bluuebunny/crossref_metadata_2025 huggingface dataset:
HII galaxies as standard candles: Evolutionary corrections
Authors: Melnick Jorge , Telles Eduardo
Published: August 2024

Over the past decade, the relation between the Balmer-line luminosity of HII galaxies and the velocity width of the emission lines, the L − σ relation, has been painstakingly calibrated as a cosmological distance indicator with seemingly spectacular results: the Hubble constant and the energy density of dark energy obtained using the L − σ indicator agree remarkably well with the values from canonical indicators. Since most of the luminosity of these young compact starburst galaxies is emitted by a few narrow emission lines, they can be observed with good precision up to redshifts of z ∼ 7 with JWST, making the L − σ indicator a potentially unique cosmological probe. However, the precision of the method remains too low to effectively constrain the relevant cosmological parameters, notably the equation of state of dark energy. The scatter of the L − σ relation is significantly larger than the random observational errors, so we do not have a good handle on the systematics of the method. In a previous paper, we posited that since the ionizing radiation of these young galaxies fades rapidly over timescales of only a few million years, age differences could be the main underlying cause of the scatter. In this paper, we explore several different ways of explaining the scatter of the correlation, but without success. We show that the majority of HII galaxies are powered by multiple starbursts of slightly different ages, and therefore that the equivalent widths are not reliable chronometers to correct the luminosities for evolution. Thus, it is not likely that the accuracy of the L − σ distance indicator can be improved in the near future. Since we do not fully understand either the systematics or the underlying physics of the L − σ relation, using large samples of distant HII galaxies may or may not improve the accuracy of the method.
Debatte zu kontrolliertem Trinken: Was wir über kontrolliertes und
reduziertes Trinken wissen und was nicht
Authors: Bischof Gallus
Published: August 2024

Kontrolliertes Trinken (KT) ist und war ein kontroverses Behandlungsziel in der
Behandlung von Alkoholkonsumstörungen. Angesichts der unzureichenden
Erreichbarkeit betroffener Menschen durch das Suchthilfesystem positionierte
sich der Dachverband der Deutschen Suchtfachgesellschaften 2019 dahingehend,
dass KT eine relevante Therapieoption darstellen könnte. Der vorliegende Beitrag
gibt vor dem Hintergrund des Positionspapiers der Dachgesellschaft einen
Überblick zum gegenwärtigen Wissensstand hinsichtlich Möglichkeiten und Grenzen
von KT in der Behandlung von Alkoholkonsumstörungen und diskutiert bedeutsame
Wissensdefizite in dem Feld.
PEth: internationale Grenzwerte, neue Ansätze und deren Relevanz in
der Praxis
Authors: Luginbühl Marc , Stöth Frederike
Published: August 2024

Der Nachweis und die Klassifizierung des Alkoholkonsums spielen eine
entscheidende Rolle in verschiedenen gesellschaftlichen Bereichen, sei es im
Straßenverkehr, im Gesundheitswesen oder am Arbeitsplatz. Die Verwendung von
Alkoholbiomarkern ermöglicht eine objektive Beurteilung der Trinkgewohnheiten
sowohl im klinischen als auch im forensischen Bereich. Neben etablierten
Biomarkern wie Ethylglukuronid (EtG) oder Carbohydrat-defizientes Transferrin
(CDT) gewinnt Phosphatidylethanol (PEth) als direkter Alkoholbiomarker zunehmend
an Bedeutung. PEth wird nur gebildet, wenn Alkohol im Körper vorhanden ist und
liefert als Bestandteil der zellulären Fraktion des Blutes Informationen über
das Konsumverhalten. Für die Interpretation wird derzeit hauptsächlich das in
menschlichem Blut am stärksten vertretene PEth 16:0/18:1 verwendet und
üblicherweise auf Basis von zwei Grenzwerten interpretiert. Diese Grenzwerte
erlauben eine Einteilung in: 1.) Abstinenz/minimalen Alkoholkonsum, 2.)
Alkoholkonsum und 3.) exzessiven, chronischen Alkoholkonsum. In diesem Artikel
werden die derzeitigen Grenzwerte für die Interpretation von
PEth-Konzentrationen diskutiert und weitere Bemühungen zur Überprüfung und
Gewährleistung der Vergleichbarkeit zwischen verschiedenen Laboren vorgestellt.
Darüber hinaus werden aktuelle und neue Ansätze im Bereich der PEth-Forschung
präsentiert. Dazu gehören neue Entwicklungen für die Normalisierung des
Hämatokrits bei der Messung von PEth, die Verwendung von Point-of-care-testing
(POCT) Geräten zur Messung von PEth am Ort der Blutentnahme, der Nachweis von
PEth in Speichel und Wangenabstrichen, die Verwendung von Immunoassays, sowie
das Potential des neu entdeckten Biomarkers Lyso-PEth. Es bleibt abzuwarten, wie
sich diese neuen Ansätze entwickeln und möglicherweise die Überwachung des
Alkoholkonsums und die Diagnose von Alkoholkonsumstörungen in Zukunft verändern
oder verbessern können. Grundsätzlich besteht noch großes Potenzial für
Fortschritte in Richtung höherer Sensitivität, Spezifität und der Anwendbarkeit
in verschiedenen klinischen Kontexten.
Hodentumor – welche Vorteile bringt der neue Tumormarker microRNA-371a-3p (M371-Test)
Authors: Dieckmann Klaus-Peter , Belge Gazanfer
Published: August 2024

Der Keimzelltumor des Hodens ist ein Musterbeispiel für die Verwendung von Serum-Tumormarkern. Das Dilemma ist, dass die aktuellen Marker beta Human Chorion Gonadotropin (bHCG) und Alpha Fetoprotein (AFP) sowie Laktatdehydrogenase (LDH) nur etwa bei 50% aller Keimzelltumoren erhöht sind. Im Jahre 2011 wurde erstmals die microRNA-371a-3p (M371) als neuer Tumormarker vorgeschlagen. MicroRNAs sind kleine RNA-Fragmente von 18–24 Basenpaaren, die eine epigenetische Bedeutung bei der Steuerung der Proteinbiosynthese haben. Die M371 kann im Serum mit PCR-Technik gemessen werden.

