bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal‐Oxo Electronic Tuning via In Situ CO Decoration for Promoting Methane Conversion to Oxygenates over Single‐Atom Catalysts
Authors: Xu Weibin , Liu Han‐Xuan , Hu Yue , Wang Zhen , Huang Zheng‐Qing , Huang Chuande , Lin Jian , Chang Chun‐Ran , Wang Aiqin , Wang Xiaodong , Zhang Tao
Published: March 2024

Direct methane conversion (DMC) to oxygenates at low temperature is of great value but remains challenging due to the high energy barrier for C−H bond activation. Here, we report that in situ decoration of Pd1‐ZSM‐5 single atom catalyst (SAC) by CO molecules significantly promoted the DMC reaction, giving the highest turnover frequency of 207 h−1 ever reported at room temperature and ~100 % oxygenates selectivity with H2O2 as oxidant. Combined characterizations and DFT calculations illustrate that the C‐atom of CO prefers to coordinate with Pd1, which donates electrons to the Pd1−O active center (L−Pd1−O, L=CO) generated by H2O2 oxidation. The correspondingly improved electron density over Pd−O pair renders a favorable heterolytic dissociation of C−H bond with low energy barrier of 0.48 eV. Applying CO decoration strategy to M1‐ZSM‐5 (M=Pd, Rh, Ru, Fe) enables improvement of oxygenates productivity by 3.2–11.3 times, highlighting the generalizability of this method in tuning metal‐oxo electronic structure of SACs for efficient DMC process.
Enantioselektive Synthese von Phosphinoboranen via kristallisationsinduzierter dynamischer Racematspaltung des lithiierten Intermediates durch Verständnis des zugrunde liegenden Epimerisierungsprozesses
Authors: Kuzu Mehmet Yasin , Schmidt Annika , Strohmann Carsten
Published: March 2024

Hier wird die erfolgreiche kristallisationsinduzierte dynamische Racematspaltung (CIDR) eines α‐lithiierten Phosphinoborans mithilfe des leicht zugänglichen und kostengünstigen chiralen Liganden (R,R)‐TMCDA beschrieben. Ausgehend von dem wichtigen P‐prochiralen Baustein Dimethylphenylphosphinoboran konnten Phosphinoborane in Ausbeuten von bis zu 80 % und Enantiomerenverhältnissen von bis zu 98 : 2 durch Kristallisation des lithiierten Zwischenprodukts erhalten werden. NMR‐basierte Deuterium‐Markierungsexperimente zeigen, dass die Epimerisierung in Lösung auf dem intermolekularen Protonentransfer zwischen dem nicht lithiierten Phosphinoboran und dem entsprechenden lithiierten Zwischenprodukt beruht, sodass die Anwesenheit überschüssigen Eduktes in einem optimierten Lösungsmittelgemisch der Hauptfaktor für eine erfolgreiche enantioselektive Synthese ist. Quantenchemische Berechnungen mit verschiedenen auf Festkörperstrukturen basierenden Modellsystemen bestätigen diese experimentellen Ergebnisse. Durch den Einblick in den Epimerisierungsmechanismus wurden wesentliche Prinzipien für die CIDR von lithiierten Phosphinoboranen aufgeklärt, die auf andere wichtige P‐stereogene Verbindungen und einfache chirale Amine erweitert werden könnten.
Efficient Homolytic Cleavage of H2O2 on Hydroxyl‐Enriched Spinel CuFe2O4 with Dual Lewis Acid Sites
Authors: Tian Lei , Tang Zi‐Jun , Hao Le‐Yang , Dai Ting , Zou Jian‐Ping , Liu Zhao‐Qing
Published: March 2024

Traditional H2O2 cleavage mediated by macroscopic electron transfer (MET) not only has low utilization of H2O2, but also sacrifices the stability of catalysts. We present a non‐redox hydroxyl‐enriched spinel (CuFe2O4) catalyst with dual Lewis acid sites to realize the homolytic cleavage of H2O2. The results of systematic experiments, in situ characterizations, and theoretical calculations confirm that tetrahedral Cu sites with optimal Lewis acidity and strong electron delocalization can synergistically elongate the O−O bonds (1.47 Å → 1.87 Å) in collaboration with adjacent bridging hydroxyl (another Lewis acid site). As a result, the free energy of H2O2 homolytic cleavage is decreased (1.28 eV → 0.98 eV). H2O2 can be efficiently split into ⋅OH induced by hydroxyl‐enriched CuFe2O4 without MET, which greatly improves the catalyst stability and the H2O2 utilization (65.2 %, nearly 2 times than traditional catalysts). The system assembled with hydroxyl‐enriched CuFe2O4 and H2O2 affords exceptional performance for organic pollutant elimination. The scale‐up experiment using a continuous flow reactor realizes long‐term stability (up to 600 mL), confirming the tremendous potential of hydroxyl‐enriched CuFe2O4 for practical applications.
Colloidal Zeta Potential Modulation as a Handle to Control the Crystallization Kinetics of Tin Halide Perovskites for Photovoltaic Applications
Authors: Wang Junfang , Huang Junjie , Abdel‐Shakour Muhammad , Liu Tianhua , Wang Xu , Pan Yongle , Wang Lixia , Cui Enhao , Hu Jin‐Song , Yang Shihe , Meng Xiangyue
Published: March 2024

