Natural flavonols: actions, mechanisms, and potential therapeutic utility for various diseases.

Background: Flavonols are phytoconstituents of biological and medicinal importance. In addition to functioning as antioxidants, flavonols may play a role in antagonizing diabetes, cancer, cardiovascular disease, and viral and bacterial diseases. Quercetin, myricetin, kaempferol, and fisetin are the major dietary flavonols. Quercetin is a potent scavenger of free radicals, providing protection from free radical damage and oxidation-associated diseases. Main body of the abstract: An extensive literature review of specific databases (e.g., Pubmed, google scholar, science direct) were conducted using the keywords "flavonol," "quercetin," "antidiabetic," "antiviral," "anticancer," and "myricetin." Some studies concluded that quercetin is a promising antioxidant agent while kaempferol could be effective against human gastric cancer. In addition, kaempferol prevents apoptosis of pancreatic beta-cells via boosting the function and survival rate of the beta-cells, leading to increased insulin secretion. Flavonols also show potential as alternatives to conventional antibiotics, restricting viral infection by antagonizing the envelope proteins to block viral entry. Short conclusion: There is substantial scientific evidence that high consumption of flavonols is associated with reduced risk of cancer and coronary diseases, free radical damage alleviation, tumor growth prevention, and insulin secretion improvement, among other diverse health benefits. Nevertheless, more studies are required to determine the appropriate dietary concentration, dose, and type of flavonol for a particular condition to prevent any adverse side effects.

Ovarian volume is more closely related to the different manifestations of polycystic ovary syndrome than follicle number per ovary / 대한생식의학회지

Objective@#Polycystic ovary (PCO), a diagnostic component of polycystic ovary syndrome (PCOS), requires either an ovarian volume (OV) criterion or a follicle number per ovary (FNPO) criterion. This study investigated the association of OV and FNPO criteria with various manifestations of PCOS. @*Methods@#This cross-sectional study was conducted at a university hospital among 100 patients newly diagnosed with PCOS (according to the revised Rotterdam criteria). Fasting blood samples were collected to measure glucose, total testosterone (TT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), lipid, insulin, and hemoglobin A1c levels. An oral glucose tolerance test was performed. Transabdominal or transvaginal ultrasound of the ovaries was done, depending on patients’ marital status. All investigations were conducted in the follicular phase of the menstrual cycle. OV >10 mL and/or FNPO ≥12 indicated PCO. A homeostasis model assessment of insulin resistance (IR) value ≥2.6 indicated IR, and metabolic syndrome (MS) was defined according to the international harmonization criteria. @*Results@#Seventy-six participants fulfilled the OV criterion, 70 fulfilled the FNPO criterion, and 89 overall had PCO. Both maximum OV and mean OV had a significant correlation with TT levels (r=0.239, p=0.017 and r=0.280, p=0.005, respectively) and the LH/FSH ratio (r=0.212, p=0.034 and r=0.200, p=0.047, respectively). Mean OV also had a significant correlation with fasting insulin levels (r=0.210, p=0.036). Multivariate binary logistic regression analysis showed that IR (odds ratio [OR], 9.429; 95% confidence interval [CI], 1.701 to 52.271; p=0.010) and MS (OR, 7.952; 95% CI, 1.821 to 34.731; p=0.006) had significant predictive associations with OV alone, even after adjustment for age and body mass index. @*Conclusion@#OV may be more closely related to the androgenic and metabolic characteristics of PCOS than FNPO.

Role of T cells in cancer immunotherapy: Opportunities and challenges.

Immunotherapies boosting the immune system's ability to target cancer cells are promising for the treatment of various tumor types, yet clinical responses differ among patients and cancers. Recently, there has been increasing interest in novel cancer immunotherapy practices aimed at triggering T cell-mediated anti-tumor responses. Antigen-directed cytotoxicity mediated by T lymphocytes has become a central focal point in the battle against cancer utilizing the immune system. The molecular and cellular mechanisms involved in the actions of T lymphocytes have directed new therapeutic approaches in cancer immunotherapy, including checkpoint blockade, adoptive and chimeric antigen receptor (CAR) T cell therapy, and cancer vaccinology. This review addresses all the strategies targeting tumor pathogenesis, including metabolic pathways, to evaluate the clinical significance of current and future immunotherapies for patients with cancer, which are further engaged in T cell activation, differentiation, and response against tumors.

