bluuebunny/crossref_metadata_2025 huggingface dataset:
PHANGS–MUSE: The H II region luminosity function of local star-forming galaxies
Authors: Santoro Francesco , Kreckel Kathryn , Belfiore Francesco , Groves Brent , Congiu Enrico , Thilker David A. , Blanc Guillermo A. , Schinnerer Eva , Ho I-Ting , Diederik Kruijssen J. M. , Meidt Sharon , Klessen Ralf S. , Schruba Andreas , Querejeta Miguel , Pessa Ismael , Chevance Mélanie , Kim Jaeyeon , Emsellem Eric , McElroy Rebecca , Barnes Ashley T. , Bigiel Frank , Boquien Médéric , Dale Daniel A. , Glover Simon C. O. , Grasha Kathryn , Lee Janice , Leroy Adam K. , Pan Hsi-An , Rosolowsky Erik , Saito Toshiki , Sanchez-Blazquez Patricia , Watkins Elizabeth J. , Williams Thomas G.
Published: November 2021

We use an unprecedented sample of about 23 000 H II regions detected at an average physical resolution of 67 pc in the PHANGS–MUSE sample to study the extragalactic H II region Hα luminosity function (LF). Our observations probe the star-forming disk of 19 nearby spiral galaxies with low inclination and located close to the star formation main sequence at z = 0. The mean LF slope, α, in our sample is =1.73 with a σ of 0.15. We find that α decreases with the galaxy’s star formation rate surface density, ΣSFR, and argue that this is driven by an enhanced clustering of young stars at high gas surface densities. Looking at the H II regions within single galaxies, we find that no significant variations occur between the LF of the inner and outer part of the star-forming disk, whereas the LF in the spiral arm areas is shallower than in the inter-arm areas for six out of the 13 galaxies with clearly visible spiral arms. We attribute these variations to the spiral arms increasing the molecular clouds’ arm–inter-arm mass contrast and find suggestive evidence that they are more evident for galaxies with stronger spiral arms. Furthermore, we find systematic variations in α between samples of H II regions with a high and low ionization parameter, q, and argue that they are driven by the aging of H II regions.
Green Bank Telescope: Overview and analysis of metrology systems and pointing performance
Authors: White E. , Ghigo F. D. , Prestage R. M. , Frayer D. T. , Maddalena R. J. , Wallace P. T. , Brandt J. J. , Egan D. , Nelson J. D. , Ray J.
Published: November 2021

With a 100 m × 110 m off-axis paraboloid dish, the Green Bank Telescope (GBT) is the largest fully steerable radio telescope on Earth. A major challenge facing large ground-based radio telescopes is achieving sufficient pointing accuracy for observing at high frequencies, up to 116 GHz in the case of the GBT. Accurate pointing requires the ability to blindly acquire source locations and perform ad hoc corrections determined by observing nearby calibrator sources in order to obtain a starting position accurate to within a small margin of error of the target’s location. The required pointing accuracy is dependent upon the half-power beamwidth, and for the higher-frequency end of GBT observing, this means that pointing must be accurate to within a few arcseconds RMS. The GBT’s off-axis design is advantageous in that it eliminates blockage of the dish and reduces sidelobe interference, and there is no evidence that the resulting asymmetric structure adversely affects pointing accuracy. However, factors such as gravitational flexure, thermal deformation, azimuth track tilt and irregularity, and small misalignments and offset errors within the telescope’s structure cause pointing inaccuracies. A pointing model was developed for the GBT to correct for these effects. The model utilizes standard geometrical corrections along with metrology data from the GBT’s structural temperature sensors and data from measurements of the track levels. In this paper we provide a summary of the GBT’s pointing model and associated corrections, as well as a discussion of relevant metrology systems and an analysis of its current nighttime pointing accuracy.
The influence of gravity on granular impacts
Authors: Sunday Cecily , Murdoch Naomi , Wilhelm Arnaud , Drilleau Melanie , Zhang Yun , Tardivel Simon , Michel Patrick
Published: November 2021

Context.Slow interactions on small body surfaces occur both naturally and through human intervention. The resettling of grains and boulders following a cratering event, as well as observations made during small body missions, can provide clues regarding the material properties and the physical evolution of a surface. In order to analyze such events, it is necessary to understand how gravity influences granular behavior.

Aims.In this work, we study slow impacts into granular materials for different collision velocities and gravity levels. Our objectives are to develop a model that describes the penetration depth in terms of the dimensionless Froude number and to use this model to understand the relationship between collision behavior, collision velocity, and gravity.

Methods.We used the soft-sphere discrete element method to simulate impacts into glass beads under gravitational accelerations ranging from 9.81 m s−2to 0.001 m s−2. We quantified collision behavior using the peak acceleration, the penetration depth, and the collision duration of the projectile, and we compared the collision behavior for impacts within a Froude number range of 0–10.

Results.The measured penetration depth and collision duration for low-velocity collisions are comparable when the impact parameters are scaled by the Froude number, and the presented model predicts the collision behavior well within the tested Froude number range. If the impact Froude number is low (0 < Fr < 1.5), the collision occurs in a regime that is dominated by a depth-dependent quasi-static friction force. If the impact Froude number is high enough (1.5 < Fr < 10), the collision enters a second regime that is dominated by inertial drag.

