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1.
Crit Rev Food Sci Nutr ; 62(25): 6872-6886, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33905261

RESUMEN

Waste in the food supply chain is estimated to be about 30-40% of the total food production, which aggravates the world hunger and increases waste management burden and environmental impact. Despite the dire food scarcity, majority of this food waste takes place in developing countries because of the lack of appropriate and affordable preservation techniques. Traditional open sun drying is the most popular food-reservation technique to the local farmers due to near-zero capital cost and cheap labor cost. However, this method is highly energy intensive, unhygienic, and time demanding. The high energy consumption resulting from uncontrolled simultaneous heat, mass, and momentum transfer processes in traditional drying systems highlights the necessity of pursuing sustainability in drying process targeting reduced energy consumption, environmental and social impacts. This paper presents a comprehensive review on the sustainable food drying technologies based on renewable energy sources, with emphasis on the developing countries. It was observed that the integration of thermal energy storage with heat pump makes the integrated drying system more efficient, and dries food with better quality. Likewise, advanced integrated drying systems, such as, solar with microwave, and heat pump with microwave make the drying process more cost and quality competent. Finally, impact of resource distribution and governmental incentives for renewable energy use in sustainable drying is discussed.


Asunto(s)
Eliminación de Residuos , Desecación , Alimentos , Abastecimiento de Alimentos , Energía Renovable
2.
Bull Math Biol ; 84(10): 116, 2022 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-36088430

RESUMEN

COVID-19 is caused by the SARS-CoV-2 virus, which is mainly transmitted directly between humans. However, it is observed that this disease can also be transmitted through an indirect route via environmental fomites. The development of appropriate and effective vaccines has allowed us to target and anticipate herd immunity. Understanding of the transmission dynamics and the persistence of the virus on environmental fomites and their resistive role on indirect transmission of the virus is an important scientific and public health challenge because it is essential to consider all possible transmission routes and route specific transmission strength to accurately quantify the herd immunity threshold. In this paper, we present a mathematical model that considers both direct and indirect transmission modes. Our analysis focuses on establishing the disease invasion threshold, investigating its sensitivity to both transmission routes and isolate route-specific transmission rate. Using the tau-leap algorithm, we perform a stochastic model simulation to address the invasion potential of both transmission routes. Our analysis shows that direct transmission has a higher invasion potential than that of the indirect transmission. As a proof of this concept, we fitted our model with early epidemic data from several countries to uniquely estimate the reproduction numbers associated with direct and indirect transmission upon confirming the identifiability of the parameters. As the indirect transmission possess lower invasion potential than direct transmission, proper estimation and necessary steps toward mitigating it would help reduce vaccination requirement.


Asunto(s)
COVID-19 , Inmunidad Colectiva , COVID-19/prevención & control , Humanos , Conceptos Matemáticos , Modelos Biológicos , SARS-CoV-2
3.
Socioecon Plann Sci ; 80: 101249, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35125526

RESUMEN

The COVID-19 pandemic has caused a global crisis with 47,209,305 confirmed cases and 1,209,505 confirmed deaths worldwide as of November 2, 2020. Forecasting confirmed cases and understanding the virus dynamics is necessary to provide valuable insights into the growth of the outbreak and facilitate policy-making regarding virus containment and utilization of medical resources. In this study, we applied a mathematical epidemic model (MEM), statistical model, and recurrent neural network (RNN) variants to forecast the cumulative confirmed cases. We proposed a reproducible framework for RNN variants that addressed the stochastic nature of RNN variants leveraging z-score outlier detection. We incorporated heterogeneity in susceptibility into the MEM considering lockdowns and the dynamic dependency of the transmission and identification rates which were estimated using Poisson likelihood fitting. While the experimental results demonstrated the superiority of RNN variants in forecasting accuracy, the MEM presented comprehensive insights into the virus spread and potential control strategies.

