bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tieftemperatur‐Elektronenspektren von Tetrahalogenomanganaten(II)
Authors: Oelkrug D. , Wölpl A. 
Published: November 2023

AbstractVon den Tetrahalogenomanganaten A2MnHal4 mit Hal = Cl, Br, J und A = (CH3)4N, (C2H5)4N, (n‐C4H9)4N wurden Absorptionsspektren in diffuser Reflexion sowie Phosphoreszenzanregungsspektren im Bereich von 19000 ‐ 38000cm−1 bei 77°K untersucht. Die meisten Elektronenübergänge sind deutlich strukturiert. Die Struktur läßt sich im wesentlichen auf Kopplung mit der totalsymmetrischen Komplexschwingung zurückführen. Darüber hinaus machen sich in einigen Absorptionsbanden Aufspaltungen bemerkbar, die vom Chlorid zum Jodid zunehmen und die mit einer Erniedrigung der Komplexsymmetrie von Td auf D2d beschrieben werden.
Complete theory of paramagnetism in transition metal ions I. The octahedral and tetrahedral d4 and d6 electron configurations
Authors: König E. , Kremer S. 
Published: November 2023

AbstractOn the basis of the diagonalization of the complete ligand field, interelectronic repulsion, spin‐orbit interaction, and Zeeman effect matrices, the magnetic properties have been calculated for the octahedral and tetrahedral d4 and d6 electron systems. The calculations were performed according to both the strong‐field and the weak‐field method and complete agreement of the results was achieved. The magnetic moment μeff is presented as function of the octahedral and tetrahedral ligand field splitting parameter 10Dq and the temperature for a fixed set of values of the Racah parameters B, C, the spin‐orbit coupling parameter, and the orbital reduction factor k. The effect of a variation in the parameter values of B, C, and k is investigated in detail. The results may be employed in an accurate comparison of experimental magnetic data with theory if, as is usually the case, the values of 10 D q, B, and C are known from optical spectra and if reasonable estimates of and k may be applied.
Über die Kernresonanzspektren symmetrischer Spinsysteme des allgemeinen Typs 2
Authors: Hägele Gerhard , Harris Robin K. 
Published: November 2023

AbstractKernresonanzspektren symmetrischer Spinsysteme des allgemeinen Typs [magnified image]2 werden für den Grenzfall verschwindender long‐range‐Kopplungen untersucht. Es resultieren explizite algebraische Ausdrücke für die Resonanzfrequenzen und deren relative Intensitäten in den X‐Kern‐Teilspektren. Die bisher bekannten symmetrischen Systeme vom Typ [AXn]2, [AMXn]2 und [ARtXn]2 werden als Sonderfälle des allgemeineren [magnified image]2‐Spinsystems erkannt.
Stromfluß bei Elektrosorptionsprozessen und Elektrosorptionswertigkeit γ
Authors: Vetter K. J. , Schultze J. W. 
Published: November 2023

AbstractDie Elektrokapillargleichung wird für Elektrosorptionsreaktionen unter Abtrennung der Effekte der diffusen Doppelschicht in Abhängigkeit von der Potentialdifferenz Δ der starren Doppelschicht (Gleichung (4)) bzw. bei Fremdelektrolyüberschuß in Abhängigkeit vom Elektrodenpotential behandelt. Die Beziehungen zwischen den Größen Elektrodenladung qm, Oberflächenüberschuß Γad* partieller Ladungsübergang λ, Stromfluß i und Adsorptionsgeschwindigkeit vad werden hergeleitet. In qm geht der Ladungsübergang mit ΔΓad ein. Der Ladungsfluß oder das Verhältnis i/vad lassen sich bei Fremdelektrolytüberschuß unter potentiostatischen Bedingungen durch die Elektrosorptionswertigkeit γ beschreiben gemäß der Gleichung (δqm/δΓad)epsi; = ipot/vad=‐ γ F. Diese Beziehung entspricht dem Faradayschen Gesetz mit einer nichtganzzahligen Wertigkeit Γ. Über die Potentialabhängigkeit (δμ/δϵ)Γ = γF folgt, daß γ sich aus Anteilen der Ionenladung, des Ladungsübergangs, der Dipolorientierung und der Kapazitätsänderung zusammensetzt.
Electron Transfer between Metal Ions through Bridging Ligands
Authors: Taube H. 
Published: November 2023

