bluuebunny/crossref_metadata_2025 huggingface dataset:
Über die Elektronenbeanspruchung bei der Chemisorption des Benzols an Nickel bei tiefen Temperaturen
Authors: Suhrmann R. , Wedler G. , Krüger G.
Published: October 2023

In Fortführung früherer Untersuchungen werden die Änderungen des elektrisches Widerstandes R and der lichtelektrischen Empfindlichkeit I ermittelt, die an aufgedampften Ni‐Filmen durch die Chemisorption von Benzoldampf niedrigen Druckes (10−4 bis 10−1 Torr) bei 90 °K hervorgerufen werden. Sowohl R als auch I nehmen zu, entsprechend einer kovalenten Bindung der Benzolmolekeln am Ni‐Film. Aus der Abhängigkeit der Werte ΔR von der gemessenen adsorbierten Menge wird die monomolekulare Bedeckung zu 55 · 1013 Molekeln pro cm2 Makrooberfläche berechnet. Der Rauhigkeitsfaktor der Filmoberfläche berechnet sich zu 2,2. Die adsorbierte Menge n, die Widerstandsänderung ΔR/R und die Zahl der Ni‐Atome des Films ergeben eine Beanspruchung von 6,3 Leitungselektronen pro Benzolmolekel. Der zeitliche Übergang von der physikalischen Adsorption zur Chemisorption läßt sich durch Reaktionen 2. und 1. Ordnung wiedergeben.
Die Kinetik der Reaktionen des Dichlormonoxyds mit NO2 mit N2O5 in der Lösungsphase
Authors: Martin H. , Meise W.
Published: October 2023

Die Reaktion des Dichlormonoxyds mit NO2/N2O4 in Trichlortrifluoräthan (CF2Cl · CFCl2) als Lösungsmittel wird spektralphotometrisch untersucht und mit der entsprechenden Gasphasenreaktion verglichen. Hinsichtlich Bruttoreaktionsgleichung, Reaktionsordnung und ‐mechanismus, auch Aktivierungsenergie stimmen Lösungs‐ und Gasreaktion überein. Nur die Zahlenwerte der die Geschwindigkeit ‐ d[Cl2O]/dt = k [Cl2O] [NO2] der Gesamtreaktion bestimmenden Konstanten k des bimolekularen Schrittes Cl2O + NO2 · NO2Cl + OCl unterscheiden sich stärker. Der Unterschied wird theoretisch gedeutet. Für die Konstante kL der Lösungs‐reaktion wird 3, 01 · 107 exp (‐ 10370/RT) 1 · mol−1 · sec−1, für das Verhältnis kL/kG bei 20 °C 0,56/0,13 = 4,3 gefunden.

Mit N2O5 reagiert Cl2O in der Lösungsphase wie in der Gasphase nicht direkt, sondern mit dessen Zerfallsprodukten. Die Konstante des N2O5‐Zerfalls in CF2Cl · CFCl2 wird zu 4,01 · 1013 exp (‐ 24500/RT) bestimmt.

Zahlenwerte der Konstanten des N2O4‐Dissoziationsgleichgewichts in CF2Cl · CFCl2 zwischen 1° und 20 °C werden mitgeteilt.
Über die Kinetik der Elektrodenprozesse bei der Carbonyl und Nitrogruppenreduktion an Quecksilberkathoden II. Die Wirkung von Inhibitoren auf die p‐Nitranilin‐Reduktion
Authors: Holleck L. , Kastening B.
Published: October 2023

Als Ursache für den Einfluß von Inhibitoren (Campher) auf die Reduktionsvorgänge an Nitroverbindungen wird eine Verlangsamung der Durchtrittsreaktionen nahegebracht, die sich aus dem Verlauf von Stromzeitkurven am polarographischen Einzeltropfen ergibt. ‐ Das Aufhören der Inhibition bei gewissen negativen Potentialen ist nicht allein auf die Potentialabhängigkeit des Adsorptionsgleichgewichts, sondern auch auf zeitlich verzögerte Einstellung dieses Gleichgewichts zurückzuführen. Hierfür ist nicht der Diffusions‐, sondern der Adsorptionsschritt verantwortlich.
Beeinflussung der katalytischen Eigenschaften des Platins durch adsorbierte Gase
Authors: Riekert Lothar
Published: October 2023

Es wurde die Reaktionsrichtung des Ameisensäurezerfalls an Platindrähten untersucht, die elektrisch auf 800 bis 1100°C erwärmt wurden. Die Geschwindigkeit der Umsetzung ist in diesem Temperaturgebiet durch Diffusionsvorgänge bestimmt. Die mengenmäßigen Anteile der Dehydrierung (HCOOH → H2 + CO2) und der Dehydratisierung (HCOOH → H2O + CO) am Umsatz hängen von der Vorbehandlung der Kontakte ab. Während ein vor der Reaktion nur in Wasserstoff ausgeglühter Katalysator ausschließlich Dehydrierung der Ameisensäure bewirkt, beträgt der Anteil der Dehydratisierung an einem Platindraht, der zuvor nacheinander in Wasserstoff, Sauerstoff und Wasserdampf ausgeglüht wurde, über 50%.

Die Reaktionen H2O + CO → H2 + CO2 bzw. H2 + CO2 → H2O + CO sind weder bei der Dehydrierung noch bei der Dehydratisierung am Reaktionsgeschehen beteiligt. Die Abhängigkeit der katalytischen Eigenschaften des Platins von der Vorbehandlung zeigt sich hier außer beim Ameisensäurezerfall auch am Beispiel der Reaktion zwischen Wasserstoff und Kohlendioxyd.
Der Zerfallsmechanismus des Wüstits Fe1 – xO unterhalb 570°C
Authors: Hoffmann Alfred
Published: October 2023

