bluuebunny/crossref_metadata_2025 huggingface dataset:
Nickel Glyoximate Based Metal–Covalent Organic Frameworks for Efficient Photocatalytic Hydrogen Evolution
Authors: Sun Lishan , Lu Meng , Yang Zongfan , Yu Zhenyi , Su Xi , Lan Ya‐Qian , Chen Long
Published: May 2022

Metal–covalent organic frameworks (MCOFs) have been recently received wide attention owing to the homogeneous distribution of active metal centers that are beneficial for enhancing the application potentials. However, metal complex based functional building blocks for MCOFs synthesis are limited. Herein, two new MCOFs (Ni‐Py‐COF and Ni‐Bn‐COF) were constructed via a novel nickel glyoximate based building block. Splendid photocatalytic activity on hydrogen evolution from water and great long‐term recyclability were achieved using these nickel glyoximate based MCOFs as photocatalysts. Excitingly, even without the addition of Pt co‐catalyst, the hydrogen evolution rates (HER) of Ni‐Py‐COF reached up to 626 μmol g−1 h−1, which is better than many porous organic polymers. This work not only expands the type of building units for MCOFs, but also provides meaningful insights for developing stable, efficient and earth‐abundant photocatalysts toward H2 generation.
Enantiomorphic Single Crystals of Linear Lead(II) Bromide Perovskitoids with White Circularly Polarized Emission
Authors: Jin Kai‐Hang , Zhang Yue , Li Kai‐Jie , Sun Meng‐En , Dong Xi‐Yan , Wang Qing‐Lun , Zang Shuang‐Quan
Published: May 2022

Chiroptical hybrid organic–inorganic perovskites are emerging as a new class of promising materials with mirror optical signal responses for optoelectronic applications. However, chiroptical white‐emission materials have been scarcely unearthed. Herein, four pairs of hybrid lead(II) bromide perovskitoids were obtained, namely, (R)‐ and (S)‐(H2MPz)PbBr4 (R/S‐MPz=(R)‐(−)/(S)‐(+)‐2‐methylpiperazine) (1 and 2), (R)‐ and (S)‐(H2MPz)3Pb2Br10⋅2 DMAc (3 and 4), (R)‐ and (S)‐(H2MPz)PbBr4⋅0.5 MeCN (5 and 6) and (R)‐ and (S)‐(H2MPz)2Pb2Br8⋅DCM (7 and 8). Notably, they all exhibit ultrabroadband emission and chiroptical signals. Perovskitoids 3–6 even achieve white circularly polarized emission with a high dissymmetric factor (glum) (±3×10−3 for 3 and 4; ±8×10−3 for 5 and 6). This new type of hybrid perovskitoids will attract attention and find applications in chiroptical fields because of the extensively and easily tunable photophysical properties.
Monitoring Reaction Intermediates to Predict Enantioselectivity Using Mass Spectrometry**
Authors: Hilgers Roelant , Yong Teng Sin , Briš Anamarija , Pereverzev Aleksandr Y. , White Paul , Jansen Jeroen J. , Roithová Jana
Published: May 2022

Enantioselective reactions are at the core of chemical synthesis. Their development mostly relies on prior knowledge, laborious product analysis and post‐rationalization by theoretical methods. Here, we introduce a simple and fast method to determine enantioselectivities based on mass spectrometry. The method is based on ion mobility separation of diastereomeric intermediates, formed from a chiral catalyst and prochiral reactants, and delayed reactant labeling experiments to link the mass spectra with the reaction kinetics in solution. The data provide rate constants along the reaction paths for the individual diastereomeric intermediates, revealing the origins of enantioselectivity. Using the derived kinetics, the enantioselectivity of the overall reaction can be predicted. Hence, this method can offer a rapid discovery and optimization of enantioselective reactions in the future. We illustrate the method for the addition of cyclopentadiene (CP) to an α,β‐unsaturated aldehyde catalyzed by a diarylprolinol silyl ether.
Flow and crystallization of saturated fatty acid methyl esters and their binary mixtures
Authors: Helsper Sedi , Hatem Wesam A. , Young Lisa , Wilhelm Zane , Liberatore Matthew W.
Published: May 2022

Demand for biodiesel has increased due to being a more environmentally‐friendly fuel. Cold weather operation of biodiesel is challenging due to fatty acid methyl ester (FAME) content in biodiesel. Saturated FAMEs crystallize at relatively high temperatures, increase the viscosity of biodiesel, and can clog fuel lines. Here, several factors altered crystallization temperature (CT) of FAMEs, including composition, shear rate, and cooling rate. The crystallization of pure and binary mixtures of methyl palmitate, methyl myristate, and methyl stearate were studied under shear flow and static conditions. Static phase CTs of pure methyl palmitate, methyl myristate, and methyl stearate were 26, 14, and 35°C, respectively. In binary mixtures, CTs were depressed up to 7°C, which agreed with freezing point depression theory. Increasing shear rate up to 100 s−1 decreased CT by 2°C compared to static conditions. Decreasing cooling rate from 1 to 0.1°C/min increased CT less than 2°C. Overall, FAME composition altered CT more than shear flow or cooling rate for pure and binary mixtures of three FAMEs.
Luminescence and morphological behaviour of the aromatic dipeptide pair having singular structural variability
Authors: Mouli M. S. S. Vinod , Agrawal Harsha Gopal , Kumar Mohit , Mishra Ashutosh Kumar
Published: May 2022

