Graphene oxide synthesis using a top–down approach and discrete characterization techniques: a holistic review

Abdullah Anwar,Chang Ta-Peng,Chen Chun-Tao 한국탄소학회 2022 Carbon Letters Vol.32 No.1

The remarkable electrical, thermal, mechanical, and optical properties of graphene and its derivative grapheme oxide have recently gained great importance, along with the large surface area and single-atoms thickness. In this respect, several techniques of synthesis such as chemical exfoliation, mechanical exfoliation, or chemical synthesis have been discovered. However, the development of graphene with fewer defects and on a large scale poses major challenges; therefore, it is increasingly necessary to produce it in large proportions with high quality. This paper reviews the top-down synthesis approach of graphene and its well-known derivative graphene oxide. Furthermore, characterization of graphene oxide nanomaterial is a critical component of the analysis. The characterization techniques employed to determine the quality, defects intensity, number of layers, and structures for graphene oxide nanomaterial at the atomic scale. This article focuses on the different involved characterization methodology for graphene oxide with their percentage utilization for the past 11 years. Additionally, reviewing all of the characterization literature for the last 11 years would be a difficult task. Therefore, the aim is to outline the existing state of graphene oxide by different characterization techniques and provide a comparative analysis based on their percentage utilization.

Comparison of normal saline solution with low-chloride solutions in renal transplants: a meta-analysis

( Abdullah Jahangir ),( Syeda Sahra ),( Muhammad Rafay Khan Niazi ),( Fasih Sami Siddiqui ),( Muhammad Yasir Anwar ),( Ahmad Jahangir ),( Elie J. El-charabaty ) 대한신장학회 2021 Kidney Research and Clinical Practice Vol.40 No.3

Background: Normal saline solution (NSS) has been the fluid of choice for renal transplant patients, but it can lead to hyperchloremic acidosis and hyperkalemia. This study was performed to compare the safety profile of low-chloride solutions with that of NSS in renal transplant patients. Methods: We conducted a systemic review search on PubMed, Embase, and the Central Cochrane Registry. Randomized clinical tri-als (RCTs) and matched cohort studies involving NSS as the control arm and low-chloride solutions as an intervention arm were cho-sen. The standardized mean difference for continuous variables, the odds ratio (OR) for discrete variables, and a 95% confidence in-terval (CI) for effect sizes were used. A p-value of <0.05 was considered statistically significant. Analysis was performed using a ran-dom-effects model irrespective of heterogeneity, which was evaluated using I² statistics. Results: Nine RCTs and one cohort study with a total of 726 patients were included. After transplantation, serum potassium was sig-nificantly lower in the low-chloride group (standardized mean difference compared to NSS group, -0.38 mEq/L; 95% CI, -0.66 to -0.11; p = 0.007). Similarly, postoperative chloride was lower in the low-chloride group (-2.41 mEq/L [-3.34 to -1.48], p < 0.001). No statistically significance was observed in delayed graft function (OR, 0.98 [0.56-1.69], p = 0.93), day 3 creatinine (-0.14 mg/dL [-0.46 to 0.18], p = 0.38), or day 7 urine output (-0.08 L [-0.29 to 0.12], p = 0.43). onclusion: Use of NSS during renal transplant leads to increased incidence of hyperchloremic acidosis with subsequent hyperkale-mia, but clinical significance in the form of delayed graft function or postoperative creatinine remains comparable to that of low-chlo-ride solutions.

Significance of Lorentz forces on Jeffrey nanofluid flows over a convectively heated flat surface featured by multiple velocity slips and dual stretching constraint: a homotopy analysis approach

Dawar Abdullah,Wakif Abderrahim,Saeed Anwar,Shah Zahir,Muhammad Taseer,Kumam Poom 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.2

Motivated by the temporal relaxation feature of the Jeffrey model and its practical uses in the rheological modeling of several vital liquids, this study aimed to present a theoretical analysis of three-dimensional MHD Jeffrey nanofluid flows over a dual stretching surface with velocity slip conditions. By adopting the nonhomogeneous nanofluid model along with the passive control approach of nanoparticles, the current flow problem is solved semi-analytically via the homotopy analysis method for convective heating and multiple slip conditions. Dynamically, the magnetic and viscoelastic parameters have a declining effect on the velocity distributions in both directions in the existence and absence of slip effects, while the Deborah number has generally an escalating influence on the flow distributions. On the other hand, the variations of the velocity profiles in both directions are always greater in the presence of slip effect as compared to the nonslip case. Besides, the velocity stretching factor rises the velocity profiles in both directions. Furthermore, this increasing impact is dominant for the velocity distribution along the $y{\rm{-}}$direction as compared to the velocity field along the $x{\rm{-}}$direction. Thermally, the greater Biot number increases the temperature distribution. However, the bigger Schmidt number reduces the concentration distribution.

