bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interaction of Sulfate Assimilation with Carbon and Nitrogen Metabolism in Lemna minor
Authors: Kopriva Stanislav , Suter Marianne , von Ballmoos Peter , Hesse Holger , Krähenbühl Urs , Rennenberg Heinz , Brunold Christian 
Published: November 2002

Abstract
Cysteine synthesis from sulfide andO-acetyl-l-serine (OAS) is a reaction interconnecting sulfate, nitrogen, and carbon assimilation. UsingLemna minor, we analyzed the effects of omission of CO2 from the atmosphere and simultaneous application of alternative carbon sources on adenosine 5′-phosphosulfate reductase (APR) and nitrate reductase (NR), the key enzymes of sulfate and nitrate assimilation, respectively. Incubation in air without CO2 led to severe decrease in APR and NR activities and mRNA levels, but ribulose-1,5-bisphosphate carboxylase/oxygenase was not considerably affected. Simultaneous addition of sucrose (Suc) prevented the reduction in enzyme activities, but not in mRNA levels. OAS, a known regulator of sulfate assimilation, could also attenuate the effect of missing CO2 on APR, but did not affect NR. When the plants were subjected to normal air after a 24-h pretreatment in air without CO2, APR and NR activities and mRNA levels recovered within the next 24 h. The addition of Suc and glucose in air without CO2 also recovered both enzyme activities, with OAS again influenced only APR.35SO4 2− feeding showed that treatment in air without CO2 severely inhibited sulfate uptake and the flux through sulfate assimilation. After a resupply of normal air or the addition of Suc, incorporation of 35S into proteins and glutathione greatly increased. OAS treatment resulted in high labeling of cysteine; the incorporation of 35S in proteins and glutathione was much less increased compared with treatment with normal air or Suc. These results corroborate the tight interconnection of sulfate, nitrate, and carbon assimilation.
Functional Analysis of Regulatory Elements in the Gene Promoter for an Abscission-Specific Cellulase from Bean and Isolation, Expression, and Binding Affinity of Three TGA-Type Basic Leucine Zipper Transcription Factors
Authors: Tucker Mark L. , Whitelaw Catherine A. , Lyssenko Nicholas N. , Nath Pravendra 
Published: November 2002

Abstract
Site-directed mutagenesis was used to identify cis-acting elements that control hormonal and abscission-specific expression of the bean (Phaseolus vulgaris) abscission cellulase (BAC) promoter. Auxin inhibition of BAC promoter expression is at least in part controlled by a negatively regulated element and ethylene induction by a positively regulated element. One of a series of 15 different 10-bp mutations created in a 2.9-kb BAC promoter reduced reporter gene expression by 60%. The native sequence for this 10-bp mutation includes a TGA-type basic leucine zipper (bZIP) motif. Tandem ligation of three 18-bp BAC elements (Z-BAC), which includes the bZIP motif to a minimal −50 35S cauliflower mosaic virus promoter, enhanced expression in abscission zones (AZs) 13-fold over that of the minimal promoter alone. The native forward orientation of the Z-BAC elements was essential for high expression levels. Expression of the Z-BAC minimal construct was 3-fold greater in AZ than stems when compared with the expression levels of an internal control with an enhanced 35S cauliflower mosaic virus promoter. Polymerase chain reaction was used to identify three TGA-type bZIP transcription factors in an AZ cDNA library. One of these factors was of the class I type and two of the class II type. RNA-blot analysis was completed for these genes and electrophoretic mobility shift assays used to confirm their binding to the Z-BAC element. Electrophoretic mobility shift assay-binding affinity was greatest for the class I TGA-type bZIP factor. The results indicate a complex interaction of negative and positive regulating transcription factors that control BAC gene expression.
Rubisco Small Subunit, Chlorophylla/b-Binding Protein and Sucrose:Fructan-6-Fructosyl Transferase Gene Expression and Sugar Status in Single Barley Leaf Cells in Situ. Cell Type Specificity and Induction by Light
Authors: Lu Chungui , Koroleva Olga A. , Farrar John F. , Gallagher Joe , Pollock Chris J. , Tomos A. Deri 
Published: November 2002

