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For the first time, we analyzed the degradation as a function of the oxide aperture in 845 nm VCSELs designed for silicon photonics (SiPh) applications. First, we evaluated the optical degradation of the devices by collecting EL images during a constant current stress. The experimental results showed an increased spreading of the optical beam of the VCSEL with increasing ageing time. Based on numerical simulations, we demonstrated that the electrical degradation (increase in series resistance) is responsible for a larger current spreading which, in turn, increases the FWHM (full width half maximum) of the optical beam. We further evaluated the series resistance variation by aging four lasers with different oxide apertures. The results of this set of experiments showed that the electrical degradation is stronger as the oxide aperture is smaller, and mostly depends on the contribution of the top DBR resistance. Thanks to our analysis we proved that the use of a larger aperture can result in a better device reliability.

We demonstrate a new post-processing approach to efficiently couple light in silicon nitride (Si$_{3}$N$_{4}$) photonic integrated circuits (PIC) via grating couplers add-ons. Thin-film coupons of apodised Si$_{3}$N$_{4}$ grating couplers enhanced with metallic bottom reflectors and adiabatic couplers are micro-transfer printed onto the input and output of Si$_{3}$N$_{4}$ waveguides, providing efficient coupling without impacting the rest of the PIC. Two-dimensional FDTD simulations predict coupling efficiencies as large as 62.4$\%$ (−2.0 dB) at a wavelength of 785 nm with a coupling optical fiber tilted at 10$^\circ$. As a proof-of-concept, we report an experimental coupling efficiency of −2.1 dB which is 3 dB better than the value obtained with standard designs of grating couplers.

This article deals for the first time with the electrical degradation of novel 845 nm vertical-cavity silicon-integrated lasers (VCSILs) for silicon photonics (SiPh). We analyzed the reliability of these devices by submitting them to high current stress. The experimental results showed that stress induced: 1) a significant increase in the series resistance, occurring in two separated time-windows and 2) a lowering of the turn-on voltage. To understand the origin of such degradation phenomena, we simulated the ${I}$ - ${V}$ characteristics and the band diagrams by a Poisson-drift-diffusion simulator. We demonstrated that the degradation was caused by the diffusion of mobile species capable of compensating the p-type doping. The diffusing species are expected to migrate from the p-contact region in the top distributed Bragg reflector (DBR) towards the active layers.

A stagewise graph has distinct edge types that represent the different stages. Two nodes can be connected by an edge of the current stage only if an edge of the preceding one is already connecting them. Stagewise graphs can represent many kinds of interactions. For example, a jobseeker-vacancy interaction can be labeled by the subsequent edge types click, apply, job interview, and, finally, hired. Also, biological and medical interactions, such as infection processes or administration of drugs, often occur in stages. In this work, we formalize link prediction problems on such graphs as ‘stagewise link prediction’. Though relevant and rapidly gaining attention, these types of problems are to date highly underexplored. We identify and address arising difficulties, such as competition in stagewise networks. We explore an activation function for stagewise modelling and an evaluation strategy that satisfies the stagewise constraints. We confirm our insights through a set of experiments on both well-chosen simulated data sets and real data related to job recommendation and synthetic biology.

This study aims to guide policymakers in allocating resources and planning for the future by consistently estimating energy data trends. Because of the complexity and uncertainty of energy demand behavior and many influencing factors, we decide to take advantage of a fuzzy regression model to determine the actual relationships in the energy demand system and provide an accurate forecast of energy demand. For this purpose, because of energy demand drivers, fuzzy possibilistic approaches with symmetric and non-symmetric triangular coefficients are integrated with the autoregressive distributed lag (ARDL) model, each in a time-series format with feedback mechanisms inside. After regularizing the L1 (Lasso regression) and L2 (ridge regression) metrics to minimize the overfitting problem, the optimal fuzzy-ARDL model is obtained. Turkey’s primary energy consumption is projected based on the best model by benchmarking the static and dynamic possibilistic fuzzy regression models according to their training and test values.

TiB2+TiB coatings were formed on Ti–6Al–4V through a molten-salt diffusional process at temperatures of 850 °C and 900 °C for 16 h. The thickness of the TiB layer increased by about two times at the higher process temperature, while the thickness of the TiB2layer remained constant. Tribocorrosion rate of Ti–6Al–4V and the coated samples was evaluated in a reciprocating sliding under a normal load of 15 N in a phosphate buffer saline (PBS) solution for 3600–36000 cycles against an alumina ball. The results showed that the tribocorrosion rate of the borided samples decreased up to 56 times compared with Ti–6Al–4V after 36000 cycles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies showed the presence of oxide-rich patches on the wear surface of Ti–6Al–4V with a thickness of up to 1 μm. TEM and atomic force microscopy (AFM) images also revealed the presence of a tribofilm with a thickness of up to 200 nm on the surface of the boride coating. In addition, X-ray photoelectron spectroscopy (XPS) analysis confirmed the tribofilm formed on the wear surface of coated samples contained B2O3/H3BO3compound, resulting in a more stable fluctuation in coefficient of friction and open circuit potential during sliding. The SEM images of the alumina wear surface showed cracks and titanium transfer layers in contact with the borided layers and Ti–6Al–4V, respectively.