Conclusions.The presented collision model can be used to constrain the properties of a granular surface material using the penetration depth measurement from a single impact event. If the projectile size, the collision velocity, the gravity level, and the final penetration depth are known and if the material density is estimated, then the internal friction angle of the material can be deduced.
On the induced geometry on surfaces in 3D contact sub-Riemannian manifolds
Authors: Barilari Davide , Boscain Ugo , Cannarsa Daniele
Published: November 2021

Given a surface S in a 3D contact sub-Riemannian manifold M, we investigate the metric structure induced on S by M, in the sense of length spaces. First, we define a coefficient K̂ at characteristic points that determines locally the characteristic foliation of S. Next, we identify some global conditions for the induced distance to be finite. In particular, we prove that the induced distance is finite for surfaces with the topology of a sphere embedded in a tight coorientable distribution, with isolated characteristic points.
Interest and outcomes of alveolar distraction osteogenesis for dental implant rehabilitation following mandibular reconstruction
Authors: Callies Philippine , Gellée Timothée , Samama Mickael
Published: November 2021

Introduction: Alveolar distraction osteogenesis (ADO) is one of vertical bone augmentation technique used to restore the vertical bone discrepancy between the transplanted graft and the residual alveolar bone after mandibular reconstruction. The aim of this article is to present the clinical outcomes of ADO applied to reconstructed mandible for three patients. Observation: Three patients underwent alveolar distraction osteogenesis procedure on mandibula reconstructed by fibula free flap (n = 2) or iliac crest free flap (n = 1). The mean bone height increase was 11 mm. 16 implants have been placed in all patients, with a success rate of 100% and a mean follow-up of 25 months. Two complications occurred without compromising the final outcome of the procedure: one fracture of the basal bone and one bony interference, both during activation phase. Commentaries: ADO can be performed on reconstructed mandible with free flap to restore alveolar height. An acceptable implant-to-crown ratio allows an optimal supported implant prosthesis. The particular antecedent of our patients can lead to uncommon complications such as basal bone fracture, but doesn't seem to compromise implant placement with good success rate. Conclusions: ADO performed on reconstructed mandible allows appropriate dental implant rehabilitation, achieving good esthetics and occlusal outcomes.
Stockage géologique de déchets et droit du sous-sol : une fracture entre intérêt public et usage industriel
Authors: Schellenberger Thomas
Published: November 2021

Le développement du stockage géologique de déchets permet de s’interroger sur la façon dont le droit français appréhende le sous-sol et ce procédé qui génère des risques et des conflits d’usages à long terme. Le stockage géologique transfert les déchets dans un espace possédant des normes et des enjeux propres. Or, l’encadrement juridique du stockage souterrain de déchets tend à enfermer le sous-sol dans une fonction d’exutoire favorable à la production industrielle. Les règles de droit sur l’accès au sous-sol en sont une illustration : on peut dire qu’il existe une fracture, dans le droit du sous-sol, entre intérêt public et usage industriel. D’un côté, le sous-sol est approprié par l’État au nom de l’intérêt général. De l’autre, cet espace est mis à disposition des exploitants industriels au détriment d’un usage public du sous-sol envisagé plus largement.
Fashion retail competition on product greenness with overconfidence
Authors: Cheng Bayi , Wang Yuqi , Shi Xinyan , Zhou Mi
Published: November 2021

In this paper, we study the impacts of overconfidence in a competitive retailer setting of green fashion. We model a green fashion supply chain comprising one unbiased manufacturer and two biased retailers, to explore how overconfidence affects greenness level of fashion products and expected profit of retailers. An overconfident retailer has a cognitive bias in which it believes consumers are more sensitive to greenness of fashion products than it really is. Our findings show that the competition between two retailers discourages greenness level of fashion products, while overconfidence can provide a counterbalance to the negative impact caused by competition. We also find, a retailer’s overconfidence is not only conducive to the greenness level of its own fashion products, but also can benefit to its rival. Moreover, it shows a low level of overconfidence can be a comparative advantage of the retailer’s profit. Even though one of the retailers is unbiased and has an advantage of information, it can still earn less than its overconfident rival.
Apart from the Medical Complaints, Why do Patients Use Emergency
Medical Services? Results of a Patient Survey
Authors: Piedmont Silke , Reinhold Anna Katharina , Bock Jens-Oliver , Rothhardt Janett , Swart Enno , Robra Bernt-Peter
Published: November 2021

Introduction Many countries face an increased use of emergency medical
services (EMS) with a decreasing percentage of life-threatening complaints.
Though there is a broad discussion among experts about the cause,
patients' self-perceived, non-medical reasons for using EMS remain
largely unknown.

Methods The written survey included EMS patients who had≥1 case of
prehospital emergency care in 2016. Four German health insurance companies sent
out postal questionnaires to 1312 insured patients. The response rate was
20%; 254 questionnaires were eligible for descriptive and interferential
analyses (t-tests, chi2-tests, logistic models).

Results The majority of respondents indicated that their EMS use was due
to an emergency or someone else’s decision (≥84%;
multiple checks allowed); 56% gave need for a quick transport as a
reason. Other frequently stated reasons addressed the health care system
(e. g., complaints outside of physicians’ opening hours) and
insecurity/anxiety about one’s state of health
(>45% of the respondents). “Social factors” were
similarly important (e. g., 42% affirming, “No one could
give me a ride to the emergency department or doctor’s
office.”). Every fifth person had contact with other emergency care
providers prior to EMS use. Respondents negating an emergency as a reason were
less likely to confirm wanting immediate medical care on site or quick
transports compared to those affirming an emergency. Patients using EMS at night
more often denied having an emergency compared to patients with access to care
during the day.

