pinecone/core-2020-05-10-deduplication huggingface dataset:
Flexural, impact, rheological and physical characterizations of POM reinforced by carbon nanotubes and paraffin oil.

The paraffin oil dispersion technique innovated in the recent years to synthesize bulk polymer nanocomposite materials has a uniform dispersion. This research work aims to study the effect of added carbon nanotubes (CNTs) on flexural, impact and rheology behaviors of polyoxymethylene (POM) reinforced by 0?0.03 wt% of CNT using paraffin oil dispersion technique. The wettability and lamellar thickness were measured and rheological performance investigated using a parallel plate rheometer. The flexural and impact mechanical properties were also evaluated. The fracture surfaces were then examined by microscopy. The results showed that the energy to break, flexural strength and modulus increased proportionally with the addition of the amount of CNT in the matrix. For the rheology behavior, the viscosity decreased at the low percentage of CNT and then increased with increase in the percentage weight ratio of CNT in the POM matrix. It was also noted that the water contact angle rose with the increase the CNT percentages.Emmag-Erasmus Mundus Maghreb & Egyp
Synthesis of Poly(hydroxamic acid) Ligand from Polymer Grafted Corn-cob Cellulose for Transition Metals Extraction

Poly(hydroxamic acid) ligand was synthesized using ester functionalities of cellulose-graft-poly(methyl acrylate) copolymer, and products are characterized by Fourier transform infrared spectroscopy, field emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy analysis. The poly(hydroxamic acid) ligand was utilized for the sensing and removal of transition metal ions form aqueous solutions. The solution pH is found a key factor for the optical detection of metal ions, and the reflectance spectra of the [Cu-ligand]n+ complex were observed to be the highest absorbance 99.5% at pH 6. With the increase of Cu2+ ion concentration, the reflectance spectra were increased, and a broad peak at 705 nm indicated that the charge transfer (π-π transition) complex was formed. The adsorption capacity with copper was found to be superior, 320 mg g−1, and adsorption capacities for other transition metal ions were also found to be good such as Fe3+, Mn2+, Co3+, Cr3+, Ni2+, and Zn2+ were 255, 260, 300, 280, 233, and 223 mg g−1, respectively, at pH 6. The experimental data show that all metal ions fitted well with the pseudo-second-order rate equation. The sorption results of the transition metal ions onto ligand were well fitted with Langmuir isotherm model (R2 > 0.98), which implies the homogenous and monolayer character of poly(hydroxamic acid) ligand surface. Eleven cycles sorption/desorption process were applied to verify the reusability of this adsorbent. The investigation of sorption and extraction efficiency in each cycle indicated that this new type of adsorbent can be recycled in many cycles with no significant loss in its original detection and removal capability
Aliphatic isocyanurates and polyisocyanurate networks

The production, processing, and application of aliphatic isocyanate (NCO)-based thermosets such as polyurethane coatings and adhesives are generally limited by the surprisingly high viscosity of tri-functionality and higher-functionality isocyanurates. These compounds are essential crosslinking additives for network formation. However, the mechanism by which these high viscosities are caused is not yet understood. In this work, model aliphatic isocyanurates were synthesized and isolated in high purity (>99%), and their viscosities were accurately determined.
It was shown that the presence of the NCO group has a strong influence on the viscosity of the system. From density
functional theory calculations, a novel and significant bimolecular binding potential of À8.7 kJ/mol was identified be-
tween NCO groups and isocyanurate rings, confirming the important role of the NCO group. This NCO-to-ring inter-
action was proposed to be the root cause for the high viscosities observed for NCO-functional isocyanurate
systems. Molecular dynamics simulations carried out to further confirm this influence also suggest that the NCO-to-
ring interaction causes a significant additional contribution to viscosity. Finally, model functional isocyanurates were
further reacted into densely crosslinked polyisocyanurate networks which showed interesting material properties.This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no. 642890 (http:// thelink-project.eu/), and it was partially supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the strategic funding UID/FIS/04650/2013, and under the project Search-ON2: NORTE-07-0162-FEDER000086
Synthesis, characterization, and functionalization of zirconium tungstate (ZrW2O8) nano‐rods for advanced polymer nanocomposites

