Megacity solid waste disposal suitability mapping in Dhaka, Bangladesh: an integrated approach using remote sensing, GIS and statistics.

Selecting suitable Megacity Solid Waste Disposal (MSWD) sites is a challenging task in densely populated deltas of developing countries, exacerbated by limited public awareness about waste management. One of the major environmental concerns in Dhaka City, the world's densest megacity, is the presence of dumps close to surface water bodies resources. This study employed the Geographic Information System (GIS)-Analytic Hierarchy Process (AHP) framework to integrate geomorphological (slope and flow accumulation), geological (lithological and lineament), hydrogeological (depth to groundwater table and surface waterbody), socioeconomic (Land use land cover, distance to settlement, road, and airport), and climatological (wind direction) determinants, coupled by land-use and hydro-environmental analyses, to map optimal dumps (MSWDO) sites. The resulting preliminary (MSWDP) map revealed 15 potential landfill areas, covering approximately 5237 hectares (ha). Combining statistical analysis of restricted areas (settlements, water bodies, land use) with AHP-based ratings, the MSWDO map revealed two optimal locations (2285 ha). Additionally, the hydro-environmental analysis confirmed the unsuitability of northern sites due to shallow groundwater (< 5.43 m) and thin clay, leaving 11 options excluded. Sites 12 (Zone A, 2255 ha) and 15 (Zone B, 30 ha), with deeper groundwater tables and thicker clay layers, emerged as optimal choices for minimizing environmental risks and ensuring effective long-term waste disposal. This study successfully integrates remote sensing, geospatial data, and GIS-AHP modeling to facilitate the development of sustainable landfill strategies in similar South Asian delta megacities. Such an approach provides valuable insights for policymakers to implement cost-effective and sustainable waste management plans, potentially minimizing the environmental risks to achieve Sustainable Development Goals (SDGs) 6, 11, 13, and 15.

Distribution and Characteristics of Congenital Cardiac Surgery Centers within Bangladesh.

Congenital heart disease is a leading cause of non-communicable childhood death. This is especially true in nations with limited resources where shortages of skilled workforce, healthcare facilities, and essential equipment limit the ability to provide care. This retrospective study was designed to determine the volume and distribution of surgical care being provided to patients with congenital heart disease in Bangladesh, as well as to characterize the facilities providing such care. Pre-existing survey data of hospitals performing congenital heart surgery in the year 2022 in Bangladesh was obtained. Additional information was gathered on these facilities, including hospital location and type. The distribution of care by geographic location, type of facility, and volume of cases was reported. Overall, a total of 2333 surgeries were performed in 2022 at 28 facilities. The majority of hospitals were performing <50 cases per year, while a small number (5) provided greater than 50.0% of all surgeries. In addition, while the majority of hospitals were private in nature, the majority of surgeries occurred at not-for-profit hospitals. There was a large geographic skew of surgeries and hospitals being located within the city of Dhaka (79.0% of centers and 94.0% of surgeries). The data suggests that, though there has been great progress in increasing the number of surgeries performed in Bangladesh, the vast majority of patients still do not have access to care. In addition, nearly all care is being provided in Dhaka, which presents challenges for patients who come from across the nation seeking care. Finally, there is a great need for further research to fully understand the challenges faced and find workable solutions.

Optimization of green silver nanoparticles as nanofungicides for management of rice bakanae disease.

