Disorders of Liver : The Role Of Germinative Layer In Inducing Hydatid Cyst

( Seyed Vahid Hosseini ),( Soheal Mansoorian ),( Seyed Mahmood Sadjjadi ),( Davood Mehrabani ),( Zahra Barzin ),( Nader Tanideh ),( Afshin Amini ),( All Rafati ),( Masoud Amini ) 대한소화기학회 2007 SIDDS Vol.9 No.-

Background/Aims: In spite of use of protoseololeidal agents during surgery, a notable rate of recurrence of disease in post-operation patients is still observed. The question exists is that alive scolices would cause any recurrence or is due to the presence of the germinative layer. The aim of this study was to evaluate the effect of scolicidal agents on this layer as well as its ability of the layer to produce any hydatid disease in an in vivo condition. Methods: Germinative layer of hydatid cyst was separated under sterile condition, was divided into 0.5 cm parts, exposed to various protoseolicidal agents for 2 minutes, and implanted in peritoneal cavity of 62 BALB-C mice. After 9 months, the peritoneum was evaluated macroscopically and microscopically for the presence of any hydatid disease. Results: After 9 months, no hydatid disease was visible in the peritoneum of all the sixty two mice. Conclusions: In this study, the germinative layer could not cause any hydatid disease but positive results of Tarakanovet al. with cultures of protoseolices and the germinative layer cells in the peritoneal cavity mice indicate to a need of another study of implantation of culture cells of the germinated layer lacking protoscolices in a larger animal study to clarify the differences.

CFD study of hydrodynamics behavior of a vibrating fluidized bed using kinetic-frictional stress model of granular flow

Seyyed Hossein Hosseini,Mahmood Reza Rahimi,Nader Azizi,Goodarz Ahmadi 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.3

The hydrodynamics of a vertically vibrating fluidized bed was studied using an Eulerian-Eulerian twofluid model (TFM) incorporating the kinetic theory of granular flow and including the frictional stress effects. Influences of frictional stresses, vibration amplitudes and frequency on behavior of the particles were studied. In the case with vertical vibration, the numerical results showed three regions of solid concentration along the bed height: a low particle concentration region near the bottom of the bed, a high concentration region in the middle of the bed, and a transition region at top of the bed. The accuracy of results was found to be closely related to the inclusion of the frictional stresses. Ability of the two-fluid model for predicting the hydrodynamics of vibrating fluidized beds was discussed and confirmed.

Association between blood pressure and parameters related to sleep disorders in Tabari cohort population

Maryam Rezapour,Mahmood Moosazadeh,Amirhossein Hessami,Mohammad Khademloo,Seyed Hamzeh Hosseini 대한고혈압학회 2022 Clinical Hypertension Vol.28 No.-

Insomnia and other sleep disorders can cause an increase in blood pressure, thereby resulting in premature death. Regarding this, the present study was conducted to investigate the relationship between hypertension and parameters related to sleep disorders in Tabari cohort population.In this cross-sectional study, the data from the enrollment phase of the Tabari cohort study were adopted. Tabari cohort is a part of the PERSIAN (Prospective Epidemiological Research Studies in Iran) cohort study. Data analysis was performed using descriptive and inferential statistics. Out of 10,255 patients enrolled in the Tabari cohort, 2,281 patients (22.2%) had hypertension. According to the results of univariable logistic regression test, the odds ratio of high blood pressure in patients with insomnia and hypersomnia is 1.22 (95% confidence interval [CI], 1.06–1.40) and 1.22 (95% CI, 1.01–1.47) times higher than normal sleep. This odds ratio was not significant after adjusting the effect of sex, age, body mass index, waist circumference, area residence, high-density lipoprotein cholesterol, triglyceride, and total cholesterol variables with multivariable logistic regression. Frequency of routine hypnotic medication usage (14.6% vs. 5.7%, P < 0.001), involuntary napping (25.3% vs. 19%, P < 0.001), and leg restlessness during sleep (14.8% vs. 11.7%, P < 0.001) was higher in hypertensive individuals than in nonhypertensive cases. This study showed that sleep disorders prevalence are higher in hypertensive patients than nonhypertensive patients. Also, routine use of hypnotics was significantly higher medication in patients with hypertension compared to that in the nonhypertensive patients.

Softening and Microstructure Evolution of Pure Copper Disks Processed by High Pressure Torsion

Seyed Amin Hosseini Kahnooj,Majid Vaseghi,Mahmood Sameezadeh 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.11

In this study after designing and manufacturing HPT’s anvils, copper disks with more than 99.99% purity were processedby HPT at two selected pressures for various turns. The results showed that the softening of Cu processed disks occurs veryquickly. Also, the softening range expanded from near the edge to near the center of processed disks, and this range was moreexpanded by increasing turns and pressure. The uniformity of hardness along the radius of the processed disk was obtainedat a pressure of 1.25 GPa for 2 turns. Microhardness-equivalent strain plots showed a maximum pick at the strain of 2–3 andthen it reached a steady-state at the equivalent strain of 5–6. Mean crystallite size and dislocation density were calculatedusing the Rietveld refinement method from XRD patterns. The results illustrated mean crystallite size and dislocation densitydue to recrystallization and recovery decreased by increasing pressure and turn. These results could help long-time applicationsof copper processed by SPD processes that are unusable due to long-time softening.