Der Zerfall des Wüstits Fe1 – xO wird wesentlich durch seine Unstöchiometrie beeinflußt. Der Gesamtzerfall 4 Fe1 – xO ⇉ Fe3O4 + (1 – 4x) α — Fe mit 0,05 ⩽ x ⩽ 0,13 kann in Abhängigkeit von der Temperatur und dem Eisenunterschuß x nach drei verschiedenen Reaktions‐mechanismen erfolgen. Der Ablauf des Zerfalls zwischen 135 und 550° wird sowohl für Wüstitproben, die primär ausgeschiedenes metallisches Eisen enthalten, als auch für Wüstitschichten von verzundertem Eisen erörtert. Während des Zerfalls entsteht zunächst ein metastabiler Wüstit, dessen Eisenunterschuß etwa zwischen 0,01 und 0,08 liegt. Die Zusammensetzung des gebildeten metastabilen Wüstits ist nur von der Temperatur und nicht von der Ausgangszusammensetzung abhängig. Anschließend bleibt die Zusammensetzung des Wüstits bis zum restlosen Zerfall bei konstanter Temperatur unverändert.
Polarisation der Wasserstoffelektrode, speziell der Pt/H2‐Elektrode, in schwach sauren und schwach alkalischen Lösungen
Authors: Nagel K. , Wendler F.
Published: October 2023

Die Polarisation der Wasserstoffelektrode, speziell der Pt/H2‐Elektrode in schwach sauren und schwach alkalischen Lösungen, wird theoretisch und experimentell untersucht, und zwar an Hand von potentiostatisch aufgenommenen Strom‐Polarisations‐Kurven J (Δg) und galvanostatischen Polarisations‐Zeit‐Kurven Δg(t)J (Lade‐ oder Anklingkurven).

Die Beschränkung auf schwach saure und schwach alkalische Lösungen gestattet die polarographische Aufnahme der Strom‐Polarisations‐Kurven und die weitgehende theoretische Deutung der Polarisationserscheinungen durch gehemmte Diffusion der H+‐Ionen, OH−‐Ionen und H2‐Molekeln. Durch Verarmung an diesen Reaktionsteilnehmern kommt es zu charakteristischen Grenzströmen. Besonders hervorzuheben ist das Auftreten von zwei anodischen Grenzströmen bei schwach alkalischen Lösungen.

Die kathodische Verarmung an H+‐Ionen bei einer sauren Wasserstoffelektrode und die anodische Verarmung an OH−‐Ionen bei einer alkalischen Wasserstoffelektrode führt zu einem Wechsel der Elektrodenreaktion, zu einer „Wechselpolarisation”︁.

Änderungen beim Übergang von saurer zu alkalischer Lösung, von kathodischer zu anodischer Belastung, von glatten zu platinierten Elektroden, von stationären Strom‐Polarisations‐Kurven zu nicht‐stationären Anklingkurven der Polarisation und von Anklingkurven bei strömenden zu Anklingkurven bei ruhenden Elektrolyten werden untersucht und für die Deutung der Polarisationserscheinungen ausgewertet.
Elektrochemische Untersuchung des Gleichgewichtes Fe + CO2 ⇄ FeO + CO
Authors: Peters H. , Mann G.
Published: October 2023

Es werden thermodynamische Daten für das Reduktionsgleichgewicht des Wüstits mitgeteilt, die nach einer neuen elektrochemischen Methode erhalten wurden. Unter Benutzung eines festen Elektrolyten mit reiner Sauerstoffionenleitung ist es möglich, eine galvanische Zelle aufzubauen, in der die angegebene Reaktion bei höheren Temperaturen reversibel abläuft. Die erhaltenen Ergebnisse sind in guter Übereinstimmung mit den nach anderen Verfahren erhaltenen Literaturwerten und zeigen die Verwendbarkeit dieser Methode.
Über die kristallographische Orientierung von Salzdendriten
Authors: Hille M. , Rau H. , Schlipf J.
Published: October 2023

Bei Wachstumsversuchen an Salzdendriten aus wäßriger Lösung bzw. aus der Schmelze wurde beobachtet, daß die kristallographische Orientierung der Dendritenachse in gesetzmäßiger Weise von der Überschreitung abhängt. Bei den Alkalihalogeniden vom Steinsalztyp z. B. erhält man bei kleinen Überschreitungen als Dendritenachse <111>, bei mittleren Überschreitungen <110>. und bei großen Überschreitungen <100>. Die theoretische Untersuchung dieser Experimente zeigt, daß als geschwindigkeitsbestimmender Schritt beim dendritischen Wachstum nur die Flächenkeimbildung in Frage kommt. Die Ergebnisse können auf Grund der von Volmer und Stranski berechneten Unterschiede der Keimbildungsarbeiten an Ecke, Kante und Fläche der Gleichgewichtsform von Ionenkristallen quantitativ gedeutet werden.
Untersuchungen mit Leitisotopen über die Ionenaustauschereigenschaften anorganischer Zinn‐ und Zirkoniumverbindungen
Authors: Merz E.
Published: October 2023

Die Abtrennung hochradioaktiver Stoffe in Kernenergieanlagen verlangt hoch strahlenresistente Ionenaustauscher. Es wurde gefunden, daß bei geeigneter Wahl der Herstellungsbedingungen die Adsorptionsprodukte von Orthophosphationen an Zinn‐bzw. Zirkoniumdioxydhydrat vorwiegend Kationenaustauscher‐Eigenschaften besitzen, während die reinen Oxydhydrate der beiden Elemente je nach dem pH‐Wert überwiegend als Anionen‐ bzw. als Kationenaustauscher wirksam sind. Diese anorganischen Stoffe zeigen neben guter Strahlenresistenz und Temperaturbeständigkeit viele Vorzüge der organischen Ionenaustauscher. Mit radioaktiven Leitisotopen wurden die Austauscherkapazitäten bestimmt und der Adsorptionsmechanismus studiert. Die Kapazitäten liegen in der Größenordnung derjenigen der organischen Austauscher. Der Adsorptionsmechanismus beruht auf einem Ionenaustausch. Ausgetauscht werden vorwiegend Wasserstoff‐ bzw. Hydroxyl‐Ionen. Die Brauchbarkeit dieser anorganischen Ionenaustauscher zu analytischen Trennungen wird an mehreren Beispielen demonstriert.
Zur Systematik der Mischungswärmen der B‐Metalle Beiträge zur Energetik metallischer Systeme. IX.
Authors: Wittig Franz Eberhard
Published: October 2023

