bluuebunny/crossref_metadata_2025 huggingface dataset:
New Magnetic compilation and interpretation of the Bay of Biscay and surrounding continental shelves
Authors: Le Maire Pauline , Thinon Isabelle , Tugend Julie , Issautier Benoît , Martelet Guillaume , Paquet Fabien , Proust Jean-Noël , Nalpas Thierry , Peyrefitte Aurélie , Canva Albane
Published: November 2021

Producing accurate structural maps is a pre-requisite to unravel the tectonic evolution of a region. For this purpose, magnetic anomaly maps are helpful data sets for the identification and mapping of geological features. We compiled 154 marine surveys and 7 aeromagnetic campaigns covering the Bay of Biscay, its surrounding continental shelves and western part of the Pyrenees. As the initial data sets had heterogeneous acquisition parameters, we applied a series of transforms before merging the data. We performed a variable reduction to the pole to localize the extrema of the anomaly vertically to their causative sources and facilitate geological interpretations. The resulting intermediate resolution maps compiled at 500 m altitude offshore and 3000 m both on- and offshore, display magnetic trends and patterns. They are enhanced by several potential field operators (analytic signal, tilt angle, vertical derivative) enabling the interpretation of the geometry of the sources causing the anomaly (3D, 2D and 2.5D). The analysis of these magnetic maps allows us to precise the distribution and segmentation of crustal domains previously identified in the Bay of Biscay and its adjacent continental shelves. A series of crustal scale structures mapped onshore and formed during and after the Variscan orogeny show well on this new map compilation, allowing the continuous onshore-offshore mapping of some of them and revealing their role in segmenting the northern margin of the Bay of Biscay. This new compilation notably reveals variations in the magnetic signature of the Ocean-Continent-Transition (OCT) that we interpret as related to an increased magmatic production of the eastern part of the Bay of Biscay OCT during continental breakup. In addition to precise previous structural maps, this new magnetic compilation opens new perspectives for the interpretation of the Bay of Biscay geodynamic setting.
Measuring the delayed neutrons multiplicity and kinetic parameters for the thermal induced fission of 235U, 239Pu and 233U
Authors: Geslot Benoit , Sardet Alix , Casoli Pierre , Leconte Pierre , De Izarra Grégoire , Chebboubi Abdelhazize , Kessedjian Grégoire , Méplan Olivier , Doré Diane , Soldner Torsten , Mutti Paolo
Published: November 2021

In the normal operation of nuclear reactors, the kinetic behavior of the neutron population in the core is driven by the so-called delayed neutrons (DN). The DN yield per fission, their average lifetime and their groups’ abundances are the main physical parameters used to predict the kinetic behavior of the reactor and its reactivity. The overall uncertainty associated to reactivity predictions, which is linked directly to the nuclear reactor safety margins, is thus closely dependent on a few parameters associated with DN.

Depending on the nuclear data library, DN kinetic parameters present significant discrepancies, even for major fissile isotopes such as 235U or 239Pu. In this context, CEA has long been working for improving DN nuclear data. In 2018, CEA launched the ALDEN project (Average Lifetime of DElayed Neutrons) in the framework of a collaboration between CEA/DES, CEA/DRF, CNRS/IN2P3 (LPSC, CENBG, LPC), ENSICAEN and Caen University. This program aims at measuring the kinetics of the delayed neutrons to derive the DN yield, their average lifetime and abundances.

Two experimental campaigns focusing on the thermal fission of 235U were conducted in 2018 and 2019. They demonstrated the concept feasibility and gave high quality estimations of the DN multiplicity (1.631 ± 0.014 %) and average lifetime (8.82 ± 0.6 s) for 235U. More recently in March 2021, a more ambitious irradiation campaign was conducted on 239Pu and 233U. This paper details the new experimental setup, which was upgraded to meet ILL safety requirements for handling plutonium. The data analysis process is presented, with a focus on the problem of dead time correction. Finally, some preliminary delayed neutron decay curves are showed and discussed.
Long Term Neutron Activation in JET DD Operation
Authors: Žohar Andrej , Lengar Igor , Batistoni Paola , Conroy Sean , Čufar Aljaž , Kierepko Renata , Kos Bor , Loreti Stefano , Mietelski Jerzy W. , Nobs Chantal R. , Packer Lee W. , Pillon Mario , Radulović Vladimir , Savva Marilia I. , Snoj Luka , Stamatelatos Ion E. , Štancar Žiga , Vasilopoulou Theodora , Wójcik-Gargula Anna
Published: November 2021

