bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium-Catalyzed Cross-Coupling of Cyanohydrins with Aryl Bromides: Construction of Biaryl Ketones
Authors: Dai Huifang , Evans P. Andrew , Majhi Jadab , Zhou Bohang , Zhuang Yuxin , Tom Mai-Jan 
Published: May 2022

AbstractThe palladium-catalyzed cross-coupling of the lithium anion of aryl tert-butyldimethylsilyl-protected cyanohydrins with aryl bromides followed by in situ deprotection with fluoride ion provides a convenient and versatile approach to biaryl ketones. This protocol represents the first example of a palladium-catalyzed arylation of a cyanohydrin, which functions as an acyl anion equivalent. Hence, in contrast to classical cross-coupling reactions, the pronucleophile component is incorporated in the product to permit further functionalization. We then highlight the synthetic utility of the new method with applications to bioactive biaryl ketones and the construction of a triaryl diketone that has been used to prepare an extended tetrathiafulvalene.
Changes, Challenges, and Variations in Neonatal-Perinatal Medicine Fellowship: A View from the Program Directors
Authors: Gray Megan M. , Bruno Christie , French Heather , Myers Patrick , Carbajal Melissa M. , Reber Kristina M. , Christou Helen , Karpen Heidi , Johnston Lindsay C. ,   on behalf of the Organization of Neonatal-Perinatal Medicine Training Program Directors
Published: May 2022

Objectives Neonatal-perinatal medicine (NPM) fellowship programs in the United States support >800 learners annually. Understanding variations in the programmatic structure, challenges, and needs is essential to optimize the educational environment and ensure the specialty's future.
Study Design NPM fellowship program directors (PDs) and associate program directors (APDs) were invited to complete an electronic survey on their program administration, recruitment, clinical training, assessment methods, scholarly program, and career pathways. Each participant identified individual programmatic strengths, challenges, opportunities, and threats to the field.
Results Representatives from 59 NPM fellowships provided data (response rate 59/96 = 61%). In total, 30% of PDs received less than the Accreditation Council for Graduate Medical Education -recommended protected time for administrative duties, and 44% of APDs received no protected time. Fellow clinical service assignments varied widely from 13 to 18 months and 90 to 175 call nights over 3 years. Recruitment practices varied across programs; 59% of respondents raised concerns over the pipeline of applicants. Conflicts between fellows and advanced practice providers were identified by 61% of responders. Programs varied in their scholarly offerings, with 44% of NPM fellowships interested in adding broader research opportunities.
Conclusion NPM fellowship leaders identified a need for improved programmatic support, enhanced measures to assess competency, opportunities to strengthen scholarly programs, shared curricular resources, and strategies to balance education with clinical demands. PDs and APDs identified threats to the future of NPM training programs including the diminishing pipeline of applicants into neonatology, challenges with clinical exposure and competence, inadequate support for the educational mission, issues supporting high-quality scholarship, and fewer graduates pursuing physician-investigator pathways. National organizations and academic institutions should take action to address these challenges so that fellowships can optimally prepare graduates to meet their patients' needs.
Key Points
Reduced Bone Mineral Density in Middle-Aged Male Patients with Adult
Growth Hormone Deficiency
Authors: Liu Shanshan , Yang Hongbo , Xu Hanyuan , Zhou Zhibo , Bai Xi , Wang Linjie , Duan Lian , Gong Fengying , Zhu Huijuan , Pan Hui 
Published: May 2022