AbstractIn considering the mechanism of charge transport between complexes undergoing an oxidation‐reduction reaction by an inner‐sphere process, a distinction is sought between a mechanism in which on the one hand there is direct charge exchange between the metal ion centers, and on the other, a two‐step process involving an intermediate reduced or oxidized form of the bridging ligand. For a number of systems with Cr(III) or Co(III) complexes being reduced by Cr(II) and single atoms bridging the two metal ion centers, it is apparent that a single‐step mechanism operates. For more complex bridging groups, mediation in the charge transfer process has thus far been observed only for ligands having conjugated bond systems, one or more polar groups being part of the conjugated bond network. For Co(III) complexes of such ligands reacting with Cr(II), circumstantial evidence points to the conclusion that a two‐step mechanism operates, this mechanism depending on the capacity that the strongly reducing reaction partner Cr(II) has of placing an electron in a pi orbital of the ligand.That this kind of mechanism operates is considered to be a consequence of the symmetry mismatch between the redox‐active orbitals on the metal centers, which have σ symmetry, and the carrier orbital on the ligand, which has pi symmetry. Evidence, again circumstantial in nature, points to the conclusion that when Ru(III), which has a vacancy in an orbital of pi symmetry, is used in place of Co(III), the mechanism changes, and now charge transfer occurs by a single‐step process.Some properties of binuclear complexes, namely, their stabilities and labilities, are considered in the light of the electronic structure of the participating metal ions. These considerations explain the bond reorganizations which accompany charge transport in oxidation‐reduction reactions. The discussion is generalized to include binuclear complexes in which there is no net bond reorganization, a principal point of interest being the energy of interaction between the metal ion partners in the binuclear combinations.
Die Kinetik der Komplexbildung des Cu(II)‐lons mit Imidazol und Ammoniak
Authors: Diebler H. , Rosen Ph. 
Published: November 2023

AbstractMit Hilfe des Temperatursprung‐Relaxationsverfahrens wurde in wäßriger Lösung die Kinetik der Bildung der 1:1‐Komplexe des Cu2+− Ions mit den Liganden Imidazol und Ammoniak untersucht. Bei 25° ergaben sich für die Bildungsgeschwindigkeitskonstanten die folgenden Werte: Imidazol, k = 5.7±108 M−1; sec−1; NH3, k = 2.0±108 M−1 sec−1. Werte dieser Gröβe sind wahrscheinlich als typisch für die Reaktionen des Cu2+ mit einfachen neutralen Liganden anzusehen. Die Ursachen für die bei einigen anderen Liganden beobachteten abweichenden Werte für k werden diskutiert. Eine Abhängigkeit der Geschwindigkeitskonstanten von der Basizität der Liganden läβt sich nicht feststellen.
Photochemie von cis‐Dichloro‐bisdipyridyl‐kobalt(III)
Authors: Ionescu M. , Kelm H. , Wasgestian F. 
Published: November 2023

AbstractBestrahlung einer wäßrigen Lösung von cis‐[Co(dipy)2Cl2]+ führt zur Reduktion des Zentralions. Die photochemischen Quantenausbeuten bei 366 mμ und 7°C erwiesen sich als unabhängig von der Komplexkonzentration, der Wasserstoffionenkonzentration (pH 1‐3) und der Gegenwart von gelostem Sauerstoff. Zusatz von 10−2 m Oxalsaure erhöhte die Quantenausbeute von 1,6 · 10−3 auf 3,2 · 10−3 mol/Einst. Im Bereich von 7° bis 40°C wurde eine geringe Temperaturabhängigkeit beobachtet, die keiner linearen Arrheniusbeziehung genügte. Bei Anregung mit Licht der Wellenlängen λ ≤ 370 mμ wurde nur eine geringe Wellenlängenabhangigkeit gefunden. Weitere Erhöhung der Anregungswellenlange lieβ die Quantenausbeute stark abfallen. Bei 546 mμ wurde eine Quantenausbeute von 5 · 10−5 mol/Einst. ermittelt.
Pulsradiolytische Untersuchung über die Bildung des Radikal‐Anions SCNS2O2‐3
Authors: Schöneshöfer M. 
Published: November 2023

