bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low temperature specific heats of the dihydrides of the light rare earth metals
Authors: Biegański Z. 
Published: October 2023

AbstractThe heat capacities of La, Ce, Pr and Nd‐dihydrides with fcc CaF2‐type structure were measured over the temperature range 20‐345 K by adiabatic calorimetry. The various terms contributing to the total specific heat have been discussed. On ground of the separated Schottky contributions to the specific heats, the influence of the crystal field of cubic symmetry on the splitting of the (2J + 1)‐fold degenerated ground levels 2F5/2, 3H4, and 4I9/2 of the Ce3+, Pr3+, and Nd3 + ions was analysed and the conclusion was drawn that the lowest lying energy levels are Γ8, Γ5, and Γ respectively. This result supports the idea of the anion‐like character (hydridic model) of hydrogen in these hydrides.
Experimente und physikalisch‐chemische Grundlagen zur Fluidchromatographie
Authors: Bartmann D. , Schneider G. M. 
Published: October 2023

AbstractBei der Fluidchromatographie werden komprimierte Gase oder Flüssigkeiten bei Temperaturen im kritischen Bereich als mobile Phasen benutzt, insbesondere zur Trennung von Substanzen mit niedriger Wanderungsgeschwindigkeit und/oder geringer thermischer Stabilität. Durch Druckänderung im überkritischen Temperaturbereich kann die Dichte der mobilen Phase kontinuierlich von gasähnlichen zu flüssigkeitsähnlichen Werten variiert und das Lösungsvermögen der mobilen Phase und damit auch die Wanderungsgeschwindigkeit der Testsubstanz in der Säule um Größenordnungen erhöht werden. Eine Apparatur mit CO2 als mobiler Phase wird beschrieben. Ergebnisse isobarer und druckprogrammierter Trennungen werden für eine Reihe von Testsubstanzen (aliphatische und zyklische Kohlenwasserstoffe mitgeteilt und bezüglich des Phasenverhaltens und der Transporteigenschaften fluider CO2‐Mischungen bei hohen Drücken diskutiert. Die experimentell ermittelten HETP‐Werte stimmen ziemlich gut mit Werten überein, die mittels einer modifizierten Van Deemter‐Gleichung mit dimensionslosen Kennzahlen berechnet wurden.
Zur Photochromie des 2,3,4,4‐Tetra‐chlor‐1‐keto‐dihydronaphthalins (β‐TkN)
Authors: Kortüm G. , Greiner G. 
Published: October 2023

Abstractβ‐TkN ist sowohl in kristallinem Zustand wie in Lösung bei Bestrahlung mit Hg 366 nm photochrom. Die Dunkelreaktion im kristallinen Zustand ist nach reflexionsspektroskopischen Messungen 1. Ordnung, die Aktivierungsenergie ergibt sich zu 27 kcal/mol. In Lösung ist die Dunkelreaktion nur bei höheren Temperaturen (30 ‐ 40°C) 1. Ordnung und ergibt eine Aktivierungsenergie von 16 kcal/mol. Bei niedrigeren Temperaturen überlagert sich eine andere Reaktion mit wesentlich kleinerer Aktivierungsenergie.Das in der Literatur beschriebene Triplett‐ESR‐Spektrum des kristallinen β‐TkN erhält man nur bei Bestrahlung mit Wellenlängen λ ≥ 313 nm. Bestrahlung mit der Gesamtstrahlung einer Hg‐Lampe ergibt ein intensives Resonanzsignal, dessen Intensität bei Verschwinden der photochromen Farbe erhalten bleibt. Das Triplettspektrum dagegen ist an den photochromen Zustand gebunden.Bei Bestrahlung von Lösungen des β‐TkN mit Hg 366 nm entsteht neben der photochromen Form ein Radikal, das sich nach seinem ESR‐Spektrum mit dem als identisch erweist, das man durch Dehydrierung von 2,3,4‐Trichlornaphthol‐(1) erhält. Es handelt sich um das Trichlornaphthoxylradikal, das mit seinem Dimeren im Gleichgewicht steht. Die Photochromie des ß‐TkN läßt sich nach diesen Meßergebnissen am besten durch die Entstehung eines Triplettzustandes des intakten Moleküls deuten.
Mechanism of Complex Formation in Non‐Aqueous Solvents III. Acetonitrile [1, 2]
Authors: Hoffmann H. , Janjic T. , Sperati R. 
Published: October 2023

