bluuebunny/crossref_metadata_2025_split huggingface dataset:
1.2 Copper(I) Hydride Catalyzed Transformations
Authors: Xiong T. , Li Y. 
Published: February 2023

AbstractCopper(I) hydride is a binary metal hydride that, due to the relatively low electropositivity of copper, features a rather covalent metal−hydrogen bond. This readily obtained species can either be pre-prepared or generated in situ, and reacts with various unsaturated bonds or polar single bonds to form intermediates with reactive C—Cu bonds, which can be captured by various electrophiles to form new chemical bonds and new stereocenters. In this chapter, some representative examples in this domain are discussed, with the methods divided into four sections based on the different kinds of electrophiles. The first three sections cover asymmetric C—N, C—C, and C—B bond formation with various electrophilic nitrogen sources, carbon-based reagents, and boranes, and the last section focuses on some racemic transformations.
1.8 Copper-Catalyzed Aerobic Oxidation of Alcohols
Authors: Sasano Y. , Iwabuchi Y. 
Published: February 2023

AbstractThe oxidation of alcohols to carbonyl compounds is one of the most important reactions in organic synthesis. Owing to current environmental concerns, catalytic alcohol oxidation using molecular oxygen as the terminal oxidant has been actively investigated. Copper is frequently used as an aerobic oxidation catalyst in organic syntheses, as well as in biological systems. Co-catalysts acting in coordination with copper to promote the aerobic oxidation of alcohols have been extensively investigated, and in this context the use of nitroxyl radicals has been identified as a promising strategy. Through the efforts of many researchers, nitroxyl radical/copper catalyst systems that efficiently oxidize traditionally more challenging aliphatic alcohols under mild conditions have recently been discovered. Methods for the synthesis of esters, imines, nitriles, amides, and imides by nitroxyl radical/copper-catalyzed aerobic alcohol oxidation in the presence of other alcohols, amines, and amides have also been developed. Nitroxyl radical/copper-catalyzed aerobic alcohol oxidation exhibits outstanding chemoselectivity, and efficiently converts alcohols bearing oxidation-prone functional groups that cannot be efficiently oxidized using conventional methods.
1.12 Nickel-Catalyzed Alkene Dicarbofunctionalization
Authors: Lee B. C. , Lin L. , Ko C. , Koh M. J. 
Published: February 2023

AbstractThe transition-metal-catalyzed cross-coupling reactions of alkenyl compounds remain one of the most versatile ways of forming C—C bonds from organohalide and organometallic species. The application of inexpensive, readily available, and non-toxic base metals, such as nickel, as catalysts gives rise to a powerful approach to access highly substituted molecules via dicarbofunctionalization. A wide array of nucleophiles and/or electrophiles can be employed, and various mechanisms have been proposed. Generally, these mechanisms can be classified as redox-neutral, reductive, asymmetric, and photoredox dicarbofunctionalizations. In this chapter, we will highlight the recent advances made in the field of nickel-catalyzed alkene dicarbofunctionalization.
1.16 Nickel-Catalyzed Bond Activation for Functional-Group Shuttling
Authors: Delcaillau T. , Morandi B. 
Published: February 2023

AbstractFunctional-group shuttling, for example through shuttle catalysis or single-bond metathesis, has recently emerged as a powerful tool in targeted organic synthesis. This concept offers several advantages in comparison with traditional catalytic reactions. It enables the use of more-benign surrogates as formal functional-group donors, leading to safer reaction profiles. These reactions also often complement traditional cross-coupling reactions by allowing for base-free conditions, since no external inorganic reagent is required. Lately, nickel has emerged as an extremely useful transition metal in catalysis, complementing and often even surpassing the efficiency of noble metals, such as palladium. The focus of this chapter is to summarize recent developments in nickel-catalyzed functional-group-shuttling reactions.
This is Ireland: commemoration as a catalyst for a new nation brand
Authors: Boughton Madeline 
Published: February 2023

