Oncological Clearance Following Resection of the Carcinoma Rectum: A Comparison between Laparoscopic and Open Anterior Resection

Till the day the rectal cancer deaths in the world is in eighth position. For rectal cancer surgery, short-term benefits are expected to be similar for laparoscopic resection of rectum (LRR) and open resection of rectum (ORR). In Bangladesh though the rectal cancer is the sixteenth most common cause of cancer deaths, there is lack of data regarding outcomes of laparoscopic and open surgical approaches for carcinoma rectum. Purpose of study was to compare oncopathological outcomes by quality of surgical resection between LRR and ORR groups. The quasi experimental study was conducted among 46 subjects who attended in the Department of Colorectal Surgery, Bangabandhu Sheikh Mujib Medical University, Bangladesh from July 2020 to June 2021 with rectal adenocarcinoma within 15cm from the anal verge. Equal number of subjects were allocated for LRR and ORR group. Oncopathological end points such as circumferential resection margin (CRM), distal resection margin (DRM), lymph nodes and quality of mesorectal excision were assessed and compared. Here every patients have given their written consent for this study. Mean age of the subjects for LRR and ORR were 45.47±12.66 and 44.47±12.48 years respectively. Majority of the subjects were in age above 40 years (67.0%). The proportion of male (56.5%) were higher than those of female (43.5%). The complete resection was better in LRR (91.3%) than ORR (87.0%) group though statistically not significant. CRM was lower in LRR (0.0%) than ORR (13.0%) group in respect of frequency distribution. DRM was negative for both LRR and ORR group (95.7% each) and it was not statistically significant. ORR met the National Comprehensive Cancer Network (NCCN) criteria of harvesting 12 lymph nodes were as in LRR group 10 lymph nodes were harvested. The mean harvested lymph nodes were 12.2±5.55 and 10.1±5.55 in LRR and ORR group respectively. The study demonstrated that LRR is better (though statistically not significant) in respect of complete resection and CRM while in harvesting lymph nodes, ORR met the NCCN criteria but LRR does not. There is no difference observed regarding DRM in both groups. On oncopathological point of view both the group showed almost equally effective results. Laparoscopic surgery can be opted as the standard operative technique for surgical management of rectal cancer.

Preparation of fluorescent sensor based on Zn metal-organic framework for detection and determination of raloxifene as an anticancer drug

Breast cancer is the second leading cause of death for women worldwide. Raloxifene (RLX) is a somewhat effective drug in lowering cholesterol, preventing and treating invasive breast cancer in postmenopausal women with osteoporosis, and does not interfere with breast tissue. Nevertheless, considering the possibility of risk in biological function due to excessive use of anticancer drugs and the adverse effects of drugs in wastewater on plants, animals, and aquatic, it is useful to determine the concentration of RLX in water and human body fluids. Here, a fluorescent metal-organic framework (MOF) nanoparticle based on trinuclear zinc clusters called Zn-MOF was presented, which is a high-performance and fast-response fluorescent chemosensor that can be used to detect RLX based on the fluorescence quenching medium in water. FTIR, XRD, SEM, and EDS analyses were used to identify the functional group and determine the structure and morphology of Zn-MOF. pH range 3-10. The prepared nanoparticles showed symmetric emission with excitation at a wavelength of 310.0 nm. The performance of the proposed fluorescent nanosensor was proportional to the quenching of the fluorescent signal with increasing RLX concentration at 404.0 nm; the quenching fluorescence response was linear in RLX concentration from 0.7 to 350 ng/mL with a significant detection limit equal to 0.485 nM.

Developing an exclusive sensor based on molecularly imprinted polymer/Multi-walled carbon nanotubes/Fe3O4@Au nanocomposite for the selective determination of an anti-cancer drug imatinib

Determination of pharmaceuticals especially anticancer drugs is one of the important issues in environmental and medical investigation and creating good information about human health. The presence sturdy introducing an electroanalytical sensor based on molecularly imprinted polymer (MIP)/Multi-walled carbon nanotubes (MWCNTs)/Au@Fe3O4 nanoparticles modified carbon paste electrode (PE) to determine imatinib (IMA). The MIP/MWCNTs/Au@Fe3O4/PE showed catalytic activity and also a sensitive strategy to sensing IMA in the concentration range 1-1000 μM with a limit of detection of 0.013 μM. The MIP/MWCNTs/Au@Fe3O4/PE has shown interesting results in the analysis of IMA in real samples, and the interference investigations results show the high selectivity of the MIP/MWCNTs/Au@Fe3O4/PE in the monitoring of IMA in complex fluids such as tablet and blood serum and results approved by F-test and t-test as statistical methods.

Cu-BTC MOF/ionic liquid nanocomposite as novel catalyst to electrochemical monitoring of digoxin in pharmaceutical and environmental samples

There is no effective environmental treatment strategy that does not include monitoring for pharmaceutical compounds in environmental and biological fluids. The widespread presence of pharmaceutical-based pollutants in water sources is a significant public health concern. The treatment process relies heavily on maintaining a stable digoxin concentration in bodily fluids. Finding the correct dose for this medication appears to be crucial. In this research, an easy and high sensibility electrochemical sensor was developed to determine digoxin based on a paste electrode (CPE) that was modified with Cu-BTC MOF and ion liquid ((IL); 1-Methyl-3-Butyl-imidazolinium bromide in this case) using voltammetric methods in 0.1 M phosphate buffer solution (PBS) at pH 5.0. The sensor's selectivity was significantly increased by using Cu-BTC MOF and IL to detect digoxin. The characteristics of the electrode modifiers were evaluated by SEM, XRD and EDS techniques. The LDR was found to be 0.1-40 μM and the LOD of 0.08 μM, respectively.

