Abrasive water jet drilling of advanced sustainable bio-fibre-reinforced polymer/hybrid composites : a comprehensive analysis of machining-induced damage responses

This paper aims at investigating the effects of variable traverse speeds on machining-induced damage of fibre-reinforced composites, using the abrasive water jet (AWJ) drilling. Three different types of epoxy-based composites laminates fabricated by vacuum bagging technique containing unidirectional (UD) flax, hybrid carbon-flax and carbon fibre-reinforced composite were used. The drilling parameters used were traverse speeds of 20, 40, 60 and 80 mm/min, constant water jet pressure of 300 MPa and a hole diameter of 10 mm. The results obtained depict that the traverse speed had a significant effect with respect to both surface roughness and delamination drilling-induced damage responses. Evidently, an increase in water jet traverse speed caused an increase in both damage responses of the three samples. Significantly, the CFRP composite sample recorded the lowest surface roughness damage response, followed by C-FFRP, while FFRP exhibited the highest. However, samples of FFRP and hybrid C-FFRP recorded lowest and highest delamination damage responses, respectively. The discrepancy in both damage responses, as further validated with micrographs of colour video microscopy (CVM), scanning electron microscopy (SEM) and X-ray micro-computed tomography (X-ray μCT), is attributed to the different mechanical properties of the reinforced fibres, fibre orientation/ply stacking and hybridisation of the samples.Peer reviewe

Diffusion-weighted magnetic resonance imaging to detect synchronous uterine endometrial and endocervical adenocarcinoma

Synchronous endometrial and cervical cancer is a very rare condition. This report describes a case of a 46-year-old woman who presented with a cervical mass that measured 5.6 cm along its longest diameter, whose biopsy analysis revealed an endocervical mucinous adenocarcinoma. She was classified as having an IB2 cervical carcinoma and treated with concurrent chemoradiation plus hysterectomy. Pathological and immunohistochemical analysis of the surgical specimens revealed a synchronous endometrioid grade 2 adenocarcinoma in the endometrium, and a well-differentiated mucinous adenocarcinoma in the cervix. Magnetic resonance imaging (MRI) studies performed prior to treatment were reviewed and apparent diffusion coefficient (ADC) maps were generated. The ADC values demonstrated distinct signal intensity differences between the endometrial and endocervical tumors. In conclusion, diffusion-weighted MRI and ADC maps can help to distinguish the site of origin of synchronous tumors

Identification of Metabolites in the Normal Ovary and Their Transformation in Primary and Metastatic Ovarian Cancer

In this study, we characterized the metabolome of the human ovary and identified metabolic alternations that coincide with primary epithelial ovarian cancer (EOC) and metastatic tumors resulting from primary ovarian cancer (MOC) using three analytical platforms: gas chromatography mass spectrometry (GC/MS) and liquid chromatography tandem mass spectrometry (LC/MS/MS) using buffer systems and instrument settings to catalog positive or negative ions. The human ovarian metabolome was found to contain 364 biochemicals and upon transformation of the ovary caused changes in energy utilization, altering metabolites associated with glycolysis and β-oxidation of fatty acids—such as carnitine (1.79 fold in EOC, p<0.001; 1.88 fold in MOC, p<0.001), acetylcarnitine (1.75 fold in EOC, p<0.001; 2.39 fold in MOC, p<0.001), and butyrylcarnitine (3.62 fold, p<0.0094 in EOC; 7.88 fold, p<0.001 in MOC). There were also significant changes in phenylalanine catabolism marked by increases in phenylpyruvate (4.21 fold; p = 0.0098) and phenyllactate (195.45 fold; p<0.0023) in EOC. Ovarian cancer also displayed an enhanced oxidative stress response as indicated by increases in 2-aminobutyrate in EOC (1.46 fold, p = 0.0316) and in MOC (2.25 fold, p<0.001) and several isoforms of tocopherols. We have also identified novel metabolites in the ovary, specifically N-acetylasparate and N-acetyl-aspartyl-glutamate, whose role in ovarian physiology has yet to be determined. These data enhance our understanding of the diverse biochemistry of the human ovary and demonstrate metabolic alterations upon transformation. Furthermore, metabolites with significant changes between groups provide insight into biochemical consequences of transformation and are candidate biomarkers of ovarian oncogenesis. Validation studies are warranted to determine whether these compounds have clinical utility in the diagnosis or clinical management of ovarian cancer patients

Protective role of melatonin in pinealectomized rat brains: in vivo magnetic resonance spectroscopic analysis

The goal of this study was to investigate the effect of melatonin on basic cerebral metabolites in pinealectomized (Px) rat brains. Twenty-one rats were randomly divided into three groups with seven rats per group. The study groups included sham-operated rats, Px rats and Px rats treated with melatonin. Melatonin administration began at 60 days following pinealectomy and continued for 21 days. At the end of the study, in vivo single voxel magnetic resonance spectroscopy was performed on whole brains to determine choline (Cho), creatine and N-acetyl aspartate (NAA) concentrations. Px rats had significantly lower NAA levels (P&lt;0.05), and significantly higher Cho levels (P&lt;0.05) when compared with sham-operated rats. Administration of melatonin had normalized NAA and Cho levels in Px rats. We propose that pinealectomy causes significant changes in cerebral metabolites which are compatible with neural loss. Melatonin administration prevents the disruptive effects of pinealectomy on brain tissue

Experimental Comparison of the Microstructure and Surface Roughness in CO2 Laser Cutting of the Titanium Alloy Ti–6Al–4V and the Pure Titanium Ti

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