AbstractThis article argues that, while state-enacted commemoration can give rise to a pre-determined narrative which aligns with political expediency, the active participation and ownership by citizens in the ritual act of commemoration facilitates an ‘experiential’ process of national identity formation, and a new model of nation branding. It takes inspiration from Kaufmann’s conceptualisation of complexity theory and the importance of ‘tipping points’ and thresholds, which events such as national commemorations represent, as key to our understanding of nations. Ireland’s unique method of citizen-led commemoration provided a channel through which ‘outsiders’, beyond the prominent elite and traditional gatekeepers, are empowered to influence, critique and embody a nation brand that is of their making. Based on interviews with key informants, from historians and brand strategists to community leaders and government officials, and a sample review of news reports, this cross-sectoral study examines the critical role of state-led, citizen-focused commemoration, as a catalyst for a new nation brand.
The devil lies in prosody
Authors: Wang Zepeng , Mao Yansheng , Xin Dan , Li Haoming , Liang Zhe 
Published: February 2023

AbstractThe current paper reports on a study investigating the prosodic features of the Chinese discourse markerhaole. The data were collected from 14 native Chinese speakers who participated in two recording sessions designed by the authors. The results indicate thathaoleas a discourse marker occurring at different syntactic positions is prosodically distinct. Specifically, in some cases,haoleat the left periphery (LP) is prosodically independent of its following utterance, whilehaoleat the right periphery (RP) is always prosodically attached to its preceding utterance. In addition,haoleat LP is higher, larger, and longer thanhaoleat RP, respectively, concerning pitch, intensity, and duration. The study suggests that these differences are closely related to the pragmatic functions ofhaoleas a discourse marker in oral interaction. The findings above may shed light on the incorporation of prosody into the pragmatic analysis of discourse markers and conversation management in general.
Frequency-dependent Scattering of Wideband Laser-generated Rayleigh Waves for Vertical Surface Crack Characterization
Authors: Xu Lei , Su Yiyin , Yang Jianwei , Su Zhongqing 
Published: February 2023

Abstract
Wideband laser-generated Rayleigh waves have been extensively exploited for surface crack characterization, most of which, nonetheless, are of a nature of either numerical simulation or experimental observation. Earlier, an elastodynamic reciprocity theorem-based theoretical model was proposed by the authors [1, 2], aimed at scrutinizing the interaction of narrowband Rayleigh-Lamb waves with a surface or subsurface crack. In this study, the model is expanded to a wideband scenario to analytically explore the interaction of a wideband laser-generated Rayleigh wave with a surface crack, as well as the resultant crack-scattered Rayleigh wavefield. First, under the narrowband scenario, a dimensionless parameter is formulated based on the closed-form solution to the magnitude of the narrowband scattered Rayleigh wavefield, revealing that the scattering effect of a surface crack on the Rayleigh waves is frequency-dependent and there exists a characteristic frequency, at which the crack-scattered Rayleigh wavefield manifests the strongest intensity. Similarly, under the wideband scenario, such dependence can be calibrated by a spectral damage indicator (SDI), which facilitates the evaluation of the severity of the surface crack using the wideband laser-generated Rayleigh wave. Proof-of-concept simulation is performed to verify the model. Quantitative agreement between the analytical and numerical results validates the accuracy of the proposed model and SDI. Experiment is also conducted to demonstrate the effectiveness of the frequency-dependent scattering of wideband laser-generated Rayleigh waves for vertical surface crack characterization.
Bose–Einstein-like condensation of deformed random matrix: a replica approach
Authors: Ikeda Harukuni 
Published: February 2023

Abstract
In this work, we investigate a symmetric deformed random matrix, which is obtained by perturbing the diagonal elements of the Wigner matrix. The eigenvector

x

m
i
n

of the minimal eigenvalue

λ

m
i
n

of the deformed random matrix tends to condensate at a single site. In certain types of perturbations and in the limit of the large components, this condensation becomes a sharp phase transition, the mechanism of which can be identified with the Bose–Einstein condensation in a mathematical level. We study this Bose–Einstein like condensation phenomenon by means of the replica method. We first derive a formula to calculate the minimal eigenvalue and the statistical properties of

x

m
i
n

. Then, we apply the formula for two solvable cases: when the distribution of the perturbation has the double peak, and when it has a continuous distribution. For the double peak, we find that at the transition point, the participation ratio changes discontinuously from a finite value to zero. On the contrary, in the case of a continuous distribution, the participation ratio goes to zero either continuously or discontinuously, depending on the distribution.
Scanning strategy optimization for the selective laser melting additive manufacturing of Ti6Al4V
Authors: Jia Yun , Zeng Chao , Xue Jiutian 
Published: February 2023