In the present manuscript, the luminescence and the self‐assembly behaviour of two aromatic dipeptides with a singular structure variable are investigated. The terminally protected dipeptides tryptophan–tyrosine (WYp) and tryptophan–phenylalanine (WFp) were synthesized using a standard solution phase procedure. Significant solvatochromic effect was observed for both the dipeptidyl entities; whilst the influence was more pronounced for the WYp entity when compared with WFp. Interesting morphological variation was observed for WFp and WYp, in which discrete and interconnected nanospheres were observed for the respective dipeptides. The results obtained signify the influence of the singular structural variation on modulating the overall functional behaviour of the short peptides motifs.
Preoperative and postoperative high angular resolution diffusion imaging tractography of cerebellar pathways in posterior fossa tumors
Authors: Ortug Alpen , Yuzbasioglu Neslihan , Akalan Nejat , Levman Jacob , Takahashi Emi
Published: May 2022

This study aimed to utilize high angular resolution diffusion magnetic resonance imaging (HARDI) tractography in the mapping of the pathways of the cerebellum associated with posterior fossa tumors (infratentorial neoplasms) and to determine whether it is useful for preoperative and postoperative evaluation. Retrospective data from 30 patients (age 2–16 yr) with posterior fossa tumor (17 low grade, 13 high grade) and 30 age‐sex‐matched healthy controls were used. Structural and diffusion‐weighted images were collected at a 3‐tesla scanner. Tractography was performed using Diffusion Toolkit software, Q‐ball model, FACT algorithm, and angle threshold of 45 degrees. Manually assessed regions of interest were placed to identify reconstructed fiber pathways passing through the superior, medial, and inferior cerebellar peduncles for the preoperative, postoperative, and healthy control groups. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), and track volume measures were obtained and analyzed. Statistically significant differences were found between the preop/postop, preop/control, and postop/control comparisons for the volume of the tracts in both groups. Displacement and disruption of the pathways seemed to differ in relation to the severity of the tumor. The loss of pathways after the operation was associated with selective resection during surgery due to tumor infiltration. There were no FA differences but significantly higher ADC in low‐grade tumors, and no difference in both FA and ADC in high‐grade tumors. The effects of posterior fossa tumors on cerebellar peduncles and reconstructed pathways were successfully evaluated by HARDI tractography. The technique appears to be useful not only for preoperative but also for postoperative evaluation.
Antibacterial Mechanism of N‐PMI and the Characteristics of PMMA‐Co‐N‐PMI Copolymer**
Authors: Shi Han , Zhuang Qixin , Zheng Anna , Zhan Pengfei , Guan Yong , Wei Dafu , Xu Xiang , Wu Tao
Published: May 2022

Aiming at the excellent killing effect of N‐phenylmaleimide (N‐PMI) on microorganisms, this article used structural simulation analysis, fluorescence analysis, confocal laser scanning microscope and SEM to find that the double bond in N‐PMI could interact with the sulfur groups in the membrane protein, changing its conformation, rupturing the plasma membrane of the cell, leaking the contents, and ultimately causing the death of the microorganisms. Therefore, once the double bond participated in the polymerization, N‐PMI lost its antimicrobial function. N‐PMI could achieve azeotropic copolymerization with MMA through reactive extrusion polymerization. N‐PMI with a content of 5 % can be evenly inserted into the PMMA chain segment during the copolymerization reaction, thereby increasing the Tg of pure PMMA by up to 15 °C, which provided the PMMA‐co‐PMI copolymer with resistance to boiling water sterilization advantageous conditions. In addition, N‐PMI with a content of 5 % has little effect on the transparency of PMMA after participating in the copolymerization. Moreover, the trace amount of residual N‐PMI made the material have excellent antimicrobial function, and the bacteriostatic zone is extremely small, which provided an excellent guarantee for the safety and durability of the material. As a medical biological material, the PMMA‐co‐PMI copolymer has a good industrialization application prospects.
Three New Pregnanes Isolated from the Cynanchum auriculatum
Authors: Fan Yi‐Min , Jin Jun , Jian Jun‐You , Gu Wei , Yuan Chun‐Mao , Hu Zhan‐Xing , Hao Xiao‐Jiang , Huang Lie‐Jun
Published: May 2022

Three new compounds named cynansteroid A (1), cynansteroid B (2) and cynansteroid C (3), together with nine known C21‐steroidal pregnane sapogenins (4–12) were isolated from the hydrolytic extract of the roots of Cynanchum auriculatum. The structures of cynansteroid A–C (1–3) were ascertained via the detailed analysis of the HR‐ESI‐MS, 1D and 2D NMR, and the calculated and experimental ECD data of cynansteroid B (2). Compound 11 displayed moderate inhibitory activity toward Verticillium dahliae Kleb (IC50=37.15 μM), furthermore, compounds 11 and 12 showed significant inhibitory activity against Phomopsis sp. (IC50=16.49 μM and 17.62 μM, respectively).
Americans' financial resilience during the pandemic
Authors: Clark Robert L. , Mitchell Olivia S.
Published: May 2022

How household wellbeing responds to pandemic‐induced financial shocks likely depends on whether people undertake certain actions that enhance their ability to withstand adverse economic events, along with their ability to efficiently respond to the shocks when they occur. This paper examines Americans' financial robustness during the Covid‐19 pandemic, using an index of financial resilience and a measure of financial fragility derived from household surveys of persons age 45–75 in spring of 2020, and in May–June 2021. We estimate the factors associated with resilience and fragility in both years, show how these two measures changed a year into the pandemic, and consider whether resilience in 2020 led to better outcomes in 2021. We conclude that higher initial levels of resilience were, in fact, associated with lower levels of financial fragility a year into the pandemic. These findings suggest that policies and programs that enhance financial resilience can help low and moderate‐income households withstand economic shocks and be able to better address unexpected income needs.
Ultrathin Two‐Dimensional Metal–Organic Framework Nanosheets Based on a Halogen‐Substituted Porphyrin Ligand: Synthesis and Catalytic Application in CO2 Reductive Amination
Authors: Dong Jurong , Mo Qijie , Wang Yufei , Jiang Long , Zhang Li , Su Cheng‐Yong
Published: May 2022

