bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three dimensional atmospheric entry simulation of a high altitude cometary dustball meteoroid
Authors: Hulfeld L. , Küchlin S. , Jenny P. 
Published: April 2021

Aims. The break-up of a dustball meteoroid is investigated numerically based on fluid dynamics simulations of the meteoroid’s atmospheric entry flow. Both thermal and mechanical break-up mechanisms are implemented, in order to investigate dustball meteoroid disintegration.
Methods. A three dimensional model of a dustball meteoroid composed of thousands of small spherical grains was used in the atmospheric entry flow simulation, performed with the direct simulation Monte Carlo (DSMC) method. The dynamics of each meteoroid grain were calculated by means of the discrete element method (DEM), which models contact dynamics between grains. By coupling DEM with DSMC, the dynamics of a dustball meteoroid were calculated during atmospheric entry. In addition, thermal computations were also carried out taking into account the incoming atmospheric heat flux, thermal radiation, and grain ablation. Thus, this methodology is able to compute mechanical as well as thermal dustball meteoroid disintegration.
Results. To test this novel multi-physics simulation framework, a prototypical dustball meteoroid, namely a Draconid meteoroid, was simulated. Using typical material properties from the literature, the Draconid meteoroid was compressed due to aerodynamic forces to roughly half its size immediately after the start of the simulation at 200 km altitude. Later, aerodynamic-induced meteoroid rotation occured until the meteoroid disintegrated mechanically at 120 km altitude. The fact that the meteoroid disintegrated mechanically is directly related to the combination of material properties used in the simulation.
Insufficiency Fractures vs. Low-Energy Pelvic Ring Fractures – Epidemiological, Diagnostic and Therapeutic Characteristics of Fragility Fractures of the Pelvic Ring
Authors: Sterneder Manuel , Lang Patricia , Riesner Hans-Joachim , Hackenbroch Carsten , Friemert Benedikt , Palm Hans-Georg 
Published: April 2021

Abstract
Background Fragility fractures of the pelvis (FFP) encompass two fracture entities: fracture after low-energy trauma and insufficiency fracture without trauma. It is unclear whether the two subgroups differ in terms of diagnosis and therapy. The aim of this retrospective study was to evaluate insufficiency fractures with regard to defined parameters and to compare specific parameters with the fractures after low-energy trauma.
Patients and Methods In the period from 2008 to 2017, 203 patients with FFP were recorded at our clinic (Level 1 Trauma Centre DGU, SAV approval). Of these, 25 had an insufficiency fracture and 178 had a pelvic ring fracture after low-energy trauma. Epidemiological, diagnostic and therapeutic parameters were examined.
Results There was a relative increase in the insufficiency fracture within the FFP (2008 – 2009: 5.0% vs. 2015 – 2017: 17.8%). In these patients, osteoporosis tended to be more pronounced than in patients after low-energy trauma (t-value: − 3.66 vs. − 3.13). The diagnosis of insufficiency fractures showed increased use of MRI and DECT (60.9% vs. 26.0%) and a high proportion of type IV fractures after FFP (40.0% vs. 7.9%). In terms of therapy, surgical treatment of the insufficiency fracture was sought more often (68,2% vs. 52,1%), with a tendency towards increased use of combined osteosynthesis procedures (14.3% vs. 7.6%).
Conclusion We were able to show that as the number of cases increases, the insufficiency fracture becomes more important within FFP. If these patients tend to have more pronounced osteoporosis, particular attention should be paid to the diagnosis and adequate therapy of the osteoporosis, especially in the case of an insufficiency fracture. In addition to the increased diagnostic testing using MRI and DECT to detect oedema and the increased surgical therapy for this type of fracture, it is also noteworthy that the insufficiency fracture can cause higher-grade fractures after FFP.
Blood Pressure Response and Vascular Function of Professional
Athletes and Controls
Authors: Bauer Pascal , Kraushaar Lutz , Hoelscher Sophie , Weber Rebecca , Akdogan Ebru , Keranov Stanislav , Dörr Oliver , Nef Holger , Hamm Christian W , Most Astrid 
Published: April 2021

