bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrafine α‐Phase Molybdenum Carbide Decorated with Platinum Nanoparticles for Efficient Hydrogen Production in Acidic and Alkaline Media
Authors: Song Hee Jo , Sung Myeong‐Chang , Yoon Hyunseok , Ju Bobae , Kim Dong‐Wan
Published: February 2019

The development of efficient electrocatalysts is important to produce clean and sustainable hydrogen fuel on a large scale. With respect to cathodic reactions, Pt exhibits an overwhelming electrocatalytic capability in the hydrogen evolution reaction (HER) in comparison with other earth‐abundant electrocatalysts, despite its rarity and high cost. So, a hybrid catalyst that combines a low‐cost electrocatalyst with Pt would balance cost‐effectiveness with catalytic activity. Herein, α‐phase molybdenum carbide (MoC1−x) nanoparticles (NPs) decorated with a small amount of Pt (MoC1−x/Pt‐NPs) are designed to achieve high‐performance hydrogen production in acidic and alkaline media. MoC1−x‐NPs exhibit good electrocatalytic HER activity as well as stability and durability. They show favorable catalytic kinetics in an alkaline medium, suggesting an active water dissociation process. After Pt decoration, Pt‐NPs that are 2–3 nm in diameter are well incorporated with MoC1−x‐NPs. MoC1−x/Pt‐NPs with a small amount of Pt (2.7–3 wt%) and are able to perform superior electrocatalytic HER activity, and possess stability and durability that is comparable to that of commercial Pt/C. Notably, they exhibit a higher intrinsic catalytic activity compared to that of Pt/C in an alkaline medium, indicating that they promote the sluggish catalytic kinetics of Pt in alkaline medium.
The Effect of Electrostatic Interaction on n‐Type Doping Efficiency of Fullerene Derivatives
Authors: Liu Jian , Maity Sudeshna , Roosloot Nathan , Qiu Xinkai , Qiu Li , Chiechi Ryan C. , Hummelen Jan C. , von Hauff Elizabeth , Koster L. Jan Anton
Published: February 2019

The molecular doping of organic semiconductors represents a key strategy for advancing organic electronic applications. However, the n‐doping of organic materials is usually less efficient than p‐doping and strategies toward the design of more efficient n‐doping still remain less explored. In this contribution, the impact of electrostatic interaction is explored on the doping efficiency of fullerene derivatives. [6,6]‐Phenyl‐C61‐butyric acid methyl ester (PCBM) and a [60]fulleropyrrolidine with a more polarizable triethylene glycol type side chain (PTEG‐1) are employed for a comparative study. It is found that the doping efficiency of lightly doped PCBM layers is limited to a few percent, while doped PTEG‐1 films exhibit very high doping efficiency approaching 100%. The enhanced n‐doping of PTEG‐1 compared with that of PCBM is further substantiated by Raman and Fourier transform infrared spectroscopic studies. The activation energy for charge generation in doped PTEG‐1 is much smaller than that of doped PCBM, which confirms a higher probability for dissociation of charge transfer complexes in the former compared to the latter. The enhanced molecular n‐doping for PTEG‐1 is attributed to the electrostatic interaction between the charge transfer complex and the polar environment offered by the triethylene glycol diether side chain.
Twist and Degrade—Impact of Molecular Structure on the Photostability of Nonfullerene Acceptors and Their Photovoltaic Blends
Authors: Luke Joel , Speller Emily M. , Wadsworth Andrew , Wyatt Mark F. , Dimitrov Stoichko , Lee Harrison K. H. , Li Zhe , Tsoi Wing C. , McCulloch Iain , Bagnis Diego , Durrant James R. , Kim Ji‐Seon
Published: February 2019

Nonfullerene acceptors (NFAs) dominate organic photovoltaic (OPV) research due to their promising efficiencies and stabilities. However, there is very little investigation into the molecular processes of degradation, which is critical to guiding design of novel NFAs for long‐lived, commercially viable OPVs. Here, the important role of molecular structure and conformation in NFA photostability in air is investigated by comparing structurally similar but conformationally different promising NFAs: planar O‐IDTBR and nonplanar O‐IDFBR. A three‐phase degradation process is identified: i) initial photoinduced conformational change (i.e., torsion about the core–benzothiadiazole dihedral), induced by noncovalent interactions with environmental molecules, ii) followed by photo‐oxidation and fragmentation, leading to chromophore bleaching and degradation product formation, and iii) finally complete chromophore bleaching. Initial conformational change is a critical prerequisite for further degradation, providing fundamental understanding of the relative stability of IDTBR and IDFBR, where the already twisted IDFBR is more prone to degradation. When blended with the donor polymer poly(3‐hexylthiophene), both NFAs exhibit improved photostability while the photostability of the polymer itself is significantly reduced by the more miscible twisted NFA. The findings elucidate the important role of NFA molecular structure in photostability of OPV systems, and provide vital insights into molecular design rules for intrinsically photostable NFAs.
Scaling of phloem hydraulic resistance in stems and leaves of the understory angiosperm shrub Illicium parviflorum
Authors: Losada Juan M. , Holbrook N. Michele
Published: February 2019

Premise of the Study

Recent studies in canopy‐dominant trees revealed axial scaling of phloem structure. However, whether this pattern is found in woody plants of the understory, the environment of most angiosperms from the ANA grade (Amborellales‐Nymphaeales‐Austrobaileyales), is unknown.

