bluuebunny/crossref_metadata_2025 huggingface dataset:
Beiträge zur Chemie des Schwefels XXXII. Kinetische Untersuchungen über den thermischen Zerfall des Disulfans H2S2
Authors: Fehér F. , Weber H.
Published: October 2023

Die in der vorliegenden Arbeit behandelte kinetische Untersuchung des thermischen Disulfanzerfalls erstreckt sich auf eine Bestimmung der Zerfallsgeschwindigkeit des flüssigen reinen Produktes in Abhängigkeit von der Zeit, von der eingesetzten Menge und von der Temperatur in dem Bereich von 20 bis 50 °C und einem Zeitraum, in dem höchstens 2% der eingesetzten H2S2‐Menge zerfallen sind. Als Meßmethode wird dabei eine in gewissen Zeitabständen mit Hilfe eines Siliconöl‐Manometers durchgeführte Feststellung des Überdrucks angewendet, welcher durch das aus der Flüssigkeit in einen abgeschlossenen Gasraum entweichende H2S hervorgerufen wird. Die Versuche haben im einzelnen folgendes ergeben:

Die je Zeiteinheit entwickelte H2S‐Menge ist proportional der eingesetzten Disulfanmenge.

Die Zerfallsgeschwindigkeit G = dX/dt ist proportional der gesamten entwickelten H2S‐Menge X. Demnach lautet das Zerfallsgesetz: G = kX.

Die Zerfallskonstante k hat bei 50 °C den Wert k = 0,56 ± 0,04h−1.

Die Temperaturabhängigkeit der Zerfallskonstante k läßt sich durch die Gleichung k = 2 · 1016 e−12500/T näherungsweise beschreiben.

Für den Temperaturquotienten Q = kT+10/kT, die Aktivierungsenergie A und die Aktionskonstante a können folgende größenordnungsmäßige Angaben gemacht werden:

Als Endprodukte entstehen bei der Alterung nach Aussagen analytischer, kryoskopischer und raman‐spektroskopischer Untersuchungen zunächst hauptsächlich Trisulfan, dann höhere Sulfane und schließlich elementarer Schwefel.

Nach diesen Feststellungen kann man die Beständigkeit des Disulfans wie folgt charakterisieren: Eine nur durch die Alterung hervorgerufene Aufschwefelung der reinen Verbindung H2S2,00 auf ein Öl der mittleren Zusammensetzung H2S2,01 dauert bei einer temperatur von 50 °C 10 Stunden, bei 20 °C 5 Wochen und bei 0 °C 2 Jahre.

Eine eingehende Diskussion der angegebenen Befunde führt zu folgender Anschauung über den Verlauf des thermischen Disulfanzerfalls im Stadium eines nicht allzu großen Umsatzes: Der zeitbestimmende Vorgang (2) ist eine Kettenreaktion, bei welcher die durch eine langsame Startreaktion (1) im Öl enthaltenen HS+ ‐Ionen autokatalytisch eine heteropolare Spaltung der S‐S‐Bindungen der Disulfanmoleküle hervorrufen. Die dabei auftretenden HS− ‐Ionen bewirken dann in der schnellen Folgereaktion (3) das Entstehen des entweichenden Monosulfans H2S unter gleichzeitiger Bildung von HS−2‐Ionen, welche sich schließlich in einer langsamen Abbruchreaktion (4) mit dem Kettenträger HS+ zu Trisulfan vereinigen.

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Zur Charakterisierung semipermeabler Membranen für osmotische Zwecke (1. Mitteilung über semipermeable Membranen.)
Authors: Meyerhoff G.
Published: October 2023

Es genügt nicht, Membranen für osmotische Zwecke ohne Berücksichtigung des gelösten Stoffes allein durch ihre Permeabilität in bezug auf das Lösungsmittel zu charakterisieren. Die drei Größen: Lösungsmittel, Gelöstes und semipermeable Membran wirken zusammen und sind daher besser als Gesamtheit zu testen. Mit einer polymolekularen Substanz, die eine breite Molekulargewichtsverteilung aufweist, erhält man je nach der Durchlässigkeit der Membran bei der Messung des osmotischen Druckes verschiedene Molekulargewichte. Die Größe des mit einer bestimmten Membran gemessenen Molekulargewichtes liefert bei Verwendung einer geeigneten Testsubstanz ein relatives Maß für die Qualität einer osmotischen Membran. Das gemessene scheinbare Molekulargewicht gibt Auskunft über den Grad der Durchlässigkeit einer Membran für das Polymere.

Mit Polystyrol III der BASF als Testsubstanz werden eine Reihe von Membranen in Toluol getestet. Außerdem wird der Zahlendurchschnitt des Molekulargewichtes ebullioskopisch ermittelt, der dem osmotischen Molekulargewicht bei einer idealen semipermeablen Substanz entspricht. Hieraus und aus Messungen der Verteilungskurve dieses Polystyrols wird eine Abschätzung gewonnen, welche Polymerisationsgrade die einzelnen Membranen zu permeieren vermögen.
Über den Einfluß organischer Lösungsmittel auf Stufenhöhe und Halbstufenpotential organischer Depolarisatoren
Authors: Schwabe K.
Published: October 2023

Der Einfluß des Gehaltes an organischen Lösungsmitteln, insbesondere Alkohole, Aceton und Dioxan, auf die Halbstufenpotentials und Stufenhöhen reversibler und irreversibler organischer Depolarisatoren wird untersucht. Bei reversiblen Prozessen, die unter Protonenaufnahme erfolgen, läßt sich die Verschiebung des Halbstufenpotentials aus der entsprechenden pH‐Verschiebung berechnen. Bei irreversiblen Stufen ist diese Verschiebung kinetisch bedingt und nicht generell voraus bestimmbar. Die diffusionsbegrenzten Stufenhöhen lassen sich aus der Viskositätsveränderung der Lösung durch den Zusatz organischer Lösungsmittel berechnen. Dagegen kann der Einfluß dieser Lösungsmittel auf kinetisch begrenzte Stufenhöhen nicht allgemein angegeben werden.
Die Beschleunigung der Emulsionspolymerisation von Styrol durch das System Kaliumpersulfat–Triäthanolamin
Authors: Bartholomé E. , Gerrens H.
Published: October 2023

