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1. Study of the energy spectrum of alpha particles in an experiment on irradiation of a boron target with a proton beam at the Prometheus accelerator

Author

Rusetskii, A. S., Negodaev, M. A., Oginov, A. V., Shpakov, V. A. Ryabov K. V., Shemyakov, A. E., and Zavestovskaya, I. N.

Subjects
Nuclear Experiment, Physics - Accelerator Physics
Abstract

The energy spectrum of alpha particles from the nuclear reaction p + $^{11}$B $\rightarrow 3\alpha$ was studied using the beam of the injector of the proton synchrotron of the Prometheus proton therapy complex. The reaction products (alpha particles) were recorded using a CR-39 track detector. The detectors were calibrated using a $^{241}$Am radioactive source. It was determined that mainly alpha particles emitted from the boron target have energies from 3 to 5.5 MeV. In this case, a significant part of the alpha particles emitted from the depths of the target have significantly lower energies compared to the calculated ones due to ionization losses. Measuring the energy spectrum of alpha particles from targets containing boron is of great scientific and practical interest for identifying the mechanisms of boron-proton capture therapy and determining the additional contribution to the therapeutic effect of proton irradiation., Comment: 8 pages, 5 figures

Published
2024

4. Technical Design Report of the Spin Physics Detector at NICA

Author

The SPD Collaboration, Abazov, V., Abramov, V., Afanasyev, L., Akhunzyanov, R., Akindinov, A., Alekseev, I., Aleshko, A., Alexakhin, V., Alexeev, G., Alimov, L., Allakhverdieva, A., Amoroso, A., Andreev, V., Andronov, E., Anikin, Yu., Anischenko, S., Anisenkov, A., Anosov, V., Antokhin, E., Antonov, A., Antsupov, S., Anufriev, A., Asadova, K., Ashraf, S., Astakhov, V., Aynikeev, A., Azarkin, M., Azorskiy, N., Bagulya, A., Baigarashev, D., Baldin, A., Baldina, E., Barbashina, N., Barnyakov, A., Barsov, S., Bartkevich, A., Baryshevsky, V., Basharina, K., Baskakov, A., Baskov, V., Batista, M., Baturitsky, M., Bautin, V., Bedareva, T., Belokurova, S., Belova, A., Belyaeva, E., Berdnikov, A., Berdnikov, Ya., Berezhnoy, A., Berngardt, A., Bespalov, Yu., Bleko, V., Bliznyuk, L., Bogoslovskii, D., Boiko, A., Boikov, A., Bolsunovskya, M., Boos, E., Borisov, V., Borsch, V., Budkouski, D., Bulanova, S., Bulekov, O., Bunichev, V., Burtebayev, N., Bychanok, D., Casanova, A., Cesar, G., Chemezov, D., Chepurnov, A., Chen, L., Chmill, V., Chukanov, A., Chuzo, A., Danilyuk, A., Datta, A., Dedovich, D., Demichev, M., Deng, G., Denisenko, I., Denisov, O., Derbysheva, T., Derkach, D., Didorenko, A., Dima, M. -O., Doinikov, A., Doronin, S., Dronik, V., Dubinin, F., Dunin, V., Durum, A., Egorov, A., El-Kholy, R., Enik, T., Ermak, D., Erofeev, D., Erokhin, A., Ezhov, D., Fedin, O., Fedotova, Ju., Feofilov, G., Filatov, Yu., Filimonov, S., Frolov, V., Galaktionov, K., Galoyan, A., Garkun, A., Gavrishchuk, O., Gerasimov, S., Gerassimov, S., Gilts, M., Gladilin, L., Golovanov, G., Golovnya, S., Golovtsov, V., Golubev, A., Golubykh, S., Goncharov, P., Gongadze, A., Greben, N., Gregoryev, A., Gribkov, D., Gridin, A., Gritsay, K., Gubachev, D., Guo, J., Gurchin, Yu., Gurinovich, A., Gurov, Yu., Guskov, A., Gutierrez, D., Guzman, F., Hakobyan, A., Han, D., Harkusha, S., Hu, Sh., Igolkin, S., Isupov, A., Ivanov, A., Ivanov, N., Ivantchenko, V., Jin, Sh., Kakurin, S., Kalinichenko, N., Kambar, Y., Kantsyrev, A., Kapitonov, I., Karjavine, V., Karpishkov, A., Katcin, A., Kekelidze, G., Kereibay, D., Khabarov, S., Kharyuzov, P., Khodzhibagiyan, H., Kidanov, E., Kidanova, E., Kim, V., Kiryanov, A., Kishchin, I., Kokoulina, E., Kolbasin, A., Komarov, V., Konak, A., Kopylov, Yu., Korjik, M., Korotkov, M., Korovkin, D., Korzenev, A., Kostenko, B., Kotova, A., Kotzinian, A., Kovalenko, V., Kovyazina, N., Kozhin, M., Kraeva, A., Kramarenko, V., Kremnev, A., Kruchonak, U., Kubankin, A., Kuchinskaia, O., Kulchitsky, Yu., Kuleshov, S., Kulikov, A., Kulikov, V., Kurbatov, V., Kurmanaliev, Zh., Kurochkin, Yu., Kutuzov, S., Kuznetsova, E., Kuyanov, I., Ladygin, E., Ladygin, V., Larionova, D., Lebedev, V., Levchuk, M., Li, P., Li, X., Li, Y., Livanov, A., Lednicki, R., Lobanov, A., Lobko, A., Loshmanova, K., Lukashevich, S., Luschevskaya, E., Lyashko, A. L'vov