bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Dimensions/Units and Universal Constants: Their Invariance in Special and General Relativity
Authors: Hehl Friedrich W. , Lämmerzahl Claus
Published: January 2019

The theory of physical dimensions and units in physics is outlined. This includes a discussion of the universal applicability and superiority of quantity equations. The International System of Units (SI) is one example thereof. By analyzing mechanics and electrodynamics, it naturally leads one, besides the dimensions of length and time, to the fundamental units of action , electric charge q, and magnetic flux ϕ. Also, and are known. These results of classical physics suggests to look into the corresponding quantum aspects of q and ϕ (and also of ): The electric charge occurs exclusively in elementary charges e, whereas the magnetic flux can have any value; in specific situations, however, in superconductors of type II at very low temperatures, ϕ appears quantized in the form of fluxons (Abrikosov vortices). And leads, of course, to the Planck quantum h. Thus, one is directed to superconductivity and, because of the resistance, to the quantum Hall effect. In this way, the Josephson and the quantum Hall effects come into focus quite naturally. One goal is to determine the behavior of the fundamental constants in special and in general relativity.
Duale Gold/Silber‐Katalyse über oxidative Addition zu Alkinylgold(III)‐Zwischenstufen und silberkatalysierte C‐H‐Aktivierung für die direkte Alkinylierung von Cyclopropenen
Authors: Yang Yangyang , Antoni Patrick , Zimmer Marc , Sekine Kohei , Mulks Florian F. , Hu Long , Zhang Lumin , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: January 2019

Während goldkatalysierte synergistische katalytische Prozesse, die Transmetallierung mit anderen Metallen einbeziehen, gut verstanden sind, sind AuI/AuIII‐Zyklen in diesen Reaktionen sehr selten. Hier wird eine goldkatalysierte direkte Alkinylierung von Cyclopropenen über zwei aktive Katalysezyklen ermöglicht, ein oxidativer Katalysezyklus mit einem über oxidative Addition gebildeten Alkinyl‐AuIII‐Komplex, und eine silbervermittelte C‐H‐Aktivierung.
Stereospecific α‐Sialylation by Site‐Selective Fluorination
Authors: Hayashi Taiki , Kehr Gerald , Bergander Klaus , Gilmour Ryan
Published: January 2019

Sialic acids are ubiquitous components of mammalian cell membranes and key regulators of cellular recognition events. Located at the non‐reducing termini of bioactive gangliosides, these essential building blocks are fused to the polysaccharide core via a characteristic α‐linkage, and rarely occur in the monomeric form. Effective chemical strategies to enable α‐sialylation are urgently required to construct well‐defined tools for glycomics. To complement existing chemoenzymatic strategies, an α‐selective process has been devised based on the site‐selective introduction of fluorine at C3 (more than 20 examples, up to 90 % yield). Predicated on localized particle charge inversion (C−Hδ+→C−Fδ−), fluorine insertion simultaneously augments the anomeric effect, enhances electrophilicity at C2 and mitigates elimination. A stereochemical induction model is postulated that spans the SN continuum and validates the role of the C−F bond in orchestrating α‐selectivity.
Production of Terephthalic Acid from Corn Stover Lignin
Authors: Song Song , Zhang Jiaguang , Gözaydın Gökalp , Yan Ning
Published: January 2019

Funneling and functionalization of a mixture of lignin‐derived monomers into a single high‐value chemical is fascinating. Reported herein is a three‐step strategy for the production of terephthalic acid (TPA) from lignin‐derived monomer mixtures, in which redundant, non‐uniform substitutes such as methoxy groups are removed and the desired carboxy groups are introduced. This strategy begins with the hydro‐treatment of corn‐stover‐derived lignin oil over a supported molybdenum catalyst to selectively remove methoxy groups. The generated 4‐alkylphenols are converted into 4‐alkylbenzoic acids by carbonylation with carbon monoxide. The Co‐Mn‐Br catalyst then oxidizes various alkyl chains into carboxy groups, transforming the 4‐alkylbenzoic acid mixture into a single product: TPA. For this route, the overall yields of TPA based on lignin content of corn stover could reach 15.5 wt %, and importantly, TPA with greater than 99 % purity was obtained simply by first decanting the reaction mixture and then washing the solid product with water.
Predicting the Limit of Intramolecular Hydrogen Bonding with Classical Molecular Dynamics
Authors: Colizzi Francesco , Hospital Adam , Zivanovic Sanja , Orozco Modesto
Published: January 2019

