bluuebunny/crossref_metadata_2025 huggingface dataset:
Prävention und Therapie der Frühgeburt. Leitlinie der DGGG, OEGGG und SGGG (S2k-Niveau, AWMF-Registernummer 015/025, Februar 2019) – Teil 2 mit Empfehlungen zur tertiären Prävention der Frühgeburt und zum Management des frühen vorzeitigen Blasensprungs
Authors: Berger Richard , Abele Harald , Bahlmann Franz , Bedei Ivonne , Doubek Klaus , Felderhoff-Müser Ursula , Fluhr Herbert , Garnier Yves , Grylka-Baeschlin Susanne , Helmer Hanns , Herting Egbert , Hoopmann Markus , Hösli Irene , Hoyme Udo , Jendreizeck Alexandra , Krentel Harald , Kuon Ruben , Lütje Wolf , Mader Silke , Maul Holger , Mendling Werner , Mitschdörfer Barbara , Nicin Tatjana , Nothacker Monika , Olbertz Dirk , Rath Werner , Roll Claudia , Schlembach Dietmar , Schleußner Ekkehard , Schütz Florian , Seifert-Klauss Vanadin , Steppat Susanne , Surbek Daniel
Published: December 2019

Ziel Offizielle Leitlinie der Deutschen Gesellschaft für Gynäkologie und Geburtshilfe (DGGG), der Österreichischen Gesellschaft für Gynäkologie und Geburtshilfe (ÖGGG) und der Schweizerischen Gesellschaft für Gynäkologie und Geburtshilfe (SGGG). Ziel der Leitlinie ist es, die Prädiktion, die Prävention und das Management der Frühgeburt anhand der aktuellen Literatur, der Erfahrung der Mitglieder der Leitlinienkommission einschließlich der Sicht der Selbsthilfe evidenzbasiert zu verbessern.

Methoden Anhand der internationalen Literatur entwickelten die Mitglieder der beteiligten Fachgesellschaften und Organisationen Empfehlungen und Statements. Diese wurden in einem formalen Prozess (strukturierte Konsensuskonferenzen mit neutraler Moderation, schriftliche Delphi-Abstimmung) verabschiedet.

Empfehlungen Der Teil 2 dieser Kurzversion der Leitlinie zeigt Statements und Empfehlungen zur tertiären Prävention der Frühgeburt sowie zum Management des frühen vorzeitigen Blasensprungs.
Neuroradiologie: diagnostische und interventionelle Untersuchungsmöglichkeiten
Authors: Kurka Denise
Published: December 2019

Neurologische Erkrankungen gehören in Europa zu den häufigsten Krankheitsbildern. Mit der Diagnostik und Therapie dieser Erkrankungen beschäftigt sich die Neuroradiologie. Dafür sind Radiologietechnologen / MTRA von großer Bedeutung, da sie die Untersuchungen durchführen. Dieser Artikel gibt einen Überblick über die diagnostischen Untersuchungsmöglichkeiten in der Neuroradiologie.
Mit der ZGN ins Neue Jahr
Authors: Singer Dominique
Published: December 2019

Liebe Leserinnen und Leser,

vor Ihnen liegt die letzte Ausgabe der Zeitschrift für Neonatologie und Geburtshilfe (ZGN) des Jahres 2019, die Ihnen einmal mehr einen abwechslungsreichen Themenquerschnitt aus der gesamten Perinatalmedizin bietet.
Backbone-Enabled Peptide Macrocyclization through Late-Stage Palladium-Catalyzed C–H Activation
Authors: Bai Zengbing , Wang Huan
Published: December 2019

Peptide macrocycles are widely used in fields ranging from medicinal chemistry to materials science. Efficient chemical methods for the synthesis of cyclic peptides with novel three-dimensional structures are highly desired to facilitate the development of this unique class of compounds. However, the range of methods available for constructing peptide macrocycles is limited compared with that for small molecules. We recently developed new methods for synthesizing highly constrained cyclic peptides with C–C crosslinks through Pd-catalyzed C–H activation reactions. These methods use endogenous backbone amides as directing groups and, therefore, have the potential for use in late-stage functionalization of peptide natural products.
Simulating waves, chaos and synchronization with a microcontroller
Authors: Welsh Andrea J. , Delgado Cristian , Lee-Trimble Casey , Kaboudian Abouzar , Fenton Flavio H.
Published: December 2019

The spatiotemporal dynamics of complex systems have been studied traditionally and visualized numerically using high-end computers. However, due to advances in microcontrollers, it is now possible to run what once were considered large-scale simulations using a very small and inexpensive single integrated circuit that can furthermore send and receive information to and from the outside world in real time. In this paper, we show how microcontrollers can be used to perform simulations of nonlinear ordinary differential equations with spatial coupling and to visualize their dynamics using arrays of light-emitting diodes and/or touchscreens. We demonstrate these abilities using three different models: two reaction-diffusion models (one neural and one cardiac) and a generic model of network oscillators. These models are commonly used to simulate various phenomena in biophysical systems, including bifurcations, waves, chaos, and synchronization. We also demonstrate how simple it is to integrate real-time user interaction with the simulations by showing examples with a light sensor, touchscreen, and web browser.
A next-generation inverse-geometry spallation-driven ultracold neutron source
Authors: Leung K. K. H. , Muhrer G. , Hügle T. , Ito T. M. , Lutz E. M. , Makela M. , Morris C. L. , Pattie R. W. , Saunders A. , Young A. R.
Published: December 2019

