-dynamic wavelength and bandwidth allocation (SD-TI-DWBA) mechanism. Simulation results show that our proposed architecture can improve the system performance and QoS metrics regarding packet delay, jitter, system throughput, and packet loss.

In this paper, an (ONU-load and RTTs)-based (OLR) dynamic wavelength and bandwidth allocation (DWBA) algorithm for upstream channel in next-generational Ethernet passive optical network (NG-EPON) is proposed. By proposing adaptive threshold grouping algorithm, the waste of bandwidth resources caused by massive guard timeslots and mismatch between assigned transmission window and frame size is reduced. By adjusting the Optical Network Unit (ONU) scheduling order, the idle time caused by Round-Trip Times (RTTs) is reduced. By proposing joint ONU grouping and RTT scheduling mechanism, load balance among wavelengths is achieved. By proposing a fair allocation scheme, the fairness of bandwidth granting for each ONU is ensured. Finally, by the simulation, the effectiveness of proposed algorithm is demonstrated. The simulation indicates that the rate of bandwidth utilization, the average package delay, the scheduling cycle and the network throughput in the system based on proposed algorithm have better performance.

According to the description of 50 Gbit/s-Ethernet Passive Optical Network (EPON) in IEEE 802.3ca new standard, multi-wavelength dynamic bandwidth allocation is needed in network uplink. In this paper, long short-term memory neural network is used to predict the network traffic in order to improve the efficiency of bandwidth allocation. At the same time, considering the different requirements of network delay and bandwidth for different types of services in the network, different allocation schemes are adopted for different priority services. The simulation results show that the neural network prediction method can effectively reduce the delay of the network. When different allocation schemes are adopted for different services, the latency of high-priority services decreases, and the latency varies with the increase of network load. The algorithm proposed in this paper meets the requirements of high-priority service. Although the latency of low-priority service is increased compared with the previous method, it has little impact on the overall service quality of the network considering that low-priority service does not have high latency requirements.

According to the description of 50 Gbit/s-Ethernet Passive Optical Network (EPON) in IEEE 802.3ca new standard, multi-wavelength dynamic bandwidth allocation is needed in network uplink. In this paper, long short-term memory neural network is used to predict the network traffic in order to improve the efficiency of bandwidth allocation. At the same time, considering the different requirements of network delay and bandwidth for different types of services in the network, different allocation schemes are adopted for different priority services. The simulation results show that the neural network prediction method can effectively reduce the delay of the network. When different allocation schemes are adopted for different services, the latency of high-priority services decreases, and the latency varies with the increase of network load. The algorithm proposed in this paper meets the requirements of high-priority service. Although the latency of low-priority service is increased compared with the previous method, it has little impact on the overall service quality of the network considering that low-priority service does not have high latency requirements.

Aim: This study aimed to compare several specific staining protocols recommended for paraffin sections and toluidine blue and light green double staining combination to be tried for the first time with routine toluidine blue staining on semithin epon sections. Material and Methods: Samples of 1x1x1 mm were taken from the liver, skin, and aorta tissues of Wistar albino adult rats. Tissue samples were fixed with 5% glutaraldehyde at +4º C overnight, postfixed with 1% osmium tetroxide for one hour, and then, blocked with Epon 812 after processing. Semithin sections of 1 μm thickness were obtained from the epon blocks. Sections were stained with Altmann's method (for mitochondria), Verhoeff's method (for elastic fibers), Gordon&Sweets' silver impregnation method (for type III collagen), toluidine blue and light green double staining combination (for type I collagen) and routine toluidine blue method. Results: In liver sections, mitochondria in hepatocytes were differentiated by the Altmann method, and stromal type III collagen fibers were distinguished with Gordon&Sweets' method. Elastic lamellar structures were easily observed in black in the aortic sections stained with the Verhoeff method. Successful results were obtained in the staining of dermal type I collagen with toluidine blue and light green double staining in skin sections. Conclusion: Since the specific staining tried for the first time gave positive results in epon sections, it was concluded that these methods can be used to determine the localization of cellular and intercellular components that are aimed to be examined at the ultrastructural level. [ABSTRACT FROM AUTHOR]