The energetics of intramolecular recognition processes are governed by the balance of pre‐organization and flexibility, which is often difficult to measure and hard to predict. Using classical MD simulations, we predict and quantify the effective strength of intramolecular hydrogen bonds between donor and acceptor sites separated by a variable alkyl linker in several solvents and crowded solutions. The balance of entropic and enthalpic contributions poses a solvent‐dependent limit to the occurrence of intramolecular H‐bonding. Still, free energies show a constant offset among different solvents with, for example, a 13 kJ mol−1 difference between water and chloroform. Molecular crowding shows little effect on the thermodynamic equilibrium, but induces variations on the H‐bond kinetics. The results are in quantitative agreement with experiments in chloroform and showcase a general strategy to investigate molecular interactions in different environments, extending the limits of current experiments towards the prospective prediction of H‐bond interactions in a variety of contexts.
Promoting the Outgrowth of Neurites on Electrospun Microfibers by Functionalization with Electrosprayed Microparticles of Fatty Acids
Authors: Xue Jiajia , Wu Tong , Li Jianhua , Zhu Chunlei , Xia Younan
Published: January 2019

Controlling the outgrowth of neurites is important for enhancing the repair of injured nerves and understanding the development of nervous systems. Herein we report a simple strategy for enhancing the outgrowth of neurites through a unique integration of topographical guidance and a chemical cue. We use electrospray to easily functionalize the surface of a substrate with microparticles of natural fatty acids at a controllable density. Through a synergistic effect from the surface roughness arising from the microparticles and the chemical cue offered by the fatty acids, the outgrowth of neurites from PC12 cells is greatly enhanced. We also functionalize the surfaces of uniaxially aligned, electrospun microfibers with the microparticles and further demonstrate that the substrates can guide and enhance directional outgrowth of neurites from both PC12 multicellular spheroids and chick embryonic dorsal root ganglia bodies.
Migratory Shift in Oxidative Cyclodehydrogenation Reaction of Tetraphenylethylenes Containing Electron‐Rich THDTAP Moiety
Authors: Wu Yuewei , Yan Chaoxian , Li Dongxu , Yuan Chengshan , Sun Jibin , Zhou Shuyun , Zhang Hao‐Li , Shao Xiangfeng
Published: January 2019

Four tetraphenylethylenes (2 a–d) containing an electron‐rich 2,3,4,6‐tetrahydro‐1,6‐dithia‐3a‐azaphenalene (THDTAP) moiety have been synthesized. The 2 a–d show aggregation‐induced emission (AIE) with yellowish green photoluminescence (PL) in THF‐H2O (v/v, 1:9) solution and in the solid state. Compounds 2 a–d undergo 1,2‐migratory shift in oxidative cyclodehydrogenation reactions to afford the unexpected products 3 a–d which display green PL in CH2Cl2 solution and are non‐emissive in the solid state. The PL intensities of 3 a–d are clearly enhanced in the presence of meta‐chloroperoxybenzoic acid (mCPBA) owing to the oxidation of the S‐atoms on the THDTAP moiety. In contrast, the PL of 2 a–d in THF‐H2O (v/v, 1:9) solution is quenched by adding mCPBA, ascribable to the oxidation of the C=C bond on the ethylene moiety. It is found that the absorption of 3 a–d is distinctly red‐shifted from the UV/Vis region to the NIR region upon acidification, arising from the protonation of the N‐atom on the THDTAP moiety. Furthermore, 3 a–d display nonlinear optical response (NLO) and optical limiting (OL) behaviour which is superior to that of the well‐known OL material C60.
Making Solid‐Phase Peptide Synthesis Greener: A Review of the Literature
Authors: Varnava Kyriakos G. , Sarojini Vijayalekshmi
Published: January 2019

To date, the synthesis of peptides is concurrent with the production of enormous amounts of toxic waste. DMF, CH2Cl2, and NMP are three of the most toxic organic solvents used in chemical synthesis and are the most common solvents used for peptide synthesis. Additionally, concerns about the hepatotoxicity caused by exposure to DMF and from the toxic and allergenic nature of additives used in peptide synthesis necessitates the need for a green, environmentally friendly, and safer protocol for peptide synthesis. This review summarizes the current literature on green solid‐phase peptide synthesis successes and challenges encountered. The review concludes with suggestions for future research towards a simple and efficient green peptide synthesis protocol.
Association between CNTNAP2 polymorphisms and autism: A family‐based study in the chinese han population and a meta‐analysis combined with GWAS data of psychiatric genomics consortium
Authors: Zhang Tian , Zhang Jishui , Wang Ziqi , Jia Meixiang , Lu Tianlan , Wang Han , Yue Weihua , Zhang Dai , Li Jun , Wang Lifang
Published: January 2019

