Studies on sub-millimeter LYSO:Ce, Ce:GAGG, and a new Ce:GFAG block detector for PET using digital silicon photomultiplier

Ullah, Muhammad Nasir,Pratiwi, Eva,Park, Jin Ho,Yamamoto, Seiichi,Kamada, Kei,Yoshikawa, Akira,Yeom, Jung-Yeol Elsevier 2018 Nuclear instruments & methods in physics research. Vol.911 No.-

<P><B>Abstract</B></P> <P>The spatial, timing, and energy resolutions of a detector affect the image quality of a positron emission tomography (PET) system. These parameters are in turn dependent on various factors, such as the choice of scintillator, photodetectors, reflector material, and surface treatment (rough or polished) of the scintillators. In this study, we investigated the performances of sub-millimeter scintillator array, LYSO:Ce (polished and rough surfaces with BaSO <SUB> 4 </SUB> reflector or enhanced specular reflector (ESR)), a gadolinium aluminum gallium garnet (Ce:GAGG, rough surface with BaSO <SUB> 4 </SUB> reflector), and a new gadolinium fine aluminum gallate (Ce:GFAG, rough surface with BaSO <SUB> 4 </SUB> reflector) detectors. The outer dimension of each scintillator block was ∼ 12 × 12 mm with a 12 × 12 matrix of 0.9 × 0 . 9 × 6 mm<SUP>3</SUP> crystal elements. These blocks were optically coupled to a digital silicon photomultiplier (dSiPM, DPC-3200-22-44) with a 1 mm thick optical guide. Experiments were conducted at a sensor temperature of ∼ 15 °C, and a two-dimensional position histogram for <SUP>22</SUP>Na gamma photons showed that all pixels were clearly resolved for all block detectors (peak-to-valley ratios ranging from 5.3 to 11.1). The average energy resolutions for the LYSO (ESR, rough), LYSO (ESR, polished), LYSO (BaSO<SUB>4</SUB>, rough), LYSO (BaSO<SUB>4</SUB>, polished), GAGG (BaSO<SUB>4</SUB>, rough), and GFAG (BaSO<SUB>4</SUB>, rough) arrays were measured as 11.3%, 10.2%, 18.7%, 10.3%, 10.0%, and 13.2% full width at half maximum (FWHM), respectively. The coincidence resolving times (with 3 × 3 × 5 mm<SUP>3</SUP> LYSO crystal as reference) for the LYSO (ESR, rough), LYSO (ESR, polished), LYSO (B aSO<SUB>4</SUB>, rough), LYSO (BaSO<SUB>4</SUB>, polished), GAGG (BaSO<SUB>4</SUB>, rough), and GFAG (BaSO<SUB>4</SUB>, rough) arrays were 209 ps, 222 ps, 197 ps, 230 ps, 321 ps, and 276 ps, respectively. In conclusion, the new GFAG scintillator may be a promising candidate for future high-resolution time-of-flight (ToF) PET systems, considering the tradeoff between its performance and potential to be grown at a lower cost.</P>

Instrumentation for Time-of-Flight Positron Emission Tomography

Ullah, Muhammad Nasir,Pratiwi, Eva,Cheon, Jimin,Choi, Hojong,Yeom, Jung Yeol The Korea Society of Nuclear Medicine 2016 핵의학 분자영상 Vol.50 No.2

Positron emission tomography (PET) is a molecular imaging modality that provides information at the molecular level. This system is composed of radiation detectors to detect incoming coincident annihilation gamma photons emitted from the radiopharmaceutical injected into a patient's body and uses these data to reconstruct images. A major trend in PET instrumentation is the development of time-of-flight positron emission tomography (ToF-PET). In ToF-PET, the time information (the instant the radiation is detected) is incorporated for image reconstruction. Therefore, precise and accurate timing recording is crucial in ToF-PET. ToF-PET leads to better localization of the annihilation event and thus results in overall improvement in the signal-to-noise ratio (SNR) of the reconstructed image. Several factors affect the timing performance of ToF-PET. In this article, the background, early research and recent advances in ToF-PET instrumentation are presented. Emphasis is placed on the various types of scintillators, photodetectors and electronic circuitry for use in ToF-PET, and their impact on timing resolution is discussed.

