Impact of Time Interval Between Chemoradiation and Surgery on Pathological Complete Response and Survival in Rectal Cancer

Akbar, Ali,Bhatti, Abu Bakar Hafeez,Niazi, Samiullah Khan,Syed, Amir Ali,Khattak, Shahid,Raza, Syed Hassan,Kazmi, Ather Saeed Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.1

Background: Limited data are available regarding the impact of time duration between chemoradiation (CRT) and surgery on pathological complete response (PCR). A PCR translates into better overall and disease free survival. The objective of this study was to determine effect of time duration on outcome after preoperative CRT in rectal cancer. Materials and Methods: A retrospective review of patients undergoing operations for rectal adenocarcinoma between January 2005 and December 2010 was performed. Patients were divided in two groups: Group 1 underwent surgery in ${\leq}8weeks$ post neoadjuvant CRT and Group 2 after 8 weeks. Patient characteristics, surgical procedure, histopathological details and number of loco-regional and distant failures were compared. Expected 5 year overall survival and disease free survival was calculated using Kaplan Meier curves and significance was determined using the log rank test. Results: There were 66 patients in group 1 and 93 in group 2. No significant difference in PCR was observed between the two. However, estimated 5 year DFS was significantly higher in Group 1 (66.7%) as compared to Group 2 (53.8%) (P=0.04). Estimated overall 5 year overall survival was not significantly different at 68.2% versus 54.3% (P= 0.09). Conclusions: Delaying surgery more than 8 weeks after preoperative CRT does not impact for PCR in rectal cancer.

Outcome of Rectal Cancer in Patients Aged 30 Years or Less in the Pakistani Population

Akbar, Ali,Bhatti, Abu Bakar Hafeez,Khattak, Shahid,Syed, Aamir Ali,Kazmi, Ather Saeed,Jamshed, Aarif Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Background: The incidence of rectal cancer is increasing in younger age groups. Limited data is available regarding survival outcome in younger patients with conflicting results from western world. The goal of this study was to determine survival in patients with rectal cancer <30 years of age and compare it with their older counterparts in the Pakistani population. Materials and Methods: A retrospective chart review of patients operated for rectal adenocarcinoma between January 2005 and December 2010 was performed. Patients were divided into two groups, Group 1 aged ${\leq}30years$ and Group 2 aged >30years. Patient characteristics, surgical procedure, histopathological details and number of loco-regional and distant failures were compared. Expected 5 year survival was calculated using Kaplan Meier curves and significance was determined using the Log rank test. Results: There were 38 patients in group 1 and 144 in group 2. A significantly high number of younger patients presented with poorly differentiated histology (44.7% vs 9.7%) (p=0.0001) and advanced pathological stage (63.1% vs 38.1%) (p=0.04). Predicted overall 5 year survival was 38% versus 57% in groups I and II, respectively (p=0.05). Disease free survival was 37% versus 52% and was significantly different (p=0.007). Conclusions: Early onset rectal cancer is associated with poor pathological features and a worse outcome in Pakistani population.

Measurement of deuterium concentration in heavy water utilizing prompt gamma neutron activation analysis (PGNAA) in comparison with MCNPX simulation results

Salahi Saeed,Mokhtari Dorostkar Mahdieh,Abdi Saray Akbar 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.11

Considering the importance of deuterium in nuclear science including medical and industrial researches such as (BNCT) and nuclear reactors respectively, it is important to study various possible ways in addition to common methods for measuring its concentration. This study is an effort to measure deuterium concentration using PGNAA. The main idea is to calculate the area under 2.23 MeV gammarays photo peak resulting from neutron collision with Hydrogen atoms which are in mix with deuterium in samples. The study carried out by both simulation and experiment. Monte Carlo MCNPX2.6 code has been used for simulation and based on its acceptable results an experimental setup has been arranged. The coordination of results was in the range of R ¼ 0.99 and R ¼ 0.98 in simulation and experiment respectively. The accuracy of the study has been investigated by measuring the concentration of an unknown sample by both PGNAA and Fourier transform infrared spectroscopy (FT-IR) methods in which there were acceptable correlation between these two methods.

