bluuebunny/crossref_metadata_2025 huggingface dataset:
Mean stress effects on Low-Cycle Fatigue behaviour of Inconel 718 alloy
Authors: Vantadori Sabrina , Carpinteri Andrea , Ronchei Camilla , Scorza Daniela , Zanichelli Andrea
Published: December 2019

Uniaxial and biaxial fatigue test results related to Inconel 718 specimens are analysed by using the critical plane-based multiaxial fatigue criterion by Carpinteri et al., formulated in terms of strain, in conjunction with a model similar to that by Smith-Watson-Topper (SWT). More precisely, both smooth solid specimens and thin-walled tubular specimens subjected to proportional and non-proportional loading consisting of tension, torsion, and combined tension and torsion loading under strain control are examined, for strain ratio equal to 0 or -1. Fatigue life is then analytically computed through the above procedure and compared with the experimental one, in terms of number of loading cycles needed to form a surface crack whose length is equal to 1 mm.
Including the normal to shear stresses ratio in fatigue life estimation for cyclic loadings
Authors: Kurek Marta
Published: December 2019

The paper presents the estimation of the fatigue life under multiaxial cyclic loading of two construction materials. The main aim of this paper is to present a new method which allows evaluation of fatigue life during the design and construction phase of machine elements. In paper three well known multiaxial fatigue criteria based on the critical plane approach verified. This paper contains a proposition to define a new way of determining an orientation angle of the critical plane. The comparison between experimental and theoretical results varying the critical plane orientation appears to be satisfactory.
General Procedure for Formulation of Multiaxial Fatigue Failure Criteria in Frequency Domain
Authors: Niesłony Adam , Böhm Michał , Owsiński Robert
Published: December 2019

Fatigue life assessment under multiaxial loading conditions needs the use of multiaxial fatigue failure criteria. There are many formulations of such criteria which are usually divided in the groups of critical plane criteria and invariants based criteria. Other classifications refer to the parameter that determines fatigue, and these are stress, strain and energy criteria. Recently, the development of computational techniques for fatigue analysis in the frequency domain have been noticed. Analyzing the literature, it can be noted that these criteria are mainly created by the new formulation of them in the new domain. There is therefore a need to develop a general approach to the problem of formulating criteria in the frequency domain on the basis of existing proposals for the time domain. The paper presents the manner in which the values appearing in the criteria in the frequency domain can be determined. In particular, the process of formulating criteria of multiaxial random fatigue, using the critical plane approach proposed by Macha was presented. During the formation the linearity of such criteria was successfully used. Situations that indicate the correctness of transformations are also presented.
The assessment of the tensile with torsion loading interaction using the selected hypotheses and the experiment
Authors: Chmelko Vladimír , Novotný Pavol
Published: December 2019

For two steels with different material properties (both cyclic and static ones) were experimentally obtained dependencies σa=f(Nf) and σa=f(Nf). The specimens of these materials were loaded with multiple tensile and torsion stress combinations. It was found out that the time-depending relationship between the individual stresses was proportional. The results for steel with high ration of Rm/Re are different comparing to the results of the second material. In this contribution, there will be confronted the experimentally obtained fatigue life-time magnitudes with selected multiaxial fatigue life-time hypotheses like Findley, McDiarmid, Dang-Van, Carpinteri-Spagnioli, and Margetin-Ďurka-Chmelko.
Multiaxial cycle counting method for non-proportional multiaxial variable loading signals based on modified maximal shear stress
Authors: Margetin Matus , Biro Dominik
Published: December 2019

One of the most challenging task in field of multiaxial fatigue is fatigue lifetime estimation of components loaded with multiaxial non-proportional variable amplitude loading. While this task consists of multiple smaller problems, one of the most crucial ones is loading cycles identification (and extraction) for future use with multiaxial damage criterions. By now, several cycle counting methods have been proposed for multiaxial loading conditions. The most wildly accepted methods are Bannantine-Socie’s method and Wang-Brown’s method (which has been later modified by Meggiolaro and Castro). The aim of this paper is the comparison of newly developed method with Bannantine-Socie’s method and Wang-Brown’s method. The new cycle counting method is based on cycle identification in relative maximum shear stress histories (calculated from multiaxial loading histories). The extracted data than composes part of each loading channel of multiaxial loading histories corresponding to identified loading cycle. The comparison of chosen methods has been done by using data sets created by authors as well as using real measured data from real operation.
Multiaxial fatigue assessment of welded steel details according to the peak stress method based on tetra elements
Authors: Campagnolo Alberto , Meneghetti Giovanni , Babini Vittorio , Riboli Matteo , Spagnoli Andrea
Published: December 2019

The Peak Stress Method (PSM) is an engineering, FE-oriented application of the notch stress intensity factor (NSIF) approach to fatigue design of welded joints, which takes advantage of the singular linear elastic peak stresses from FE analyses with coarse meshes. Originally, the PSM was calibrated by using 3D, eight-node brick elements, taking advantage of the submodeling technique. Recently, the PSM has been calibrated by using ten-node tetra elements, which are able to directly discretize complex 3D geometries without the need for submodels. The PSM was validated for pure axial or bending loadings as well as pure torsion loadings; recently it has been extended to multiaxial loadings by adopting a design stress, the so-called equivalent peak stress, in conjunction with a reference design fatigue curve. After having briefly recalled the calibration of the PSM with tetra elements, the paper presents some applications of the PSM relevant to steel plate-to-tube welded details of industrial interest under in-phase bending-torsion fatigue loadings. Experimental data have been re-analysed using the PSM based on tetra elements. Eventually a good agreement between experimental and theoretical results has been obtained in terms of fatigue crack initiation location as well as total fatigue life.
An axiomatic approach to the design and operation of a wood pellet production line
Authors: Rodrigues Fábio , Fradinho João , Cavique Miguel , Gabriel-Santos António , Mourão António
Published: December 2019