Effects of Maillard reaction on physicochemical and functional properties of walnut protein isolate

Sahibzada Fahim Ullah,Nasir Mehmood Khan,Farman Ali,Shujaat Ahmad,Zia Ullah Khan,Noor Rehman,Abdul Khaliq Jan,Nawshad Muhammad 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5

In this study, the Maillard reaction (MR) ofglucose was applied to improve the physicochemical andfunctional properties of walnut protein isolate (WNPI). TheMR products (MRPs) were prepared with glucose at 0 h(MRP0), 1 h (MRP1), 2 h (MRP2) and 3 h (MRP3) heatingat 95 C. The Infra-Red spectrum showed reduction ofamide and S–H functionalities in MRPs with completeintermixing of glucose in MRP3. Scanning electronmicroscopy indicated changes in the morphology of MRP3which also exhibited promising antioxidant effect. Significantdecrease (P\0.05) in hydrophobicity values (Ho)and increase (P\0.05) in emulsifying activity/emulsifyingstability indexes values were observed for MRPs. Uniform droplet distribution was observed in microscopyof emulsions while an increase in the interfacial proteinconcentration (U) was obtained for MRPs. These resultssuggest that MR is useful in improving the utilization ofthis protein in food product development.

Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study

Ali, Gowhar,Subhan, Fazal,Islam, Nazar Ul,Ullah, Nasir,Shahid, Muhammad,Ullah, Sami,Ullah, Ihsan,Shah, Rehmat,Khan, Ikhtiar,Sewell, Robert D. E.,Abbas, Ghulam 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

The aim of the current study was to explore in vivo any relative gastroulcerogenic prospective propensity of newly synthesized nitrogen containing derivatives of salicyl alcohol; compound (I) [1-(2-hydroxybenzyl) piperidinium chloride], compound (II) [4-carbamoyl-1-(2- hydroxybenzyl)piperidinium chloride] and aspirin in albino rats. The experimental groups received the following oral treatments daily for 6 days: group I saline control; group II, standard (aspirin) treatment group [150 mg/kg of body weight]; group III, test (compound I) treatment group [100, 150 mg/kg]; group IV, test (compound II) treatment group [100, 150 mg/kg]. The results showed that in the case of the aspirin treated group and compound (I) [150 mg/kg], there was a significant increase in gastric volume, free acidity, total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastric mucosa of these treated groups revealed detectable morphological changes. Utilizing the same protocol, synthetic compound (I) [100 mg/kg] and (II) [100, 150 mg/kg] exhibited no statistically significant ulcerogenic or cytotoxic properties. A cyclooxygenase (COX) selectivity test indicated the preferential inhibition of COX-I and COX-II enzymes by compounds (I) and (II). This study therefore indicates that these synthetic compounds may possess reduced ulcerogenic potential and could be a functional substitute to aspirin.

Comparative evaluation of gastroulcerogenic potential of nitrogen isoforms of salicyl alcohol and aspirin in rats: biochemical and histological study

Gowhar Ali,Fazal Subhan,Nazar Ul Islam,Nasir Ullah,Muhammad Shahid,Sami Ullah,Ihsan Ullah,Rehmat Shah,Ikhtiar Khan,Robert D. E. Sewell,Ghulam Abbas 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.7

