Frequency and voltage partitioning in presence of renewable energy resources for power system (example: North Chile power network)

This paper investigates techniques for frequency and voltage partitioning of power network based on the graph-theory. These methods divide the power system into distinguished regions to avoid the spread of disturbances and to minimize the interaction between these regions for frequency and voltage control of power system. In case of required active and reactive power for improving the performance of the power system, control can be performed regionally instead of a centralized controller. In this paper, renewable energy sources are connected to the power network to verify the effect of these sources on the power systems partitioning and performance. The number of regions is found based on the frequency sensitivity for frequency partitioning and bus voltage for voltage partitioning to disturbances being applied to loads in each region. The methodology is applied to the north part of Chile power network. The results show the performance and ability of graph frequency and voltage partitioning algorithm to divide large scale power systems to smaller regions for applying decentralized controllers.Peer ReviewedPostprint (published version

Investigation of NQO1 genetic polymorphism, NQO1 gene expression and PAH-DNA adducts in ESCC. A case-control study from Iran

We evaluated the effect of NQO1 genetic variation on PAH-DNA adducts in esophageal squamous cell carcinoma (ESCC) in northeast Iran. Golestan Province in northeast of Iran has one of the highest esophageal cancer incidences in the world. The study included 93 ESCC cases and 50 control individuals who were seen at the clinical cancer center in Golestan province. NQO1 C609T genotypes were determined by PCR-RFLP analysis. NQO1 gene expression in tissue samples was determined by quantitative real-time PCR. Immunohistochemical techniques were used to detect PAH-DNA adducts in ESCC and normal esophageal tissues. The distributions of NQO1 genetic polymorphism between cases and the control group were not significantly different. NQO1 gene expression was not higher in tumor tissues than in normal esophageal tissues adjacent to the ESCC; expression was higher in tumor tissues that had the NQO1 T allele. NQO1 gene expression was high in normal esophageal tissues. The level of PAH-DNA adducts was significantly higher in ESCC tissues of cases than in normal tissues adjacent to tumor tissues and in normal esophageal tissues of healthy controls. There were no significant differences between the adduct levels of normal esophageal tissues of patients and controls. There was also no significant relationship between cigarette smoking and PAH-DNA adducts. We concluded that PAHs are a risk factor for ESCC and that PAH-DNA adducts have potential as a biomarker for risk of ESCC

Combination of gastric atrophy, reflux symptoms and histological subtype indicates two distinct aetiologies of gatric cardia cancer.

<b>INTRODUCTION</b> Atrophic gastritis is a risk factor for non-cardia gastric cancer, and gastro-oesophageal reflux disease (GORD) for oesophageal adenocarcinoma. The role of atrophic gastritis and GORD in the aetiology of adenocarcinoma of the cardia remains unclear. We have investigated the association between adenocarcinoma of the different regions of the upper gastrointestinal tract and atrophic gastritis and GORD symptoms. <b>METHODS</b> 138 patients with upper GI adenocarcinoma and age and sex matched controls were studied. Serum pepsinogen I/II was used as a marker of atrophic gastritis and categorised to five quintiles. History of GORD symptoms, smoking and H.pylori infection was incorporated in logistic regression analysis. Lauren classification of gastric cancer was used to subtype gastric and oesophageal adenocarcinoma. <b>RESULTS</b> Non-cardia cancer was associated with atrophic gastritis but not with GORD symptoms; 55% of these cancers were intestinal subtype. Oesophageal adenocarcinoma was associated with GORD symptoms, but not with atrophic gastritis; 84% were intestinal subtype. Cardia cancer was positively associated with both severe gastric atrophy [OR, 95% CI: 3.92 (1.77 – 8.67)] and with frequent GORD symptoms [OR, 95% CI: 10.08 (2.29 – 44.36)] though the latter was only apparent in the nonatrophic subgroup and in the intestinal subtype. The association of cardia cancer with atrophy was stronger for the diffuse versus intestinal subtype and this was the converse of the association observed with non-cardia cancer. <b>CONCLUSION</b> These findings indicate two distinct aetiologies of cardia cancer, one arising from severe atrophic gastritis and being of intestinal or diffuse subtype similar to non-cardia cancer, and one related to GORD and intestinal in subtype, similar to oesophageal adenocarcinoma. Gastric atrophy, GORD symptoms and histological subtype may distinguish between gastric versus oesophageal origin of cardia cancer

