The mirror type magnetic mass-analyzer axial aberration, caused by ions travelling through the mirror outside the median plane is estimated. A technique for the mass-analyzer acceptance optimization is given.

A quantitative simulation of a system of optical concentrators based on Winston’s hexagonal cones, intended for the registration camera of the TAIGA-IACT Cherenkov gamma-ray telescope, has been performed. The data on the transmission of the cones are obtained; the distributions of the photon flux intensity in the plane of the detector are given. On the basis of the results obtained, an optimal configuration of optical concentrators is proposed, taking into account the design features of the mount, mirror and TAIGA-IACT camera, as well as the features of its new detector units.

An ion optical analysis of a static mass analyzer, based on a second-order focusing magnetic mirror, was conducted while accounting for aberrations caused by the movement of ions outside the mean plane of the mass analyzer. As part of this study, an optimization algorithm was developed for the four-dimensional acceptance of the mass analyzer at a fixed resolution, formulated within the framework of the inverse problem.

We propose the design of a compact Mattauch–Herzog ion-optical system featuring a double-focusing static mass spectrometer with a cylindrical electrostatic deflector. This system offers second-order angle focusing and first-order energy focusing along the focal line. The collimating system ensures the optimal vertical acceptance of the mass analyzer and maximum ion transmission within the working mass range. The described ion-optical system serves as a foundation for small-sized mass spectrometers, weighing up to 50 kg, including turbo-molecular and foreline pumps, while maintaining high analytical performance.

The first-order input and output edge transfer matrix elements of the magnetic sector in a static mass spectrometer are derived based on the conservation law of the generalized momentum of ions in a magnetic field. The structure of the edge matrix is shown to be ambiguous and dependent on the effective model, which considers the displacement of ion trajectories in the edge field. A comparison of the results obtained with traditional methods, such as expanding the edge field components and trajectory equations into asymptotic series and integrating successive approximations, reveals significant differences in the first-order edge matrix elements in the effective model of the magnetic sector, where the ideal uniform field is bounded by Herzog boundaries, compared to the published data. Algorithms for matching the input and output axes of the magnetic sector, taking into account the action of the edge fields, are given.

Quantitative modeling of a system of optical concentrators based on an improved design of Winston hexagonal cones, providing a possibility of using light filters and intended for the registration camera of a small-size Cherenkov gamma-ray telescope, has been performed. The transmission of the cones is calculated, and the intensity distributions of the photon flux in the detector plane are given. Based on the results obtained, an optimal configuration of optical concentrators is proposed with an account for design features of the TAIGA-IACT mount, mirror, and camera, as well as of new detector units. The results obtained for the considered system are compared with the previously published models.

The mirror type magnetic mass-analyzer axial aberration, caused by ions travelling through the mirror outside the median plane is estimated. A technique for the mass-analyzer acceptance optimization is given.

We derived identities that relate the angular and coordinate elements of the 2nd order transfer matrix, which determine the axial aberration of static mass analyzers in the fringing field of the magnetic sector with an arbitrary entrance of ions. These identities can be used as criteria for the correct calculation of the axial aberration of the mass analyzer and its resolution.

Элементы 1-го порядка входной и выходной краевых матриц перехода магнитного сектора выведены из закона сохранения обобщенного импульса ионов в магнитном поле. Показано, что вид краевой матрицы не однозначен и зависит от эффективной модели, в рамках которой учитывается снос траекторий в краевом поле. Сравнение с аналогичными данными, найденными традиционным методом, а именно разложением компонент краевого поля и траекторных уравнений в асимптотические ряды и интегрированием порядковых приближений, показало, что, если область идеального поля эффективного магнитного сектора ограничена границами Герцога, то полученные элементы краевой матрицы 1-го порядка значительно отличаются от опубликованных данных.

Full-particle massive modeling of physical processes in the Earth’s atmosphere leading to generation of Cherenkov radiation in γ-ray- and proton-induced extensive air showers (EASs), as well as Monte Carlo modeling of photon transport in small-size Cherenkov telescope and signal registration with a camera based on OnSemi MicroFJ type semiconductor photomultiplier (SiPM) detectors have been performed. Calculations have been carried out for primaries with energies in the 0.3–30 TeV range and a Cherenkov telescope with an ≃10 m2 mirror similar to that employed at the TAIGA observatory. It is shown that, even with strict selection criteria ensuring high-quality EAS images, the threshold detection energy of the SiPM-based camera would not exceed 0.8 TeV, which is about twice as low as the detection threshold (≃1.5 TeV) of a small-size TAIGA-IACT telescope camera based on vacuum photomultipliers.