Mit einem hohen Maß an formaler Evidenz konnte gezeigt werden, dass M371 eine Sensitivität von etwa 90% und eine Spezifität von über 90% für Keimzelltumoren des Hodens aufweist. Die M371 ist dabei für Seminome und Nichtseminome gleichermaßen sensitiv und spezifisch. Allerdings exprimieren Teratome den Marker nicht, wie auch nichtgerminale Hodentumoren und Karzinome anderer Organe. Der Marker weist eine sehr kurze Halbwertszeit von <24 Stunden auf.

In naher Zukunft darf erwartet werden, dass der Test substanzielle Hilfe geben wird bei vielen klinischen Entscheidungssituationen, die bisher nur unbefriedigend zu lösen waren. Dies dürfte vor allem für die folgenden sechs Szenarien zutreffen: (1) Abklärung eines zufällig entdeckten kleinen Hodentumors mit Weichenstellung in Richtung organerhaltender Exzision versus Ablatio testis; (2) Vereinfachung der Nachsorge von Hodentumoren durch Reduktion der Bildgebung; (3) Einschätzung unklarer Lymphknotenvergrößerungen im Rahmen des klinischen Stagings; (4) Abklärung von unklaren (falsch positiven) Erhöhungen der klassischen Tumormarker; (5) rasche Beurteilung des Ansprechens auf Therapie aufgrund der kurzen Halbwertszeit; (6) Hilfe bei der Entscheidungsfindung für die Behandlung von Residualtumoren nach Chemotherapie, insbesondere bei Resttumoren des Seminoms.

Die Entdeckung und Entwicklung des Tumormarkers M371 stellt einen Meilenstein dar bei der Ausformung pragmatischer Therapiekonzepte für Keimzelltumoren.
Effectiveness of Risk Analysis Index Frailty Scores as a Predictor of Adverse Outcomes in Lower Extremity Reconstruction
Authors: Swiekatowski Kylie R. , Barrera Jose E. , Hopkins David , Manisundaram Arvind D. , Bhadkamkar Mohin A. , Wu-Fienberg Yuewei
Published: August 2024

Background The rising clinical importance of assessing frailty is driven by its predictive capability for postoperative outcomes. This study assesses the effectiveness of RAI-rev (Revised Risk Analysis Index) in predicting adverse outcomes in lower extremity (LE) flap reconstruction.

Methods Analyzing NSQIP (National Surgical Quality Improvement Program) data from 2015 to 2020, we compared demographics, perioperative factors, and 30-day outcomes in all locoregional and free-flap cases. Frailty scores, calculated using RAI-rev, were categorized with <15 as nonfrail and >35 as the most frail. Adjusted odds ratios (aORs) for specific complications were calculated using nonfrail as the reference group. Frailty scores in locoregional flaps were compared with those in free flaps.

Results We identified 270 locoregional and 107 free-flap cases. Higher RAI-rev scores in locoregional flaps correlated with increased complications, such as deep surgical site infection (1% nonfrail vs. 20% RAI 31–35), stroke (0% nonfrail vs. 17% most frail), and mortality (0% nonfrail vs. 17% most frail). Locoregional flap cases with RAI-rev scores in the most frail group had a significantly elevated aOR for stroke (51.0, 95% confidence interval [CI]: 1.8–1402.5, p = 0.02), mortality (43.1, 95% CI: 1.6–1167.6, p = 0.03), and any complication (6.8, 95% CI: 1.2–37.4, p = 0.03). In free-flap cases, higher RAI-rev scores were associated with increased complications, with only sepsis showing a statistically significant difference (6% nonfrail vs. 100% most frail; aOR: 42.3, CI: 1.45–1245.3, p = 0.03). Free-flap cases had a significantly lower RAI-rev score compared with locoregional flap cases (14.91 vs. 17.64, p = 0.01).

Conclusion Elevated RAI-rev scores (>35) correlated with more complications in locoregional flaps, while free-flap reconstruction patients had generally low RAI-rev scores. This suggests that free flaps are less commonly recommended for presumed higher risk patients. The study demonstrates that RAI-rev may be able to serve as a risk calculator in LE reconstruction, aiding in the assessment of candidates for limb salvage versus amputation.
Final Analysis Results from the AGEHA Study: Emicizumab Prophylaxis for Acquired Hemophilia A with or without Immunosuppressive Therapy
Authors: Shima Midori , Suzuki Nobuaki , Nishikii Hidekazu , Amano Kagehiro , Ogawa Yoshiyuki , Kobayashi Ryota , Ozaki Ryoto , Yoneyama Koichiro , Mizuno Narumi , Sakaida Emiko , Saito Makoto , Okamura Takashi , Ito Toshihiro , Hattori Norimichi , Higasa Satoshi , Seki Yoshinobu , Nogami Keiji
Published: August 2024

Background Primary analysis of the phase III AGEHA study suggested a favorable benefit–risk profile for emicizumab prophylaxis in patients with acquired hemophilia A (PwAHA); however, only patients undergoing immunosuppressive therapy (IST; Cohort 1) were included.