Die Bruttoreaktionsgeschwindigkeit VBr der mit Kaliumpersulfat angeregten Emulsionspolymerisation von Styrol erhöht sich bei Zugabe kleiner Mengen Triäthanolamin beträchtlich. Diese Beschleunigung wird im Dilatometer kinetisch untersucht. Meßreihen mit wechselnder Amin‐ bzw. Persulfatkonzentration zeigen, daß die Wirkung des Triäthanolamins nur in einer Erhöhung der Startgeschwindigkeit VSt besteht. Wachstumsgeschwindigkeit Vw und Monomerenkonzentration CM werden nicht beeinflußt. Nach dem bekannten Mechanismus von Smith und Ewart ergibt die Erhöhung der Startgeschwindigkeit die Bildung einer größeren Zahl N von Latexteilchen je cm3 und da VBr proportional N ist, indirekt auch eine Erhöhung der Bruttoreaktionsgeschwindigkeit. Die Startreaktion besteht in der Bildung von Radikalen aus dem Persulfat. Ihre Beschleunigung kommt dadurch zustande, daß zum monomolekularen thermischen Zerfall des Persulfates bei Anwesenheit von Triäthanolamin noch eine bimolekulare Reaktion zwischen Amin und Persulfat hinzukommt, die je Molekül Persulfat ein reaktionsfähiges Radikal liefert. Die Konstante k2 der bimolekularen Reaktion wird bestimmt und ihre Temperaturabhängigkeit gemessen.
Infrarotspektroskopische Untersuchungen mit linear polarisiertem Licht an organischen, polykristallinen Schichten
Authors: Mecke R. , Greinacher E.
Published: October 2023

Es wird experimentell nachgewiesen, daß IR‐spektroskopische Messungen mit linear polarisiertem Licht an orientierten Kristallschichten für die Zuordnung der Absorptionsbanden zu den einzelnen Symmetrieklassen sehr nützliche und allgemein anwendbare Kriterien liefern. Die dadurch gegebenen Zuordnungsmöglichkeiten werden an den Beispielen des 1‐Brom‐nonadekans, 1, 18‐Dibrom‐oktadekans, Phenols, Deuterophenols, Diphenyls, Tolans, Stilbens, Azobenzols und Nitrosobenzols dargelegt. Mit Hilfe der Polarisationsmessung lassen sich außerdem auch sehr geringe Aufspaltungen von Banden Kristallspektrum nachweisen.
Fluoreszenz‐ und Absorptionsspektren von Molekülverbindungen bei tiefen Temperaturen. Energieübergänge in Molekülverbindungen
Authors: Czekalla J. , Briegleb G. , Herre W. , Glier R.
Published: October 2023

Durch lichtelektrische Messung der Absorptions‐ und Fluoreszenzspektren von Molekülverbindungen des Hexamethylbenzols mit acht verschiedenen Akzeptoren in Propyläther/Isopentan bei – 190°C konnte gezeigt werden, daß die Verschiebung der charge transfer‐Absorption, die durch die unterschiedlichen Elektronenaffinitäten der Akzeptoren bedingt ist, von einer analogen Verschiebung der Emissionsbande begleitet ist. Absorption und Emission sind in allen Fällen spiegelsymmetrisch und dem gleichen Elektronenübergang zuzuordnen. Die Emission ist somit als charge transfer‐Fluoreszenz zu deuten und steht in keinem Zusammenhang mit der Phosphoreszenz der Kohlenwasserstoffkomponente der Molekülverbindung. Die Richtigkeit dieser Deutung ist inzwischen durch Messung der Abklingzeiten bestätigt worden, über die in Kürze berichtet wird. Sie wird durch die Entdeckung der sensibilisierten Phosphoreszenz an der Verbindung Tetrachlorphthalsäureanhydrid‐Naphthalin gestützt. Beide Emissionsvorgänge werden an Hand eines Potentialkurvenschemas auf der Grundlage der Mullikenschen charge transfer‐Theorie erläutert.
Geschmolzenes Antimon(III)‐bromid als ionisierendes Lösungsmittel und das Verhalten darin gelöster Substanzen. I
Authors: Jander Gerhart , Weis Josef
Published: October 2023

Es wird gezeigt, daß geschmolzenes Antimon(III)‐bromid hinsichtlich seiner Eigenschaften als Solvens in die Reihe der ionisierenden, „wasserähnlichen”︁ Lösungsmittel einzuordnen ist.

Geschmolzenes SbBr3 vermag eine beträchtliche Zahl von anorganischen und organischen Substanzen aufzulösen.

Zahlreiche Substanzen kristallisieren aus diesen Lösungen als Doppelverbindungen mit SbBr3 aus. Man kann daher auf weitgehende Solvatation der in Antimonbromid gelösten Stoffe schließen.

Die Auflösungen zahlreicher Substanzen in SbBr3 leiten ähnlich wie wäßrige. Elektrolytlösungen den elektrischen Strom recht gut, während reines geschmolzenes SbBr3 nur eine geringe spezifische Leitfähigkeit von 1 · 10−5 rez. Ohm · cm bei 100 °C aufweist. Die Eigenleitfähigkeit wird auf eine geringfügige Dissoziation nach folgendem Schema zurückgeführt: SbBr3 ⇌ SbBr2+ + Br− · solv.

Danach sind Stoffe, welche im gelösten Zustande SbBr2+‐Ionen abspalten können, Säurenanaloge im Solvens SbBr3. Stoffe, die Br−‐Ionen liefern können, sind Basenanaloge.

Basenanaloge Verbindungen sind z.B. KBr, TIBr u. ä. Bromide. Säurenanaloge Verbindungen sind einige Antimon(III)‐salze, die im gelösten Zustande in der Form SbBr2 [X] vorliegen. Verschiedene Bromide mehr‐wertiger Elemente sind „potentielle Elektrolyte”︁, die in Lösung Solvate mit säurenanalogen Eigenschaften bilden, z. B. die Verbindung AlBr3: AlBr3 + SbBr3 = SbBr3 · AlBr3 = SbBr2 [AlBr4].

