The ultrasound-assisted extraction (UAE) of oleuropein (OLE), verbascoside (VER), and luteolin-4'-
-glucoside (L4OG), as the major phenolics from olive leaves, was optimized using response surface ...methodology (RSM). A Box⁻Behnken design (BBD) was used to monitor the effect of different modes of ultrasound operation (pulsed and continuous), liquid⁻solid (L⁻S) ratio, and sonication time on each phenolic yield. The yield of UAE and conventional solid extraction (CSE) was determined after performing ultrahigh-performance liquid chromatography with a diode-array detector (UHPLC-DAD) analysis on the extracts. The results suggested that, under optimal conditions, the concentrations of OLE, VER, and L4OG were 13.386, 0.363, and 0.527 mg/g of dry powdered olive leaves (DPOL), respectively. Verification of experiments was carried out under the modified optimal conditions and the relative errors between the predicted and experimental values were dependent on the examined phenolic compound (OLE 8.63%, VER 11.3%, and L4OG 22.48%). In comparison with CSE, UAE improved the yields of OLE, VER, and L4OG (32.6%, 41.8%, and 47.5%, respectively, after 1 min) at a temperature of 60 °C, an L⁻S ratio of 15 (
), and in the continuous mode of UAE. We demonstrated that the UAE technique is an efficient method for enhancing yields of OLE, VER, and L4OG in olive-leaf extracts, while the chosen model was adequate to optimize the extraction of major phenolic compounds from olive leaves.
Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound that utilizes low-intensity pulsed waves. Its effect on bones that heal by intramembranous ossification has not been sufficiently ...investigated. In this study, we examined LIPUS and the autologous bone, to determine their effect on the healing of the critical-size bone defect (CSBD) of the rat calvaria. The bone samples underwent histological, histomorphometric and immunohistochemical analyses. Both LIPUS and autologous bone promoted osteogenesis, leading to almost complete closure of the bone defect. On day 30, the bone volume was the highest in the autologous bone group (20.35%), followed by the LIPUS group (19.12%), and the lowest value was in the control group (5.11%). The autologous bone group exhibited the highest intensities of COX-2 (167.7 ± 1.1) and Osx (177.1 ± 0.9) expression on day 30. In the LIPUS group, the highest intensity of COX-2 expression was found on day 7 (169.7 ±1.6) and day 15 (92.7 ± 2.2), while the highest Osx expression was on day 7 (131.9 ± 0.9). In conclusion, this study suggests that LIPUS could represent a viable alternative to autologous bone grafts in repairing bone defects that are ossified by intramembranous ossification.
Background
The spread and invasion of malignant melanoma cells involve degradation and reorganization of the extracellular matrix by the activation of several matrix metalloproteinases (MMPs). This ...study analyzed the expression of MMP‐1, MMP‐2, and MMP‐13 proteins in primary nodular melanoma (NM) and dysplastic nevi (DN) as a significant risk factor for melanoma development. The secondary goal was to analyze the correlation of MMPs protein expression in NM with tumor invasion, BRAF V600 mutation status, and overall survival.
Methods
Immunohistochemistry for MMP‐1, MMP‐2, and MMP‐13 was performed on nodular melanoma (n = 52) and dysplastic nevi (n = 28) on tissue microarray (TMA). BRAF V600 mutation analysis on NM samples was performed by the Sanger sequencing method.
Results
A high level of MMPs expression in NM samples (>30%) compared with DN (<8%) was statistically significant (P < 0.001). BRAF V600 mutations were detected in 15 of 39 (38.5%) NM samples. This study revealed an interesting finding that MMP‐1 and MMP‐13 protein expression in the BRAF V600 mutated melanomas were significantly lower than in the BRAF V600 wild type (P < 0.05).
Conclusion
Cox analysis revealed that Clark categories, Breslow thickness, and MMP‐1 high protein expression are predictive factors for shorter overall survival (P < 0.05).
