Nanofiller-conjugated percolating conductive network modified polymerization reaction characteristics of aromatic thermosetting copolyester resin

Deliberately controlled interfacial interactions between incorporated nanofiller particles and host polymer backbone chains constitute a critical element in the realm of polymer nanocomposites with tailorable multifunctional properties. We demonstrate the physicochemical effects induced by graphene nanoplatelets (GNP) of different sizes on the condensation polymerization reaction of aromatic thermosetting copolyester (ATSP) through the formation of electrically conductive percolating networks as enabled by interfacial interactions. Carboxylic acid and acetoxy-capped precursor oligomers of ATSP are solid-state mixed with chemically pristine GNP particles at various loading levels. Upon in situ endothermic condensation polymerization reaction, crosslinked backbone of the ATSP foam matrix is formed while the carbonaceous nanofillers are incorporated into the polymer network via covalent conjugation with functional end-groups of the oligomers. The controlled GNP size promotes different electrical percolation thresholds and ultimate electrical conductivities. Microstructural analysis demonstrates GNP distributions in the matrix as well as morphological modifications induced by the formation of conductive percolating GNP networks. Cure characteristics reveal the thermochemical changes prompted in the polymerization processes for GNP content above the requirement for percolation formation. Chemical spectroscopy of the ATSP nanocomposite morphology exhibits the formation of a robust interfacial coupling mechanism between the GNPs and ATSP backbone. The findings here may guide the developmental efforts of nanocomposites through better identifying roles of the morphology and content of nanofillers in polymerization processes.

Physicochemical effects induced by graphene nanoplatelets on the in situ polycondensation reaction of aromatic thermosetting copolyester through the formation of conductive percolating network assembled via interfacial interactions.     

Comparative evaluation of the effects of ciprofibrate and fenofibrate on lipids, lipoproteins and apoproteins A and B

In a double-blind study over a 3-month period, a daily dose of 100 mg ciprofibrate, prescribed in a single administration and a daily dose of 300 mg fenofibrate, prescribed in 3 administrations, significantly reduced the mean values of total cholesterol, LDL cholesterol and VLDL cholesterol, apoprotein B (P less than 0.001) and increased the mean values of HDL cholesterol (P less than 0.01) and total apoprotein A (P less than 0.05). The study, followed-up as an open trial using higher doses (100 or 200 mg/day ciprofibrate, 400 mg/day fenofibrate) tried to demonstrate clearly the benefit of therapy after 9 months with the 2 drugs and to establish the dose-response effects. Comparison of the 2 drugs at the optimal dosages, after 9 months of treatment, showed ciprofibrate to be more effective in increasing HDL cholesterol (P less than 0.05) and apo A (P less than 0.001). No other significant differences in terms of either therapeutic efficacy or biological tolerance became apparent between the 2 drugs. The results obtained in this comparative study were in accordance to those observed in separate trials for ciprofibrate or fenofibrate. Ciprofibrate has the benefit of a long half-life and may also be administered in the form of a single daily dose to patients suffering from major type II hyperlipoproteinaemia.     

Delayed presentation of a large congenital laryngeal cleft in an adult

Laryngeal clefts are rare congenital malformations of the posterior laryngotracheal wall that lead to an abnormal communication between the airway and pharyngo-oesophageal tract. The condition is almost universally identified during infancy with minor laryngeal clefts very rarely diagnosed in adulthood. We present our tertiary centre’s experience of a large laryngeal cleft presenting at an advanced age, with the aim of increasing awareness of this correctible cause of respiratory distress and aspiration in adults.     

Lymph Node Ratio May Be Supplementary to TNM Nodal Classification in Node-positive Breast Carcinoma Based on the Results of 2,151 Patients

Background

The aim of the present study was to determine how lymph node ratio (LNR; the ratio of the number of metastatic lymph nodes to the number of removed lymph nodes) can supplement the TNM nodal classification in breast carcinoma.

Methods

We retrospectively reviewed the file records of 2,151 patients.

Results

Lymph node ratio-based low- (LNR ≤ 0.20), intermediate- (LNR 0.21–0.65), and high-risk (LNR > 0.65) patient groups had significantly different disease-free survival (DFS) (P < 0.001). The DFS of patients with N1, N2, and N3 disease was significantly different (P < 0.001). When LNR and TNM nodal groupings were included together in the Cox analysis, both groupings had independent prognostic significance (P < 0.001 and P < 0.001, respectively). The most significant LNR threshold value separating patients in low-risk and high-risk groups in terms of disease recurrence was 0.20 for N1 disease (P < 0.001), 0.35 for N2 disease (P < 0.001), and 0.90 for N3 disease (P < 0.001).

Conclusions

Lymph node ratio and TNM nodal groupings show no superiority over each other in categorizing patients with node-positive breast carcinoma into prognostic groups of low-, intermediate-, and high-risk. However, LNR grouping may supplement TNM nodal classification by categorizing patients within each TNM nodal group into low-risk and high-risk groups with significantly different survival.