bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemische Synthese mit Gasförmigen Molekularen Ionen: Gewinnung von [B12Br11N2]− aus einem Massenspektrometer
Authors: Rohdenburg Markus , Warneke Ziyan , Knorke Harald , Icker Maik , Warneke Jonas 
Published: August 2023

AbstractIn der Massenspektrometrie werden häufig kurzlebige Ionen in der Gasphase beobachtet, die zuvor nicht in Lösung oder in der Bulkphase synthetisiert worden sind. Diese schwer zugänglichen Ionen werden daher oft primär als analytisch wertvoll für grundlegende Gasphasenstudien angesehen. Hier wird der Nachweis erbracht, dass die Produkte von Ionen‐Molekül‐Reaktionen in Massenspektrometern auf Oberflächen gesammelt werden können, um kondensierte Materie zu erzeugen und somit als Bausteine für die Synthese neuer Verbindungen zu dienen. Das hochreaktive Fragmentanion [B12Br11]− wurde in einem Massenspektrometer erzeugt und in Anwesenheit von molekularem Stickstoff in [B12Br11N2]− umgewandelt, gefolgt von seiner Massenselektion und sanften Deposition auf Oberflächen. Die Molekularstruktur des bisher nie zuvor synthetisierten [B12Br11N2]− wurde mit konventionellen Methoden der Molekularanalyse, einschließlich magnetischer Kernresonanz‐ und Infrarotspektroskopie, bestätigt. Das [B12Br11N2]−‐Ion ist auf Oberflächen und in Lösung bei Raumtemperatur stabil, aber Erhitzen führt zur Abspaltung von N2 und ermöglicht den Zugang zu dem hochreaktiven Zwischenprodukt [B12Br11]− in der kondensierten Phase, das beispielsweise als Reagenz für elektrophile aromatische Substitutionen weiterverwendet werden kann. Die Isolierung von [B12Br11N2]− erweitert somit das Repertoire der verfügbaren Diazo‐Ionen, die als vielseitige Zwischenprodukte bei verschiedenen chemischen Umwandlungen eingesetzt werden können.
Two‐Way Catalysis in a Diels–Alder Reaction Limits Inhibition Induced by an External Electric Field
Authors: Gopakumar Karthik , Shaik Sason , Ramanan Rajeev 
Published: August 2023

AbstractOriented external electric fields (EEFs) act as catalysts that can induce selectivity in chemical reactions. The responses of the Diels–Alder (DA) reaction between butadiene and ethylene (BDE‐DA) as well as cyclopentadiene and ethylene (CPDE‐DA) towards EEF stimuli are investigated here using density functional theory (B3LYP) calculations. EEF is a vector that catalyzes the reaction in one direction while inhibiting it in the opposite direction. Here we report that the inhibitive direction becomes rate‐enhancing after some increase in the EEF. The EEF value that brings about the maximum possible inhibition for the reaction is defined as the electrostatic resistance point (ERP). The possibility of both normal and inverse electron‐demand DA reactions causes catalytic activity in both directions of the EEF starting at a unique ERP value. The C5 substituents of cyclopentadiene control the ERP values depending upon the resistance power that the functional group provides against the EEF. The endo and exo diastereomeric transition states of the DA reaction have distinct ERP values and the difference (ΔERP) provides the through‐space electrostatic contribution to the stereoselectivity on a relative scale. Thus, the ERP values can be used as a gauge for the electrostatic interactions between substituent groups and external stimuli.
Porous PTFE supported bis(siloxane imidazole) functionalized Norbornyl copolymer composite anion exchange membrane for alkaline fuel cells
Authors: Li Quan , He Xiaohui , Huang Liang , Lu Yao , Zou Shaoyu , Ye Jia , Huang Longming , Yu Nengquan , Fu Zhihui , Zang Xiujing , Chen Defu 
Published: August 2023

