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1.
Mymensingh Med J ; 33(3): 656-663, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38944703

RESUMEN

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease of airflow limitation that is not fully reversible. COPD affects the lungs and produces significant systemic consequences. In Bangladesh, the prevalence of COPD after 40 years of age is 21.24% and the general population is 4.3%. COPD leads to a sedentary life, which reduces the functional status of the individual. Functional status assessment is vital for appropriate therapy and rehabilitation programs in COPD patients. A Sit-to-stand test (STST) has been proposed as a better alternative to 6MWT, but a Squat-to-stand test (SqTST) to test their ability to stand from the squatting position will be more appropriate in rural patients. This study was conducted using a cross-sectional observational design from July 2020 and September 2021 in the Department of Respiratory Medicine at the National Institute of Diseases of the Chest and Hospital, Bangladesh. Sixty (60) diagnosed cases of COPD patients were enrolled in this study. Severities of airflow obstruction according to GOLD were categorized on the basis of post-bronchodilator FEV1 by spirometry. SqTST was performed on all patients, and functional status was recorded. All data were collected using a preformed questionnaire. Statistical analyses of the findings were carried out using SPSS version 23.0. In this study, the majority of 21(35.0%) patients had very severe COPD, and almost half (48.3%) of the patients had abnormal SqTST. A significant relation was found between the severity of COPD with SqTST (p=0.001). Based on the receiver-operator characteristic (ROC) curve, SqTST had an area under curve 0.901. SqTST had 82.1% sensitivity, 85.7% specificity, 83.3% accuracy, 91.4% positive predictive value, and 72.0% negative predictive value to find severe COPD cases in stable COPD patients. ROC was constructed using SqTST, which gave a cut-off value <7.0, with 82.1% sensitivity and 85.7% specificity for predicting severe COPD. From this study, it may be concluded that SqTST is a clinically useful tool to assess the functional status of stable COPD patients.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Masculino , Estudios Transversales , Femenino , Persona de Mediana Edad , Bangladesh/epidemiología , Anciano , Prueba de Esfuerzo/métodos , Pruebas de Función Respiratoria/métodos , Curva ROC
2.
Heliyon ; 10(11): e31833, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38845888

RESUMEN

Cylinders and thick walled cylindrical shells are commonly utilized in several industries to transport and store fluids under certain pressure and temperature conditions. In the present paper, a numerical solution is developed in order to investigate displacement, temperature and stress fields in a rotating pressure vessel made of generalized functionally graded material (FGM) subjected to different thermo-mechanical boundary conditions. The aim is to investigate the effect of Poisson ratio, internal pressure and temperature and inhomogeneity parameters on the stress and deformation distributions of the rotating pressure vessel. The material is considered isotropic nonhomogeneous and linearly elastic with its properties varying along the radial direction. Additionally, certain conditions, such as exterior or interior problems where r → ∞ or r → 0, respectively, are impossible to resolve using the variation of attributes as a power-law distribution. An approach to the spatial Young modulus distribution that is more broad has been suggested in the literature which can be applied to such physical challenges. The rotation of the pressure vessel is considered in the analysis, and the temperature distribution is assumed to be non-uniform. Since an analytical solution to the differential equation is not accessible, the conventional Galerkin discretization approach of the Finite Element Method (FEM) is applied, nowadays is considered one of the main numerical tools for solving Boundary Value Problems (BVP). It is addressed how stress, strain, and displacement are affected by the inhomogeneity parameter, rotation speed, pressure, temperature, and Poisson ratio. The examination of the various findings indicates that changes in the temperature profile, rotation, and inhomogeneity parameter on the thermoelastic field have a substantial impact on the stress and strain in the FGM cylinder. The findings indicate that the Poisson ratio and inhomogeneity parameters have a significant impact on the stress and deformation distributions. According to the results, the above-mentioned parameters can be adapted to control the thermoelastic filed in a FGM cylinder. The present research offers significant perspectives on the development and enhancement of rotating FGM pressure vessels intended for high-temperature applications.

3.
Small ; : e2311472, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38651243

RESUMEN

Covalent organic frameworks (COFs), which have layered stacking structures, extended π-conjugation, and periodic frameworks have become a promising class of materials for a wide range of applications. However, their synthetic pathways frequently need high temperatures, enclosed systems under high pressures, an inert atmosphere, and extended reaction time, which restrict their practicality in real-world applications. Herein, the use of gamma irradiation is presented to synthesize highly crystalline COFs at room temperature under an open-air condition within a short time. This is demonstrated that there is no significant difference in crystallinity of COFs by gamma irradiation under air, N2 or Ar atmosphere conditions. Moreover, this approach can successfully fabricate COFs in the vessel with different degrees of transparency or even in a plastic container. Importantly, this strategy is applicable not only to imine linkage of COFs but also effective to the imide linkages of COFs. Most importantly, these COFs demonstrate improved crystallinity, surface area, and thermal stability in comparison to the corresponding materials synthesized via the solvothermal method. Finally, a COF synthesized through gamma irradiation exhibits remarkable photocatalytic activity in promoting the sacrificial hydrogen evolution from water, displaying a more catalytic efficiency compared with that of its solvothermal analogue.