Welding and cutting of metals produce large amounts of particulate matter (PM), which poses a significant health risk to exposed workers. Appropriate biological markers to estimate exposure are of ...great interest for occupational health and safety. Here, hair and nail samples from metal workers were analyzed, which appear to be more suitable than blood or urine samples for assessing long-term exposure. Four workshops working with steel components were included in the study. The hair and nail samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to measure the concentrations of 12 elements. At the workplaces, the concentrations of 15 elements in particulate matter were determined using X-ray fluorescence (XRF) and particle-induced X-ray emission (PIXE) techniques. The hair and nail samples of the workers contained significantly higher metal concentrations than the analytical results of a nonexposed control group. The most significant difference between the groups was found for Ti, Mn, Fe, and Co.
Poly(lactic acid) (PLA), compared to other biodegradable polymers, has one of the highest consumption volumes in the world. Due to its specific properties, especially those that make it ecologically ...acceptable, it has a wide application from food packaging to medical implants. In this work, commercially available 3D printing filament of PLA was used. The objective was to investigate the effects of γ-radiation on structural changes, mechanical and thermal behaviour of the material. The samples were irradiated with total doses of 25 kGy, 50 kGy, 100 kGy and 200 kGy. The experimental techniques used to investigate the structural changes in PLA filaments were electron spin resonance (ESR) and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and universal testing machine were applied in monitoring changes in thermal and mechanical behaviour, respectively. The formation and stability of free radicals were studied by ESR, which confirmed that the radical concentration depends on the applied absorbed dose, while the spectral lineshape appears to be dose independent. The loss of the ESR signal, directly related to the decrease of radical concentration, was monitored as a function of time for all applied absorbed doses. The breaking force and the Young's modulus were determined and compared. Results have shown that both the concentration and decay rate constant of radicals depend on the absorbed dose. Compressive strength test, a new approach in considering the mechanical changes in irradiated PLA indicated a loss of material elasticity and an increase of brittleness by increasing absorbed dose.
•PLA filaments irradiated in 60Co γ-source up to 200 kGy were studied.•Based on ESR results, the dose dependent radical decay rate constants were determined.•Mechanical changes were studied by a compressive strength test – a new approach.
We investigated whether tumour markers carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), cancer antigen 125 (CA-125), and cytokeratin 19 fragment (CYFRA 21-1) in pleural effusions and ...serum can be used to distinguish pleural effusion aetiology.
During the first thoracentesis, we measured pleural fluid and serum tumour marker concentrations and calculated the pleural fluid/serum ratio for patients diagnosed with pleural effusion, using electrochemiluminescence immunoassays. Receiver operating characteristic (ROC) analysis was carried out and the Hanley and McNeil method was used to test the significance of the difference between the areas under ROC curves (AUCs). In order to detect which tumour marker best discriminates between malignant and non-malignant pleural effusions and to establish the predictive value of those markers, discriminant function analysis (DFA) and logistic regression analysis were utilized.
Serum tumour markers CYFRA 21-1 and NSE as well as pleural NSE were good predictors of pleural effusion malignancy and their combined model was found statistically significant (Chi-square = 28.415, P < 0.001). Respective ROC analysis showed significant discrimination value of the combination of these three markers (AUC = 0.79).
Serum markers showed superiority to pleural fluid markers in determining pleural fluid aetiology. Serum CYFRA 21-1 and NSE concentrations as well as pleural fluid NSE values had the highest clinical value in differentiating between malignant and non-malignant pleural effusions. The combination of these three markers produced a significant model to resolve pleural effusion aetiology.
•Quality assurance of ultrasound transducers in the hospital environment.•Method can be used to distinguish highly non-uniform beams with high value of BNR.•Influence of exposure duration on obtained ...ERA and BNR values was analysed.