AbstractAnion exchange membrane plays a vital role in alkaline anion exchange membrane fuel cell (AEMFC). In this work, a combination strategy of organic–inorganic nanocomposite technology and compounding with PTFE matrix was adopted, which effectively improve the dimensional stability and mechanical properties of AEMs. TGA test results showed that the AEMs had excellent thermal stability with initial thermal decomposition temperature higher than 260°C. SEM showed that the functionalized norbornyl copolymer CL‐aP(NB‐MGE‐b‐NB‐MHE) penetrated into the micropores structure of PTFE, and they had good interface bonding morphology. Composite AEMs had excellent swelling resistance, and the highest swelling ratio was only 7.53% at 80°C. PTFE/CL40‐aP(NB‐MGE‐b‐NB‐MHE) had the highest ionic conductivity (74.40 mS cm−1, 80°C). After immersing in 1 M NaOH solution for 500 h at 60°C, the initial ionic conductivity could be maintained above 90%. The open‐circuit voltage of PTFE/CL40‐aP(NB‐MGE‐b‐NB‐MHE) in H2/O2 fuel cell tests was 1.01 V, and the peak power density reached 182 mW cm−2 at the current density of 398 mA cm−2.
Marine megafauna catch in Thai small‐scale fisheries
Authors: Svarachorn Thevarit , Temple Andrew J. , Berggren Per 
Published: August 2023

AbstractSmall‐scale fisheries are a global conservation threat to marine megafauna (marine mammals, sea turtles, and elasmobranchs). There is currently limited information about marine megafauna catch in Thailand's small‐scale fisheries, which is required for effective management.This study represents the first independent catch assessment of marine megafauna in Thai small‐scale fisheries. Data on catch and fisheries effort across 1 year (2016–2017) were collected from questionnaire interviews with 535 fishers in 17 provinces along the Gulf of Thailand and the Andaman Sea coasts. Catch per unit effort was calculated for marine megafauna by fishing gear types and extrapolated to estimate annual catches using Thai official fisheries statistics.The annual estimated catches were 5.66 million (95% confidence interval, CI: 4.10–7.82 million) rays, 457,864 (95% CI: 192,352–969,166) sharks, 2,400 (95% CI: 1610–3,537) sea turtles, 790 (95% CI: 519–1,167) small cetaceans, and 72 (95% CI: 19–194) dugongs in Thai small‐scale fisheries.Gillnets had the highest catch per unit effort for all megafauna groups in both sea areas except for sea turtles, where pound nets had the highest catch per unit effort in the Gulf of Thailand. Further, among gillnets, crab gillnets had the highest catch per unit effort for all groups except dugongs, where ray gillnets had the highest catch per unit effort. Accounting for effort, crab gillnets and shrimp trammel nets were responsible for most of the megafauna catch, where crab gillnets contributed 72%–95% of the annual estimated marine megafauna catch. Crab gillnets and shrimp trammel nets were used by 46% and 40% respectively of the interviewed fishers and by 27% and 15% respectively of all small‐scale fishers operating in Thai waters.Restrictions for gillnet fishing effort (crab gillnets specifically) are needed to prevent extirpation of threatened megafauna species that are important for ecosystem resilience and productivity.
Robust weighted fusion Kalman filters under linearly correlated noise and mixed uncertainties of noise variances, multiplicative noises, and multiple networked inducements
Authors: Yang Chunshan , Zhao Ying , Liu Zheng 
Published: August 2023

AbstractThe paper solves the robust weighted fusion Kalman filtering problem for systems with linearly correlated noise and mixed uncertainties of noise variances, multiplicative noises, and multiple networked inducements including missing measurements, packets dropouts, and two‐step random measurement delays. It is assumed that system noise variances are uncertain but bounded above, and the other four uncertainties are compensated to fictitious white noise by the proposed model‐transformation method. For the transformed local multimodel system with correlated fictitious noise, the robust local time‐varying recursive Kalman filters are presented by decorrelation technique and minimax robust filtering principle. Then the six weighted fusion robust Kalman filters are presented in a unified form. The robustness of local and fused robust Kalman filters is proved by the extended Lyapunov equation approach, matrix factorization, and elementary transformation. Further, the local and fused steady‐state robust Kalman filters are designed. Finally, a simulation study applied to F404 aircraft engine system is provided to examine effectiveness and applicability of the proposed algorithm.
Vine Shoots‐Derived Hard Carbons as Anodes for Sodium‐Ion Batteries: Role of Annealing Temperature in Regulating Their Structure and Morphology
Authors: Alvira Darío , Antorán Daniel , Vidal Mariano , Sebastian Victor , Manyà Joan J. 
Published: August 2023

