Effect of Humidity and Temperature on the Impedances and Voltage of Al/Gr-Jelly/Cu-Rubber Composite-Based Flexible Electrochemical Sensors

Here we present the fabrication of graphene and jelly (superabsorbent polymer) electrolyte composite-based shockproof flexible electrochemical sensors (Al/Gr-Jelly/Cu) and their properties under the effect of humidity and temperature. A layer of graphene mixed in jelly electrolyte was drop-casted onto porous rubber substrates between preliminary fixed aluminum (Al) and copper (Cu) electrodes followed by rubbing-in. It was observed that the graphene and jelly mixture was mechanically soft and flexible, similar to jelly. Electrically, this mixture (graphene and jelly) behaved as a flexible electrolyte. It was observed that under the effect of humidity ranging from 47 to 98%, the impedances of the sensors decreased by 2.0 times on average. Under the effect of temperatures ranging from 21 to 41 °C the impedances decreased by 2.4 times. The average temperature coefficient of impedances was equal to −0.03 °C⁻¹. The electrochemical voltage generated by the flexible jelly electrolyte sensors was also investigated. It was found that the initial open-circuit voltages were equal to 201 mV and increased slightly, by 5–10% under the effect of humidity and temperature as well. The short-circuit currents under the effect of humidity and temperature increased by 2–3 times. The Al/Gr-Jelly/Cu electrochemical sensors may be used as prototypes for the development of the jelly electronic-based devices.

Heavy metals contamination and associated health risks in food webs-a review focuses on food safety and environmental sustainability in Bangladesh

Heavy metals occur naturally in very small amounts in living organisms, but exposure to their higher concentrations is hazardous. Heavy metals at hazardous levels are commonly found in foodstuffs of Bangladesh, mainly due to the lack of safety guidelines and poor management of industrial effluents. Several lines of evidence suggest that the level of heavy metals in foodstuffs of Bangladesh is higher than the acceptable limits set by World Health Organization/Food and Agriculture Organization. Literature survey revealed that the sources and transport pathways of heavy metals in the ecosystem and the abundance of heavy metals in the food products of Bangladesh are potential threats to food safety. However, an extensive assessment of the toxicity of heavy metals in food webs is lacking. Although widespread heavy metal contamination in various foodstuffs and environmental matrices have been summarized in some reports, a critical evaluation regarding multi-trophic transfer and the health risk of heavy metal exposure through food chain toxicity in Bangladesh has not been performed. This systematic review critically discussed heavy metal contamination, exposure toxicity, research gaps, existing legislation, and sustainable remediation strategies to enhance Bangladesh's food safety. In particular, this study for the first time explored the potential multi-trophic transfer of heavy metals via food webs in Bangladesh. Furthermore, we recommended a conceptual policy framework to combat heavy metal contaminations in Bangladesh.

Role of Rotaviral Antigen Detection by ICT in Acute Diarrhoeic Children below 5 Years in a Tertiary Care Hospital of Bangladesh

Rotavirus is responsible for acute severe watery diarrhoea in young children. Early and rapid detection of Rotavirus infection can help to reduce inappropriate administration of antibiotics and has future positive impact on prevention of drug resistance. This cross-sectional study was designed to determine the role of Rotaviral antigen detection by ICT from stool sample of acute diarrhoeal children below five years admitted in Sylhet MAG Osmani Medical College Hospital, Sylhet and was carried out in the Department of Microbiology in collaboration with the Department of Paediatrics during the period from 1st January 2018 to 31st December 2018. Total 184 children of under five years of age with acute watery diarrhoea were enrolled in this study. Rotaviral antigen was detected by ELISA (Enzyme Linked Immunosorbent Assay) and ICT (Immunochromatographic test) from stool samples. Out of 184 stool samples, Rotaviral antigen was found positive in 84 and 86 cases by ICT and ELISA methods, respectively. ICT showed sensitivity of 90.70% and specificity of 93.88% when compared with ELISA. The Rotavirus infection was found highest in male children (61.90%) and in age group of 7 to 12 months (51.89%). Considering the importance of Rotaviral diarrhoea, rapid detection of Rotavirus infection by ICT is essentially needed and might be practiced routinely as it is relatively reliable, easy to perform and cost-effective. It is particularly important in Bangladesh, where diarrhoea is still contributing a significant proportion of morbidity and mortality in under five children.