4.
Heliyon ; 10(6): e28110, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38533082

RESUMEN

Polymeric materials are being increasingly used to replace many metallic components due to their beneficial properties such as higher strength-to-weight ratio and corrosion resistance. However, the widespread use of polymers poses a risk to the environment as they are not biodegradable. The addition of the waste jute fiber and sawdust fiber as reinforcement to the epoxy resin improved its toughness and induced the biodegradability of the polymer. To examine the effect of the jute fiber and sawdust fiber on biodegradability, the composites were then kept in the drainage system for one year, and the impact energy and fracture morphology of the as-cast and weathered samples were examined using a drop ball impact test and a Charpy impact test. During the weathering period, weight gain was initially observed due to the water absorption by the porous fibers, but after three months, the composites started to lose weight due to the degradation of the fiber by swelling and microbial attacks. Microorganisms in the drainage system used the fiber as their energy source, which resulted in the deterioration of the fiber and the production of CO2. The production of CO2 was identified by the FTIR analysis of the weathered composite samples. TGA analysis of the as-cast and weathered samples reveals the reduction of the onset thermal degradation temperature of the weathered composites due to the degradation of the composites. The fiber disintegrated through microbial attack and the fiber swelling caused by the absorption of water by jute fiber and sawdust fiber is identified through SEM imaging. The SEM image also reveals the formation of biofilms and the growth of microorganisms at the fibers. A higher growth rate of the microorganisms was observed in the jute fiber composite than in the sawdust fiber composite, as sawdust contains a high level of lignin that protects it from degradation. The results of this study suggest that both sawdust fiber and jute fiber composites induce biodegradability in the epoxy matrix, but jute fiber was more prominent in this regard. The discovery paves the way for using natural fibers in biodegradable polymer composites, reducing polymeric pollution in the environment.

5.
Heliyon ; 10(4): e25969, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38390054

RESUMEN

This study aims to develop an exact analytical solution for steady-state thermo-mechanical stress in a functionally graded (FG) thick-walled cylindrical vessel. The cylinder is subjected to combined rotational speed and internal pressures while the thermal load is with convective and radiative boundary conditions. The dimensionless governing equations and boundary conditions, represented as a quartic equation, are derived and solved using Ferrari's method. The temperature, displacement, and stress fields across the thick-walled cylindrical vessel are calculated by finding the roots of the quartic equation. In order to investigate the accuracy of the exact analytical solution, a numerical model is constructed based on a standard Galerkin discretization approach of the finite element method (FEM). The analytical solutions and the results obtained through FEM show a high level of agreement. Furthermore, the study analyzes the effects of material parameters on temperature, displacement, and stress fields. Displacement, temperature, and stress fields are presented in the form of dimensionless graphs along the radial direction. For the considered parametric studies, results revealed that parabolic grading is beneficial than conventional grading. This study reveals that for the thermal loading, the maximum temperature, displacement, and tangential stress decrease for the parabolic grading. A similar but lower value of temperature, displacement, and tangential stress is also observed in the case of thermomechanical loading. This study is expected to assist in the assessment of the reliability of load calculations and contribute to the overall durability of pressure vessels. The results obtained from this study can provide valuable insights into thermo-elasticity and the thermo-mechanical behavior of thick-walled cylindrical vessels and can aid in the design and optimization of such systems.

6.
Nat Commun ; 15(1): 707, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38267492

RESUMEN

Designing an organic polymer photocatalyst for efficient hydrogen evolution with visible and near-infrared (NIR) light activity is still a major challenge. Unlike the common behavior of gradually increasing the charge recombination while shrinking the bandgap, we present here a series of polymer nanoparticles (Pdots) based on ITIC and BTIC units with different π-linkers between the acceptor-donor-acceptor (A-D-A) repeated moieties of the polymer. These polymers act as an efficient single polymer photocatalyst for H2 evolution under both visible and NIR light, without combining or hybridizing with other materials. Importantly, the difluorothiophene (ThF) π-linker facilitates the charge transfer between acceptors of different repeated moieties (A-D-A-(π-Linker)-A-D-A), leading to the enhancement of charge separation between D and A. As a result, the PITIC-ThF Pdots exhibit superior hydrogen evolution rates of 279 µmol/h and 20.5 µmol/h with visible (>420 nm) and NIR (>780 nm) light irradiation, respectively. Furthermore, PITIC-ThF Pdots exhibit a promising apparent quantum yield (AQY) at 700 nm (4.76%).