Tin halide perovskites (THPs) have demonstrated exceptional potential for various applications owing to their low toxicity and excellent optoelectronic properties. However, the crystallization kinetics of THPs are less controllable than its lead counterpart because of the higher Lewis acidity of Sn2+, leading to THP films with poor morphology and rampant defects. Here, a colloidal zeta potential modulation approach is developed to improve the crystallization kinetics of THP films inspired by the classical Derjaguin‐Landau‐Verwey‐Overbeek (DLVO) theory. After adding 3‐aminopyrrolidine dihydro iodate (APDI2) in the precursor solution to change the zeta potential of the pristine colloids, the total interaction potential energy between colloidal particles with APDI2 could be controllably reduced, resulting in a higher coagulation probability and a lower critical nuclei concentration. In situ laser light scattering measurements confirmed the increased nucleation rate of the THP colloids with APDI2. The resulting film with APDI2 shows a pinhole‐free morphology with fewer defects, achieving an impressive efficiency of 15.13 %.
Enantioselective Synthesis of Phosphine Boranes via Crystallization‐Induced Dynamic Resolution of Lithiated Intermediate by Understanding the Underlying Epimerization Process
Authors: Kuzu Mehmet Yasin , Schmidt Annika , Strohmann Carsten
Published: March 2024

Described herein is the successful crystallization‐induced dynamic resolution (CIDR) of an α‐lithiated phosphine borane utilizing the easily accessible and inexpensive ligand (R,R)‐TMCDA. Starting from the essential P‐prochiral building block dimethyl phenyl phosphine borane we were able to obtain phosphine boranes in yields up to 80 % and e.r. up to 98 : 2 by crystallization of the lithiated intermediate prior to the trapping reaction. NMR‐based deuterium labeling experiments indicate that the epimerization in solution is based on the intermolecular proton transfer between nonlithiated phosphine borane and the corresponding lithiated intermediate, rendering the presence of the remaining starting compound in an optimized solvent mixture the main factor for successful enantioselective synthesis. Quantum chemical calculations using different model systems based on solid state structures confirm these experimental results. By gaining insights into the epimerization mechanism, essential principles for CIDR of lithiated phosphine boranes are elucidated that may be expanded to other important P‐stereogenic compounds and simple chiral amines.
Alkoxycarbonyl Groups in Metalloesters Showing Oxocarbenium‐like Structure and Alkylating Reactivity
Authors: Xu Yingzhuang , Feng Bingjian , Li Songyi , Fang Huayi
Published: March 2024

In contrast to the well‐documented acylating reactivity, the alkylating reactivity of the alkoxycarbonyl group, as signified by its oxocarbenium‐like resonance structure, remains almost unexplored. Herein, the first series of Co/Ni dinuclear metalloesters exhibiting the novel oxocarbenium‐like alkoxycarbonyl groups were synthesized and characterized. In these deformed alkoxycarbonyl groups, the Ccarbonyl−Oalkoxyl bonds were contracted to 1.177(11)~1.191(9) Å with the elongations of the Ccarbonyl=Ocarbonyl bonds to 1.368(13)~1.441(9) Å. Meanwhile, the O−Calkyl bonds were also elongated to 1.522(11) ~1.607(15) Å, and were by far the longest O−Calkyl bonds reported for alkoxycarbonyl groups. As triggered by the long O−Calkyl distances, the alkylating reactivity of the oxocarbenium‐like methoxycarbonyl group towards a series of C/N/O‐nucleophiles via the rare BAL2 mechanism at ambient conditions was examined. Furthermore, the homo‐etherifications of alcohols mediated by the Co/Ni dinuclear metalloesters were investigated. The yields followed the trend ethanol≫n‐propanol≫n‐butanol ≈n‐pentanol, that closely related to the structure features of the alkoxycarbonyl groups in corresponding metalloesters: while the ethoxycarbonyl group showed the reactive oxocarbenium‐like framework, the n‐propoxycarbonyl group displayed the dioxocarbenium‐like skeleton with a shorter O−Calkyl bond; In comparison, the classical frameworks with unactivated alkyl moieties were observed for n‐butoxycarbonyl and n‐pentoxycarbonyl groups.
Dietary low‐fat content supplemented with oxytetracycline impairs physiological functions in Nile tilapia (Oreochromis niloticus) fingerlings
Authors: Limbu Samwel Mchele
Published: March 2024

Nutrition modulates the vulnerability of animals to xenobiotics insults including antibiotics in cultured fish. However, studies exploring the role of low‐fat diet (LFD) in modulating adverse effects of antibiotics are currently limited. This study explored the physiological effects of feeding LFD supplemented with oxytetracycline (OTC) in Nile tilapia (Oreochromis niloticus) fingerlings. Thirty Nile tilapia (8.64 ± 0.44 g) were tagged and randomly stocked into three tanks and fed on a control diet (CD, 70 g/kg lipid), LFD (20 g/kg lipid) and the LFD supplemented with 2.00 g/kg diet of OTC (80 mg/kg body weight/day), hereafter LFD + OTC for 9 weeks. The results indicated that the Nile tilapia fed on LFD + OTC reduced growth performance and feed utilization efficiency than those fed on CD and LFD. Moreover, the fish fed on LFD + OTC had lower body composition, nutrients digestibility and mesenteric fat index than those fed on CD and LFD. Feeding the fish with LFD + OTC decreased antioxidant capacity in the liver than those fed on CD and LFD. The Nile tilapia fed on LFD + OTC increased hepatotoxicity than those fed on CD and LFD. Feeding the Nile tilapia on LFD + OTC decreased immunity response in the kidney and liver than those fed on CD and LFD. The LFD + OTC affected nutrients metabolism in the liver and serum than other diets. Taken together, feeding LFD with OTC impairs physiological functions of Nile tilapia by inhibiting growth performance, antioxidant capacity, immunity response and nutrient metabolism.
Preventive maintenance for coherent systems considering postponed replacement
Authors: Asadi Majid
Published: March 2024