The Effect of Variation of Stories’ Plan Size along Height of Relatively Tall Steel Buildings on Their Seismic Behavior

Shahbazi Fatemeh,Hosseini Mahmood 한국강구조학회 2024 International Journal of Steel Structures Vol.24 No.1

In urban environments, in many cases, buildings with unequal story plan sizes are desired, resulting in non-uniform mass/ stiff ness distributions along the buildings’ height. In this study, three groups of 12-story steel buildings with uniform, ascending, and descending story plan size distribution (PSD) along their height, but having the same total architectural space, were investigated to determine how this distribution aff ects their seismic performance. First, three site conditions—stiff , medium, and soft—were considered, and all buildings were designed by considering moment frames with concentrical bracings as their lateral load-bearing systems. Then, for each site class, seven appropriate sets of accelerograms were selected, and using nonlinear time history analyses, the buildings’ seismic performance levels were compared based on the formation of plastic hinges (PHs). Results show that non-uniform PSD can be quite eff ective on the seismic performance of buildings’ structures, so that on hard and soft sites, the number of PHs exceeding the collapse prevention performance level in buildings with ascending and descending PSD, respectively, decreases by approximately 30–45% and 20–40% compared with the uniform buildings. Therefore, it is explicitly concluded that employing buildings with uniform plan sizes does not necessarily lead to a higher seismic performance level.

Assessing Markov and Time Homogeneity Assumptions in Multi-state Models: Application in Patients with Gastric Cancer Undergoing Surgery in the Iran Cancer Institute

Zare, Ali,Mahmoodi, Mahmood,Mohammad, Kazem,Zeraati, Hojjat,Hosseini, Mostafa,Naieni, Kourosh Holakouie Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Background: Multi-state models are appropriate for cancer studies such as gastrectomy which have high mortality statistics. These models can be used to better describe the natural disease process. But reaching that goal requires making assumptions like Markov and homogeneity with time. The present study aims to investigate these hypotheses. Materials and Methods: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. To assess Markov assumption and time homogeneity in modeling transition rates among states of multi-state model, Cox-Snell residuals, Akaikie information criteria and Schoenfeld residuals were used, respectively. Results: The assessment of Markov assumption based on Cox-Snell residuals and Akaikie information criterion showed that Markov assumption was not held just for transition rate of relapse (state 1 ${\rightarrow}$ state 2) and for other transition rates - death hazard without relapse (state 1 ${\rightarrow}$ state 3) and death hazard with relapse (state 2 ${\rightarrow}$ state 3) - this assumption could also be made. Moreover, the assessment of time homogeneity assumption based on Schoenfeld residuals revealed that this assumption - regarding the general test and each of the variables in the model- was held just for relapse (state 1 ${\rightarrow}$ state 2) and death hazard with a relapse (state 2 ${\rightarrow}$ state 3). Conclusions: Most researchers take account of assumptions such as Markov and time homogeneity in modeling transition rates. These assumptions can make the multi-state model simpler but if these assumptions are not made, they will lead to incorrect inferences and improper fitting.

Experimental and Numerical Study of Pyramidal Steel Damper for Use in Frames with Diagonal Bracing

Hossein Labibi,Mohsen Gerami,Mahmood Hosseini 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.5

Convergent bracing system has long been considered by structural designers. However, the performance of this system during an earthquake has disadvantages such as high base shear and low energy absorption due to buckling of the braces. Thus, researchers have tried to improve the behavior of the structure by proposing the use of diff erent dampers in the lateral bearing section. Meanwhile, yielding dampers as low-cost dampers with easy manufacturing technology compared to visco-elastic and non-buckling dampers have always attracted the attention of researchers. However, the proposed designs have generally a one-level behavior and the yielding members cause instability of the frame in the case of the failure. Accordingly, in this research, a new type of steel yielding damper with multi-level performance has been introduced, in which the fl exural yield of the parallel trapezoidal plates has been used for the energy absorption process. Also, to ensure the stability of the braced frame in severe earthquakes, a simple support system has been included in its design. The damper has a pyramidal core that can be adjusted for stiff ness and functional levels based on the seismic requirements of the frame. To perform this research, while performing fi nite element modeling, the relevant specimens were made and subjected to cyclic loading experimental tests. Also, a comparative nonlinear time history analyses on a seven story CBF frame has been done. The results indicated the appropriate and stable cyclic behavior of the two-level pyramidal damper, tolerance of cumulative displacements of about 2000 mm, absorption of a signifi cant energy of 50 kJ and signifi cant improvement in time history responses. Finally, multi-line behavior curve and a capacity chart of the damper is presented.