With the recent search for sustainable energies, the use of forest residues has never been so important and profitable. Biomass production companies are in a constant search for new methods to reuse what is otherwise seen as waste. In this context, wooden pellets have been a booming market. In Portugal, its production increased from 400 000 to 1 200 000 metric tons per year in the period 2008-2014. This production represents a growth of 300% in 6 years, most of it used for exportation. The manufacturing process is empiric and lacks a scientific approach. In this paper, Axiomatic Design is used to analyse a production line of wooden pellets aiming to identify couplings, both in the equipment and in the production process, and to propose solutions that follow the independence axiom.
Incorporating Patent Analysis in Axiomatic Design for New Product Development
Authors: Lin Wenguang , Xiao Renbin , Lai Rongshen , Guo Xiaozhen
Published: December 2019

Axiomatic design theory is widely used in new product development by providing design solutions through mapping between functional requirements and design parameters. However, the theory does not provide a method to help designer obtain and select design parameters. To this end, this paper introduces patent analysis to overcome the deficiency. Firstly, functional requirements are transformed into patent search terms, and design parameters are obtained from patents. Secondly, morphological matrix is used to represent the relationships between target function and multiple design parameters. Thirdly, design parameters with higher patent frequency are chose and combined into a new scheme. Finally, the scheme is evaluated by the independent axiom of Axiomatic Design theory. The methodology is demonstrated and validated with a case study of spa shower.
Axiomatic design and virtual verification for blackbody cavity sensor
Authors: Cheng Jiangfeng , Juang Chia-Feng , Chen Weihai , Mei Guohui
Published: December 2019

The blackbody cavity sensor for continuous temperature measurement of molten steel has been widely used in steel industry. However, due to the closed bottom of the inner tube, the temperature measurement accuracy is seriously affected. It’s urgent to redesign and improve the sensor, which involves multidisciplinary knowledge, including materials, heat and flow science. This paper first clarifies the relationship between sensor functional requirements and various physical structure parameters from the perspective of axiomatic design. On this basis, the virtual models of the blackbody cavity sensor are established, including geometry model, multi-physical field model, material physical properties and boundary conditions. And then through comparison between experiment and simulation, it is found that for the temperature measurement accuracy, the deviations between the simulation and the actual experimental result are less than 1.5℃. This verifies the accuracy of the virtual model.
Nature's Design's: The Biology of Survival
Authors: Mantri Pam , Thomas John
Published: December 2019

Life has existed on earth for at least 3.95 billion years. All along, the flame of life has been successfully passed on from generation to generation, and species to species across an immense temporal span. This includes at least five mass-extinction events that wiped out over 70% of all species in each such biotic crisis. Against such immense odds, life has learned to thrive despite repeat assaults. And the ingenuity embedded within natures designs has been an integral part of this inspiring story. For example, the ancient bacterial flagellum is powered by the Mot Complex which is part of a perfectly circular nanoscale rotary engine. It is obvious that nature came upon the wheel much before human arrival (i.e., at least as far back as 2.7 billion years). Many are the design lessons that may be gleaned from studying nature. This paper looks at the immense evolutionary design-laboratory that nature evolves its designs within, and frames it along side an Axiomatic/Complex-Adaptive/Stigmergic Systems perspective.
PWR effect on crack initiation under equi-biaxial loading development of the experiment
Authors: Gourdin Cédric , Perez Gregory , Dhahri Hager , Courtin Stéphan , Le Roux Jean Christophe , Maitournam Habibou
Published: December 2019

The lifetime extension of the nuclear power stations is considered as an energy challenge worldwide. That is why, the risk analysis and the study of various effects of different factors that could potentially represent a hazard to a safe long term operation are necessary. The methodology for fatigue dimensions of the Pressurized Water Reactor components (PWR) is based on the use of design curves established from test carried out in air at 20 °C on smooth specimens by integrating safety coefficient that covers the dispersion of tests associated with the effects of structures. To formally integrate these effects, some international codes have already proposed and suggested a modification of the austenitic stainless steels fatigue curve combined with a calculation of an environmental penalty factor, namely Fen, which has to be multiplied by the usual fatigue usage factor. The aim of this paper is to present a new device “FABIME2E” developed in the CEA-LISN in collaboration with EDF and AREVA. These new tests allow quantifying accurately the effect of PWR environment on semi-structure specimen. This new device combines the structural effect like equi-biaxiality and mean strain and the environmental penalty effect with the use of PWR environment during the fatigue tests.
Update ESC-Leitlinie: Kardiovaskuläre Erkrankungen während der Schwangerschaft – Worauf kommt es an?
Authors: Klein Kathrin , Karathanos Athanasios , Heinen Yvonne
Published: December 2019

Was ist neu?

Frühzeitige Beratung schon vor der Schwangerschaft Alle herzkranken Patientinnen sollten vor einer Schwangerschaft entsprechend ihrem Risikoprofil anhand der mWHO-Klassifizierung (modifizierte World Health Organization) für mütterliches Risiko beraten werden, im besten Fall von einem Schwangerschafts-Herz-Team.