Pattern of Glomerular Disease in a Tertiary Care Hospital of Bangladesh

Glomerular disease is one of the most important causes of chronic kidney disease in developing countries like Bangladesh as well as the whole world. The pattern of glomerular disease varies in different countries and can have different clinical presentations. The aim of the study was to analyze the clinical profile and to determine the histological pattern of glomerular diseases in a large tertiary care hospital in Bangladesh. All kidney biopsies performed in Mymensingh Medical College Hospital, Bangladesh from October 2018 to March 2020 were prospectively analyzed in the study. A total of 101 patients with kidney biopsy were examined by clinical and laboratory findings and by light and immuno-fluorescence microscopy. The mean age was 30.0±14.6 years and 50(49.5%) were male and 51(50.5%) were female with a male to female ratio of 1:1. The clinical syndromes namely nephrotic syndrome, nephritic syndrome, nephrito-nephrotic presentation, RPGN like presentation, macroscopic haematuria and asymptomatic urine abnormality were present in 31.7%, 34.5%, 22.8%, 11.9%, 19.8% and 10.9% patients respectively. The most common histological varieties found in the study were mesangial proliferative glomerulonephritis (MesPGN) (18.8%) and focal segmental glomerulosclerosis (FSGS) (18.8%). Other histopathological pattern among the studied subjects revealed minimal change disease (MCD) in 5.9%, membranous nephropathy (MN) in 7.9%, membranoproliferative glomerulonephritis (MPGN) in 16.8%, IgA nephropathy in 5%, IgM nephropathy in 2%, IgG nephropathy in 2%, diffuse proliferative glomerulonephritis (DPGN) in 1%, focal proliferative glomerulo-nephritis (FPGN) in 3%, crescentic GN in 3%, lupus nephritis (LN) in 13.9%, amyloidosis in 1% and fibrillary glomerulopathy in 1% patient. The pattern of glomerular disease found in this study was similar to other studies performed in Bangladesh with a little variation. It may guide the future researchers to establish a national kidney biopsy registry in Bangladesh.

Short Term Outcome of Therapeutic ERCP in the Management of Biliary Ascariasis in a Tertiary Care Hospital of Bangladesh

The history of ascariasis is very old. It is endemic in various parts of Bangladesh. Hepatobiliary ascariasis is a well-known complication of the intestinal ascariasis. Although cosmopolitan, it predominantly affects people in Asia, Africa, and South America. This was a prospective observational study conducted from July to December 2014 to explore the short term outcome of therapeutic ERCP in the treatment of biliary ascariasis in a tertiary care hospital of Bangladesh. A total of 60 cases of biliary ascariasis were selected conveniently in this study. Data were collected by face-to-face interviews and observation with the help of data sheet. Data were checked for quality control and analyzed by computer using SPSS software. The mean±SD age of the patients was 30.96±7.66 years. All the patients were aged between 17 and 55 years and predominantly affect women in the 3rd and 4th decades. The most common presentation was upper abdominal pain in 47(83.32%) of the patients. Ultrasound was the diagnostic tool of choice, where biliary ascariasis was found in 40(66.7%) of patients. ERCP is reserved mainly for therapeutic purposes and found successful in 57(95%) of the patients.