Difference in presentation, outcomes, and hospital epidemiologic trend of COVID-19 among first, second, and third waves in Dhaka Medical College

BackgroundThis study aimed to examine the differences in epidemiologic and disease aspects among patients with COVID-19 MethodsWe reviewed the hospital records between April 2020 and September 2021 and followed up on the patients for post-COVID complications. FindingsOlder adult patients were predominantly affected during the first and second waves, followed by middle-aged patients. Men were predominantly admitted, considering the three waves; although more women were admitted in the second wave. Cough was more common in the second and third waves than in the first wave 522 (59.7%). Respiratory distress was the most common in the third wave, 251(67.1%), and least common in the first wave 403 (46.1%). Anosmia was more common in the third wave 116 (31.2%). In the third wave, patients presenting in a critical state 23 (6.2%) and severe disease 152 (40.8%) were more common. The hospital admission median (IQR) was longer in the first wave, 12 (8-20), than in other waves. More patients were admitted in the first wave (52%) than in the other waves, and patients received more oxygen in the third wave (75%) than in the other waves. Death occurred more commonly in the first wave (51%) than in the other waves. Patients were investigated more commonly in the first and third waves than in the second wave. The positivity rate was high in the third wave (22.8%) than in other waves. In the third wave, the positivity rate was higher in women (24.3%) than in men. Post-covid cough increased in the second wave and fatigue was higher in the third wave than in other waves. Tiredness and memory loss was greater during the second wave than in other waves. ConclusionThis study revealed that the presenting symptoms, outcomes, and epidemiologic trends differed during the COVID-19 waves.

Acoustic computing: At tunable pseudospin-1 Hermitian Dirac-like cone.

Hermitian Dirac-like cones are proposed for creating acoustic logic gates herein. The predictive phenomenon of creating Dirac-like cones near a bipolar antisymmetric deaf band was found to be useful for acoustic computing of Boolean algebra. Unlike previous approaches, Dirac-like cone creates exclusive opportunity to perform all possible Boolean algebra computation with valid inputs. The phenomenon is demonstrated in two-dimensional phononic crystals (PnCs), consisting of tunable square columns in air media. By predictive tuning of the deaf bands, a triply to doubly degenerated Dirac-like cone is reported to form and is particularly useful for acoustic computing. It is only possible when a bottom band has a negative curvature that is lifted from a nearby doubly degenerated band with positive curvature, which is again degenerated with a deaf band. On the contrary, similar computing possibilities are difficult when the bottom band degenerates with the deaf band and the top band is lifted. Using these phenomena, acoustic logic gates are designed to perform Boolean algebra through AND, NAND, OR, and NOR gate operations. A simple one degree of freedom system and a complex six degrees of freedom system are proposed and demonstrated in which simple rotation of the PnCs activates a specific gate.

Health hazards related to using masks and/or personal protective equipment among physicians working in public hospitals in Dhaka: A cross-sectional study.

BACKGROUND: Wearing masks or personal protective equipment (PPE) has become an integral part of the occupational life of physicians due to the coronavirus disease 2019 (COVID-19) pandemic. Most physicians have been developing various health hazards related to the use of different protective gears. This study aimed to determine the burden and spectrum of various health hazards associated with using masks or PPE and their associated risk factors. METHODS: This cross-sectional survey was conducted in Dhaka Medical College from March 01-May 30, 2021, among physicians from different public hospitals in Dhaka, Bangladesh. We analyzed the responses of 506 physicians who completed case record forms through Google forms or hard copies. FINDINGS: The mean (SD) age of the respondents was 35.4 [7.7], and 69.4% were men. Approximately 40% were using full PPE, and 55% were using N-95 masks. A total of 489 (96.6%) patients experienced at least one health hazard. The reported severe health hazards were syncope, severe dyspnea, severe chest pain, and anaphylaxis. Headache, dizziness, mood irritation, chest pain, excessive sweating, panic attack, and permanent facial disfigurement were the minor health hazards reported. Extended periods of work in the COVID-19-unit, reuse of masks, diabetes, obesity, and mental stress were risk factors for dyspnea. The risk factors for headaches were female sex, diabetes, and previous primary headaches. Furthermore, female sex and reusing masks for an extended period (> 6 h) were risk factors for facial disfigurement. The risk factors for excessive sweating were female sex and additional evening office practice for an extended period. CONCLUSIONS: Healthcare workers experienced several occupational hazards after using masks and PPE. Therefore, an appropriate policy is required to reduce such risks.