Diagnostik vor und während der Schwangerschaft Bei Verdacht auf eine pulmonale Hypertonie hat die Rechtsherzkatheteruntersuchung nach entsprechender Risiko-Nutzen-Abwägung eine IC-Empfehlung, auch während der Schwangerschaft. Für Rhythmusstörungen wurden Überwachungsstufen für die Geburt abhängig vom Arrhythmierisiko definiert.

Spezielle Krankheitsbilder Zur Thromboseprophylaxe und -therapie ist körpergewichtsadaptiert niedermolekulares Heparin mit wöchentlichen Anti-Xa-Spiegel-Kontrollen oder unfraktioniertes Heparin mit regelmäßigen aPTT-Kontrollen empfohlen. Eine orale Antikoagulation darf bei niedriger Dosierung neu auch schon während des 1. Trimenons eingesetzt werden. Bei hochgradiger Mitralklappenstenose wird nun eine Behandlung vor der Schwangerschaft empfohlen. Die Empfehlung zur Katheterablation von symptomatischen supraventrikulären Tachykardien wurde von IIbC auf IIaC hochgestuft. Bromocriptin erhielt eine Empfehlung bei postpartaler Kardiomyopathie (IIbB). Bei herzkranken Patientinnen sollte ab der 40. Schwangerschaftswoche eine Geburtseinleitung erwogen werden.

Medikamente – Welche sind wann sicher? In der PLLR (Pregnancy and Lactation Rule) hat die neue Leitlinie 150 Medikamente mit ihrem Gefährdungspotenzial aufgeführt. Darüber hinaus können die Webseiten www.safefetus.com oder www.embryotox.de genutzt werden.
Mikrobiom und metabolische/bariatrische Chirurgie
Authors: Seyfried Florian , Hering Ilona , Hankir Mohamed
Published: December 2019

﻿Derzeit ist die metabolische/bariatrische Chirurgie die einzige evidenzbasierte Therapie, die bei einem Großteil der morbid adipösen Patienten zu einer relevanten und nachhaltigen Gewichtsabnahme und Verbesserung der Adipositas-assoziierten Morbidität führt. Das historische Konzept, dass die dominanten zugrundeliegenden Mechanismen der bariatrischen/metabolischen Chirurgie eine Nahrungsrestriktion (durch Verkleinerung des Magens) und eine Malabsorption von Makronährstoffen (durch einen intestinalen Bypass der oralen Dünndarmabschnitte) sind, ist mittlerweile widerlegt.

Grundlagenwissenschaftliche Studien konnten zeigen, dass der Darm als physiologische Schaltzentrale dient und nach anatomischer Umstellung, wie beispielsweise nach einer Magenbypass-Operation, veränderte neuronale und endokrine Signale an unterschiedliche Organsysteme aussendet.

Es existiert eine robuste, spezies-übergreifende Datenlage, dass es nach metabolischer/bariatrischer Chirurgie zu einer nachhaltigen Veränderung des Mikrobioms kommt. Insgesamt ist eine erhöhte Vielfältigkeit der Bakterienstämme mit einer häufigen Reduktion von Firmicutes und Bacteroidetes und eine Erhöhung von Proteobakterien beschrieben. Dabei scheint die Veränderung des Mikrobioms Chirurgie- und Prozeduren-spezifisch und nicht Folge der erreichten Gewichtsabnahme zu sein. Die biologische Relevanz konnte mehrfach experimentell in konzeptionellen Beweisstudien (Mikrobiomtransfer) gezeigt werden. Experimentelle Daten legen nahe, dass die Zusammensetzung des Mikrobioms nicht nur durch die Operation selbst verändert wird und damit unterschiedliche Systeme (entero-endokrin, Darmbarriere, Konjugation von Gallensäuren) maßgeblich beeinflusst, sondern auch einen Einfluss auf den Wirkungsgrad der Operation selbst zu haben scheint. Trotzdem sind die verfügbaren Daten meist nur beschreibend und zeigen Assoziationen auf. Den Einfluss des veränderten Mikrobioms auf das gesamte Metabolom und vice versa ist bisher nur unzureichend verstanden und muss in weiterführenden Studien weiter untersucht werden.
Lokal fortgeschrittenes Endometriumkarzinom
Authors: Kretzschmar Alexander
Published: December 2019

Bei Patientinnen mit einem lokal fortgeschrittenen Endometriumkarzinom (Stadium III oder IV) bringt eine Radiotherapie (4500 cGy in 25 Fraktionen à 180 cGy) zusätzlich zu einer adjuvanten 6-monatige Platin-basierten Chemotherapie (Cisplatin 50 mg2 i. v. an Tag 1 und 29) hinsichtlich des progressionsfreien Überlebens als primärem Endpunkt keinen Vorteil gegenüber einer Chemotherapie allein.
Autologer Fetttransfer
Authors: Kretzschmar Alexander
Published: December 2019

Die autologe Fetttransplantation, auch als Lipofilling oder Lipotransfer bezeichnet, erfreut sich seit einigen Jahren einer steigenden Beliebtheit nicht nur bei der Brustaugmentation, sondern auch bei der sekundären Rekonstruktion der Brust. Dr. Daniela Rezek, Wesel, beschäftigte sich auf dem DGS 2019 mit dem aktuellen Erkenntnisstand.
Entstauungstherapie bei Lymphödem
Authors: Finkenrath M.
Published: December 2019