An objective criterion of the computation accuracy of ion trajectories aberration components in magnetic edge fields of static mass analyzers is derived.

Full-particle modeling of gamma-ray and proton induced extensive air showers (EASs) in the Earth's atmosphere as well as Monte Carlo modeling of photon transport in a small size Cherenkov telescope and signal registration with its camera based on the OnSemi MicroFJ SiPM detectors have been performed. Calculations have been carried out for primaries within the 0.3 - 30 TeV range and a telescope with a 10 m(2) mirror similar to the unit employed at the TAIGA observatory. It has been shown that even with strict selection criteria aimed at high quality EAS images, the threshold detection energy of the SiPM-based camera would not exceed 0.8 TeV - about twice as low as the current threshold of the TAIGA-IACT camera based on vacuum photomultipliers.

A quantitative simulation of a system of optical concentrators based on Winston's hexagonal cones, intended for the registration camera of the TAIGA-IACT Cherenkov gamma-ray telescope, has been performed. The data on the transmission of the cones are obtained; the distributions of the photon flux intensity in the plane of the detector are given. On the basis of the results obtained, an optimal configuration of optical concentrators is proposed, taking into account the design features of the mount, mirror and TAIGA-IACT camera, as well as the features of its new detector units.

Human induced pluripotent stem (iPS) cells have the potential to give rise to a new era in Parkinson's disease (PD) research. As a unique source of midbrain dopaminergic (DA) neurons, iPS cells provide unparalleled capabilities for investigating the pathogenesis of PD, the development of novel anti-parkinsonian drugs, and personalized therapy design. Significant progress in developmental biology of midbrain DA neurons laid the foundation for their efficient derivation from iPS cells. The introduction of 3D culture methods to mimic the brain microenvironment further expanded the vast opportunities of iPS cell-based research of the neurodegenerative diseases. However, while the benefits for basic and applied studies provided by iPS cells receive widespread coverage in the current literature, the drawbacks of this model in its current state, and in particular, the aspects of differentiation protocols requiring further refinement are commonly overlooked. This review summarizes the recent data on general and subtype-specific features of midbrain DA neurons and their development. Here, we review the current protocols for derivation of DA neurons from human iPS cells and outline their general weak spots. The associated gaps in the contemporary knowledge are considered and the possible directions for future research that may assist in improving the differentiation conditions and increase the efficiency of using iPS cell-derived neurons for PD drug development are discussed.

Induced pluripotent stem cells (iPSCs) are analogous to embryonic stem cells in their properties, and might be derived from adult somatic cells. There exist two main approaches to practical application of iPSCs technologies they are regenerative medicine and human diseases modeling. Nowadays the process of iPSCs obtaining is being investigated in many world laboratories, but there are no standards in the iPSC obtaining technology. This work was aimed to develop a simple, cheap and practical protocol for obtaining iPSCs and to establish a collection of iPCS lines derived from cells of patients with a Parkinson disease to make a cell model of this disease. The work resulted in a development of the protocol to produce iPSCs based on a lentiviral delivery of transgenes into cells. iPCS lines from 3 patients with inherited Parkinson disease forms have been obtained.