Simple turn-off fluorescence sensor for determination of raloxifene using gold nanoparticles stabilized by chitosan hydrogel

It is essential to develop a simple, applicable, and reliable assay to anticancer drug raloxifene (RAF) because of its significant usage and side effect due to entering residue in the environment. Fluorescence sensors developed and widely used because of them high selectivity, fast-response, and highly-sensitivity. The gold nanoparticles using chitosan hydrogel was synthesized and applied as a fluorescence sensor to determine the trace amount of RAF. The characterization methods including DLS, FE-SEM, EDX, XRD, and FT-IR were performed to confirm the synthesized structure. This sensor turned off the fluorescent signals proportional to RAF concentrations at 400 nm. The RAF can be detected in the linear range from 5 × 10^-7 to 5 × 10^-5 M. Limits of detection and quantification were obtained as 34 × 10^-8 and 11 × 10^-7 M as well as the relative standard deviation calculated as 1.63% in RAF measuring. The effective parameters on quenching efficiency were studied by central composite design (CCD) with response surface methodology (RSM). The effective parameters in RAF determination, include analyte concentration, temperature, contact time, and pH, were obtained as 35 μM, 30 °C, 8 min, and pH = 8.5. The sensor was applied to determine the RAF concentrations in biological and environmental samples with satisfactory recoveries between 97.5% and 109%.

Clinical Outcome of 0.2% Glyceryl Trinitrate Topical Ointment Compared to Lateral Internal Sphincterotomy in the Treatment of Patient with Chronic Anal Fissure: A Randomized Control Trial

The objective of study was to evaluate the clinical outcome of topical 0.2% Glyceryl trinitrate topical (GTN) ointment in the treatment of chronic anal fissure. This randomized control trial was carried out in the Colorectal Surgery Unit, Department of Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh from May 2015 to April 2016. Total 94 patients were included in this trial, where 47(50.0%) patients were treated by 0.2% GTN ointment as Trial group 12 hourly for 8 weeks and 47(50.0%) patients by lateral internal sphincterotomy (LIS) as Control group in this study. Patients were randomized in two groups by lottery following purposive sampling. Post-procedural outcome variables with 6 months follow up were evaluated. Majority of the patients were found in between 20 to 40 years of age in both groups. The mean age was 34.6±10.4 years and 33.2±8.6 years in GTN and LIS respectively. Overall male female ratio was 0.88:1. All (100.0%) patients presented with pain in anus and 86.15% patients presented with per rectal bleeding. Pain relief in GTN arm versus LIS arm in 2nd and 6th week was 55.31% vs. 76.6%, 74.5% vs. 87.23% with no significant difference between two groups. But at 6 month it was 57.44% vs. 93.6% respectively. The fall in pain relief at 6th month in GTN arm was due to recurrence of fissure. At the end of 2nd, 6th week and 6month, cessation of bleeding improved gradually in both groups after treatment but the improvement was significantly better in LIS group than in GTN group indicating sphincterotomy stops bleeding better. Healing after 2nd week in both groups was minimum but equal 2(4.26%) patients. After 6 weeks LIS group had significant better healing than GTN 40(85.1%) versus 26(55.3%) with p value <0.001. In 6 month time GTN group had increased healing but LIS group had significant better healing than GTN group 42(89.36) vs. 32(68.08) with p value 0.004. Transient flatus and liquid incontinence were 8.51% and 6.4% respectively in LIS group with 0.0% in GTN group. Headache and recurrence were significantly higher in GTN group 61.7% and 34.04% with p<0.001. Lateral internal anal sphincterotomy is superior to the topical application of 0.2% nitroglycerin ointment in the treatment of chronic anal fissure with the advantages of good symptomatic relief, high rate of healing and a very low rate of transient continence disturbances.

Survey of antibacterial activity and release kinetics of gold-decorated magnetic nanoparticles of Fe0 conjugated with sulfamethoxazole against Escherichia coli and Staphylococcus aureus

Drug delivery of antibiotics with magnetic nanoparticles improved by coating metals such as gold and silver has recently been studied. This work describe a simple method to synthesize modified magnetic nanoparticles which have high ability to modify the customary formulation of antibiotics such as sulfamethoxazole (SMX) and pursuant study of adsorption-desorption (release) of this drug. These synthesized nanoparticles were characterized by different methods, including field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and mapping, Fourier-transform infrared spectroscopy, X-ray diffraction, vibrating-sample magnetometry, thermogravimetric analysis and zeta potential test. Present assay showed a well correlation with the introduced carrier for the drug. Also the hypothesis were proved by some adsorption isotherm models and drug kinetics studies of carriers with different drug release kinetics models. This study confirmed the adsorption isotherm models and kinetics of drug sorbate are Temkin and Pseudo-First-Order Lagergren models, respectively; the kinetics of drug release from this carrier is based on Zero-Order model. The values of MIC in antibacterial test for pure SMX and SMX conjugated nanoparticles against Escherichia coli were calculated to be 14 and 2.5 μg/mL, respectively, and these values against Staphylococcus aureus were 24 and 1.25 μg/mL, respectively.