Development of L-cysteine sensor based on thallium oxide coupled multi-walled carbon nanotube nanocomposites with electrochemical approach

Here, Nanocomposites of thallium oxide doped multi-walled carbon nanotube (Tl2O.MWCNT NCs) were prepared by utilizing the wet-chemical method (WCM) in an alkaline phase at low temperature. Different optical procedures (FTIR: Fourier Transform Infra-Red Spectroscopy, XRD: Powder X-ray diffraction, FESEM: Field-Emission Scanning Electron Microscopy, XEDS: X-ray Electron Dispersive Spectroscopy, TEM: Tunneling Electron Microscopy, and XPS: X-ray photoelectron spectroscopy) were used to fully characterize (Optical, structural, crystalline, morphological, and elemental etc.) of the prepared Tl2O.MWCNT NCs. Modification of the thin-layer with NCs onto glassy carbon electrode (GCE) is prepared and applied for the enzyme-free detection of selective and sensitive L-cysteine by electrochemical approach. Using a reliable current-voltage approach, analytical sensing indexes such as sensitivity, LDR, LOD, LOQ, durability, and interference were assessed by fabricated sensor probe (GCE/Tl2O.MWCNT NCs/CPM) in selective detection of L-cysteine in a room condition, whereas nafion was used as conducting polymer matrix (CPM) during the fabrication of GCE with NCs. L-cysteine calibration plot was found to be linear over an extensive range of concentration. The calibration curve was used to calculate the sensing parameters such as sensitivity (316.46 pAμM-1cm-2), LOD down to (~18.90 ± 1.89 pM), and LOQ (63.0 pM) of the prepared sensor. The use of a simple WCM to validate the Tl2O.MWCNT NCs is a good approach for developing a NCs-based sensor for enzyme-free biomolecule identification and detection in the biomedical and health care fields in a broad scale. This proposed sensor (GCE/Tl2O.MWCNT NCs/CPM) is used to detect selective L-cysteine in real biological samples such as human, mouse, and rabbit serum and found acceptable and satisfactory results.

Analysis of cold-start NO2 and NOx emissions, and the NO2/NOx ratio in a diesel engine powered with different diesel-biodiesel blends

In the transportation sector, the share of biofuels such as biodiesel is increasing and it is known that such fuels significantly affect NOx emissions. In addition to NOx emission from diesel engines, which is a significant challenge to vehicle manufacturers in the most recent emissions regulation (Euro 6.2), this study investigates NO₂ which is a toxic emission that is currently unregulated but is a focus to be regulated in the next regulation (Euro 7). This manuscript studies how the increasing share of biofuels affects the NO₂, NOx, and NO₂/NOx ratio during cold-start (in which the after-treatment systems are not well-effective and mostly happens in urban areas). Using a turbocharged cummins diesel engine (with common-rail system) fueled with diesel and biofuel derived from coconut (10 and 20% blending ratio), this study divides the engine warm-up period into 7 stages and investigates official cold- and hot-operation periods in addition to some intermediate stages that are not defined as cold in the regulation and also cannot be considered as hot-operation. Engine coolant, lubricating oil and exhaust temperatures, injection timing, cylinder pressure, and rate of heat release data were used to explain the observed trends. Results showed that cold-operation NOx, NO₂, and NO₂/NOx ratio were 31-60%, 1.14-2.42 times, and 3-8% higher than the hot-operation, respectively. In most stages, NO₂ and the NO₂/NOx ratio with diesel had the lowest value and they increased with an increase of biofuel in the blend. An injection strategy change significantly shifted the in-cylinder pressure and heat release diagrams, aligned with the sudden NOx drop during the engine warm-up. The adverse effect of cold-operation on NOx emissions increased with increasing biofuel share.