Conclusion The study identified a bundle of reasons leading to EMS use
apart from medical complaints. Attempts for needs-oriented EMS use should
essentially include optimization of the health care and social support system
and measures to reduce patients’ insecurity.
Therapieadhärenz 3 Monate nach Einleitung einer nichtinvasiven CPAP-Therapie bei 1078 Patienten mit obstruktiver Schlafapnoe (OSA)
Authors: Koehler Julian , Hildebrandt Olaf , Cassel Werner , Conradt Regina , Mayr Petra , Alter Peter , Viniol Christian
Published: November 2021

Einleitung Die nächtliche kontinuierliche positive Überdruckatmung (CPAP) gilt als therapeutischer Goldstandard einer obstruktiven Schlafapnoe (OSA). Die CPAP-Therapie stellt zumeist eine Dauertherapie mit geringen Nebenwirkungen dar. Trotzdem ist die Therapietreue unbefriedigend. In dieser Arbeit wurden die Therapietreue betrachtet und typische Probleme katalogisiert.

Methode 1078 OSA-Patienten wurden nach diagnostischer Polygrafie (PG) oder Polysomnografie (PSG) auf eine CPAP-Therapie eingestellt. Die Therapietreue wurde nach 3 Monaten nachverfolgt. Folgende Therapieadhärenz-Gruppen wurden festgelegt: 1. gute CPAP-Einstellung und Nutzung, 2. CPAP-Abbruch nach anfänglicher Nutzung, 3. mangelnde CPAP-Nutzung wegen Nebenwirkungen, 4. Abbruch aufgrund fehlender Motivation/geringem Leidensdruck, 5. Masken-Unverträglichkeit, 6. CPAP-Versagen aufgrund fehlenden Therapieeffekts, 7. Umstellung auf anderes Beatmungsverfahren, 8. keine Kontrolle erfolgt.

Ergebnisse Von 1078 CPAP-Patienten erschienen 830 Patienten (77 %) zur Therapiekontrolle. Hiervon waren 450 Patienten (54,2 %) in Gruppe 1, 216 Patienten (26 %) in Gruppe 2, 71 Patienten (8,5 %) in Gruppe 3, 35 Patienten (4,2 %) in Gruppe 4, 14 Patienten (1,7 %) in Gruppe 5, 3 Patienten (0,4 %) in Gruppe 6 und 41 Patienten (4,9 %) in Gruppe 7. Ein geringer obstruktiver Ereignisindex, niedriger CPAP-Druck und tendenziell auch ein geringer Epworth-Sleepiness-Score waren Prädiktoren für CPAP-Versagen. Für die Therapietreue konnten keine signifikanten Prädiktoren dargestellt werden.

Diskussion Eine effektive Therapienutzung von 54 % nach 3 Monaten ist ein suboptimales Ergebnis. Prädiktoren für CPAP-Versagen waren Parameter, die vor Therapie auf geringen Leidensdruck der Patienten deuteten. Trotz großer Patientenkohorte konnten keine signifikanten CPAP-Adhärenz-Prädiktoren durch anthropometrische oder PSG-Daten dargestellt werden. Vielmehr könnten Erfahrungen in den ersten Therapietagen ausschlaggebend sein. CPAP-Geräte bieten Komforteinstellungen, die kenntnisgerecht auf den Patienten individualisiert werden müssen. Eine große Auswahl an unterschiedlichen Maskenformen erfordert Erfahrung und Training bei der patientenorientierten Maskenanpassung. Eine 3-monatige Wiedervorstellung erscheint zu lang, um Therapieprobleme zeitnah mit dem Patienten zu besprechen. Telemedizinische Möglichkeiten oder kurzfristige telefonische Beratungsoptionen sollten in Betracht gezogen werden.
Endocannabinoid Modulation Using Monoacylglycerol Lipase Inhibition
in Tourette Syndrome: A Phase 1 Randomized, Placebo-Controlled
Study
Authors: Müller-Vahl Kirsten R. , Fremer Carolin , Beals Chan , Ivkovic Jelena , Loft Henrik , Schindler Christoph
Published: November 2021

Introduction Tourette syndrome (TS) is a complex neurodevelopmental
disorder characterized by chronic motor and vocal tics. While consistently
effective treatment is lacking, evidence indicates that the modulation of
endocannabinoid system is potentially beneficial. Lu AG06466 (previously
ABX-1431) is a highly selective inhibitor of monoacylglycerol lipase, the
primary enzyme responsible for the degradation of the endocannabinoid ligand
2-arachidonoylglycerol. This exploratory study aimed to determine the effect of
Lu AG06466 versus placebo on tics and other symptoms in patients with TS.

Methods In this phase 1b cross-over study, 20 adult patients with TS on
standard-of-care medications were randomized to a single fasted dose of Lu
AG06466 (40 mg) or placebo in period 1, followed by the other treatment
in period 2. The effects on tics, premonitory urges, and psychiatric
comorbidities were evaluated using a variety of scaled approaches at different
time points before and after treatment.