7.
Mymensingh Med J ; 32(4): 975-982, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37777889

RESUMEN

Cerebrovascular disease is the third most familiar cause of mortality worldwide and in Bangladesh. The reported prevalence of stroke in Bangladesh is 0.3%. Age, high serum glucose, elevated admission blood pressure, fever, large infarction size, and hyperhomocysteinemia has been reported to be risk factor for early post-stroke neurological deterioration. Early serum homocysteine level estimation can predict the early prognosis of ischemic stroke. In a developing country like Bangladesh, an earlier stroke outcome prediction for guiding therapeutic approach is essential. This study aimed to specify the role of estimating serum homocysteine during the early phase of acute ischemic stroke to assume an early prognosis that would guide- a management plan, the need to stay in the hospital and the need for intervention. This cross-sectional descriptive study was performed at the Department of Medicine, Mymensingh Medical College Hospital, Bangladesh from October 2021 to April 2022. Radiologically confirmed all ischemic stroke patients admitted at the Department of Medicine, Mymensingh Medical College Hospital, during the study period fulfilling the inclusion and exclusion criteria were included in this study. Non-probability purposive sampling technique was used. Data was collected using a pre-designed case record form. Quantitative data were represented as mean and standard deviation and qualitative data as frequency and percentage. The comparison was made by Chi-square test and independent samples t-test using SPSS (version 26.0). During the study period, among 716 stroke patients, 59 ischemic stroke patients were included in this study. The mean age of the patients was 64.0±11.72 years. After 72 hours of supportive treatment, early neurological outcomes were observed using NIHSS scoring. Out of 59 patients, the condition of 45(76.0%) patients improved or remained stable (END-) and the state of 14(24.0%) patients worsened (END+). Elderly age-raised temperature and elevated blood glucose level are known to increase infarction size, but only elevated temperature (p value 0.009) has statistical significance in this study. The mean homocysteine level ±SD was 20.22±6.95µmol/L, which is above the normal (<15µmol/L). The level was above average for both outcome groups. Serum homocysteine level was significantly higher in END(+) group (31.59±2.98µmol/L) than END(-) group (16.69±2.66µmol/L) and p value was <0.001.


Asunto(s)
Isquemia Encefálica , Hipertensión , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Anciano , Persona de Mediana Edad , Accidente Cerebrovascular Isquémico/complicaciones , Estudios Transversales , Pronóstico , Hipertensión/complicaciones , Infarto/complicaciones
8.
Mymensingh Med J ; 32(4): 1178-1183, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37777918

RESUMEN

Covid-19 has become a pandemic since its emergence in Wuhan, China. It involves Gastro intestinal (GI) system and diarrhea is recognized as an important symptom. Diarrhea is also associated with disease severity. This study was conducted to see the prevalence of diarrhea in Covid-19 positive patient and its relation with disease severity. Prospective observational study done among consecutive Covid-19 positive patient of both sex admitted in Mugda Medical College Hospital in Dhaka from February 2021 to April 2021. Informations were collected by face to face interview and severity was assessed on bedside. Among 166 Covid-19 positive patient 40.0% developed diarrhea. Mean age of the diarrheal patients was 44.21±14.40. Women affected more than men (51.0% versus 49.0%). In majority patient (62.0%) diarrhea persist for 3-7 days and majority had frequency of bowel movement 3-5 times per day. Regarding Bristol stool type 47.0% had stool type 6 followed by stool type 7(43.0%) and stool type 5(10.0%). Half of the diarrheal patient (48.0%) had severe pneumonia. Severe pneumonia is significantly more common in non-diarrheal patients (65.0%) than in diarrheal patient (35.0%) (p=0.007). This study reflects that a large number of Covid-19 positive patients developed diarrhea. Half of the diarrheal patients had severe pneumonia. But severe pneumonia is significantly common in non-diarrheal patient than diarrheal patients.


