Papers by MOHAMMED HARUNA AHMED
Type 2 diabetes (T2D) and obesity are highly prevalent disorders reflecting a complex interplay o... more Type 2 diabetes (T2D) and obesity are highly prevalent disorders reflecting a complex interplay of genetics, epigenetics, and environment. They constitute serious health problems and lead to significant morbidity and mortality. The overall aim of this thesis was to shed some light on the molecular mechanisms underlying pathogenesis of T2D and obesity by studies in rat and man. In Paper I, adenylyl cyclase 3 (Ac3) mRNA expression levels in pancreatic islets and striatum/hypothalamus regions of brain of diabetic Goto-Kakizaki (GK) rats were higher compared with control Wistar rats, while its expression was intermediate in islets and brain regions of insulin-treated GK rats. This study proposes that increased Ac3 mRNA expression in these tissues is partially a primary and inherited defect and not solely secondary to hyperglycaemia, and that AC3 may participate in the regulation of glucose homeostasis via insulin secretion and CNS. In Paper II, protein kinase Cα (PKCα) and PKCζ mRNA exp...
Materials, 2022
Contamination of zirconia restorations before cementation can impair the resin–zirconia bonding d... more Contamination of zirconia restorations before cementation can impair the resin–zirconia bonding durability. The objective of this study was to evaluate the effect of human saliva or blood decontamination with 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing cleaner on the resin–zirconia shear bond strength (SBS). Methods: A total of 220 zirconia specimens were prepared and air-abraded and randomly distributed into 11 groups (n = 20 per group). Except for the control group (no contamination), zirconia specimens were contaminated with either human saliva (five groups) or blood (five groups), and then subjected to one of five cleaning methods: water rinsing, 38% phosphoric acid etchant (Pulpdent Corp., Watertown, MA, USA), 70% isopropanol alcohol (Avalon Pharma, Riyadh, Saudi Arabia), Ivoclean (Ivoclar Vivadent, Schaan, Lichtenstein) and Katana Cleaner (Kuraray Noritake, Tokyo, Japan). The resin–zirconia SBS was tested at 24 h and after thermocycling (10 k cycles). Thre...
Journal of Ultrasound in Medicine, 2006
European Journal of Dentistry, 2015
Objective: The aim of this study was to investigate the vertical mandibular asymmetry in a group ... more Objective: The aim of this study was to investigate the vertical mandibular asymmetry in a group of adult patients with different types of malocclusions, based on Angle's dental classification. Materials and Methods: A sample of 102 patients (age range 19–28) who went for routine orthodontic treatment in the institution were divided into four groups: Class I, 26 patients; Class II/1, 30 patients; Class III, 23 patients; and control group (CG) with normal occlusion, 23 patients. Condylar asymmetry index (CAI), ramal asymmetry index (RAI), condylar-plus-ramal asymmetry index values were measured for all patients on panoramic radiographs. Data were analyzed using Kruskal–Wallis and Mann–Whitney U-test at the 95% confidence level (P < 0.05). Results: The results of the analysis showed that different occlusal types significantly affected the vertical symmetry of the mandible at the condylar level. Class I and Class II/1 malocclusion groups showed a significant difference in CAI va...
Objective: The purpose of this study was to perform the chemical analysis of stones to know the p... more Objective: The purpose of this study was to perform the chemical analysis of stones to know the pattern of biochemical composition of stones in Sudanese subjects. Methods: 169 renal stones were analyzed during the period from February to December 2008. 96 patients were referred to Gezira Hospital for Renal diseases and Surgery (GHRDS), Gezira state, central Sudan. The stones were analyzed by semi quantitative method in the Gezira central laboratory. Kits were used for chemical analysis of stones. Calcium, phosphate, oxalate, uric acid, carbonate and cystine were determined. Results: Male to female ratio was 2:1. Calcium, oxalate and uric acid were the most common forms of stones (90.5%), followed by phosphate (4.7%), carbonate (3.0%) and cystine which accounted for 1.8% of the study subjects. Conclusion: The relative frequency of calcium oxalate stones in our study about University Of Gezira
The journal of physical chemistry. B, Jan 22, 2013
Water in the presence of electrolytes plays an important role in biological and industrial proces... more Water in the presence of electrolytes plays an important role in biological and industrial processes. The properties of water, such as the intermolecular coupling, Fermi resonance (FR), hydrogen-bonding, and Raman cross section were investigated by measuring the Raman spectra in the OD and OH stretch regions in presence of alkali halides (NaX; X = F, Cl, Br, I). It is observed that the changes in spectral characteristics by the addition of NaX in D2O are similar to those obtained by the addition of H2O in D2O. The spectral width decreases significantly by the addition of NaX in D2O (H2O) than that in the isotopically diluted water. Quantitative estimation, on the basis of integrated Raman intensity, revealed that the relative Raman cross section, σ(H)/σ(b) (σ(H) and σ(b) are the average Raman cross section of water in the first hydration shell of X(-) and in bulk, respectively), in D2O and H2O is higher than those in the respective isotopically diluted water. These results suggest t...
