bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tachyonic de Sitter Solutions of 10d Type II Supergravities
Authors: Andriot David 
Published: June 2021

AbstractCosmological models of the early or late universe exhibit (quasi) de Sitter space‐times with different stability properties. Considering models derived from string theory, the swampland program does not provide for now a definite characterisation of this stability. In this work we focus on de Sitter solutions of 10d type II supergravities, candidates for classical de Sitter string backgrounds: surprisingly, all known examples are unstable with . We aim at proving the existence of such a systematic tachyon, and getting formally a bound on the value of . To that end, we develop three methods, giving us various sufficient conditions for having a tachyon upon assumptions, in analogy with de Sitter no‐go theorems. Our analysis eventually indicates the existence of variety of different tachyons, and related bounds on . We use this knowledge to find 10 new de Sitter solutions of type IIB supergravity, that have tachyons of a different kind, higher values and new 6d geometries. One solution even appears to be stable, with however non‐compact extra dimensions.
Decomposition‐based over‐parameterization forgetting factor stochastic gradient algorithm for Hammerstein‐Wiener nonlinear systems with non‐uniform sampling
Authors: Liu Qilin , Xiao Yongsong , Ding Feng , Hayat Tasawar 
Published: June 2021

AbstractThis article investigates the parameter estimation problems of Hammerstein‐Wiener nonlinear systems with non‐uniform sampling. The over‐parameterization identification model for the Hammerstein‐Wiener nonlinear systems is established from the non‐uniformly sampled input‐output data. By applying the gradient search principle, we derive an over‐parameterization forgetting factor stochastic gradient algorithm for identifying the nonlinear systems. In order to improve the parameter estimation accuracy, a decomposition‐based over‐parameterization forgetting factor stochastic gradient algorithm is presented by using the decomposition technique. The key is to transform the original system into two subsystems and to estimate the parameters of each subsystem, respectively. The simulation results indicate that the proposed algorithms are effective.
A system approach to enable digital beamforming with direct radiating arrays: The joint use of precoding and sparse arrays
Authors: Vidal Florian , Legay Hervé , Goussetis George , Segneri Andrea 
Published: June 2021

SummaryDigital beamforming with an active array antenna has become, these past years, the holy grail for flexible satellite payloads. This architecture enables a power, frequency and beam steering flexibility that meets the requirements of a wide range of user terminal distributions. Matching these distributions may be challenging, especially if user terminals are co‐located. In this case, narrower beams are needed to utilise high‐frequency reuse factors while avoiding inter‐beam interference. Small beamwidths, however, require large antenna diameters, which implies for conventional antenna arrays many radiating elements and subsequently an increased complexity. A way to reduce the number of radiating elements is to resort to sparse arrays with an irregular layout of radiating elements. A disadvantage of this type of antenna is their high side lobe levels when scanning the beams. A robust on‐board precoding strategy based on the knowledge of the users' positions and the antenna gain over the coverage is proposed to mitigate the interference arising from high side lobe levels. A circular direct radiating array and a sparse direct radiating array based on a sunflower design are compared with respect to the capacities they can achieve, and the complexity of the processor required to perform full digital beamforming.
Quantitative Ultrafast Electron‐Temperature Dynamics in Photo‐Excited Au Nanoparticles
Authors: Sygletou Maria , Benedetti Stefania , Ferrera Marzia , Pierantozzi Gian Marco , Cucini Riccardo , Della Valle Giuseppe , Carrara Pietro , De Vita Alessandro , di Bona Alessandro , Torelli Piero , Catone Daniele , Panaccione Giancarlo , Canepa Maurizio , Bisio Francesco 
Published: June 2021

AbstractThe femtosecond evolution of the electronic temperature of laser‐excited gold nanoparticles is measured, by means of ultrafast time‐resolved photoemission spectroscopy induced by extreme‐ultraviolet radiation pulses. The temperature of the electron gas is deduced by recording and fitting high‐resolution photo	emission spectra around the Fermi edge of gold nanoparticles providing a direct, unambiguous picture of the ultrafast electron‐gas dynamics. These results will be instrumental to the refinement of existing models of femtosecond processes in laterally‐confined and bulk condensed‐matter systems, and for understanding more deeply the role of hot electrons in technological applications.
Bioinspired Electrolysis for Green Molecular Transformations of Organic Halides Catalyzed by B12 Complex
Authors: Shimakoshi Hisashi , Hisaeda Yoshio 
Published: June 2021