Objectives To present final analysis results of AGEHA, including data on IST-ineligible patients (Cohort 2) and on long-term prophylaxis with emicizumab.

Methods For patients in both Cohorts 1 and 2, emicizumab was administered subcutaneously at 6 mg/kg on Day 1, 3 mg/kg on Day 2, and 1.5 mg/kg once weekly from Day 8 onward.

Results Twelve patients (Cohort 1) and two patients (Cohort 2) were enrolled. Duration of emicizumab treatment was 8 to 639 days (median: 44.5 days) in Cohort 1 and 64 and 450 days in Cohort 2. In both cohorts, no major bleeds were observed after initial emicizumab administration. Six patients started their first rehabilitation sessions during emicizumab treatment and no rehabilitation-related bleeds occurred. Twenty-three surgeries were performed under emicizumab prophylaxis and there were no bleeds related to surgeries. Although asymptomatic deep vein thrombosis was reported in one patient in the primary analysis, no other thrombotic events occurred thereafter. Two patients developed anti-emicizumab antibodies, one of whom showed accelerated emicizumab clearance. Tailored IST approaches (delayed initiation, no use, or reduced dose) were successfully executed in three patients undergoing emicizumab prophylaxis.

Conclusion These results suggest that emicizumab prophylaxis has a favorable benefit–risk profile in PwAHA regardless of eligibility for IST.
Fallopian tube catheterization under 3D vaginal ultrasound guidance followed by highly selective hysterosalpingo-foam sonography: an outpatient procedure
Authors: Melcer Yaakov , Pekar-Zlotin Marina , YOUNGSTER Michal , Gat Itai , Maymon Ron
Published: August 2024

To describe the feasibility of our preliminary outpatient fallopian tube catheterization procedure under 3D vaginal ultrasound (US) guidance followed by highly selective hysterosalpingo-foam sonography (HyFoSy) in infertile women diagnosed with proximal tubal obstruction.

A prospective trial was conducted from October 2022 to December 2023. 3D vaginal US was used to establish the precise location of the tip of the selective salpingography catheter at the tubal ostium. A roadrunner was used to cannulate the occluded portion of the fallopian tube. After tubal cannulation, ExEm foam was injected under direct US guidance to confirm tubal recanalization and its passage through the fallopian tubes.

During the study period, a total of 14 women with proximal tubal occlusion underwent this procedure. Tubal patency was achieved in 92.8% of cases. No immediate and remote complications were observed. To date, 3 (21.4%) of the patients conceived after tubal catheterization and 1 had a live birth.

Outpatient fallopian tube catheterization under 3D vaginal US guidance, followed by selective HyFoSy, can be successfully implemented for the diagnosis and treatment of patients with proximal tubal occlusion. The 3D modality allows volume capture of the required acquisition and subsequent post-imaging analysis, thus permitting further examination and study. Additional experience is needed to determine the feasibility of this innovative procedure and to identify the patient subgroups that would benefit the most from this approach.
Design and Synthesis of Out/Out, Out/In, and In/In Epoxides in Polycyclic Cage Frameworks
Authors: Kotha Sambasivarao , Salman Mohammad
Published: August 2024

We report a useful synthetic approach to assemble in/in epoxide, in/out epoxide, and out/out epoxide in cage systems using the Corey–Chaykovsky reaction and the Peterson olefination as key steps. In this regard, a variety of pentacycloundecane (PCUD) based cage compounds containing oxirane rings with diverse stereochemical disposition were synthesized via a simple synthetic sequence. Five cage diones were used for this purpose, and the starting cage diones were prepared with easily accessible starting materials such as 1,4-hydroquinone derivatives and cyclopentadiene. Here, we have used the Diels–Alder (DA) reaction, a [2+2] photocycloaddition, the Corey–Chaykovsky reaction, and the Peterson olefination as crucial steps to prepare the target molecules.
Nickel-Catalyzed O-Methylation of Cinnamic Acid Using DMSO as Methyl Surrogate
Authors: Phukan Prodeep , Talukdar Hrishikesh
Published: August 2024

A new method for the O-methylation of cinnamic acid employing DMSO as the methylating agent has been devised, employing a Ni-DMAP complex as catalyst along with Ag2O and dimethylamine as additives. This protocol demonstrates broad substrate compatibility and good tolerance towards various functional groups. The key advantages of this approach include the utilization of cost-effective catalysts, moderate to high yield of the products, and short reaction time.
Sequential Copper-Catalyzed Amidation and Hydroxylation for Acetaminophen Synthesis
Authors: Yoo Dongwon , Kim Young Gyu , Seo Youngran
Published: August 2024

A sequential Cu-catalyzed amidation and hydroxylation of p-dihalobenzenes is applied to synthesize acetaminophen. This method allows the direct introduction of acetamido and hydroxy groups under acid-free conditions without forming other regioisomers. By using a one-pot process, acetaminophen can be prepared with an overall yield of up to 74%.
Synthesis of Phosphorodiamidate Morpholino Oligonucleotides (PMOs) Using Staudinger Reduction as a Deblocking Condition and Its Usefulness for Orthogonal Conjugation in Bi- and Trifunctionalized PMOs
Authors: Sinha Surajit , Pratihar Subhamoy , Qasim Md
Published: August 2024

