bluuebunny/crossref_metadata_2025 huggingface dataset:
Dinuclear copper(II) complex with a benzimidazole derivative: Crystal structure, theoretical calculations, and cytotoxic activity
Authors: Cassemiro Bruna G. , Santos Jefferson S. , Oliveira Willian X.C. , Pereira‐Maia Elene C. , Galvão Breno R.L. , do Pim Walace D. , Silva‐Caldeira Priscila P.
Published: January 2020

This work describes a facile synthesis of 5,6‐dimethyl‐2‐(pyridin‐2‐yl)‐1‐[(pyridin‐2‐yl)methyl]‐1H‐benzimidazole (dppb) and the preparation of a dinuclear copper(II) complex bearing this ligand in a ring‐like conformation of formula [Cu(dppb)(acn)ClO4]2(ClO4)2·4acn (1), where acn represents acetonitrile. The crystal structure of the complex was determined by single‐crystal X‐ray diffraction experiment, which showed that dppb acts as a bridge in 1 due to its bidentate–monodentate μ‐κ2NN′:κN″coordination mode, and the coordination sphere of each metal center is completed by one acn molecule and one perchlorate ion. The structure of dinuclear copper(II) complex is symmetric and the two square–pyramidal copper(II) centers are separated by 5.381(1) Å. The geometry optimization, electronic structure, and vibrational spectrum of the [Cu(dppb)(acn)ClO4]22+ cation were calculated using the density functional theory method. The geometrical parameters obtained theoretically were remarkably similar to those observed in the crystal structure of 1 and the calculated vibrational frequencies are in satisfactory coherence with experimental data. In solution, the prepared complex can bind to DNA (Kb = 1.43 × 105 M−1) and inhibit the growth of a human chronic myelogenous leukemia cell line (K562) in a concentration‐dependent manner; importantly, it is almost four times more active than the corresponding free benzimidazole.
Pyrazole‐3‐carboxylates assisted N‐heterocyclic carbene palladium complexes: synthesis, characterization, and catalytic activities towards arylation of azoles with arylsulfonyl hydrazides
Authors: Yang Jin
Published: January 2020

Four mononuclear and dinuclear pyrazole‐3‐carboxylates assisted NHC–Pd complexes have been synthesized and characterized. Notably, the bridge‐cleavage reactions of [Pd(μ‐Cl)(Cl)(NHC)]2 with 1H‐pyrazole‐3‐carboxylic acid afforded dinuclear complexes [(NHC)Pd(μ‐1H‐pyrazolato‐3‐carboxylate)]2, in which the 1H‐pyrazolato‐3‐carboxylate was employed as a N^N^O dianionic chelating and bridging ligand. To further explore the structural features and catalytic properties of the complexes, 1‐methyl‐1H‐pyrazole‐3‐carboxylic acid was introduced into the coordination with [Pd(μ‐Cl)(Cl)(NHC)]2 and the corresponding mononuclear complexes (NHC)PdCl(1‐methyl‐1H‐pyrazole‐3‐carboxylate) were obtained. The catalytic properties of the complexes in desulfitative arylation of azoles with arylsulfonyl hydrazides were initially investigated.
TiO2 Nanoparticles Immobilized on Carbon Nanotubes: An Efficient Heterogeneous Catalyst in Cyclocondensation Reaction of Isatins with Malononitrile and 4‐Hydroxycoumarin or 3,4‐Methylenedioxyphenol under Mild Reaction Conditions
Authors: Abdolmohammadi Shahrzad , Rasouli Nasrabadi Seyed Reza , Dabiri Mohammad Reza , Banihashemi Jozdani Sayed Mustafa
Published: January 2020

TiO2 nanoparticles supported on carbon nanotubes (TiO2‐CNTs) as an efficient heterogeneous catalyst was used for the synthesis of spiro[3,4′]1,3‐dihydro‐2H‐indol‐2‐one‐2′‐amino‐5′‐oxo‐4'H,5'H‐pyrano[3′,2′‐c]chromen‐3′‐yl cyanides and spiro[3,8′]1,3‐dihydro‐2H‐indol‐2‐one‐6′‐amino‐8'H‐[1′,3′]dioxolo[4′,5′‐g]chromen‐7′‐yl cyanides via the cyclocondensation reaction of isatins with malononitrile and 4‐hydroxycoumarin or 3,4‐methylenedioxyphenol in aqueous media at room temperature. This reaction offers several sustainable and economic benefits such as high yields of products, convenient operation, and use of non‐toxic catalyst in water media.
Structure–property relationship of poly(cyclohexane 1,4‐dimethylene terephthalate) modified with high trans‐1,4‐cyclohexanedimethanol and 2,6‐naphthalene dicarboxylicacid
Authors: Hussain Fiaz , Park Sangwon , Jeong Jaemin , Kang Soo‐Jung , Kim Jinhwan
Published: January 2020