Abstract
We describe a highly efficient two-step single-cell reverse transcriptase-polymerase chain reaction technique for analyzing gene expression at the single-cell level. Good reproducibility and a linear dose response indicated that the technique has high specificity and sensitivity for detection and quantification of rare RNA.Actin could be used as an internal standard. The expression of message for Rubisco small subunit (RbcS), chlorophyll a/b-binding protein (Cab), sucrose (Suc):fructan-6-fructosyl transferase (6-SFT), and Actin were measured in individual photosynthetic cells of the barley (Hordeum vulgare) leaf. Only Actin was found in the non-photosynthetic epidermal cells. Cab,RbcS, and 6-SFT genes were expressed at a low level in mesophyll and parenchymatous bundle sheath (BS) cells when sampled from plants held in dark for 40 h. Expression increased considerably after illumination. The amount of 6-SFT,Cab, and RbcS transcript increased more in mesophyll cells than in the parenchymatous BS cells. The difference may be caused by different chloroplast structure and posttranscriptional control in mesophyll and BS cells. When similar single-cell samples were assayed for Suc, glucose, and fructan, there was high correlation between 6-SFT gene expression and Suc and glucose concentrations. This is consistent with Suc concentration being the trigger for transcription. Together with earlier demonstrations that the mesophyll cells have a higher sugar threshold for fructan polymerization, our data may indicate separate control of transcription and enzyme activity. Values for the sugar concentrations of the individual cell types are reported.
Amphiphilic Perfluoroalkylated Derivatives of Aliphatic Triols: Hemocompatibility and Effect on Perfluorocarbon Emulsion
Authors: Církva Vladimír , Kaplánek Robert , Paleta Oldřich , Kodíček Milan 
Published: November 2002

Two sets of amphiphilic perfluoroalkylated aliphatic triols were prepared in a two-step synthesis: a protected glycerol, 4-hydroxymethyl-2,2-dimethyl-1,3-dioxolane (1) and protected 2-hydroxymethyl-2-methylpropane-1,3-diol, 5-hydroxymethyl-2,2,5-trimethyl-1,3-dioxane (11) were fluoroalkylated with racemic 2-(2,2,3,3,4,4,5,5,5-nonafluoropentyl)- (2), or 2-(2,2,3,3,4,4,5,5,6,6,7,7,7-tridecafluoroheptyl)- (3) or 2-(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-heptadecafluorononyl)oxirane (4) using boron trifluoride diethyl etherate as a catalyst to afford intermediates 5-7 and 12-14, which were deprotected by re-acetalization to the target triols HOCH2CH(OH)CH2OCH2CH(OH)CH2CF2(CF2)nCF3 (n = 2, 4, 6) 8-10 and (OHCH2)2C(CH3)CH2OCH2CH(OH)CH2CF2(CF2)nCF3 (n = 2, 4, 6) 15-17. Regioselectivity of competitive fluoroalkylation of propane-1,2-diol and butane-1,3-diol appeared to be considerably dependent on the catalyst up to 93 rel.% for the preferential fluoroalkylation at the primary hydroxy group. Hemocompatibility of the triols 8-10 and 15-17, which was very high for linear-chain amphiphiles 9 and 10, showed particular dependence on the starting triol and perfluoroalkyl-chain length. All amphiphiles 8-10 and 15-17 displayed very good compatibility with perfluorodecalin-Pluronic F-68 water emulsion.
ADAM AND THE ANGELS: AN EXAMINATION OF MYTHIC ELEMENTS IN ISLAMIC SOURCES
Authors: Chipman Leigh 
Published: November 2002

AbstractThis paper examines the involvement of the angels in the creation of Adam as an example of mythopoetic activity in Islam. This involvement takes the form of the angels' reaction to Adam's creation and to Adam's superior knowledge. These themes also developed within an anti-Gnostic polemic; the figure of the First Man is important for Gnosticism no less than for Judaism or Islam, yet their visions of this figure differed greatly. The relations between Adam and the angels is an important refraction of the differences between these religions. Comparison of tales from three Islamic genres—tafsīr, ta'rīh and qisas al-anbiyā'—with rabbinical legends shows that, contrary to expectations, Islamic material provides a more mythic conception of these themes than does Jewish midrash.
Prosocial dynamics in multiagent systems
Authors: Santos Fernando P. 
Published: January 2024

AbstractMeeting today's major scientific and societal challenges requires understanding dynamics of prosociality in complex adaptive systems. Artificial intelligence (AI) is intimately connected with these challenges, both as an application domain and as a source of new computational techniques: On the one hand, AI suggests new algorithmic recommendations and interaction paradigms, offering novel possibilities to engineer cooperation and alleviate conflict in multiagent (hybrid) systems; on the other hand, new learning algorithms provide improved techniques to simulate sophisticated agents and increasingly realistic environments. In various settings, prosocial actions are socially desirable yet individually costly, thereby introducing a social dilemma of cooperation. How can AI enable cooperation in such domains? How to understand long‐term dynamics in adaptive populations subject to such cooperation dilemmas? How to design cooperation incentives in multiagent learning systems? These are questions that I have been exploring and that I discussed during the New Faculty Highlights program at AAAI 2023. This paper summarizes and extends that talk.
Evaluation of Dynamic Effects of Depressive Symptoms on Physical Function in Knee Osteoarthritis
Authors: Mehta Rhea , Hochberg Marc , Shardell Michelle , Ryan Alice , Dong Yu , Beamer Brock A. , Peer Jason , Stuart Elizabeth A. , Schuler Megan , Gallo Joseph J. , Rathbun Alan M. 
Published: January 2024

