bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of a Strategy for the Total Synthesis of (+)‐Cornexistin
Authors: Wildermuth Raphael E. , Steinborn Christian , Barber David M. , Mühlfenzl Kim S. , Kendlbacher Mario , Mayer Peter , Wurst Klaus , Magauer Thomas 
Published: June 2021

AbstractHerein is given a full account of the evolution of the first total synthesis of (+)‐cornexistin. Initial efforts were based on masking the reactive maleic anhydride moiety as a 3,4‐substituted furan and on forming the nine‐membered carbocycle in an intramolecular Conia‐ene or Nozaki–Hiyama–Kishi (NHK) reaction. Those strategies suffered from low yields and were jeopardized by a late‐stage installation of the Z‐alkene, as well as the stereocenters along the eastern periphery. These issues were addressed by employing a chiral‐pool strategy that involved construction of the crucial stereocenters at C2, C3 and C8 at an early stage with installation of the maleic anhydride as late as possible. The successful approach featured an intermolecular NHK coupling to install the Z‐alkene, a syn‐Evans‐aldol reaction to forge the stereocenters along the eastern periphery, an intramolecular allylic alkylation to close the nine‐membered carbocycle, and a challenging stepwise hydrolysis of a β‐keto nitrile to furnish the maleic anhydride.
Calcium alginate‐regenerated spent bleaching earth composite beads for efficient removal of methylene blue
Authors: Aberkane Dihia , Meziti Chafika , Ihaddaden Soraya , Boukerroui Abdelhamid , Cagnon Benoît 
Published: June 2021

AbstractThis study aims to find an alternative method to the landfill of spent bleaching earth (SBE), which is a solid waste generated by the refining of edible oil that causes enormous ecological and environmental problems. This solid waste is clay loaded with impurities, colourants, and a large amount of oil entrained during the various stages of refining. In this study, the SBE was initially regenerated (RSBE) by thermal processing in a muffle furnace (temperature: 400°C, time: 1 h) followed by washing with an HCl solution. Then, the regenerated materials were encapsulated with calcium alginate (Alg) to form adsorbent composite beads (Alg‐RSBE). Different Alg/RSBE ratios were applied during materials elaboration, yielding beads denoted Alg‐RSBE 1/1 (1/1, w/w), Alg‐RSBE 1/2 (1/2, w/w), and Alg‐RSBE 1/3 (1/3, w/w), respectively. The Alg–RSBE composite beads were characterized by several methods (FTIR, SEM, EDX, TGA, pHPZC) and used as adsorbents of methylene blue (MB) in a fixed‐bed adsorption system. The adsorption of MB was studied at different experimental conditions such as contact time and initial MB concentration. The results showed that the kinetics of MB adsorption fitted to pseudo‐second‐order kinetics and the adsorption isotherm fitted to Langmuir isotherm. Among the three types of Alg‐RSBE composite beads, Alg‐RSBE 1/1 presents the highest MB adsorption capacity at 833.33 mg/g. Intraparticle and film diffusion equations were used to evaluate the kinetic data. Finally, the regeneration study showed that MB dye was successfully desorbed from Alg‐RSBE 1/1 with removal percentages from 93.32% to 88.15% after six cycles.
TDO2 overexpression correlates with poor prognosis, cancer stemness, and resistance to cetuximab in bladder cancer
Authors: Pham Quoc Thang , Taniyama Daiki , Akabane Shintaro , Harada Kenji , Babasaki Takashi , Sekino Yohei , Hayashi Tetsuraro , Sakamoto Naoya , Sentani Kazuhiro , Oue Naohide , Yasui Wataru 
Published: June 2021