Methods

We used seedlings and adult plants of the understory tropical shrub Illicium parviflorum, a member of the lineage Austrobaileyales, to explore the anatomy and physiology of the phloem in their aerial parts, including changes through ontogeny.

Key Results

Adult plants maintain a similar proportion of phloem tissue across stem diameters, but larger conduit dimensions and number cause the hydraulic resistance of the phloem to decrease toward the base of the plant. Small sieve plate pores resulted in an overall higher sieve tube hydraulic resistance than has been reported in other woody angiosperms. Sieve elements increase in size from minor to major leaf veins, but were shorter and narrower in petioles. The low carbon assimilation rates of seedlings and mature plants contrasted with a 3‐fold higher phloem sap velocity in seedlings, suggesting that phloem transport velocity is modulated through ontogeny.

Conclusions

The overall architecture of the phloem tissue in this understory angiosperm shrub scales in a manner consistent with taller trees that make up the forest canopy. Thus, the evolution of larger sieve plate pores in canopy‐dominant trees may have played a key role in allowing woody angiosperms to extend beyond their understory origins.
Spontaneous pneumothorax and hemothorax frequently precede the arterial and intestinal complications of vascular Ehlers–Danlos syndrome
Authors: Shalhub Sherene , Neptune Enid , Sanchez Desiree E. , Dua Anahita , Arellano Nelson , McDonnell Nazli B. , Milewicz Dianna M.
Published: February 2019

Vascular Ehlers–Danlos syndrome (vEDS) is a connective tissue disorder due to defective type III collagen production and is associated with arterial rupture, spontaneous intestinal perforation, and gravid uterine rupture. Spontaneous pneumothorax and/or hemothorax (P/HTX) also occurs in vEDS patients. The temporal relation of pulmonary manifestations to arterial and intestinal complications in vEDS has not been well described. This was investigated in a multi‐institutional retrospective case series of vEDS patients with confirmatory testing for COL3A1 mutation between 2000 and 2012. Data abstracted included demographics, family histories, presentation, and management of associated complications. Ninety‐six cases (39% males, mean age 38.6 ± 15.5 years, range 8–79) had confirmatory testing for vEDS. P/HTX was documented in 17 (17.7%) cases. Most P/HTX preceded the diagnosis of vEDS (81%). Diagnosis of vEDS was made after arterial or intestinal complications at a mean of 7 years (range 0–26) post the initial P/HTX. In conclusion, spontaneous P/HTX is an early manifestation of vEDS frequently preceding an arterial complication or intestinal perforation. Thus, a spontaneous P/HTX in a young patient should trigger a differential diagnosis that includes vEDS. This should lead to an investigation of other vEDS features and subsequent genetic testing if vEDS features are present.
The neuroplastic effect of olfactory training to the recovery of olfactory system in mouse model
Authors: Kim Boo‐Young , Park Ju Yeon , Kim Eui Jin , Kim Byung Guk , Kim Sung Won , Kim Soo Whan
Published: February 2019

Background

Several studies have reported the benefits of olfactory training (OT) in the olfactory nervous system of mouse models. Therefore, in this study we performed next‐generation sequencing to evaluate the effects of OT on mRNA sequencing in the olfactory area.

Methods

Mice in each group were administered 300 mg of 3‐methylindole per kilogram of mouse weight. The olfactory function was evaluated by a food‐finding test once a week. The olfactory neuroepithelium was harvested for histologic examination and protein analysis. Subsequently, data analysis, gene ontology and pathway analysis, quantitative real‐time polymerase chain reaction of mRNA, and Western blot analysis were conducted.

Results

Mice were divided into 4 groups according to treatment. Control, anosmia, training, and steroid group mice resumed food finding. Olfactory Maker Protein, olfr1507, ADCY3, and GNAL mRNA expression was higher in the olfactory neuroepithelium of OT than anosmia group mice. In total, 26,364 mRNAs were analyzed. Comparison of the results of OT vs anosmia revealed that ADCY8,10, GFAP, NGF, NGFR, GFAP, and BDNF mRNAs were upregulated in the gene ontology.

Conclusion

OT improved olfactory function, as indicated by the food‐finding test. OT improved the olfactory recovery time to stimulate olfactory nerve regeneration. OT may initially stimulate the olfactory receptor, followed by neurogenesis. Steroid therapy and OT operated under completely different mechanisms in the upregulated gene study. These results indicate that OT may be one of the future modalities for treating olfactory impairment.
Catalyst‐Free Deaminative Functionalizations of Primary Amines by Photoinduced Single‐Electron Transfer
Authors: Wu Jingjing , Grant Phillip S. , Li Xiabing , Noble Adam , Aggarwal Varinder K.
Published: February 2019

The use of pyridinium‐activated primary amines as photoactive functional groups for deaminative generation of alkyl radicals under catalyst‐free conditions is described. By taking advantage of the visible light absorptivity of electron donor–acceptor complexes between Katritzky pyridinium salts and either Hantzsch ester or Et3N, photoinduced single‐electron transfer could be initiated in the absence of a photocatalyst. This general reactivity platform has been applied to deaminative alkylation (Giese), allylation, vinylation, alkynylation, thioetherification, and hydrodeamination reactions. The mild conditions are amenable to a diverse range of primary and secondary alkyl pyridiniums and demonstrate broad functional group tolerance.
Chemical Syntheses and Chemical Biology of Carboxyl Polyether Ionophores: Recent Highlights
Authors: Liu Han , Lin Shaoquan , Jacobsen Kristian M. , Poulsen Thomas B.
Published: February 2019

