Tajik National University

The paper presents the results of photometric observations of the near-Earth asteroid (65803) Didymos, conducted on the 70-cm AZT-8 telescope of the Hisar Astronomical Observatory of the Institute of Astrophysics of the National Academy of Sciences of Tajikistan over seven nights from August 29 to September 6, 2022. Using the Lomb–Scargle method, the asteroid’s rotation period was determined to be P = 2.3562 ± 0.0040 h. The uncertainty ΔP was estimated using three independent methods: Bootstrap (Monte Carlo), FWHM, and Q-factor. Analysis of the phase curve using a two-harmonic Fourier series confirms the double-humped shape of the light curve, characteristic of rotating irregularly shaped objects. The results are consistent with period estimates obtained before the DART space experiment and can be used for further modeling.

Background . Human papillomavirus (HPV) causes 4.5 % of all new cancer cases worldwide, including cervical cancer. Cervical cancer accounts for the vast majority (83 %) of HPV-associated cancers. Aim . To evaluate the first results of the immunization campaign against human papillomavirus in girls aged 10–14 years in the context of increasing incidence of cervical cancer in the Republic of Tajikistan. Materials and Methods. The study analyzed statistical data and reports from the Republican Center for Immunoprophylaxis on the progress of HPV immunization in the republic, as well as on the incidence of cervical cancer, obtained from various specialized medical institutions for the period 2014–2025. Results and Discussion . In 2025, 434 new cases of cervical cancer were registered in the Republic of Tajikistan, with a prevalence rate of 4.1 cases per 100,000 women. Over the past five years (2021 to 2025), this rate has increased by 1.5 times. This annual increase is due to the expansion of visual screening coverage under the state program, as well as a possible increase in actual incidence. Since July 2025, the Republic of Tajikistan has become the 53rd country in the WHO European Region to introduce HPV vaccination into its National Immunization Program. The government officially announced the launch of an HPV vaccination campaign for girls aged 10–14 years on October 1, 2025. The preferred vaccination regimen for Tajikistan is the single-dose quadrivalent Gardasil® vaccine, manufactured by Merck & Co. (USA). Thanks to collaboration with GAVI, Tajikistan received 623,000 doses of this vaccine. As of October 31, 2025, the number of girls aged 10–14 vaccinated nationwide reached 95.4 % of the target population, or 522,134 girls. The range of vaccination coverage across all regions of the country ranged from 94.9 % to 96.9 %. During the specified period, 48 cases of adverse reactions after immunization against HPV were registered, which amounted to 0.009 %. The most common symptoms were: weakness/malaise (n = 15; 31.25 %); redness of the skin/face (n = 10; 20.8 %); nausea (n = 8; 16.7 %); fainting (n = 7; 14.6 %); increased body temperature (n = 7; 14.6 %) and collapse (n = 5; 10.4 %). Conclusion . Introduction routine HPV vaccination in the National Immunization Schedule of the Republic of Tajikistan is a prudent and strategically important step. Implementing these measures creates the foundation for achieving national and international goals to eliminate cervical cancer and improve the reproductive and public health of women in the country.

The widespread use of duralumin in aviation, transportation and other industries is due to its high strength characteristics, low density and good manufacturability during casting and pressure treatment. This alloy belongs to the class of structural materials based on aluminum, reinforced with additives of copper, manganese, magnesium and lithium. Its operational properties are largely determined by the modes of heat treatment and the composition of alloying elements. One of the key factors limiting the durability of duralumin in aggressive environments is the tendency to local corrosion, in particular to pitting, which in freshwater is assessed primarily by the depth of the lesion. Duralumin alloy is widely used in the aircraft industry, in the manufacture of high-speed trains (for example, Shinkansen trains) and in many other branches of engineering, as it is significantly more durable than pure aluminum. Along with its high performance properties, the diverse use of duralumin is due to its high technological efficiency, which creates the prerequisites for obtaining products using all known methods of casting and plastic processing. Duralumin belongs to the category of structural alloys, which are characterized by increased strength. They are based on aluminum. Copper, manganese, and magnesium are used as additives in different percentages. The properties of duralumin depend on the heat treatment and the amount of alloying elements added. The paper presents the results of a study of the effect of cerium on the anodic behavior of aluminum alloy AlMg5.5Li2.1Zr0.15 type duralumin in the medium of electrolyte NaCl. The study of the corrosion-electrochemical behavior of alloys was carried out by the potentiostatic method in a potentiodynamic mode with a potential sweep rate of 2 mV⋅s- 1. It was shown that cerium additives reduce the rate of anodic corrosion of the initial alloy AlMg5.5Li2.1Zr0.15 by 20-30%. It was found that an increase in the concentration of chloride ion contributes to an increase in the rate of anodic corrosion, regardless of the cerium content in the alloy AlMg5.5Li2.1Zr0.15 of the duralumin type.