Autism is a childhood neuropsychiatric disorder with evidence of a strong genetic component in the complex etiologies. Contactin‐associated protein‐like 2 (CNTNAP2), a member of the neurexin superfamily, plays an essential role in neural development. CNTNAP2 was considered as one of the most susceptible genes for autism spectrum disorder (ASD). Some studies indicated the association of CNTNAP2 with ASD, while others reported no association. Given the inconsistent results of the previous studies, we performed a family‐based association study between 9 single‐nucleotide polymorphisms (SNPs) of CNTNAP2 and autism in 640 autistic trios in the Chinese Han population. Then, an updated meta‐analysis, combined with the data from Psychiatric Genomics Consortium (iPSYCH‐PGC ASD, 2017) and available association studies, was conducted. No SNPs were significantly associated with autism in the Chinese Han population. In the meta‐analysis, the two frequently reported SNPs (rs2710102 and rs7794745) showed no significant association with ASD. Therefore, CNTNAP2 polymorphisms might not be associated with autism. Autism Research 2019, 12: 553–561. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

In present family‐based association study, no single‐nucleotide polymorphisms (SNPs) were significantly associated with autism in the Chinese Han population. In the updated meta‐analysis, the association between the two frequently reported SNPs (rs2710102 and rs7794745) in CNTNAP2 and the risk of ASD was explored. However, the results showed no significant association. Therefore, our study suggested that CNTNAP2 polymorphisms might not be associated with autism.
Women's periconceptional lowered carbohydrate intake and NTD‐affected pregnancy risk in the era of prefortification with folic acid
Authors: Shaw Gary M. , Yang Wei
Published: January 2019

Background

A recent study observed women's restricted carbohydrate diet in the year before conception was associated with increased risk of neural tube defect (NTD)‐affected pregnancies. That study corresponded to the era of postfortification of folic acid. Because folic acid and carbohydrate measures would derive from similar foods, investigators of that study could not determine whether the increased risk with restricted carbohydrate intake was a consequence of lower folate intake. We extend their novel observation by examining rigorous NTD data prior to folic acid fortification.

Methods

Data were derived from a population‐based case–control study of fetuses and infants with NTDs among 1989–1991 California births. Interviews were conducted with mothers of 449 NTD cases and with mothers of 458 nonmalformed controls. A standard 100‐item food frequency questionnaire was used to assess macro‐ and micronutrient intakes based on reported intakes 3 months before conception.

Results

Case mothers were twice as likely to have consumed a low carbohydrate (≤5th percentile intake among controls) diet with a crude odds ratio of 2.0 (95% confidence interval, 1.2–3.4). Adjustment for race/ethnicity, education, alcohol intake, and folic acid use made very little difference on the odds ratio. Adjustment for total energy intake appeared to be the only factor to slightly attenuate the odds ratio.

Conclusion

Our findings indicate that the association between low carbohydrate intake and NTD risk may not be wholly a function of low folic acid in the postfortification era. Such a finding offers new clues to pursue for the seemingly folate‐insensitive NTDs that continue to occur.
High quantum yield and well‐dispersed quantum dots luminescent composite through sodium carboxymethyl starch
Authors: Liu Cui , Liu Yang , Deng Heming , Tang Shun , Cao Yuan‐Cheng
Published: January 2019

It is a challenging task to prepare well‐dispersed and highly luminescent quantum dots (QDs) powder and a new strategy is reported in this article. Sodium carboxymethyl starch (CMS‐Na) was employed in this work to prepare the QDs–starch composite. Ultraviolet (UV) light shows that the blank starches had no fluorescence, while the QDs‐starches were highly luminescent. Scanning electron microscopy (SEM) observation shows that the QDs–starch composite has the typical particle morphology with the diameter around 200 nm. Energy dispersive X‐ray spectroscopy (EDX) results show that there are intensive tellurium (Te) and cadmium (Cd) element signals. Combined fluorescent lifetime and steady‐state spectrometer show that the QDs–starch quantum yields (QYs) increase when the QDs loading increases from 1 × 10−6 mol/g to 2 × 10−6 mol/g, but when the loadings further increase, the QYs decrease slightly. For the red colour (λem = 660 nm) QDs, the QYs can reach to as high as 28.2%, and for the other colour QDs they can also have the QYs above 22%. Time‐resolved photobleaching experiments show that the fluorescent QDs–starch composite has a half‐decay time of 40.23 s. These results indicate that the CMS‐Na is a promising QDs dispersant to obtain high QY QD composites.
Synergistic Surface Passivation of CH3NH3PbBr3 Perovskite Quantum Dots with Phosphonic Acid and (3‐Aminopropyl)triethoxysilane
Authors: Xu Ke , Vickers Evan T. , Rao Longshi , Lindley Sarah A. , Allen A'Lester C. , Luo Binbin , Li Xueming , Zhang Jin Zhong
Published: January 2019