Multidrug Resistance in Cancer: Understanding Molecular Mechanisms, Immunoprevention and Therapeutic Approaches.

Cancer is one of the leading causes of death worldwide. Several treatments are available for cancer treatment, but many treatment methods are ineffective against multidrug-resistant cancer. Multidrug resistance (MDR) represents a major obstacle to effective therapeutic interventions against cancer. This review describes the known MDR mechanisms in cancer cells and discusses ongoing laboratory approaches and novel therapeutic strategies that aim to inhibit, circumvent, or reverse MDR development in various cancer types. In this review, we discuss both intrinsic and acquired drug resistance, in addition to highlighting hypoxia- and autophagy-mediated drug resistance mechanisms. Several factors, including individual genetic differences, such as mutations, altered epigenetics, enhanced drug efflux, cell death inhibition, and various other molecular and cellular mechanisms, are responsible for the development of resistance against anticancer agents. Drug resistance can also depend on cellular autophagic and hypoxic status. The expression of drug-resistant genes and the regulatory mechanisms that determine drug resistance are also discussed. Methods to circumvent MDR, including immunoprevention, the use of microparticles and nanomedicine might result in better strategies for fighting cancer.

Experiences of the physicians in the largest COVID-19 dedicated hospital of Bangladesh about COVID-19 and its aftermath

BackgroundThe doctors and the other health care workers are the first-line fighters against COVID-19. This study aims to identify the prevalence, risk factors, clinical severity of COVID-19 infection among the doctors working in the COVID unit. We also analyzed the hospital data for admission and RT-PCR positivity among the physicians. MethodsIt was a cross-sectional survey and review of the hospital database. We surveyed from September 2021 to October 2021 and explored the hospital data from march 2020 to September 2021.We included 342 physicians for analysis in the survey. We reviewed hospital data of 1578 total admitted patients and 336 RT-PCR test positive physicians for analyzing the hospital admission rate, the positivity rate for COVID-19 among the physicians and the other patients in the different COVID-19 surges. FindingsIn this study, we demonstrated the physicians sufferings during the pandemic era. We have observed four surges in the hospital admission and RT-PCR for COVID-19 positivity rate among the physicians and the general population. The physicians experienced a similar surge in the hospital admission and positivity rate to the general population. The hospital admission was lower in the fourth surge among the physicians than the general population. The positivity rate was higher in the first, second and third surge among the physicians. In the survey, a total of 146(42%) respondents had COVID-19 infection, and among them, 50(34.2%) had re-detectable positive SARS-CoV-2 infection. Most of them experienced mild (77[52.7%]) to moderate (41[28.1%]) symptoms. Increasing age (OR, 95%CI, p-value; 1.15, 1.05-1.25, 0.002), male sex (OR, 95%CI, p-value; 5.8, 3.2-9.8, <0.001), and diabetes (OR, 95%CI, p-value; 25.6, 2-327.2, 0.01) were the risk factor of having COVID-19. Female sex and diabetes were the risk factors for re-detectable positive SARS-CoV-2 infection. (OR, 95%CI, p-value; 0.24, 0.09-0.67, 0.006; 44, 8.9-218.7, <0.001 respectively). Most respondents suffered for 7-14 days. Total 98(67%) suffered from post-COVID fatigue. ConclusionsThe physicians observed four surges in hospital admission and COVID-19 positivity rate. A significant number of the COVID-warrior became positive for SARS-CoV-2, had re-detectable positive SARS-CoV-2 infection, and suffered in the post-COVID-19 state.