AbstractBei der Oxidation von SCN− durch OH in wäßriger Lösung wird in Gegenwart kleiner Mengen S2O2‐3 neben den Radikalanionen (SCN)−2 und S4O2‐3 auch SCNS2O2‐3 erzeugt. SCNS2O2‐3 absorbiert maximal bei 4200 Å mit ϵ → = 7.4·103 M−1 cm−1. Die Gleichgewichtemagnified imagestellen sich bei hohen SCN−‐Konzentrationen sehr schnell ein. Die Gleichgewichtskonstanten betragen 1,6·102 bzw. 8,3·10−4 M. Ferner wurden die Konstanten der Gleichgewichtemagnified imagezu > 8,3 · 102 bzw, 3,1 · 10−8 M berechnet.
Mass Spectrometric Investigations of Silver Halides II: Temperature Dependence of the Mass Spectrum of Silver Chloride
Authors: Gräber P. , Weil K. G. 
Published: November 2023

AbstractIt is shown that two effects are responsible for the temperature dependence of the mass spectrum of silver chloride: the temperature dependence of the vapor pressure in the Knudsen cell and the temperature dependence of the fragmentation reactions of the parent ions after their formation in the ionisation chamber. A procedure is demonstrated which even in this case enables us to determine enthalpies of vaporisation for monomeric and trimeric silver chloride molecules. The following results are obtainedmagnified imageFinally it was possible to derive from the experiments values for the enthalpies of vaporisation and sublimation at lower temperatures. These led to a value for the enthalpy of dissociation of AgCl (gas) into the elements: D = 305 ± kJ mol−1 (298 K), in good accordance with a value given in Part I of this series.
The Orientation of the Water Molecules in the Hydration Sphere of F− and in the Hydrophobic Hydration Sphere
Authors: Hertz H. G. , Rädle C. 
Published: November 2023

AbstractNuclear magnetic relaxation rates of 19F in aqueous KF solutions and of the proton in aqueous solutions of formic acid, HCOOD, of pro‐pionic acid, CHD2CD2COOD, and of methanol, CHD2OD are reported. The solvent water is 16OD2 to which suitable amounts of 17OD2 or 16OH2 are added. From the intermolecular relaxation rate of the solute nucleus (19F or H), caused by the dipole‐dipole interaction with the magnetic nuclei in the solvent, the orientation of the water molecules in the hydration sphere of the solute particle has been derived. Our results regarding the angle of the electric dipole moment of the H2O molecule relative to a radial reference axis are: βo = 50° for F−. βo = 96° for formic acid, βo = 107.5° for propionic acid and βo = 102.5° for methanol.
Hyperfiltration of Saccharide Solutions
Authors: Wiedner G. , Woermann D. 
Published: November 2023

AbstractFor a membrane system near equilibrium, the thermodynamics of irreversible processes yields an expression relating the filtration coefficient of the solute, its chemical flux and the volume flow through the membrane. This relation was checked experimentally and found to be correct for the investigated membrane system. Furthermore, the filtration coefficient and the rejection for saccharides of various molecular weights was determined.
Nationalising the international in China: A phenomenological study on the purpose of international schooling in an era of regulation
Authors: Poole Adam , Qin Yunyun 
Published: November 2023

AbstractRecent policy changes to the regulation of international schooling for Chinese nationals in China have seen restrictions on curriculum, admissions and ownership. While there is evidence of the impact of these changes at the institutional level, it is not clear how recent regulation has impacted the actors at the phenomenological level. In order to address this gap, we situate recent regulation within the concept of cosmopolitan nationalism, which highlights the interplay of local and global forces and places lived experience at the forefront of analysis. We also draw on qualitative survey and in‐depth interview data with teachers from an international school in China that explored their understandings of international schooling. By analysing the teachers’ understandings of international schooling, we were able to gain an insight into the impact of regulation at the level of lived experience. Overall, we found little evidence that regulation had impacted the teachers’ beliefs about international schooling, suggesting either the normalisation of regulation or a lag between its implementation and internalisation. Our findings also suggested two main configurations of cosmopolitan nationalism held by the teachers. The first, which we refer to as ‘cosmopolitanism with national characteristics’, positions international schools as a more diverse and care‐free alternative to domestic schooling. The second configuration of cosmopolitan nationalism, which we refer to as ‘nationalism with cosmopolitan characteristics’, positions the nation as the foundation and cosmopolitan‐related aspects as peripheral.
Knockout of the lysosomal membrane protein, LAMP2C, improves transient gene expression in HEK293 cells via increased intracellular plasmid availability
Authors: Kim Dongwoo , Kim Seul Mi , Lee Jaejin , Kim Jiwon , Lee Jae Seong 
Published: November 2023