Nanomaterials based on zirconium tungstate (ZrW2O8) exhibit numerous outstanding properties that make them ideal candidates for the development of high-performance composites. Low coefficient of thermal expansion for advanced materials is a promising direction in the field of insulating nanocomposites. However, the agglomeration of zirconium tungstate (ZrW2O8)-based nanomaterials in the polymer matrix is a limiting factor in their successful applications, and studies on surface functionalization ZrW2O8 for advanced nanocomposites are very limited. In this work, ZrW2O8 nano-rods were synthesized using a hydrothermal method and subsequently functionalized in a solvent-free aqueous medium using dopamine. Both pristine and functionalized nano-rods were thoroughly characterized using Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction, Scanning Electron Microscopy (SEM), and transmission electron microscopy techniques, which confirmed the successful functionalization of the nanomaterials. Polymer nanocomposites were also prepared using epoxy resin as a model matrix. Polymer nanocomposites with functionalized ZrW2O8 nano-rods exhibited low coefficient of thermal expansion and enhanced tensile properties. The improved properties of the nanocomposites render them suitable for electronic applications
Fabrication and optimization of proton conductive polybenzimidazole electrospun nanofiber membranes

Phosphoric acid (PA)–doped polybenzimidazole (PBI) proton exchange membranes have received attention because of their good mechanical properties, moderate gas permeability, and superior proton conductivity under high temperature operation. Among PBI-based film membranes, nanofibrous membranes withstand to higher strain because of strongly oriented polymer chains while exhibiting higher specific surface area with increased number of proton-conducting sites. In this study, PBI electrospun nanofibers were produced and doped with PA to operate as high temperature proton exchange membrane, while changes in proton conductivity and morphologies were monitored. Proton conductive PBI nanofiber membranes by using the process parameters of 15 kV and 100 μL/h at 15 wt% PBI/dimethylacetamide polymer concentration were prepared by varying PA doping time as 24, 48, 72, and 96 hours. The morphological changes associated with PA doping addressed that acid doping significantly caused swelling and 2-fold increase in mean fiber diameter. Tensile strength of the membranes is found to be increased by doping level, whereas the strain at break (15%) decreased because of the brittle nature of H-bond network. 72 hour doped PBI membranes demonstrated highest proton conductivity whereas the decrease on conductivity for 96-hour doped PBI membranes, which could be attributed to the morphological changes due to H-bond network and acid leaking, was noted. Overall, the results suggested that of 72-hour doped PBI membranes with proton conductivity of 123 mS/cm could be a potential candidate for proton exchange membrane fuel cell
Preparation of aqueous anionic poly(urethane-urea) dispersions. Influence of the incorporation of acrylic, polycarbonate and perfluoro-oligoether diols on the dispersion and polymer properties

Aqueous poly(urethane‐urea) dispersions were prepared by the prepolymer mixing technique, without using any organic solvent. This work focused on the incorporation into the prepolymer chain of specific macrodiols bearing acrylic, polycarbonate and perfluoro‐oligoether chains, in conjunction with a poly(propylene oxide) diol (Mn = 1000). All the dispersions were synthesized with a fixed NCO/OH ratio, using α,α,α′,α′‐tetramethyl‐1,3‐xylylene diisocayanate, a fixed proportion of emulsifying agent (dimethylol propionic acid, neutralized with triethylamine) and the same chain extender (1,2‐ethylene diamine). The properties of both the dispersions and the dried polymer films were characterized as a function of the nature of the specific incorporated diol and its proportion in the polymer chain, in order to establish criteria leading to an optimized performance in terms of particle size, viscosity, and polymer film properties
Expression of the PDGF α-receptor 1.5 kb transcript, OCT-4, and c-KIT in human normal and malignant tissues. Implications for the early diagnosis of testicular germ cell tumours and for our understanding of regulatory mechanisms

