Endometrial Cancer Detection by DNA Methylation Analysis in Cervical Papanicolaou Brush Samples.

Background: Endometrial cancer (EC) is the leading gynecological cancer worldwide, yet current EC screening approaches are not satisfying. The purpose of this retrospective study was to evaluate the feasibility and capability of DNA methylation analysis in cervical Papanicolaou (Pap) brush samples for EC detection. Methods: We used quantitative methylation-sensitive PCR (qMS-PCR) to determine the methylation status of candidate genes in EC tissue samples, as well as cervical Pap brushes. The ability of RASSF1A and HIST1H4F to serve as diagnostic markers for EC was then examined in cervical Pap brush samples from women with endometrial lesions of varying degrees of severity. Results: Methylated RASSF1A and HIST1H4F were found in EC tissues. Further, methylation of the two genes was also observed in cervical Pap smear samples from EC patients. Methylation levels of RASSF1A and HIST1H4F increased as endometrial lesions progressed, and cervical Pap brush samples from women affected by EC exhibited significantly higher levels of methylated RASSF1A and HIST1H4F compared to noncancerous controls (P < .001). Receiver operating characteristic (ROC) curves and area under the curve (AUC) analyses revealed RASSF1A and HIST1H4F methylation with a combined AUC of 0.938 and 0.951 for EC/pre-EC detection in cervical Pap brush samples, respectively. Conclusion: These findings demonstrate that DNA methylation analysis in cervical Pap brush samples may be helpful for EC detection, broadening the scope of the commonly used cytological screening. Our proof-of-concept study provides new insights into the field of clinical EC diagnosis.

Dynamic viscosity of methane hydrate systems from non-Einsteinian, plasma-functionalized carbon nanotube nanofluids.

The viscosity of oxygen-functionalized multi-walled carbon nanotube (O-MWCNT) nanofluids was measured for concentrations from 0.1 to 10 ppm under conditions of 0 to 30 MPag pressures and 0 to 10 °C temperatures. The presence of O-MWCNTs did not affect the temperature dependence of viscosity but did reduce the effective viscosity of solution due to cumulative hydrogen bond-disrupting surface effects, which overcame internal drag forces. O-MWCNTs added a weak pressure dependence to the viscosity of solution because of their ability to align more with the flow direction as pressure increased. In the liquid to hydrate phase transition, the times to reach the maximum viscosity were faster in O-MWCNT systems compared to the pure water baseline. However, the presence of O-MWCNTs limited the conditions at which hydrates formed as increased nanoparticle collisions in those systems inhibited the formation of critical clusters of hydrate nuclei. The times to viscosity values most relevant to technological applications were minimally 28.02% (200 mPa s) and 21.08% (500 mPa s) slower than the baseline, both in the 1 ppm system, even though all systems were faster to the final viscosity. This was attributed to O-MWCNT entanglement, which resulted in a hydrate slurry occurring at lower viscosity values.

The behaviour of plasma-functionalized graphene nanoflake nanofluids during phase change from liquid water to solid ice.

Emerging nanofluid-based technologies for cooling, transport, and storage applications have previously been enhanced through the use of graphene nanoflake (GNF) nanofluids. Many of the beneficial effects of GNFs have now been documented, though little work has yet been completed to characterize the morphological behaviour of GNF nanofluids both during and after the phase change process. In this study, the crystallization behaviour of sessile water droplets was evaluated for two plasma-functionalized, hydrophilic GNF concentrations (20 and 100 ppm) at three driving force temperatures (-5 °C, -10 °C, and -20 °C). At low driving forces, the GNFs were wholly expelled from the solid matrix due to low crystallization velocities. At high driving forces, more rapid crystallization rates resulted in the entrapment of GNFs within the air bubbles and inter-dendritic spaces of the solid droplet. However, individual particle dispersion was not achieved within the solid matrix at any driving force. Furthermore, for all experimental conditions, the functionalized GNF clusters which formed during freezing did not disperse spontaneously upon melting as drying-like effects may have altered the attraction properties of their surfaces and destabilized the suspension. Compared to previous studies using multi-walled carbon nanotubes, the GNFs were found to have higher liquid mobility at the solid front, provide less resistance to that front as it ascended, and be better dispersed after melting. These effects may have been geometrical; the square nanoflake geometry does not result in any physical particle entanglement.

Theoretical investigation on the chemoselective N-heterocyclic carbene-catalyzed cross-benzoin reactions.

A density functional theory study was performed to understand the detailed mechanisms of the cross-benzoin reactions catalyzed by N-heterocyclic carbene (NHC) species. Our theoretical study predicted that the first H-transfer operates with water in solution as a mediator, and the second H-transfer undergoes a concerted mechanism rather than a stepwise one. In addition, the chemoselectivity of the reactions studied in this work has been explored. P1 was obtained as a major product mainly due to the more stable intermediate formed by reaction of NHC with reactant R1. Different steric effects resulting from the fused six-membered ring in transition state TS7 and the fused five-membered ring in transition state TS13 are the origin leading to the chemoselectivity.