In the 2019 C38 Deuterium-Deuterium campaign at JET several different ITER-relevant materials and dosimetry foils were irradiated in a specially designed long-term irradiation station located inside the vacuum vessel with the purpose of testing the activation of ITER materials by fusion neutrons. The samples were exposed to a neutron fluence of 1.9E14 n/cm2 during JET discharges performed in the experimental campaign over a period of 5 months. Gamma ray spectroscopy measurements were performed on irradiated samples to determine the activation of different long-lived isotopes in the samples. Monte Carlo computational analysis was performed to support the experiment by using the measured neutron yield and irradiation time. In this paper we focus on the computational analysis of the dosimetry foils that are used in order to measure the local neutron energy spectrum and flux. The foils were chosen to cover different neutron energies: thus Yttrium and some of the Nickel and Cobalt reactions were used to determine the Deuterium-Tritium fusion fraction, while Scandium and Iron and some of the Nickel and Cobalt reactions were used for comparison of the computed activity with the experimental measurements. The obtained C/E values show a reasonably good agreement between calculated and measured activity, thus validating the computational methodology and providing the basis for the analysis of the ITER-relevant materials and future experiments performed at JET in the Deuterium-Tritium campaign.
Sensitivity Analysis of an Advanced Transmission Measurement Method for Thermal Neutrons Absorbers Detection in Irradiated Beryllium
Authors: Wróblewska Małgorzata , Blanchet David , Lyoussi Abdallah , Blaise Patrick , Marcinkowska Zuzanna , Jagielski Jacek , Boettcher Agnieszka
Published: November 2021

This paper presents an advanced optimization analysis of the newly developed transmission measurement method conducted in the MARIA MTR reactor for thermal neutrons absorbers estimation in irradiated beryllium elements. Several neutron sources in combination with various thermal neutron detectors are investigated, along with the optimization of the moderating polyethylene layer to improve the signal to background ratio. It was concluded that the use of239PuBe or241AmB neutron source with polyethylene of 0.95 g/cm3density and ∼4.5 cm thickness, as well as either235U lined fission chamber or BF3detectors are meeting the requirements for the use in the experiment.
New Neutron Imaging Facility development at the Penn State Breazeale Nuclear Reactor
Authors: Kenges Alibek , Unlu Kenan , Beck Daniel
Published: November 2021

Preliminary results of characterization experiments for the New Neutron Imaging Facility (NIF) that is being developed at the Penn State Breazeale Nuclear reactor are presented in the following sections. The methodology of neutron beam characterization described in the American Society for Testing and Materials (ASTM) documents for the neutron imaging systems have been followed to improve the NIF at Penn State to a Category I facility by ASTM designation of quality. Preliminary results showed that our system is capable of producing images of high quality, corresponding to Category I; however, further experiments are needed for full declaration of our facility as such. Additionally, the effective collimation ratio (L/D ratio) of our current system is ∼110 with the capability of improvement to ∼150. The thermal flux at the exit surface of the neutron beam is equal to 5.4 × 106n cm−2s−1 at 1MWth reactor power, which corresponds to the industry comparable value.
Development of a Wideband Current Amplifier dedicated to Fission Chamber Measurement
Authors: Bisiach Danilo , Barbot Loïc , De Izarra Grégoire , Destouches Christophe , Cargnelutti Manuel , Zorzut Sebastjan
Published: November 2021

Fission chambers are widely used in nuclear reactors, either occasionally to probe the neutron flux maps in nuclear power plants or as part of the nuclear instrumentation used in research reactors to characterize neutron flux levels in irradiation locations.

Wide dynamic range acquisition systems are very limited in the nuclear instrumentation market. Thus, since 2012, CEA is developing the MONACO system, which allows measurement in pulse, fluctuation, and current mode running simultaneously on the same channel.

The simultaneous use of three measurement modes places high requirements on the amplification stage. Indeed, the current mode exploits a bandwidth between 0 and a few kHz, while the fluctuation mode is based on the frequency range of 100 kHz 1MHz. Finally, for the pulse mode, it is necessary to identify current pulses of a few uA in amplitude and with a duration of about ten nanoseconds, which implies a bandwidth that extends up to 10 or 20 MHz.

In the frame of the industrialization of the MONACO system, a new preamplifier was designed to meet those requirements. With a first prototype, LDCI and I-TECH performed very promising bench tests in October 2020. Tests with synthetic signals corresponding to pulse and fluctuation mode showed very good performance of the electronics. The positive and negative current pulses are correctly amplified and the measurement noise was estimated at 0.1 µApp thanks to proper electronic shielding. The DC measurement is also satisfactory in the tested range with an accuracy of less than nA and a bandwidth of 1kHz. Preamplifier qualifications are planned within realistic experiments using a fission chamber placed in a neutron field.
Numerical simulations in support of the design of an ultrasonic device for sub-assembly identification
Authors: Paumel Kevin , Maurel Tom , Lhuillier Christian
Published: November 2021

In this paper, it is shown how numerical simulations can help designing an ultrasonic instrument operating in harsh conditions. To prevent fuel handling errors in sodium cooled fast reactors, the identification of fuel sub-assemblies using ultrasound is being investigated. It is based on the interpretation of a code (aligned notches) engraved on the sub-assembly head using an emitting/receiving ultrasonic sensor. This reading is performed in liquid sodium with high temperature (up to 600°C) transducers. A first experiment in liquid sodium demonstrated the feasibility of this method. The reading quality and robustness depend on various parameters related to the ultrasonic beam (spectral response, focal distance, focal spot size), the code geometry (especially the notches’ dimensions) and geometrical alignments. In order to avoid numerous experiments, two numerical models are developed. The first one is a finite element simulation of the sensor providing its radiated field. This model is validated with the well-known analytic solution of the Rayleigh integral; then it is applied to the sensor used in the sodium experiment. The focal distance and focal spot diameter are close to the expected values. The second simulation, using CIVA software, provides the ultrasonic scan of the code. The result is in good agreement with the sodium experiment and a first comparison with a water experiment shows that this numerical tool is relevant for easily taking into account misalignment and misorientation of the scan.
Novel Model-Based approach for instrumentation and control of nuclear reactors
Authors: Ouni Bassem , Aussagues Christophe , Dhouib Saadia , Mraidha Chokri
Published: November 2021

