19 research outputs found
Analysis of UV induced dehydrochlorinated PVC (With hydroquinone) using direct pyrolysis mass spectrometry (DPMS), TGA, UV/VIS-NIR and FTIR techniques
Cataloged from PDF version of article.Poly(vinyl chloride) (PVC) degrades easily upon heat and light exposure via loss of HCl.
The mechanism of this process is well understood, known as the zip mechanism and the
dehydrochlorination results in conjugated segments, polyenes. It is also possible to utilize
PVC polymer as an in-situ acid donor since the main degradation product is HCl.
Addition of hydroquinone (HQ) into PVC matrix sensitizes the photodehydrochlorination
of PVC at 312 nm.
In this study the effects of photodehydrochlorination on thermal and material properties
of PVC were investigated using DPMS and TGA as well as UV-Vis-NIR and FTIR
techniques. In addition, the photodegradation of PVC/PVAc blend, copolymer (PVC-coPVAc)
and PVAc were similarly investigated. Dehydrochlorination of the polymers
resulting from UV-exposure were also investigated for doping of PANI in blends.
HCl evolution behavior of the UV dehydrochlorinated PVC exhibits a characteristic
property which is different from the unirradiated ones. Both DPMS and TGA results
confirms the sensitization of PVC photodehydrochlorination at 312 nm by hydroquinone
(HQ) resulting in a temperature onset that is the lowest (140
oC). HQ assistance upon 312
nm UV exposure is not significantly observed in the copolymer. The low temperature onset of UV-induced copolymer is a promising result to produce longer polyene chains,
since polymer backbone starts to decompose after ca. 220
oC, using copolymer might be
an alternative to PVC.Avcı, ErcanM.S
Determination of Comfort Areas According to the Wind Chill Index of the Central Anatolia Region
Coğrafy
Investigation of Apoptotic Effect of Sinapic Acid in Hep3B and HepG2 Human Hepatocellular Carcinoma Cells
Hepatocellular carcinoma is one of the most common malignancies in worldwide. Sinapic acid (SA) is a phytochemical found in various fruits and vegetables. The aim of the study was to investigate the effect of SA on apoptosis in Hep3B and HepG2 hepatocellular carcinoma cells. XTT assay was used to determine the cytotoxic effect of SA. Total RNA isolation was conducted using TRIzol Reagent. Relative mRNA expression levels of important genes in apoptosis including CASP3, CASP7, CASP8, CASP9, BAX, BCL2, FAS and CYCS were quantified using qPCR in control and dose groups. The IC50 dose of SA in Hep3B and HepG2 cells were found to be 1000 µM and 1150 µM for 72 h, respectively. According to qPCR results, significant increases in the expressions of CASP3 and FAS were determined as 23.37 and 27.47 folds in treated Hep3B cells. On the other hand, SA in HepG2 cells caused a significant increase in the expressions of CASP3, CASP8, CASP9, BAX and FAS as 1.53, 1.77, 1.21, 1.47 and 1.39 folds respectively, compared with the control group. It is considered that SA may cause apoptosis in Hep3B and HepG2 cells. Further studies with SA should be conducted to can be therapeutic agent on hepatocellular carcinoma
Apoptotic Effect of Ginnalin A on MDA-MB-231 and MCF7 Human Breast Cancer Cell Lines
Breast cancer is the most common type of cancer in women. The aim of this study was to investigate the effects of Ginnalin A (GA), an important phenolic compounds of maple syrup, on apoptosis in MDA-MB-231 and MCF-7 human breast cancer cells. The effect of GA on cell viability was determined by using XTT method. Expressions of genes are important in apoptosis including CASP3, CASP7, CASP8, CASP9, BCL2, BAX, CYCS, FAS and P53 were evaluated by qPCR. IC50 dose of GA was found as 160 μM in MDA-MB-231 and 300 μM in MCF7 cells, for 72 h. According to the qPCR results, a significant increase in the expression of CASP3, CASP8, CASP9, CYCS, FAS and P53 genes was observed as 3.88, 12.11, 4.76, 8.17, 4.27 and 3.31 folds, respectively in MDA-MB-231. In MCF-7 cells, the expression of CASP9 and P53 genes significantly increased to 8.24 and 3.39 folds, respectively, while the expression of BCL2 gene significantly decreased to 1.85 fold, compared with the control group. In conclusion, it is thought that GA demonstrates apoptotic effect by regulating expression of important genes in apoptosis on breast cancer cells. However, further functional analyses are required to clarify its effect on breast cancer
Determining biological variation of serum parathyroid hormone in healthy adults
