Finite element analysis and structure optimization of a gantry-type high-precision machine tool.

The high-precision machine tool's dynamic, static, and rigid nature directly affects the machining efficiency and surface quality. Static and dynamic analyses are essential for the design and improvement of precision machine to ensure good tool performance under difficult and demanding machining conditions. In this study, the performance of a high-precision machine tool was analyzed using its virtual model created using CAD. Static and model analysis using ANSYS Workbench software was conducted to establish the tool's static deformation and static stiffness. Furthermore, the static and dynamic characteristics of the tool were explored using a finite element modeling approach to study their performance. In particular, the structure, static force, modal, frequency spectrum, and topology optimization of machine tools were primarily analyzed. Using model analysis, we found the first four different frequencies (22.5, 28.9, 40.6, and 47.4 Hz) and vibration type, which suggested of a weak link. Further static structural analysis revealed that the deformation of the spindle was 67.26 µm. An experimental static rigidity analysis was performed, and the experimental deformation values of the tool and spindle were obtained. The static and dynamic characteristics, as well as the accuracy and efficiency of the finite element model, were verified by comparing the data with the finite element analysis (FEA) results. Subsequently, we modified the settings and analysis model to ensure that the analysis results were consistent with the experimental findings. The error between the two results was within 1.56%. For an applied load of 5000 N on the spindle nose, the tool nose transient response was 0.5 s based on transient analysis. Under the condition that the structural deformation is as constant as possible, the lightweight structure may achieve the minimum weight and enhance the natural frequency; thus, the ideal structure will be obtained, and finite element analysis will then be performed. The optimal conditions for topology optimization include a lightweight structure, reduced structural deformation, and increased natural frequency of the structure. The developed method improves structural optimization, increases the ability of the product to be manufactured, and offers designers a variety of price-effective options.

Impact of nanoparticles on human health and disease.

Nanoparticles (NPs) are small particles with a surface area ranging from 1 to 100 nm in diameter that are rampantly used in different fields, e.g., medicine, engineering, and others. Because of their unique properties, such as their tiny size, magnetic properties, quantum size effects, and macroscopic quantum tunnelling effects, they are crucial for a wide range of potential applications. NPs play a significant role in the treatment of vascular disorders, the production of vaccines, and the development of drug carriers for diverse therapies due to their bioavailability, targeting ability, and efficacy. However, significant risks to the environment and health are also associated with it. NPs cause necrotic plasma membrane rupture or apoptosis, which leads to cell death. NPs interfere with cell signalling, endosomal membranes, and organelles like the nucleus or mitochondria, affecting their function. NPs cause autophagic cell death, which causes a stress response and sterile inflammation. The primary routes for the entry of NPs into the human body are inhalation, ingestion, and skin contact. NPs accumulate in the respiratory system based on their size, shape, and surface properties. NPs can cause lung inflammation and fibrosis, disrupt the endocrine system by attaching to hormone receptors, and produce reactive oxygen species (ROS) associated with DNA damage, oligospermia, and male infertility. Carcinogenic properties of NPs cause mutations, apoptosis, and inflammatory responses. Collaborative research between ecologists and epidemiologists may enlighten ways to reduce the harmful effects of NPs.

Development and implementation of a potential coronavirus disease 2019 (COVID-19) vaccine: A systematic review and meta-analysis of vaccine clinical trials.

BACKGROUND: To date, there is no comprehensive systematic review and meta-analysis to assess the suitability of COVID-19 vaccines for mass immunization. The current systematic review and meta-analysis was conducted to evaluate the safety and immunogenicity of novel COVID-19 vaccine candidates under clinical trial evaluation and present a contemporary update on the development and implementation of a potential vaccines. METHODS: For this study PubMed, MEDLINE, and Embase electronic databases were used to search for eligible studies on the interface between novel coronavirus and vaccine design until December 31, 2020. RESULTS: We have included fourteen non-randomized and randomized controlled phase I-III trials. Implementation of a universal vaccination program with proven safety and efficacy through robust clinical evaluation is the long-term goal for preventing COVID-19. The immunization program must be cost-effective for mass production and accessibility. Despite pioneering techniques for the fast-track development of the vaccine in the current global emergency, mass production and availability of an effective COVID-19 vaccine could take some more time. CONCLUSION: Our findings suggest a revisiting of the reported solicited and unsolicited systemic adverse events for COVID-19 candidate vaccines. Hence, it is alarming to judiciously expose thousands of participants to COVID-19 candidate vaccines at Phase-3 trials that have adverse events and insufficient evidence on safety and effectiveness that necessitates further justification.