Individual and Occupational Factors Associated With Low Back Pain: The First-ever Occupational Health Study Among Bangladeshi Online Professionals / 예방의학회지

Objectives@#Low back pain (LBP) is a common chronic condition among sedentary workers that causes long-term productivity loss. This study aimed to identify the relationships of individual and occupational factors with LBP among Bangladeshi online professionals. @*Methods@#We conducted a cross-sectional study involving 468 full-time online professionals who usually worked in a sitting position. One-month LBP complaints were assessed using a musculoskeletal subscale of subjective health complaints. The chi-square test was used to measure associations between categorical predictors and LBP, and multivariable logistic regression was conducted to identify the variables significantly associated with LBP. @*Results@#LBP within the last month was reported by 65.6% of participants. Multivariable logistic regression analysis indicated that age >30 years (adjusted odds ratio [aOR], 0.40; 95% confidence interval [CI], 0.23 to 0.70) and being married (aOR, 0.59; 95% CI, 0.36 to 0.97) had significant negative associations with LBP. Significant positive associations were found for spending >50 hours weekly on average working in a sitting position (aOR, 1.61; 95% CI, 1.05 to 2.49), being overweight and obese (aOR, 1.87; 95% CI, 1.16 to 2.99), sleeping on a soft mattress (aOR, 2.01; 95% CI, 1.06 to 3.80), and ex-smoking status (aOR, 3.33; 95% CI, 1.41 to 7.87). @*Conclusions@#A high prevalence of LBP was found among full-time online professionals. Long working hours in a sitting position showed a significant association with developing LBP. Smoking history, body mass index, and sleeping arrangements should also be considered while considering solutions for LBP prevalence among online professionals.

Wastewater based surveillance system to detect SARS-CoV-2 genetic material for countries with on-site sanitation facilities: an experience from Bangladesh

The presence of SARS-CoV-2 genetic materials in wastewater has become a matter of grave for many countries of the world. Wastewater based epidemiology, in this context, emerged as an important tool in developed countries where proper sewage system is available. Due to the recent shift in the spread of the infection from urban to rural areas, it is now equally important to develop a similar mechanism for rural areas as well. Considering the urgency of the issue a study was conducted in 14 districts of Bangladesh and a total of 238 sewage samples were collected in two different periods from December 2020 to January 2021. We are the first to propose a surveillance system for both urban and rural areas where a proper sewage system is absent. Based on RT-PCR analysis of the water samples, in more than 92% of cases, we found the presence of the SARS-COV-2 gene (ORF1ab, N, and Internal Control-IC). The trend of Ct value varies for different study locations. The spread of genetic material for on-site ({Delta}m = 0.0749) sanitation system was found more prominent than that of off-site sewage system ({Delta}m = 0.0219); which indicated the shift of genetic material from urban to rural areas. Wastewater samples were also measured for physicochemical parameters, including pH (6.30 - 12.50) and temperature (22.10 - 32.60) {o}C. The highest viral titer of 1975 copy/mL in sewage sample was observed in a sample collected from the isolation ward of the SARS-COV-2 hospital. Additionally, a correlation was found between bacterial load and SARS-CoV-2 genetic materials. The results indicated the association of increased Ct values with decreasing number of patients and vice versa. The findings reported in this paper contributed to the field of wastewater-based epidemiology dealing with SARS-COV-2 surveillance for developing countries where proper sewage system is absent and highlighting some of the challenges associated with this approach in such settings. HighlightsO_LIDevelopment of wastewater-based surveillance system based on on-site sanitation system for developing countries. C_LIO_LIAssociation of different environmental parameters with the presence of SARS CoV-2 genetic material in wastewater. C_LIO_LIPrediction of the viral concentration of sewage system using viral load and copy number parameter. C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/21261347v2_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@1f7847dorg.highwire.dtl.DTLVardef@11b2c93org.highwire.dtl.DTLVardef@10b9fe1org.highwire.dtl.DTLVardef@2d9e8d_HPS_FORMAT_FIGEXP M_FIG C_FIG

Association of ABO blood groups with presentation and outcomes of confirmed SARS CoV-2 infection: A prospective study in the largest COVID-19 dedicated hospital in Bangladesh.

