Correction: Development of electrochemical sensors for quick detection of environmental (soil and water) NPK ions.

[This corrects the article DOI: 10.1039/D4RA00034J.].

Development of electrochemical sensors for quick detection of environmental (soil and water) NPK ions.

All over the world, technology is becoming more and more prevalent in agriculture. Different types of instruments are already being used in this sector. For the time being, every farmer is trying to produce more crops on a piece of land. Eventually, soil loses its nutrients; however, to grow more crops, farmers use more fertilizers without knowing the proper conditions of the soil in real time. To overcome this issue, many scientists have recently focused on developing electrochemical sensors to detect macronutrients, i.e., nitrogen (N), phosphorus (P), and potassium (K), in soil or water rapidly. In this review, we focus mainly on the recent developments in electrochemical sensors used for the detection of nutrients (NPK) in different types of samples. As it is outlined, the use of smart and portable electrochemical sensors can be helpful for the reduction of excess fertilizer and can play a vital role in maintaining suitable conditions in soils and water. We are optimistic that this review can guide researchers in the development of a portable and suitable NPK detection system for soil nutrients.

Zinc oxide nanorod/rutin modified electrode for the detection of Thiourea in real samples.

In this work, a novel electrochemical detection strategy was developed based on a metal-organic framework of zinc oxide nanorod nanoparticles and rutin for selective screening of Thiourea as toxic chemicals. The zinc oxide nanorod were synthesized by following direct chemical precipitation methods and characterized by X-ray diffraction and X-ray photoelectron spectroscopy analysis. The surface of modified electrodes was also characterized by field emission scanning electron microscopes, energy-dispersive X-ray spectroscopy, and attenuated total reflectance flourier transform infrared spectroscopy. Furthermore, the electrochemical activity of the developed sensor was tested by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The modified electrode showed outstanding electro-catalytic activity towards the detection of Thiourea in phosphate buffer saline at a high pH level of 12.0. The proposed sensor showed a linear range of linearity in a concentration ranging from 5.0 × 10-6 - 900 × 10-6 molL-1 and a detection limit of 2.0 × 10-6 molL-1. Moreover, the selectivity of the developed electrochemical sensor was investigated for the detection of Thiourea in the presence of organic compounds and a group of anions. Furthermore, the proposed strategy demonstrated an excellent recovery value in the spiked farmland water and fruit juice sample.

Nanostructured wearable electrochemical and biosensor towards healthcare management: a review.

In recent years, there has been a rapid increase in demand for wearable sensors, particularly these tracking the surroundings, fitness, and health of people. Thus, selective detection in human body fluid is a demand for a smart lifestyle by quick monitoring of electrolytes, drugs, toxins, metabolites and biomolecules, proteins, and the immune system. In this review, these parameters along with the main features of the latest and mostly cited research work on nanostructured wearable electrochemical and biosensors are surveyed. This study aims to help researchers and engineers choose the most suitable selective and sensitive sensor. Wearable sensors have broad and effective sensing platforms, such as contact lenses, Google Glass, skin-patch, mouth gourds, smartwatches, underwear, wristbands, and others. For increasing sensor reliability, additional advancements in electrochemical and biosensor precision, stability in uncontrolled environments, and reproducible sample conveyance are necessary. In addition, the optimistic future of wearable electrochemical sensors in fields, such as remote and customized healthcare and well-being is discussed. Overall, wearable electrochemical and biosensing technologies hold great promise for improving personal healthcare and monitoring performance with the potential to have a significant impact on daily lives. These technologies enable real-time body sensing and the communication of comprehensive physiological information.

Copper oxide nanoflowers/poly-l-glutamic acid modified advanced electrochemical sensor for selective detection of l-tryptophan in real samples.

The main objective of this research work is to develop a low-cost sensor to detect l-tryptophan (L-tryp) in real sample medium based on a modified glassy carbon electrode. For this, copper oxide nanoflowers (CuONFs) and poly-l-glutamic acid (PGA) were used to modify GCE. The prepared NFs and PGA coated electrode was characterized using field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Furthermore, the electrochemical activity was performed by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). The modified electrode showed excellent electro-catalytic activity towards L-tryp detection in PBS solution at neutral pH 7.0. Based on the physiological pH condition, the proposed electrochemical sensor can detect L-tryp concentration with a linear range of 1.0 × 10-4-8.0 × 10-8 molL-1 with having a detection limit of 5.0 × 10-8 molL-1 and sensitivity of 0.6µA/µMcm2. The selectivity of L-tryp was tested with a mixture of salt and uric acid solution at the above conditions. Finally, this strategy demonstrated excellent recovery value in real sample analysis like milk and urine.