One primary objective of reliability engineering is to achieve optimal maintenance of technical systems, which ensures they remain in good operating condition. This paper proposes an age‐based preventive optimal maintenance policy for ‐component coherent systems. Under this proposed strategy, the system begins operating at and undergoes preventative maintenance (PM) at a time . If the system fails before , it will be replaced with a new one. If the system is still functioning at time , an assessment is made based on the number of failed components to determine whether the system should be replaced or allowed to continue operating. If the number of failures at is below a predetermined threshold , the PM time is postponed and a new PM time will be scheduled, and the system continues operating in the interval . Otherwise, the entire system is preventively replaced at with a new one. In this scenario, we use a cost function to determine the optimal values of decision variables , , and . To examine the effectiveness of our proposed model, we analyze some examples of coherent systems using graphical and numerical methods.
What are topic emotions? A comparison of children's emotional responses to climate change, climate change learning and climate change picturebooks
Authors: Oberman Rowan
Published: March 2024

Pekrun and his colleagues highlight the significance and diversity of emotion in education. Their analysis suggests that these emotions can be categorised by their stimuli into those related to the classroom: activities, outcomes, relationships, topics and knowledge processes (epistemic). Most research in this area has focused on achievement emotions, with relatively limited research exploring topic emotions. This paper develops a framework for conceptualising topic emotions. It reports on a design‐based study that captured children's expressions of emotion in response to a climate change education programme using picturebooks. The data brought together emotional responses to climate change, to learning about climate change and to climate‐related picturebooks. Qualitative analysis of these responses highlights how they differ not only with regard to the emotions expressed, but also the structure of the emotional experience. Emotional responses to the broad topic of climate change were expressed as ongoing analytical judgements, where those related to learning about climate change were immersive and finite. Reading climate‐related picturebooks involved exploring how emotion is communicated and evoked. This supported quasi‐emotional experiences, where the reader imagines the emotions of the characters. The picturebooks are also shown to create vicarious emotional experiences, involving ethical‐based responses to the behaviour and circumstances depicted. Based on this analysis, the paper proposes a framework for disaggregating these differing emotional experiences related to topic.
New insights on social finance research in the sustainable development context
Authors: Gonzalez‐Ruiz Juan David , Marín‐Rodríguez Nini Johana , Weber Olaf
Published: March 2024

Research on sustainable finance has experienced significant growth in recent years, but the exploration from a comprehensive perspective is still in its nascent stages. As of July 2023, our research revealed that this area remains relatively underexplored in the existing body of knowledge, leading to a notable lack of comprehensive research analyzing the current state‐of‐the‐art in the social finance arena. To address this gap, our study takes a pioneering approach by utilizing scientometrics and network analysis techniques, specifically employing VOSviewer and Bibliometrix in conjunction with Web of Science and Scopus databases. By merging data from both sources and removing duplicate entries, we established a consolidated database of 401 relevant studies. Through our analysis, we have identified prominent authors, sources, and the most influential studies in the social finance arena. Additionally, we examined the coupling of studies and authors to ascertain their significance in this emerging domain. The results have unveiled several prominent further research, including mainly social banking, Islamic finance, social innovation, the impact of the COVID‐19 pandemic, impact investing, social impact bonds, and Sustainable Development Goals. By shedding light on the current landscape, our findings comprehensively understand the field's progress and potential directions. This insight is valuable for market participants, researchers, policymakers, and decision‐makers seeking to navigate and contribute to the evolving landscape of sustainable finance with a social focus. Furthermore, our innovative use of scientometrics and network analysis sets a precedent for future research exploring the complex interplay between finance, development, and sustainability.
Examples and tutorials on using Google Colab and Gradio to create online interactive student‐learning modules
Authors: Ferreira Ricardo , Canesche Michael , Jamieson Peter , Neto Omar P. Vilela , Nacif Jose A. M.
Published: March 2024

This work provides online learning modules and instructions on how educators can leverage these technologies to help students learn in a personalized online environment. In particular, we focus on Google Colab, and the features provided by the Gradio Python library to provide interactivity within these modules. The contributions of this work include: (1) Development of a teaching framework using Gradio/Colab that offers automated grading and feedback for both educators and students; (2) Design of a versatile proposal, accommodating beginners with a straightforward interface while addressing the needs of advanced learners; (3) Creation of a comprehensive set of examples tailored for teaching digital logic subjects, with adaptability for application in various computer science areas. (4) A classification of these example learning modules in terms of their learning level for the students; (5) A novel client‐server approach based on Colab/Gradio, allowing teachers to manage the main notebook efficiently while providing a lightweight and reliable interface for students. The goal of this work is to further expose educators to the remarkable capabilities that cloud computing brings to online supplemental education, noting that large language models such as ChatGPT complement this work, in that chatbots will be able to guide students in these dynamic simulations.
Fullertubes inhibit mycobacterial viability and prevent biofilm formation by disrupting the cell wall
Authors: Shenoy Varun , Gunda Rashmika , Noble Cora , Haraguchi Annalisa , Stevenson Steven , Daniel Jaiyanth
Published: March 2024