I., Lysan, V., Lyubovitskij, V., Madigozhin, D., Makarenko, V., Makarov, N., Makhmanazarov, R., Maleev, V., Maletic, D., Malinin, A., Maltsev, A., Maltsev, N., Malkhasyan, A., Malyshev, M., Mamoutova, O., Manakonov, A., Marova, A., Merkin, M., Meshkov, I., Metchinsky, V., Minko, O., Mitrankov, Yu., Mitrankova, M., Mkrtchyan, A., Mkrtchyan, H., Mohamed, R., Morozova, S., Morozikhin, A., Mosolova, E., Mossolov, V., Movchan, S., Mukhamejanov, Y., Mukhamejanova, A., Muzyaev, E., Myktybekov, D., Nagorniy, S., Nassurlla, M., Nechaeva, P., Negodaev, M., Nesterov, V., Nevmerzhitsky, M., Nigmatkulov, G., Nikiforov, D., Nikitin, V., Nikolaev, A., Oleynik, D., Onuchin, V., Orlov, I., Orlova, A., Ososkov, G., Panzieri, D., Parsamyan, B., Pavzderin, P., Pavlov, V., Pedraza, M., Perelygin, V., Peshkov, D., Petrosyan, A., Petrov, M., Petrov, V., Petrukhin, K., Piskun, A., Pivovarov, S., Polishchuk, I., Polozov, P., Polyanskii, V., Ponomarev, A., Popov, V., Popovich, S., Prokhorova, D., Prokofiev, N., Prokoshin, F., Puchkov, A., Pudin, I., Pyata, E., Ratnikov, F., Rasin, V., Red'kov, V., Reshetin, A., Reznikov, S., Rogacheva, N., Romakhov, S., Rouba, A., Rudnev, V., Rusinov, V., Rusov, D., Ryltsov, V., Saduyev, N., Safonov, A., Sakhiyev, S., Salamatin, K., Saleev, V., Samartsev, A., Samigullin, E., Samoylov, O., Saprunov, E., Savenkov, A., Seleznev, A., Semak, A., Senkov, D., Sergeev, A., Seryogin, L., Seryubin, S., Shabanov, A., Shahinyan, A., Shavrin, A., Shein, I., Sheremeteva, A., Shevchenko, V., Shilyaev, K., Shimansky, S., Shinbulatov, S., Shipilov, F., Shipilova, A., Shkarovskiy, S., Shoukovy, D., Shpakov, K., Shreyber, I., Shtejer, K., Shulyakovsky, R., Shunko, A., Sinelshchikova, S., Skachkova, A., Skalnenkov, A., Smirnov, A., Smirnov, S., Snesarev, A., Solin, A., Solin jr., A., Soldatov, E., Solovtsov, V., Song, J., Sosnov, D., Stavinskiy, A., Stekacheva, D., Streletskaya, E., Strikhanov, M., Suarez, O., Sukhikh, A., Sukhovarov, S., Sulin, V., Sultanov, R., Sun, P., Svirida, D., Syresin, E., Tadevosyan, V., Tarasov, O., Tarkovsky, E., Tchekhovsky, V., Tcherniaev, E., Terekhin, A., Terkulov, A., Tereshchenko, V., Teryaev, O., Teterin, P., Tishevsky, A., Tokmenin, V., Topilin, N., Tsiareshka, P., Tumasyan, A., Tyumenkov, G., Usenko, E., Uvarov, L., Uzhinsky, V., Uzikov, Yu., Valiev, F., Vasilieva, E., Vasyukov, A., Vechernin, V., Verkheev, A., Vertogradov, L., Vertogradova, Yu., Vidal, R., Voitishin, N., Volkov, I., Volkov, P., Vorobyov, A., Voskanyan, H., Wang, H., Wang, Y., Xu, T., Yanovich, A., Yeletskikh, I., Yerezhep, N., Yurchenko, S., Zakharov, A., Zamiatin, N., Zamora-Saá, J., Zarochentsev, A., Zelenov, A., Zemlyanichkina, E., Zhabitsky, M., Zhang, J., Zhang, Zh., Zhemchugov, A., Zherebchevsky, V., Zhevlakov, A., Zhigareva, N., Zhou, J., Zhuang, X., Zhukov, I., Zhuravlev, N., Zinin, A., Zmeev, S., Zolotykh, D., Zubarev, E., and Zvyagina, A.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The Spin Physics Detector collaboration proposes to install a universal detector in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron and other spin-related phenomena using a unique possibility to operate with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to $10^{32}$ cm$^{-2}$ s$^{-1}$. As the main goal, the experiment aims to provide access to the gluon TMD PDFs in the proton and deuteron, as well as the gluon transversity distribution and tensor PDFs in the deuteron, via the measurement of specific single and double spin asymmetries using different complementary probes such as charmonia, open charm, and prompt photon production processes. Other polarized and unpolarized physics is possible, especially at the first stage of NICA operation with reduced luminosity and collision energy of the proton and ion beams. This document is dedicated exclusively to technical issues of the SPD setup construction.