Genome Sequence of a SARS-CoV-2 P.1 Variant of Concern (20J/501Y.V3) from Bangladesh.

This study reports the coding-complete genome sequence, with variant identifications and phylogenetic analysis, of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) P.1 variant (20J/501Y.V3), obtained from an oropharyngeal swab specimen from a female Bangladeshi patient diagnosed with coronavirus disease 2019 (COVID-19) with no travel history.

Vas Deferens Calcification in a Diabetic CKD: An Incidental Finding.

Vas deferens calcification is a very rare condition. The causes can be categorized as inflammatory and non-inflammatory type. We are presenting such a non inflammatory type of bilateral vas calcification in a diabetic chronic kidney diseases (CKD) patient. Presented patient a 50 years old man admitted in Samorita Hospital Ltd., Dhaka, Bangladesh on 03 August 2014 in cabin - 537 with registration number 1904/14. He was labeled as Diabetes mellitus (DM), Hypertension (HTN), CKD & Urinary tract infection (UTI). Vas deferens calcification was diagnosed incidentally by X-ray KUB. Subsequently we have discussed all possible causes in this report. The purpose of presenting this rare imaging finding is to emphasize the under diagnosis of the disease and causes. It can also be diagnosed by simple, easily available and cheap investigations like Plain X ray KUB.

Reports of Coding-Complete Genome Sequences of Five 2019 Novel Coronavirus (SARS-CoV-2) Strains Isolated in Bangladesh.

This study determined five coding-complete genome sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains isolated from oropharyngeal swab specimens of Bangladeshi patients who were diagnosed with coronavirus disease 2019 (COVID-19) and had no travel history.

Seasonal Pattern of Pathogenic V. cholerae and V. paraheamolyticus in Surface Water of Dhaka, Bangladesh.

V. cholerae and V. parahaemolyticus are responsible for majority of the Vibrio-related infections world wide. In this observational study, we selected three important river and pondsites of Dhaka city, Bangladesh to observe the presence of pathogenic V. cholerae, and V. parahaemolyticus. Surface water samples were collected from July 2013 to April 2014. Identification of V. cholerae was confirmed by the presence of ompW gene by PCR. Vibrio cholerae was found in the unique dual peak (March to May and September to November) patternin Mirpur-1 Mazar pond and Abdullahpur bridge river site, like many other studies reported earlier in Dhaka with only one exception of finding V. cholerae in the month of July 2013 in Mirpur-1 Mazar pond. A single peak was found from September to November in Mirpur-1 river sites. The ctxB positive non- O1 V. cholerae has also been reported. The presence of ctxB gene was observed by MAMA PCR. The O1 and O139 serogroups were confirmed by O1rfb and O139 rfb genes in PCR. Both classical and El-Tor biotypes were observed in this one year round study. V. paraheamolyticus was confirmed by the presence of ToxRVP gene and all the strains were negative for tdh pathogenic gene by PCR. This study observed for the first time the seasonal pattern of V. parahaemolyticus in water bodies in Bangladesh showing a peak from February to April in all three sampling sites and another additional peak which span from August to September in Mirpur-1 Mazar pond, Dhaka, Bangladesh.

A Novel Pathogenic ß-Thalassemia Mutation Identified at Codon 8 (HBB: c.27delG) in a Bangladeshi Family Acquired De Novo.

In Bangladesh, the practice of ß-thalassemia (ß-thal) carrier screening and prenatal diagnosis (PND) by ß-globin gene sequencing has been initiated to prevent the birth of affected children. The study aimed to describe a novel de novo mutation of the ß-globin gene and its clinical implication. Out of 100 Bangladeshi ß-thal carrier families, one patient with hematological and clinical features associated with ß-thal and her parents were included. Molecular characterizations of ß-globin gene mutations were performed by direct sequencing. A novel nucleotide deletion mutation at codon 8 in the first exon of the ß-globin gene (HBB: c.27delG) was found in a 1-year-old child of the studied family in a heterozygous state along with common Hb E (HBB: c.79G>A). The mutation caused a frameshift to a new stop codon at codon 18 resulting in a ß0-thal phenotype. The proband exhibited a ß-thal intermedia (ß-TI)-like genotype, however, showed ß-thal major (ß-TM)-like complications and was transfusion-dependent. Her mother had a profile consistent with the Hb E trait, while the father had normal hematological indices. Mutation analyses revealed the mother to be heterozygous for Hb E, while the father had a normal genotype. The novel mutation was assumed to be inherited de novo by the paternity test. The study documented a novel pathogenic mutation in the ß-globin gene in a Bangladeshi family by ß-globin gene sequencing.