Mycobacterium tuberculosis and nontuberculous mycobacteria such as Mycobacterium abscessus cause diseases that are becoming increasingly difficult to treat due to emerging antibiotic resistance. The development of new antimicrobial molecules is vital for combating these pathogens. Carbon nanomaterials (CNMs) are a class of carbon‐containing nanoparticles with promising antimicrobial effects. Fullertubes (C90) are novel carbon allotropes with a structure unique among CNMs. The effects of fullertubes on any living cell have not been studied. In this study, we demonstrate that pristine fullertube dispersions show antimicrobial effects on Mycobacterium smegmatis and M. abscessus. Using scanning electron microscopy, light microscopy, and molecular probes, we investigated the effects of these CNMs on mycobacterial cell viability, cellular integrity, and biofilm formation. C90 fullertubes at 1 µM inhibited mycobacterial viability by 97%. Scanning electron microscopy revealed that the cell wall structure of M. smegmatis and M. abscessus was severely damaged within 24 h of exposure to fullertubes. Additionally, exposure to fullertubes nearly abrogated the acid‐fast staining property of M. smegmatis. Using SYTO‐9 and propidium iodide, we show that exposure to the novel fullertubes compromises the integrity of the mycobacterial cell. We also show that the permeability of the mycobacterial cell wall was increased after exposure to fullertubes from our assays utilizing the molecular probe dichlorofluorescein and ethidium bromide transport. C90 fullertubes at 0.37 µM and C60 fullerenes at 0.56 µM inhibited pellicle biofilm formation by 70% and 90%, respectively. This is the first report on the antimycobacterial activities of fullertubes and fullerenes.
Introducing Weakly Ligated Tris(trifluoromethyl)copper(III)
Authors: Motornov Vladimir , Procházka Martin , Alpuente Nora , Salvador Pedro , Slavíček Petr , Klepetářová Blanka , Ribas Xavi , Beier Petr
Published: March 2024

Tris(trifluoromethyl)copper(III), Cu(CF3)3, was prepared for the first time and fully characterized in the form of weakly coordinated highly reactive solvent neutral adducts (DMF)2Cu(CF3)3 and (MeCN)Cu(CF3)3. Free Cu(CF3)3 is an elusive molecule of distorted T‐shaped geometry with Lewis acid properties, which is stabilized by solvation. Substitution of solvent molecules with monoanionic ligands in mild conditions afforded the first Cu(III)(CF3)3 carboxylates [Cu(CF3)3(OAc)]− and [Cu(CF3)3(OBz)]− and Cu(III) nitrito complex [Cu(CF3)3(ONO)]−. An improved synthesis of valuable Grushin's trifluoromethylation reagents via the intermediacy of (MeCN)Cu(CF3)3 was developed. (DMF)2Cu(CF3)3 demonstrated promising properties in photoinduced radical C‐H trifluoromethylation. Oxidation state theoretical studies showed the Cu(CF3)3 compounds to be borderline between classical Cu(III) and inverted ligand field Cu(I) assignment.
Interseeded cover crops in wide‐row corn: An opportunity for northern cropping systems
Authors: Goettl Brady , Andersen Bryce , DeSutter Thomas , Franzen David , Wick Abbey
Published: March 2024

Cover crops are an effective way to reduce soil erosion and promote soil health. However, in North Dakota and other northern climates where corn (Zea mays L.) is an important commodity crop, killing frosts generally occur before harvest, leaving little opportunity for cover crop planting. By interseeding cover crops into corn during the growing season, the cover crops are given a longer period to establish. The purpose of this study was to identify the impact cover crops interseeded into wide‐row (60‐inch) corn have on soil water content and corn productivity. Two experimental sites were established in 2020 near Leonard and Rutland, ND. Both sites were organized into randomized complete block designs, with three cover crop treatments in Leonard (n = 9) and four cover crop treatments in Rutland (n = 16). Cover crops were no‐till drilled into the corn at the V4 growth stage. The cover crop treatments were diverse mixes developed to either provide pollinator habitat, overwinter, or winter‐kill. Throughout the growing season, soil gravimetric water content and cover crop biomass was monitored. At the end of the growing season, dry cover crop biomass ranged from 189 to 1445 lb ac−1. The presence and type of interseeded cover crops did not have a statistically significant effect on soil water content or corn yield. It is suspected the above average precipitation during the month of July led to adequate amounts of soil water for the entirety of the cover crop growing season, limiting the difference between treatments.
Pd(0)‐Catalyzed Asymmetric Intramolecular Grignard‐Type Reaction of Vinyl Iodide‐Carbonyl
Authors: Dong Ming , Tong Xiaofeng
Published: March 2024

The insertion of carbonyl into C(sp2)−Pd(II) σ‐bond (Grignard‐type addition) was not established until the 1990s. While this elemental reaction has been well explored since then, its application in Pd(0) asymmetric catalysis remain elusive. Herein, we report the Pd(0)‐catalyzed asymmetric intramolecular Grignard‐type reaction of vinyl iodide‐carbonyl in the presence of HCO2H additive, affording cyclic allylic alcohol with good to excellent enantioselectivity and diastereoselectivity. Mechanistic studies suggested that besides serving as an efficient reductant, HCO2H is also capable of facilitating protonation of the involved secondary alkoxyl‐Pd(II), thus completely suppressing the β‐H elimination. Moreover, no KIE was found in the competing reaction between vinyl iodide‐aldehyde and 1‐deuterated one, demonstrating the facile step of aldehyde insertion.
Phenanthrothiophene‐Triazine Star‐Shaped Discotic Liquid Crystals: Synthesis, Self‐Assembly, and Stimuli‐Responsive Fluorescence Properties
Authors: Zeng Chong‐Yang , Deng Wen‐Jing , Zhao Ke‐Qing , Redshaw Carl , Donnio Bertrand
Published: March 2024