Anhand des nachfolgenden Fallberichtes soll gezeigt werden, welche Möglichkeiten in der Praxis bei einem häufig auftretendem lymphologischen Krankheitsbild, dem postoperativ nach Lymphknotenexstirpation entstandenen Lymphödem Grad II der Beine durchführbar sind und welche Leiden dieses Krankheitsbild für die Patienten (bis hin zur Immobilität) mit sich bringt. Der Ablauf von der Diagnostik (Eruieren der Ursache) über die Einleitung der initial standardisierten Therapie soll erläutert werden. Im weiteren Verlauf muss diese Therapie – auch das soll dargestellt werden – regelmäßig individuell angepasst werden. Darüber hinaus wird gezeigt, wie wichtig die Patientenaufklärung und -compliance bei diesem Krankheitsbild sind.
Fortgeschrittenes Harnblasenkarzinom
Authors: Krome Susanne
Published: December 2019

Urothelkarzinome weisen unterschiedliche Genprofile auf. Aberrationen des Fibroblasten-Wachstumsfaktor-Rezeptors (FGFR) sind dabei häufig. In der offenen Phase-2B-Studie hat sich der Pan-FGFR-Inhibitor Erdafitinib bei intensiv vorbehandelten Patienten mit inoperablen, lokal fortgeschrittenen und metastasierten Urothelkarzinomen als gut wirksam erwiesen. Die objektive Ansprechrate betrug 40 %, aber fast jeder 2. Patient hatte unerwünschte Wirkungen ≥ Grad 3.
Arteriell bedingte Beinschmerzen
Authors: Kalka Christoph
Published: December 2019

In der differentialdiagnostischen Abwägung von Beinschmerzen spielen arterielle Gefäßerkrankungen eine wichtige Rolle. Nicht selten allerdings werden in der täglichen Arztpraxis zunächst orthopädische und neurologische Ursachen in Erwägung gezogen. Ein Grund ist sicher die facettenreiche Symptomatik und die Heterogenität arterieller Durchblutungsstörungen.

Obwohl arteriell bedingte Schmerzen der Beine überwiegend arteriosklerotischer Genese sind, sollte das Vorliegen nicht-arteriosklerotischer Ursachen wie die Embolie, die Gefäßdissektion, Kompressionssyndrome und inflammatorische Erkrankungen immer in Erwägung gezogen werden. Prognoseentscheidend ist das Erkennen einer arteriell bedingten Problematik, die Abschätzung des Schweregrades der Durchblutungsstörung und dadurch auch des Amputationsrisikos der Extremität sowie ein zügiges Management.
Beinschmerz – dermatologische Ursachen
Authors: Kahle Birgit
Published: December 2019

Einleitung Als Grund für akute oder chronische Beinschmerzen werden oft vaskuläre Erkrankungen vermutet. Es stellt sich die Frage, ob auch dermatologische Krankheiten mit Beinschmerzen einhergehen.

Methode Dermatologische Krankheitsbilder werden hinsichtlich einer begleitenden oder kausalen Schmerzhaftigkeit systematisch dargestellt.

Ergebnisse Bei Infektionserkrankungen der Haut steht der Schmerz im Vordergrund, allergische oder toxische Kontaktdermatitiden, Juckreizerkrankungen sowie kutane Autoimmunerkrankungen gehen mit Schmerzen einher.

Zusammenfassung Bei unklaren Beinschmerzen sollte auch an eine zugrundeliegende dermatologische Erkrankung gedacht werden. Der Schmerz kann als Prodromalsymptom bei Herpes zoster auftreten.
Chronische lymphatische Leukämie
Authors: Schmale Ine
Published: December 2019

Zum 15. Mal seit der ersten Tagung im Jahr 1981 wurde in Lugano die International Conference on Malignant Lymphoma (ICML) abgehalten. Die wachsende Besucherzahl hat der familiär-wissenschaftlichen Stimmung des Kongresses keinen Abbruch getan. Neue Daten zur Grundlagen-, translationalen und klinischen Forschung zu malignen Lymphomen werden unter Hämatologen, klinischen und radiologischen Onkologen, Pathologen sowie führenden Forschern aus der ganzen Welt diskutiert. In diesem Jahr gehörten die Studien CLL14 und CLL12 der Deutschen CLL-Studiengruppe zu den wichtigsten Highlights der internationalen Lymphom-Konferenz.
Laparoskopische Hemikolektomie rechts mit kompletter mesokolischer Exzision (CME)
Authors: Brunner Maximilian , Weber Georg F. , Wiesmüller Felix , Weber Klaus , Maak Matthias , Kersting Stephan , Grützmann Robert , Krautz Christian
Published: December 2019

Einleitung Die komplette mesokolische Exzision (CME) gehört laut der deutschen S3-Leitlinie bei onkologischen Kolonresektionen zur Guten Klinischen Praxis (GCP, Good Clinical Practice). Diese Empfehlung basiert auf der Evidenz, dass die Entfernung des onkologisch relevanten Mesokolons ohne Verletzung der strukturellen Integrität sowie die zentrale vaskuläre Ligatur mit radikaler Lymphknotendissektion im Rahmen von CME-Kolonresektionen mit besseren histopathologischen Qualitätskriterien und besseren onkologischen Ergebnissen im Vergleich zu konventionellen Kolonresektionen einhergehen. Allerdings weisen Kolonresektionen mit CME besonders im rechten Hemikolon durch die anatomische Nähe zu Magen, Duodenum und Pankreas und einer hohen Variabilität der Gefäßstrukturen (z. B. des Truncus Henle) eine höhere Komplexität auf. Um die Sicherheit von laparoskopischen Hemikolektomien rechts mit CME zu erhöhen und die Weiterbildung dieses Eingriffes sicher und strukturiert zu ermöglichen, wurde von einer deutschen Expertengruppe für die laparoskopische Hemikolektomie rechts ein standardisiertes Vorgehen mit Sicherheitsblicken entwickelt. Im folgenden Video wird die Durchführung einer Hemikolektomie rechts mit CME gemäß dem von der Deutschen Expertengruppe Lap-CME erstbeschriebenen Konzept dargestellt.

