bluuebunny/crossref_metadata_2025 huggingface dataset:
Frontiers in Radical Fluoromethylation by Visible‐Light Organic Photocatalysis
Authors: Koike Takashi
Published: February 2020

Fluoromethyl groups, including tri‐, di‐, and mono‐fluoromethyl (CF3, CF2H, and CH2F, respectively) groups, are important structural motifs in medicinal chemistry. Radical fluoromethylation has attracted significant interest for the late‐stage functionalization of complex bioactive molecules. Recently, light energy has been used for radical reactions in synthesis of various valuable products. Strategies using organic photocatalysts (OPCs) are beneficial for synthetic radical chemistry and various aspects of “sustainable development goals (SDGs)”. Particularly, over the past several years, considerable progress has been made in the field of photoinduced radical fluoromethylation by OPCs. In this minireview, the concepts of representative reaction systems for fluoromethyl radical generation will be discussed.
Genomic Encryption of Digital Data Stored in Synthetic DNA
Authors: Grass Robert N. , Heckel Reinhard , Dessimoz Christophe , Stark Wendelin J.
Published: February 2020

Today, we can read human genomes and store digital data robustly in synthetic DNA. Herein, we report a strategy to intertwine these two technologies to enable the secure storage of valuable information in synthetic DNA, protected with personalized keys. We show that genetic short tandem repeats (STRs) contain sufficient entropy to generate strong encryption keys, and that only one technology, DNA sequencing, is required to simultaneously read the key and the data. Using this approach, we experimentally generated 80 bit strong keys from human DNA, and used such a key to encrypt 17 kB of digital information stored in synthetic DNA. Finally, the decrypted information was recovered perfectly from a single massively parallel sequencing run.
Perylene Bisimide and Naphthyl‐Based Molecular Dyads: Hydrogen Bonds Driving Co‐planarization and Anomalous Temperature‐Response Fluorescence
Authors: Shang Congdi , Wang Gang , Liu Ke , Jiang Qingwei , Liu Fengyi , Chou Pi‐Tai , Fang Yu
Published: February 2020

The origin of the positive temperature effect in fluorescence emission of a newly designed perylene bisimide (PBI) derivative with two naphthyl units containing ortho‐methoxy group (NM) at its bay positions (PBI‐2NM) was elucidated. A key point is the finding of a weak hydrogen bond (<5.0 kcal mol−1) between the methoxy group of the NM unit and a nearby hydrogen atom of the PBI core. It is the bonding that drives co‐planarization of the different aromatic units, resulting in delocalization of the π‐electrons of the compound as synthesized, inducing fluorescence quenching via intramolecular charge transfer (ICT). With increasing temperature, the co‐planar structure could be distorted in part, resulting in a decreased degree of ICT, and hence leading to enhanced fluorescence emission. The unique positive temperature effect in emission induced by H‐bond‐driven co‐planarization may pave a new avenue in designing functional molecular systems complementary to conventional methods.
Comparative analysis of model reduction strategies for circuit based periodic control problems
Authors: Hossain Mohammad‐Sahadet , Tahsin Aniqa , Omar Sufi Galib , Hossain Khan Ekram
Published: February 2020

This paper is a comparative analysis of two prominent iterative algorithms for model order reduction of linear time‐varying (LTV) periodic systems where the system's matrices are singular. Our proposed method is based on a reformulation of the LTV model to an equivalent linear time‐invariant (LTI) model using a suitable discretization procedure. The resulting LTI model is reduced in two ways, once by applying a balanced truncation method and once by applying a Krylov‐based method known as iterative rational Krylov algorithm (IRKA). During the application of balanced truncation, the low‐rank Cholesky factorized alternating directions implicit (LRCF‐ADI) method is used to estimate the solutions of the corresponding LTI form of Lyapunov equations. Since the system's matrices are singular, the concept of pseudo‐inverse is adopted to compute the shift parameters needed in the LRCF‐ADI iterations. For the Krylov‐based IRKA, our work is twofold. We solve the time‐invariant Lyapunov equation for the observability Gramian and apply a moment‐matching Krylov technique. The accuracy and effectiveness of the two proposed techniques are demonstrated with the help of frequency response graphs, bode plots, and eigenstructure of the main and reduced models.
Debating Eukaryogenesis—Part 1: Does Eukaryogenesis Presuppose Symbiosis Before Uptake?
Authors: Speijer Dave
Published: February 2020

Eukaryotic origins are heavily debated. The author as well as others have proposed that they are inextricably linked with the arrival of a pre‐mitochondrion of alphaproteobacterial‐like ancestry, in a so‐called symbiogenic scenario. The ensuing mutual adaptation of archaeal host and endosymbiont seems to have been a defining influence during the processes leading to the last eukaryotic common ancestor. An unresolved question in this scenario deals with the means by which the bacterium ends up inside. Older hypotheses revolve around the application of known antagonistic interactions, the bacterium being prey or parasite. Here, in reviewing the field, the author argues that such models share flaws, hence making them less likely, and that a “pre‐symbiotic stage” would have eased ongoing metabolic integration. Based on this the author will speculate about the nature of the (endo) symbiosis that started eukaryotic evolution–in the context of bacterial entry being a relatively “early” event–and stress the differences between this uptake and subsequent ones. He will also briefly discuss how the mutual adaptation following the merger progressed and how many eukaryotic hallmarks can be understood in light of coadaptation. Also see the video abstract here https://youtu.be/ekqtNleVJpU
Microbial β‐Galactosidases of industrial importance: Computational studies on the effects of point mutations on the lactose hydrolysis reaction
Authors: de Andrade Bruna C. , Timmers Luis F. S. M. , Renard Gaby , Volpato Giandra , de Souza Claucia F. V.
Published: February 2020