AbstractSodium‐ion batteries (SIBs) are considered one of the most promising large‐scale and low‐cost energy storage systems due to the abundance and low price of sodium. Herein, hard carbons from a sustainable biomass feedstock (vine shoots) were synthesized via a simple two‐step carbonization process at different highest temperatures to be used as anodes in SIBs. The hard carbon produced at 1200 °C delivered the highest reversible capacity (270 mAh g−1 at 0.03 A g−1, with an acceptable initial coulombic efficiency of 71 %) since a suitable balance between the pseudographitic domains growth and the retention of microporosity, defects, and functional groups was achieved. A prominent cycling stability with a capacity retention of 97 % over 315 cycles was also attained. Comprehensive characterization unraveled a three‐stage sodium storage mechanism based on adsorption, intercalation, and filling of pores. A remarkable specific capacity underestimation of up to 38 % was also found when a two‐electrode half‐cell configuration was employed to measure the rate performance. To avoid this systematic error caused by the counter/reference electrode polarization, we strongly recommend the use of a three‐electrode setup or a full‐cell configuration to correctly evaluate the anode response at moderate and high current rates.
Impact of ethanol on continuous inline diafiltration of liposomal drug products
Authors: Worsham Robert D. , Thomas Vaughan , Farid Suzanne S. 
Published: August 2023

AbstractLiposomal drug products are playing an increasing role in the field of drug delivery. With this increased demand comes the need to increase the capabilities and capacity of manufacturing options. Continuous manufacturing techniques present a significant opportunity to address these needs for liposomal manufacturing processes. Liposomal formulations have unique considerations that impact translation from batch to continuous process designs. This article examines aspects of converting to a continuous design that were previously viewed as inconsequential in a batch process. The batch process involves the removal of ethanol (EtOH) through tangential flow filtration (TFF). EtOH was found to reduce the permeability of the hollow fibers used for TFF. This effect was determined to have minimal impact on the overall batch process design but considerable influence on the design of continuous TFF such as inline diafiltration (ILDF). Using a pilot scale setup, EtOH was found to decrease permeability in an inverse manner to EtOH concentration. Further assessment found that dilution of the EtOH levels prior to diafiltration can significantly reduce the amount of ILDF stages needed and that a continuous design requires less buffer to the commensurate batch design.
A drug‐selectable acoustic reporter gene system for human cell ultrasound imaging
Authors: Howells Alessandro R. , Welch Phoebe J. , Kim John , Forest Craig R. , Shi Chengzhi , Lian Xiaojun Lance 
Published: August 2023

AbstractA promising new field of genetically encoded ultrasound contrast agents in the form of gas vesicles has recently emerged, which could extend the specificity of medical ultrasound imaging. However, given the delicate genetic nature of how these genes are integrated and expressed, current methods of producing gas vesicle‐expressing mammalian cell lines requires significant cell processing time to establish a clonal/polyclonal line that robustly expresses the gas vesicles sufficiently enough for ultrasound contrast. Here, we describe an inducible and drug‐selectable acoustic reporter gene system that can enable gas vesicle expression in mammalian cell lines, which we demonstrate using HEK293T cells. Our drug‐selectable construct design increases the stability and proportion of cells that successfully integrate all plasmids into their genome, thus reducing the amount of cell processing time required. Additionally, we demonstrate that our drug‐selectable strategy forgoes the need for single‐cell cloning and fluorescence‐activated cell sorting, and that a drug‐selected mixed population is sufficient to generate robust ultrasound contrast. Successful gas vesicle expression was optically and ultrasonically verified, with cells expressing gas vesicles exhibiting an 80% greater signal‐to‐noise ratio compared to negative controls and a 500% greater signal‐to‐noise ratio compared to wild‐type HEK293T cells. This technology presents a new reporter gene paradigm by which ultrasound can be harnessed to visualize specific cell types for applications including cellular reporting and cell therapies.
Improved endotoxin removal using ecofriendly detergents for intensified plasmid capture
Authors: Kiesewetter André , Gupta Akshat , Heinen‐Kreuzig Anja , Greenhalgh Trish , Stein Andreas 
Published: August 2023