Asunto(s)
COVID-19 , Masculino , Humanos , Femenino , Prevalencia , COVID-19/complicaciones , COVID-19/epidemiología , Bangladesh/epidemiología , Diarrea/epidemiología , Diarrea/etiología , Hospitales
9.
Mymensingh Med J ; 32(2): 330-337, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37002742

RESUMEN

A prostate gland biopsy is a test to remove small sample of prostate tissue to be examined under a microscope. A biopsy may be done when a blood test shows a high level of prostate-specific antigen (PSA) or after a digital rectal examination finds an abnormal prostate or a lump. Transrectal ultrasound (TRUS) guided biopsy is a commonly performed procedure for the detection of prostate cancer. It is associated with serious complication like urosepsis. Although the incidence of post-TRUS urosepsis is low, when it occurs it is typically serious and leads to hospitalization. Antibiotics are used prior, during and after the procedure to prevent infections as a result of TRUS biopsy. Ciprofloxacin is being used as antibiotic of choice for a long time. Antibiotic prophylaxis may prevent such complications. This cross-sectional descriptive type of observational study was taken place in Dhaka Medical College Hospital, Dhaka, Bangladesh from January 2010 to December 2011 among purposively selected 70 patients with an aim to determine the urosepsis and bacteriuria after TRUS guided prostate biopsy. Patients attending the Urology OPD in DMCH having of LUTS and other non-specific symptoms were evaluated by history, physical examination including digital rectal examination (DRE) and necessary investigations like serum PSA to identify the potential candidates. Patients with abnormal DRE findings and increased PSA level were included in this study and those who had any painful anal and rectal condition, bleeding diathesis, anticoagulant therapy and any known allergy to lidocaine, previously undergone prostrate biopsy and those who refused to give the informed consent were excluded from this study. Data were collected on variables of interest using a structured case record form. Data were processed and analyzed using Statistical package for social science (SPSS), version 17.0. Frequency of bacteriuria and urosepsis was measured according to urine and blood culture report. Sensitivity pattern was also seen. According to this study, the frequency of bacteriuria and urosepsis was 17.1% and 5.7% respectively. Most common uropathogen was E coli both in urine and blood culture. Organisms (100.0%) were found resistant to ciprofloxacin and amoxicillin. Most of the pathogens were sensitive to tobramycin, gentamycin and cefipime. A potentially dangerous ciprofloxacin resistant organism (ESBL producing E. coli) was found positive in 25.0% of culture positive patients.


Asunto(s)
Bacteriuria , Neoplasias de la Próstata , Sepsis , Masculino , Humanos , Próstata/patología , Bacteriuria/tratamiento farmacológico , Bacteriuria/patología , Escherichia coli , Antígeno Prostático Específico , Estudios Transversales , Bangladesh , Biopsia/métodos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/patología , Ciprofloxacina/uso terapéutico , Antibacterianos/uso terapéutico , Sepsis/etiología
10.
Mymensingh Med J ; 32(2): 437-447, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37002755

RESUMEN

Brachial plexus injury is not uncommon in our country like Bangladesh and it causes functional damage and physical disability of the upper limbs. Most of the cases were caused by motor vehicle accident. We have conducted a prospective study for the operative treatment of 105 adult traumatic brachial plexus injury cases in Hand unit in the department of Orthopaedics, Bangabandhu Sheikh Mujib Medial University (BSMMU) during January 2012 to July 2019. The main surgical options for brachial plexus injury include primary reconstructive surgery such as neurolysis, direct repair, nerve graft, nerve transfer (neurotization) and possibly free functioning (gracilis) muscle transfer and secondary reconstructive procedure such as tendon transfer, arthrodesis, FFMT and bony procedure. Each of these procedures is used either alone or in combination for particular clinical scenarios. Aims and objectives of this study was to restoration of shoulder abduction and external rotation, elbow flexion and hand function are goal of treatment of adult traumatic brachial plexus injury. Age range was from 14 years to 55 years (mean age 26 years). Male were 95 and female were 10 cases. Time from trauma to surgery was valid 3 months to 9 months. Motor cycle accident was most common mechanism of injury. Upper plexus (C5, C6) injury was 52 cases, extended upper plexus (C5, C6 & C7) injury was 19 cases and global brachial plexus injury was 34 cases. When there is high suspicion of root avulsions, early exploration and reconstruction is indicated. Operate these patients 2-3 months after their injury. In other patients without high suspicion of root avulsion, we routinely perform exploration between 3 to 6 months after injury when no adequate sign of recovery are present. Common reconstructive options are any injury with neuroma in continuity with conductive nerve action potential (NAP): only neurolysis or any injury with nerve rupture or postganglionic neuroma not conducting nerve Action potential (NAP) and good proximal nerve: Direct repair or repair with nerve graft or nerve transfer if possible. Follow up period from 6 months to 6 years. The best results were obtained in C5, C6 and C5, C6 & C7 brachial plexus injury cases. SAN to SSN, Oberlin II and long head triceps motor branch to anterior division of axillary nerve transfer for C5 & C6 injury or upper plexus injury and in addition intercostals nerve to anterior division of axillary nerve and AIN branch of median nerve to ECRB for C5, C6 & C7 (extended upper plexus injury). Extra-plexus and intra-plexus neurotization was done in global brachial plexus injury cases and 5 cases by contra-lateral C7 to median nerve by vascularised ulnar nerve graft and only 2 cases contra-lateral C7 to lower trunk through pre spinal or pre tracheal route were done and only one case by FFMT. Few cases gain shoulder abduction and elbow flexion but no improvement of hand function and most cases even by FFMT still in follow up. Results of surgical treatment of upper and extended upper brachial plexus injury cases were satisfactory on the other hand recovery of shoulder abduction and elbow flexion was acceptable and comparable to other study in global brachial plexus injury and recovery of hand function were poor.