A central goal of chemical biology is to develop molecular probes that enable fundamental studies of cellular systems. In the hierarchy of bioactive molecules, the so‐called ionophore class occupies an unflattering position in the lower branches, with typical labels being “non‐specific” and “toxic”. In fact, the mere possibility that a candidate molecule possesses “ionophore activity” typically prompts its removal from further studies; ionophores—from a chemical genetics perspective—are molecular outlaws. In stark contrast to this overall poor reputation of ionophores, synthetic chemistry owes some of its most amazing achievements to studies of ionophore natural products, in particular the carboxyl polyethers renowned for their intricate molecular structures. These compounds have for decades been academic battlegrounds where new synthetic methodology is tested and retrosynthetic tactics perfected. Herein, we review the most exciting recent advances in carboxyl polyether ionophore (CPI) synthesis and in addition discuss the burgeoning field of CPI chemical biology.
CO2‐philic polyether‐block‐amide/glycerol triacetate blend membranes: gas‐permeation performance, thermal stability, and storage stability
Authors: Feng Shichao , Ren Jizhong , Zhao Dan , Li Hui , Hua Kaisheng , Li Xinxue , Deng Maicun
Published: February 2019

Polyether‐block‐amide (Pebax)/glycerol triacetate (GTA) blend membranes with various compositions were prepared with a solution‐casting method. The gas‐separation performance, thermal stability, and storage stability of the prepared membranes were investigated at different pressures and temperatures. The Arrhenius equation was used to describe the gas‐permeation performance of the Pebax1074/GTA membranes with a low GTA concentration (≤40 wt %) rather than those membranes with a high GTA concentration (>40 wt %). A higher GTA content, lower treatment temperature, and storage temperature increased the gas permeability and induced a stronger hydrostatic pressure effect. The low‐storage temperature was beneficial for fixing GTA on the blend membrane. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47620.
Acid‐treated Bentonite as filler in the development of novel composite PVA hydrogels
Authors: Sanchez Laura M. , Alvarez Vera A. , Ollier Romina P.
Published: February 2019

In this study, novel eco‐friendly hydrogel adsorbents were synthesized based on poly(vinyl alcohol) (PVA) and different contents of an acid‐treated bentonite (1–5 wt %). The hydrogels were prepared by freezing–thawing, which is a simple and nontoxic method. The materials were morphologically and thermally characterized by means of swelling assays, X‐ray diffraction, scanning electron microscopy, dynamic scanning calorimetry, and thermogravimetric analysis in order to evaluate the effect of acid‐treated bentonite loading. The composite hydrogels showed very distinct porous structure and thermal features in comparison to neat PVA as a consequence of the addition of the clay. Moreover, the performance of the obtained composite hydrogels was tested toward the adsorption of cationic (methylene blue) and anionic dyes (methyl red and methyl orange) from aqueous media. The presence of acid bentonite seems to be beneficial for improving the removal capacity of PVA‐based hydrogels. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47663.
Improved fracturing fluid using: Organic amino boron composite crosslinker with BN covalent bond
Authors: Zhang Zhaoyang , Mao Jincheng , Zhang Yang , Han Tianxing , Yang Bo , Xiao Wei
Published: February 2019

In order to create an improved fracturing fluid, an organic amine boron composite crosslinker (ABC‐1) was prepared from boric acid, triethylenetetramine, ethylene glycol, and mannitol. It has no irritating smell and its synthesis is simple, making it suitable for large‐scale field applications. To illustrate the advantages of the new crosslinker, it was compared to the organic borate crosslinker prepared from boric acid, ethylene glycol, and mannitol. The sand‐carrying capacities, micronetwork structure, and rheological behaviors of fluids with these crosslinkers were investigated at 90, 100, and 110 °C. The results show that the additional BN r covalent bond in the ABC‐1 crosslinker leads to the formation of a denser network structure making it possible to reduce the amount of thickener by about 10%. The temperature resistance could also be enhanced at least 10 °C. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47675.
Anatomical Sciences in Chiropractic Education: A Survey of Chiropractic Programs in Australia
Authors: Giuriato Rosemary , Štrkalj Goran , Meyer Amanda J. , Pather Nalini
Published: February 2019

Human anatomy knowledge is a core requirement for all health care clinicians. There is a paucity of information relating to anatomy content and delivery in Australian chiropractic programs. The aim of this study was to describe anatomy teaching in Australian chiropractic programs, utilizing a survey which was distributed to all four programs, requesting information on: anatomy program structure, delivery methods, assessment, teaching resources, and academic staff profile at their institution. The survey was undertaken in 2016 and documented practices in that academic year. All four institutions responded. There was a reported difference in the teaching hours, content, delivery and assessment of anatomy utilized in Australian chiropractic programs. Anatomy was compulsory at all four institutions with the mean total of 214 (SD ± 100.2) teaching hours. Teaching was undertaken by permanent ongoing (30%) and sessional academic staff, and student to teacher ratio varied from 15:1 to 12:1. A variety of teaching resources were utilized, including human tissue access, either as prosected cadavers or plastinated body parts. The results of this survey confirm that anatomy has an established place in chiropractic education programs in Australia and while curricular variations exist, all programs had similar course design, delivery, and assessment methods. This study confirmed the provision of a strong foundation in topographical anatomy and neuroanatomy, while other anatomical sciences, such as histology and embryology were not consistently delivered. Formalization of a core anatomy curriculum together with competency standards is needed to assist program evaluation and development, and for accreditation purposes.
The Spectrum of Learning and Teaching: The Impact of a Fourth‐Year Anatomy Course on Medical Student Knowledge and Confidence
Authors: Lufler Rebecca S. , Lazarus Michelle D. , Stefanik Joshua J.
Published: February 2019