AbstractThe aim of the work was to investigate the bone mineral density (BMD) in
middle-aged male patients with both childhood-onset (CO) and adulthood-onset
(AO) adult growth hormone deficiency (AGHD). In this retrospective
cross-sectional study in a major medical center in China, dual X-ray
absorptiometry was performed in 50 male AGHD patients (average age was
35.2±9.8 years) and 50 age- and BMI-matched non-athletic healthy men.
BMD was compared between AGHD patients and controls. Compared with healthy
controls, AGHD group had significantly decreased IGF-1 (p1<0.001) and
IGF-1 SDS (p1<0.001). Serum testosterone levels were significantly lower
in AGHD patients (p1<0.001), mainly in AO AGHD patients
(p3<0.001). The BMD of the femoral neck, trochanter, femoral shaft,
total hip, and lumbar spine were significantly lower in all AGHD patients
compared with healthy controls (all p1<0.05), especially in CO AGHD
patients (all p2<0.05). Multiple stepwise linear regression indicated
AGHD was negatively correlated with BMD at each site (β<0,
p<0.05). Additionally, serum testosterone level was an independent
influencing factor of BMD of the femoral neck (β=0.256,
p=0.018) and lumbar spine (β=0.219, p=0.040).
BMD was significantly reduced in AGHD patients, especially in CO AGHD patients.
Our data suggested that the status of growth hormone deficiency and testosterone
level were important for maintaining of bone mineral density in middle-aged male
patients with AGHD.
Necrotizing Enterocolitis in Very Low Birth Weight Neonates: A Natural History Study
Authors: Mara Kristin C. , Clark Reese H. , Carey William A. 
Published: May 2022

Objective We characterize the most recent natural history of necrotizing enterocolitis (NEC), as this is an essential first step in guiding the prevention and treatment of this disease in the present day.
Study Design We performed a retrospective cohort study of neonates who were born at 23 to 29 weeks' gestation and birth weight <1,500 g who received care from the Pediatrix Medical Group between 2004 and 2019. We assessed the incidence of medical and surgical NEC and the patterns of initial antibiotic treatment to develop a contemporary cohort for further analysis. Among patients discharged between 2015 and 2019, we characterized the stage-specific risk factors for patients diagnosed with medical or surgical NEC, as well as patterns of disease onset, progression, biomarkers, and outcomes. We used the same approach to characterize patients diagnosed with suspected NEC.
Results Among 34,032 patients in the contemporary cohort, 1,150 (3.4%) were diagnosed with medical NEC and 543 (1.6%) were diagnosed with surgical NEC. The temporal pattern of disease onset was different for medical and surgical NEC, with gestational age– and birth weight–specific risk disparities emerging earlier in surgical NEC. Thirty-day mortality was much greater among surgical NEC patients (medical NEC 16.4% vs. surgical NEC 43.0%), as were rates of various in-hospital and long-term outcomes. Suspected NEC was diagnosed in 1,256 (3.7%) patients, among whom risk factors and disease onset, progression, and outcomes closely resembled those of medical NEC.
Conclusion Analyzing data from a contemporary cohort enabled us to characterize the current, stage-specific natural history of NEC, including novel insights into suspected NEC. Future studies could leverage this cohort to characterize how specific patient characteristics, care processes, or biomarkers may influence or predict disease outcomes.
Key Points
Investigating the effect of vocational education and training on rural women’s empowerment
Authors: Ebrahimi R. , Choobchian S. , Farhadian H. , Goli I. , Farmandeh E. , Azadi H. 
Published: May 2022

AbstractThis research is an attempt to identify the most important dimensions of vocational education and training (VET) on empowering rural women, a topic that has received less attention. The present study is a quantitative, non-experimental, applied, survey research, whose statistical population includes rural women and girls who participated in VET classes. The research tool was a researcher-designed questionnaire. The reliability and validity of the research tool using a pilot test and calculating Cronbach’s alpha, AVE, and CR coefficients were shown to indicate the high capability of the research tool to collect data. The results showed that among the four dimensions of VET, the role of content and educator was more than other dimensions and these dimensions of training had improved the economic empowerment of rural women, which was often at the lowest level. The conceptual framework presented can be used as a guide to achieving sustainable development goals of the millennium; and should be considered at the national and international levels. The paper makes an impact on the growing body of knowledge by emphasizing on more important dimensions of education; which can be effective for the empowerment of women, especially in the economic dimension. In the existing studies on empowering rural women, none of them examined the effect of all different components of education on women’s overall empowerment, which are among the innovations of the present study and should be considered in future planning.
Core–hole delocalization for modeling x-ray spectroscopies: A cautionary tale
Authors: Brumboiu Iulia Emilia , Fransson Thomas 
Published: May 2022