AbstractBackgroundBladder cancer (BC) is the 10th most common cancer in the world. BC with muscle invasion results in a poor prognosis and is usually fatal. Cancer cell metabolism has an essential role in the development and progression of tumors. Expression of tryptophan 2,3‐dioxygenase (TDO2) is associated with tumor progression and worse survival in some other cancers. However, no studies have been performed to uncover the biofunctional roles of TDO2 in BC.AimThis study aim to investigate the clinicopathologic significance of TDO2 in BC.Methods and resultsTDO2 expression was evaluated by qRT‐PCR and immunohistochemistry in an integrated analysis with the Cancer Genome Atlas (TCGA) and other published datasets. TDO2 overexpression was significantly associated with T classification, N classification, and M classification, tumor stage, recurrence, and basal type, and with the expression of CD44 and aldehyde dehydrogenase 1 (ALDH1) in BC. High TDO2 expression correlated with poor outcome of BC patients. Using BC cell lines with knockdown and forced expression of TDO2, we found that TDO2 was involved in the growth, migration, and invasiveness of BC cells. Moreover, TDO2 was found to be crucial for spheroid formation in BC cells. Importantly, TDO2 promoted BC cells resistance to cetuximab through integration of the EGFR pathway.ConclusionOur results indicate that TDO2 might take an essential part in BC progression and could be a potential marker for targeted therapy in BC.
Group 12 Carbonates and their Binary Complexes with Nitrogen Bases and FH2Z Molecules (Z=P, As, Sb): Synergism in Forming Ternary Complexes
Authors: Liu Na , Li Qingzhong 
Published: June 2021

AbstractMCO3(M=Zn, Cd, Hg) forms a spodium bond with nitrogen‐containing bases (HCN, NHCH2, NH3) and a pnicogen bond with FH2Z (Z=P, As, Sb). The spodium bond is very strong with the interaction energy ranging from −31 kcal/mol to −56 kcal/mol. Both NHCH2and NH3have an equal electrostatic potential on the N atom, but the corresponding interaction energy is differentiated by 1.5–4 kcal/mol due to the existence of spodium and hydrogen bonds in the complex with NHCH2as the electron donor. The spodium bond is weakest in the HCN complex, which is not consistent with the change of the binding distance. The spodium bond becomes stronger in the CdCO3<ZnCO3<HgCO3sequence although the positive electrostatic potential on the Hg atom is smallest. This is because the electrostatic interaction is dominant in the spodium‐bonded complexes of CdCO3and ZnCO3but the polarization interaction in that of HgCO3. The pnicogen bond is much weaker than the spodium bond and the former has a larger enhancement than the latter in the FH2Z⋅⋅⋅OCO2M⋅⋅⋅N‐base ternary complexes.
Label‐Free Protein Glycosylation Analysis Using NanoMonitor—An Ultrasensitive Electrochemical Biosensor
Authors: Ganguly Antra , Lin Kai‐Chun , Muthukumar Sriram , Nagaraj Vinay J. , Prasad Shalini 
Published: June 2021

AbstractGlycans (oligosaccharide chains attached to glycoproteins) are a promising class of biomarkers, found in body fluids such as serum, saliva, urine, etc., that can be used for the diagnosis of disease conditions. Subtle changes in glycans resulting from altered glycosylation machinery have been reported during various diseases, including carcinogenesis. In this article, we detail protocols for the rapid, label‐free analysis of glycans using a previously developed highly sensitive and selective electrochemical impedance spectroscopy−based biosensing diagnostic platform called “NanoMonitor.” The glycosensor operation is based on the specific affinity capture of the target glycans on the sensor surface by glycan‐binding proteins known as lectins. This glycan‐lectin binding activity modulates the impedance of the electrical double layer at the buffer‐electrode interface. Protocols for the preparation of glycoprotein samples and glycosylation analysis using NanoMonitor and lectin‐based ELISA are described here. The data obtained using these protocols show that NanoMonitor is capable of distinguishing between glycoform variants of the glycoprotein fetuin and glycoproteins derived from cultured human pancreatic cancer cells with high sensitivity (orders of magnitude higher than lectin‐based ELISA) and selectivity. The results obtained indicate that NanoMonitor protocols can be further developed to enable use of NanoMonitor as a handheld electronic biosensor device for routine multiplexed detection of glycan biomarkers from clinical samples. © 2021 Wiley Periodicals LLC.Basic Protocol 1: Preparing the NanoMonitor surface for glycan biosensingSupport Protocol: Synthesis of glycoform variants of fetuinBasic Protocol 2: Performing Electrochemical Impedance Spectroscopy (EIS) for analyzing glycoprotein structures
The current state of uncertainty reporting in ecosystem studies: a systematic evaluation of peer‐reviewed literature
Authors: Yanai Ruth D. , Mann Thomas A. , Hong Sunghoon D. , Pu Ge , Zukswert Jenna M. 
Published: June 2021