Cancer initiating properties of erythrosine supplemented with sub necrotic dose of diethyl nitrosamine: potential effects on biochemical parameters of liver, Vitamin C and E

Firoz Anwar,Rajbala Singh,Gohar Mushtaq,Abdul Rehman Al-Maliki,Abdullah Sabih,F. A. Al-Abbasi,Aftab Ahmad,Muhammad Afzal,Imran Kazm,Ruqaiyah Kha 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.3

Hepatocellular carcinoma (HCC) is the fifth and third most common cause of cancer-related deaths. Erythrosine, a commonly used coloring agent in tablet preparation was studied for its role when supplemented with sub necrotic dose of DENA (n-diethyl nitrosamine) to induced HCC in Wistar rats. Single dose of chemical carcinogen DENA with intraperitoneal injection (20 mg/kg) administered before Erythrosine at a dose 0.014 mg/kg by p.o, DENA treated rats and alone. Exposure of DENA and Erythrosine alters the levels of Serum glutamate oxaloacetate transaminase (SGO T), Serum glutamate pyrophosphate transaminase (SGPT), Alkaline phosphate (ALP), Total Bilirubin (TBR), Blood uric acid, urea, lipid profile and Serum alpha-feto protein (AFP) in Wistar rats, with further alteration in intracellular antioxidant enzyme profile Lipid Per oxidation (LPO), Glutathione Peroxidase (GPx), Melanoaldehyde (MDA), Glutathione Reductase (GR), Catalase (CAT), Glutathione (GSH), Glutathione- S-Transferase (GST), Superoxide Dismutase (SOD) along with Vit. C and Vit. E conc.. Moreover Histopathological examinations of the liver tissue showed marked effect of DENA and Erythrosine exposure on liver structure. The results concluded that Erythrosine used as coloring agent for tablet coating as well as food colorant in India, was found to be an inducer as liver proliferating agent and promoter of HCC.

The control of an upper extremity exoskeleton for stroke rehabilitation: An active force control scheme approach

Majeed, Anwar P.P. Abdul,Taha, Zahari,Abdullah, Muhammad Amirul,Azmi, Kamil Zakwan Mohd,Zakaria, Muhammad Aizzat Techno-Press 2018 Advances in robotics research Vol.2 No.3

This study evaluates the efficacy of a class robust control scheme namely active force control in performing a joint based trajectory tracking of an upper limb exoskeleton in rehabilitating the elbow joint. The plant of the exoskeleton system is obtained via system identification method whilst the PD gains were tuned heuristically. The estimated inertial parameter that enables the AFC disturbance rejection effect is attained by means of a non-nature based metaheuristic optimisation technique known as simulated Kalman filter (SKF). It was demonstrated from the present investigation that the proposed PDAFC scheme outperformed the classical PD algorithm in tracking the prescribed trajectory both in the presence and without the presence of disturbance attributed by the mannequin limb weights (1 kg and 1.5 kg) that mimics the weight of actual human limb weight. Therefore, it is apparent from the results obtained from the present study that the proposed control scheme, i.e., PDAFC is suitable for the application of exoskeleton for stroke rehabilitation.

Automated Gastrointestinal Tract Classification Via Deep Learning and The Ensemble Method

Omair Rashed Abdulwareth Alman,Mohd Azraai Mohd Razman,Ismail Mohd Khairuddin,Muhammad Amirul Abdullah,Anwar P.P. Abdul Majeed 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

Colorectal cancer is a leading cause of death among the cancer family with a record of almost a million moralities in 2020 alone. While the treatment of colorectal cancer is very difficult, early diagnosis can help immensely with treatment, eliminating the risks, and recovery. In most cases early diagnosis is possible by catching any of the precursors of the disease, many of which appear on the Gastrointestinal tract. The use of machine learning to automate the process of gastrointestinal tract examination could accelerate the process of diagnosis, and increase its efficiency. This study suggests the use of the stacking ensemble method with multiple pre-trained CNN models for an accurate classification of GI tract using the publicly available dataset Kvasir. The pre-trained models used in this study were ResNet50, MobileNetV2, and Xception, all of which were ensembled and trained on a subset of the data and tested on another to eliminate bias, and evaluates the model’s capacity for generalization. Overall, the model demonstrated impressive performance at 99.2% accuracy, 0.9977 AUC, and 99.29% F1-score, especially compared to the individual constituent models and other models discussed in the review section of the study.