The influence of core–hole delocalization for x-ray photoelectron, x-ray absorption, and x-ray emission spectrum calculations is investigated in detail using approaches including response theory, transition-potential methods, and ground state schemes. The question of a localized/delocalized vacancy is relevant for systems with symmetrically equivalent atoms, as well as near-degeneracies that can distribute the core orbitals over several atoms. We show that the issues relating to core–hole delocalization are present for calculations considering explicit core–hole states, e.g., when using a core-excited or core-ionized reference state or for fractional occupation numbers. As electron correlation eventually alleviates the issues, but even when using coupled-cluster single-double and perturbative triple, there is a notable discrepancy between core-ionization energies obtained with localized and delocalized core–holes (0.5 eV for the carbon K-edge). Within density functional theory, the discrepancy correlates with the exchange interaction involving the core orbitals of the same spin symmetry as the delocalized core–hole. The use of a localized core–hole allows for a reasonably good inclusion of relaxation at a lower level of theory, whereas the proper symmetry solution involving a delocalized core–hole requires higher levels of theory to account for the correlation effects involved in orbital relaxation. For linear response methods, we further show that if x-ray absorption spectra are modeled by considering symmetry-unique sets of atoms, care has to be taken such that there are no delocalizations of the core orbitals, which would otherwise introduce shifts in absolute energies and relative features.
Broad-frequency range of a 250 GHz medium-power gyrotron traveling-wave amplifier with a distributed-loss structure
Authors: Yeh Yi Sheng , Hung Chien-Lun , Chang Tsun-Hsu 
Published: May 2022

A gyrotron traveling-wave amplifier (gyro-TWA) with a distributed-loss structure can achieve high gain over a broad bandwidth. In this study, a low-voltage, low-current subterahertz gyro-TWA with medium power (∼10 W) over a broad-frequency range (∼10 GHz) is designed. The excessive length of the copper section in this gyro-TWA leads to reflective oscillations and absolute instabilities. Reflective oscillations can be suppressed for a gyro-TWA with a high lossy-section resistivity and a short copper section. Absolute instabilities, conversely, can be suppressed for a gyro-TWA with a long lossy section and high lossy-section resistivity. The proposed gyro-TWA has a high lossy-section resistivity, a long lossy section, and a short copper section, which not only avoids mode competition but also achieves the desired characteristics of a high gain and broad-frequency range. For a 12 kV, 0.3 A electron beam, the frequency range of the 250 GHz 10 W level gyro-TWA with a distributed-loss structure, is ∼10 GHz when the input power is between 1 and 10 mW.
Structural insights of a highly potent pan-neutralizing SARS-CoV-2 human monoclonal antibody
Authors: Torres Jonathan L. , Ozorowski Gabriel , Andreano Emanuele , Liu Hejun , Copps Jeffrey , Piccini Giulia , Donnici Lorena , Conti Matteo , Planchais Cyril , Planas Delphine , Manganaro Noemi , Pantano Elisa , Paciello Ida , Pileri Piero , Bruel Timothée , Montomoli Emanuele , Mouquet Hugo , Schwartz Olivier , Sala Claudia , De Francesco Raffaele , Wilson Ian A. , Rappuoli Rino , Ward Andrew B. 
Published: May 2022

Significance
Clinical candidate monoclonal antibody J08 binds the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S-protein independent of known escape mutations and is able to potently neutralize most variants of concern (VoCs). Here, we explore these properties using cell-based assays and structural studies. A relatively small epitope footprint high on the receptor binding domain (RBD) ridge and the ability to bind multiple conformational states of the S-protein contribute to strong neutralization across several variants.
Increased efficiency of charge-mediated fusion in polymer/lipid hybrid membranes
Authors: Marušič Nika , Otrin Lado , Rauchhaus Jonas , Zhao Ziliang , Kyrilis Fotis L. , Hamdi Farzad , Kastritis Panagiotis L. , Dimova Rumiana , Ivanov Ivan , Sundmacher Kai 
Published: May 2022

