Introduction: Hearing loss is an important public health issue that negatively affects children’s speech, cognitive development, academic performance, and social interaction. Even mild hearing impairment may lead to adverse developmental outcomes. However, data on hearing loss among primary school children in Mongolia remain limited. Goals: To determine the prevalence, type, and severity of hearing loss among primary school students in Ulaanbaatar and to assess associated socio-demographic factors. Material and Method: A school-based cross-sectional study was conducted among 1,254 primary school students. Hearing screening was performed using pure-tone audiometry following a standardized protocol. Students who failed the screening were referred for confirmatory diagnostic audiometry. Hearing loss was classified as mild (21–35 dB), moderate (36–50 dB), and severe (≥50 dB). Socio-demographic data were collected using a structured questionnaire. Statistical analysis data were analyzed using RStudio software. Descriptive statistics were used to summarize participant characteristics. Associations between hearing loss and independent variables were examined using chi-square tests and logistic regression analysis. Variables with p<0.20 in univariate analysis were included in the multivariable logistic regression model. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported, and p<0.05 was considered statistically significant. Ethical considerations: The study protocol was approved by the Institutional Ethics Committee (Approval No. 2024/3 06). Written informed consent was obtained from parents or legal guardians, and assent was obtained from participating students prior to data collection. Results: Of the 1,254 students, 116 (9.2%) required further evaluation, and hearing loss was confirmed in 23 students (1.8%). Most cases were mild in severity. Paternal education level was significantly associated with hearing loss (p=0.028), whereas no significant associations were observed for sex or household income. Conclusion The prevalence of hearing loss among primary school students in Ulaanbaatar was 1.8%, with most cases being mild and unilateral. These findings highlight the importance of implementing regular school-based hearing screening programs and improving parental awareness of children’s hearing health.

Background: To prevent and combat the spread of the COVID-19 pandemic, the Government of Mongolia has implemented measures such as movement and time restrictions, social distancing and isolation, closure of schools, kindergartens and public places, immunization, and others. It has caused adverse consequences for people, social relations, and the economy, causing health, social, economic, and humanitarian crises. Not only does this situation, medical students, as frontline healthcare workers, are more susceptible to virus infection. Vaccines against COVID-19 have been researched quickly due to the pandemic and are being used under emergency use authorization. In our country the approach of mixing vaccine doses from different manufacturers was used (fractional doses). Therefore, there is no study on the exposure of medical students to the COVID-19 infection and the adverse effects after receiving a dose of a heterologous vaccine. Objective: To study the exposure to the COVID-19 infection and vaccination status of medical students. Methods: The survey was conducted from November 2023 to December 2023 using a cross-sectional study design, and 170 students who study at ASUSU and live in the dormitory were included. Results: A total of 170 students participated in the study. 55.9% (n=95) of them were in the first year, 22.4% (n=38) were in the second year, 10% (n=17) were in the third year, 7.6% (n=13) were in the fourth year, 2.4% (n=4) were from the 5th year and 1.8% (n=3) were from the 6th year students. 88.2% (n=150) of students were female and 11.8% (n=20) were male. In this study, 37.1% of the students were infected by COVID-19 infection previously. Among them, 50% of the students were infected from family members, 16.7% from the school environment, and 15.2% did not know about the source of infection. 76.2% of the respondents were diagnosed with COVID-19 in a medical institution, and forty-one students answered that they were treated at the hospital. 83% of the cases were treated at home and were cured within 14 days. In contrast, 93.8% of the hospitalized students were treated within four months to 1 year. The current study demonstrates neurological, respiratory, sensory, cardiovascular, psychiatric, digestive, and dermatological symptoms were in 37.6%, 24.1%, 27.6%, 17.6%, 11.8%, 11.2%, and 10% of the students who participated in the study, respectively. For a year or more, symptoms of all organ systems were present, but neurological symptoms appeared to be the highest. 55.9% (n=115) of the enrolled students received 3 or 4 doses of the vaccine, 3.5% (n=6) did not receive the vaccine. In total, 35% (n=60) of the enrolled students experienced side effects and 65% (n=106) had no side effects. Conclusion In this study, 37.1% of the students were infected by COVID-19 infection previously. According to the current study, symptoms related to the nervous system was the most prevalent and 55.9% (n=115) of the enrolled students received 3 or 4 doses of the vaccine. In total, 35% (n=60) of the enrolled students experienced side effects.

