Improved Diagnostic Accuracy in Characterization of Adnexal Masses by Detection of Choline Peak Using 1H MR Spectroscopy in Comparison to Internal Reference at 3 Tesla

Malek, Mahrooz,Pourashraf, Maryam,Gilani, Mitra Modares,Gity, Masoumeh Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

Background: The aim of this study was to assess the role of the presence of a choline peak in 3 Tesla 1H magnetic resonance spectroscopy (MRS) for differentiating benign from malignant adnexal masses. Materials and Methods: A total of 46 adnexal masses (23 malignant and 23 benign) underwent 1H MRS study prior to surgery to assess the presence of choline peak. Results: A choline peak was detected in 16 malignant masses (69.5%) and was absent in the other 7 (30.5%). A choline peak was only detected in 6 (26%) of the benign adnexal masses. The presence of an MRS choline peak had a sensitivity of 69.5%, a specificity of 74%, a positive predictive value (PPV) of 72.7%, and a negative predictive value (NPV) of 71% for diagnosing malignant adnexal masses. A significant difference between the frequency of mean choline peaks in benign and malignant adnexal masses was observed (P value < 0.01). Conclusions: A 1H MRS choline peak is seen in malignant adnexal masses more frequently than the benign masses, and may be helpful for diagnosing malignant adnexal masses.

The Clinical Significance of Occult Gastrointestinal Primary Tumours in Metastatic Cancer: A Population Retrospective Cohort Study

Malek B. Hannouf,Eric Winquist,Salaheddin M. Mahmud,Muriel Brackstone,Sisira Sarma,George Rodrigues,Peter K. Rogan,Jeffrey S. Hoch,Gregory S. Zaric 대한암학회 2018 Cancer Research and Treatment Vol.50 No.1

Purpose The purpose of this study was to estimate the incidence of occult gastrointestinal (GI) primary tumours in patients with metastatic cancer of uncertain primary origin and evaluate their influence on treatments and overall survival (OS). Materials and Methods We used population heath data from Manitoba, Canada to identify all patients initially diagnosed with metastatic cancer between 2002 and 2011. We defined patients to have “occult” primary tumour if the primary was found at least 6 months after initial diagnosis. Otherwise, we considered primary tumours as “obvious.” We used propensity-score methods to match each patient with occult GI tumour to four patients with obvious GI tumour on all known clinicopathologic features. We compared treatments and 2-year survival data between the two patient groups and assessed treatment effect on OS using Cox regression adjustment. Results Eighty-three patients had occult GI primary tumours, accounting for 17.6% of men and 14% of women with metastatic cancer of uncertain primary. A 1:4 matching created a matched group of 332 patients with obvious GI primary tumour. Occult cases compared to the matched group were less likely to receive surgical interventions and targeted biological therapy, and more likely to receive cytotoxic empiric chemotherapeutic agents. Having an occult GI tumour was associated with reduced OS and appeared to be a nonsignificant independent predictor of OS when adjusting for treatment differences. Conclusion GI tumours are the most common occult primary tumours in men and the second most common in women. Patients with occult GI primary tumours are potentially being undertreated with available GI site-specific and targeted therapies.

Synthesis and characterization of Al-SiO2 composites

Malek Ali,Abderraouf Gherissi 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.3

In this paper, aluminum matrix composites are successfully synthesized by melting of Al scrap at 850 oC. The reinforcementswere then added gradually for 10 minutes to the molten aluminum with different amounts weight ratios (10, and 20) wt.%of SiO2. Mixtures were stirred with 450 rpm for 10 minutes after the additions of SiO2. The mixture was poured into previouslyprepared sand mold. The uniaxial tensile, cupping, and biaxial tensile tests were conducted by Gant Universal test machine, andlocal designed biaxial tensile machine. Al-SiO2 composites presented good resistance to both uniaxial and biaxial tensile tests. It was observed that the ultimate tensile strength for Al- SiO2 composites with 0, 10, and 20 wt% of SiO2 were 25 MPa, 62 MPa,and 65 MPa and respectively. The Al- 20 % wt of SiO2 composite presents good resistance to biaxial tensile test, and both ofcomposites present a lower deformation ratio. The cupping results were promising for the composite with a ratio of 10 % wtit was deformed without failure until the depth d = 1.8 mm, whereas many cracks have been observed with 20 %wt of SiO2 atsmall forming depth. Experimental and a finite-element simulation for biaxial and cupping test gave very closed results.

