bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of friction-stir welding on the microstructure and mechanical properties of an Al-Mg-Si alloy
Authors: Vysotskiy I , Malopheyev S , Mironov S , Kaibyshev R
Published: November 2019

In this work, sheets of an Al-Mg-Si alloy were joined by double-side friction stir welding and tempered by standard post-weld artificial aging. The combination of relatively high FSW tool rotation and welding speed with subsequent post-weld artificial aging allowed obtaining welds with high joint efficiency. However, a high sensibility of joint efficiency from FSW tool rotation speed at constant welding speed was found. In turns, the joint efficiency of the friction-stir welds for ultimate tensile strength was found to be 72% at 800 rpm and 92% at 1100 rpm, respectively. The reasons of difference in the mechanical properties of the welds are studied.
Structure and strength of the 1570C aluminum alloy after complex SPD processing
Authors: Markushev M V , Avtokratova E V , Sitdikov O Sh , Linderov M L , Merson D L , Vinogradov A
Published: November 2019

The effect of severe plastic deformation (SPD), realized via multi-directional forging (MDF) at a constant temperature of 325 °C, as well as via a combination of MDF with subsequent room temperature rolling or high pressure torsion, on the microstructure, static and fatigue strength parameters of an ingot of non-age-hardenable commercial aluminum alloy 1570C (Al-5Mg-0.18Mn-0.2Sc-0.08Zr) was studied. It is found that the most effective treatment to enhance the balance of the alloy properties involves a sequence of hot MDF and cold rolling due to the development of a work hardened ultrafine-grain structure with uniformly distributed nanosized aluminides of transition metals. The role of precipitates in the alloy structure- and property-formation is discussed.
Effect of preliminary and post-SPD aging on nanostructuring and strengthening of the HPT processed 2024 aluminum alloy
Authors: Markushev M V , Krymskiy S V , Avtokratova E V , Sitdikov O Sh
Published: November 2019

Structural and mechanical behaviors of the 2024 commercial aluminum alloy, differed by heterogeneity of the initial structure, were examined after severe plastic deformation and further annealing. The superior strengthening of the pre-quenched alloy under high-pressure torsion (HPT) at room temperature was caused by the development of a more equiaxed nanostructure of the matrix with a lower fragment size than in pre-aged T6 condition. Post-HPT annealing at 100 °C led to extra strengthening of the pre-quenched alloy only due to the age hardening effect. The nature of the alloy behavior is discussed.
Abnormal grain growth in fine-grained aluminum produced by friction-stir welding
Authors: Mironov S , Kaibyshev R
Published: November 2019

In this work, fundamental aspects of abnormal grain growth, which typically occurs during annealing of friction-stir welded (FSW) aluminium, were studied. To this end, crystallographic orientations of abnormally-coarse grains were systematically examined. Statistical analysis showed that those were not random. Specifically, it was found that the abnormal grain growth resulted in ~30°<111> rotation of FSW-induced B/-B {112}<110> texture. Accordingly, the abnormal character of the grain growth was interpreted in terms of increased mobility of 30°<111> boundaries.
Mechanical behavior and impact toughness of the ultrafine-grained VT8M-1 alloy
Authors: Modina Iu M , Polyakova V V , Dyakonov G S , Polyakov A V , Semenova I P , Raab A G
Published: November 2019

This paper reports on a study of the relationship between the microstructure, mechanical behavior and impact toughness of the two-phase Ti alloy VT8M-1 (Ti-5.7Al-3.8Mo-1.2Zr-1.3Sn) in the ultrafine-grained (UFG) state, which was produced by two different techniques – equal-channel angular pressing (ECAP) and rotary swaging (RS). It is shown that both processing techniques enable forming a UFG structure and enhanced mechanical properties in the alloy. The UFG structures formed in the billets are characterized by different shapes and sizes of the α- and β-phases. The relationship between the structure, strength, ductility and impact toughness of the alloy processed by RS and ECAP is discussed.
Effect of ultrasonic pretreatment on the superplasticity of titanium alloy Ti-6Al-4V processed by ECAP
Authors: Mukhametgalina A A , Murzinova M A , Nazarov A A
Published: November 2019

Improving the superplasticity characteristics of alloys widely used in industry, such as titanium alloy Ti-6Al-4V, is an important practical problem. Processing by the methods of severe plastic deformation can reduce the temperature of superplasticity. However, the material exhibits high flow stresses. In this work we studied the effect of preliminary ultrasonic treatment with an amplitude of oscillating tension-compression stresses of 100 MPa on the characteristics of superplasticity of the Ti-6Al-4V alloy processed by equal channel angular pressing (ECAP). It is shown that high-frequency oscillating stresses resulted in the reduction of the flow stress, the increase in elongation and the strain rate sensitivity coefficient during tensile tests in the conditions of superplasticity.
The microstructure and properties of the alloy Ti-5Al-0.5V subjected to ECAP and ultrasonic treatment
Authors: Mukhametgalina A A , Murzinova M A , Nazarov A A
Published: November 2019

This work presents the results of a study of the mechanical properties of a titanium alloy Ti-5Al processed by equal channel angular pressing (ECAP) and ultrasonic treatment (UST). The UST was carried out at a frequency of 20 kHz with an amplitude of oscillating tension-compression stresses of 100 MPa. It was shown that the alloy subjected to UST exhibited low temperature superplastic properties. Its elongation exceeded a value of 300%, the coefficient m was 0.3 at a strain rate of 1.7×10−4 1/s.
Microstructure evolution of a Re-containing nickel-based superalloy by hot deformation and cold severe plastic deformation
Authors: Mukhtarov Sh , Shakhov R , Ganeev A
Published: November 2019