Optical networks have undergone a remarkable transformation with the adoption of Artificial Intelligence (AI) techniques such as Machine Learning (ML) and Deep Learning (DL). The Next Generation (NG)-EPON is one such technology that is essential for supporting high-bandwidth applications like 4K video streaming, ultra-high-definition (UHD) CCTV, and other emerging video-type applications that have strict Quality-of-Service (QoS) requirements. In this paper, we present a ground-breaking Temporal Dynamic Wavelength Bandwidth Allocation (T-DWBA) mechanism based on the Long-Short-Term-Memory (LSTM) architecture. The T-DWBA uses past experiences to learn data as knowledge and predict time series with time lags of unknown size. Our proposed mechanism reduces upstream control message overheads, eliminates idle periods, and significantly improves bandwidth utilization, ensuring superior QoS specifically for video-type applications. The simulation results show that the T-DWBA significantly enhances system performance, reducing packet delay, and jitter, and improving bandwidth utilization. The use of AI techniques like ML and DL coupled with the recent advancements in SDN-Enabled Broadband Access (SEBA), hardware/software, and cloud technologies provide the perfect platform for deploying our proposed T-DWBA mechanism. Overall, our research proposes a promising solution for boosting EPON performance, revolutionizing optical networks, and providing seamless access to high-quality video streaming for a next-generation audience.

Background: Post-induction anaesthesia often promotes intraoperative hypotension (IOH) that can worsen postoperative outcomes. This study aims to assess the benefit of norepinephrine versus ephedrine at the induction of anaesthesia to prevent postoperative complications following major abdominal surgery by preventing IOH., Methods and Analysis: The EPON STUDY is a prospective single-centre randomised controlled trial with the planned inclusion of 500 patients scheduled for major abdominal surgery at the Amiens University Hospital. The inclusion criteria are patients aged over 50 years weighing more than 50 kg with an American Society of Anesthesiologists physical status score of ≥2 undergoing major abdominal surgery under general anaesthesia. Patients are allocated either to the intervention group (n=250) or the standard group (n=250). In the intervention group, the prevention of post-induction IOH is performed with norepinephrine (dilution to 0.016 mg/mL) using an electric syringe pump at a rate of 0.48 mg/h (30 mL/h) from the start of anaesthesia and then titrated to achieve the haemodynamic target. In the control group, the prevention of post-induction IOH is performed with manual titration of ephedrine, with a maximal dose of 30 mg, followed by perfusion with norepinephrine. In both groups, the haemodynamic target to maintain is a mean arterial pressure (MAP) of 65 mm Hg or 70 mm Hg for patients with a medical history of hypertension. An intention-to-treat analysis will be performed. The primary outcome is the Clavien-Dindo score assessed up to 30 days postoperatively. The secondary endpoints are the length of hospital stay and length of stay in an intensive care unit/postoperative care unit; postoperative renal function; postoperative cardiovascular, respiratory, neurological, haematological and infectious complications at 1 month; and volume of intraoperative vascular filling and mortality at 1 month., Ethics and Dissemination: Ethical approval was obtained from the committee of protection of the persons of Ile de France in May 2021 (number 21 05 41). The authors will be involved in disseminating the research findings (through attending conferences and co-authoring papers). The results of the study will be disseminated via peer-reviewed publications and presentations at national and international conferences., Trial Registration Number: NCT05276596., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract Biotin ligases have been developed as proximity biotinylation enzymes for analyses of the interactome. However, there has been no report on the application of proximity labeling for in-resin correlative light-electron microscopy of Epon-embedded cells. In this study, we established a proximity-labeled in-resin CLEM of Epon-embedded cells using miniTurbo, a biotin ligase. Biotinylation by miniTurbo was observed in cells within 10 min following the addition of biotin to the medium. Using fluorophore-conjugated streptavidin, intracellular biotinylated proteins were labeled after fixation of cells with a mixture of paraformaldehyde and glutaraldehyde. Fluorescence of these proteins was resistant to osmium tetroxide staining and was detected in 100-nm ultrathin sections of Epon-embedded cells. Ultrastructures of organelles were preserved well in the same sections. Fluorescence in sections was about 14-fold brighter than that in the sections of Epon-embedded cells expressing mCherry2 and was detectable for 14 days. When mitochondria-localized miniTurbo was expressed in the cells, mitochondria-like fluorescent signals were detected in the sections, and ultrastructures of mitochondria were observed as fluorescence-positive structures in the same sections by scanning electron microscopy. Proximity labeling using miniTurbo led to more stable and brighter fluorescent signals in the ultrathin sections of Epon-embedded cells, resulting in better performance of in-resin CLEM.