Impact of COVID-19 on clinical trials and clinical research: A systematic review.

Background: The World Health Organization has reported more than 31,186,000 confirmed cases of coronavirus disease-19 (COVID-19), including 962,343 deaths, worldwide as on September 21, 2020. The current COVID-19 pandemic is affecting clinical research activities in most parts of the world. The focus on developing a vaccine for SARS-CoV-2 and the treatment of COVID-19 is, in fact, disrupting many upcoming and/or ongoing clinical trials on other diseases around the globe. On March 18, 2020, the United States Food and Drug Administration (FDA) issued an updated guideline for the conduct of clinical trials during the current health emergency situation. The potential challenges, such as social distancing and quarantines, result in study participants' inaccessibility and trial personnel for in-person scheduled study visits and/or follow-up. Due to the sudden onset and wide-spread impact of COVID-19, its influence on the management of clinical trials and research necessitates urgent attention. Therefore, our systematic review of the literature aims to assess the impact of the COVID-19 pandemic on the conduction of clinical trials and research. The search for the relevant articles for review included the keywords "COVID-19" AND "clinical trial" in PubMed, MEDLINE, Embase, Google scholar and Google electronic databases. Key findings include: delaying subject enrollment and operational gaps in most ongoing clinical trials, which in turn has a negative impact on trial programmes and data integrity. Globally, most sites conducting clinical trials other than COVID-19 are experiencing a delay in timelines and a complete halt of operations in lieu of this pandemic, thus affecting clinical research outcomes.

Cigarette smoking dose-response and suicidal ideation among young people in Nepal: a cross-sectional study.

BACKGROUND: Worldwide, tobacco smoking is a major risk factor for morbidity and early mortality among adult population. The present study aimed to find out the association between current smoking and suicidal ideation among young people in Nepal. MATERIALS AND METHODS: A cross-sectional questionnaire-based survey was carried out among 452 youths from Pokhara, Nepal. The present study included both genders (age 18-24 years) who were smokers as well as non-smokers. RESULTS: Across the study period, 452 participants were identified after matching for age, and sex (226 in the smoking group and 226 in the non-smoking group). The mean age of participants was 21.6±1.2 years and 58.8% were males. The overall rate of suicidal ideation in our cohort was 8.9%. Smokers were slightly more likely to report suicidal ideation than non-smokers (aOR 1.12). The risk of developing suicidal ideation was 3.56 (95% CI 1.26-10.09) times more in individuals who smoked greater than 3.5 cigarettes per week (p=0.01). CONCLUSION: The rate of suicidal ideation was slightly higher among smokers and a dose-response relationship was identified with the number of cigarettes smoked per week. Being aware of the link between smoking and suicidal ideation may help health care professionals working with young people to address more effectively the issues of mental well-being and thoughts about suicide.

Ethnic Variations in Perception of Human Papillomavirus and its Vaccination among Young Women in Nepal .