AbstractThe kinetics of the formation and dissociation of the complexes of Ni(NO3)2, Ni(CH3‐ρ‐SO3)2 and Ni(CF3COO)2 in the solvent acetonitrile have been investigated using relaxation techniques. In solutions of all these salts two temperature and concentration dependent relaxation times were observed and associated with the mono‐ and the bis‐complex. A third relaxation time that was found in solutions of Ni(NO3)2 with C > 10−3 m was assigned to a triscomplex. The formation and dissociation rate constants of the complexes and their activation parameters were evaluated. The rate constant for the solvent exchange from a Ni2+ ‐ion was determined from the forward rate constant of the monocomplex. This rate constant (k = 2 ± 103 sec−1 at 20°) and the activation parameters ΔH* (15 ± 0.5 kcal) and ΔS* (6.5 ± 2 e.u.) are in agreement with literature values that have been obtained from nmr‐measurements. Hence, it is shown that the rate determining step for the complex formation is the release of a coordinated CH3 · CN molecule from the inner coordination sphere. Furthermore a linear relation is formed between the activation enthalpies and activation entropies for the dissociation rate constant of the complexes.
Determination of the Rate Constant for the Reaction OH + H2S by a Pulsed Photolysis — Resonance Fluorescence Method
Authors: Stuhl F. 
Published: October 2023

AbstractThe kinetic behavior of OH radicals in the presence of a large excess of H2S has been studied using a pulsed photolysis‐resonance fluorescence technique. The rate constant for the reaction of OH with H2S was determined to be 3.1 (±0.5) · 10−12 cm−3 molecule−1 sec−1 at 298°K. The significance of this result is discussed with regard to the balance of atmospheric sulfur.
Die Thermochromie, Piezochromie und Photochromie der Dehydrodianthrone
Authors: Kortüm Custav 
Published: October 2023

AbstractThermochromie, Piezochromie und Photochromie gehören zu den interessantesten und faszinierendsten Erscheinungen, die aufs engste mit reversiblen Umwandlungen von Molekülformen ineinander zusammenhängen. Sie finden statt unter dem Einfluß äußerer Variabler wie Druck oder Temperatur bzw. als Folge photochemischer Anregung in höhere Energiezustände, die unter geeigneten Bedingungen von Temperatur und Viskosität des Lösungsmittels eingefroren werden können. Solche Umwandlungen lassen sich mit Hilfe der Absorptionsspektren der verschiedenen Molekülformen verfolgen, und man kann versuchen, aus diesen Spektren und den Bedingungen, unter denen sie auftreten, auf die Konfiguration der einzelnen Formen zu schließen. Vom Dehydrodianthron, dem Prototyp der thermochromen, piezochromen und photochromen Åthylene, gibt es bisher fünf verschiedene Isomere bzw. Konformere, die auf diese Weise charakterisiert werden konnten. Dagegen macht trotz moderner Untersuchungsmethoden wie Fluorescenz‐, Phosphorescenz‐, Infrarot‐, NMR‐ und ESR‐Spektren, flash‐Experimenten u. a. die Zuordnung der einzelnen Isomeren zu bestimmten Molekülkonfigurationen noch immer große Schwierigkeiten, wodurch das Interesse an dieser Problematik immer wieder neu geweckt wird.
Photoreaktionen kleiner organischer Moleküle II. Die Photoionenspektren der Isomeren Propylen‐Cyclopropan und Acetaldehyd‐Äthylenoxyd
Authors: Kräßig R. , Reinke D. , Baumgärtel H. 
Published: October 2023