AbstractNaturally‐occurring B12‐dependent enzymes catalyze various molecular transformations that are of particular interest from the viewpoint of biological chemistry as well as synthetic organic chemistry. Inspired by the unique property of the B12‐dependent enzymes, various catalytic reactions have been developed using its model complex. Among the B12 model complexes, heptamethyl cobyrinate, synthesized from natural vitamin B12, is highly soluble in various organic solvents and a redox active cobalt complex with an excellent catalysis in electroorganic synthesis. The electrochemical dechlorination of pollutant organic chlorides, such as DDT, was effectively catalyzed by the B12 complex. Modification of the electrode surface by the sol‐gel method to immobilize the B12 complex was also developed. The B12 modified electrodes were effective for the dehalogenation of organic halides with high turnover numbers based on the immobilized B12 complex. Electrolysis of an organic halide catalyzed by the B12 complex provided dechlorinated products under anaerobic conditions, while the electrolysis under aerobic conditions afforded oxygen incorporated products, such as an ester and amide along with dechlorination. Benzotrichloride was transformed into ethylbenzoate or N,N‐diethylbenzamide in the presence of ethanol or diethylamine, respectively. This amide formation was further expanded to a unique paired electrolysis. Electrochemical reductions of an alkene and alkyne were also catalyzed by the B12 complex. A cobalt‐hydrogen complex should be formed as a bioinspired intermediate. Using the B12 complex, light‐assisted electrosynthesis was also developed to save the applied energy.
Inhibition of Tau aggregation with BSc3094 reduces Tau and decreases cognitive deficits in rTg4510 mice
Authors: Anglada‐Huguet Marta , Rodrigues Sara , Hochgräfe Katja , Mandelkow Eckhard , Mandelkow Eva‐Maria 
Published: June 2021

AbstractBackgroundOne of the major hallmarks of Alzheimer's disease (AD)is the aberrant modification and aggregation of the microtubule‐associated protein Tau . The extent of Tau pathology correlates with cognitive decline, strongly implicating Tau in the pathogenesis of the disease. Because the inhibition of Tau aggregation may be a promising therapeutic target, we tested the efficacy of BSc3094, an inhibitor of Tau aggregation, in reducing Tau pathology and ameliorating the disease symptoms in transgenic mice.MethodsMice expressing human Tau with the P301L mutation (line rTg4510) were infused with BSc3094 into the lateral ventricle using Alzet osmotic pumps connected to a cannula that was placed on the skull of the mice, thus bypassing the blood‐brain barrier (BBB) . The drug treatment lasted for 2 months, and the effect of BSc3094 on cognition and on reversing hallmarks of Tau pathology was assessed.ResultsBSc3094 significantly reduced the levels of Tau phosphorylation and sarkosyl‐insoluble Tau. In addition, the drug improved cognition in different behavioral tasks and reduced anxiety‐like behavior in the transgenic mice used in the study.ConclusionsOur in vivo investigations demonstrated that BSc3094 is capable of partially reducing the pathological hallmarks typically observed in Tau transgenic mice, highlighting BSc3094 as a promising compound for a future therapeutic approach for AD.
Terms, definitions and measurements to describe sonographic features of lymph nodes: consensus opinion from the Vulvar International Tumor Analysis (VITA) group
Authors: Fischerova D. , Garganese G. , Reina H. , Fragomeni S. M. , Cibula D. , Nanka O. , Rettenbacher T. , Testa A. C. , Epstein E. , Guiggi I. , Frühauf F. , Manegold G. , Scambia G. , Valentin L. 
Published: June 2021