The physics model of a next-generation spallation-driven high-current ultracold neutron (UCN) source capable of delivering an extracted UCN rate of around an order of magnitude higher than the strongest proposed sources, and around three orders of magnitude higher than existing sources, is presented. This UCN-current-optimized source would dramatically improve cutting-edge UCN measurements that are currently statistically limited. A novel “Inverse Geometry” design is used with 40 l of superfluid 4He (He-II), which acts as the converter of cold neutrons to UCNs, cooled with state-of-the-art subcooled cryogenic technology to ∼1.6K. Our source design is optimized for a 100 W maximum heat load constraint on the He-II and its vessel. In this paper, we first explore modifying the Lujan Center Mark-3 target for UCN production as a benchmark. In our Inverse Geometry, the spallation target is wrapped symmetrically around the cryogenic UCN converter to permit raster scanning the proton beam over a relatively large volume of tungsten spallation target to reduce the demand on the cooling requirements, which makes it reasonable to assume that water edge-cooling only is sufficient. Our design is refined in several steps to reach a UCN production rate PUCN=2.1×109s−1 under our other restriction of 1MW maximum available proton beam power. We then study the effects of the He-II scattering kernel used as well as reductions in PUCN due to pressurization to reach PUCN=1.8×109s−1. Finally, we provide a design for the UCN extraction system that takes into account the required He-II heat transport properties and implementation of a He-II containment foil that allows UCN transmission. We estimate a total useful UCN current from our source of Ruse≈5×108s−1 from an 18cm diameter guide ∼5m from the source. Under a conservative “no return” (or “single passage”) approximation, this rate can produce an extracted density of >1×104UCNcm−3 in <1000l external experimental volumes with a 58Ni (335neV) cutoff potential.
On the analytical solution of the two-phase Couette flow with wall transpiration
Authors: Smuda Martin , Oberlack Martin
Published: December 2019

The two-phase Couette flow with transpiration through both walls is considered, where there is a constant blowing v0 at the lower wall and a corresponding suction at the upper wall. The interface between both fluids is initially flat and, hence, stays flat as it moves upward at the constant speed of the transpiration velocity v0. The corresponding initial value problem is subject to three dimensionless numbers consisting of the Reynolds number Re and the viscosity and density ratios, ϵ and γ. The solution is obtained by the unified transform method (Fokas method) in the form of an integral representation depending on initial and all boundary values including the Dirichlet and Neumann values at the interface. The unknown values at the moving interface are determined by a system of linear Volterra integral equations (VIEs). The VIEs are of the second kind with continuous and bounded kernels. Hence, the entire two-phase spatiotemporal 1 + 1 system has dimensionally reduced. The system of VIEs is solved via a standard marching method. For the numerical computation of the complex integral contours, a parameterized hyperbola is used. The influence of the dimensionless numbers Re, γ, and ϵ is studied exemplarily. The most notable effect results from ϵ that gives rise to a kink in the velocity at the moving interface. Both ratios, ϵ and γ, allow for very different flow regimes in each fluid phase such as nearly pure Couette flows and transpiration dominated flows with strongly curved velocity profiles. Those regimes are mainly determined by the effective Reynolds number in the respective phases.
Effect of site energy fluctuation on charge transport in disordered organic molecules
Authors: Navamani K. , Pati Swapan K. , Senthilkumar K.
Published: December 2019

Effect of dynamics of site energy disorder on charge transport in organic molecular semiconductors is not yet well-established. In order to study the relationship between the dynamics of site energy disorder and charge transport, we have performed a multiscale study on dialkyl substituted thienothiophene capped benzobisthiazole (BDHTT-BBT) and methyl-substituted dicyanovinyl-capped quinquethiophene (DCV5T-Me) molecular solids. In this study, we explore the structural dynamics and correlated charge transport by electronic structure calculations, molecular dynamics, and kinetic Monte-Carlo simulations. We have also proposed the differential entropy dependent diffusion and charge density equations to study the electric field drifted diffusion property and carrier density. In this investigation, we have addressed the transformation mechanism from dynamic to static disorder in the extended stacked molecular units. Here, the decrease in the charge transfer rate due to site energy fluctuations reveals the dispersion transport along the extended π-stacked molecules. Furthermore, the calculated current density for a different set of site energy difference values shows the validity and the limitations of the Einstein relation. Based on the calculated ideality factor, we have classified the charge transport in these molecules as either the Langevin or the Shockley-Read-Hall type mechanism. Through the calculated mobility, current density, and ideality factor analysis, we categorize the applicability of molecules of interest for photovoltaic or light emitting diode applications.
Role of adsorbed water in inducing electron accumulation in InN
Authors: Wang Qi , Joshi Siddharth , Smieszek Nicholas , Chakrapani Vidhya
Published: December 2019

Nominally undoped indium nitride (InN) is known to have an electron accumulation layer on its surface, and prior studies have shown this layer to be sensitive to chemical species. However, the exact roles of these species and the underlying mechanism of e− accumulation layer formation are not clear. In this work, it is shown that ambient adsorbed water on the InN surface strongly enhances the e− accumulation layer formed due to intrinsic surface states. Desorption of ambient physisorbates leads to a decrease in band bending, an increase in work function in undoped InN, and the observation of a p-type Mott-Schottky behavior in Mg:doped InN. The underlying mechanism of this surface-adsorbed water interaction may be through a process called “surface transfer doping,” which has previously been reported in hydrogenated diamond and other semiconductors such as GaN and ZnO.
Time-dependent density matrix renormalization group quantum dynamics for realistic chemical systems
Authors: Xie Xiaoyu , Liu Yuyang , Yao Yao , Schollwöck Ulrich , Liu Chungen , Ma Haibo
Published: December 2019