Technological platforms dedicated for digital instrumentation and control of nuclear reactors are quite complex in terms of functionalities and devices. Hence, the design of these platforms requires high-level abstraction layers able to reduce the complexity, to rise the automation and to check the consistency between different development stages. The development of such systems is a challenging task that requires modeling of various components at different levels of abstraction and viewpoints, notably functional, hardware and software levels. In this paper, a new system engineering methodology is proposed to provide high-level models of different components and inter/intra-communication between them. These models are used for system specification, architecture design, performance evaluation or verification and validation. This approach focuses on the internal behavior of different components at different levels of abstraction in order to enable the interoperability of these components and to enhance cooperation between different stakeholders of the development process. An experimental setup has been carried out to validate this approach by customizing an open source model based engineering tool, Eclipse Papyrus, towards a significant reduction of system development cost in terms of engineering resources and equipment devices.
Sorting fission from parasitic coincidences of neutrons and gamma rays in plastic scintillators using particle times of flight
Authors: Bottau V. , Carasco C. , Perot B. , Eleon C. , De Stefano R. , Isnel L. , Tsekhanovich I.
Published: November 2021

This work addresses the use of plastic scintillators as an alternative to3He detectors for radioactive waste drum characterization. The time response of scintillators is three orders of magnitude faster than that of gas proportional counters and they offer similar neutron detection efficiency at lower cost. However, they are sensitive to gamma rays and the commonly used Pulse Shape Discrimination technique is not possible with basic PVT scintillators. This paper reports on an innovative data processing technique allowing to extract spontaneous fission events from parasitic coincidences, such as those from the (α,n) reactions accompanied by correlated gamma rays or from pure gamma-ray sources emitting correlated radiations. The proposed approach makes advantage of differences in the pulse detection times recorded in measurements with the252Cf, AmBe and60Co sources. More precisely, a 2D histogram of time delays between the detected 2ndand 1stpulses, on the x-axis, and between the 3rdand 2ndpulses, on the y-axis, is found to allow for selection of a region of interest most relevant to spontaneous fission events.
Localization of nuclear materials in large concrete radioactive waste packages using photofission delayed gamma rays
Authors: Delarue Manon , Simon Eric , Pérot Bertrand , Allinei Pierre-Guy , Estre Nicolas , Eck Daniel , Payan Emmanuel , Tisseur David , Gueton O. , Ricard Denise , Collot Johann
Published: November 2021

The characterization of radioactive waste packages is mandatory for their transport, interim storage and final disposal. In this framework, the Nuclear Measurement Laboratory of CEA DES IRESNE Institute, at Cadarache, France, uses a high-energy electron linear accelerator (LINAC) to produce an interrogating bremsstrahlung beam with endpoint energies ranging from 9 to 21 MeV to perform X-ray imaging and high-energy photon interrogation on large concrete packages. In particular, highenergy photon beam induces photofission reactions in both fissile (235U, 239Pu, 241Pu) and fertile (238U, 240Pu, 232Th, etc.) actinides possibly present in the radioactive waste. In order to assess their mass, we use delayed gamma rays emitted by their photofission products, which are measured with a 50 % relative efficiency High-Purity Germanium (HPGe) detector. Actinide differentiation, which is important for the fissile mass estimation, is based on the ratios of gamma rays emitted by different photofission products and requires appropriate corrections for the gamma attenuation in concrete. To this aim, we report here a localization method of point-like nuclear materials in the concrete matrix, based on the differential attenuation of several gamma rays emitted by a same photofission product. We use here the 1435.9 and 2639.6 keV lines of 138Cs, with both experimental data and MCNP numerical simulations to determine the (r,θ) coordinates of nuclear materials. Then, the depth inside the concrete matrix, which is determined with a precision of a few percent, mainly depending on counting statistics on 1435.9 and 2639.6 keV net peak areas, is used to correct for the different gamma ratios used in the actinide identification method. Experimental tests with uranium samples have been performed to validate the localization method.
Study of Neutron Background in order to Improve Radioactive Waste Drum Characterization
Authors: Lelaizant Gabrielle
Published: November 2021

A usual way of radioactive waste drums characterization combines gamma spectrometry measurements with passive neutron measurements. The CEA facility for waste drum characterization hereby described has been operated for more than 30 years. In this framework, a large variety of waste drums has been characterized in terms of spectra, densities, materials and radioactivity levels. As the facility was first dedicated to measure Intermediate-Level Long-lived Waste, the neutron background was not significant compared to expected neutron emitters from waste packages. These last years, Dismantling and Decommissioning operations have been advanced in this CEA site to the point where they are now associated with mostly Very Low Level Waste production. Therefore, neutron background is becoming significant. Using the large variety of past characterized drums brings the opportunity to study this background. The present study has been led over a sample of almost 1500 drums over a wide waste density range. These drums have been selected over the last 20 years by taking into account only one criterion: without any expected neutron emitters from the waste itself. This work first presents the technical settings of the measurement facility before describing the raw data of the measurements. Next, a statistical study over raw data enables to better acknowledge the neutron spallation background behavior in terms of time, density and materials. Ensues a way of using this new knowledge in order to improve how to take into account neutron spallation background in passive neutron measurements of packages of low actinides activities and high densities.
Particle Identification and Tracking by the Use of a Pixel-Based Semiconductor Radiation Detector Coupled with Voltage Controlled Oscillators
Authors: Coulié K. , Rahajandraibe W. , Ottaviani L.
Published: November 2021

