bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of an Enzymatic Process for the Synthesis of the Key Intermediate of Telotristat Ethyl
Authors: Li Hengyu , Zhang Wenhe , Jiang Xianyan , Wang Huibin , Wang Qi , Wang Jiajun , Jia Xian , Qin Bin , You Song 
Published: November 2020

Abstract(R)‐1‐(4‐chloro‐2‐(3‐methyl‐1H‐pyrazol‐1‐yl)phenyl)‐2,2,2‐trifluoroethan‐1‐ol [(R)‐2] is a key chiral intermediate in the synthesis of telotristat ethyl, an anti‐carcinoid syndrome drug. However, the synthetic methods for (R)‐2 mainly include chemical reductions, rarely involving biocatalysis or bioreduction until now. Here, we report a method for obtaining (R)‐2 by biocatalytic reduction of corresponding prochiral acetophenone (1) with bulky o‐substitution using recombinant Lactobacillus fermentum short‐chain dehydrogenase/reductase 1 (LfSDR1) as a biocatalyst. Further engineering of LfSDR1 variants could access asymmetric reduction of 1 and yield (R)‐2 with a >99% ee and a >99% conversion. In addition, through the test of different co‐solvents and a series of initial substrate concentrations, substrate 1 with the concentration of 60 g/L can be completely converted into (R)‐2 on a preparative scale (1.13 g, 3.93 mmol, 75.6% isolated yield) in 24 hours. This study presents an efficient enzymatic process for the biocatalytic synthesis of key chiral intermediate (R)‐2 in the synthesis of telotristat ethyl.magnified image
Phylogeographic structure and continued surveys of a Vulnerable South African freshwater crab (Potamonautidae, Potamonautes lividus): Implications for the IUCN Red Listing of the Afrotropical fauna
Authors: Daniels Savel Regan , James Nicola C. , Gouws Gavin 
Published: November 2020

Abstract

In the present study, the phylogeography of the only southern African freshwater crab listed as Vulnerable (VU) on the International Union for Conservation of Nature (IUCN) Red List, Potamonautes lividus, was investigated by surveying several localities in the Eastern Cape and KwaZulu‐Natal provinces in South Africa. Both nuclear and mitochondrial DNA (nDNA and mtDNA) markers were used and, as it was hypothesized that marked genetic differentiation should be present, niche modelling was undertaken to explore the distribution of the species along the east coast of South Africa. In addition, shortfalls in the present approach to IUCN Red Listing, as illustrated by this Vulnerable species of crab, are discussed.
Results from the mtDNA revealed the presence of two haploclades, confined to specimens from the two provinces, respectively, and the general absence of maternal dispersal, a fact that was further validated by the fixation index (FST) data and high ΦST values. Within the Eastern Cape haploclade, low‐frequency maternal dispersal occurred, corroborated by the low value of FST. In contrast, no haplotypes were shared in the KwaZulu‐Natal haploclade, as corroborated by the marked differences in FST.
The microsatellite data demonstrated the presence of higher frequency, possibly paternally biased, dispersal of specimens between the Eastern Cape and KwaZulu‐Natal provinces. The results suggest the presence of two distinct management units within P. lividus. An estimate of divergence time suggests a late Pleistocene cladogenesis between the Eastern Cape and KwaZulu‐Natal haploclades.
Considering the presence of P. lividus in several newly formed nature conservation areas in both provinces, and its potential presence in the intermediary area, based on maximum entropy (Maxent) niche modelling, our data suggest that the species status in the IUCN Red List should be downgraded to Least Concern.
A comparison of all the Endangered, Vulnerable, and Critically Endangered IUCN Red Listed freshwater crabs for the entire Afrotropical region reveals the lack of recent sampling in the three biodiversity hot spots in West, Central, and East Africa, with mountainous areas containing a disproportionate number of species but with most species being devoid of phylogeographical study.
Historical and contemporary habitat use of sperm whales around the Galápagos Archipelago: Implications for conservation
Authors: Eguiguren Ana , Pirotta Enrico , Boerder Kristina , Cantor Maurício , Merlen Godfrey , Whitehead Hal 
Published: November 2020

