Power Allocation Framework for OFDMA-based Decode-and-Forward Cellular Relay Networks

Yalda Farazmand,Attahiru S. Alfa 한국통신학회 2014 Journal of communications and networks Vol.16 No.5

In this paper, a framework for power allocation ofdownlink transmissions in orthogonal frequency division multipleaccess-based decode-and-forward cellular relay networks is investigated. We consider a system with a single base station communicatingwith multiple users assisted by multiple relays. The relayshave limited power which must be divided among the usersthey support in order to maximize the data rate of the whole network. Advanced power allocation schemes are crucial for such networks. The optimal relay power allocation which maximizes thedata rate is proposed as an upper bound, by finding the optimalpower requirement for each user based on knapsack problem formulation. Then by considering the fairness, a new relay power allocationscheme, called weighted-based scheme, is proposed. Finally,an efficient power reallocation scheme is proposed to efficiently utilizethe power and improve the data rate of the network. Simulationresults demonstrate that the proposed power allocation schemescan significantly improve the data rate of the network comparedto the traditional scheme.

Human sperm parameter improvement associated with Ceratonia siliqua extract as a cryopreservation supplement after vitrification

Tooba Farazmand,Fatemeh Mansouri,Yeganeh Koohestanidehaghi,Erfan Shahandeh The Korean Society for Reproductive Medicine 2023 Clinical and Experimental Reproductive Medicine Vol.50 No.2

Objective: Given the destructive effects of oxidative stress on sperm structure, this study was conducted to investigate the antioxidant effects of different concentrations of Ceratonia siliqua plant extract on human sperm parameters after the freezing-thawing process. Methods: A total of 20 normozoospermic samples were frozen. Each sample was divided into two control groups (fresh and cryopreservation) and three cryopreservation experimental groups (containing C. siliqua extract at concentrations of 20, 30, and 40 ㎍/mL in the freezing extender). Motility, intracellular levels of reactive oxygen species (ROS), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), viability, and acrosome reaction parameters were evaluated. Results: Statistical analysis showed that the highest motility, viability, and PMI were associated with the 20 ㎍/mL concentration of C. siliqua extract. At all concentrations, intracellular ROS levels were significantly lower and the levels of MMP and the acrosome reaction were significantly higher than in the cryopreservation control group (p≤0.05). Conclusion: C. siliqua extract supplements at concentrations of 20, 30, and 40 ㎍/mL improved sperm motility, viability, PMI, MMP, intracellular ROS, and the acrosome reaction.

Biodegradation of tetrachloroethylene by a newly isolated aerobic Sphingopyxis ummariensis VR13

Neda Badali Varzaghani,Soheila Shokrollahzadeh,Abbas Farazmand 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.8

Chlorinated aliphatic solvents are major sources of groundwater and soil contamination. In this study, an aerobic bacterial strain, Sphingopyxis ummariensis VR13, which has been newly isolated from petrochemical wastewater sludge, was used for the dechlorination of PCE in relatively high concentrations. The addition of a co-substrate as glucose and yeast extract enhanced the dechlorination of PCE. An adaptation of the bacterial cells to PCE resulted in a significant increase in the PCE degradation yield (62.9-39.4%) at relatively high initial PCE concentrations (0.4-5 mM). The adapted cells achieved the highest biodegradation yield (64.8%) in 1.2mM. However, the maximum dechlorination percentage (41.6%) was measured in lower PCE concentration. The kinetic studies showed that PCE degradation was associated with the biomass growth because a higher removal of PCE (64.8%) occurred in a higher cell density. The degradation kinetics of PCE was properly fitted by Monod-like equation with the specific degradation rate of 7.2mmol PCE (g biomass)−1d−1, which was even faster than the reported anaerobic bacteria at this concentration. This strain can be used in the aerobic degradation of PCE.

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.

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.