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Abstract Nonlocal metasurfaces have recently enabled an ultra-compact, low-power and high-speed platform to perform analog image processing. While several computational tasks have been demonstrated based on this platform, most of the previous studies have focused only on spatial operations, such as spatial differentiation and edge detection. Here, we demonstrate that metasurfaces with temporal nonlocalities – that is, with a tailored dispersive response – can be used to implement time-domain signal processing in deeply subwavelength footprints. In particular, we experimentally demonstrate a passive metasurface performing first-order differentiation of input signals with high-fidelity and high-efficiency. We also show that this approach is prone to scalability and cascaded computation. Our work paves the way to a new generation of ultra-compact, passive devices for all-optical computation, with applications in neural networks and neuromorphic computing.

Background. Chronic lymphocytic leukemia (CLL) is the second most common hematological malignancy without a trend towards a decrease in its incidence. 66 % of patients with CLL experience bone fractures as a result of osteoporosis in all age groups, and the detection frequency is no more than 15 %. Insufficient understanding of the osteoporosis pathogenesis in CLL leads to problems in diagnosis, prevention and therapy.The aim of the study. To analyze modern data on the features of the osteoporosis pathogenesis in chronic lymphocytic leukemia.Results and discussion. Osteoporosis is formed when osteoresorption prevails over osteosynthesis due to intercellular interactions of bone tissue and the immune system, dysregulation of intracellular signaling pathways RANKL/RANK/OPG, Wnt, FoxO, RUNX2, initiated by cytokines, growth factors, prostaglandins, and hormones. The degree of osteoresorption in CLL is associated with the severity of the clinical course, chemotherapy and hormonal deprivation. The osteoporosis pathogenesis in CLL is considered as part of a complex set of events, including, firstly, the interaction between leukemic cells (overexpression of PTHrP, RANKL) and bone cells (synthesis of growth factors), which forms a vicious circle of osteoresorption and tumor growth. Secondly, pro-inflammatory markers in CLL (tumor necrosis factor α, interleukin (IL) 1β, IL-6, IL-8, IL-11, granulocyte-macrophage colony-stimulating factor, macrophage colony-stimulating factor, transforming growth factor β, prostaglandin E2) limit osteoblast-induced osteosynthesis and stimulate the expansion of osteoclasts from monocytic suppressor cells of myeloid origin with or without the participation of the RANKL/RANK system. Thirdly, oxidative stress in CLL and impaired efficiency of antioxidant protection with the participation of fibroblast growth factor 23, transcription factor Nrf-2 with activation of JNK, ERK1/2, NF-κB, and also an increase in the RANKL/OPG ratio lead to inhibition of osteoblastogenesis.Conclusion. Analyzing and systematizing data on the osteoporosis pathogenesis in CLL are instrumental for the development of diagnostic criteria for osteoporosis in chronic lymphocytic leukemia that are much-needed in clinical practice and for the improvement of therapeutic tactics.

Abstract Background Thromboinflammation is caused by mutual activation of platelets and neutrophils. The site of thromboinflammation is determined by chemoattracting agents release by endothelium, immune cells, and platelets. Impaired neutrophil chemotaxis contributes to the pathogenesis of Shwachman-Diamond syndrome (SDS). In this hereditary disorder, neutrophils are known to have aberrant chemoattractant-induced F-actin properties. Here, we aim to determine whether neutrophil chemotaxis could be analyzed using our previously developed ex vivo assay of the neutrophils crawling among the growing thrombi. Methods Adult and pediatric healthy donors, alongside with pediatric patients with SDS, were recruited for the study. Thrombus formation and granulocyte movement in hirudinated whole blood were visualized by fluorescent microscopy in fibrillar collagen-coated parallel-plate flow chambers. Alternatively, fibrinogen, fibronectin, vWF, or single tumor cells immobilized on coverslips were used. A computational model of chemokine distribution in flow chamber with a virtual neutrophil moving in it was used to analyze the observed data. Results The movement of healthy donor neutrophils predominantly occurred in the direction and vicinity of thrombi grown on collagen or around tumor cells. For SDS patients or on coatings other than collagen, the movement was characterized by randomness and significantly reduced velocities. Increase in wall shear rates to 300–500 1/s led to an increase in the proportion of rolling neutrophils. A stochastic algorithm simulating leucocyte chemotaxis movement in the calculated chemoattractant field could reproduce the experimental trajectories of moving neutrophils for 72% of cells. Conclusions In samples from healthy donors, but not SDS patients, neutrophils move in the direction of large, chemoattractant-releasing platelet thrombi growing on collagen.