Abstract

Sperm whales have occupied the waters off the Galápagos Islands, Ecuador, for at least the past 200 years. During the 19th century, they were the target of intensive whaling that severely depleted the population. In recent times, after commercial whaling ended, sperm whales in the region remain vulnerable to multiple threats, especially potential entanglement in fishing gear, which may hinder their ability to recover from the whaling era.
As a highly mobile, long‐lived species, long‐term analysis of the habitat use of sperm whales is necessary to establish effective conservation and management strategies. Here, contemporary (1985–2014) and historical (1830–1850) sperm whale habitat use off the Galápagos Islands was analysed and contrasted to the extent of the Galápagos Marine Reserve (GMR). Contemporary habitat use and its variability over time were modelled as a function of geographic, oceanographic, and topographic variables using generalized additive models.
The fine‐scale habitat (<50 km) used by sperm whales was associated with topographic (i.e. depth and slope) and oceanographic characteristics (i.e. relative sea surface temperature and standard deviation of sea surface temperature), but these preferences varied over time.
While historical and contemporary data indicate that sperm whale habitat primarily occurred within the boundaries of the GMR, in recent years, whales were found up to 30.1% of the time outside the GMR, potentially overlapping with commercial fisheries operating in the area.
The dynamic nature of the relationship of this nomadic species with its habitat highlights the need of large‐scale conservation efforts across the Eastern Tropical Pacific region, including the wide‐scale enforcement of regulations requiring the use of Automatic Identification System in fishing vessels, the promotion of on‐board fisheries observer programmes, the development of adaptive management strategies, and international collaboration to identify and mitigate threats.
Singlet Oxygen in Lithium−Oxygen Batteries
Authors: Hong Misun , Byon Hye Ryung 
Published: November 2020

AbstractSinglet oxygen (1O2) is one of the most critical species leading to parasitic side reactions and poor reversibility in non‐aqueous Li−O2 batteries. 1O2 is generated via the disproportionation of the superoxide radical (O2.−) in O2/Li2O2 electrochemistry. The mechanistic and computational studies on 1O2 formation revealed the significant roles of the associated cations, solvation ability of aprotic solvents, H+ source, and catalyst/electrode materials. Along with efforts to alleviate 1O2 production, trapping and eliminating 1O2 have been attempted using molecular agents. Anthracene derivatives trap 1O2 and form endoperoxides, which can be quantitatively detected using in situ fluorescence analysis. Physical quenchers that convert 1O2 to 3O2 are desirable for cycling of Li−O2 cells because quencher molecules are reusable. We highlight the recent reports on the formation and elimination of 1O2, and challenges and perspectives of suppressing the 1O2 effect on the performance of Li−O2 cells.
Investigation of Li Anode/FeS2 Cathode Electrochemical Properties for Optimizing High‐Power Thermal Batteries
Authors: Im Chae‐Nam , Hun Choi Chi , Yu Hye‐Ryeon , Ahn Tae‐Young , Yoon Hyun‐Ki , Seong Yeo Jae , Cho Jang‐Hyeon 
Published: November 2020

AbstractHerein, the discharge properties of lithium (Li) anode with FeS2 cathode system are investigated under different pressure loads, weight percent of Li, temperatures, and current densities to provide a fundamental understanding of the operational safety, electrochemical properties, and optimization parameters for Li anode‐based thermal batteries. The lithium anode was prepared via physically mixing Li with Fe powder. The Li−Si alloy, the most common anode for thermal batteries, was investigated simultaneously to show the clear distinction in electrochemical performance between the Li anode and Li−Si anode. For achieving high operational safety and discharge performance with Li anode, the recommended pressure load and weight percent of Li are below 6 kgf cm−2 and 15 wt%, respectively, to prevent any leakage or short‐circuiting problems. The discharge at 500 °C and 0.2–0.4 A cm−2 exhibits the optimal performance for the Li anode and FeS2 cathode system. Finally, the thermal batteries with 17 cells are manufactured to confirm the aforementioned parameters at −32 and 63 °C to demonstrate that the previous results coincide with the actual battery level experiments. Due to the intertwined nature of the parameters, the optimization should always be conducted in a holistic manner to obtain high‐performance thermal batteries for future military applications.
Influence of Chemical Composition and Domain Morphology of Li2MnO3 on Battery Properties
Authors: Hikima Kazuhiro , Taminato Sou , Hinuma Yoyo , Shimizu Keisuke , Suzuki Kota , Hirayama Masaaki , Yasuno Satoshi , Tamura Kazuhisa , Kanno Ryoji 
Published: November 2020