There is growing demand from accrediting agencies for improved basic science integration into fourth‐year medical curricula and inculcation of medical students with teaching skills. The objective of this study was to determine the effectiveness of a fourth‐year medical school elective course focused on teaching gross anatomy on anatomical knowledge and teaching confidence. Fourth‐year medical student “teacher” participants' gross anatomy knowledge was assessed before and after the course. Students rated their overall perceived anatomy knowledge and teaching skills on a scale from 0 (worst) to 10 (best), and responded to specific knowledge and teaching confidence items using a similar scale. First‐year students were surveyed to evaluate the effectiveness of the fourth‐year student teaching on their learning. Thirty‐two students completed the course. The mean anatomy knowledge pretest score and posttest scores were 43.2 (±22.1) and 74.1 (±18.4), respectively (P < 0.001). The mean perceived anatomy knowledge ratings before and after the course were 6.19 (±1.84) and 7.84 (±1.30), respectively (P < 0.0001) and mean perceived teaching skills ratings before and after the course were 7.94 (±1.24) and 8.53 (±0.95), respectively (P = 0.002). Student feedback highlighted five themes which impacted fourth‐year teaching assistant effectiveness, including social/cognitive congruence and improved access to learning opportunities. Together these results suggest that integrating fourth‐year medical students in anatomy teaching increases their anatomical knowledge and improves measures of perceived confidence in both teaching and anatomy knowledge. The thematic analysis revealed that this initiative has positive benefits for first‐year students.
Fault reconstruction for delay systems via least squares and time‐shifted sliding mode observers
Authors: Pinto Hardy L. C. P. , Oliveira Tiago Roux , Hsu Liu
Published: February 2019

In this article, we address the problem of fault reconstruction in delayed systems by introducing a time‐shifted sliding mode observer (SMO). While time‐varying delays of arbitrary duration are considered in the measured output signal, the actuator fault is parametrized as a weighted sum of known regressor functions with unknown coefficients. The prediction scheme utilizes the variation of constants formula to obtain the present time estimate of the unmeasured state. The fault is also identified at present time by means of the continuous‐time Least Squares approaches. Ideal sliding mode can be guaranteed in theory, even in the presence of such adverse delays, since there is no chattering in the output estimation error of the SMO. An application to petroleum engineering with numerical simulations is presented to show the effectiveness of the proposed method.
Robust H∞ sliding mode observer‐based fault‐tolerant control for One‐sided Lipschitz nonlinear systems
Authors: Rastegari Abbas , Arefi Mohammad Mehdi , Asemani Mohammad Hassan
Published: February 2019

This paper presents fault tolerant controllers for a class of one‐sided Lipschitz nonlinear systems with external disturbances. A sliding mode observer (SMO) is integrated with the H∞ filtering approach as the fault detection and isolation module. The problem is investigated in the presence of faults and disturbances simultaneously. The H∞‐SMO is capable of approximating faults accurately, while reducing the effect of disturbances in the estimation of the state vector and occurred faults. Accordingly, using only a single SMO, the estimation error of the state vector and faults can be made simultaneously arbitrarily small. In addition, to deal with the weighted bilinear form appearing in the one‐sided Lipschitz condition, the quadratically inner bounded condition presented in the literature is employed in this paper as a useful solution. The proposed method guarantees the stability of the overall closed‐loop system, and after a short transient time, the estimation errors for state vector and fault signal converge to a small neighborhood of the origin. The effectiveness of the presented algorithm is confirmed in two examples including a single arm robot with a flexible joint and a numerical simulation.
Facile reflux synthesis of polyethyleneimine‐capped fluorescent carbon dots for sequential bioassays toward Cu2+/H2S and its application for a logic system
Authors: Chen Zi‐Han , Han Xin‐Yue , Lin Zi‐Yang , Fan Yu‐Lin , Shi Guoyue , Zhang Shengqiang , Zhang Min
Published: February 2019

In this work, we present a novel facile strategy for green synthesis of polyethyleneimine (PEI)‐capped carbon dots (PEI‐CDs), in which citric acid and PEI were chosen as reactants and highly fluorescent PEI‐CDs could be readily obtained via a simple one‐pot refluxing under 120 °C within 2 H. Fluorescence studies indicate that the as‐prepared PEI‐CDs exhibit strong fluorescence emission at 446 nm with excitation at 365 nm. Upon the sequential addition of Cu2+ and H2S, PEI‐CDs result in an interesting “ON−OFF−ON” three‐state emission responses, promising a bifunctional sensory platform. Moreover, the Cu2+/H2S‐facilated reversible fluorescence changes of PEI‐CDs have demonstrated the design of an INHIBIT logic system based on Boolean logic.
Differentially sensitive neuronal subpopulations in the central nervous system and the formation of hindbrain heterotopias in ethanol‐exposed zebrafish
Authors: Buckley Desire M. , Sidik Alfire , Kar Ranjeet D. , Eberhart Johann K.
Published: February 2019

Background

A cardinal feature of prenatal ethanol exposure is CNS damage, resulting in a continuum of neurological and behavioral impairments that are described by the term fetal alcohol spectrum disorders (FASD). FASDs are variable and depend on several factors, including the amount, timing, and duration of prenatal ethanol exposure. To enhance interventions for CNS dysfunction, it is necessary to identify ethanol‐sensitive neuronal populations and expand the understanding of factors that modify ethanol teratogenesis.