Asunto(s)
Plexo Braquial , Articulación del Codo , Transferencia de Nervios , Humanos , Adulto , Masculino , Femenino , Adolescente , Estudios Prospectivos , Plexo Braquial/cirugía , Codo/inervación , Articulación del Codo/cirugía , Articulación del Codo/inervación , Transferencia de Nervios/métodos , Resultado del Tratamiento , Rango del Movimiento Articular
11.
Mymensingh Med J ; 32(2): 476-479, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37002760

RESUMEN

The conventional technique of harvesting free non-vascularized fibular grafting is associated with different scale of morbidity and usually a long scar. We follow a technique that causes minimum interference to the surrounding soft tissues to harvest the desired length of fibula. This prospective study was performed at Department of Orthopaedics, Dhaka Medical College Hospital from January 2018 to December 2018. Thirty patients of average age 10.5 years (range 8 to 14 years) were taken up for the study. The fibula was harvested by two separate incisions, 1 cm each at proximal and distal extent of proposed length of graft after elevating the periosteum circumferentially using a periosteum elevator. Compression bandage and above knee plaster immobilization was applied that help to reduce hematoma formation. The mean follow up is 12 months. The patients were evaluated clinically and by radiology. Twenty nine patients showed good results. One patient had delayed wound healing resulting in fair result. This modified approach of harvesting fibula reduces donor site morbidity and is safer and easier than conventional approach.


Asunto(s)
Trasplante Óseo , Peroné , Humanos , Niño , Adolescente , Peroné/trasplante , Estudios Prospectivos , Trasplante Óseo/métodos , Bangladesh , Estudios Retrospectivos , Resultado del Tratamiento , Estudios de Seguimiento
12.
Mymensingh Med J ; 32(2): 590-592, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37002776

RESUMEN

Congenital coronary ostial stenosis or atresia (COSA) is a spectrum of rare developmental conditions with different pathophysiologic mechanisms and clinical implications. Although COSA includes various entities, these entities have two features in common. First the defect is congenital, although it may progress during pre-natal and post natal life. Second the developmental defect may cause ostial or proximal coronary obstruction (that is stenosis or atresia). Coronary ostial stenosis or atresia affects the left coronary (L-COSA) more frequently than it does the right coronary artery. Systemic Lupus Erythematosus (SLE) is not an uncommon disease in young female, but combination of congenital coronary ostial stenosis with systemic lupus erythematosus make the case very rarer. Here we presented A 17 years old girl got admitted to Bangabandhu Sheikh Mujib Medical University, Bangladesh for evaluation of on and off chest pain of CCS-III to CCS-IV for 1 day on 17 September 2019.


Asunto(s)
Oclusión Coronaria , Lupus Eritematoso Sistémico , Humanos , Femenino , Adolescente , Constricción Patológica , Angiografía Coronaria , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Bangladesh
13.
Heliyon ; 9(4): e15106, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37089288

RESUMEN

The magnetic properties, magnetocaloric effect, and critical analysis of magnetic behavior of Co1+xCrxFe2-xO4 (x = 0.125, 0.250, 0.375, and 0.500) with a non-stoichiometric ratio are studied in detail. All the synthesized samples exhibit single-domain behavior. The Cr3+ associated with excess Co2+ led to tuning the magnetic moment, exchange interaction, magnetocrystalline anisotropy constant, and microwave frequency. The second-order magnetic phase transition has been confirmed from the Arrot and Arrot-Noakes plots for all the samples. The Cr3+ associated with excess Co2+ also tuned the magnetocaloric (MCE) properties showing the maximum relative cooling power of 156 J kg-1, which is a higher value than that of previously reported Cr3+ substituted stoichiometric cobalt ferrite. The reliability of MCE and the nature of the magnetic phase transition of the investigated samples are confirmed by analyzing the critical exponent analysis, universal curve scaling, and scaling analysis of MCE.