AbstractThe reaction mechanism, which is the changes that happen during electrochemical cycling, in Li2MnO3 with a layered rock‐salt (O3) structure was examined using model electrodes in a liquid battery. Epitaxial films of Li2MnO3(001) with thickness of 30 nm, various Li/Mn atomic ratios, and different morphologies were fabricated by pulsed laser deposition. These electrodes showed charge–discharge capacity ranging from 150 to 300 mAh g−1, with different degradation characteristics depending on the composition and morphology. Films with nominal (Li/Mn atomic ratio=2.07) and Li‐rich (Li/Mn ratio=2.28) underwent irreversible structural transformation to an activated phase, regardless of the grain size, during the first cycling to 4.8 V. The interlayer spacing increased after activation, which may be a result of a transition to a O1 stacking structure. Li layer and transition metal layer octahedra share faces in the O1 structure, hence, Li diffusion would be easier and therefore results in activation considered to the O1 structure. Further degradation was slower in the nominal film, but the reason cannot be clearly ascribed to composition or grain size. Ex situ hard X‐ray photoelectron spectroscopy (HAXPES) results suggest that some O were oxidized but others were not during charge. The Li‐rich film showed large interactions with a solid‐electrolyte interface layer by virtue of the high Li concentration.
The neurotoxic effect of isoflurane on age‐defined neurons generated from tertiary dentate matrix in mice
Authors: Xiao Xin‐Li , Wu Jing‐Tao , Zhang Han‐Ze , Wang Yi‐Di , Zhang Jing‐Qiao , Liu Le‐Fan , Yu‐Chen  , Min‐Li  , Yang Peng‐Bo , Wu Xiao‐Lin , Liu Jian‐Xin 
Published: November 2020

AbstractIntroductionRecent animal studies showed that isoflurane exposure may lead to the disturbance of hippocampal neurogenesis and later cognitive impairment. However, much less is known about the effect of isoflurane exposure on the neurons generated form tertiary dentate matrix, even though a great increase of granule cell population during the infantile period is principally derived from this area.MethodsTo label the new cells originated from the tertiary dentate matrix, the mice were injected with BrdU on postnatal day 6 (P6). Then, the mice were exposed to isoflurane for 4 hr at 1, 8, 21, and 42 days after BrdU injection, and the brains were collected 24 hr later. The loss of newly generated cells/neurons with different developmental stage was assessed by BrdU, BrdU + DCX, BrdU + NeuN, or BrdU + Prox‐1 staining, respectively.ResultsWe found that the isoflurane exposure significantly decreased the numbers of nascent cells (1 day old) and mature neurons (42 days old), but had no effect on the immature (8 days old) and early mature neurons (8 and 21 days old, respectively).ConclusionThe results suggested isoflurane exposure exerts the neurotoxic effects on the tertiary dentate matrix‐originated cells with an age‐defined pattern in mice, which partly explain the cognitive impairment resulting from isoflurane exposure to the young brain.
Benzene Diazonium Sulfonate Modified Nanoporous Gold Electrodes for the Direct Detection of Copper(II) Ions
Authors: Siepenkoetter Till , Mastin Hélène , Salaj‐Kosla Urszula , Magner Edmond 
Published: November 2020

AbstractThe detection of Cu2+on surface modified nanoporous gold in aqueous solution is reported. Nanoporous gold electrodes were prepared with a wide range of pore sizes by dealloying of sputtered gold–silver alloys in concentrated nitric acid. Varying the pore sizes can significantly improve the electroactive surface area of the electrodes as well as protect the surface from biofouling materials, both necessary for the direct detection of trace metals in untreated samples. Two surface modificationsi. e. a self‐assembled monolayer of 3‐mercapto‐1‐propanesulfonate and electro‐grafted benzene diazonium sulfonate were evaluated. Underpotential deposition of Cu2+and subsequent stripping of the deposited copper was achieved utilizing square wave voltammetry. The sensor was capable of accurately measuring Cu2+concentrations in a range of water samples (tap, rain and river water) without the necessity of prior pre‐treatment of the samples. The sensor had a linear range of 0.2 to 25 μM, which encompasses the accepted maximum limit for the concentration of copper in drinking water (20.5 μM). The sensitivity was 8.18 μA cm−2 μM−1with a limit of detection of 18.9 nM (∼1.2 ppb). The response of the sensor in artificial human serum was unaffected by the sample matrix, demonstrating the ability of the system to resist fouling by serum
The Effect of Cation Mixing in LiNiO2 toward the Oxygen Evolution Reaction
Authors: Ren Yadan , Yamaguchi Ryusei , Uchiyama Tomoki , Orikasa Yuki , Watanabe Toshiki , Yamamoto Kentaro , Matsunaga Toshiyuki , Nishiki Yoshinori , Mitsushima Shigenori , Uchimoto Yoshiharu 
Published: November 2020