AbstractEs werden die Photoionenspektren von Propylen, Cyclopropan, Acetaldehyd und Äthylenoxyd im Energiebereich von 9 bis 27 eV mitgeteilt. Aus den Auftrittspotentialen von Photoreaktionen werden die Bildungsenthalpien der Reaktionsprodukte berechnet und der Verlauf der beobachteten Reaktionen diskutiert. Die Produkte der Photodissoziation isomerer Verbindungen werden verglichen. Einige lonisierungspotentiale und Bindungsenergien werden ermittelt.
Messungen der scheinbaren Molwärme von Benzol im Zeolithen Linde 13 X
Authors: Basler W. , Lechert H. 
Published: October 2023

AbstractDie scheinbare Molwärme von adsorbiertem Benzol im Zeolith Linde 13 X wurde für verschiedene Belegungen im Temperaturbereich 90  300 K gemessen. Bei keiner Belegung wurde eine Übergangswärme gefunden. Der mit kernmagnetischer Resonanz nachgewiesene Übergang des Adsorbats aus einem Zustand guter in einen geringer Beweglichkeit ist demnach nicht mit einer Änderung des Ordnungszustandes verbunden. Bei Vollbelegung ist die scheinbare Molwärme des Adsorbats gleich der Molwärme bei konstantem Volumen von kristallinem Benzol.
Fortschritte in der kernmagnetischen Resonanzspektroskopie
Authors: Dreeskamp H. 
Published: October 2023

AbstractEs wird ein Überblick gegeben über einige neuere Entwicklungen der NMR mit besonderer Berücksichtigung experimenteller Techniken Diese werden klassifiziert nach den speziellen Wechselwirkungen. die ihnen zugrunde liegen wie Kern‐Kern (indirekt und direkt). Kern‐Gitter und Kern‐Elektron. Beispiele aus den Gebieten Fourier‐Transform‐NMR. INDOR. Multipulssequenzen. Orientierte Moleküle, C‐13‐Spin‐Gitter‐Relaxation, Verschiebungsreagenzien und CIDNP werden gebracht und Aussagen. die sie ermöglichen. aufgezeigt.
Zeitaufgelöste Fluoreszenzspektren dünner Filme von Anthracen und Pyren
Authors: Haller W. , Stichtenoth H. , Perkampus H.‐H. 
Published: October 2023

AbstractDie Temperaturabhängigkeit der im Nanosekundenbereich zeitlich aufgelösten Fluoreszenzspektren dünner Filme von Anthracen und Pyren wurde im Temperaturbereich von 77 bis 300 K untersucht. Die Herstellung der Filme erfolgte durch Aufsublimieren der Substanz im Hochvakuum auf eine durch flüssigen Stickstoff gekühlte Quarzplatte.Die Strukturänderung der Filme von der glasigen, amorphen Phase des frisch aufsublimierten Filmes bis zur mehr mikrokristallinen bei Zimmertemperatur konnte an Hand der zeitaufgelösten Spektren verfolgt werden.Der Vergleich der Momentan‐ mit den Gesamtspektren zeigt anschaulich das Vorkommen verschiedener Abklingvorgänge, die der ungestörten Kristallfluoreszenz, der Excimerenfluoreszenz und weiteren Störstellenemissionen zuzuordnen sind Frühere Messungen der Fluoreszenzabklingzeiten wurden damit bestätigt.
Interferometrische Messungen über den Einfluß von H2O und CO2 auf die Schwingungsrelaxation von Stickstoff
Authors: Schmalz F. , Just Th. 
Published: October 2023

AbstractDie Schwingungsrelaxationszeiten von N2 – CO2‐ und N2 – H2O‐Gemischen hinter Stoßwellen wurden im Temperaturbereich 1200 ÷ 2200K untersucht. Aus den Messungen ergibt sich für die Relaxation von N2 bei unendlicher Verdünnung in H2O
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Es zeigte sich, daß wahrend der N2‐Relaxation die Schwingungen des H,O stets voll angeregt und im Gleichgewicht mit der Translation sind. Vergleichende theoretische Abschätzungen der elementaren Energieaustauschprozesse deuten darauf hin, daß im untersuchten Temperaturbereich T ‐ R ‐ V‐Vorgange dominierend sind.
A Bayesian approach for mixed effects state‐space models under skewness and heavy tails
Authors: Hernandez‐Velasco Lina L. , Abanto‐Valle Carlos A. , Dey Dipak K. , Castro Luis M. 
Published: October 2023