CH3NH3PbBr3 perovskite quantum dots (PQDs) are synthesized by using four different linear alkyl phosphonic acids (PAs) in conjunction with (3‐aminopropyl)triethoxysilane (APTES) as capping ligands. The resultant PQDs are characterized by means of XRD, TEM, Raman spectroscopy, FTIR spectroscopy, UV/Vis, photoluminescence (PL), time‐resolved PL, and X‐ray photoelectron spectroscopy (XPS). PA chain length is shown to control the PQD size (ca. 2.9–4.2 nm) and excitonic absorption band positions (λ=488–525 nm), with shorter chain lengths corresponding to smaller sizes and bluer absorptions. All samples show a high PL quantum yield (ca. 46–83 %) and high PL stability; this is indicative of a low density of band gap trap states and effective surface passivation. Stability is higher for smaller PQDs; this is attributed to better passivation due to better solubility and less steric hindrance of the shorter PA ligands. Based on the FTIR, Raman, and XPS results, it is proposed that Pb2+ and CH3NH3+ surface defects are passivated by R−PO32− or R−PO2(OH)−, whereas Br− surface defects are passivated by R−NH3+ moieties. This study establishes the combination of PA and APTES ligands as a highly effective dual passivation system for the synergistic passivation of multiple surface defects of PQDs through primarily ionic bonding.
Weak Pnictogen Bond with Bismuth: Experimental Evidence Based on Bi−P Through‐Space Coupling
Authors: Mokrai Réka , Barrett Jamie , Apperley David C. , Batsanov Andrei S. , Benkő Zoltán , Heift Dominikus
Published: January 2019

To study pnictogen bonding involving bismuth, flexible accordion‐like molecular complexes of the composition [P(C6H4‐o‐CH2SCH3)3BiX3], (X=Cl, Br, I) have been synthesised and characterised. The strength of the weak and mainly electrostatic interaction between the Bi and P centres strongly depends on the character of the halogen substituent on bismuth, which is confirmed by single‐crystal X‐ray diffraction analyses, DFT and ab initio computations. Significantly, 209Bi–31P through‐space coupling (J=2560 Hz) is observed in solid‐state 31P NMR spectra, which is so far unprecedented in the literature, delivering direct information on the magnitude of this pnictogen interaction.
Fluoromethylene Transfer from Diarylfluoromethylsulfonium Salts: Synthesis of Fluorinated Epoxides
Authors: Veliks Janis , Kazia Armands
Published: January 2019

Diarylfluoromethyl sulfonium salts are efficient fluoromethylene transfer reagents equivalent to fluorocarbene, which is difficult to access. This was demonstrated by the development of a monofluorinated Johnson–Corey–Chaykovsky reaction with ketones and aldehydes, delivering uncommon 2‐unsubstituted fluoroepoxides. This is the first evidence for the feasibility of sulfur fluoromethylylide and its action as a reaction intermediate.
Quantification of Entrainment Using an Optical Inline Probe
Authors: Lichti Markus , Schulz Jonas , Bart Hans‐Jörg
Published: January 2019

In distillation and absorption processes, entrainment above trays or packings reduces stage and column efficiency. A modified version of the optical multimode online probe enables a seminal insight and, thus, quantification of entrained droplets on various axial and radial positions. A purging mechanism inhibits precipitation of droplets on the front lenses, while telecentric optics and illumination provide distance‐independent and precise imaging of entrained droplets between two valve trays. Experiments were performed in a DN 450 cold flow (air‐water) test rig. The results were compared with noninvasive phase Doppler anemometry data.
A Novel Ratiometric Fluorescent Probe for Highly Sensitive and Selective Detection of β‐Galactosidase in Living Cells
Authors: Chen Min , Mu Lixuan , Cao Xingxing , She Guangwei , Shi Wensheng
Published: January 2019

Summary of main observation and conclusion

β‐Galactosidase, a glycoside hydrolase enzyme, has been proved to be an important biomarker of cell senescence and primary ovarian cancer. Effective detection of β‐galactosidase has attracted wide attention. Herein, one ratiometric fluorescent probe has been successfully synthesized for detecting the β‐galactosidase in living cells. The as‐prepared probe exhibits two emission peaks at 490 nm and 530 nm, respectively, and the ratio of fluorescence intensities from the two emission peaks could be utilized to monitor the β‐galactosidase. This present ratiometric fluorescent probe is, therefore, very promising for effective, sensitive, and selective detection of the β‐galactosidase in living cells.
Training and accreditation standards for pathologists undertaking clinical trial work
Authors: Rees Gabrielle , Salto‐Tellez Manuel , Lee Jessica L , Oien Karin , Verrill Clare , Freeman Alex , Mirabile Ilaria , West Nicholas P ,   on behalf of the National Cancer Research Institute (NCRI) Cellular‐Molecular Pathology (CM‐Path) clinical trials working group
Published: January 2019

