Effects of Extremely Low Frequency Magnetic Field on the Lens of the Rats

The present aim of the study is to evaluate the effects of extremely low frequency magnetic field (ELF MF) on lens epithelial cells. Twenty adult female Spraque Dawley rats were divided into two groups, each containing 10 rats. The experimental group received magnetic field 2 hours/day for 7 days. The second group receiving standard laboratory care, was used as a control. The specimens were evaluated for cataractogenesis alteretion of lens and histological changes in lens epithelial cells.On biomicroscopic examination, no pathological damage to the lens was detected. In addition, on microscopic examination of materials in the controls, there were also no changes in lens fibrils and lens epithelial cells. In experimental group, however, only a slight pleomorphism was determined at the surface of epithelial cells.In the study, it is cocluded that ELF MF exposure do might not lead to histopathological alterations of the lens fibrils and lens epithelial cells

The Protective Effect of L-carnitine on Ionizing Radiation-induced Free Oxygen Radicals

Ionizing radiation is known to generate reactive oxygen species (ROS) that can be removed by antioxidants.  L-carnitine, a natural component of mammalian tissue, is a necessary factor in the utilization of long-chain  fatty acids to produce energy. Furthermore it has been shown that L-carnitine is an antioxidant which has  a scavenger effect on ROS and a stabilizing effect on damaged cell membranes. The aim of the study was  to evaluate the potential protective effect of L-carnitine on radiation-induced free radicals in hamsters. Lcarnitine  was given by gavage at a dose of 50 mg/kg for 15 consecutive days before irradiation with a single  dose of 8 Gy. 24 h after radiation exposure, the hamsters were sacrificed and samples were taken from  blood and tissues, and the biochemical and histopatological determinations were carried out. In the irradiated  group, there were significant increases in plasma and liver malondialdehyde (MDA) with marked  reduction in glutathione (GSH) levels in the liver, compared with controls. In red blood cells, superoxide  dismutase (SOD) and catalase activities were also reduced. All these effects were reversed by L-carnitine.  In conclusion, L-carnitine with its antioxidant and free radical scavenging properties could play a modulatory  role against the cellular damage produced by free radicals induced by ionizing radiation.

Effect of Gilsonite Use on Storage Stability of Styrene-butadiene-styrene Modified Bitumen

Styrene-butadiene-styrene (SBS) polymer is one of the most preferred additives to improve performance in hot mix asphalt pavements. The storage instability, in other words, the separation of a polymer-rich phase from the bitumen-rich phase in the course of storage and transportation is one of the prevalent problems in SBS modified bitumen. The present study attempted to obtain modified bitumen at the same performance level with the SBS modified bitumen, but stable with respect to the storage stability. For this purpose, both SBS and American Gilsonite (AG) were used in modified bitumen production. It was determined that modified bitumen at the same performance level was obtained with the use of 5 % SBS or 18 % AG in bitumen modification. It was also determined that the performance levels of the modified bitumen obtained with the use of 2 % SBS + 13 % AG, 3 % SBS + 10 % AG and 4 % SBS + 6 % AG were similar. Additionally, 2 %, 3 % and 4 % SBS modified bitumen were used for the assessment of storage stability properties of the SBS modified binders. These 8 different modified bitumen samples were tested for storage stability based on the EN 13399 standard. Penetration, softening point, rotational viscometer, bending beam rheometer, and dynamic shear rheometer tests were conducted on the samples. Based on all conducted tests, it was determined that more stable binders were obtained with the use of AG and SBS in terms of storage stability compared to solely SBS modified bitumen

REMOVAL OF PHENOL USING POLYMER COATED MAGNETIC NANOPARTICULAR ACTIVATED CARBON

Copyright © 2021 The Author(s). Phenol is a toxic organic pollutant which is present in many industrial effluent streams originating from petrochemical industry, ceramic production process, wood plants and resin manufacturing plants. Phenol is difficult to remove from most wastewater effluent streams. In the presented study, phenol removal from wastewater sample was investigated using the adsorption method. The experiments were conducted to investigate the adsorption performance of activated carbon (AC), magnetic activated carbon (MagAC), styrenebutadiene styrene magnetic activated carbon (SBS/MagAC) and poly charbonat magnetic activated carbon (PC/MagAC) samples. The effects of various parameters, for example, temperature, solid-liquid ratio, adsorbent type, initial phenol concentrations and solution pH were investigated under similar experimental conditions. The results showed that the maximum adsorption of 98-99% was achieved at low pH values with the use of both AC and MagAC adsorbent materials. It was also found that the polymer coated magnetic materials did not perform very well at high pH values. The experimental data also showed that MagAC and SBS/MagAC were more effective than AC and PC/MagAC to remove phenol. In conclusion, we found that phenol can be removed more easily from the aqueous medium by using both magnetic and polymeric materials.Muğla Sıtkı Koçman Üniversity, Research Project Coordination Unit, project (19/081/01/1/1)