The microstructure evolutions of the cast rhenium containing nickel-based superalloy subjected to thermomechanical treatment and severe plastic deformation by high pressure torsion were investigated. Thermomechanical treatment led to the formation a fine-grained structure with γ grain size of about 7 μm and both large precipitates of the γ’ phase with a size of 1-5 μm and dispersed precipitates with a size of about 0.2 μm. Microstructure of the superalloy subjected to high pressure torsion up to 5 revolutions was nanocrystalline with partly dissolved of the dispersed γ′ precipitates. The effect of different kinds of deformation and subsequent annealing on the microstructure, grain boundaries and microhardness changes are also discussed.
Microstructure and microhardness studies of Inconel 718, manufactured by selective laser melting and subjected to severe plastic deformation and annealing
Authors: Mukhtarova K Sh , Shakhov R V , Smirnov V V , Mukhtarov Sh Kh
Published: November 2019

Microstructure investigations and microhardness measurements have been comparatively performed for the nickel-based superalloy Inconel 718 produced by selective laser melting (SLM) and conventional technology. The superalloy produced by SLM had a finer γ grain size and a developed dislocation substructure in contrast to a conventional wrought material. High pressure torsion of the superalloy led to a refinement in the microstructure and an increase in the microhardness in both superalloys. Annealing at 600 °C for 2 hours of the deformed superalloys caused an additional increase in microhardness. The microhardness of the SLM material was slightly higher than that of the conventional superalloy.
Effect of severe plastic deformation on the physical and mechanical properties of the ultrafine-grained β-alloy Ti-15Mo
Authors: Polyakova V V , Gatina S A , Polyakov A A , Semenova I P
Published: November 2019

The influence of severe plastic deformation on physical and mechanical properties of the pseudo-β-alloy Ti-15Mo alloy has been investigated.
High strength and high conductive copper-based alloy produced by SPD for contact wires for high speed railway lines - A short review
Authors: Ravisankar B , Sivaprasad K , Ramesh Babu N , Raab G I , Valiev R Z
Published: November 2019

The development of high-speed railway lines, the requirements for contact wires of catenary becomes more essential. The contact wire should be strong, wear resistant and fatigue resistant, and also possess good thermal stability along with high electrical conductivity. At present, copper wires alloyed with cadmium are used. The replacement is more of a necessity since cadmium is a material hazardous to environment, and it is already banned by several countries. Over the last several decades, growing attention has been focused on the development of copper-based alloys with high strength and good electrical conductivity. Novel severe plastic deformation (SPD) procedure, namely equal-channel angular pressing (ECAP), has been applied for obtaining ultrafine-grained (UFG) materials with high strength and good electrical conductivity. This overview mainly focuses on the suitability of ECAPed copper and its alloys for contact wires in high-speed railway lines.
Computer simulation of the SPD process of a low-alloyed chromium bronze using a virtual full factorial experiment
Authors: Semenov V I , Tontchev N T , Shuster L Sh , Raab G I , Kamburov V V
Published: November 2019

Using computer simulation in the DEFORM-3D software package, we performed a virtual full factorial experiment for the ECAP-Conform processing of the low-alloyed chromium bronze Cu-0.14%Cr. In the course of the experiment we evaluated the effect of independent parameters (the rotation speed of the working wheel, the friction factor at the lateral surfaces of the working wheel and the friction factor between a billet and the die). As a result of the experiment, we obtained a regression equation and determined the most important individual factors and their combinations that influence the response parameter – the deformation force.
Evaluation of the tribological properties of a magnesium alloy of the Mg-Ca system depending on the structure of the material under study
Authors: Semenov V I , Lin H-C , Shuster L Sh , Chiu C
Published: November 2019

The paper presents the results of a study of the tribological characteristics of the contact of the tool steel of composition Fe-18W-4Cr-1.2V with a magnesium alloy of the Mg-Ca system, strengthened by SPD using the method of ECAP. It has been established that the SPD processing of a magnesium alloy, due to an increase in strength as a result of the grain structure refinement, makes it possible to significantly reduce the integral value of the friction coefficient in the moving friction contact. In addition, the SPD processing of the material under study leads to a decrease in the molecular component of the friction coefficient.
The effect of combined thermomechanical treatment on the structure, phases and hardness of a superelastic Ti-Zr-Nb bar stock
Authors: Sheremetyev V , Kudryashova A , Derkach M , Lukashevich K , Andreev V , Galkin S , Prokoshkin S , Brailovski V
Published: November 2019

The superelastic Ti-19Zr-14Nb (at.%) alloy was subjected to a novel sequence of thermomechanical treatment, including radial shear rolling, rotary forging and post-deformation annealing. The features of the grain structure, phase composition and hardness of a long-length bar stock for fabrication of bone implants were analyzed. It was shown that after the aforementioned combined thermomechanical treatment followed by annealing in the 550-750 °C temperature range, the produced bar stock demonstrates uniformly distributed grains of β-phase and uniform hardness across its section.
Microstructure and properties of permanent joints of ultrafine-grained titanium alloys produced by linear friction welding
Authors: Suleymanova G R , Medvedev A Y , Dyakonov G S , Yakovleva T V , Izmailova N F , Raab G I , Semenova I P
Published: November 2019