Hydrolysis efficiency of β‐galactosidases is affected due to a strong inhibition by galactose, hampering the complete lactose hydrolysis. One alternative to reduce this inhibition is to perform mutations in the enzyme's active site. The aim of this study was to evaluate the effect of point mutations on the active site of different microbial β‐galactosidases, using computational techniques. The enzymes of Aspergillus niger (AnβGal), Aspergillus oryzae (AoβGal), Bacillus circulans (BcβGal), Bifidobacterium bifidum (BbβGal), and Kluyveromyces lactis (KlβGal) were used. The mutations were carried out in all residues that were up to 4.5 Å from the galactose/lactose molecules and binding energy was computed. The mutants Tyr96Ala (AnβGal), Asn140Ala and Asn199Ala (AoβGal), Arg111Ala and Glu355Ala (BcβGal), Arg122Ala and Phe358Ala (BbβGal), Tyr523Ala, Phe620Ala, and Trp582Ala (KlβGal) had the best results, with higher effect on galactose binding energy and lower effect on lactose affinity. To maximize enzyme reactions by reducing galactose affinity, double mutations were proposed for BcβGal, BbβGal, and KlβGal. The double mutations in BcβGal and BbβGal caused the highest reduction in galactose affinity, while no satisfactory results were observed to KlβGal. Using computational tools, mutants that reduced galactose affinity without significantly affecting lactose binding were proposed. The mutations proposed can be used to reduce the negative feedback process, improving the catalytic characteristics of β‐galactosidases and rendering them promising for industrial applications.
Activation of C−H Bond of Propane by Strong Basic Sites Generated by Bulk Proton Conduction on V‐Modified Hydroxyapatites for the Formation of Propene.
Authors: Petit Sarah , Thomas Cyril , Millot Yannick , Krafft Jean‐Marc , Laberty‐Robert Christel , Costentin Guylène
Published: February 2020

Insights into the catalytic transformation of propane to propene on V‐apatite catalysts are provided based on structure‐reactivity relationships. Substitution of phosphates by vanadates in the hydroxyapatite structure leads to the formation of Ca10(PO4)6‐x(VO4)x(OH)2‐yOy V‐oxy‐hydroxy‐apatite solid solutions (x=0→6). Bulk vanadium incorporation promotes (i) calcium rich terminations (XPS, CO adsorption), (ii) proton deficiency inside the OH− channels (1H NMR) giving rise to O2− native species, (iii) the thermally‐activated formation of additional O2− species along the OH− channels resulting in H‐bonding interaction (in situ DRIFT) and (iv) the proton conduction process that eventually results in the surface exposure of O2− species (in situ impedance spectroscopy). The exposure of Ca2+−O2− surface acid‐base pairs allows the dissociation of hydrogen, emphasizing the strong basicity of the related O2− species. Whereas an increasing vanadium content is beneficial to propene selectivity, it scarcely impacts propane conversion. The reaction proceeds mainly upon oxidative dehydrogenation, even if the minor dehydrogenation route is also observed. Surface O2− generated thanks to proton mobility are involved in the C−H bond activation, as shown by the synergistic effect between the oxidative dehydrogenation of propane reaction and the bulk proton conduction measured under operando conditions. This puts emphasis on the key role of strong basic sites for propane activation.
Design of hierarchical, three‐dimensional free‐standing single‐atom electrode for H2O2 production in acidic media
Authors: Zhang Jincheng , Yang Hongbin , Gao Jiajian , Xi Shibo , Cai Weizheng , Zhang Junming , Cui Ping , Liu Bin
Published: February 2020

Electrochemical reduction of molecular O2 to hydrogen peroxide (H2O2) offers a promising solution for water purification and environmental remediation. Here, we design a hierarchical free‐standing single‐Co‐atom (with Co–N4 coordination) electrode for oxygen reduction reaction (ORR) via a two‐electron pathway to make H2O2 in acidic media. The current density of the single‐Co‐atom electrode reached 51 mA/cm2 at 0.1 V vs reversible hydrogen electrode, lasting for more than 10 hours of continuous operation with H2O2 selectivity greater than 80%. Toward practical application, the single‐Co‐atom electrode was directly used to assemble an electrochemical cell to produce H2O2 at a rate of 676 mol/kgcat/h with a cell voltage of about 1.6 V.
Synthetic Ellagic Acid Glycosides Inhibit Early Stage Adhesion of Streptococcus agalactiae Biofilms as Observed by Scanning Electron Microscopy
Authors: Chambers Schuyler A. , Gaddy Jennifer A. , Townsend Steven D.
Published: February 2020

Ellagic acid derivatives possess antimicrobial and antibiofilm properties across a wide‐range of microbial pathogens. Due to their poor solubility and ambident reactivity it is challenging to synthesize, purify, and characterize the activity of ellagic acid glycosides. In this study, we have synthesized three ellagic acid glycoconjugates and evaluated their antimicrobial and antibiofilm activity in Streptococcus agalactiae (Group B Streptococcus, GBS). Their significant impacts on biofilm formation were examined via SEM to reveal early‐stage inhibition of cellular adhesion. Additionally, the synthetic glycosides were evaluated against five of the six ESKAPE pathogens and two fungal pathogens. These studies reveal that the ellagic acid glycosides possess inhibitory effects on the growth of gram‐negative pathogens.
3D‐Structured Monoliths of Nanoporous Polymers by Additive Manufacturing
Authors: Hock Sebastian , Rose Marcus
Published: February 2020