ABSTRACTIn centers with access to high‐end ultrasound machines and expert sonologists, ultrasound is used to detect metastases in regional lymph nodes from melanoma, breast cancer and vulvar cancer. There is, as yet, no international consensus on ultrasound assessment of lymph nodes in any disease or medical condition. The lack of standardized ultrasound nomenclature to describe lymph nodes makes it difficult to compare results from different ultrasound studies and to find reliable ultrasound features for distinguishing non‐infiltrated lymph nodes from lymph nodes infiltrated by cancer or lymphoma cells. The Vulvar International Tumor Analysis (VITA) collaborative group consists of gynecologists, gynecologic oncologists and radiologists with expertise in gynecologic cancer, particularly in the ultrasound staging and treatment of vulvar cancer. The work herein is a consensus opinion on terms, definitions and measurements which may be used to describe inguinal lymph nodes on grayscale and color/power Doppler ultrasound. The proposed nomenclature need not be limited to the description of inguinal lymph nodes as part of vulvar cancer staging; it can be used to describe peripheral lymph nodes in general, as well as non‐peripheral (i.e. parietal or visceral) lymph nodes if these can be visualized clearly. The association between the ultrasound features described here and histopathological diagnosis has not yet been established. VITA terms and definitions lay the foundations for prospective studies aiming to identify ultrasound features typical of metastases and other pathology in lymph nodes and studies to elucidate the role of ultrasound in staging of vulvar and other malignancies. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.
Bell–like [Ga5] clusters in Sr3Li5Ga5: synthesis, crystal structure and bonding analysis.
Authors: Kotsch Matthias , Prots Yurii , Ormeci Alim , Senyshyn Anatoliy , Kohout Miroslav , Grin Yuri 
Published: June 2021

AbstractDuring the search for a possible replacement of the europium in the structure Eu3Li5+xGa5−x (x = 0.15) in order to facilitate the analysis of the chemical bonding in the bell–like [Ga5] clusters, the isostructural compound Sr3Li5Ga5 (space group R
m, a = 9.6040(5) Å, c = 22.061(1) Å) was discovered. A detailed investigation of the bonding situation in the first five–membered nonconvex Ga cluster utilizing the electron localizability approach became possible, revealing not only first signs of a transition from a Zintl to a Wade cluster, but also the presence of a [Sr6] polycation.
Complications in AVM Surgery
Authors: Cenzato Marco , Boeris Davide , Piparo Maurizio , Fratianni Alessia , Piano Maria Angela , Dones Flavia , Crisà Francesco M. , D’Aliberti Giuseppe 
Published: June 2021

AbstractIn AVM surgery perioperative complications can arise and can have serious perioperative consequences. Surgically related complications in AVM treatment, in many cases, can be avoided by paying attention to details:1. Careful selection of the patient: - addressing a patient with eloquent AVM to Gamma Knife treatment - preoperative treatment with selective embolization of the accessible deep feeders - preoperative gamma knife or embolize those patient with an over-expressed venous pattern2. Meticulous coagulation of deep medullary feeders: - Using dirty coagulation - Using dry non-stick coagulation - Using micro clips - Using laser - Reaching the choroidal vessel in the ventricle when possible - Avoiding occlusive coagulation with hemostatic agents3. Check and avoiding any residual of the AVM4. Keep the patient under pressure control during postoperative periodFulfilling these steps contributes to reduce complications in this difficult surgery, leading to a safer treatment that compares favorably with natural history of brain arteriovenous malformations.
Spinal Dural AVFs: Classifications and Advanced Imaging
Authors: Tanaka Michihiro 
Published: June 2021

AbstractSpinal dural arteriovenous fistulas (SDAVFs) are the most common vascular shunts of the spine. They occur predominantly in men (more than 80%), commonly involve the thoracolumbar spine, and usually cause progressive myelopathy because of venous congestion of the spinal cord. Recent advanced imaging technology can visualize the detailed angioarchitecture of the spinal cord, and this provides more information of the regional microanatomy related with the shunt disease. We retrospectively analyzed the location of the shunt with adjacent vasculatures and assessed the efficacy and the sensitivity of each imaging modality. Based on these data, a new concept of classification for SDAVFs was reviewed.
When Is Diagnostic Subtraction Angiography Indicated Before Clipping of Unruptured and Ruptured Intracranial Aneurysms? An International Survey of Current Practice
Authors: Sebök Martina , Dufour Jean-Philippe , Cenzato Marco , Kaku Yasuhiko , Tanaka Michihiro , Tsukahara Tetsuya , Regli Luca , Esposito Giuseppe 
Published: June 2021