BACKGROUND: Globally, studies have shown conflicting results regarding the association of blood groups with SARS CoV-2 infection. OBJECTIVE: To observe the association between ABO blood groups and the presentation and outcomes of confirmed COVID-19 cases. DESIGN, SETTING, AND PARTICIPANTS: This was a prospective cohort study of patients with mild-to-moderately severe COVID-19 infections who presented in the COVID-19 unit of Dhaka Medical College Hospital and were enrolled between 01 June and 25 August, 2020. Patients were followed up for at least 30 days after disease onset. We grouped participants with A-positive and A-negative blood groups into group I and participants with other blood groups into group II. RESULTS: The cohort included 438 patients; 52 patients were lost to follow-up, five died, and 381 completed the study. The prevalence of blood group A [144 (32.9%)] was significantly higher among COVID-19 patients than in the general population (p < 0.001). The presenting age [mean (SD)] of group I [42.1 (14.5)] was higher than that of group II [38.8 (12.4), p = 0.014]. Sex (p = 0.23) and co-morbidity (hypertension, p = 0.34; diabetes, p = 0.13) did not differ between the patients in groups I and II. No differences were observed regarding important presenting symptoms, including fever (p = 0.72), cough (p = 0.69), and respiratory distress (p = 0.09). There was no significant difference in the median duration of symptoms in the two group (12 days), and conversion to the next level of severity was observed in 26 (20.6%) and 36 patients (13.8%) in group I and II, respectively. However, persistent positivity of RT-PCR at 14 days of initial positivity was more frequent among the patients in group I [24 (19%)] than among those in group II [29 (11.1%)]. CONCLUSIONS: The prevalence of blood group A was higher among COVID-19 patients. Although ABO blood groups were not associated with the presentation or recovery period of COVID-19, patients with blood group A had delayed seroconversion.

What is the extent of COVID-19 vaccine hesitancy in Bangladesh? : A cross-sectional rapid national survey

objectivesTo assess COVID-19 vaccine hesitancy in Bangladesh and identify population subgroups with higher odds of vaccine hesitancy. designA nationally representative cross-sectional survey was used. Univariate analysis was employed to compute vaccine hesitancy proportions and compare them across groups and multiple logistic regression analyses were performed to compute the adjusted odds ratio. settingBangladesh participantsA total of 1134 participants from the general population, aged 18 years and above. outcome measuresPrevalence and predictors of vaccine hesitancy. results32.5% of participants showed COVID-19 vaccine hesitancy. Hesitancy was high among respondents who were males, over age 60, unemployed, from low-income families, from central Bangladesh including Dhaka, living in rented houses, tobacco users, politically affiliated, participants who did not believe in the vaccines effectiveness for Bangladeshis and those who did not have any physical illnesses in the last year. In the multilevel logistic regression models, respondents who were transgender (AOR= 3.62), married (AOR=1.49), tobacco users (AOR=1.33), those who did not get any physical illnesses in the last year (AOR=1.49), those with political affiliations with opposition parties (AOR= 1.48), those who believed COVID-19 vaccines will not be effective for Bangladeshis (AOR= 3.20), and those who were slightly concerned (AOR = 2.87) or not concerned at all (AOR = 7.45) about themselves or a family member getting infected with COVID-19 in the next one year were significantly associated with vaccine hesitancy (p < 0.05). conclusionsGiven the high prevalence of COVID-19 vaccine hesitancy, it is important to promote evidence-based communication, mass media campaigns, and policy initiatives across Bangladesh to reduce vaccine hesitancy among the Bangladeshi population. Strengths and Limitations of the studyO_LIThis study is the first its kind to measure COVID-19 vaccine hesitancy in Bangladesh. C_LIO_LIIn this study, randomly selected participants were interviewed face to face, enabling a nearly true representative sample of the Bangladeshi general population. C_LIO_LIThis study identified a wide range of sub-groups of the general population with higher odds of COVID-19 vaccine hesitancy relating to their sociodemographic characteristics in Bangladesh; thus, providing baseline evidence for the low and middle-income and low-resourced countries worldwide. C_LIO_LITraditional media and social media influence on COVID-19 vaccine hesitancy was not measured which is a major limitation of this study. C_LI