Recent advances in 3D printing provide great opportunities for the utilization of functional materials in chemical engineering and heterogeneous catalysis. In this work cylindrical monoliths with varying geometries of transport channels are designed and printed by a fused deposition modeling (FDM) 3D printer from thermoplastic polymers. Their hydrodynamic characteristics are investigated. For a proof of concept composite monoliths of microporous hyper‐crosslinked polymers (HCP) are printed. They contain up to 40 wt % of HCP with an accessible specific surface area of up to 171 m2g−1.
Heterogeneous Photocatalysis in Organic Synthesis
Authors: Gisbertz Sebastian , Pieber Bartholomäus
Published: February 2020

Visible light photocatalysis relies mainly on expensive noble metal complexes and organic dyes that are not recyclable. Heterogeneous semiconductors, which are mainly applied for artificial photosynthesis and wastewater treatment, are a promising sustainable alternative and gain increasing attention. Inorganic and organic semiconductors with suitable bandgaps are among the most widely studied heterogeneous photocatalysts due to their high stability and recyclability. More recently, microporous materials, such as conjugated organic polymers, covalent organic frameworks, and metal organic frameworks that can be tuned and designed on a molecular level showed promising results. This review provides an overview of the most common heterogeneous photocatalysts with a focus on their applicability in organic synthesis.
Saltwater intrusion affects nutrient concentrations in soil porewater and surface waters of coastal habitats
Authors: Weissman Danielle S. , Tully Katherine L.
Published: February 2020

Coastal ecosystems are undergoing major biogeochemical shifts due to climate change and sea level rise. At the same time, agricultural fertilizer applications are increasing coastal nutrient inputs. In this study, we examine the potential impact of saltwater intrusion (SWI) on nitrogen (N) and phosphorus (P) concentrations in soil porewater and surface water of different habitats within the Chesapeake Bay estuary. Study sites are located along Maryland's Lower Eastern Shore and were monitored over three summers from 2016 to 2018. These sites encompass various habitats on the land–sea interface, consisting of healthy forests, intruded forests, abandoned fields, intruded fields, agricultural ditches, tidal creeks, and tidal salt marshes. Intruded fields were being actively farmed at the time of the study. Soil porewater and surface water grab samples were collected from the habitats and analyzed for electrical conductivity, pH, dissolved organic P (DOP), dissolved inorganic P in the form of soluble reactive P (SRP), dissolved inorganic N as ammonium‐N (NH4‐N), and total dissolved iron (TDFe). Electrical conductivity was greatest in the marshes (16.58 mS/cm averaged across all years) and did not significantly differ among intruded forests, intruded fields, and agricultural ditches. As a legacy of heavy fertilizer use, DOP concentrations exceeded 0.45 mg P/L in all habitats. Concentrations of inorganic N and P differed significantly by habitat. Concentrations of NH4‐N were significantly higher in salt marsh soil porewater than in any other habitat measured. Overall, SRP concentrations were the highest in the soil porewater of intruded fields and marshes and in the surface water of agricultural ditches (0.30, 0.29, and 0.33 mg P/L averaged across all years, respectively). These concentrations greatly exceeded recommended U.S. Environmental Protection Agency nutrient pollution thresholds for the region. In its oxidized state, dissolved iron can bind to SRP and prevent it from becoming bioavailable. However, TDFe concentrations in the ditches, tidal creeks, and marshes were too low to adequately buffer against SRP loss to downstream areas. As SWI moves salts inland and increases hydrologic connectivity across coastal landscapes, it is important to consider the mechanisms through which nutrients may be released from coastal soils and their potential to impact downstream water quality.
Variation in individual reproductive performance amplified with population size in a long‐lived carnivore
Authors: Badger Janelle J. , Bowen W. Don , den Heyer Cornelia E. , Breed Greg A.
Published: February 2020

Individual variation in reproductive ability is a key component of natural selection within populations, driving the evolution of life histories and population responses to changing environmental conditions. Evidence that population density affects individual‐level fitness in wild populations is limited, particularly for long‐lived animals, which are difficult to observe on a biologically relevant scale. We tested for individual heterogeneity in reproductive performance in female grey seals (Halichoerus grypus) using 35 yr of mark–resighting data at Sable Island, Canada (43.93° N 59.91° W). We used Bayesian generalized linear mixed‐effect models and multistate open robust design mark–resight models to investigate whether population size negatively influences individual reproductive performance. We measured reproductive performance in two ways: reproductive frequency (the probability of returning to the island to breed) and annual provisioning performance (the probability of successfully weaning a pup given a female bred). Sighting histories of 1,655 known‐aged females with a total of 22,961 pupping events were used for analysis. After accounting for effects of female age, parity, and random year effects, we found that both provisioning performance and reproductive frequency demonstrated a strong, positive correlation with population size. Among‐individual variance in reproductive traits and responses to population size indicated considerable heterogeneity in overall reproductive performance. As population size grew, “robust” females increased their reproductive performance more than their more “frail” conspecifics in both reproductive traits, resulting in an amplification of differences among individuals. Consequently, simulations from posterior distributions revealed a large fitness consequence of heterogeneity in this population, with “frail” individuals having 47.1% fewer successful pups than more “robust” females (mean reproductive output ± SD: 9.12 ± 3.77 pups for frail individuals, 16.97 ± 2.94 for robust individuals). Repeatability of overall reproductive performance across environments indicates individual quality may be more influential to lifetime reproductive success than costs associated with reproductive investment. This quantification of relative fitness and its dynamics is crucial to understanding broad evolutionary processes in natural populations.
Evaluating Metal Ion Identity on Catalytic Silylation of Dinitrogen Using a Series of Trimetallic Complexes
Authors: Eaton Mary C. , Knight Brian J. , Catalano Vincent J. , Murray Leslie J.
Published: February 2020