AbstractIncreasing plasmid demand for both production of viral and gene therapies as well as nucleic acid based vaccines has highlighted bottlenecks in production. One bottleneck is traditional bead‐based chromatography as a capture step. To meet the needs of fast‐growing markets, new production solutions are needed. These solutions must enable efficient capture of a diverse range of plasmid types and excellent clearance of bacterial host impurities, such as endotoxin. Enhanced endotoxin clearance during chromatographic purification has previously been demonstrated with detergents such as Triton™ X‐100. However, degradation products of Triton™ X‐100 are known to have a negative environmental impact, and more sustainable, environmentally benign alternatives have been identified. This work establishes an efficient, intensified plasmid capture using convective anion exchange (AEX) chromatography. The feasibility of the intensified capture approach was assessed with different membrane and a monolith AEX supports. Various detergents from different physico‐chemical classes were evaluated with different AEX technologies. Purification efficiency evaluated endotoxin and host cell protein (HCP) clearance, plasmid yield, potential interference of the detergents with analytical in‐process control assays, and overall process compatibility. This comprehensive screening approach provides valuable insights to intensified plasmid production.
Heterologous Expression and Partial Characterization of a Putative Opine Dehydrogenase from a Metagenomic Sequence of Desulfohalobium retbaense
Authors: Kaličanin Nevena , Balaž Ana Marija , Prodanović Olivera , Prodanović Radivoje 
Published: August 2023

AbstractThe aim of this research was to prove the function of the putative opine dehydrogenase from Desulfohalobium retbaense and to characterize the enzyme in terms of functional and kinetic parameters. A putative opine dehydrogenase was identified from a metagenomic library by a sequence‐based technique search of the metagenomic library, and afterward was successfully heterologously produced in Escherichia coli. In order to examine its potential for applications in the synthesis of secondary amines, first the substrate specificity of the enzyme towards different amino donors and amino acceptors was determined. The highest affinity was observed towards small amino acids, preferentially L‐alanine, and when it comes to α‐keto acids, pyruvate proved to be a preferential amino acceptor. The highest activity was observed at pH 6.5 in the absence of salts. The enzyme showed remarkable stability in a wide range of experimental conditions, such as broad pH stability (from 6.0–11.0 after 30 min incubation in buffers at a certain pH), stability in the presence of NaCl up to 3.0 M for 24 h, it retained 80 % of the initial activity after 1 h incubation at 45 °C, and 65 % of the initial activity after 24 h incubation in 30 % dimethyl sulfoxide.
Low‐temperature synthesis of HfC/HfO2 nanocomposites from a commercial single‐source precursor
Authors: Mujib Shakir Bin , Arunachalam Saravanan R. , Singh Gurpreet 
Published: August 2023

AbstractA liquid‐phase polymer‐to‐ceramic approach is reported for the synthesis of hafnium carbide (HfC)/hafnium oxide (HfO2) composite particles from a commercial precursor. Typically, HfC ceramics have been obtained by sintering of fine powders, which usually results in large particle size and high porosity during densification. In this study a single‐source liquid precursor was first cured at low temperature and then pyrolyzed at varying conditions to achieve HfC ceramics. The chemical structure of the liquid and cured precursors, and the resulting HfC ceramics was studied using various analytical techniques. The nuclear magnetic resonance and Fourier transform infrared spectroscopy indicated the presence of partially hydrated hafnium oxychloride (Hf–O–Cl·nH2O) in the precursor. Scanning electron microscopy of the resulting HfC crystals showed a size distribution in the range of approx. 600–700 nm. The X‐ray diffraction of the pyrolyzed samples confirmed the formation of crystalline HfC along with monoclinic‐HfO2 and free carbon phase. The formation of HfO2 in the ceramics was significantly reduced by controlling the low‐temperature curing temperature. Pyrolysis at various temperatures showed that HfC formation occurred even at 1000°C. These results show that the reported precursor could be promising for the direct synthesis of ultrahigh temperature HfC ceramics and for precursor infiltration pyrolysis of reinforced ceramic matrix composites.
Prognostic significance of long noncoding RNA TTN‐AS1 in various malignancies
Authors: Lin Guangyao , Liu Xiyu , Cong Chao , Xu Lianwei 
Published: August 2023