4.
Ecotoxicol Environ Saf ; 202: 110865, 2020 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-32570103

RESUMEN

Crop production in acid soils is facing enormous challenges due to low soil quality associated with an increase in the acidification rate and aluminum toxicity. Despite comprehensive prior work with biochar application on nutrient availability and crop productivity in acid soils, little information is available about the recommendation or standardization of biochar application rates that are more suitable for soil fertility improvement under different soil environments (physico-chemical properties) for maximizing the benefits of biochar applications and minimizing the potential environmental risk. Thus, the objective of this study was to investigate the effectiveness of poultry litter (PL) and poultry litter biochar (PLB) in ameliorating the fertility of acid soils through incubation and pot experiments. The soil was amended with different materials as follows; lime (1 g kg-1), PL (5, 10 and 15 g kg-1) and PLB (5, 10 and 15 g kg-1) along with control (non-amended). A pot experiment was also conducted using similar treatments to observe the responses of maize crop to the different amendments. The results indicated an increase in the pH and a decrease in exchangeable acidity in lime, PL and PLB amended soils. Lower soil pH, base cations and soil available phosphorus (P), and higher exchangeable acidity were found in control than the amended soils. Compared to PL and lime, PLB achieved greater increase rate in soil pH and reduction rate in soil exchangeable acidity with increased soil exchangeable base cations. An increase in soil available calcium (Ca) was observed in the lime treatment, while in PL and PLB treatments, there was an increase in soil available Ca, magnesium (Mg), potassium (K) and P. Application of the amendments increased availability of nitrogen (N), P, K, Ca and Mg relative to the control for maize in the pot experiment. When PL and PLB amendments were compared, it was found that the PLB was the best choice for the amelioration of acid soils as well as nutrient uptake by maize plants. It is suggested that application of PLB at the rate of 15 g kg-1 is suitable for maize growth in acid soils.


Asunto(s)
Carbón Orgánico , Restauración y Remediación Ambiental/métodos , Zea mays/fisiología , Ácidos , Animales , Calcio , Compuestos de Calcio , Magnesio , Nitrógeno , Óxidos , Fósforo , Potasio , Aves de Corral , Suelo/química , Contaminantes del Suelo/análisis , Zea mays/crecimiento & desarrollo
5.
J Theor Biol ; 419: 66-76, 2017 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-28185864

RESUMEN

In 2005, Lacroix et al. demonstrated that infected humans are more attractive to mosquitoes, a phenomenon known as the vector-bias effect. The aim of this study was to determine how a vector-bias effect affects the changes in the dynamics of malaria transmission, and the changes in control strategies and cost-effectiveness for optimal control considering the regional characteristics or force of infections for different transmission rates. We used a vector-bias mathematical model and considered two different incidence areas: a high transmission area and a low transmission area. Our results showed that the dynamics in the two areas differed; as bias exists and the strategy for optimal control could be changed in the different areas. Thus, this work may give that considering the vector-bias effect in different areas facilitates prediction of the future dynamics and make decisions for establishing controls. We also mention the evolution of malaria parasites in this study.


Asunto(s)
Algoritmos , Anopheles/parasitología , Insectos Vectores/parasitología , Malaria Falciparum/parasitología , Modelos Teóricos , Plasmodium falciparum/fisiología , África/epidemiología , Animales , Brasil/epidemiología , Enfermedades Endémicas/prevención & control , Interacciones Huésped-Parásitos , Humanos , Incidencia , India/epidemiología , Indonesia/epidemiología , Malaria Falciparum/epidemiología , Malaria Falciparum/transmisión , México/epidemiología , Plasmodium falciparum/aislamiento & purificación , Arabia Saudita/epidemiología
6.
Mymensingh Med J ; 25(4): 686-690, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27941731