AbstractWorkload-indexed blood pressure response (wiBPR) to exercise has been shown
to be superior to peak systolic blood pressure (SBP) in predicting mortality
in healthy men. Thus far, however, markers of wiBPR have not been evaluated
for athletes and the association with vascular function is unclear. We
examined 95 male professional athletes (26±5 y) and 30 male controls
(26±4 y). We assessed vascular functional parameters at rest and
wiBPR with a graded bicycle ergometer test and compared values for athletes
with those of controls. Athletes had a lower pulse wave velocity
(6.4±0.9 vs. 7.2±1.5 m/s, p=0.001) compared
to controls. SBP/Watt slope (0.34±0.13 vs.
0.44±0.12 mmHg/W), SBP/MET slope
(6.2±1.8 vs. 7.85±1.8 mmHg/MET) and peak
SBP/Watt ratio (0.61±0.12 vs.
0.95±0.17 mmHg/W) were lower in athletes than in
controls (p<0.001). The SBP/Watt and SBP/MET slope
in athletes were comparable to the reference values, whereas the peak
SBP/Watt-ratio was lower. All vascular functional parameters
measured were not significantly correlated to the wiBPR in either athletes
or controls. In conclusion, our findings indicate the potential use of the
SBP/Watt and SBP/MET slope in pre-participation screening of
athletes. Further, vascular functional parameters, measured at rest, were
unrelated to the wiBPR in athletes and controls.
Eintrübung von Intraokularlinsen
Authors: Khoramnia Ramin 
Published: April 2021

ZusammenfassungDas Spektrum an Komplikationen und die Explantationsgründe bei der Verwendung von Intraokularlinsen (IOL) haben sich durch die Weiterentwicklung der Kataraktchirurgie verändert. Eintrübungen des Materials beeinflussen dabei unterschiedlich stark die optische Qualität. Im Fall einer störenden Eintrübung des Materials ist auch heute noch – trotz aller Fortschritte auf dem Gebiet der IOL-Materialien – ein Austausch der IOL die einzige Behandlungsoption.
Tetrahydroxydiboron-Initiated Atom-Transfer Radical Cyclization
Authors: Wang Pengfei , Li Yuli , Wang Guangwei 
Published: April 2021

AbstractIn this work, the first diboron reagent initiated atom-transfer radical cyclization was reported, in which the boryl radicals were generated by the homolytic cleavage of a B–B single bond weakened by the coordination of Lewis base. To clarify the role of carbonate and DMF in the cleavage of B–B bond, we calculated the free energy diagram of two pathways by density functional theory (DFT) investigations. The DFT calculation showed that the presence of carbonate facilitates the B–B bond cleavage to form boron radicals, which can be further stabilized by DMF. Subsequent atom-transfer cyclization initiated by stabilized dihydroxyboron radical is also energetically favored.
Clinical Outcome of Single-Stage Decompression and Posterior Stabilization in Thoracolumbar Spinal Tuberculosis
Authors: Patro Susanta Kumar , Nayak Biswaranjan , Krishnamurthy Balappa Holeppagol , Kumar Arun , Biswal Debabrata , Sahoo Prafulla Kumar 
Published: April 2021

Abstract
Background Thoracolumbar spine constitutes the most common site for spinal tuberculosis. Though the treatment of spinal tuberculosis is antitubercular drugs initially, the patient with neurologic weakness warrants definitive surgical procedure of decompression and stabilization. Even though many investigators have reported favorable results with anterior decompression and stabilization surgery, due to the increased morbidity and complications, the posterior-only approach with decompression and stabilization has evolved as the operation of choice in recent time.
Methods All patients aged between 18 and 70 years with clinically and radiologically proven symptomatic thoracolumbar spinal tuberculosis who failed with conservative treatment for 4 weeks or developed neurologic weakness between the treatments are included in this study. All patients were offered decompression and posterior stabilization with transpedicular screws and rods after explaining the above procedure. Clinical outcome was measured by modified Frankel grading; AIS (American Spinal Injury Association impairment score) grade impairment score; and pain assessment done with visual analog scale (VAS) pre- and postoperatively and at 3, 6, and 9 months of interval.
Results The postoperative pain relief, neurologic improvement as per modified Frankel grade, AIS grade, and improvement in erythrocyte sedimentation rate and C-reactive protein were significant as compared with the preoperative status. The surgical interventions thus prove to have adequate relief to the patient and arresting the disease progression. The surgical outcome has very minimal intra- and postoperative complications.
Conclusion Single-stage decompression and posterior stabilization in thoracolumbar spinal tuberculosis is safe, effective, and results in good clinical outcome. The advantages of surgery include thorough debridement, decompression, and achievement of spinal stabilization.
Material of Choice in Pediatric Cranioplasty
Authors: Salam Anooja Abdul , Ibbett Imogen , Thani Nova 
Published: April 2021