Lipophilic biphenylthiophene‐ and phenanthrothiophene‐triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki‐Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli‐responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON‐OFF switch). DFT computational studies show that intramolecular charge transfer (ICT) phenomena occurs for both molecules, and reveal that protonation enhances the electron‐withdrawing ability of the triazine core and reduces the band gap. This acidochromic behavior was applied to a prototype fluorescent anti‐counterfeiting device. They also specifically recognize Fe3+ through coordination, and the recognition mechanism is closely related to the photoinduced electron transfer between Fe3+ and BPTT10/CPTT10. CPTTn self‐assemble into columnar rectangular (Colrec) mesophase, which can be modulated by oleic acid via the formation of a hydrogen‐bonded supramolecular liquid crystal hexagonal Colhex mesophase. Finally, CPTTn also form organic gels in alkanes at low critical gel concentration (3.0 mg/mL). Therefore, these star‐shaped triazine molecules possess many interesting features and thus hold great promises for information processing, liquid crystal semiconductors and organogelators.
NBN‐ and BNB‐Phenalenyls: the Yin and Yang of Heteroatom‐doped π Systems
Authors: Scholz Alexander S. , Massoth Julian G. , Stoess Lennart , Bolte Michael , Braun Markus , Lerner Hans‐Wolfram , Mewes Jan‐M. , Wagner Matthias , Froitzheim Thomas
Published: March 2024

NBN‐ and BNB‐doped phenalenyls are isoelectronic to phenalenyl anions and cations, respectively. They represent a pair of complementary molecules that have essentially identical structures but opposite properties as electron donors and acceptors. The NBN‐phenalenyls 1–4 considered here were prepared from N,N’‐dimethyl‐1,8‐diaminonaphthalene and readily available boron‐containing building blocks (i. e., BH3⋅SMe2 (1), p‐CF3‐C6H4B(OH)2 (2), C6H5B(OH)2 (3), or MesBCl2/iPr2NEt (4)). Treatment of 1 with 4‐Me2N‐2,6‐Me2‐C6H2Li gave the corresponding NBN derivative 5. The BNB‐phenalenyl 6 was synthesized from 1,8‐naphthalenediyl‐bridged diborane(6), PhNH2, and MesMgBr. A computational study reveals that the photoemission of 1, 4, and 5 originates from locally excited (LE) states at the NBN‐phenalenyl fragments, while that of 2 is dominated by charge transfer (CT) from the NBN‐phenalenyl to the p‐CF3‐C6H4 fragment. Depending on the dihedral angle θ between its Ph and NBN planes, compound 3 emits mainly from a less polar LE (θ >55°) or more polar CT state (θ <55°). In turn, the energetic preference for either state is governed by the polarity of the solvent used. An equimolar aggregate of the NBN‐ and BNB‐phenalenyls 3 and 6 (in THF/H2O) shows a distinct red‐shifted emission compared to that of the individual components, which originates from an intermolecular CT state.
Chiral Phenol‐2NO Ligand Cooperation with Achiral Organic Base in the Zn(II)‐Catalyzed Asymmetric Alkylation Reaction of Indoles
Authors: Xu Ke‐Lan , Wang Yu‐Heng , Wang Xi‐Rui , Hu Pan , Pan Bo‐Wen , Zhang Wen‐Jing , Chen Zi‐Yue , Zhou Ying , Liu Xiong‐Li
Published: March 2024

Comprehensive Summary

The privileged C2‐symmetric rigid phenol‐type ligand is more attractive but challenging in asymmetric catalysis. Herein, we designed and synthesized a class of rigid‐featured chiral tridentate Phenol‐2NO ligands, that incorporate the advantages of both the phenol skeleton and pyrroloimidazolone‐based N‐oxide moiety, from readily available L‐prolinamides in operationally simple two steps and up to 44% overall yield. More importantly, using an achiral quinoline derivative as an additive, the newly developed Phenol‐2NO ligand could serve as the anioic ligand upon deprotonative activation to coordinate to Zn(II) to form a highly enantioselective catalyst for the asymmetric Michael‐type Friedel‐Crafts alkylation reaction of indoles with 2,3‐dioxopyrrolidines. Excellent yields (up to 90%) and high enantioselectivities (up to 99% ee) are obtained for a wide range of substrates under mild conditions. Experiments and DFT calculations revealed the reaction mechanism and the origins of the enantioselectivity. This also represented the first activation of phenol‐type ligand/metal complex by an achiral organic base as the additive in asymmetric catalysis.
Secondary analysis of late major gastrointestinal and genitourinary toxicities in unfavorable‐risk prostate cancer patients receiving docetaxel: Insights from a randomized trial
Authors: Walburn Tyler , Chen Ming‐Hui , Loffredo Marian , McMahon Elizabeth , Orio Peter F. , Nguyen Paul L. , D’Amico Anthony V. , Sayan Mutlay
Published: March 2024

Background

This study sought to evaluate the late toxicity associated with neoadjuvant and concurrent docetaxel and radiation therapy in patients with prostate cancer.

Methods

A secondary analysis was performed of the phase 3 multicenter randomized trial (Dana‐Farber Cancer Institute 05‐043) including 350 patients with nonmetastatic unfavorable‐risk prostate cancer. Patients were randomized 1:1 to receive androgen deprivation therapy, radiation therapy, and docetaxel versus androgen deprivation therapy and radiation therapy. The study assessed the cumulative incidence rates of grade 2 and grade 3 or higher gastrointestinal, genitourinary, and sexual toxicity. A multivariable Fine and Gray’s competing risks regression model adjusted for age at randomization and pelvic lymph node radiation therapy was used to evaluate the treatment effect of docetaxel on time to late genitourinary and gastrointestinal toxicities.

Results

The study included 338 patients who primarily had minimal or no comorbidity (74.9%) and median age 66 years (interquartile range: 61,71). At a median follow‐up of 10.2 years, docetaxel was not associated with increased risk of any grade 3 or higher (adjusted hazard ratio [AHR], 0.98; 95% confidence interval [CI], 0.36–2.67; p = .96) or grade 2 gastrointestinal (p = .75), genitourinary (p = .44), and sexual (p = .29) toxicity. Age was associated with increased grade 3 or higher (AHR, 1.08; 95% CI, 1.01–1.16; p = .03) and grade 2 gastrointestinal toxicity (AHR, 1.11; 95% CI, 1.03–1.20; p = .005). A nonsignificant trend (p = .09) toward increased late grade 3 or higher toxicity was observed for pelvic radiation therapy use.