Electronic and/or vibronic coherence has been found by recent ultrafast spectroscopy experiments in many chemical, biological, and material systems. This indicates that there are strong and complicated interactions between electronic states and vibration modes in realistic chemical systems. Therefore, simulations of quantum dynamics with a large number of electronic and vibrational degrees of freedom are highly desirable. Due to the efficient compression and localized representation of quantum states in the matrix-product state (MPS) formulation, time-evolution methods based on the MPS framework, which we summarily refer to as tDMRG (time-dependent density-matrix renormalization group) methods, are considered to be promising candidates to study the quantum dynamics of realistic chemical systems. In this work, we benchmark the performances of four different tDMRG methods, including global Taylor, global Krylov, and local one-site and two-site time-dependent variational principles (1TDVP and 2TDVP), with a comparison to multiconfiguration time-dependent Hartree and experimental results. Two typical chemical systems of internal conversion and singlet fission are investigated: one containing strong and high-order local and nonlocal electron-vibration couplings and the other exhibiting a continuous phonon bath. The comparison shows that the tDMRG methods (particularly, the 2TDVP method) can describe the full quantum dynamics in large chemical systems accurately and efficiently. Several key parameters in the tDMRG calculation including the truncation error threshold, time interval, and ordering of local sites were also investigated to strike the balance between efficiency and accuracy of results.
Type-II heterostructures of α-V2O5 nanowires interfaced with cadmium chalcogenide quantum dots: Programmable energetic offsets, ultrafast charge transfer, and photocatalytic hydrogen evolution
Authors: Chauhan Saurabh , Sheng Aaron , Cho Junsang , Razek Sara Abdel , Suwandaratne Nuwanthi , Sfeir Matthew Y. , Piper Louis F. J. , Banerjee Sarbajit , Watson David F.
Published: December 2019

We synthesized a new class of heterostructures by depositing CdS, CdSe, or CdTe quantum dots (QDs) onto α-V2O5 nanowires (NWs) via either successive ionic layer adsorption and reaction (SILAR) or linker-assisted assembly (LAA). SILAR yielded the highest loadings of QDs per NW, whereas LAA enabled better control over the size and properties of QDs. Soft and hard x-ray photoelectron spectroscopy in conjunction with density functional theory calculations revealed that all α-V2O5/QD heterostructures exhibited Type-II band offset energetics, with a staggered gap where the conduction- and valence-band edges of α-V2O5 NWs lie at lower energies (relative to the vacuum level) than their QD counterparts. Transient absorption spectroscopy measurements revealed that the Type-II energetic offsets promoted the ultrafast (10−12–10−11 s) separation of photogenerated electrons and holes across the NW/QD interface to yield long-lived (10−6 s) charge-separated states. Charge-transfer dynamics and charge-recombination time scales varied subtly with the composition of heterostructures and the nature of the NW/QD interface, with both charge separation and recombination occurring more rapidly within SILAR-derived heterostructures. LAA-derived α-V2O5/CdSe heterostructures promoted the photocatalytic reduction of aqueous protons to H2 with a 20-fold or greater enhancement relative to isolated colloidal CdSe QDs or dispersed α-V2O5 NWs. The separation of photoexcited electrons and holes across the NW/QD interface could thus be exploited in redox photocatalysis. In light of their programmable compositions and properties and their Type-II energetics that drive ultrafast charge separation, the α-V2O5/QD heterostructures are a promising new class of photocatalyst architectures ripe for continued exploration.
Dielectric response function for colloidal semiconductor quantum dots
Authors: Karpulevich Anastasia , Bui Hanh , Wang Zhi , Hapke Sören , Palencia Ramírez Cristina , Weller Horst , Bester Gabriel
Published: December 2019

We calculate the optical properties of InP and CdSe colloidal quantum dots (QDs) within the framework of the atomic effective pseudopotential approach and the screened configuration interaction theory. We obtain an excellent agreement with experiment with our microscopic and space-dependent screening function where the dielectric constant varies in real space with a sharp transition (width of ≈0.18 nm) from the QD material high-frequency bulk value inside the QD to the solvent or passivant high-frequency value outside. We obtain a reasonable agreement (with deviations less than 140 meV) for a computationally less demanding solvent-independent screening using the full high-frequency bulk screening, in contrast to the more commonly used reduced QD radius-dependent screening constant. We show theoretically that for QDs passivated with long-chained organic molecules, the influence of the solvent on the optical gap is in the range of 10 meV, while QDs passivated with short ligands can experience shifts in the order of 100 meV. Experiments on CdSe QDs passivated with octadecylphosphonic acid (ODPA, long-chained ligand) in two different solvents (toluene and chloroform) confirm the bandgap dependence. While the optical gap is weakly affected by the environment, the quasiparticle gap and the exciton binding energy show a strong environmental dependence. Finally, we show that the optical bandgap does not depend significantly on the crystal structure (wurtzite or zincblende) or the morphological details (faceted or “spherical” shape).
The rise of 2D dielectrics/ferroelectrics
Authors: Osada Minoru , Sasaki Takayoshi
Published: December 2019

Ultrathin films with high-k dielectric/ferroelectric properties form the basis of modern electronics. With further miniaturization of electronic devices, conventional materials are expected to experience a challenge because of their critical thickness, where the dielectric/ferroelectric responses are unstable or even disappeared if the film thickness is reduced to the nanometer scale or below a two-dimensional (2D) limit. Owing to the benefit of preparing stable atomically thin film, 2D materials present tantalizing prospects for scaling high-k dielectric/ferroelectric technologies down to the actual atomic scale. Here, we review recent progress in 2D dielectrics/ferroelectrics and related device applications.
Switching behavior of the magnetic resonance in a monoaxial chiral magnetic crystal CrNb3S6
Authors: Shimamoto Y. , Goncalves F. J. T. , Sogo T. , Kousaka Y. , Togawa Y.
Published: December 2019