AbstractHuman immunodeficiency virus (HIV) dynamics have been the focus of epidemiological and biostatistical research during the past decades to understand the progression of acquired immunodeficiency syndrome (AIDS) in the population. Although there are several approaches for modeling HIV dynamics, one of the most popular is based on Gaussian mixed‐effects models because of its simplicity from the implementation and interpretation viewpoints. However, in some situations, Gaussian mixed‐effects models cannot (a) capture serial correlation existing in longitudinal data, (b) deal with missing observations properly, and (c) accommodate skewness and heavy tails frequently presented in patients' profiles. For those cases, mixed‐effects state‐space models (MESSM) become a powerful tool for modeling correlated observations, including HIV dynamics, because of their flexibility in modeling the unobserved states and the observations in a simple way. Consequently, our proposal considers an MESSM where the observations' error distribution is a skew‐t. This new approach is more flexible and can accommodate data sets exhibiting skewness and heavy tails. Under the Bayesian paradigm, an efficient Markov chain Monte Carlo algorithm is implemented. To evaluate the properties of the proposed models, we carried out some exciting simulation studies, including missing data in the generated data sets. Finally, we illustrate our approach with an application in the AIDS Clinical Trial Group Study 315 (ACTG‐315) clinical trial data set.
Enhanced binding and inhibition of SARS‐CoV‐2 by a plant‐derived ACE2 protein containing a fused mu tailpiece
Authors: Lim Sohee , Kwon Hyung‐Jun , Jeong Dae Gwin , Nie Hualin , Lee Sanghee , Ko Seo‐Rin , Lee Kyu‐Sun , Ryu Young Bae , Mason Hugh S. , Kim Hyun‐Soon , Shin Ah‐Young , Kwon Suk‐Yoon 
Published: October 2023

AbstractInfectious diseases such as Coronavirus disease 2019 (COVID‐19) and Middle East respiratory syndrome (MERS) present an increasingly persistent crisis in many parts of the world. COVID‐19 is caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The angiotensin‐converting enzyme 2 (ACE2) is a crucial cellular receptor for SARS‐CoV‐2 infection. Inhibition of the interaction between SARS‐CoV‐2 and ACE2 has been proposed as a target for the prevention and treatment of COVID‐19. We produced four recombinant plant‐derived ACE2 isoforms with or without the mu tailpiece (μ‐tp) of immunoglobulin M (IgM) and the KDEL endoplasmic reticulum retention motif in a plant expression system. The plant‐derived ACE2 isoforms bound whole SARS‐CoV‐2 virus and the isolated receptor binding domains of SARS‐CoV‐2 Alpha, Beta, Gamma, Delta, and Omicron variants. Fusion of μ‐tp and KDEL to the ACE2 protein (ACE2 μK) had enhanced binding activity with SARS‐CoV‐2 in comparison with unmodified ACE2 protein derived from CHO cells. Furthermore, the plant‐derived ACE2 μK protein exhibited no cytotoxic effects on Vero E6 cells and effectively inhibited SARS‐CoV‐2 infection. The efficient and rapid scalability of plant‐derived ACE2 μK protein offers potential for the development of preventive and therapeutic agents in the early response to future viral outbreaks.
Delayed coronary perforation four days after percutaneous coronary intervention with subsequent cardiac tamponade: A case report
Authors: Al Mawed Mohammad , Vlachojannis Marios , Pula Arianit , Gielen Stephan 
Published: October 2023