Ultrathin two‐dimensional metal–organic framework nanosheets have emerged as a promising kind of heterogeneous catalysts. Herein, we report a series of 2D porphyrinic metal–organic framework nanosheets (X‐PMOF, X=F, Cl, Br), which was prepared from the self‐assembly of a halogen‐based porphyrin ligand X‐TCPP (X‐TCPP=5‐(4‐halogenatedphenyl)‐10,15,20‐tris(4‐carboxyphenyl)‐porphyrin) and ZrCl4 in the presence of trifluoroacetic acid as the modulating reagent. The framework of X‐PMOF possessed the ftw topology as in MOF‐525. The lamellar X‐PMOF nanosheets with the thickness of down to 4.5 nm were assembled and aggregated into a flower‐like morphology. With the introduction of iridium(III) atoms into the porphyrin rings, the resultant X‐PMOF(Ir) nanosheets were prepared by a similar method. Catalytic results show that Br‐PMOF(Ir) nanosheets were efficient for CO2 reduction and aminolysis, giving rise to formamides in high yields under room temperature and atmospheric pressure, and can be recycled and reused for 3 runs. The total turnover number of Br‐PMOF(Ir) after 3 runs was 1644 based on Ir. Mechanistic studies disclose that the high efficiency of Br‐PMOF(Ir) nanosheets was ascribed to three factors, including the superior activation capability of iridium(III) porphyrin for Si−H bonds, more active sites on the external surfaces of Br‐PMOF(Ir) nanosheets, and the defects caused by unsymmetrical porphyrin ligand that increased the framework's affinity towards CO2.
Recent Advances in the Synthesis and Biological Applications of Peptidoglycan Fragments
Authors: Vacariu Condurache M. , Tanner Martin E.
Published: May 2022

The biosynthesis, breakdown, and modification of peptidoglycan (PG) play vital roles in both bacterial viability and in the response of human physiology to bacterial infection. Studies on PG biochemistry are hampered by the fact that PG is an inhomogeneous insoluble macromolecule. Chemical synthesis is therefore an important means to obtain PG fragments that may serve as enzyme substrates and elicitors of the human immune response. This review outlines the recent advances in the synthesis and biochemical studies of PG fragments, PG biosynthetic intermediates (such as Park's nucleotides and PG lipids), and PG breakdown products (such as muramyl dipeptides and anhydro‐muramic acid‐containing fragments). A rich variety of synthetic approaches has been applied to preparing such compounds since carbohydrate, peptide, and phospholipid chemical methodologies must all be applied.
Hierarchically Porous Poly(ionic liquid) – Organic Cage Composite Membrane for Efficient Iodine Capture
Authors: Zhao Xue‐Jing , Liu Si‐Hua , Sun Jian‐Ke
Published: May 2022

The effective capture of iodine with high volatility and poisonousness is significant for reprocessing the spent nuclear fuel. In this article, we report a hierarchically porous poly(ionic liquid)‐organic cage composite membrane (PIL@CC3) possessing a gradient content distribution of CC3 cage crystals throughout the membrane to capture iodine vapor. The introduction of microporous CC3 can significantly enhance the uptake capacity of iodine up to 980 mg g−1, which is superior to that of a pristine PIL membrane carrying large meso‐ and macropores (99 mg g−1), and CC3 crystalline powder (662 mg g−1). Such enhanced performance benefits from the micro‐meso‐macroporous structure of the PIL@CC3 membrane in which the large meso‐ and macropores facilitate the mass transfer of iodine molecules from the external environment into the surface of the CC3 crystal, followed by diffusion of iodine molecules from the CC3 surface into the interior and exterior pores of the CC3 crystal. In addition, the asymmetric distribution of CC3 crystals across the PIL@CC3 membrane also displays its advantage in intercepting trace iodine, revealing its great potential for practical application. This study provides an idea for constructing hierarchically porous membrane composites for the removal of toxic vapors.
Lewis Acid Assisted Brønsted Acid Catalysed Decarbonylation of Isocyanates: A Combined DFT and Experimental Study
Authors: Dasgupta Ayan , van Ingen Yara , Guerzoni Michael G. , Farshadfar Kaveh , Rawson Jeremy M. , Richards Emma , Ariafard Alireza , Melen Rebecca L.
Published: May 2022

An efficient and mild reaction protocol for the decarbonylation of isocyanates has been developed using catalytic amounts of Lewis acidic boranes. The electronic nature (electron withdrawing, electron neutral, and electron donating) and the position of the substituents (ortho/meta/para) bound to isocyanate controls the chain length and composition of the products formed in the reaction. Detailed DFT studies were undertaken to account for the formation of the mono/di‐carboxamidation products and benzoxazolone compounds.
Opioid Ligands Addressing Unconventional Binding Sites and More Than One Opioid Receptor Subtype
Authors: Drakopoulos Antonios , Moianos Dimitrios , Prifti Georgia‐Myrto , Zoidis Grigoris , Decker Michael
Published: May 2022

Opioid receptors (ORs) represent one of the most significant groups of G‐protein coupled receptor (GPCR) drug targets and also act as prototypical models for GPCR function. In a constant effort to develop drugs with less side effects, and tools to explore the ORs nature and function, various (poly)pharmacological ligand design approaches have been performed. That is, besides classical ligands, a great number of bivalent ligands (i. e. aiming on two distinct OR subtypes), univalent heteromer‐selective ligands and bitopic and allosteric ligands have been synthesized for the ORs. The scope of our review is to present the most important of the aforementioned ligands, highlight their properties and exhibit the current state‐of‐the‐art pallet of promising drug candidates or useful molecular tools for the ORs.
Potentially traumatic events and post‐traumatic growth among Chinese peacekeepers: A moderated mediation model
Authors: Qu Jingrui , Tu Zhihao , Zheng Xican , Wang Minjie , Shen Xinghua
Published: May 2022