A particle detection chain based on a CMOS SOI VCO circuit associated to a matrix of detection is presented. The solution is optimized for the recognition and tracking of various particles. Two ions are considered: an alpha and an aluminum. These two ions were chosen because there are very different in terms of energy and LET variations.
Design of a High-Energy and High-Resolution detector for X-ray computed tomography
Authors: Maulin Maëva , Eck Daniel , Estre Nicolas , Payan Emmanuel , Sardet Alix , Tisseur David , Kessedjian Grégoire
Published: November 2021

The Nuclear Measurement Laboratory (LMN) at CEA Cadarache in France is developing a high-energy tomograph reaching energies up to 21 MeV with high dose rates. It allows performing tomographies on massive objects (5 tons, 140 cm diameter) with a multimillimetric spatial resolution. For the control of absence of cracks, bubbles or defects in the concrete coating of some CEA waste drums, the laboratory needs a “high-resolution” version of this tomograph. The purpose of this study is to design an imaging detector able to provide a high spatial resolution on large objects with high dose resistance and scanning times of a few hours. To achieve this design, several steps are necessary and will be presented:

– A first step consists in characterizing the current detection elements of the tomograph, such as the camera and its lens with experimental measurements. This enables to compare performance of these elements with that available on the market and to consider a replacement.

– Then, the scintillator is selected according to experimental measurements on few scintillator types and a state of the art.

– Next, the detector configuration is optimized to achieve the higher spatial resolution.

Throughout these steps, we present the design of a highresolution detector with a spatial resolution around 300 µm for a 10%contrast.
Performance and Applications of Silicon Carbide Neutron Detectors in Harsh Nuclear Environments
Authors: Ruddy Frank H. , Ottaviani Laurent , Lyoussi Abdallah , Destouches Christophe , Palais Olivier , Reynard-Carette Christelle
Published: November 2021

Silicon carbide (SiC) semiconductor is an ideal material for solid-state nuclear radiation detectors to be used in high-temperature, high-radiation environments. Such harsh environments are typically encountered in nuclear reactor measurement locations as well as high-level radioactive waste and/or “hot” dismantlingdecommissioning operations. In the present fleet of commercial nuclear reactors, temperatures in excess of 300 °C are often encountered, and temperatures up to 800 °C are anticipated in advanced reactor designs. The wide bandgap for SiC (3.27 eV) compared to more widely used semiconductors such as silicon (1.12 eV at room temperature) has allowed low-noise measurements to be carried out at temperatures up to 700 °C. The concentration of thermally induced charge carriers in SiC at 700 °C is about four orders of magnitude less than that of silicon at room temperature. Furthermore, SiC radiation detectors have been demonstrated to be much more resistant to the effects of radiation-induced damage than more conventional semiconductors such as silicon, germanium, or cadmium zinc telluride (CZT), and have been demonstrated to be operational after extremely high gamma-ray, neutron, and charged-particle doses. The purpose of the present review is to provide an updated state of the art for SiC neutron detectors and to explore their applications in harsh high-temperature, high-radiation nuclear reactor applications. Conclusions related to the current state-of-the-art of SiC neutron detectors will be presented, and specific ideal applications will be discussed.
Scanning of a Double-Sided Germanium Strip Detector
Authors: Sharma Arzoo , Palit R. , Kojouharov I. , Gerl J. , Gorska-Ott M. , Schaffner H. , Habermann T. , Saha S. , Das Biswajit , Dey P. , Donthi R. , Naidu B.S. , Mandal S. , Singh Pushpendra P.
Published: November 2021

This work presents the results from the characterization of a Position-Sensitive Planar Germanium (PSPGe) detector. The PSPGe detector is a double-sided orthogonal strip detector consisting of 10x10 electrical segmentation along the horizontal and vertical directions. The characterization was performed using the coincidence setup between the PSPGe detector and the well-characterized scanning system employing the positron annihilation correlation principle. The scanning system consists of a Position Sensitive Detector (PSD) and 22Na positron source. The main objective of this study is to deploy PSPGe detector for future decay experiments at the Facility for Antiproton and Ion Research (FAIR), Germany. The measurements have been performed to find the depth of gamma-ray interaction in the planar segmented detector. The 2-Dimensional image obtained from the PSD has been used to find the depth of gamma-ray interaction in the planar strip detector using pulse shape analysis. In addition, the sensitivity of PSPGe detector has been investigated by calculating the rise-time from pulse shapes for the front and back strips of the detector.
Experimental and Simulation Investigation of Micro- and Nano-Structured Neutron Detectors
Authors: Logoglu Faruk , Albert Patrick , Wolfe Douglas , Flaska Marek
Published: November 2021