Development of Methanol Sensor Based on Sol-Gel Drop-Coating Co3O4·CdO·ZnO Nanoparticles Modified Gold-Coated µ-Chip by Electro-Oxidation Process

Herein, novel Co₃O₄·CdO·ZnO-based tri-metallic oxide nanoparticles (CCZ) were synthesized by a simple solution method in basic phase. We have used Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscope (FESEM), Dynamic Light Scattering (DLS), Tunneling Electron Microscopy (TEM), and Energy-Dispersive Spectroscopy (EDS) techniques to characterize the CCZ nanoparticles. XRD, TEM, DLS, and FESEM investigations have confirmed the tri-metallic nanoparticles’ structure, while XPS and EDS analyses have shown the elemental compositions of the CCZ nanoparticles. Later, a Au/μ-Chip was modified with the CCZ nanoparticles using a conducting binder, PEDOT: PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) in a sol-gel system, and dried completely in air. Then, the CCZ/Au/μ-Chip sensor was used to detect methanol (MeOH) in phosphate buffer solution (PBS). Outstanding sensing performance was achieved for the CCZ/Au/μ-Chip sensor, such as excellent sensitivity (1.3842 µAµM⁻¹cm⁻²), a wide linear dynamic range of 1.0 nM–2.0 mM (R² = 0.9992), an ultra-low detection limit (32.8 ± 0.1 pM at S/N = 3), a fast response time (~11 s), and excellent reproducibility and repeatability. This CCZ/Au/μ-Chip sensor was further applied with appropriate quantification results in real environmental sample analyses.

Sensitive Detection of Thiourea Hazardous Toxin with Sandwich-Type Nafion/CuO/ZnO Nanospikes/Glassy Carbon Composite Electrodes

In this research study, we developed a voltammetric electrochemical sensor probe with a copolymer Nafion (Sulfonated Tetrafluoroethylene-based Fluoro-polymer) decorated with hydrothermally prepared sandwich-type CuO/ZnO nanospikes (NSs) onto a glassy carbon electrode (GCE) for reliable thiourea (TU) detection. The detailed characterizations in terms of structural morphology, binding energy, elemental compositions, grain size and crystallinity for synthesized NSs were performed by field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. The differential pulse voltammetric (DPV) analysis for TU showed good linearity at current-versus-TU concentration on the calibration plot in the 0.15~1.20 mM range, which is defined as a dynamic detection range (LDR) of TU in a phosphate buffer solution. Considering the slope of LDR over the GCE-coated NSs surface area (0.0316 cm2), the TU sensor sensitivity (0.4122 µA µM-1 cm-2) was obtained. Besides this, the low limit (LOD) for TU detection was calculated and found to be 23.03 ± 1.15 µM. The fabricated Nafion/CuO/ZnO NSs/GCE sensor probe was created as a reliable sensor based on reproducibility, interference effect, stability and response time. Real bio-samples were investigated and the results confirm the anticipated reliability of the TU sensor probe. Thus, this is a noble way to develop enzyme-free electrochemical sensors that could be an alternative approach for the detection of chemicals in the field of enzyme-free biosensor development technology.

Bacillus-Mediated Silver Nanoparticle Synthesis and Its Antagonistic Activity against Bacterial and Fungal Pathogens

In this article, the supernatant of the soil-borne pathogen Bacillus mn14 was used as the catalyst for the synthesis of AgNPs. The antibacterial and antifungal activity of Bs-AgNPs was evaluated, in which S. viridans and R. solani showed susceptibility at 70 µL and 100 µL concentrations. Enzyme properties of the isolates, according to minimal inhibitory action and a growth-enhancing hormone-indole acetic acid (IAA) study of the isolates, were expressed in TLC as a purple color with an Rf value of 0.7. UV/Vis spectroscopy revealed the presence of small-sized AgNPs, with a surface plasmon resonance (SPR) peak at 450 nm. The particle size analyzer identified the average diameter of the particles as 40.2 nm. The X-ray diffraction study confirmed the crystalline nature and face-centered cubic type of the silver nanoparticle. Scanning electron microscopy characterized the globular, small, round shape of the silver nanoparticle. AFM revealed the two-dimensional topology of the silver nanoparticle with a characteristic size ranging around 50 nm. Confocal microscopy showed the cell-wall disruption of S. viridans treated with Bs-AgNPs. High-content screening and compound microscopy revealed the destruction of mycelia of R. solani after exposure to Bs-AgNPs. Furthermore, the Bs-AgNPs cured sheath blight disease by reducing lesion length and enhancing root and shoot length in Oryza sativa seeds. This soil-borne pathogen Bacillus-mediated synthesis approach of AgNPs appears to be cost-efficient, ecofriendly, and farmer-friendly, representing an easy way of providing valuable nutritious edibles in the future.