A series of novel poly(1,4‐cyclohexanedimthylene terephthalate‐co‐1,4‐cyclohxylenedimethylene 2,6‐naphthalenedicarboxylate) (PCTN) copolyesters were successfully melt polymerized using different content of trans‐ or cis‐isomers. Before evaluations, the performance properties, their actual chemical composition, chemical structure, and molecular weight were determined using proton nuclear magnetic resonance (1H‐NMR), Fourier transform infrared spectroscopy (FTIR), and intrinsic viscosity (IV) measurements. Thermal studies of obtained copolyesters were carried out using differential scanning calorimetry (DSC). Thermal degradation behaviors were analyzed by thermogravimetric analysis (TGA). Randomly oriented film specimens were developed using a hot‐press and their thermal, barrier, dimensional stability, and optical properties were analyzed and compared with conventional poly(ethylene terephthalate) (PET) and poly(ethylene naphthalate) (PEN). The results revealed that glass transition temperature (Tg), melting temperature (Tm), and crystallinity (Xc) of the synthesized copolyesters are increased in a linear trend by increasing the trans‐1,4‐cyclohexanedimethanol (trans‐CHDM) isomers. It was also found that synthesized films had better thermal, barrier, optical, and dimensional stability properties than conventional PET and PEN films. Results clearly indicated that high trans‐CHDM isomers significantly improve the performance properties of the fabricated films. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48950.
Rationally designed curcumin laden glycopolymeric nanoparticles: Implications on cellular uptake and anticancer efficacy
Authors: Rao N. Naga Malleswara , Sharma Shipra , Palodkar Krushna Kaduba , Sadhu Veera , Sharma Manu , Sainath Annadanam V. Sesha
Published: January 2020

Overexpression of glucose transport proteins (GLUTs) plays a pivotal role in the survival of cancer cells. Hence, targeting GLUTs receptors using glucose‐based polymers can fill up the lacuna of cancer treatment by confining the dissemination and accumulation of chemotherapeutic drugs on cancer cells. The present study addressed the preparation of glycohomopolymer (PMG), PEG‐based di‐ (PEG‐b‐PMG) and tri‐block (PMG‐b‐PEG‐b‐PMG) polymers using atom transfer radical polymerization and their potential in the development of novel nanoparticulate drug delivery system. Curcumin‐loaded glycopolymer nanoparticles were fabricated by nanoprecipitation method and investigated for various physicochemical parameters such as particle size, zeta potential, polydispersity index, drug loading, morphology, and dissolution profile. Homoglycopolymer nanoparticles exhibited lower average particle size (240.16 ± 21.41 nm), higher zeta potential (−28.72 ± 4.25 mV), and entrapment efficiency (74.61 ± 5.03%) compared to their block copolymer counterparts. Optimized formulation exhibited diffusion and dissolution‐controlled drug release behavior. In vitro cell line studies demonstrated significantly superior cytotoxicity, clonogenic inhibitory and cellular uptake potential in MCF‐7 cells besides receptor recognizing property of optimized curcumin nanoparticulate formulation compared to free curcumin. These findings elucidate that curcumin homoglucopyranoside nanocarriers can be a promising drug delivery option for effective management of breast cancer. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48954.
Overexpression of stilbene synthase genes to modulate the properties of plants and plant cell cultures
Authors: Kiselev Konstantin V. , Dubrovina Alexandra S.
Published: January 2020

Plant stilbenes have attracted special attention as they possess valuable health benefits and improve plant resistance to environmental stresses. Stilbenes are synthesized via the phenylpropanoid pathway, where stilbene synthase (STS, EC 2.3.1.95) directly catalyzes the formation of t‐resveratrol (monomeric stilbene). This review discusses the features of using STS genes in genetic engineering and plant biotechnology with the purpose to increase plant resistance to environmental stresses and to modify secondary metabolite production.
DNA bioassays based on the fluorescence ‘turn off’ of silver nanocluster beacon
Authors: Wen Qiu‐Lin , Peng Jun , Liu An‐Yong , Wang Jun , Hu Yi‐Lin , Ling Jian , Cao Qiu‐E
Published: January 2020

Recognition and quantification of oligonucleotide sequences play important roles in medical diagnosis. In this study, a new fluorescent oligonucleotide‐stabilized silver nanocluster beacon (NCB) probe was designed for sensitive detection of oligonucleotide sequence targets. This probe contained two tailored DNA strands. One strand was a signal probe strand containing a cytosine‐rich strand template for fluorescent silver nanocluster (Ag NC) synthesis and a detection sections at each end. The other strand was a fluorescence enhancing strand containing a guanine‐rich section for signal enhancement at one end and a linker section complementary to one end of the signal probe strand. After synthesis of the Ag NCs and hybridization of the two strands, the fluorescence intensity of the as‐prepared silver NCB was enhanced 200‐fold compared with the Ag NCs. Two NCBs were designed to detect two disease‐related oligonucleotide sequences, and results indicated that the two target oligonucleotide sequences in the range 50.0–600.0 and 50.0–200.0 nM could be linearly detected with detection limits of 20 and 25 nM, respectively. The developed fluorescence method using NCBs for oligonucleotide sequence detection was sensitive, facile and had potential for use in bioanalysis and diagnosis.
Protective role of poly(lactic‐co‐glycolic) acid nanoparticle loaded with resveratrol against isoproterenol‐induced myocardial infarction
Authors: Sun Liqiang , Hu Yucai , Mishra Anurag , Sreeharsha Nagaraja , Moktan Jeet B. , Kumar Piyush , Wang Lei
Published: January 2020