Results All scales showed an overall trend of tic reduction, with two out
of three tic scales (including the Total Tic Score of the Yale Global Tic
Severity Score) showing a significant effect of a single dose of Lu AG06466
versus placebo at various timepoints. Treatment with Lu AG06466 resulted in a
significant reduction in premonitory urges versus placebo. Single doses of Lu
AG06466 were generally well-tolerated, and the most common adverse events were
headache, somnolence, and fatigue.

Conclusion In this exploratory trial, a single dose of Lu AG06466 showed
statistically significant positive effects on key measures of TS symptoms.
New Avenues in Copper-Mediated Trifluoromethylation Reactions Using Fluoroform as the CF3 Source
Authors: Tsui Gavin Chit , Yang Xinkan
Published: November 2021

Organic molecules containing the trifluoromethyl (CF3) group play a vital role in pharmaceuticals, agrochemicals, and materials. New trifluoromethylation methods should encompass capabilities to address issues in efficiency, selectivity, and CF3 source all at once. Fluoroform (CF3H), an industrial byproduct, has emerged as an attractive CF3 source. The reaction profile of the [CuCF3] reagent derived from fluo­roform has surpassed its original applications in cross-coupling-type trifluoromethylation. We have discovered a host of unique copper-mediated trifluoromethylation reactions using [CuCF3] from fluoroform, especially under oxidative conditions, to deliver efficient and selective synthesis of trifluoromethylated compounds.

1 Introduction

2 Construction of C–CF3 Bonds for the Synthesis of Trifluoromethylated Building Blocks

2.1 C(sp)–CF3 Bond Formation

2.2 C(sp2)–CF3 Bond Formation

2.3 C(sp3)–CF3 Bond Formation

3 Domino Synthesis of Trifluoromethylated Heterocycles

3.1 3-(Trifluoromethyl)indoles

3.2 3-(Trifluoromethyl)benzofurans

3.3 2-(Trifluoromethyl)indoles

4 Trifluoromethylative Difunctionalization of Arynes

4.1 Trifluoromethylation–Allylation of Arynes

4.2 1,2-Bis(trifluoromethylation) of Arynes

5 Pentafluoroethylation of Unactivated Alkenes

6 Conclusion
Chemoselective Reduction of Tertiary Amides by 1,3-Diphenyl­disiloxane (DPDS)
Authors: Hammerstad Travis A. , Hegde Pooja V. , Aldrich Courtney C. , Wang Kathleen J.
Published: November 2021

A convenient procedure for the chemoselective reduction of tertiary amides at room temperature in the presence of air and moisture using 1,3-diphenyldisiloxane (DPDS) is developed. The reaction conditions tolerate a significant number of functional groups including esters, nitriles, secondary amides, carbamates, sulfoxides, sulfones, sulfonyl fluorides, halogens, aryl-nitro groups, and arylamines. The conditions reported are the mildest to date and utilize EtOAc, a preferred solvent given its excellent safety profile and lower environmental impact. The ease of setup and broad chemoselectivity make this method attractive for organic synthesis, and the results further demonstrate the utility of DPDS as a selective reducing agent.
Fracture Strength of Monolithic Zirconia Crowns with Modified Vertical Preparation: A Comparative In Vitro Study
Authors: Abdulazeez Marwah Ismael , Majeed Manhal A.
Published: November 2021

Objective The aim of this study was to evaluate the influence of different marginal designs (deep chamfer, vertical, and modified vertical with reverse shoulder) on the fracture strength and failure modes of monolithic zirconia crowns.

Materials and Methods Thirty sound human maxillary first premolar teeth with comparable size were used in this study. The teeth were divided randomly into three groups according to the preparation design (n = 10): (1) group A: teeth prepared with a deep chamfer finish line; (2) group B: teeth prepared with vertical preparation; and (3) group C: teeth prepared with modified vertical preparation, where a reverse shoulder of 1 mm was placed on the buccal surface at the junction of middle and occlusal thirds. All samples were scanned by using an intraoral scanner (CEREC Omnicam, Sirona, Germany), and then the crowns were designed by using Sirona InLab 20.0 software and milled with a 5-axis machine. Each crown was then cemented on its respective tooth with self-adhesive resin cement by using a custom-made cementation device. A single load to failure test was used to assess the fracture load of each crown by using a computerized universal testing machine that automatically recorded the fracture load of each sample in Newton (N).

Statistical Analysis The data were analyzed statistically by using one-way analysis of variance test and Bonferroni test at a level of significance of 0.05.

Results The highest mean of fracture load was recorded by chamfer (2,969.8 N), which followed by modified vertical (2,899.3 N) and the lowest mean of fracture load was recorded by vertical (2,717.9 N). One-way ANOVA test revealed a significant difference among the three groups. Bonferroni test showed a significant difference between group A and group B, while a nonsignificant difference was revealed between group C with group A and group B.