AbstractTransparency in reporting is essential to scientific progress. No report should be considered complete without a full account of uncertainties, including those due to natural variation and measurement and model error and those incurred by handling problematic data, such as outliers. We randomly selected 132 papers published in 2019 from a list of 100 scientific journals to characterize the current state of uncertainty reporting in ecosystem studies. Each paper was evaluated for the extent to which it reported measures of uncertainty in any of four topic areas common to ecosystem studies: vegetation, soils, precipitation, and surface water. We found that most papers reported a minority of the uncertainty sources we deemed relevant. Papers on surface water reported the highest fraction of uncertainty sources (averaging 47% ± 5%), followed by soils (45% ± 4%), vegetation (32% ± 4%), and precipitation (21% ± 8%). A greater fraction of relevant uncertainty sources were reported when the topics were the primary focus of the paper (44% ± 3%) than when they were not (32% ± 4%). Sampling error—the uncertainty in replicate measurements—was the source most commonly reported in studies of vegetation (84%), soil mass (56%), and surface water (76% of papers). The source of measurement error most often reported was chemical analysis, with 41% of papers on surface water and 75% of papers on precipitation reporting this source, if applicable. In contrast, only 1 of 12 papers reporting chemistry of vegetation provided information on analytical uncertainty. Fewer papers reported what methods were used for handling missing or unusable data and observations below detection limits, but it was difficult to judge whether these sources were relevant if they were not mentioned. Finally, we found that a minority of the papers made all (21%) or some (an additional 21%) of their data available in online repositories, after correcting for a failure rate of 13% of the links. Clearly, there is room for improving the completeness and transparency of scientific reporting in ecosystem studies.
Projected change in rangeland fractional component cover across the sagebrush biome under climate change through 2085
Authors: Rigge Matthew , Shi Hua , Postma Kory 
Published: June 2021

AbstractClimate change over the past century has altered vegetation community composition and species distributions across rangelands in the western United States. The scale and magnitude of climatic influences are unknown. While many studies have projected the effects of climate change using several modeling approaches, none has evaluated the impacts to fractional component cover at a 30‐m resolution across the full sagebrush (Artemisiaspp.) biome. We used fractional component cover data for rangeland functional groups and weather data from the 1985 to 2018 reference period in conjunction with soils and topography data to develop empirical models describing the spatiotemporal variation in component cover. To investigate the ramifications of future change across the western United States, we extended models based on historical relationships over the reference period to model landscape effects based on future weather conditions from two emission scenarios and three time periods (2020s, 2050s, and 2080s). We tested both generalized additive models (GAMs) and regression tree models, finding that the former led to superior spatial and statistical results. Our results indicate more xeric vegetation across most of the study area, with an increasing dominance of non‐sagebrush shrubs, annual herbaceous cover, and bare ground over herbaceous and sagebrush cover in both the representative concentration pathway (RCP) 4.5 and 8.5 scenarios. In general, both scenarios yielded similar results, but RCP 8.5 tended to be more extreme, with greater change relative to the reference period. Results demonstrate that in cool sites some degree of warming to growing season maximum temperature or nongrowing season minimum temperature could be beneficial to sagebrush and shrub growth. However, warming nongrowing season maximum temperature was beneficial to shrub, but not to sagebrush growth. Our results inform rangeland managers of potential future vegetation composition, cover, and species distributions, which could improve prioritization of conservation and restoration efforts.
Importance of low‐relief nursery habitat for reef fishes
Authors: Dance Michael A. , Rooker Jay R. , Kline Richard J. , Quigg Antonietta , Stunz Gregory R. , Wells R. J. David , Lara Kirsten , Lee Jessica , Suarez Bobbie 
Published: June 2021

