bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geant4 Monte Carlo simulation study of the secondary radiation fields at the laser-driven ion source LION
Authors: Tisi M. , Mares V. , Schreiber J. , Englbrecht F. S. , Rühm W. 
Published: December 2021

AbstractAt the Center for Advanced Laser Applications (CALA), Garching, Germany, the LION (Laser-driven ION Acceleration) experiment is being commissioned, aiming at the production of laser-driven bunches of protons and light ions with multi-MeV energies and repetition frequency up to 1 Hz. A Geant4 Monte Carlo-based study of the secondary neutron and photon fields expected during LION’s different commissioning phases is presented. Goal of this study is the characterization of the secondary radiation environment present inside and outside the LION cave. Three different primary proton spectra, taken from experimental results reported in the literature and representative of three different future stages of the LION’s commissioning path are used. Together with protons, also electrons are emitted through laser-target interaction and are also responsible for the production of secondary radiation. For the electron component of the three source terms, a simplified exponential model is used. Moreover, in order to reduce the simulation complexity, a two-components simplified geometrical model of proton and electron sources is proposed. It has been found that the radiation environment inside the experimental cave is either dominated by photons or neutrons depending on the position in the room and the source term used. The higher the intensity of the source, the higher the neutron contribution to the total dose for all scored positions. Maximum neutron and photon ambient dose equivalent values normalized to 109 simulated incident primaries were calculated at the exit of the vacuum chamber, where values of about 85 nSv (109 primaries)−1 and 1.0 μSv (109 primaries)−1 were found.
Reporter gene-based optoacoustic imaging of E. coli targeted colon cancer in vivo
Authors: Yun Misun , You Sung-Hwan , Nguyen Vu Hong , Prakash Jaya , Glasl Sarah , Gujrati Vipul , Choy Hyon E. , Stiel Andre C. , Min Jung-Joon , Ntziachristos Vasilis 
Published: December 2021

AbstractBacteria-mediated cancer-targeted therapy is a novel experimental strategy for the treatment of cancers. Bacteria can be engineered to overcome a major challenge of existing therapeutics by differentiating between malignant and healthy tissue. A prerequisite for further development and study of engineered bacteria is a suitable imaging concept which allows bacterial visualization in tissue and monitoring bacterial targeting and proliferation. Optoacoustics (OA) is an evolving technology allowing whole-tumor imaging and thereby direct observation of bacterial colonization in tumor regions. However, bacterial detection using OA is currently hampered by the lack of endogenous contrast or suitable transgene fluorescent labels. Here, we demonstrate improved visualization of cancer-targeting bacteria using OA imaging and E. coli engineered to express tyrosinase, which uses L-tyrosine as the substrate to produce the strong optoacoustic probe melanin in the tumor microenvironment. Tumors of animals injected with tyrosinase-expressing E. coli showed strong melanin signals, allowing to resolve bacterial growth in the tumor over time using multispectral OA tomography (MSOT). MSOT imaging of melanin accumulation in tumors was confirmed by melanin and E. coli staining. Our results demonstrate that using tyrosinase-expressing E. coli enables non-invasive, longitudinal monitoring of bacterial targeting and proliferation in cancer using MSOT.
Electron microscopy analysis of femtosecond laser-assisted capsulotomy before and after lens fragmentation
Authors: Mayer Wolfgang J. , Ohlmann Andreas , Schuh Anna , Priglinger Siegfried , Kohnen Thomas , Shajari Mehdi 
Published: December 2021

AbstractStudying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with “valleys and mountains “ as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.
Characterization of COVID-19 outbreaks in three nursing homes during the first wave in Berlin, Germany
Authors: Roth Alexandra , Feller Silke , Ruhnau Andreas , Plamp Lena , Viereck Ute , Weber Kerstin , Maertens Dominic , Hoor Ilona , Gamradt Ronny , Freyer Pia , Wenke-Gellert Frank , Terjaew Andreas , Zintel Andreas , Markus Juliane , Gögelein-Mahfouz Ines , Savaskan Nicolai 
Published: December 2021

AbstractSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) belongs to the coronavirus family and is characterized by its high transmission competence. Elderly COVID-19 patients are at significantly higher risk of severe course of disease and death. Therefore, outbreaks in nursing homes are particularly challenging for facility managers and health authorities. Here, we report three outbreaks of COVID-19 related to nursing homes (NH01.a, NH02 and NH03) with almost 1000 affected individuals during the first COVID-19 wave in Berlin, Germany. The occurrence of cases and the measures taken were analyzed retrospectively. In all three outbreaks, the index persons were nursing home employees or volunteers. Measures taken were quarantine of contacts, close-meshed tests, separation of the affected housing unit, suspension of admission, ban on visiting, and equipping staff with personal protective equipment, of which there was a shortage in Germany at the beginning of the pandemic. A court-ordered quarantine became necessary for three residents of NH01.a due to cognitive disabilities. In total, 61 persons were tested positive for SARS-CoV-2 in NH01.a, ten persons in NH02, and sixteen persons in NH03. Seventeen patients (27.9%) of NH01.a and three patients (18.8%) of NH03 were referred to hospital. Of all confirmed cases, thirteen (21.3%) related to NH01.a and four (25.0%) related to NH03 died as a result of the infection. Besides one 82 year old volunteer, all deceased persons were residents aged between 66 and 98. Our results emphasize the importance of a previously developed containment and cluster strategy for nursing homes. Due to the particular vulnerability of the residents, immediate action, close cooperation and communication between the facility management, residents, visitors and the health authorities are essential in the case of confirmed COVID-19 cases in healthcare facilities.
Electron counting in cationic and anionic silver clusters doped with a 3d transition-metal atom: endo- vs. exohedral geometry
Authors: Minamikawa Kento , Sarugaku Shun , Arakawa Masashi , Terasaki Akira 
Published: December 2021

Cationic and anionic AgNM+/− (M = Sc–Ni) clusters are explored to examine the electron-counting rule. Among 18-valence-electron clusters, endohedrally doped ones are stable due to superatomic electron-shell closure involving delocalized 3d electrons.
One-pot, microwave-assisted copper(i)-catalysed dithiocarbamation: facile introduction of dithiocarbamate on imidazopyridines
Authors: Laxmikeshav Kritika , Sakla Akash P. , John Stephy Elza , Shankaraiah Nagula 
Published: December 2021

Microwave-assisted dithiocarbamation of various imidazoheterocycles with in situ generated dithiocarbamates via a water-soluble Cu(i) catalyst using benign solvent, enabling catalyst recyclability, scalability, less reaction time and high yields.
The influence of surface charge on the tumor-targeting behavior of Fe3O4 nanoparticles for MRI
Authors: Yue Saisai , Zhang Xin , Xu Yuping , Zhu Lichong , Cheng Junwei , Qiao Yuanyuan , Dai Suyang , Zhu Jialin , Jiang Ni , Wu Hao , Zhang Peisen , Hou Yi 
Published: December 2021

The effect of surface charge on the tumor-targeting in vivo is different from that at cell level. The neutral nanoparticles exhibit stronger tumor uptake, while the charged ones accelerate the RES/MPS uptake, making their active-targeting useless.
Dual‐band design and decoupling between two planar inverted‐F antennas using linear parasitic elements and bridge line
Authors: Phung Quang Quan , Nguyen Tuan Hung , Michishita Naobumi , Sato Hiroshi , Koyanagi Yoshio , Morishita Hisashi 
Published: December 2021

AbstractIn this study, a simple technique is proposed to simultaneously achieve dual‐band characteristics and low mutual coupling between two planar inverted‐F antennas (PIFAs), which is one of the most popular antennas used in handset terminals such as mobile phones. The PIFAs initially operate only at a single band at 2.0 GHz (UTMS band). Although several solutions have been proposed to increase the operating frequency band as well as reduce the mutual coupling between multiple‐input multiple‐output antennas, most of them require adjustment of the original antenna size or configuration. This would be disadvantageous if these methods are applied under design conditions that hinder the adjustment of the original antenna. The proposed method uses a combination of linear parasitic elements (LPEs) and a bridge line (BL) and then loads them onto PIFAs. The loading of LPEs increases the operating frequency band at 2.4 GHz, which can help the PIFAs achieve dual‐band operation. Furthermore, the BL transmits opposite‐phase currents to cancel the coupling current between the two PIFAs. Consequently, the mutual coupling can be reduced to less than −10 dB in the dual band without having to adjust the original PIFAs.
High‐resolution angle estimation method in partly calibrated subarray‐based bistatic multiple‐input multiple‐output radar with unknown non‐uniform noise
Authors: Hu Jurong , Baidoo Evans , Bao Zeng 
Published: December 2021