We report catalytic silylation of dinitrogen to tris(trimethylsilyl)amine by a series of trinuclear first row transition metal complexes (M = Cr, Mn, Fe, Co, Ni) housed in our tris(β‐diketiminate) cyclophane (L3–). Yields are expectedly dependent on metal ion type ranging from 14 to 199 equiv. NH4+/complex after protonolysis for the Mn to Co congeners, respectively. For the series of complexes, the observed trend for the number of turnovers as a function of metal ion type is Co > Fe > Cr > Ni > Mn, consistent with prior reports of greater efficacy of Co over Fe in other ligand systems for this reaction.
Thermal and Light‐Activated Spin Crossover in Iron(III) qnal Complexes
Authors: Thammasangwan Warisa , Harding Phimphaka , Telfer Shane G. , Alkaş Adil , Phonsri Wasinee , Murray Keith S. , Clérac Rodolphe , Rouzières Mathieu , Chastanet Guillaume , Harding David J.
Published: February 2020

Three iron(III) complexes, [Fe(qnal)2]Y {qnal = 1‐[(8‐quinolinylimino)methyl]‐2‐naphthalenolate; Y = NO3 1, BPh4·CH2Cl2 2, NCS 3} have been prepared to explore anion effects in spin crossover systems. Structural studies on 2 reveal supramolecular chains formed by π–π and C–H···π interactions between the [Fe(qnal)2]+ cations. Magnetic susceptibility measurements show the onset of spin crossover in 1 above 200 K, while complete spin crossover is observed in 2 and 3 with T1/2 = 285 and 340 K, respectively. Unusually, 2 also undergoes light‐induced excited spin state trapping (LIESST) at 980 nm with ca. 65 % efficiency and T(LIESST) = 25 K and reverse‐LIESST at 660 nm with full reversibility over many cycles. The results highlight the important influence that the anion has on thermal and light‐activated spin crossover properties.
Catalytic Electrosynthesis of N,O‐Heterocycles – Recent Advances
Authors: Listratova Anna V. , Sbei Najoua , Voskressensky Leonid G.
Published: February 2020

Recognized as gentler and more environmentally friendly compared to conventional methods, catalytic electrochemical reactions are a powerful tool for constructing heterocycles. Of special interest is indirect electrolysis, where the use of a redox mediator provides an additional means of reaction control, thus avoiding over‐oxidation and facilitating improved selectivity. This minireview describes recent advances in catalytic electrochemical reactions for synthesizing N,O‐heterocycles that appeared from 2018 until September 2019.
A Chemoselective and Desulfurative Chan–Lam Coupling: C–N Bond Formation between Benzimidazoline‐2‐Thiones and Arylboronic Acids
Authors: Chen Jin‐Quan , Liu Xing , Guo Jia , Dong Zhi‐Bing
Published: February 2020

An efficient method for the chemoselective and desulfurative Chan–Lam cross‐coupling based on benzimidazoline‐2‐thiones was developed. By modulating the amount of the catalyst Cu(OAc)2·H2O, alkali, temperature, and solvent, the desulfurizational C–N bond formation product (N‐arylbenzimidazoles) could be selectively furnished smoothly. The features of this protocol are an inexpensive and readily available catalyst, ligand‐free conditions, wide substrate scope, easy performance, and moderate to excellent yields. It shows potential synthetic value for the preparation of a diversity of arylbenzoheterocyclic compounds, which are potentially active in pharmaceuticals and agrochemicals.
Pyridine‐ and Quinoline‐Based Gold(III) Complexes: Synthesis, Characterization, and Application
Authors: Reiersølmoen Ann Christin , Fiksdahl Anne
Published: February 2020

Studies on gold(III) coordination of a series of prepared polydentate pyridine and quinoline based ligands are reported. Characterization (1H, 13C, 15N NMR, and XRD) of the novel gold(III) complexes, prepared in 31–98 % yield, revealed different coordination ability of the pyridine and quinoline nitrogen atoms. Testing of catalytic activity in cyclopropanation of propargyl ester and styrene demonstrated that all the new ligated gold(III) complexes were catalytically active and outperformed KAuCl4. The superior activity of the particular Au(III)‐pyridine‐oxazole complexes may indicate de‐coordination of the pyridine‐N ligand as a crucial step for efficient generation of catalytic activity.
Ag−Co3O4 @ Nr GO Material Synthesized by One‐pot Hydrothermal Method for Carcinoembryonic Antigen (CEA) Detection of Enzyme‐mimetic Electrochemical Immunosensor
Authors: Wu M. , Zhao C. L. , Yang Y. X. , Cao K. H. , Qiao X. W. , Hong C. L.
Published: February 2020