Die Mischungswärmen in binären Systemen der B‐Metalle Zink, Cadmium, Indium, Thallium, Zinn, Blei und Wismut wurden mit einem neuen Hochtemperaturkalorimeter gemessen. Diese werden auf die Zahl der statistisch verteilten A‐B‐Bindungen bezogen und als sogenannte ξ‐Kurven in homologen Reihen über‐sichtlich zusammengefaßt, in denen alle binären Systeme eines B‐Metalls mit allen anderen enthalten sind. Diese homologen Reihen zeigen eine Anzahl von Regelmäßigkeiten. Innerhalb einer Gruppe des Perioden‐Systems ergibt sich die negativste Mischungswärme, wenn sich der zweite Partner B in derselben Periode befindet, wie die erste Komponente A, während um so positivere Werte resultieren, je weiter die Periode der zweiten Komponente B von A entfernt ist. Innerhalb einer Periode ist der Verlauf durch die Position des ersten Partners A im Perioden‐System gegeben, wobei sich in benachbarten Perioden einer homologen Reihe ein analoger Verlauf ergibt. Ein Minimum der Mischungswärmen findet sich in den III‐V‐Systemen. Bezüglich der Gestalt der ξ‐Kurven ergeben sich je nach Position beider Partner im Perioden‐System verschiedene Typen. In den homologen Reihen des Zinks und des Cadmiums bestehen die ξ‐Kurven aus einem nahezu linearen Teil, dem bei kleineren Konzentrationen des höherwertigen zweiten Partners B ein steiler Anstieg nach positiven Werten überlagert ist, der am besten durch eine Exponential‐Funktion wiedergegeben wird. Die erste partielle Mischungswärme ist immer positiver bei Metallen, die im Perioden‐System weiter rechts oder unten stehen als Zink oder Cadmium. Die Unsymmetrie nimmt mit zunehmendem Unter‐schied der Valenzen beider Komponenten zu. Auch die Neigung des geradlinigen Teils ist vielfach proportional der Änderung der Valenzelektronenkonzentration. Ein Teil der Unsymmetrie wird aber durch den exponentiellen Anstieg bedingt, der im Anschluß an Überlegungen Kubaschewskis durch die Auflösung fester gebundener Bereiche gedeutet werden kann. Es werden die Konsequenzen dieses Modells erörtert, wobei sich qualitative Beziehungen zu den Abweichungen von der Verteilungsfunktion des Kugelmodells, zum Leitfähigkeitsmechanismus, zur spezifischen Wärme oberhalb des Schmelzpunktes und der Temperaturabhängigkeit der Mischungswärmen ergeben.
Die Dispersion des Kerr‐Effekts [1] II. Partieller Beitrag einer Absorptionsbande zum Kerr‐Effekt, zur Polarisierbarkeit und den Hyperpolarisierbarkeiten
Authors: Kuball H. G. , Galler W.
Published: October 2023

Mit der Beziehung für die optische Polarisierbarkeit nach Wigner‐Weiskopf erhält man eine Gleichung für die Frequenzabhängigkeit der Kerr‐Konstanten, die es erlaubt, aus der im Bereich einer Absorptionsbande experimentell bestimmten Dispersion der Doppelbrechung den Anteil des Anisotropie‐, des Dipolgliedes und der Hyperpolarisierbarkeitsglieder B und C getrennt zu bestimmen, wenn dabei der Kerr‐Effekt als Summe von partiellen Beiträgen der einzelnen Absorptionsbanden dargestellt wird. Aus diesen Anteilen ergibt sich der Beitrag der Absorptionsbande zur Polarisierbarkeit und den Hyperpolarisierbarkeiten. Eine unabhängige Darstellung der Dispersion folgt aus einer Kramers‐Kronig‐Relation zwischen dem Kerr‐Effekt und dem Elektrodichroismus. Hierbei werden die vier Anteile der Kerr‐Konstanten und die Polarisierbarkeit und die Hyperpolarisierbarkeiten aus der Frequenzabhängigkeit der Absorptionsbande berechnet.

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Absorptionsbande eine Amplitude der molaren Kerr‐Konstanten in der Größenordnung von 10−6 bis 10−7 gemessen. An der molaren Kerr‐Konstanten sind bei diesen Verbindungen im wesentlichen das Dipol‐ und das Hyperpolarisierbarkeitsglied B beteiligt. Die Größe der Amplitude wird durch das Dipolglied bestimmt, während das Hyperpolarisierbarkeitsglied B auf Grund seiner besonderen Frequenzabhängigkeit nur die Kurve des Dipolgliedes nach kleineren Wellenzahlen verschiebt. Die Amplituden des Beitrags der Absorptionsbanden zur Polarisierbarkeit und den beiden Hyperpolarisierbarkeiten sind bei den drei Verbindungen in der Größenordnung 10−22, 10−27 und 10−31 (cgs). Die experimentell bestimmten und die aus dem Spektrum berechneten vier Anteile der Kerr‐Konstanten und auch die Polarisierbarkeit und die Hyperpolarisierbarkeiten stimmen innerhalb der Fehlergrenze überein.
Ein Vergleich der IR‐Spektren von 9,10‐Dichlorphenanthren und Phenanthren zwischen 200 und 3200 cm−1
Authors: Witt K. , Mecke R.
Published: October 2023

Die IR‐Spektren von 9,10‐Dichlorphenanthren in Lösung und orientierter kristalliner Schicht im polarisierten Licht werden verglichen mit dem IR‐Spektrum von Phenanthren. Der Dichroismus der Banden ermöglicht eine gute Trennung der drei IR‐aktiven Schwingungsrassen (bei Postulierung einer C2v‐Symmetrie) und stützt in vielen Punkten die Zuordnung des Phenanthrenspektrums. Eine vollständige Zuordnung des Spektrums von 9,10‐Dichlorphenanthren jedoch kann noch nicht gegeben werden, da Substituentenschwingungen und Schwingungskopplung nicht einwandfrei zu bestimmen sind.
Über die anodische Auflösung von Zinkoxid‐Einkristallen unter Lichteinwirkung
Authors: Hauffe Karl , Range Jochen
Published: October 2023

An Hand von Strom‐Spannungs‐Kurven im Dunkeln und unter Einstrahlung von 365‐nm‐Licht an der Kette