AbstractNickel‐based oxide catalysts are widely used for the oxygen evolution reaction (OER) in alkaline water electrolysis because of their low cost and high activity. In particular, the LiNiO2 catalyst shows high activity. Therefore, to elucidate the fundamental relationship between the local structure, catalyst activity, and stability of LiNiO2, we investigated the cation mixing effect by mixing sites of lithium and nickel ions in the LiNiO2‐based catalysts. Lower degrees of cation mixing lead to higher intrinsic OER activity but lower long‐term stability. The X‐ray absorption spectra (XAS) displayed a strong hybridization state of the Ni 3d and O 2p orbitals, which is the origin of the different catalytic activity behaviors. Meanwhile, operando XAS studies combined with potentiostatic stability tests and inductively coupled plasma optical emission spectrometry (ICP‐OES) demonstrated the Li ion loss during the OER process. Thus, the instability of LiNiO2 originates from de‐intercalation of Li ions and this irreversible structure change deteriorates the performance. Hindering the lithium diffusion path by cation mixing is a useful strategy for maintaining performance. This strategy could provide a novel design principle for compatible high activity and long‐lasting catalysts by reasonable structure mediation.
Carbon‐based metal‐free catalysts for electrochemical CO2 reduction: Activity, selectivity, and stability
Authors: Masood ul Hasan Israr , Peng Luwei , Mao Jianfeng , He Ruinan , Wang Yongxia , Fu Jing , Xu Nengneng , Qiao Jinli 
Published: November 2020

AbstractZero or negative emissions of carbon dioxide (CO2) is the need of the times, as inexorable rising and alarming levels of CO2 in the atmosphere lead to global warming and severe climate change. The electrochemical CO2 reduction (eCO2R) to value‐added fuels and chemicals by using renewable electricity provides a cleaner and more sustainable route with economic benefits, in which the key is to develop clean and economical electrocatalysts. Carbon‐based catalyst materials possess desirable properties such as high offset potential for H2 evolution and chemical stability at the negative applied potential. Although it is still challenging to achieve highly efficient carbon‐based catalysts, considerable efforts have been devoted to overcoming the low selectivity, activity, and stability. Here, we summarize and discuss the recent progress in carbon‐based metal‐free catalysts including carbon nanotubes, carbon nanofibers, carbon nanoribbons, graphene, carbon nitride, and diamonds with an emphasis on their activity, product selectivity, and stability. In addition, the key challenges and future potential approaches for efficient eCO2R to low carbon‐based fuels are highlighted. For a good understanding of the whole history of the development of eCO2R, the CO2 reduction reactions, principles, and techniques including the role of electrolytes, electrochemical cell design and evaluation, product selectivity, and structural composition are also discussed. The metal/metal oxides decorated with carbon‐based electrocatalysts are also summarized. We aim to provide insights for further development of carbon‐based metal‐free electrocatalysts for CO2 reduction from the perspective of both fundamental understanding and technological applications in the future.
Synthesis of Tunable Syngas on Cobalt‐Based Catalysts towards Carbon Dioxide Reduction
Authors: Huang Mengke , Kong Xiangdong , Wang Cheng , Geng Zhigang , Zeng Jie , Bao Jun 
Published: November 2020

AbstractCO2 electroreduction, which coupled the application of renewable electricity, paved a promising way for syngas synthesis. Herein, we demonstrated that Co‐based N doped carbon prepared by a simple pyrolysis method provided an ideal platform to generate syngas with tunable ratios of H2 to CO. During CO2 electroreduction, Co‐based N doped carbon exhibited the highest faradaic efficiency (FE) of 56.3% for CO with a total current density of 10.8 mA cm−2 at −0.9 V versus reversible hydrogen electrode. Structural characterizations showed that the co‐existence of Co0 and Co2+ was responsible for the synthesis of tunable syngas. Notably, we obtained syngas with tunable ratios of H2 to CO ranging from ∼1 : 1 to 3 : 1 with the highest current density reaching 47.6 mA cm−2. This work provides a green way to produce syngas for further applications.
Innovative Protocols in the Catalytic Oxidation of 5‐Hydroxymethylfurfural
Authors: Su Ting , Zhao Deyang , Wang Yantao , Lü Hongying , Varma Rajender S. , Len Christophe 
Published: November 2020