Our study is aimed at evaluating the effects of pretreatment with Poly(lactic‐co‐glycolic) acid nanoparticle loaded with resveratrol (RSV PLGA NPs) compared to conventional resveratrol (RSV) on isoproterenol (ISO) induced myocardial infarction (MI) in rats. Sixty rats were randomly divided into six groups of 10 rats each. RSV and RSV PLGA NPs were given by gavage in two different doses (50 mg/kg body weight [BW] and 100 mg/kg BW) for 3 weeks. RSV and RSV PLGA NPs were given for 2 weeks starting 1 week before ISO administration. The blood samples were taken 24 hr after the last dose of ISO. The antioxidant, anti‐inflammatory, and cardioprotective effects were evaluated in all groups. Only 100 mg/kg dose of RSV and both doses of RSV PLGA NPs offered a cardioprotective effect by preventing cardiac troponin T (cTnT) levels, lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) activities leakage from cardiomyocytes, with the best result for RSV PLGA NPs. All the oxidative stress parameters were significantly improved after RSV PLGA NPs compared to RSV pretreatment. RSV PLGA NPs were more efficient than RSV in limiting the increase in inflammatory cytokine expressions such as tumor necrosis factor‐alpha (TNF‐α), interleukin 1 beta (IL‐1β), and NF‐kappaB (NF‐kB) expression. In addition, RSV PLGA NPs significantly upregulated eNOS expression and downregulated iNOS expression. RSV PLGA NPs better prevented myocardial necrosis and reduced interstitial edema and neutrophil infiltration than RSV, on histopathological examination. Therefore, improving the bioactivity of RSV by nanotechnology may help limit cardiac injury after myocardial infarction.
Cigarette smoking increases the risk of nasopharyngeal carcinoma through the elevated level of IgA antibody against Epstein‐Barr virus capsid antigen: A mediation analysis
Authors: Hsu Wan‐Lun , Chien Yin‐Chu , Huang Yen‐Tsung , Yu Kelly J. , Ko Jenq‐Yuh , Lin Ching‐Yuan , Tsou Yung‐An , Leu Yi‐Shing , Liao Li‐Jen , Chang Yen‐Liang , Su Jia‐Ying , Liu Zhiwei , Wang Cheng‐Ping , Terng Shyuang‐Der , Hua Chun‐Hung , Lee Jehn‐Chuan , Yang Tsung‐Lin , Kate Hsiao Chu‐Hsing , Wu Ming‐Shiang , Tsai Ming‐Hsui , Liu Ming‐Jiung , Lou Pei‐Jen , Hildesheim Allan , Chen Chien‐Jen ,   the GEV‐NPC Study Group
Published: January 2020

Background

The study aims are to evaluate the associations between nasopharyngeal carcinoma (NPC) risk and cigarette smoking and to explore the effects of cigarette smoking on Epstein‐Barr virus (EBV) infection for NPC risk.

Methods

1235 male NPC cases and 1262 hospital‐based male controls matched to cases were recruited across six collaborative hospitals between 2010 and 2014. Using a standardized questionnaire, information on cigarette smoking and other potential risk factors for NPC was obtained. Blood was collected and used for anti‐EBV VCA IgA and anti‐EBV EA‐EBNA1 IgA testing using standard methods. Unconditional logistic regression analysis was used to estimate odds ratio (OR) with 95% confidence interval (CI) for each risk factor after adjusting for confounders.

Results

63.6% of cases and 44.0% of controls reported ever smoking cigarettes. After full adjustment, current smokers had a significant 1.60‐fold (95% CI = 1.30‐1.97) and former smokers a borderline significant 1.27‐fold (95% CI = 1.00‐1.60) increased NPC risk compared to never smokers. NPC risk increased with increasing duration, intensity, and pack‐years of cigarette smoking but not with age at smoking initiation. Among controls, anti‐EBV VCA IgA seropositivity rate was higher in current smokers than never smokers (14.0% vs 8.4%; OR = 1.82; 95% CI = 1.19‐2.79). Mediation analyses showed that more than 90% of the cigarette smoking effect on NPC risk is mediated through anti‐EBV VCA IgA.

Conclusion

This study confirms the association between long‐term cigarette smoking and NPC and demonstrates that current smoking is associated with seropositivity of anti‐EBV VCA IgA antibodies.
EGCG exerts its protective effect by mitigating the release of lysosomal enzymes in aged rat liver on exposure to high cholesterol diet
Authors: Ravindran Rajeswari , Jaganathan Ravindran , Periandavan Kalaiselvi
Published: January 2020

The aim is to test the hypothesis whether the cholesterol loaded lysosomes are capable of mediating lysosomal membrane permeabilization (LMP) during aging and to study the efficacy of epigallocatechin‐3‐gallate (EGCG) in preserving the lysosomal membrane stability. Aged rats were fed with high cholesterol diet (HCD) and treated with EGCG orally. Serum and tissue lipid status, cholesterol levels in lysosomal fraction, activities of lysosomal enzymes in lysosomal, and cytosolic fractions were measured. Transmission electron microscopic studies (TEM), oil red “O” (ORO) staining, and immunohistochemical analysis of oxidized low density lipoprotein (OxLDL) were carried out. Significant increase in serum, tissue lipid profile, and lysosomal cholesterol levels were observed in aged HCD‐fed rats with a concomitant decrease in high density lipoprotein (HDL) levels. We also observed a significant increase in lipid accumulation in hepatocytes of aged HCD‐fed rats by TEM, ORO, and immunohistochemical staining. Upon treatment with EGCG to aged HCD‐fed animals, we found augmented levels of HDL with a concomitant decrease in lysosomal cholesterol levels and other lipoproteins. TEM studies and immunohistochemistry of OxLDL also showed a marked reduction in lipid deposition of hepatocytes. Thus, EGCG has preserved the lysosomal membrane stability in HCD stressed aged rats.