Rice bakanae, a devastating seed-borne disease caused by Fusarium species requires a more attractive and eco-friendly management strategy. The optimization of plant-mediated silver nanoparticles (AgNPs) as nanofungicides by targeting Fusarium species may be a rational approach. In this study, Azadirachta indica leaf aqueous extract-based AgNPs (AiLAE-AgNPs) were synthesized through the optimization of three reaction parameters: A. indica leaf amount, plant extract-to-AgNO3 ratio (reactant ratio), and incubation time. The optimized green AgNPs were characterized using ultraviolet-visible light (UV-Vis) spectroscopy, field emission scanning electron microscopy (FESEM) with energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), dynamic light scattering (DLS), and powder X-ray diffraction (XRD) techniques. The optimal conditions for producing spherical, unique, and diminutive-sized AgNPs ranging from 4 to 27 nm, with an average size of 15 nm, were 2 g AiLAE at a 1:19 ratio (extract-to-AgNO3) and incubated for 4 h. Fusarium isolates collected from infected soils and identified as F. fujikuroi (40) and F. proliferatum (58 and 65) by PCR were used for seed infestation. The AgNPs exhibited concentration-dependent mycelial growth inhibition with EC50 values ranging from 2.95 to 5.50 µg/mL. The AgNPs displayed exposure time-dependent seed disinfectant potential (complete CFU reduction in F. fujikuroi (40) and F. proliferatum (58) was observed at a concentration of 17.24 µg/mL). The optimized green AgNPs were non-toxic to germinating seeds, and completely cured bakanae under net-house conditions, suggesting their great nano-fungicidal potency for food security and sustainable agriculture.

Self-organizing map improves understanding on the hydrochemical processes in aquifer systems.

The holistic understanding of hydrochemical features is a crucial task for management and protection of water resources. However, it is challenging for a complex region, where multiple factors can cause hydrochemical changes in studied catchment. We collected 208 groundwater samples from such region in Kumamoto, southern Japan to explicitly characterize these processes by applying machine learning technique. The analyzed groundwater chemistry data like major cations and anions were fed to the self-organizing map (SOM) and the results were compared with classical classification approaches like Stiff diagram, standalone cluster analysis and score plots of principal component analysis (PCA). The SOM with integrated application of clustering divided the data into 11 clusters in this complex region. We confirmed that the results provide much greater details for the associated hydrochemical and contamination processes than the traditional approaches, which show quite good correspondence with the recent high resolution hydrological simulation model and aspects from geochemical modeling. However, the careful application of the SOM is necessary for obtaining accurate results. This study tested different normalization approaches for selecting the best SOM map and found that the topographic error (TE) was more important over the quantization error (QE). For instance, the lower QE obtained from min-max and log normalizations showed problems after clustering the SOM map, since the QE did not confirm the topological preservation. In contrast, the lowest TE obtained from Z-transformation data showed better spatial matching of the clusters with relevant hydrochemical characteristics. The results from this study clearly demonstrated that the SOM is a helpful approach for explicit understanding of the hydrochemical processes on reginal scale that may capably facilitate better groundwater resource management.

Isolation, Identification and Genetic Characterization of Antibiotic Resistant Escherichia coli from Frozen Chicken Meat Obtained from Supermarkets at Dhaka City in Bangladesh.

Antimicrobials have been used to improve animal welfare, food security, and food safety that promote the emergence, selection, and dissemination of antimicrobial-resistant (AMR) bacteria. In this study, 50 E. coli were isolated from frozen chicken meat samples in Dhaka city. Antibiotic sensitivity patterns were assessed through the disk diffusion method and finally screened for the presence of antimicrobial resistance genes (ARG) using the polymerase chain reaction (PCR). Among the 160 samples, the prevalence of E. coli was observed in fifty samples (31.25%). All of these isolates were found resistant to at least one antimicrobial agent, and 52.0% of the isolates were resistant against 4-7 different antimicrobials. High resistance was shown to tetracycline (66.0%), followed by resistance to erythromycin (42.0%), ampicillin and streptomycin (38.0%), and sulfonamide (28.0%). In addition, the most prevalent ARGs were tet(A) (66.0%), ereA (64.0%), tet(B) (60.0%), aadA1 and sulI (56.0%), blaCITM (48.0%) and blaSHV (40.0%). About 90.0% of isolates were multidrug resistant. This study reveals for the first time the current situation of E. coli AMR in broilers, which is helpful for the clinical control of disease as well as for the development of policies and guidelines to reduce AMR in broilers production in Bangladesh.

Realizing Einstein's Mirror: Optomechanical Damping with a Thermal Photon Gas.