Facile Synthesis of NiO/ZnO nanocomposite as an effective platform for electrochemical determination of carbamazepine

The pharmaceutical science demand for sustainable and selective electrochemical sensors which exhibit ultrasensitive capabilities for the monitoring of different drugs. In an attempt to build a useful electrochemical sensor, we describe a most efficient method for the fabrication of NiO/ZnO nanocomposite through aqueous chemical growth method. The successfully synthesized NiO/ZnO nanocomposite is successfully employed to modify a glassy carbon electrode in order to build a sensitive and reliable electrochemical sensor for the detection of carbamazepine (CBZ), an anticonvulsant drug. The morphological texture, functionalities and crystalline structure of prepared nanocomposite were determined via FTIR, XRD, EDX, TEM, and SEM analysis. In order to examine the charge transfer kinetics, the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to exploit the electrochemical properties of the synthesized nanocomposite. The NiO/ZnO nanocomposite exhibited excellent electron transfer kinetics and less resistive behavior than the individual NiO and ZnO nanoparticles. The differential pulse voltammetry and cyclic voltammetry tools were used for the fluent determination of CBZ. Certain parameters were optimized to develop an effective method including optimum scan rate 60 mV/s, potential range from 0.4 to 1.4 V and BRB as supporting electrolyte with pH 3. The developed sensor showed exceptional response for CBZ under the linear dynamic range from 5 to 100 μM. The limit of detection of proposed NiO/ZnO sensor for the CBZ was calculated to be 0.08 μM. The analytical approach of prepared electrochemical sensor was investigated in different pharmaceutical formulation with acceptable percent recoveries ranging from 96.7 to 98.6%.

Magnetic nanoparticles based on cerium MOF supported on the MWCNT as a fluorescence quenching sensor for determination of 6-mercaptopurine

In this study, a new magnetic nanocomposite was developed as an efficient and fast-response fluorescence quenching sensor for determination of anticancer drug 6-mercaptopurine (6-MP). For this purpose, the needle-shape fluorescence metal-organic framework of cerium (Ce-MOF) were successfully synthesized on the surface of multiwalled carbon nanotubes using 1,3,5-benzenetricarboxylic acid ligand via a facile solvothermal assisted route and magnetized. The accuracy of the proposed synthesis was confirmed using the FT-IR, FE-SEM, XRD, and VSM methods. The obtained product as presented the fluorescence emission in 331 nm by excitation of 293 nm in excitation/emission slit widths of 10.0 nm. The operation of suggested method is based on quenching the fluorescence signal in accordance with increasing the 6-MP concentration. The proposed assay effectively detected the trace amount of 6-MP in the linear range of 1.0 × 10^-6 to 7 × 10^-5 M. The limit of detection and limit of quantification were obtained as 8.6 × 10^-7 and 2.86 × 10^-6 M, respectively. The analyte molecule was determined in real samples with satisfactory recoveries between 98.75 and 105.33.

Ultrasensitive and highly selective "turn-on" fluorescent sensor for the detection and measurement of melatonin in juice samples

Melatonin (MLT), a hormone related to the regulation of brain functions, is directly related to sleep quality and is considered to be a possible adjuvant therapy for patients needing hospitalization for coronavirus disease 2019 pneumonia, and accurate measurement of MLT is crucial. Herein, a new, highly sensitive, and easy operation fluorescent probe was provided based on Zr metal-organic framework encapsulation into the molecularly imprinted polymer (MOF@MIP). By combining unique properties of MIP and fluorescent MOF, selectivity and operation of the applied method were significantly improved. Different characterization methods, such as XRD, FT-IR, and FE-SEM, were used to confirm the synthesis reliability. MOF@MIP was successfully used for the precise identification and ultrasensitive detection for trace amounts of MLT. The detection mechanism for the analytical system is based on the ''turn-on'' fluorescence (FL) signal in 404 nm. The findings proved that it is possible to detect trace amounts of MLT in real samples including grape, cherry, and sour cherry juice. The linear range and the limit of detection (LOD) for trace amounts of MLT were obtained as 1-100 ng/mL and 0.18 ng/mL, respectively.

New fabrication of CuFe2O4/PAMAM nanocomposites by an efficient removal performance for organic dyes: Kinetic study

Today, removing pollutants from water sources is essential because of the population increase and the growing need for safe drinking water. Dyes are one of the most critical pollutants from industrial effluents such as paper and textile industries that profoundly affect the environment. There are several ways to remove environmental contaminants. Magnetic nanoparticles have a high ability to adsorb dyes. Of course, increasing the interaction between magnetic nanomaterials and pollutants is also essential, which can be done using porous materials such as dendrimers. In this work, the synthesis of CuFe₂O₄ magnetite nanoparticles within the polyamidoamine dendrimers structure was used as an efficient sorbent to remove both alizarin reds (ARS) and brilliant green (BG) dyes. Moreover, various parameters for dyes removal were studied. The optimum removal conditions were obtained for ARS within 30 min at a sorbent dose of 2 mg per 5 mL for the initial dye concentration of 7.0 ppm in pH 6 at 25 °C, and for BG within 45 min at a sorbent dose of 5 mg per 5 mL for the initial dye concentration of 17.0 ppm in pH 8 at 25 °C. At the optimum values of the above parameters, both dyes' removal efficiency was more than 97%. Also, the obtained results showed that the adsorption isotherm follows the Langmuir model and Temkin model for ARS and BG, respectively. This method was successfully used for the removal of both dyes in water samples.