Peacekeepers are inherently exposed to potentially traumatic events (PTEs) in the line of duty. However, little is known about whether PTEs during peacekeeping missions may foster post‐traumatic growth (PTG) among peacekeepers and its mechanisms. This study aimed to investigate the association between PTEs and PTG among Chinese peacekeepers, as well as the mediating role of coping style and the moderating role of resilience. Five hundred ninety‐five Chinese peacekeepers completing the United Nations (UN) peacekeeping mission in South Sudan and returning to China were recruited to complete Peacekeeping Traumatic Stress Exposure Scale, Posttraumatic Growth Inventory, Simplified Coping Style Questionnaire and the Chinese version of Connor and Davidson's Resilience Scale. PTEs were positively associated with PTG among Chinese peacekeepers. Coping style partially mediated the association between PTEs and PTG. Resilience moderated the association between coping style and PTG. Specifically, at a lower level of resilience, positive coping style was more effective in predicting PTG. This study contributes to understanding the complex association between PTEs in peacekeeping missions, coping style, resilience and PTG by focusing on the experiences of Chinese peacekeepers and adds value to the current literature on psychological health in peacekeepers.
Early stages of speciation with gene flow in the Amazilia Hummingbird (Amazilis amazilia) subspecies complex of Western South America
Authors: Cowles Sarah A. , Witt Christopher C. , Bonaccorso Elisa , Grewe Felix , Uy J. Albert C.
Published: May 2022

Disentangling the factors underlying the diversification of geographically variable species with a wide geographical range is essential to understanding the initial stages and drivers of the speciation process. The Amazilia Hummingbird, Amazilis amazilia, is found along the Pacific coast from northern Ecuador down to the Nazca Valley of Peru, and is currently classified as six phenotypically differentiated subspecies. We aimed to resolve the evolutionary relationships of the six subspecies, to assess the geographical pattern and extent of evolutionary divergence, and to test for introgression using both a mtDNA marker and a genome‐by‐sequencing dataset from 86 individuals from across the species range. The consensus phylogenetic tree separated the six subspecies into three distinct clades, corresponding with the Ecuador lowlands (A. amazilia dumerilii), the Ecuador highlands (A. amazilia alticola and A. amazilia azuay), and the Peruvian coast (A. amazilia leucophoea, A. amazilia amazilia, and A. amazilia caeruleigularis). However, an unresolved mtDNA network suggests that the diversification of the subspecies was recent and rapid. We found evidence of gene flow among the subspecies A. amazilia dumerilii, A. amazilia alticola, and A. amazilia leucophoea, with strong genetic isolation of the subspecies A. amazilia azuay in the isolated Yunguilla Valley of Ecuador. Finally, environmental data from each subspecies’ capture locations were concordant with the three distinct clades. Overall, our results suggest that both expansions into new habitats and geographic isolation shaped the present‐day phylogeny and range of the A. amazilia subspecies, and that A. amazilia azuay may be genetically divergent enough to be considered a separate species.
Genetic diversity and demographic history of the Old World Bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), in Ethiopia inferred from mitochondrial gene sequences
Authors: Fite Tarekegn , Tefera Tadele , Goftishu Muluken , Damte Tebekew
Published: May 2022

The Old World bollworm, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae), is a globally distributed agricultural and horticultural insect pest. Despite the economic importance of this insect in Ethiopia, its genetic diversity and demographic history are poorly understood. We examined the nucleotide variation of the mitochondrial cytochrome c oxidase subunit I (COI) gene fragment of 74 H. armigera individuals from six collection sites in Ethiopia. We recorded 15 COI haplotypes in H. armigera, ten globally shared and five exclusive to Ethiopia (HaET15, HaET14, HaET10, HaET7, and HaET4). Haplotype HaET1 was the most widely geographically distributed and frequent (71.62%). Analysis of molecular variance (AMOVA) revealed a high and significant level of variation within H. armigera populations (θST = −0.0135). Negative values of the neutrality test and nonsignificant index of mismatch distribution supported the demographic expansion of H. armigera populations in Ethiopia; furthermore, this was also supported by the nonsignificant values of the sum of squared deviations (SSD) and raggedness index (r). The high genetic variation and population expansion of H. armigera have immense implications for devising locally adapted management strategies in area‐wide integrated pest management IPM programs. However, a comprehensive study of H. armigera genetic diversity and population structure using various molecular markers is needed for future confirmation.
Phenotypic responses to light, water, and nutrient conditions in the allopolyploid Arabidopsis suecica and its parent species A. thaliana and A. arenosa: Does the allopolyploid outrange its parents?
Authors: Kornstad Torbjørn , Ohlson Mikael , Fjellheim Siri
Published: May 2022

Polyploid species possess more than two sets of chromosomes and may show high gene redundancy, hybrid vigor, and masking of deleterious alleles compared to their parent species. Following this, it is hypothesized that this makes them better at adapting to novel environments than their parent species, possibly due to phenotypic plasticity. The allopolyploid Arabidopsis suecica and its parent species A. arenosa and A. thaliana were chosen as a model system to investigate relationships between phenotypic plasticity, fitness, and genetic variation. Particularly, we test if A. suecica is more plastic, show higher genetic diversity, and/or have higher fitness than its parent species. Wild Norwegian populations of each species were analyzed for phenotypic responses to differences in availability of nutrient, water, and light, while genetic diversity was assessed through analysis of AFLP markers. Arabidopsis arenosa showed a higher level of phenotypic plasticity and higher levels of genetic diversity than the two other species, probably related to its outbreeding reproduction strategy. Furthermore, a general positive relationship between genetic diversity and phenotypic plasticity was found. Low genetic diversity was found in the inbreeding A. thaliana. Geographic spacing of populations might explain the clear genetic structure in A. arenosa, while the lack of structure in A. suecica could be due to coherent populations. Fitness measured as allocation of resources to reproduction, pointed toward A. arenosa having lower fitness under poor environmental conditions. Arabidopsis suecica, on the other hand, showed tendencies toward keeping up fitness under different environmental conditions.
The benefits of merging passive and active tracking approaches: New insights into riverine migration by salmonid smolts
Authors: Chavarie Louise , Honkanen Hannele M. , Newton Matthew , Lilly Jessie M. , Greetham Hannah R. , Adams Colin E.
Published: May 2022