Mental wellbeing in the Bangladeshi healthy population during nationwide lockdown over COVID-19: an online cross-sectional survey

BackgroundWe aim to profile and contextualize the level of positive mental health among the healthy population during the beginning of nationwide lockdown over COVID-19 in Bangladesh. Design and settingAn online sample of 1404 healthy individuals was collected through the authors networks with residents and popular media in Bangladesh. The survey was conducted between March 27, 2020, and April 7, 2020, following the Bangladesh governments lockdown announcement. MethodA questionnaire comprising the Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) and sociodemographic information was posted to an online survey. ResultsThe mean wellbeing value was 38.4 (standard deviation, 11.2), indicating a lower mental health level exist in adults. Also, the mean wellbeing score for males was 39.0 (10.8) units compared to females with scores 37.0 (11.2), and the highest scores for government workers was 41.2 (11.8). Unemployment (35.6) or business employees (35.5) have a lower level of mental health. In the lockout days, the elderly population of age 50 years and above had high day-to-day variation of wellbeing scores. After confounding adjustment in multivariable linear regression models, there found a better wellbeing scores for males (estimate = 1.79, 95% CI = 0.5, 3.1), and government-workers (estimate = 5.86, 95% CI = 2.2, 9.5). Moreover, the never-married female had significantly higher well-being score compared to married women (estimate = 3.31, 95% CI = 1.0, 5.7). ConclusionThe COVID-19 pandemic has been associated with low mental wellbeing that indicates depression in our study. Suggestions for improvement will be implemented to promote the mental health to women, unemployed and business communities. Older people 50 years of age and over reported a greater day-to-day variation in their mental health. The married women with their decreased mental wellbeing should be given special consideration. The research will help let clinicians and policymakers decide where the measures can be implemented to improve their mental health during and after this pandemic.

Countries are Clustered but Number of Tests is not Vital to Predict Global COVID-19 Confirmed Cases: A Machine Learning Approach

COVID-19 disease is a global pandemic and it appears as pandemic for each and every nation and territory in the earth.This paper focusses on analysing the global COVID-19 data by popular machine learning techniques to know which covariates are importantly associated with the cumulative number of confirmed cases, whether the countries are clustered with respect to the covariates considered, whether the variation in the covariates are explained by any latent factor. Regression tree, cluster analysis and principal component analysis are implemented to global COVID-19 data of 133 countries obtained from the worldometer website as reported as on April 17, 2020. Our results suggest that there are four major clusters among the countries. First cluster consists of 8 countries where cumulative infected cases and deaths are highest. It is also revealed that there are two principal components. The countries which play vital role to explain the 60% variation of the total variations by the first component characterized by all variables except the rate variables include USA, Spain, Italy, France, Germany, UK, and Iran. Remaining countries contribute to explaining 20% variation of the total variations by the second component characterized by only three rate variables. We also found that the number of tests by the country variable among other variables country, number of active cases, number of deaths, number of recovered patients, number of serious cases, and number of new cases is an unimportant variable to predict cumulative number of confirmed cases. Hence, the number of tests might play vital role to individual country level who are in the primary level of virus spread but not to the global level.