Methods

To investigate the susceptibility of different neuronal subtypes, we exposed transgenic zebrafish (Danio rerio) to several ethanol concentrations (0.25, 0.5, 1.0, 1.5, or 2.0%), at different hours post fertilization (hpf; 0, 6, or 24 hpf), for various durations (0–24, 0–48, 4–24, 6–24, 6–48,or 24–48 hpf). Following exposure, embryo survival rates were determined, and CNS neurogenesis, differentiation, and patterning were assessed.

Results

Embryo survival rates decrease as ethanol concentrations increase and drastically decline when exposed from 0–24 hpf compared to 4–24 hpf. Abnormal tangential migration of facial motor neurons is observed in isl1:gfp embryos exposed to ethanol concentrations as low as 0.25%, and the formation of IVth ventricle heterotopias are revealed by embryos exposed to ≥1.0% ethanol. Whereas, expression of olig2:dsred and ptf1a:gfp in the cerebellum and spinal cord are largely unaffected. While levels of etv4 mRNA are overtly resistant to ethanol, we observe significant reductions in ptch2 mRNA levels.

Conclusions

These data show differentially sensitive CNS neuron subpopulations with susceptibility to low levels of ethanol. In addition, these data reveal the formation of ethanol‐induced hindbrain heterotopias.
Do Telomeres Influence Pace‐of‐Life‐Strategies in Response to Environmental Conditions Over a Lifetime and Between Generations?
Authors: Giraudeau Mathieu , Angelier Frederic , Sepp Tuul
Published: February 2019

The complexity of the physiological phenotype currently prevents us from identifying an integrative measure to assess how the internal state and environmental conditions modify life‐history strategies. In this article, it is proposed that shorter telomeres should lead to a faster pace‐of‐life where investment in self‐maintenance is decreased as a means of saving energy for reproduction, but at the cost of somatic durability. Inversely, longer telomeres would favor an increased investment in soma maintenance and thus a longer reproductive lifespan (i.e., slower pace‐of‐life). Under this hypothesis, telomere dynamics could be such an integrative mediator, which will assemble the information about oxidative stress levels, inflammation status and stress reactivity, and relate this information to the potential lifespan of the organism and its pace‐of‐life strategy. The signaling function of telomere dynamics can also reach over generations, a phenomenon in which the telomere lengths of gametes would provide a channel through which offspring would receive information about their environment early in their development, hence increasing the possibilities for developmental plasticity.
Stable isotope dilution assay for the accurate determination of tricaine in fish samples by HPLC–MS–MS
Authors: Xie Chaonan , Li Qin , Han Gang , Liu Huan , Yang Jien , Li Jincheng
Published: February 2019

Tricaine methanesulfonate is one of most commonly used anesthetics in fish during blood sampling, artificial propagation and long‐distance transportation. In this study, an accurate method for the quantitative determination of tricaine in fish samples by a stable isotope dilution assay coupled with high‐performance liquid chromatography–triple quadrupole mass spectrometry was developed. Tricaine‐D5 was synthesized and used as an isotopically labeled internal standard for the determination of tricaine. The analytical performance of the method was validated for tricaine determination in marine fish and freshwater fish. The determination of tricaine was linear in the range of 2.0–200.0 μg L−1. The limit of detection and limit of quantitation for fish muscle tissues were 1.0 and 4.0 μg kg−1, respectively. Good recoveries were obtained in the range of 92.08–97.50%. The inter‐ and intra‐assay relative standard deviations (RSD values) were investigated, and the values were 0.39–3.01 and 0.85–2.77%, respectively. The values of CCα and CCβ were 10.21–10.43 and 10.42–10.87 μg kg−1, respectively. The clearance of MS‐222 from grass carp was further studied using our method. The results demonstrate that MS‐222 could be well absorbed and rapidly eliminated after bath administration.
Cumulative evidence for association between genetic polymorphisms and esophageal cancer susceptibility: A review with evidence from meta‐analysis and genome‐wide association studies
Authors: Tian Jie , Liu Caiyang , Liu Guanchu , Zuo Chunjian , Chen Huanwen
Published: February 2019