A high‐sensitivity carcinoembryonic antigen immunosensor was successfully prepared via a one‐step hydrothermal method, wherein nitrogen‐doped graphene oxide (Nr GO) loaded Ag and Co3O4 nanomaterials were synthesized using ammonia as the nitrogen source. Doping nitrogen atoms into the graphene structure forms a new type of N‐type semiconductor with an increased number of graphene layers and more active sites for bonding with chemicals, thereby providing excellent in biocompatibility and good electrical conductivity. The electrical signal of the sensor is further amplified due to the good catalytic effect of Co3O4 and Ag NPs on H2O2. The signal probe requires neither pretreatment nor acid treatment, and can be easy to loaded with metal‐immobilized antibodies, which greatly simplifies the detection step not shorten the detection time. The sensor has good sensitivity to detecting carcinoembryonic antigen (CEA) and can easily operate, and requires mild reaction conditions. Under optimal experimental conditions, the linear range of the sensor is 0.001–200 ng ⋅ mL−1, the detection limit is 0.18 pg ⋅ mL−1, and the linear correlation coefficient is 0.991, which can be used for CEA determination of the actual sample.
Inflammation‐Induced Long Intergenic Noncoding RNA (LINC00665) Increases Malignancy Through Activating the Double‐Stranded RNA–Activated Protein Kinase/Nuclear Factor Kappa B Pathway in Hepatocellular Carcinoma
Authors: Ding Jie , Zhao Jingjing , Huan Lin , Liu Yizhe , Qiao Yejun , Wang Zhen , Chen Zhiao , Huang Shenglin , Zhao Yingjun , He Xianghuo
Published: February 2020

Background and Aims

The nuclear factor kappa B (NF‐κB) signaling pathway is important for linking inflammation and tumorigenesis. Here, we characterized an NF‐κB signaling activation–induced long intergenic noncoding (LINC) RNA in hepatocellular carcinoma (HCC), LINC00665, that contributes to the enhanced cell proliferation of HCC cells both in vitro and in vivo.

Approach and Results

LINC00665 physically interacts with the double‐stranded RNA (dsRNA)‐activated protein kinase (PKR), enhances its activation, and maintains its protein stability by blocking ubiquitin/proteasome‐dependent degradation, resulting in a positive feedback regulation of NF‐κB signaling in HCC cells. Notably, patients with HCC and higher LINC00665 have poorer outcomes in the clinic.

Conclusions

Our findings indicate that LINC00665 is involved in the NF‐κB signaling activation in HCC cells and that the inflammatory LINC00665/PKR/NF‐κB loop plays important oncogenic roles in hepatic cancer progression and may be a potential therapeutic target.
The protective effect of EGF‐activated ROS in human corneal epithelial cells by inducing mitochondrial autophagy via activation TRPM2
Authors: Huo Yanan , Chen Wei , Zheng Xiaoxiao , Zhao Jinchuan , Zhang Qi , Hou Yuerou , Cai Ying , Lu Xuemei , Jin Xiuming
Published: February 2020

Oxidative stress is a major pathogenesis of some ocular surface diseases. Our previous study demonstrated that epidermal growth factor (EGF)‐activated reactive oxygen species (ROS) could protect against human corneal epithelial cell (HCE) injury. In the present study, we aimed to explore the role and mechanisms of oxidative stress and mitochondrial autophagy in HCE cells subjected to scratch injury. CCK‐8 assays, EdU assays, Western blot analysis, wound‐healing assays, and flow cytometry were conducted to determine cell viability, proliferation, protein expression, cell apoptosis, and intracellular ROS levels, respectively. The results showed that EGF could promote damage repair and inhibit cell apoptosis in scratch injured HCE cells by upregulating ROS (**p < .01, ***p < .001). EGF also induced mitochondrial autophagy and alleviated mitochondrial damage. Interestingly, the combination of the mitochondrial autophagy inhibitor and mitochondrial division inhibitor 1 (MDIVI‐1) with EGF could reduce cell proliferation, viability, and the ROS level (*p < .05, **p < .01, ***p < .001). Treatment using the ROS inhibitor N‐acetyl‐
l‐cysteine abrogated the increase in mitochondrial membrane potential after EGF treatment. (*p < .05). Taken together, these findings indicated that EGF plays an important role in HCE damage repair and could activate ROS to protect against HCE injury by inducing mitochondrial autophagy via activation of TRPM2.
High efficiency enzymatic synthesis of triglycerides with varying chain length and degree of unsaturation in a solvent‐free system under vacuum
Authors: Bi Yanlan , Chen Jiali , Liu Taiyu , Yang Guolong , Zhang Lu
Published: February 2020

BACKGROUND

Triglycerides with varying chain length and unsaturation degree are now in high demand in the food and pharmaceutical industries. Enzymatic catalyzed synthesis methods are favored over chemical‐based processes in the commercial production of triglycerides. This study found that the application of vacuum can improve the efficiency and productivity of enzymatic synthesis of various triglycerides using Novozym 435 (EC 3.1.1.3), an immobilized lipase B from Candida antarctica. The system was used for esterification of fatty acids varying in chain length, unsaturation degree, and oxidation degree.

RESULTS

The vacuum condition was not applicable to short chain fatty acids (C4–C6) due to loss of fatty acids in the reaction. The conversions of C4–C6 saturated fatty acids were low (15–35%) under atmospheric pressure. Under vacuum, high conversions (>95%) and triglyceride yields (approximately 90%) were achieved in the esterification of glycerol with several medium‐chain and long‐chain (C8–C18) saturated fatty acids. Moreover, unsaturation degree of fatty acids also affected the triglyceride yield. The triglyceride contents synthesized from C18:2n‐6 (76.17 ± 0.45%) was significantly lower (P < 0.05) than those from C18:0 (91.59 ± 1.58%) and C18:1n‐9 (90.77 ± 0.85%). Furthermore, fatty acids with a high oxidation degree had negative effect on triglyceride synthesis. This vacuum solvent free system allowed the synthesis enzyme to be reused 11 times without significant decrease in the lipase activity for esterification of fatty acids.