The synthesis of short phosphorodiamidate morpholino oligonucleotides (PMOs) has been successfully achieved using azidoaryl carbamate protected chlorophosphoramidate monomers. The deprotection step carried out in a neutral medium with triphenylphosphine-based reagents avoids the need for chlorinated solvents. This method uses a meticulously tailored combination of resin support, solvents, deblocking agents, and coupling reagents to ensure efficient synthesis. Additionally, the azidoaryl carbamate protecting group has been adapted as an orthogonal protection, enabling the development of bi- and trifunctionalized PMOs for bioconjugation. These advancements are expected to broaden the potential applications of PMOs in biomedical research.
Impella 5.5 Support for Delayed Surgical Ventricular Septal Defect Repair—A Paradigm Shift?
Authors: Eghbalzadeh Kaveh , Großmann Clara , Krasivskyi Ihor , Djordjevic Ilija , Kuhn Elmar W. , Origel Romero Christian , Bakhtiary Farhad , Mader Navid , Deppe Antje Christin , Wahlers Thorsten C. W.
Published: August 2024

Background Ventricular septal defects (VSDs) remain a rare but life-threatening complication of myocardial infarction. Although the incidence has decreased due to better treatment options, the mortality rate remains high. The timing of VSD repair remains critical to outcome. The use of mechanical circulatory support is rarely described in the literature, although it may help to delay repair to allow tissue stabilization. While Impella is currently considered contraindicated due to the potential worsening of the right-to-left shunt and possible systemic embolization of necrotic debris, there is no comprehensive evidence for this. Therefore, we aimed to analyze whether the use of Impella 5.5 as a first choice for patients undergoing VSD repair should be considered for discussion.

Methods This retrospective study analyses four consecutive patients who underwent delayed ventricular septal repair after prior implantation of Impella 5.5 (Abiomed Inc., Danvers, Massachusetts, United States).

Results A total of 75% of patients (n = 3) presented with acute right heart failure prior to implantation with a mean systolic pulmonary artery pressure of 64 ± 3.0 mmHg. Implantation was performed under local anesthesia in three cases. The mean time to surgery was 9.8 ± 3.1 days. All patients remained on the Impella 5.5 device postoperatively. Weaning from Impella 5.5 was successful in 75% (n = 3). The mean length of stay in the intensive care unit was 22.3 ± 7.5 days.

Conclusion Preoperative implantation of the Impella 5.5 device is a safe and feasible option for patients undergoing VSD repair. Outcomes may be improved by performing Impella implantation under local anesthesia and continuing Impella support after VSD repair. However, it is important to note that these patients represent a high-risk cohort and the mortality rate remains high.
A choice architect’s guide to the (autonomous) galaxy: a systematic scoping review of nudge intrusiveness in food choices
Authors: Lemken Dominic , Erhard Ainslee , Wahnschafft Simone
Published: August 2024

In seeking to uphold consumer autonomy in the design and implementation of nudge interventions, choice architects must concern themselves with preserving both the availability of options made to consumers (freedom of choice), and the capacity of consumers to deliberate and choose (agency) Several studies aim to examine the extent to which nudges truly uphold autonomy; however, most examine self-reported perceived intrusiveness on autonomy, rather than considering autonomy from the perspective of how nudges are designed. Leveraging a systematic scoping review of nudges related to food choice (N = 146), a common policy arena for nudge interventions, we develop a typology of three mechanisms of nudge design that, when not considered, could unduly intrude upon autonomy: (1) the effort to opt out, delineated along economic and physical sub-dimensions; (2) affective influence, such as social reference messaging and emotional appeals; and (3) non-transparency, including of the nudge itself and of non-nudged alternative options. We discuss how each mechanism manifested in reviewed studies, and ultimately offer possible criteria that can be used to evaluate nudge intrusiveness along each mechanism. This typology can support choice architects to discern how nudges might better protect consumer autonomy, and ultimately uphold it in pursuit of behavior change. Our scoping review further provides empirical support for the concept of resistible yet effective nudges.
Orbital stability of multi-peakons for a generalized Dullin–Gottwald–Holm equation
Authors: Wang Jiajing , Deng Tongjie , Zhang Kelei
Published: August 2024

In this paper, we consider a generalized Dullin–Gottwald–Holm equation. The equation admits single peakons and multi-peakons. Using energy argument and combining the method of the orbital stability of a single peakon with monotonicity of the local energy norm, we prove that the sum of N sufficiently decoupled peakons is orbitally stable in the energy space.
Ferroelectric AlBN films by molecular beam epitaxy
Authors: Savant Chandrashekhar , Gund Ved , Nomoto Kazuki , Maeda Takuya , Jadhav Shubham , Lee Joongwon , Ramesh Madhav , Kim Eungkyun , Nguyen Thai-Son , Chen Yu-Hsin , Casamento Joseph , Rana Farhan , Lal Amit , Xing Huili Grace , Jena Debdeep
Published: August 2024

We report the properties of molecular beam epitaxy deposited AlBN thin films on a recently developed epitaxial nitride metal electrode, Nb2N. While a control AlN thin film exhibits standard capacitive behavior, distinct ferroelectric switching is observed in the AlBN films with increasing Boron mole fraction. The measured remnant polarization Pr∼15μC/cm2 and coercive field Ec∼ 1.45 MV/cm in these films are smaller than those recently reported on films deposited by sputtering, due to incomplete wake-up, limited by current leakage. Because AlBN preserves the ultrawide energy bandgap of AlN compared to other nitride hi-K dielectrics and ferroelectrics, and it can be epitaxially integrated with GaN and AlN semiconductors, its development will enable several opportunities for unique electronic, photonic, and memory devices.
Partial discharge detection, diagnosis, and location technology based on a novel transient earth voltage-ultrasonic integrated sensor used for switchgear equipment
Authors: Han Xutao , Wang Haotian , Sun Yuan , Chen Huan , Meng Xuan , Zhou Yang , Zhang Xuanrui , Li Junhao
Published: August 2024