COVID-19 Outbreak Situations in Bangladesh: An Empirical Analysis

COVID-19 disease, as popularly known as Coronavirus 2019 disease, has been emerged from Wuhan, China in December 2019 and now is a pandemic for almost every nation in the earth. It affects every country without considering countrys race, nationality and economic status. This paper aims at analysing primarily the current situations of Bangladesh and predicting infections and deaths for moderated term intervals by a proposed projection technique called Infection Trajectory-Pathway Strategy (ITPS) and for short term intervals prediction for total infections, deaths along with total number of severe patients and Intensive Care Unit (ICU) patients by polynomial regression modeling approach. Since April 7, Bangladesh has started to face critical situations as the number of infections has accelerated very fast in the following days. However, the fatality rate decreases considerably from 15.7 on April 1 to 4.9 on April 14, which is still high among the south asian countries. Of the 1012 cases reported on April 14, almost 70% are the male, 42% are from the capital Dhaka. We have found that the potential pathway of infections for Bangldesh would be the similar pathways that are experienced by Austria, Netherlands, Israel, France and United Kingdom. These countries are ahead a number of weeks and days in terms of infection cases since their 100-th confirmed cases. Our proposed projection method ITPS suggests that by May 10, Bangladesh will cross 12000 incidences and 720 deaths which, by May 16 will be 27000 and 1644 respectively. On the other hand, the regression model suggests that by the end of April, total number of infections, deaths, severe patients and ICU patients will be 5780, 347, 775, and 694 respectively. This study will be favorable for the administrative units of Bangladesh to plan for the next few weeks and to consider various aspects related to the control of COVID-19 outspread in Bangladesh.

Evidence of dissipative and growing nonlinearity in Lamb waves due to stress-relaxation and material degradation in composites.

Experimentally observed dissipated nonlinearity in Lamb wave propagation in composites due to stress-relaxation is reported herein. It was found that the stress relaxation in composite is inherently coupled with the second order nonlinear parameter derived from the Lamb wave modes. Due to the combined effect of internal stresses and damage accumulation in composites, the second harmonic frequency was found to be shifted towards the lower frequency with increasing amplitude, which was partially recovered and shifted back during the stress relaxation. A comprehensive fatigue experiment was conducted on ASTM standard composite specimens with fatigue loading sequences and relaxation, while the guided Lamb wave signals were collected using piezoelectric sensors integrated with the specimens. A remarkable ∼27% reduction of acoustic nonlinearity was observed during relaxation. Rate and degree of relaxation were found to be the function of number and frequency of loading cycles and inherently correlated with the remaining strength of the composites.

Peri-Elastodynamic Simulations of Guided Ultrasonic Waves in Plate-Like Structure with Surface Mounted PZT.

Peridynamic based elastodynamic computation tool named Peri-elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-elastodynamics method is not only capable of simulating two dimensional (2D) in plane wave under plane strain condition formulated previously but also capable of accurately simulating the out of plane Symmetric and Antisymmetric Lamb wave modes in plate like structures in 3D. For structural health monitoring (SHM) of plate-like structures and nondestructive evaluation (NDE) of MEMS devices, it is necessary to simulate the 3D wave-damage interaction scenarios and visualize the different wave features due to damages. Hence, in addition, to simulating the guided ultrasonic wave modes in pristine material, Lamb waves were also simulated in a damaged plate. The accuracy of the proposed technique is verified by comparing the modes generated in the plate and the mode shapes across the thickness of the plate with theoretical wave analysis.

Clinical and morphological pattern of brain arteriovenous malformations (BAVMs) in a tertiary care hospital in Bangladesh.