BACKGROUND: The Human Papillomavirus (HPV) is strongly associated with cervical and other cancers. In women, cervical cancer is the third most common cancer. HPV infection can be largely prevented through vaccination of (adolescent) girls. At the same time, Nepal is a low-income country experiencing a cultural change in attitudes towards sex and sexual behaviour. However, in the adolescent population knowledge about HPV, factors associated with an increased risk of HPV and the existence of the vaccination is often low. MATERIALS AND METHODS: This was a cross-sectional study with female students enrolled in health and non-health science courses in Pokhara, Nepal. The questionnaire included demographic details, knowledge and attitude questions related to HPV, associated risk behaviour and its vaccination. Descriptive statistics, including Chi-Square test, were used to identify statistically significant relationships. Ethical approval was granted by the relevant authority in Nepal. RESULTS: Hindu religion (75.0 %; 95% CI: 70.9, 78.6) and Newari caste (75.5%; CI: 61.1, 86.7) were more aware about HPV, HPV vaccination. Hindus religion (55.6%; 95% CI: 51.2, 60.0) and Dalit caste (61.6%, 95% CI: 53.3, 69.4) more willing to be vaccinated than other religions and other castes, respectively. Not unsurprisingly, students on health-related courses had a greater awareness of HPV, HPV vaccination and were more willing to be vaccinated than students on other courses. Similar patterns of association arose for knowledge related to those sexually active at an early age; HPV risk and multiple sex partners; and fact that condoms cannot fully prevent the transmission of HPV. CONCLUSION: Knowledge about the link between HPV and (a) early sexual initiation, (b) having multiple sexual partners, and (c) the limited protection of condoms and other birth control measures was poor in our study compared to similar research conducted in other parts of the world. One key implication is the need for education campaigns in Nepal to educate young women and their parents about HPV, its risk factors and the benefits of vaccination. .

Self-medication practice among preclinical university students in a medical school from the city of Pokhara, Nepal.

BACKGROUND: In developing countries like Nepal medicines can be acquired from the chemist's without of a prescription which sometime may have many drawbacks due to intake of excessive drugs without a proper diagnosis. The primary objective of the study was to find out the pattern of self-medication practice among the preclinical medical students at Manipal College of Medical Sciences. MATERIALS AND METHODS: This was a cross sectional study carried out using structured questionnaire at Manipal College of Medical Sciences, Pokhara, Nepal between November 2012- July 2014. RESULTS: The overall response rate of this study was 95.31%. 81.35% of the students were practicing self-medication in this institution. Most common group of drugs that were consumed were antipyretics 31%, antibiotics 26.2%, analgesics 18.89%, antihistaminics 10.1% respectively. Paracetamol was the most common drug used for self-medication 31%, followed by Azithromycin 17.6% and combination of Paracetamol and Ibuprofen 15.6%, Cetirizine 8.6%, Amoxicillin 6.5%, Omeprazole 6.3%, Albendazole 3.3%, Mefenemic acid 2.8%, Cefpodoxime2% respectively. CONCLUSION: Medical student should be educated through awareness programme regarding pros and cons of self-medication practice and they should be motivated regarding the rationale use of antibiotics. .

Pharmacotherapy of Bipolar Affective Disorder: A Hospital based Study from Sub Himalayan Valley of Nepal.

INTRODUCTION: In Bipolar disorder the mood of the patients fluctuates between depression and mania. The main objective of the study was to find out the commonest mood stabilizers used for the treatment of Bipolar affective disorders in Western Nepal in hospitalized patients in an actual clinical set up. METHODS: This was a cross-sectional study which was conducted between October 2009 and September 2010 at Psychiatric ward at Manipal teaching hospital, Pokhara, Nepal, a tertiary care hospital situated in Western Nepal. The diagnosis of the disease was based on ICD-10 (Tenth revision) Classification of mental and Behavioural disorders, Diagnostic Criteria for Research. We calculated odds ratio and their 95% confidence intervals (95% CI). p< 0.05 was considered as statistically significant. RESULTS: 62.1% of the patients were less than 40 yrs, 56.3% were male, 72.4% were unemployed and 75.9% of the patients were having monthly income <10,000/month. As far as ethnicity is concerned 37.9% of the cases were Brahmin and by occupation 29.9% of the patients were students followed by housewife 25.3%, labour 17.2%, retired 13.8% respectively. Drugs and Psychotherapy [OR 1.4, 95% (CI 0.575, 3.4017)] was prescribed in age <40 years as compared to age>40 yrs. Male patients [OR 7.22, 95% (CI 0.862, 60.499)] and [OR 2.353, 95% (CI 0.857, 6.455)] received drugs by trade names and drugs not from the national drug list of Nepal as compared to females. Monthly income <10,000/month and [OR 2.8, 95% (CI 0.742, 10.56)] tendency of receiving drugs by trade names. Among the mood elevators Sodium valproate was the commonest drug to be prescribed in 51/87(58.6%) patients followed by Lithium in 30/87 (34.5%) cases and Carbamazepine in 6/87 (6.9%) cases. Sodium valproate was prescribed at 1,000 mg/day, Lithium was prescribed at 900 mg/day in and Carbamazepine was prescribed at 800 mg/day. CONCLUSION: Among all the mood elevators Sodium valproate is the commonest drug prescribed for the treatment of bipolar affective disorder, recommended that there is a trend of using newer drugs like sodium valproate rather than the conventional mood stabilizers like Lithium for bipolar affective disorder in Western Development region of Nepal.