Medium-voltage (MV) switchgear and gas insulated switchgear (GIS) are essential components of power-grid systems. Their safe operation is crucial for the electricity consumption of users. However, insulation faults often occur during the operation of MV switchgear and GIS because of pollution, humidity, heat, mechanical shock, and other factors. Partial discharge (PD) measurements are the most effective indicator to prevent insulation failure. Transient earth voltage (TEV) and ultrasonic methods are the most popular PD measurement methods for switchgear. Currently, these two methods are used widely and independently. In this study, a novel TEV-ultrasonic integrated sensor is proposed based on the independent structure of the TEV and the ultrasonic sensor. The performance parameters of the proposed sensor were tested on test platforms. PD measurement experiments were conducted in a 10 kV switchgear and 220 kV GIS to analyze the performance of the integrated sensor. The results show that the sensor can simultaneously measure the TEV and ultrasonic signals in the same location. The integrated sensor can realize effective and sensitive detection, precise location, and accurate diagnosis of PD in the MV switchgear and GIS.
The role of interfacial Dzyaloshinskii–Moriya interaction in different heavy metal-based perpendicular magnetic systems and its application in spintronic devices
Authors: Wang Guo-Cai , Du Wei , Guo Lei , Su Hua , Tang Xiao-Li
Published: August 2024

The interfacial Dzyaloshinskii–Moriya interaction (DMI) acting as an essential source to stabilize spin textures in ferromagnetic ultrathin films has revealed its significant role in spin–orbit torque (SOT)-driven magnetic switching. Based on a convincing homochiral Néel domain wall model, the in-plane (IP) magnetic field associated with the DMI effect has been confirmed as an essential prerequisite for deterministic SOT-driven switching. Although the presence of the IP field is required, the impact of IP field magnitude combined with the DMI effect on SOT-driven switching in different heavy metals (HMs) has never been considered together. In this research, SOT-induced switching under various IP fields in Pt, W, or Ta/CoFeB/MgO systems has been studied. The results show that the critical threshold current IC is almost independent of the IP field in the Pt-based structure; however, it significantly decreases with an increase in the IP field in the W- and Ta-based systems. Combining the derived DMI field and the magnetic domain nucleation, it is concluded that the significant difference in DMI fields and the domains' nucleating positions are the main reasons for the above phenomenon. Exploiting the distinct dependent properties of IC on the IP field, a six resistance state multilevel storage and five programmable spin logic gates are proposed and realized. This study provides insight into the special ability of the SOT effect modulated by the DMI, and also expands an effective way to construct spin-based devices based on this unique spintronic effect.
Magneto-mechanical coupling in ferromagnetic shape memory alloys: Mechanical experimental investigation under magnetic field in NiMnGaCu alloy
Authors: Villa F. , Bassani E. , Passaretti F. , Tomasi C. , Villa E.
Published: August 2024

Ferromagnetic shape memory alloys attracted increasing interest as multicaloric materials for solid state refrigeration. The most effective field coupling is achieved through the combination of the magnetic and mechanical induction of thermoelastic martensitic transformation. In the present work, we present an experimental investigation on NiMnGaCu polycrystalline cast alloy, by means of an experimental setup for compression tests in isothermal conditions under a longitudinal magnetic field. The setup has been ad hoc designed and developed specifically for this purpose. In this way, we can measure the elastocaloric and magnetocaloric effect at the same time. Moreover, the evolution of the entropy changes ΔS and the functional caloric parameters vs the magnetic field is evaluated. The application of magnetic field seems to act like a supplementary mechanical longitudinal stress. These preliminary results are fundamental to achieve a comprehensive understanding and modeling of coupled multicaloric phenomena.
Ab initio prediction of phase stability of quaternary Mo1−xMxAlB (M = Cr, Fe, Mn, Nb, Sc, Ta, Ti, V, and W) MAB solid solutions
Authors: Samanta Bipasa , Dilanga Siriwardane Edirisuriya M. , Çakır Deniz
Published: August 2024

In this study, we explored the phase stability of quaternary Mo1−xMxAlB (M = Cr, Fe, Mn, Nb, Sc, Ta, Ti, V, and W) solid solutions by employing a cluster expansion method to generate structures with different concentrations of M atoms. Using the first-principles calculations based on density functional theory, we predicted that these compounds exhibit a preference for either fully random structures or phase-segregated (M-rich regions) phases against the competing phases. To evaluate the Gibbs free energy of Mo1−xMxAlB alloys, we investigated the impact of various entropy contributions, including configurational, electronic, and vibrational entropy. Our study revealed that configurational entropy plays an important role in stabilizing the random phases observed in Mo1−xMxAlB compounds, highlighting its importance in understanding the thermodynamic behavior of these alloys. However, the vibrational and electronic entropy changes with respect to competing phases can stabilize or destabilize Mo1−xMxAlB depending on their sign. Our results indicate that, while W is soluble across the entire range of mixing ratios, Sc and Ti are completely insoluble in any ratio. On the other hand, Cr, Ta, Nb, and V can be successfully incorporated into the MoAlB lattice at varying fractions at elevated temperatures. The size, valence electron concentration, and electronegativity differences between Mo and M can be utilized as descriptors to identify stable Mo1−xMxAlB compounds. We extensively examined the structural, dynamical stability, thermal conductivity, and mechanical properties of Mo1−xMxAlB compounds. We analyze their dependence on the choice of the M element incorporated in the alloy. Our findings can guide the design and engineering of these materials to tailor their properties to specific applications based on the choice of the M element.
Complex network analysis of a premixed swirling flame influenced by precessing vortex core
Authors: Ren Yongzhi , Wang Qiuxiao , Guan Yu , Xia Xi , Qi Fei
Published: August 2024