AbstractCoastal restoration projects to mitigate environmental impacts have increased global demand for sand resources. Unfortunately, these resources are often extracted from sand/shell banks on the inner continental shelf, resulting in significant alteration or loss of low‐relief reefs in coastal oceans. Experimental reefs (oyster shell, limestone rubble, composite) were deployed in the western Gulf of Mexico to assess their potential value as nurseries for newly settled reef fishes. Occurrence, abundance, and species richness of juvenile fishes were significantly higher on all three types of low‐relief reefs compared with unconsolidated sediment. Moreover, reefs served as nursery habitat for a range of reef fish taxa (angelfishes, grunts, sea basses, snappers, and triggerfishes). Red snapper (Lutjanus campechanus) was the dominant species present on all experimental reefs (100% occurrence), and mean density of this species was markedly higher on each of the three low‐relief reefs (>40.0 individuals/reef) relative to comparable areas over unconsolidated sediment (0.2 individuals). Our results suggest creation or restoration of structurally complex habitat on the inner shelf has the potential to markedly increase early life survival and expedite the recovery of exploited reef fish populations, and therefore may represent a critical conservation tool for increasing recruitment and maintaining reef fish diversity.
Shifting macroecological patterns and static theory failure in a stressed alpine plant community
Authors: Franzman Juliette , Brush Micah , Umemura Kaito , Ray Courtenay , Blonder Benjamin , Harte John 
Published: June 2021

AbstractAccumulating evidence suggests that ecological communities undergoing change in response to either anthropogenic or natural disturbances exhibit macroecological patterns that differ from those observed in similar types of communities in relatively undisturbed sites. In contrast to such cross‐site comparisons, however, there are few empirical studies of shifts over time in the shapes of macroecological patterns. Here, we provide a dramatic example of a plant community in which the species–area relationship and the species‐abundance distribution change markedly over a period of six years. These patterns increasingly deviate from the predictions of the maximum entropy theory of ecology (METE), which successfully predicts macroecological patterns in relatively static systems. The error in the species–area relationship prediction additionally correlates over time with increased stress measured as mortality minus recruitment, providing a link between demography and the failure of macroecological theory. Information on the dynamic state of an ecosystem inferred from snapshot measurements of macroecological community structure can potentially assist in identifying causes and consequences of disturbance and extending the domain of current theories and models to disturbed ecosystems.
Big bees spread disease: body size mediates transmission of a bumble bee pathogen
Authors: Van Wyk Jennifer I. , Amponsah Eugene R. , Ng Wee Hao , Adler Lynn S. 
Published: June 2021

AbstractTrait variation can have important consequences for the outcomes of species interactions. Even though some traits vary as much within species as across related species, models and empirical studies typically do not consider the role of intraspecific trait variation for processes such as disease transmission. For example, many pollinator species are in decline because of a variety of stressors including pathogens, but the role of intraspecific trait variation in mediating disease dynamics is rarely considered. For example, pollinator body size could affect pathogen transmission via differences in resistance, foraging behavior and physiology. We tested effects of body size on pollinator pathogen transmission using the common eastern bumble beeBombus impatiensin field tents, introducing an infected “donor” microcolony of large or small workers with an uninfected average‐sized “recipient” microcolony and allowing bees to forage for 9–16 d. Small donor bees had nearly 50% higher infection intensity (cells/0.02 μL) than large donor bees, but large donor bees were twice as likely to transmitCrithidia bombito recipient bees. Both behavioral and physiological mechanisms may underlie this apparent paradox. Compared to small bees, large bees foraged more and produced more feces; simulations showed that foraging and defecation rates together had stronger effects on transmission than did donor infection intensity. Thus, effects of bee size on contact rates and pathogen supply may play significant roles in disease transmission, demonstrating the multifaceted impacts of traits on transmission dynamics.
The impact of DNA extract homogenization and replication on marine sediment metabarcoding diversity and heterogeneity
Authors: Hestetun Jon Thomassen , Lanzén Anders , Skaar Katrine Sandnes , Dahlgren Thomas G. 
Published: June 2021

AbstractMetabarcoding of environmental DNA (eDNA) is an attractive complement to morphological methods for surveys and routine monitoring of marine sediment benthic communities. However, metabarcoding and other genetic techniques are heavily affected by choices made during sampling, processing, and analysis. Here, we investigated the effect of different eDNA extraction protocols on observed alpha‐ and beta diversity of replicates from the same grab. Specifically, we compared (A) homogenization intensity during sediment DNA extraction, (B) extraction replicates vs larger sediment extraction volume, and (C) pre‐ and post‐PCR extract pooling. Using the 18S V1‐V2 region marker, we show that a Precellys homogenizer protocol during DNA extraction can significantly improve sediment metabarcoding results in terms of captured diversity and inter‐replicate homogeneity compared to vortexing only. This effect superseded that of increased sediment extract volume. Pre‐PCR pooling of DNA extraction replicates increased observed rarefied richness compared to data from single extracts only, but not to the extent of sample extract replicates amplified individually before pooling. We argue that this discrepancy was due to a reduction both in recovered sample diversity, but also the number of PCR artifacts and PCR drift. Our results demonstrate that extraction replicates of smaller sediment volumes, in combination with moderate Precellys homogenization and pre‐PCR pooling, are a cost‐effective way to increase the amount of organism diversity that is recovered from sediment eDNA metabarcoding samples.
Tofacitinib therapy intercepts macrophage metabolic reprogramming instigated by SARS‐CoV‐2 Spike protein
Authors: Palasiewicz Karol , Umar Sadiq , Romay Bianca , Zomorrodi Ryan K. , Shahrara Shiva 
Published: June 2021