Human testicular germ cell tumours of adolescents and adults (TGCTs), including their precursor lesion carcinoma in situ (CIS), show expression of a 1.5 kb alternative transcript of the platelet-derived growth factor (PDGF) α-receptor gene. The so-called P2 promoter involved is located in intron 12 and its activity was found to be mutually exclusive with activity of the classical promoter (P1), which encodes the full-length receptor. The presence of the 1.5 kb transcript could be a putative marker for the early molecular diagnosis of TGCTs. In order to validate the RT-PCR approach, this study shows that not more than 100 transcripts are necessary to obtain positivity in the test used; moreover, samples from TGCTs or CIS-containing tissues can be diluted many-fold before resulting in false-negative findings. This study also shows that within TGCTs, as in TGCT-derived cell lines, expression of the 1.5 kb transcript is differentiation-dependent and positively correlated with expression of the embryonic transcription factor OCT-4/POU5F1. Furthermore, the results indicate that in some non-TGCT cancers and cell lines the 1.5 kb transcript is also expressed, but without concomitant OCT-4/POU5F1 expression. The 1.5 kb transcript is also present in early B cells and derived leukaemias (B-ALL). In spite of similarities in chromosomal location, down-regulation upon differentiation of TGCTs, and PDGF α-receptor and c-KIT. (the stem cell factor receptor) both being a tyrosine kinase receptor, no correlation was found between activity of the P2 promoter of the PDGF α-receptor gene and expression of c-KIT. In conclusion, the 1.5 kb transcript of the PDGF α-receptor is expressed in various cells and tissues, including particular blood cells. Although this may hamper the use of this transcript as a marker for malignancies in general, it does not appear to interfere with assays for the early detection of TGCTs. Copyrigh
Value of tissue markers p27kip1, MIB-1, and CD44s for the pre-operative prediction of tumour features in screen-detected prostate cancer

The pre-operative prediction of prognostic tumour features in the radical prostatectomy specimen using routine clinicopathological variables remains limited. The present study evaluated the predictive value of the cell-cycle protein p27kip1, the proliferation marker MIB-1, and the cell-adhesion protein CD44s, determined on the diagnostic needle biopsy of asymptomatic men screened for prostate cancer. Of 81 screen-detected prostate cancers, representative biopsy cores and matched radical prostatectomy specimens were immunohistochemically stained for these tissue markers. Conventional pre-operative and post-operative clinicopathological variables were assessed and cancers were divided according to a validated tumour classification model (potentially harmless, clinically significant). Low (<50%) p27kip1 expression, high (≥10%) MIB-1 expression, and low (<25%) CD44s expression were considered adverse prognostic signs. Binary logistic regression analysis was performed to assess the most valuable predictors of clinically significant disease. An adverse prognostic immunostaining assessment on the biopsy was found in 10 (12.3%), 17 (21.0%), and 25 (30.9%) cases for p27kip1, MIB-1, and CD44s, respectively. The concordance in tissue marker assessment between the biopsy specimen and matched radical prostatectomy specimens was low for all three. The positive predictive value (PPV) of p27kip1 was 90.0%, remarkably higher than that of MIB-1 and CD44s (41.2% and 52.0%, respectively), indicating that a low radical prostatectomy p27kip1 score is expected if the biopsy p27kip1 score is low. Logistic regression analysis revealed that biopsy Gleason score (p<0.01) and p27kip1 assessment (p<0.01) remained the only significant predictors of clinically significant disease. All cases with low p27kip1 expression were found to have clinically significant disease after radical prostatectomy. The assessment of p27kip1 in the biopsy specimen might thus assist in distinguishing between potentially aggressive and potentially non-aggressive disease in prostate cancer screening. Copyrigh
Barret's adenocarcinomas resemble adenocarcinomas of the gastric cardia in terms of chromosomal copy number changes, but relate to squamous cell carcinomas of the distal oesophagus with respect to the presence of high-level amplifications