Single particle mineralogy of microparticles from Himalayan ice-cores using SEM/EDX and ATR-FTIR imaging techniques for identification of volcanic ash signatures

Malek, Md Abdul,Eom, Hyo-Jin,Hwang, Heejin,Hur, Soon Do,Hong, Sungmin,Hou, Shugui,Ro, Chul-Un Elsevier 2019 Chemical geology Vol.504 No.-

<P><B>Abstract</B></P> <P>In this study, insoluble microparticles from four discrete layers of ice-cores drilled out from the East Rongbuk glacier of the Himalayas were characterized on a single particle basis by scanning electron microscopy coupled with energy dispersive X-ray spectrometry (SEM/EDX) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) imaging. The combined application of the two single particle analytical techniques for the analysis of the same individual particles provided complementary information, i.e., their elemental compositions and morphology by SEM/EDX and their molecular species, functional groups, and crystallinity by ATR-FTIR imaging, which is crucial for the definite identification of the mineral species including their polymorphs. The results showed that the integrated signatures of volcanic ash (VA), involving their mineralogical characteristics for silica polymorphs, vitreous nature of silica and silicate particles, chemical heterogeneity within the micrometer sized particles, and unique morphology, can be used to clearly differentiate micrometer sized VA from the mineral dust of a soil origin on a single-particle basis. The different mineralogical characteristics among the volcanic samples would be due to their association with different volcanic eruptions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Single particle mineralogy of microparticles from ice-cores </LI> <LI> Combined use of SEM/EDX and ATR-FTIR imaging for analysis of the same single particles </LI> <LI> Integrated volcanic ash signatures observed for cryptotephra ice-core samples </LI> <LI> Diverse silica polymorph and vitreous silica contents for ice-core samples </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

FAR INFRARED GALAXIES IN AKARI'S EYE

Malek, K.,Pollo, A.,Takeuchi, T.T.,Giovannoli, E.,Buat, V.,Burgarella, D.,Malkan, M. The Korean Astronomical Society 2012 天文學論叢 Vol.27 No.4

We present the results of Spectral Energy Distribution (SED) fitting of far-infrared galaxies detected in the AKARI Deep Field-South (ADF-S) Survey and discuss their physical properties. Additionally, we perform a comparison between photometric redshifts estimated using only optical and both optical and infrared data. We conclude that our sample consists mostly of nearby galaxies rich in dust and young stars. We observe an improvement in the estimation of photometric redshifts when the IR data are included, comparing to a standard approach based mainly on the optical to UV photometry.

Combined influence of porosity and elastic foundation parameters on the bending behavior of advanced sandwich structures

Malek Hadji,Abdelhakim Bouhadra,Belgacem Mamen,Abderahmane Menasria,Abdelmoumen Anis Bousahla,Fouad Bourada,Mohamed Bourada,Kouider Halim Benrahou,Abdelouahed Tounsi 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.1

Elastic bending of imperfect functionally graded sandwich plates (FGSPs) laying on the Winkler-Pasternak foundation and subjected to sinusoidal loads is analyzed. The analyses have been established using the quasi-3D sinusoidal shear deformation model. In this theory, the number of unknowns is condensed to only five unknowns using integral-undefined terms without requiring any correction shear factor. Moreover, the current constituent material properties of the middle layer is considered homogeneous and isotropic. But those of the top and bottom face sheets of the graded porous sandwich plate (FGSP) are supposed to vary regularly and continuously in the direction of thickness according to the trigonometric volume fraction’s model. The corresponding equilibrium equations of FGSPs with simply supported edges are derived via the static version of the Hamilton’s principle. The differential equations of the system are resolved via Navier’s method for various schemes of FGSPs. The current study examine the impact of the material index, porosity, side-to-thickness ratio, aspect ratio, and the WinklerPasternak foundation on the displacements, axial and shear stresses of the sandwich structure.