The process of smolting is a critical phase in the life cycle of anadromous salmonids, and it has been associated with substantial rates of mortality. Survival during freshwater and marine migration is known to have population‐level effects; thus, an understanding of the patterns of mortality has the potential to yield important insights into population bottlenecks. Despite important advancements in tracking techniques, the specifics of mortality events in anadromous salmonids during their initial migration to sea remain somewhat elusive. Here, we develop a framework combining spatial and temporal detections of smolt riverine migration from two tracking techniques, which enable inferences to be made about mortality locations, causes, and rates. In this study, we demonstrate that during their initial riverine transitional phase, smolts were particularly vulnerable to predators. Specifically, avian predation appeared to be the main cause of mortality (42%), although piscine predation events were not trivial (14%). Our results suggested some direct and indirect tagging‐induced mortality (e.g., through increased predation vulnerability), which highlights the importance of determining tagging mortality in a telemetry study to ensure adequate interpretation of migration success. Overall, by estimating migration loss and its variability, our study framework should help to guide management actions to mitigate the widespread population declines these species are currently facing.
Tropical montane forest in South Asia: Composition, structure, and dieback in relation to soils and topography
Authors: Lakkana Tithira , Ashton Mark S. , Hooper Elaine R. , Perera Anoma , Ediriweera Sisira
Published: May 2022

We evaluated the composition, structure, and dieback of a montane forest in relation to soils and physiography of an important biogeographic region that has been sparsely studied. Our objectives were to (1) describe the forest composition and structure; (2) assess the current extent of dieback; and (3) relate tree composition, structure, and dieback proneness to edaphic and physiographic measures. We enumerated all live and dead standing plants ≥3 cm dbh, in thirty 20 × 15 m2 overstory plots. We measured all regeneration ≤1 m height in subplots, sampled soils and measures of physiography, and visually rated the proportion of crown dieback, and recorded standing dead trees. Woody plants belonged to 58 species and 25 families, of which 5% were dead. The plant families Lauraceae, Myrtaceae, and Symplocaceae represented over 50% of the basal area; Rubiaceae alone represented 25% of the stems. Multiple regressions revealed measures of edaphic and physiographic factors are associated with tree species richness and diversity, structure (e.g., basal area and stem density), and tree dieback and standing dead trees. Canopy openness and measures of soil toxicity from metals (Al and Cu) on clay‐based soils showed a predictably negative relationship with tree species richness and diversity. Basal area and stem density are positively associated with aspect and slope, and predictably negatively associated with canopy openness. Lastly, dieback and standing dead trees of the dominant canopy tree species are both positively associated with south and southwest aspects. The forest is now in a period of regeneration recovery with high numbers of regenerating secondary successional species. We propose the primary underlying factors that caused the dieback of this forest was a drought during 1970–1980 compounded by accumulations of salts and metals in the soil conveyed by winds from the sea (sodium) and from an ancient period of metallurgy downwind of the forest. However, our results are only suggestive of these causative factors and further study is necessary to confirm or refute these speculative causes for dieback.
Multimorbidity, guideline‐directed medical therapies, and associated outcomes among hospitalized heart failure patients
Authors: Takeuchi Shinsuke , Kohno Takashi , Goda Ayumi , Shiraishi Yasuyuki , Kawana Masataka , Saji Mike , Nagatomo Yuji , Nishihata Yosuke , Takei Makoto , Nakano Shintaro , Soejima Kyoko , Kohsaka Shun , Yoshikawa Tsutomu ,   West Tokyo Heart Failure Registry Investigators
Published: May 2022

Aims

Multimorbidity is common among heart failure (HF) patients and may attenuate guideline‐directed medical therapy (GDMT). Multimorbid patients are under‐represented in clinical trials; therefore, the effect of multimorbidity clustering on the prognosis of HF patients remains unknown. We evaluated the prevalence of multimorbidity clusters among consecutively registered hospitalized HF patients and assessed whether GDMT attenuated outcomes.

Methods and results

We examined 1924 hospitalized HF patients with reduced left ventricular ejection fraction (<50%) in a multicentre registry (West Tokyo HF Registry: WET‐HF). Ten comorbid conditions in the WET‐HF were abstracted: coronary artery disease, atrial fibrillation, stroke, anaemia, chronic obstructive pulmonary disease, renal dysfunction, obesity, hypertension, dyslipidaemia, and diabetes. Patients were divided into three groups (0–2: n = 451; 3–4: n = 787; and ≥5: n = 686) based on the number of comorbid conditions. The primary composite endpoint was all‐cause mortality and HF rehospitalization. The most prevalent comorbidities were renal dysfunction (67.9%), hypertension (66.0%), and anaemia (53.8%). Increased comorbidity was associated with increased adverse outcomes [3–4: hazard ratio (HR) 1.42, 95% confidence interval (CI) 1.13–1.77, P = 0.003; ≥5: HR 2.12, 95%CI 1.69–2.65, P < 0.001; and reference: 0–2] and lower GDMT prescription rate (0–2: 69.2%; 3–4: 57.7%; and ≥5: 57.6%). GDMT was associated with decreased adverse outcomes; this association was maintained even as the comorbidity burden increased but tended to weaken (0–2: HR 0.53, 95%CI 0.35–0.78; P = 0.001; 3–4: HR 0.82, 95%CI 0.65–1.04, P = 0.095; and ≥5: HR 0.81, 95%CI 0.65–1.00, P = 0.053; P for interaction = 0.156).