14.
Appl Radiat Isot ; 196: 110771, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36933313

RESUMEN

Thermoluminescence (TL) materials have a broad variety of uses in various fields, such as clinical research, individual dosimetry, and environmental dosimetry, amongst others. However, the use of individual neutron dosimetry has been developing more aggressively lately. In this regard, present study establishes a relationship between the neutron dosage and the optical property changes of graphite-rich materials caused by high doses of neutron radiation. This has been done with the intention of developing a novel, graphite-based radiation dosimeter. Herein, the TL yield of commercially graphite-rich materials (i.e. graphite sheet, 2B and HB grade pencils) irradiated by neutron radiation with doses ranging from 250 Gy to 1500 Gy has been investigated. The samples were bombarded with thermal neutrons as well as a negligible amount of gamma rays, from the nuclear reactor TRIGA-II installed at the Bangladesh Atomic Energy Commission. The shape of the glow curves was observed to be independent of the given dosage, with the predominant TL dosimetric peak maintained within the region of 163 °C-168 °C for each sample. By studying the glow curves of the irradiated samples, some of the most well theoretical models and techniques were used to compute the kinetic parameters such as the order of kinetics (b), activation energy (E) or trap depth, frequency factor (s) or escape probability, and trap lifetime (τ). All of the samples were found to have a good linear response over the whole dosage range, with 2B grade of polymer pencil lead graphite (PPLGs) demonstrating a higher level of sensitivity than both HB grade and graphite sheet (GS) samples. Additionally, the level of sensitivity shown by each of them is highest at the lowest dosage that was given, and it decreases as the dose increases. Importantly, the phenomenon of dose-dependent structural modifications and internal annealing of defects has been observed by assessing the area of deconvoluted micro-Raman spectra of graphite-rich materials in high-frequency areas. This trend is consistent with the cyclical pattern reported in the intensity ratio of defect and graphite modes in previously investigated carbon-rich media. Such recurrent occurrences suggest the idea of employing Raman microspectroscopy as a radiation damage study tool for carbonaceous materials. The excellent responses of the key TL properties of the 2B grade pencil demonstrate its usefulness as a passive radiation dosimeter. As a consequence, the findings suggest that graphite-rich materials have the potential to be useful as a low-cost passive radiation dosimeter, with applications in radiotherapy and manufacturing.

15.
Trop Anim Health Prod ; 55(2): 120, 2023 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-36930420

RESUMEN

The objective of this study was to figure out the prevalence and probable causes of repeat breeding (RB) in dairy cows. Hence, a cross-sectional study was conducted on randomly selected 265 dairy farms in Sirajganj, Bogura, Rangpur, Satkhira, and Munshiganj districts of Bangladesh from December 2018 to February 2019. Data were collected through a direct interview method using a survey questionnaire. The reproductive organs of repeat breeder cows were examined for pathological, infectious, and functional reasons, and genital tract abnormalities. Additionally, the influence of nutrition, season, and age on the frequency of RB was recorded. The prevalence of RB was 28% among the 3824 cows investigated. Among the total repeat breeder cases, 72.54% of RB cases were found in Holstein-Friesian crossbred, 23.90% in Jersey crossbred, 1.50% in Sahiwal crossbred, and 2.06% in indigenous cows. The prevalence of RB was significantly highest (P < 0.01) in Satkhira (44.35%) and lowest in the Munshiganj district (15.87%). Data indicated that a major proportion of cows significantly (P < 0.05) faced RB problems due to functional causes (34.18%), followed by pathological causes (28.01%), genital tract abnormalities (21.32%), and infectious causes (16.49%). Furthermore, the cows were remarkably (P < 0.001) affected in RB during the summer season and nutritional deficient diseases like milk fever (70%). Age (3-7 years) had a significant (P < 0.001) effect on the RB occurrence (90%) in crossbred cows. However, particular focus should be given to systematic breeding, balanced nutrition, artificial inseminator efficiency, and hygienic inseminating tools to reduce RB incidence in high-yielding crossbred cows.