AbstractIntroduction: The goal of this survey is to investigate the indications for preoperative digital subtraction angiography (DSA) before clipping of ruptured and unruptured intracranial aneurysms in an international panel of neurovascular specialists.Methods: An anonymous survey of 23 multiple-choice questions relating to indications for DSA before clipping of an intracranial aneurysm was distributed to the international panel of attendees of the European-Japanese Cerebrovascular Congress (EJCVC), which took place in Milan, Italy on 7–9 June 2018. The survey was collected during the same conference. Descriptive statistics were used to analyze the data.Results: A total of 93 surveys were distributed, and 67 (72%) completed surveys were returned by responders from 13 different countries. Eighty-five percent of all responders were neurosurgeons. For unruptured and ruptured middle cerebral artery (MCA) aneurysms without life-threatening hematoma, approximately 60% of responders perform surgery without preoperative DSA. For aneurysms in other locations than MCA, microsurgery is done without preoperative DSA in 68% of unruptured and in 73% of ruptured cases. In cases of ruptured MCA or ruptured non-MCA aneurysms with life-threatening hematoma, surgery is performed without DSA in 97% and 96% of patients, respectively. Factors which lead to preoperative DSA being performed were: aneurysmal shape (fusiform, dissecting), etiology (infectious), size (>25 mm), possible presence of perforators or efferent vessels arising from the aneurysm, intra-aneurysmal thrombus, previous treatment, location (posterior circulation and paraclinoid aneurysm) and flow-replacement bypass contemplated for final aneurysm treatment. These are all factors that qualify an aneurysm as a complex aneurysm.Conclusion: There is still a high variability in the surgeons’ preoperative workup regarding the indication for DSA before clipping of ruptured and unruptured intracranial aneurysms, except for ruptured aneurysms with life-threatening hematoma. There is a general consensus among cerebrovascular specialists that any angioanatomical feature indicating a complex aneurysm should lead to a more detailed workup including preoperative DSA.
Intraoperative BOLD-fMRI Cerebrovascular Reactivity Assessment
Authors: Muscas Giovanni , van Niftrik Christiaan Hendrik Bas , Sebök Martina , Esposito Giuseppe , Regli Luca , Fierstra Jorn 
Published: June 2021

AbstractBlood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has gained attention in recent years as an effective way to investigate CVR, a measure of the hemodynamic state of the brain, with high spatial and temporal resolution. An association between impaired CVR and diverse pathologies has been observed, especially in ischemic cerebrovascular diseases and brain gliomas. The ability to obtain this information intraoperatively is novel and has not been widely tested. We report our first experience with this intraoperative technique in vascular and oncologic neurosurgical patients, discuss the results of its feasibility, and the possible developments of the intraoperative employment of BOLD-CVR.
The Hybrid Neurosurgeon: The Japanese Experience
Authors: Kaku Yasuhiko , Yamada Takumi , Yasuda Shouji , Kanou Kiyomitsu , Oka Naoki , Kokuzawa Jouji 
Published: June 2021

AbstractObjective: In Japan, hybrid neurosurgeons who perform both open surgical clipping as well as endovascular embolization for the treatment of intracranial aneurysms are common. Although many Japanese neurosurgeons can perform surgical clipping of middle cerebral artery aneurysms or internal carotid artery—posterior communicating artery aneurysms and coil embolization of cerebral aneurysms using simple techniques—only a limited number of neurosurgeons are able to perform surgical clipping and endovascular procedures for anterior communicating artery aneurysms, paraclinoid, or posterior circulation aneurysms using both treatment modalities equally and safely. Materials and methods: The senior author’s personal experience of more than 500 cases each of surgical clipping and endovascular embolization over the past 25 years included 110 cases of basilar tip aneurysms and 104 cases of paraclinoid internal carotid artery (ICA) aneurysms. Results: The safety and efficacy of both treatments appears to be the same, while the durability of surgical clipping is superior to that of endovascular embolization. Among the 110 basilar tip aneurysms, 18 patients were treated by surgical clipping and 94 were treated by endovascular embolization. The initial results of endovascular therapy seemed to be better than those of surgical clipping, although the rate of retreatment was higher. Among the 104 cases of paraclinoid ICA aneurysm, 23 patients were treated by surgical clipping and 81 were treated by endovascular embolization. The results of both treatments seemed to be same, while surgical clipping had apparently good long-term durability. Over the past 15 years, the frequency of surgical clipping for basilar tip aneurysms has decreased, and the procedure may eventually be abandoned for this type of aneurysm. However, surgical clipping still offers several advantages in the treatment of paraclinoid aneurysms. Conclusions: Hybrid neurosurgeons can make reasonable decisions concerning the choice of treatment for cerebral aneurysms, as they perform both treatments and understand the benefits and drawbacks of each modality.
Microneurosurgery for Paraclinoid Aneurysms in the Context of Flow Diverters
Authors: Luzzi Sabino , Del Maestro Mattia , Galzio Renato 
Published: June 2021