An increasing number of publications had reported the association between single‐nucleotide polymorphisms (SNPs) and esophageal cancer (EC) risk in the past decades. Results from these publications were controversial. We used PubMed, Medline, and Web of Science to identify meta‐analysis articles published before 30 July 2018, that summarize a comprehensive investigation for cumulative evidence of genetic polymorphisms of EC and its subtype risk. Two methods, Venice criteria and false‐positive report probability (FPRP) tests, were used to assess cumulative evidence of significant associations. At last, 107 meta‐analyses were considered to be in conformity with the inclusion criteria, yielding 51 variants associated with EC or esophageal squamous cell carcinoma (ESCC). Thirty‐eight variants were considered to be nominally significant associated with risk of EC or ESCC, whereas the rest showed non‐association. In additional, five variants on five genes were rated as strong cumulative epidemiological evidence for a nominally significant association with EC and ESCC risk, including CYP1A1 rs1048943, EGF rs444903, HOTAIR rs920778, MMP2 rs243865, and PLCE1 rs2274223, 10 variants were rated as moderate, and 18 variants were rated as weak. Additionally, 17 SNPs were verified noteworthy in six genomewide association studies (GWAS) using FPRP methods. Collectively, this review offered a comprehensively referenced information with cumulative evidence of associations between genetic polymorphisms and EC and ESCC risk.
Magnolol induces cell death through PI3K/Akt‐mediated epigenetic modifications boosting treatment of BRAF‐ and NRAS‐mutant melanoma
Authors: Emran Abdullah Al , Chinna Chowdary Brinda Reddy , Ahmed Farzana , Hammerlindl Heinz , Huefner Antje , Haass Nikolas K. , Schuehly Wolfgang , Schaider Helmut
Published: February 2019

Most BRAF‐mutant melanoma patients experience a fulminate relapse after several months of treatment with BRAF/MEK inhibitors. To improve therapeutic efficacy, natural plant‐derived compounds might be considered as potent additives. Here, we show that magnolol, a constituent of Magnolia officinalis, induced G1 arrest, apoptosis and cell death in BRAF‐ and NRAS‐mutant melanoma cells at low concentration, with no effect in BRAF‐ and NRAS wild‐type melanoma cells and human keratinocytes. This was confirmed in a 3D spheroid model. The apoptosis‐inducing effect of magnolol was completely rescued by activating Akt suggesting a mechanism relying primarily on Akt signaling. Magnolol significantly downregulated the PI3K/Akt pathway which led to a global decrease of the active histone mark H3K4me3. Alongside, the repressive histone mark H3K9me3 was increased as a response to DNA damage. Magnolol‐induced alterations of histone modifications are reversible upon activation of the Akt pathway. Magnolol‐induced a synergistic effect in combination with either BRAF/MEK inhibitors dabrafenib/trametinib or docetaxel at a lower concentration than usually applied in melanoma patients. Combination of magnolol with targeted therapy or chemotherapy also led to analogous effects on histone marks, which was rescued by Akt pathway activation. Our study revealed a novel epigenetic mechanism of magnolol‐induced cell death in melanoma. Magnolol might therefore be a clinically useful addition to BRAF/MEK inhibitors with enhanced efficacy delaying or preventing disease recurrence.
Volatile Chemical Composition, Antibacterial and Antifungal Activities of Extracts from Different Parts of Globba schomburgkii Hook.f.
Authors: Doungchawee Jeerapat , Kulsing Chadin , Suekaew Naruemon , Na Pombejra Sarisa , Chavasiri Warinthorn , Plabutong Napasawan , Thammahong Arsa , Khotavivattana Tanatorn
Published: February 2019

Globba schomburgkii Hook.f. is an ornamental plant that has recently found increasing demand as cut flowers, hence generating a significant number of by‐products from different parts of the plant. To investigate the further applications of these by‐products, twelve crude extracts from rhizomes, stalks, leaves, and flowers were prepared by serial exhaustive extraction. The volatile composition of these extracts was analyzed by GC/MS; a total of 89 compounds were identified, most of which were sesquiterpenes as well as some labdane‐type diterpenes. The antimicrobial activities of these extracts were evaluated, revealing a correlation between the terpenoid content and antibacterial activities. Notably, the dichloromethane extracts of rhizomes and flowers, which contained the highest amount of terpenoids (e. g., α‐gurjunene, guaia‐9,11‐diene, γ‐bicyclohomofarnesal, β‐caryophyllene, and caryophyllene oxide), displayed the most prominent antibacterial activities. This work demonstrates the potential use of the crude extracts from G. schomburgkii as natural antibacterial ingredients for pharmaceutical and other applications.
Tailored Hollow Core/Mesoporous Shell Carbon Nanofibers as Highly Efficient and Durable Cathode Catalyst Supports for Polymer Electrolyte Fuel Cells
Authors: Karuppanan Karthikeyan K. , Raghu Appu V. , Panthalingal Manoj Kumar , Pullithadathil Biji
Published: February 2019

An electrocatalyst support material based on hierarchical mesoporous hollow carbon nanofibers (mPHCNFs) has been developed by co‐axial electrospinning and has been deployed for the fabrication of polymer electrolyte membrane fuel cells (PEMFCs). The synergistic effect of a high specific surface area (780 m2/g), homogeneous formation of mesopores (20–50 nm), and hollow nanochannels in the carbon nanofiber matrix lead to the uniform distribution of Pt electrocatalysts. XPS analysis revealed that the presence of nitrogen species in the mesoporous hollow carbon nanofibers in the form of pyridinic, pyrrolic, and quaternary nitrogen atoms played a crucial role in the augmentation of triple‐phase boundaries. Pt/mPHCNFs exhibited superior electrocatalytic activity towards the oxygen reduction reaction with a positively shifted onset potential (62 mV) and half‐wave potential (86 mV) as well as a high limiting current density (4.76 mA/cm2) compared to commercial electrocatalysts. The Pt/mPHCNFs catalyst exhibited excellent stability in acidic medium and showed only 23 mV loss in the half‐wave potential; whereas, Pt/CNFs (35 mV) and Pt/C (77 mV) exhibited a much higher shift in half‐wave potential. The PEMFC testing of the membrane electrode assembly based on Pt/mPHCNFs (411 mW/cm2) revealed a superior performance compared to Pt/CNFs (297.4 mW/cm2) and Pt/C (212.8 mW/cm2). This method can offer an effective strategy for the development of durable, low‐cost, and high‐performance PEMFCs.
Uncatalyzed Oxidative C−H Amination of 9,10‐Dihydro‐9‐Heteroanthracenes: A Mechanistic Study
Authors: van Leest Nicolaas P. , Grooten Lars , van der Vlugt Jarl Ivar , de Bruin Bas
Published: February 2019