RESUMEN

The aim of this study was to determine the frequency of structural variations in nose & paranasal sinuses in computed tomography in Bangladeshi people. This retrospective study was done at the Sir Salimullah Medical College Mitford Hospital and Apollo Hospitals, Dhaka, Bangladesh. Fifty (50) CT scan of Nose and Para nasal sinuses were collected from the patients presented with different sinonasal pathologies in OPD, IPD of both hospitals from July 2013 to June 2014. The scans were reviewed for the presence of different structural variations of nose and paranasal sinuses. The age range of the patients was 25 to 65 years. The most common anatomical variation in this study was hypertrophied inferior turbinate (82%) followed by ethmoidal bulla (70%), deviated nasal septum (64%), agar nasi cell (40%), concha bullosa (38%). In most of the patients we found more than one variation. There is wide range of anatomical variations in nose and paranasal sinuses which might be regarded as the aetiological factors of different sinonasal pathologies. To maximize patients' benefit and to avoid unexpected situations during surgeries as well as dreadful complications, individualized pre-planning through tomographic study should be considered.


Asunto(s)
Enfermedades Nasales , Adulto , Anciano , Bangladesh , Humanos , Persona de Mediana Edad , Tabique Nasal , Senos Paranasales , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
7.
Mymensingh Med J ; 25(2): 221-5, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27277351

RESUMEN

Coronary Angiogram (CAG) has been used to detect coronary artery disease in myocardial infarction (both STEMI and NSTEMI) patients. The purpose of this study was to compare the degree of coronary artery disease among STEMI and NSTEMI patients. Among acute coronary syndrome in NSTEMI we found more widespread coronary artery disease other than STEMI. Lack of documentations encouraged us to perform this study in our center. In this retrospective observational study we summarized all myocardial infarction (MI) patients who underwent coronary angiography (CAG) from August 2013 to August 2014 at Enam Medical College Hospital, Dhaka, Bangladesh and data of degree of coronary artery disease were recorded. Data of 100 consecutive MI patients who underwent CAG during that period were recorded. Among them 50 patients having STEMI as Group I (male 45, female 5) & other 50 patients sustained NSTEMI as Group II (male 38, female 12). Among NSTEMI patient group 80% were having multi-vessel disease and in STEMI patient group 80% having single vessel disease and remaining having multi-vessel disease. The degree of coronary artery disease is extensive in NSTEMI patients than in STEMI group. Coronary angiogram can visualize the degree of coronary artery involvement and is a useful screening modality to compare disease extent in MI patients.


Asunto(s)
Síndrome Coronario Agudo/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Infarto del Miocardio/diagnóstico por imagen , Adulto , Anciano , Bangladesh , Angiografía Coronaria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
8.
Mymensingh Med J ; 24(2): 411-5, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26007276

RESUMEN

Gitelman's syndrome is an autosomal recessive renal tubular disorder characterized by severe hypomagnesaemia, hypokalaemia, metabolic alkalosis and hypocalcaemia. It is caused by defective NaCl transport in the Distal Convoluted Tubule and presents in adolescence or adulthood, with a distinctly more benign course than Bartter's Syndrome. The dominant clinical features are muscle weakness, fatigue, carpopedal spasm, cramps and tetany. We report the case of a 26 year old male who presented with flaccid quadriparesis and carpopedal spasms, hypokalaemia, hypomagnesaemia, hypocalcaemia and severe urinary magnesium wasting. He was treated with potassium and magnesium supplementation and regained full function of all limbs.


Asunto(s)
Síndrome de Gitelman , Hipocalcemia , Adulto , Alcalosis , Síndrome de Bartter , Humanos , Hipopotasemia , Masculino
9.
Chaos ; 24(3): 033130, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25273210

RESUMEN

Positron-acoustic (PA) solitary waves (SWs) and double layers (DLs) in four-component plasmas consisting of immobile positive ions, mobile cold positrons, and superthermal (kappa distributed) hot positrons and electrons are investigated both numerically and analytically by deriving Korteweg-de Vries (K-dV), modified K-dV (mK-dV), and Gardner equations along with their DLs solutions using the reductive perturbation method. It is examined that depending on the plasma parameters, the K-dV SWs, Gardner SWs, and DLs support either compressive or rarefactive structures, whereas mK-dV SWs support only compressive structure. It is also found that the presence of superthermal (kappa distributed) hot positrons and hot electrons significantly modify the basic features of PA SWs as well as PA DLs. Besides, the critical number density ratio of hot positrons and cold positrons play an important role in the polarity of PA SWs and DLs. The implications of our results in different space as well as laboratory plasma environments are briefly discussed.