Die elektrischen Leitfähigkeiten und der kryoskopisch bestimmbare Verteilungszustand dieser Stoffe im Solvens SbBr3 werden untersucht.
Diffusion und Sedimentation in Mehrstoffgemischen
Authors: Haase R. , Schönert H.
Published: October 2023

Der allgemeine Zusammenhang zwischen den Diffusions‐ und Sedimentationskoeffizienten für ein fluides Mehrstoffgemisch wird aus den generellen Bedingungen für das Sedimentationsgleichgewicht abgeleitet, und zwar auch für den Fall, daß die Zahl der unabhängig wandernden Stoffe nicht mit der Komponentenzahl im Sinne der Phasenregel übereinstimmt. Es wird weiterhin gezeigt, daß derartige Beziehungen keine Rückschlüsse auf die Solvatation von gelösten Stoffen gestatten. Schließlich wird der Übergang zu unendlicher Verdünnung in bezug auf einer. bestimmten Stoff ‐ der ein Elektrolyt oder Nichtelektrolyt sein kann, in der Praxis aber stets hochmolekular ist ‐ ausführlich diskutiert. Die sich dabei ergebenden Grenzgesetze sind Verallgemeinerungen der Svedbergschen Formel.
Vergleichende Untersuchungen über die Kinetik der Emulsionspolymerisation von Styrol, Kernmethylstyrol und Kerndimethylstyrol
Authors: Gerrens H. , Kohnlein E.
Published: October 2023

Die Kinetik der Emulsionspolymerisation der drei Monomeren mit Amphoseife als Emulgator und K2S2O3 als Initiator wird nach früher beschriebenen Methoden untersucht. Bruttoreaktionsgeschwindigkeiten vBr und Viskositätszahlen vergleichbarer Versuche nehmen in der Reihenfolge Styrol‐Methylstyrol‐Dimethylstyrol ab. Bei alien drei Monomeren ist vBr ˜ c3/5S und vBr ˜ c3/5Kat wie die Theorie von Smith und Ewart es verlangt. Aber nur Styrol zeigt die gleiche Abhängigkeit auch für die Teilchenzahl N, während beim Methylstyrol N ˜ c0,72S und N ˜ c0,18Kat und beim Dimethylstyrol N ˜ c1,0S und ˜ c0.09Kat gefunden werden. Nach einer neuen Methode wird die mittlere Radikalkonzentration je Latexteilchen n bestimmt. Nur beim Styrol ist n̄ ≈︂ 0,5 und unabhängig von Emulgatorkonzentration cS und Initiatorkonzentration CKat. Beim Methylstyrol liegt n̄ zwischen 0,6 und 2,1 und beim Dimethylstyrol ist n̄ > 2,4, bei beiden Monomeren steigt n̄ bei Zunahme von CKat und Abnahme von cS Ursache dafür ist ein vom Styrol zum Dimethylstyrol langsamer werdender Kettenabbruch, der auf sterische Hinderung durch die Methyl‐gruppe zurückzuführen ist. Die andere Abhangigkeit der Teilchenzahl N von den Variablen folgt daraus, daß mit n̄ auch die Volumenwachstumsgeschwindigkeit μ eines Latexteilchens ansteigt. Es werden Werte für die Wachstumskonstante kw und die Abbruchkonstante k2 bei verschiedenen Temperaturen angegeben.
Response‐adaptive randomization for multiarm clinical trials using context‐dependent information measures
Authors: Kasianova Ksenia , Kelbert Mark , Mozgunov Pavel
Published: October 2023

Theoretical‐information approach applied to the clinical trial designs appeared to bring several advantages when tackling a problem of finding a balance between power and expected number of successes (ENS). In particular, it was shown that the built‐in parameter of the weight function allows finding the desired trade‐off between the statistical power and number of treated patients in the context of small population Phase II clinical trials. However, in real clinical trials, randomized designs are more preferable. The goal of this research is to introduce randomization to a deterministic entropy‐based sequential trial procedure generalized to multiarm setting. Several methods of randomization applied to an entropy‐based design are investigated in terms of statistical power and ENS. Namely, the four design types are considered: (a) deterministic procedures, (b) naive randomization using the inverse of entropy criteria as weights, (c) block randomization, and (d) randomized penalty parameter. The randomized entropy‐based designs are compared to randomized Gittins index (GI) and fixed randomization (FR). After the comprehensive simulation study, the following conclusion on block randomization is made: for both entropy‐based and GI‐based block randomization designs the degree of randomization induced by forward‐looking procedures is insufficient to achieve a decent statistical power. Therefore, we propose an adjustment for the forward‐looking procedure that improves power with almost no cost in terms of ENS. In addition, the properties of randomization procedures based on randomly drawn penalty parameter are also thoroughly investigated.
Addressing social trauma with existential‐integrative psychology in adults with autism spectrum disorder
Authors: Mercutio Elektra
Published: October 2023

In this theoretical review and analysis, I examine the existing literature regarding social trauma in autism spectrum disorder (ASD) after proposing existential‐integrative adaptations of trauma‐specific interventions that account for many of the novel characteristics and features that manifest in ASD. Practitioners interested in reimagining how they enter trauma work with this population will find multiple descriptions by providing an overview of core challenges and how those challenges influence susceptibility to the experience of social trauma and general trauma in ASD.
Analytical Tools for Dynamic Combinatorial Libraries of Cyclic Peptides
Authors: Peker Taleen , Zagiel Benjamin , Rocard Lou , Bich Claudia , Sachon Emmanuelle , Moumné Roba
Published: October 2023