Indikation Karzinom des Colon ascendens.

Prozedur Laparoskopische Hemikolektomie rechts mit kompletter mesokolischer Exzision (CME).

Schlussfolgerung Die vorgeschlagene Standardisierung der laparoskopischen Hemikolektomie rechts mit CME nimmt die erhöhte Komplexität der Operation auf und strukturiert sie in wohldefinierte Schritte mit kritischen Sicherheitsblicken als Kontrollinstanzen, was zu einer Minimierung intraoperativer Komplikationen und einer erhöhten Sicherheit für den Patienten sowie zu einer Verbesserung der strukturierten Weiterbildung führen dürfte.
Leitevent: Beschaffungskongress der Krankenhäuser 2019
Authors: Lorenz Oliver
Published: December 2019

Der Beschaffungskongress der Krankenhäuser, der in diesem Jahr am 4. und 5. Dezember in Berlin stattfindet, hat sich seit seiner Gründung zum zentralen Leitevent für die Branche Einkauf, Logistik und IT im Gesundheitswesen entwickelt.
Interview mit Ralf Bannwarth: „Transparenter, strukturierter, schneller“
Authors: Rößing Sabine
Published: December 2019

Ralf Bannwarth, Leitung Einkauf und Medizintechnik der Alb Fils Kliniken spricht in Klinik Einkauf über den Nutzen von Industriepartnerschaften aus der Krankenhaus-Perspektive.
Arzneimittelversorgung der Zukunft: Mehr Arzneimittelsicherheit durch Unit Dose
Authors: Negele Hans-Jörg , Königer Kim Kristian
Published: December 2019

Die Verbreitung von Unit-Dose-Versorgung in Kliniken variiert weltweit erheblich: In den USA erfolgt die Bereitstellung von Arzneimitteln durch die Krankenhausapotheke in ca. 90 Prozent weitestgehend automatisiert und patientenindividuell. In den Niederlanden, Belgien oder Spanien sind es ca. 50 Prozent. Deutschland hinkt mit ca. 8 Prozent deutlich hinterher. Dabei hat eine Unit-Dose-Versorgung sehr viele Vorteile.
Apothekenlogistik: Der Einsatz von Automatisierung in der Apotheke
Authors: Hintze Marcus , Laciok Sylvia , Wibbeling Sebastian
Published: December 2019

Der Bereich der Arzneimittelversorgung ist ein hochsensibles Thema in Kliniken. Immer häufiger setzen Apotheker dabei auf automatische Unterstützung wie Kommissionierautomaten oder Unit-Dose-Anlagen. Bereits in der Vorplanung einer Umstrukturierung der Krankenhausapotheke ist es wichtig, ein ganzheitliches Apothekenkonzept von der Verordnung bis zur Verabreichung zu entwickeln und unterschiedliche Konzepte qualitativ und quantitativ zu vergleichen.
Erfahrungsbericht: Patiententransport als Puffer und Bindeglied
Authors: Moser Hannes
Published: December 2019

Für optimale Prozesse ist es wichtig, dass die Patienten zur richtigen Zeit am richtigen Ort sind. Der Einsatz moderner Informations- und Kommunikationstechnologien kann hier – durch eine verbesserte Dispositionsleistung – maßgebliche Vorteile bringen.
Edwards: Industrie-Partnerschaft HPI: „Es wird Zeit für einen wertebasierten Einkauf“
Authors: Fellner Dieter
Published: December 2019

Edwards Lifesciences stellt im Rahmen von Produktpartnerschaften Krankenhäusern Know-How zur Verfügung und hebt das Niveau mit dem Projekt Hypotension Prediction Index (HPI) nun noch einmal eine Ebene höher. Auf der Basis eines Algorithmus warnt HPI vor plötzlichem Blutdruckabfall während langwieriger und schwerer Operationen.
Extraordinary acoustic transmission based on a both-sides-open disk resonator array
Authors: Lee Yi-Lung , Chang Mu-Shen , Wei Kuang-Hung , Li Ting-Kuo , Ni Chia-Ying , Chiu Chien-Chang , Tsai Ying-Pin , Weng Yu-Ming , Hsiao Fu-Li
Published: December 2019

Extraordinary acoustic transmission (EAT) is investigated numerically and experimentally using a square lattice array (SLA) of both-sides-open disk resonators (BSODRs) in a steel slab immersed in water. Each BSODR comprises a disk resonator sandwiched by two tubes and is formed by sticking three steel plates together, where each plate is perforated with a SLA of holes. The lattice constants of the three plates are the same, but the diameters of the holes in the middle plate are larger than those in the top and bottom plates. The BSODR resonance results in low-frequency EAT, and it is shown that the BSODR’s resonant behavior can be predicted using a spring–mass model. The EAT frequency can be reduced significantly by adjusting the diameters of the disk resonator and the tubes without changing their thicknesses. Oblique-incidence transmission shows that the low-frequency EAT is insensitive to the angle of incidence, and vibration of the top and bottom steel plates produces strong Fano-like line shapes in the EAT. Additionally, diffraction of the incident wave causes the steel plates to vibrate, and this excites two minor transmission peaks that correspond to Wood’s anomalies. As the disk resonator diameter increases, several eigenmodes that are dominated by the vibrations of the steel plates appear and lead to additional high-frequency EAT peaks; this behavior may suit applications that require robustness against variations in the ambient material properties. This structure provides increased flexibility for control of the EAT effect and can be applied in acoustic filters and sensors.
Image enhancement of photoacoustic imaging for early endometrial cancer detection by employing a filtered delay multiply and sum beamforming algorithm
Authors: Lin Yongping , Zheng Rongsheng , Zhang Xiaoman , Li Zhifang , Li Hui
Published: December 2019