Published
2024

12. Design, optimization and experimental characterization of RF injectors for high brightness electron beams and plasma acceleration

Author

Shpakov, V., Alesini, D., Anania, M. P., Behtouei, M., Buonomo, B., Bellaveglia, M., Biagioni, A., Cardelli, F., Carillo, M., Chiadroni, E., Cianchi, A., Costa, G., Del Giorno, M., Faillace, L., Ferrario, M., del Franco, M., Franzini, G., Galletti, M., Giannessi, L., Giribono, A., Liedl, A., Lollo, V., Mostacci, A., Di Pirro, G., Piersanti, L., Pompili, R., Di Raddo, G., Romeo, S., Silvi, G., Stella, A., Vaccarezza, C., Villa, F., and Vannozzi, A.

Subjects
Physics - Accelerator Physics, Physics - Instrumentation and Detectors
Abstract

In this article, we share our experience related to the new photo-injector commissioning at the SPARC\_LAB test facility. The new photo-injector was installed into an existing machine and our goal was not only to improve the final beam parameters themselves but to improve the machine handling in day-to-day operations as well. Thus, besides the pure beam characterization, this article contains information about the improvements, that were introduced into the new photo-injector design from the machine maintenance point of view, and the benefits, that we gained by using the new technique to assemble the gun itself.