Significance of the study

The research article is focused mainly on the effect of EGCG and its capability on mitigating the release of lysosomal enzymes in aged animals fed with HCD. The study signifies the cellular function of the organelle lysosome following administration of aged rats with HCD, which would make the readers to understand the action of EGCG and the interrelationship of both cholesterol and activity of lysosomes when cholesterol is loaded.
A less‐invasive totally‐endovascular (LITE) technique for trans‐femoral transcatheter aortic valve replacement
Authors: Burzotta Francesco , Aurigemma Cristina , Romagnoli Enrico , Shoeib Osama , Russo Giulio , Zambrano Aniello , Verdirosi Diana , Leone Antonio Maria , Bruno Piergiorgio , Trani Carlo
Published: January 2020

Objectives

To describe and report the results of an original technique for trans‐femoral (TF) transcatheter‐aortic‐valve‐replacement (TAVR).

Background

TF approach represents the commonest TAVR technique. The best technique for TF‐TAVR is not recognized.

Methods

We developed a less‐invasive totally‐endovascular (LITE) technique for TF‐TAVR. The key aspects are:

precise TAVR access puncture using angiographic‐guidewire‐ultrasound guidance

radial approach as the “secondary access” (to guide valve positioning, to check femoral‐access hemostasis and to manage eventual access‐site complications)

non‐invasive pacing (by retrograde left ventricle stimulation or by definitive pace‐maker external programmer)

The LITE technique has been systematically adopted at our Institution. Procedure details, complications and clinical events occurring during hospitalization were prospectively recorded. Major vascular complications and life‐threatening or major bleedings were the primary study end‐points.

Results

A total of 153 consecutive patients referred for TF‐TAVR were approached using the LITE technique. Mean predicted surgical operative mortality was 4.9% and mean TAVR predicted mortality was 3.9%. In 132 (86.3%) patients, TAVR was completed without the need for additional femoral artery access or transvenous temporary pace‐maker implantation. Major vascular complications occurred in 2 (1.3%), life‐threatening or major bleedings occurred in 4 (2.6%) patients. All‐cause death occurred in 3 patients (2.0%).

Conclusions

TF‐TAVR according to LITE technique is feasible and is associated with very low rates of vascular or bleeding complications.
Application of the SCAI classification in a cohort of patients with cardiogenic shock
Authors: Schrage Benedikt , Dabboura Salim , Yan Isabell , Hilal Rafel , Neumann Johannes T. , Sörensen Nils A. , Goßling Alina , Becher Peter Moritz , Grahn Hanno , Wagner Tobias , Seiffert Moritz , Kluge Stefan , Reichenspurner Hermann , Blankenberg Stefan , Westermann Dirk
Published: January 2020

Background

The Society of Cardiovascular Angiography and Interventions (SCAI) have recently proposed a new classification of cardiogenic shock (CS) dividing patients into five subgroups.

Objective

Aim of this study was to apply the SCAI classification to a cohort of patients presenting with CS and to evaluate its ability to predict 30‐day survival.

Methods

SCAI CS subgroups were interpreted based on the recent consensus statement and then applied to N = 1,007 consecutive patients presenting with CS or large myocardial infarction (MI) between October 2009 and October 2017. The association between SCAI classification and 30‐day all‐cause mortality was assessed by logistic regression analysis.

Results

Mean age in the study cohort was 67 (±15) years, 72% were male. Mean lactate at baseline was 6.05 (±5.13) mmol/l and 51% of the patients had prior cardiac arrest. Overall survival probability was 50.6% (95% confidence interval [CI] 47.5–54.0%). In view of the SCAI classification, the survival probability was 96.4% (95% CI 93.7–99.0%) in class A, 66.1% (95% CI 50.2–87.1%) in class B, 46.1% (95% CI 40.6–52.4%) in class C, 33.1% (95% CI 26.6–41.1%) in class D, and 22.6% (95% CI 17.1–30.0%) in class E. Higher SCAI classification was significantly associated with lower 30‐day survival (p < .01).

Conclusion

In this large clinical cohort, the SCAI classification was significantly associated with 30‐day survival. This finding supports the rationale of the SCAI CS classification and calls for a validation in a prospective trial.
Chronic lymphocytic leukemia with progressive anemia secondary to development of composite lymphoma
Authors: McGinnis Eric , England James T. , Craig Jeffrey W. , Moshref Razavi Habib
Published: January 2020

Deterioration of hematologic parameters in lymphoma patients is often attributed to disease progression, comorbidities, or treatment effects. Second primary malignancies occur at increased frequency in CLL and must also be considered.
Learning curve for transcatheter aortic valve replacement for native aortic regurgitation: Safety and technical performance study
Authors: Liu Lulu , Zhang Jian , Peng Ying , Shi Jun , Qin Chaoyi , Qian Hong , Xiao Zhenghua , Guo Yingqiang
Published: January 2020

Background

Transcatheter aortic valve replacement (TAVR) is a fundamentally new procedure for the treatment of native aortic regurgitation (AR). The number of cases needed to gain proficiency with the procedure is unknown.

Hypothesis

This study aimed to evaluate the learning curve for TAVR for native AR.

Methods

This study retrospectively reviewed a prospective database from 134 consecutive native AR patients who underwent the J‐valve TAVR system, which performed by a single team interventional cardiologist. The cumulative sum (CUSUM) method was used to analyze the learning curve. Patients were divided into two groups in chronological order, defined by the surgeon's early (group 1: the first 52 cases) and skilled (group 2: the next 82 cases) experience. Demographic data, intraoperative characteristics, and short‐term surgical outcomes were compared between the two groups.