10.
Mymensingh Med J ; 23(3): 566-71, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25178612

RESUMEN

Histoplasma capsulatum is an endemic granulomatous fungus disease. Involving the larynx of an immunocompetent patient with this is a rare manifestation. A sixty years old farmer who was previously diagnosed and treated as pulmonary tuberculosis was presented as a progressive change of voice and intermittent attack of unproductive cough with no history of stridor and fever for last 7 months. Clinical and imaging investigations were suggestive of laryngeal tuberculosis or laryngeal neoplasm. Laryngoscopy revealed edema, erythema and leukoplakia of the right vocal cord. Histopathological report showed intracellular hyphae of Histoplasma capsulatum, features were consistent with histoplasmosis. Patient were treated accordingly and improved. Laryngeal histoplasmosis present as a mimicker of squamous cell carcinoma or tuberculosis, may lead to the misdiagnosis and mistreatment of tuberculosis or laryngeal cancer. A high index of suspicion and a thorough histologic workup is needed to establish the diagnosis correctly.


Asunto(s)
Histoplasmosis/diagnóstico , Enfermedades de la Laringe/diagnóstico , Animales , Errores Diagnósticos , Histoplasmosis/patología , Humanos , Enfermedades de la Laringe/patología , Masculino , Persona de Mediana Edad
11.
Mymensingh Med J ; 23(4): 658-66, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25481582

RESUMEN

Metastatic dissemination into lymph nodes of neck occurs frequently in head neck cancers which down grade the patient's curability and survival. Neck dissection is a curable option for its management. To evaluate the complications following different types of neck dissection. This cross sectional study was conducted among patients undergone different types of neck dissection due to cervical nodal metastasis and attended follow up during July 2010 to June 2011 in Department of ENTs and Head-Neck surgery Dhaka Medical College Hospital, Dhaka, Bangladesh. Among 30 selected patient, 23 were male (76.67%) and 7 were female (23.33%), age ranged from 31-72 years (Mean=59.1±5.44). In different modalities of neck dissection 11 were modified neck dissection (36.67%) and 10(33.33%) were radical neck dissection. Common indication was carcinoma of unknown origin (66.67%). Involved neck nodes were commonly level II-IV (69.99%). Nodal stage was N2(50%) and N3 (40%).Common immediate complications were bleeding 03(10%), facial oedema 02 (6.67%) and thoracic duct injury 02(6.67%). Intermediate complications were seroma 05(16.67%), wound infection 04(13.33%) and chylous fistula 02(6.67%), Late Complications were hypertrophic scar 07(23.33%) and shoulder syndrome 06(20%). Proper indications, skilled surgery along with early recognize and treatment in both early and late manifestations of neck dissection preventing its grave sequence.


Asunto(s)
Carcinoma , Neoplasias de Cabeza y Cuello , Ganglios Linfáticos/patología , Metástasis Linfática , Disección del Cuello , Complicaciones Posoperatorias , Bangladesh/epidemiología , Carcinoma/secundario , Carcinoma/cirugía , Estudios Transversales , Detección Precoz del Cáncer , Intervención Médica Temprana , Femenino , Neoplasias de Cabeza y Cuello/mortalidad , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/cirugía , Humanos , Masculino , Persona de Mediana Edad , Disección del Cuello/efectos adversos , Disección del Cuello/métodos , Estadificación de Neoplasias , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Centros de Atención Terciaria/estadística & datos numéricos
12.
Appl Clin Inform ; 15(3): 469-478, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38897231