Cytotoxicity Study of Cadmium-Selenium Quantum Dots (Cdse QDs) for Destroying the Human HepG2 Liver Cancer Cell

In this approach, Hepatocellular carcinoma (HCC) is originated from hepatocytes cell, which can spread several parts in the body. It increases the death rate of cancer patients and more common in men rather than female. Patients having large tumor are growing through expensive treatment such as chemotherapy, radiotherapy and surgery. Nano medicine such as nano-dimensional particles as well as quantum dots might be an alternative treatment with greater efficiency in cancer biology field. Modification of surface and chemical properties of cadmium groups quantum dots can easily penetrate into the cancer cell without harming normal tissues. Here, Cadmium-Selenium Quantum Dot nanomaterials (CdSe QDs) have been prepared in solution phase with 0.1 M concentration, which was potentially applied for the destroying of HepG2 cancer cell with 24 hour and 36 hour of incubation. Due to their size, surface properties, lower cost, QDs can easily attached to the cell and able to damage the cells more rapidly in vitro process. For cell death, gene expression and morphological changing analysis were completed MTT, Flow Cytometry, qRT-PCR assay. Finally, the cell deaths were observed by cell shrinkage, rupture of membrane and expression of apoptotic gene (Bcl2, Beta catenin, Bax) were positive comparing untreated HepG2 cell line.

Photocatalytic performance, anti-bacterial activities and 3-chlorophenol sensor fabrication using MnAl2O4·ZnAl2O4 nanomaterials

A MnAl₂O₄·ZnAl₂O₄ nanomaterial was synthesized by co-precipitation and characterized by XRD, SEM, EDS, TEM, AFM, FTIR, PL, CV and EIS. The photocatalytic activity of the nanocomposite against MV dye and its MDR anti-bacterial functions were studied. The nanocomposite shows excellent photocatalytic as well as anti-bacterial activity. A MnAl₂O₄·ZnAl₂O₄ nanomaterial/Nafion/GCE electrode was fabricated and implemented as the working electrode of a 3-CP sensor. The sensor exhibited good sensitivity, with the lowest detection limit, fast response time, large linear dynamic range (LDR), and long-term stability in the chemical environment. The estimated sensitivity is 70.07 μA mM^-1 cm^-2. The LDR, limit of detection (LOD), and limit of quantification (LOQ) are 0.1 nM to 0.01 M, 0.0014 ± 0.0001 nM, and 0.004 nM, respectively. The MnAl₂O₄·ZnAl₂O₄ nanomaterial/Nafion/GCE is a promising fabricated sensor probe for the selective detection of 3-CP for the environmental safety and healthcare fields on a large scale.

Sociodemographic and Clinico-laboratory Profile of Expanded Dengue Syndrome: Experience from a Tertiary Hospital of Dhaka, Bangladesh