A new method for the one‐step C−H amination of xanthene and thioxanthene with sulfonamides is reported, without the need for any metal catalyst. A benzoquinone was employed as a hydride (or two‐electron and one‐proton) acceptor. Moreover, a previously unknown and uncatalyzed reaction between iminoiodanes and xanthene, thioxanthene and dihydroacridines (9,10‐dihydro‐9‐heteroanthracenes or dihydroheteroanthracenes) is disclosed. The reactions proceed through hydride transfer from the heteroarene substrate to the iminoiodane or benzoquinone, followed by conjugate addition of the sulfonamide to the oxidized heteroaromatic compounds. These findings may have important mechanistic implications for metal‐catalyzed C−H amination processes involving nitrene transfer from iminoiodanes to dihydroheteroanthracenes. Due to the weak C−H bond, xanthene is an often‐employed substrate in mechanistic studies of C−H amination reactions, which are generally proposed to proceed via metal‐catalyzed nitrene insertion, especially for reactions involving nitrene or imido complexes that are less reactive (i.e., less strongly oxidizing). However, these substrates clearly undergo non‐catalyzed (proton‐coupled) redox coupling with amines, thus providing alternative pathways to the widely assumed metal‐catalyzed pathways.
Polyhydroxyalkanoate‐Modified Bacterium Regulates Biomass Structure and Promotes Synthesis of Carbon Materials for High‐Performance Supercapacitors
Authors: Zhang Kejing , Liu Mingren , Si Mengying , Wang Zhongren , Zhuo Shengnan , Chai Liyuan , Shi Yan
Published: February 2019

Biomass‐derived carbons have been extensively explored as electrode materials in supercapacitors. However, the type of biomass selected and its specific structure affects the synthesis of the advanced biomass‐derived carbon materials. A green and facile method for the synthesis of carbon material with nanoscale and microscale porous structures for supercapacitors has been developed, based on regulating the original cell structure of the bacterial strain. The cell structure is modified in situ by regulating the accumulation of polyhydroxyalkanoate under controlled cultivation conditions. The novel bacterial in situ modification and nitrogen doping endow this hierarchically derived carbon material with improved performance. This material exhibits an extremely high specific capacitance (420 F g−1 at 1 A g−1) and long cycling stability (97 % capacitance retention after 10 000 cycles at 5 A g−1) in aqueous electrolytes. More importantly, the symmetric supercapacitor delivers a superior energy density of 60.76 Wh kg−1 at 625 W kg−1 in an ionic liquid electrolyte system. Moreover, all components in the synthesis are low in cost, environmentally friendly, and biocompatible. With these unique features, the bacterial self‐modification mode opens new avenues into the design and production of a wide range of hierarchical structures.
Correlation of cytopathology with flow cytometry and histopathology for the diagnosis of hematologic malignancies in young adults presenting with cervical lymphadenopathy
Authors: Choy Bonnie , Venkataraman Girish , Biernacka Anna , Lastra Ricardo R. , Mueller Jeffery , Setia Namrata , Reeves Ward , Antic Tatjana
Published: February 2019

Background

Fine‐needle aspiration (FNA) is frequently utilized in the diagnostic workup of lymphadenopathy. We evaluated the correlation of cytopathology with flow cytometry and tissue biopsy results and assessed the prevalence of specific malignancies in young adults presenting with cervical lymphadenopathy.

Methods

Database was searched for cervical lymph node FNA performed by a cytopathologist in patients aged 18‐30 years from 2005 to 2017.

Results

Cervical lymph node FNA was performed on 48 patients without prior history of malignancy. Nineteen patients had cytology results only, of which all were interpreted as benign reactive lymph node. None developed subsequent malignancies. The remaining 29 patients had cytology with flow cytometry and/or tissue biopsy results. A benign reactive cytology diagnosis was rendered in 18 (62%) cases, of which 11 had concordant diagnosis on flow cytometry, 2 had tissue biopsy, and 3 had both. Eleven (38%) patients had cytology results concerning for a hematologic malignancy, of which 7 were confirmed by flow cytometry and 3 by both flow cytometry and tissue biopsy. Cervical lymph node FNA has 94.1% sensitivity, 83.3% specificity, 88.9% positive predictive value, and 90.9% negative predictive value. The most common hematologic malignancy in our young adult population presenting with cervical lymphadenopathy was Hodgkin lymphoma.