Molecular characterization of extended spectrum ßlactamase producing bacteria isolated from urinary tract infected patients, Bangladesh.

The aims of the study were to examine the presence of extended spectrum ßlactamase (ESBL) producing pathogen in urinary tract infected (UTI) patients and their respected molecular characterization and classification. The isolates collected from UTI patients attending a private hospital during the period between January and June, 2012, were biochemically identified and subjected to double disc synergy method for the detection of ESBL. ESBL genes were detected by multiplex PCR and antibiotic sensitivity test was performed. Thirty two percent of all Gram negative isolates were found as ESBL producer. Among 65 ESBL positive isolates, 77% were Escherichia coli, 20% Klebsiella pneumoniae and 3% were Pseudomonas spp. Around 48% isolates were found carrying at least one of the four ESBL genes, blaCTX-M, blaTEM, blaSHV and blaOXA, and were found in 32%, 23%, 18.5% and 3% of the isolates respectively. In antibiotic sensitivity assay, higher resistance was found in E. coli than K. pneumonia against ciprofloxacin and nalidixic acid. Interestingly, two E. coli and three K. pneumonia strains were found resistant to only 3rd generation cephalosporines, but susceptible to all other antibiotics assessed. One E. coli strain was found resistant to ciprofloxacin but sensitive to nalidixic acid. Pseudomonas spp. was found resistant to most of the antibiotics. The susceptible rate to nitrofurantoin, amikacin, and gentamicin was also not satisfactory. Susceptibility (100%) to meropenem and imipenem render these as good alternatives to treat UTI. The majority of the isolates were positive for blaCTX-M and adverted to molecular class A. Two strains carrying blaOXA gene along with blaSHV/blaTEM/blaCTX-M, could not be included in any of the established ESBL classification.

Serum Zinc, Copper, Magnesium & Phosphorus Level in Children with Severe Acute Malnutrition (SAM).

Malnutrition is widely prevalent among hospitalized children in most developing countries including Bangladesh. Though malnutrition accounts for the high rate of under 5 mortality sometimes it is overlooked. Keeping in this in mind A comparative cross sectional study was done in Mymensingh Medical College Hospital from 1st October 2009 to 31st May 2011. Children aged 1-5 years with presence of one or more criteria WHM <70%, WHZ-score <-3SD, Bipedal edema & Mid upper arm circumference <110mm were taken as study group and children aged 1-5 years with normal growth allowable normal range of variation is between 3rd and 97th centile curve or median (50th centile) ±2SD of weight for age growth chart (CDC growth chart, USA, 2000) were taken as reference group. Persistent diarrhea, Patients taking medications containing zinc, copper, magnesium, phosphorus & calcium, PEM with shock were excluded from study group. Nutritional assessment was done according to WHO criteria of SAM. Serum Zinc, Copper Magnesium and Phosphorus level were determined by Atomic Absorption Spectrometry using UNICAM - AA Spectrometer, model no. 969, Spain. Total 120 study populations were taken. Ninety Out of 120 were taken as a study group (SAM) & 30 were reference group. In reference group serum Zn, Cu, Mg, P value was 103.80±8.86µg/dl, 135.92±13.57µg/dl, 2.31±0.18mg/dl, 3.96±0.22mg/dl respectively. In study group serum Zn, Cu, Mg, P value was 60.33±11.08µg/dl, 80.60±15.46µg/dl, 1.47±0.22mg/dl, 2.00±0.52mg/dl respectively. All these results show that there is significant difference between study group & reference group. Considering the decreased level of these parameters, close biochemical monitoring and follow up should be emphasized for the children with SAM.

Comparison between azithromycin and cefixime in the treatment of typhoid fever in children.

An intervention study was carried out in the department of paediatrics of Mymensingh Medical College Hospital, Mymensingh to compare the clinical efficacy of Azithromycin in the treatment of childhood typhoid fever with that of cefixime for a period of one year from January 2011 to December 2011. A total of 60 cases of typhoid fever were enrolled in to a randomized clinical trial and was divided into two groups. The inclusion criteria of the cases were: Documented fever for more than 4 days plus two or more of the following clinical features: toxic physical appearance, intestinal complaints, coated tongue, ceacal gurgling, hepatomegaly and splenomegaly, diarrhoea and constipation plus positive Widal test and/or blood culture positivity. Patients who had complication like GIT heamorrhage; intestinal perforaion and/or shock were excluded from the study. Data were collected in a structured questionnaire. Azithromycin was given at a dose of 10mg/kg/day for a period of 07 days Cefixime was given at a dose of 20mg/kg/day in two divided dose for 14 days. The mean time of defervesence was 4.05+1.14 days with azithromycin and 3.41+0.95 with cefixime respectively. The minimum defervesence time was 02 days and maximum defervesence time was 07 days. Clinical cure rate was 87% in azithromycin group and 93% in cefixime group. No serious adverse effect was noted related to azithromycin and cefixime therapy except nausea, vomiting, diarrhoea and jaundice. It was found that azithromycin is almost as effective as cefixime in the treatment of typhoid fever.