CONCLUSION

The studied vacuum facilitated triglyceride synthesis process provides an economically attractive yet sustainable solution for the production of a wide range of triglyceride products. © 2020 Society of Chemical Industry
Geomorphological and seismostratigraphic evidence for multidirectional polyphase glaciation of the northern Celtic Sea
Authors: Tóth Zsuzsanna , McCarron Stephen , Wheeler Andrew J. , Wenau Stefan , Davis Stephen , Lim Aaron , Spiess Volkhard
Published: February 2020

High‐resolution seismic and bathymetric data offshore southeast Ireland and LIDaR data in County Waterford are presented that partially overlap previous studies. The observed Quaternary stratigraphic succession offshore southeast Ireland (between Dungarvan and Kilmore Quay) records a sequence of depositional and erosional events that supports regional glacial models derived from nearby coastal sediment stratigraphies and landforms. A regionally widespread, acoustically massive facies interpreted as the ‘Irish Sea Till’ infills an uneven, channelized bedrock surface overlying irregular mounds and deposits in bedrock lows that are probably earlier Pleistocene diamicts. The till is truncated and overlain by a thin, stratified facies, suggesting the development of a regional palaeolake following ice recession of the Irish Sea Ice Stream. A north–south oriented seabed ridge to the north is interpreted as an esker, representing southward flowing subglacial drainage associated with a restricted ice sheet advance of the Irish Ice Sheet onto the Celtic Sea shelf. Onshore topographic data reveal streamlined bedforms that corroborate a southerly advance of ice onto the shelf across County Waterford. The combined evidence supports previous palaeoglaciological models. Significantly, for the first time, this study defines a southern limit for a Late Midlandian Irish Ice Sheet advance onto the Celtic Sea shelf. © 2020 John Wiley & Sons, Ltd.
Changes in volatile flavor compounds of peppers during hot air drying process based on headspace‐gas chromatography‐ion mobility spectrometry (HS‐GC‐IMS)
Authors: Ge Shuai , Chen Yuyu , Ding Shenghua , Zhou Hui , Jiang Liwen , Yi Youjin , Deng Fangming , Wang Rongrong
Published: February 2020

BACKGROUND

Flavor plays a critical role in defining sensory and consumer acceptance of dried pepper, and it can be affected by temperature and moisture content during hot air drying (HAD). Thus, headspace‐gas chromatography‐ion mobility spectrometry (HS‐GC‐IMS) was used to analyze changes in volatile compounds of pepper during the HAD process with different drying temperatures.

RESULTS

A total of 45 volatile flavor compounds were identified, including 11 esters, 11 aldehydes, nine alcohols, five ketones, three furans, three acids, two pyrazines, and one ether. The results showed that with the loss of moisture during drying, aldehydes and alcohols decreased, esters initially increased and then decreased. However, propyl acetate, 2,3‐butanediol, 2‐acetylfuran, and 2‐methylpyrazine increased. Moreover, drying temperature was closely related to the change of volatile flavor compounds. Aldehydes, alcohols, and some other volatile flavor compounds (methyl salicylate, ethyl acetate, 2‐methylpyrazine, dipropyl disulfide) decreased with an increase of temperature (60–80 °C) at the same moisture content, while high temperature could promote the formation of ethyl octanoate, methyl octanoate, benzaldehyde, furfurol, acetal, 5‐methylfurfural, and 2‐acetylfuran. Based on principal components analysis and heat map clustering analysis, peppers dried at 70 or 80 °C presented similar composition, and the loss of volatile flavor compounds was more than samples died at 60 °C during the HAD process.

CONCLUSION

Overall, the flavor quality of peppers dried at 60 °C was better than that of other treatments during the HAD process. HS‐GC‐IMS was a reliable and effective means of analyzing volatile flavor compounds in peppers during the drying process. © 2020 Society of Chemical Industry
Species‐Habitat Relationships and Priority Areas for Marsh‐Breeding Birds in Ontario
Authors: Tozer Douglas C. , Stewart Rebecca L. M. , Steele Owen , Gloutney Mark
Published: February 2020