Change of Hemoglobin Level among Exclusively Breastfed Term and Preterm Babies up to Six Months of Age

There is progressive increase of Hb levels is observed during course of intrauterine development of fetus but high concentrations found at birth. In preterm neonate normal Hb is characteristically deviated from term neonate. Breast milk is the only natural ideal food for both term and preterm babies from birth up to 6 months. Preterm milk was found to contain significantly higher concentrations nutrients particularly iron than term milk. Preterm human milk is more suitable for the premature infant than term human milk. As Hb concentration varies in term and preterm babies in different counties in different feeding practices. The purpose of this longitudinal descriptive study is to find out the pattern of changes in the Hb level among exclusively breastfed preterm and term infants during the first six months of life. This study was carried in the Neonatal Intensive Care Unit (NICU), Mymensingh Medical College Hospital (MMCH), Mymensingh from September 2016 to February 2018. One hundred fifty (150) neonates both term and preterm were included in this study and followed up to 6 months of age. After admission informed written consent was taken from parents, thorough history taking and clinical examination were done. Data were collected in a pre-designed case record form. All the babies of Group A provided 2mg/kg iron supplementation from 6 weeks for 2 months for universal recommendation. Hb level was measured of all exclusively breast feed babies at admission after birth then next follow-up at 6 weeks, 3 months and 6 months. All information regarding history, anthropometrics measurement, Hb level was recorded in structural questionnaire. Data analysis was done by SPSS version 20.0. Male were predominant in both groups. Most of the preterm (72.0%) and term babies (65.3%) were delivered by vaginal route. Mean Hb level was found significantly higher among preterm babies than term babies after birth were 16.55g/dl and 15.98g/dl respectively. Sharp fall of Hb concentration was observed after birth up to 6 weeks in both preterm and term babies but Hb level was found significantly lower in preterm in comparison to term babies (9.27gm/dl vs. 9.58gm/dl). In term babies, even after 6 weeks fall of Hb level continued to 3 months of age followed by gradual increase up to 6 months without iron supplementation. Hb level of in preterm babies gradually increased from 6 weeks up to 6 months with universal iron supplementation. Hb level fall sharply up to 6 weeks in both exclusively breastfed term and preterm babies but even after 6 weeks term babies experienced gradual fall of Hb levels up to 3 months. Hb level increases in exclusively breast-fed term babies without iron supplementation from 3 months of age. Hb level in exclusively breastfed preterm babies increase from 6 weeks onward might be effect of universal iron supplementation.

Overweight and Obesity among Children of Primary Schools of Mymensingh Municipal Area

Obesity is now recognized as a major cause of morbidity and mortality throughout the world. The relative percentage of change is higher in developing countries. Childhood obesity has become a serious public health emerging problem because of its strong association with adulthood obesity and related adverse health consequences. The main objective of the study was to find out the status of overweight and obesity among primary school children of Mymensingh municipal area. This cross sectional descriptive study was carried out among primary school children of Mymensingh municipal area from September 2016 to February 2018. Total 1450 students were enrolled from 6 schools. Schools were selected by random lottery method. Data was collected in predesigned case record forms by investigator with the help of students, teachers and parents. Anthropometry was measured by principal investigator. Body mass index (BMI) was calculated and plotted by using Center for disease control (CDC) BMI growth charts for age and sex. Children were categorized as obese, overweight, normal and underweight. Data analysis was done by computer software SPSS version 20.0. Mean age of children was 9.0±1.124 years. There was 47.4% male and 52.6% female. Among the 1450 children 18.6% obese, 17.5% overweight, 53.5% normal and 10.4% underweight. So, total 36.1% children had BMI above normal limit. Obesity was found more common among male children (p<0.001). Obesity and overweight was significantly associated with fast food consumption (p<0.001), playing computer and mobile games (p<0.001), watching TV (p<0.001), higher parent's education (p<0.001), higher parent's income (p<0.001), service holder father (p<0.001), family history of overweight or obesity (p<0.001), single child in family (p<0.001) and increased birth weight (p<0.001). A large number of primary school children in Mymensingh municipal area were overweight and obese. Childhood obesity and overweight varies from school to school. Childhood obesity and overweight is an emerging and growing health issue in municipal area.

Action mechanisms and biocontrol of Purpureocillium lilacinum against green mould caused by Penicillium digitatum in orange fruit

AIMS

The present study evaluated, for the first time, the inhibitory effects of the filtrate of Purpureocillium lilacinum against Penicillium digitatum.