AbstractThe molecular mechanism of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) Spike protein was characterized to identify novel therapies. The impact of tofacitinib, IL‐6R Ab, or TNFi therapy was determined on Spike protein or LPS/IFN‐γ‐induced signaling, inflammation, and metabolic reprogramming in MΦs and/or rheumatoid arthritis (RA) fibroblast‐like synoviocyte (FLS). ACE2 frequency was markedly expanded in MΦs compared to T cells and RA FLS. Tofacitinib suppresses Spike protein potentiated STAT1 signaling, whereas this function was unchanged by TNFi. Tofacitinib impairs IL‐6/IFN/LPS‐induced STAT1 and STAT3 phosphorylation in RA MΦs and FLS. Interestingly, tofacitinib had a broader inhibitory effect on the monokines, glycolytic regulators, or oxidative metabolites compared to IL‐6R Ab and TNFi in Spike‐protein‐activated MΦs. In contrast, all three therapies disrupted IFN‐α and IFN‐β secretion in response to Spike protein; nonetheless, the IFN‐γ was only curtailed by tofacitinib or IL‐6R Ab. While tofacitinib counteracted MΦ metabolic rewiring instigated by Spike protein, it was inconsequential on the glycolysis expansion mediated via HK2 and/or LDHA in the activated RA MΦ and FLS. Nevertheless, the potentiated inflammatory response and the diminished oxidative phosphorylation modulated by Spike protein and/or LPS/IFN‐γ stimulation in MΦs or RA FLS were reversed by tofacitinib. In conclusion, tofacitinib suppresses MΦ inflammation and immunometabolism triggered by Spike protein and may provide a promising strategy for COVID‐19 patients.
Synthesis and Magnetic Properties of Two‐Step‐Coordination Schiff Base Clusters
Authors: Peters Laurens C. J. M. , Engelkamp Hans , Zeitler Uli , Christianen Peter C. M. , Tinnemans Paul , Maan Jan‐Kees , Rowan Alan E. 
Published: June 2021

AbstractA new family of paramagnetic coordination compounds based on a diimine‐pyridine pincer ligand has been prepared, using a two‐step synthetic approach. The sequential introduction of identical or different transition metals (Co, Mn, Ni, Zn) afforded mono‐, di‐, tri‐ and tetranuclear clusters, whose crystal structure has been determined. Magnetic studies reveal that the metals within the trinuclear manganese cluster engage in a small ferromagnetic exchange interaction (J=0.15 K). These studies enable the design of new clusters with specific magnetic properties.
Asymmetric Total Synthesis of (−)‐Dehydrocostus Lactone by Domino Metathesis
Authors: Kaden Felix , Nowotni Susanne , Höfner Franziska , Lorenz Melanie , Barthel André , Jäger Anne , Hennersdorf Felix , Weigand Jan J. , Metz Peter 
Published: June 2021

AbstractAn efficient total synthesis of the sesquiterpenoid (−)‐dehydrocostus lactone is reported. Our earlier approach by a domino enediyne metathesis was extended by a domino dienyne metathesis strategy to give access to suitably functionalized hydroazulene cores. Highly stereoselective asymmetric anti aldol reactions provided the enantiopure substrates for this key step of our synthesis. Multiple hydroboration/oxidation of the resulting hydroazulenes set up three out of four stereogenic centers in a single step. First, oxidation to give a diketo‐γ‐lactone enabled an enantioselective formal synthesis of the target guaianolide. Subsequently, the final steps of this approach were improved by using a double carbonyl olefination at the stage of a masked γ‐butyrolactone, which completed the synthesis in a much more efficient way.