Electrochemical Dopamine Sensors Based on Graphene

Rahman, Md. Mahbubur,Lee, Jae-Joon The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.2

The large surface area and the high electrical conductivity of graphene (GP) allow it to act as an "electron wire" between the redox center of biomolecules and an electrode surface. The faster electron transfer kinetics and excellent catalytic activity of GP facilitate the accurate and selective electrochemical detection of biomolecules. This mini-review provides an overview of the recent developments and progress of GP, functionalized or doped GP, and GP-composites based sensors for the selective and interference-free detection of dopamine (DA). The electrochemical principles and future perspective and challenges of DA sensors were also discussed based on GP.

Natural vs synchronized estrus : determinants of successful pregnancy in ewes using frozen-thawed Suffolk semen

Md. Mahbubur Rahman,Nazmun Naher,Md. Mofijul Isam,Moinul Hasan,Farhana Naznin,Mohammad Musharraf Uddin Bhuiyan,Farida Yeasmin Bari,Nasrin Sultana Juyena 한국동물생명공학회(구 한국동물번식학회) 2020 Journal of Animal Reproduction and Biotechnology Vol.35 No.2

The pregnancy rate in indigenous ewes inseminated with frozen-thawed Suffolk semen following natural and synchronized estrus was determined. The serum Progesterone and Estrogen concentration and vaginal electrical resistance (VER) of ewes at the time of Artificial Insemination (AI) were observed as successful pregnancy determinants. 21 healthy ewes were selected for this experiment during January-April, 2017. 10 ewes were inseminated in natural estrus. Whereas, 11 ewes were inseminated after estrus synchronization using intravaginal sponges containing 60 mg medroxyprogesterone acetate. Trans-cervical Al (TCAI) was performed in all ewes within 12-16 hours of observed heat. Prostaglandin E1 analogue impregnated vaginal sponge was used for cervical relaxation 6-8 hours before insemination. Pregnancy was diagnosed through trans-abdominal ultrasonography after 40 days of AI. The pregnancy rate of ewes in synchronized estrus was higher (54.5%) than in natural estrus (30%). Higher serum Progesterone level (0.90 ± 0.02 ng/mL) and significantly (p < 0.001) lower VER (257.78 ± 10.11 ohm) were observed at the time of AI in ewes becoming pregnant. Results suggest that higher Progesterone concentration and lower VER could be considered as pregnancy indicators. Oestrous synchronization could be implemented to increase the pregnancy rate in ewes.

Ensuring Quality in Biometric Systems

Md. Mahbubur Rahman,Amit Karmaker,Md.Mahmudul Hasan,Samsuddin Ahmed 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.4

Biometric system is using for personal recognition of people in many social and economical activities now a days. A good biometric trait should be measurable, distinctive and stable over time. Real-world deployment of biometric systems often has to contend with degraded signal quality and erratic behavior of the biometric data. For last few years biometric data quality measure become an important concern after poor pathological sample and other many causes. The user, sensor and environmental facts are causes to quality degradation of biometric system. This study approaches that have been used to extract additional information about the biometric data that can then be used to improve performance in degraded conditions and also discuss about the sensor and environmental facts .This study will also discuss how this problem can be overcome to maintain the quality in biometric system with a special emphasis on face, fingerprint, iris modalities with different organizational standards.

Effect of Titanium Nanorods in the Photoelectrode on the Efficiency of Dye Sensitized Solar Cells

Rahman, Md. Mahbubur,Kim, Hyun-Yong,Jeon, Young-Deok,Jung, In-Soo,Noh, Kwang-Mo,Lee, Jae-Joon Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

The effect of $TiO_2$ nanorods (TNR) and nanoparticles (TNP) composite photoelectrodes and the role of TNR to enhance the energy conversion efficiency in dye-sensitized solar cells (DSSCs) was investigated. The 5% TNR content into the TNP photoelectrode significantly increased the short-circuit current density ($J_{sc}$) and the open-circuit potential ($V_{oc}$) with the overall energy conversion efficiency enhancement of 13.6% compared to the pure TNP photoelectrode. From the photochemical and impedemetric analysis, the increased $J_{sc}$ and $V_{oc}$ for the 5% TNR/TNP composite photoelectrode was attributed to the scattering effect of TNR, reduced electron diffusion path and the suppression of charge recombination between the composite photoelectrode and electrolyte or dye.