Target‐directed dynamic combinatorial chemistry is a very attractive strategy for the discovery of bioactive peptides. However, its application has not yet been demonstrated, presumably due to analytical challenges that arise from the diversity of a peptide library with combinatorial side‐chains. We previously reported an efficient method to generate, under biocompatible conditions, large dynamic libraries of cyclic peptides grafted with amino acid's side‐chains, by thiol‐to‐thioester exchanges. In this work, we present analytical tools to easily characterize such libraries by HPLC and mass spectrometry, and in particular to simplify the isomers’ distinction requiring sequencing by MS/MS fragmentations. After structural optimization, the cyclic scaffold exhibits a UV‐tag, absorbing at 415 nm, and an ornithine residue which favors the regioselective ring‐opening and simultaneous MS/MS fragmentation, in the gas‐phase.
Hexaguanidino‐Triptycenes and Triphenylenes: Electronic Coupling in Molecules Containing Three Redox‐Active o‐Diguanidinobenzene Units Connected either Directly or Interacting Through Homoconjugation
Authors: Haaf Sebastian , Engels Eliane , Kaifer Elisabeth , Himmel Hans‐Jörg
Published: October 2023

Novel redox‐active hexaguanidine molecules with multiple redox states were synthesized by connecting three o‐diguanidinobenzene units. In 2,3,6,7,14,15‐hexaguanidino‐triptycenes, the three redox‐active o‐diguanidinobenzene units are connected through C−C bonds to the sp3‐hybridized bridgehead C atoms, and in 2,3,6,7,10,11‐hexaguanidino‐triphenylenes they are directly connected. The connectivity difference leads to different electronic coupling between the three redox‐active o‐diguanidinobenzene units, with homoconjugation being present in the triptycene, but not in the triphenylene compounds. Motivated by the appearance of an intense low‐energy electronic transition, we especially analysed the effect of homoconjugation on the electronic structure and charge delocalization in the dicationic redox state of the triptycene derivatives. Then, several trinuclear high‐spin cobalt (and copper) complexes were synthesized with the triphenylene and triptycene ligands, and the magnetic coupling and redox properties analysed. By choice of the coligands (hexafluoroacetylacetonate, trifluoroacetylacetonate and acetylacetonate), oxidation could be switched between metal‐ and ligand‐centered redox events, leading to drastic changes in the magnetic or optical properties, especially as a consequence of homoconjugation in the triptycene derivatives.
Membranbasierte Bereitstellung von CO2 für die dezentrale Algenproduktion in einer Bioenergiefassade
Authors: Wolff Thorsten , Brinkmann Torsten , Scholles Carsten , Kerner Martin
Published: October 2023

Diese Studie unterstreicht die Bedeutung einer nachhaltigen Energieversorgung im Hinblick auf den Klimawandel. Es wird ein Weg aufgezeigt, wie eine dezentrale Wärmeversorgung in städtischen Gebieten basierend auf erneuerbaren Energien mit einer Algenproduktion kombiniert werden kann. Die dezentral erzeugten CO2‐Emissionen werden mittels Membrantrenntechnik für die Biomasseproduktion nutzbar gemacht. Das Betriebsverhalten der CO2‐selektiven Membranmaterialien wurde über einen Betriebszeitraum von fast 10 Jahren beobachtet. Dies liefert einen soliden Nachweis für die Betriebsbereitschaft der Polymermembran und der Membranmodultechnologie. So wird eine weitere Optimierung des Trennverfahrens für zukünftige Anwendungen, auch in einem breiteren Einsatzspektrum, ermöglicht.
Manipulating Nanowires in Interconnecting Layer for Efficient Tandem Organic Photovoltaics†
Authors: Tang Yanjie , Fu Jiaming , Li Hao , Ryu Du Hyeon , Shin Won Suk , Zhang Jianqi , Yang Yi , Yang Yiming , Li Deyuan , Zheng Zhong , Zhang Shaoqing , Hou Jianhui
Published: October 2023

Comprehensive Summary

Owing to the function of manipulating light absorption distribution, tandem organic solar cells containing multiple sub‐cells exhibit high power conversion efficiencies. However, there is a substantial challenge in precisely controlling the inter‐subcells carrier migration which determines the balance of charge transport across the entire device. The conductivity of “nanowires”‐like conducting channel in interconnecting layer between sub‐cells should be improved which calls for fine engineering on the morphology of polyelectrolyte in interconnecting layer. Here, we develop a simple method to effectively manipulating the domains of conductive components in commercially available polyelectrolyte PEDOT:PSS. The use of poor solvent could effectively modify the configuration of polystyrene sulfonic acid and thus the space for conductive components. Based on our strategy, the insulated shells wrapping conductive domains are thinned and the efficiencies of tandem organic solar cells are improved. We believe our method might provide guidance for the manufacture of tandem organic solar cells.
A model for predicting postoperative persistent acute kidney injury (AKI) in AKI after cardiac surgery patients with normal baseline renal function
Authors: Chen Yuanhan , Mo Zhiming , Chu Hong , Hu Penghua , Fan Wei , Wu Yanhua , Song Li , Zhang Li , Li Zhilian , Liu Shuangxin , Ye Zhiming , Liang Xinling
Published: October 2023

Background

Persistent acute kidney injury (AKI) after cardiac surgery is not uncommon and linked to poor outcomes.

Hypothesis

The purpose was to develop a model for predicting postoperative persistent AKI in patients with normal baseline renal function who experienced AKI after cardiac surgery.

Methods

Data from 5368 patients with normal renal function at baseline who experienced AKI after cardiopulmonary bypass cardiac surgery in our hospital were retrospectively evaluated. Among them, 3768 patients were randomly assigned to develop the model, while the remaining patients were used to validate the model. The new model was developed using logistic regression with variables selected using least absolute shrinkage and selection operator regression.

Results

The incidence of persistent AKI was 50.6% in the development group. Nine variables were selected for the model, including age, hypertension, diabetes, coronary heart disease, cardiopulmonary bypass time, AKI stage at initial diagnosis after cardiac surgery, postoperative serum magnesium level of <0.8 mmol/L, postoperative duration of mechanical ventilation, and postoperative intra‐aortic balloon pump use. The model's performance was good in the validation group. The area under the receiver operating characteristic curve was 0.761 (95% confidence interval: 0.737–0.784). Observations and predictions from the model agreed well in the calibration plot. The model was also clinically useful based on decision curve analysis.