Correlation between grades of intraventricular hemorrhage and severity of hypoxic ischemic encephalopathy in perinatal asphyxia.

This study was done to find out the correlation between various grades of Intraventricular Hemorrhage (IVH) and stages of HIE in perinatal asphyxia and to determine the short-term outcome of the affected baby. This observational study was conducted in Neonatal ward of Dhaka Shishu Hospital (DHS) and Dhaka Medical College Hospital for period of 37 months from January 2004 to January 2007. Total 189 perinatally asphyxiated babies were enrolled for HIE staging and cranial Ultrasonogram (USG) to find out grades of IVH. Finally 178 newborns were fulfilling all the necessary criteria for statistical analysis of the collected data on prescribed questionnaire. Among 178 perinatally asphyxiated newborns HIE stages - I, II, III were 50(28%), 10(56%) and 28(16%) respectively. Out of this 178 neonates total 50(28%) developed various grades IVH. Grades of IVH, I, II, III, IV were 15(30%), 18(36%), 10(20%) and 7(14%) respectively. There was significant correlation between the severity of HIE staging and grades of IVH. Short term outcome was poor in HIE-III, IVH grade III and IV. There is a direct relationship between different grades of IVH and stages of HIE. That is more the severe stages of HIE there is more chances to develop severe grades of IVH, Immediate morbidity and mortality is dependent on the grades of IVH and severity of stages of HIE.

Comparison of trabeculectomy with mitomycin-C versus medical treatment in moderate stage of steroid induced glaucoma.

This prospective, comparative and interventional study was done to compare the effects of Trabeculectomy with Mitomycin-C and medical treatment with Timolol maleate 0.5% by controlling IOP (intra ocular pressure) and assessing the visual acuity (VA) and mean sensitivity (MS) of visual field in moderate stage of steroid induced glaucoma and conducted in the Department of Ophthalmology, Bangabandhu Sheikh Mujib Medical University, Dhaka, from July 2004 to June 2009. Sixty eyes of thirty patients with glaucoma due to use of topical steroids for >1 year. IOP range was 22-30 mm of Hg, visual field with (MD) mean deviation >6 to 12 dB and (MS) mean sensitivity >12-21dB, C:D ratio 0.7-0.8 and visual acuity 6/9 to 6/6 were included in this study. At first, topical steroid was stopped. Sample was collected in lottery method. Patients were divided into two groups. In Group I, 30 eyes were treated with Timolol maleate 0.5%. In Group II, 30 eyes were treated surgically by Trabeculectomy with Mitomycin-C. Follow-up were done on 1st POD, after 7 days, 1 month, 3 months and 6 months. Successful IOP control (<15mm of Hg) were achieved in 23 eyes (77%) in Group I and 30 eyes (100%) in Group II and were highly significant (p<0.001). Visual acuity and mean sensitivity also improved more in Group II than the Group I. It was also highly significant (p<0.001). So, Trabeculectomy with mitomycin-C is effective procedure in comparison to medical treatment for steroid induced glaucoma.

Effect of topical Beta blocker (Timolol maleate 0.5%) in primary open angle glaucoma.

The study was undertaken to measure the effects of Beta blocker (Timolol maleate 0.5%) in moderate and advanced stage of primary open angle glaucoma by controlling intra-ocular pressure (IOP) and assessing the visual acuity (VA) and mean sensitivity (MS) of visual field. Study was done in the department of Ophthalmology, Bangabandhu Sheikh Mujib Medical University, Shahbagh, Dhaka from January 2002 to December 2005. It was a Prospective and interventional study. Thirty patients of bilateral primary open angle glaucoma were treated medically by B-blocker (Timolol maleate 0.5%) two times daily. Follow up were done after 7 days, 1 month, 3 months and 6 months. Before treatment Intra ocular pressure (IOP) range was 22-30 mm of Hg (mean 23.40 ± 2.04). After beta-blockers IOP reduced to the range of 10-20mm of Hg (mean 13.12 ± 2.01) which was statistically significant (p>0.02) in moderate stage & 8-18 mm Hg (mean 13.50 ± 2.0) in advance stage which was also statistically significant (p<0.02). VA and MS also improved in 15 eyes (50%), remained unchanged in 9 eyes (30%) and deteriorated in 6 eyes (20%) in moderate stage and also improved in 15 eyes (50%), remained unchanged in 6 eyes (20%) and deteriorated in 9 eyes (30%) in advanced stage. Success rate was 80% in moderate (p>0.02) & 70% in advanced stage (p<0.02) and which was statistically significant.