Conclusion Within the limitations of this in vitro study, the mean values of fracture strength of monolithic zirconia crowns of all groups were higher than the maximum occlusal forces in the premolar region. The modification of the vertical preparation with a reverse shoulder placed at the buccal surface improved the fracture strength up to the point that it was statistically nonsignificant with the chamfer group.
Divergent Synthesis of Chalcogenylated Quinolin-2-ones and Spiro[4,5]trienones via Intramolecular Cyclization of N-Aryl­propynamides Mediated by Diselenides/Disulfides and PhICl2
Authors: Du Yunfei , Li Xiaoxian , Zhang Beibei , Yu Zhenyang , Zhang Dongke , Shi Haofeng , Xu Lingzhi
Published: November 2021

The reaction of N-arylpropynamides with (dichloroiodo)benzene (PhICl2) and diselenides/disulfides resulted in a divergent synthesis of chalcogenylated quinolinones and spiro[4.5]trienes through intramolecular electrophilic cyclization and chalcogenylation. The chalcogenyl functional group was introduced by an electrophilic reactive organosulfenyl chloride or selenenyl chloride species, generated in situ from the reaction of disulfides/diselenides and PhICl2. Notably, the divergent cyclization pathways were determined by the substituent type on the aniline ring in N-arylpropynamide substrates. Substrates bearing a fluoro, methoxy or trifluoromethoxy group at the para-position of the aniline underwent an alternative spiralization pathway to give the 3-chalcogenylated spiro[4,5]trienones.
Duration of Exposure to General Endotracheal Anesthesia during Cesarean Deliveries at Term and Perinatal Complications
Authors: Swanson Kate , Liang Luzhou , Grobman William A. , Higgins Nicole , Roy Archana , Son Moeun
Published: November 2021

Objective To examine whether the duration of time from initiation of general endotracheal anesthesia (GETA) to delivery for cesarean deliveries (CDs) performed is related to perinatal outcomes.

Study Design This is a retrospective study of patients with singleton nonanomalous gestations undergoing CD ≥37 weeks of gestation under GETA with reassuring fetal status at a single tertiary care center from 2000 to 2016. Duration from GETA initiation until delivery was calculated as the time interval from GETA induction to delivery (I-D), categorized into tertiles. Outcomes for those in the tertile with the shortest I-D were compared with those in the other two tertiles. The primary perinatal outcome was a composite of complications (continuous positive airway pressure or high-flow nasal cannula for ≥2 consecutive hours, inspired oxygen ≥30% for ≥4 consecutive hours, mechanical ventilation, stillbirth, or neonatal death ≤72 hours after birth). Secondary outcomes were 5-minute Apgar score <7 and a composite of maternal morbidity (bladder injury, bowel injury, and extension of hysterotomy). Bivariable and multivariable analyses were used to compare outcomes.

Results Two hundred eighteen maternal–perinatal dyads were analyzed. They were dichotomized based on I-D ≤4 minutes (those in the tertile with the shortest duration) or >4 minutes. Women with I-D >4 minutes were more likely to have prior abdominal surgery and less likely to have labored prior to CD. I-D >4 minutes was associated with significantly increased frequency of the primary perinatal outcome. This persisted after multivariable adjustment. In bivariable analysis, 5-minute Apgar <7 was more common in the group with I-D >4 minutes, but this did not persist in multivariable analysis. Frequency of maternal morbidity did not differ.

Conclusion When CD is performed at term using GETA without evidence of nonreassuring fetal status prior to delivery, I-D interval >4 minutes is associated with increased frequency of perinatal complications.

Key Points
Development of Sacral Ratio Percentile Card for Children: A Preliminary Report
Authors: Bahadir Kutay , Arikan-Ergun Bilgesu , Elhan Atilla Halil , Ergun Ergun , Aktug Tanju
Published: November 2021

Introduction Sacrospinal anomalies that may accompany anorectal malformations may cause fecal and urinary incontinence despite proper anomaly treatment. The sacral ratio has been suggested in the determination of both the prognosis in terms of incontinence and the need for further examination for sacrospinal anomalies. The normal and clinically decisive values of sacral ratio are given differently in publications. We aimed to determine the distribution of the sacral ratio in children under 12 months and to develop the sacral ratio percentile card that will enable one to give an age-independent parametric result in clinical evaluations.

Materials and Methods The files of patients under 1 year of age who had anteroposterior direct radiography including pelvis were reviewed retrospectively. Sacral ratio was studied for 360 patients, 30 patients per month. Percentile card was developed with LMS software and reference values were used as 1, 2, 3, 4, and 10%.

Results The lowest sacral ratio value was 0.514 and the highest value was 0.936. There was no statistical difference between the mean sacral ratio of the cases when they were classified on a monthly basis (p = 0.191). Low percentile values were found slightly different at first 4 months of age.

Conclusion Although the mean of sacral ratio does not change significantly during the first year of life, values that are considered pathological for patients are within different percentile limits depending on age. Instead of using sacral ratio with some clinically decisive values, we think that parametric evaluation with the help of the percentile card will increase its clinical value.
Raman scattering of plane-wave and twisted light off chiral molecular liquids
Authors: Büscher Florian , Müllner Silvia , Wulferding Dirk , Pashkevich Yu. G. , Gnezdilov V. , Peshkov A. A. , Surzhykov A. , Lemmens Peter
Published: November 2021