In endometrial cancer, patients in early stages have a 91% 5-year survival chance. By contrast, patients in advanced stages have only 20% survival chance. Therefore, early diagnosis of endometrial cancer is very important. Photoacoustic imaging is able to distinguish benign from malignant tumors. However, the images acquired through photoacoustic imaging contain inherent artifacts, caused by imperfect reconstruction algorithms. In this paper, to improve the said images, a filtered delay-multiply-and-sum (F-DMAS) algorithm, which was proven to have an increased dynamic range and better quality of B-mode images was employed in the reconstruction process. First, the images of two blood vessel phantom experiments, acquired through photoacoustic imaging, were reconstructed by employing the F-DMAS algorithm. The results show the lateral resolutions of the system improving from 2.22 mm (with traditional photoacoustic imaging reconstruction algorithms) to 1.47 mm. Next, images of a pig uterus, filled with intralipid-20% emulsion, were also reconstructed by employing the F-DMAS algorithm. The average signal-to-noise ratio increased from 11.14 dB (with traditional photoacoustic imaging reconstruction algorithms) to 64.90 dB. In order to improve the continuity of the 3D PA image, F-DMAS with an adaptive coefficient was discussed to find the best balance between the signal-to-noise ratio and continuity. In conclusion, this paper demonstrates that the use of F-DMAS algorithms in the reconstruction of the images acquired through photoacoustic imaging in clinical investigations would improve the detection rate of early endometrial cancer.
Borrmann modulation of terahertz absorption in 3D printing microlattices
Authors: Zhang Wenya , Chen Jian , Lu Weixin , Hou Bo
Published: December 2019

We have fabricated a three-dimensional (3D) microlattice, composed of orthogonal polymer rods along three dimensions and featured with a sub-millimeter scale size, with a photopolymerizing 3D printer. The reflection and transmission spectra of the microlattice have been measured in terahertz time-domain spectroscopy and compared with numerical simulations. Due to Debye relaxation loss of the constituent photopolymer, the microlattice gives rise to absorption in the measured frequencies. In particular, the absorption modulation is observed across the bandgap, corresponding to the lower/upper band edges, and is a straightforward manifestation of the Borrmann effect.
Calculation of anharmonic effect of the reactions related to NO2 in fuel combustion mechanism
Authors: Yao Li , Xia Wenwen , Zhao Rui , Yang Kun
Published: December 2019

According to the existing combustion mechanisms, the main reactions related to NO2 have been investigated in this research. Based on the transition state theory, the YL method proposed by Yao and Lin is utilized to obtain both the anharmonic and harmonic rate constants in a canonical system, respectively. The anharmonic effect of these reactions is also examined by comparing the anharmonic rate constant with the harmonic rate constant. The calculations indicate that there is a junction between the anharmonic and harmonic rate constants, and the anharmonic rate is lower than the harmonic one at high temperature. The results show that the anharmonic effect is significant and cannot be ignored, especially at high temperature. Finally, inspired by the least square idea, the kinetics and thermodynamic parameters of reaction mechanism involving NO2 are also given in fuel combustion processes.
Comparison of operator splitting schemes for the numerical solution of the Allen-Cahn equation
Authors: Ayub Sana , Affan Hira , Shah Abdullah
Published: December 2019

In this paper, we have analyzed the first- and second-order operator splitting schemes for the numerical solution of the Allen-Cahn equation. Different possibilities are considered for the derivation of the schemes. The numerical errors are computed in order to verify the effectiveness of each scheme. Validation of the schemes is provided by numerically solving some well-known examples.
Study of hemiwicking with lattice Boltzmann simulations: A wetting state is dynamically trapped by pinning of imbibition front
Authors: Pi Yueyang , Liu Xuejuan , Zhang Bo , Zhang Chi
Published: December 2019

Hemiwicking has been introduced to describe the wetting state in which a liquid film surrounds a drop. To fully understand this special wetting state, we performed energy analysis and systematic lattice Boltzmann (LB) simulations on the wetting state through spreading liquid droplets on pillared hydrophilic substrates. Although the energy analysis shows that the hemiwicking is energetically unfavorable, droplets in stable hemiwicking are indeed observed in our LB simulations. This observation led us to conclude that we have obtained a result that is the same as the result obtained in the published experiment and theory: hemiwicking is dynamically trapped by the pinning of the imbibition front during invasion of the substrate texture by the liquid film. Our simulations show that the special wetting state is always found to emerge near the phase boundary between the liquid film and the Wenzel state. For the morphology of the droplet, strong deviation of the apparent contact angle from hemiwicking is observed when the contact line of the liquid imbibition film is close to the spherical caplike droplet. We also show that there exist at least two different kinetic pathways for the formation of hemiwicking, including spreading and evaporation.
Improving interfacial electrochemistry of LiNi0.5Mn1.5O4 cathode coated by Mn3O4
Authors: Deng Miao-miao , Zhang Da-wei , Shao Yu , He Xiao-dong , Yasmin Aqsa , Chen Chun-hua
Published: December 2019