Electrodeposition of Gold on Fluorine-Doped Tin Oxide: Characterization and Application for Catalytic Oxidation of Nitrite

Rahman, Md. Mahbubur,Li, Xiao-Bo,Lopa, Nasrin Siraj,Lee, Jae-Joon Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.7

Sub-micrometer size gold particles were electrodeposited on a transparent fluorine-doped tin oxide (FTO) from acetonitrile solution containing $AuCl_4{^-}$ and tetramethylammonium tetraflouroborate (TMATFB) for detecting $NO_2{^-}$. A series of two-electron ($2e^-$) and one-electron ($1e^-$) reductions of the $AuCl_4{^-}-AuCl_2{^-}-Au$ redox systems were observed at FTO and a highly stable and homogeneous distribution of Au on FTO (Au/FTO) was obtained by stepping the potential from 0 to -0.55 V (vs. Ag/$Ag^+$). The Au/FTO electrode exhibited sufficiently high catalytic activity toward the oxidation of $NO_2{^-}$ with a detection limit (S/N = 3) and sensitivity of 2.95 ${\mu}M$ and 223.4 ${\mu}A{\cdot}cm^{-2}{\cdot}mM^{-1}$, respectively, under optimal conditions. It exhibited an interference-free signal for $NO_2{^-}$ detection with excellent recoveries from real samples.

Relationships between blood Mg2+ and energy metabolites/enzymes after acute exhaustive swimming exercise in rats.

Rahman, Md Mahbubur,Lee, Sei-Jin,Mun, A-Reum,Adam, Gareeballah Osman,Park, Ra-Mi,Kim, Gi-Beum,Kang, Hyung-Sub,Kim, Jin-Shang,Kim, Shang-Jin,Kim, Sung-Zoo Humana Press 2014 Biological trace element research Vol.161 No.1

<P>Magnesium (Mg) plays a central role in neuronal activity, cardiac excitability, neuromuscular transmission, muscular contraction, vasomotor tone, and blood pressure, all of which are significantly related to physical performance. To date, the available data about detection of blood total Mg (tMg; free-ionized, protein-bound, and anion-complex forms) are inconsistent, and there is limited information on blood free-ionized Mg (Mg(2+)) in relation to physical exercise. The aim of this study was to determine the biochemical changes related to energy metabolism after acute exhaustive swimming exercise (AESE) in rats in an attempt to correlate the role of blood Mg(2+) with metabolites/enzymes related to energy production. After AESE, blood Mg(2+), tMg, K(+), partial pressure of carbon dioxide, lactate, total protein (T-PRO), high-density lipoprotein (HDL), creatinine (CRE), blood urea nitrogen (BUN), uric acid (UA), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alanine phosphatase (ALP), lactate dehydrogenase (LDH), and creatinine kinase (CK) were significantly increased, whereas pH, partial pressure of oxygen, oxygen saturation, the Mg(2+)/tMg and Ca(2+)/Mg(2+) ratios, HCO3 (-), glucose, triglyceride (TG), and low-density lipoprotein (LDL) were significantly decreased. During AESE, lactate, T-PRO, albumin, AST, ALP, LDH, CK, CRE, BUN, and UA showed significant positive correlations with changes in blood Mg(2+), while glucose, TG, and LDL correlated to Mg(2+) in a negative manner. In conclusion, AESE induced increases in both blood Mg(2+) and tMg, accompanied by changes in blood metabolites and enzymes related to energy metabolism due to increased metabolic demands and mechanical damages.</P>

A Conducting Poly(N-(1-Naphthyl)ethylenediamine dihydrochloride) Nanofibers for the Sensitive and Interference-Free Detection of Dopamine

Rahman, Md. Mahbubur,Ahmed, Arif,Lee, Jae-Joon The Electrochemical Society 2018 Journal of the Electrochemical Society Vol.165 No.3

<P>This research demonstrated the development of a stable, sensitive, and selective electrochemical method based on poly(N-(1-Naphthyl) ethylenediamine dihydrochloride) nanofibers-modified anodized glassy carbon electrode (PNEDA/AGCE) for the detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). The PNEDA/AGCE sensor could easily separate the oxidation signals of AA, DA, and UA from their mixture solution in PBS (pH 7.0). It showed linear behavior over wide concentration ranges for DA sensing and the detection limits were ca. 0.070 and 0.075 mu M in PBS (pH 7.0) and diluted human serum samples respectively, while the sensitivities were ca. 0.085 and 0.080 mu A.mu M-1, respectively. The high sensitivity for the PNEDA/AGCE sensor can be ascribed to the facile H-bonding interaction between the free -NH2 groups of PNEDA and oxidizable -OH groups of DA, which was verified by Gradient-corrected density functional theory (DFT) calculation. The PNEDA/AGCE sensor showed excellent repeatability and reproducibility with very low RSD (%) and excellent recoveries of DA concentrations in human serum samples. (C) 2018 The Electrochemical Society.</P>