Abstract
Minimizing the residual stress and deformation of the manufactured product consequent to the selective laser melting (SLM) process is always a primary focus in the realm of additive manufacturing. This paper studied the influence of different scanning strategies on the thermal-mecha nical characteristics of SLM of Ti6Al4V. Numerical simulation and experimental tests were employed concerning three scanning strategies of the SLM process: Z-shaped, outer spiral, and inner spiral. Allowing for the latent heat of phase change, thermal radiation, and convection effect, the temperature history, and distribution of the specimen were analyzed, based on which the indirect thermal-mechanical coupling method was engaged for the residual stress and deformation analysis. The result shows good consistency in deformation characteristics between the numerical prediction and experimental observation. A reasonable scanning strategy is beneficial to mitigating the non-uniform distribution of the residual stress, and compared with the outer spiral and inner spiral strategies, the z-shaped scanning strategy may have a better effect in forming accuracy and mechanical properties.
Reducing oil and gas well leakage: a review of leakage drivers, methane detection and repair options
Authors: Hachem Khalil El , Kang Mary 
Published: February 2023

Abstract
Oil and gas wells (OGWs) with integrity failures can be a conduit for methane and contaminant leakage to groundwater aquifers, surface water bodies and the atmosphere. While there have been numerous reviews addressing OGW leakage, there is a gap in the literature regarding an examination of OGW leakage that encompasses both abandoned and active wells, as well as factors that impact leakage, methane emission measurements, and options for repairing leaks. Here, we review the literature to evaluate factors and policies affecting leakage of active and abandoned OGWs, studies quantifying OGW methane emissions, and leakage repair and emission reduction options. Furthermore, our review places a greater emphasis on abandoned oil and gas wells and does not focus on one well type, such as unconventional wells. Of the 38 factors in published literature reviewed here, studies find that 15 (39%) factors, including geographic location, well deviation, casing quality and plugging status consistently affect OGW leakage. For 15 (39%) factors, including surface casing depth, well elevation and land cover, one or two studies show that they do not affect OGW leakage. For the remaining eight (21%) factors, including well age, studies show conflicting results. Although increased frequency of well monitoring and repair can lead to reduced OGW leakage, several studies indicate that monitoring and repair requirements are not always enforced. Moreover, we find 13 studies quantifying OGW methane emissions to the atmosphere at the oil and gas wellhead scale across Canada and the United States with major gaps in the geographical distribution of the collected data. Moreover, although studies measuring abandoned wells include measurements from orphaned wells, available measurements do not differentiate between orphaned and abandoned OGWs, which is important for policy makers aiming to quantify methane emission reductions of plugging hundreds of thousands of orphaned wells. To repair OGW leakage, we find that most studies focus on well cement and casing repair. There are alternatives to cement and casing repair that only reduce methane emissions, such as soil methane oxidation, but their widespread applicability requires further study. Overall, our review of factors affecting OGW leakage can be used to identify OGWs with high leakage potential and guide OGW leakage monitoring and repair policies, thereby reducing climate and environmental impacts.
Equivariant quantum differential equation and qKZ equations for a projective space: Stokes bases as exceptional collections, Stokes matrices as Gram matrices, and \textcyr{B}-Theorem
Authors: Cotti Giordano , Varchenko Alexander 
Published: February 2023

In the previous paper by Tarasov and Varchenko the equivariant quantum differential equation (

q
D
E

qDE

) for a projective space was considered and a compatible system of difference

q
K
Z

qKZ

equations was introduced; the space of solutions to the joint system of the

q
D
E

qDE

and

q
K
Z

qKZ

equations was identified with the space of the equivariant

K
K

-theory algebra of the projective space; Stokes bases in the space of solutions were identified with exceptional bases in the equivariant

K
K

-theory algebra. This paper is a continuation of the paper by Tarasov and Varchenko.