BACKGROUND: We have conducted this study to examine the clinical and morphological pattern of brain arteriovenous malformations (BAVMs) along with their treatment and short term outcome in a tertiary care hospital in Bangladesh. This retrospective chart review was carried out from the records of neuro-endovascular division at Department of Neurology, Dhaka Medical College Hospital (DMCH) from January 2010 to June 2013. A total 60 patients were evaluated. All the necessary information regarding the demographic, clinical, morphologic and treatment profile was gathered through a predesigned questionnaire. To our knowledge, we have the largest cohort of BAVM patients in Bangladesh and this is the first of this kind of study done in Bangladesh. RESULTS: The mean age at diagnosis was 30.3 years with a standard deviation of ±14.3 and the majority was teenagers (30%). Intracerebral hemorrhage was the commonest (70%) type of presentation at diagnosis, followed by headache (50%), altered consciousness (50%), vomiting (40%) and seizure (40%). Majority of the AVMs had feeders from anterior circulation (50%) and most of the AVMs (73.3%) were supplied from the main feeders, whereas the rest from distal vessels. Regarding venous drainage, AVMs drained mostly either to superficial (43.3%) or deep (40%) venous system. AVMs frequently had larger (40%) nidus size and a slow to medium flow (60%), through the nidus. An eloquent AVM location was found in 50% of the patients. Intranidal aneurysm was found in 10% AVM and angiopathic AVM in 13.3%. Patients were treated by endovascular embolization (31) or surgical excision (11) or conservative approach. There was one event of death, both in embolization group and surgically treated group before discharge. The patients were followed up for 1.3 ± 0.8 years. The rate of rebleed was 6.6, 30 and 60% during follow up in endovascular, surgical and conservatively treated group. Though five patients in conservative group died during this time, no deaths reported in intervention group (endovascular or surgery). CONCLUSION: Intracerebral hemorrhages, headache, altered consciousness and seizure are common clinical presentations of AVM at diagnosis. The remarkable morphologic features are larger AVM size at eloquent location, medium to slow flow with frequent feeders from main vessels of anterior circulation and drainage to superficial venous systems. Endovascular embolization or surgical excision of AVM are relatively safe and effective and provides better short term outcome than conservative approach.

Antiepileptic drug utilization in Bangladesh: experience from Dhaka Medical College Hospital.

BACKGROUND: Epilepsy is a common health problem which carries a huge medical social psychological and economic impact for a developing country. The aim of this hospital-based study was to get an insight into the effectiveness and tolerability of low cost antiepileptic drugs (AEDs) in Bangladeshi people with epilepsy. METHODS: This retrospective chart review was done from hospital records in weekly Epilepsy outdoor clinic of Department of Neurology, Dhaka Medical College Hospital (DMCH) from October 1998 to February 2013. A total of 854 epilepsy patients met the eligibility criteria (had a complete record of two years of follow up data) from hospital database. A checklist was used to take demographics (age and gender), epilepsy treatment and adverse event related data. At least two years of follow up data were considered for analysis. RESULTS: Out of 854 patients selected, majority of the patients attending outdoor clinic were >11-30 years age group (55.2%) with a mean age of 20.3 ± 9 years and with a male (53%) predominance. Focal epilepsy were more common (53%), among whom secondary generalized epilepsy was the most frequent diagnosis (67%) followed by complex partial seizure (21%). Among those with Idiopathic Generalized Epilepsy (46%), generalized tonic clonic seizure was encountered in 74% and absence seizure was observed in 13%. The number of patients on monotherapy and dual AED therapy were 67% and 24% respectively and polytherapy (i.e. >3 AEDs) was used only in 9%. CBZ (67%) was the most frequently prescribed AED, followed by VPA (43%), PHB (17%), and PHT (8%). CBZ was prescribed in 37% patients as monotherapy followed by VPA in 21% and PHB in 8% patients. Newer generation drugs eg lemotrigine and topiramate were used only as add on therapy in combination with CBZ and VPA in only 2% patients. The treatment retention rates over the follow up period for the AEDs in monotherapy varied between 86 and 91% and were highest for CBZ, followed by VPA. Most of the combination regimens had a treatment retention rate of 100%. The effectiveness of AED in terms of reduction of seizure frequency was highest for PHT (100%) and PHB (98%) followed by CBZ (96%) and VPA (95%). PHB and PHT were the cheapest of all AEDs (42 I$ and 56 I$/ year respectively). The costs of VPA and CBZ were two times and LTG and TOP were six to eight times higher. Adverse drug reaction (ADR) were observed among 140 (24.5%) of those with monotherapy. PHT (64%) was the most common drug to cause ADR, CBZ was at the bottom of the list to cause adverse effect (11.6%). VPA and PHB caused weight gain commonly. Adjustment of drug dose or withdrawal due to ADRs was necessary in 39% with PHT and 26% with PHB. CONCLUSION: Though PHT and PHB are cheapest and efficacious among all, CBZ and VPA are less costly, effective and well tolerated drug for seizure control in context of Bangladesh.