Аксиальная аберрация ионно-оптической системы статического масс-анализатора является одним из главных факторов, ограничивающих пропускание и чувствительность прибора. Описывается алгоритм выбора оптимальной коллимирующей системы масс-анализатора, позволяющей эффективно уменьшать данную аберрацию при минимальных потерях интенсивности масс-спектральных линий. Алгоритм основан на представлении рассматриваемой аберрации в фазовом пространстве в виде эллипса и оптимальной аппроксимации этого аберрационного эллипса многоугольником c заданным числом вершин. Показано, что при отсутствии ограничений решением соответствующих оптимизационных задач являются фазовые многоугольники, порождаемые вписанными в единичный круг либо описанными вокруг единичного круга правильными многоугольниками с тем же самым количеством вершин. После этого единичный круг вместе с многоугольниками растягивается до размеров заданного аберрационного эллипса вдоль его главных осей. Дополнительная свобода вращения исходного многоугольника относительно центра единичного круга может быть использована для более удобного расположения вспомогательных щелей коллимирующей системы. The axial aberration of the ion-optical system of a static mass analyzer is one of the significant factors that limits the transmittance and sensitivity of the device due to the need to significantly reduce the vertical component of the ion beam emittance to get the required mass spectral resolution. An algorithm for choosing the optimal collimating system of the mass analyzer is described, which allows one to effectively reduce this aberration with minimal loss of intensity of the mass spectral lines. The algorithm is based on the representation of the considered aberration in phase space as an ellipse and the optimal approximation of this aberration ellipse by a polygon with a given number of vertices. In the absence of restrictions. The solution of the corresponding optimization problems is constructed as phase polygons generated by regular polygons inscribed in a unit circle or described around a unit circle with the same number of vertices. Then the unit circle along with the polygons is stretched to the size of a given aberration ellipse along its main axes. Additional freedom of rotation of the initial polygon relative to the center of the unit circle can be used for more convenient location of auxiliary slits of the collimating system.

We have modeled propagation of source signal and noise for a future camera of TAIGA-IACT Cherenkov gamma-ray telescope, which will be based on silicon photomultipliers sensitive in the 240 -- 600 nm range. It has been shown that employment of such detectors instead of traditional vacuum photomultipliers will allow one to decrease the energy threshold by a factor of about 2.5: from ~ 1.5 TeV down to ~ 0.6 TeV. We have also shown that application of a standard ultraviolet filter ZWB3 will decrease the source signal by a factor of 3, while the noise signal from the night sky will be decreased by a factor of 6. In this way the duty cycle of the telescope can be extended (the telescope will be able to operate during moonlit nights and during twilight) and the energy threshold further decreased down to ~ 0.3 TeV. A narrow 260 -- 300 nm filter can be employed to improve gamma-hadron separation of primary cosmic particles in the ~ 25 -- 50 TeV band.

The technology for producing human induced pluripotent stem cells (iPSCs) and the possibility of directed differentiation into specialized cells of all body tissues have opened unique opportunities for studying the molecular genetic basis of the pathogenesis of neurodegenerative diseases in vitro and effective screening for compounds with neuroprotective activity. The aim of this work was to obtain glial cell cultures from iPSCs of a healthy donor and a patient with the familial form of Parkinson's disease (G2019S mutation in the LRRK2) and to characterize them. At the first stage, we compared the three previously described protocols for the differentiation of glial cells from neural precursors of human iPSCs and selected the method most acceptable under our conditions in terms of the quality and time necessary for obtaining the desired cultures. Glial cell cultures obtained by this method were characterized by the levels of expression of a number of neuroglial differentiation genes. Also, in the resulting cultures, we analyzed the expression of genes of some neurotrophic factors (GDNF, BDNF, NGF, NT3). It was shown that the culture medium conditioned by glial cells from a patient with Parkinson's disease had a negative effect on the growth of neurites of dopaminergic neurons in differentiated cultures of a healthy donor, decreasing their length by a factor of 2.

Source and noise signals in a new camera of the TAIGA-IACT Cherenkov γ-ray telescope based on silicon photomultipliers (SiPM) have been simulated. It is shown that application of modern silicon photomultipliers as detecting elements of TAIGA-IACT (instead of the currently used conventional vacuum photomultipliers) will make it possible to reduce the threshold detection energy of cosmic γ quanta by a factor of about 2.5 (from ≃1.5 to ≃0.6 TeV). It is also shown that employment of a standard ZWB3 UV filter mask in the TAIGA-IACT camera would reduce the average signal level by a factor of about 3 and the noise (background) level from the night sky by a factor of about 6, which would allow one to extend the duty cycle of the telescope (in particular, to carry out observations during moonlit nights and twilights) and to additionally reduce the threshold detection energy down to ≃0.3 TeV. The application of a narrower UV filter of 260–300 nm bandwidth can increase the efficiency of determining the primary particle type (γ-hadron separation) in the energy range from ~25 up to ~50 TeV.