ObjectiveTo assess how changes in depressive symptoms influence physical function over time among those with radiographic knee osteoarthritis (OA).MethodsParticipants from the Osteoarthritis Initiative with radiographic knee OA (n = 2,212) and complete data were identified at baseline. Depressive symptoms were assessed as a time‐varying score at baseline and the first three annual follow‐up visits using the Center for Epidemiological Studies Depression Scale (CES‐D) Scale. Physical function was measured at the first four follow‐up visits using 20‐meter gait speed meters per second. The following two marginal structural models were fit: one assessing the main effect of depressive symptoms on gait speed and another assessing time‐specific associations.ResultsTime‐adjusted results indicated that higher CES‐D scores were significantly associated with slower gait speed (−0.0048; 95% confidence interval −0.0082 to −0.0014), and time‐specific associations of CES‐D were largest during the first follow‐up interval (−0.0082; 95% confidence interval −0.0128 to −0.0035). During subsequent follow‐up time points, the influence of depressive symptoms on gait speed diminished.ConclusionThe negative effect of depressive symptoms on physical function may decrease over time as knee OA progresses.
Progress of Gate‐Defined Semiconductor Spin Qubit: Host Materials and Device Geometries
Authors: Liu Yang , Guan Shan , Luo Jun‐Wei , Li Shu‐Shen 
Published: January 2024

AbstractQuantum computing offers the potential to revolutionize information processing by exploiting the principles of quantum mechanics. Among the diverse quantum bit (qubit) technologies, silicon‐based semiconductor spin qubits have emerged as a promising contender due to their potential scalability and compatibility with existing semiconductor technologies. In this paper, the latest developments of spin qubits in gate‐defined semiconducting nanostructures made of silicon and germanium, starting from the basic properties of electron and hole states in group‐IV semiconductors, are reviewed. Specifically, various nanostructures that exploit their unique microscopic properties for qubit implementations, elaborating on the advances and challenges in experiments, are discussed. Strategies for enhancing qubit performance, such as designing new nanostructures and identifying suitable operating points, particularly those involving the valleys of electron qubits and the heavy‐hole–light‐hole mixing of hole qubits, are also highlighted. This comprehensive review thus provides valuable insights into the current state‐of‐the‐art in semiconductor quantum computing and suggests avenues for future research.
A Protein‐Adsorbent Hydrogel with Tunable Stiffness for Tissue Culture Demonstrates Matrix‐Dependent Stiffness Responses
Authors: Li Linqing , Griebel Megan E. , Uroz Marina , Bubli Saniya Yesmin , Gagnon Keith A. , Trappmann Britta , Baker Brendon M. , Eyckmans Jeroen , Chen Christopher S. 
Published: January 2024

AbstractAlthough tissue culture plastic has been widely employed for cell culture, the rigidity of plastic is not physiologic. Softer hydrogels used to culture cells have not been widely adopted in part because coupling chemistries are required to covalently capture extracellular matrix (ECM) proteins and support cell adhesion. To create an in vitro system with tunable stiffnesses that readily adsorbs ECM proteins for cell culture, a novel hydrophobic hydrogel system is presented via chemically converting hydroxyl residues on the dextran backbone to methacrylate groups, thereby transforming non‐protein adhesive, hydrophilic dextran to highly protein adsorbent substrates. Increasing methacrylate functionality increases the hydrophobicity in the resulting hydrogels and enhances ECM protein adsorption without additional chemical reactions. These hydrophobic hydrogels permit facile and tunable modulation of substrate stiffness independent of hydrophobicity or ECM coatings. Using this approach, it is shown that substrate stiffness and ECM adsorption work together to affect cell morphology and proliferation, but the strengths of these effects vary in different cell types. Furthermore, it is revealed that stiffness‐mediated differentiation of dermal fibroblasts into myofibroblasts is modulated by the substrate ECM. The material system demonstrates remarkable simplicity and flexibility to tune ECM coatings and substrate stiffness and study their effects on cell function.
Perforin‐Mimicking Molecular Drillings Enable Macroporous Hollow Lignin Spheres for Performance‐Configurable Materials
Authors: Wang Hairong , Tan Shujun , Su Zhenhua , Li Mingfei , Hao Xiang , Peng Feng 
Published: January 2024