Dengue is endemic in more than a hundred countries throughout the tropics. The classic presentation of dengue fever has expanded its horizon by involving different organ systems, and these system-specific presentations pose a diagnostic dilemma. The objective of this prospective observational study was to evaluate the sociodemographic, and clinical profile of expanded dengue syndrome (EDS) patients admitted to a tertiary hospital in Dhaka, Bangladesh. Data were collected from all admitted patients from April 2019 to September 2019 and diagnosed with dengue. The patients with dengue having EDS were followed up till discharge. Of 4200 dengue cases admitted during this period, 108 patients (2.57%) were diagnosed with EDS. Among the EDS cases, 94% were from Dhaka city, and 6% were outside Dhaka city; 66% of the patients were male. Gastrointestinal (GI) manifestations were the most common (87%) type of EDS, and among the GI presentations, acute acalculous cholecystitis (38.3%), acute pancreatitis (30.85%), acute hepatitis (21.27%) were the most frequent. Among the EDS cases, 5.55% had a central nervous system (CNS), 4.6% cardiovascular (CVS), and 1.88% had renal complications; 0.93% presented with myositis. The majority (90.74%) of the patients recovered with conservative management, 10 (9.26%) died. This study shows that expanded dengue syndrome (EDS) is not uncommon in Bangladesh's dengue viral infection. A high degree of clinical suspicion is the key to early diagnosis and treatment.

Frequency of Osteoporosis among Chronic Obstructive Pulmonary Disease Patients Attending Respiratory Medicine Out Patient Department, BSMMU

Osteoporosis is an important systemic manifestation of Chronic Obstructive Pulmonary Disease (COPD). Osteoporosis is a systemic disease of bone which may present as low bone mass and micro-architectural disarray that increases the risk of fracture. The World Health Organization defines osteoporosis as bone density ≥2.5 standard deviations below the bone density of a normal young adult. Osteopenia, a less severe form of bone loss, is defined as a bone density between 1 and 2.5 standard deviations below that reference point. The aetiology of osteoporosis in COPD patients remain unclear, but several factors significantly correspond to reduced bone density in COPD, including older age, female sex and body mass index (BMI). However, the relationship to other factors, such as FEV₁, tobacco smoking, physical inactivity and corticosteroid therapy, are still an unresolved issue. This cross-sectional study was done in the Department of Respiratory Medicine, BSMMU from March 2018 to March 2019. A total of 86 patients of which prevalence of osteoporosis is 29.1%, osteopenia 50% and normal BMD in 20.9%, majority of them was belonging to age group 51-60 years. Male were predominant with male-female ratio of 3.5:1. The frequency of osteoporosis was 32.0%, 64.0% and 4.0% in moderate, severe and in very severe COPD patients, respectively. The frequency of osteopenia was 14.0% in mild, 53.5% in moderate, 20.9% in severe and 11.6% were in very severe COPD patients. The p value (p=0.018) was significant for prevalence osteoporosis and osteopenia with increase in severity of COPD. The prevalence of osteoporosis and osteopenia was high in COPD patients under study. The frequency of osteoporosis and osteopenia was more with severity of COPD.

Clinical and Neuro-radiological Profile of Symptomatic Cytomegalovirus Infection in Infants in a Tertiary Care Hospital

Congenital CMV infection is the most common mother to child infection having spectrum of clinical presentation which can lead to severe neurological sequelae. Early assessment of disease severity from clinical and neuroimage profile is essential to initiate proper treatment and to predict the outcome is crucial. This cross sectional observational study was conducted at Dhaka Medical College Hospital a tertiary care centre of Bangladesh from January 2019 to June 2020 in the department of pediatrics. This study was carried on among 123 infants of aged 0-12 months with polymerase chain reaction proven congenital cytomegalovirus infection over a period of 18 months. Mean age of our study group is 7.01±2.02 months, with male predominance (85.00%); majority of our infants came from lower socioeconomic background of rural area. Only 5.70% took more than two antenatal visits, 70.00% had history of perinatal asphyxia where 54.50% developed neonatal seizure. Microcephaly was present among 69.10% children, epilepsy, movement disorder, central visual impairment, different level of hearing impairment (78.90%) and severe psychomotor retardation (83.80% - 87.80%) was the most consistent initial presentation of our study group. Neuroimage abnormality was present among 94.30% of infants where cortical atrophy (86.20%) and intracranial calcification (55.30%) was the most common findings, different type of congenital malformations was also observed among the study group. Multiple logistic regression analysis showed significant value for abnormal neuroimage findings as a predictor of severity of psychomotor retardation. Congenital cytomegalovirus infection is one of the leading cause of hearing impairment and psychomotor retardation, where neuroimage findings could guide to predict the severity of psychomotor retardation.