Metall | ZnO‐Einkristall | Elektrolyt | Pt

wurde der Durchtritt von Elektronen und Ionen durch die Phasengrenze ZnO/Elektrolyt ermittelt. Auf Grund des anodischen Teils der Strom‐Spannungs‐Kurven im Dunkeln und unter Licht darf geschlossen werden, daß ein Übergang von Elektronen vom Elektrolyten ins Leitungsband des Zinkoxids nicht ohne weiteres möglich ist. Im Dunkeln können leicht Elektronen aus dem Leitungsband in den Elektrolyten treten. Bei Lichteinwirkung hingegen tritt eine Rekombination der Defektelektronen der Elektron‐Lochpaare mit den von den Sauerstoffionen bzw. den Elektrolytionen abgebbaren Elektronen ein. Die von den Elektron‐Lochpaaren stammenden zurückbleibenden Elektronen fließen nunmehr als freie Ladungsträger zur positiv polarisierten Elektrode ab. In Gegenwart von Chinhydron im Elektrolyten wird grundsätzlich am Mechanismus nichts geändert.

Infolge dieser elektronischen Umladungsreaktion und der hierdurch verursachten Desorption des Sauerstoffs können die überschüssigen Zn2+‐Ionen in den Elektrolyten übertreten. Bei Fehlen geeigneter Redoxsysteme, die eine Sauerstoffumladung verhindern, kommt es zu einem Ausbau von ZnO, der in sauren Bereichen (pH = 3 bis 4) in Form hexagonaler Löcher auftritt, wenn man die (0001)‐Fläche des Einkristalls mit dem Elektrolyten in Berührung bringt.

Aus den Kapazitätsmessungen sowohl im Dunkeln als auch unter Licht kann geschlossen werden, daß praktisch der gesamte Spannungsabfall in der Verarmungsrandschicht des Zinkoxids in der Nähe der Phasengrenze ZnO/Elektrolyt liegt.
Oxysterol mixture and, in particular, 27‐hydroxycholesterol drive M2 polarization of human macrophages
Authors: Marengo Barbara , Bellora Francesca , Ricciarelli Roberta , De Ciucis Chiara , Furfaro AnnaLisa , Leardi Riccardo , Colla Renata , Pacini Davide , Traverso Nicola , Moretta Alessandro , Pronzato Maria Adelaide , Bottino Cristina , Domenicotti Cinzia
Published: October 2023

Macrophages play a crucial role in atherosclerosis progression. Classically activated M1 macrophages have been found in rupture‐prone atherosclerotic plaques whereas alternatively activated macrophages, M2, localize in stable plaque. Macrophage accumulation of cholesterol and of its oxidized derivatives (oxysterols) leads to the formation of foam cells, a hallmark of atherosclerotic lesions. In this study, the effects of oxysterols in determining the functional polarization of human macrophages were investigated. Monocytes, purified from peripheral blood mononuclear cells of healthy donors, were differentiated into macrophages (M0) and treated with an oxysterol mixture, cholesterol, or ethanol, every 4 H for a total of 4, 8, and 12 H. The administration of the compounds was repeated in order to maintain the levels of oxysterols constant throughout the treatment. Compared with ethanol treatment, the oxysterol mixture decreased the surface expression of CD36 and CD204 scavenger receptors and reduced the amount of reactive oxygen species whereas it did not affect either cell viability or matrix metalloprotease‐9 activity. Moreover, the oxysterol mixture increased the expression of both liver X receptor α and ATP‐binding cassette transporter 1. An enhanced secretion of the immunoregulatory cytokine IL‐10 accompanied these events. The results supported the hypothesis that the constant levels of oxysterols and, in particular, of 27‐hydroxycholesterol stimulate macrophage polarization toward the M2 immunomodulatory functional phenotype, contributing to the stabilization of atherosclerotic plaques. © 2015 The Authors BioFactors published by Wiley Periodicals, Inc. on behalf of International Union of Biochemistry and Molecular Biology, 42(1):80–92, 2016
Proanthocyanidins in health and disease
Authors: Bladé Cinta , Aragonès Gerard , Arola‐Arnal Anna , Muguerza Begoña , Bravo Francisca Isabel , Salvadó M. Josepa , Arola Lluis , Suárez Manuel
Published: October 2023

Proanthocyanidins (PAs) are the most abundant flavonoids in the human diet. Several epidemiological studies connect PA consumption and health benefits and the designation of PAs as healthy compounds started at the early stages of the 20th century. The beneficial health properties of PAs are attributed to their conjugated and colonic metabolites. Therefore, gut microbial compositions can determine the effectiveness of PAs. Reciprocally, dietary polyphenols can act as prebiotics. Recently, it has also been described that PAs modulate the circadian rhythm. Biochemical and epigenetic mechanisms, including the modulation of microRNAs, allow PAs to modulate cell functionality. PA effects in metabolic diseases are also reviewed. © 2016 BioFactors, 42(1):5–12, 2016
A galectin‐specific signature in the gut delineates Crohn's disease and ulcerative colitis from other human inflammatory intestinal disorders
Authors: Papa Gobbi Rodrigo , De Francesco Nicolás , Bondar Constanza , Muglia Cecilia , Chirdo Fernando , Rumbo Martín , Rocca Andrés , Toscano Marta A. , Sambuelli Alicia , Rabinovich Gabriel A. , Docena Guillermo H.
Published: October 2023

Inflammatory bowel diseases (IBD) are chronic and relapsing inflammatory conditions of the gastrointestinal tract including Crohn's disease (CD) and ulcerative colitis (UC). Galectins, defined by shared consensus amino acid sequence and affinity for β‐galactosides, are critical modulators of the inflammatory response. However, the relevance of the galectin network in the pathogenesis of human IBD has not yet been explored. Here, we analyzed the expression of relevant members of the galectin family in intestinal biopsies, and identified their contribution as novel mucosal markers in IBD. Colonic biopsies were obtained from 59 IBD patients (22 CD and 37 UC), 9 patients with gut rejection after transplantation, 8 adult celiac patients, and 32 non‐IBD donors. Galectin mRNA expression was analyzed by RT‐PCR and qPCR using specific primers for individual galectins. A linear discriminant analysis (LDA) was used to analyze galectin expression in individual intestinal samples. Expression of common mucosal‐associated galectins (Gal‐1, −3, −4, −9) is dysregulated in inflamed tissues of IBD patients compared with non‐inflamed IBD or control samples. LDA discriminated between different inflammation grades in active IBD and showed that remission IBD samples were clusterized with control samples. Galectin profiling could not distinguish CD and UC. Furthermore, inflamed IBD was discriminated from inflamed tissue of rejected gut in transplanted patients and duodenum of celiac patients, which could not be distinguished from control duodenum samples. The integrative analysis of galectins discriminated IBD from other intestinal inflammatory conditions and could be used as potential mucosal biomarker. © 2016 BioFactors, 42(1):93–105, 2016
Effect of chromium picolinate and melatonin either in single or in a combination in high carbohydrate diet‐fed male Wistar rats
Authors: Doddigarla Zephy , Ahmad Jamal , Parwez Iqbal
Published: October 2023