We report broadband microwave spectroscopy in micrometer-sized platelet devices of a monoaxial chiral magnetic crystal CrNb3S6 with a helical c axis perpendicular to the device plane. In this device configuration, we found that the resonance of a chiral spin soliton lattice is insensitive to the direction of magnetic field H. In contrast to such behavior, resonance signals were largely suppressed in the ferromagnetic phase when the direction of H is parallel to a dominant component of the driving microwave field. Thus, by interchanging between the chiral spin soliton lattice and ferromagnetic phases, the microwave resonance can be switched on and off. The present device configuration allows us to demonstrate a switching performance, together with discrete changes in the resonance frequency by changing the H strength.
Conservation translocation – an increasingly viable option for managing threatened plant species
Authors: Zimmer Heidi C. , Auld Tony D. , Cuneo Peter , Offord Catherine A. , Commander Lucy E.
Published: December 2019

Translocation is the establishment and augmentation of plant populations using ex situ material, and can reduce extinction risk. Historically, translocation has been considered to be high cost and high risk, but today, translocation is increasingly recognised as a necessary option for managing many threatened plant species. To examine the viability of translocation as a management action, we analysed the frequency of it being a recommended management action, its estimated cost over time, and its perceived likelihood of success as compared with other management actions. We did this using the 368 threatened plant species in the New South Wales state register of threatened species management strategies (the Saving our Species (SOS) database). Translocation was recommended as a management action for 30% of threatened plants (112 species), mostly in response to demographic threats (i.e. threats affecting species with small population sizes/restricted distributions, for example, environmental and demographic stochasticity or low genetic diversity). The estimated cost of translocation per species was similar to other common management actions. However, expert elicitation data (in the SoS database) indicated that translocation was less certain of a beneficial outcome, compared with almost all other management actions. Based on these findings, we create a decision framework, which uses the principles of extinction risk assessment to assist conservation managers in determining when translocation is most likely to be beneficial. We suggest that the use of translocation to mitigate the risk of extinction associated with small population sizes/restricted ranges is supported by the principles of extinction risk assessment. With a growing knowledge base, and costs comparable to other management actions, translocation is becoming an increasingly viable option for the conservation management of threatened plants, provided best practice guidelines are followed.
Nitrous oxide emission factor from cattle urine and dung in native grassland of the Pampa biome, South Brazil
Authors: Schirmann Janquieli , Bastos Diego Fernandes de , Weiler Douglas Adams , Veloso Murilo G. , Dieckow Jeferson , Carvalho Paulo Cesar de Faccio , Bayer Cimélio
Published: December 2019

Native grassland supports extensive livestock production in the Pampas of South America, but the impact of cattle excreta on nitrous oxide (N2O) emissions remains unknown in this biome. The objective of this study was to determine the N2O emission factor (EF-N2O, % of N applied that is emitted as N2O) for urine and dung from beef cattle grazing on native grasslands. A field trial was conducted under low and moderate forage allowances (FA4 and FA12; i.e. 4 and 12 kg dry matter/100 kg live weight respectively) during the 30th year of a long-term grassland experiment on a Typic Paleudult in South Brazil. Urine and dung were applied onto separate patches, at rates equivalent to one average urination or defecation; and N2O fluxes were monitored with closed static chambers over 338 days. In adjacent microplots receiving the same excreta treatment, water-filled pore space, nitrate, ammonium and extractable dissolved organic carbon were monitored in the top 0.1 m of soil. Averaged across the forage allowances, daily soil N2O fluxes were low in the control without excreta (1.3 g N ha–1), but increased upon application of dung (3.8 g N ha–1) and urine (66 g N ha–1). The annual N2O emission and the EF-N2O for urine were greater under FA12 than FA4, but no difference was observed for dung. The positive relationships between N2O-N emissions and ammonium intensity and nitrate intensity suggest that N2O may have been produced concurrently by nitrification, nitrifier/denitrification and denitrification. On average, the EF-N2O was almost 10 times higher for urine than for dung (0.74% vs 0.08%), both much lower than the IPCC’s Tier 1 default value of 2%. Our findings reinforce the need for disaggregating the EF-N2O for urine and dung and of revising the IPCC’s Tier 1 EF-N2O.
Structures and functions of penta-EF-hand calcium-binding proteins and their interacting partners: enigmatic relationships between ALG-2 and calpain-7
Authors: Maki Masatoshi
Published: December 2019

The penta-EF-hand (PEF) protein family includes ALG-2 (gene name, PDCD6) and its paralogs as well as classical calpain family members. ALG-2 is a prototypic PEF protein that is widely distributed in eukaryotes and interacts with a variety of proteins in a Ca2+-dependent manner. Mammalian ALG-2 and its interacting partners have various modulatory roles including roles in cell death, signal transduction, membrane repair, ER-to-Golgi vesicular transport, and RNA processing. Some ALG-2-interacting proteins are key factors that function in the endosomal sorting complex required for transport (ESCRT) system. On the other hand, mammalian calpain-7 (CAPN7) lacks the PEF domain but contains two microtubule-interacting and trafficking (MIT) domains in tandem. CAPN7 interacts with a subset of ESCRT-III proteins through the MIT domains and regulates EGF receptor downregulation. Structures and functions of ALG-2 and those of its interacting partners as well as relationships with the calpain family are reviewed in this article.
LncRNA-encoded polypeptide ASRPS inhibits triple-negative breast cancer angiogenesis
Authors: Wang Yirong , Wu Siqi , Zhu Xun , Zhang Liyuan , Deng Jieqiong , Li Fang , Guo Binbin , Zhang Shenghua , Wu Rui , Zhang Zheng , Wang Kexin , Lu Jiachun , Zhou Yifeng
Published: December 2019