This work investigates the influences of precessing vortex cores (PVCs) on the coherent interactions in the transient flow and heat release fields of a weak premixed swirling flame, based on a 10-kHz simultaneous measurement of OH* chemiluminescence and stereoscopic particle image velocimetry together with the state-of-the-art vortical and heat release rate (HRR) network analyses. The PVC effect is studied by contrasting the lifted helical and attached symmetric states of a unique transitioning V-shaped flame, corresponding to an alternate quasi-periodic appearance and disappearance of PVC in the inner shear layer (ISL). The results suggest that the emergence of PVC significantly escalates the coherent oscillation in the ISL, leading to the break of the scale-free topology in the vortical network. However, the PVC also promotes coherence in the local HRR variation, resulting in improved connectivity in the positive HRR network and enhanced assortative mixing in the negative HRR network. Furthermore, the flame mode transition is also captured by the differences in the mean degree of the positive HRR network and the power-law fitting goodness of the negative HRR network, showing promises of complex network analysis in distinguishing the flame dynamical modes.
SOFI: Finding point group symmetries in atomic clusters as finding the set of degenerate solutions in a shape-matching problem
Authors: Gunde M. , Salles N. , Grisanti L. , Martin-Samos L. , Hemeryck A.
Published: August 2024

Point Group (PG) symmetries play a fundamental role in many aspects of theoretical chemistry and computational materials science. With the objective to automatize the search of PG symmetry operations of generic atomic clusters, we present a new algorithm called Symmetry Operation FInder (SOFI). SOFI addresses the problem of identifying PG symmetry by framing it as a degenerate shape-matching problem, where the multiple solutions correspond to distinct symmetry operations. The developed algorithm is compared against three other algorithms dedicated to PG identification on a large set of atomic clusters. The results, along with some illustrative use cases, showcase the effectiveness of SOFI. The SOFI algorithm is released as part of the iterative rotations and assignments library, accessible at https://github.com/mammasmias/IterativeRotationsAssignments.
Perspective: Entropy-stabilized oxide memristors
Authors: Chae Sieun , Yoo Sangmin , Kioupakis Emmanouil , Lu Wei D. , Heron John T.
Published: August 2024

A memristor array has emerged as a potential computing hardware for artificial intelligence (AI). It has an inherent memory effect that allows information storage in the form of easily programmable electrical conductance, making it suitable for efficient data processing without shuttling of data between the processor and memory. To realize its full potential for AI applications, fine-tuning of internal device dynamics is required to implement a network system that employs dynamic functions. Here, we provide a perspective on multicationic entropy-stabilized oxides as a widely tunable materials system for memristor applications. We highlight the potential for efficient data processing in machine learning tasks enabled by the implementation of “task specific” neural networks that derive from this material tunability.
Contributions of interfacial spin–orbit coupling to magnetic and spintronic properties in AuPt/ferromagnet bilayers
Authors: Yun Deok Hyun , Han Ki-Hyuk , Nah Young-Jun , Kim YongJin , Jang Seung-Hun , Kang Min-Gu , Shin Sang-Ho , Min Byoung-Chul , Koo Hyun Cheol , Ju Byeong-Kwon , Lee OukJae
Published: August 2024

We investigate the relationships between various magnetic and spintronic properties within AuPt/ferromagnet (FM) bilayers (FM = CoFe, CoFeB, Py, and Co). A linear correlation between the volume and surface magnetic anisotropies is identified, potentially influenced by the magnetoelastic effect. The FM thickness dependence of the magnetic damping indicates that spin-memory loss due to the interfacial spin–orbit coupling (ISOC) and spin pumping to the heavy-metal layer contribute little to the damping. Instead, a notable contribution from two magnon scattering to the damping is recognized in AuPt/(Co, CoFe, CoFeB) bilayers, possibly originating from a magnetic inhomogeneity due to the ISOC. In addition, in contrast to the magnetic damping, spin–orbit-torque efficiencies are unlikely related to the ISOC in AuPt/FM systems. This work offers valuable insights into the correlations among magnetic and spintronic parameters arising from the interfaces, ultimately aiding in the advancement of magnetic memory and information processing systems.
Structure-preserving and efficient numerical simulation for diffuse interface model of two-phase magnetohydrodynamics
Authors: Shi Kaiwen , Su Haiyan , Feng Xinlong
Published: August 2024

In this paper, we propose a novel diffuse interface model of two-phase magnetohydrodynamics (MHD) based on a magnetic vector potential formulation in the three-dimensional case. This model ensures an exact divergence-free approximation of the magnetic field by introducing a magnetic vector potential A and defining the magnetic field by B=curlA. The resulting framework constitutes a highly coupled, nonlinear saddle point system consisting of the Cahn–Hilliard system and MHD potential system. To solve the model efficiently, we present two fully decoupled, first-order, linear, and unconditionally energy-stable schemes and strictly prove their well-posedness and energy stability. Finally, we present several numerical examples that demonstrate the stability and effectiveness of our schemes.
The orientation dependence of cavity-modified chemistry
Authors: Liebenthal Marcus Dante , DePrince A. Eugene
Published: August 2024