This paper presents the results of a study of the microstructure and mechanical properties of welded joints obtained by linear friction welding of samples from heat-resistant titanium alloys VT8M-1 (Ti-5.4Al-1Sn-1Zr-4Mo-0.15Si) and VT25U(Ti-6.5Al-1.8Sn-4Zr-4Mo-1W-0.2Si). In the VT8M-1 alloy, an ultrafine-grained (UFG) structure was formed prior to welding. The features of the phase and structural transformations in the areas of contact and thermomechanical effect of welding were shown, as well as the microhardness distribution across the width of the welded joints. The obtained values of strength characteristics of a welded joint during short-term and long-term tests at 400 °C indicate their correspondence to the level of the monolithic VT8M-1 alloy with a UFG structure.
Effect of precipitation under long-term aging at 650 °C on the tensile strength of advanced 10%Cr heat-resistant steel
Authors: Dudova N , Mishnev R , Tikhonova M , Kaibyshev R
Published: November 2019

The effect of long-term aging for 103 to 3.9·104 h at 650 °C on the microstructure, dispersion of secondary phases, and tensile strength properties was studied in a low-nitrogen 10%Cr martensitic steel with 3%Co and 0.008%B additives. Tensile tests of small specimens cut from grip portions of creep tested specimens were carried out at ambient and elevated (650 °C) temperatures. An increase in the yield stress and ultimate tensile strength after 10,000 h of aging was revealed to be associated with the precipitation of V-rich MX carbonitrides, which compensated for the coarsening of the boundary particles and depletion of W and Mo solutes from the ferritic matrix. The effect of changes of the microstructure and dispersion of secondary phases on strengthening of the steel is discussed.
Study of the dynamic strength of the ultrafine-grained titanium VT 1-0
Authors: Evstifeev A D , Valiev R R
Published: November 2019

We report the results from the testing of the strength properties of the ultrafine-grained Ti alloy VT 1-0 under dynamic and static loading. A comparative analysis was made of the ultimate static and dynamic strength of the small-sized samples of the material subjected to severe plastic deformation. The importance of studying the dynamic strength of Ti alloys is closely related to their practical application in structures and parts operating under high dynamic loads.
Corrosion resistance of ultrafine-grained pure titanium in simulated sea water
Authors: Li X , Dong Y , Alexandrov I V , Dan Z , Chang H
Published: November 2019

Corrosion resistance of ultrafine-grained Ti processed by equal channel angular pressing with 3 passes was investigated. Results indicated that corrosion rate of ultrafine-grained Ti significantly reduced in comparison with coarse grain Ti. Furthermore, corrosion resistance of 3 passes ECAP sample had an obvious distinguish for different extraction planes; normal plane has shown a best corrosion resistance than transversal and extrusion plane, which could be attributed to higher fraction of low angle grain boundary.
Microstructure and mechanical properties of workpieces of the ultrafine-grained two-phase Ti alloy produced by die forging
Authors: Yakovleva T V , Dyakonov G S , Stotskiy A G , Semenova I P
Published: November 2019

The paper presents the results of studies of the microstructure and mechanical properties of experimental workpieces of the ultrafine-grained (UFG) VT8M-1 (Ti–5.7Al– 3.8Mo–1.2Zr–1.3Sn in wt%) alloy produced by isothermal die forging (IDF). The UFG structure in the VT8M-1 alloy was formed by a high-performance method, namely rotary swaging (RS). The structural parameters (the shape and size of the α- and β-phases) and the homogeneity of the UFG structure were analyzed in different sections of forgings. It was shown that the fraction of the primary α- phase decreases, and the size of the secondary equiaxed grains of the α- and β-phases increases from 0.3 to 0.9 µm as a result of recrystallization during IDF. The relationship between the microstructure and mechanical properties of the forged workpieces of the UFG VT8M-1 alloy is discussed.
Microstructure and mechanical properties of nanostructured Cu-Zn alloys by ECAP and rolling
Authors: Zaynullina L I , Alexandrov I V , Wei W
Published: November 2019

The results of investigation of the Cu–Zn system alloys with 10 wt.% and 30 wt.% Zn, the stacking fault energy (SFE) of which differs by a factor of 2.5, are presented. ECAP and subsequent flat rolling resulted in the refinement of the microstructure. Flat rolling with the reduction degree 95% resulted in the decrease of the concentration of nanotwins formed during ECAP. Flat rolling of ultra-fine grained (UFG) alloys leads to the strength increase and ductility decrease explained by the refinement of the microstructure and decrease in the concentration of deformation twins.
Invited Commentary: Women’s Reproductive Life Spans and Subsequent Inflammatory Profiles—How to Best Measure Reproductive Life Span and the Need for Baseline Assessments
Authors: Schliep Karen C
Published: November 2019