AbstractThe advent of flow diverter (FD) stents has apparently reduced the role of microneurosurgery for paraclinoid aneurysms despite sparse high-quality evidence about their long-term effects.The present study critically reviews the overall results of a microneurosurgical series of 57 paraclinoid aneurysms.Of these aneurysms, 47.4% were regular in size while 19.3 were giant. Barami type I was predominant. In 21 aneurysms a hemorrhagic onset occurred. Pterional approach with intradural anterior clinoidectomy was preferred by far. Clipping was possible in 91.2% of aneurysms and a high-flow bypass was the choice in five cases. An mRS of 0–2 was achieved in 77.3% of patients, typically <50 years old.Visual field appeared improved or unchanged in 36.3% and 63.6% of the symptomatic patients, respectively. In 76.1% of incidental aneurysms, campimetry was unaffected by surgery.A complete aneurysm exclusion was achieved in 93% of cases using a single procedure. No recurrences were documented on an average follow-up of 54.1 ± 34 months.Microneurosurgery is still a valuable, definitive, and durable option for Barami type Ia, Ib, or II paraclinoid aneurysm, especially in patients <50 years old and visually symptomatic. Conditions other than these are ideal candidates for FD stents.
Interleukin-2 PET imaging in patients with metastatic melanoma before and during immune checkpoint inhibitor therapy
Authors: van de Donk Pim P. , Wind Thijs T. , Hooiveld-Noeken Jahlisa S. , van der Veen Elly L. , Glaudemans Andor W. J. M. , Diepstra Arjan , Jalving Mathilde , de Vries Elisabeth G. E. , de Vries Erik F. J. , Hospers Geke A. P. 
Published: June 2021

Abstract
Purpose
Immune checkpoint inhibitors can induce a T cell–mediated anti-tumor immune response in patients with melanoma. Visualizing T cell activity using positron emission tomography (PET) might allow early insight into treatment efficacy. Activated tumor–infiltrating T cells express the high-affinity interleukin-2 receptor (IL-2R). Therefore, we performed a pilot study, using fluorine-18-labeled IL-2 ([18F]FB-IL2 PET), to evaluate whether a treatment-induced immune response can be detected.

Methods
Patients with metastatic melanoma received ~ 200 MBq [18F]FB-IL2 intravenously, followed by a PET/CT scan before and during immune checkpoint inhibitor therapy. [18F]FB-IL2 uptake was measured as standardized uptake value in healthy tissues (SUVmean) and tumor lesions (SUVmax). Response to therapy was assessed using RECIST v1.1. Archival tumor tissues were used for immunohistochemical analyses of T cell infiltration.

Results
Baseline [18F]FB-IL2 PET scans were performed in 13 patients. SUVmean at baseline was highest in the kidneys (14.2, IQR: 11.6–18.0) and liver (10.6, IQR: 8.6–13.4). In lymphoid tissues, uptake was highest in spleen (10.9, IQR: 8.8–12.4) and bone marrow (2.5, IQR: 2.1–3.0). SUVmax in tumor lesions (n = 41) at baseline was 1.9 (IQR: 1.7–2.3). In 11 patients, serial imaging was performed, three at week 6, seven at week 2, and one at week 4. Median [18F]FB-IL2 tumor uptake decreased from 1.8 (IQR: 1.7–2.1) at baseline to 1.7 (IQR: 1.4–2.1) during treatment (p = 0.043). Changes in [18F]FB-IL2 tumor uptake did not correlate with response. IL-2R expression in four archival tumor tissues was low and did not correlate with baseline [18F]FB-IL2 uptake. No [18F]FB-IL2-related side effects occurred.

Conclusion
PET imaging of the IL-2R, using [18F]FB-IL2, is safe and feasible. In this small patient group, serial [18F]FB-IL2-PET imaging did not detect a treatment-related immune response.

Trial registration
Clinicaltrials.gov: NCT02922283; EudraCT: 2014-003387.20