We present an experimental study of the quasi-elastic Raman scattering (QES) of plane-wave and twisted light by liquid crystals. Depending on their temperature, these crystals can exhibit isotropic, nematic and chiral nematic phases. The question is addressed of how the phase of a crystal and the state of incident light can affect the quasi–elastic energy spectra of the scattered radiation, whose shape is usually described by the combination of Lorentzian and Gaussian components. Special attention is paid to the chiral phase, for which the Raman QES spectrum is dominated by a Lorentzian with reduced linewidth, pointing to diminished disorder and configurational entropy. Moreover, this phase is also known for a regime of iridescence (selective backscattering) which arises when the wavelength of incident light becomes comparable with the chiral pitch length. Detailed measurements, performed in this resonant regime and by employing twisted light, carrying various projections of the orbital angular momentum (OAM), have indicated a low-energy scattering surplus depending on OAM. We argue that this observation might indicate a transfer of angular momentum between light and liquid crystal.
Robustness of the chiral-icosahedral golden shell I-Au60 in multi-shell structures
Authors: Mullins S. M. , Whetten R. L. , Weissker H.-Ch. , López-Lozano X.
Published: November 2021

Motivated by the recent theoretical discovery [S.-M. Mullins et al., Nat. Commun. 9, 3352 (2018)] of a surprisingly contracted 60-atom hollow shell of chiral-icosahedral symmetry (I-Au60) of remarkable rigidity and electronegativity, we have explored, via first-principles density functional theory calculations, its physico-chemical interactions with internal and external shells, enabling conclusions regarding its robustness and identifying composite forms in which an identifiable I-Au60 structure may be realized as a product of natural or laboratory processes. The dimensions and rigidity of I-Au60 suggest a templating approach; e.g., an Ih-C60 fullerene fits nicely within its interior, as a nested cage. In this work, we have focused on its susceptibility, i.e., the extent to which the unique structural and electronic properties of I-Au60 are modified by incorporation into selected multi-shell structures. Our results confirm that the I-Au60 shell is robustly maintained and protected in various bilayer structures: Ih-C60@I-Au60, Ih-Au32@I-Au602+, Au60(MgCp)12, and their silver analogs. A detailed analysis of the structural and electronic properties of the selected I-Au60 shell-based nanostructures is presented. We found that the I-Au60 shell structure is quite well retained in several robust forms. In all cases, the I-symmetry is preserved, and the I-Au60 shell is slightly deformed only in the case of the Ih-C60@I-Au60 system. This analysis serves to stimulate and provide guidance toward the identification and isolation of various I-Au60 shell-based nanostructures, with much potential for future applications. We conclude with a critical comparative discussion of these systems and of the implications for continuing theoretical and experimental investigations.
Assessing and rationalizing the performance of Hessian update schemes for reaction path Hamiltonian rate calculations
Authors: Chantreau Majerus R. , Robertson C. , Habershon S.
Published: November 2021

The reaction path Hamiltonian (RPH) can be used to calculate chemical reaction rate constants, going beyond transition-state theory in taking account of recrossing by providing an approximation to the dynamic transmission coefficient. However, the RPH necessitates the calculation of the Hessian matrix at a number of points along the minimum energy path; the associated computational cost stands as a bottleneck in RPH calculations, especially if one is interested in using high-accuracy electronic structure methods. In this work, four different Hessian update schemes (symmetric rank-1, Powell-symmetric Broyden, Bofill, and TS-BFGS updates) are assessed to see whether or not they reliably reproduce calculated transmission coefficients for three different chemical reactions. Based on the reactions investigated, the symmetric rank-1 Hessian update was the least appropriate for RPH construction, giving different transmission coefficients from the standard analytical Hessian approach, as well as inconsistent frequencies and coupling properties. The Bofill scheme, the Powell-symmetric Broyden scheme, and the TS-BFGS scheme were the most reliable Hessian update methods, with transmission coefficients that were in good agreement with those calculated by the standard RPH calculations. The relative accuracy of the different Hessian update schemes is further rationalized by investigating the approximated Coriolis and curvature coupling terms along the reaction-path, providing insight into when these schemes would be expected to work well. Furthermore, the associated computational cost associated with the RPH calculations was substantially reduced by the tested update schemes. Together, these results provide useful rules-of-thumb for using Hessian update schemes in RPH simulations.
Transverse magnetic modes of localized spoof surface plasmons
Authors: Li Si-Qi , Du Chao-Hai , Han Feng-Yuan , Wang Yi-Dong , Gao Zi-Chao , Tan Yun-Hua , Liu Pu-Kun
Published: November 2021

Electric and magnetic modes establish the basis of the localized spoof surface plasmons (LSSPs), both of which are transverse electric (TE) modes. In this paper, the concept of transverse magnetic (TM) modes of LSSPs is proposed, and the double-layer planar-circular-grating resonator is demonstrated to support the TM modes in addition to the TE modes. In numerical simulations, the TE and TM modes were excited by a plane wave and an aperture, respectively, and their resonant frequencies and electromagnetic field distributions were demonstrated to be different. The electric field of the TE mode is parallel to the grating, while the magnetic field of the TM mode is parallel to the grating. In experiments, multiple TE and TM LSSPs modes were excited by a magnetic coupler. The magnetic coupler can be rotated to distinguish the TM modes from the TE ones, which provides conclusive evidence of the existence of the TM modes. Compared with the TE LSSPs modes, the TM LSSPs modes have the advantages of high sensitivity to the distance between layers and high quality factors (Q-factors), which hold promise for providing improvements on compact applications of LSSPs. Based on the proposed concept, therefore, the classification standard of the LSSPs is expanded to make it more scientific and comprehensive.
The role of hydrophobic hydration in the free energy of chemical reactions at the gold/water interface: Size and position effects
Authors: Serva Alessandra , Havenith Martina , Pezzotti Simone
Published: November 2021

