Modified Bautista–Manero (MBM) modelling for hyperbolic contraction–expansion flows

In this study, modelling of network-structured material flow is considered through a rounded-corner, hyperbolic 4:1:4 contraction-expansion geometry, under axisymmetric configuration. Three representative constitutive models are adopted to represent networked behaviour and to investigate the flow of wormlike micellar fluids in this context. This includes the MBM model (for base thixotropic properties), some newly proposed micellar models (NM_τp & NM_T; for advanced thixotropic modelling), and the EPPT model (for contrast against non-thixotropic properties). In this configuration, emphasis is placed upon interpretation of flow behaviour for these constitutive models, against their response in simple rheometrical flows. To best determine the factors that contribute to epd-prediction, current findings have also been contrasted against those reported earlier in Lopez-Aguilar et al. [1], for the counterpart abrupt rounded-corner, axisymmetric 4:1:4 contraction-expansion flow

The Role of the Gap Junction Protein Connexin32 in the Myelin Sheath

X-linked Charcot-Marie-Tooth disease (CMTX) is caused by mutations in the gap junction gene connexin32 (Cx32). To date, 89 different mutations have been found, including deletions, insertions, missense, and nonsense mutations, and at least two mutations in the non-coding region. Different mutations appear to have different effects on the synthesis and localization of Cx32 protein. Both myelinating Schwann cells and oligodendrocytes express Cx32 mRNA and protein, and the localization of Cx32 protein matches the location of putative gap junctions previously seen by freeze-fracture electron microscopy. In myelinating Schwann cells, Cx32 protein is found in incisures and paranodes. Preliminary data suggest that gap junctions form a radial channel that directly traverses the myelin sheath. It is plausible that mutations in Cx32 disrupt the gap junctions in the myelin sheath, thereby abolishing this radial pathway and leading to peripheral neuropathy

Preoperative nasopharyngeal swab testing and postoperative pulmonary complications in patients undergoing elective surgery during the SARS-CoV-2 pandemic.

BACKGROUND: Surgical services are preparing to scale up in areas affected by COVID-19. This study aimed to evaluate the association between preoperative SARS-CoV-2 testing and postoperative pulmonary complications in patients undergoing elective cancer surgery. METHODS: This international cohort study included adult patients undergoing elective surgery for cancer in areas affected by SARS-CoV-2 up to 19 April 2020. Patients suspected of SARS-CoV-2 infection before operation were excluded. The primary outcome measure was postoperative pulmonary complications at 30 days after surgery. Preoperative testing strategies were adjusted for confounding using mixed-effects models. RESULTS: Of 8784 patients (432 hospitals, 53 countries), 2303 patients (26.2 per cent) underwent preoperative testing: 1458 (16.6 per cent) had a swab test, 521 (5.9 per cent) CT only, and 324 (3.7 per cent) swab and CT. Pulmonary complications occurred in 3.9 per cent, whereas SARS-CoV-2 infection was confirmed in 2.6 per cent. After risk adjustment, having at least one negative preoperative nasopharyngeal swab test (adjusted odds ratio 0.68, 95 per cent confidence interval 0.68 to 0.98; P = 0.040) was associated with a lower rate of pulmonary complications. Swab testing was beneficial before major surgery and in areas with a high 14-day SARS-CoV-2 case notification rate, but not before minor surgery or in low-risk areas. To prevent one pulmonary complication, the number needed to swab test before major or minor surgery was 18 and 48 respectively in high-risk areas, and 73 and 387 in low-risk areas. CONCLUSION: Preoperative nasopharyngeal swab testing was beneficial before major surgery and in high SARS-CoV-2 risk areas. There was no proven benefit of swab testing before minor surgery in low-risk areas