RESUMEN

BACKGROUND: In times of omnipresent digitization and big data, telemedicine and electronic case files (ECFs) are gaining ground for networking between players in the health care sector. In the context of the SALUS study, this approach is applied in practice in the form of electronic platforms to display and process disease-relevant data of glaucoma patients. OBJECTIVES: The SALUS ECF is designed and implemented to support data acquisition and presentation, monitoring, and outcome control for patients suffering from glaucoma in a clinical setting. Its main aim is to provide a means for out- and inpatient exchange of information between various stakeholders with an intuitive user interface in ophthalmologic care. Instrument data, anamnestic data, and diagnostic assessments need to be accessible and historic data stored for patient monitoring. Quality control of the data is ensured by a reading center. METHODS: Based on an intensive requirement analysis, we implemented the ECF as a web-based application in React with a Datomic back-end exposing REST and GraphQL APIs for data access and import. A flexible role management was developed, which addresses the various tasks of multiple stakeholders in the SALUS study. Data security is ensured by a comprehensive encryption concept. We evaluated the usability and efficiency of the ECF by measuring the durations medical doctors need to enter and work with the data. RESULTS: The evaluation showed that the ECF is time-saving in comparison to paper-based assessments and offers supportive monitoring and outcome control for numerical and imaging-related data. By allowing patients and physicians to access the digital ECF, data connectivity as well as patient autonomy were enhanced. CONCLUSION: ECFs have a great potential to efficiently support all patients and stakeholders involved in the care of glaucoma patients. They benefit from the efficient management and view of the data tailored to their specific role.


Asunto(s)
Glaucoma , Glaucoma/diagnóstico , Humanos , Tonometría Ocular , Autocuidado , Telemedicina , Registros Electrónicos de Salud
13.
Mymensingh Med J ; 33(2): 426-432, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38557521

RESUMEN

Functional dyspepsia (FD) is a common gastrointestinal problem in the world. The Rome III consensus subdivided functional dyspepsia into two groups: meal-related postprandial distress syndrome (PDS) and meal-unrelated epigastric pain syndrome (EPS). Limited data are available regarding FD in Bangladesh. The aim of this study was to investigate the demographic and clinical characteristics of FD and its sub-types. This cross-sectional study was conducted in which we recruited patients who attended the outpatient department of Gastroenterology of Bangabandhu Sheikh Mujib Medical University, Bangladesh from March 2017 to February 2018. Patients fulfilling Rome III FD criteria and a negative upper GIT endoscopy were included for this study. The patients were then subdivided into 'pure' PDS (i.e. meeting criteria for PDS without EPS symptoms), 'pure' EPS (i.e., meeting criteria for EPS without PDS symptoms), and overlapping PDS-EPS (i.e., symptoms of both PDS and EPS) groups. Total of 368 FD patients (56.0% females, mean age 32.8±8.6 years, BMI: 22.0±2.7), were included in this study. Out of them, 112(30.4%) patients (57.2% females, mean age 33.9±9.3 years, BMI: 22.0±2.7) fulfilled criteria of pure EPS and 64(17.4%) patients (68.8% females, mean age 33.2±7.8 years, BMI: 22.1±2.4) fulfilled criteria of pure PDS. However, the majority of patients [192(52.2%), 52.1% females, mean age 32.0±8.4 years, BMI: 21.9±2.8] had symptoms of overlapping EPS-PDS. More than 40% of patients in our study presented with 3 or more of the four key symptoms of FD. A longer duration of presenting symptoms was seen among patients with overlapping EPS-PDS in comparison to pure EPS and pure PDS (p<0.001). A significant overlap of symptoms of both EPS and PDS was noticed among patients with FD. The value of dividing functional dyspepsia into the subgroups of PDS and EPS is thus questionable. Further research and modification of the diagnostic criteria for FD subtypes are necessary.