Conclusions

Docetaxel combined with radiotherapy has an acceptable long‐term toxicity profile.
A recurrence for the surface area of the (n,k)$$ \left(n,k\right) $$‐star graph
Authors: Gibbons Ethan , Qiu Ke
Published: March 2024

We present a simple recurrence for the surface area of the ‐star graph, , that is, the number of nodes at a certain distance from the identity node in the graph, an important parameter for interconnection networks in parallel computing. The family of the ‐star graphs includes several popular interconnection networks such as the star graph and the alternating group network. Previously, a surface area recurrence has been obtained for a special case, for example, when , in the family of ‐star. Our recurrence gives one single recurrence for all graphs in the family, thus completely solving the surface area of ‐star for all . Compared to explicit surface area formulas previously obtained through complicated and involved combinatorial analysis and generating function approach, our derivation is more elementary and our recurrence gives a way to compute the surface area of the ‐star efficiently.
Adiabat‐to‐Diabat Angle in Seam Space: Renner‐Teller‐Type and Pseudo‐Jahn‐Teller‐Type Problems
Authors: Chen Benny Jun , Pradhan Ekadashi , Nooijen Marcel , Zeng Tao
Published: March 2024

In this study, we examine the adiabat‐to‐diabat (ATD) angles for trajectories in 2‐dimensional vibrational subspace of the seam space of two degenerate states. In circulating around the tangential touching degeneracy center, the ATD angle is changed by
or 0, similar to the Renner‐Teller problem and the pseudo‐Jahn‐Teller problem, respectively. These ATD angle profiles may be indistinguishable from those of circulating multiple conical intersections or a pseudo‐Jahn‐Teller center. Methods to discern those seemingly indistinguishable cases are proposed. A sharp zigzag variation of the ATD angle is seen as a feature for trajectories that graze a pseudo‐Jahn‐Teller‐type tangential touching center, in contrast to the monotonic steep variation for grazing a conical intersection or a Renner‐Teller‐type tangential touching center.
Triplet Excited State Mechanistic Study of meso‐Substituted Methylthio Bodipy Derivative: Time‐Resolved Optical and Electron Paramagnetic Resonance Spectral Studies
Authors: Imran Muhammad , Kurganskii Ivan , Taddei Maria , Butera Valeria , Zhao Jianzhang , Fedin Matvey V. , Di Donato Mariangela , Mazzone Gloria
Published: March 2024

Understanding the intersystem crossing (ISC) mechanism of organic compounds is essential for designing new triplet photosensitizers. Herein, we investigated the ISC mechanism of a heavy atom‐free Bodipy derivative with thiomethyl substitution (S−BDP). A long‐lived triplet state was observed with nanosecond transient absorption spectroscopy with lifetime of 7.5 ms in a polymer film and 178 μs intrinsic lifetime in fluid solution, much longer as compared with what was previously reported (apparent triplet lifetime=15.5 μs). Femtosecond transient absorption studies retrieved an ISC time constant of ∼3 ns. Time‐resolved electron paramagnetic resonance (TREPR) indicated a special triplet electron spin polarization phase (ESP) pattern (a, e, a, e, a, e) for S−BDP, different from the ESP (e, e, e, a, a, a) typical for the spin‐orbital coupling (SOC) mechanism. This indicates that the electron spin selectivity of the ISC of S−BDP is different from that of the normal SOC effect in iodo‐Bodipy. Simulations of the TREPR spectra give a zero‐field‐splitting D parameter of −2257 MHz, much smaller as compared to the reference 2,6‐diiodo‐Bodipy (D=−4380 MHz). The computed SOC matrix elements (0.28–1.59 cm−1) and energy gaps for the S1/Tn states suggest that the energy matching between the S1 and T2/T3 states (supported by the largest kISC ∼109 s−1) enhances the ISC for this compound.
Mononuclear Iron Pyridinethiolate Complex Promoted CO2 Photoreduction via Rapid Intramolecular Electron Transfer
Authors: Zhang Yong‐Kang , Zhao Lan , Xie Wen‐Jun , Li Hong‐Ru , He Liang‐Nian
Published: March 2024

Designing earth‐abundant metal complexes as efficient molecular photocatalysts for visible light‐driven CO2 reduction is a key challenge in artificial photosynthesis. Here, we demonstrated the first example of a mononuclear iron pyridine‐thiolate complex that functions both as a photosensitizer and catalyst for CO2 reduction. This single‐component bifunctional molecular photocatalyst efficiently reduced CO2 to formate and CO with a total turnover number (TON) of 46 and turnover frequency (TOF) of 11.5 h−1 in 4 h under visible light irradiation. Notably, the quantum yield was determined to be 8.4 % for the generation of formate and CO at 400 nm. Quenching experiments indicate that high photocatalytic activity is mainly attributed to the rapid intramolecular quenching protocol. The mechanism investigation by DFT calculation and electrochemical studies revealed that the protonation of Febpy(pyS)2 is indispensable step for photocatalytic CO2 reduction.
Spatial transcriptomics reveals prognosis‐associated cellular heterogeneity in the papillary thyroid carcinoma microenvironment
Authors: Yan Kai , Liu Qing‐Zhi , Huang Rong‐Rong , Jiang Yi‐Hua , Bian Zhen‐Hua , Li Si‐Jin , Li Liang , Shen Fei , Tsuneyama Koichi , Zhang Qing‐Ling , Lian Zhe‐Xiong , Guan Haixia , Xu Bo
Published: March 2024

Background

Papillary thyroid carcinoma (PTC) is the most common malignant endocrine tumour, and its incidence and prevalence are increasing considerably. Cellular heterogeneity in the tumour microenvironment is important for PTC prognosis. Spatial transcriptomics is a powerful technique for cellular heterogeneity study.