Abstract5‐Hydroxymethylfurfural (HMF) has been identified as one of the most promising biomass‐based multi‐purpose platform molecules. Innovative protocols, namely electrocatalysis, photocatalysis, and microwave (MW)‐assisted chemistry, as well as continuous‐flow systems, add a new dimension and another promising toolbox for the oxidation of HMF in recent years. This Minireview deals with recent progress in the catalytic oxidation of HMF to 2,5‐furandicarboxylic acid (FDCA) and other intermediates using noble, non‐noble, and metal‐free systems deploying emerging protocols. Selective HMF downstream oxidation products could be obtained not only via common catalyst modifications, namely nature of the metal, preparative method, and the property of deployed support, but also by using innovative processes.
Adding the third dimension to studies of parallel evolution of morphology and function: An exploration based on parapatric lake‐stream stickleback
Authors: Haines Grant E. , Stuart Yoel E. , Hanson Dieta , Tasneem Tania , Bolnick Daniel I. , Larsson Hans C. E. , Hendry Andrew P. 
Published: November 2020

AbstractRecent methodological advances have led to a rapid expansion of evolutionary studies employing three‐dimensional landmark‐based geometric morphometrics (GM). GM methods generally enable researchers to capture and compare complex shape phenotypes, and to quantify their relationship to environmental gradients. However, some recent studies have shown that the common, inexpensive, and relatively rapid two‐dimensional GM methods can distort important information and produce misleading results because they cannot capture variation in the depth (Z) dimension. We use micro‐CT scanned threespine stickleback (Gasterosteus aculeatusLinnaeus, 1758) from six parapatric lake‐stream populations on Vancouver Island, British Columbia, to test whether the loss of the depth dimension in 2D GM studies results in misleading interpretations of parallel evolution. Using joint locations described with 2D or 3D landmarks, we compare results from separate 2D and 3D shape spaces, from a combined 2D‐3D shape space, and from estimates of biomechanical function. We show that, although shape is distorted enough in 2D projections to strongly influence the interpretation of morphological parallelism, estimates of biomechanical function are relatively robust to the loss of the Z dimension.
Similar mechanisms underlie beta diversity of bryophytes in two archipelagos with different isolation time
Authors: Liu Jinliang , Zheng Shilu , Tiwari Ravi Mohan , Liu Libin , Han Wenjuan , Liu Jiajia 
Published: November 2020

AbstractCommunity assembly of island plants is a central topic in island biogeography. Most previous studies have focused on seed plants, while our understanding of bryophytes is limited. Specifically, how dispersal limitation and habitat heterogeneity shape beta diversity of bryophyte communities on islands remains unknown. We used two datasets of bryophyte communities from an artificial (~60 yr of isolation) and natural archipelago (~8500 yr of isolation) to understand their beta diversity patterns. The null model, in which species could disperse randomly and colonize successfully between islands, but the number of species on each island and the frequency of each species occurrence across all islands remain unchanged, was used to calculate expected beta diversity. Although we found significant differences in species composition between the two archipelagos, the difference in observed beta diversity was negligible. Further, there was no significant difference between observed and expected beta diversity in each archipelago. The difference in island area, rather than isolation, was significantly correlated with the beta diversity of bryophytes in both archipelagos. Our results suggest that the dispersal limitation is not the major ecological process driving the assembly of bryophyte communities in both archipelagos, but the habitat heterogeneity related to island area determines the beta diversity of bryophytes.
Heracleum moellendorffii root extracts exert immunostimulatory activity through TLR2/4‐dependent MAPK activation in mouse macrophages, RAW264.7 cells
Authors: Son Ho Jun , Eo Hyun Ji , Park Gwang Hun , Jeong Jin Boo 
Published: November 2020

AbstractHeracleum moellendorffii (H. moellendorffii) is a family of Umbelliferae and has long been used for food and medicinal purposes. However, the immune‐enhancing activity of H. moellendorffii has not been studied. Thus, we evaluated in vitro immune‐enhancing activity of H. moellendorffii through macrophage activation using RAW264.7 cells. Heracleum moellendorffii Root extracts (HMR) increased the production of immunomodulators such as NO, iNOS, IL‐1β, IL‐6 IL‐12, TNF‐α, and MCP‐1 and activated phagocytosis in RAW264.7 cells. Inhibition of TLR2 and TLR4 reduced the production of immunomodulators induced by HMR. Inhibition of MAPK signaling attenuated the production of immunomodulators induced by HMR, but inhibitions of NF‐κB or PI3K/AKT signaling did not affect HMR‐mediated production of immunomodulators. HMR activated MAPK signaling pathway, and activation of MAPK signaling pathways by HMR was reversed by TLR2 and TLR4 inhibition. Based on the results of this study, HMR is thought to activate macrophages through the production of immunomodulators and phagocytosis activation through TLR2/4‐dependent MAPK signaling pathway. Therefore, it is thought that HMR has the potential to be used as an agent for enhancing immunity.