Conclusions

It is feasible by using the model to identify persistent AKI after cardiac surgery in patients with normal baseline renal function who experienced postoperative AKI, which may aid in patient stratification and individualized precision treatment strategy.
Usefulness of endoscopic ultrasound‐guided transhepatic biliary drainage with a 22‐gauge fine‐needle aspiration needle and 0.018‐inch guidewire in the procedure's induction phase
Authors: Yane Kei , Yoshida Masahiro , Imagawa Takayuki , Morita Kotaro , Ihara Hideyuki , Hanada Kota , Hirokawa Sota , Tomita Yusuke , Minagawa Takeyoshi , Okagawa Yutaka , Sumiyoshi Tetsuya , Hirayama Michiaki , Kondo Hitoshi
Published: October 2023

Endoscopic ultrasound (EUS)‐guided transhepatic biliary drainage is usually performed with a 19‐gauge fine‐needle aspiration (FNA) needle and a 0.025‐inch guidewire. The combination of a 22‐gauge FNA needle and a 0.018‐inch guidewire is reported to be effective as a rescue option when the bile duct diameter is small or technically challenging. Experts in EUS‐guided transhepatic biliary drainage have reported that bile duct puncture with a 19‐gauge FNA needle is possible in most cases, but is not easy to reproduce by endoscopists with less experience in EUS‐guided transhepatic biliary drainage. We investigated the usefulness of EUS‐guided transhepatic biliary drainage using a 22‐gauge FNA needle and a 0.018‐inch guidewire during the procedure's induction phase. Consecutive patients who underwent EUS‐guided transhepatic biliary drainage at our institution from March 2021 to May 2023 were evaluated, and 37 were included. Biliary drainage was performed for malignant bile duct stricture in 36 patients and choledocholithiasis in one patient. The median target bile duct diameter was 4.5 mm (2.5–9.4). Biliary access, fistula dilation, and stent placement were successful in the 37 patients (100%). The median procedure time was 35 min (16–125). Adverse events occurred in four (10.8%) patients. EUS‐guided transhepatic biliary drainage using a 22‐gauge FNA needle and a 0.018‐inch guidewire is a useful and promising option for endoscopists with limited experience in EUS‐guided transhepatic biliary drainage in the procedure's induction phase.
DABCO‐Promoted Bicyclization/Rearrangement Reaction Synthesis of Tetrasubstituted Furans and Furo[3,4‐d]pyrimidine‐2,4‐diones from 1,4‐Enediones
Authors: Zhang Wen‐Wen , Gan Shao‐Ting , Qin Zhao‐Yi , Jin Mei , Liu Shan , Shu Wen‐Ming , Wu An‐Xin
Published: October 2023

A DABCO‐promoted bicyclization/rearrangement reaction has been developed for the synthesis of tetrasubstituted furans from 1,4‐enediones at room temperature. This transformation involves aza‐Michael addition, intramolecular bicyclization, and rearrangement processes. In addition, the 4‐ureidofuran‐3‐carboxylate ester products can further be converted to furo[3,4‐d]pyrimidine‐2,4‐diones through intramolecular substitution cyclization under heating conditions.
An Intramolecular Enyne Metathesis Approach for the Synthesis of Cyclic 3‐Substituted Unsaturated Sulfones
Authors: Lin Dandan , Sullivan Anna , Cîrceie Martha , Chiericoni Vittoria , Karpov Jaroslav , Kluza Kacper , O'Neill Niamh , Risse Wilhelm , Evans Paul
Published: October 2023

Studies into the ring‐closing enyne metathesis of a series of nine sulfone containing enynes is described. The readily accessible sulfone substrates were shown to undergo cyclisation to form 3‐subsituted 2,5‐dihydrothiophene 1,1‐dioxides (sulfolenes) and one 3,6‐dihydro‐2H‐thiopyran 1,1‐dioxide. The success of this process depended on the substrate's substitution pattern. Moderate to good yields of the products were obtained when the ene component was monosubstituted and it was found that the reactions proceeded most efficiently using the 2nd generation Grubbs catalysts, at elevated temperatures.
The simultaneous voltammetric detection of guanine and inosine using a hybrid nanocomposite of multi‐walled carbon nanotubes and iron oxide nanoparticles
Authors: Soltani Niloufar , Noroozifar Meissam , Kerman Kagan
Published: October 2023

In this proof‐of‐concept study, a graphite paste electrode was modified with a novel hybrid nanocomposite of multi‐walled carbon nanotubes and iron‐oxide nanoparticles for the simultaneous voltammetric detection of guanine and inosine. The nanocomposite was characterized using transmission electron microscopy. The incorporation of iron oxide nanoparticles with multiwalled carbon nanotubes to the modified graphite paste electrode provided an enhanced electrocatalytic activity as studied by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. The linearity ranges were 0.1–9.0 μM and 0.5–55 μM with a detection limit of 0.05 μM and 0.12 μM for guanine and inosine, respectively. Moreover, chronoamperometric studies were carried out for the determination of diffusion coefficients, and heterogenous rate constants of guanine and inosine. The sensor was also used for the simultaneous detection of guanine and inosine in commercially available bovine serum samples with recovery values ranging from 96 % to 104 %. We envisage the nanocomposite‐modified sensor provides a promising platform for the detection of guanine and inosine in pharmaceutical formulations and biological samples as biomarkers of oxidative damage related to cancer research.
Efficacy and tolerability of dolutegravir/lamivudine versus dolutegravir/rilpivirine in switching from a three‐drug regimen based on nonnucleoside reverse transcriptase inhibitors: A retrospective cohort study
Authors: Lagi Filippo , Giacomelli Andrea , Borghi Vanni , Ciccullo Arturo , Taramasso Lucia , Madeddu Giordano , D'Ettorre Gabriella , Giacometti Andrea , Ducci Filippo , De Vito Andrea , Pincino Rachele , Di Giambenedetto Simona , Mussini Cristina , Antinori Spinello , Sterrantino Gaetana
Published: October 2023

