bluuebunny/crossref_metadata_2025_split huggingface dataset:
Revisiting the Fundamental Nature of Metal‐Ligand Bonding: An Impartial and Automated Fitting Procedure for Angular Overlap Model Parameters
Authors: Buchhorn Moritz , Deeth Robert J. , Krewald Vera 
Published: January 2022

AbstractThe properties and reactivities of transition metal complexes are often discussed in terms of Ligand Field Theory (LFT), and with ab initio LFT a direct connection to quantum chemical wavefunctions was recently established. The Angular Overlap Model (AOM) is a widely used, ligand‐specific parameterization scheme of the ligand field splitting that has, however, been restricted by the availability and resolution of experimental data. Using ab initio LFT, we present here a generalised, symmetry‐independent and automated fitting procedure for AOM parameters that is even applicable to formally underdetermined or experimentally inaccessible systems. This method allows quantitative evaluations of assumptions commonly made in AOM applications, for example, transferability or the relative magnitudes of AOM parameters, and the response of the ligand field to structural or electronic changes. A two‐dimensional spectrochemical series of tetrahedral halido metalates ([MIIX4]2−, M=Mn−Cu) served as a case study. A previously unknown linear relationship between the halide ligands’ chemical hardness and their AOM parameters was found. The impartial and automated procedure for identifying AOM parameters introduced here can be used to systematically improve our understanding of ligand–metal interactions in coordination complexes.
d‐Orbital Reconstructions Forced by Double Bow‐Shaped Deformations and Second Coordination Sphere Effects of Cu(II) Heme Analogs in HER**
Authors: Liu Qiuhua , Ren Wanjie , Zhang Siwei , Huang Yang , Chen Dilong , Zeng Wennan , Zhou Zaichun , He Lin , Guo Wenping , Li Jianfeng 
Published: January 2022

AbstractBoth geometric architecture and electronic configurations of heme proteins contribute to its activity. In this work we designed and synthesized a series of four copper(II) porphyrin complexes (4‐, 3‐, 2‐ and 1‐Cu) where the molecular conformations are modulated by a pair of stepwise shortened straps on the same porphyrin side (cis‐ortho) to give double bow‐shaped skeletons. Single crystal structures demonstrate that the straps gradually increase the saddle deformation and the deviation of the metal centers, which is in accordance with two, unusual d‐orbital reconstructions of two different ground states, as revealed by 4 K EPR and DFT calculations. In the study of the electrocatalytic hydrogen evolution reaction (HER), 1‐Cu, with the shortest straps, showed the most apparent improvement of activity. Second coordination sphere (SCS) effects created by the double bow‐shaped architecture and the strong saddle porphyrin core in 1‐Cu are found to play key roles in proton trapping during the catalytic process. The work contributes a novel strategy to improve the catalytic performance of heme analogs through ligand geometric modulation.
Weak Antiferromagnetic Exchange and Ferromagnetic Alignment of FeII (S=2) Spins in Differently Charged {HAT ⋅ (FeIICl2)3}n (n=2‐ and 3‐) Assemblies of Hexaazatriphenylenes (HAT)
Authors: Mikhailenko Maxim V. , Khasanov Salavat S. , Shestakov Alexader F. , Kuzmin Aleksey V. , Otsuka Akihiro , Yamochi Hideki , Kitagawa Hiroshi , Konarev Dmitri V. 
Published: January 2022