Abstract
Background Current evidence is lacking regarding the optimum material required for cranioplasty in the pediatric population when native bone cannot be replaced. The aim of our survey was to examine current practice in Australia and New Zealand regarding pediatric cranioplasty material.
Methods The online tool SurveyMonkey was used to survey 244 neurosurgeons in Australasia. The survey consisted of five questions concerning preference of material and donor origin for pediatric cranioplasty.
Results Twenty-two neurosurgeons (9%) participated. The results indicate that with small skull defects (< 3 cm) in patients aged 0 to 2years, conservative management with observation alone is the preferred option (65%). In patients aged 3 to 10 years, autologous donor bone was the most popular option, whereas for 11+ years, hydroxyapatite (HA) was the material of choice, followed by titanium. For defects of more than 3 cm, autologous donor bone was preferred in under 11 years. In patients older than 11 years, titanium was the preferred choice (46.67%). The preferred donor origin for autologous cranioplasty in small skull defects (< 3 cm) was split calvarial grafts for all age groups. However, 68.42% of respondents managed those under 2 years conservatively. In large skull defects (> 3 cm), the preferred donor origin was split calvarial grafts for patients older than 3 years (48.3%). In patients aged 0 to 2 years, exchange cranioplasty was the preferred option when cranioplasty was performed.
Conclusion The current practice in Australia and New Zealand is to use autologous donor bone in preference to synthetic materials for cranioplasty in children under 11 years. In children older than 11 years, hydroxyapatite and titanium are the materials of choice.
A Novel Placement Technique of S2 Screw (from S2 to Promontorium) and Double Screwing from S2
Authors: Dalbayrak Sedat , Öğrenci Ahmet , Akar Ezgi , Koban Orkun , Yılmaz Mesut 
Published: April 2021

AbstractSince pseudoarthrosis or screw loosening is frequently seen in lumbosacral stabilizations ending in S1, S2 screws are used more frequently to support S1 screws. This study aims to describe a new screw placement technique and location from S2. Revision surgery was applied to the patient who had previously undergone surgery with the rigid instrumentation system and encountered pseudoarthrosis during the follow-up period. Instrumentation was performed from S2 to the promontorium. The patient’s chronic low back pain arising due to pseudoarthrosis was reduced and a strong lumbosacral dynamic instrumentation was performed to the patient. Dual screw placement from S2 and/or screw placement in the S2-promontorium direction is a new alternative to provide a powerful instrumentation.
Broadband all-silicon hybrid plasmonic TM-pass polarizer using bend waveguides
Authors: Saber Md Ghulam , Plant David V. , Abadía Nicolás 
Published: April 2021

A complementary–metal–oxide semiconductor (CMOS) compatible all-silicon TM-pass polarizer using plasmonic bends is proposed. To simplify the fabrication and be compatible with the CMOS process, we employ only two materials: silicon and silicon dioxide. Highly doped silicon is used to support the plasmons. We obtain an extinction ratio and an insertion loss of 45.4 and 1.7 dB, respectively, at 1550 nm and a maximum extinction ratio of 58 dB. This is the highest reported extinction ratio for a TM-pass polarizer to the best of our knowledge. Furthermore, we achieved &gt;20 dB of extinction ratio and &lt;2 dB of insertion loss over 72 nm bandwidth for a device footprint &lt;8.8 × 5.4 μm2. To achieve this, we exploit the properties of tight bends in plasmonic waveguides. Another advantage of the device is that it is robust against fabrication variations.
Study on broadband low-frequency sound insulation of multi-channel resonator acoustic metamaterials
Authors: Xu Chi , Guo Hui , Chen Yinghang , Dong Xiaori , Ye Hongling , Wang Yansong 
Published: April 2021

A novel acoustic metamaterial structure, made up of both resonator and multiple channels, is proposed to insulate low-frequency broadband noises. Three bandgaps with a total width of 658 Hz can be obtained below 900 Hz when the structure appears as a single negative characteristic within specific frequency ranges. These bandgaps are caused by the standing-wave characteristics under the coupling action of the interior and exterior cavities and the multiple channels. By changing structural parameters and materials, the low-frequency broadband sound insulation performance of the structure can be improved. Experimental results further prove the sound insulation characteristics. The results obtained herein can be used as a guide toward achieving low-frequency broadband sound insulation using a lightweight structure.
Phylogenetically diverse diets favor more complex venoms in North American pitvipers
Authors: Holding Matthew L. , Strickland Jason L. , Rautsaw Rhett M. , Hofmann Erich P. , Mason Andrew J. , Hogan Michael P. , Nystrom Gunnar S. , Ellsworth Schyler A. , Colston Timothy J. , Borja Miguel , Castañeda-Gaytán Gamaliel , Grünwald Christoph I. , Jones Jason M. , Freitas-de-Sousa Luciana A. , Viala Vincent Louis , Margres Mark J. , Hingst-Zaher Erika , Junqueira-de-Azevedo Inácio L. M. , Moura-da-Silva Ana M. , Grazziotin Felipe G. , Gibbs H. Lisle , Rokyta Darin R. , Parkinson Christopher L. 
Published: April 2021