Introduction: Khuumii (throat singing) is a unique form of art derived from the nomadic population of Central Asia, producing two or more “simultaneous” sounds and melodies through the organ of speech. Material and Methods: The aim of the study is to identify the anatomical structures involved in the formation of khuumii and the features and patterns of their functions and compare each type of khuumii as performed by Mongolian people. A total of 60 participants aged 18-60 years (54 men and 6 women) were selected by non-random sampling method using cross-sectional study. Statistical analysis was performed using SPSS 23 software using questionnaires, X-ray, endoscopy, sound research method, and general blood tests. Results: 90.7% of the khuumii singers were male and 9.3% were female. The average height of the participants was 172.91±0.93 cm (arithmetic mean and mean error), average body weight was 77.53±2.46 kg, and body mass index was 25.93±5.31 respectively. Heart rate was 92.19±20.71 per minute prior to khuumii while 133.19±19.09 after performing khuumii and 85.81-98.56 at 95% confidence interval. In terms of ethnicity (ethnographically), the Khalkh were the largest ethnic group (72.1%), followed by Bayad, Buryatia, Darkhad, Torguud, and Oirat (2.3%), respectively. 60.5% of the participants were professional khuumii singers who graduated from relevant universities and colleges. The process of Khuumii was recorded by X-ray examination, and laryngeal endoscopy evaluated the movement of true and false vocal chords, interstitial volume, movements of epiglottis and arytenoid cartilage, and mucosa. Khuumii increases the workload of the cardiovascular system by 70-80%. Furthermore, the sound frequency is 2-4 times higher than that of normal speech, and sound volume is 0.5-1 times higher. 95.3% of throat singers did not have a sore throat, 88.4% did not experience heavy breathing, and 74.1% had no hoarseness. During the formation of khuumii sound, thoracic cavity, diaphragm, and lungs regulate the intensity of the air reaching the vocal folds, exert pressure on the airways and vibrate the sound waves through air flows passing through the larynx and vocal folds. Mouth-nose cavity as well as pharynx are responsible for echoing the sound. Conclusion It is appropriate to divide khuumii into two main types according to structural and functional changes in the organs involved; shakhaa and kharkhiraa. Khuumii, the “Human music” originating from the people of Altai Khangai basin by imitating the sounds of nature with their own voice in ancient times, spread all over the world from Mongolia and it is proposed to classify khuumii into two main types of shakhaa and kharkhiraa in terms of structural involvement and functionality.

Background: Data from yearly statistical reports on morbidity and mortality in Mongolia show that young adults account for approximately 20-26% of all stroke patients as opposed to 10-13% in Western countries. Objectives: The aim of this study was to compare characteristics of ischemic stroke between young (20-49 years) and old (50-79 years) patients undergoing investigations and treatment according to one common protocol in a tertiary hospital. Material and Methods: This hospital based prospective study included 110 young and 130 old patients with acute ischemic stroke. Data regarding the etiology of the stroke, diagnostic neuroimaging test results and degree of functional improvement of patients were examined during their observation. Results: The frequency of ischemic stroke at the age of 20-49 years grows from 9.6% to 24.2% and is predominant in the male sex (17.1%), which indicates a young stroke in mongolians is not uncommon. Young adults with ischemic stroke frequently bear both traditional and specific vascular risk factorsthan elderly people (p<0.05). The most common TOAST subtype in the young and old groups was undetermined (26.4% vs.12.3%; p=0.004), other determined cause (22.7% vs. 6.9%; p<0.001), and cardioembolism (20.0% vs. 22.3%) followed by Large-artery atherosclerosis (17.3% vs. 26.2%) and small vessel occlusion (15.6% vs. 33.8%; p<0.001). Partial anterior circulation infarcts were more common among young patients (p<0.001), than in posterior circulation infarcts. Silent brain infarcts and leukoaraiosis are not uncommon brain imaging findings (<0.05) in hypertensive and migraineur patients and should not be overlooked due to their potential prognostic relevance. Outcomes in young adults with hemispheric ischemic stroke can safely be improved with Low- molecular-weight-heparin therapy (OR 1.58; 95% CI, 0.99-2.51; p=0.001).
There were large differences between two groups concerning the 6-month outcome which showed beneficial effect for young stroke patients (mRS:89.1% vs. 66.9%, p=0.002; BI: 84.2% vs.73.1%). Conclusion There are significant differences between young and old patients with ischemic stroke regarding to risk factors, etiological subtypes and improvement of functional deficits associated with the stroke. However, severity of stroke on admittance is similar but six weeks outcome is different among young and old patients with relatively rapid improvement of functional deficit in young stroke patients than old one (mRS: 89.1% vs. 66.9%, p=0.002; BI: 84.2% vs.73.1%).