This study is designed to know the effects of chromium picolinate (CrPic) and melatonin (Mel) each alone and in a combination on high carbohydrate diet‐fed (HCD‐fed) male Wistar rats that exhibit insulin resistance (IR), hyperglycemia, and oxidative stress. Wistar rats have been categorized into five groups. Each group consisted of six male Wistar rats, control rats (group I), HCD (group II), HCD + CrPic (group III), HCD + Mel (group IV), and HCD + CrPic + Mel (group V). Insignificant differences were observed in serum levels of superoxide dismutase, nitric oxide, and zinc in group III, group IV, and group V when each group was compared with group II rats respectively. Significant differences were observed in group III, group IV, and group V when each group was compared with group II in homeostasis model assessment‐estimated IR (P < 0.05, <0.0.05, <0.05), and in the levels of blood glucose (P < 0.05, <0.0.05, <0.05), total cholesterol (P < 0.05, <0.001, <0.001), triacylglycerols (<0.05, <0.001, <0.001), high density lipoprotein cholesterol (P < 0.05, <0.001, <0.001), malondialdehyde (P < 0.05, <0.05, <0.001), catalase (P <0.05, <0.05, <0.05), glutathione (P < 0.05, <0.05, <0.05), Mel (P < 0.05, <0.05, <0.001), and copper (P < 0.05, <0.05, < 0.001). In view of these results, HCD‐fed male Wistar rats that are destined to attain IR and T2DM through diet can be prevented by giving CrPic and Mel administration in alone or in a combination. © 2015 BioFactors, 42(1):106–114, 2016
Coenzyme Q10 redox state predicts the concentration of c‐reactive protein in a large caucasian cohort
Authors: Fischer Alexandra , Onur Simone , Niklowitz Petra , Menke Thomas , Laudes Matthias , Döring Frank
Published: October 2023

In the present study the relationship between the CoQ10 redox state (% oxidized form of CoQ10) and the serum level of c‐reactive protein (CRP) was investigated in a large Caucasian study population (n = 1319). In order to evaluate independently the influence of the variables that predict the outcome of CRP, an analysis of covariance (ANCOVA) was performed with CRP as the dependent variable. Gender was taken as an independent factor and CoQ10 redox and BMI as independent covariates. Results were substantiated with findings from a human intervention study (n = 53), receiving 150 mg/day ubiquinol for 14 days. Spearman's correlation revealed a significant (P < 0.001) association between the CoQ10 redox state and CRP concentrations in the whole study population. Thus, higher CRP concentrations were found in subjects having more oxidized CoQ10. Similar results were evident for further inflammatory markers (interleukin‐6, number of leucocytes). The ANCOVA revealed a significant (P < 0.001) prediction of CRP concentrations by CoQ10 redox state, after controlling for the effect of BMI and separately for gender. In the intervention study it was further found that the oral intake of ubiquinol increased its proportion significantly (P < 0.001), with the highest increase in those persons having a low basal serum ubiquinol content (<92.3%). Here it was discovered that the ubiquinol status significantly correlated to the concentration of the inflammation marker monocyte chemotactic protein 1. It is concluded that CoQ10 redox state predicts the concentration of CRP. Persons at risk with lower ubiquinol status, higher BMI, and low grade inflammation may benefit from ubiquinol supplementation. © 2016 BioFactors, 42(3):268–276, 2016
Anandamide interferes with human endometrial stromal‐derived cell differentiation: An effect dependent on inhibition of cyclooxygenase‐2 expression and prostaglandin E2 release
Authors: Almada Marta , Cunha Sara , Fonseca Bruno M. , Amaral Cristina , Piscitelli Fabiana , Di Marzo Vincenzo , Correia‐da‐Silva Georgina , Teixeira Natércia
Published: October 2023

The human endometrium undergoes cyclical growth, differentiation, and regression periods throughout the reproductive life. The process in which endometrial stromal cells proliferate and differentiate into decidual cells, named decidualization, prepares a receptive endometrium for implantation. Prostaglandins (PGs) and endocannabinoids (eCBs) are crucial mediators of this process. We have recently reported that the eCB anandamide (AEA) interferes with rat stromal cell differentiation, and on the other hand, PGs are also crucial for decidualization. Therefore, in this study, we analyzed the AEA levels, both in nondifferentiated and in decidualizing human endometrial stromal cells by liquid chromatography‐mass spectrometry, and investigated the impact of AEA on PG release and cyclooxygenase‐2 (COX‐2) expression in human endometrial stromal‐derived cell differentiation. For that, an ultra‐performance liquid chromatography‐mass spectrometry/mass spectrometry method to measure prostaglandin E2 (PGE2) and prostaglandin F2α in biological samples was developed and validated. We demonstrate that AEA levels in decidualizing cells are lower than those in nondifferentiated cells, whereas PGE2 levels and COX‐2 expression are up‐regulated. Thus, low AEA levels may be essential for the onset of decidualization. On the contrary, in AEA‐treated cells undergoing decidualization, a decrease of COX‐2 protein levels and PGE2 production, in a manner dependent on cannabinoid receptor 1 activation, was observed. Overall, these findings suggest that a deregulation of the intricate network that drives cell differentiation may compromise pregnancy and fertility. It is clinically relevant to understand the mechanisms that influence eCB and PG levels in the endometrium because they may shed light on the sequence of events that lead to a successful pregnancy. © 2016 BioFactors, 42(3):277–286, 2016
Effects of n‐3 pufas on fasting plasma glucose and insulin resistance in patients with impaired fasting glucose or impaired glucose tolerance
Authors: Derosa Giuseppe , Cicero Arrigo F.G. , D'Angelo Angela , Borghi Claudio , Maffioli Pamela
Published: October 2023