We describe the relation between solutions to the joint system of the

q
D
E

qDE

and

q
K
Z

qKZ

equations and the topological-enumerative solution to the

q
D
E

qDE

only, definitionned as a generating function of equivariant descendant Gromov-Witten invariants. The relation is in terms of the equivariant graded Chern character on the equivariant

K
K

-theory algebra, the equivariant Gamma class of the projective space, and the equivariant first Chern class of the tangent bundle of the projective space.

We consider a Stokes basis, the associated exceptional basis in the equivariant K-theory algebra, and the associated Stokes matrix. We show that the Stokes matrix equals the Gram matrix of the equivariant Grothendieck-Euler-Poincaré pairing wrt to the basis, which is the left dual to the associated exceptional basis.

We identify the Stokes bases in the space of solutions with explicit full exceptional collections in the equivariant derived category of coherent sheaves on the projective space, where the elements of those exceptional collections are just line bundles on the projective space and exterior powers of the tangent bundle of the projective space.

These statements are equivariant analogs of results of G. Cotti, B. Dubro-vin, D. Guzzetti, and S. Galkin, V. Golyshev, H. Iritani.
Decolonizing Classics in Africa: the work of Alexander Kwapong
Authors: Goff Barbara 
Published: February 2023

Abstract
Alexander Osei Adum Kwapong (1927–2014) was a notable classical scholar who studied at the renowned Achimota School of Ghana, and gained a PhD in Ancient History from King’s College, Cambridge. He subsequently became the first African Vice-Chancellor of the University of Ghana, and went on to a career in several institutions of higher education. As with some other African Classical scholars, the attitude towards the Classics represented in his writings repays examination, especially on the following issues: to what extent does he see his professional activity as ‘decolonizing’? To what extent are the Classics within his work already unmoored from any significantly European identity? Drawing on his autobiography and several more or less formal texts about the Classics in Africa, I shall tease out the possible complexities of Kwapong’s positions. Although ‘decolonizing’ does not necessarily mean the same in his writings as in our current preoccupations, his version of Classics as a discipline is geared towards promoting a usable history of Africa, a productive account of Africa’s place in the world, and an open dialogue among cultures.
Prophylactic and therapeutic vaccination protects sperm health from Chlamydia muridarum-induced abnormalities
Authors: Bryan Emily R , Trim Logan K , Sadowski Pawel , Paramasivan Selvam , Kim Jay J , Gough Kyle , Worley Sophia , Maidment Toby I , Carey Alison J , Mihalas Bettina , McLaughlin Eileen A , Beagley Kenneth W 
Published: February 2023

Abstract
Chlamydia is the most common bacterial sexually transmitted infection worldwide and it is widely acknowledged that controlling the rampant community transmission of this infection requires vaccine development. In this study, for the first time, we elucidate the long-term response to male mouse chlamydial vaccination with chlamydial major outer membrane protein (MOMP) and ISCOMATRIX (IMX) both prophylactically and in a novel therapeutic setting. Vaccination significantly reduced and, in some cases, cleared chlamydial burden from the prostates, epididymides, and testes, which correlates with high IgG and IgA tires in tissues and serum. Important markers of sperm health and fertility were protected including sperm motility and proteins associated with fertility in men. Within splenocytes, expression of IFNγ, TNFα, IL17, IL13, IL10, and TGFβ were changed by both infection and vaccination within CD4 and CD8 T cells and regulatory T cells. Within the testicular tissue, phenotypic and concentration changes were observed in macrophages and T cells (resident and transitory). This revealed some pathogenic phenotypes associated with infection and critically that vaccination allows maintenance of testicular homeostasis, likely by preventing significant influx of CD4 T cells and promoting IL10 production. Finally, we demonstrated the testes contained immature (B220+) B cells and mature (CD138+) Chlamydia-specific plasma cells. Thus, through vaccination, we can maintain the healthy function of the testes, which is vital to protection of male fertility.
A new class of peptides from wasp venom: a pathway to antiepileptic/neuroprotective drugs
Authors: Mortari Márcia Renata , Cunha Alexandra O S , dos Anjos Lilian C , Amaral Henrique O , Quintanilha Maria Varela Torres , Gelfuso Erica A , Homem-de-Mello Mauricio , de Almeida Hugo , Rego Solange , Maigret Bernard , Lopes Norberto P , dos Santos Wagner F 
Published: February 2023