Three different cancers predominantly occur at the gastro-oesophageal junction: squamous cell carcinomas of the distal oesophagus, adenocarcinomas of the distal oesophagus (Barrett's carcinomas), and adenocarcinomas of the gastric cardia. The aim of the present study was to investigate how, and to what extent, Barrett's carcinoma differs from adenocarcinoma of the gastric cardia on the one hand and squamous cell carcinoma of the distal oesophagus on the other, with respect to chromosomal aberrations and related gene expression. The present study analysed 14 squamous cell carcinomas, 24 Barrett's carcinomas, and 16 carcinomas of the gastric cardia. Comparative genomic hybridization revealed chromosomal abnormalities in all cases. Typical chromosomal aberrations for the squamous cell carcinoma type were gains at 3q and 11q13, and losses at 3p, 4q, 9p, 11q, and 13q. In contrast, typical copy number changes for both cardiac and Barrett's adenocarcinomas were gains at 2q, 7p, and 13q, and losses at 17p. High-level amplification occurred in all three groups, but its frequency in the cardiac carcinomas was lower than in the other two groups. In conclusion, squamous cell carcinomas are characterized by chromosomal aberrations which are distinct from those seen in carcinomas of the gastric cardia and in Barrett's adenocarcinomas. With respect to Barrett's cancer, the chromosomal aberrations more closely reflect the adenocarcinoma phenotype than the squamous origin of the epithelium. Copyrigh
Emphysema : the challenge of the remodelled lung

Emphysema is recognized as the component of chronic obstructive airways disease that\ud
is responsible for airways obstruction. Different patterns of emphysema are, however,\ud
recognized, suggesting possible different pathogenetic processes within the lung. This,\ud
coupled with the associated idea of susceptibility factors to the development of emphysema,\ud
has led to studies of genes that may be involved in the defence of the lung from proteolytic\ud
and oxidative damage. These studies have been driven by the goal of finding a treatment for\ud
emphysema, but appear to have lost sight of the fundamental remodelling of the lung that\ud
has occurred in patients with emphysema and the fact that it is not a single morphological\ud
entity.peer-reviewe
Identification of numerical chromosome aberrations in archival tumours by in situ hybridization to routine paraffin sections: Evaluation of 23 phaeochromocytomas

We have applied non-isotopic in situ hybridization (ISH) to interphase cell nuclei of 23 phaeochromocytomas (18 primary and 5 metastatic tumours) within routine paraffin-embedded tissue sections. Each tumour was screened for numerical aberrations with a defined alphoid repetitive DNA probe set containing DNA probes specific for chromosomes 1, 7, 15, and Y. Normal adrenal medullas and other normal human cell types served as cytogenetic controls. Preservation of tissue morphology enabled targeted analysis of tumour cells. The presence of numerical chromosome changes in the tumour cells could easily be evaluated by comparing the ISH results of the DNA probes. Numerical abnormalities not previously reported in this neoplasm included overrepresentation of chromosomes 1 and 7, loss of chromosome 15, and both gain and loss of chromosome Y (P values <0.01). The percentage of aneuploid cell nuclei in a tumour correlated well with the percentage of cells in the 4C peak of flow cytometric DNA histograms from these neoplasms. We conclude that interphase ISH can be used for the identification of new and reported cytogenetic changes in tumour cell nuclei within archival tissue sections. This novel procedure also allows for retrospective analysis of previously not karyotyped material
Expression of p53 in oligodendrogliomas

The expression of the nuclear protein p53 in oligodendrogliomas was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7) on formalin-fixed, paraffin-embedded material in 84 histologically verified cases, and compared with the histopathological grade and survival. p53-immunoreactive cells were found in 75 per cent of the samples acquired at the first biopsy. The p53 labelling index was not related to the degree of nuclear anaplasia. Tumour cases with more than 75 per cent p53 immunostained cells had a rapidly fatal clinical course. However, no significant correlation was found between p53 labelling index and tumour grade, mitotic index, or ploidy status. In most tumour recurrences (n=25), the p53 labelling index increased or remained at the level of the first biopsy. In five cases (6 per cent), p53 was absent in the first sample as well as in the recurrence. Irrespective of the underlying aberration of either the gene or the metabolic pathway of p53, it is concluded that a high percentage (i.e., more than 75 per cent) of p53-immunolabelled cells is predictive of an unfavourable clinical course, while a percentage lower than 75 per cent immunoreactive cells does not exclude a rapid fatal outcome
An in vitro model of urothelial regeneration: Effects of growth factors and extracellular matrix proteins