Fabrication of gold nanoparticle/multi walled carbon nanotube hybrids by in situ reaction in water using poly(acryloyl beta-alanine).

Fabrication of a hybrid consists of gold nanoparticles and multi walled carbon nanotubes (MWCNTs) with the help of poly (amino acid) was investigated. Poly(acryloyl beta-alanine) was synthesized by precipitation polymerization in tetrahydrofuran. The polymers were used to form hybrids with MWCNTs in aqueous media. Subsequently, the polymer functionalized MWCNTs were fabricated by in situ formed gold nanoparticles. The fabrication by gold nanoparticles was confirmed by transmission electron microscopic analyses. The fabrication was attempted with different concentrations of lithium auric chloride solutions in the range of 0.1-1.2 mM in water. The lower concentration of the gold precursor solution resulted in the formation and attachment of gold nanoparticles without aggregation while the higher concentration above 1.0 mM led to the aggregation of gold nanoparticles. The gold nanoparticles were observed only on the surface of MWCNTs and none was in the bulk aqueous phase.

Beta thalassemia in a tertiary care hospital with their chelation habit.

Beta-thalassemia which is one of the most common genetic disorders in Bangladesh encompasses a group of monogemic diseases that have reduced synthesis or no synthesis of one or more globin chain of haemoglobin. The defects involved are extremely heterogenous and give rise to a large phenotypic spectrum with patients that are almost asymptomatic to cases in which regular blood transfusions are required to sustain life. The aim of the study is to estimate the frequency of beta thalassemia among the blood recipients in the Day Care Centre of Transfusion Medicine Department of Mymensingh Medical College Hospital from July, 2009 to June, 2010 along with their chelation habit. Retrospective cross-sectional study with the sample size of 784, clinical and family data was collected and descriptive statistics were done in the Laboratory of Transfusion Medicine Department. Among the 784 subjects, the beta thalassemia was 521 (66.46%), among the thalassemic patients only 59(11.32%) take injection Dysferrioxamine (Dysferol), the iron chelating agent. Male are predominant than female (63.53%). Those of the affected patients 67.18% were in age group 6 to 20 years. Although beta thalassemia is one of the first monogemic diseases and represents a global health problem, only recently has the scientific community started to focus on the real molecular mechanisms that underline this disease, opening new & exciting therapeutic perspectives for thalassemic patients worldwide. It is concluded from our study that availability of blood transfusion facilities along with an orally and cheaper iron chelator is an urgent need to ensure the management of needy thalassemic patients in Bangladesh.

Chikungunya virus infection, a threat to public health.

Many countries in the world have reported human infections by chikungunya virus (CHIKV) a mosquito-borne togavirus belonging to the genus alpha virus. After half a century of focal out breaks of acute febrile poly arthralgia, the disease had spread unexpectedly in the past decade with large outbreaks in Africa around the Indian Ocean and in Bangladesh. In Asia, CHIKV is thought to be transmitted by the same mosquito as dengue, Aedes aegypti and Aedes albopictus. Due to similarities in clinical presentation with dengue, limited awareness and a lack of laboratory diagnostic facilities, CHIKV is probably often under diagnosed or misdiagnosed as dengue. Treatment is supportive. The prognosis is generally good although some patients experience chronic arthritis. There is no vaccine or antiviral therapy against CHIKV. Early identification of disease and control of vector will prevent the spread of disease.

Iron chelation therapy and thalassemia - an overview.

New developments in the epidemiology, treatment and prognosis of thalassemia have dramatically altered the approach to the care of affected patients. In the last 30 years, conventional treatment of ß-thalassemia major, based primarily on regular blood transfusions and iron chelation therapy with desferrioxamine (DFO) has markedly improved the prognosis of the disease. Adequate administration of parenteral DFO reduces or prevents iron accumulation. The unavailability of DFO (dysferol) for most patients with thalassemia major and the failure of prescribed therapy to prevent complications in other patients have led to a search for alternative iron chelators; one of them, deferiprone (DFP) has been commercially available. Patients may ultimately benefit from having a choice between several chelators, including orally active drugs. Combination therapy and organ-targeted chelation, may soon have a considerable impact on the therapeutic outcome and quality of life of patients with thalassemia.