AbstractHexaazatrianthracene (HATA) and hexaazatriphenylenehexacarbonitrile {HAT(CN)6} are reduced by metallic iron in the presence of crystal violet (CV+)(Cl−). Anionic ligands are produced, which simultaneously coordinate three FeIICl2 to form (CV+)2{HATA ⋅ (FeIICl2)3}2− ⋅ 3 C6H4Cl2 (1) and (CV+)3{HAT(CN)6. (FeIICl2)3}3− ⋅ 0.5CVCl ⋅ 2.5 C6H4Cl2 (2). High‐spin (S=2) FeII atoms in both structures are arranged in equilateral triangles at a distance of 7 Å. An antiferromagnetic exchange is observed between FeII in {HATA ⋅ (FeIICl2)3}2− (1) with a Weiss temperature (Θ) of −80 K, the PHI estimated exchange interaction (J) is −4.7 cm−1. The {HAT(CN)6 ⋅ (FeIICl2)3}3− assembly is obtained in 2. The formation of HAT(CN)6.3− is supported by the appearance of an intense EPR signal with g=2.0037. The magnetic behavior of 2 is described by a strong antiferromagnetic coupling between the FeII and HAT(CN)6.3− spins with J1=−164 cm−1 (−2 J formalism) and by a weaker antiferromagnetic coupling between the FeII spins with J2=−15.4 cm−1. The stronger coupling results in the spins of the three FeIICl2 units to be aligned parallel to each other in the assembly. As a result, an increase of the χMT values is observed with the decrease of temperature from 9.82 at 300 K up to 15.06 emu ⋅ K/mol at 6 K, and the Weiss temperature is also positive being at +23 K. Thus, a change in the charge and spin state of the HAT‐type ligand to ⋅3− results in ferromagnetic alignment of the FeII spins, yielding a high‐spin (S=11/2) system. DFT calculations showed that, due to the high symmetry and nearly degenerated LUMO of both HATA and HAT(CN)6, their complexes with FeIICl2 have a variety of closely lying excited high‐spin states with multiplicity up to S=15/2.
An Adaptive Hydrogen‐Bonded Organic Framework for the Exclusive Recognition of p‐Xylene
Authors: Ma Li , Xie Yi , Khoo Rebecca Shu Hui , Arman Hadi , Wang Bin , Zhou Wei , Zhang Jian , Lin Rui‐Biao , Chen Banglin 
Published: January 2022

AbstractSeparation of xylene isomers is one of the most important but most challenging and energy‐intensive separation processes in the petrochemical industry. Here, we report an adaptive hydrogen‐bonded organic framework (HOF‐29) constructed from a porphyrin based organic building block 4,4′,4′′,4′′′‐(porphyrin‐5,10,15,20‐tetrayl) tetrabenzonitrile (PTTBN), exhibiting the exclusive molecular recognition of p‐xylene (pX) over its isomers of o‐xylene (oX) and m‐xylene (mX), as clearly demonstrated in the single crystal structure transformation and 1H NMR studies. Single crystal structure studies show that single‐crystal‐to‐single‐crystal transformation from the as‐synthesized HOF‐29 to the pX exclusively included HOF‐29⊃pX is triggered by the encapsulation of pX molecules, accompanied by sliding of the 2D layers and local distortion of the ligand, which provides multiple C−H⋅⋅⋅π interactions.
Revealing Functional Significance of Interleukin‐2 Glycoproteoforms Enabled by Expressed Serine Ligation
Authors: Zhao Jie , Liu Jiazhi , Liu Xinnan , Cao Qi , Zhao Hongbo , Liu Lizhen , Ye Farong , Wang Can , Shao Hong , Xue Dongxiang , Tao Houchao , Li Bin , Yu Biao , Wang Ping 
Published: January 2022

Comprehensive SummaryNaturally occurring interleukin‐2 (IL‐2) is a pleiotropic glycoprotein that regulates immune responses by controlling the differentiation and homeostasis of T cells. Non‐glycosylated IL‐2 has been used in clinical settings for three decades. However, the function of the O‐glycan of native IL‐2 remains elusive. Herein, to stress this issue, we report a highly efficient semi‐synthesis of homogeneous glycosylated IL‐2 with various glycoproteoforms on a multi‐milligram scale. The glycopeptide fragment was prepared by chemical synthesis and then merged with recombinant fragment via a serine ligation to generate the desired glycoprotein in a single operation. Biological evaluation of the homogenous glycoprotein library reveals that the activity of IL‐2 in activating individual T cell subset is glycan dependent, thus highlighting the possibility of further improving current clinical medicine.
Aggregative Growth of Oligopeptide‐Protected Gold Nanoclusters into Plasmonic Particles
Authors: Zheng Zhiren , Hu Yanyan , Lv Ying , Liu Lu , Fan Daoqing , Zhang Lichao , Chen Ling , Yu Haizhu , Zhu Manzhou 
Published: January 2022

AbstractThe stimuli response of nanomaterials represents a highly appealing characteristic, whereas the practical applications (in catalysis, biosensing etc.) are largely restricted by the limited understanding on the recognition mechanism. Herein, we report a pH‐regulated size evolution from atomically precise Au nanoclusters (NCs) to plasmonic nanoparticles (NPs). The spectral monitoring demonstrates a three‐stage aggregative growth pathway. First, the non‐covalent interactions among the exterior oligopeptide ligands are gradually enhanced with the increased alkalinity, and then the Au−S bonding is partially disrupted, with the exposed Au atoms aggregating to form relatively larger, polydisperse clusters under weak alkaline conditions. Finally, size‐redistribution occurs slowly under strong alkaline conditions to form the plasmonic particles. The controllable transition sheds light on the transition characteristics from molecular state to metallic state of Au nanomaterials.
Role of minimally invasive surgery in the treatment of gallbladder metastatic melanoma. A review of the literature and a case report
Authors: Bangeas Petros Ioannis , Bekiaridou Alexandra , Tsolakidis Alexandros , Efthymiadis Kostantinos Georgios , Drevelegkas Kostantinos , Giakoustidis Dimitris , Giakoustidis Alexandros , Alexidis Petros , Papadopoulos Vassileios Nikolaos 
Published: January 2022