We are investigating different micro- and nano-structure approaches to neutron detection based on inorganic scintillators. Specifically, we have been assessing various neutron converter-scintillator configurations through simulations and experiments. One promising inorganic scintillator is ZnO due to its relatively high light yield[1], reasonable optical transparency in the visible region[2], and relatively low refractive index[3] compared to other Zn-based crystals such as ZnS[4]. Accurate optical data and rigid simulation tools are necessary to optimize the dimensions of the neutron converter/scintillator systems. Accurate optical data are necessary since the optical parameters of a material depend on a variety of factors, including but not limited to its morphology, crystal structure, surface quality (surface roughness), as well as the temperature at which it was manufactured. Therefore, literature data show significant discrepancy when it comes to the optical parameters for the material and it is important to accurately measure these quantities for the specific sample of interest. Neutron detection is a complex process that includes neutron transport, charged particle transport, and light transport in the active detection medium. Hence, a rigid simulation tool is required to handle all these different areas of physics with sufficient accuracy. In this work, Geant4 has been chosen to carry out the simulations of these processes. Geant4 (GEometry ANd Tracking) is a toolkit used in various applications including high energy physics, astrophysics, and radiation detection[5]. The optical simulation capabilities of Geant4 have been validated by comparing the transmission and reflection data from UV-Vis spectroscopy to the Geant4 models for different Zn-based crystals. After validating the optical response of single crystals, simulation models were constructed to model more complex structures of ZnS-based alpha detection sheets (EJ-440) from Eljen Technology. Optical parameters validated with experimental results have been used in radiation simulation in Geant4. This study will serve as a basis for our ongoing effort to optimize and manufacture an efficient and compact fast neutron detection module with microand nano-structures.
Towards the experimental validation of a small Time-Projection-Chamber for the quasi-absolute measurement of the fission cross section
Authors: Chatel Carole , Mathieu Ludovic , Aïche Mourad , Diakaki Maria , Noguere Gilles , Bouland Olivier
Published: November 2021

To accurately measure neutron-induced fission cross sections, to characterize neutron-beam lines or to make dosimetric investigations, it is necessary to have high accuracy measurements of neutron fluence. It is possible to perform independent and precise neutron flux measurements with respect to the 1H(n,n)p elastic scattering cross section. The use of a silicon detector is recommended from 1 to 70 MeV neutron energy. However, it has been observed that a high electrons background forbids its use below 1 MeV. Hence, a new gaseous proton-recoil telescope is developed and characterized to overcome this limit. It should provide quasi-absolute neutron flux measurements with an accuracy around 3% and is not sensible to gamma and electrons background. It consists in two ionization chambers read by a segmented micromegas technology detection plane. The gas pressure inside is adjustable to the proton range in the detector and therefore to the neutron energy. This detector is described in details below and the newest results of its characterization are presented. A special attention is paid to detection efficiency measurements.
Impact of School Closures on the Proportion of Children in the
COVID-19 Pandemic: An Example from the Winter Lockdown in
Germany
Authors: Sorg Anna-Lisa , Kaiser Veronika , Becht Selina , Simon Arne , von Kries Rüdiger
Published: November 2021

Background In addition to widely used basic hygiene measures in school,
school closures are applied to contain SARS-CoV-2 spread, although the effect on
the pandemic is unclear. We proposed a simple approach to disentangle the effect
of school closures from other lockdown measures on the pandemic course based on
publicly available data in Germany.

Methods We used data on the number of SARS-CoV-2 cases from the onset of
the pandemic to 14th April 2021. We compared the proportion of children
(5–14 years old) in all cases prior to the lockdown measures, including
school closure, to that during a ten-week lockdown in Germany. The total number
of paediatric cases occurring during lockdown was compared to the number
expected in absence of school closures. The latter was calculated based on the
actual weekly number of all cases and the pre-lockdown proportion of paediatric
cases.

Results The proportion of children in all cases was 2.3 percentage points
lower at the nadir than the proportion before the lockdown. The estimated total
number of paediatric cases prevented by school closures was estimated at 13,246
amounting to 24% of the expected cases in absence of school
closures.

Conclusion School closure during the winter lockdown reduced the number of
expected SARS-CoV-2 cases in children in absence of school closures. The
contribution of these prevented cases to the total population incidence is
small. These data might provide the basis to model the effect of school closures
in addition to basic hygiene measures on the course of the COVID-19
pandemic.
Akute myeloische Leukämie
Authors: Braitmaier Helmine
Published: November 2021

Die Therapie der äußerst heterogenen akuten myeloischen Leukämie (AML) richtet sich zunehmend nach den genetischen Veränderungen in den Leukämiezellen. Neue Substanzen haben das therapeutische Portfolio in den letzten Jahren erheblich erweitert und die Prognose der Patienten verbessert, berichtete Prof. Christoph Röllig, Dresden, auf dem 9. Sommersymposium „Lymphome & Leukämien“ 2021 der Universitätsklinik Köln.
Chronische myeloische Leukämie
Authors: Helmine Braitmaier
Published: November 2021