AbstractThe ability of venom-derived peptides to disrupt physiological processes in mammals provides an exciting source for pharmacological development. Our research group has identified a new class of neuroactive peptides from the venom of a Brazilian social wasp, Polybia occidentalis, with the potential pharmacological profile to treat epilepsies. The study was divided into five phases: Phase 1 concerned the extraction, isolation and purification of Occidentalin-1202(n) from the crude venom, followed by the synthesis of an identical analogue peptide, named Occidentalin-1202(s). In Phase 2, we described the effects of both peptides in two acute models of epilepsy—kainic acid and pentylenetetrazole-induced model of seizures—and measured estimated ED50 and therapeutic index values, electroencephalographic studies and C-fos evaluation. Phase 3 was a compilation of advanced tests performed with Occidentalin-1202(s) only, reporting histopathological features and its performance in the pilocarpine-induced status epilepticus. After the determination of the antiepileptic activity of Occidentalin-1202(s), Phase 4 consisted of evaluating its potential adverse effects, after chronic administration, on motor coordination (Rotarod) and cognitive impairment (Morris water maze) tests. Finally, in Phase 5, we proposed a mechanism of action using computational models with kainate receptors. The new peptide was able to cross the blood–brain barrier and showed potent antiseizure effects in acute (kainic acid and pentylenetetrazole) and chronic (temporal lobe epilepsy model induced by pilocarpine) models. Motor and cognitive behaviour were not adversely affected, and a potential neuroprotective effect was observed. Occidentalin-1202 can be a potent blocker of the kainate receptor, as assessed by computational analysis, preventing glutamate and kainic acid from binding to the receptor’s active site. Occidentalin-1202 is a peptide with promising applicability to treat epilepsy and can be considered an interesting drug model for the development of new medicines.
Diffuse myocardial fibrosis precedes subclinical functional myocardial impairment and provides prognostic information in systemic sclerosis
Authors: Gotschy Alexander , Jordan Suzana , Stoeck Christian T , von Deuster Constantin , Peer Tatiana , Gastl Mareike , Vishnevskiy Valery , Wissmann Lukas , Dobrota Rucsandra , Mihai Carina , Becker Mike O , Maurer Britta , Kozerke Sebastian , Ruschitzka Frank , Distler Oliver , Manka Robert 
Published: February 2023

AbstractAimsMyocardial involvement is common in patients with systemic sclerosis (SSc) and causes myocardial fibrosis and subtle ventricular dysfunction. However, the temporal onset of myocardial involvement during the progression of the disease and its prognostic value are yet unknown. We used cardiovascular magnetic resonance (CMR) to investigate subclinical functional impairment and diffuse myocardial fibrosis in patients with very early diagnosis of SSc (VEDOSS) and established SSc and examined whether this was associated with mortality.Methods and resultsOne hundred and ten SSc patients (86 established SSc, 24 VEDOSS) and 15 healthy controls were prospectively recruited. The patients were followed-up for a median duration of 7.0 years (interquartile range 6.0–7.3 years). Study subjects underwent CMR including assessment of myocardial fibrosis [native T1 and extracellular volume (ECV)] and measurement of global longitudinal (GLS) and circumferential (GCS) myocardial strain. Native T1 values and ECV were elevated in VEDOSS and SSc patients compared with controls (P &lt; 0.001). GLS was similar in VEDOSS and controls but significantly impaired in patients with established SSc (P &lt; 0.001). GCS was similar over all groups (P = 0.88). There were 12 deaths during follow-up. Elevated native T1 [hazard ratio (HR) 5.8, 95% confidence interval (CI): 1.7–20.4; P = 0.006] and reduced GLS (HR 6.1, 95% CI: 1.3–29.9; P = 0.038) identified subjects with increased risk of death. Only native T1 was predictive for cardiovascular mortality (P &lt; 0.001).ConclusionSubclinical myocardial involvement first manifests as diffuse myocardial fibrosis identified by the expansion of ECV and increased native T1 in VEDOSS patients while subtle functional impairment only occurs in established SSc. Native T1 and GLS have prognostic value for all-cause mortality in SSc patients.