Results

CUSUM plots revealed decreasing procedure time and fluoroscopy time after patients 52 and 43, respectively. The patient date consistently demonstrated that high‐risk scores and major perioperative parameters were comparable between the two groups. The use of contrast dye (group 1, 94.22 ± 30.07 mL; group 2, 70.43 ± 15.02 mL, P<.05), total procedure time (group 1, 84.96 ± 17.76 minutes; group 2, 59.95 ± 12.83 minutes, P<.05), and fluoroscopy time (group 1, 11.52 ± 3.81 minutes; group 2, 6.47 ± 1.53 minutes, P<.05) were significantly reduced in group 2. The overall device success rate in group 1 was 96.2% vs 96.3% in group 2 and remained high (P = 1.0). The overall 30‐day mortality was 3.8% in group 2 (group 1, 0 to group 2, 3.8%; P = .16). The complications rate, such as pulmonary hypertension, chronic kidney disease, and coronary artery disease were higher in group 2.

Conclusions

For a surgeon without previous TAVR experience, 52 cases of performance is the minimal requirement to gain the proficiency of TAVR for native AR. The skilled surgeons have been observed with reduced procedural time, fluoroscopy times, radiation exposure dose, and contrast volume usage. However, the overall prognosis was not significantly different between the two groups.
Emerging roles of the centrosome in neuronal development
Authors: Meka Durga Praveen , Scharrenberg Robin , Calderon de Anda Froylan
Published: January 2020

The role of the centrosome—a microtubule‐organizing center—in neuronal development has been under scrutiny and is controversial. The function and position of the centrosome have been shown to play an important role in selecting the position of axon outgrowth in cultured neurons and in situ. However, other studies have shown that axonal growth is independent of centrosomal functions. Recent discoveries define the centrosome as an F‐actin organizing organelle in various cell types; thus, giving a whole new perspective to the role of the centrosome in lymphocyte polarity, cell division, and neuronal development. These discoveries compel the need to revisit centrosomal functions by investigating the fundamental mechanisms that regulate centrosomal F‐actin remodeling during neuronal differentiation and polarization. In this review, we summarize the up‐to‐date knowledge regarding the function of the centrosome in neuronal differentiation. We put special emphasis on recent findings describing the centrosome as an F‐actin organizing center. Additionally, with the available data regarding centrosome, microtubules and F‐actin organization, we provide a model on how centrosomal F‐actin could be modulating neuronal differentiation and polarity.
How To Produce Methane Precursor in the Upper Ocean by An Untypical Non‐Heme Fe‐Dependent Methylphosphonate Synthase?
Authors: Yan Ji‐Fan , Chen Shi‐Lu
Published: January 2020

A new methane formation pathway, which uses methylphosphonate (MPn) as the methane precursor, has been discovered in the upper ocean. Methylphosphonate synthase (MPnS) is a key piece in this pathway to produce MPn from 2‐hydroxyethylphosphonate (2‐HEP), using an untypical 2‐His‐1‐Gln non‐heme iron architecture. Herein, the MPnS reaction mechanism was demonstrated by the density functional calculations to mainly include the substrate hydroxyl deprotonation, the formation of a MPn radical and a formate, and the hydrogen abstraction of formate by MPn radical. The second‐shell Lys28’ may serve as a proton reservoir activating 2‐HEP and regenerating the Fe site. The Fe‐bound superoxide radical is a bifunctional species to deprotonate the substrate hydroxyl and abstract the substrate methylene hydrogen. Several alternative mechanisms have been ruled out. Furthermore, the catalytic activity of MPnS was found to be inactivated/reduced by the mutation of Gln152E/Gln152H/Gln152D, rendering a significant evolutionary advantage with an uncommon 2‐His‐1‐Gln triad introduced to the ferrous coordination sphere.
Space‐charge‐limited current of vacuum arc thruster
Authors: Zhang Tianping , Chang Lei , Hu Xinyue , Wang Runlong , Zhang Huijie , Wu Xianming , Sun Xinfeng , Hu Ning
Published: January 2020

To optimize thrust performance, the expression of space‐charge‐limited current for vacuum arc thruster is derived from Poisson's equation. The commonly used ring‐type and coaxial‐type vacuum arc thrusters are simplified to the equivalent current sheet in planar geometry and cylindrical capacitor, respectively, for this calculation. Both the spatial distribution and peak magnitude of space‐charge‐limited current are given explicitly, together with their dependences on gap distance, applied voltage, charge number, and ion mass. For typical experimental parameters of the vacuum arc thruster, it is shown that the maximum current density drops significantly when the gap distance becomes large and grows when the applied voltage increases; moreover, a cathode material of lower atomic weight yields a higher current density. The expressions of total current for these two types of vacuum arc thruster are also presented. This work, to our best knowledge, is the first application of space‐charge‐limited current to the vacuum arc thruster and practically very interesting for engineering design.
Interrelated ecological impacts of climate change on an apex predator
Authors: Laidre Kristin L. , Atkinson Stephen , Regehr Eric V. , Stern Harry L. , Born Erik W. , Wiig Øystein , Lunn Nicholas J. , Dyck Markus
Published: January 2020