Asunto(s)
Dispepsia , Adulto , Femenino , Humanos , Adulto Joven , Masculino , Dispepsia/diagnóstico , Dispepsia/epidemiología , Dolor Abdominal/epidemiología , Dolor Abdominal/etiología , Bangladesh/epidemiología , Centros de Atención Terciaria , Estudios Transversales , Demografía
14.
Res Sq ; 2024 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-38562683

RESUMEN

Background: Cancer remains a leading cause of death worldwide and continues to disproportionately impact certain populations. Several frameworks have been developed that illustrate the multiple determinants of cancer. Expanding upon the work of others, we present an applied framework for cancer prevention and control designed to help clinicians, as well as public health practitioners and researchers, better address differences in cancer outcomes. Methods: The framework was developed by the Cancer Prevention and Control Research Network's Health Behaviors Workgroup. An initial framework draft was developed based on workgroup discussion, public health theory, and rapid literature review on the determinants of cancer. The framework was refined through interviews and focus groups with Federally Qualified Health Center providers (n=2) and cancer patients (n=2); participants were asked to provide feedback on the framework's causal pathways, completeness, and applicability to their work and personal life. Results: The framework provides an overview of the relationships between sociodemographic inequalities, social and structural determinants, and key risk factors associated with cancer diagnosis, survivorship, and cancer morbidity and mortality across the lifespan. The framework emphasizes how health-risk behaviors like cigarette smoking interact with psychological, psychosocial, biological, and psychosocial risk factors, as well as healthcare-related behavior and other chronic diseases. Importantly, the framework emphasizes addressing social and structural determinants that influence health behaviors to reduce the burden of cancer and improve health equity. Aligned with previous theory, our framework underscores the importance of addressing co-occurring risk factors and disease states, understanding the complex relationships between factors that influence cancer, and assessing how multiple forms of inequality or disadvantage intersect to increase cancer risk across the lifespan. Conclusions: This paper presents an applied framework for cancer prevention and control to address cancer differences. Because the framework highlights determinants and factors that influence cancer risk at multiple levels, it can be used to inform the development, implementation, and evaluation of interventions to address cancer morbidity and mortality.

15.
Eur J Neurol ; 20(9): 1264-71, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23581473

RESUMEN

BACKGROUND AND PURPOSE: To evaluate the associations between retinal nerve fiber layer (RNFL) thickness and lipid profiles in multiple sclerosis (MS). METHODS: This study enrolled 136 patients with MS (n = 272 eyes; 108 females, 28 males, mean age: 46.7 ± 8.9 years); 45% had a history of optic neuritis (ON). Subjects received optical coherence tomography (OCT) testing to assess RNFL thickness and visual acuity testing with Snellen charts. A subset of 88 patients received pattern reversal visual-evoked potential (PRVEP) testing. Lipid profiles consisting of serum high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and total cholesterol (TC) levels were obtained within ± 6 months of OCT. Regression analyses were used to assess the associations between RNFL thickness and lipid profile variables. RESULTS: Low RNFL thickness (P = 0.008) and higher PRVEP latency (P = 0.017) were associated with high LDL cholesterol > 100 mg/dl status. Low RNFL thickness (P = 0.008) and higher PRVEP latency (P = 0.043) were associated with high HDL cholesterol levels. Low RNFL thickness was also associated with HDL cholesterol > 60 mg/dl status (P = 0.001) and with TC > 200 mg/dl status (P = 0.015). The probability of average RNFL thickness in the lowest tertile (≤ 33rd percentile) was associated with interactions between TC > 200 mg/dl status (P = 0.001, odds ratio = 7.5, 95% confidence interval = 2.7-21) with affected/unaffected by ON status. CONCLUSIONS: High cholesterol adversely affects RNFL thickness in patients with MS with ON.


Asunto(s)
Colesterol/sangre , Esclerosis Múltiple/patología , Neuritis Óptica/patología , Neuronas Retinianas/patología , Potenciales Evocados Visuales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/sangre , Neuritis Óptica/sangre , Tomografía de Coherencia Óptica , Agudeza Visual
16.
Chaos ; 23(1): 013147, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23556984

RESUMEN

A rigorous theoretical investigation has been performed on dust-acoustic (DA) solitary structures in an unmagnetized dusty plasma, consisting of negatively charged mobile dust grains, Boltzmann distributed electrons, and nonthermally distributed ions of two distinct temperatures. The Korteweg-de Vries (K-dV), modified K-dV (mK-dV) and Gardner equations, and their solitary waves (SWs) and double layer (DL) (in case of Gardner equation) solutions are derived by using the reductive perturbation technique. The basic features of the DA Gardner solitons (GSs) and DLs are studied analytically as well as numerically. It has been observed that the GSs significantly differ from K-dV and mK-dV solitons, and only positive potential DLs exist in the system. It is also studied that two-temperature nonthermal ions significantly modify the nature and basic properties of the DA SWs. The present investigation can be very effective for understanding and studying the nonlinear characteristics of the DA waves in laboratory and space dusty plasmas.