Significance
The discovery that amphiphilic polymers, similar to phospholipids, can self-assemble to vesicles has inspired numerous applications. For instance, these polymersomes are employed for drug delivery due to their increased chemical and mechanical stability. These polymers can be also mixed with lipids to form the so-called hybrid membranes, which provide further biocompatibility, while new properties emerge. However, the fusion of these hybrids is to date barely explored. Herein, we determined that hybrid vesicles made of poly(dimethylsiloxane)-graft-poly(ethylene oxide) and oppositely charged lipids undergo rapid fusion, surpassing the efficiency in natural membranes. We provide biophysical insights into the mechanism and demonstrate that anionic lipids are not strictly required when the process is employed for the integration of membrane proteins.
In situ evidence for Paleoindian hematite quarrying at the Powars II site (48PL330), Wyoming
Authors: Pelton Spencer R. , Becerra-Valdivia Lorena , Craib Alexander , Allaun Sarah , Mahan Chase , Koenig Charles , Kelley Erin , Zeimens George , Frison George C. 
Published: May 2022

Significance
Red ocher (also known as hematite) is relatively common in Paleoindian sites exceeding ca. 11,000 calibrated years B.P. in the Great Plains and Rocky Mountains of North America. Red ocher fulfilled a wide range of functions within Paleoindian societies, as indicated by its association with graves, caches, campsites, hide-working implements, and kill sites. To date, the Powars II site is the only red ocher quarry identified in the North American archaeological record north of Mesoamerica. Prior studies of Powars II were based on analyses of artifacts recovered from a redeposited context. This study presents in situ evidence for red ocher quarrying at Powars II.
Repérage automatisé de l’hyponymie dans des corpus spécialisés en français à l’aide de Sketch Engine
Authors: San Martín Antonio , Trekker Catherine , León-Araúz Pilar 
Published: May 2022

AbstractHyponymy is an essential semantic relation in terminology, as it represents the hierarchical organization of concepts. Much has been written about hyponymy extraction. However, terminologists working with French do not currently have user-friendly and freely available tools to automatically extract hyper-hyponymic pairs from their own corpora. This paper presents the most recent version of the ESSG (EcoLexicon Semantic Sketch Grammar) methodology, a knowledge-pattern-based approach that enables Sketch Engine to extract semantic relations. This methodology is applied to the development and evaluation of the ESSG-fr, a semantic sketch grammar for hyponymy extraction in French. The evaluation results show that the ESSG-fr is a reliable domain-independent tool for terminologists wishing to extract simple hyper-hyponymic pairs and the corresponding concordances from specialized corpora.
Case Report of a Criminal Dismemberment in Northeast Brazil
Authors: Pessoa Soriano Evelyne , Araújo Maria do Socorro Dantas de , Pereira Francisca de Assis Nascimento , Melo Francisca Divina Silveira de , Freire Cristiane Helena da Silva Barbosa , Carvalho Marcus Vitor Diniz de 
Published: May 2022

AbstractSeveral decomposed body parts were received for examination by the Forensic Anthropology section of the Medico-legal Institute of João Pessoa, Paraíba, Brazil. The portions of the lower and upper limbs, ribs, vertebrae, and a skull were thoroughly examined. The biological profile indicated a male individual with an estimated age range between 23 and 57 years and a mean age of 35.2 years (SD = 9.4; phase IV, Suchey-Brooks). The skeleton showed injuries caused by sharp force and sharp-blunt force trauma that affected all body segments. Macroscopically, the lesions are mainly in the diaphyseal segments of the long bones, sacrum, pelvis, mandible, maxilla, scapulae, sternum, vertebrae, the distal epiphysis of the left fibula, and the distal epiphysis of the left tibia displayed characteristics compatible with injuries produced perimortem. It was not possible to determine the cause of death. DNA analysis resulted in a positive identification. Because of common difficulties faced in forensic practice, it is often not possible for forensic anthropologists to go to the crime scene, X-ray or body scanners are frequently unavailable, and the victim’s medical and/or dental records are sometimes absent. These difficulties make identification ultimately depend on genetic analysis, which is more time-consuming than other identification methods. Despite this, bone fragment examination in dismemberment cases is a complex task. Forensic Anthropology can shed light on cases involving the identification of dismembered remains, which are challenging because of the number of traumatic injuries, as well as different injury patterns, on bones.
Interpretable machine-learning identification of the crossover from subradiance to superradiance in an atomic array
Authors: Lin C Y , Jen H H 
Published: May 2022