Status of Serum Calcium, Phosphate and Intact Parathyroid Hormone in Predialysis Chronic Kidney Disease Patients of Stage-3 to Stage-5 Compared To KDOQI Guideline

The chronic kidney disease (CKD) is associated with a variety of bone disorders and disorders of calcium and phosphorus metabolism. Bone disease associated with chronic kidney disease having higher rate of CKD progression and increased risk of death. To see the status of serum calcium, phosphate and intact parathyroid hormone in pre-dialysis CKD (stage- 3 to 5) patients. This was a across sectional study done in outpatient department of Nephrology of National Institute of Kidney Diseases and Urology, Dhaka, between 1st June 2012 to 31st May 2013. The patients of CKD stage 3, 4 and 5 yet not on dialysis attending out patients department of Nephrology, NIKDU by using MDRD-4 equation according to K/DOQI guidelines and reviewing previous medical records and investigation reports were enrolled in this study. There after serum calcium (corrected for serum albumin), phosphate and iPTH levels were measured and compared with the recommended target ranges in K/DOQI guideline. The number of patients with serum levels according to K/DOQI guidelines for different stages CKD(3,4,5) were as follows: serum calcium: 56.6, 58.5 and 76.7; serum phosphate: 55.2, 58.5 and 56.7; iPTH 37.9, 12.2 and 36.7 and Ca x P product 100.0, 97.6 and 86.7, respectively. The percentages of patients (who received drug) with serum calcium levels within according to K/DOQI guidelines for stages 3, 4 and 5 were as follows: serum calcium: 63.2%, 64.7% and 83.3%; respectively, serum phosphate: 63.2%, 61.8% and 66.7%; respectively, iPTH 42.1%, 14.7% and 4.7% and Ca x P product 100.0%, 100.0% and 87.5%, respectively. On the other hand patients who didn't receive drug the percentages of patients with serum calcium levels according to K/DOQI guidelines for CKD stages 3, 4 and 5 were as follows: serum calcium: 50.0%, 28.6% and 50.0%; respectively, serum phosphate: 40.0%, 42.9% and 16.7%; respectively, iPTH 30.0%, 14.7% and 16.7% and Ca x P product 100.0%, 85.7% and 83.3%, respectively. The patients achieving the four recommendations of K/DOQI guidelines was 4(13.8%) in stage-3, 3(7.3%) in stage-4 and 5(16.7%) in stage-5. More than half of the pre-dialysis patients of CKD were within target range of serum calcium and phosphate recommended in K/DOQI guideline and this proportion was more in those who were taking both phosphate binder and Vit-D. Ca x P was within target range in almost all patients so it may not be an important parameter for therapeutic decision making. However majority of the patients were out of target range of iPTH even though having normal serum calcium and phosphate level. So emphasis should be given in monitoring of iPTH level in early stages of CKD.

Assessment of Melamine in Different Water Samples with ZnO-doped Co3 O4 Nanoparticles on a Glassy Carbon Electrode by Differential Pulse Voltammetry