AbstractPlasmid‐based transfection can be used in many applications such as transient gene expression (TGE)‐based therapeutic protein production. These applications preferentially require maximization of intracellular plasmid availability. Here, we applied a lysosome engineering approach to alleviate lysosome‐mediated nucleic acid degradation and enhance the TGE in mammalian cells. By knocking out the lysosomal membrane protein LAMP2C, which is known to be the main player in RNautophagy/DNautophagy (RDA), we significantly improved transient fluorescent protein expression in HEK293 cells by improving the retention rate of transfected plasmids; however, this effect was not observed in CHO cells. Additional knockout of a lysosomal membrane transporter and another RDA player, SIDT2, was ineffective, regardless of the presence of LAMP2C. LAMP2C knockout enhanced TGE‐based mAb production in HEK293 cells by up to 2.82‐fold increase in specific mAb productivity. Taken together, these results demonstrate that HEK293 cells can be engineered to improve the usage of the transfected plasmid via knockout of the lysosomal membrane protein LAMP2C and provide efficient host cells in TGE systems for therapeutic protein production.
Correlation of microbial community structure and volatile flavor compounds during corn yellow wine fermentation
Authors: Guo Jianhua , Zhao Xiaoxu , Shi Jie 
Published: November 2023

AbstractHigh‐throughput sequencing was used to define microbial community structure and GC–MS to identify volatile flavor substances during fermentation of corn yellow wine, and results were analyzed by multivariate statistical analysis. Seventeen bacterial phyla, 239 bacterial genera, 4 fungal phyla, and 18 fungal genera were found and changes in community structure occurred during fermentation. Twenty‐four volatile flavor substances, including 14 esters and 5 alcohols, were detected and changes during fermentation recorded. Sixteen microbial genera correlated with volatile flavor substances and Weissella, Lactobacillus, Pseudomonas, Rhodotorul, and Kwoniella had significant correlation with ethyl esters and higher alcohols. Micro‐organisms thus influence flavor development during corn yellow wine fermentation.
Brazilian Green Propolis’ Artepillin C and Its Acetylated Derivative Activate the NGF‐Signaling Pathways and Induce Neurite Outgrowth in NGF‐Deprived PC12 Cells
Authors: Rocha Caldas Gabriel , do Amaral Lilian , Munhoz Rodrigues Débora , Mayrink de Miranda Aline , Aparecida Guinaim dos Santos Neife , Machado Rocha Leandro , Tame Parreira Renato Luis , Cardozo dos Santos Antônio , Kenupp Bastos Jairo 
Published: November 2023

AbstractArtepillin C is the most studied compound in Brazilian Green Propolis and, along with its acetylated derivative, displays neurotrophic activity on PC12 cells. Specific inhibitors of the trkA receptor (K252a), PI3K/Akt (LY294002), and MAPK/ERK (U0126) signaling pathways were used to investigate the neurotrophic mechanism. The expression of proteins involved in axonal and synaptic plasticity (GAP‐43 and Synapsin I) was assessed by western blotting. Additionally, physicochemical properties, pharmacokinetics, and drug‐likeness were evaluated by the SwissADME web tool. Both compounds induced neurite outgrowth by activating the NGF‐signaling pathways but through different neuronal proteins. Furthermore, in silico analyses showed interesting physicochemical and pharmacokinetic properties of these compounds. Therefore, these compounds could play an important role in axonal and synaptic plasticity and should be further investigated.
Polyoxometalate as an Effective Catalyst for Catalytic Lignin into Value‐Added Molecules
Authors: Zhang Haichuan , Fu Shiyu 
Published: November 2023

AbstractLignin, an inherently heterogeneous arylpropanoid polymer, presents a unique resource for the sustainable manufacture of aromatic chemicals and fuels. Recently, numerous catalytic strategies for lignin valorization have been explored. Polyoxometalates (POMs), with their distinctive structures enabling control of redox processes in lignin conversion, have been of particular interest. However, a comprehensive assessment of this emerging field of study is currently missing. This paper aims to fill this gap with a detailed review of the use of POMs for catalytic lignin conversion into value‐added compounds. This review delves into various catalytic lignin conversion techniques, including thermal catalysis, electrocatalysis, and tandem processes for lignin separation, depolymerization, and upgrading. Moreover, we highlight innovative investigations utilizing polyoxometalate‐ionic liquids (POM‐ILs), POM‐deep eutectic solvents (POM‐DESs), and solidification or immobilization techniques for POMs as lignin valorization catalysts. Lastly, we discuss the future prospects and challenges in the domain of POM catalytic lignin conversion.
Loose and Encased Graphite for Methylene Blue Adsorption: Process Optimization and Principal Component Analysis
Authors: Mah Cheng Yee , Azhar Nurul Natasha , Wong Voon Loong , Chen Yi-Lee , Yagoub Sami Abdelrahman Musa , Teo Swee Sen , Su Shao Feng , Yeap Swee Pin 
Published: November 2023