Real‐life comparisons of dolutegravir/rilpivirine (DTG/RPV) and DTG/lamivudine (3TC) regimens in people living with human immunodeficiency virus (PLWHIV) who switched from a standard three‐drug regimen based on nonnucleoside reverse transcriptase inhibitors (NNRTIs) are missing. This study aimed to compare DTG/3TC and DTG/RPV in virologically suppressed patients (HIV‐RNA < 50 copies/mL) coming from any NNRTI‐based regimen in terms of discontinuation due to virologic failure (VF) discontinuation rates due to all causes, and adverse events. As a secondary outcome, we evaluated the difference in creatinine, total cholesterol, CD4, and triglycerides from baseline to weeks 48 after the switch. Of the 415 PLWHs included in the study, 278 (66.9%) switched to DTG/3TC, and 137 (33.1%) switched to DTG/RPV. Overall, 48 PLWHs (11.6%) discontinued the treatment:38 with DTG/3TC and 10 with DTG/RPV with similar discontinuation rates: 5.01 × 100 py (95% confidence interval [CI] 3.64–6.94) and 4.66 × 100 py (95% CI 2.51–8.67), respectively. The most common reason for discontinuation was toxicity (26 patients, 22/278 [7.9%] in the DTG/3TC group and 4/137 [2.9%] in the DTG/RPV group), mainly neurologic toxicity (never above grade 2). We found no differences in discontinuation rates due to treatment adverse events. Two study participants experienced virological failure in the DTG/3TC arm. We observed no significant difference in CD4 cell counts, lipid parameters, or renal function between the two groups at 48 weeks. This study demonstrated that, in clinical practice, a two‐drug regimen with DTG/3TC or DTG/RPV is characterized by a low discontinuation rate and VF in virologically suppressed PLWHs switched from an NNRTI‐based three antiretroviral drugs regimen.
Insight into the effect of large yellow croaker roe phospholipids on the physical properties of surimi gel and their interaction mechanism with myofibrillar protein
Authors: Du Yanyu , Lan Jiaojiao , Zhong Rongbin , Shi Feifei , Yang Qian , Liang Peng
Published: October 2023

BACKGROUND

The present study aimed to investigate the effects of large yellow croaker roe phospholipids (LYCRPLs) on the physical properties of surimi gels and to clarify their interaction mechanism with myofibrillar proteins (MPs) in terms of chemical forces and the spatial conformation.

RESULTS

LYCRPLs could improve the gel strength, textural properties, rheological properties and water‐holding capacity of surimi gels. Moreover, the interaction mechanism between LYCRPLs with MPs was revealed through intermolecular forces, Fourier transform infrared spectroscopy and ultraviolet visible absorption spectroscopy. The findings demonstrated that LYCRPLs enhanced the surface hydrophobicity and particle size of MPs, facilitating expansion and cross‐linking of MPs.

CONCLUSION

These results provide a theoretical basis for improving the characteristics of surimi gels and thus facilitate the application of LYCRPLs in the aquatic food industry. © 2023 Society of Chemical Industry.
A repository of grade 1 and 2 meningioma MRIs in a public dataset for radiomics reproducibility tests
Authors: Vassantachart April , Cao Yufeng , Shen Zhilei , Cheng Karen , Gribble Michael , Ye Jason C. , Zada Gabriel , Hurth Kyle , Mathew Anna , Guzman Samuel , Yang Wensha
Published: October 2023

Purpose

Meningiomas are the most common primary brain tumors in adults with management varying widely based on World Health Organization (WHO) grade. However, there are limited datasets available for researchers to develop and validate radiomic models. The purpose of our manuscript is to report on the first dataset of meningiomas in The Cancer Imaging Archive (TCIA).

Acquisition and validation methods

The dataset consists of pre‐operative MRIs from 96 patients with meningiomas who underwent resection from 2010–2019 and include axial T1post and T2‐FLAIR sequences—55 grade 1 and 41 grade 2. Meningioma grade was confirmed based on the 2016 WHO Bluebook classification guideline by two neuropathologists and one neuropathology fellow. The hyperintense T1post tumor and hyperintense T2‐FLAIR regions were manually contoured on both sequences and resampled to an isotropic resolution of 1 × 1 × 1 mm3. The entire dataset was reviewed by a certified medical physicist.

Data format and usage notes

The data was imported into TCIA for storage and can be accessed at https://doi.org/10.7937/0TKV‐1A36. The total size of the dataset is 8.8GB, with 47 519 individual Digital Imaging and Communications in Medicine (DICOM) files consisting of 384 image series, and 192 structures.

Potential applications

Grade 1 and 2 meningiomas have different treatment paradigms and are often treated based on radiologic diagnosis alone. Therefore, predicting grade prior to treatment is essential in clinical decision‐making. This dataset will allow researchers to create models to auto‐differentiate grade 1 and 2 meningiomas as well as evaluate for other pathologic features including mitotic index, brain invasion, and atypical features. Limitations of this study are the small sample size and inclusion of only two MRI sequences. However, there are no meningioma datasets on TCIA and limited datasets elsewhere although meningiomas are the most common intracranial tumor in adults.
A novel, end‐to‐end framework for avoiding collisions between the patient's body and gantry in proton therapy
Authors: Yamazaki Yuhei , Terunuma Toshiyuki , Kato Takahiro , Komori Shinya , Sakae Takeji
Published: October 2023

Background

Administration of external radiation therapy via proton therapy systems carries a risk of occasional collisions between the patient's body and gantry, which is increased by the snout placed near the patient for better dose distribution. Although treatment planning software (TPS) can simulate controlled collisions, the computed tomography (CT) data used for treatment planning are insufficient given that collisions can occur outside the CT imaging region. Thus, imaging the three‐dimensional (3D) surface outside the CT range and combining the data with those obtained by CT are essential for avoiding collisions.

Purpose

To construct a prototype for 3D surface imaging and an end‐to‐end framework for preventing collisions between the patient's body and the gantry.

Methods

We obtained 3D surface data using a light sectioning method (LSM). By installing only cameras in front of the CT, we achieved LSM using the CT couch motion and preinstalled patient‐positioning lasers. The camera image contained both sagittal and coronal lines, which are unnecessary for LSM and were removed by deep learning. We combined LSM 3D surface data and original CT data to create synthetic Digital Imaging and Communications in Medicine (DICOM) data. Subsequently, we compared the TPS snout auto‐optimization using the original CT data with the synthetic DICOM data.