Inflammatory processes are known to drive the pathogenesis of several chronic diseases, including cardiovascular disease and Alzheimer disease, as well as all-cause mortality. Emerging research indicates that women who have a longer reproductive life span—roughly determined as the period from menarche to menopause or lifetime number of ovulatory cycles after accounting for anovulatory time spans—are at lower risk for these inflammation-related chronic diseases. The paradox is that ovulation is known to induce acute inflammation. Given the limited research assessing the relationship between reproductive life span and later inflammatory profiles, Huang et al. (Am J Epidemiol. 2020;189(7):660–670) set out to investigate this relationship within 2 of the most robust longitudinal cohort studies of women, the Nurses’ Health studies. They found that after adjustment for other inflammation-related factors, including adiposity, exercise, and diet, lifetime ovulatory years was associated with lower C-reactive protein levels in both premenopausal and postmenopausal women. Huang et al. call attention to several challenges in research on women’s reproductive life spans, including how to appropriately capture lifetime ovulatory cycles and the need for repeated measurements of inflammatory biomarkers across the life course if we wish to understand pathogenic processes linking reproductive factors to subsequent chronic disease.
The Time of the Latinx Nineteenth Century
Authors: Balachandran Orihuela Sharada
Published: November 2019

The Latino Nineteenth Century: Archival Encounters in American Literary History (2016), edited by Rodrigo Lazo and Jesse Alemán, is a formative volume that, in its capaciousness, reorients nineteenth-century literary history toward a substantial engagement with Latinx and Latin American literary and cultural production. Consisting of 15 sections written by leading scholars in the field of nineteenth-century Latinx literary studies, the volume tackles an impressive range of nineteenth-century Latinx thinkers and texts. The essays collected here oscillate seamlessly from macro to micro scales of space, move across the long nineteenth century, and engage with an array of printed materials of the Latinx nineteenth century. This volume is about multiplicity: from Jessie Alemán’s Philadelphia to Juan Poblete’s essay on the close ties between California and Chile in the nineteenth century; from the instances of failed immigration outlined by Robert McKee Irwin to Kirsten Silva Gruesz’s migratory “errancy”; from José Aranda’s essay on Mexican American modernity to Marissa Lopez’s argument about Latino dismodernity. Ultimately, the editors and contributors reveal the numerous nineteenth centuries across the hemisphere, and help us imagine the intersections of US literary history and Latinx studies in the nineteenth century.
SimRVSequences: an R package to simulate genetic sequence data for pedigrees
Authors: Nieuwoudt Christina , Brooks-Wilson Angela , Graham Jinko
Published: November 2019

We present the R package SimRVSequences to simulate sequence data for pedigrees. SimRVSequences allows for simulations of large numbers of single-nucleotide variants (SNVs) and scales well with increasing numbers of pedigrees. Users provide a sample of pedigrees and SNV data from a sample of unrelated individuals.

Availability and implementation

SimRVSequences is publicly-available on CRAN https://cran.r-project.org/web/packages/SimRVSequences/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Detection of differentially methylated CpG sites between tumor samples with uneven tumor purities
Authors: Zhang Weiwei , Li Ziyi , Wei Nana , Wu Hua-Jun , Zheng Xiaoqi
Published: November 2019

Motivation

Inference of differentially methylated (DM) CpG sites between two groups of tumor samples with different geno- or pheno-types is a critical step to uncover the epigenetic mechanism of tumorigenesis, and identify biomarkers for cancer subtyping. However, as a major source of confounding factor, uneven distributions of tumor purity between two groups of tumor samples will lead to biased discovery of DM sites if not properly accounted for.

Results

We here propose InfiniumDM, a generalized least square model to adjust tumor purity effect for differential methylation analysis. Our method is applicable to a variety of experimental designs including with or without normal controls, different sources of normal tissue contaminations. We compared our method with conventional methods including minfi, limma and limma corrected by tumor purity using simulated datasets. Our method shows significantly better performance at different levels of differential methylation thresholds, sample sizes, mean purity deviations and so on. We also applied the proposed method to breast cancer samples from TCGA database to further evaluate its performance. Overall, both simulation and real data analyses demonstrate favorable performance over existing methods serving similar purpose.

Availability and implementation

InfiniumDM is a part of R package InfiniumPurify, which is freely available from GitHub (https://github.com/Xiaoqizheng/InfiniumPurify).

Supplementary information

Supplementary data are available at Bioinformatics online.
Microglia and macrophage phenotypes in intracerebral haemorrhage injury: therapeutic opportunities
Authors: Bai Qian , Xue Mengzhou , Yong V Wee
Published: November 2019

The prognosis of intracerebral haemorrhage continues to be devastating despite much research into this condition. A prominent feature of intracerebral haemorrhage is neuroinflammation, particularly the excessive representation of pro-inflammatory CNS-intrinsic microglia and monocyte-derived macrophages that infiltrate from the circulation. The pro-inflammatory microglia/macrophages produce injury-enhancing factors, including inflammatory cytokines, matrix metalloproteinases and reactive oxygen species. Conversely, the regulatory microglia/macrophages with potential reparative and anti-inflammatory roles are outcompeted in the early stages after intracerebral haemorrhage, and their beneficial roles appear to be overwhelmed by pro-inflammatory microglia/macrophages. In this review, we describe the activation of microglia/macrophages following intracerebral haemorrhage in animal models and clinical subjects, and consider their multiple mechanisms of cellular injury after haemorrhage. We review strategies and medications aimed at suppressing the pro-inflammatory activities of microglia/macrophages, and those directed at elevating the regulatory properties of these myeloid cells after intracerebral haemorrhage. We consider the translational potential of these medications from preclinical models to clinical use after intracerebral haemorrhage injury, and suggest that several approaches still lack the experimental support necessary for use in humans. Nonetheless, the preclinical data support the use of deactivator or inhibitor of pro-inflammatory microglia/macrophages, whilst enhancing the regulatory phenotype, as part of the therapeutic approach to improve the prognosis of intracerebral haemorrhage.
Subjective Uncontrollability over Aversive Events Reduces Working Memory Performance and Related Large-Scale Network Interactions
Authors: Wanke Nadine , Schwabe Lars
Published: November 2019