Conclusions

Comorbidity clusters were prevalent and associated with poorer outcomes. GDMT remained beneficial regardless of the comorbidity burden but tended to weaken with increasing comorbidity burden. Further research is required to optimize medical care in these patients.
Ruthenium‐Catalyzed Intermolecular Cyclization and N‐Methylation of Salicyl N‐Tosylhydrazones
Authors: Kurma Siva Hariprasad , Kolla Sai Teja , Sridhar Balasubramanian , Bhimapaka China Raju
Published: May 2022

3‐(2,2‐dichloroacetyl)‐2H‐Chromen‐2‐ones were prepared by treating salicyl N‐tosylhydrazones with ethyl 4,4,4‐trichloro‐3‐oxobutanoate in presence of catalytic amount of La(OTf)3 and RuCl3 ⋅ 3H2O for the first time. The chromenones were formed through C‐C, C‐O bond formations, detosylation and more importantly dechlorination protocol. One of the compound 3‐(2,2‐dichloroacetyl)‐6‐methyl‐2H‐chromen‐2‐one structure was confirmed by single‐crystal X‐ray analysis. Further, salicyl N‐tosylhydrazones when treated with dimethyl (1‐diazo‐2‐oxopropyl)‐phosphonate (Bestmann‐Ohira reagent) in presence of K2CO3 and RuCl3 ⋅ 3H2O provided (E)‐N′‐(2‐hydroxybenzylidene)‐N,4‐dimethylbenzenesulfono hydrazide.
Geographical reconfiguration in global value chains: Search within limited space?
Authors: Rodriguez Carlos , Ciravegna Luciano , Petersen Bent
Published: May 2022

Research summary

Negative performance feedback in offshoring service activities entices firms to undertake geographical reconfiguration of their global value chains (GVCs) as a substitute for, or complement to, change of governance modes, decomposition of offshored activities, or shift of local service providers. In this study, we build on performance feedback theory and the concept of problemistic search to examine the extent to which firms move offshored service activities to new countries when facing negative performance gaps. We also examine if these relocations take place within a search space limited by the managers' cognitive span. We formulate a set of hypotheses revolving around this idea of search within a limited space. Our hypotheses are supported when tested on a sample of global sourcing projects undertaken by 223 firms between 1995 and 2012.

Managerial summary

The essence of reconfiguration is the continuous search for efficient combinations of functions, local service providers (when functions are outsourced), governance modes, and—in our case—locations. Limiting the search for improved combinations to fewer locations entails a higher dependence on these locations maintaining the country‐location‐specific advantages that made them attractive in the first place. It is thus possible that multinational enterprise (MNE) managers who reconfigure their GVC in a geographically bounded way in the long run will struggle to compete with MNEs that search for optimality within a broader range of locations as possible remedies for the GVC operations that experience negative performance gaps.
Evaluation of subclasses for T4‐classified squamous cell carcinoma of the external auditory canal
Authors: Nabuurs Cindy H. , Kievit Wietske , Leemans C. René , Smit Conrad F. G. M. , van den Brekel Michiel W. M. , Pauw Robert J. , van der Laan Bernard F. A. M. , Jansen Jeroen C. , Lacko Martin , Braunius Weibel W. , Dai Chunfu , Shi Xunbei , Danesi Giovanni , Bouček Jan , Takes Robert P. , Kunst Henricus P. M.
Published: May 2022

Background

T4‐classified squamous cell carcinoma (SCC) of external auditory canal (EAC) can potentially involve different anatomical structures, which could translate into different treatment strategies and survival outcomes within one classification. Our aim is to evaluate the clinical added value of T4‐subclasses proposed by Lavieille and by Zanoletti.

Methods

Retrospective data, including patients with primary operated cT4‐classified EAC SCC, was obtained from 12 international hospitals. We subclassified according to the T4‐subclasses. The treatment strategies, disease‐free survival (DFS) and overall survival per subclass were calculated.

Results

A total of 130 T4‐classified EAC SCC were included. We found commonly used treatment strategies per subclass according to Lavieille and the DFS seems also to differ per subclass. Subclass according to Zanoletti showed comparable treatment strategies and survival outcomes per subclass.

Conclusion

Our study suggests that the subclass according Lavieille might have added value in clinical practice to improve care of T4‐classified EAC SCC.
LINC00240 knockdown inhibits nasopharyngeal carcinoma progress by targeting miR‐26a‐5p
Authors: Chen Xing , Wu Guixiang , Qing Jing , Li Chunlin , Chen Xudong , Shen Jian
Published: May 2022

Objective

This study intended to explore the regulatory functions of LINC00240 on nasopharyngeal carcinoma (NPC).

Methods

MiR‐26a‐5p inhibitor, mimic, and siLINC00240 were transfected into NPC cells. QRT‐PCR was employed to assess miR‐26a‐5p and LINC00240 expressions. The targeting relationship of LINC00240 and miR‐26a‐5p was analyzed through dual luciferase reporter and RNA immunoprecipitation assay. Cell counting kit‐8 assay, colony formation assay, flow cytometry assay, wound healing assay, Transwell assay and in vitro angiogenesis assay were adopted for the evaluation of the effects of LINC00240 or miR‐26a‐5p and LINC00240 on NPC cells regarding cell proliferation, apoptosis and cycle, migration, invasion, and angiogenesis. EZH2, cell cycle, and epithelial‐mesenchymal transition (EMT)‐related protein expression was tested through Western blot.