Climate change has broad ecological implications for species that rely on sensitive habitats. For some top predators, loss of habitat is expected to lead to cascading behavioral, nutritional, and reproductive changes that ultimately accelerate population declines. In the case of the polar bear (Ursus maritimus), declining Arctic sea ice reduces access to prey and lengthens seasonal fasting periods. We used a novel combination of physical capture, biopsy darting, and visual aerial observation data to project reproductive performance for polar bears by linking sea ice loss to changes in habitat use, body condition (i.e., fatness), and cub production. Satellite telemetry data from 43 (1991–1997) and 38 (2009–2015) adult female polar bears in the Baffin Bay subpopulation showed that bears now spend an additional 30 d on land (90 d in total) in the 2000s compared to the 1990s, a change closely correlated with changes in spring sea ice breakup and fall sea ice formation. Body condition declined for all sex, age, and reproductive classes and was positively correlated with sea ice availability in the current and previous year. Furthermore, cub litter size was positively correlated with maternal condition and spring breakup date (i.e., later breakup leading to larger litters), and negatively correlated with the duration of the ice‐free period (i.e., longer ice‐free periods leading to smaller litters). Based on these relationships, we projected reproductive performance three polar bear generations into the future (approximately 35 yr). Results indicate that two‐cub litters, previously the norm, could largely disappear from Baffin Bay as sea ice loss continues. Our findings demonstrate how concurrent analysis of multiple data types collected over long periods from polar bears can provide a mechanistic understanding of the ecological implications of climate change. This information is needed for long‐term conservation planning, which includes quantitative harvest risk assessments that incorporate estimated or assumed trends in future environmental carrying capacity.
Modular chromosome rearrangements reveal parallel and nonparallel adaptation in a marine fish
Authors: Kess Tony , Bentzen Paul , Lehnert Sarah J. , Sylvester Emma V. A. , Lien Sigbjørn , Kent Matthew P. , Sinclair‐Waters Marion , Morris Corey , Wringe Brendan , Fairweather Robert , Bradbury Ian R.
Published: January 2020

Genomic architecture and standing variation can play a key role in ecological adaptation and contribute to the predictability of evolution. In Atlantic cod (Gadus morhua), four large chromosomal rearrangements have been associated with ecological gradients and migratory behavior in regional analyses. However, the degree of parallelism, the extent of independent inheritance, and functional distinctiveness of these rearrangements remain poorly understood. Here, we use a 12K single nucleotide polymorphism (SNP) array to demonstrate extensive individual variation in rearrangement genotype within populations across the species range, suggesting that local adaptation to fine‐scale ecological variation is enabled by rearrangements with independent inheritance. Our results demonstrate significant association of rearrangements with migration phenotype and environmental gradients across the species range. Individual rearrangements exhibit functional modularity, but also contain loci showing multiple environmental associations. Clustering in genetic distance trees and reduced differentiation within rearrangements across the species range are consistent with shared variation as a source of contemporary adaptive diversity in Atlantic cod. Conversely, we also find that haplotypes in the LG12 and LG1 rearranged region have diverged across the Atlantic, despite consistent environmental associations. Exchange of these structurally variable genomic regions, as well as local selective pressures, has likely facilitated individual diversity within Atlantic cod stocks. Our results highlight the importance of genomic architecture and standing variation in enabling fine‐scale adaptation in marine species.
Generalist Eimeria species in rodents: Multilocus analyses indicate inadequate resolution of established markers
Authors: Jarquín‐Díaz Víctor Hugo , Balard Alice , Mácová Anna , Jost Jenny , Roth von Szepesbéla Tabea , Berktold Karin , Tank Steffen , Kvičerová Jana , Heitlinger Emanuel
Published: January 2020

Intracellular parasites of the genus Eimeria are described as tissue/host‐specific. Phylogenetic classification of rodent Eimeria suggested that some species have a broader host range than previously assumed. We explore whether Eimeria spp. infecting house mice are misclassified by the most widely used molecular markers due to a lack of resolution, or whether, instead, these parasite species are indeed infecting multiple host species.

With the commonly used markers (18S/COI), we recovered monophyletic clades of E. falciformis and E. vermiformis from Mus that included E. apionodes identified in other rodent host species (Apodemus spp., Myodes glareolus, and Microtus arvalis). A lack of internal resolution in these clades could suggest the existence of a species complex with a wide host range infecting murid and cricetid rodents. We question, however, the power of COI and 18S markers to provide adequate resolution for assessing host specificity. In addition to the rarely used marker ORF470 from the apicoplast genome, we present multilocus genotyping as an alternative approach. Phylogenetic analysis of 35 nuclear markers differentiated E. falciformis from house mice from isolates from Apodemus hosts. Isolates of E. vermiformis from Mus are still found in clusters interspersed with non‐Mus isolates, even with this high‐resolution data.

In conclusion, we show that species‐level resolution should not be assumed for COI and 18S markers in coccidia. Host–parasite cospeciation at shallow phylogenetic nodes, as well as contemporary coccidian host ranges more generally, is still open questions that need to be addressed using novel genetic markers with higher resolution.
Ocean currents and the population genetic signature of fish migrations
Authors: Krueck Nils C. , Treml Eric A. , Innes David J. , Ovenden Jennifer R.
Published: January 2020

Animal migrations are a fascinating and global phenomenon, yet they are often difficult to study and sometimes poorly understood. Here, we build on classic ecological theory by hypothesizing that some enigmatic spawning migrations across coastal marine habitats can be inferred from the population genetic signature of larval dispersal by ocean currents. We test this assumption by integrating spatially realistic simulations of alternative spawning migration routes, associated patterns of larval dispersal, and associated variation in the population genetic structure of eastern Australian sea mullet (Mugil cephalus). We then use simulation results to assess the implications of alternative spawning destinations for larval replenishment, and we contrast simulated against measured population genetic variation. Both analyses suggest that the spawning migrations of M. cephalus in eastern Australia are likely to be localized (approximately 100 km along the shore), and that spawning is likely to occur in inshore waters. Our conclusions are supported by multiple lines of evidence available through independent studies, but they challenge the more traditional assumption of a single, long‐distance migration event with subsequent offshore spawning in the East Australian Current. More generally, our study operationalizes classic theory on the relationship between fish migrations, ocean currents, and reproductive success. However, rather than confirming the traditionally assumed adaptation of migratory behavior to dominant ocean current flow, our findings support the concept of a genetically measurable link between fish migrations and local oceanographic conditions, specifically water temperature and coastal retention of larvae. We believe that future studies using similar approaches for high resolution and spatially realistic ecological–genetic scenario testing can help rapidly advance our understanding of key ecological processes in many other marine species.
Metabolic insight into bacterial community assembly across ecosystem boundaries
Authors: Wisnoski Nathan I. , Muscarella Mario E. , Larsen Megan L. , Peralta Ariane L. , Lennon Jay T.
Published: January 2020