Recent theoretical studies have explored how ultra-strong light–matter coupling can be used as a handle to control chemical transformations. Ab initio cavity quantum electrodynamics calculations demonstrate that large changes to reaction energies or barrier heights can be realized by coupling electronic degrees of freedom to vacuum fluctuations associated with an optical cavity mode, provided that large enough coupling strengths can be achieved. In many cases, the cavity effects display a pronounced orientational dependence. Here, we highlight the critical role that geometry relaxation can play in such studies. As an example, we consider a recent work [Pavošević et al., Nat. Commun. 14, 2766 (2023)] that explored the influence of an optical cavity on Diels–Alder cycloaddition reactions and reported large changes to reaction enthalpies and barrier heights, as well as the observation that changes in orientation can inhibit the reaction or select for one reaction product or another. Those calculations used fixed molecular geometries optimized in the absence of the cavity and fixed relative orientations of the molecules and the cavity mode polarization axis. Here, we show that when given a chance to relax in the presence of the cavity, the molecular species reorient in a way that eliminates the orientational dependence. Moreover, in this case, we find that qualitatively different conclusions regarding the impact of the cavity on the thermodynamics of the reaction can be drawn from calculations that consider relaxed vs unrelaxed molecular structures.
Accuracy and limitations of the bond polarizability model in modeling of Raman scattering from molecular dynamics simulations
Authors: Paul Atanu , Rubenstein Maya , Ruffino Anthony , Masiuk Stefan , Spanier Jonathan E. , Grinberg Ilya
Published: August 2024

Calculation of Raman scattering from molecular dynamics (MD) simulations requires accurate modeling of the evolution of the electronic polarizability of the system along its MD trajectory. For large systems, this necessitates the use of atomistic models to represent the dependence of electronic polarizability on atomic coordinates. The bond polarizability model (BPM) is the simplest such model and has been used for modeling the Raman spectra of molecular systems but has not been applied to solid-state systems. Here, we systematically investigate the accuracy and limitations of the BPM parameterized from the density functional theory results for a series of simple molecules, such as CO2, SO2, H2S, H2O, NH3, and CH4; the more complex CH2O, CH3OH, CH3CH2OH, and thiophene molecules; and the BaTiO3 and CsPbBr3 perovskite solids. We find that BPM can reliably reproduce the overall features of the Raman spectra, such as shifts of peak positions. However, with the exception of highly symmetric systems, the assumption of non-interacting bonds limits the quantitative accuracy of the BPM; this assumption also leads to qualitatively inaccurate polarizability evolution and Raman spectra for systems where large deviations from the ground state structure are present.
Simultaneous tracking of ultrafast surface and gas-phase dynamics in solid–gas interfacial reactions
Authors: Blackman Keith , Segrest Eric , Turner George , Machamer Kai , Gupta Aakash , Khan Pathan Md Afjal , Berriel S. Novia , Banerjee Parag , Vaida Mihai E.
Published: August 2024

Real-time detection of intermediate species and final products at the surface and near-surface in interfacial solid–gas reactions is critical for an accurate understanding of heterogeneous reaction mechanisms. In this article, an experimental method that can simultaneously monitor the ultrafast dynamics at the surface and above the surface in photoinduced heterogeneous reactions is presented. This method relies on a combination of mass spectrometry and femtosecond pump–probe spectroscopy. As a model system, the photoinduced reaction of methyl iodide on and above a cerium oxide surface is investigated. The species that are simultaneously detected from the surface and gas-phase present distinct features in the mass spectra, such as a sharp peak followed by an adjacent broad shoulder. The sharp peak is attributed to the species detected from the surface, while the broad shoulder is due to the detection of gas-phase species above the surface, as confirmed by multiple experiments. By monitoring the evolution of the sharp peak and broad shoulder as a function of the pump–probe time delay, transient signals are obtained that describe the ultrafast photoinduced reaction dynamics of methyl iodide on the surface and in the gas-phase. Finally, SimION simulations are performed to confirm the origin of the ions produced on the surface and in the gas-phase.
A new method to calculate broadband dielectric spectra of solvents from molecular dynamics simulations demonstrated with polarizable force fields
Authors: Bone Rebecca A. , Chung Moses K. J. , Ponder Jay W. , Riccardi Demian , Muzny Chris , Sundararaman Ravishankar , Schwarz Kathleen
Published: August 2024

Simulating the dielectric spectra of solvents requires the nuanced definition of inter- and intra-molecular forces. Non-polarizable force fields, while thoroughly benchmarked for dielectric applications, do not capture all the spectral features of solvents, such as water. Conversely, polarizable force fields have been largely untested in the context of dielectric spectroscopy but include charge and dipole fluctuations that contribute to intermolecular interactions. We benchmark non-polarizable force fields and the polarizable force fields AMOEBA03 and HIPPO for liquid water and find that the polarizable force fields can capture all the experimentally observed spectral features with varying degrees of accuracy. However, the non-polarizable force fields miss at least one peak. To diagnose this deficiency, we decompose the liquid water spectra from polarizable force fields at multiple temperatures into static and induced dipole contributions and find that the peak originates from induced dipole contributions. Broadening our inquiry to other solvents parameterized with the AMOEBA09 force field, we demonstrate good agreement between the experimental and simulated dielectric spectra of methanol and formamide. To produce these spectra, we develop a new computational approach to calculate the dielectric spectrum via the fluctuation dissipation theorem. This method minimizes the error in both the low and high frequency portions of the spectrum, improving the overall accuracy of the simulated spectrum and broadening the computed frequency range.
Redox gating-induced modulation of charge carrier density and lattice expansion in LaNiO3 thin films
Authors: Cao Hui , Liu Changjiang , Fong Dillon D. , Bhattacharya Anand , Tirrell Matthew V. , Zhou Hua , Chen Wei
Published: August 2024