AbstractBackgroundPrimary and secondary gallbladder melanomas are rare, and only 58 cases have been reported in scientific literature to date. This paper aimed to explore the role of minimally invasive surgery in the management of gallbladder metastatic melanomas.CaseHerein, we present the case of a 68‐year‐old man with metastatic gallbladder melanoma who was treated with laparoscopic cholecystectomy. Our case management was then compared with that of other cases reported in the literature.ConclusionCurrently, metastatic melanomas can be considered as a potentially curable disease. Palliation of symptoms and fast recovery following minimally invasive procedures could be beneficial for these patients. Particularly, laparoscopic procedures appear to prolong the survival of gallbladder melanoma patients.
Identification of Cooperative Reaction Sites in Metal−Organic Framework Catalysts for High Yielding Lactic Acid Production from d‐Xylose
Authors: Rungtaweevoranit Bunyarat , Chaipojjana Kawisa , Junkaew Anchalee , Thongratkaew Sutarat , Impeng Sarawoot , Faungnawakij Kajornsak 
Published: January 2022

AbstractDetermining the roles of surface functionality of heterogeneous acid catalysts is important for many industrial catalysts. In this study, the decisive structure of metal−organic frameworks (MOFs) is utilized to identify important features for the effective conversion of d‐xylose into lactic acid. Several acidic MOFs are tested and the combination of Lewis acidity and adjacent hydroxy sites is found to be critical to attain high lactic acid yields. This hypothesis is corroborated experimentally by modification of the MOF to increase such sites, which affords an enhanced lactic acid yield of 79 %, and investigation of the acidity by using in situ FTIR spectroscopy. Density functional theory calculations disclose the cooperative behavior of Lewis acid sites and hydroxy groups in promoting the Cannizzaro reaction, a key step in the production of lactic acid.
Diastereodivergent Synthesis of (+)‐α‐Conhydrine and (−)‐β‐Conhydrine from a η,γ‐Dibromo‐β‐ketosulfoxide
Authors: Salom‐Roig Xavier J. 
Published: January 2022

AbstractDiastereodivergent syntheses of the enantiopure hemlock alkaloid (+)‐α‐conhydrine and its diastereomer (−)‐β‐conhydrine are reported. Our approach relies on efficient Crystallization‐Induced Diastereomer Transformation (CIDT) of an epimeric mixture of a η,γ‐dibromo‐β‐ketosulfoxide, optically pure only at the sulfur atom, that provided a stable α‐bromoketone, and diastereoselective β‐ketosulfoxide reduction that led to the corresponding anti and syn‐bromohydrins with high level of asymmetric induction.
The relationship between social isolation and anxiety in people with cognitive impairment in the United States
Authors: Hwang Yeji , Massimo Lauren , Aryal Subhash , Hodgson Nancy A. 
Published: January 2022

AbstractObjectivesSocial isolation among older adults with cognitive impairment is understudied. The purpose of this study is to examine the relationship between social isolation and anxiety in people with cognitive impairment in the United States.Methods/DesignSecondary data analyses were conducted using the National Social Life, Health, and Aging Project (NSHAP) Wave 2 (2010–2011) dataset which includes a nationally representative sample of American older adults living at home. A total of 1343 people who had probable cognitive impairment measured by a Montreal Cognitive Assessment (MoCA) score of 22 or less were selected. Anxiety was measured using the anxiety measure of Hospital Anxiety and Depression Scale (HADS‐A) and social isolation was measured using Perceived Social Isolation Scale. A weighted multivariable linear regression analysis and weighted F tests were used to examine the relationship between social isolation and anxiety.ResultsWe observed that greater social isolation was related to increased anxiety in people with cognitive impairment (coefficients = 0.7242, t = 2.51, p = 0.015), adjusting for severity of cognitive impairment, race, pain, depression, activities of daily living, and instrumental activities of daily living. Weighted F tests showed that persons with clinically significant anxiety (HADS‐A ≥ 8) had higher levels of loneliness, including feeling a lack of companionship, feeling left out, and greater social isolation.ConclusionsThe results of our study suggest that people with cognitive impairment can feel social isolation and it may contribute to their anxiety. Health care professionals, family, and friends of people with cognitive impairment should pay greater attention to social isolation of their loved ones.
Influence of periaqueductal gray on other salience network nodes predicts social sensitivity
Authors: Rijpma Myrthe G. , Yang Winson F.Z. , Toller Gianina , Battistella Giovanni , Sokolov Arseny A. , Sturm Virginia E. , Seeley William W. , Kramer Joel H. , Miller Bruce L. , Rankin Katherine P. 
Published: January 2022