A novel combined approach for gas compressors surge suppression based on robust adaptive control and backstepping

Malek Ghanavati,Karim Salahshoor,Mohammad Reza Jahed Motlagh,Amin Ramazani,Ali Moarefianpour 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.2

Nowadays, there is a great interest in using active control methods to increase the compressor working range. The advantage of this controlling method is that the performance point can be located in the vicinity of maximum pressure and efficiency. However, most of the existing controllers require an awareness of compressor characteristic, disturbance upper bound, throttle gain, and throttle valve feature; this is why they are limited in engineering applications. In order to overcome the weakness of the existing controllers, this research employs a novel combined controlling method based on robust adaptive control, which is designed using backstepping technique because the compressor behavior is nonlinear. The increased efficiency and improved operational area for the compressor are provided by this controller without requiring any knowledge or information regarding the compressor characteristic, disturbance upper bound, throttle gain, and throttle valve feature. The adaptive controller has been used to compensate for uncertainties of the compressor characteristic and throttle valve as well as the un-modeled dynamics. Also, the controller robustness is a barrier against the time-varying disturbances in flow and pressure applied to the system. Finally, simulation results showed that the designed controller, in addition to assure the system stability, developed the compressor working range, and the convergence of system states was achieved after applying disturbance in flow and pressure.

Design for Viability of Complex Engineered Systems under Uncertainty

Malek Tahoori,Jafar Gheidar-Kheljani,Mohammad Hossein Karimi Gavara 대한산업공학회 2017 Industrial Engineeering & Management Systems Vol.16 No.4

Complex Engineered Systems generally operate in uncertain environments. Uncertainty can affect the system value delivery through different ways. Viability is the Modern non-functional properties represented as a response to decreasing the impact of dynamic complexities on systems value delivery, therefore system designers used viability principles as an option for executing a design decision or feature in order to respond to variations in the operational context. As there may be numerous system architectures based on different adaptable options, assessing the viability of these architectures under uncertainty as for the basis of compression and selecting the optimized one is an important problem now a day. In this paper for surmounting above problem, a 9 step model is proposed which calculate the viability of assumed architecture under uncertainty by representing the regions in the system that is mostly impacted by the operational uncertainties. To represent the applicability of proposed model a simplified example of Synthetic Aperture Radar satellite observed, the viability of assumed system has been calculated and then some viable options imposed to the system architecture. The recalculated viability value of the assumed system and monitoring of all process steps by experts have shown the applicability and logicality of the model.

Transformation and powder Characteristics of TiO2 during high energy milling

Malek Ali 한양대학교 세라믹연구소 2014 Journal of Ceramic Processing Research Vol.15 No.5

Ball-milling is a way of inducing phase transformations, chemical reactions and changes in the reactivity of solids. Anatase to rutile phase transformation was studied by milled samples. Ball milling was carried out by planetary milling with different milling medium, Ball-to-Powder Ratio (BPR), and different milling time. The results revealed that the anatase to rutile transformation completed after 20 hours by dry milling whereas there is no phase transformation by wet milling even after 60 h milling time. The amount of energy by using (BPR 5 : 1) during all dry milling periods was not enough to transfer the phase from anatase to rutile while anatase phase completely transferred to rutile by using BPR (10 : 1 and 20 : 1). The Crystallite size decreasing with increasing milling time. Crystallite size estimated from X-ray Diffraction (XRD) data. Scanning Electron Microscopy (SEM) micrographs clearly show more agglomeration by using BPR (20 : 1). less agglomeration and smaller size of the powder particles were obtained by wet milling compared to dry milling.

Climate effect on tree-ring widths of Fagus orientalis in the Caspian forests, northern Iran

Malek Haghshenas,Mohammad Reza Marvi Mohadjer,Pedram Attarod,Kambiz Pourtahmasi,Jeff Feldhaus,Seyed Mohammad Moein Sadeghi 한국산림과학회 2016 Forest Science And Technology Vol.12 No.4

This study aims at understanding the impacts of climate factors on the annual growth variations of oriental beech (Fagus orientalis Lipsky) at the Kheyrud Forest Research Station located in the Caspian forests of northern Iran. To this end, 18 disc samples were randomly taken from altitudes of 1038 to 1152 m above sea level. Tree rings were measured using TSAP-win software and a LINTABII machine. Since false and missing rings are typical in beech trees, skeleton plots were created to enhance crossdating accuracy. Chronologies were observed for a total of 15 samples. Meteorological data for rainfall and air temperature were recorded at the Nowshahr Meteorological Station, located near the study sites. Results showed a significant correlation between mean annual air temperature and radial growth (R D 0.54). Within the growing season, August temperatures reveal a significant correlation with tree ring (R D 0.41) while the highest association was observed in the previous December (R D 0.44) and the least association was found in February (R D 0.31). Excluding March (R D 0.33), there appeared to be no significant correlation between precipitation accumulated during and prior to the growing season and tree ring. In addition to oriental beech, there are many other species important to this region that may be sensitive to increasing temperatures.