Asunto(s)
Acústica , Polvo , Dinámicas no Lineales , Temperatura , Simulación por Computador , Electrones , Iones , Movimiento (Física) , Análisis Numérico Asistido por Computador , Sonido , Factores de Tiempo
17.
NPJ Syst Biol Appl ; 9(1): 17, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37221258

RESUMEN

A maximum-tolerated dose (MTD) reduces the drug-sensitive cell population, though it may result in the competitive release of drug resistance. Alternative treatment strategies such as adaptive therapy (AT) or dose modulation aim to impose competitive stress on drug-resistant cell populations by maintaining a sufficient number of drug-sensitive cells. However, given the heterogeneous treatment response and tolerable tumor burden level of individual patients, determining an effective dose that can fine-tune competitive stress remains challenging. This study presents a mathematical model-driven approach that determines the plausible existence of an effective dose window (EDW) as a range of doses that conserve sufficient sensitive cells while maintaining the tumor volume below a threshold tolerable tumor volume (TTV). We use a mathematical model that explains intratumor cell competition. Analyzing the model, we derive an EDW determined by TTV and the competitive strength. By applying a fixed endpoint optimal control model, we determine the minimal dose to contain cancer at a TTV. As a proof of concept, we study the existence of EDW for a small cohort of melanoma patients by fitting the model to longitudinal tumor response data. We performed identifiability analysis, and for the patients with uniquely identifiable parameters, we deduced patient-specific EDW and minimal dose. The tumor volume for a patient could be theoretically contained at the TTV either using continuous dose or AT strategy with doses belonging to EDW. Further, we conclude that the lower bound of the EDW approximates the minimum effective dose (MED) for containing tumor volume at the TTV.


Asunto(s)
Melanoma , Humanos , Carga Tumoral
18.
Comput Biol Med ; 162: 107035, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37276754

RESUMEN

Adaptive therapy (AT) is an evolution-based treatment strategy that exploits cell-cell competition. Acquired resistance can change the competitive nature of cancer cells in a tumor, impacting AT outcomes. We aimed to determine if adaptive therapy can still be effective with cell's acquiring resistance. We developed an agent-based model for spatial tumor growth considering three different types of acquired resistance: random genetic mutations during cell division, drug-induced reversible (plastic) phenotypic changes, and drug-induced irreversible phenotypic changes. These three resistance mechanisms lead to different spatial distributions of resistant cells. To quantify the spatial distribution, we propose an extension of Ripley's K-function, Sampled Ripley's K-function (SRKF), which calculates the non-randomness of the resistance distribution over the tumor domain. Our model predicts that the emergent spatial distribution of resistance can determine the time to progression under both adaptive and continuous therapy (CT). Notably, a high rate of random genetic mutations leads to quicker progression under AT than CT due to the emergence of many small clumps of resistant cells. Drug-induced phenotypic changes accelerate tumor progression irrespective of the treatment strategy. Low-rate switching to a sensitive state reduces the benefits of AT compared to CT. Furthermore, we also demonstrated that drug-induced resistance necessitates aggressive treatment under CT, regardless of the presence of cancer-associated fibroblasts. However, there is an optimal dose that can most effectively delay tumor relapse under AT by suppressing resistance. In conclusion, this study demonstrates that diverse resistance mechanisms can shape the distribution of resistance and thus determine the efficacy of adaptive therapy.