Published
2022
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16. The Autophagic and Apoptotic Death of Forebrain Neurons of Rats with Global Brain Ischemia Is Diminished by the Intranasal Administration of Insulin: Possible Mechanism of Its Action

Author

Irina O. Zakharova, Liubov V. Bayunova, Daria K. Avrova, Alina D. Tretyakova, Alexander O. Shpakov, and Natalia F. Avrova

Subjects
forebrain ischemia, intranasal insulin, autophagy, apoptosis, neuronal viability, protein kinases, Biology (General), QH301-705.5
Abstract

Insulin is a promising neuroprotector. To better understand the mechanism of insulin action, it was important to show its ability to diminish autophagic neuronal death in animals with brain ischemic and reperfusion injury. In forebrain ischemia and reperfusion, the number of live neurons in the hippocampal CA1 region and frontal cortex of rats decreased to a large extent. Intracerebroventricular administration of the autophagy and apoptosis inhibitors to ischemic rats significantly increased the number of live neurons and showed that the main part of neurons died from autophagy and apoptosis. Intranasal administration of 0.5 IU of insulin per rat (before ischemia and daily during reperfusion) increased the number of live neurons in the hippocampal CA1 region and frontal brain cortex. In addition, insulin significantly diminished the level of autophagic marker LC3B-II in these forebrain regions, which markedly increased during ischemia and reperfusion. Our studies demonstrated for the first time the ability of insulin to decrease autophagic neuronal death, caused by brain ischemia and reperfusion. Insulin administered intranasally activated the Akt-kinase (activating the mTORC1 complex, which inhibits autophagy) and inhibited the AMP-activated protein kinase (which activates autophagy) in the hippocampus and frontal cortex of rats with brain ischemia and reperfusion.

Published
2024
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17. Free electron laser seeded by betatron radiation

Author

Ghigo, A., Galletti, M., Shpakov, V., Curcio, A., and Petrillo, V.

Subjects
Physics - Accelerator Physics
Abstract

In this paper the use of betatron radiation as a seed for the Free Electron Laser (FEL) is presented. The scheme shown can be adopted from all FEL driven by plasma accelerated electron beams via Particle or Laser Wake Field Acceleration. Intense radiation in the region of X ray characterized by a broad spectrum, the betatron radiation, is indeed produced in the plasma acceleration process from the electron passing through the ionized gas. It is proposed to use this radiation, suitably selected in wavelength and properly synchronized, to stimulate the emission of the Free Electron Laser., Comment: FEL 2022 proceedings, TUP25

Published
2022

19. Artificial intelligence system based on multi-value classification of fully connected neural network for construction management

Author

Honcharenko, Tetyana, Akselrod, Roman, Shpakov, Andrii, and Khomenko, Oleksandr

Subjects
Computer Science - Machine Learning, Computer Science - Artificial Intelligence
Abstract

This study is devoted to solving the problem to determine the professional adaptive capabilities of construction management staff using artificial intelligence systems.It is proposed Fully Connected Feed-Forward Neural Network architecture and performed empirical modeling to create a Data Set. Model of artificial intelligence system allows evaluating the processes in an Fully Connected Feed-Forward Neural Network during the execution of multi-value classification of professional areas. A method has been developed for the training process of a machine learning model, which reflects the internal connections between the components of an artificial intelligence system that allow it to learn from training data. To train the neural network, a data set of 35 input parameters and 29 output parameters was used; the amount of data in the set is 936 data lines. Neural network training occurred in the proportion of 10% and 90%, respectively. Results of this study research can be used to further improve the knowledge and skills necessary for successful professional realization., Comment: 10 pages, 7 figures

Published
2022

26. Temporal map of electromagnetic emissions produced by laboratory atmospheric discharges.

Author

Parkevich, E. V., Shpakov, K. V., Baidin, I. S., Rodionov, A. A., Khirianova, A. I., Bolotov, Ya.K., and Ryabov, V. A.

