Nonlinear Thermopower Behaviour of N-Type Carbon Nanofibres and Their Melt Mixed Polypropylene Composites.

The temperature dependent electrical conductivity σ (T) and thermopower (Seebeck coefficient) S (T) from 303.15 K (30 °C) to 373.15 K (100 °C) of an as-received commercial n-type vapour grown carbon nanofibre (CNF) powder and its melt-mixed polypropylene (PP) composite with 5 wt.% of CNFs have been analysed. At 30 °C, the σ and S of the CNF powder are ~136 S m-1 and -5.1 µV K-1, respectively, whereas its PP/CNF composite showed lower conductivities and less negative S-values of ~15 S m-1 and -3.4 µV K-1, respectively. The σ (T) of both samples presents a dσ/dT < 0 character described by the 3D variable range hopping (VRH) model. In contrast, their S (T) shows a dS/dT > 0 character, also observed in some doped multiwall carbon nanotube (MWCNT) mats with nonlinear thermopower behaviour, and explained here from the contribution of impurities in the CNF structure such as oxygen and sulphur, which cause sharply varying and localized states at approximately 0.09 eV above their Fermi energy level (EF).

H3K27me3 expression and methylation status in histological variants of malignant peripheral nerve sheath tumours.

Diagnosing MPNST can be challenging, but genetic alterations recently identified in polycomb repressive complex 2 (PRC2) core component genes, EED and SUZ12, resulting in global loss of the histone 3 lysine 27 trimethylation (H3K27me3) epigenetic mark, represent drivers of malignancy and a valuable diagnostic tool. However, the reported loss of H3K27me3 expression ranges from 35% to 84%. We show that advances in molecular pathology now allow many MPNST mimics to be classified confidently. We confirm that MPNSTs harbouring mutations in PRC2 core components are associated with loss of H3K27me3 expression; whole-genome doubling was detected in 68%, and SSTR2 was amplified in 32% of MPNSTs. We demonstrate that loss of H3K27me3 expression occurs overall in 38% of MPNSTs, but is lost in 76% of histologically classical cases, whereas loss was detected in only 23% cases with heterologous elements and 14% where the diagnosis could not be provided on morphology alone. H3K27me3 loss is rarely seen in other high-grade sarcomas and was not found to be associated with an inferior outcome in MPNST. We show that DNA methylation profiling distinguishes MPNST from its histological mimics, was unrelated to anatomical site, and formed two main clusters, MeGroups 4 and 5. MeGroup 4 represents classical MPNSTs lacking H3K27me3 expression in the majority of cases, whereas MeGroup 5 comprises MPNSTs exhibiting non-classical histology and expressing H3K27me3 and cluster with undifferentiated sarcomas. The two MeGroups are distinguished by differentially methylated PRC2-associated genes, the majority of which are hypermethylated in the promoter regions in MeGroup 4, indicating that the PRC2 target genes are not expressed in these tumours. The methylation profiles of MPNSTs with retention of H3K27me3 in MeGroups 4 and 5 are independent of mutations in PRC2 core components and the driver(s) in these groups remain to be identified. Our results open new avenues of investigation. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

The influence of breastfeeding on children’s health, well-being and development: A theoretical and empirical review / La influencia de la lactancia materna en la salud infantil, el bienestar y el desarrollo: una revisión teórica y empírica

El objetivo fue examinar el efecto de la lactancia materna en la salud infantil, el bienestar y el desarrollo. La revisión de la literatura se acercó a varias dimensiones de la salud del niño y el desarrollo, a fin de evaluar en cuáles hay realmente beneficios de la leche materna y en cuáles no se encuentra una asociación positiva con la lactancia. La hipótesis general de la Organización Mundial de la Salud (oms) de recomendar la lactancia materna durante los primeros seis meses de vida del niño no parece estar confirmada por la literatura, ya que los estudios disponibles se centran en los efectos benéficos muy específicos de la lactancia materna. Por otra parte, las limitaciones de la literatura incluyen la existencia de resultados incongruentes y aspectos metodológicos menos sólidos que deben ser resueltos en futuras investigaciones. Dadas las implicaciones clínicas, sociales y culturales de las políticas referentes a la lactancia materna, es necesario explicar las discrepancias encontradas entre los estudios, y confirmar si la lactancia materna se correlaciona significativamente con la salud de los niños y su bienestar o si en realidad son creencias de salud.

The objective was to examine the impact of breastfeeding on children's health, well-being and development. This literature review approached several dimensions of the child's health and development, in order to assess which ones actually benefit from the maternal milk, and which dimensions do not support a positive association with breastfeeding. The general assumption of the World Health Organization (WHO) of recommending breastfeeding during the first six months of the child's life does not seem to be confirmed by the literature, since the available studies are centred in very specific beneficial effects of maternal breastfeeding. Furthermore, the limitations of the literature include the existence of incongruent results and less solid methodological aspects that should be solved in future research. Given the clinical, social and cultural implications of the politics regarding maternal breast feeding, it is necessary to explain the discrepancies found between studies, and to confirm if maternal breastfeeding is significantly correlated with the children’s health and well-being or if they actually are health beliefs.

Galectin-3 overexpression in invasive laryngeal carcinoma, assessed by computer-assisted analysis.

The larynx is the most common site of malignancy in the upper aerodigestive tract. In Brazil, malignant laryngeal lesions represent 2% of all cancers, with approximately 3000 annual deaths. The association between human papillomavirus (HPV) and laryngeal cancer is still controversial. The aim of the present retrospective study was to determine the expression of galectin-3 immunoperoxidase in laryngeal carcinoma by examining paraffin-embedded larynx biopsies from 65 patients, 10 in situ laryngeal carcinomas, 27 laryngeal carcinomas without metastases, and 28 with metastases. Twenty-eight cervical lymph nodes from patients with metastatic lesions were also evaluated. Nested PCR was performed to detect and type HPV DNA. Galectin-3 expression was assessed by immunohistochemistry using a computer-assisted system. Among 65 patients, 55 (84.6%) were positive to beta-globin (internal control); 10 (15.4%) patients were beta-globin negative and were excluded from the HPV evaluation. Thus, 7 (12.7%) out of 55 patients were HPV positive and 48 (87.3%) out of 55 patients were HPV negative. High expression of galectin-3 was observed in invasive laryngeal tumors, suggesting that galectin-3 could be associated with the invasiveness and aggressiveness of laryngeal carcinomas.