Lack of control over significant events may induce a state of learned helplessness that is characterized by cognitive, motivational, and affective deficits. Although highly relevant in the pathogenesis of several mental disorders, the extent of the cognitive deficits induced by experiences of uncontrollability and the neural mechanisms underlying such deficits in humans remain poorly understood. Using functional magnetic resonance imaging (fMRI), we tested here whether uncontrollability over aversive events impairs subsequent working memory performance and, if so, which neural processes are involved in such deficits. We assessed working memory and the involved neurocircuitry in the MRI scanner before and after participants underwent a task in which they could either learn to avoid electric shocks or had no instrumental control over shocks. Our results show that subjective, but not objective, uncontrollability over aversive events impaired working memory performance. This impact of subjective uncontrollability was linked to altered prefrontal and parahippocampal activities and connectivity as well as decreased crosstalk between frontoparietal executive and salience networks. Our findings show that the perceived uncontrollability over aversive events, rather than the aversive events themselves or the actual, objective control over them, disrupts subsequent working memory processes, most likely through altered crosstalk between prefrontal, temporal, and parietal areas.
Simultaneous Pharmacokinetics Estimation of Nateglinide and Pioglitazone by RP-HPLC: Computational Study to Unlock the Synergism
Authors: Dey Suddhasattya , Basak Souvik , De Anjan , Alam Shahreja Parvez , Hossain Tabassum , Saha Achintya , Ghosh Manik , Karmakar Tanushree
Published: November 2019

Nateglinide (NAT) and Pioglitazone (PIO) are an antidiabetic drugs combination and currently under clinical trial in countries like Japan. In this study, an alternative, a simple, sensitive high-performance liquid chromatography method has been developed (limit of detection: 15 ng/mL and limit of quantification: 50 ng/mL) for simultaneous estimation of this drug combination in rat plasma. Most remarkably, bioavailability of NAT has been increased markedly on coadministration with PIO, than when it was administered alone. Thus, PIO is assumed to retard the catabolism of NAT by inhibiting metabolic liver-microsomal enzyme, especially CYP2C9. Using a Waters Nova-Pak C 18 column (150 × 3.9 mm, 4 μm) and a mobile phase of acetonitrile: 10 mM KH2PO4 (60: 40, V/V (volume by volume)) pH 3.5, the analysis was performed at 210 nm with a flow rate of 1.5 mL/min. In silico docking via molecular dynamics simulation revealed that NAT-CYP2C9 binding affinity may be reduced after PIO attachment, presumably due to the binding site overlapping of the two drugs. Thus, it has been proposed that NAT and PIO may be an efficient synergistic fixed dose combination against diabetes mellitus, and the above method can foster a simple but highly sensitive bioanalytical estimation for routine analysis.
Radio-tracking reveals insight into survival and dynamic habitat selection of fledgling Cerulean Warblers
Authors: Raybuck Douglas W , Larkin Jeffery L , Stoleson Scott H , Boves Than J
Published: November 2019

For most bird species, little is known about their ecology and survival between fledging and independence despite the potential for post-fledging survival to be a factor limiting population dynamics. Cerulean Warblers (Setophaga cerulea) are a declining migratory species, and full-life-cycle conservation efforts that include the post-fledging period are warranted to attempt to reverse their decline. To understand movement, habitat selection, and survival, we radio-tracked 20 fledglings throughout the dependent post-fledging period. Broods were split by their parents, typically (88%) left parental breeding territories within 12 days, and survivors moved 2.4 ± 0.7 km (mean ± SE) from their nest within the 28.1 ± 1.8 day tracking period. Fledglings were usually observed in the mid-canopy to upper canopy and selected habitat with greater mid-story cover, less basal area, and areas closer to water bodies, compared to available points, when considering data from the entire post-fledgling period. However, habitat selection varied with fledgling age. Young fledglings (0–2 days post-fledging) selected areas with greater sapling cover and less stand basal area, but as fledglings matured, they selected areas farther from canopy gaps with greater mid-story cover. Compared with nesting habitat selected by parents, fledglings used areas with smaller and more numerous trees, fewer canopy gaps, and greater mid-story cover. Survival of the entire period was 48 ± 14% and most (8/10) mortalities occurred within the first 3 days post-fledging. Evidence indicated eastern chipmunks (Tamias striatus) as the most common predator. Providing or retaining large tracts of forest is recommended to prevent the restriction of post-fledging dispersal, and managing forests to maintain a heterogeneous landscape that includes stands with numerous canopy gaps and dense understory (e.g., shelterwood harvests or late seral stage conditions) as well as stands with a dense mid-story (e.g., younger stands and riparian areas) appears to be important for this life stage.
O3 DIRECT ORAL FEEDING FOLLOWING MINIMALLY INVASIVE ESOPHAGECTOMY (NUTRIENT II TRIAL): AN INTERNATIONAL, MULTICENTER, OPEN-LABEL RANDOMIZED CONTROLLED TRIAL
Authors: Berkelmans Gijs H K , Fransen Laura F C , Dolmans-Zwartjes Annemarie C P , Kouwenhoven Ewout A , van Det Marc J , Nilsson Magnus , Nieuwenhuijzen Grard A P , Luyer Misha D P
Published: November 2019

Aim

Patients undergoing an esophagectomy are often kept nil-by-mouth postoperatively out of fear for increasing anastomotic leakage and pulmonary complications. This study investigates the effect of direct start of oral feeding following minimally invasive esophagectomy (MIE) compared to standard of care.