Effect of Stress Conditions on Collapse Deformation Behavior of a Rockfill Material

Ali Akbar Heshmati,Ahmadreza Tabibnejad,Hossein Salehzadeh,Saeed Hashemi Tabatabaei 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.6

A set of saturated and dry-saturated large-scale triaxial tests were conducted in order to explore the effects of stress conditions on the saturation-induced collapse deformation behavior of a rockfill material. Specimens were tested in different confining pressures and for dry-saturated tests the specimens were submerged in various shear stress levels. The results indicate that in all of the drysaturated tests a sudden reduction in the volume of the specimens was observed during the submerging process. The ratio of the minimum axial strength of a submerged specimen (at the end of the saturation process) to the shear strength of the specimen before saturation is defined as the coefficient of stress recovery, Csr. Results of the dry-saturated tests showed that this ratio increases as the confining pressure increases and decreases by increasing the shear stress level. According to the results of dry-saturated tests the values of internal friction angle reduction caused by saturation (Δφc), the ratio of the elasticity modulus of the material after saturation to its elasticity modulus in dry condition, i.e., Ewet/Edry, and also the saturation induced sudden volumetric strain (εvc) decrease as the confining pressure increases. However the shear stress level does not have any meaningful effect on the variation of Dfc, Ewet/Edry and (εvc).

Effect of Gradation Curve and Dry Density on Collapse Deformation Behavior of a Rockfill Material

Ahmadreza Tabibnejad,Ali Akbar Heshmati,Hossein Salehzadeh,Saeed Hashemi Tabatabaei 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.3

Rockfill material, such as other coarse grained materials, undergoes rapid or sudden settlements of relatively large values, withoutany changes in the applied loads and only because of submerging. In the literature this phenomenon is called collapse deformation. The effects of gradation curve and dry density on the collapse deformation behavior of a rockfill material were explored and thechanges in the strength and deformability parameters of this material caused by submerging were determined. Two large scale triaxialequipments with three different sample diameters of 20, 30 and 80 cm were employed and a set of dry-saturated tests wereconducted. Specimens with different gradation curves and various initial dry densities were tested. The results indicate that in all ofthe dry-saturated tests, sudden reductions in the shear strengths and volumes of the specimens were observed during the submergingprocess. The effects of material maximum particle size, fines content and initial dry density on the value of sudden shear strengthreduction, internal friction angle reduction caused by saturation (Δφc), the change in elasticity modulus of the material due tosubmerging, i.e., (Ewet/Edry), and also the saturation-induced sudden volumetric strain (εvc) were evaluated and discussed.

Qualitative study of the fractional order nonlinear chaotic model: electronic realization and secure data enhancement

Khan Najeeb Alam,Akbar Saeed,Qureshi Muhammad Ali,Hameed Tooba,Khan Nadeem Alam 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.2

In this work, we explore the superposition of two well-known chaotic oscillators, namely, the Duffing double-well and the forced van der Pol with the fractional order derivative. The proportional fractional derivative has been taken for numerical simulations and highly chaotic solution to improve some information of security systems has been found. The existence and the uniqueness of a super system are stated in the form of theorems using the Lipschitz condition locally. The qualitative properties of chaotic dynamics are described by mean of Lyapunov exponent (LE), eigenvalues, bifurcation and Poincaré maps. The analog circuit is also intended, with the help of different physical instruments, to validate the superposition of chaotic systems. The randomness level of a superposition chaotic system is tested via standard test suite, and the qualified set of a 32-bit array with high haphazardness is used for encryption as well as decryption. Furthermore, a security analysis is performed using different parameters, such as the uncertainty, similarity etc. The outcomes for the properties, time evolution, phase portrait, and oscilloscopic views are presented in tabulated and graphical forms.

Analytical solution for analyzing initial curvature effect on vibrational behavior of PM beams integrated with FGP layers based on trigonometric theories

Mousavi, S. Behnam,Amir, Saeed,Jafari, Akbar,Arshid, Ehsan Techno-Press 2021 Advances in nano research Vol.10 No.3

In the current study, the free vibrational behavior of a Porous Micro (PM) beam which is integrated with Functionally Graded Piezoelectric (FGP) layers with initial curvature is considered based on the two trigonometric shear deformation theories namely SSDBT and Tan-SDBT. The structure's mechanical properties are varied through its thicknesses following the given functions. The curved microbeam is exposed to electro-mechanical preload and also is rested on a Pasternak type of elastic foundation. Hamilton's principle is used to extract the motion equations and the MCST is used to capture the size effect. Navier's solution method is selected as an analytical method to solve the motion equations for a simply supported ends case and by validating the results for a simpler state with previously published works, effects of different important parameters on the behavior of the structure are considered. It is found that although increasing the porosity reduces the natural frequency, but enhancing the volume fraction of CNTs increasing it. Also, by increasing the central angle of the curved beam the vibrations of the structure increases. Designing and manufacturing more efficient smart structures such as sensors and actuators are of the aims of this study.