ABSTRACTChaperone-assisted selective autophagy (CASA) is a highly selective pathway for the disposal of misfolding and aggregating proteins. In muscle, CASA assures muscle integrity by favoring the turnover of structural components damaged by mechanical strain. In neurons, CASA promotes the removal of aggregating substrates. A crucial player of CASA is HSPB8 (heat shock protein family B (small) member 8), which acts in a complex with HSPA, their cochaperone BAG3, and the E3 ubiquitin ligase STUB1. Recently, four novel HSPB8frameshift (fs) gene mutations have been linked to neuromyopathies, and encode carboxy-terminally mutated HSPB8, sharing a common C-terminal extension. Here, we analyzed the biochemical and functional alterations associated with the HSPB8_fs mutant proteins. We demonstrated that HSPB8_fs mutants are highly insoluble and tend to form proteinaceous aggregates in the cytoplasm. Notably, all HSPB8 frameshift mutants retain their ability to interact with CASA members but sequester them into the HSPB8-positive aggregates together with two autophagy receptors SQSTM1/p62 and TAX1BP1. This copartitioning process negatively affects the CASA capability to remove its clients and causes a general failure in proteostasis response. Further analyses revealed that the aggregation of the HSPB8_fs mutants occurs independently of the other CASA members or from the autophagy receptors interaction, but it is an intrinsic feature of the mutated amino acid sequence. HSPB8_fs mutants aggregation alters the differentiation capacity of muscle cells and impairs sarcomere organization. Collectively, these results shed light on a potential pathogenic mechanism shared by the HSPB8_fs mutants described in neuromuscular diseases.Abbreviations: ACD: α-crystallin domain; ACTN: actinin alpha; BAG3: BAG cochaperone 3; C: carboxy; CASA: chaperone-assisted selective autophagy; CE: carboxy-terminal extension; CLEM: correlative light and electron microscopy; CMT2L: Charcot-Marie-Tooth type 2L; CTR: carboxy-terminal region; dHMNII: distal hereditary motor neuropathy type II; EV: empty vector; FRA: filter retardation assay; fs: frameshift; HSPA/HSP70: heat shock protein family A (Hsp70); HSPB1/Hsp27: heat shock protein family B (small) member 1; HSPB8/Hsp22: heat shock protein family B (small) member 8; HTT: huntingtin; KO: knockout; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MD: molecular dynamics; MTOC: microtubule organizing center; MYH: myosin heavy chain; MYOG: myogenin; NBR1: NBR1 autophagy cargo receptor; CALCOCO2/NDP52: calcium binding and coiled-coil domain 2; NSC34: Neuroblastoma X Spinal Cord 34; OPTN: optineurin; polyQ: polyglutamine; SQSTM1/p62: sequestosome 1; STUB1/CHIP: STIP1 homology and U-box containing protein 1; TARDBP/TDP-43: TAR DNA binding protein; TAX1BP1: Tax1 binding protein 1; TUBA: tubulin alpha; WT: wild-type.

For the first time we investigate the optical degradation of vertical-cavity silicon-integrated lasers VCSILs) designed for operation at 845 nm in photonic integrated circuits (PICs). The study is based on the combined electro-optical characterization of VCSIL, submitted to constant-current stress tests at different current levels. The original results obtained within the manuscript indicate that degradation is related to the diffusion of impurities. Remarkably, depending on the region through which these impurities are migrating, the diffusion process affects device characteristics in different ways. During Phase 1 (Ph1), compensating impurities originating from the metal-semiconductor contact cross the top DBR, thus degrading mirror reflectivity, which is rarely observed in the literature, and leading to an increase in the threshold current of the device. As the impurities start reaching the active region we observe the onset of Phase 2 (Ph2), during which both threshold current and sub-threshold slope worsen, due to the increase of the Shockley-Read-Hall recombination rate. This phase is also characterized by a measurable increase in series resistance, which is ascribed to a change in the resistance of the oxide aperture. The identification of the root cause of physical degradation represents a fundamental step for future lifetime improvement of these novel optical sources, which are set to replace conventional solid-state sources in the $0.85 \mu \text{m}$ communication window.