Methods

In conjunction with a clinical pathologist identification method, spatial transcriptomics was employed to characterise the spatial location and RNA profiles of PTC‐associated cells within the tissue sections. The spatial RNA‐clinical signature genes for each cell type were extracted and applied to outlining the distribution regions of specific cells on the entire section. The cellular heterogeneity of each cell type was further revealed by ContourPlot analysis, monocle analysis, trajectory analysis, ligand–receptor analysis and Gene Ontology enrichment analysis.

Results

The spatial distribution region of tumour cells, typical and atypical follicular cells (FCs and AFCs) and immune cells were accurately and comprehensively identified in all five PTC tissue sections. AFCs were identified as a transitional state between FCs and tumour cells, exhibiting a higher resemblance to the latter. Three tumour foci were shared among all patients out of the 13 observed. Notably, tumour foci No. 2 displayed elevated expression levels of genes associated with lower relapse‐free survival in PTC patients. We discovered key ligand–receptor interactions, including LAMB3–ITGA2, FN1–ITGA3 and FN1–SDC4, involved in the transition of PTC cells from FCs to AFCs and eventually to tumour cells. High expression of these patterns correlated with reduced relapse‐free survival. In the tumour immune microenvironment, reduced interaction between myeloid‐derived TGFB1 and TGFBR1 in tumour focus No. 2 contributed to tumourigenesis and increased heterogeneity. The spatial RNA‐clinical analysis method developed here revealed prognosis‐associated cellular heterogeneity in the PTC microenvironment.

Conclusions

The occurrence of tumour foci No. 2 and three enhanced ligand–receptor interactions in the AFC area/tumour foci reduced the relapse‐free survival of PTC patients, potentially leading to improved prognostic strategies and targeted therapies for PTC patients.
Analysis of single nuclear chromatin accessibility reveals unique myeloid populations in human pancreatic ductal adenocarcinoma
Authors: Pratt Hillary G. , Ma Li , Dziadowicz Sebastian A. , Ott Sascha , Whalley Thomas , Szomolay Barbara , Eubank Timothy D. , Hu Gangqing , Boone Brian A.
Published: March 2024

Background

A better understanding of the pancreatic ductal adenocarcinoma (PDAC) immune microenvironment is critical to developing new treatments and improving outcomes. Myeloid cells are of particular importance for PDAC progression; however, the presence of heterogenous subsets with different ontogeny and impact, along with some fluidity between them, (infiltrating monocytes vs. tissue‐resident macrophages; M1 vs. M2) makes characterisation of myeloid populations challenging. Recent advances in single cell sequencing technology provide tools for characterisation of immune cell infiltrates, and open chromatin provides source and function data for myeloid cells to assist in more comprehensive characterisation. Thus, we explore single nuclear assay for transposase accessible chromatin (ATAC) sequencing (snATAC‐Seq), a method to analyse open gene promoters and transcription factor binding, as an important means for discerning the myeloid composition in human PDAC tumours.

Methods

Frozen pancreatic tissues (benign or PDAC) were prepared for snATAC‐Seq using 10× Chromium technology. Signac was used for preliminary analysis, clustering and differentially accessible chromatin region identification. The genes annotated in promoter regions were used for Gene Ontology (GO) enrichment and cell type annotation. Gene signatures were used for survival analysis with The Cancer Genome Atlas (TCGA)‐pancreatic adenocarcinoma (PAAD) dataset.

Results

Myeloid cell transcription factor activities were higher in tumour than benign pancreatic samples, enabling us to further stratify tumour myeloid populations. Subcluster analysis revealed eight distinct myeloid populations. GO enrichment demonstrated unique functions for myeloid populations, including interleukin‐1b signalling (recruited monocytes) and intracellular protein transport (dendritic cells). The identified gene signature for dendritic cells influenced survival (hazard ratio = .63, p = .03) in the TCGA‐PAAD dataset, which was unique to PDAC.

Conclusions

These data suggest snATAC‐Seq as a method for analysis of frozen human pancreatic tissues to distinguish myeloid populations. An improved understanding of myeloid cell heterogeneity and function is important for developing new treatment targets in PDAC.
The past, present, and future of predator–prey interactions in a warming world: Using species distribution modeling to forecast ectotherm–endotherm niche overlap
Authors: Hill Jessica L. , Grisnik Matthew , Hanscom Ryan J. , Sukumaran Jeet , Higham Timothy E. , Clark Rulon W.
Published: March 2024