Triple-negative breast cancer (TNBC) is a subtype of breast cancer (BC) with the most aggressive phenotype and poor overall survival. Using bioinformatics tools, we identified LINC00908 encoding a 60–aa polypeptide and differentially expressed in TNBC tissues. We named this endogenously expressed polypeptide ASRPS (a small regulatory peptide of STAT3). ASRPS expression was down-regulated in TNBCs and associated with poor overall survival. We showed that LINC00908 was directly regulated by ERα, which was responsible for the differential down-regulation of LINC00908 in TNBCs. ASRPS directly bound to STAT3 through the coiled coil domain (CCD) and down-regulated STAT3 phosphorylation, which led to reduced expression of VEGF. In human endothelial cells, a mouse xenograft breast cancer model, and a mouse spontaneous BC model, ASRPS expression reduced angiogenesis. In a mouse xenograft breast cancer model, down-regulation of ASRPS promoted tumor growth, and ASRPS acted as an antitumor peptide. We presented strong evidence that LINC00908-encoded polypeptide ASRPS represented a TNBC-specific target for treatment.
Interleukin-15 (dys)regulation of lymphoid homeostasis: Implications for therapy of autoimmunity and cancer
Authors: Waldmann Thomas A. , Miljkovic Milos D. , Conlon Kevin C.
Published: December 2019

IL-15, a pleiotropic cytokine, stimulates generation of NK, NK-T, γδ, ILC1, and memory CD8 T cells. IL-15 disorders play pathogenetic roles in organ-specific autoimmune diseases including celiac disease. Diverse approaches are developed to block IL-15 action. IL-15 administered to patients with malignancy yielded dramatic increases in NK numbers and modest increases in CD8 T cells. Due to immunological checkpoints, to achieve major cancer therapeutic efficacy, IL-15 will be used in combination therapy, and combination trials with checkpoint inhibitors, with anti-CD40 to yield tumor-specific CD8 T cells, and with anticancer monoclonal antibodies to increase ADCC and antitumor efficacy, have been initiated.
Regulation of the germinal center and humoral immunity by interleukin-21
Authors: Tangye Stuart G. , Ma Cindy S.
Published: December 2019

Cytokines play critical roles in regulating the development, survival, differentiation, and function of immune cells. Cytokines exert their function by binding specific receptor complexes on the surface of immune cells and activating intracellular signaling pathways, thereby resulting in induction of specific transcription factors and regulated expression of target genes. While the function of cytokines is often fundamental for the generation of robust and effective immunity following infection or vaccination, aberrant production or function of cytokines can underpin immunopathology. IL-21 is a pleiotropic cytokine produced predominantly by CD4+ T cells. Gene-targeting studies in mice, in vitro analyses of human and murine lymphocytes, and the recent discoveries and analyses of humans with germline loss-of-function mutations in IL21 or IL21R have revealed diverse roles of IL-21 in immune regulation and effector function. This review will focus on recent advances in IL-21 biology that have highlighted its critical role in T cell–dependent B cell activation, germinal center reactions, and humoral immunity and how impaired responses to, or production of, IL-21 can lead to immune dysregulation.
Breakdown voltage enhancement in GaN channel and AlGaN channel HEMTs using large gate metal height*
Authors: Wang Zhong-Xu , Du Lin , Liu Jun-Wei , Wang Ying , Jiang Yun , Ji Si-Wei , Dong Shi-Wei , Chen Wei-Wei , Tan Xiao-Hong , Li Jin-Long , Li Xiao-Jun , Zhao Sheng-Lei , Zhang Jin-Cheng , Hao Yue
Published: December 2019

A large gate metal height technique is proposed to enhance breakdown voltage in GaN channel and AlGaN channel high-electron-mobility-transistors (HEMTs). For GaN channel HEMTs with gate–drain spacing L
GD = 2.5 μm, the breakdown voltage V
BR increases from 518 V to 582 V by increasing gate metal height h from 0.2 μm to 0.4 μm. For GaN channel HEMTs with L
GD = 7 μm, V
BR increases from 953 V to 1310 V by increasing h from 0.8 μm to 1.6 μm. The breakdown voltage enhancement results from the increase of the gate sidewall capacitance and depletion region extension. For Al0.4Ga0.6N channel HEMT with L
GD = 7 μm, V
BR increases from 1535 V to 1763 V by increasing h from 0.8 μm to 1.6 μm, resulting in a high average breakdown electric field of 2.51 MV/cm. Simulation and analysis indicate that the high gate metal height is an effective method to enhance breakdown voltage in GaN-based HEMTs, and this method can be utilized in all the lateral semiconductor devices.
Phase jump in resonance harmonic emission driven by strong laser fields*
Authors: Zhao Yuan-Yuan , Zhao Di , Jiang Chen-Wei , Fang Ai-Ping , Gao Shao-Yan , Li Fu-Li
Published: December 2019