Clinical trials rely on multidisciplinary teams for successful delivery. Pathologists should be involved in clinical trial design from the outset to ensure that protocols are optimised to deliver maximum data collection and translational research opportunities. Clinical trials must be performed according to the principles of Good Clinical Practice (GCP) and the trial sponsor has an obligation to ensure that all of the personnel involved in the trial have undergone training relevant to their role. Pathologists who are involved in the delivery of clinical trials are often required to undergo formal GCP training and may additionally undergo Good Clinical Laboratory Practice training if they are involved in the laboratory analysis of trials samples. Further training can be provided via trial‐specific investigator meetings, which may be either multidisciplinary or discipline‐specific events. Pathologists should also ensure that they undertake External Quality Assurance schemes relevant to the area of diagnostic practice required in the trial. The level of engagement of pathologists in academia and clinical trials research has declined in the United Kingdom over recent years. This paper recommends the optimal training and accreditation for pathologists undertaking clinical trials activities with the aim of facilitating increased engagement. Clinical trials training should ideally be provided to all pathologists through centrally organised educational events, with additional training provided to pathologists in training through local postgraduate teaching. Pathologists in training should also be strongly encouraged to undertake GCP training. It is hoped that these recommendations will increase the number of pathologists who take part in clinical trials research in order to ensure a high level and standard of data collection and to maximise the translational research opportunities.
Altered profile of circulating microparticles in nonvalvular atrial fibrillation
Authors: Siwaponanan Panjaree , Keawvichit Rassamon , Udompunturak Suthipol , Hunnangkul Saowalak , Reesukumal Kanit , Sukapirom Kasama , Pattanapanyasat Kovit , Krittayaphong Rungroj
Published: January 2019

Background

Nonvalvular atrial fibrillation (AF) is the most common cardiac arrhythmia, and it is associated with the prothrombotic state. Circulating microparticles (cMPs) are membrane vesicles that are shed from many cell types in response to cell activation and cell apoptosis. Several studies reported that cMPs may play a role in the hypercoagulable state that can be observed in patients with AF. The aim of this study was to determine the levels of total cMPs and characterize their cellular origins in AF patients.

Methods

Atotal of 66 AF patients and 33 healthy controls were enrolled. This study investigated total cMP levels and their cellular origin in AF patients using polychromatic flow cytometry.

Results

AF patients had significantly higher levels of total cMPs (median 36.38, interquartile range [IQR] 21.16‐68.50 × 105 counts/mL vs median 15.21, IQR 9.91‐30.86 × 105 counts/mL; P = 0.004), platelet‐derived MPs (PMPs) (median 10.61, IQR 6.55‐18.04 × 105 counts/mL vs median 7.83, IQR 4.44‐10.26 × 10/mL; P = 0.009), and endothelial‐derived MPs (EMPs CD31+ CD41−) (median 2.94, IQR 1.78‐0.60 × 105 counts/mL vs median 1.16, IQR 0.71‐2.30 × 105 counts/mL; P = 0.001) than healthy controls after adjusting for potential confounders. Phosphatidylserine positive MP (PS + MP) levels were similar compared between AF patients and healthy controls.

Conclusion

The results of this study revealed a marked increase in total cMP levels, and evidence of elevated endothelial damage and platelet activation, as demonstrated by increased PMP and EMP levels, in AF patients. Additional study is needed to further elucidate the role of cMPs (PMPs and EMPs) in the pathophysiology of and the complications associated with AF.
Prehensile kinematics of the marmoset monkey: Implications for the evolution of visually‐guided behaviors
Authors: Fox Dylan M. , Mundinano Inaki‐Carril , Bourne James A.
Published: January 2019