In this work the surface of LiNi0.5Mn1.5O4 (LMN) particles is modified by Mn3O4 coating through a simple wet grinding method, the electronic conductivity is significantly improved from 1.53×10−7 S/cm to 3.15×10−5 S/cm after 2.6 wt% Mn3O4 coating. The electrochemical test results indicate that Mn3O4 coating dramatically enhances both rate performance and cycling capability (at 55 °C) of LNM. Among the samples, 2.6 wt% Mn3O4-coated LNM not only exhibits excellent rate capability (a large capacity of 108 mAh/g at 10 C rate) but also shows 78% capacity retention at 55 °C and 1 C rate after 100 cycles.
Magnetic semimetals host massless quasiparticles
Authors: Middleton Christine
Published: December 2019

Two materials have an unusual electronic band structure that can support fast, low-dissipation electronic transport.
Should carbon emissions be taxed or capped and traded?
Authors: Kramer David
Published: December 2019

In the fight against climate change, many nations and states have put systems in place to price carbon dioxide emissions. There is no consensus on which of two mechanisms is better.
The challenge and promise of studying burning plasmas
Authors: Hawryluk Richard J. , Zohm Hartmut
Published: December 2019

Answers to open questions that will be addressed by the ITER experiment should enable the production of fusion energy.
Effect of Substitution for Insertion of CO2 into Epoxides and Aziridines: An Ab Initio Study
Authors: Yang Yunhan , Li Fenji , Yang Cuicui , Jia Lijuan , Yang Lijuan , Xia Futing , Peng Jinhui
Published: December 2019

The insertion of CO2 into epoxides and aziridines has been studied using density functional theory (B3LYP) and ab initio (MP2) methods, and the effect of substitution for the two reactions are further explored. It is found that the reactivity of epoxides and aziridines are similar, and insertion of CO2 proceeds through a concerted mechanism. The substitutions of methyl and phenyl does not change the reaction mechanism, but the transition state for the substitution on the attacking position becomes loose with a lower free energy barrier. The substitutions of methyl and phenyl decrease the free energy barrier, with phenyl substitution having a greater affect. The results also show that the free energy barriers for the insertions of CO2 into aziridines are ~10kcalmol−1 lower than the corresponding reactions of CO2 with epoxides.
Importance of refractory ligands and their photodegradation for iron oceanic inventories and cycling
Authors: Hassler Christel , Cabanes Damien , Blanco-Ameijeiras Sonia , Sander Sylvia G. , Benner Ronald
Published: December 2019

Iron is an essential micronutrient that limits primary production in up to 40% of the surface ocean and influences carbon dioxide uptake and climate change. Dissolved iron is mostly associated with loosely characterised organic molecules, called ligands, which define key aspects of the iron cycle such as its residence time, distribution and bioavailability to plankton. Models based on in situ ligand distributions and the behaviour of purified compounds include long-lived ligands in the deep ocean, bioreactive ligands in the surface ocean and photochemical processes as important components of the iron cycle. Herein, we further characterise biologically refractory ligands in dissolved organic matter (DOM) from the deep ocean and labile ligands in DOM from the surface ocean, and their photochemical and biological reactivities. Experimental results indicated that photodegradation of upwelled refractory iron-binding ligands can fuel iron remineralisation and its association with labile organic ligands, thus enhancing iron bioavailability in surface waters. These observations better elucidate the roles of biologically refractory and labile molecules and global overturning circulation in the ocean iron cycle, with implications for the initiation and sustainment of biological activity in iron-limited regions and the residence time of iron in the ocean.
1 Assessing the energy status of porcine embryos by means of biodynamic imaging
Authors: Lorenzo I. , Li Z. , Torres M. , Machaty Z. , Nolte D.
Published: December 2019

Assisted reproductive technologies are powerful tools for enhancing production in livestock or treating infertility in humans. Unfortunately, the success rate of the technologies is rather low. A major reason for the poor efficiency is the lack of methods to reliably assess the developmental potential of the embryos before transfer into recipients. Therefore, a noninvasive method to ensure the selection of only the best embryos for transfer would be highly desirable. Biodynamic imaging is a compelling new microscopy that uses intracellular Doppler spectroscopy to perform label-free, noninvasive optical measurements of cellular fitness. The aim of this study was to investigate whether biodynamic imaging can be used to assess the energy status of the embryos, which may be indicative of their viability. Porcine oocytes matured invitro were parthenogenetically activated by an electrical pulse and cultured for 2 days. The parthenotes were then divided into two groups, and approximately half of them were incubated for an additional 2 days in the presence of 20mM sodium azide. Sodium azide is an inhibitor of oxidative phosphorylation and is known to block ATP production. The rest of the embryos were cultured without sodium azide and used as a control to indicate normal ATP levels. At the end of the culture period embryos that reached the 8- to 16-cell stage were evaluated by our biodynamic imaging system to assess their energy status, after which they were lysed and their ATP contents were determined by means of a bioluminescence assay. A total of 68 embryos (32 treated with the inhibitor and 36 control) were evaluated. The ATP content analysis showed that the control embryos had significantly more ATP than those treated with sodium azide as determined by Student's t-test (5.04±1.07 vs. 1.31±0.57; P<0.05). A correlative study was then completed where biodynamic biomarkers were used to classify embryos to estimate the ability of biodynamic imaging to identify embryos with high or low energy status. A set of 13 biomarkers representing each embryo as a feature vector was used to train a classifier. We found that the cross-validated classifier had a sensitivity and specificity of ~80%. In addition, a receiver-operator curve constructed by varying the ATP threshold of the independent bioluminescence assay had an area-under-the-curve of 0.81. These results indicate that biodynamic imaging is able to determine the energy status of the embryos noninvasively and has great potential in the assessment of embryo viability.
112 The effect of biological extenders on invitro induction of the acrosome reaction in bovine spermatozoa
Authors: Gatenby L. , Bondioli K. R.
Published: December 2019

