Heterogeneous SnCl_2/SiO_2 versus Homogeneous SnCl_2 Acid Catalysis in the Benzo[N,N]-heterocyclic Condensation

Hossein Reza Darabi,Kioumars Aghapoor,Farshid Mohsenzadeh,Mohammad Reza Jalali,Shiva Talebian,Leila Ebadi-Nia,Ehsan Khatamifar,Ali Aghaee 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and SnCl_2·2H_2O was finally selected. Among various solid supports activated with SnCl_2, heterogeneous SnCl_2/SiO_2 proved to be the most effective and significantly higher conversions were achieved compared to SnCl_2·2H_2O itself. The results of TG-DTA and BET indicated that dispersed SnCl_2 coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.

Heterogeneous SnCl₂/SiO₂ versus Homogeneous SnCl₂ Acid Catalysis in the Benzo[N,N]-heterocyclic Condensation

Darabi, Hossein Reza,Aghapoor, Kioumars,Mohsenzadeh, Farshid,Jalali, Mohammad Reza,Talebian, Shiva,Ebadi-Nia, Leila,Khatamifar, Ehsan,Aghaee, Ali Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.1

The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and $SnCl_2{\cdot}2H_2O$ was finally selected. Among various solid supports activated with $SnCl_2$, heterogeneous $SnCl_2/SiO_2$ proved to be the most effective and significantly higher conversions were achieved compared to $SnCl_2{\cdot}2H_2O$ itself. The results of TG-DTA and BET indicated that dispersed $SnCl_2$ coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.

Robust Shape Control of Two SMA Actuators Attached to a Flexible Beam Based on DK Iteration

Farshid Alambeigi,Ali Zamani,Gholamreza Vossoughi,Mohammad Reza Zakerzadeh 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10

There has been great demand for shape memory alloy (SMA) wires as actuators for shape control of flexible structures. The experimental setup of this study consists of a flexible beam actuated by two active SMA actuators. The input applied to the SMA actuator in this setup is electrical current while the output is the strain or position. To control strain of the actuator, the SMA wire is heated resistively in order to reach the desired temperature calculated by inverse of the phenomenological model. In heating the SMA wire resistively, the controllable quantity is the heat input to the wire via an applied current. In controller design, changes of physical properties of SMA wires and the surrounding air due to temperature change must be taken into consideration. This adds uncertainty to the presented model. Furthermore, both wires must approach the desired temperature while maintaining the same temperature history. Moreover, a suitable shape control requires overdamped response. A 2-DOF robust controller is designed in this study in order to achieve all the above requirements. The robust controller by the DK iteration method is designed after modeling of the system uncertainties. Required simulations are performed for evaluation of the controller. Obtained results show the ability of controller against time variant uncertainties.

Comparison of postoperative paresthesia after sagittal split osteotomy among different fixation methods: a one year follow-up study

Reza Tabrizi,Kousha Bakrani,Farshid Bastami 대한구강악안면외과학회 2019 대한구강악안면외과학회지 Vol.45 No.4

Objectives: Postoperative paresthesia is a common complication after sagittal split osteotomy (SSO). This study aimed to compare paresthesia among different fixation methods one year postoperative. Materials and Methods: This prospective cohort study assessed subjects in four groups: class II with miniplate fixation (Group 1), class II with three-screw fixation (Group 2), class III with miniplate fixation (Group 3), and class III with three-screw fixation (Group 4). Paresthesia was evaluated one year postoperative based on a 0-10 visual analogue scale. Pearson correlation was used to evaluate associations of age and mandibular movement with paresthesia. ANOVA was used to compare paresthesia among groups. Results: A total of 80 subjects were enrolled, with 20 subjects in each of the four groups. The Pearson correlation test demonstrated a significant correlation between mandibular movement and paresthesia (P=0.001). Comparison of paresthesia among the groups showed significant differences among groups 1 and 2, 2 and 3, and 3 and 4 (P<0.05). Conclusion: The three-screw fixation method led to more paresthesia one year postoperative compared with miniplate fixation. In addition, the magnitude of mandibular movement had a positive correlation with paresthesia.