AbstractThe intrinsic connectivity of the salience network (SN) plays an important role in social behavior, however the directional influence that individual nodes have on each other has not yet been fully determined. In this study, we used spectral dynamic causal modeling to characterize the effective connectivity patterns in the SN for 44 healthy older adults and for 44 patients with behavioral variant frontotemporal dementia (bvFTD) who have focal SN dysfunction. We examined the relationship of SN effective connections with individuals' socioemotional sensitivity, using the revised self‐monitoring scale, an informant‐facing questionnaire that assesses sensitivity to expressive behavior. Overall, average SN effective connectivity for bvFTD patients differs from healthy older adults in cortical, hypothalamic, and thalamic nodes. For the majority of healthy individuals, strong periaqueductal gray (PAG) output to right cortical (p < .01) and thalamic nodes (p < .05), but not PAG output to other central pattern generators contributed to sensitivity to socioemotional cues. This effect did not exist for the majority of bvFTD patients; PAG output toward other SN nodes was weak, and this lack of output negatively influenced socioemotional sensitivity. Instead, input to the left vAI from other SN nodes supported patients' sensitivity to others' socioemotional behavior (p < .05), though less effectively. The key role of PAG output to cortical and thalamic nodes for socioemotional sensitivity suggests that its core functions, that is, generating autonomic changes in the body, and moreover representing the internal state of the body, is necessary for optimal social responsiveness, and its breakdown is central to bvFTD patients' social behavior deficits.
Use of serum B‐cell maturation antigen levels to predict outcomes for myeloma patients treated with ruxolitinib, lenalidomide and methylprednisolone
Authors: Bujarski Sean , Sutanto Christine , Spektor Tanya M. , To Jennifer , Swift Regina A. , Green Tracy , Eades Benjamin R. , Emamy‐Sadr Marsiye , Souther Eric , Berenson James R. 
Published: January 2022

AbstractPrevious retrospective studies have shown that serum B‐cell maturation antigen (sBCMA) levels predict outcomes among patients with multiple myeloma (MM) undergoing new treatments. Specifically, baseline levels and changes during treatment of this protein predict both progression free survival (PFS) and overall survival. However, prospective studies are lacking evaluating sBCMA for determining outcomes among MM patients undergoing new treatments. Thus, we evaluated whether its baseline levels and changes during treatment in the amount of this serum marker predict outcomes among 38 relapsed/refractory MM patients treated with ruxolitinib, lenalidomide and methylprednisolone in a phase 1 trial. Patients with baseline sBCMA levels in the lowest three quartiles had longer PFS (median PFS 136 vs. 28 days; p < 0.0001). This was also shown for patients with baseline levels below the median (median PFS 140 vs. 77 days; p = 0.0225). PFS was shorter for patients whose sBCMA levels increased ≥25% through their first cycle (median PFS: 50 vs. 134 days, p = 0.0022), second cycle (median PFS: 50 vs. 141 days, p = 0.0273), and during the first three cycles of study treatment (median PFS: 50 vs. 220 days, p < 0.0001). No patient whose sBCMA increased ≥25% during cycle 1 responded whereas the majority (58%) of patients whose level increased <25% responded. This is the first prospective study to determine whether sBCMA levels predict outcomes for MM patients undergoing a non‐BCMA directed treatment regimen and demonstrates that baseline levels and its changes during treatment predict PFS and the likelihood of responding to their treatment. These results add to the growing literature suggesting that this serum marker will be useful for determining outcomes for patients undergoing treatment for MM.
COVID‐opt‐aiNet: A clinical decision support system for COVID‐19 detection
Authors: Kanwal Summrina , Khan Faiza , Alamri Sultan , Dashtipur Kia , Gogate Mandar 
Published: January 2022