Background & Methods

Elements of enhanced recovery after surgery (ERAS) protocols have been successfully introduced in patients undergoing an esophagectomy. However, start of oral intake, which is an essential part of the ERAS protocols, remains a matter of debate.

Patients in this multicenter, international randomized controlled trial were randomized to directly start oral feeding (intervention) after a MIE with intrathoracic anastomosis or to receive nil-by-mouth and tube feeding for five days postoperative (control group). Primary outcome was time to functional recovery. Secondary outcome parameters included anastomotic leakage, pneumonia rate and other surgical complications scored by predefined definitions.

Results

Baseline characteristics were similar in the intervention (n=65) and control (n=67) group. Functional recovery was seven days for patients receiving direct oral feeding compared to eight days in the control group (p-value 0.436). Anastomotic leakage rate did not differ in the intervention (18.5%) and control group (16.4%, p-value 0.757). Pneumonia rates were comparable between the intervention (24.6%) and control group (34.3%, p-value 0.221). Other morbidity rates were similar, except for chyle leakage which was more prevalent in the standard of care group (p-value 0.032).

Conclusions

Direct oral feeding after an esophagectomy does not affect functional recovery and did not increase incidence or severity of postoperative complications.
FULMINANT CEREBRAL AIR EMBOLISM FOLLOWING ENDOVAC-THERAPY IN ESOPHAGEAL ANASTOMOTIC LEAKAGE – A RARE COMPLICATION
Authors: Herzberg J , Jenner R , Strate T , Honarpisheh H
Published: November 2019

Aim

Anastomotic leakages after esophageal surgery is a major complication with an increased risk of mortality and an extended ICU and hospital stay.

Surgical revisions or endoscopic interventions are standard procedures in treatment of such complications. The use of endoscopic endoluminal vacuum therapy (EVT) as introduced in the last years is considered a safe treatment.

Background & Methods

We analyzed 78 patients who underwent a surgical resection of the esophagus from January 2015 until December 2018. We compared patients with endovac-therapy to patients without such endoscopic intervention. Length of stay in ICU and in hospital, patient’s demographics and perioperative parameters were analyzed.

Results

In our center, we performed 78 esophageal resections from January 2015 to December 2018. In 14.1% (11 patients) an anastomotic leakage appeared, in 10 patients (12.8% of all cases) we performed an endovac-therapy. In the endovac- group, the mean postoperative hospital stay was 39 days (± 18 days), which is a significant longer postoperative in-hospital time in compare to the other patients (mean 17 days, ±8 days, p=0,004). Patients demographics and perioperative parameters were comparable in both groups.

The postoperative 90-days mortality in the endovac-group was 20% (2 patients), in compare to a 90-days mortality rate of 4.4% in the group without an EVT.

In one case we found the rare complication of an air embolism following an extended 35 days endovac-therapy.

Endovac-therapy is a useful tool in the treatment of anastomotic leakage, although it is associated with a significantly prolonged hospital stay. Air embolism during endovac-therapy such as reported in this analysis, is a rare complication associated with endoscopic treatments. This is the first reported case of such an air embolism during endovac-therapy.

Using carbon dioxide for endoscopic interventions might reduce the risk for air embolism, especially in high-risk-patients.
P6 HIATAL HERNIA REPAIR BY TENSION-FREE MESH CLOSURE OR SIMPLE SUTURING OF THE DIAPHRAGMATIC HIATUS
Authors: Apostolos Analatos , Bengt Håkanson , Lars Lundell , Mats Lindblad , Anders Thorell
Published: November 2019

Aim

To assess the anatomical and functional results of the use of a mesh for the repairing of hiatal hernia in patients with gastro-esophageal reflux disease (GERD)

Background & Methods

In hiatal hernia repair during antireflux surgery, less focus has traditionally been directed towards the restoration of the diaphragmatic hiatus. In other types of hernia repair, the use of a mesh-reinforced, tension-free technique has been shown to be associated with reduced recurrence rates. Patients (n=159) undergoing Nissen fundoplication for gastro-esophageal reflux disease were randomized to closure of the diaphragmatic hiatus with either crural sutures alone (n=77) or tension-free closure with a non-absorbable mesh (Crurasoft®, n=82). Primary outcome was radiologically verified recurrent hiatal hernia. Secondary outcomes were intra-and postoperative complications and courses, symptomatic recurrence, use of PPI, postoperative oesophageal acid exposure and Quality of Life.

Results

At 3 years recurrence rates were 12 % and 9 % in the mesh and suture groups respectively (p=0,61). Control of GERD symptoms, use of PPI and oesophageal acid exposure did not differ between groups. At the same time obstructive eating complaints were reduced in both groups compared to the preoperative setting (p<0.05) but more patients scored dysphagia for solid food after mesh closure (p=0,027). Quality of life scores were significantly improved throughout the follow up without differences between groups.