Current approaches in intensification of long-course chemoradiotherapy in locally advanced rectal cancer: a review

Peiman Haddad,Reza Ghalehtaki,Arefeh Saeedian,Farshid Farhan,Mohammad Babaei,Mahdi Aghili 대한방사선종양학회 2021 Radiation Oncology Journal Vol.39 No.2

Rectal cancer is one of the most prevalent cancers in the world. In many countries, the current standard of care is long-course chemoradiation (CRT), followed by total mesorectal excision. Some efforts have been made by intensifying radiation or chemotherapy components of the neoadjuvant therapy to further decrease the local recurrence and augment surgery’s feasibility and improve the oncological outcomes. This paper reviews recent intensified neoadjuvant interventions in locally advanced rectal cancer (LARC) in terms of efficacy and treatment-related toxicity. Many maneuvers have been made so far to improve the oncological outcomes of rectal cancer with intensified neoadjuvant long-course CRT. Some of these approaches seem compelling and deserve further study, while some have just increased the treatment-related toxicities without evident benefits. Those endeavors with greater pathological complete response than the standard of care may make us await the long-term results on survival rates and chronic treatment-related toxicity. After introduction of neoadjuvant CRT for LARC there have been many efforts to improve its outcomes. Here, this study gathered most of these efforts that intensified the neoadjuvant therapy with some being promising and some being futile.

Preoperative short course radiotherapy with concurrent and consolidation chemotherapies followed by delayed surgery in locally advanced rectal cancer: preliminary results

Mahdi Aghili,Sarvazad Sotoudeh,Reza Ghalehtaki,Mohammad Babaei,Borna Farazmand,Mohammad-Sadegh Fazeli,Amir Keshvari,Peiman Haddad,Farshid Farhan 대한방사선종양학회 2018 Radiation Oncology Journal Vol.36 No.1

Purpose: This study aimed to assess complications and outcomes of a new approach, that is, combining short course radiotherapy (SRT), concurrent and consolidative chemotherapies, and delayed surgery. Materials and Methods: In this single arm phase II prospective clinical trial, patients with T3-4 or N+ M0 rectal adenocarcinoma were enrolled. Patients who received induction chemotherapy or previous pelvic radiotherapy were excluded. Study protocol consisted of three-dimensional conformal SRT (25 Gy in 5 fractions in 1 week) with concurrent and consolidation chemotherapies including capecitabine and oxaliplatin. Total mesorectal excision was done at least 8 weeks after the last fraction of radiotherapy. Primary outcome was complete pathologic response and secondary outcomes were treatment related complications. Results: Thirty-three patients completed the planned preoperative chemoradiation and 26 of them underwent surgery (24 low anterior resection and 2 abdominoperineal resection). Acute proctitis grades 2 and 3 were seen in 11 (33.3%) and 7 (21.2%) patients, respectively. There were no grades 3 and 4 subacute hematologic and non-hematologic (genitourinary and peripheral neuropathy) toxicities and perioperative morbidities such as anastomose leakage. Grade 2 or higher late toxicities were observed among 29.6% of the patients. Complete pathologic response was achieved in 8 (30.8%) patients who underwent surgery. The 3-year overall survival and local control rates were 65% and 94%, respectively. Conclusion: This study showed that SRT combined with concurrent and consolidation chemotherapies followed by delayed surgery is not only feasible and tolerable without significant toxicity but also, associated with promising complete pathologic response rates.

Preoperative short course radiotherapy with concurrent and consolidation chemotherapies followed by delayed surgery in locally advanced rectal cancer: preliminary results

Aghili, Mahdi,Sotoudeh, Sarvazad,Ghalehtaki, Reza,Babaei, Mohammad,Farazmand, Borna,Fazeli, Mohammad-Sadegh,Keshvari, Amir,Haddad, Peiman,Farhan, Farshid The Korean Society for Radiation Oncology 2018 Radiation Oncology Journal Vol.36 No.1

Purpose: This study aimed to assess complications and outcomes of a new approach, that is, combining short course radiotherapy (SRT), concurrent and consolidative chemotherapies, and delayed surgery. Materials and Methods: In this single arm phase II prospective clinical trial, patients with T3-4 or N+ M0 rectal adenocarcinoma were enrolled. Patients who received induction chemotherapy or previous pelvic radiotherapy were excluded. Study protocol consisted of three-dimensional conformal SRT (25 Gy in 5 fractions in 1 week) with concurrent and consolidation chemotherapies including capecitabine and oxaliplatin. Total mesorectal excision was done at least 8 weeks after the last fraction of radiotherapy. Primary outcome was complete pathologic response and secondary outcomes were treatment related complications. Results: Thirty-three patients completed the planned preoperative chemoradiation and 26 of them underwent surgery (24 low anterior resection and 2 abdominoperineal resection). Acute proctitis grades 2 and 3 were seen in 11 (33.3%) and 7 (21.2%) patients, respectively. There were no grades 3 and 4 subacute hematologic and non-hematologic (genitourinary and peripheral neuropathy) toxicities and perioperative morbidities such as anastomose leakage. Grade 2 or higher late toxicities were observed among 29.6% of the patients. Complete pathologic response was achieved in 8 (30.8%) patients who underwent surgery. The 3-year overall survival and local control rates were 65% and 94%, respectively. Conclusion: This study showed that SRT combined with concurrent and consolidation chemotherapies followed by delayed surgery is not only feasible and tolerable without significant toxicity but also, associated with promising complete pathologic response rates.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: preliminary results of a randomized controlled trial