AbstractGraphite is often converted to expanded graphite or graphene for water remediation. However, these processes require extra chemicals and energy. This study tested loose and encased pristine graphite powders for dye removal. The loose graphite exhibited good methylene blue removal (>97 % across pH levels), indicating that π‐π interaction is the governing factor besides electrostatic attraction. Notably, 5 g of loose graphite led to 100 % removal. Langmuir isotherm fitting disclosed a maximum adsorption capacity of 4.7059 mg g−1. Principal component analysis showed that dye concentration and adsorbent dosage had a greater impact than pH and contact time. However, encasing graphite in a tea bag inhibits adsorption; future studies could explore options facilitating adsorbate penetration into tea bags.
Population Pharmacokinetics of Tenofovir Alafenamide Fumarate and Its Metabolite Tenofovir in Healthy Chinese Volunteers
Authors: Ji Xingfang , Li Yunfei , Wang Zhipeng , Gao Yuan , Wang Ling 
Published: November 2023

AbstractTenofovir alafenamide fumarate (TAF) is a first‐line drug for treating hepatitis B virus infection. This study aimed to establish the prodrug–metabolite population pharmacokinetic (PK) model for TAF and its metabolite tenofovir (TFV) in healthy Chinese volunteers and evaluate the factors affecting the PK. Using 1043 TAF and 1198 TFV plasma sample concentrations collected from 67 healthy volunteers, a population PK model was developed using the nonlinear mixed‐effects model. The 1‐compartment model containing 4 transit compartments and the 2‐compartment model accurately described the PK of TAF and TFV, respectively. Covariates such as meal state and sex were found to be statistically significant and potentially clinically relevant. Both internal and external validations demonstrated good stability and predictive performance of the connected model. This study elucidated the PK process by which TAF was absorbed, converted, and finally metabolized and eliminated as TFV, and explored the sources of interindividual variability between TAF and TFV.
Impact of the COVID‐19 pandemic on the time to emergency endoscopy and clinical outcomes in patients with upper gastrointestinal bleeding
Authors: Komatsu Takumi , Sato Yoshinori , Kuroki Yuichiro , Yoshida Yoshihito , Aoyama Natsumi , Iijima Yoshihiko , Nakamoto Yusuke , Kato Masaki , Kiyokawa Hirofumi , Tanabe Kenichiro , Matsunaga Koutaro , Maehata Tadateru , Yasuda Hiroshi , Matsumoto Nobuyuki , Tateishi Keisuke 
Published: November 2023

AbstractObjectivesTo investigate endoscopic management and clinical outcomes in patients with non‐variceal upper gastrointestinal (GI) bleeding during the coronavirus disease 2019 pandemic.MethodsWe retrospectively analyzed the data of 332 patients with non‐variceal upper GI bleeding who underwent emergency upper GI endoscopy at three hospitals during the pandemic (April 2020–June 2021) and before the pandemic (January 2019–March 2020). The number of emergency upper GI endoscopies, time from hospital arrival to endoscopy, mortality within 30 days, rebleeding within 30 days, interventional radiology (IVR)/surgery requirement, composite outcome, rates of endoscopic hemostasis procedures, and second‐look endoscopy were investigated using logistic regression.ResultsOverall, 152 and 180 patients underwent emergency upper GI endoscopies during and before the pandemic, respectively. The mean time from arrival to endoscopy was longer during the pandemic than before it (11.7 vs. 6.1 h, p < 0.01). Multivariate analysis revealed that mortality within 30 days (odds ratio [OR]: 2.27, p = 0.26), rebleeding within 30 days (OR: 0.43, p = 0.17), IVR/surgery requirement (OR: 1.79, p = 0.33), and composite outcome (OR: 0.98, p = 0.96) did not differ significantly between the periods; conversely, endoscopic hemostasis procedures (OR: 0.38, p < 0.01) and second‐look endoscopies (OR: 0.04, p < 0.01) were less likely to be performed during the pandemic than before it.ConclusionsAlthough the time from arrival to endoscopy was significantly longer during the pandemic, it did not affect mortality and rebleeding.