Conclusion

Tension-free crural repair with non-absorbable mesh does not reduce the incidence of recurrent hiatal hernia compared to crural sutures alone in GERD patients undergoing total fundoplication. This, together with the finding of increased dysphagia at 3 years postoperatively, suggests that mesh closure cannot be recommended for routine use in laparoscopic hiatal hernia repair for GERD.
P7 THE IMPACT OF PREHABILITATION ON PARAMETERS OF BODY COMPOSITION IN PATIENTS UNDERGOING MULTIMODAL THERAPY FOR OESOPHAGO-GASTRIC (OG) CANCER
Authors: Emre Doganay , Piers R Boshier , Laura J Halliday , Rob Thomas , Donald E Low , Krishna Moorthy
Published: November 2019

Aims

This study characterises changes in body composition and physical performance during neoadjuvant therapy in the context of prehabilitation before oesophago-gastric resection.

Background & Methods

Neoadjuvant therapy has deleterious effects on functional capacity and may lead to a decline in physical fitness and skeletal muscle mass. This is a retrospective review of oesophago-gastric cancer patients undergoing prehabilitation. Assessment of body composition (skeletal muscle, visceral and subcutaneous adipose tissue) was performed from L3 axial CT images acquired at the time of diagnosis and after neoadjuvant therapy.

Results

42 patients (33M, 65.7±11.1) met the inclusion criteria. Patients body weight (81.8±21.3 kg vs. 81.3±21 kg, p=0.668) and BMI (27.9±7.2 kg/m2 vs. 27.8±7.0 kg/m2, p=0.648) did not change significantly between the study time points. There was no significant difference between estimated lean body mass (39.2±13.2 vs. 38.3±10.1; 95%CI -2.5 to 4.3 p=0.592) and fat mass (30.6±15.4 vs. 28.6±14.0; 95%CI -1.7 to 5.7, p=0.284). Skeletal muscle index significantly decreased (46.5±9.9 to 43.1±9.8; 95%CI 2.1 to 4.6, p<0.001). Patients who were adherent to the prehabilitation programme had a significantly higher skeletal muscle index compared to noncompliant patients (47.4±10.4 vs. 40.2±8.9; 95%CI 1.5 to 13.5, p=0.016). Patients who achieved a higher MET-minutes were less likely to be sarcopenic (F(1,40 = 6.1, p = 0.018)).There was no decline in physical performance (Median IQR; VO2max ml kg−1min−1) during neoadjuvant therapy (17.5 [14-19.3] vs. 17.5 [13.3-19.3]; p=0.164).

Conclusion

this is the first study to report variations in parameters of body composition in patients undergoing a prehabilitation programme. Findings suggest that prehabilitation may be a useful adjunct in limiting the extent of sarcopenia and patient deconditioning during neoadjuvant therapy.
P8 KERATIN 17 PROMOTES CELLS PROLIFERATION AND METASTASIS IN ESOPHAGEAL SQUAMOUS CELL CARCINOMA
Authors: Zhun Liu , Zhimin Shen , Peipei Zhang , Shaobin Yu , Lei Gao , Sui Chen , Mingqiang Kang
Published: November 2019

Background

Keratin17(KRT17), as a multifunction cytoskeletal protein, associated with a multitudinous of biological processes, including cell proliferation, migration, and invasion. Previously, we have found up-expression of KRT17 genes in ESCC tissues. Currently, published kinds of researches claimed KRT17 is engaged in the tumorigenesis and progression of multiple cancers. However, the prognostic significance of KRT17 in ESCC patients and its effects in ESCC progression remains indistinct.

Methods

We verified the expression level of KRT17 in ESCC tissues by Western blotting and q-PCR and constructed KRT17 upregulated and knockdown EC9706 and Eca109 cells by Lentivirus overexpression and CAS9. The function of KRT17 in ESCC proliferation and metastasis were studied in vitro. We performed CCK-8 assays and plate colony formation assays and the plate colony formation assays to explore the effect of KRT17 on the proliferation, Moreover, the trans-well migration chamber experiment and wound healing test was taken to reveal the impact of KRT17 on migration capabilities.

Results

We verified that KRT17 is overexpressed in ESCC tissues and the role of KRT17 in the malignant behavior of ESCC in vitro and vivo . In CCK-8 assays and plate colony formation assays. We conformed proliferation capacity was notably enhanced by overexpression of KRT17 but compromised when KRT17 was knocked out. On the other hand, we used the plate colony formation assays to explore the effect of KRT17 on the proliferation of ESCC cells. KRT17 up-regulated significantly strengthened the proliferation while the KRT17 knockdown was weakened. To reveal the impact of KRT17 on migration, the trans-well migration chamber experiment was used to compare the role of down-regulation and up-regulation of KRT17 in migration; the results demonstrated that reducing expression of KRT17 significantly blocked the movement of ESCC cells as compared with the empty vector control. Otherwise, it has been confirmed that the cell migration ability employs a wound healing/scratch test because wound closure is generally a measure of cell motility. The results showed KRT17 overexpression notably reinforced the mobility of ESCC cells compared with the empty groups, whereas KRT17 knockdown cells prolonged the time to close the injury compared to blank groups. Collectively, these discoveries support that the increased expression of KRT17 in ESCC cells promoted a more proliferation and migratory phenotype in vitro.