Although the cellular turnover of resting urothelium is very low, its regenerative capacity is known to be outstanding. In organotypic mouse urothelial cultures closely mimicking the differentiation and multilayering of normal urothelium, we examined the cell biological mechanisms underlying urothelial regeneration and the specific role of growth factors and several extracellular matrix (ECM) components. Exposure to epidermal growth factor (EGF) and acidic fibroblast growth factor (aFGF) and culture on laminin resulted in enhanced expansion of the urothelium. Microscopy and assessment of proliferative activity revealed that enhanced urothelial expansion due to EGF could be attributed to increased proliferative activity and an increase in cell numbers, whereas aFGF-stimulated expansion must be considered the consequence of increased cellularity and migration. Laminin-enhanced urothelial expansion was shown to be the result of spreading of the entire urothelial organotypic culture. This was associated with a considerable decrease in the number of cell layers. A synergistic effect of growth factors and laminin was not found. This organotypic urothelial cell culture model seems to be very useful in studying strategies to improve urothelial regeneration
Accumulation of p53 protein in normal, dysplastic, and neoplastic Barrett's oesophagus

Accumulation of p53 protein was determined by immunohistochemisty in archival material of biopsy specimens from 102 patients with Barrett's oesophagus with different grades of dysplasia, in 24 oesophageal adenocarcinomas associated with Barrett's oesophagus, and in 23 cases of metaplatic epithelium adjacent to these carcinomas. Immunostaining for the p53 protein was found in 23/102 (23 per cent) cases of the Barrett's oesophagus biopsies and in 12/23 (52 per cent) cases of Barrett's oesophagus adjacent to adenocarcinoma. Significant correlations were found between the grade of dysplasia and p53 immunoreactivity in both Barrett's biopsies without adenocarcinoma (P<0.001) and Barrett's oesophagus adjacent to adenocarcinoma (P<0.05). In the adenocarcinomas, intense nuclear immunohistochemical staining for p53 was diffusely or focally present in 20/24 (83 per cent) of the specimens. In Barrett's oesophagus, p53 is a progression marker with high expression in high-grade dysplasia (89 per cent) and adenocarcinoma (83 per cent)
EGFR amplification and lack of activating mutations in metaplastic breast carcinomas

Metaplastic breast carcinomas are reported to harbour epidermal growth factor receptor
(EGFR) overexpression in up to 80% of the cases, but EGFR gene amplification is the
underlying genetic mechanism in around one-third of these. In this study, EGFR gene
amplification as defined by chromogenic in situ hybridization and protein overexpression
was examined in a cohort of 47 metaplastic breast carcinomas. Furthermore, the presence
of activating EGFR mutations in exons 18, 19, 20, and 21 was investigated. Thirty-two cases showed EGFR overexpression and of these, 11 (34%) harboured EGFR gene amplification.
In addition, EGFR amplification showed a statistically significant association with EGFR
overexpression (p < 0.0094) and was restricted to carcinomas with homologous metaplasia.
Ten cases, five with and five without EGFR amplification, were subjected to microarraybased
CGH, which demonstrated that EGFR copy number gain may occur by amplification
of a discrete genomic region or by gains of the short arm of chromosome 7 with a
breakpoint near the EGFR gene locus, the minimal region of amplification mapping to
EGFR, LANCL2, and SEC61G. No activating EGFR mutations were identified, suggesting
that this is unlikely to be a common alternative underlying genetic mechanism for EGFR
expression in metaplastic breast carcinomas. Given that metaplastic breast carcinomas are
resistant to conventional chemotherapy or hormone therapy regimens and that tumours
with EGFR amplification are reported to be sensitive to EGFR tyrosine kinase inhibitors,
these findings indicate that further studies are warranted to explore EGFR tyrosine kinase
inhibitors as potential therapeutic agents for metaplastic breast carcinomas harbouring
amplification of 7p11.2