Belemnite rostra are very abundant in Mesozoic marine deposits in many regions. Despite this abundance, soft-tissue specimens of belemnites informing about anatomy and proportions of these coleoid cephalopods are extremely rare and limited to a few moderately large genera like Passaloteuthisand Hibolithes. For all other genera, we can make inferences on their body proportions and body as well as mantle length by extrapolating from complete material. We collected data of the proportions of the hard parts of some Jurassic belemnites in order to learn about shared characteristics in their gross anatomy. This knowledge is then applied to the Bajocian genus Megateuthis, which is the largest known belemnite genus worldwide. Our results provide simple ratios that can be used to estimate belemnite body size, where only the rostrum is known.

Photonic Integrate Circuita, which combine a collection of optoelectronic functions on a single chip, are an increasingly common part of everyday life. They are used in high-speed optical transceivers that link server racks in data centers, including the one used to deliver the IEEE Spectrum website, in lidars to keep self-driving cars on track, and in spectrometers to spot chemicals in the atmosphere, among many other applications. All these systems have grown less expensive and, in some cases have become economically feasible, by making most of the IC with silicon fabrication technologies.

Silicon photonics (SiPh) is a disruptive technology in the field of integrated photonics and has experienced rapid development over the past two decades. Various high-performance Si and Ge/Si-based components have been developed on this platform that allow for complex photonic integrated circuits (PICs) with small footprint. These PICs have found use in a wide range of applications. Nevertheless, some non-native functions are still desired, despite the versatility of Si, to improve the overall performance of Si PICs and at the same time cut the cost of the eventual Si photonic system-on-chip. Heterogeneous integration is verified as an effective solution to address this issue, e.g. through die-wafer-bonding and flip-chip. In this paper, we discuss another technology, micro-transfer printing, for the integration of non-native material films/opto-electronic components on SiPh-based platforms. This technology allows for efficient use of non-native materials and enables the (co-)integration of a wide range of materials/devices on wafer scale in a massively parallel way. In this paper we review some of the recent developments in the integration of non-native optical functions on Si photonic platforms using micro-transfer printing.

Introduction: Hereditary transthyretin-mediated (hATTR) amyloidosis, a genetic disease caused by mutations in the transthyretin gene, leads to progressive sensory and autonomic neuropathy and/or cardiomyopathy and is associated with renal and ophthalmologic manifestations and a poor prognosis. Methods: This is a retrospective study based on data collected from the medical records of patients with hATTR amyloidosis treated with patisiran between 01 July 2018 and 01 February 2021. Six Belgian neuromuscular reference centers participated, covering all patisiran-treated hATTR amyloidosis patients at the study time. This study was conducted to collect data requested in the context of the reimbursement of patisiran in Belgium. Results: Thirty-one patients were diagnosed with hATTR amyloidosis with polyneuropathy, Coutinho stage 1 or 2, and eligible for active treatment during the data collection period. Of the hATTR amyloidosis patients treated with patisiran (n= 12), seven and five had polyneuropathy stages 1 and 2, respectively. Six patients had cardiac symptoms (New York Heart Association class 2 or above). Follow-up information was available for nine patients. Following patisiran treatment, eight patients showed stable or improved assessments for most neurological or cardiological parameters. Only one patient presented with worsening statuses at the end of the data collection period. Conclusions: The patients with hATTR amyloidosis in Belgium have similar baseline demographics and disease characteristics to those studied in the patisiran APOLLO study and show a similar therapeutic response in the real-world, altering the expected disease progression in most patients.

Photonic integrated circuits (PICs) are expected to add practicality and new functionalities in a considerable number of optical applications, including optical microscopy. Here, we present a PIC design allowing a far-field structured UV illumination pattern with a fringe period as low as $\text{370}\,\text{nm}$, a fringe visibility of 0.83 over field of views of more than $150\,\mu \text{m}\,\times 200\,\mu \text{m}$ and a radiant intensity as large as $\text{0.49}\,\text{mW}$. The circuits include single mode waveguides with propagation losses of $\text{3}\,\text{dB/cm}$ at a wavelength $\lambda =360\,\text{nm}$, two diffraction gratings for beam shaping out of the chip plane, a beam splitter and a phase shifter. Using fluorescent gratings with pitches longer or shorter than the wavelength, as control objects, and a collecting lens with a numerical aperture of 0.5, the current PICs enable to highlight experimentally the Moiré pattern at the heart of the optical resolution enhancement and to achieve a doubling of the optical resolution in the direction of the illumination.

•Maximal physical performance (MPP) tests are often used in low back pain patients.•Theories suggest that pain-related psychological factors may influence MPP.•Overall, pain-related psychological factors were only weakly associated with MPP.•Future studies should use a person-centred approach to assess these relations.

The chaperone protein BiP is the master regulator of the unfolded protein response in the endoplasmic reticulum. BiP chaperone activity is regulated by the post-translational modification AMPylation, exclusively provided by FICD. We investigated whether FICDvariants identified in patients with motor neuron disease could interfere with BiP activity regulation.