AbstractCoronary artery perforation (CAP) is a rare but lethal complication of percutaneous coronary interventions (PCIs), and its incidence has been increasing with advances in PCI techniques. Delayed CAP presents a highly challenging complication, as it occurs 30 min−9 days after intervention, making subsequent diagnosis and treatment difficult. We present the case of a 63‐year‐old male patient who underwent PCI for an obtuse marginalis II because of posterior wall myocardial infarction. Following 4 days of uneventful postoperative stay, the patient developed angina pectoris and hypotension 4 h after reinitiation of anticoagulant therapy with edoxaban. Angiography revealed distal vessel perforation from a side branch of the obtuse marginalis II. The vessel was occluded using autologous fat embolization via a microcatheter, resulting in complete sealing of the perforation. After discharge, 4 weeks after the infarction, the patient started rehabilitation therapy. Distal vessel perforations are typically caused by wire damage. In our case, we also suspected distal wire perforation, which was initially not recognized possibly due to distal occlusion through the thrombotic material. The temporal correlation between the re‐initiation of anticoagulant therapy and the occurrence of cardiac tamponade suggests that the thrombotic material was resolved due to the former. The management of delayed CAP does not differ from that of CAP; thus, this rare complication should be considered even days after PCI as it could prove lethal if not recognized early.
Healing and stent coverage with the new ultrathin sirolimus‐eluting stent with abluminal biodegradable polymer
Authors: Jun Eun Jung , Hong Seung‐Pyo , Kim Bitna , Lee Jin Bae , Shin Eun‐Seok 
Published: October 2023

AbstractBackgroundGenoss drug‐eluting stent (DES) (Genoss Company Limited) is a new ultrathin sirolimus‐eluting stent with an abluminal biodegradable polymer and a cobalt–chromium platform.AimsThe aim of this study was to evaluate vascular healing and neointimal coverage after implantation of the Genoss DES using optical coherence tomography (OCT) 6 months postimplantation.MethodsFrom August 22, 2019 to June 17, 2020, this multicenter, observational, investigator‐initiated study enrolled 20 patients who underwent OCT examination 6 months after Genoss DES implantation and provided informed consent. An analyst, blinded to the patients' and procedural information analyzed OCT images at an independent core laboratory.ResultsOf the 20 patients, 19 with 27 stents in 21 lesions from 21 vessels were included in the analysis, while one patient withdrew consent and was unwilling to undergo follow‐up OCT. OCT analysis was performed 204.4 ± 31.9 days after Genoss DES implantation. A total of 4285 stent struts from 661 cross‐sections were analyzed. Strut tissue coverage was observed in 98.7 ± 4.3% of struts, with 0.1 ± 1.2% malapposed struts per lesion. The mean thickness of neointimal hyperplasia (NIH) on the covered struts was 0.12 ± 0.04 mm.ConclusionsSix months after stent implantation, most Genoss DES struts were covered with a thin layer of NIH that was evenly distributed along the stent length. This pilot study evaluated the outcomes of 6 months dual antiplatelet therapy in the context of ultrathin strut stents, providing insight into developing ethical standards and a scientific foundation for conducting an adequately designed clinical trial.
Preemptive alcohol septal ablation prior to transcatheter mitral valve replacement
Authors: Wong Ningyan , Lim D. Scott , Yount Kenan , Yarboro Leora , Ailawadi Gorav , Ragosta Michael 
Published: October 2023

AbstractBackgroundAlcohol septal ablation (ASA) has been shown to increase the neo‐left ventricular outflow tract (LVOT) area before transcatheter mitral valve replacement (TMVR) but there is little literature on its success and use with dedicated devices.AimsTo describe our experience with preemptive ASA to increase the predicted neo‐LVOT area and its utility with both dedicated TMVR devices and balloon‐expandable valves.MethodsAll patients who underwent ASA for TMVR candidacy in our center between May 2018 and October 2022 and had computed tomography (CT) scans done before and after ASA were included. Each CT was assessed for the minimum predicted neo‐LVOT area at end‐systole, using a virtual valve of the desired TMVR device for each patient. The primary outcome was an increase in the predicted neo‐LVOT area after ASA that was deemed sufficient for safe implantation of the desired TMVR device. The secondary outcome was the absence of acute LVOT obstruction after TMVR.ResultsA total of 12 patients underwent ASA and all but 1 (n = 11, 91.6%) achieved the primary outcome of having sufficient predicted neo‐LVOT area to proceed with TMVR. The mean increase in neo‐LVOT area after ASA was 126 ± 64 mm2 (median 119.5, interquartile range: 65.0–163.5 mm2). Two patients (16.7%) required a permanent pacemaker after ASA. Nine patients went on and underwent TMVR with their respective devices and none had LVOT obstruction after the procedure. Among the remaining three patients, one had insufficient neo‐LVOT clearance after ASA, one had unrelated mortality before TMVR, and one had advanced heart failure before TMVR.ConclusionIn appropriately selected patients and at centers experienced with ASA, preemptive ASA can achieve sufficient neo‐LVOT clearance for TMVR with a variety of devices in approximately 90% of patients.
Resonant bubbles in a vertically vibrating liquid column
Authors: Baird M. H. I. 
Published: October 2023