Dinamička simulacija mehaničkih opterećenja – pristup zasnovan na svojstvima industrijskih elektromotornih pogona

Dynamic emulation of mechanical loads presents a modern and interesting approach for testing and validating performance of electrical drives without a real mechanical load included in the test rig. The paper presents an approach to dynamic emulation of mechanical loads when the load torque and inertia mass of emulated load can be significantly greater than that of laboratory test rig. Closed-loop control of load torque and feedforward compensation of inertia and friction torques are used in a test rig. The approach is focused on the use with standard industrial converters. The described method can be used for design and validation of speed control algorithms in mechatronic applications. Experimental results with the emulation of linear loads are presented in end of the paper.Dinamička simulacija mehaničkih opterećenja predstavlja moderan i zanimljiv pristup testiranju i validaciji ponašanja elektromotornih pogona bez uključenog stvarnog mehaničkog opterećenja u eksperimentalni postav. U radu je predstavljen pristup s dinamičkom simulacijom mehaničkih opterećenja za slučaj kada moment tereta ili moment tromosti simuliranog tereta mogu biti daleko veći od onih dostupnih u eksperimentalnom postavu. U postavu se koristi upravljanje momentom tereta u zatvorenoj petlji uz unaprijednu petlju kompenzacije momenta tromosti i momenata trenja. Pristup je usmjeren na upotrebu standardnih industrijskih pretvarača. Opisana metoda može se koristiti za sintezu i validaciju algoritama za upravljanje po brzini u mehatroničkim primjenama. U radu su predstavljeni eksperimentalni rezultati za slučaj simulacije linearnih tereta

Targeted intraoperative radiotherapy tumour bed boost during breast conserving surgery after neoadjuvant chemotherapy in HER2 positive and triple negative breast cancer

Introduction: Targeted intraoperative radiotherapy (TARGIT - IORT) as a tumour bed boost after breast conserving surgery is well established for women with early breast cancer. A previous study from our group shows a beneficial effect of TARGIT-IORT on overall survival (OS) but not diseasefree survival (DFS) after neoadjuvant chemotherapy compared to an external boost suggesting a potential non-inferiority of TARGIT-IORT. In this study, we present results regarding the high-risk subset of patients (i.e. with triple negative (TN) and HER2 positive tumours) from this cohort. Method: In this non-randomized cohort study involving patients with HER2 positive (n= 28) and triple negative (n=42) tumours after NACT we compared outcomes of 40 patients with tumour bed boost applied with TARGIT IORT during lumpectomy versus 30 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Rates of DFS and OS were compared. Results: Median follow up was 49 months. In comparison of TARGIT-IORT vs. EBRT 5-year Kaplan- Meier estimates of OS showed no significant difference among patients with HER2 positive tumours (100% vs. 91.7%, log rank p = 0.22). The same was seen for DFS (83.3% vs. 77.0%, log rank p=0.38). The results for TN cases were similar (OS : 87.5% vs. 74.1%, log rank p=0.488; DFS 87.5% vs. 60%, log rank p=0.22). Conclusion: Although survival estimates trended towards favouring TARGIT-IORT, no significant differences could be observed and the significantly positive result for OS favoring TARGIT-IORT in the whole cohort of 116 patients could not be reproduced in this subset analysis of patients with TN and HER2 positive tumours. This may be contributable to the limited number of patients but may also indicate that effects seen in the whole cohort were mainly driven by ER and/or PR positive and HER2 negative tumours. Most importantly, non-inferiority of TARGIT-IORT as an intraoperative boost could be reproduced in these high-risk patients

Targeted intraoperative radiotherapy tumour bed boost during breast conserving surgery after neoadjuvant chemotherapy

