Influence of ZrO2 modifier and Mo precursor on the state of active component in MoO3/Al2O3 catalysts

The effects of precursor and the method of support modification on the properties of supported metathesis catalysts for reaction of ethylene and trans-butene-2 into propylene are considered. The objects of the research are the catalyst comprising γ-Al2O3-supported molybdenum oxide as well as the modified alumina-based supports. The Mo precursors used is shown to significantly affect the state of the supported component. The distribution and morphology of the particles of active component inside the pores of the support differ for the ZrO2-modified samples prepared by impregnation and wet mixing methods

Lepton pair production by high-energy neutrino in an external electromagnetic field

The process of the lepton pair production by a neutrino propagating in an external electromagnetic field is investigated in the framework of the Standard Model. Relatively simple exact expression for the probability as the single integral is obtained, which is suitable for a quantitative analysis.Comment: 9 pages, LATEX, 2 PS figures, submitted to Modern Physics Letters

The role of immunotherapy in the management of metastatic/recurrent female reproductive system neoplasms

In 2019 malignant neoplasms of the female reproductive system (ovarian cancer, (OC), endometrial carcinoma (EC) and cervical cancer (CC) were diagnosed in 58 860 patients – 17.6% of all malignant tumors in women in Russia. The morbidity and mortality rates from these neoplasms remain high over the past 10 years. This article provides a detailed review of the current evidence base for  the  use of  various immunotherapeutic agents in  mentioned malignant neoplasms. It has been demonstrated that in  relapsed OC (ROC), the  only proved indication for  immunotherapy is tumors with microsatellite instability (MSI), whereas PD-L1 does not have an independent role in this disease. MSI occurs in approximately 8% of patients with metastatic OC. A significantly higher frequency MSI — up to 25% is detected in metastatic EC. MSI-positive subtype of the disease is characterized by an extremely high sensitivity to immunotherapy - the  rate of  objective response with pembrolizumab exceeds 50%. For  MS-stable  EC, the  combination of  pembrolizumab and lenvatinib is an effective therapeutic option. In  advanced CC, on the other hand, PD-L1 has a predictive role for immunotherapy efficacy — the KEYNOTE-158 study showed that about 15% of  patients with extensively pretreated metastatic PD-L1-positive CC can achieve long-term remission with pembrolizumab compared to 0% in PD-L1 negative tumors. Current evidence shows that PD-L1 expression can be observed in ≥ 30% of patients

Terahertz Response of Field-Effect Transistors in Saturation Regime

We report on the broadband THz response of InGaAs/GaAs HEMTs operating at 1.63 THz and room temperature deep in the saturation regime. We demonstrate that responses show linear increase with drain-to-source voltage (or drain bias current) and reach very high values up to 170V/W. We also develop a phenomenological theory valid both in the ohmic and in the saturation regimes.Comment: 11 pages, 3 figure

Low-Frequency Noise Spectroscopy of Charge-Density-Wave Phase Transitions in Vertical Quasi-2D Devices

We report results regarding the electron transport in vertical quasi-2D layered 1T-TaS2 charge-density-wave devices. The low-frequency noise spectroscopy was used as a tool to study changes in the cross-plane electrical characteristics of the quasi-2D material below room temperature. The noise spectral density revealed strong peaks - changing by more than an order-of-magnitude - at the temperatures closely matching the electrical resistance steps. Some of the noise peaks appeared below the temperature of the commensurate to nearly-commensurate charge-density-wave transition, possibly indicating the presence of the debated "hidden" phase transitions. These results confirm the potential of the noise spectroscopy for investigations of electron transport and phase transitions in novel materials.Comment: 16 pages; 5 figure

Market ranking of successful digital business models

The transition from industrial to service economy resulted in a wider adoption of asset-light strategies and technology-enabled business models. In the last ten years, digital companies have ascended to the top of the most valuable firms lists. Various aspects of digital business models have been exhaustively discussed in management literature, but their economic dimension remains under-researched.We analyze how strategy and business model add value and propose using historical volatility of valuation multiples for ranking companies by the degree of investors’ understanding of a firm’s strategy and business model in addition to ratings of companies by market capitalization. This ranking, in our view, is particularly helpful in analyzing business models of digital companies where most of the value is in intangible assets and economic goodwill. We also propose a way of expanding this research topic in the future

Results of a search for 2β\beta-decay of 136^{136}Xe with high-pressure copper proportional counters in Baksan Neutrino Observatory

The experiment for the 2$\beta$-decay of $^{136}$Xe search with two high-pressure copper proportional counters has been held in Baksan neutrino observatory. The search for the process is based on comparison of spectra measured with natural and enriched xenon. No evidence has been found for 2$\beta$(2$\nu$)- and 2$\beta$(0$\nu$)-decay. The decay half lifetime limit based on data measured during 8000 h is T$_{1/2}$$\geq8.5\cdot10^{21}$yr for 2$\nu$-mode and T$_{1/2}$$\geq3.1\cdot10^{23}$yr for 0$\nu$-mode (90%C.L.).Comment: 9 pages, 8 figures; talk at the NANP'05 Conference; submitted to Phys. At. Nuc

Estimated Inpatient Hospital Stay in Individual Wards: Guidelines on Radiation Safety after Radioiodine Therapy

Radionuclide therapy safety requirements are regulated by the Russian Radiation Safety Standards (RRSS), which state the maximum allowed radionuclide activity in the body and the equivalent dose rate (EDR) of gamma radiation. Therefore, it is necessary to estimate the time of an inpatient hospital stay in specially designed radionuclide therapy wards. The article presents the findings of individual 131I biokinetics studies in 64 patients admitted to radioiodine therapy of thyrotoxicosis and differentiated thyroid cancer. We developed a method to calculate the time interval to reach the EDR of 20μSv/h and the recommended EDR of 3 and 0.3μSv/h for adults and children, respectively. It is based on the measurement of the 131I excretion constant. Keywords: Radioiodine therapy, Radiation safety, Guidelin

Evaluation of the PV cell operation temperature in the process of fast switching to open-circuit mode

A procedure for measuring the overheating temperature (ΔT ) of a p-n junction area in the structure of photovoltaic (PV) cells converting laser or solar radiations relative to the ambient temperature has been proposed for the conditions of connecting to an electric load. The basis of the procedure is the measurement of the open-circuit voltage (VO C ) during the initial time period after the fast disconnection of the external resistive load. The simultaneous temperature control on an external heated part of a PV module gives the means for determining the value of VO C at ambient temperature. Comparing it with that measured after switching OFF the load makes the calculation of ΔT possible. Calibration data on the VO C = f(T ) dependences for single-junction AlGaAs/GaAs and triple-junction InGaP/GaAs/Ge PV cells are presented. The temperature dynamics in the PV cells has been determined under flash illumination and during fast commutation of the load. Temperature measurements were taken in two cases: converting continuous laser power by single-junction cells and converting solar power by triple-junction cells operating in the concentrator modules