We present a theoretical investigation of the multiphoton resonance dynamics in the high-order-harmonic generation (HHG) process driven by a strong driving continuous wave (CW) field along with a weak control harmonic field. The Floquet theorem is employed to provide a nonperturbative and exact treatment of the interaction between a quantum system and the combined laser field. Multiple multiphoton-transition paths for the harmonic emission are coherently summed. The phase information about paths can be extracted via the Fourier transform analysis of the harmonic signals which oscillate as a function of the relative phase between driving and control fields. Phase jumps are observed when sweeping across the resonance by varying the frequency or intensity of the driving field. The phase variation as a function of driving frequency at a fixed intensity and as a function of the intensity at a fixed driving frequency allows us to determine the intensity dependence of the transition energy of quantum systems.
Prospects for future asymmetric collisions in the LHC
Authors: Jebramcik Marc Andre , Jowett John M
Published: December 2019

The proton-lead runs of the LHC in 2012, 2013 and 2016 provided luminosity far beyond expectations in a diversity of operating conditions and led to important new results in high-density QCD. This has permitted the scope of the future physics programme to be expanded in a recent review. Besides further high-luminosity proton-lead (p–Pb) collisions, lighter nuclei are also under consideration. A short proton-oxygen run, on the model of the 2012 p-Pb run, would be of interest for cosmic-ray physics. Collisions of protons with argon, other noble gases and nuclei of lighter metals are also discussed. We provide an overview of the operational strategies and potential performance of various options. Potential performance limits from moving beam-beam encounters at injection and various beam-loss mechanisms are evaluated in the light of our understanding of the LHC to date.
Beam-Gas and Beam-Thermal photon scattering in CEPC
Authors: Bai S , Yu C H , Wang Y W , Zhang Y , Wang D , Geng H P , Gao J
Published: December 2019

The Circular Electron Positron Collider (CEPC) is a proposed Higgs factory with center of mass energy of 240GeV to measure the properties of Higgs boson and test the standard model accurately. Beam loss background in detectors is an important topic at CEPC. Beam-Gas scattering (BG) and Beam-Thermal photon scattering (BTH), although not so serious as Radiative Bhabha scattering (RBB) and Beamstrahlung (BS), are also important components of the beam induced backgrounds at CEPC due to the beam lifetime. In this paper, we evaluated the beam-gas and beam-thermal photon scattering in simulation and designed collimators to suppress the radiation level on the machine and the detector.
Microphonics Suppression In Ariel Acm1 Cry- Omodule
Authors: Ma Yanyun , Fong K. , Keir J. , Kishi D. , Koscielniak S.R. , Lang D. , Laxdal R.E. , Sekhon R.S.
Published: December 2019

Now 30 MeV stage of the ARIEL (The Advanced Rare Isotope Laboratory) e-Linac is under commissioning which includes an injector cryomodule (ICM) and the first accelerator cryomodule (ACM1). The two ACM1 cavities are driven by a single klystron with vector-sum control and running in CW mode. During the commissioning, the ACM1 cavities gradient and stability were limited by a ponderomotive effect [1-4]. Acoustic noise from the environment including vibration sources from water- and air-cooling systems, cryogenic system and vacuum system have been identified. In this paper, the progress of the microphonics suppression of ACM1 is presented.
Beam dynamics of high chromaticity lattice for Iranian light source facility (ILSF) storage ring
Authors: Foroughi F , Jazayeri S M , Ahmadi E , Rahighi J , Dastan S
Published: December 2019

One of the limiting factors of electron beam lifetime in low emittance storage rings is Head-Tail (HT) instability. Low emittance storage rings typically have a large negative natural chromaticity due to the strong quadrupoles. Above transition large negative natural chromaticity leads to large Head-Tail instability which limit the beam lifetime. Since the threshold current of HT instability is directly related to linear chromaticity, increasing the linear chromaticity to slightly positive value is a solution to prevent HT instability. In this paper we in-creased the chromaticity of Iranian Light Source Facility (ILSF) to (+4, +4) and we will investigate the beam dynamics of ILSF 3GeV storage ring in high chromaticity. For reaching this aim we have used two families of sextupoles for chromaticity correction and then optimized them to maximize the dynamic aperture and Touschek lifetime. The beam dynamics of high chromaticity lattice is presented in this paper.
PETRA IV Study with Non-Interleaved Sextupole Scheme
Authors: Chao Hung-Chun , Gavalda X N , Brinkmann R
Published: December 2019

This study is an attempt to design PETRA IV storage ring, which is an upgrade from PETRA III toward a diffraction-limit synchrotron light source, based on the noninterleaved sextupole scheme. The lattice is constructed by mixing different types of cells. There are two basic building blocks. The double minus identity (DMI) cell dedicated for the chromaticity correction with non-interleaved sextupoles is tightly built up, while the combined function FODO cell with dispersion suppressors provides straights with small beta functions ideally for undulators. In addition, the hybrid section including a 10-m long super insertion device (ID) is custom-made to adapt to DESY’s current site plan. The beam dynamic behaviors are simulated and discussed.
Low-energy beam transport system for MESA
Authors: Matejcek C. , Aulenbacher K. , Friederich S.
Published: December 2019

An important part of the new accelerator MESA (Mainz Energy-recovering Superconducting Accelerator) is the low-energy beam transport system connecting the 100 keV electron source with the injector. The present setup includes the chopper and bunching system. The devices are of highest importance in order to achieve sufficient bunch compression, particularly at higher bunch charges and currents. With the circularly deflecting cavity of the chopper system it is possible to measure the longitudinal profile of the bunches upstream of the buncher, whereas downstream the longitudinal size will be measured by Smith-Purcell radiation. Based on experimental results obtained from this setup, we will discuss the beam parameters and compare them with simulations of the beamline.
Stimulated emission of THz coherent diffraction radiation in an optical cavity by a multibunch electron beam
Authors: Honda Y. , Aryshev A. , Kato R. , Miyajima T. , Obina T. , Shimada M. , Takai R. , Uchiyama T. , Yamamoto N.
Published: December 2019