Introduction: Measurement of parathyroid hormone (PTH) is essential in the investigation and management of calcium metabolism disorders. To assess the significance of any assay result when clinical decision making biological variation (BV) of the measurand must be taken into consideration. The aim of the present study is determining the BV parameters for serum PTH. Materials and methods: Blood samples were taken at weekly intervals from 20 healthy subjects for ten weeks in this prospective BV study. Serum “intact PTH” concentrations were measured with electrochemiluminescence method. Biological variation parameters were estimated using the approach proposed by Fraser. Results: The values of within-subject biological variation (CVI), between-subject biological variation (CVG), analytical variation (CVA), reference change value (RCV) and individuality index (II) for serum PTH were 21.1%, 24.9%, 3.8%, 59.4% and 0.8%, respectively. Within-subject biological variation and CVG were also determined according to gender separately; 18.5% and 24.0%; 26.2% and 18.6% for male and female, respectively. Calculated desirable precision and bias goals were < 10.6% and < 6.3%, respectively. Conclusion: This study may contribute to BV data on serum PTH as it includes a sufficient number of volunteers from both genders over an acceptable period of time. We do not recommend the usage of population-based reference intervals for serum PTH concentrations. Reference change value may be helpful for the evaluation of serial serum PTH results. Nonetheless, evaluation of data according to gender is necessary when setting analytical performance specifications. © 2019, Biochemia Medica, Editorial Office. All rights reserved
Biological variation components of glycated hemoglobin HbA1c on tosoh G7
Aim: Biological variation (BV) of the HbA1c test can be affected by analysis method, sampling period, and disease activity. The aim of the present study was to examine the impact of CVI, CVA, and II for Tosoh G7 system. Material and Method: 96 samples from 12 healthy volunteers were collected for every two weeks during a two-month period. HbA1c levels of all samples were measured by G7 HPLC (non-porous ion-exchange) Analyser. Biological variation parameters CVI, CVA, CVG, RCV, and II were calculated. Results: The mean of HbA1c was 5.10% (32.3 mmol/mol). CVA was calculated as 2.81%. The CVI and CVG for HbA1c were 1.69% and 7.56%, respectively. RCV and II values were 9.08% and 0.22. Discussion: According to our results, the sampling period and study method were fundamental to determining biological variation parameters. When using the Tosoh G7 system, we observed similar results to other methods, e.g. boronate affinity or immunoturbidimetry. Low individuality index of HbA1 c presented that the analyte had marked individuality and that the population-based reference values had low utility for disease monitoring. Thus, estimation and inclusion of RCV in laboratory reports for HbA1c will guide the clinicians in evaluating the importance of difference between serial results and glycemic status of the patients
The effectiveness and safety of neoadjuvant pertuzumab and trastuzumab in women with locally advanced, inflammatory, or early-stage human epidermal growth factor receptor 2-positive breast cancer: Turkish Oncology Group study
In our study, we aimed to evaluate the pathological response rates and side effect profile of adding pertuzumab to the treatment of HER2+ locally advanced, inflammatory, or early-stage breast cancer. This study was conducted by the Turkish Oncology Group (TOG) with data collected from 32 centers. Our study was multicentric, and a total of 364 patients were included. The median age of the patients was 49 years (18-85 years). Two hundred fifteen (60%) of the cases were hormone receptor/HER2+ positive(ER+ or PR+, or both), and 149 (40%) of them were HER2-rich (ER and PR negative). The number of complete responses was 124 (54%) in the docetaxel+trastuzumab+pertuzumab arm and 102 (45%) in the paclitaxel+trastuzumab+pertuzumab arm, and there was no difference between the groups in terms of complete response. In 226 (62%) patients with complete response, a significant correlation was found with DCIS, tumor focality, removed lymph node, and ER status P < 0.05. Anemia, nausea, vomiting, myalgia, alopecia, and mucosal inflammation were significantly higher in the docetaxel arm, P < 0.05. In our study, no statistical difference was found between the before-after echocardiography values. DCIS positivity in biopsy before neoadjuvant chemotherapy, tumor focality; the number of lymph nodes removed and ER status were found to be associated with pCR. In conclusion, we think that studies evaluating pCR-related clinicopathological variables and radiological imaging features will play a critical role in the development of nonsurgical treatment approaches