METHODS AND RESULTS

No direct contact between P. lilacinum and P. digitatum was observed during the dual culture test and the inhibition zone was 6·1 mm. The filtrate of P. lilacinum completely inhibited P. digitatum growth and spore germination at the concentration of 64%. The filtrate increased the permeability of the cell membrane and the content of MDA in P. digitatum. The ergosterol content in P. digitatum was strongly inhibited at 32% by 81·1%. The green mould incidence and severity in filtrate-treated fruit at 64% were 71·7 and 80·7% lower than in the control, respectively. The filtrate enhanced the activity of PAL, PPO and POD enzymes in orange fruit. The POD and PAL gene expression levels were significantly upregulated in the fruit treated with the filtrate.

CONCLUSIONS

This study indicated that the antifungal mechanism of P. lilacinum filtrate against P. digitatum is mainly by the damage of the fungal cell membrane and its components.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work provides the pioneer evidence on the application of P. lilacinum filtrate as a novel biocontrol agent for orange green mould.

Hand Sewn versus Stapled Closure of Duodenal Stump after Gastric Resection

This prospective comparative study was done to compare the outcome of stapled closure of the duodenal stump with hand-sewn closure during gastric resection in terms of total operating time, postoperative duodenal stump leakage, postoperative hospital stay, and surgical cost. This study was conducted from January 2013 to August 2014. Patients who were admitted to the Department of Surgery, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh with the indication of distal or total gastrectomy were included in the study. A total of 32 patients were enrolled in this study with 16 in each group, they were divided either into Group I (Hand Sewn) or Group II (stapling). Mean±SD age of Group I was 53.38±8.69 and Group II was 50.88±9.56 (p=0.445). Male patients were predominant than the female with a male: female ratio being 3.57:1. Mean±SD total operating time was 154.38±16.32 minutes and 136.88±17.40 minutes in Group I and Group II respectively (p=0.001). In Group I, 2(12.5%) patients and in Group II, 1(6.3%) patient had duodenal stump leakage which showed no statistically significant difference (p=0.999). Postoperative hospital stay had no statistically significant difference (p=0.923). The surgical cost had a significant difference (p=0.001) which is more in Group II. This study showed there was a significant reduction in total operating time but there was no significant difference in occurring of duodenal stump leakage or postoperative hospital stay. However, use of stapler hastens the surgeon's job and it relieves extra pressure of them.

A hierarchical 3D camellia-like molybdenum tungsten disulfide architectures for the determination of morphine and tramadol

A practical technique was applied to fabricate MoWS₂ nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. The characterization of MoWS₂ nanocomposite was investigated by several techniques to identify the size, crystal structure, and elemental composition. MoWS₂ nanocomposite exhibited a unique and well-defined hierarchical structure with neatly and densely piled nanopetals acting as the active sites in the electrocatalytic reactions. A carbon screen-printed electrode (CSPE) modified with interesting MoWS₂ nanopetals (MoWS₂/CSPE) was constructed. Subsequently, the electrochemical oxidation of morphine on fabricated MoWS₂/CSPE was studied. Experimental results confirm that under optimized conditions, the maximum oxidation current of morphine occurs at 275 mV in the case of MoWS₂/CSPE that is around 100 mV more negative than that observed in the case of the unmodified CSPE and about 2.6 times increase was observed for the oxidation peak current. The analytical approach was obtained by differential pulse voltammetry in accordance with the relationship between the oxidation peak current and the morphine concentration. The oxidation peak currents for morphine were found to vary linearly with its concentrations in the range of 4.8 × 10^-8-5.05 × 10^-4 M with the detection limit of 1.44 × 10^-8 M. Two completely separated signals occured at the potentials of 275 mV and 920 mV for oxidation of morphine and tramadol at the surface of MoWS₂/CSPE which are sufficient for determination of morphine in the presence of tramadol. The presence of morphine was also detected in real samples using the introduced approach. Graphical abstract Schematic representation of fabrication of the MoWS₂ nanocomposite through a one-pot hydrothermal method for use as the electrocatalyst. A carbon screen-printed electrode was modified with MoWS₂ nanocomposite. Subsequently, the electrochemical oxidation of morphine on the fabricated electrode was studied.

Fluorescence detection of laccases activity by the photoinduced electron transfer (PET) process

Laccases play a vital role in some physiological processes, for example in morphogenesis, carbon cycle, and defense against parasitism. So, designing a high-sensitivity accurate method is essential for researchers. In this study, a simple fluorescence method based on the function of carbon nitride (g-C₃N₄) by dopamine is synthesized. For the design of this sensor, carbon nitride (g-C₃N₄) is initially synthesis by using a simple method, which is carried out by heating melamine at 550 °C for 3 h and modifying it with dopamine by a linker such as glutaraldehyde. However, the g-C₃N₄-Dopa produced by this method, with an excitation wavelength of 330 nm, has a fluorescence emission at 466 nm. When laccase and g-C₃N₄-Dopa were mixed, dopamine with redox property was oxidized to dopaquinone; this causes the phenomenon of photoinduced electron transfer (PET) process between g-C₃N₄ and the dopaquinone. Hence, fluorescence quenching occurs due to this phenomenon. As a result of these discussions, a sensor for the laccase activity was designed based on the fluorescence quenching degree, supporting a linear range of 0.0-400.0 U L^-1 with the detection limit of 2.0 U L^-1. Using this sensor, the activity of the laccase enzyme in the human serum samples is measured. Dopamine-functionalized carbon nitride was prepared and utilized for the highly sensitive detection of laccases activity.