Seit der Einführung von Tyrosinkinase-Inhibitoren (TKI) können viele Patienten mit chronisch myeloischer Leukämie (CML) zwar inzwischen eine fast normale Lebenserwartung erreichen, eine medikamentöse Heilung ist jedoch noch nicht möglich. Schreitet die Erkrankung bis zur Blastenkrise fort, ist sie nur noch schwer zu behandeln, und die Patienten haben ein hohes Risiko, zu versterben. Neue Medikamente zielen darauf ab, das Fortschreiten der CML bei immer mehr Patienten zu verhindern, um in der Folge eine Therapiedeeskalation durchführen zu können.
Glioblastome
Authors: Kretzschmar Alexander
Published: November 2021

Glioblastome (GBM) sind hinsichtlich ihrer Histologie, Proliferation und Infiltration des Gehirnparenchyms sehr heterogen. Offenbar gibt es innerhalb dieser Malignome Areale mit funktional intakten Nervenzellen. Eine US-Arbeitsgruppe konnte jetzt mithilfe von fMRT-Aufnahmen während des Ruhezustandes des Gehirns (resting state; rs-fMRT) derartige funktionell intakte neuronale Strukturen bei fast allen (93 %) der untersuchten 57 GBM-Patienten in vordefinierten Arealen (Regions of Interest; ROI) nachweisen.
Orbital Fractures
Authors: Zhou Peiran , Chambers Christopher B.
Published: November 2021

Orbital fractures are common in facial trauma and can be a challenge to treat. Understanding anatomy of the orbit, the clinical evaluation, indications for surgery, surgical approaches, complications, and postoperative are essential in providing appropriate treatment for patients who have sustained orbital fractures. In this article, the authors review the diagnostic evaluation, acute management, treatment options, and common complications of orbital fractures, as well as recent advancements in orbital fracture repairs.
Design, Synthesis, and Cytotoxic Activity of New Tubulysin Analogues
Authors: Tran Anh Tuan , Tran Chien Van , Le Hai Van , Tran Loc Van , Tran Thao Thi Phuong , Tran Sung Van
Published: November 2021

Synthesis of tubulysin analogues, containing an N-methyl substituent on tubuvaline-amide together with the replacement of either the hydrophobic N-terminal N-methyl pipecolic acid (Mep) or at both N- and C- terminal peptides with available heteroaromatic acids and an unsaturated tubuphenylalanine moiety, respectively, were described. The in vitro cytotoxic activity by SRB assay on five cancer cell lines for sixteen tubulysins was evaluated. Among them, five analogues exhibited strong cytotoxic activities against five human cancer cell lines, including human breast carcinoma (MCF7), human colorectal adenocarcinoma (HT-29), HL-60, SW-480, human lung adenocarcinoma (A459). Interestingly, one analogue showed the strongest cytotoxicity on all five tested cell lines even much higher toxicity than the reference compound ellipticine.
Manifold topology, observables, and gauge group
Authors: Morchio G. , Strocchi F.
Published: November 2021

The relation between the manifold topology, observables, and gauge group is clarified on the basis of the classification of the representations of the algebra of observables associated with positions and displacements on the manifold. The guiding, physically motivated, principles are (i) locality, i.e., the generating role of the algebras localized in small, topologically trivial, regions, (ii) diffeomorphism covariance, which guarantees the intrinsic character of the analysis, and (iii) the exclusion of additional local degrees of freedom with respect to the Schrödinger representation. The locally normal representations of the resulting observable algebra are classified by unitary representations of the fundamental group of the manifold, which actually generate an observable, “topological,” subalgebra. The result is confronted with the standard approach based on the introduction of the universal covering M̃ of M and on the decomposition of L2(M̃) according to the spectrum of the fundamental group, which plays the role of a gauge group. It is shown that in this way one obtains all the representations of the observables iff the fundamental group is amenable. The implications on the observability of the permutation group in particle statistics are discussed.
Assessing wind gust characteristics at wind turbine relevant height
Authors: Shu Z. R. , Chan P. W. , Li Q. S. , He Y. C. , Yan B. W. , Li L. , Lu C. , Zhang L. , Yang H. L.
Published: November 2021

Wind gust characteristics at wind turbine relevant height are closely tied with wind turbine design and wind power generation, however, they have not been detailed and documented. In this study, high-resolution wind data recorded by 3D sonic anemometers at a tall meteorological tower were analyzed to determine 12 descriptors of wind gusts and to identify the parent distributions that best fit these parameters. The main statistics were estimated using wind data from the 160 m height. It is found that the log-logistic distribution is most appropriate for a 10-min mean wind speed, gust magnitude, gust factor, and turbulence intensity; the gamma distribution appears to best fit peak factor, rise magnitude, lapse magnitude, lapse time, and gust length scale, while gust amplitude, rise time, and gust asymmetric factor are typically log-normally distributed. Gust factors tend to decrease with mean wind speed but increase as a function of turbulence intensity. The results also indicate that these wind gust descriptive parameters are height-dependent in which the 10-min mean wind speed, gust magnitude, gust length scale, rise time, and lapse time usually possess larger values at higher heights, whereas the remaining parameters exhibit negative correlation with height.
Influence of charged walls and defects on DC resistivity and dielectric relaxations in Cu-Cl boracite
Authors: Cochard C. , Granzow T. , Fernandez-Posada C. M. , Carpenter M. A. , McQuaid R. G. P. , Guy J. G. M. , Whatmore R. W. , Gregg J. M.
Published: November 2021