Einstein described the damping and thermalization of the center-of-mass motion of a mirror placed inside a blackbody cavity by collisions with thermal photons. While the time for damping even a microscale or nanoscale object is so long that it is not experimentally viable, we show that this damping is feasible using the high-intensity light from an amplified thermal light source with a well-defined chemical potential. We predict this damping of the center-of-mass motion will occur on timescales of tens of seconds for small optomechanical systems.

Midterm Outcome of Septal Myectomy for Hypertrophic Obstructive Cardiomyopathy (HOCM): A Single-Center Observational Study.

BACKGROUND: For years, septal myectomy has been considered the best available treatment for hypertrophic cardiomyopathy. In Bangladesh, however, this technique is only nascent. We present a case series of septal myectomy with outcomes after 1 to 6 years at the National Heart Foundation Hospital & Research Institute. METHODS: For this study, 21 patients who underwent septal myectomy from 2014 to 2019 were monitored retrospectively. Evidence was collected from the hospital database and followed up via telephone conversations using a structured questionnaire. Patients' preoperative, postoperative, and follow-up clinical data were collected and analyzed. RESULTS: The results reveal that after septal myectomy, there were significant improvements in terms of left ventricular outflow gradient (P ≤ .01), septal thickness (P ≤ .01), left ventricular ejection fraction (P = .001), pulmonary arterial systolic pressure (P ≤ .01), mitral regurgitation (P ≤ .01), systolic anterior motion (P ≤ .01), and New York Heart Association class (P ≤ .01). CONCLUSION: This study suggests that septal myectomy be offered to symptomatic hypertrophic obstructive cardiomyopathy patients, as its survival benefits and symptoms relief are excellent. This study suggests that septal myectomy that dynamic obstruction at the left ventricular outflow tract is the major hemodynamic problem. We hope that with appropriate measures, new myectomy programs in our country can provide extended longevity and restore the quality of life.

Preliminary Study on Biosensor-Type Time-Temperature Integrator for Intelligent Food Packaging.

A glucose biosensor was utilized as a platform for the time-temperature integrator (TTI), a device for intelligent food packaging. The TTI system is composed of glucose oxidase, glucose, a pH indicator, and a three-electrode potentiostat, which produces an electrical signal as well as color development. The reaction kinetics of these response variables were analyzed under isothermal conditions. The reaction rates of the electrical current and color changes were 0.0360 ± 0.0020 (95% confidence limit), 0.0566 ± 0.0026, 0.0716 ± 0.0024, 0.1073 ± 0.0028 µA/min, and 0.0187 ± 0.0005, 0.0293 ± 0.0018, 0.0363 ± 0.0012, 0.0540 ± 0.0019 1/min, at 5, 15, 25, and 35 °C, respectively. The Arrhenius activation energy of the current reaction (Eacurrent) was 25.0 ± 1.6 kJ/mol and the Eacolor of the color reactions was 24.2 ± 0.6 kJ/mol. The similarity of these Ea shows agreement in the prediction of food qualities between the electrical signal and color development. Consequently, the function of the new time-temperature integrator system could be extended to that of a biosensor compatible with any electrical utilization equipment.

An analytical model for the detection of levitated nanoparticles in optomechanics.

Interferometric position detection of levitated particles is crucial for the centre-of-mass (CM) motion cooling and manipulation of levitated particles. In combination with balanced detection and feedback cooling, this system has provided picometer scale position sensitivity, zeptonewton force detection, and sub-millikelvin CM temperatures. In this article, we develop an analytical model of this detection system and compare its performance with experimental results allowing us to explain the presence of spurious frequencies in the spectra.

Burning and graphitization of optically levitated nanodiamonds in vacuum.

A nitrogen-vacancy (NV(-)) centre in a nanodiamond, levitated in high vacuum, has recently been proposed as a probe for demonstrating mesoscopic centre-of-mass superpositions and for testing quantum gravity. Here, we study the behaviour of optically levitated nanodiamonds containing NV(-) centres at sub-atmospheric pressures and show that while they burn in air, this can be prevented by replacing the air with nitrogen. However, in nitrogen the nanodiamonds graphitize below ≈10 mB. Exploiting the Brownian motion of a levitated nanodiamond, we extract its internal temperature (T(i)) and find that it would be detrimental to the NV(-) centre's spin coherence time. These values of T(i) make it clear that the diamond is not melting, contradicting a recent suggestion. Additionally, using the measured damping rate of a levitated nanoparticle at a given pressure, we propose a new way of determining its size.