Accelerator-based terahertz (THz) radiation has been expected to realize a highpower broad-band source. Employing a low-emittance and short-bunch electron beam at a high repetition rate, a scheme to resonantly excite optical cavity modes of THz spectrum range via coherent diffraction radiation has been proposed. The confocal cavity design is the special case that resonance conditions of all the eigen modes coincide, resulting in realizing broad-band excitation. But in general cases of non-confocal cavities, the resonance condition depends on the mode, and the resonance peak becomes wide and weak. We performed an experiment with a non-confocal cavity as a follow-up experiment of that we have done with a confocal cavity. The result confirmed that the confocal design is the key for a broad-band source.
The Beam-based Alignment Simulation and Preliminary Experiment at SXFEL
Authors: Zeng L , Feng C , Gu D , Deng H , Liu B , Zhao Z , Wang G
Published: December 2019

The Shanghai soft X-ray Free-electron Laser facility (SXFEL) is now serving as an experimental platform for fundamental free-electron laser (FEL) principal tests. This facility puts very tight tolerances on the straightness of the electron beam trajectory (within 5 μm). It is hard to achieve the required orbit due to the off-axis fields of the misaligned quadrupoles and undulator segments especially for the SXFEL driven by relatively low energy LINAC (840 MeV). The tight tolerances can be met through beam-based alignment (BBA) technique. In this paper, the BBA simulation and preliminary experiment results at SXFEL are presented. To further improve the electron beam trajectory by calculating the undulator misalignment, the feasibility of genetic algorithm (GA) based BBA has been studied.
Beam motion and photon flux dips during injection at the Taiwan Photon Source
Authors: Huang Chih-Hsien , Hsu Kuo-Tung , Chen Chia-Hsiang , Wu Chun-Yi , Liu Yi-Chih , Chang Ho-Ping , Fann Chyi-Shyan , Liao Chih-Yu , Cheng Yung-Sen , Chiu Pei-Chen , Hu Kuo-Hwa
Published: December 2019

The Taiwan photon source (TPS) is a 3 GeV synchrotron light source now in routine operation at the NSRRC. At the beginning of beam commissioning, significant photon flux dips could be observed at injection due to a blow-up of the beam size. To eliminate this transient effect, all four kickers were rematched. The leakage field was shielded and the induced current loops at vacuum chambers in the injection area were also eliminated. These efforts reduced the horizontal betatron oscillations and orbit distortions to around one-tenth. In order to decrease the recovery time of photon dips during injection, the operational chromaticity was reduced to improve incoherent effects. After all those improvements, the photon flux dips during injection dropped to 30 % and the recovery time to less than 1 msec.
A Novel Non-Linear Strip-Line Kicker Driven by Fast Pulser in Common Mode
Authors: Chen J. , Wang L. , Li Y. , Shi H. , Duan Z. , Wang N. , Huo L. , Wang G.
Published: December 2019

The next generation storage ring-based light sources adopt multi-bend achromat lattices to achieve a low emittance. The dynamic apertures of these machines are usually less than 10 mm so that the traditional pulsed local bump injection is difficult to achieve. Off-axis injection with a pulsed multipole or a non-linear kicker could be a viable solution which requires a moderate dynamic aperture of a few mm. In this paper, a novel non-linear kicker design is presented. Unlike pulsed sextupole or nonlinear kicker magnet, the nonlinear kicker we proposed is a traveling wave kicker with 2 strip-line electrodes driven by a nanosecond-level fast pulser in common mode. The disturbance to the stored beam is minimal since the perturbation is limited to the target bunch alone.
Status of the Horizon 2020 EuPRAXIA conceptual design study*
Authors: Weikum M K , Akhter T , Alesini D , Alexandrova A S , Anania M P , Andreev N E , Andriyash I A , Aschikhin A , Assmann R W , Audet T , Bacci A , Barna I F , Beaton A , Beck A , Beluze A , Bernhard A , Bielawski S , Bisesto F G , Brandi F , Brinkmann R , Bruendermann E , Büscher M , Bussmann M H , Bussolino G , Chance A , Chen M , Chiadroni E , Cianchi A , Clarke J A , Cole J , Couprie M E , Croia M , Cros B , Crump P A , Dattoli G , Del Dotto A , Delerue N , De Nicola S , Dias J M , Dorda U , Fedele R , Ferran Pousa A , Ferrario M , Filippi F , Fiore G , Fonseca R A , Galimberti M , Gallo A , Ghaith A , Giove D , Giribono A , Gizzi L A , Grüner F J , Habib A F , Haefner C , Heinemann T , Hidding B , Holzer B J , Hooker S M , Hosokai T , Huebner M , Irman A , Jafarinia F J , Jaroszynski D A , Joshi C , Kaluza M , Kando M , Karger O S , Karsch S , Khazanov E , Khikhlukha D , Knetsch A , Kocon D , Koester P , Kononenko O S , Korn G , Kostyukov I , Kruchinin K O , Labate L , Blanc C Le , Lechner C , Leemans W , Lehrach A , Li X , Libov V , Lifschitz A , Litvinenko V , Lu W , Lundh O , Maier A R , Malka V , Manahan G G , Mangles S P D , Marchetti B , Martinez de la Ossa A , Martins J L , Mason P D , Massimo F , Mathieu F , Maynard G , Mazzotta Z , Molodozhentsev A Y , Mostacci A , Mueller A - S , Murphy C D , Najmudin Z , Nghiem P A P , Nguyen F , Niknejadi P , Osterhoff J , Oumbarek Espinos D , Papadopoulos D N , Patrizi B , Petrillo V , Pocsai M A , Poder K , Pompili R , Pribyl L , Pugacheva D , Rajeev P P , Romeo S , Rossetti Conti M , Rossi A R , Rossmanith R , Roussel E , Sahai A A , Sarri G , Schaper L , Scherkl P , Schramm U , Schroeder C B , Scifo J , Serafini L , Sheng Z M , Siders C , Silva L O , Silva T , Simon C , Sinha U , Specka A , Streeter M J V , Svystun E N , Symes D , Szwaj C , Tauscher G E , Terzani D , Thompson N , Toci G , Tomassini P , Torres R , Ullmann D , Vaccarezza C , Vannini M , Vieira J M , Villa F , Wahlstrom C - G , Walczak R , Walker P A , Wang K , Welsch C P , Wiggins S M , Wolfenden J , Xia G , Yabashi M , Zhu J , Zigler A
Published: December 2019