Charged domain walls form spontaneously in Cu-Cl boracite on cooling through the phase transition. These walls exhibit changed conductivity compared to the bulk and motion consistent with the existence of negative capacitance. Here, we present the dielectric permittivity and DC resistivity of bulk Cu-Cl boracite as a function of temperature (−140 to 150 °C) and frequency (1 mHz to 10 MHz). The thermal behavior of the two observed dielectric relaxations and the DC resistivity is discussed. We propose that the relaxations can be explained by the existence of point defects, most likely local complexes created by a change of valence of Cu and accompanying oxygen vacancies. In addition, the sudden change in resistivity seen at the phase transition suggests that conductive domain walls contribute significantly to the conductivity in the ferroelectric phase.
A visco-inertial formulation for capillarity in irregular channels and tubes
Authors: Shobeiri Amin , Ponga Mauricio
Published: November 2021

We propose a novel formulation of capillarity, which geometrically extends the Bosanquet equation to irregular geometries, taking the effect of inertia and the dynamic contact angle into account. The governing equation is an integrodifferential equation that is solved numerically and compared with computer simulations, experimental data, and other cases available in the literature. The numerical examples investigated in this work show that contrary to flat channels and tubes, inertial effects decay much slower in corrugated channels and tubes due to the walls' geometrical fluctuations. We also draw the paramount conclusion that the true solution for Jurin's height in irregular capillaries is path-dependent and highly sensitive to the initial conditions, and no single static-equilibrium solution can necessarily be attributed to the eventual position of the meniscus. Resulting from the non-linear dynamics, the multiple equilibria in the presence of gravity for irregular capillaries can only be analyzed if the effect of inertia is considered, which has largely been neglected in the literature thus far.
Antisense oligonucleotide technology as a research tool in plant biology
Authors: Wdowikowska Anna , Janicka Malgorzata
Published: November 2021

An antisense oligonucleotide (ASO) is a short single-stranded deoxyribonucleotide complementary to the sense strand of a selected nucleic acid. As a result, an ASO can modulate gene expression through several mechanisms. The technology based on ASO has already been applied in studies on gene function in mammalian cells and selective therapeutic strategies for many diseases. The conceptual simplicity and low cost of this method, and the developments in the field of plant genome sequencing observed in the last decades, have paved the way for the ASO method also in plant biology. It is applied in gene function analysis as well as the development of non-invasive plant production technology involving gene modifications without transgenesis. Therefore, the first part of this review provides a comprehensive overview of the structure, mechanism of action and delivery methods of ASOs in plants and shows the most important features essential for the proper design of individual experiments. We also discuss potential issues and difficulties that may arise during practical ASO implementation. The second part of this article contains an analysis of ASO applications in various studies in the field of plant biology. We presented for the first time that ASOs were also successfully applied in cucumber.
Nitric oxide and spermidine alleviate arsenic-incited oxidative damage in
Authors: Thapar Kapoor Riti , Ingo Hefft Daniel , Ahmad Ajaz
Published: November 2021

Anthropogenic activities such as mining, fossil fuel combustion, fertilisers and pesticides utilisation in agriculture, metallurgic processes and disposal of industrial wastes have contributed an exponential rise in arsenic content in environment. The present paper deals with arsenate (AsV) incited stress in chickpea (Cicer arietinum L.) plants and its alleviation through the application of nitric oxide (NO) and spermidine (SPD). The exposure of C. arietinum to AsV reduced seedling length, biomass, relative water content and biochemical constituents. All the above-mentioned parameters were escalated when sodium nitroprusside (SNP) or SPD were utilised alone or in combination with AsV. The electrolyte leakage and malondialdehyde content were increased in chickpea treated with AsV, but reduced in combine treatment (As + SNP + SPD). In chickpea seedlings, 89.4, 248.4 and 333.3% stimulation were recorded in sugar, proline and glycine betaine contents, respectively, with As + SNP + SPD treatment in comparison to control. SNP and SPD modulated function of glyoxalase enzymes by which methylglyoxal (MG) was significantly detoxified in C. arietinum. Maximum reduction 45.2% was observed in MG content in SNP + SPD treatment over AsV stress. Hence, synergistic application of NO and SPD protected chickpea plants against AsV-generated stress by strengthening the antioxidant defence and glyoxalase system, which helped in regulation of biochemical pathways.
Nitric oxide effectively orchestrates postharvest flower senescence: a case study of
Authors: Ul Haq Aehsan , Lateef Lone Mohammad , Farooq Sumira , Parveen Shazia , Altaf Foziya , Tahir Inayatullah , Ingo Hefft Daniel , Ahmad Ajaz , Ahmad Parvaiz
Published: November 2021