Asunto(s)
Lactancia , Leche , Femenino , Bovinos , Animales , Bangladesh/epidemiología , Prevalencia , Estudios Transversales , Industria Lechera/métodos
16.
Sci Rep ; 13(1): 4879, 2023 03 25.
Artículo en Inglés | MEDLINE | ID: mdl-36966196

RESUMEN

Core body temperature (CBT) regulation is crucial for mammalian wellbeing and survival. Cattle pant to dissipate excess heat to regulate CBT when ambient conditions exceed thermoneutral zones. However, to date, neither the variability in cattle heat response, the lagged response of CBT to thermal indices, nor the diurnal patterns of thermal indices, CBT and panting have been reported in the literature. We decomposed thermal indices, CBT and panting time-series data for 99 feedlot heifers across three discrete heat events into diurnal, trend and residual components. Both raw and decomposed data were analysed to explore the lagged CBT and panting responses and the association between series. We show ambient thermal conditions impact CBT with a 1-h lag despite a lag of between 1.5 to 3 h from raw data. Average individual panting scores were used to identify heat-susceptible and heat-tolerant cattle. Heat-susceptible cattle showed greater CBT (P < 0.01) between 8:00 and 23:00 and greater panting duration (P < 0.05) between 10:00 and 18:00 than heat-tolerant cattle under the same thermal conditions and these variations followed a similar pattern despite differences in cattle breed. This new information enables targeted amelioration and selection of individuals against heat susceptibility.


Asunto(s)
Regulación de la Temperatura Corporal , Temperatura Corporal , Bovinos , Animales , Femenino , Regulación de la Temperatura Corporal/fisiología , Calor , Mamíferos
17.
Mymensingh Med J ; 32(1): 213-220, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36594323

RESUMEN

Hearing loss can be congenital or acquired. Most of the time congenital hearing loss means profound sensorineural hearing loss. The invention of cochlear implantation has already an established role in improving the hearing capability in congenital sensorineural hearing loss. To speak properly after cochlear implant, one needs to go for speech therapy or audio-verbal therapy. Speech therapy has become an integral part of the cochlear implantation program. In Bangladesh cochlear implantation (CI) programs started around 15 years ago, which was limited to Bangabandhu Sheikh Mujib Medical University (BSMMU) and Combined Military Hospital (CMH). Our government takes initiative to provide this service to poor and lower income people. National Institute of ENT (NIENT) was the first government hospital where CI started in 2018 and the project is now ongoing. After CI auditory, verbal therapy (AVT) was given at the same institute. No study has not been done to find out the outcome of AVT. NIENT has taken steps to find out the functional and speech outcome of cochlear implanted children considering the two standard criteria: CAP and SIR score. This retrospective study was done to find out the auditory verbal outcome of unilaterally CI children in different ages and conducted at department of Audiology, National Institute of ENT, Tejgaon, Dhaka, Bangladesh from January 2021 to June 2021. The children who underwent cochlear implants and took the auditory verbal therapy were included in this study. Though it is a retrospective study, a written informed consent has been taken from the patient's parents as the cases are minor in age. From the record review, CAP and SIR scores were recorded four times: before implantation 1 time, after cochlear implantation 3 times (At the end of 3, 6 and 12 months after starting of AVT of Cochlear implantees). From the study it has been observed that out of 50 implantees, 48.0% of children's age range was in between >3 to ≤5 years. Most of the implantees were from rural areas and also from lower income group. The study showed significant association with CAP and SIR score at the end of one year of AVT. No significant association was found in different age groups with scores of CAP and SIR. But the parent's education showed significant association with CAP score at the end one year of AVT. Though the age of the recipient is not significantly associated with the AVT outcome but maternal education plays an important role in improving CAP and SIR score. So, maternal education or understanding along with professional speech therapy is vital for better AVT outcome.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Sordera , Pérdida Auditiva Sensorineural , Niño , Humanos , Preescolar , Estudios Retrospectivos , Inteligibilidad del Habla , Bangladesh , Pérdida Auditiva Sensorineural/cirugía , Sordera/cirugía , Resultado del Tratamiento
18.
RSC Adv ; 12(53): 34584-34600, 2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36545635