Chromogenic in situ hybridisation test for breast cancer patients with equivocal IHC results - A study from Iran

Background: HER2/neu overexpression on cell membranes of breast cancer cells is due to HER2/neu gene amplification and it is important to identify potential candidates for anti HER2 therapy with trastuzumab. IHC, FISH and CISH are standard FDA approved assays currently used to determine HER2 status in routine practice. The aim of this study was to determine HER2 gene amplification, using the CISH method in breast carcinoma samples which had IHC +2 reactions. Materials and Methods: This study was conducted from 2008-2010 using 334 consecutive breast carcinoma samples referred from local laboratories to Mehr Hospital. CISH assays were performed for all cases, and IHC tests were also done for determining efficacy and accuracy of local labs. HER2 status in local IHC tests was compared with central IHC and CISH results. Results: Of 334 breast cancer patients, 16 were negative for HER2 IHC (0, +1), 201 cases were equivocal (+2), and 31 positive (+3). Of 334 referral cases, 88 were CISH positive (26.3) and 246 were CISH negative (73.7). Of 201 IHC +2 cases, HER2 gene amplification was observed in 42 cases (kappa: 0.42). A 29.9 concordance was found between local IHC and central IHC. Sensitivity and specificity of local IHC were 90 and 53.8, respectively. Conclusions: Low accuracy of IHC results in local labs was associated with the following factors: using former FDA-approved criteria for HER2 interpretation, utilizing non-validated kits, and lack of any quality assurance program. Therefore, following the new 2014 ASCO/CAP guideline and comprehensive quality assurance should be implemented to ensure accuracy of HER2 testing

Benign metastasizing leiomyoma of the uterus

Herein, we report on a well-characterized benign metastasizing lelomyoma, presented in an unusual site. Up to the knowledge of authors, so far, only 76 cases of benign metastasizing leiomyoma have been reported. The tumor presented as a retroperitoneal mass three years after a hysterectomy Performed for leiomyomatosis of the uterus with extensive areas of hyalinization. Histopathologic and immunohistochemical studies of the resected mass were similar to the uterine leiomyoma, showing moderate cellularity of bland looking smooth muscle cells with minimal atypia, inconspicuous mitosis, and no necrosis in a hyalinized background

Relationship study of the verified human epidermal growth factor receptor 2 amplification with other tumor markers and clinicohistopathological characteristics in patients with invasive breast cancer, using chromogenic in situ hybridization

Objective: Human epidermal growth factor receptor 2 (HER-2), as a crucial factor involved in about 20 of breast cancer cases, is one of the most reliable tumor markers to determine prognosis and therapeutic trend of this disease. This marker is generally assessed by immunohistochemistry (IHC) technique. In the cases that result of IHC test cast doubt (+2), the test should be repeated or validated by applying in situ hybridization techniques, like chromogenic in situ hybridization (CISH). In this regard, the goal of current study was to figure out the link between different clinicopathological characteristics of patients suffering from invasive breast cancer, using tumor markers, hormone receptor (HR) and HER-2. Comparing IHC and CISH techniques for evaluating diagnostic value and usefulness of HER-2 were also the other objective of this study. Materials and Methods: Based on this retrospective study, histological markers of 113 individuals suffering from invasive breast cancer -such as estrogen receptor (ER), progesterone receptor, HER-2 receptor, E-cadherin, CK5/6, vimentin and Ki67 were examined by IHC technique. HER-2 amplification of all patients was also evaluated by CISH. Clinicopathological information of the patients was also extracted from medical documents and their associations with tumor markers were statistically evaluated. Results: There is a significant relationship between tumor size, CK5/6 and tumor grade with HR status. Similar relationship was observed between HER-2 status and HR status, as well as vascular invasion (P<0.05). The comparison of HER-2 amplification showed no complete concordance of the result obtained from these two techniques, with score +3. Conclusion: Since the status of HER-2 is very important in decision making of the treatment process, CISH technique is recommended in the malignant conditions as the primary test, instead of IHC. In this study, we also determined that HER-2 expression is greatly correlated with ER- and PR- status. This might propose a better prognosis for HER-2+ patients. © 2019 Royan Institute (ACECR). All rights reserved

The prevalence and associated factors of microsatellite instability in ovarian epithelial cancers detected by molecular genetic studies in a sample of Iranian women