Science in China Series E: Technological Sciences, 2010
There is an increasing interest in cross flow turbines (also known as Banki turbines) for small a... more There is an increasing interest in cross flow turbines (also known as Banki turbines) for small and low head applications because of their simple structure as well as low capital and maintenance costs. The present work aims at implementing the direct drive turbine (DDT) of cross flow type for wave power generation. A numerical wave tank was used to simulate
Science in China Series E: Technological Sciences, 2010
A general purpose viscous flow solver Ansys CFX was used to study a Savonius type wave energy con... more A general purpose viscous flow solver Ansys CFX was used to study a Savonius type wave energy converter in a 3D numerical viscous wave tank. This paper presents the results of a computational fluid dynamics (CFD) analysis of the effect of blade configuration on the performance of two Savonius rotors for wave energy extraction. A piston-type wave generator was incorporated in the computational domain to generate the desired incident waves. A complete OWC system with a 3-bladed Savonius rotor was modeled in a three dimensional numerical wave tank and the hydrodynamic conversion efficiency was estimated. The flow over the rotors was assumed to be two-dimensional (2D), viscous, turbulent and unsteady. The CFX code was used with a solver of the coupled conservation equations of mass, momentum and energy, with an implicit time scheme and with the adoption of the hexahedral mesh and the moving mesh techniques in areas of moving surfaces. Turbulence was modeled with the k-e model. The results indicated that the developed models are suitable to analyze the water flows both in the chamber and in the turbine. For the turbine, the numerical results of pressure and torque were compared for the two cases.
2003 International Conference on Geometric Modeling and Graphics, 2003. Proceedings
Page 1. Saudi Arabian License Plate Recognition System Muhammad Sarfraz, Mohammed Jameel Ahmed, a... more Page 1. Saudi Arabian License Plate Recognition System Muhammad Sarfraz, Mohammed Jameel Ahmed, and Syed A. Ghazi Department of Information and Computer Science, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. ...
2014 IEEE 11th International Multi-Conference on Systems, Signals & Devices (SSD14), 2014
ABSTRACT Desalination is the process of removal of salts from seawater or brackish water to produ... more ABSTRACT Desalination is the process of removal of salts from seawater or brackish water to produce fresh water. This paper presents the performance evaluation of a small-scale reverse osmosis desalination system, run on batteries. The system is The data acquisition and monitoring device used is from the National Instruments, compatible with Lab VIEW software which provides a visual medium for monitoring the process parameters. For the purpose of performance evaluation, the system is run at steady state for a period of time and the corresponding current and voltage across the system is recorded every second. The product flow rate in liters/min and the product water conductivity in ppm are studied for the given duration of time. Performance evaluation parameters namely, the salt rejection, based on the product and feed water salinity, the recovery ratio based on feed water and product water flow rates and the specific energy consumption in kWh/m3 are also calculated.
2009 IEEE International Conference on Communications, 2009
Intelligent service management techniques play an important role in the continuously and rapidly ... more Intelligent service management techniques play an important role in the continuously and rapidly evolving area of technologically advanced services. High tech companies are looking for better ways to deliver and preserve services to their customers in a competitive way. This paper introduces a new architecture for a scalable service monitoring and support system called Call Home Analysis and Response System (CHARS). The proposed system utilizes data de-noising and filtering techniques to meet the service management requirements of large-scale service deployments. The system utilizes intra and inter-element correlation of events to enhance the services delivered to endusers. Our results demonstrate that the proposed system is effective in covering the performance and fault management aspects for large-scale deployments of advanced services.
Islets, 2012
Adenylyl cyclase 3 (AC3) is expressed in pancreatic islets of the Goto-Kakizaki (GK) rat, a spont... more Adenylyl cyclase 3 (AC3) is expressed in pancreatic islets of the Goto-Kakizaki (GK) rat, a spontaneous animal model of type 2 diabetes (T2D), and also exerts genetic effects on the regulation of body weight in man. In addition to pancreatic islets, the central nervous system (CNS) plays an important role in the pathogenesis of T2D and obesity by regulating feeding behavior, body weight and glucose metabolism. In the present study, we have investigated AC3 expression in pancreatic islets, striatum and hypothalamus of GK rats to evaluate its role in the regulation of glucose homeostasis. GK and Wistar rats at the age of 2.5 mo were used. A group of GK rats were implanted with sustained insulin release chips for 15 d. Plasma glucose and serum insulin levels were measured. AC3 gene expression levels in pancreatic islets, striatum and hypothalamus were determined by using real-time RT-PCR. Results indicated that plasma glucose levels in Wistar rats were found to be similar to insulin-treated GK rats, and significantly lower compared with non-treated GK rats. AC3 expression levels in pancreatic islets, striatum and hypothalamus of GK rats were higher compared with Wistar rats, while the levels were intermediate in insulin-treated GK rats. The AC3 expression display patterns between pancreatic islets and striatum-hypothalamus were similar. The present study thus provides the first evidence that AC3 is overexpressed in the regions of striatum and hypothalamus of brain, and similarly in pancreatic islets of GK rats suggesting that AC3 plays a role in regulation of glucose homeostasis via CNS and insulin secretion.