Throughout the primate lineage, there is a wide diversity of prehensile capacity that is thought to stem from individual species foraging patterns. While many studies have explored primates with precise hand grips, such as higher apes, few have considered primates that lack opposition movements. The New World marmoset monkey occupies an intriguing niche, displaying adept control of their hand movements yet their absence of opposable digits results in relatively imprecise grasping actions when compared with those observed in Old World monkeys, apes, and humans. The marmoset monkey offers a unique composition of ancestral primate corticospinal organization combined with skilled hand use to explore the evolution and development of visually‐guided actions. In this study, four adult marmosets were trained to perform a series of visually‐guided tasks, designed to assess their control over locating and retrieving objects of differing dimensions. Two of these animals received a neonatal lesion of the inferior pulvinar (unilateral), a thalamic nucleus previously demonstrated to be involved in visuomotor development. The kinematics of their reaching and grasping patterns were recorded for offline analysis. Predictive modeling revealed that maximum grip aperture, time to reach peak velocity and hand use were reliable predictors of distinguishing between cohorts. A consistent feature observed across all tasks was that they do not precisely scale their grip according to the dimensions of the target object which may be attributed to their lack of independent digit control. Therefore, the marmoset monkey represents a previously understudied position in the evolution of primate reach and grasp behavior.
Subject‐specific loads on the lumbar spine in detailed finite element models scaled geometrically and kinematic‐driven by radiography images
Authors: Dehghan‐Hamani Iraj , Arjmand Navid , Shirazi‐Adl Aboulfazl
Published: January 2019

Traditional load‐control musculoskeletal and finite element (FE) models of the spine fail to accurately predict in vivo intervertebral joint loads due mainly to the simplifications and assumptions when estimating redundant trunk muscle forces. An alternative powerful protocol that bypasses the calculation of muscle forces is to drive the detailed FE models by image‐based in vivo displacements. Development of subject‐specific models, however, both involves the risk of extensive radiation exposures while imaging in supine and upright postures and is time consuming in terms of the reconstruction of the vertebrae, discs, ligaments, and facets geometries. This study therefore aimed to introduce a remedy for the development of subject‐specific FE models by scaling the geometry of an existing detailed FE model of the T12‐S1 lumbar spine. Five subject‐specific scaled models were driven by their own radiography image‐based displacements in order to predict joint loads, ligament forces, facet joint forces, and disc fiber strains during relaxed upright as well as moderate flexion and extension tasks. The predicted intradiscal pressures were found in adequate agreement with in vivo data for upright, flexion, and extension tasks. There were however large intersubject variations in the estimated joint loads and facet forces.
Insight into the Mechanisms of Scale Inhibition: A Case Study of a Task‐Specific Fluorescent‐Tagged Scale Inhibitor Location on Gypsum Crystals
Authors: Oshchepkov Maxim , Kamagurov Semen , Tkachenko Sergei , Ryabova Anastasiya , Popov Konstantin
Published: January 2019

Scaling in reverse osmosis facilities, boilers, heat exchangers, evaporation plants, and oilfield applications is a serious problem worldwide. In order to provide a new insight into the mechanism of the scale formation and inhibition, a novel fluorescent‐tagged bisphosphonate scale inhibitor 1‐hydroxy‐7‐(6‐methoxy‐1,3‐dioxo‐1H‐benzo[de]isoquinolin‐2(3H)‐yl)heptane‐1,1‐diyl‐di(phosphonic acid), (HEDP−F) was synthesized and used for fluorescent microscope visualization of gypsum crystal formation in supersaturated aqueous solutions. The visualization of HEDP−F location on gypsum crystals has demonstrated that the bisphosphonate molecules do not act as they are expected to do according to the current scale inhibition theory. At ambient temperature the gypsum macrocrystals are found to form, and then to grow without visible sorption of bisphosphonate on the crystal edges or any other gypsum crystal growth centers. A tentative nonconventional mechanism of scale inhibition in the bulk supersaturated aqueous solutions of gypsum is proposed.
On‐Command Regulation of Kinase Activity using Photonic Stimuli
Authors: Fleming Cassandra L. , Grøtli Morten , Andréasson Joakim
Published: January 2019

The underlying role that many kinases play in complex cellular pathways as well as disease remains unclear. To better understand the role that kinases play in both health and disease states, the use of light as an external stimulus to modulate kinase activity with high spatiotemporal resolution has gained increasing interest over the years. Herein we highlight the progress made towards the development of light‐responsive kinase enzymes and small molecule inhibitors. In these examples, photolabile caging groups and photoswitchable entities have been utilised to modulate either kinase activation or inhibition in a light‐controlled manner.
Characterization of Xenopus laevis guanine deaminase reveals new insights for its expression and function in the embryonic kidney
Authors: Slater Paula G. , Cammarata Garrett M. , Monahan Connor , Bowers Jackson T. , Yan Oliver , Lee Sangmook , Lowery Laura Anne
Published: January 2019

Background

The mammalian guanine deaminase (GDA), called cypin, is important for proper neural development, by regulating dendritic arborization through modulation of microtubule (MT) dynamics. Additionally, cypin can promote MT assembly in vitro. However, it has never been tested whether cypin (or other GDA orthologs) binds to MTs or modulates MT dynamics. Here, we address these questions and characterize Xenopus laevis GDA (Gda) for the first time during embryonic development.