Asunto(s)
Resistencia a Antineoplásicos , Neoplasias , Humanos , Resistencia a Antineoplásicos/genética , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/patología
19.
Mymensingh Med J ; 32(3): 833-840, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37391982

RESUMEN

When performing infra-umbilical procedures, caudal epidural analgesia with bupivacaine is frequently used to provide both intra- and post-operative analgesia. Dexmedetomidine, an alpha 2 agonistsare extensively used in neuraxial blocks and peripheral nerve blocks to prolong the action of bupivacaine. To find out the effects of dexmedetomidine as an adjuvant to bupivacaine for caudal analgesia in children undergoing infra-umbilical surgery. This was a randomized, controlled double-blinded prospective observational study and was performed from July 2019 to December 2019. A total of 60 (Sixty) patients with different infra-umbilical surgical problems underwent different procedure under caudal anaesthesia in different operation theatre in Bangabandhu Sheikh Mujib Medical University, Dhaka were enrolled in this study. Elaborate personal history, meticulous clinical examinations and relevant laboratory investigations was done. Post-operative adverse effects also were monitored. All information from history of illness, clinical, laboratory findings, duration of analgesia and post-operative adverse effects were recorded in a preformed data sheet (Appendix-I) and statistical analysis was done by SPSS 22.0. Mean age of the children in Group A (dexmedetomidine + bupivacaine) was 5.50±2.61 years and in Group B (bupivacaine) was 5.66±2.75. Mean weight of the children in Group A was 19.22±8.58 kg and in Group B was 19.70±8.94 kg in this study. Mean duration of anaesthesia was 27.5±6.5 minute in Group A and 28.5±5.5 minute in Group B. The mean duration of analgesia was 4.32±0.54 hours for Group A and 2.12±0.32 hours in Group B. In Group A, 46.7% patients required 1 and 3.3% required 2 rescue analgesic but in Group B, 43.3% patients required single rescue analgesic and 33.3% required two rescue analgesics (p<0.05). In Group A, 6.7% patients had nausea/ vomiting and in Group B, 16.7% patients had nausea/ vomiting (p>0.05). It can be concluded that dexmedetomidine with bupivacaine for caudal analgesia in infra-umbilical surgery significantly prolongs the duration of postoperative analgesia when compared to bupivacaine alone without any side-effects.


Asunto(s)
Analgesia , Dexmedetomidina , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Humanos , Niño , Preescolar , Bupivacaína/uso terapéutico , Dexmedetomidina/uso terapéutico , Bangladesh , Náusea
20.
Mymensingh Med J ; 32(4): 1140-1148, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37777913

RESUMEN

When healthy women undergo caesarean section (CS) under sub arachnoid anaesthesia, transient electrocardiographic changes, such as ST-segment depression and T-wave abnormalities, are observed. During an elective caesarean section under sub arachnoid anaesthesia, about one-third of healthy parturient experience chest pain and ECG changes suggestive of myocardial ischemia. To assess the ST-segment and Rate Pressure Product changes with chest pain in patients with elective caesarean section under subarachnoid block. The Department of Anesthesia, Analgesia and Intensive Care Medicine at Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh was the site of this prospective observational study. The study included 86 healthy women between the ages of 20 and 35 who needed an elective caesarean section under a single shot sub arachnoid block and who visited the Department of Anesthesia, Analgesia, and Intensive Care Medicine at BSMMU in Shahbagh, Dhaka from January 2019 to June 2019. In comparison to the no chest pain group, ST-segment changes among the chest pain group at delivery, 5 minute, 10 minute after delivery and at the end of the surgery were highly significant (p=0.001). Comparatively, Rate Pressure Product changes were found to be significantly higher in the group with chest pain than in the group without chest pain (p=0.001). It is concluded that there is a substantial association of chest pain with rate pressure product and ST-segment changes after subarachroid block in caesarean section.


Asunto(s)
Anestesia Raquidea , Isquemia Miocárdica , Humanos , Femenino , Embarazo , Adulto Joven , Adulto , Cesárea/efectos adversos , Bangladesh , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/etiología
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