Determination of Trace Amounts of Zinc by Flame Atomic Absorption Spectrometry After Preconcentration with Modified Clinoptilolite Zeolite

Natural clinoptilolite was used as a sorbent material for solid-phase extraction and preconcentration of zinc. Clinoptilolite was first saturated with cadmium (II) and then modified with benzyldimethyltetradecylammonium chloride for increasing adsorption of 3-(2-arsenophenylazo)-4,5-dihydroxy-2,7-naphthalene disulfonic acid (neothorin). Zinc was quantitatively retained on the adsorbent by the column method in the pH range of 3.84.2 at a flow rate of 1 mL/min. It was eluted from the column with 5.0 mL 2 M nitric acid solution at a flow rate of 1 mL/min and determined by flame atomic absorption spectrometry at 213.9 nm. Zinc could be concentrated from a 0.03 g/L solution with a preconcentration factor of 170. Relative standard deviation for 8 replicate determinations of 2.5 g zinc in the final solution was 0.92. The interference of a large number of anions and cations was studied in detail to optimize the conditions, and the method was successfully applied for determination of zinc in standard and real water samples.

A New Method for Application of the Water-Soluble Dye SPADNS in a Carbon Paste Electrode for Determination of Trace Amounts of Copper

2-(P-sulfophenylazo)-1,8-dihydroxy-3,6-naphthalene disulfate (SPADNS) was adsorbed on surfactant modified zeolite type A by electrostatic interaction in the aqueous phase. The dye was strongly retained and not easily leached from the surfactant-modified zeolite matrix. This compound was incorporated into a carbon paste electrode for anodic stripping voltammetric determination of trace amounts of copper. The calibration plot was linear over the copper concentration range 2.0800 g/L. The detection limit was found to be 0.4 g/L Cu(II), and for 5 successive determinations of 50 and 150 g/L Cu(II) the relative standard deviations were 1.6 and 1.2, respectively. The modified electrode prepared in this study could be used for the determination of Cu(II) in water samples and human hair with good results.

Determination of Trace Amounts of Nickel, Manganese, Cobalt, and Zinc in Environmental Samples After Separation and Preconcentration by Use of Polyacrylic Acid/Alumina Sorbent

Manganese, nickel, cobalt, and zinc are elements that appear together in many real samples. In this work, a simple, rapid, and sensitive method has been used for the simultaneous separation and preconcentration of trace amounts of these elements using water-soluble polyacrylic acid on alumina as a sorbent in a glass column system. A solution containing Mn, Ni, Co, and Zn was passed through the column at pH 7, and desorption was carried with 5.0 mL of 0.03 M nitric acid. Linearity was maintained between 0.255.0 103, 0.046.0 103, 0.108.0 103, and 0.0281.0 103 ng/mL for Ni, Mn, Co, and Zn, respectively, in the original solution. Eight replicate determinations of a mixture containing 1.0 g/mL of each of the elements in the final solution gave relative standard deviations of 1.4, 1.5, 2.4, and 1.2 for Ni, Mn, Co, and Zn, respectively. The sorption capacities for Mn (mg/g sorbent) obtained were 16.0 for Mn, 9.0 for Ni, 12.0 for Co, and 10.0 for Zn. By using 5.0 mL elution solution, preconcentration factors of 400, 500, 700, and 460 could be obtained for Ni, Mn, Zn, and Co, respectively.

Simultaneous Determination of Nickel and Copper by H-Point Standard Addition MethodFirst-Order Derivative Spectrophotometry in Plant Samples After Separation and Preconcentration on Modified Natural Clinoptilolite as a New Sorbent

For the simultaneous determination of nickel(II) and copper(II) in plant samples, a rapid and accurate method was developed. In this method, solid-phase extraction (SPE) and first-order derivative spectrophotometry (FDS) are combined, and the result is coupled with the H-point standard addition method (HPSAM). Compared with normal spectrophotometry, derivative spectrophotometry offers the advantages of increased selectivity and sensitivity. As there is no need for carrying out any pretreatment of the sample, the spectrophotometry method is easy, but because of a high detection limit, it is not so practical. In order to decrease the detection limit, it is suggested to combine spectrophotometry with a preconcentration method such as SPE. In the present work, after separation and preconcentration of Ni(II) and Cu(II) on modified clinoptilolite zeolite that is loaded with 2-[1-(2-hydroxy-5-sulforphenyl)-3-phenyl-5-formazano]-benzoic acid monosodium salt (zincon) as a selective chromogenic reagent, FDS-HPSAM, which is a simple and selective spectrophotometric method, has been applied for simultaneous determination of these ions.With optimum conditions, the detection limit in original solutions is 0.7 and 0.5 ng/mL, respectively, for nickel and copper. The linear concentration ranges in the proposed method for nickel and copper ions in original solutions are 1.1 to 3.0 103 and 0.9 to 2.0 103 ng/mL, respectively. The recommended procedure is applied to successful determination of Cu(II) and Ni(II) in standard and real samples.