Results

We find that exogenously expressed human cypin and Gda both display a cytosolic distribution in primary embryonic cells. Furthermore, while expression of human cypin can promote MT polymerization, Xenopus Gda has no effect. Additionally, we find that the tubulin‐binding collapsin response mediator protein (CRMP) homology domain is only partially conserved between cypin and Gda. This likely explains the divergence in function, as we discovered that the cypin region containing the CRMP homology and PDZ‐binding domain is necessary for regulating MT dynamics. Finally, we observed that gda is strongly expressed in the kidneys during late embryonic development, although it does not appear to be critical for kidney development.

Conclusions

Together, these results suggest that GDA has diverged in function between mammals and amphibians, and that mammalian GDA plays an indirect role in regulating MT dynamics. Developmental Dynamics 248:296–305, 2019. © 2019 Wiley Periodicals, Inc.
(Meta)population dynamics determine effective spatial distributions of mosquito‐borne disease control
Authors: Schwab Samantha R. , Stone Chris M. , Fonseca Dina M. , Fefferman Nina H.
Published: January 2019

Recent epidemics of mosquito‐borne dengue and Zika viruses demonstrate the urgent need for effective measures to control these diseases. The best method currently available to prevent or reduce the size of outbreaks is to reduce the abundance of their mosquito vectors, but there is little consensus on which mechanisms of control are most effective, or when and where they should be implemented. Although the optimal methods are likely context dependent, broadly applicable strategies for mosquito control, such as how to distribute limited resources across a landscape in times of high epidemic risk, can mitigate (re)emerging outbreaks. We used mathematical simulations to examine how the spatial distribution of larval mosquito control affects the size of disease outbreaks, and how mosquito metapopulation dynamics and demography might impact the efficacy of different spatial distributions of control. We found that the birth rate and mechanism of density‐dependent regulation of mosquito populations affected the average outbreak size across all control distributions. These factors also determined whether control distributions favoring the interior or the edges of the landscape most effectively reduced human infections. Thus, understanding local mosquito population regulation and dispersion can lead to more effective control strategies.
A multilocus phylogeny of the fish genus Poeciliopsis: Solving taxonomic uncertainties and preliminary evidence of reticulation
Authors: Mateos Mariana , Domínguez‐Domínguez Omar , Varela‐Romero Alejandro
Published: January 2019

The fish genus Poeciliopsis constitutes a valuable research system for evolutionary ecology, whose phylogenetic relationships have not been fully elucidated. We conducted a multilocus phylogenetic study of the genus based on seven nuclear and two mitochondrial loci with a thorough set of analytical approaches, that is, concatenated (also known as super‐matrix), species trees, and phylogenetic networks. Although several relationships remain unresolved, the overall results uncovered phylogenetic affinities among several members of this genus. A population previously considered of undetermined taxonomic status could be unequivocally assigned to P. scarlli; revealing a relatively recent dispersal event across the Trans‐Mexican Volcanic Belt (TMVB) or Pacific Ocean, which constitute a strong barrier to north–south dispersal of many terrestrial and freshwater taxa. The closest relatives of P. balsas, a species distributed south of the TMVB, are distributed in the north; representing an additional north–south split in the genus. An undescribed species of Poeciliopsis, with a highly restricted distribution (i.e., a short stretch of the Rio Concepcion; just south of the US‐Mexico border), falls within the Leptorhaphis species complex. Our results are inconsistent with the hypothesis that this species originated by “breakdown” of an asexual hybrid lineage. On the other hand, network analyses suggest one or more possible cases of reticulation within the genus that require further evaluation with genome‐wide marker representation and additional analytical tools. The most strongly supported case of reticulation occurred within the subgenus Aulophallus (restricted to Central America), and implies a hybrid origin for P. retropinna (i.e., between P. paucimaculata and P. elongata). We consider that P. balsas and P. new species are of conservation concern.
Life in a northern town: rural villages in the boreal forest are islands of habitat for an endangered bat
Authors: Thomas Julie P. , Jung Thomas S.
Published: January 2019