Background: According to the report of see in 2016, 90% of adults are using mobile phones and 64% smart phones, and healthcare organizations are beginning to explore the opportunities in which mobile phones can improve and streamline care. In this study involves the risk of pathogenic virus and bacteria of mobile phones used by healthcare workers. That detected common adenovirus and influenza virus as well as streptococci and staphylococci. Material: In this study was carried out in bacteriology laboratory at the "School of Biomedicine MNUMS". The research collected from the random methods and Mongolian National University of Medical Science‟s 80 students are participated and take a test sample that detected bacteria, them using smart phones. After all students from gave them a survey about usages and clean of smart phones. Results: The results revealed 66% of pathogenic bacterial contamination. Our survey was detected in 33 (63,5%) S.aureus, S.pneumoniae-5 (9.4%) E.coli 2 (3.8%) Bacillus, spp-4 (7.6%) Enterococcus-6 (11.5%) Acinetobacter-2 (3.8%). HOW TO CLEAN YOUR CELL PHONE? asked to total participate in this study. They said that they cleaned up their cell phones in 55.9% once every 3-7days, 11.9% once every 10-14 days and 32.2% once a month and more than. Conclution Are participated in this survey sample have been contaminated bacteria 66%. In total samples have been detected 63,5% in S.aureus and 11.5% in Enterococcus. So students‟ mobile phones may become rick high reservoir of microorganism for infections.

BACKGROUND: In the recent years, mesenchymal stem cells have become increasingly utilized in regenerative medicine and tissue engineering applications because of their properties for self-renewal, differentiation and immunoregulation. The use of stem cells of various clinical applications is highly expected and the production of good quality stem cells is very critical for basic studies. In the bone marrow, hematopoietic and mesenchymal stem cells from an unique niche in which the oxygen tension is low. Hypoxia may have a role in maintaining stem cell fate, self renewal and multi-potency. We investigated whether low oxygen culture would be beneficial for hematopoietic stem cell and mesenchymalstemcell. MATERIAL: BMCs from 8-12 week aged, 15 mice were subjected to hypoxic conditioning by culture for 8-10 days in 20%, 3%, 1% oxygen. For culture 1x105cell/ml were seeded in colony forming assay and 2x106cell/ml were seeded in L-glutamin mediain chamber slide. We counted cell colonies under different hypoxic condiontins by Olympus IX71 fluorescence microscope. After cell culture in chamber slide, we stained cells by anti-CD90 and anti-CD105 then counted positive cells by Olympus IX71 fluorescence microscope. RESULTS: Compared to normoxic cells and hypoxic cells well morphologically differentiated and counted by Olympus IX71 microscope. More colonies were observed at 3%, 1% oxygen. Statistical significances were identified with granulocytes and macrophage colony (p<0.05) in hypoxic condition. More anti-CD90 and anti-CD105 markers were observed at 3% oxygen condition. Statistical significances were identified in 3% oxygen condition with cell markers(p<0.001). CONCLUSIONS: Our data suggests low physiological oxygen culture could improve the stemness of macrophage and granulocytes colony and improve the differentiation of mesenchymal cells. Long term culturewith additional cell markers will be necessary to confirm whether low physiological oxygen levels also improve genomic stability

Introduction: Rongalite have many names, the trade name for sodium hydroxymethylsulfinate also sodium formaldehydesulfoxylate. It causes serious side effects to human body and is forbidden to be used as food additives by law. It is still frequently used illegally in rice and flour products. Based on this study, we determination rongalite level in some friut widespread of in our country. The study was done materials used in Lingonberry, Blueberry, Hippophae, Blackcurrant fruits collected in Khuvsgul. To determine rongalite was followed by protocol to sanitation-laboratory of food of the school of social of health in MNUMS used for NC-860 Universal Food Safety Analyzer. The concentration in sample that were measure to 153.88- 213.85 mg/kg of Lingonberry, Blueberry, Hippophae, Blackcurrant fruits weight. Materials and methods : The study was done materials used in a Lingonberry, Blueberry, Hippophae, Blackcurrant fruits collected in Khuvsgul. To determine rongalite was followed by protocol to sanitation-laboratory of food of the school of social of health in MNUMS used for NC-860 Universal Food Safety Analyzer. Weigh accurately 5.0 g of the fruit in a plastic extract bottle, add 20 ml of distilled water, extract for 10 min by centrifugated. Than filtrate into 6 time respectively test tubes through 0.45 μm membrane using remove the color. Rongalite determined in use a disposable test tube, add 1 drop of oxidizing reagent. Amount of rongalite used for NC-860 Universal Food Safety Analyzer. Result and discussion Based on the obtained result, the maximum concentration observed in Blueberry was 213.85 mg/kg, and the minimum concentration observed in Hippophae was 153.88 mg/kg, the concentration observed in Lingonberry was 192.8 mg/kg, the concentration observed in Blackcurrant was 155.29 mg/kg of contained weight respectively. The difference of rongalite concentrations in wheat powder and rice powder was 0.41 mg/kg in China. Identified to the result was higher than other research.