SignificanceWhy biological complexity evolves is a major question in the life sciences, but the specific selection pressures favoring simple or complex traits remain unclear. Using high-resolution measurements of venom complexity in North American pitvipers, we link changes in complexity to natural history via phylogenetic diversity of snake diets. The results indicate that venom complexity evolves in response to phylogenetic diversity in a community of species, likely reflecting divergence in the physiological targets of venom. The nature of a species community, rather than their richness alone, is an important feature in the evolution of complex traits.
Evidence from South Africa for a protracted end-Permian extinction on land
Authors: Viglietti Pia A. , Benson Roger B. J. , Smith Roger M. H. , Botha Jennifer , Kammerer Christian F. , Skosan Zaituna , Butler Elize , Crean Annelise , Eloff Bobby , Kaal Sheena , Mohoi Joël , Molehe William , Mtalana Nolusindiso , Mtungata Sibusiso , Ntheri Nthaopa , Ntsala Thabang , Nyaphuli John , October Paul , Skinner Georgina , Strong Mike , Stummer Hedi , Wolvaardt Frederik P. , Angielczyk Kenneth D. 
Published: April 2021

Significance
Mass extinctions permanently altered life’s evolutionary trajectory five times in Earth’s history, and the end-Permian extinction was the greatest of these biotic crises. South Africa’s unparalleled fossil record provides a window into mass extinction dynamics on land. We analyze a unique dataset comprising hundreds of precisely positioned tetrapod fossils, identifying a protracted (∼1 Ma) extinction. This contrasts with the rapid marine extinction, demonstrating that the effects of biotic crises vary prominently among Earth’s surface environments. We also identify the blooming of “disaster taxa” before the main extinction rather than in its aftermath as assumed previously. These changes contributed to breaking the incumbency of previously dominant mammal relatives (synapsids) after the extinction and to the Triassic rise of crocodile- and dinosaur-line archosaurs.
Assessment of battery utilization and energy consumption in the large-scale development of urban electric vehicles
Authors: Zhao Yang , Wang Zhenpo , Shen Zuo-Jun Max , Sun Fengchun 
Published: April 2021

Significance
The surging demand for battery resources and energy from EVs signifies a need to reassess the real-world battery utilization and energy consumption of urban EVs. In this work, we incorporate unique and previously unavailable datasets of urban-scale EV operation to better understand the battery utilization and energy consumption of large-scale EV utilization. High-resolution operating data of EVs across multiple regions are collected and integrated with vehicle feature data as the input for modeling. Accordingly, we expose several issues that have nonnegligible impacts on battery resources and the urban power supply, such as low battery utilization and seasonal changes in the energy consumption of EVs. The provided models and data can be extensively utilized for further EV-related resource and energy investigations.
People have shaped most of terrestrial nature for at least 12,000 years
Authors: Ellis Erle C. , Gauthier Nicolas , Klein Goldewijk Kees , Bliege Bird Rebecca , Boivin Nicole , Díaz Sandra , Fuller Dorian Q. , Gill Jacquelyn L. , Kaplan Jed O. , Kingston Naomi , Locke Harvey , McMichael Crystal N. H. , Ranco Darren , Rick Torben C. , Shaw M. Rebecca , Stephens Lucas , Svenning Jens-Christian , Watson James E. M. 
Published: April 2021

SignificanceThe current biodiversity crisis is often depicted as a struggle to preserve untouched habitats. Here, we combine global maps of human populations and land use over the past 12,000 y with current biodiversity data to show that nearly three quarters of terrestrial nature has long been shaped by diverse histories of human habitation and use by Indigenous and traditional peoples. With rare exceptions, current biodiversity losses are caused not by human conversion or degradation of untouched ecosystems, but rather by the appropriation, colonization, and intensification of use in lands inhabited and used by prior societies. Global land use history confirms that empowering the environmental stewardship of Indigenous peoples and local communities will be critical to conserving biodiversity across the planet.
Temporally and spatially partitioned neuropeptide release from individual clock neurons
Authors: Klose Markus K. , Bruchez Marcel P. , Deitcher David L. , Levitan Edwin S. 
Published: April 2021