Aim: to evaluate if a supplementation with n‐3 PUFAs at high doses could give a regression of the condition of impaired glycemia. Methods: we enrolled 281 overweight/obese patients with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT); 138 subjects were randomized to n‐3 PUFAs group, 1 g three times a day, and 143 to placebo for 18 months. We assessed at baseline, and after 9, and 18 months: circumferences, body mass index (BMI), fasting plasma glucose (FPG), fasting plasma insulin (FPI), HOMA‐index, lipid profile. At baseline and at the end of the study, all patients underwent an oral glucose tolerance test (OGTT). Results: we observed a decrease of glycemia and HOMA‐IR with n‐3 PUFAs, compared to baseline, and to placebo. Fasting plasma insulin decreased with n‐3 PUFAs and increased with placebo. HDL‐cholesterol increased after 18 months of n‐3 PUFAs, while triglycerides decreased compared to baseline and to placebo. After OGTT performed at the end of the study, more patients returned to a condition of euglycemia with n‐3 PUFAs compared to placebo. Conclusions: n‐3 PUFAs were effective in reducing glycemia in patients affected by IFG or IGT and seem to be helpful to slow the development of type 2 diabetes mellitus. © 2016 BioFactors, 42(3):316–322, 2016
Lactoferrin during lactation reduces lipopolysaccharide‐induced brain injury
Authors: Ginet Vanessa , van de Looij Yohan , Petrenko Volodymyr , Toulotte Audrey , Kiss Jozsef , Hüppi Petra S. , Sizonenko Stéphane V
Published: October 2023

Lactoferrin (Lf), component of maternal milk, has antioxidant, anti‐inflammatory and antimicrobial properties. Neuroprotective effects of Lf on the immature brain have been recently shown in rodent models of intrauterine growth restriction and cerebral hypoxia/ischemia. Here we postulated that Lf could also have beneficial effects on preterm inflammatory brain injury. Lf was supplemented in maternal food during lactation and lipopolysaccharide (LPS) was injected in subcortical white matter of rat pups at postnatal day 3 (P3). Effect of maternal Lf supplementation was investigated 24 h (P4), 4 (P7), or 21 days (P24) after LPS injection mainly on the striatum. Lateral ventricle and brain structures volumes were quantified. Microstructure was evaluated by diffusion tensor imaging, neurite orientation dispersion and density imaging as well as electron microscopy. Neurochemical profile was measured by 1H‐magnetic resonance spectroscopy. GFAP protein, proinflammatory cytokines mRNA expression microglial activation were assessed. Lf displayed neuroprotective effects as shown by reduced LPS‐induced ventriculomegaly, brain tissue loss, and microstructural modifications, including myelination deficit. 1H‐MRS neurochemical profile was less altered through an antioxidant action of Lf. Despite the lack of effect on LPS‐induced proinflammatory cytokines genes expression and on reactive gliosis, microglia was less activated under Lf treatment. In conclusion, Lf supplemented in food during lactation attenuated acute and long‐term cerebral LPS‐induced alterations. This provides a new evidence for a promising use of Lf as a preventive neuroprotective approach in preterm encephalopathy. © 2016 BioFactors, 42(3):323–336, 2016
Introduction to Special Section: Considerations and Potential Impacts
Authors: Garcia Moriana M. , Colegrove Tod
Published: October 2023

EDITOR'S SUMMARY

ASIS&T Special Interest Group/Scientific and Technical Information convened a panel at the ASIS&T 2014 Annual Meeting that explored potential impacts of 3D design and printing on libraries, museums and educational institutions. Rooted in the 1970s, the current 3D printing process was first used in 1984 and now allows limitless creations to be made by downloading or scanning and printing a digital file. The tangible product vitalizes interaction with the original and among viewers, enhances understanding and stimulates creativity. But, as with the use of photocopiers, questions of ethics and intellectual property arise. Management of the technology also raises practical questions of access, workflow, budgeting and support.

This special section delves into 3D technologies as teaching tools and considers policy, copyright and intellectual freedom, critical issues for information professionals. Articles open with a discussion of the use of 3D printers in library makerspaces by community members, the potential for broad experiential learning and practical issues for libraries. An exploration of 3D printer use for academic studies far beyond traditional areas follows, with a look at collaborative efforts between university departments to support and use the equipment and a reminder of the need for ethical management and consumer education about 3D resources. The final articles explore the benefits of manipulating 3D copies of museum pieces and enjoying the creative potential for hands‐on activities in various settings, as well as contemplating libraries' role in adapting intellectual freedom policy for 3D technologies.
Digital Fabrication Technology in the Library: Where We Are and Where We Are Going
Authors: Prato Stephanie C. , Britton Lauren
Published: October 2023

EDITOR'S SUMMARY

Makerspaces are environments where crafters and techies can come together to create, share and learn. Many libraries support the maker movement by providing access to a variety of technologies from sewing machines and looms to recording equipment and production tools, an expansion of services that is in line with promoting literacy, community and lifelong learning. About one third of makerspaces charged a fee or required membership in 2013, though some, including libraries and museums, are supported by major funding agencies. Digital fabrication technology or 3D printers are increasingly available through library‐based makerspaces and extend opportunities for STEM education, but libraries face challenges from high initial and ongoing costs, user training and even encouraging users in 3D thinking and design. 3D printers can be a powerful stimulus for creativity, learning and sharing, even promoting jobs and community development.
How 3D Printers Support Teaching in Engineering, Technology and Beyond
Authors: Van Epps Amy , Huston Davin , Sherrill John , Alvar Ann , Bowen Anna
Published: October 2023