AbstractUniformly distributed white noise is often the desirable noise assumption for partly calibrated subarray‐based radar systems. However, this assumption may practically not always be guaranteed. In this study, the angle estimation problem of the partly calibrated multi‐subarray‐based bistatic multiple‐input multiple‐output radar, where intersubarray calibration errors and non‐uniform noise coexist, is considered. In addition, an inverse transformation‐based enhanced Capon method is proposed to adapt to such a challenging situation. First, the noise‐free covariance matrix of each subarray is obtained by formulating an imaginary selecting matrix following a covariance matrix invariance approach which performs an inverse transformation of the matrix. Thus, the noise identities at the different antennas of the subarray are estimated as nuisance parameters at the expense of the target signals. Second, assuming that the calibration within each subarray is well configured such that the steering vector of a subarray is known, knowledge is required of the intersubarray calibration mismatches. To this, a high‐resolution Capon estimator which applies a combination of root and local searching orientation of the antenna arrays is implemented. The proposed approach resolves the intersubarray calibration errors and ultimately leads to obtaining the joint direction of departure and direction of arrival estimation of the target. Evidence of the proposed algorithm's validity and effectiveness over existing methods is demonstrated in numerical simulations under varying conditions.
Accreting protoplanets: Spectral signatures and magnitude of gas and dust extinction at Hα
Authors: Marleau G.-D. , Aoyama Y. , Kuiper R. , Follette K. , Turner N. J. , Cugno G. , Manara C. F. , Haffert S. Y. , Kitzmann D. , Ringqvist S. C. , Wagner K. R. , van Boekel R. , Sallum S. , Janson M. , Schmidt T. O. B. , Venuti L. , Lovis Ch. , Mordasini C. 
Published: December 2021

Context.Accreting planetary-mass objects have been detected at Hα, but targeted searches have mainly resulted in non-detections. Accretion tracers in the planetary-mass regime could originate from the shock itself, making them particularly susceptible to extinction by the accreting material. High-resolution (R> 50 000) spectrographs operating at Hαshould soon enable one to study how the incoming material shapes the line profile.Aims.We calculate how much the gas and dust accreting onto a planet reduce the Hαflux from the shock at the planetary surface and how they affect the line shape. We also study the absorption-modified relationship between the Hαluminosity and accretion rate.Methods.We computed the high-resolution radiative transfer of the Hαline using a one-dimensional velocity–density–temperature structure for the inflowing matter in three representative accretion geometries: spherical symmetry, polar inflow, and magnetospheric accretion. For each, we explored the wide relevant ranges of the accretion rate and planet mass. We used detailed gas opacities and carefully estimated possible dust opacities.Results.At accretion rates ofṀ≲ 3 × 10−6 MJyr−1, gas extinction is negligible for spherical or polar inflow and at mostAHα≲ 0.5 mag for magnetospheric accretion. Up toṀ≈ 3 × 10−4 MJyr−1, the gas contributesAHα≲ 4 mag. This contribution decreases with mass. We estimate realistic dust opacities at Hαto beκ~ 0.01–10 cm2g−1, which is 10–104times lower than in the interstellar medium. Extinction flattens theLHα–Ṁrelationship, which becomes non-monotonic with a maximum luminosityLHα~ 10−4 L⊙towardsṀ≈ 10−4 MJyr−1for a planet mass ~10 MJ. In magnetospheric accretion, the gas can introduce features in the line profile, while the velocity gradient smears them out in other geometries.Conclusions.For a wide part of parameter space, extinction by the accreting matter should be negligible, simplifying the interpretation of observations, especially for planets in gaps. At highṀ, strong absorption reduces the Hαflux, and some measurements can be interpreted as twoṀvalues. Highly resolved line profiles (R~ 105) can provide (complex) constraints on the thermal and dynamical structure of the accretion flow.
Characterization of exoplanetary atmospheres through a model-unbiased spectral survey methodology
Authors: Lira-Barria A. , Rojo P. M. , Mendez R. A. 
Published: December 2021