Results

LINC00240 had a high expression in NPC tissues and cell lines. Silenced LINC00240 significantly suppressed the 5‐8F and HK1 cell proliferation, invasion, migration, and angiogenesis, but raised cell apoptosis, and cells were blocked in G0/G1 phase. MiR‐26a‐5p was a target of LINC00240. MiR‐26a‐5p upregulation suppressed the NPC cell proliferation, migration, invasion, angiogenesis, N‐cadherin and EZH2 expression, while it elevated apoptosis and p21, p27 and E‐cadherin expressions, whereas miR‐26a‐5p downregulation performed conversely. LINC00240 knockdown partially offset the effects of miR‐26a‐5p downregulation on cell proliferation, migration, invasion, angiogenesis, apoptosis, and EZH2.

Conclusion

LINC00240 knockdown restrained cell proliferation, invasion, migration, and angiogenesis, while it advanced apoptosis via miR‐26a‐5p in NPC by EZH2 inhibition.
The role of ERNDIM diagnostic proficiency schemes in improving the quality of diagnostic testing for inherited metabolic diseases
Authors: Mathis Déborah , Croft Joanne , Chrastina Petr , Fowler Brian , Vianey‐Saban Christine , Ruijter George J. G.
Published: May 2022

External quality assurance (EQA) is crucial to monitor and improve the quality of biochemical genetic testing. ERNDIM (www.erndim.org), established in 1994, aims at reliable and standardized procedures for diagnosis, treatment and monitoring of inherited metabolic disease (IMD) by providing EQA schemes and educational activities. Currently, ERNDIM provides 16 different EQA schemes including quantitative schemes for various metabolite groups, and interpretive schemes such as diagnostic proficiency testing (DPT). DPT schemes focus on the ability of laboratories to correctly identify and interpret abnormalities in authentic urine samples across a wide range of IMDs. In the DPT schemes, six samples each year are distributed together with clinical information. Laboratories choose and perform the tests needed to reach a diagnosis. Data were collected on 345 samples, distributed to up to 105 laboratories worldwide. Diagnostic proficiency (the % of total points possible for all participating laboratories within a scheme for analysis and interpretation) ranged widely: amino acid disorders (n = 20), range 33%–100%, mean 84%; organic acid disorders (n = 35), range 14%–100%, mean 84%; lysosomal storage disorders (n = 13), range 20%–97%, mean 73%; purine/pyrimidine disorders (n = 9), range 37%–100%, mean 70%; miscellaneous disorders (n = 8), range 17%–100%, mean 65%; no IMD, range 65%–95%, mean 85%. When a sample with the same disorder was distributed in a subsequent survey, performance improved in 75 cases with no improvement seen in 32, suggesting overall improvement of performance. ERNDIM diagnostic proficiency testing is a valuable activity which can help to assess laboratory performance, identify methodological/technical challenges, be informative during quality audits and contribute to a better clinical appreciation of diagnostic uncertainty.
Design of imprinting matrix for dual template sensing via electropolymerized polythiophene films
Authors: Singh Ritu , Singh Meenakshi
Published: May 2022

This work presents the design of 3‐thiophene acetic acid (3‐TAA) polymer matrix based molecularly imprinted polymer (MIP)/reduced graphene oxide (RGO) composite for sensitive and selective detection of antipyrine (AnP) and ethionamide (ETH) simultaneously. Dual drug embedded molecularly imprinted polymer (MIP) based electrochemical sensor was developed via electropolymerization of 3‐TAA. AnP and ETH were embedded inside a polymer matrix based on their 3‐D orientation and interaction(s) with functional monomer(s). Their extraction from polymeric matrix generates cavities complimentary to shape and size of AnP and ETH. The extraction of templates was confirmed by differential pulse voltammetry (DPV) as well as high‐performance liquid chromatography (HPLC). The designed sensor selectively captures and produces the electrochemical signal for imprinted drugs. The electrochemical behaviour of AnP and ETH was investigated by DPV technique. The sensitivity for both drug molecules was commendable on a single polymeric composite with RGO on GC electrode (LOD of 0.117 μM for AnP and 0.15 μM for ETH). Also, the sensor exhibited excellent selectivity towards AnP and ETH in the presence of other analogous interferent molecules. Thus, the designed sensor showed high sensitivity as well as high selectivity for imprinted dual drug molecules on a single platform.
Impact of Sustained Synovitis on Knee Joint Structural Degeneration: 4‐Year MRI Data from the Osteoarthritis Initiative
Authors: Ramezanpour Sara , Kanthawang Thanat , Lynch John , McCulloch Charles E. , Nevitt Michael C. , Link Thomas M. , Joseph Gabby B.
Published: May 2022

Background

Synovial inflammation is a risk factor for osteoarthritis (OA). But to date, there is limited information on how inflammation impacts progression of knee OA.

Purpose

To investigate how sustained synovitis, assessed with semi‐quantitative magnetic resonance imaging (MRI) scores, impacts progression of knee degenerative changes over 4 years.

Study Type

Retrospective cohort study.

Subjects

In 249 participants (N = 132 women [53%]), from the Osteoarthritis Initiative (OAI) two definitions for synovitis were used resulting in two groups of participants with sustained synovitis at baseline, 2‐year, and 4‐year follow‐up (N = 80 and N = 132), and two groups without synovitis at all three time points (N = 81 and N = 47).

Field Strength/Sequence

3 T intermediate‐weighted (IW) turbo spin‐echo (TSE) sequence and three‐dimensional (3D) dual‐echo steady‐state (DESS) sequence.