Nitric oxide releasing compound sodium nitroprusside (SNP) is regarded as novel chemical to beat the daunting challenges of postharvest losses in cut flowers. In the recent years, it has yielded propitious results as postharvest vase preservative for cut flowers. Our study explicates the efficacy of SNP in mitigating postharvest senescence in Consolida ajacis (L.) Schur cut spikes. The freshly excised C. ajacis spikes were subjected to different SNP treatments viz, 20 μM, 40 μM, 60 μM and 80 μM. The control spikes were held in distilled water. The spikes held in test solutions showed a marked improvement in vase life and flower quality. Our results indicate a profound surge in sugars, phenols and soluble proteins in SNP-treated spikes over control. Moreover, the SNP treatments improved membrane stability as signposted by decreased lipoxygenase activity (LOX). The SNP treatments also upregulated different antioxidant enzymes viz, ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD). The current study recommends 40 μM SNP as optimum concentration for preserving floral quality and extending display period of C. ajacis spikes. Together, these findings reveal that SNP at proper dosage can efficiently alleviate deteriorative postharvest changes by modulating physiological and biochemical mechanisms underlying senescence.
Interaction effects of temperature and light on shoot architecture, growth dynamics and gas exchange of young
Authors: Abeysinghe Subhashini K. , Greer Dennis H. , Rogiers Suzy Y.
Published: November 2021

To examine the interactive effect of temperature and photon flux density (PFD) on growth dynamics and gas exchange of young Vitis vinifera L. cv. Shiraz vines, a controlled environment study was conducted by exposing vines to two different temperatures combined with either high or low PFD. Shoot growth was accelerated and the phyllochron of Shiraz leaves was hastened in the low temperature (25/12°C) × low PFD condition (350 μmol m−2 s−1). In early emerging leaves, leaf area was responsive to temperature whereas in later emerging leaves it was dependent on light intensity. The high temperature (32/20°C) × high PFD (700 μmol m−2 s−1) treatment delayed internode extension of early emerging internodes. However, low temperature × high PFD increased leaf gas exchange across the different growth stages. The net shoot carbon balance was greater for the low temperature × high PFD treatment. Dry matter accumulation was also greater in early emerging internodes irrespective of treatment. These results on young Shiraz vines indicate that 25°C is favourable to 32°C, and some growth characteristics are accelerated at low PFD while others favour higher PFD.
Raf-like kinases and receptor-like (pseudo)kinase GHR1 are required for stomatal vapor pressure difference response
Authors: Hsu Po-Kai , Takahashi Yohei , Merilo Ebe , Costa Alex , Zhang Li , Kernig Klara , Lee Katie H. , Schroeder Julian I.
Published: November 2021

Significance

With the continuing increase in global temperatures, plants transpire more water due to the increasing vapor pressure deficit. Stomatal pores in plants close rapidly in response to the rising vapor pressure deficit to counteract water loss. We demonstrate that mutations in the stomatal CO2signaling pathway do not impair the response to an increase in vapor pressure difference (VPD). Osmotic stress causes cytoplasmic Ca2+transients in guard cells. Nevertheless, we show that diverse investigated higher-order calcium-signaling mutants do not affect the VPD response. We reveal that B3 family Raf-like protein kinases and a plasma membrane receptor-like protein GHR1 function in the elusive leaf-to-air VPD-mediated stomatal closure pathway. Notably,ghr1mutant alleles disrupt the classical “wrong-way” stomatal VPD response.
Homeostatic regulation of axonal Kv1.1 channels accounts for both synaptic and intrinsic modifications in the hippocampal CA3 circuit
Authors: Zbili Mickaël , Rama Sylvain , Benitez Maria-José , Fronzaroli-Molinieres Laure , Bialowas Andrzej , Boumedine-Guignon Norah , Garrido Juan José , Debanne Dominique
Published: November 2021

Significance

The mechanisms linking homeostatic regulation of synaptic transmission to homeostatic regulation of intrinsic excitability are poorly understood. We show here that chronic blockade of excitatory synaptic receptors in the CA3 area induces an up-regulation of both synaptic transmission and intrinsic excitability. Enhanced excitability was found to result from a reduction in Kv1.1 channel density at the axon initial segment. In parallel, enhanced synaptic transmission was largely due to a loss of presynaptic Kv1.1 function. We conclude that the regulation of axonal Kv1.1 channels constitutes a significant mechanism linking homeostatic regulation of synaptic transmission and homeostatic regulation of intrinsic excitability in CA3 circuits.
High
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He in central Panama reveals a distal connection to the Galápagos plume
Authors: Bekaert David V. , Gazel Esteban , Turner Stephen , Behn Mark D. , de Moor J. Marten , Zahirovic Sabin , Manea Vlad C. , Hoernle Kaj , Fischer Tobias P. , Hammerstrom Alexander , Seltzer Alan M. , Kulongoski Justin T. , Patel Bina S. , Schrenk Matthew O. , Halldórsson Sæmundur A. , Nakagawa Mayuko , Ramírez Carlos J. , Krantz John A. , Yücel Mustafa , Ballentine Christopher J. , Giovannelli Donato , Lloyd Karen G. , Barry Peter H.
Published: November 2021

Significance

We report the discovery of anomalously high
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He in “cold” geothermal fluids of central Panama, far from any active volcanoes. Combined with independent constraints from lava geochemistry, mantle source geochemical anomalies in Central America require a Galápagos plume contribution that is not derived from hotspot track recycling. Instead, these signals likely originate from large-scale transport of Galápagos plume material at sublithospheric depths. Mantle flow modeling and geophysical observations further indicate these geochemical anomalies could result from a Galápagos plume-influenced asthenospheric “mantle wind” that is actively “blowing” through a slab window beneath central Panama. The lateral transport of plume material represents a potentially widespread yet underappreciated mechanism that scatters enriched geochemical signatures in mantle domains far from plumes.