Kilonovae are the electromagnetic transients created by the radioactive decay of freshly synthesized elements in the environment surrounding a neutron star merger. To study the fundamental physics in these complex environments, kilonova modeling requires, in part, the use of radiative transfer simulations. The microphysics involved in these simulations results in high computational cost, prompting the use of emulators for parameter inference applications. Utilizing a training set of 22 248 high-fidelity simulations (composed of 412 unique ejecta parameter combinations evaluated at 54 viewing angles), we use a neural network to efficiently train on existing radiative transfer simulations and predict light curves for new parameters in a fast and computationally efficient manner. Our neural network can generate millions of new light curves in under a minute. We discuss our emulator's degree of off-sample reliability and parameter inference of the AT2017gfo observational data. Finally, we discuss tension introduced by multiband inference in the parameter inference results, particularly with regard to the neural network's recovery of viewing angle.

The electromagnetic emission from the nonrelativistic ejecta launched in neutron star mergers (either dynamically or through a disk wind) has the potential to probe both the total mass and composition of this ejecta. These observations are crucial in understanding the role of these mergers in the production of r -process elements in the Universe. However, many properties of the ejecta can alter the light curves and we must both identify which properties play a role in shaping this emission and understand the effects these properties have on the emission before we can use observations to place strong constraints on the amount of r -process elements produced in the merger. This paper focuses on understanding the effect of the velocity distribution (amount of mass moving at different velocities) for lanthanide-rich ejecta on the light curves and spectra. The simulations use distributions guided by recent calculations of disk outflows and compare the velocity-distribution effects to those of ejecta mass, velocity, and composition. Our comparisons show that uncertainties in the velocity distribution can lead to a factor of 2–4 uncertainties in the inferred ejecta mass based on peak infrared luminosities. We also show that early-time UV or optical observations may be able to constrain the velocity distribution, reducing the uncertainty in the ejecta mass.

The interaction of β -particles with the weakly ionized plasma background is an important mechanism for powering the kilonova (KN) transient signal from neutron star mergers. For this purpose, we present an implementation of the approximate fast-particle collision kernel, described by Inokuti following the seminal formulation of Bethe, in a spectral solver of the Vlasov–Maxwell–Boltzmann equation. In particular, we expand the fast-particle plane-wave atomic excitation kernel into coefficients of the Hermite basis, and derive the relevant discrete spectral system. In this fast-particle limit, the approach permits the direct use of atomic data, including optical oscillator strengths, normally applied to photon–matter interaction. The resulting spectral matrix is implemented in the MASS-APP spectral solver framework, in a way that avoids full matrix storage per spatial zone. We numerically verify aspects of the matrix construction, and present a proof-of-principle 3D simulation of a 2D axisymmetric KN ejecta snapshot. Our preliminary numerical results indicate that a reasonable choice of Hermite basis parameters for β -particles in the KN is a bulk velocity parameter u = 0, a thermal velocity parameter α = 0.5 c , and a 9 × 9 × 9 mode velocity basis set (Hermite orders of 0–8 in each dimension). For interior-ejecta sample zones, we estimate that the ratio of thermalization from large-angle (≳2.°5) bound excitation scattering to total thermalization is ∼0.002–0.003.

Dermoid nasal cysts (congenital nasal median heterotopias) are a rare congenital pathology in children., Objective: Yo consider the clinical picture, methods of radiation diagnosis and to study the surgical results of a dermoid cyst of the nose according to the literature., Materials and Methods: A retrospective review of medical histories with the diagnosis of "Dermoid cyst of the back of the nose and nasal cavity, epidermal cyst of the back of the nose, glioma, encephalocele" was conducted from 2017 to 2022 in the Pediatric Otorhinolaryngological Department of the National Medical Research Center for Otorhinolaryngology of the Federal Medical-Biological Agency of Russia. The case histories were analyzed by the nature of the lesion, the imaging techniques performed, the course of the operation and the results obtained., Material and Methods: A total of 16 medical histories were analyzed, the average age was 4.5 years (range 10 months - 15 years), over the past 5 years with a diagnosis of "Dermoid cyst of the nasal dorsum and nasal cavity, glioma, epidermal cyst of the nasal dorsum, encephalocele". All patients underwent magnetic resonance imaging (MRI) in the preoperative period, 14 patients also underwent computed tomography (CT)., Result: Of these, 7 had a confirmed dermoid cyst with a fistula, 3 patients without a fistula, 3 patients had glioma, and 1 had encephalocele, 2 patients had an epidermoid cyst. A fistulous opening of the dermoid cyst of the nasal dorsum and nasal cavity was observed in the upper third of the nasal dorsum in 3 children, in the middle third in 2 patients and in the lower third in 2 children. The article presents a scheme for the characteristics of the lesion and the tactics of surgical treatment in comparison with the data of foreign authors. Intraoperatively, intracranial spread occurred in 6 patients. Various surgical approaches for intracranial proliferation and a corresponding literature review are also presented. Catamnestic follow-up ranged from 1 to 5 years (on average, 3.5 years), no relapses or postoperative complications were noted., Conclusion: Nasal median heterotopias are a rare congenital anomaly. Preoperative preparation should include CT and MRI to assess the lesion and exclude intracranial spread. The surgical approach depended directly on the localization of heterotopia and its spread. All patients had a good cosmetic result after the surgical treatment performed by us according to the author's method.