Mahdi Aghili,Nastaran Khalili,Neda Khalili,Mohammad Babaei,Farshid Farhan,Peiman Haddad,Samaneh Salarvand,Amir Keshvari,Mohammad Sadegh Fazeli,Negin Mohammadi,Reza Ghalehtaki 대한방사선종양학회 2020 Radiation Oncology Journal Vol.38 No.2

Purpose: Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients. Materials and Methods: In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/㎡ from day 1-5 twice daily and oxaliplatin 50 mg/㎡ on day 1 once daily). Patients in group II (long-course) received a total dose of 50-50.4 Gy/25-28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m2 twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade. Results: In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in the group II (long-course) was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the short-course and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333). Conclusion: For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

Strongyloides stercoralis and other intestinal parasites in patients receiving immunosuppressive drugs in northern Iran: a closer look at risk factors

Leila Mirzaei,Keyhan Ashrafi,Zahra Atrkar Roushan,Mohammad Reza Mahmoudi,Irandokht Shenavar Masooleh,Behnaz Rahmati,Farshid Saadat,Hamed Mirjalali,Meysam Sharifdini 한국역학회 2021 Epidemiology and Health Vol.43 No.-

OBJECTIVES: The objective of this study was to evaluate the prevalence of Strongyloides stercoralis and other intestinal parasites in patients receiving immunosuppressive drugs in northern Iran and to investigate related risk factors. METHODS: This cross-sectional study was conducted among 494 patients receiving immunosuppressive drugs, including cancer patients undergoing chemotherapy (n=188) and those treated with prolonged corticosteroid administration (n=306). All fresh fecal samples were examined using the direct wet-mount, formalin ethyl acetate concentration, and agar plate culture techniques. RESULTS: In total, 16.8% of patients were positive for at least 1 intestinal parasite; the helminthic and protozoan infection rates were 5.1% and 12.3%, respectively. The infection rate was significantly higher in corticosteroid-treated individuals (19.6%) than cancer patients (12.2%) (p<0.05). The prevalence rate of S. stercoralis among patients receiving chemotherapy and those treated with corticosteroids were 4.3% and 5.2%, respectively. The prevalence rate of S. stercoralis infection was significantly higher in older patients (p<0.05). CONCLUSIONS: Strongyloidiasis is one of the most common parasites among patients receiving immunosuppressive drugs in northern Iran. Early diagnosis and proper treatment of these patients are necessary to minimize the complications of severe strongyloidiasis.

An approach to minimize reactivity penalty of Gd2O3 burnable absorber at the early stage of fuel burnup in Pressurized Water Reactor

Nabila Umme Mahbuba,Sahadath Md. Hossain,Hossain Md. Towhid,Reza Farshid 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.9

The high capture cross-section (sc) of Gadolinium (Gd-155 and Gd-157) causes reactivity penalty and swing at the initial stage of fuel burnup in Pressurized Water Reactor (PWR). The present study is concerned with the feasibility of the combination of mixed burnable poison with both low and high sc as an approach to minimize these effects. Two considered reference designs are fuel assemblies with 24 IBA rods of Gd2O3 and Er2O3 respectively. Models comprise nuclear fuel with a homogeneous mixture of Er2O3, AmO2, SmO2, and HfO2 with Gd2O3 as well as the coating of PaO2 and ZrB2 on the Gd2O3 pellet's outer surface. The infinite multiplication factor was determined and reactivity was calculated considering 3% neutron leakage rate. All models except Er2O3 and SmO2 showed expected results namely higher values of these parameters than the reference design of Gd2O3 at the early burnup period. The highest value was found for the model of PaO2 and Gd2O3 followed by ZrB2 and HfO2. The cycle burnup, discharge burnup, and cycle length for three batch refueling were calculated using Linear Reactivity Model (LRM). The pin power distribution, energy-dependent neutron flux and Fuel Temperature Coefficient (FTC) were also studied. An optimization of model 1 was carried out to investigate effects of different isotopic compositions of Gd2O3 and absorber coating thickness