Significance
It is believed that electrical activity simultaneously stimulates widespread release sites in single neurons to elicit neuropeptide-dependent behaviors. However, optically detecting neuropeptide release in the intact brain shows that clock neurons release neuropeptides from different sites at different times of the day. This is possible because one neuronal compartment, the soma, uses biochemical signaling instead of electrical activity to evoke release. Disrupting somatic release affects specific features of circadian locomotor activity and sleep. Thus, neuropeptide release is elicited by independent triggers from distinct parts of clock neurons to engage different regions of behavior-regulating circuitry. This strategy for expanding the connectome may be used for other neuropeptide-dependent behaviors, such as feeding and pain perception.
1940 nm, 1966 nm and 2066 nm multi-wavelength CW and passively-Q-switched operation of L-shaped Tm3+:Lu2O3 ceramic laser in-band fiber-laser pumped at 1670 nm
Authors: Antipov O L , Getmanovskiy Yu A , Balabanov S S , Larin S V , Sharkov V V 
Published: April 2021

Abstract
A Tm3+:Lu2O3 ceramics laser with the L-shaped cavity in-band pumped by a fiber laser at 1670 nm was studied in CW and passively Q-switched multi-wavelength regimes. The CW laser operated at 2066 nm at the weak pump power and self-tuned to 1966 nm and further to 1940 nm at higher pump power. The maximum power in the CW regime at 1940 nm reached 9.5 W, while the average power of 3.6 W was registered in the Q-switched regime with the pulse repetition rate of 110–170 kHz and the pulse duration of 200–240 ns. The Q-switched operation was obtained using a Cr2+:ZnSe saturable absorber. Pulsed regime started at the shortest wavelength of 1940 nm and self-tuned to the double-wavelength of 1940 nm and 1966 nm at higher pump power.
Correlation between cooling power and heat quantity of Er-Ho binary nitride as regenerator of 4K-GM cryocooler
Authors: Arita S , Takahashi K , Shiraishi T , Fujieda S , Nakagawa T , Yamamoto T A , Seino S , Masuyama S 
Published: April 2021

Abstract
Advanced regenerator materials of erbium and holmium binary nitrides, Er
x
Ho1-x
N (x = 0 - 1) were studied. Its specific heat vs. temperature curve, possesses a peak due to the magnetic phase transition at their Curie temperature. The cooling power at 4.2 K of a commercial 4K-GM cryocooler filled with the binary nitride of x = 0.625, 0.75, 0.875 or 1 was evaluated. It was found that the cooling power at 4.2 K has a good linear correlation with the heat quantity, which is calculated by integrating C with respect to T in the region of 4.2 - 7.0 K. Three binary nitrides (x = 0.625, 0.875 and 1) filled in series along the regenerator column gave 26% higher cooling power than that filled with HoCu2.
Dielectric BN nanosheet / PVDF composites with high thermal conductivity
Authors: Zhou Zhengrong , Zhang Chi , Zhao Yalin , Wu Zhixiong , Zhang Hua , Guo Shibin , Huang Rongjin , Li Laifeng 
Published: April 2021

Abstract
With the development of electronic devices, high thermal conductivity polymer will become an ideal electronic packaging material. Therefore, Polyvinylidene fluoride (PVDF) nanocomposite was prepared doped with boron nitride nanosheet (BNNS), which has significantly improved thermal conductivity, excellent electrical insulation and outstanding flexibility. These nanocomposite films were prepared by mixing BNNS/PVDF in organic solution, drying, slicing, and then hot-pressing. Compared with the pristine polymers, the nanocomposite films have excellent thermal conduction, which indicates that new high-performance thermal conductivity materials will play an important role in high-power density electronic devices.
Rotating magnetization method for inspection of local defect in HTS conductor
Authors: Onodera Y , Mito T , Hirano N 
Published: April 2021

Abstract
High temperature superconducting (HTS) magnet used for a accelerator for high energy physics or a large-scale magnetic confinement system for nuclear fusion requires large current capacity HTS conductor in order to dump the stored magnetic energy quickly to protect the coil when quench has been occurred. To realize the HTS conductor, superimposed or stacked HTS tapes conductors are invented. However, local degradation of the critical current has been observed in the production of HTS conductors. Therefore, to confirm the soundness of the HTS conductor, it is necessary to establish the non-destructive detection method for the observation of degraded HTS tapes. In this study, we have investigated to inspect the degradation position in stacked HTS tapes by adopting rotating magnetization measurement method. This measurement method is measuring magnetization signal by rotating and transporting stacked HTS tapes in a static magnetic field. As a result, intentionally introduced buckling defect positions were detected by this measurement method.