Results

The mean positional error for LSM of the arms and head was 0.7 ± 0.8  and 0.8 ± 0.8 mm for axial and sagittal imaging, respectively. The TPS snout auto‐optimization indicated that the original CT data would cause collisions; however, the synthetic DICOM data prevented these collisions.

Conclusions

The prototype system's acquisition accuracy for 3D surface data was approximately 1 mm, which was sufficient for the collision simulation. The use of a TPS with collision avoidance can help optimize the snout position using synthetic DICOM data. Our proposed method requires no external software for collision simulation and can be integrated into the clinical workflow to improve treatment planning efficiency.
A case of tuberculous pleurisy characterized by bleeding and necrosis documented by medical thoracoscope
Authors: Zhang Minlong , Yang Cuiping , Guo Yinghua
Published: October 2023

Key message

Tuberculous pleurisy is a main cause of pleural effusions. The main histological abnormalities in pleural biopsy of tuberculous pleurisy are caseating granulomas and epithelioid cell granuloma. In our case, chronic inflammation of fibrous tissue with bleeding, necrosis, and exudation were observed during a medical thoracoscopy as manifestations of tuberculous pleurisy.
Neugeborenen-Screening aus Trockenblut (NBS) in Deutschland
Authors: Nennstiel Uta , Odenwald Birgit , Throner Veronika , Blankenstein Oliver , Vieth Andreas , Ratzel Rudolf , Coenen Michaela , Brockow Inken
Published: October 2023

Das Neugeborenen-Screening aus Trockenblut (Newborn Blood Spot Screening, NBS) ist eine seit vielen Jahren etablierte hocheffektive Maßnahme der Sekundärprävention. Aufgrund der Entwicklung neuer diagnostischer und therapeutischer Möglichkeiten für seltene angeborene Krankheiten ist davon auszugehen, dass in Zukunft weitere Zielkrankheiten in das NBS aufgenommen werden. Vor diesem Hintergrund wurde im Auftrag des GKV-Spitzenverbandes ein Konzept für die Weiterentwicklung des NBS entwickelt. Als Grundlage hierfür dienten eine systematische Literaturrecherche und die Erhebung des Status quo in Deutschland anhand von quantitativen und qualitativen Methoden.

Entscheidend für den Erfolg des NBS ist, dass möglichst alle von einer Zielkrankheit betroffenen Neugeborenen frühzeitig diagnostiziert und behandelt werden und der bei jedem Screening zu erwartende Schaden (z. B. durch falsch-positive Befunde) möglichst gering gehalten wird. Hierfür ist die Organisation des Screenings im Sinne eines integrierten Programms durch eine zentrale Koordination mit standardisierten Strukturen, kontinuierlichem Qualitätsmanagement und einer datenschutzkonformen Digitalisierung erforderlich.

Obwohl das NBS in Deutschland insgesamt erfolgreich umgesetzt wird, zeigen sich im Rahmen des hier vorgestellten Forschungsprojekts auch Schwächen und Handlungsbedarf. Erarbeitete Vorschläge und Empfehlungen wurden in einem Konzeptpapier festgehalten, das Ansätze für eine dem aktuellen Forschungsstand entsprechende Weiterentwicklung des NBS aufzeigt und dabei sich ändernde Anforderungen an die Infrastruktur und Prozesse im Gesundheitssystem berücksichtigt. In diesem Übersichtsartikel werden Herausforderungen, aktueller Stand und Lösungsansätze zu zentralen Themenfeldern des Konzeptpapiers zusammenfassend dargestellt.
Identifying QTLs involved in hybrid performance and heterotic group complementarity: new GWAS models applied to factorial and admixed diallel maize hybrid panels
Authors: Beugnot Aurélien , Mary-Huard Tristan , Bauland Cyril , Combes Valerie , Madur Delphine , Lagardère Bernard , Palaffre Carine , Charcosset Alain , Moreau Laurence , Fievet Julie B.
Published: October 2023

Key message

An original GWAS model integrating the ancestry of alleles was proposed and allowed the detection of background specific additive and dominance QTLs involved in heterotic group complementarity and hybrid performance.

Maize genetic diversity is structured into genetic groups selected and improved relative to each other. This process increases group complementarity and differentiation over time and ensures that the hybrids produced from inter-group crosses exhibit high performances and heterosis. To identify loci involved in hybrid performance and heterotic group complementarity, we introduced an original association study model that disentangles allelic effects from the heterotic group origin of the alleles and compared it with a conventional additive/dominance model. This new model was applied on a factorial between Dent and Flint lines and a diallel between Dent-Flint admixed lines with two different layers of analysis: within each environment and in a multiple-environment context. We identified several strong additive QTLs for all traits, including some well-known additive QTLs for flowering time (in the region of Vgt1/2 on chromosome 8). Yield trait displayed significant non-additive effects in the diallel panel. Most of the detected Yield QTLs exhibited overdominance or, more likely, pseudo-overdominance effects. Apparent overdominance at these QTLs contributed to a part of the genetic group complementarity. The comparison between environments revealed a higher stability of additive QTL effects than non-additive ones. Several QTLs showed variations of effects according to the local heterotic group origin. We also revealed large chromosomic regions that display genetic group origin effects. Altogether, our results illustrate how admixed panels combined with dedicated GWAS modeling allow the identification of new QTLs that could not be revealed by a classical hybrid panel analyzed with traditional modeling.
Trends in prescribing and outcomes in obese versus non-obese patients receiving rivaroxaban therapy: an observational study using real-world data
Authors: Alalawneh Majdoleen , Rachid Ousama , Abdallah Ibtihal , Mahfouz Ahmed , Elewa Hazem , Danjuma Mohammed Ibn-Mas‘ud , Mohamed Asmaa Ezzeldin , Awaisu Ahmed
Published: October 2023

Purpose

To investigate real-world prescribing trends and clinical outcomes based on body mass index (BMI) categorization in patients who received rivaroxaban therapy.