Awareness of breast cancer warning signs and screening methods among female residents of Pokhara valley, Nepal.

BACKGROUND: Breast cancer is the second most common cancer in the world and by far the most frequent cancer among women. OBJECTIVE: The present study was undertaken to assess the awareness of breast cancer warning signs and screening methods among the women of Pokhara valley, Nepal. MATERIALS AND METHODS: A cross-sectional questionnaire survey was carried out in a community setting with the female population. The questionnaire was administered in face-to-face interviews by trained research assistants. RESULTS: Nepalese women demonstrated poor awareness of warning signs like a breast lump, lump under the armpit, bleeding or discharge from the nipple, pulling of the nipple, changes in the position of the nipple, nipple rash, redness of the breast skin, changes in the size of the breast or nipple, changes in the shape of the breast or nipple, pain in the breast or armpit, and dimpling of the breast skin. While 100% of nurses were aware about breast self- examination (BSE), mammography and warning signs of breast cancer. Levels of knowledge were significantly poorer in women with other occupations. Graduates were more aware about BSE, mammogram and warning signs of breast cancer compared to those with other educational levels. CONCLUSIONS: The findings indicated that the level of awareness of breast cancer, including knowledge of warning signs and BSE, is sub-optimal among Nepalese women.

Socio demographic profile and utilization pattern of antipsychotic drugs among schizophrenic inpatients: a cross sectional study from western region of Nepal.

BACKGROUND: Currently a large number of atypical antipsychotics available in the market are endorsed as better option for treating schizophrenia than the typical antipsychotics. Information regarding the utilization pattern of antipsychotic drugs is lacking in Nepalese population particularly in Western Nepal. By means of this study one is expected to acquire an idea concerning clinician's preference to the antipsychotic drugs in actual clinical setup. The main objective of the study was to find the commonest antipsychotics prescribed in a tertiary care center among hospitalized patients in Western Nepal. METHODS: This cross sectional study was carried out between 1st January 2009 and 31th December 2010 at Manipal Teaching Hospital, Nepal. The diagnosis of schizophrenia was based on ICD-10 (Tenth revision).The main outcome variables of the study was commonest antipsychotic drug prescribed. Z test, Chi square test and logistic regression were used for analytical purpose. P-value < 0.05 was considered to be statistically significant. This is the first study done on the utilization pattern of antipsychotics drugs among hospitalized patients in Nepal. RESULTS: Out of 210 cases of schizophrenia, most of the patients were less than 40 yrs. 78.6%, male 61.9%, unemployed 86.7% and having their monthly income less than NPR 10000 /month 80.5%. As far as religion, 78.1% patients were the Hindus and ethnically schizophrenia was common among the Dalit 26.2%. The study revealed that 46.2% of patients were students followed by 25.2% of housewives. Olanzapine was the commonest antipsychotic drug to be prescribed 34.3%. It was observed that the psychiatrists had a tendency of using antipsychotic drugs by trade names [OR 3.3 (1.407, 8.031)] in male patients as compared to female patients. CONCLUSION: According to the utilization pattern of antipsychotics, it is concluded that atypical antipsychotics were used relatively more commonly than that of typical antipsychotics. Among the atypical antipsychotic drugs, there is a trend of using Olanzapine during Schizophrenia as compared to other atypical antipsychotic drugs in Western Nepal.