Context. Collecting a large variety of exoplanetary atmosphere measurements is crucial to improve our understanding of exoplanets. In this context, it is likely that the field would benefit from broad species surveys, particularly using transit spectroscopy, which is the most successful technique of exoplanetary atmosphere characterization so far.
Aims. Our goal is to develop a model-unbiased technique using transit spectroscopy to analyze every qualified atomic spectral line in exoplanetary transit data, and search for relative absorption, that is, a decrease in the flux of the line when the planet is transiting.
Methods. We analyzed archive data from HDS at Subaru, HIRES at Keck, UVES at VLT, and HARPS at LaSilla to test our spectral survey methodology. It first filtered individual lines by relative noise levels. It also corrected for spectral offsets and telluric contamination. Our methodology performed an analysis along time and wavelength. The latter employed a bootstrap corroboration.
Results. We highlight the possible detections of Mn I and V II in HD 209459b data taken by HDS at Subaru (5.9σ at 5916.4 Å, 5.1σ at 6021.8 Å). The previous detection of Ca I in the same planet is classified as inconclusive by our algorithm, but we support the previous detection of Sc II (3.5σ at 6604.6 Å). We also highlight the possible detection of Ca I, Sc II, and Ti II in HD 189733 data taken by UVES at VLT (4.4σ at 6572.8 Å, 6.8σ at 6604.6 Å, and 3.5σ at 5910.1 Å), in addition to the possible detection of Al I in WASP-74b data taken by UVES at VLT (5.6σ at 6696.0 Å).
Accretion processes in the galaxy cluster Hydra A/Abell 780
Authors: Girardi M. , Boschin W. , Nonino M. , Innocentin C. , De Grandi S. 
Published: December 2021

Context. Clusters of galaxies evolve and accrete mass, mostly from small galaxy systems.
Aims. Our aim is to study the velocity field of the galaxy cluster Abell 780, which is known for the powerful radio source Hydra A at its center and where a spectacular X-ray tail associated with the galaxy LEDA 87445 has been discovered.
Methods. Our analysis is based on the new spectroscopic data for hundreds of galaxies obtained with the Italian Telescopio Nazionale Galileo and the Very Large Telescope. We have constructed a redshift catalog of 623 galaxies and selected a sample of 126 cluster members. We analyzed the internal structure of the cluster using a number of techniques.
Results. We estimate the mean redshift z = 0.0545, the line-of-sight velocity dispersion σV ∼ 800 km s−1, and the dynamical mass M200 ∼ 5.4 × 1014 M⊙. The global properties of Abell 780 are typical of relaxed clusters. On a smaller scale, we can detect the presence of a galaxy group associated with LEDA 87445 in projected phase space. The mean velocity and position of the center of the group agree well with the velocity and position of LEDA 87445. We estimate the following parameters of the collision. The group is characterized by a higher velocity relative to the main system. It is infalling at a rest frame velocity of Vrf ∼ +870 km s−1 and lies at a projected distance of D ∼ 1.1 Mpc to the south, slightly southeast of the cluster center. The mass ratio of the group to the cluster is ∼1:5. We also find evidence of an asymmetry in the velocity distribution of galaxies in the inner cluster region, which might be related to a small low-velocity group detected as a substructure at Vrf ∼ −750 km s−1.
Conclusions. We conclude that A780, although dynamically relaxed at first sight, contains small substructures that may have some impact on the energetics of the core region.
Should We Look beyond Revised International Prognostic Scoring System: A Retrospective Observational Study of Progression of Myelodysplastic Syndrome to Acute Leukemia
Authors: Nagarjun Bangalore Rammohan , Kalaharaghini Rajashekar , Sawhney Jyoti , Trivedi Pina J. , Dhandapani Karthik , Parikh Biren 
Published: December 2021