Comparison between Parametric and Semi-parametric Cox Models in Modeling Transition Rates of a Multi-state Model: Application in Patients with Gastric Cancer Undergoing Surgery at the Iran Cancer Institute

Zare, Ali,Mahmoodi, Mahmood,Mohammad, Kazem,Zeraati, Hojjat,Hosseini, Mostafa,Naieni, Kourosh Holakouie Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Background: Research on cancers with a high rate of mortality such as those occurring in the stomach requires using models which can provide a closer examination of disease processes and provide researchers with more accurate data. Various models have been designed based on this issue and the present study aimed at evaluating such models. Materials and Methods: Data from 330 patients with gastric cancer undergoing surgery at Iran Cancer Institute from 1995 to 1999 were analyzed. Cox-Snell Residuals and Akaike Information Criterion were used to compare parametric and semi-parametric Cox models in modeling transition rates among different states of a multi-state model. R 2.15.1 software was used for all data analyses. Results: Analysis of Cox-Snell Residuals and Akaike Information Criterion for all probable transitions among different states revealed that parametric models represented a better fitness. Log-logistic, Gompertz and Log-normal models were good choices for modeling transition rate for relapse hazard (state $1{\rightarrow}state$ 2), death hazard without a relapse (state $1{\rightarrow}state$ 3) and death hazard with a relapse (state $2{\rightarrow}state$ 3), respectively. Conclusions: Although the semi-parametric Cox model is often used by most cancer researchers in modeling transition rates of multistate models, parametric models in similar situations- as they do not need proportional hazards assumption and consider a specific statistical distribution for time to occurrence of next state in case this assumption is not made - are more credible alternatives.

Cyclic Performance and Mechanical Characteristics of the Oval-Shaped Damper

Mehdi Najari Varzaneh,Mahmood Hosseini 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.11

Every year earthquake damage causes hundreds of death all over the world. As much as possible, buildings should be kept in the elastic zone during an earthquake, therefore, the failure of building the main member is reduced. This paper investigated an oval steel shaped yielding damper used for seismic protection of chevron steel braced frames. The damper is designed to deform in-elastically under shear deformation to become energy dissipated. This oval steel shaped damper improves the braces buckling problem and reduces the required area cross section of chevron steel bracing members. To do this, eight models of the damper are proposed. For this purpose, finite element (FE) analysis with ABAQUS software is used to investigate and model the oval-shaped damper (OSD). The present study also investigated the damper strength parameters and seismic performance for applying to the steel braces frame. It is shown that the damper added between the chevron braces and the upper beam can reduce the lateral displacement and base frame force. Hence, the oval steel shaped damper is capable to absorb a great amount of energy with a stable hysteresis behavior. To do this, relationships are proposed and developed based on the maximum capability of the damper. The results show that this damper is responsible for absorbing input energy and increasing ductility frame coefficient. By comparing the analytical method and theoretical results, it is calculated that the proposed equations can be adapted to calculate seismic parameters like ultimate stress, ultimate shear force, plastic moment, elastic stiffness, stiffness degradation, deformation capacity, and resistance of the damper and calculate the exact location of plastic hinge. The structural designer, researchers and someone who like to develop the researches, it can be used and benefit for structural engineering.

Exploring the Potential of Explicit/Implicit Teaching through Plays for EFL Learners’ Pragmatic Development

S. Mohammad Baqerzadeh Hosseini,Mahmood Safari 아시아테플 2018 The Journal of Asia TEFL Vol.15 No.4

The present study investigated the possible contribution of plays as a medium of instruction for pragmatic development through explicit and implicit instruction. To this end, 80 English-major university students formed four intact experimental groups: two literary and two nonliterary groups. One of the literary groups (Implicit Play) received typographically enhanced plays containing the speech acts of apology, request, and refusal, and the other (Explicit Play) received the same plus metapragmatic instruction on the speech acts. The medium of instruction for the nonliterary groups were dialogs containing the given functions; they were also given either enhanced input (Implicit Dialog) or input plus metapragmatic information (Explicit Dialog). All the groups took a written discourse completion test (WDCT) and a multiple-choice discourse completion test (MDCT) before and after instruction. Analysis of the groups’ performance on the WDCT pretest and posttest did not show an advantage for the literary medium, that is, there was no significant difference between literary and nonliterary groups. It was rather the mode of instruction that mattered most; explicit groups outperformed their implicit counterparts. As for the groups’ performance on the MDCT pre and posttest, analyses revealed that the groups had improved, but there was no significant difference among the groups as a result of the four teaching conditions, suggesting that pragmatic instruction regardless of the medium and mode of teaching can improve learners’ knowledge of speech acts.