Methods

This was a retrospective cohort study involving all patients who received rivaroxaban therapy across all Hamad Medical Corporation (HMC) hospitals from 2015 to 2020.

Results

The number of patients initiated on rivaroxaban therapy significantly increased from 152 (3.3%) in 2015 to 1342 (28.9%) in 2020 (p <0.001). Within BMI categories, a similar increasing trend was observed in underweight, normal, and overweight patients, while from 2018 to 2020, there was a decreasing trend in rivaroxaban prescribing in all obese classes. The prevalence rate of all-cause mortality differed significantly between the BMI groups, with the highest mortality being among morbidly obese patients (BMI ≥ 40 kg/m2) (p< 0.001). On the other hand, no significant differences were found between the BMI groups in terms of bleeding, pulmonary embolism, deep vein thrombosis and stroke incidences. Multivariate logistic regression analyses showed that the likelihood of all-cause mortality was significantly higher in overweight and all categories of obese patients compared to underweight patients: overweight (OR: 5.3, 95% CI: 2.3–11.9, p< 0.001); obese class 1 (OR: 5.4, 95% CI: 2.3 – 12.2, p< 0.001); obese class 2 (OR: 6.5, 95% CI: 2.7 – 15.6, p< 0.001); and obese class 3 (OR: 3.7, 95% CI: 1.6 – 8.7, p = 0.003).

Conclusions

Rivaroxaban prescribing has significantly increased over the years across general population, with a noticeable decline in obese population during the last few years (from 2018 onwards). Furthermore, an appreciable association was evident between all-cause mortality and BMI of these patients.
The Timing of Operative Intervention for Pediatric Burn Patients in Malawi
Authors: Davis Dylane , An Selena , Kayange Linda , Wolf Lindsey , Boddie Olivia , Charles Anthony , Gallaher Jared
Published: October 2023

Background

Defining the optimal timing of operative intervention for pediatric burn patients in a resource‐limited environment is challenging. We sought to characterize the association between mortality and the timing of operative intervention at a burn center in Lilongwe, Malawi.

Methods

This is a retrospective analysis of burn patients (<18 years old) presenting to Kamuzu Central Hospital from 2011 to 2022. We compared patients who underwent excision and/or burn grafting based on the timing of the operation. We used logistic regression modeling to estimate the adjusted odds ratio of death based on the timing of surgery.

Results

We included 2502 patients with a median age of 3 years (IQR 1–5) and a male preponderance (56.8%). 411 patients (16.4%) had surgery with a median time to surgery of 18 days (IQR 8–34). The crude mortality rate among all patients was 17.0% and 9.1% among the operative cohort. The odds ratio of mortality for patients undergoing surgery within 3 days from presentation was 5.00 (95% CI 2.19, 11.44) after adjusting for age, sex, % total burn surface area (TBSA), and flame burn. The risk was highest for the youngest patients.

Conclusions

Children who underwent burn excision and/or grafting in the first 3 days of hospitalization had a much higher risk of death than patients undergoing surgical intervention later. Delaying operative intervention till >72 h for pediatric patients, especially those under 5 years old, may confer a survival advantage. More investment is needed in early resuscitation and monitoring for this patient population.
Use of the sun compass by monocularly occluded homing pigeons in a food localisation task in an outdoor arena
Authors: Cioccarelli Sara , Bianchi Benedetta , Giunchi Dimitri , Gagliardo Anna
Published: October 2023

Functional asymmetries of the avian visual system can be studied in monocularly occluded birds, as their hemispheres are largely independent. Right and left monocularly occluded homing pigeons and control birds under binocular view have been trained in a food localisation task in an octagonal outdoor arena provided with one coloured beacon on each wall. The three groups were tested after the removal of the visual beacons, so to assess their sun compass learning abilities. Pigeons using the left eye/right hemisphere system exhibited slower learning compared to the other monocular group. During the test in the arena void of visual beacons, the three groups of birds, regardless of their visual condition, were generally able to identify the training sector by exclusively relying on sun compass information. However, the directional choices of the pigeons with the left eye/right hemisphere in use were significantly affected by the removal of the beacons, while both control pigeons and birds with the right eye/left hemisphere in use displayed unaltered performances during the test. A subsample of pigeons of each group were re-trained in the octagonal arena with visual beacons present and tested after the removal of visual beacons after a 6 h fast clock-shift treatment. All birds displayed the expected deflection consistent to the sun compass use. While birds using either the left or the right visual systems were equally able to learn a sun compass-mediated spatial task, the left eye/right hemisphere visual system displayed an advantage in relying on visual beacons.
Quality of life outcomes after deep brain stimulation in acquired dystonia: a systematic review and meta-analysis
Authors: Aihemaitiniyazi Adilijiang , Zhang Huawei , Hu Yue , Li Tiemin , Liu Changqing
Published: October 2023

Background

Dystonia is a condition that affects the ability to control the movement and function of the body’s muscles. It can cause not only physical problems, but also mental problems, resulting in impaired health-related quality of life (HRQoL). However, the effect of deep brain stimulation on quality of life in acquired dystonia remains unclear.

Methods

We conducted a systematic literature review from January 2000 to October 2022，determined the eligible studies, and performed a meta-analysis of HRQoL outcomes based on the Short-Form Health Survey-36 (SF-36) after DBS to evaluate the effects of DBS on physical and mental QoL.

Results

A total of 14 studies met the inclusion criteria and were systematically reviewed. A comprehensive meta-analysis was performed for 9 studies that reported physical and psychological data or physical component summary (PCS), or mental component summary (MCS) for SF-36. The mean (SD) age at DBS implantation was 34.29 (10.3) years, and the follow-up period after implantation was 2.21 (2.80) years. The random effects model meta-analysis revealed that both physical and mental domains of the SF-36 improved following DBS. There was no statistically significant difference between the physical domains (effect size=1.34; p<0.0001) and the mental domains (effect size=1.38; p<0.0001).

Conclusion

This is the first meta-analysis that demonstrates significant benefits in HRQoL following DBS in patients with acquired dystonia. There were significant improvements in both physical QoL and mental QoL.