Modelling of the low-impulse blast behaviour of fibre–metal laminates based on different aluminium alloys

A parametric study has been undertaken in order to investigate the influence of the properties of the aluminium alloy on the blast response of fibre–metal laminates (FMLs). The finite element (FE) models have been developed and validated using experimental data from tests on FMLs based on a 2024-O aluminium alloy and a woven glass–fibre/polypropylene composite (GFPP). A vectorized user material subroutine (VUMAT) was employed to define Hashin’s 3D rate-dependant damage constitutive model of the GFPP. Using the validated models, a parametric study has been carried out to investigate the blast resistance of FML panels based on the four aluminium alloys, namely 2024-O, 2024-T3, 6061-T6 and 7075-T6. It has been shown that there is an approximation linear relationship between the dimensionless back face displacement and the dimensionless impulse for all aluminium alloys investigated here. It has also shown that the residual displacement of back surface of the FML panels and the internal debonding are dependent on the yield strength of the aluminium alloy

Optimizing working space in laparoscopy: CT-measurement of the effect of neuromuscular blockade and its reversal in a porcine model

Objective: The objective of this paper was to determine the effect of neuromuscular blockade (NMB) on working space in a porcine laparoscopy model. Background: Conflicting results on the effect of NMB on laparoscopic working space are found in literature. Almost all studies are limited by absence of objective assessment of working space or use surrogate outcomes. Methods: In a standardized porcine laparoscopy model, laparoscopic working-space dimensions with and without NMB were investigated in 16 animals using computed tomography at intra-abdominal pressures of 0, 5, 10, and 15 mmHg during multiple runs of abdominal insufflation. Results: No statistically significant effect of NMB on abdominal dimensions and laparoscopic working-space volume was found during CO2 pneumoperitoneum. In contrast, the effect of pre-stretching of the abdominal wall by a previous abdominal insufflation was found to be significant. Conclusions: This experimental study confirms the results from several clinical studies that NMB does not influence laparoscopic working space. Studies dealing with working space during laparoscopy should take note of pre-stretching bias

Bacteriophage DNA glucosylation impairs target DNA binding by type I and II but not by type V CRISPR-Cas effector complexes

Prokaryotes encode various host defense systems that provide protection against mobile genetic elements. Restriction-modification (R-M) and CRISPR-Cas systems mediate host defense by sequence specific targeting of invasive DNA. T-even bacteriophages employ covalent modifications of nucleobases to avoid binding and therefore cleavage of their DNA by restriction endonucleases. Here, we describe that DNA glucosylation of bacteriophage genomes affects interference of some but not all CRISPR-Cas systems. We show that glucosyl modification of 5-hydroxymethylated cytosines in the DNA of bacteriophage T4 interferes with type I-E and type II-A CRISPR-Cas systems by lowering the affinity of the Cascade and Cas9-crRNA complexes for their target DNA. On the contrary, the type V-A nuclease Cas12a (also known as Cpf1) is not impaired in binding and cleavage of glucosylated target DNA, likely due to a more open structural architecture of the protein. Our results suggest that CRISPR-Cas systems have contributed to the selective pressure on phages to develop more generic solutions to escape sequence specific host defense systems

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) among travellers to Africa : destination-specific data pooled from three European prospective studies

Background: One third of travellers to low- and middle-income regions of the tropics and subtropics become colonized by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). The risk varies by destination and, for each traveller, may be substantially further increased by travellers' diarrhoea (TD) and antibiotic use. Despite the risk of TD in Africa, ESBL-PE acquisition rates in all studies are lower there than in Asia. Africa has become increasingly popular as a destination for international travellers, yet minimal data are available from the continent's subregions and countries. Methods: We analysed subregion- and country-specific data on carriage and risk factors for ESBL-PE colonization pooled from three prospective studies conducted between 2009 and 2013 among Finnish and Dutch travellers. The data were subjected to multivariable analysis of risk factors. In addition, we compared our data to two recent large investigations reporting data by subregion and country. Results: Our joint analysis comprised data on 396 travellers. The ESBL-PE colonization rate was highest in Northern Africa, followed by Middle and Eastern Africa, and lowest in Southern and Western Africa. Of individual countries with more than 15 visitors, the highest rates were seen for Egypt (12/17; 70.6%), Ghana (6/23; 26.1%), and Tanzania (14/81; 17.3%); the rates among travellers to Egypt were comparable to those reported in South and Southeast Asia. In a pooled multivariable analysis, travel destination, age, overnight hospitalisation abroad, TD, and use of fluoroquinolones were independently associated with increased ESBL-PE colonization rates. Conlusions: Even in areas with relatively low risk of colonization, antimicrobials clearly predispose to colonization with ESBL-PE. Travellers to Africa should be cautioned against unnecessary use of antibiotics.Peer reviewe