The movement of organisms across habitat boundaries has important consequences for populations, communities, and ecosystems. However, because most species are not well adapted to all habitat types, dispersal into suboptimal habitats could induce physiological changes associated with persistence strategies that influence community assembly. For example, high rates of cross‐boundary dispersal are thought to maintain sink populations of terrestrial bacteria in aquatic habitats, but these bacteria may also persist by lowering their metabolic activity, introducing metabolic heterogeneity that buffers the population against species sorting. To differentiate between these assembly processes, we analyzed bacterial composition along a hydrological flow path from terrestrial soils through an aquatic reservoir by sequencing the active and total (active + inactive) portions of the community. When metabolic heterogeneity was ignored, our data were consistent with views that cross‐boundary dispersal is important for structuring aquatic bacterial communities. In contrast, we found evidence for strong species sorting in the active portion of the aquatic community, suggesting that dispersal may have a weaker effect than persistence strategies on aquatic community assembly. By accounting for metabolic heterogeneity in complex communities, our findings clarify the roles of local‐ and regional‐scale assembly processes in terrestrial‐aquatic meta‐ecosystems.
Examination of the dielectrophoretic spectra of MCF7 breast cancer cells and leukocytes
Authors: Çağlayan Zeynep , Demircan Yalçın Yağmur , Külah Haluk
Published: January 2020

The detection of circulating tumor cells (CTCs) in blood is crucial to assess metastatic progression and to guide therapy. Dielectrophoresis (DEP) is a powerful cell surface marker‐free method that allows intrinsic dielectric properties of suspended cells to be exploited for CTC enrichment/isolation from blood. Design of a successful DEP‐based CTC enrichment/isolation system requires that the DEP response of the targeted particles should accurately be known. This paper presents a DEP spectrum method to investigate the DEP spectra of cells without directly analyzing their membrane and cytoplasmic properties in contrast to the methods in literature, which employ theoretical assumptions and complex modeling. Integrating electric field simulations based on DEP theory with the experimental data enables determination of the DEP spectra of leukocyte subpopulations, polymorphonuclear and mononuclear leukocytes, and MCF7 breast cancer cells as a model of CTC due to their metastatic origin over the frequency range 100 kHz–50 MHz at 10 Vpp. In agreement with earlier findings, differential DEP responses were detected for mononuclear and polymorphonuclear leukocytes due to the richness of the cell surface features and morphologies of the different leukocyte types. The data reveal that the strength of the DEP force exerted on MCF7 cells was particularly high between 850 kHz and 20 MHz. These results illustrate that the proposed technique has the potential to provide a generic platform to identify DEP responses of different biological particles.
Naturalistic outcomes for a day‐hospital programme in a mixed diagnostic sample of adolescents with eating disorders
Authors: Reilly Erin E. , Rockwell Roxanne E. , Ramirez Ana L. , Anderson Leslie K. , Brown Tiffany A. , Wierenga Christina E. , Kaye Walter H.
Published: January 2020

Despite initial data suggesting positive treatment outcomes for adolescent eating disorder day‐hospital programmes (DHPs), existing studies have included limited follow‐up, small samples, and a focus on restricting‐type eating disorders. To address these gaps, we explored naturalistic outcomes for an adolescent eating disorders DHP. Adolescent participants (N = 265) completed measurements at treatment admission, discharge (n = 170), and various lengths of follow‐up (n = 126; Mfollow up = 278.87 days). Results from multilevel models indicated significant increases in body weight for the anorexia nervosa group throughout treatment and maintenance of increased body weight from discharge to follow‐up. In bulimic spectrum disorders, binge eating and purging significantly decreased from intake to discharge and did not change from discharge to follow‐up. Across the entire sample, eating disorder symptoms decreased from intake to discharge and did not change from discharge to follow‐up. Further, anxiety and depression decreased over the course of treatment and continued to decrease over the follow‐up period. The current investigation represents the first study to explore longitudinal DHP outcomes within adolescent bulimic spectrum eating disorders. Our findings also highlight many challenges inherent in conducting naturalistic research; it is critical that the field continue to develop solutions to the barriers inherent in conducting longitudinal research on eating disorder treatment.
Computation of storage power and energy to stabilize a wind‐and‐solar‐only Australian National Electricity Market grid
Authors: Boretti Alberto , Nayfeh Jamal , Al‐Kouz Wael
Published: January 2020