An accidental fatal attack on domestic pigeons by honey bees in Bangladesh

RAHMAN, Md. Mahbubur,LEE, Sei-Jin,KIM, Gi-Beum,YANG, Dong Kwon,ALAM, Md. Rafiqul,KIM, Shang-Jin The Japanese Society of Veterinary Science 2015 The Journal of veterinary medical science Vol.77 No.11

<P>Fatalities among avian species due to multiple bee stings are rare. Sixteen pigeons on a farm in Bangladesh each suffered multiple bee stings. Ten of the pigeons died before treatment, 5 (4–11 stings) died within 12 hr after treatment, and 1 pigeon (only 3 stings) survived. Body temperature, heart rate, respiratory rate, hematocrit, hemoglobin, erythrocytes, thrombocytes, MCV, MCH and MCHC decreased significantly after the incident, but leucocytes, heterophils, basophils, eosinophils, monocytes, ALT, AST, LDH, CK, creatinine, BUN and UA increased markedly. Overall, the hematological and biochemical changes in the bee-stung pigeons were similar to those of mammals; however, avian species may be more sensitive to bee stings than mammals.</P>

Low-Temperature Chemical Sintered TiO₂ Photoanodes Based on a Binary Liquid Mixture for Flexible Dye-Sensitized Solar Cells

Md. Mahbubur, Rahman,Hyeong Cheol, Kang,Kicheon, Yoo,Jae-Joon, Lee The Korean Electrochemical Society 2022 Journal of electrochemical science and technology Vol.13 No.4

A chemically sintered and binder-free paste of TiO₂ nanoparticles (NPs) was prepared using a binary-liquid mixture of 1-octanol and CCl₄. The 1:1 (v/v) complex of CCl₄ and 1-octanol easily interacted chemically with the TiO₂ NPs and induced the formation of a highly viscous paste. The as-prepared binary-liquid paste (P_BL)-based TiO₂ film exhibited the complete removal of the binary-liquid and residuals with the subsequent low-temperature sintering (~150℃) and UV-O₃ treatment. This facilitated the fabrication of TiO₂ photoanodes for flexible dye-sensitized solar cells (f-DSSCs). For comparison purposes, pure 1-octanol-based TiO₂ paste (P_O) with moderate viscosity was prepared. The P_BL-based TiO₂ film exhibited strong adhesion and high mechanical stability with the conducting oxide coated glass and plastic substrates compared to the P_O-based film. The corresponding low-temperature sintered P_BL-based f-DSSC showed a power conversion efficiency (PCE) of 3.5%, while it was 2.0% for P_O-based f-DSSC. The P_BL-based low- and high-temperature (500℃) sintered glass-based rigid DSSCs exhibited the PCE of 6.0 and 6.3%, respectively, while this value was 7.1% for a 500℃ sintered rigid DSSC based on a commercial (or conventional) paste.

Prevalence of Ruminal Lactic Acidosis and Clinical Assessments of Four Therapeutics in Goats of Bangladesh

Md Mahbubur Rahman,Mohammad Saiful Islam,Adam G.O,Md. Rafiqul Alam,유명조 한국임상수의학회 2014 한국임상수의학회지 Vol.31 No.3

Acidosis conditions either acute or chronic following ingestion of excessive amounts of readily fermentedcarbohydrate are great production problems for goat in Bangladesh. This study designed to investigate the prevalenceof lactic acidosis and then response to different therapeutic agents. For this purpose, 1,128 goat were examined atoutdoor District Veterinary Hospital, Faridpur, Bangladseh for treatment of which 40 goats were found positive forlactic acidosis showing 3.55% prevalence of disease. The highest occurrence found in female (4.64%) of over 3 yearsage (4.64%) in indigenous goat (2.7%). For therapeutic assessment the forty affected goats were divided into fourgroups A, B, C and D comprising of 10 animals each. Group A were given magnesium hydroxide 8% w/v at 1 g/kg body weight orally. In group B magnesium hydroxide 8% w/v at a dose as group A combination with 7.5% sodiumbicarbonate at the rate of 0.9 ml/Kg body weight intravenously administered. Goat in group D were treated with mixtureof ginger, nuxvomica, sodium carbonate, cobalt sulphate, dried ferrous sulphate and thiamin mononitrate at the rateof 1 g/kg body weight orally. Goat of group C treated with combination drugs of group A, B and D. The rectaltemperature, pulse rate, respiration rate, was performed before and after treatment. It was found that the highest recoveryin group C with an average period of 21 ± 1.8 hours. It was concluded that lactic acidosis is a common disease ofgoats and its severity can be effectively reduced by using combination drugs.