The aim of the current study was to explorein vivo any relative gastroulcerogenic prospective propensityof newly synthesized nitrogen containing derivativesof salicyl alcohol; compound (I) [1-(2-hydroxybenzyl)piperidinium chloride], compound (II) [4-carbamoyl-1-(2-hydroxybenzyl)piperidinium chloride] and aspirin in albinorats. The experimental groups received the following oraltreatments daily for 6 days: group I saline control; group II,standard (aspirin) treatment group [150 mg/kg of bodyweight]; group III, test (compound I) treatment group [100,150 mg/kg]; group IV, test (compound II) treatment group[100, 150 mg/kg]. The results showed that in the case of theaspirin treated group and compound (I) [150 mg/kg], therewas a significant increase in gastric volume, free acidity,total acidity, ulcer score and a decrease in gastric pH. Furthermore, histopathological examination of gastricmucosa of these treated groups revealed detectable morphologicalchanges. Utilizing the same protocol, syntheticcompound (I) [100 mg/kg] and (II) [100, 150 mg/kg]exhibited no statistically significant ulcerogenic or cytotoxicproperties. A cyclooxygenase (COX) selectivity test indicatedthe preferential inhibition of COX-I and COX-IIenzymes by compounds (I) and (II). This study thereforeindicates that these synthetic compounds may possessreduced ulcerogenic potential and could be a functionalsubstitute to aspirin.

Density Functional Quantum Computations to Investigate the Physical Prospects of Lead-Free Chloro-Perovskites QAgCl 3 (Q = K, Rb) for Optoelectronic Applications

Saeed Ullah,Munawar Abbas,Saad Tariq,Khalid Mujasam Batoo,Nasir Rahman,Uzma Gul,Mudasser Husain,Sajjad Hussain,Mohamed Musa Saad Hasb Elkhalig,Muhammad Usman Ghani 한국전기전자재료학회 2024 Transactions on Electrical and Electronic Material Vol.25 No.3

In this study, a theoretical investigation employing the Wien2k package within DFT framework was conducted to inspect mechanical, structural, and optoelectronic properties of silver-based cubic chloro-perovskites QAgCl 3 . Stability of these compounds was confi rmed by fi tting optimized data to Birch Muranghan equation, enthalpy of formation and tolerance factor. The mBJ potential was utilized to compute band profi les, revealing semiconducting nature mainly from Ag d-states and Cl p-states. Born-Huang criteria confi rmed mechanical stability, while other elastic parameters indicated ionic bonding, anisotropy, stiff ness, ductility, fracture resistance, and bond-bending resistance. Optical study suggested suitability for practical optoelectronic devices, with a lack of absorbance in the visible region. These outcomes off er a platform for further experimental and theoretical research.

Investigation of Optical Properties of Ceramic Ce:GAGG by High Temperature Annealing

박찬선,Muhammad Nasir Ullah,김찬호,Shinhaeng Cho,염정열 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.75 No.12

An as-fabricated cerium-doped ceramic scintillator Gd$_3$Al$_2$Ga$_3$O$_{12}$ (Ce:GAGG) was thermally annealed at different temperatures. The light output and energy resolution of the scintillators were measured before and after thermal treatment. The effect of thermal annealing in the air at high temperature (at 1000 $^\circ$C for 5 hours) deforms the microstructure by mitigating oxygen vacancies of the ceramic scintillator. This has been proven by XPS study that showed the existence of oxygen vacancies and subsequent decrease of oxygen deficiency amid annealing treatment that led to an output signal increase. The diffusion ability of oxygen atoms by annealing played a key role in compensating for defect sites. In this study, by controlling thermodynamic conditions, the light output was enhanced by $\sim$30.4\% and the energy resolution improved by $\sim$2.4\% after annealing at 1000 $^\circ$C in the air.

Raspberry Pi assisted facial expression recognition framework for smart security in law-enforcement services

Sajjad, Muhammad,Nasir, Mansoor,Ullah, Fath U Min,Muhammad, Khan,Sangaiah, Arun Kumar,Baik, Sung Wook Elsevier science 2019 Information sciences Vol.479 No.-