AbstractBackgroundIncreasing evidence has demonstrated that high TTN‐AS1 expression is highly related to poor prognosis in diverse human cancers. However, the findings concerning the prognostic value of TTN‐AS1 were inconsistent, as these conclusions were usually drawn with relatively small sample sizes. Hence, this meta‐analysis proposes to investigate the prognostic significance of TTN‐AS1 in multiple malignancies systematically.MethodsWeb of Science, Springer, Embase, PubMed, Cochrane Library, and Scopus databases were comprehensively searched to retrieve studies related to the TTN‐AS1 expression with the prognosis of malignancies. The significance of the TTN‐AS1 in cancers was estimated by hazard ratios (HRs) or odds ratios (ORs). Additionally, the Gene Expression Profiling Interactive Analysis (GEPIA) analysis tool was used to strengthen our results further.ResultsTwenty studies involving 17 different cancers and 1330 patients were recruited into this meta‐analysis. The research revealed that high TTN‐AS1 expression was remarkably associated with unfavorable overall survival (OS) (HR = 2.07, 95%CI [1.78, 2.41], p < .00001) when compared with low TTN‐AS1 expression in malignancies. Additionally, elevated TTN‐AS1 expression significantly contributed to lymph node metastasis (OR = 4.09, 95%CI [3.08, 5.44], p < .0001), larger tumor size (OR = 2.42, 95%CI [1.56, 3.77], p < .0001), worse tumor differentiation (OR = 0.36, 95%CI [0.22, 0.59], p < .0001) and more advanced tumor stage (OR = 0.29, 95%CI [0.22, 0.38], p < .0001) with low or no heterogeneity existing. Moreover, high TTN‐AS1 expression was connected with worse disease‐free survival in five different cancers based on the GEPIA online database.ConclusionsThe results of this meta‐analysis support that high TTN‐AS1 expression significantly correlates with worse prognosis in various cancers. Therefore, TTN‐AS1 may be considered as a novel biomarker for malignancies.
Effects of shading intensities on the yield and contents of anthocyanin and soluble sugar in tubers of purple sweet potato
Authors: Jin Zhaoqiang , Wang Yidan , Si Chengcheng , Kumar Sunjeet , Nie Lixiao , Khan Mohammad Nauman 
Published: August 2023

AbstractLight intensity is an important factor affecting crop yield and quality. Studies on the effect of light intensity on the synthesis and accumulation of anthocyanin and soluble sugar in purple sweet potato tubers (Ipomea batatas L.) have rarely been documented. In this experiment, the effects of different shading intensities (no shading [L0], 20% shading [L1], 40% shading [L2], 60% shading [L3], and 80% shading [L4]) on the agronomic traits, fresh tuber yield, anthocyanin, and soluble sugar contents of purple sweet potatoes were investigated. Results showed that the fresh tuber yield was not decreased, and the accumulation of anthocyanin and soluble sugars in the tubers was increased under L1 compared to L0; however, these parameters were significantly decreased from L2 to L4 treatments. Further analysis showed that anthocyanin synthase (ANS) may be the restriction enzyme for anthocyanin synthesis in purple sweet potato tubers, and either excessive or insufficient light intensity decreased ANS activity. Results suggested that purple sweet potatoes might be planted in intercropping system with a little insufficient light intensity in tropical areas. However, the mechanisms underlying the effects of shading intensities on the yield and contents of anthocyanin and soluble sugar in tubers of purple sweet potato will be addressed in the future.
Tuning the Interfaces of ZnO/ZnCr2O4 Derived from Layered‐Double‐Hydroxide Precursors to Advance Nitrogen Photofixation
Authors: Gao Junyu , Wu Fan , Zhao Yunxuan , Bian Xuanang , Zhou Chao , Tang Junwang , Zhang Tierui 
Published: August 2023

AbstractDrawing inspiration from the enzyme nitrogenase in nature, researchers are increasingly delving into semiconductor photocatalytic nitrogen fixation due to its similar surface catalytic processes. Herein, we reported a facile and efficient approach to achieving the regulation of ZnO/ZnCr2O4 photocatalysts with ZnCr‐layered double hydroxide (ZnCr‐LDH) as precursors. By optimizing the composition ratio of Zn/Cr in ZnCr‐LDH to tune interfaces, we can achieve an enhanced nitrogen photofixation performance (an ammonia evolution rate of 31.7 μmol g−1 h−1 using pure water as a proton source) under ambient conditions. Further, photo‐electrochemical measurements and transient surface photovoltage spectroscopy revealed that the enhanced photocatalytic activity can be ascribed to the effective carrier separation efficiency, originating from the abundant composite interfaces. This work further demonstrated a promising and viable strategy for the synthesis of nanocomposite photocatalysts for nitrogen photofixation and other challenging photocatalytic reactions.