The evaluation of the performance of nine physiotherapy ultrasound transducers used clinically was performed in the hospital environment using an acoustically absorbing thermocromic tile developed at the National Physical Laboratory (UK). The method consists of exposing an acoustic absorber tile, part of which contains a thermochromic pigment, to the ultrasonic beam, thereby forming an image of the intensity profile of the transducer. Images acquired using thermochromic materials were postprocessed in order to estimate effective radiating area (ERA) and beam nonuniformity ratio (BNR) for ultrasound transducers operating within the frequency range from 1.0 to 3.3 MHz, and nominal applied intensities in the range of 1–2W/cm2. Results of our measurements have shown that thermocromic tile can be used for quality control of ultrasound transducers in the hospital environment. Experimental results show that proposed method can be used to distinguish highly non - uniform ultrasound beams with high value of BNR.
Influence of exposure duration on obtained ERA and BNR values was also analysed. Our results show that values for ERA increase with insonation time, while BNR values decrease. In order to compare our results with theory we have estimated temperature rise in thermochromic material experimentally and compare it with theoretical prediction.
Fine aerosol pollution is one of the most important factors in air pollution monitoring. Industrial production often represents significant source of aerosol pollution in surrounding areas, and ...therefore, it is important to understand its impact on air quality. In order to investigate contribution coming from the oil refinery to air pollution, PM2.5 (particulate matter with aerodynamic diameter smaller than 2.5 μm) samples were collected in the vicinity of an oil refinery during the 1‐year period. At the same time, PM2.5 was sampled in the city of Rijeka, Croatia, at the distance that is about 10 km far from the refinery. This site was used for comparison. The sampling was performed with two cyclone samplers on thin polytetrafluoroethylene filters. PM2.5 was sampled for 24 h every other day, simultaneously at both locations. In total, 306 samples were collected. The samples were analysed using X‐ray fluorescence and particle‐induced X‐ray emission to obtain concentrations of 17 elements from Na to Pb. Additionally, concentrations of black carbon were determined using laser‐integrated plate method. It was found that concentrations of S, V, and Ni, elements characteristic for oil burning, were substantially higher at the refinery sampling site comparing to the reference location. Obtained concentrations were statistically evaluated by performing positive matrix factorization to identify oil refinery as one of the pollution sources in the vicinity of such a facility. The same method was also performed at the urban site where the contribution from oil refinery was not separated from other similar sources.
During metal welding and cutting, large amounts of particulate matter (PM) are produced that might represent a significant health risk for the exposed workers. In the present pilot study, we ...performed an elemental analysis of fine PM collected in a metal workshop. Also, elemental analysis of the hair and nail samples collected from workers exposed to the workshop dust and control group was done. Concentrations of 15 elements in PM were measured with X‐Ray Fluorescence (XRF) and Particle Induced X‐ray Emission (PIXE), whereas inductively coupled plasma mass spectrometry (ICP‐MS) was used to determine 12 elements in hair and nail samples. Mean 8‐hr concentrations of PM2.5, Fe, and Mn in the vicinity of welders were up to 1803, 860, and 30 μg/m3, respectively, whereas in the nearby city, daily PM2.5 concentrations are on average 11 μg/m3. We found that several elements, especially Fe and Mn, had substantially higher concentrations in hair and nail samples of exposed workers than in the control group, which indicates the accumulation of metals in workers' tissues, although limit values were not exceeded.
Significant nonuniformities in the acoustic intensity distribution generated by physiotherapy ultrasound treatment heads are not uncommon, potentially leading to significant localised temperature ...rises and tissue damage. An acoustic absorber tile containing a thermochromic pigment has been developed to provide rapid quality assurance of physiotherapy ultrasound treatment heads by virtue of a thermochromic colour change, indicating the time-averaged intensity distributions generated by these devices. As a bench-top device, the use of the tile is designed to mimic the nature of the physiotherapeutic application, requiring minimal training. Two designs where thermochromic pigments are added to the various polymeric layers of the tile are presented. Testing has been conducted with two physiotherapy treatment heads of differing performance, one of them notably exhibiting a strong "hot-spot" in localised acoustic time-averaged intensity. Findings show good qualitative agreement with classical hydrophone scans. Techniques are explored for the correction of nonlinearities in the thermochromic relationship, to enhance the accuracy of quantitative assessment.
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