Subjects
*SCINTILLATION counters, *X-rays, *PHOTONS, *WAVELENGTHS, *VOLTAGE
Abstract

We exhaustively investigate the temporal correlations between the ultrahigh-frequency (of the order of 1–6 GHz), very high-frequency (of the order of 10–100 MHz), and x-ray (photons with energies from 5 keV to 1 MeV) emissions together with the optical emissions in the near-infrared (within 700–1100 nm) and near-ultraviolet (within 300–400 nm) wavelength regions. The emissions are produced by a laboratory atmospheric discharge developing in an 55 cm air gap at voltages up to 1 MV. When registering various electromagnetic emissions, the discharge current and voltage are measured, as well as nanosecond imaging of the discharge evolution in its own glow is performed. The spatiotemporal localization of the discharge regions associated with the x-ray generation is carried out by employing the group of fast scintillation detectors, and the evolution of plasma structures during the x-ray generation is traced. A chronological map is constructed providing an in-depth understanding of the temporal character and correlations of various electromagnetic emissions. The map allows one to analyze fast ionization processes occurring in the gas-discharge medium and triggering the generation of the corresponding emissions. The generation mechanisms of the considered emissions in an extended high-voltage discharge are discussed. The findings can be helpful in revealing the sources of various electromagnetic emissions accompanying the formation of laboratory and atmospheric discharges. [ABSTRACT FROM AUTHOR]

Published
2024
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27. Angular anisotropy of hard x rays produced by laboratory atmospheric discharges.

Author

Parkevich, E. V., Shpakov, K. V., Baidin, I. S., Rodionov, A. A., Khirianova, A. I., Bolotov, Ya. K., and Ryabov, V. A.

Subjects
*HARD X-rays, *PLASMA flow, *X-rays, *STATISTICS, *PHOTONS
Abstract

The temporal, spectral, and angular characteristics of the x-ray emissions (photons with energies within 5–1000 keV) are exhaustively investigated during the discharge formation at voltages up to 1 MV in approximately 55 cm air gaps. The temporal correlations between the x-ray emissions and discharge voltage and current waveforms are established. The evolution of the discharge plasma structures developing in the time periods of the x-ray generation is traced with a nanosecond resolution. Based on statistical data, theoretical analysis, and estimates the regularities in the x-ray emission characteristics are revealed together with their relationship with the ionization processes occurring in the gas-discharge medium. On the basis of the obtained experimental data, the probable x-ray generation mechanisms are discussed. The findings can provide a deeper understanding of the physics behind the sources of hard x rays arising during the development of laboratory and atmospheric discharges. [ABSTRACT FROM AUTHOR]

Published
2024
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32. First emittance measurement of the beam-driven plasma wakefield accelerated electron beam

Author

Shpakov, V., Anania, M. P., Behtouei, M., Bellaveglia, M., Biagioni, A., Cesarini, M., Chiadroni, E., Cianchi, A., Costa, G., Croia, M., Del Dotto, A., Diomede, M., Dipace, F., Ferrario, M., Galletti, M., Giribono, A., Liedl, A., Lollo, V., Magnisi, L., Mostacci, A., Di Pirro, G., Piersanti, L., Pompili, R., Romeo, S., Rossi, A. R., Scifo, J., Vaccarezza, C., Villa, F., and Zigler, A.

Subjects
Physics - Accelerator Physics
Abstract

Next-generation plasma-based accelerators can push electron beams to GeV energies within centimetre distances. The plasma, excited by a driver pulse, is indeed able to sustain huge electric fields that can efficiently accelerate a trailing witness bunch, which was experimentally demonstrated on multiple occasions. Thus, the main focus of the current research is being shifted towards achieving a high quality of the beam after the plasma acceleration. In this letter we present beam-driven plasma wakefield acceleration experiment, where initially preformed high-quality witness beam was accelerated inside the plasma and characterized. In this experiment the witness beam quality after the acceleration was maintained on high level, with $0.2\%$ final energy spread and $3.8~\mu m$ resulting normalized transverse emittance after the acceleration. In this article, for the first time to our knowledge, the emittance of the PWFA beam was directly measured.