The Australian NEM grid data is a unique example worldwide. No other country supplies high frequency (5‐minutes‐sampling‐interval) data of power generation by all the facilities connected to a grid. The NEM grid has power demands between 18 and 36 GW, on average 27 GW. Presently, wind energy nominal capacity is 6.7 GW, solar energy nominal capacity is 11.4 GW storage power and energy is negligible. Capacity factors are about 0.33 for wind, and about 0.125 for solar (0.27 facilities, 0.10 rooftop). Wind and solar capacities must be increased to 53.2 and 90.5 GW (growth factor 7.94) to cover the NEM grid demand. Minimum storage power needed is more than 45 GW net, while the net storable energy is computed as 3500 GW h. The nominal power and energy are much more than that, depending on the specific technology adopted, as storage only works at a fraction of the nominal power during charge and discharge, and only a fraction of the nominal capacity, with round‐trip efficiencies everything but unity. While the trend is to move towards more solar rooftop, this not the case, as it further increases variability and needs larger storage.
Impact of Hydroponic Oxygen Control in Sulfide Toxicity to Early Life Stages of Wild Rice (Zizania palustris)
Authors: Fort Douglas J. , Mathis Michael B. , Anderson Kurt , Beranek Rob
Published: January 2020

Low-headspace oxygen was used in the hydroponic design to evaluate the toxicity of sulfide to wild rice (Zizania palustris). Oxygen levels in the headspace gas phase were maintained at <0.005 atm. The results indicated that mesocotyl emergence was the most sensitive endpoint (≥3.1 mg/L sulfide and 0.8 mg/L iron [Fe]). At 2.8 mg Fe/L, ≥7.8 mg/L sulfide was required to reduce emergence, shoot weight, and shoot length. Overall, the results were similar to those of previous studies in which atmospheric oxygen was maintained in the headspace gas phase, demonstrating that the oxygen level in the headspace gas phase during mesocotyl emergence and early growth was not a significant factor in sulfide tolerance. Environ Toxicol Chem 2020;39:659–666. © 2020 SETAC
Measurement of ultra‐fast signal progression related to face processing by 7T fMRI
Authors: Choi Uk‐Su , Sung Yul‐Wan , Ogawa Seiji
Published: January 2020

Given that the brain is a dynamic system, the temporal characteristics of brain function are important. Previous functional magnetic resonance imaging (fMRI) studies have attempted to overcome the limitations of temporal resolution to investigate dynamic states of brain activity. However, finding an fMRI method with sufficient temporal resolution to keep up with the progress of neuronal signals in the brain is challenging. This study aimed to detect between‐hemisphere signal progression, occurring on a timescale of tens of milliseconds, in the ventral brain regions involved in face processing. To this end, we devised an inter‐stimulus interval (ISI) stimulation scheme and used a 7T MRI system to obtain fMRI signals with a high signal‐to‐noise ratio. We conducted two experiments: one to measure signal suppression depending on the ISI and another to measure the relationship between the amount of suppression and the ISI. These two experiments enabled us to measure the signal transfer time from a brain region in the ventral visual stream to its counterpart in the opposite hemisphere through the corpus callosum. These findings demonstrate the feasibility of using fMRI to measure ultra‐fast signals (tens of milliseconds) and could facilitate the elucidation of further aspects of dynamic brain function.
Tractostorm: The what, why, and how of tractography dissection reproducibility
Authors: Rheault Francois , De Benedictis Alessandro , Daducci Alessandro , Maffei Chiara , Tax Chantal M. W. , Romascano David , Caverzasi Eduardo , Morency Felix C. , Corrivetti Francesco , Pestilli Franco , Girard Gabriel , Theaud Guillaume , Zemmoura Ilyess , Hau Janice , Glavin Kelly , Jordan Kesshi M. , Pomiecko Kristofer , Chamberland Maxime , Barakovic Muhamed , Goyette Nil , Poulin Philippe , Chenot Quentin , Panesar Sandip S. , Sarubbo Silvio , Petit Laurent , Descoteaux Maxime
Published: January 2020

Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called “virtual dissection.” Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. It is our opinion that if the field of dMRI tractography wants to be taken seriously as a widespread clinical tool, it is imperative to harmonize WM bundle segmentations and develop protocols aimed to be used in clinical settings. The EADC‐ADNI Harmonized Hippocampal Protocol achieved such standardization through a series of steps that must be reproduced for every WM bundle. This article is an observation of the problematic. A specific bundle segmentation protocol was used in order to provide a real‐life example, but the contribution of this article is to discuss the need for reproducibility and standardized protocol, as for any measurement tool. This study required the participation of 11 experts and 13 nonexperts in neuroanatomy and “virtual dissection” across various laboratories and hospitals. Intra‐rater agreement (Dice score) was approximately 0.77, while inter‐rater was approximately 0.65. The protocol provided to participants was not necessarily optimal, but its design mimics, in essence, what will be required in future protocols. Reporting tractometry results such as average fractional anisotropy, volume or streamline count of a particular bundle without a sufficient reproducibility score could make the analysis and interpretations more difficult. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction protocols in this era of open and collaborative science.
Liver Diseases in the Perinatal Period: Interactions Between Mother and Infant
Authors: Ibrahim Samar H. , Jonas Maureen M. , Taylor Sarah A. , Gutierrez Sanchez Luz Helena , Wolf Jaqueline L. , Sundaram Shikha S.
Published: January 2020

Liver diseases affecting the mother and infant dyad may present in the perinatal period from 20 weeks of gestation to 28 days of life. This review will focus on the current approach to neonatal acute liver failure and the progress made in the diagnosis and management of gestational alloimmune liver disease. It will highlight mother‐to‐child transmission of viral hepatitis, both management and public health implications. Emerging concepts implicating maternal obesity and nutrition in the development of a rapidly progressive nonalcoholic steatohepatitis phenotype in the offspring will be discussed. Finally, the presentation and management of acute fatty liver of pregnancy and intrahepatic cholestasis of pregnancy, and their impact on the fetus, will be reviewed.