BackgroundHydroquinone (1,4 di-hydroxy benzene) is an aromatic organic compound with diverse biologicalfunctions that are commonly used as pigment or cosmetic additives. Its chemical structure has twohydroxyl groups bonded to a benzene ring in a para position. In the nature hydroquinone have a primaryreagent in the defensive glands of bombardier beetles, along with hydrogen peroxide, which collects in areservoir [1]. Hydroquinone glycoside form is 4-hydroxyphenyl-α-D-glucopyranoside (α- Arbutin). Arbutinis a potent inhibitor of melanin synthesis and has been reported to possess inhibitory activity on lipidperoxidation and is used in the cosmetic industry for its antibacterial and skin lightening effects [9]. It isfaster and more effictive another commonly used skin lightener, even at use very low concentrations.Material and MethodsThe in vitro glycosylation reaction was carried out as described in materials and methods. DNA wasextracted than E.coli BL 21 and E.coli JM 109 hosts were used for expression of proteins. The purifiedprotein was then analyzed by 12% SDS-PAGE than used for enzymatic recycle system. Hydroquinonereaction mixture was incubated at 37ºC for 8 and 24 hour than quenched by heating in boiling waterfor 10 min. The reactions products was first analyzed by TLC followed by HPLC analysis.ResultsThis work substrate hydroquinone for the enhancement of enzymatic recycling system glycosylation. TLCand HPLC analyses of the products were carried out to the recycled system worked and glycosylationproduct.ConclusionIn this study, hydroxyl groups of the para position of hydroquinone involved for glycosylation to comparewith standards were analysed by TLC and HPLC. When the compared 8 hour reactions obtained theapparent glycosylation and stability of the recycling system.

Сэтгэцийн шалтгаант толгой эргэх зовуурь нь олон талт, нийлмэл шинж чанарыг агуулдаг тул чих хамар хоолой,мэдрэлийн болон сэтгэцийн эмчийн анхаарлыг татдаг. Толгой эргэлтийн шалтгаанд суурилсан ангиллын дагуу:1) Байршлаас хамаарах хоргүй толгой эргэлт, 2) Сэтгэцийн шалтгаант толгой эргэлт, 3) Cуурийн мигрень, 4)Вестибуляр нейронит зэрэг хэлбэрүүдэд хуваагдана. Нийт толгой эргэлтийн шалтгааны дотор 2-р байрандсэтгэцийн шалтгаант толгой эргэлт ордог. Ийнхүү энэ хэлбэрийн толгой эргэлт харьцангуй элбэг тохиолдох боловчоношлох асуудал эмч нарын дунд хангалттай биш байна. Сэтгэцийн шалтгаант толгой эргэлтийг оношлоход юуныөмнө үүдэвчийн тогтолцооны эмгэг, органик гаралтай тэнцвэрийн өөрчлөлт, ухаан алдалт, муужралт зэргийгүгүйсгэх шаардлагатай. Дараа нь тухайн зовуурь нь стресс, сэтгэл хөдлөлийн өөрчлөлт, айдас-түгшүүр, сэтгэлгутралтай холбоотой эсэхийг тодруулна. Суурь сэтгэцийн эмгэгээс хамааран эмчилгээг чиглүүлэх хэрэгтэй.Сэтгэцийн шалтгаант толгой эргэлтэнд эхний сонголтын эм нь СЭØСС антидепрессант ба цөөн тохиолдолдГЦА-г хэрэглэнэ. Сэтгэл засал эмчилгээг хийх нь үр дүнтэй.

Судалгааны ажлын зорилго: Изониазид эмийн шалтгаант элэгний архаг үрэвслийн эмгэг загвар үүсгэх. Сүүлийн жилүүдэд манай орны нийт хүн амын дунд хоол боловсруулах эрхтэний өвчлөл хоёрдугаарт орж байгаа бөгөөд эмийн шалтгаант элэгний үрэвсэл нэмэгдэж байна. Мөн халдварт өвчний дунд сүреэгийн өвчлөл дээгүүр байна. Бид судалгааг туршилтын амьтанд Изониазид эмээр элэгний үрэвслийн эмгэг загвар үүсгэсэн ба тус бүрт 21 харх байхаар эрүүл, хяналтын (изониазид 50мг/кг) гэсэн 2 бүлэгт хувааж үзсэн. Шинжилгээнд биохимийн үзүүлэлт болон эдийн шинжилгээг 7, 14, 21 хоногт хийсэн. Судалгааны дүнд Изонизид эмийг уулгасан бүлгийн биохимийн шинжилгээнд 7 дах өдөр эрүүл бүлэгтэй харьцуулахад статистикийн ач холбогдол бүхий ялгаатай байсан. Мөн 21 дэх хоногт элэгний эс задарлын шинж илэрч байгаа нь статистик ач холбогдолтой дүн гарсан.