Separation and Preconcentration of Trace Amounts of Gold(III) Ions Using Modified Multiwalled Carbon Nanotube Sorbent Prior to Flame Atomic Absorption Spectrometry Determination

Multiwalled carbon nanotubes are attractive as sorbents for SPE because they can be used for enrichment of organic compounds and metal ions at trace levels. In this study, multiwalled carbon nanotubes were oxidized with concentrated HNO3, and then the oxidized multiwalled carbon nanotubes were modified with 5-(4-dimethylaminobenzyliden)-rhodanine. The modified multiwalled carbon nanotubes were used as a solid sorbent for separation and preconcentration of trace amounts of Au(III) ions. The sorption of Au(III) ions was quantitative in the pH range of 2.05.0, whereas quantitative desorption occurred instantaneously with 5.0 mL 2.0 M Na2S2O3. The eluted solution was aspirated directly into the flame for atomic absorption spectrometry. The proposed method resulted in an enrichment factor of 94. The RSD of the method was 1.11 (n = 10, 2.0 g/mL) and the LOD was 0.15 ng/mL. The calibration curve for Au(III) was linear between 0.53 ng/mL and 36.0 g/mL in the initial solution, with an R2 value of 0.9999. The sorbent capacity of the modified multiwalled carbon nanotubes was 7.3 mg Au(III)/g sorbent. The influences of the experimental parameters, including sample pH, sample flow rate, eluent volume and flow rate, sample volume, and interference of some ions on the recoveries of the Au ions, were investigated. The proposed method was applied for preconcentration and determination of Au in different samples.

Determination of Trace Amounts of Lead and Manganese in Water Samples After Simultaneous Preconcentration onto Modified Amberlite XAD-4 Resin

A procedure for simultaneous separation and preconcentration of trace amounts of manganese and lead has been proposed. It is based on the adsorption of manganese and lead ions onto a column of Amberlite XAD-4 resin loaded with pyrocatechol reagent. Manganese and lead were quantitatively retained on the column in the pH range 4.06.5 at a flow rate of 2 mL/min. The manganese and lead ions were eluted with 5.0 mL of 4 M HNO3 solutions. Manganese and lead were measured by flame atomic absorption spectrometry. In this case, 100.0 ng manganese and 1000.0 ng lead were concentrated in the column from 800 mL of aqueous sample, where their concentrations were as low as 0.125 and 1.25 ng/mL, respectively. Seven replicate determinations of mixtures of 1.0 g/mL manganese and 2.0 g/mL lead in the final solution gave a mean absorbance of 0.1926 and 0.0832 with RSD values of 1.1 and 1.2, respectively. The LODs were 1.76 ng/mL for Mn(II) and 37.28 ng/mL for Pb(II) (3bl/m) in the final solution, with a preconcentration factor of 160. Sensitivities for 1 absorbance for Mn(II) and Pb(II) were 7.0 and 74.7 ng/mL, respectively. The interference of a large number of anions and cations has been studied and the optimized conditions were used for determination of trace amounts of manganese and lead in various environmental and standard samples.

Facile synthesis and characterization of magnetic nanocomposite ZnO/CoFe2O4 hetero-structure for rapid photocatalytic degradation of imidacloprid

This work has attempted to investigate the potential of ZnO/CoFe₂O₄ magnetic nanocomposite to mineralize imidacloprid completely to have sustainable pollutant free and safe water supply. The co-precipitation method was performed to prepare the composites; was performed to characterize composites, scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive x-ray crystallography (EDX), x-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and vibrating sample magnetometer (VSM). It was attempted to explore and enhance parameters influencing the process and the percentage of imidacloprid degradation, including photocatalyst amount, pesticide concentration, pH, radiation time, and temperature. UV-Vis spectrophotometer was used for the degradation percent of organochlorine pesticides. Parameters affecting the process, including photocatalyst amount, pesticide concentration, pH, radiation time, and temperature effect on the percentage of imidacloprid degradation were Investigated and optimized. 0.05 g of photocatalyst, with a concentration of 5 ppm for 45 min under light exposure was obtained at pH 10 at room temperature.

Flame Atomic Absorption Spectrometric Determination of Trace Amounts of Nickel after Extraction and Preconcentration onto Natural Modified Analcime Zeolite Loaded with 2-(5-Bromo-2-Pyridylazo)-5-Diethylaminophenol

Nickel is a moderately toxic element compared with other transition metals. However, inhalation of nickel and its compounds leads to serious problems, including cancer of the respiratory system and a skin disorder, nickel-eczema. Thus, attention has focused on the toxicity of nickel at low concentrations, and the development of reliable, analytical approaches for the determination of trace amounts of nickel is needed. This paper describes a simple, rapid, and sensitive flame atomic absorption spectrometric method for the determination of trace amounts of nickel in various samples after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex on a modified Analcime column in the pH range of 7.5–10.5. The retained analyte on the Analcime is recovered with 5.0 mL 2M nitric acid and determined by flame atomic absorption spectrometry. The detection limit is 20 ng/mL, and the calibration curve is linear for analyte concentrations in the range of 0.1–8 μg/mL final solution, with a correlation coefficient of 0.9993. Eight replicate determinations of nickel at 2 μg/mL in the final solution gave an absorbance of 0.1222, with a relative standard deviation (RSD) of ±1.2%. The interference of a large number of anions and cations was studied, and the proposed method was used for the determination of nickel in various standard reference samples. The accuracy of the proposed method was evaluated by analyzing standard reference samples, and the results were satisfactory (recoveries of &gt;96%; RSD of &lt;3.5%).