Evaluation of Time-Temperature Integrators (TTIs) with Microorganism-Entrapped Microbeads Produced Using Homogenization and SPG Membrane Emulsification Techniques.

A comparative study was conducted to evaluate precision and accuracy in controlling the temperature dependence of encapsulated microbial time-temperature integrators (TTIs) developed using two different emulsification techniques. Weissela cibaria CIFP 009 cells, immobilized within 2% Na-alginate gel microbeads using homogenization (5,000, 7,000, and 10,000 rpm) and Shirasu porous glass (SPG) membrane technologies (10 µm), were applied to microbial TTIs. The prepared micobeads were characterized with respect to their size, size distribution, shape and morphology, entrapment efficiency, and bead production yield. Additionally, fermentation process parameters including growth rate were investigated. The TTI responses (changes in pH and titratable acidity (TA)) were evaluated as a function of temperature (20°C, 25°C, and 30°C). In comparison with conventional methods, SPG membrane technology was able not only to produce highly uniform, small-sized beads with the narrowest size distribution, but also the bead production yield was found to be nearly 3.0 to 4.5 times higher. However, among the TTIs produced using the homogenization technique, poor linearity (R(2)) in terms of TA was observed for the 5,000 and 7,000 rpm treatments. Consequently, microbeads produced by the SPG membrane and by homogenization at 10,000 rpm were selected for adjusting the temperature dependence. The Ea values of TTIs containing 0.5, 1.0, and 1.5 g microbeads, prepared by SPG membrane and conventional methods, were estimated to be 86.0, 83.5, and 76.6 kJ/mol, and 85.5, 73.5, and 62.2 kJ/mol, respectively. Therefore, microbial TTIs developed using SPG membrane technology are much more efficient in controlling temperature dependence.

Gd2O3 nanoparticles: size-dependent nuclear magnetic resonance.

In this communication, we demonstrate that there is an optimum gadolinium oxide (Gd(2)O(3)) nanoparticle size of 2.3 nm; in the presence of Gd(2)O(3) particles smaller and larger than this critical size, the spin-lattice relaxation rate (T(1) = 1/r(1)) of water protons at 7.0 T drastically decreases. Since r(1) is directly related to the quality of magnetic resonance imaging, the results presented here have significant implications for clinical diagnostics.

Extraordinary optical transmission: coupling of the Wood-Rayleigh anomaly and the Fabry-Perot resonance.

In this Letter, we demonstrate for the first time that by combining the effects of the Wood-Rayleigh anomaly (WRA) and the Fabry-Perot (FP) resonance, transmission efficiencies of one-dimensional metallo-dielectric gratings on substrates can be significantly improved compared to when these two phenomena work separately. Results of combining the WRA and the FP resonance can be utilized to eliminate the necessity of using the index matching technique and the core-shell structure for enhancing the performance of extraordinary optical transmission devices. Further, the outcomes of combining the WRA and the FP resonance can elucidate some of the unexplained results in the literature.

Augmented post-induction therapy for children with high-risk acute lymphoblastic leukemia and a slow response to initial therapy.