Conclusion

FNA is a useful first‐line diagnostic procedure for assessing cervical lymphadenopathy in young adults to allow for better triage of specimens for flow cytometry and/or tissue biopsy concerning for a hematologic malignancy and potentially avoid invasive excisional biopsy in a proportion of cases.
Transcriptome analysis predicts mode of action of benzimidazole molecules against Staphylococcus aureus UAMS‐1
Authors: Chauhan Deepika , Hati Santanu , Priyadarshini Richa , Sen Subhabrata
Published: February 2019

Antimicrobial drug resistance is one of the most critical problems that plagued the human race in modern times. Discovery of novel antibiotics is important to counter this threat. Accordingly, herein we have reported the discovery of substituted benzimidazole class of molecules with antimicrobial property (specifically against Staphylococcus aureus). They were initially identified through a random screening and a novel catalytic synthetic strategy was utilized to access them. in vitro screening and phenotypic profiling revealed the antimicrobial nature. De novo transcriptome and gene analyses predicted the putative targets. This work provides a solid foundation for developing the benzimidazoles as a target specific antimicrobial preclinical candidate.
A comparison of techniques for classifying behavior from accelerometers for two species of seabird
Authors: Patterson Allison , Gilchrist Hugh Grant , Chivers Lorraine , Hatch Scott , Elliott Kyle
Published: February 2019

The behavior of many wild animals remains a mystery, as it is difficult to quantify behavior of species that cannot be easily followed throughout their daily or seasonal movements. Accelerometers can solve some of these mysteries, as they collect activity data at a high temporal resolution (<1 s), can be relatively small (<1 g) so they minimally disrupt behavior, and are increasingly capable of recording data for long periods. Nonetheless, there is a need for increased validation of methods to classify animal behavior from accelerometers to promote widespread adoption of this technology in ecology. We assessed the accuracy of six different behavioral assignment methods for two species of seabird, thick‐billed murres (Uria lomvia) and black‐legged kittiwakes (Rissa tridactyla). We identified three behaviors using tri‐axial accelerometers: standing, swimming, and flying, after classifying diving using a pressure sensor for murres. We evaluated six classification methods relative to independent classifications from concurrent GPS tracking data. We used four variables for classification: depth, wing beat frequency, pitch, and dynamic acceleration. Average accuracy for all methods was >98% for murres, and 89% and 93% for kittiwakes during incubation and chick rearing, respectively. Variable selection showed that classification accuracy did not improve with more than two (kittiwakes) or three (murres) variables. We conclude that simple methods of behavioral classification can be as accurate for classifying basic behaviors as more complex approaches, and that identifying suitable accelerometer metrics is more important than using a particular classification method when the objective is to develop a daily activity or energy budget. Highly accurate daily activity budgets can be generated from accelerometer data using multiple methods and a small number of accelerometer metrics; therefore, identifying a suitable behavioral classification method should not be a barrier to using accelerometers in studies of seabird behavior and ecology.
Geographic patterns in morphometric and genetic variation for coyote populations with emphasis on southeastern coyotes
Authors: Hinton Joseph W. , Heppenheimer Elizabeth , West Kyla M. , Caudill Danny , Karlin Melissa L. , Kilgo John C. , Mayer John Joseph , Miller Karl V. , Walch Margaret , vonHoldt Bridgett , Chamberlain Michael J.
Published: February 2019

Prior to 1900, coyotes (Canis latrans) were restricted to the western and central regions of North America, but by the early 2000s, coyotes became ubiquitous throughout the eastern United States. Information regarding morphological and genetic structure of coyote populations in the southeastern United States is limited, and where data exist, they are rarely compared to those from other regions of North America. We assessed geographic patterns in morphology and genetics of coyotes with special consideration of coyotes in the southeastern United States. Mean body mass of coyote populations increased along a west‐to‐east gradient, with southeastern coyotes being intermediate to western and northeastern coyotes. Similarly, principal component analysis of body mass and linear body measurements suggested that southeastern coyotes were intermediate to western and northeastern coyotes in body size but exhibited shorter tails and ears from other populations. Genetic analyses indicated that southeastern coyotes represented a distinct genetic cluster that differentiated strongly from western and northeastern coyotes. We postulate that southeastern coyotes experienced lower immigration from western populations than did northeastern coyotes, and over time, genetically diverged from both western and northeastern populations. Coyotes colonizing eastern North America experienced different selective pressures than did stable populations in the core range, and we offer that the larger body size of eastern coyotes reflects an adaptation that improved dispersal capabilities of individuals in the expanding range.
Copper‐Catalyzed Annulation/A3‐Coupling Cascade: Diastereodivergent Synthesis of Sterically Hindered Monocyclic Oxazolidines Bearing Multiple Stereocenters
Authors: Feng Huangdi , Zhang Yazhen , Zhang Zedi , Chen Fubei , Huang Liliang
Published: February 2019

The Cu‐catalyzed synthesis of densely functionalized chiral oxazolidines with three stereogenic centers via an annulation/A3‐coupling cascade is described using chiral 1,2‐amino alcohol precursors. The solvent‐free synthetic approach tolerates an extremely broad substrate scope of the starting compounds (aldehydes, and alkynes), and provides the sterically hindered target monocyclic molecules with good yields and excellent diastereomeric ratio. Moreover, changing the alkyne to a propiolic acid is demonstrated here to be useful, and the corresponding titled products can be employed as a convenient building block for the preparation of 1,4‐diamino‐2‐butynes via one‐pot, two‐step sequential reaction.