AbstractDespite the first observations that the perforin can punch holes in target cells for live/dead cycles in the human immune system over 110 years ago, emulating this behavior in materials science remains challenging. Here, a perforin‐mimicking molecular drilling strategy is employed to engineer macroporous hollow lignin spheres as performance‐configurable catalysts, adhesives, and gels. Using a toolbox of over 20 molecular compounds, the local curvature of amphiphilic lignin is modulated to generate macroporous spheres with hole sizes ranging from 0 to 100 nm. Multiscale control is precisely achieved through noncovalent assembly directing catalysis, synthesis, and polymerization. Exceptional performance mutations correlate with the changes in hole size, including an increase in catalytic efficiency from 50% to 100%, transition from nonstick synthetics to ultrastrong adhesives (adhesion ≈18.3 MPa, exceeding that of classic epoxies), and transformation of viscous sols to tough nanogels. Thus, this study provides a robust and versatile noncovalent route for mimicking perforin‐induced structural variations in cells, representing a significant stride toward the exquisite orchestration of assemblies over multiple length scales.
High‐Toughness CO2‐Sourced Ionic Polyurea Adhesives
Authors: Ou Xu , Pan Ji , Liu Qinbo , Niu Yajuan , Zhou Yingjie , Yan Feng 
Published: January 2024

AbstractPolyurea (PUa) adhesives are renowned for their exceptional adhesion to diverse substrates even in harsh environments. However, the presence of quadruple bidentate intermolecular hydrogen bonds in the polymer chains creates a trade‐off between cohesive energy and interfacial adhesive energy. To overcome this challenge, a series of CO2‐sourced ionic PUa adhesives with ultratough adhesion to various substrates are developed. The incorporated ionic segments within the adhesive serve to partially mitigate the intermolecular hydrogen bonding interactions while conferring unique electrostatic interactions, leading to both high cohesive energy and interfacial adhesive energy. The maximum adhesive strength of 10.9 MPa can be attained by ionizing the CO2‐sourced PUa using bromopropane and subsequently exchanging the anion with lithium bis(trifluoromethylsulfonyl)imide. Additionally, these ionic PUa adhesives demonstrate several desirable properties such as low‐temperature stability (−80 °C), resistance to organic solvents and water, high flame retardancy, antibacterial activity, and UV‐fluorescence, thereby expanding their potential applications. This study presents a general and effective approach for designing high‐strength adhesives suitable for a wide array of uses.
Effect of microstructure tuning by rapid heat cycle molding on the photodegradation behavior of isotactic polypropylene
Authors: Li Jiquan , Chen Yanben , Xie Jun , Jiang Shaofei , Lu Chunfu 
Published: January 2024

AbstractRapid heat cycling molding (RHCM) is an injection molding technique that improves the product quality of isotactic polypropylene (iPP) by tuning the microstructure, but its effect on the photodegradation stability remains to be investigated. In this work, the effect of RHCM tuned microstructure on the photodegradation behavior of iPP was investigated and compared with conventional injection molding (CIM). Differential scanning calorimetry (DSC), x‐ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), atomic force microscopy (AFM), and shore durometer (D scale) were used to examine the photodegradation behavior of iPP samples. The results showed that RHCM increased the crystallinity, crystal size, and β‐crystal content of iPP samples. With the increase of photodegradation time, iPP samples injected with RHCM showed higher stability in terms of microstructure and surface quality. The relative changes in CI and Ra of RHCM90 were reduced by 48% and 40% after 800 h of UV irradiation, respectively. In addition, the combined results of dynamic mechanical analysis (DMA) and UV–visible absorption spectrum showed that RHCM promoted the development of crystalline structure and reduced the mobility of the surface chain segments as well as UV absorption coefficient. These combined effects contributed positively to its photodegradation stability.
Die Nibelungenbrücke als Pilotprojekt der digital unterstützten Bauwerkserhaltung
Authors: Kang Chongjie , Voigt Chris , Eisermann Cedric , Kerkeni Naceur , Hegger Josef , Hermann Wladimir , Jackmuth Andreas , Marzahn Gero , Marx Steffen 
Published: January 2024