Effect of Cationic and Anionic Porphyrins on the Structure and Activity of Adenosine Deaminase

Davood Ajloo,Samaneh Hajipour,Ali Akbar Saboury,Saeed Zakavi 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.9

Kinetic and structural studies have been carried out on the effects of meso-tetrakis(4-sulfonatophenyl)-porphyrin (H_2TPPS_4) as an anionic and meso-tetrakis(3-N-methyl-pyridyl)porphyrin (H_2TMPYP) as a cationic porphyrin with adenosine deaminase (ADA) in 25 mM citrate/phosphate buffer, pH = 4-8, at 37 ^oC using UVvis spectrophotometry, circular dichroism (CD), fluorescence spectrophotometry as well as molecular dynamics (MD) and molecular docking. Kinetic results showed that the two porphyrins are non-competitive inhibitors. Increasing pH, increases K_I and cationic porphyrin has a higher K_I and lower binding constant (K_b)at all pH ranges. Analyzing the secondary structure revealed that both ligands decrease the secondary structure and that the anionic porphyrin is more effective.

Diversity in Betasatellites Associated with Cotton Leaf Curl Disease During Source-To-Sink Movement Through a Resistant Host

Iftikhar Ali Khan,Khalid Pervaiz Akhtar,Fazal Akbar,Ishtiaq Hassan,Imran Amin,Muhammad Saeed,Shahid Mansoor 한국식물병리학회 2016 Plant Pathology Journal Vol.32 No.1

Cotton leaf curl is devastating disease of cotton characterized by leaf curling, vein darkening and enations. The disease symptoms are induced by DNA satellite known as Cotton leaf curl Multan betasatellite (CLCuMuB), dominant betasatellite in cotton but another betasatellite known as Chili leaf curl betasatellite (ChLCB) is also found associated with the disease. Grafting experiment was performed to determine if host plant resistance is determinant of dominant population of betasatellite in cotton (several distinct strains of CLCuMuB are associated with the disease). Infected scion of Gossypium hirsutum collected from field (the source) was grafted on G. arboreum, a diploid cotton species, resistant to the disease. A healthy scion of G. hirsutum (sink) was grafted at the top of G. arboreum to determine the movement of virus/betasatellite to upper susceptible scion of G. hirsutum. Symptoms of disease appeared in the upper scion and presence of virus/betasatellite in the upper scion was confirmed via molecular techniques, showing that virus/betasatellite was able to move to upper scion through resistant G. arboreum. However, no symptoms appeared on G. arboreum. Betasatelites were cloned and sequenced from lower scion, upper scion and G. arboreum which show that the lower scion contained both CLCuMuB and ChLCB, however only ChLCB was found in G. arboreum. The upper scion contained CLCuMuB with a deletion of 78 nucleotides (nt) in the non-coding region between Arich sequence and βC1 gene and insertion of 27 nt in the middle of βC1 ORF. This study may help in investigating molecular basis of resistance in G. arboreum.

Diversity in Betasatellites Associated with Cotton Leaf Curl Disease During Source-To-Sink Movement Through a Resistant Host

Khan, Iftikhar Ali,Akhtar, Khalid Pervaiz,Akbar, Fazal,Hassan, Ishtiaq,Amin, Imran,Saeed, Muhammad,Mansoor, Shahid The Korean Society of Plant Pathology 2016 Plant Pathology Journal Vol.32 No.1

Cotton leaf curl is devastating disease of cotton characterized by leaf curling, vein darkening and enations. The disease symptoms are induced by DNA satellite known as Cotton leaf curl Multan betasatellite (CLCuMuB), dominant betasatellite in cotton but another betasatellite known as Chili leaf curl betasatellite (ChLCB) is also found associated with the disease. Grafting experiment was performed to determine if host plant resistance is determinant of dominant population of betasatellite in cotton (several distinct strains of CLCuMuB are associated with the disease). Infected scion of Gossypium hirsutum collected from field (the source) was grafted on G. arboreum, a diploid cotton species, resistant to the disease. A healthy scion of G. hirsutum (sink) was grafted at the top of G. arboreum to determine the movement of virus/betasatellite to upper susceptible scion of G. hirsutum. Symptoms of disease appeared in the upper scion and presence of virus/betasatellite in the upper scion was confirmed via molecular techniques, showing that virus/betasatellite was able to move to upper scion through resistant G. arboreum. However, no symptoms appeared on G. arboreum. Betasatelites were cloned and sequenced from lower scion, upper scion and G. arboreum which show that the lower scion contained both CLCuMuB and ChLCB, however only ChLCB was found in G. arboreum. The upper scion contained CLCuMuB with a deletion of 78 nucleotides (nt) in the non-coding region between Arich sequence and ${\beta}C1$ gene and insertion of 27 nt in the middle of ${\beta}C1$ ORF. This study may help in investigating molecular basis of resistance in G. arboreum.