Redox gating involves the use of reversible redox functionalities combined with ionic electrolytes to substantially alter the charge carrier density in functional condensed materials. This modification leads to the emergence of physical properties not observed in the original material. In our study, we focus on redox gating applied to a LaNiO3 (001) film within a field-effect device and identify a critical gate voltage of 0.7 V. Hall measurements indicate that redox gating markedly increases the charge carrier density in LaNiO3, reaching over 1014 cm−2. This increase is primarily due to the injection of electrons into LaNiO3, which offsets the existing hole carriers. These adjustments in the carrier concentration result in reversible lattice expansion in LaNiO3 when gate voltages are below 0.7 V. This expansion correlates well with theoretical models that consider adjustments to the Ni–O bond length, influenced by oxygen ligand holes. Conversely, at gate voltages above 0.7 V, there are significant changes in resistivity, lattice structure, and Ni valence, stemming from the formation of oxygen vacancies in the LaNiO3 film.
On the nature of initial solvation in bulk polar liquids: Gaussian or exponential?
Authors: Chawla Sakshi , Dhamija Shaina , Bhutani Garima , De Arijit Kumar
Published: August 2024

Measurement of time evolution of fluorescence of a probe solute has been a quintessential technique to quantify how dipolar solvent molecules dynamically minimize the free energy of an electronically excited probe. During such solvation dynamics in bulk liquids, a substantial part of relaxation was shown to complete within sub-100 fs from time-gated fluorescence measurements, as also predicted by molecular dynamics simulation studies. However, equivalent quantification of solvation timescales by femtosecond pump–probe and broadband fluorescence measurements revealed an exponential nature of this initial relaxation having quite different timescales. Here, we set out to unveil the reason behind these puzzling contradictions. We introduce a method for estimating probe wavelength-dependent instrument response and demonstrate that the observation of the Gaussian vs exponential nature of initial relaxation is indeed dependent on the method of data analysis. These findings call for further experimental investigation and parallel development of theoretical models to elucidate the molecular-level mechanism accounting for different types of early time solvation.
Commercial nanodiamonds for precise fluorescence-based temperature sensing
Authors: Pedroza-Montero F. A. , Santacruz-Gomez K. J. , Meléndrez-Amavizca R. , Barboza-Flores M.
Published: August 2024

Nanothermometry is crucial for understanding physical, chemical, and biological systems, which require precise temperature measurement. Fluorescent nanodiamonds containing nitrogen-vacancy (NV) color centers offer an approach to temperature sensing. In this study, we present the spectrofluorometric characteristics of the NV zero-phonon lines (575 and 637 nm), in 100 nm nanodiamonds in aqueous volume ensembles at a concentration of 0.5 mg/ml, across the temperature range of 30–45 °C. The NV0 and NV− fluorescence intensities achieved high linear correlation values of 0.99 (INV0) and 0.94 (INV−), respectively, demonstrating their efficiency in high precision temperature assessment. Additionally, we explore NV0 width as temperature increases, NV populations intensity ratios, and INV0/INV− ratios to gain insights into thermal quenching phenomena in fluorescent nanodiamonds, where upon heating, an increasing trend for INV−/(INV0+INV−) is observed, while an antisymmetric effect takes place for INV0/(INV0+INV−). These findings indicate the potential of commercial nanodiamonds for precise all-optical fluorescence-based temperature sensing.
Hydrodynamic instability of shear imposed falling film over a uniformly heated inclined undulated substrate
Authors: Hossain Md. Mouzakkir , Ghosh Sukhendu , Behera Harekrushna , Sekhar G. P. Raja
Published: August 2024

Linear and weakly nonlinear stability analyses of an externally shear-imposed, gravity-driven falling film over a uniformly heated wavy substrate are studied. The longwave asymptotic expansion technique is utilized to formulate a single nonlinear free surface deflection equation. The linear stability criteria for the onset of instability are derived using the normal mode form in the linearized portion of the surface deformation equation. Linear stability theory reveals that the flow-directed sturdy external shear grows the surface wave instability by increasing the net driving force. On the contrary, the upstream-directed imposed shear may reduce the surface mode instability by restricting the gravity-driving force, which has the consequence of weakening the bulk velocity of the liquid film. However, the surface mode can be stabilized/destabilized by increasing the temperature-dependent density/surface-tension variation. Furthermore, the bottom steepness shows dual behavior on the surface instability depending upon the wavy wall's portion (uphill/downhill). At the downhill portion, the surface wave becomes more unstable than at the bottom substrate's uphill portion. Moreover, the multi-scale method is incorporated to obtain the complex Ginzburg–Landau equation in order to study the weakly nonlinear stability, confirming the existence of various flow regions of the liquid film. At any bottom portion (uphill/downhill), the flow-directed external shear expands the supercritical stable zones, which causes an amplification in the nonlinear wave amplitude, and the backflow-directed shear plays a counterproductive role. On the other hand, the supercritical stable region decreases or increases as long as the linear variation of density or surface tension increases with respect to the temperature, whereas the sub-critical unstable region exhibits an inverse trend.
Phase of the second-order susceptibility in vibrational sum frequency generation spectroscopy: Origins, utility, and measurement techniques
Authors: Hore Dennis K.
Published: August 2024

Vibrational sum frequency generation can provide valuable structural information at surfaces and buried interfaces. Relating the measured spectra to the complex-valued second-order susceptibility χ(2) is at the heart of the technique and a requisite step in nearly all subsequent analyses. The magnitude and phase of χ(2) as a function of frequency reveal important information about molecules and materials in regions where centrosymmetry is broken. In this tutorial-style perspective, the origins of the χ(2) phase are first described, followed by the utility of phase determination. Finally, some practical methods of phase extraction are discussed.