Populations of marsh‐breeding birds have declined throughout the southern Laurentian Great Lakes basin. To advance conservation of these species, we used occupancy modeling, a regional prioritization scheme, and data from Birds Canada's Great Lakes Marsh Monitoring Program (2016–2018) to describe species‐habitat relationships and identify priority habitat areas for 7 obligate marsh‐breeding bird species in southern Ontario, Canada: American bittern (Botaurus lentiginosus), common gallinule (Gallinula galeata), least bittern (Ixobrychus exilis), marsh wren (Cistothorus palustris), pied‐billed grebe (Podilymbus podiceps), sora (Porzana carolina), and Virginia rail (Rallus limicola). Given these species respond to land cover at widely varying spatial scales, we initially identified the most informative scale (buffer = 100 m, 200 m, 400 m, 800 m, 1,600 m, 3,200 m, or 6,400 m) for marsh, urban, agricultural, and forest cover to increase model performance. We also considered climate variables, whether sample sites were along a Great Lakes coastline or inland, and covariates influencing detection. Occupancy was best explained by land cover at a wide range of spatial scales depending on the species. All species except Virginia rail responded positively to marsh cover; American bittern and Virginia rail responded negatively to urban cover; least bittern, pied‐billed grebe, and Virginia rail responded negatively and sora responded positively to agricultural cover; and American bittern, common gallinule, marsh wren, and pied‐billed grebe responded negatively and Virginia rail responded positively to forest cover. Only American bittern responded negatively to mean May–June temperature; only pied‐billed grebe responded positively to start of growing season; and only Virginia rail had higher occupancy at inland marshes compared to coastal. We combined predictions from the best model for each of 5 species with reasonably good model fit (we excluded sora and Virginia rail) to identify priority habitat areas for marsh‐breeding birds. Expansion of wetland conservation work from existing priority areas based on waterfowl to also include these new additional priority areas based on marsh‐breeding birds will be an important step towards conservation of all birds, and will help slow or maybe even reverse declining population trends. Some restoration activities outside but adjacent to priority areas will also be important for rebuilding marshes for these species across this intensively farmed and developed region. © 2020 The Wildlife Society.
The promise of immunotherapy in the treatment of young adults with oral tongue cancer
Authors: Nasser Hassan , St. John Maie A.
Published: February 2020

Historically considered a disease of the older male resulting from cumulative tobacco and alcohol use, more recently we have witnessed a rise in the global incidence of oral tongue squamous cell carcinoma in younger adults, particularly those without any identifiable risk factor exposure. These patients appear to be at higher overall risk for locoregional treatment failure and often experience a more heterogeneous clinical course, with some afflicted with particularly aggressive, rapidly progressive disease. Recent research efforts have supported the idea that although this disease may be genomically similar in these groups, and molecular differences in the tumor immune microenvironment may account for biological differences between young and older patients, as well as patients with and without exposure to alcohol or tobacco. In this review, we seek to summarize current knowledge regarding pathogenesis of oral tongue carcinoma in the young adult patient and examine the potential role of the immune response in disease progression and as a target for novel immunotherapies.
Transposon mutagenesis in Mycobacterium kansasii links a small RNA gene to colony morphology and biofilm formation and identifies 9,885 intragenic insertions that do not compromise colony outgrowth
Authors: Budell William C. , Germain Gabrielle A. , Janisch Niklas , McKie‐Krisberg Zaid , Jayaprakash Anitha D. , Resnick Andrew E. , Quadri Luis E. N.
Published: February 2020

Mycobacterium kansasii (Mk) is a resilient opportunistic human pathogen that causes tuberculosis‐like chronic pulmonary disease and mortality stemming from comorbidities and treatment failure. The standard treatment of Mk infections requires costly, long‐term, multidrug courses with adverse side effects. The emergence of drug‐resistant isolates further complicates the already challenging drug therapy regimens and threatens to compromise the future control of Mk infections. Despite the increasingly recognized global burden of Mk infections, the biology of this opportunistic pathogen remains essentially unexplored. In particular, studies reporting gene function or generation of defined mutants are scarce. Moreover, no transposon (Tn) mutagenesis tool has been validated for use in Mk, a situation limiting the repertoire of genetic approaches available to accelerate the dissection of gene function and the generation of gene knockout mutants in this poorly characterized pathogen. In this study, we validated the functionality of a powerful Tn mutagenesis tool in Mk and used this tool in conjunction with a forward genetic screen to establish a previously unrecognized role of a conserved mycobacterial small RNA gene of unknown function in colony morphology features and biofilm formation. We also combined Tn mutagenesis with next‐generation sequencing to identify 12,071 Tn insertions that do not compromise viability in vitro. Finally, we demonstrated the susceptibility of the Galleria mellonella larva to Mk, setting the stage for further exploration of this simple and economical infection model system to the study of this pathogen.
Growth in the High‐Risk Newborn Infant Post‐Discharge: Results from a Neonatal Intensive Care Unit Nutrition Follow‐up Clinic
Authors: Zhang Xiaoyi , Donnelly Brynn , Thomas Jessina , Sams Lauren , O'Brien Karen , Taylor Sarah N. , Jump Candi S.
Published: February 2020

Growth and nutrition in preterm infants have long‐term implications for neurodevelopmental and cardiometabolic outcomes. Many infants are discharged from the neonatal intensive care unit (NICU) with growth restriction, but often without a specialized team to monitor postdischarge growth. At our institution, we addressed our ongoing concerns for the health and growth of these infants post‐discharge by creating a Nutrition NICU Graduate Clinic. This clinic serves infants discharged from our NICU who were born with very low birth weight, had difficulty growing or feeding while inpatient, had a gastrostomy tube placed during hospitalization, or were deemed high risk for other reasons by our neonatal team, with the first clinic visit within 5 weeks of discharge. Data from our first 227 patients at time of discharge, first clinic visit, and any available second clinic visits are described. Anthropometrics show a high rate of extrauterine growth restriction at time of discharge with continued growth restriction at follow‐up. Feeding regimens prescribed at discharge and variations from the prescribed regimen at time of follow‐up are described. At time of first clinic visit, most patients (92.2%) required a medical or dietary intervention by our team. Our findings illustrate the need for early and specialized nutrition follow‐up in this patient population to improve growth trajectory post‐discharge.
An asymmetric information mean‐field type linear‐quadratic stochastic Stackelberg differential game with one leader and two followers
Authors: Wang Guangchen , Wang Yu , Zhang Susu
Published: February 2020