Determination of Trace Levels of Manganese in Various Biological and Environmental Samples by Atomic Absorption Spectrometry after Solid–Liquid Extraction and Preconcentration with the Ion Pair Formed by the Nitroso-S Anion and the Tetradecyldimethylbenzylammonium Cation

Manganese is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium (TDBA) chloride on microcrystalline naphthalene in the pH range 9.5–10.6 from large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of the manganese complex and naphthalene is dissolved in 5 mL dimethylformamide and the metal is determined by flame atomic absorption spectrometry. Alternatively, the manganese complex can be quantitatively adsorbed on TDBA–naphthalene adsorbent packed in a column and determined similarly. About 0.2 μg manganese can be concentrated in a column from 400 mL aqueous sample with a concentration as low as 0.5 ng/mL. Eight replicate determinations of manganese at 0.8 μg/mL gave a mean absorbance of 0.156 for the final solution with a relative standard deviation of 1.4%. The sensitivity for 1% absorption was 23 ng/mL. The interference of a large number of anions and cations was studied, and the optimized conditions developed were used for trace determinations of manganese in various alloys, and in biological and environmental samples.

A catechol biosensor based on immobilizing laccase to Fe3O4@Au core-shell nanoparticles

This work is directed towards the synthesis of the magnetic nanoparticle in a core and a gold shell with immobilized of laccase on its surface (Fe₃O₄@Au@ Lac). The prepared Fe₃O₄@Au@ Lac core/shell nanoparticles are characterized by means TEM, SEM, DLS, zeta potential, UV-Vis, and TGA. Meanwhile, as an example of the applications, Biosensor activity was investigated by using the oxidation of catechol and recording the UV-Vis absorption in the 402 nm wavelength. The biosensor also demonstrated optimum activity at pH 5.0, reaction time at 40 min, and 35 mg the amount of biosensor. Linear response in the catechol concentration range of 5.0-70.0 μM. The limit of detection and the apparent Michaels-Menten constant (K_m) of the biosensor were 2 μM and 15 μM respectively.

Extra Skeletal Ewing's Sarcoma Involving Perineum of a Young Male Patient

Ewing's Sarcoma is the second most common primary malignant bone tumor in children and young adults after osteosarcoma but exceptionally it can arise from extra skeletal sites also. Extra skeletal Ewing's sarcoma is of neuroectodermal origin and usually involves extremities, retroperitoneum and paravertebral regions. No case of extra skeletal Ewing's sarcoma involving perineum is yet reported. A 16 years old male patient admitted to colorectal surgery department of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh in July 2015 having swellings in perineum as well as both inguinal regions. The swelling was near to anal verge. FNAC from perineal swelling and inguinal lymph node demonstrate small blue round cell tumor. After operation the tumor size was 5cm×4cm, cell type was malignant round cell arranged in sheet and perivascular forming rosette. Extra skeletal Ewing's sarcoma can be a differential diagnosis of soft tissue tumor arising in perineum.

Synthesis, characterization and application of a MnFe2O4@poly(o-toluidine) nanocomposite for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons

A nanocomposite of poly(o-toluidine)-coated MnFe₂O₄ magnetic nanoparticles with a core–shell structure was synthesized by the chemical co-precipitation method and employed as a magnetic adsorbent for solid-phase extraction of ten polycyclic aromatic hydrocarbons (PAHs).

A Zn based metal organic framework nanocomposite: synthesis, characterization and application for preconcentration of cadmium prior to its determination by FAAS

The SEM image of a synthesized metal–organic framework (MOF) with Zn and benzene-1,3-dicarboxylic acid via hydrothermal method as a selective nanoadsorbent for the preconcentration of trace amount of cadmium via SPE method and determination by FAAS.

Synthesis and application of a novel nanostructured ion-imprinted polymer for the preconcentration and determination of thallium(I) ions in water samples

A novel synthesized nanostructured ion-imprinted polymer (IIP) was investigated for the determination of trace amount of thallium(I). For this purpose, the thallium(I) IIP particles were synthesized using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, methyl-2-[2-(2-2-[2-(methoxycarbonyl) phenoxy] ethoxyethoxy) ethoxy] benzoate as the chelating agent and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The prepared IIP particles were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA). Various experimental factors such as pH, the amount of IIP particles, sorption and desorption time, sample volume, elution condition, and potentially interfering ions systematically examined. Under the optimum conditions, a sensitive response to Tl(I) within a wide concentration range (0.05-18 μg L(-1)) was achieved. The limit of detection (LOD, 3Sb/m) was 6.3 ng L(-1). The maximum adsorption capacity of the novel imprinted adsorbent for Tl(I) was calculated to be 18.3 mg g(-1). The relative standard deviation (RSD) for eight replicate detections of 0.1 μg L(-1) of thallium(I) was found to be 4.0%. An enrichment factor (EF) of 100 was obtained by this method. The proposed technique was successfully applied to monitoring thallium in different water samples and the certified reference material.