Abstract
Light–matter interacting quantum systems manifest strong correlations that lead to distinct cooperative spontaneous emissions of subradiance or superradiance. To demonstrate the essence of finite-range correlations in such systems, we consider an atomic array under the resonant dipole–dipole interactions (RDDI) and apply an interpretable machine learning (ML) with the integrated gradients to identify the crossover between the subradiant and superradiant sectors. The machine shows that the next nearest-neighbor (NN) couplings in RDDI play as much as the roles of NN ones in determining the whole eigenspectrum within the training sets. Our results present the advantage of ML approach with explainable ability to reveal the underlying mechanism of correlations in quantum optical systems, which can be potentially applied to investigate many other strongly interacting quantum many-body systems.
Generation of entangled photons with a second-order nonlinear photonic crystal and a beam splitter
Authors: Azuma Hiroo 
Published: May 2022

Abstract
We discuss the generation of entangled photons using a nonlinear photonic crystal and beam splitter. In our method, the photonic crystal is assumed to be composed of a material with a large second-order nonlinear optical susceptibility

χ

(
2
)

. Our proposal relies on two facts: (1) A nonlinear photonic crystal changes coherent incident light into squeezed light. (2) A beam splitter transforms the squeezed light into entangled light beams flying in two different directions. We estimate the yield efficiency of pairs of entangled photons per pulse of the very weak coherent light for our method at 0.0783 for a specific concrete example. Our method is more effective because the conversion efficiency (entangled biphotons per incident pump photons) in the spontaneous parametric downconversion is of the order of

4
×

10

−
6

. The only drawback is that it requires very fine tuning of the frequency of signal photons fed into the photonic crystal; for example, an adjustment is given by

Δ
ν
=
3.11
×

10

8

Hz for the signal light of

ν
=
3.23
×

10

14

Hz. We investigate the application of entangled photons produced by our method to the BB84 quantum key distribution protocol, and we explore how to detect an eavesdropper. We suggest that our method is promising for decoy-state quantum key distribution using weak coherent light.
Topologically protected energy-time entangled biphoton states in photonic crystals
Authors: Jiang Zhen , Xi Chaoxiang , He Guangqiang , Jiang Chun 
Published: May 2022

Abstract
The concepts of topological phases have been widely exploited in quantum optics in recent years. Here we demonstrate a topological insulator implementing topological protection of correlated biphoton states. A degenerate four-wave mixing (FWM) process of pseudospin states propagating along the topological interface is numerically simulated. Strikingly, the signal and idler photons generated from the FWM process are clarified to be entangled between two degrees of freedom—the frequencies of photon pairs and their time of arrival. The topological edge states of the pump, signal, and idler are robust against the sharp bends and defects, revealing the topological protection of energy-time entangled biphoton states. These findings could pave the way for unprecedented topological quantum devices.
A new high-pressure structure of SiO2 directly converted from α-quartz under nonhydrostatic compression
Authors: Tsuchiya Taku , Nakagawa Saito 
Published: May 2022

Abstract
High-pressure behavior of SiO2 is one of the prototypical subjects in several research areas including condensed matter physics, inorganic chemistry, mineralogy, materials science, and crystallography. Therefore, numerous studies have been performed on the structure evolution of SiO2 under pressure. Here, we show a new structure directly converted from α-quartz under uniaxial compression. Our ab initio calculations elucidate a simple transition pathway from α-quartz to the Fe2P-type phase, and an intermediate state with the Li2ZrF6-type structure appears in this structure conversion. Some interesting properties are found on this intermediate state. (1) The Li2ZrF6-type phase is metastable probably due to a volumetric unbalance between the Li and Zr sites but becomes more energetically stable than α-quartz over ∼12 GPa. (2) It is vibrationally stable at 0 GPa, suggesting that this phase can be recovered down to ambient condition once synthesized. (3) The crystal structures of Li2ZrF6-type SiO2 and phase D, one of dense magnesium hydrous silicates, are found identical, suggesting the stabilization of their solid solution under high-P, T condition.