Assessment

Synovitis was scored semi‐quantitatively using the Anterior Cruciate Ligament Osteoarthritis Score (ACLOAS), MRI Osteoarthritis Knee Score (MOAKS), and synovial proliferation score (SPS). Two MRI‐based definitions of synovitis were used: (i) score ≥2 based on cumulative score of MOAKS and ACLOAS, and (ii) score ≥3 based on the cumulative score of ACLOAS, MOAKS, and SPS. Changes in structural abnormalities from baseline to year 4 measured using the whole‐organ MRI score (WORMS) were defined as outcomes.

Statistical Tests

Linear regression models were used to compare the differences in longitudinal changes in WORMS scores between participants with and without sustained synovitis for each definition of sustained synovitis. A P‐value of <0.05 was considered statistically significant.

Results

Significantly higher rates of progression were found in participants with synovitis for patellar (Beta coeff. = 0.29) and medial tibial cartilage abnormalities (Beta coeff. = 0.29) for definition (i). For definition (ii), patellar (Beta coeff. = 0.36) and medial femoral cartilage (Beta coeff. = 0.30) abnormalities demonstrated significant differences.

Data Conclusion

Greater progression of structural degenerative disease was observed in individuals with sustained synovitis compared to those without sustained synovitis, suggesting that sustained synovitis is associated with progressive OA.

Level of Evidence

3

Technical Efficacy

Stage 2
Directionally Sensitive Fractal Radiomics Compatible With Irregularly Shaped Magnetic Resonance Tumor Regions of Interest: Association With Osteosarcoma Chemoresistance
Authors: Djuričić Goran J. , Ahammer Helmut , Rajković Stanislav , Kovač Jelena Djokić , Milošević Zorica , Sopta Jelena P. , Radulovic Marko
Published: May 2022

Background

Computational analysis of routinely acquired MRI has potential to improve the tumor chemoresistance prediction and to provide decision support in precision medicine, which may extend patient survival. Most radiomic analytical methods are compatible only with rectangular regions of interest (ROIs) and irregular tumor shape is therefore an important limitation. Furthermore, the currently used analytical methods are not directionally sensitive.

Purpose

To implement a tumor analysis that is directionally sensitive and compatible with irregularly shaped ROIs.

Study Type

Retrospective.

Subjects

A total of 54 patients with histopathologic diagnosis of primary osteosarcoma on tubular long bones and with prechemotherapy MRI.

Field Strength/Sequence

A 1.5 T, T2‐weighted‐short‐tau‐inversion‐recovery‐fast‐spin‐echo.

Assessment

A model to explore associations with osteosarcoma chemo‐responsiveness included MRI data obtained before OsteoSa MAP neoadjuvant cytotoxic chemotherapy. Osteosarcoma morphology was analyzed in the MRI data by calculation of the nondirectional two‐dimensional (2D) and directional and nondirectional one‐dimensional (1D) Higuchi dimensions (Dh). MAP chemotherapy response was assessed by histopathological necrosis.

Statistical Tests

The area under the receiver operating characteristic (ROC) curve (AUC) evaluated the association of the calculated features with the actual chemoresponsiveness, using tumor histopathological necrosis (95%) as the endpoint. Least absolute shrinkage and selection operator (LASSO) machine learning and multivariable regression were used for feature selection. Significance was set at <0.05.

Results

The nondirectional 1D Dh reached an AUC of 0.88 in association with the 95% tumor necrosis, while the directional 1D analysis along 180 radial lines significantly improved this association according to the Hanley/McNeil test, reaching an AUC of 0.95. The model defined by variable selection using LASSO reached an AUC of 0.98. The directional analysis showed an optimal predictive range between 90° and 97° and revealed structural osteosarcoma anisotropy manifested by its directionally dependent textural properties.

Data Conclusion

Directionally sensitive radiomics had superior predictive performance in comparison to the standard nondirectional image analysis algorithms with AUCs reaching 0.95 and full compatibility with irregularly shaped ROIs.

Evidence Level

3

Technical Efficacy

Stage 1
Discovery and pharmacodynamic evaluation of the novel butene lactone derivativeM355against influenza A virus in vitro and in vivo
Authors: Geng Jingwei , Hu Xiaoning , Zhang Zhongmou , Gu Zichen , Li Yuanyuan , Mou Xiaodong , Mao Lu , Ge Yongzhuang , Yang Xinyu , Song Yihui , Liu Hongmin , Wang Linqing , Wei Zhanyong , Wang Zhenya , Xu Haiwei
Published: May 2022

A new series of butene lactone derivatives were designed according to an influenza neuraminidase target and their antiviral activities against H1N1 infection of Madin–Darby canine kidney cells were evaluated. Among them, a compound that was given the nameM355was identified as the most potent against H1N1 (EC50 = 14.7 μM) with low toxicity (CC50 = 538.13 μM). It also visibly reduced the virus‐induced cytopathic effect. Time‐of‐addition analysis indicated that H1N1 was mostly suppressed byM355at the late stage of its infectious cycle.M355inhibited neuraminidase in a dose‐dependent fashion to a similar extent as oseltamivir, which was also indicated by a computer modeling experiment. In a mouse model, lung lesions and virus load were reduced and the expression of nucleoprotein was moderated byM355. The enzyme‐linked immunosorbent assay and quantitative real‐time polymerase chain reaction analyses revealed that the levels of interferon‐γ, interferon regulatory factor‐3, Toll‐like receptor‐3, tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐6, and IL‐8 were downregulated in theM355‐treated groups, whereas the levels of IL‐10 and IL‐13 were upregulated. Similarly, IgG was found to be increased in infected mice plasma. These results demonstrate thatM355inhibit the expression of H1N1 in both cellular and animal models. Thus,M355has the potential to be effective in the treatment of influenza A virus infection.