AbstractDas Bauwesen zählt zu den Hauptkonsumenten natürlicher Ressourcen, weshalb hier Einsparungen besonders effektiv wären. Da 54 % des jährlichen Abfallaufkommens in Deutschland auf Bau‐ und Abbruchabfälle zurückzuführen sind, kann insbesondere durch den Erhalt des Bauwerksbestands ein wesentlicher Beitrag zum Umwelt‐ und Ressourcenschutz geleistet werden. Um die Lebensdauer von Bauwerken unter Wahrung deren Standsicherheit und Funktionsfähigkeit zu verlängern, bedarf es jedoch effektiver Überwachungs‐ sowie Instandhaltungskonzepte. Dieser Beitrag behandelt ein Pilotprojekt, bei dem die Nibelungenbrücke Worms als Validierungsbauwerk dient, um eine neue, digital gestützte Instandhaltungsstrategie zu entwickeln. Zunächst werden das Bauwerk sowie dessen Instandhaltungshistorie vorgestellt. Anschließend wird das Pilotprojekt in den Kontext des DFG‐Schwerpunktprogramms SPP 2388 „Hundert plus“ gesetzt. Danach werden die spezifischen Schwerpunkte des Pilotprojekts, darunter die geometrische Modellierung, das Structural Health Monitoring (SHM), der Digitale Zwilling, die Stufe‐4‐Nachrechnung und die Beurteilung der detektierten Bauwerksschäden, erläutert. Abschließend werden Schlussfolgerungen und Ausblicke gegeben.
Tailoring the Active Species Distribution of Heterogeneous Catalyst for Regulating the Chain Structure of Nascent Polyethylene
Authors: Li Wei , Wang Jingdai , Yang Yongrong 
Published: January 2024

AbstractHeterogeneous catalysis is the most widely used process for ethylene polymerization in industry. Active site distribution is one of the crucial issues in the heterogeneous catalysis, which strongly influences the catalytic process and the microstructure of synthesized polyethylene. In this respect, aiming at an explicit understanding of the progress, the challenge and the possible future directions in the study of heterogeneous catalysis of ethylene polymerization, the recent strategies of designing heterogeneous catalysts are reviewed from the perspective of tailoring the active site distribution, where the regulation of chain structures, including molecular weight distribution, branch distribution and entanglement state, are highlighted. The in situ and operando characterizations are also reviewed for assisting the understanding of structural information in heterogeneous catalysts.
One‐Pot N‐Alkylation of Amines over Ni(II) Embedded Reusable Porous Organic Polymer via Borrowing Hydrogen Strategy
Authors: Pathak Debabrat , Kumar Kalita Bikash , Sharma Himanshu , Biswakarma Nishant , Deka Ramesh Ch. , Sarma Bipul 
Published: January 2024

AbstractThe first‐of‐its‐kind, one‐pot N‐alkylation reaction of amines over Ni(II) impregnated porous organic polymer of highly dense N‐rich skeleton is reported. The primeval Ni(II) decorated hollow spherical porous polymer is synthesized and employed in a series of catalytic reactions involving C−N bond formation. The catalytic reactions are optimised to yield the desired product highlighting the role of different substituents present on the reactants towards the overall selectivity and efficiency. The detailed reaction mechanism is corroborated with computation validating a three‐step arrow formalism viz. dehydrogenation of the alcohol, condensation with amines to generate the imine as intermediate followed by hydrogenation by a borrowing strategy to yield the final product. The role of the bare support material in the first step and that of the Ni(II) centres of the support material in the third step is marked as pivotal for the forward reaction to proceed with enriching sustainability and feasibility.
Regio‐ and Enantioselective Synthesis of 1,2‐Diamines by Formal Hydroamination of Enamines: Scope, Mechanism, and Asymmetric Synthesis of Orthogonally Protected Bis‐Piperazines as a Privileged Scaffold
Authors: Mohiti Maziar , Lu Yu , He Hui , Ni Shao‐Fei , Somfai Peter 
Published: January 2024

AbstractWe have previously reported the first formal hydroamination of enamines for the synthesis of chiral 1,2‐diamines. Here, we describe: (i) the discovery, optimization, and substrate expansion of this reaction; (ii) a novel and straightforward protocol for the “click‐type” synthesis of enamines in quantitative yield utilizing sodium sulfate in a dual role as an ancillary and dehydrating agent without the need for workup or purification; (iii) the application of this methodology to the first enantioselective synthesis of orthogonally protected 1,1′‐(1‐(4‐fluorophenyl)ethane‐1,2‐diyl) piperazines, a scaffold for rapid lead optimization in drug discovery; (iv) a computational investigation into the mechanism and rationalization of the enantioselectivities of the reaction.