<P><B>Abstract</B></P> <P>Facial expression recognition is an active research area for which the research community has presented a number of approaches due to its diverse applicability in different real-world situations such as real-time suspicious activity recognition for smart security, monitoring, marketing, and group sentiment analysis. However, developing a robust application with high accuracy is still a challenging task mainly due to the inherent problems related to human emotions, lack of sufficient data, and computational complexity. In this paper, we propose a novel, cost-effective, and energy-efficient framework designed for suspicious activity recognition based on facial expression analysis for smart security in law-enforcement services. The Raspberry Pi camera captures the video stream and detects faces using the Viola Jones algorithm. The face region is pre-processed using Gabor filter and median filter prior to feature extraction. Oriented FAST and Rotated BRIEF (ORB) features are then extracted and the support vector machine (SVM) classifier is trained, which predicts the known emotions (Angry, Disgust, Fear, Happy, Neutral, Sad, and Surprise). Based on the collective emotions of the faces, we predict the sentiment behind the scene. Using this approach, we predict if a certain situation is hostile and can prevent it prior to its occurrence. The system is tested on three publically available datasets: Cohen Kande (CK+), MMI, and JAFEE. A detailed comparative analysis based on SURF, SIFT, and ORB is also presented. Experimental results verify the efficiency and effectiveness of the proposed system in accurate recognition of suspicious activity compared to state-of-the-art methods and validate its superiority for enhancing security in law enforcement services.</P>

Experimental analysis of ILSS of glass fibre reinforced thermoplastic and thermoset textile composites enhanced with multiwalled carbon nanotubes

Saamia Zahid,Muhammad Ali Nasir,Saad Nauman,Mehmet Karahan,Yasir Nawab,H. M. Ali,Yasir Khalid,Muhammad Nabeel,Mudaser Ullah 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

In this study experimental investigation of interlaminar shear strength of glass fibre reinforced thermoplastic polyurethane (TPU) and epoxy based thermosets composites enhanced with multi walled carbon nanotubes (MWCNTs) is presented, and comparison is made between thermoplastic and thermosets composites. Suspension of MWCNTs in TPU and epoxy matrix was prepared using magnetic stirring and sonication technique. Both thermoplastic reinforced glass fibre and thermosets reinforced glass fibre composites were manufactured using hand layup technique. Carbon nanotubes were added in the concentrations of 0.1 %weight, 0.3 %weight and 0.5 %weight in both types of composites. Results showed that as the concentration of CNTs increases, the ILSS of the nanocomposites was also improved. With an addition of 0.5 % weight CNTs, there was improvement of 24.37 % in ILSS in epoxy based composites and 10.05 % enhancement in thermoplastic polyurethane reinforced glass fibre composites. The average ILSS obtained for thermoplastic polyurethane composites was less than that of epoxy composites. The TPU based composites also demonstrated inelastic deformations without any trace of brittle fracture. The pristine epoxy based composites on the other hand did show inelastic deformations followed by brittle fracture. Higher concentrations of MWCNTs led to an absence of brittle fracture during the tests, owing to the crack bridging effect of the CNTs.

Effect of extraction methods on structural, physiochemical and functional properties of dietary fiber from defatted walnut flour

Gul Mali Khan,Nasir Mehmood Khan,Zia Ullah Khan,Farman Ali,Abdul Khaliq Jan,Nawshad Muhammad,Rizwan Elahi 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.4

The effect of different extraction methods i.e. extraction with alkali (AEDF), enzyme (EEDF) and enzyme plus shear emulsifying hydrolysis (SEDF) on structure, physiochemical as well as the functional characteristics of dietary fiber (DF) from defatted walnut flour were studied. AEDF process showed significantly higher (P\0.05) amount of water retention capacity (WRC; 5.39 g/g), water swelling capacity (WSC; 3.16 g/mL), and particle size; while, shown lower value of oil adsorption capacity (OAC; 29 g/g) amongst all. Compared to AEDF, no major differences were observed in network except the matrix in EEDF and SEDF was more porous and honey comb like. DF extracted through AEDF, EEDF and SEDF showed good viscosity and emulsifying activity however, less stability indices. The results from this study suggest that AEDF and EEDF and SEDF had specific effects on the structure-functional properties of DF from defatted walnut flour, which has great potential in food applications.