Introduction: The use of targeted intraoperative radiotherapy (TARGIT-IORT) as a tumour bed boost during breast conserving surgery (BCS) for breast cancer has been reported since 1998. We present its use in patients undergoing breast conservation following neoadjuvant therapy (NACT). / Method: In this retrospective study involving 116 patients after NACT we compared outcomes of 61 patients who received a tumour bed boost with IORT during lumpectomy versus 55 patients treated in the previous 13 months with external (EBRT) boost. All patients received whole breast radiotherapy. Local recurrence free survival (LRFS), disease free survival (DFS), distant disease free survival (DDFS), breast-cancer mortality (BCM), non-breast-cancer mortality (NBCM) and overall mortality (OS) were compared. / Results: Median follow up was 49 months. The differences in LRFS, DFS and BCM were not statistically significant. The 5-year Kaplan-Meier estimate of OS was significantly better by 15% with IORT: IORT 2 events 96.7%(95%CI 87.5 – 99.2), EBRT 9 events 81.7% (95%CI 67.6 – 90.1), HR 0.19 (0.04 – 0.87), log rank p = 0.016, mainly due to a reduction of 10.1% in NBCM: IORT 100%, EBRT 89.9% (77.3 – 95.7), HR (not calculable), log rank p=0.015. The DDFS was: IORT 3 events, 95.1% (85.5-98.4), EBRT 12 events, 69.0% (49.1 – 82.4), HR 0.23 (0.06-0.80), log rank p=0.012. Conclusion: IORT during lumpectomy after neoadjuvant chemotherapy as a tumour bed boost appears to give results that are not worse than external beam radiotherapy boost. These data give further support to the inclusion of such patients in the TARGIT-B (Boost) randomised trial that is testing whether IORT Boost is superior to EBRT Boost

Targeted Intraoperative Radiotherapy Tumour Bed Boost during Breast-Conserving Surgery after Neoadjuvant Chemotherapy - a Subgroup Analysis of Hormone Receptor-Positive HER2-Negative Breast Cancer

INTRODUCTION: In a previous study our group showed a beneficial effect of targeted intraoperative radiotherapy (TARGIT-IORT) as an intraoperative boost on overall survival after neoadjuvant chemotherapy (NACT) compared to an external boost (EBRT). In this study we present the results of a detailed subgroup analysis of the hormone receptor (HR)-positive HER2-negative patients. METHODS: In this cohort study involving 46 patients with HR-positive HER2-negative breast cancer after NACT, we compared the outcomes of 21 patients who received an IORT boost to those of 25 patients treated with an EBRT boost. All patients received whole breast radiotherapy. RESULTS: Median follow-up was 49 months. Whereas disease-freesurvival and breast cancer-specific mortality were not significantly different between the groups, the 5-year Kaplan-Meier estimate of overall mortality was significantly lower by 21% with IORT, p = 0.028. Non-breast cancer-specific mortality was significantly lower by 16% with IORT, p = 0.047. CONCLUSION: Although our results have to be interpreted with caution, we have shown that the improved overall survival demonstrated previously could be reproduced in the HR-positive HER2-negative subgroup. These data give further support to the inclusion of such patients in the TARGIT-B (Boost) randomised trial that is testing whether IORT boost is superior to EBRT boost

Interactions between polymeric nanoparticles and different buffers as investigated by zeta potential measurements and molecular dynamics simulations

Zeta potential is an essential surface parameter in the characterization of nanoparticles, determined at the interface of loosely bound ions (diffuse layer) at the nanoparticle surface and free ions in solution. The ionic concentration and pH of the solution are known to, by definition, influence the composition of the diffuse layer and zeta potential accordingly. Thus, to fix the solution's pH for valid zeta potential measurements, buffers are frequently used. However, an issue that remains largely neglected is that buffers could also additionally alter the electrokinetic properties of nanoparticles through specific molecular interactions. Therefore, a thorough molecular understanding of buffer-nanoparticle interactions is needed to correctly implement zeta potential results. Thus, in order to study nanoparticle-buffer interactions, we first adopted a simple experimental approach of measuring zeta potential of common polymeric nanoparticle systems at different buffer concentrations, pH, and nanoparticle-buffer fraction ratios. We observed that zwitterionic/cationic buffer molecules impart significant interference to the electrokinetic properties of structurally diverse polymer nanoparticles, by causing zeta potential suppression or even inversion during the experiments. In parallel, advancement in computation resources nowadays allow studying intermolecular interactions of nanoparticles and other complex molecules by molecular dynamics (MD) simulations. Thus, by performing MD simulations for six different polymeric nanomaterials with commonly used buffer molecules, we found that noncovalent interactions play a significant role in altering the observed zeta potential values, which may contribute to erroneous results and false particle characterizations if not taken properly into account in zeta potential measurements.</p