Climate change has the potential to disrupt species interactions across global ecosystems. Ectotherm–endotherm interactions may be especially prone to this risk due to the possible mismatch between the species in physiological response and performance. However, few studies have examined how changing temperatures might differentially impact species' niches or available suitable habitat when they have very different modes of thermoregulation. An ideal system for studying this interaction is the predator–prey system. In this study, we used ecological niche modeling to characterize the niche overlap and examine biogeography in past and future climate conditions of prairie rattlesnakes (Crotalus viridis) and Ord's kangaroo rats (Dipodomys ordii), an endotherm–ectotherm pair typifying a predator–prey species interaction. Our models show a high niche overlap between these two species (D = 0.863 and I = 0.979) and further affirm similar paleoecological distributions during the last glacial maximum (LGM) and mid‐Holocene (MH). Under future climate change scenarios, we found that prairie rattlesnakes may experience a reduction in overall suitable habitat (RCP 2.6 = −1.82%, 4.5 = −4.62%, 8.5 = −7.34%), whereas Ord's kangaroo rats may experience an increase (RCP 2.6 = 9.8%, 4.5 = 11.71%, 8.5 = 8.37%). We found a shared trend of stable suitable habitat at northern latitudes but reduced suitability in southern portions of the range, and we propose future monitoring and conservation be focused on those areas. Overall, we demonstrate a biogeographic example of how interacting ectotherm–endotherm species may have mismatched responses under climate change scenarios and the models presented here can serve as a starting point for further investigation into the biogeography of these systems.
Foray movements are common and vary with natal habitat for a highly mobile bird
Authors: Poli Caroline L. , Meyer Kenneth D. , Darby Philip C. , Dudek Sarah J. , Kent Gina , Fletcher Robert J.
Published: March 2024

Understanding dispersal is central to interpreting the effects of climate change, habitat loss and habitat fragmentation, and species invasions. Prior to dispersal, animals may gather information about the surrounding landscape via forays, or systematic, short‐duration looping movements away from and back to the original location. Despite theory emphasizing that forays can be beneficial for dispersing organisms and that such behaviors are predicted to be common, relatively little is known about forays in wild populations. Theory predicts that individuals that use forays may delay dispersal and such behaviors should increase survival, yet empirical tests of these predictions remain scarce. We tested these predictions in a natural system using the critically endangered snail kite (Rostrhaumus sociabilis), a wetland‐dependent raptor. We GPS tracked 104 snail kites from fledging through emigration from the natal site across their breeding range to understand the demographic consequences of movement. We found that forays were common (82.7% of individuals tracked), and natal habitat played an important role in the initiation, execution, and outcome of foray behavior. The effect of foraying on survival was indirect, where forayers emigrated later than non‐forayers, and individuals that emigrated later had the highest survival. Poor hydrological conditions in the natal environment were especially important for eliciting forays. Finally, females responded more strongly to natal hydrology than males, making more forays and significantly longer, more distant trips. These results emphasize the fundamental role of natal habitat for determining behavioral patterns, strengthen links between individual movement decisions and their demographic consequences, and provide an important behavioral focal point for interpreting movement tracks that would not otherwise be captured by conventional movement models.
Popperian ecology is a delusion
Authors: Raerinne Jani
Published: March 2024

During the last 50 years, a group of ecologists has repeatedly used Popper's falsificationism in normative claims concerning how research in ecology should be conducted and/or how ecology should be corrected. Other ecologists seem to be dissatisfied with these criticisms. Nevertheless, they have not provided systematic analyses of how and why the Popperian criticisms of ecology fail. I have two aims in this article First, I show how so‐called Popperian ecologists have not only failed to use but have misused – if not abused – Popper in their criticisms of ecology. That is, the Popperian criticisms of ecology lack the justification the critics claim it has. Second, I claim that Popper's falsificationism is an unsuitable philosophy of science for ecology. In other words, ecology should not be criticized nor evaluated from the Popperian perspective in the first place.
Brown bear digging decreases tree growth: Implication for ecological role of top predators in anthropogenic landscapes
Authors: Tomita Kanji M. , Hiura Tsutom
Published: March 2024

Large carnivores have recently increased in number and recolonized in human‐dominated landscapes; however, their ecological roles in these landscapes have not been well studied. In the Shiretoko World Heritage (SWH) site, brown bears have recolonized a previously abandoned mosaic landscape of natural forests and conifer plantations after land abandonment. We previously reported that the bears had recently begun to dig for cicada nymphs in association with the creation of larch plantations. As a result, this digging activity decreased soil nutrients. To deepen the understanding of the novel ecological role of brown bears within human‐modified landscapes, we examined the impacts of brown bear digging on the growth of larch trees. We found that brown bear digging decreased fine root biomass of larch, soil water, and nitrogen availability. Brown bear digging negatively affected needle nitrogen content, but not carbon isotope ratios, a water stress index of trees. Tree ring data suggest that digging negatively affected the radial growth of larches. The results imply that digging decreases tree growth due to limited soil nitrogen uptake. Our findings indicate that the ecological roles of large carnivores may differ between natural and anthropogenic landscapes.
Advancements in Battery Cooling Techniques for Enhanced Performance and Safety in Electric Vehicles: A Comprehensive Review
Authors: Rallabandi Sivakrishnamraju , Issac Selvaraj Rajay Vedaraj
Published: March 2024

The automotive industry is transitioning toward electric vehicles (EVs) to control fossil fuel dependence, reduce CO2emissions, and mitigate pollution. EVs powered by lithium‐ion batteries (LIBs) have gained significant popularity due to their low operational costs and high energy density. Despite the substantial popularity of EVs powered by LIBs, their widespread commercial deployment has been impeded by challenges associated with operating temperatures. These temperature variations can adversely affect battery performance, degradation, and safety, posing hurdles to overcome for their efficient integration into vehicles. To address these issues, the development of high‐performance effective cooling techniques is crucial in mitigating the adverse effects of surface temperatures on battery cells. This review article aims to provide a comprehensive analysis of the advancements and enhancements in battery cooling techniques and their impact on EVs. It explores various cooling and heating methods to improve the performance and lifespan of EV batteries. It delves into suitable cooling methods as effective strategies for managing high surface temperatures and enhancing thermal efficiency. The study encompasses a comprehensive analysis of different cooling system designs with innovative approaches. Furthermore, this article outlines future research directions and potential solutions for developing battery cooling systems in electric and hybrid electric vehicles.