In-resin CLEM (Correlative Light and Electron Microscopy) of Epon-embedded cells involves correlating fluorescence microscopy with electron microscopy in the same Epon-embedded ultrathin section. This method offers the advantage of high positional accuracy compared to standard CLEM. However, it requires the expression of recombinant proteins. In order to detect the localization of endogenous target(s) and their localized ultrastructures of Epon-embedded samples using in-resin CLEM, we investigated whether immunological and affinity-labeling using fluorescent dyes applied to in-resin CLEM of Epon-embedded cells. The orange fluorescent (λem ∼550 nm) and far-red (λem ∼650 nm) fluorescent dyes examined maintained a sufficient level of fluorescent intensity after staining with osmium tetroxide and subsequent dehydration treatment with ethanol. Immunological in-resin CLEM of mitochondria and the Golgi apparatus was achieved using anti-TOM20, anti-GM130 antibodies, and fluorescent dyes. Two-color in-resin CLEM revealed that wheat germ agglutinin-puncta showed the ultrastructures of multivesicular body-like structures. Finally, taking the advantage of high positional accuracy, volume in-resin CLEM of mitochondria in the semi-thin section (2 μm thick) of Epon-embedded cells was performed by focused ion beam scanning electron microscopy. These results suggested that the application of immunological reaction and affinity-labeling with fluorescent dyes to in-resin CLEM of Epon-embedded cells is suitable for analyzing the localization of endogenous targets and their ultrastructures by scanning and transmission electron microscopy.

For the future high-speed next-generation Ethernet passive optical network (NG-EPON) system, the low-cost system could be kept by adopting low bandwidth devices. To compensate for the signal distortion and improve the performance of high-speed bandwidth limited system, we propose a special feature vector construction to achieve a new equalizer scheme based on support vector machines (SVM) classifier. For the first time, we mathematically analyze the model of the bandwidth-limited optical transmission system and theoretically derive the linear separability of the proposed feature vector formed linear hyperplane in 100-Gb/s NG-EPON system. Furthermore, 4 × 25-Gb/s non-return to zero (NRZ) and 2 × 50-Gb/s four-level pulse amplitude modulation (PAM-4) per wavelength transmission experiments with 10-G class optics system are demonstrated to prove the feasibility of our scheme. The experimental results show that, for 25-Gb/s/λ NRZ transmission, compared to the decision feedback equalizer (DFE) and feed-forward equalizer (FFE), the receiver sensitivity achieved by our scheme can be improved by about 0.5-dB @BER=3.8e-3 with limited training sequence. For the 50-Gb/s/λ PAM-4 case, the SVM-based equalization method improves the receiver sensitivity for about 1-dB.

Correlative light and electron microscopy (CLEM) is a comprehensive microscopy that combines the localization information provided by fluorescence microscopy (FM) and the context of cellular ultrastructure acquired by electron microscopy (EM). CLEM is a trade-off between fluorescence and ultrastructure, and usually, ultrastructure compromises fluorescence. Compared with other hydrophilic embedding resins, such as glycidyl methacrylate, HM20, or K4M, Epon is superior in ultrastructure preservation and sectioning properties. Previously, we had demonstrated that mEosEM can survive osmium tetroxide fixation and Epon embedding. Using mEosEM, we achieved, for the first time, Epon post embedding CLEM, which maintains the fluorescence and the ultrastructure simultaneously. Here, we provide step-by-step details about the EM sample preparation, the FM imaging, the EM imaging, and the image alignment. We also improve the procedures for identifying the same cell imaged by FM imaging during the EM imaging and detail the registration between the FM and EM images. We believe one can easily achieve Epon post embedding correlative light and electron microscopy following this new protocol in traditional EM facilities.