The FASEB Journal, 2010
The hair follicle is a cyclic biological system that progresses through stages of growth, regress... more The hair follicle is a cyclic biological system that progresses through stages of growth, regression, and quiescence, which involves dynamic changes in a program of gene regulation. Micro-RNAs (miRNAs) are critically important for the control of gene expression and silencing. Here, we show that global miRNA expression in the skin markedly changes during distinct stages of the hair cycle in mice. Furthermore, we show that expression of miR-31 markedly increases during anagen and decreases during catagen and telogen. Administration of antisense miR-31 inhibitor into mouse skin during the early- and midanagen phases of the hair cycle results in accelerated anagen development, and altered differentiation of hair matrix keratinocytes and hair shaft formation. Microarray, qRT-PCR and Western blot analyses revealed that miR-31 negatively regulates expression of Fgf10, the components of Wnt and BMP signaling pathways Sclerostin and BAMBI, and Dlx3 transcription factor, as well as selected keratin genes, both in vitro and in vivo. Using luciferase reporter assay, we show that Krt16, Krt17, Dlx3, and Fgf10 serve as direct miR-31 targets. Thus, by targeting a number of growth regulatory molecules and cytoskeletal proteins, miR-31 is involved in establishing an optimal balance of gene expression in the hair follicle required for its proper growth and hair fiber formation.
Obesity, 2013
Type 2 diabetes (T2D) and obesity are highly prevalent disorders reflecting a complex interplay o... more Type 2 diabetes (T2D) and obesity are highly prevalent disorders reflecting a complex interplay of genetics, epigenetics, and environment. They constitute serious health problems and lead to significant morbidity and mortality. The overall aim of this thesis was to shed some light on the molecular mechanisms underlying pathogenesis of T2D and obesity by studies in rat and man. In Paper I, adenylyl cyclase 3 (Ac3) mRNA expression levels in pancreatic islets and striatum/hypothalamus regions of brain of diabetic Goto-Kakizaki (GK) rats were higher compared with control Wistar rats, while its expression was intermediate in islets and brain regions of insulin-treated GK rats. This study proposes that increased Ac3 mRNA expression in these tissues is partially a primary and inherited defect and not solely secondary to hyperglycaemia, and that AC3 may participate in the regulation of glucose homeostasis via insulin secretion and CNS. In Paper II, protein kinase Cα (PKCα) and PKCζ mRNA expressions in pancreatic islets were decreased in GK compared with Wistar rats, with intermediate expressions in the insulin-treated GK group. PKCα and phosphorylated PKCα (p-PKCα) protein expressions in islets were diminished in GK compared with insulin-treated GK and Wistar rats. Islet PKCζ protein expression was reduced in both GK and insulin-treated GK compared with Wistar rats, but p-PKCζ was reduced only in GK compared with insulin-treated GK and Wistar rats. PKCε was lower in islets of GK compared with insulin-treated GK and Wistar rats, at both the mRNA and protein levels. PKCδ and p-PKCδ protein expressions in islets were decreased in GK compared with insulin-treated GK and Wistar rats. In liver, PKCδ and PKCζ mRNA expressions were decreased in both GK and insulin-treated GK compared with Wistar rats. Hepatic PKCζ protein expression was diminished in GK rats with and without insulin treatment compared with Wistar rats. Although PKCδ showed no difference at the protein level, p-PKCδ/PKCδ was reduced in liver of GK compared with Wistar rats. PKCε mRNA expression in liver was down-regulated in insulin-treated GK compared with non-treated GK and Wistar rats. Therefore, this study suggests defects in PKCα and PKCε expressions in pancreatic islets of GK rats secondary to hyperglycaemia. In liver, PKCε mRNA expression in liver could be under control of insulin. In Paper III, mRNA expressions, enzyme activities, and protein levels of succinyl-CoA:3ketoacid-CoA transferase (SCOT) and ATP citrate lyase (ATPCL) were decreased in pancreatic islets of GK compared with Wistar rats. Two cell lines with the severest knockdown of SCOT enzyme activity and protein, SCOT 1676 and SCOT 1184, showed the severest reduction in secretagogue-stimulated insulin secretion. This study confirms that the mitochondrial pathways involving SCOT, instead of or synergizing with the pathway involving ATPCL, are important potentiators of glucose-stimulated insulin secretion (GSIS). In Paper IV, we studied the association of adrenergic receptor alpha 2A (ADRA2A) genetic polymorphisms with obesity and/or T2D in a Swedish cohort. The single nucleotide polymorphism (SNP) rs553668 was associated with T2D in men, but this association disappeared after adjusting for age and body mass index (BMI). Associations were also detected when comparing obese subjects with normal glucose tolerance (NGT) and lean NGT subjects, and in obese but not lean T2D patients. In women, multiple logistic regression regarding SNP rs521674 demonstrated an association with T2D when including age as a covariant. However, correcting for BMI removed this association. When age was included in the model, the increased risk of rs521674 was seen in obese, but not in lean, T2D women. This study provides evidence that ADRA2A genetic polymorphisms are mainly associated with obesity and may also relate to T2D in a Swedish population. In conclusion, this thesis has revealed molecular pathogenetic defects related to T2D and obesity, and may thus create a basis for more precise and improved therapeutic approaches.