AbstractCoronavirus disease (COVID‐19) has had a major and sometimes lethal effect on global public health. COVID‐19 detection is a difficult task that necessitates the use of intelligent diagnosis algorithms. Numerous studies have suggested the use of artificial intelligence (AI) and machine learning (ML) techniques to detect COVID‐19 infection in patients through chest X‐ray image analysis. The use of medical imaging with different modalities for COVID‐19 detection has become an important means of containing the spread of this disease. However, medical images are not sufficiently adequate for routine clinical use; there is, therefore, an increasing need for AI to be applied to improve the diagnostic performance of medical image analysis. Regrettably, due to the evolving nature of the COVID‐19 global epidemic, the systematic collection of a large data set for deep neural network (DNN)/ML training is problematic. Inspired by these studies, and to aid in the medical diagnosis and control of this contagious disease, we suggest a novel approach that ensembles the feature selection capability of the optimized artificial immune networks (opt‐aiNet) algorithm with deep learning (DL) and ML techniques for better prediction of the disease. In this article, we experimented with a DNN, a convolutional neural network (CNN), bidirectional long‐short‐term memory, a support vector machine (SVM), and logistic regression for the effective detection of COVID‐19 in patients. We illustrate the effectiveness of this proposed technique by using COVID‐19 image datasets with a variety of modalities. An empirical study using the COVID‐19 image dataset demonstrates that the proposed hybrid approaches, named COVID‐opt‐aiNet, improve classification accuracy by up to 98%–99% for SVM, 96%–97% for DNN, and 70.85%–71% for CNN, to name a few examples. Furthermore, statistical analysis ensures the validity of our proposed algorithms. The source code can be downloaded from Github: https://github.com/faizakhan1925/COVID-opt-aiNet.
Derivation of a natural language processing algorithm to identify febrile infants
Authors: Yaeger Jeffrey P. , Lu Jiahao , Jones Jeremiah , Ertefaie Ashkan , Fiscella Kevin , Gildea Daniel 
Published: January 2022

AbstractBackgroundDiagnostic codes can retrospectively identify samples of febrile infants, but sensitivity is low, resulting in many febrile infants eluding detection. To ensure study samples are representative, an improved approach is needed.ObjectiveTo derive and internally validate a natural language processing algorithm to identify febrile infants and compare its performance to diagnostic codes.MethodsThis cross‐sectional study consisted of infants aged 0–90 days brought to one pediatric emergency department from January 2016 to December 2017. We aimed to identify infants with fever, defined as a documented temperature ≥38°C. We used 2017 clinical notes to develop two rule‐based algorithms to identify infants with fever and tested them on data from 2016. Using manual abstraction as the gold standard, we compared performance of the two rule‐based algorithms (Models 1, 2) to four previously published diagnostic code groups (Models 5–8) using area under the receiver‐operating characteristics curve (AUC), sensitivity, and specificity.ResultsFor the test set (n = 1190 infants), 184 infants were febrile (15.5%). The AUCs (0.92–0.95) and sensitivities (86%–92%) of Models 1 and 2 were significantly greater than Models 5–8 (0.67–0.74; 20%–74%) with similar specificities (93%–99%). In contrast to Models 5–8, samples from Models 1 and 2 demonstrated similar characteristics to the gold standard, including fever prevalence, median age, and rates of bacterial infections, hospitalizations, and severe outcomes.ConclusionsFindings suggest rule‐based algorithms can accurately identify febrile infants with greater sensitivity while preserving specificity compared to diagnostic codes. If externally validated, rule‐based algorithms may be important tools to create representative study samples, thereby improving generalizability of findings.
Inpatient outcomes for children receiving empiric methicillin‐resistant Staphylococcus aureus coverage for complicated pneumonia
Authors: Markham Jessica L. , Hackman Sophia , Hall Matt , Burns Alaina , Goldman Jennifer L. 
Published: January 2022

AbstractRigorous evidence for antibiotic management of pediatric complicated pneumonia is lacking, likely contributing to variation in empiric antibiotic(s). Using the Pediatric Health Information System database, we sought to describe use and clinical outcomes of children hospitalized with complicated pneumonia who received empiric antibiotic regimens with and without methicillin‐resistant Staphylococcus aureus (MRSA) coverage. We evaluated empiric antibiotic selection on Day 0–1, grouping based on use of an antibiotic with or without MRSA coverage. We used generalized linear mixed effects models to examine the association of MRSA coverage and outcomes. Across 46 children's hospitals, 71.5% of children (N = 1279) received an empiric antibiotic regimen with MRSA coverage. In adjusted analyses, length of stay, need for repeat pleural drainage procedures, 7‐day emergency department revisits and 7‐day readmissions were similar between groups. Future prospective studies examining the need for MRSA coverage may assist in refining national treatment guidelines for complicated pneumonia in children.