Published
2021
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34. Influence of metformin therapy and treatment with an allosteric luteinizing hormone agonist and chorionic gonadotropin on spermatogenesis in male rats with obesity

Author

K. V. Derkach, I. Yu. Morina, L. V. Bayunova, A. A. Bakhtuykov, E. A. Didenko, V. N. Sorokoumov, I. V. Romanova, and A. O. Shpakov

Subjects
obesity, spermatogenesis, metformin, luteinizing hormone receptor, human chorionic gonadotropin, allosteric agonist, testosterone, Physiology, QP1-981, Biochemistry, QD415-436
Abstract

BACKGROUND: In men, obesity is accompanied by a complex of metabolic and hormonal disorders, which leads to androgen deficiency and impaired spermatogenesis. Antidiabetic drugs, including metformin (MF), and luteinizing hormone receptor (LHR) agonists, which activate testicular steroidogenesis, can be used to correct reproductive dysfunctions. However, in diet-induced obesity (DIO), their effectiveness and mechanisms of action are poorly understood.AIM: In men, obesity is accompanied by a complex of metabolic and hormonal disorders, which leads to androgen deficiency and impaired spermatogenesis. Antidiabetic drugs, including metformin (MF), and luteinizing hormone receptor (LHR) agonists, which activate testicular steroidogenesis, can be used to correct reproductive dysfunctions. However, in dietinduced obesity (DIO), their effectiveness and mechanisms of action are poorly understood.MATERIALS AND METHODS: Obesity in male Wistar rats was induced by a 23-week diet enriched with saturated fats. MF treatment was carried out for 5 weeks at a dose of 120 mg/kg/day (orally), and the treatment with hCG and TP03 was carried out for 5 days at daily doses of 20 IU/rat (s.c.) and 15 mg/kg (i.p.), respectively. Using microscopy and histochemical analysis, the number and motility of spermatozoa (SP), the number of their defective forms and the morphology of the seminiferous tubules were assessed, and the levels of testosterone and other hormones in the blood were measured using ELISA.RESULTS: MF, hCG, and TP03 to varying degrees increased the number of SP and the proportion of their mobile forms, including those with forward movement, which were reduced in DIO rats, and also normalized the thickness of the epithelium of the seminiferous tubules and the number of spermatogonia and pachytene spermatocytes in them, but did not reduced the proportion of defective forms of SP, increased in DIO. In the case of MF, this was associated with the drug-induced normalization of body weight, glucose tolerance, and the insulin and leptin levels in DIO rats. The positive effect of hCG and TP03 on spermatogenesis was due to their stimulating effect on testosterone production.CONCLUSION: The use of long-term MF therapy and short-term courses of LHR-agonists normalizes impaired spermatogenesis in DIO, which indicates the prospects for their use to improve male fertility in obesity, and in the case of MF therapy, normalization of the metabolic and hormonal status is of great importance, while in the case of LHR-agonists the most important factor is their steroidogenic effect.

Published
2023
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35. Energy spread minimization in a beam-driven plasma wakefield accelerator

Author

Pompili, R., Anania, M. P., Behtouei, M., Bellaveglia, M., Biagioni, A., Bisesto, F. G., Cesarini, M., Chiadroni, E., Cianchi, A., Costa, G., Croia, M., Del Dotto, A., Di Giovenale, D., Diomede, M., Dipace, F., Ferrario, M., Giribono, A., Lollo, V., Magnisi, L., Marongiu, M., Mostacci, A., Di Pirro, G., Romeo, S., Rossi, A. R., Scifo, J., Shpakov, V., Vaccarezza, C., Villa, F., and Zigler, A.