Metal/water interfaces catalyze a large variety of chemical reactions, which often involve small hydrophobic molecules. In the present theoretical study, we show that hydrophobic hydration at the Au(100)/water interface actively contributes to the reaction free energy by up to several hundreds of meV. This occurs either in adsorption/desorption reaction steps, where the vertical distance from the surface changes in going from reactants to products, or in addition and elimination reaction steps, where two small reactants merge into a larger product and vice versa. We find that size and position effects cannot be captured by treating them as independent variables. Instead, their simultaneous evaluation allows us to map the important contributions, and we provide examples of their combinations for which interfacial reactions can be either favored or disfavored. By taking a N2 and a CO2 reduction pathway as test cases, we show that explicitly considering hydrophobic effects is important for the selectivity and rate of these relevant interfacial processes.
Microscopic characterization of fatty liver-based emulsions: Bridging microstructure and texture in foie gras and pâté
Authors: Via Matias A. , Baechle Mathias , Stephan Alexander , Vilgis Thomas A. , Clausen Mathias P.
Published: November 2021

An analysis of food materials often involves characterization of the molecular composition of the food matrix and measuring its mechanical properties. However, there is a gap in understanding how food materials organize at the microscopic level. This article shows the application of minimally invasive coherent anti-Stokes Raman scattering (CARS) microscopy to visualize the fat distribution in duck liver-based products. Further, in combination with quantitative image analysis, CARS provides a viable route for understanding how food texture is related to food microstructure. Strong correlations were found between microscopic structural descriptors of the fat particle (abundance, shape, and size) and rheological and textural parameters (hardness, storage modulus). Foie gras was found to have an irregular shaped fat network connected via relatively weak links that yield under stress correlating with foie gras being harder, more elastic, and more brittle in comparison with a homemade duck liver pâté. In turn, the higher total number of fat particles, more round and smooth in shape, found in the pâté was responsible for it being softer and less prone to fracture. Understanding the relation between molecular composition, microscopic structure, and macroscopic texture provides opportunities for future modification of pâté formulation and/or a new preparation technique using microstructure as a texture indicator.
Tunable topological valley Hall edge state based on large optical Kerr effect
Authors: Guo Kai , Xue Qingsong , Chen Fujia , Zhou Keya , Liu Shutian , Guo Zhongyi
Published: November 2021

Most of the photonic valley-Hall edge states were constructed by changing structures to break the spatial inversion symmetry, restricting the practical application potential. In this paper, we construct a tunable topological valley-Hall edge state based on the large optical Kerr effect. It is demonstrated that topological phase transition happens by engineering the intensity of the injected pump and that a valley-Hall edge state can be generated at the interface between two regions with different topological properties. In addition, eigenfrequency and transmission characteristics of the edge state as a function of applied pump intensity are investigated. The topological protected valley-dependent transmission is studied under non-uniform distributed pump intensity. This work may open a new path toward designing reconfigurable all-optical metadevices.
Dynamics of droplet impacting on a cone
Authors: Luo Jia , Chu Fuqiang , Ni Zhongyuan , Zhang Jun , Wen Dongsheng
Published: November 2021

Droplet rebound dynamics on superhydrophobic surfaces has attracted much attention due to its importance in numerous technical applications, such as anti-icing and fluid transportation. It has been demonstrated that changing the macro-structure of the superhydrophobic surface could result in significant change in droplet morphology and hydrodynamics. Here, we conduct both experimental and numerical studies of droplet impacting on a cone and identify three different dynamic phases by changing the impacting conditions, i.e., the Weber number and the cone angle. The spreading and retracting dynamics are studied for each phase. Particularly, it is found that in phase 3, where the droplet leaves the surface as a ring, the contact time is reduced by 54% compared with that of a flat surface. A theoretical model based on energy analysis is developed to get the rebound point in phase 3, which agrees well with the simulation result. Besides, the effect of Weber number and cone angle on the contact time is explored. Finally, the phase diagram of the three phases distribution with We and cone angle is given, which can provide guidance to related applications.
Open quantum dynamics theory for a complex subenvironment system with a quantum thermostat: Application to a spin heat bath
Authors: Nakamura Kiyoto , Tanimura Yoshitaka
Published: November 2021

Complex environments, such as molecular matrices and biological material, play a fundamental role in many important dynamic processes in condensed phases. Because it is extremely difficult to conduct full quantum dynamics simulations on such environments due to their many degrees of freedom, here, we treat in detail the environment only around the main system of interest (the subenvironment), while the other degrees of freedom needed to maintain the equilibrium temperature are described by a simple harmonic bath, which we call a quantum thermostat. The noise generated by the subenvironment is spatially non-local and non-Gaussian and cannot be characterized by the fluctuation–dissipation theorem. We describe this model by simulating the dynamics of a two-level system (TLS) that interacts with a subenvironment consisting of a one-dimensional XXZ spin chain. The hierarchical Schrödinger equations of motion are employed to describe the quantum thermostat, allowing for time-irreversible simulations of the dynamics at arbitrary temperature. To see the effects of a quantum phase transition of the subenvironment, we investigate the decoherence and relaxation processes of the TLS at zero and finite temperatures for various values of the spin anisotropy. We observed the decoherence of the TLS at finite temperature even when the anisotropy of the XXZ model is enormous. We also found that the population-relaxation dynamics of the TLS changed in a complex manner with the change in the anisotropy and the ferromagnetic or antiferromagnetic orders of spins.
Characteristic gas cavity patterns formed with gas injection into horizontally co-flowing water
Authors: Kang Can , Mao Ning , Ding Kejin , Li Changjiang
Published: November 2021