Journal of Physics: Conference Series, 2011
Reciprocating compressors are widely used in industry for various purposes and faults occurring i... more Reciprocating compressors are widely used in industry for various purposes and faults occurring in them can degrade their performance, consume additional energy and even cause severe damage to the machine. Vibration monitoring techniques are often used for early fault detection and diagnosis, but it is difficult to prescribe a given set of effective diagnostic features because of the wide variety
The Journal of Chemical Physics, 1988
ABSTRACT The combination of vibrational overtone excitation with time-resolved laser induced fluo... more ABSTRACT The combination of vibrational overtone excitation with time-resolved laser induced fluorescence detection of the excited molecule permits the study of collisional energy transfer in highly vibrationally excited molecules with single quantum state resolution. We apply this new technique to aceytlene excited in the region of the second CH stretching overtone transition (3νCH) (&amp;egr;vib =9640 cm−1) and probed via the A˜ electronic state. Our results show that self-relaxation proceeds at essentially the gas kinetic collision rate while quenching by the rare gases He, Ar, and Xe is only about a factor of two slower. The insensitivity of the relaxation rate to the structure of the collision partner clearly points to rotational relaxation or intramolecular vibrational energy transfer as the mechanism for collisionally depopulating the initially prepared state.
Indian Journal of Urology, 2008
A case of 14-year-old girl is reported who presented with features of tuberculous subacute intest... more A case of 14-year-old girl is reported who presented with features of tuberculous subacute intestinal obstruction. Exploratory laparotomy revealed a urachal cyst associated with pseudomyxoma peritonei (PMP). Histopathology conÞ rmed a moderately differentiated mucin secreting adenocarcinoma of urachal cyst associated with PMP. The adenocarcinoma of urachal cyst associated with PMP is further reviewed.
Endocrine Practice, 2004
Objective: To present a case of untreated long-term idiopathic neurohypophysial diabetes insipidu... more Objective: To present a case of untreated long-term idiopathic neurohypophysial diabetes insipidus (DI) with structural and functional renal abnormalities that regressed after treatment. Methods: We describe the clinical course, biochemical data, and imaging findings in a man with idiopathic neurohypophysial DI in whom structural and functional abnormalities involving the urinary tract diminished after treatment. The patient underwent intravenous pyelography, retrograde pyelography, computed tomographic (CT) scanning of the kidneys and abdomen, iodohippurate renal scanning, and voiding cystourethrography. Ultrasonography of the kidneys at presentation and at 8-year followup and serial determinations of serum creatinine for a period of 9 years were also done. Results: A 43-year-old man had polyuria for 30 years attributable to untreated idiopathic neurohypophysial DI. He presented with bilateral flank pain and a high serum creatinine level (156 µmol/L). Ultrasonography, intravenous pyelography, retrograde pyelography, and CT scan of the kidneys demonstrated severe bilateral hydronephrosis, notably dilated and tortuous ureters, a distended bladder, and atrophy of the left renal cortex. Retrograde pyelography and voiding cystourethrography confirmed the absence of mechanical obstruction or urinary reflux. A renal scan study showed bilaterally impaired function. Treatment with intranasally administered desmopressin and clean intermittent straight bladder catheterization resulted in resolution of flank pain, improvement of renal function, normalization of serum creatinine levels, and decreased hydronephrosis during 9 years of follow-up. Conclusion: This case provides information about renal abnormalities in the natural history of a long-term polyuric state, idiopathic neurohypophysial DI, before and after treatment. Reversibility of renal structural and functional abnormalities after treatment is documented. Recognition of renal abnormalities associated with untreated neurohypophysial DI is important for prevention and treatment of such complications.
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Papers by MOHAMMED HARUNA AHMED