EDITOR'S SUMMARY

The rise of 3D printers derives from the need to create physical prototypes for engineering and manufacturing rapidly and inexpensively, but the technology has been widely adopted for innumerable applications. A library can provide a central point of access and support for 3D printing for students and faculty across disciplines and programs beyond engineering and technology. Nontraditional uses include teaching persuasive communications through visual rhetoric in an English class, creating objects that can diffuse stereotypes and attitudes and enhancing understanding of physical anatomy. Numerous 3D model datasets and software are available for printing projects. 3D printing not only promotes learning but inspires creativity and fun.
Library as Collaboratory: Partnerships, Knowledge Transfer and Dialogue in Library‐based 3D Services
Authors: Messner Kevin R.
Published: October 2023

EDITOR'S SUMMARY

Since 2012 the 3D printing operation at Miami University's Business, Engineering, Science and Technology Library has developed into a high demand service that promotes learning for a broad range of users. With the first two basic 3D printers set up in separate locations, multiple operators developed skills and provided backup support for each other. A variety of user groups emerged beyond the expected subject disciplines and applications, and, with a growing circle of users, students have been employed for printing tasks, gaining technical skills and enabling the library to expand its services. Placing printers in highly visible locations prompted interest and interactions among onlookers. Strong demand for the 3D printing service has necessitated coordination between the library and departments, collaboration between departments, prioritization of needs and funding for more durable equipment, while stimulating developments in curricula and research agendas.
Museums and 3D Printing: More Than a Workshop Novelty, Connecting to Collections and the Classroom
Authors: Hancock Megan
Published: October 2023

EDITOR'S SUMMARY

A typical museum visitor views an artwork for about half a minute, but 3D scanning and printing technology can help provide a more meaningful experience. Several museums have invited audiences to hands‐on 3D scanning and printing events, encouraging them to engage with museum pieces more deeply, creating 3D photo files and ultimately constructing 3D printed models of the pieces that can be manipulated and interacted with in new ways. The ARTLAB+ program in Washington, D.C., and the Parachute Factory in New Mexico are examples of makerspaces focusing on hands‐on activities with cutting edge technologies including 3D printers for a variety of users. A special exhibit on 3D technology at the British Museum and Samsung Digital Discovery Center enabled visitors to recreate museum pieces with computer‐aided design technology, 3D pens and 3D printing. A resource list describes additional projects and information sources.
Terpenoids from Euphorbia helioscopia and Their Cytotoxic Activities against H1975 Cells
Authors: Zhang Xiong , Peng Ming‐You , Feng En‐Ming , Li Qing‐Dan , Chen Lu , Yang Hu‐Cheng , Guo Bing , Liang Hong , Di Ying‐Tong , Tang Lei , Yan Ying
Published: October 2023

Three previously undescribed diterpenoids, helioscopnoids A–C, and eight known compounds were isolated from the whole plants of Euphorbia helioscopia. Their structures were established by extensive analysis of spectra and data comparison with previous literatures. Among them, compound 4 was identified as 24,24‐dimethoxy‐25,26,27‐trinoreuphan‐3β‐ol with revised configurations of C‐13, C‐14, and C‐17 (13R*, 14R*, 17R*). Cytotoxicity assays revealed that all compounds exhibited varying levels of cytotoxicity against H1975 cells, with compound 9 displaying the most potent activity, as indicated by cell viability rates of 18.13 % and 20.76 % at concentrations of 20 μM and 5 μM, respectively. This study expands the understanding of E. helioscopia terpenoids’ structural diversity and biological activities, contributing to the exploration of potential therapeutic applications.
From Natural Insulin to Designed Analogs: A Chemical Biology Exploration
Authors: Zhang Yanxian , Hung‐Chieh Chou Danny
Published: October 2023

Since its discovery in 1921, insulin has been at the forefront of scientific breakthroughs. From its amino acid sequencing to the revelation of its three‐dimensional structure, the progress in insulin research has spurred significant therapeutic breakthroughs. In recent years, protein engineering has introduced innovative chemical and enzymatic methods for insulin modification, fostering the development of therapeutics with tailored pharmacological profiles. Alongside these advances, the quest for self‐regulated, glucose‐responsive insulin remains a holy grail in the field. In this article, we highlight the pivotal role of chemical biology in driving these innovations and discuss how it continues to shape the future trajectory of insulin research.
Bioorthogonal Chemistry in Translational Research: Advances and Opportunities
Authors: Chaudhuri Ritapa , Bhattacharya Semantee , Dash Jyotirmayee
Published: October 2023

Bioorthogonal chemistry is a rapidly expanding field of research that involves the use of small molecules that can react selectively with biomolecules in living cells and organisms, without causing any harm or interference with native biochemical processes. It has made significant contributions to the field of biology and medicine by enabling selective labeling, imaging, drug targeting, and manipulation of bio‐macromolecules in living systems. This approach offers numerous advantages over traditional chemistry‐based methods, including high specificity, compatibility with biological systems, and minimal interference with biological processes. In this review, we provide an overview of the recent advancements in bioorthogonal chemistry and their current and potential applications in translational research. We present an update on this innovative chemical approach that has been utilized in cells and living systems during the last five years for biomedical applications. We also highlight the nucleic acid‐templated synthesis of small molecules by using bioorthogonal chemistry. Overall, bioorthogonal chemistry provides a powerful toolset for studying and manipulating complex biological systems, and holds great potential for advancing translational research.
Ectopic pancreatic tissue in a cholecystectomy specimen: A rare incidental pathologic finding
Authors: Zaresharifi Nooshin , Khalili Anita , Eftekhari Behrad , Layegh Hojjat
Published: October 2023

Ectopic pancreatic tissue is a rare congenital abnormality defined as the abnormal location of pancreatic tissue outside the anatomical site of the pancreas without any anatomical or vascular connection to it, which is often discovered incidentally. This is a case of a 40‐year‐old man who was admitted to our surgical department for emergency cholecystectomy due to acute gangrenous cholecystitis. Preoperative ultrasound imaging was indicative only of multiple stones in the gallbladder. Postoperative histopathological examination revealed an area of wall thickening in the neck region of the gallbladder consists of ectopic pancreatic tissue. We emphasize the role of a precise pathologic examination even in routine surgical specimens such as a cholecystectomy specimen, since no preoperative evaluation can be affirmative of such incidental but momentous histopathologic findings. Anatomical pathologists must be aware of the rare presentation of Ectopic Pancreatic Tissue (EPT) in gallbladder which may masquerade as a malignancy.
A late diagnosis of primary intestinal lymphangiectasia in a Syrian girl
Authors: Najjar Afaf Mohammad Maher , Babensi Nour Khaled , Ghazal Ahmad , Brimo Alsaman Muhamad Zakaria , Ismail Alaa aldin , Alnaeb Hasnaa
Published: October 2023