The Horizon 2020 project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) is producing a conceptual design report for a highly compact and cost-effective European facility with multi-GeV electron beams accelerated using plasmas. EuPRAXIA will be set up as a distributed Open Innovation platform with two construction sites, one with a focus on beam-driven plasma acceleration (PWFA) and another site with a focus on laser-driven plasma acceleration (LWFA). User areas at both sites will provide access to free-electron laser pilot experiments, positron generation and acceleration, compact radiation sources, and test beams for high-energy physics detector development. Support centres in four different countries will complement the pan-European implementation of this infrastructure.
Beam Optics Study on FFA-MERIT Ring
Authors: Okita H. , Taniguchi A. , Kuriyama Y. , Uesugi T. , Ishi Y. , Mori Y , Muto M. , Ono Y. , Ikeda N. , Yonemura Y. , Sato A. , Kinsho M. , Miyake Y. , Yoshimoto M. , Okabe K.
Published: December 2019

An intense negative muon source MERIT (Multiplex Energy Recovery Internal Target) for the nuclear transformation to mitigate the long-lived fission products from nuclear plants has been proposed. For the purpose of proof-of-principle of MERIT scheme, a FFA(Fixed Field Alternating focusing) ring has been developed. The beam optics of the FFA-MERIT ring has been studied.

This work is partially supported by ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Government of Japan).
SESRI 300MeV Proton and Heavy Ion Accelerator
Authors: Jiang H. P. , Liu J. L. , Hao H. F. , Zhang J. , Chen Q. M. , Chen W. , Han Z. N. , Zhang T.
Published: December 2019

The SESRI (Space Environment Simulation and Research Infrastructure) is the new national research infrastructure under construction at Harbin Institute of Technology (HIT) in China. This infrastructure is specifically built to simulate the space environment on the ground. The SESRI has kinds of accelerators, and the 300MeV proton and heavy ion accelerator is a major radiation source, which will supply 100-300MeV protons and 7-85MeV/u heavy ions for studying the interaction of high energy space particle radiation with material, device, module and biological entity. To meet above requirements, the facility adopts the combination of room temperature ECR (Electron Cyclotron Resonance) ion source, linac injector and synchrotron. The ion source is required to provide all stable nuclide beams from H+
2 to Bi. The linac injector supplies 1MeV/u heavy ion beams and 5MeV proton beam by using RFQ (Radio Frequency Quadrupole) and IH-DTL (Interdigital H-mode type Drift Tube Linac) linac structures. The synchrotron accelerates heavy ions up to 85MeV/u and proton beam 300MeV. And the 3rd integer resonance and RF-KO (RF-Knock-Out) method are adopted for slow extraction. The status of 300MeV proton and heavy ion accelerator design and construction works are briefly described below.
Numerical and experimental evaluation of the DQW crab cavity cryomodule thermal budget
Authors: Cano-Pleite E. , Brodzinski K. , Capatina O. , Carra F.
Published: December 2019

One of the key devices of the HL-LHC project are SRF Crab Cavities. A cryomodule with two Double Quarter Wave (DQW) crab cavities has been fabricated at CERN in 2017 and successfully tested with beam in the Super Proton Synchrotron (SPS) in 2018. The aim of this study is to present and compare the estimation of the thermal budget for the different components of the cryomodule, performed with numerical and semi-analytical methods, with the experimental measurements carried out on the cryomodule before its installation in the SPS.
The development programme of cathodes and electron guns for the Hollow Electron Lenses of the High Luminosity LHC project1
Authors: Perini D. , Gobbi G. , Shao W. , Feng J. , Zhang K. , Li Z. , Wang J. , Wang Y. , Liu W. , Yang Y. , Stancari G. , Crawford D. , Ruan J. , Valerio L.
Published: December 2019

The High Luminosity LHC project (HL-LHC) foresees the construction and installation of important new equipment to increase the performance of the LHC machine. The Hollow Electron Lens (HEL) is a promising system to control the beam halo. It improves the beam collimation system of the HL-LHC and mitigates possible equipment damage in case of failure scenarios from halo losses. The halo can store up to 30 MJ energy. The specifications for this new device are quite demanding. The source, an electron gun with an annular shaped cathode, has to deliver a current up to 5 A. This is five times higher than the current in the existing electron lenses in Fermi and Brookhaven national laboratories. This note describes the programme carried out to design and test high-perveance guns equipped with two types of high-performance scandate cathodes. The size of the final gun is now considerably smaller than the one of the first prototype, allowing a reduction of diameter and cost of the superconducting magnet system used to steer the electron beam. The tests carried out at FNAL, BVERI and BJUT demonstrated that the developed cathodes fulfil the specifications and can supply a 5 A fully Space Charge Limited (SCL) current.