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE) among travellers to Africa : destination-specific data pooled from three European prospective studies

Abstract Background One third of travellers to low- and middle-income regions of the tropics and subtropics become colonized by extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-PE). The risk varies by destination and, for each traveller, may be substantially further increased by travellers’ diarrhoea (TD) and antibiotic use. Despite the risk of TD in Africa, ESBL-PE acquisition rates in all studies are lower there than in Asia. Africa has become increasingly popular as a destination for international travellers, yet minimal data are available from the continent’s subregions and countries. Methods We analysed subregion- and country-specific data on carriage and risk factors for ESBL-PE colonization pooled from three prospective studies conducted between 2009 and 2013 among Finnish and Dutch travellers. The data were subjected to multivariable analysis of risk factors. In addition, we compared our data to two recent large investigations reporting data by subregion and country. Results Our joint analysis comprised data on 396 travellers. The ESBL-PE colonization rate was highest in Northern Africa, followed by Middle and Eastern Africa, and lowest in Southern and Western Africa. Of individual countries with more than 15 visitors, the highest rates were seen for Egypt (12/17; 70.6%), Ghana (6/23; 26.1%), and Tanzania (14/81; 17.3%); the rates among travellers to Egypt were comparable to those reported in South and Southeast Asia. In a pooled multivariable analysis, travel destination, age, overnight hospitalisation abroad, TD, and use of fluoroquinolones were independently associated with increased ESBL-PE colonization rates. Conlusions Even in areas with relatively low risk of colonization, antimicrobials clearly predispose to colonization with ESBL-PE. Travellers to Africa should be cautioned against unnecessary use of antibiotics

Level of arterial ligation in total mesorectal excision (TME): an anatomical study

Introduction: High-tie ligation is a common practice in rectal cancer surgery. However, it compromises perfusion of the proximal limb of the anastomosis. This anatomical study was designed to assess the value of low-tie ligation in order to obtain a tension-free anastomosis. Materials and methods: Consecutive high- and low-tie resections were performed on 15 formalin-fixed specimens, with or without splenic flexure mobilization. If the proximal colon limb could reach the superior aspect of the symphysis pubis with more than 3 cm, the limb would be long enough for a tension-free colorectal anastomosis. Results: In 80% of cases, it was not necessary to perform high-tie ligation as sufficient length was gained with low-tie ligation. The descending branch of the left colic artery was the limiting factor in the other 20% of cases. Resecting half the sigmoid resulted in four times as many tension-free anastomoses after low-tie resection. Conclusion: In the majority of cases, it was not necessary to perform high-tie ligation in order to create a tension-free anastomosis. Low-tie ligation was applicable in 80% of cases and might prevent anastomotic leakage due to insufficient blood supply of the proximal colon limb

Contacts and contracts: Cross-level network dynamics in the development of an aircraft material

In this paper, we investigate how interorganizational networks and interpersonal networks interact over time. We present a retrospective longitudinal case study of the network system that developed a novel aircraft material and analyze changeepisodes from a structurationist perspective. We identify five types of episodes in which interpersonal and interorganizational networks interact (persistence, prospecting, consolidation, reconfiguration, and dissolution) and analyze conditionsfor these episodes and sequences among them. Our findings advance a cross-level perspective on embeddedness and show how individuals may draw on relational and structural embeddedness as distributed resources. The multiple levels of embeddedness impact network dynamics by introducing converging and diverging dialectics, thereby limiting path dependence and proactive network orchestration

Dynamics of Responses in Compatible Potato - Potato virus Y Interaction Are Modulated by Salicylic Acid

To investigate the dynamics of the potato – Potato virus Y (PVY) compatible interaction in relation to salicylic acid - controlled pathways we performed experiments using non-transgenic potato cv. Désirée, transgenic NahG-Désirée, cv. Igor and PVYNTN, the most aggressive strain of PVY. The importance of salicylic acid in viral multiplication and symptom development was confirmed by pronounced symptom development in NahG-Désirée, depleted in salicylic acid, and reversion of the effect after spraying with 2,6-dichloroisonicotinic acid (a salicylic acid - analogue). We have employed quantitative PCR for monitoring virus multiplication, as well as plant responses through expression of selected marker genes of photosynthetic activity, carbohydrate metabolism and the defence response. Viral multiplication was the slowest in inoculated potato of cv. Désirée, the only asymptomatic genotype in the study. The intensity of defence-related gene expression was much stronger in both sensitive genotypes (NahG-Désirée and cv. Igor) at the site of inoculation than in asymptomatic plants (cv. Désirée). Photosynthesis and carbohydrate metabolism gene expression differed between the symptomatic and asymptomatic phenotypes. The differential gene expression pattern of the two sensitive genotypes indicates that the outcome of the interaction does not rely simply on one regulatory component, but similar phenotypical features can result from distinct responses at the molecular level