AbstractIntroduction Myelodysplastic syndrome (MDS) is a clonal stem cell disorder and heterogeneous condition resulting in peripheral cytopenias with marrow dysplasia due to ineffective hematopoiesis. The revised International Prognostic Scoring System (IPSS-R) predicts the risk of progression to acute leukemia (AL). Indian data on MDS and its progression to AL are limited. Additionally, the cytogenetic findings are dictated by patients' racial background. Study intended to analyze the cytogenetic profile of the patients with MDS.Objectives This study aimed to (1) evaluate the clinicohematologic and morphologic spectrum of newly diagnosed MDS cases, (2) evaluate the cytogenetic profile of these cases, and (3) study the cases progressed to AL.Materials and Methods MDS cases diagnosed and followed-up during a 5-year study period, from January 2015 to December 2019, were included in the study and the study was conducted at regional cancer center in Western India. De novo diagnosed MDS cases with complete workup were considered and MDS due to secondary causes were excluded. Baseline clinical, hematologic findings were tabulated along with cytogenetics and risk stratified as per IPSS-R, and their progression was studied.Results A total of 63 cases of de novo MDS were diagnosed over a period of 5 years with 45 cases on follow-up and 15 cases (33.3%) progressed to AL. Maximum number of cases belonged to MDS-excess blast (EB) category accounting to 48 cases (76.1%). Apparently normal karyotyping was the commonest cytogenetic finding in 33 MDS cases (61.2%) and in 8 cases that progressed to AL (53.4%).Conclusion MDS cases diagnosed at relatively early age were at higher risk of progression to AL. Majority of the cases that progressed to AL were risk stratified in high and very high risk groups and 10 cases which progressed to AL belonged to good category, interestingly apparent normal karyotyping was the commonest cytogenetic finding in more than 50% of the cases progressed to AL. Molecular mutations could only explain this progression and studies integrating molecular mutations with present IPSS-R scoring system should be conducted, as it could translate into better risk stratification and help in early identification and better management of cases at risk in progression to AL.
Surgical Epicondylar Axis of the Knee and Its Relationship to the Axial Tibia Alignment in Knee Osteoarthritis: The Concept of Proximal Twist Tibia
Authors: Farinelli Luca , Baldini Marco , Faragalli Andrea , Carle Flavia , Ulisse Serena , Gigante Antonio 
Published: December 2021

AbstractThe proximal tibia and distal femur are intimately linked with the biomechanics of the knee and they are to be considered in total knee arthroplasty (TKA). The aim of the present study was to evaluate the proximal tibial torsion (PTT) in relation to surgical epicondylar axis (SEA) in a healthy cohort and a pathological cohort affected by knee osteoarthritis (OA). We retrospectively analyzed computed tomography of OA knee of 59 patients before they underwent TKA and nonarthritic knee of 39 patients as control. Posterior condylar angle (PCAn), femoral tibial torsion (SEA-proximal tibial condyle [PTC] and SEA-PTT), PTT (PTC-PTT and posterior condylar axes [PCAx]-PTC), and distance between tibial tuberosity and the trochlear groove (TT-TG) were measured. No differences were found for gender, age, TT-TG, and PCAn angles. Statistically significant differences were found for all the other angles considered. Significant correlation was found between tibial torsion and SEA-PTT angles, between PCAx-PTC and SEA-PTC, between SEA-PTT and SEA-PTC, and between PCAx-PTC and SEA-PTT. All measures, except TT-TG and PCAn angles, showed high validity (area under the curve [AUC] > 75%) in associating with OA, with SEA-PTT displaying the highest validity with an AUC of 94.38%. This is the first study to find significant differences in terms of proximal tibia geometry and anatomy between nonarthritic and OA knees. From our results, we reported that OA group was characterized by a greater internal rotation of tibia with respect to SEAs compared with control group. Since the design of the study cannot evaluate a cause–effect relationship, further studies need to be performed to assess the potential implications of these anatomic differences for knee OA and arthroplasty surgeries.