This paper is concerned with an asymmetric information linear‐quadratic (AILQ) stochastic Stackelberg differential game with one leader and two followers, where the game system is governed by mean‐field type stochastic differential equation (MF‐SDE). With the help of two systems of Riccati equations, the followers solve a MF‐type stochastic LQ game problem with partial information first, and then, the leader turns to address an optimal control problem driven by linear MF‐type forward‐backward stochastic differential filtering equation (MF‐FBSDFE). By maximum principle, direct construction method and optimal filtering, the open‐loop Stackelberg solution is expressed as a feedback form of state, state estimation, and state mean.
Critical role for iron accumulation in the pathogenesis of fibrotic lung disease
Authors: Ali Md Khadem , Kim Richard Y , Brown Alexandra C , Donovan Chantal , Vanka Kanth S , Mayall Jemma R , Liu Gang , Pillar Amber L , Jones‐Freeman Bernadette , Xenaki Dikaia , Borghuis Theo , Karim Rafia , Pinkerton James W , Aryal Ritambhara , Heidari Moones , Martin Kristy L , Burgess Janette K , Oliver Brian G , Trinder Debbie , Johnstone Daniel M , Milward Elizabeth A , Hansbro Philip M , Horvat Jay C
Published: February 2020

Increased iron levels and dysregulated iron homeostasis, or both, occur in several lung diseases. Here, the effects of iron accumulation on the pathogenesis of pulmonary fibrosis and associated lung function decline was investigated using a combination of murine models of iron overload and bleomycin‐induced pulmonary fibrosis, primary human lung fibroblasts treated with iron, and histological samples from patients with or without idiopathic pulmonary fibrosis (IPF). Iron levels are significantly increased in iron overloaded transferrin receptor 2 (Tfr2) mutant mice and homeostatic iron regulator (Hfe) gene–deficient mice and this is associated with increases in airway fibrosis and reduced lung function. Furthermore, fibrosis and lung function decline are associated with pulmonary iron accumulation in bleomycin‐induced pulmonary fibrosis. In addition, we show that iron accumulation is increased in lung sections from patients with IPF and that human lung fibroblasts show greater proliferation and cytokine and extracellular matrix responses when exposed to increased iron levels. Significantly, we show that intranasal treatment with the iron chelator, deferoxamine (DFO), from the time when pulmonary iron levels accumulate, prevents airway fibrosis and decline in lung function in experimental pulmonary fibrosis. Pulmonary fibrosis is associated with an increase in Tfr1+ macrophages that display altered phenotype in disease, and DFO treatment modified the abundance of these cells. These experimental and clinical data demonstrate that increased accumulation of pulmonary iron plays a key role in the pathogenesis of pulmonary fibrosis and lung function decline. Furthermore, these data highlight the potential for the therapeutic targeting of increased pulmonary iron in the treatment of fibrotic lung diseases such as IPF. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Simulation of heat–water–mechanics process in a freezing soil under stepwise freezing
Authors: Bai Ruiqiang , Lai Yuanming , You Zhemin , Ren Jingge
Published: February 2020

Frost heave is a process coupling heat transfer, water migration, water–ice phase change and deformation. Frost heave forms various landforms, such as frost mounds, ice pitons, sorted polygons and stone circles, and potentially induces a variety of engineering failures, such as building inclination, differential engineering foundation and pavement cracking. To understand the mechanism of frost heave under complex freezing paths, we provide a numerical heat–water–mechanics model that incorporates shrinkage in an unfrozen zone and uses a water content criterion to judge the formation of the ice lens. The model is then used to simulate the moisture, temperature, deformation and ice lens of a freezing soil during stepwise freezing. The simulated results for temperature, displacement and the ice lens are in good agreement with measured data, indicating that the model can be used to describe the heat–water–mechanics process in freezing soils under a complex freezing path. The freezing path determines the soil's water content profile in a manner like that in a stepwise freezing process, where each step produces a water‐content peak at the frozen fringe of the step. The model must consider shrinkage of the unfrozen area, or the amount of frost heave would be overestimated and the predicted ice lens would unrealistically be found in the frozen zone.
Investigating the slope failures at the Lou rock glacier front, French Alps
Authors: Marcer Marco , Ringsø Nielsen Steffen , Ribeyre Charles , Kummert Mario , Duvillard Pierre‐Allain , Schoeneich Philippe , Bodin Xavier , Genuite Kim
Published: February 2020

On August 14
2015 a large debris flow initiated by the occurrence of two slope failures at the front of the Lou rock glacier flooded part of the town of Lanslevillard, France. The present study aims to understand the meteorological and geomorphological context that led to these failures. Investigations were conducted by combining meteorological data, surface movements, and geophysical transects. The analysis indicates that the Lou rock glacier is directly connected to an active torrential channel and has a natural predisposition to frontal failure due to the steepness of its front. The slope failures were triggered after a heat wave followed by a three‐week period of almost continuous rainfall. Water flowing on top of the permafrost table was observed in the two head scarps, suggesting that regressive erosion consecutive to this concentrated subsurface water flow triggered the failures. For one of the slides, traces of previous failures were observable on historical aerial imagery dating back to the 1950's, while the second slide corresponded to a novel event and developed on the frontal slope of a fast‐moving and destabilized rock glacier lobe. We also discuss the increase in local predisposition to failure related to the remarkable morphological modifications such as frontal advance and development of surface cracks associated with the lobe destabilization.