Key Clinical Message

Primary intestinal lymphangiectasia is a rare disease that affects children and young adults, causing mainly gastrointestinal disorders that lead to edema and immunologic abnormalities. The majority of patients typically present bilateral lower limb edema, along with pericarditis, pleural effusion, or chylous ascites. The goal of the treatment is to restrict the consumption of long‐chain fats and administer a formula that includes protein and medium‐chain triglycerides. Here, we report 11‐year‐old Syrian girl presented to the hospital with 2 years history of diarrhea and generalized edema. Furthermore, investigation showed ascites and pleural effusion. The disease was detected by several biopsies from duodenum that showed dilation of the lymph vessels within the lamina propria without any evidence for inflammation. She was managed by modifying her diet and albumin transfusion, which caused significant improvement in the child's condition.
A case of bladder and pelvic dead space inflammation successfully treated with endoscopic ultrasound drainage
Authors: Hiyama Kazuhiro , Kirino Izumi , Fukui Yasuo
Published: October 2023

Key Clinical Message

Interventional endoscopic ultrasound (EUS) is effective not only for biopsy, but also for abscess drainage. We report the first use of EUS to drain inflammation of the bladder and pelvic dead space through the ileal conduit. EUS‐guided drainage is effective in treating postoperative abscesses and should be employed more routinely.

The patient was a 77‐year‐old man with a vesicoureteral fistula. An ileal conduit was placed after abdominoperineal resection and partial bladder resection for local, postoperative recurrence of rectal cancer. During postoperative chemotherapy, the patient developed a high‐grade fever and after a thorough examination, he was diagnosed with bladder and pelvic dead‐space inflammation. All urine flowed through the ileal conduit, and it was assumed that secretions from the residual bladder and prostate gland had accumulated in the bladder and pelvic cavity, resulting in infection. A transcutaneous drain was inserted through the perineum and the infection was controlled, but it flared up again after the drain was removed. We concluded that long‐term drainage was necessary and successfully controlled the infection by placing a plastic stent through the ileal conduit into the bladder and pelvic dead space under ultrasound endoscopy. This is the first report of ultrasound endoscopic drainage of an abscess through the ileal conduit.
A Modular and Convergent Synthetic Route to Supramolecular Cyclic Dimers Based on Amidinium‐Carboxylate Interactions
Authors: López‐Martín Isabel , Veiga‐Herrero Jacobo , Aparicio Fátima , González‐Rodríguez David
Published: October 2023

We describe herein the optimized design and modular synthetic approach towards supramolecularly programmed monomers that can form discrete macrocyclic species of controllable size and shape through amidinium‐carboxylate interactions in apolar and polar media.
An Aryl‐ether‐linked Covalent Organic Framework Modified with Thioamide Groups for Selective Extraction of Palladium from Strong Acid Solutions
Authors: Zhao Fuqiang , Bai Yaoyao , Zhou Xiaoyuan , He Linwei , Tao Yunnan , Chen Junchang , Zhang Mingxing , Guo Qi , Ma Zhonglin , Chen Long , Zhu Lin , Duan Tao , Chai Zhifang , Wang Shuao
Published: October 2023

Efficient adsorption of palladium ions from acid nuclear waste solution is crucial for ensuring the safety of vitrification process for radioactive waste. However, the limited stability and selectivity of most current adsorbents hinder their practical applications under strong acid and intense radiation conditions. Herein, to address these limitations, we designed and synthesized an aryl‐ether‐linked covalent organic framework (COF‐316‐DM) grafted dimethylthiocarbamoyl groups on the pore walls. This unique structure endows COF‐316‐DM with high stability and exceptional palladium capture capacity. The robust polyarylether linkage enables COF‐316‐DM to withstand irradiation doses of 200 or 400 kGy of β/γ ray. Furthermore, COF‐316‐DM demonstrates fast adsorption kinetics, high adsorption capacity (147 mg g−1), and excellent reusability in 4 M nitric acid. Moreover, COF‐316‐DM exhibits remarkable selectivity for palladium ions in the presence of 17 interference ions, simulating high level liquid waste scenario. The superior adsorption performance can be attributed to the strong binding affinity between the thioamide groups and Pd2+ ions, as confirmed by the comprehensive analysis of FT‐IR and XPS spectra. Our findings highlight the potential of COFs with robust linkers and tailored functional groups for efficient and selective capture of metal ions, even in harsh environmental conditions.
Control of Substrate Conformation by Hydrogen Bonding in a Retaining β‐Endoglycosidase
Authors: Nin‐Hill Alba , Ardevol Albert , Biarnés Xevi , Planas Antoni , Rovira Carme
Published: October 2023

Bacterial β‐glycosidases are hydrolytic enzymes that depolymerize polysaccharides such as β‐cellulose, β‐glucans and β‐xylans from different sources, offering diverse biomedical and industrial uses. It has been shown that a conformational change of the substrate, from a relaxed 4C1 conformation to a distorted 1S3/1,4B conformation of the reactive sugar, is necessary for catalysis. However, the molecular determinants that stabilize the substrate's distortion are poorly understood. Here we use quantum mechanics/molecular mechanics (QM/MM)‐based molecular dynamics methods to assess the impact of the interaction between the reactive sugar, i. e. the one at subsite −1, and the catalytic nucleophile (a glutamate) on substrate conformation. We show that the hydrogen bond involving the C2 exocyclic group and the nucleophile controls substrate conformation: its presence preserves sugar distortion, whereas its absence (e.g. in an enzyme mutant) knocks it out. We also show that 2‐deoxy‐2‐fluoro derivatives, widely used to trap the reaction intermediates by X‐ray crystallography, reproduce the conformation of the hydrolysable substrate at the experimental conditions. These results highlight the importance of the 2‐OH⋅⋅⋅nucleophile interaction in substrate recognition and catalysis in endo‐glycosidases and can inform mutational campaigns aimed to search for more efficient enzymes.