Subjects
Physics - Accelerator Physics, Physics - Plasma Physics
Abstract

Next-generation plasma-based accelerators can push electron bunches to gigaelectronvolt energies within centimetre distances. The plasma, excited by a driver pulse, generates large electric fields that can efficiently accelerate a trailing witness bunch making possible the realization of laboratory-scale applications ranging from high-energy colliders to ultra-bright light sources. So far several experiments have demonstrated a significant acceleration but the resulting beam quality, especially the energy spread, is still far from state of the art conventional accelerators. Here we show the results of a beam-driven plasma acceleration experiment where we used an electron bunch as a driver followed by an ultra-short witness. The experiment demonstrates, for the first time, an innovative method to achieve an ultra-low energy spread of the accelerated witness of about 0.1%. This is an order of magnitude smaller than what has been obtained so far. The result can lead to a major breakthrough toward the optimization of the plasma acceleration process and its implementation in forthcoming compact machines for user-oriented applications.

Published
2020
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38. Hormonal and Allosteric Regulation of the Luteinizing Hormone/Chorionic Gonadotropin Receptor

Author

Alexander O. Shpakov

Subjects
luteinizing hormone, human chorionic gonadotropin, luteinizing hormone/chorionic gonadotropin receptor, allosteric regulator, allosteric site, adenylyl cyclase, β-arrestin, biased signaling, steroidogenesis, ovulation, Biochemistry, QD415-436, Biology (General), QH301-705.5
Abstract

Luteinizing hormone (LH) and human chorionic gonadotropin (CG), like follicle-stimulating hormone, are the most important regulators of the reproductive system. They exert their effect on the cell through the LH/CG receptor (LHCGR), which belongs to the family of G protein-coupled receptors. Binding to gonadotropin induces the interaction of LHCGR with various types of heterotrimeric G proteins (Gs, Gq/11, Gi) and β-arrestins, which leads to stimulation (Gs) or inhibition (Gi) of cyclic adenosine monophosphate-dependent cascades, activation of the phospholipase pathway (Gq/11), and also to the formation of signalosomes that mediate the stimulation of mitogen-activated protein kinases (β-arrestins). The efficiency and selectivity of activation of intracellular cascades by different gonadotropins varies, which is due to differences in their interaction with the ligand-binding site of LHCGR. Gonadotropin signaling largely depends on the status of N- and O-glycosylation of LH and CG, on the formation of homo- and heterodimeric receptor complexes, on the cell-specific microenvironment of LHCGR and the presence of autoantibodies to it, and allosteric mechanisms are important in the implementation of these influences, which is due to the multiplicity of allosteric sites in different loci of the LHCGR. The development of low-molecular-weight allosteric regulators of LHCGR with different profiles of pharmacological activity, which can be used in medicine for the correction of reproductive disorders and in assisted reproductive technologies, is promising. These and other issues regarding the hormonal and allosteric regulation of LHCGR are summarized and discussed in this review.

Published
2024
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45. Longitudinal phase-space manipulation with beam-driven plasma wakefields

Author

Shpakov, V., Anania, M. P., Bellaveglia, M., Biagioni, A., Bisesto, F., Cardelli, F., Cesarini, M., Chiadroni, E., Cianchi, A., Costa, G., Croia, M., DelDotto, A., DiGiovenale, D., Diomede, M., Ferrario, M., Filippi, F., Giribono, A., Lollo, V., Marongiu, M., Martinelli, V., Mostacci, A., Piersanti, L., DiPirro, G., Pompili, R., Romeo, S., Scifo, J., Vaccarezza, C., Villa, F., and Zigler, A.

Subjects
Physics - Accelerator Physics
Abstract

The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in field of next-generation compact and cost affordable particle accelerators, to be used in many fields for industrial, medical and research applications. The ability to shape the beam longitudinal phase-space, in particular, plays a key role to achieve high-peak brightness. Here we present a new approach that allows to tune the longitudinal phase-space of a high-brightness beam by means of a plasma wakefields. The electron beam passing through the plasma drives large wakefields that are used to manipulate the time-energy correlation of particles along the beam itself. We experimentally demonstrate that such solution is highly tunable by simply adjusting the density of the plasma and can be used to imprint or remove any correlation onto the beam. This is a fundamental requirement when dealing with largely time-energy correlated beams coming from future plasma accelerators.

Published
2019
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