AbstractThis paper reports measurements and theory concerning stationary, resonant single bubbles which have been formed in a vertically vibrating liquid column at frequencies of 40–1050 c./s. With liquids of high viscosity (ca. 10 poise) the bubbles can be made large enough to occupy the entire cross‐section of the 2 1/2 in. diameter column: intense agitation is produced in the liquid above the large bubble or slug. Theoretical equations are derived for the resonant frequency of the stationary bubbles: agreement with measured frequency is within 20% for bubbles which only partly fill the column cross‐section and within 10% for bubbles occupying the entire cross‐section. Viscous damping appears to be important in the latter case.
Age distributions for flow systems
Authors: Cha Lin Chuan , Fan Liang‐Tseng 
Published: October 2023

AbstractA generalized treatment of age distributions in a flow system is proposed. In this work the inflowing stream is allowed to have an arbitrary but stationary age distribution before entering the system. The inventory material may also have an arbitrary age distribution initially. The flow rate of inflowing stream may be a variable with respect to time in certain special cases.
A study of the condensation of binary vapors of miscible liquids: Part 2: Heat transfer co‐efficients for filmwise and non‐filmwise condensation
Authors: Mirkovich V. V. , Missen R. W. 
Published: October 2023

AbstractHeat transfer coefficients for total condensation at 750 mm. Hg of saturated, binary vapors have been measured for the four systems n‐pentane + n‐hexane, methanol + methylene dichloride, n‐pentane + methanol, and n‐pentane + methylene dichloride. Condensation was entirely filmwise for the first two systems, but was non‐filmwise (dropwise in the extreme) for the last two at low temperature differences for solutions dilute in n‐pentane. In the non‐filmwise cases the heat transfer coefficients are greater than expected for filmwise condensation, but the difference is not nearly as great as occurs for steam condensation. This indicates the existence of a resistance in the vapor film for mixtures, as postulated by Colburn and Drew in 1937. Dropwise condensation of vapor mixtures does not require a promoter, and indicates that interfacial tension forces may not always be neglected in considering the stability of homogeneous condensate films for mixtures.
Integrability of SLE via conformal welding of random surfaces
Authors: Ang Morris , Holden Nina , Sun Xin 
Published: October 2023

AbstractWe demonstrate how to obtain integrability results for the Schramm‐Loewner evolution (SLE) from Liouville conformal field theory (LCFT) and the mating‐of‐trees framework for Liouville quantum gravity (LQG). In particular, we prove an exact formula for the law of a conformal derivative of a classical variant of SLE called . Our proof is built on two connections between SLE, LCFT, and mating‐of‐trees. Firstly, LCFT and mating‐of‐trees provide equivalent but complementary methods to describe natural random surfaces in LQG. Using a novel tool that we call the uniform embedding of an LQG surface, we extend earlier equivalence results by allowing fewer marked points and more generic singularities. Secondly, the conformal welding of these random surfaces produces SLE curves as their interfaces. In particular, we rely on the conformal welding results proved in our companion paper Ang, Holden and Sun (2023). Our paper is an essential part of a program proving integrability results for SLE, LCFT, and mating‐of‐trees based on these two connections.