BACKGROUND: Children with high-risk acute lymphoblastic leukemia (ALL) who have a slow response to initial chemotherapy (more than 25 percent blasts in the bone marrow on day 7) have a poor outcome despite intensive therapy. We conducted a randomized trial in which such patients were treated with either an augmented intensive regimen of post-induction chemotherapy or a standard regimen of intensive post-induction chemotherapy. OBJECTIVE: To compare the effect of augmented therapy with standard intensive post induction therapy in children with high-risk ALL who entered remission after a slow response to initial therapy. METHODS: Between January 2005 and December 2011, 311 children with newly diagnosed ALL who were either 1 to 9 years of age with white cell counts of at least 50,000 per cubic millimeter or 10 years of age or older, had a slow response to initial therapy, and entered remission at the end of induction chemotherapy were randomly assigned to receive standard therapy (156 children) or augmented therapy (155). Those with lymphomatous features were excluded. Event-free survival and overall survival were assessed from the end of induction treatment. RESULTS: The outcome at five years was significantly better in the augmented-therapy group than in the standard-therapy group. The difference between treatments was most pronounced among patients one to nine years of age, all of whom had white-cell counts of at least 50,000 per cubic millimeter (P<0.001). Risk factors for an adverse event in the entire cohort included a white-cell count of 200,000 per cubic millimeter or higher (P=0.004). The toxic effects of augmented therapy were considerable but manageable. CONCLUSION: Augmented post-induction chemotherapy results in an excellent outcome for most patients with high-risk ALL and a slow response to initial therapy.

Ultra small Gd(2)O(3) nanoparticles: Absorption and emission properties.

In this paper, we report a facile method for synthesis of ultra small (1-3nm) gadolinium oxide (Gd(2)O(3)) nanoparticles using citric acid (CA) as a capping agent. The dependence of nanoparticle (NP) size on the ratio between CA and gadolinium (Gd) is investigated. Absorption properties of the ultra small Gd(2)O(3) NPs in UV region have four characteristic peaks at 312nm, 274nm, 253nm and 228nm. Finally, we show that the Gd(2)O(3) nanoparticles synthesized by this method induce triplet emission (phosphorescence) from CA and EG in the NIR region.

Modified perfusion fluid for renal transplantation in developing countries: our initial experience.

INTRODUCTION: Organ preservation is an important step in transplantation. Perfusion fluid plays a vital role in this matter. As in many other developing countries, perfusion fluid is not readily available and is costly. Alternatively, the commonly used Hartmann's solution does not have preservation quality. Hence, to meet the demand, a modified perfusion fluid was prepared following standard preservative flush principles. MATERIALS AND METHODS: Hartmann's solution was modified by adding potassium chloride, magnesium sulfate, mannitol, dexamethasone, and insulin. The whole process was performed under aseptic conditions. The final composition was a hypertonic solution similar to Marshall's solution. RESULTS: Upon use in 14 renal transplantation operations we observed the modified solution to be protective for kidney storage for more than 4 hours, namely, a mean cold ischemia time of 187.50 +/- 30.58 minutes (range 156-254 minutes). There was no apparent deterioration in posttransplantation graft function. All 14 grafts worked from the operative day with a mean creatinine reduction rate in the first 24 hours of 198.90 +/- 46.12 mumol/L and mean serum creatinine level at 21 days of 138.70 +/- 16.16 mumol/L. These results were not significantly different from those achieved with Collin's solution. CONCLUSION: A modified perfusion fluid was effective, cheaper, and easy to prepare; therefore it is suitable for transplantation in developing countries.

Acute and long-term neurological complications in children with acute lymphoblastic leukemia.

The pattern of acute and long-term neurological complications in 133 children with acute lymphoblastic leukemia (ALL) treated with two treatment protocol was reviewed. Twenty patients developed neurological complications. Nine out of 20 patients received MRC UK ALL X and the remaining 11 received MRC UK ALL XI protocol. There was no difference of neurological complications between MRC UKALL X and UK ALL XI protocol groups. The numbers of patients who developed neurological complications during induction of remission period were 11 of 133 patients (8.2%). 122 patients were observed during the maintenance period of treatment (from 6 months to 36 months). Six out of 122 patients developed neurological complications during this period. 88 patients were followed for a period of up to 6 months after the cessation of chemotherapy, i.e., in the late period. Neurological complications were found in 3 during this period. Neurological complications rate was 4 times higher in the relapsed group than in the no relapsed group (p < 0.05). Systemic chemotherapy (including vincristine, high-dose methotrexate) and intrathecal chemotherapy seem to be the most common predisposing factors.