In this investigation, a melamine electrochemical sensor has been developed by using wet-chemically synthesized low-dimensional aggregated nanoparticles (NPs) of ZnO-doped Co₃ O₄ as sensing substrate that were decorated onto flat glassy carbon electrode (GCE). The characterization of NPs such as UV-Vis, FTIR, XRD, XPS, EDS, and FESEM was done for detailed investigations in optical, functional, structural, elemental, and morphological analyses. The ZnO-doped Co₃ O₄ NPs decorated GCE was used as a sensing probe to analyze the target chemical melamine in a phosphate buffer at pH 5.7 by applying differential pulse voltammetry (DPV). It exhibited good performances in terms of sensor analytical parameters such as large linear dynamic range (LDR; 0.15-1.35 mM) of melamine detection, high sensitivity (80.6 μA mM^-1  cm^-2 ), low limit of detection (LOD; 0.118±0.005 mM), low limit of quantification (LOQ; 0.393 mM), and fast response time (30 s). Besides this, the good reproducibility (in several hours) and repeatability were investigated under identical conditions. Moreover, it was implemented to measure the long-time stability, electron mobility, less charge-transfer resistance, and analyzed diffusion-controlled process for the oxidation reaction of the NPs assembled working GCE electrode, which showed outstanding chemical sensor performances. For validation, real environmental samples were collected from various water sources and investigated successfully with regard to the reliability of the selective melamine detection with prepared NPs coated sensor probe. Therefore, this approach might be introduced as an alternative route in the sensor technology to detect selectively unsafe chemicals by an electrochemical method with nanostructure-doped materials for the safety of environmental, ecological, healthcare fields in a broad scale.

Nanoremediation technologies for sustainable remediation of contaminated environments: Recent advances and challenges

A major and growing concern within society is the lack of innovative and effective solutions to mitigate the challenge of environmental pollution. Uncontrolled release of pollutants into the environment as a result of urbanisation and industrialisation is a staggering problem of global concern. Although, the eco-toxicity of nanotechnology is still an issue of debate, however, nanoremediation is a promising emerging technology to tackle environmental contamination, especially dealing with recalcitrant contaminants. Nanoremediation represents an innovative approach for safe and sustainable remediation of persistent organic compounds such as pesticides, chlorinated solvents, brominated or halogenated chemicals, perfluoroalkyl and polyfluoroalkyl substances (PFAS), and heavy metals. This comprehensive review article provides a critical outlook on the recent advances and future perspectives of nanoremediation technologies such as photocatalysis, nano-sensing etc., applied for environmental decontamination. Moreover, sustainability assessment of nanoremediation technologies was taken into consideration for tackling legacy contamination with special focus on health and environmental impacts. The review further outlines the ecological implications of nanotechnology and provides consensus recommendations on the use of nanotechnology for a better present and sustainable future.

Frequency of Eosinophilic Esophagitis among Patients with Gastroesophageal Reflux Symptoms in an Academic Hospital of Bangladesh: A Cross Sectional Study

Eosinophilic esophagitis (EoE) is a disease of modern era. It was first described 40 years back. Since then it has drawn an immense interest among the clinicians. It is diagnosed by the presence of eosinophils count ≥15/HPF on esophageal biopsied mucosa in patients with symptoms of esopohageal dysfunction. It is more prevalent among patients with gastroesophageal reflux disease. As its symptoms overlap with that of gastroesophageal reflux disease (GERD), it is frequently overlooked & misdiagnosed which increases patients' sufferings. No data is available in Bangladesh. The objective of the study was to find out the frequency of eosinophilic esophagitis among patients with gastroesophageal reflux symptoms. The study was conducted at the Outpatient department of the department of Gastroenterology of Dhaka Medical College Hospital, Dhaka, Bangladesh from September 2018 to April 2019. One hundred and thirty three (133) consecutive patients with symptoms suggestive of gastroesophageal reflux disease based on validated questionnaire underwent upper GI endoscopy. Biopsies were taken from proximal and distal esophagus as well as any other endoscopically abnormal esophageal mucosal lesion. Among 133 patients with gastroesophageal reflux symptoms, 7 patients (5.3%) were found to be positive for eosinophilic esophagitis. Mean age at diagnosis was 37.28±13.38 years. It was more common in younger age group. Female patients (56%) were more than male patients (44%). Heart burn was the major symptom followed by acid regurgitation. Nocturnal cough showed statistically significant relationship with eosinophilic esophagitis. Although the frequency is low, it may be considered as a differential diagnosis among patients with GERD.