Conclusion

The breakthrough indicated that the up-regulation of KRT17 in ESCC is closely related to malignant progression. Our data confirmed that KRT17 plays an essential role in reinforcing proliferation and metastasis in ESCC. Thence, KRT17 may serve as a significant molecular target for the diagnosis and therapy of ESCC.
P101 THE IMPACT OF PARATRACHEAL LYMPHADENECTOMY ON LYMPH NODE YIELD AND SHORT-TERM OUTCOMES IN ESOPHAGECTOMY: A NATIONAL PROPENSITY SCORE MATCHED ANALYSIS
Authors: Kingma B F , Hagens E R C , van Berge Henegouwen M I , Borggreve A S , Ruurda J P , Gisbertz S S , van Hillegersberg R
Published: November 2019

Aim

This study aimed to investigate the impact of paratracheal lymphadenectomy on lymph node yield and short-term outcomes in patients undergoing esophagectomy for cancer.

Background & Methods

Although the addition of paratracheal lymphadenectomy to a standard two-field lymphadenectomy possibly may provide survival benefits for patients undergoing esophagectomy for esophageal cancer, the required dissection along the recurrent laryngeal nerves might be associated with increased morbidity. To investigate the impact of paratracheal lymphadenectomy on short-term oncological outcomes and postoperative complications, this nation-wide population-based cohort study included esophageal cancer patients who underwent neoadjuvant chemoradiotherapy followed by elective transthoracic esophagectomy with at least subcarinal and para-esophageal lymphadenectomy from the Dutch Upper Gastrointestinal Cancer Audit (DUCA). After propensity score matching Ivor Lewis and McKeown approaches separately, the lymph node yield and clinical outcomes were compared between patients who underwent paratracheal lymphadenectomy versus patients who did not.

Results

Between 2011-2017, a total of 2128 patients were included. A total of 770 patients (n=385 vs. n=385) and 516 patients (n=258 vs. n=258) were matched for the Ivor Lewis and McKeown approaches, respectively. Paratracheal lymphadenectomy was associated with a higher total lymph node yield in both Ivor Lewis (23 vs. 19 nodes, P<0.001) and McKeown (21 vs. 19 nodes, P=0.015) esophagectomy. In McKeown esophagectomy, paratracheal lymphadenectomy was associated with significantly more advanced pathological nodal staging (pN0; 57% vs. 69%, pN1; 25% vs. 16%, pN2; 12% vs. 11%, pN3; 6% vs. 3%, P=0.006). No significant differences were observed regarding recurrent laryngeal nerve injury, other postoperative complications, and mortality, although a higher re-intervention rate was found after paratracheal lymphadenectomy during McKeown esophagectomy (30% vs. 18%, P=0.002) In patients undergoing Ivor Lewis esophagectomy, paratracheal lymphadenectomy was associated with increased length of stay (12 vs. 11 days, P<0.048).

Conclusion

In patients undergoing transthoracic esophagectomy for cancer, the addition of paratracheal lymphadenectomy results in a higher lymph node yield with comparable complication and mortality rates.
O112 SURVEILLANCE USING FDG-UPTAKE IN THE PRIMARY TUMOUR ON PET/CT IN PATIENTS WITH OESOPHAGEAL CANCER AND A CLINICALLY COMPLETE RESPONSE AFTER NEOADJUVANT CHEMORADIOTHERAPY
Authors: Valkema M J , van der Wilk B J , Eyck B M , Wijnhoven B P L , Spaander M C W , Lagarde S M , Nieuwenhuijzen G A P , Sosef M N , Van Lanschot J J B , Valkema R
Published: November 2019

Aim

In oesophageal cancer patients, clinical response to neoadjuvant chemoradiotherapy (nCRT) according to CROSS is assessed after 12 weeks, potentially followed by active surveillance in case of clinically complete response (cCR). Detection of residual tumour by FDG-PET/CT alone is inaccurate, since this cannot be distinguished reliably from post-radiation oesophagitis. We hypothesize that when inflammation diminishes, increasing FDG-uptake over time may be a sensitive parameter to detect local recurrence. We studied the detection of tumour recurrence with PET/CT during systematic follow-up in clinically complete responders beyond 12 weeks after nCRT.

Background & Methods

Patients from the preSANO- and SANO- trials were included who obtained cCR (no residual tumour on bite-on-bite biopsies and EUS with FNA of suspected lymph nodes) 12 weeks after completion of nCRT, but declined subsequent surgery. Patients were offered active surveillance, including PET/CT every 3 months. Standardised uptake values corrected for lean body mass (SUL) were measured at the primary tumour site. The percentage change in maximum SUL value (SULmax) between the last follow-up scan and the scan 12 weeks after nCRT was calculated. Tumour recurrence was defined as biopsy-proven vital tumour.

Results

Some 33 patients were eligible for analysis. In 17 of 33 (52%) patients, no biopsy-proven local recurrence was found during a median follow-up of 16 months (range 4.0-25) after CROSS. Some 16 of 33 (48%) patients had tumour recurrence within a median of 6.9 months after CROSS (range 5.3-36). We observed two different patterns of FDG uptake suggesting local recurrence. Three of 16 patients had sudden intense increase in SULmax (mean delta%-SULmax of 216%±42%). In the other 13 of 16 patients with local recurrence, an insidious gradual increase in FDG uptake was seen compared to patients without recurrence: mean delta%-SULmax of 21%±18% versus -10%±22% respectively.

Conclusion

Increasing FDG-uptake during active surveillance beyond 12 weeks after nCRT was associated with local recurrence and stable FDG-uptake with ongoing local tumour control. Thus, serial PET/CT might be a useful tool to distinguish tumour recurrence from SUL fluctuations in complete responders. To define a cut-off value of delta%-SULmax for local recurrence a larger number of patients is needed.