RESUMEN

In this study, we have synthesized pristine and [0.5,1.5, and 2.5] M% samarium (Sm)-incorporating α-MoO3 2D-layered nanoplates utilizing a facile hydrothermal process, and investigated the physical properties along with antibacterial effectiveness. X-ray diffraction (XRD) patterns confirmed the single-phase, stable orthorhombic polycrystalline structure of the as-prepared samples. The crystallite size, lattice strain, and dislocation density were measured using both Debye-Scherrer (D-S) and Williamson-Hall (W-H) techniques. Both pristine and Sm-incorporating α-MoO3 samples showed two-dimensional (2D) layered nanoplate-type surface morphology, revealed by field emission scanning electron microscopy (FE-SEM) images. Energy dispersive X-ray spectroscopy (EDS) confirmed the presence of Sm contents in the α-MoO3 matrix. After Sm incorporation in α-MoO3, the different functional groups as well as vibrational groups were observed by Fourier-transform infrared (FTIR) spectroscopy and Raman spectroscopy analyses, respectively. The optical band gaps were measured from UV-vis diffuse reflectance spectroscopy (DRS) by employing the Kubelka-Munk formula and interestingly it is found that the bandgap energy (E g) gradually decreased from 2.96 to 2.83 eV with the increment of Sm content. When compared to pristine α-MoO3, the Sm-incorporating samples experienced a steady improvement in room temperature ferromagnetic (RTFM) behavior as Sm content increased, as measured by hysteresis loops. The antibacterial activities of both samples were assessed against Gram-positive: Staphylococcus aureus (S. aureus), and Gram-negative: Escherichia coli (E. coli) and Salmonella enteritidis (S. enteritidis) bacteria by the agar well diffusion method and enhanced antibacterial activity was observed as the Sm concentration increased, compared to pristine nanoplates. The obtained results suggest that the synthesized Sm-incorporating α-MoO3 2D-layered nanoplate could be a potential antibacterial agent.

19.
Mymensingh Med J ; 31(4): 931-936, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36189535

RESUMEN

Among all mandibular fracture 25.0 to 40.0% fractures are regarded as condylar and subcondylar fracture. Commonly, reduction of subcondylar fracture is done under general anaesthesia. Different approaches were found for the surgical treatment of condylar fractures besides intraoral approaches such as the pre-auricular, submandibular, rhytidectomy, retromandibular. This is a prospective observational study which was performed to find out the outcome of retromandibular approach for subcondylar fracture treatment of mandible i.e. to find out correction of occlusion and establishment of jaw function, infection, hematoma, salivary fistula, facial nerve damage, haematoma etc complication. Surgical treatment of subcondylar fractures of 15 patients was done in Dhaka Dental College and Hospital and different private centres in Dhaka and Mymensingh, Bangladesh from January 2019 to December 2021 in retromandibular transparortid approach. The patients were evaluated for hematoma, infection, Frey's syndrome, salivary fistula, facial nerve damage, occlusion, fracture site stability, chronic pain in the fracture site and temporomandibular joint movements in the post operative period. Facial nerve injury was not observed. Postoperative swelling of parotid region developed in first two patients. Single patient developed paresis in zygomatic branch of facial nerve causing left upper eyelid muscle weak and after two weeks of physiotherapy it became normal. Salivary fistula developed in three patients which resolved spontaneously. Outcome of this approach like good anatomy and function was found in all cases. Good articular function was obtained in all the cases. By this retromandibular approach condylar fracture reduction; fixation and healing were managed comfortably. However, direct vision of facial nerve fibres has limited the risk of facial nerve injury.


Asunto(s)
Cóndilo Mandibular , Fracturas Mandibulares , Bangladesh , Fijación Interna de Fracturas , Hematoma/etiología , Humanos , Cóndilo Mandibular/lesiones , Cóndilo Mandibular/cirugía , Fracturas Mandibulares/etiología , Fracturas Mandibulares/cirugía , Resultado del Tratamiento
20.
Mymensingh Med J ; 31(4): 925-930, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36189534

RESUMEN

Well established and common practice in conservative management of omphalocele major is escharotics therapy with different topical agents. Among them mercurochrome, alcohol, silver salts, povidone iodine, acacia nilotca paste are commonly used. It is a comparative study between application of acacia nilotica paste and povidone iodine solution as a primary non surgical treatment of omphalocele major regarding efficacy and safety of these two topical agents. A double blind randomized controlled study was conducted at the department of Paediatric Surgery, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from July 2016 to June 2019. In this study 20 cases of omphalocele major and randomly divided into two equal groups. Group A and Group B treated with acacia nilotica paste and povidone iodine solution respectively. Gastroschisis, ruptured-omphalocele major or omphalocele minor excluded in this study. The size of the fascial defect in cm, time required for full oral feeding tolerance and duration of hospital stay were evaluating parameters. Patients with Group A tolerated full oral feeding earlier, shorter total hospital stay duration and low mortality rate than those from Group B. Application of acacia nilotica is a safe and effective treatment of omphalocele major regarding rapid full oral feeding tolerance, shorter hospital stay and low mortality rate.


Asunto(s)
Acacia , Antiinfecciosos Locales , Hernia Umbilical , Antiinfecciosos Locales/uso terapéutico , Niño , Hernia Umbilical/tratamiento farmacológico , Hernia Umbilical/cirugía , Humanos , Merbromina/uso terapéutico , Povidona Yodada/uso terapéutico , Sales (Química)/uso terapéutico , Plata/uso terapéutico
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