Background: Microsatellite instability, the main genetic element in HNPCC syndrome, is associated with a number of cancers, including ovarian epithelial carcinomas. These cancers have distinct characteristics compared to non-MSI related ones. Objectives: The present study aims at determining the prevalence of microsatellite instability in ovarian carcinomas and their associated factors in Iranian patients. Methods: Paraffin-embedded blocks, belonging to 37 patients with definite diagnosis of ovarian epithelial cancers, were retrieved from the archives. After DNA extraction from tumor tissue and PCR reaction, the results were assessed in accordance with melting curve analysis. Subsequently, the relationship among microsatellite status and tumor histology, grade, stage, and size were investigated statistically. Results: The predominant histological type was serous histology. Four out of 37 carcinomas were microsatellite unstable (10.8) and only 1 was MSI-high type (2.1). The MSI was more frequent among younger patients with unilateral, non-serous histology, non-high grade, and stage I tumors without omental involvement. After statistical analysis, the only significant relationship was found between histological type (non-serous) and microsatellite status. Conclusions: Microsatellite stable and unstable ovarian cancers may have different associations with various factors in a sample of Iranian women. The identification of these characteristics may help narrow down indications to test this prognostic and predictive genetic error. © 2017, Cancer Research Center (CRC), Shahid Beheshti University of Medical Sciences

The prevalence and associated factors of microsatellite instability in ovarian epithelial cancers detected by molecular genetic studies in a sample of Iranian women

Background: Microsatellite instability, the main genetic element in HNPCC syndrome, is associated with a number of cancers, including ovarian epithelial carcinomas. These cancers have distinct characteristics compared to non-MSI related ones. Objectives: The present study aims at determining the prevalence of microsatellite instability in ovarian carcinomas and their associated factors in Iranian patients. Methods: Paraffin-embedded blocks, belonging to 37 patients with definite diagnosis of ovarian epithelial cancers, were retrieved from the archives. After DNA extraction from tumor tissue and PCR reaction, the results were assessed in accordance with melting curve analysis. Subsequently, the relationship among microsatellite status and tumor histology, grade, stage, and size were investigated statistically. Results: The predominant histological type was serous histology. Four out of 37 carcinomas were microsatellite unstable (10.8) and only 1 was MSI-high type (2.1). The MSI was more frequent among younger patients with unilateral, non-serous histology, non-high grade, and stage I tumors without omental involvement. After statistical analysis, the only significant relationship was found between histological type (non-serous) and microsatellite status. Conclusions: Microsatellite stable and unstable ovarian cancers may have different associations with various factors in a sample of Iranian women. The identification of these characteristics may help narrow down indications to test this prognostic and predictive genetic error. © 2017, Cancer Research Center (CRC), Shahid Beheshti University of Medical Sciences

Sensitive high-resolution melting analysis for screening of kras and braf mutations in Iranian human metastatic colorectal cancers

Background: Investigations of methods for detection of mutations have uncovered major weaknesses of direct sequencing and pyrosequencing, with their high costs and low sensitivity in screening for both known and unknown mutations. High resolution melting (HRM) analysis is an alternative tool for the rapid detection of mutations. Here we describe the accuracy of HRM in screening for KRAS and BRAF mutations in metastatic colorectal cancer (mCRCs) samples. Materials and Methods: A total of 1000 mCRC patients in Mehr Hospital, Tehran, Iran, from Feb 2008 to May 2012 were examined for KRAS mutations and 242 of them were selected for further assessment of BRAF mutations by HRM analysis. In order to calculate the sensitivity and specificity, HRM results were checked by pyrosequencing as the golden standard and Dxs Therascreen as a further method. Results: In the total of 1,000 participants, there were 664 (66.4) with wild type and 336 (33.6) with mutant codons 12 and/or 13 of the KRAS gene. Among 242 samples randomly checked for the BRAF gene, all were wild type by HRM. Pyrosequencing and Dxs Therascreen results were in line with those of the HRM. In this regard, the sensitivity and specificity of HRM were evaluated as 100. Conclusion: The findings suggest that the HRM, in comparison with DNA sequencing, is a more appropriate method for precise scanning of KRAS and BRAF mutations. It is also possible to state that HRM may be an attractive technique for the detection of known or unknown somatic mutations in other genes