The present study aims to reveal two-phase flow characteristics as gas is injected into co-flowing water. A computational fluid dynamics work was conducted using the volume of fluid model and the delayed detached eddy simulation. The numerical scheme was validated through experimental results. Effects of the upstream water velocity and the gas injection rate on flow patterns were investigated. Characteristics of gas cavities were compared under different operating conditions. In both experimental and numerical results, unique patterns of gas cavities are obtained. A large cavity is attached to the nozzle outlet, and simultaneously, bubbles are shed from the cavity front. With increasing gas injection rate, the attached cavity is pinched off as it extends in a streamwise direction. As the velocity of water increases, scattered pinch-off frequencies are evidenced and cavity instability is enhanced. Liquid wake downstream of the nozzle contributes significantly to the collapse of the gas cavity. A long and stable gas cavity is produced at high upstream water velocities and gas injection rates.
Electromagnetically induced transparency under phase modulation of interacting radiations
Authors: Parshkov O.M.
Published: November 2021

We report the results of an analytical and numerical analysis of the evolution of nanosecond probe pulses in the case of electromagnetically induced transparency in the Λ-scheme of degenerate quantum transitions. It is assumed that the probe and control fields at the active medium input are elliptically polarised, and one of them is phase modulated. It is shown analytically that probe radiation in a medium is the sum of two normal modes propagating independently of each other. Because the group velocities of normal mode pulses are different, a single probe pulse entering the medium decays inside the medium into separate pulses, each of which transfers the energy of one of the normal modes. Numerical simulations have shown that with a sufficiently large phase modulation, normal modes, whose intensity on the input surface is described by a bell-shaped curve, turn into trains of subpulses in the medium. Phase modulation of the input field has practically no effect on the group propagation velocities of normal modes, but it reduces the transparency of the medium for probe radiation.
Application of complex fully connected neural networks to compensate for nonlinearity in fibre-optic communication lines with polarisation division multiplexing
Authors: Bogdanov S.A. , Sidelnikov O.S. , Redyuk A.A.
Published: November 2021

A scheme is proposed to compensate for nonlinear distortions in extended fibre-optic communication lines with polarisation division multiplexing, based on fully connected neural networks with complex-valued arithmetic. The activation function of the developed scheme makes it possible to take into account the nonlinear interaction of signals from different polarisation components. This scheme is compared with a linear one and a neural network that processes signals of different polarisations independently, and the superiority of the proposed neural network architecture is demonstrated.
Reflectogram shape deformation in distributed fibre systems in the presence of spontaneous noise in the probe radiation
Authors: Kalmykov N.I. , Kovalenko D.A. , Lobach I.A. , Kablukov S.I.
Published: November 2021

We report a study of the effect of spontaneous emission-induced noise in probe pulsed radiation on the reflectogram shape deformation in a distributed temperature sensor based on Raman scattering of light. Since the fraction of spontaneous emission in the used erbiumdoped amplifier can reach 50 % of the total power, this leads to deviations of reflectograms in the temperature sensor from the theoretical exponential dependence and, as a result, can yield a temperature measurement error of several degrees. Filtering the radiation with an amplitude modulator makes it possible to reduce these deviations. The influence of spontaneous emission on reflectograms is studied theoretically and experimentally.
Mid-IR supercontinuum generation initiated by two-cascade stimulated Raman scattering in D2-filled revolver fibre
Authors: Yatsenko Yu.P. , Gladyshev A.V. , Bufetov I.A.
Published: November 2021

We report a numerical study of coherent mid-IR supercontinuum generation at wavelengths above 2.4 μm, initiated by two-cascade stimulated Raman scattering in a deuterium-filled revolver fibre pumped by positively chirped picosecond pulses at a wavelength of 1.03 μm. It is shown that the highest efficiency of conversion to the second Stokes is ensured by fibre lengths at which the spectrum is strongly broadened by Kerr nonlinear effects. A range of optimal parameters (deuterium pressure, fibre length, pulse energy, and pulse duration) is found that ensure quantum efficiency at a level of 50 % and a mid-IR supercontinuum width above 1000 nm. The coherence properties of the supercontinuum are shown to be determined by the pulse duration, the magnitude of the pulse chirp, and dispersion characteristics in each transmission band of the fibre. We demonstrate the feasibility of generating a single compressed mid-IR pulse of 20-fs duration with an energy of 1.9 μJ.
All-glass single-mode microstructured optical fibres with a large-diameter core and low bending losses
Authors: Denisov A.N. , Semjonov S.L.
Published: November 2021

All-glass microstructured optical fibres (MOFs) with a core 20 μm in diameter and two rings of circular fluorine-doped silica glass elements with a reduced refractive index, different diameters, and different distances between them are theoretically studied. The properties of these MOFs are numerically analysed using the finite element method. The leakage losses for the fundamental and higher-order modes in the spectral range 0.75−1.65 μm are calculated for straight and bent MOFs. It is shown that the considered MOF design allows single-mode operation in the range 0.98−1.26 μm at a bending radius of down to 0.08 m, the leakage losses for the bent MOF at a wavelength of 1.05 μm being 0.046 dB m−1.