Biological extenders in semen are used to protect the integrity of the sperm cells during cryopreservation. The two most common extenders are egg yolk and milk, and initial experiments describing heparin capacitation for IVF were conducted with semen frozen in egg yolk extender. However, semen of many bulls used for IVF is frozen in milk-based extender, and it is not clear whether this affects the response to heparin capacitation. This study aims to assess whether the use of milk- or egg-based extenders in frozen-thawed bovine semen affects sperm's ability to undergo the acrosome reaction, utilising either the endogenous progesterone pathway or calcium ionophore A23187 to induce the acrosome reaction following heparin capacitation. Frozen semen from 12 bulls (6 using egg yolk citrate-based extender containing 20% egg yolk, and 6 using milk-based extender) was used for no less than 3 replicates each. All semen was commercially processed and cryopreserved using the same methodology. Semen was thawed and separated using a Percoll gradient and centrifugation at 400×g for 10min, then incubated for 4h in a capacitating medium containing heparin (10μgmL−1) at a concentration of 1×106 spermmL−1. Capacitated sperm were then introduced to progesterone (10μM) or A23187 (10 μM) for acrosome induction and stained with fluorescein isothiocyanate-conjugated peanut agglutinin (5μgmL−1). After treatment and staining, the sperm were analysed using flow cytometry to determine the percentage of populations with fluorescent acrosomes, indicating an exposed acrosome and an ongoing acrosome reaction. Fluorescent microscopy was also used to confirm fluorescence in acrosome-reacting samples. Results were analysed as a 2×3 factorial design by ANOVA with extender and acrosome induction treatment as factors. For egg yolk-extended semen, the mean percent of acrosome-reacted sperm was 83.7 (±6.8), 81.8 (±7), and 15.0 (±7.5) for sperm treated with progesterone, A23187, and heparin only, respectively. Compared to milk-extended semen, for which the mean percent acrosome-reacted was 15.0 (±8.2), 14.8 (±7.4), and 12.0 (±6.8) for progesterone, A23187, and heparin only, respectively. Significant differences were observed between extenders, with egg yolk-extended semen having a significantly greater response to acrosome reaction-inducing agents than semen extended with milk-based extenders (P<0.05). Also, it was observed that progesterone induced a similar percentage of acrosome reactions as A23187. Variation between bulls in the response to heparin capacitation has been observed and cannot be eliminated in this study. The difference observed between extenders warrants further study with a split ejaculate design. The possibility that the semen extender used during cryopreservation affects the response to heparin capacitation suggests that this should be accounted for in IVF protocols to increase the efficiency of this technology.
119 Short spermatozoa-oocyte co-incubation improves outcomes of IVF in sheep
Authors: Anzalone D. , Czernik M. , Palazzese L. , Ressaissi Y. , Scapolo P. , Loi P.
Published: December 2019

The assisted reproductive technique IVF is routinely applied in humans and large animals, both to boost reproductive performance and also for basic research. Despite its value, IVF has seen very little progress in the last two decades and relies on established paradigms, such as overnight sperm-egg co-incubation. However, the long exposure of oocytes to spermatozoa in a dish increases the risk of polyspermy and could be detrimental for early stages of embryonic development. We identified a time window within which fertilization occurs, in order to reduce the length of sperm-egg co-incubation and optimize the procedure, comparing polyspermy rate and embryo development after short (shIVF) and overnight (o/nIVF) spermatozoa-oocyte co-incubation. A total of 666 invitro-matured sheep oocytes were co-incubated with spermatozoa in IVF medium (synthetic oviductal fluid (SOF) with 20% oestrus sheep serum and 16 µM isoproterenol). First, small batches of oocytes were collected every 30min to check for the presence of a fertilizing spermatozoon. To assess this, cumulus cells were removed and presumptive fertilized oocytes were fixed and stained with propidium iodide for nuclei and Pisum sativum agglutinin for zona pellucida (ZP) detection, respectively. Then, pronuclear formation (PN) and embryo development were evaluated after 16h (PN), 24h (2 cells), and 7 days of culture (blastocyst). The oocytes that were not cleaved at 24h were stained for DNA content with Hoechst 33342. Furthermore, we evaluated embryo quality by counting cells of 8-day blastocysts after differential staining of inner cell mass (ICM) and trophectoderm (TE). We found that spermatozoa reach the ZP no earlier than 90min from the beginning of co-incubation and achieve fertilization within 4h. Polyspermic fertilization (>2PN) was lower in shIVF (6.5%) than in o/nIVF (17.8%; P=0.006). This proportion of polyspermy was maintained between groups in noncleaved oocytes at 24h from fertilization. Likewise, cleavage and blastocyst rate were higher in shIVF compared with the o/n-IVF group (2-cells: 48.3% vs. 31.6%, P=0.001; blastocyst: 29.4% vs. 20.5%, P=0.046, respectively). Differential staining of blastocysts revealed no significant difference in cell number between the blastocysts of the two groups. This work demonstrates that 4h of sperm-egg interaction are sufficient to achieve fertilization, reduce polyspermy, and improve the rate of embryos reaching blastocyst stage without compromising embryo quality.