Urban development is detrimental to many wildlife species; however, endangered little brown bats (Myotis lucifugus) may be attracted to human settlements, making them a synurbic species. Buildings likely provide high‐quality roosting habitat, which may be a limiting factor in the boreal forest where trees are typically small and potentially unsuitable for hosting large maternity colonies. In the boreal forest, there are relatively few urban developments in a matrix of wilderness and apparently suboptimal natural roosting habitat; thus, we hypothesized that isolated rural villages were islands of summer habitat for little brown bats that may be important for their conservation and recovery. To test this hypothesis, we investigated the relationship between little brown bat activity, foraging rates, and proximity to rural villages. We expected bat activity and foraging rates to increase with proximity to villages, as bats should optimally forage near their roosts to minimize flight costs. We used ultrasonic detectors to passively monitor bat activity near three rural villages in Yukon, Canada, and characterized bat habitat with forest measurements and remotely sensed data. Bat activity increased with proximity to village centers, but foraging activity did not, suggesting that human settlements in the boreal forest were important as roosting rather than foraging habitat. Bat activity was higher near water bodies and areas with relatively high densities of linear features (e.g., roads and transmission lines), perhaps because prey were most abundant near water features and along forest edges. The island phenomenon we observed (i.e., higher bat activity near villages) has also been documented in larger human settlements at lower latitudes, where urban areas provided better roosting habitat than surrounding agricultural matrices. Given that little brown bats were concentrated near rural villages, small human settlements should be a focus of conservation efforts in the boreal forest—particularly the identification and protection of buildings used as maternity colonies. Our study advances knowledge of little brown bat habitat requirements in the boreal forest and identifies habitats that may be important for their recovery.
Soluble neprilysin does not correlate with prognosis in pulmonary hypertension
Authors: Yoshihisa Akiomi , Yokokawa Tetsuro , Misaka Tomofumi , Oikawa Masayoshi , Kobayashi Atsushi , Yamaki Takayoshi , Sugimoto Koichi , Kunii Hiroyuki , Nakazato Kazuhiko , Takeishi Yasuchika
Published: January 2019

Aims

It has been reported that circulating soluble neprilysin (sNEP), which catalyses the degradation of several vasodilator peptides such as natriuretic peptides, predicts prognosis in heart failure patients with reduced ejection fraction. Hypoxia‐induced decrease in NEP expression in lungs has been reported. However, the associations between sNEP and haemodynamic parameters, as well as the prognostic impact of sNEP in pulmonary hypertension (PH), remain unclear. We aimed to clarify the relationships between sNEP and natriuretic peptide, haemodynamics (e.g. parameters of echocardiography and right heart catheter) or prognosis in PH patients.

Methods and results

First, we examined the associations between sNEP levels and natriuretic peptide, echocardiography, or right heart catheter in PH patients (mean pulmonary artery pressure ≥ 25 mmHg and pulmonary artery wedge pressure ≤ 15 mm Hg on the basis of right heart catheterization, n = 79). Next, we followed up the patients for all‐cause mortality. Laboratory data revealed no significant correlations between sNEP and B‐type natriuretic peptide (R = 0.022, P = 0.872), N‐terminal proBNP (R = −0.018, P = 0.872), and high‐sensitivity troponin I (R = 0.206, P = 0.107). Regarding the parameters of echocardiography and right heart catheter, there were no significant correlations between sNEP and left ventricular ejection fraction (R = −0.036, P = 0.764), right ventricular fractional area change (R = −0.259, P = 0.064), tricuspid valve pressure gradient (R = −0.037, P = 0.767), and any of the right heart catheter parameters. In the Kaplan–Meier analysis (mean follow‐up, 1284 days, log‐rank P = 0.531), all‐cause mortality rates were comparable between the higher NEP group (sNEP ≥ median levels of 1.45 ng/mL, n = 39) and the lower NEP group (sNEP < 1.45 ng/mL, n = 40). In the Cox proportional hazard analysis, sNEP was not a predictor of all‐cause mortality (hazard ratio 0.902, 95% CI 0.674–1.207, P = 0.487) in PH patients.

Conclusions

Circulating sNEP does not correlate with natriuretic peptide, haemodynamic parameters, or prognosis in patients with PH.
Reductive Disproportionation of CO2 Mediated by Bimetallic Nickelate(–I)/Group 13 Complexes
Authors: Vollmer Matthew V. , Cammarota Ryan C. , Lu Connie C.
Published: January 2019

The reactivity of bimetallic nickel(–I)/group 13 complexes towards carbon dioxide is presented. Reaction of the anionic [NiML]– complexes, where M is Al or Ga, and L is {N[(o‐C6H4)NCH2PiPr2]3}3–, with CO2 (1 atm) results in reductive disproportion of CO2 to afford CO32–, NiML, and the mono‐carbonyl adducts, (CO)NiML. The (CO)NiML complexes, where M is Al, Ga, or In, were independently synthesized and characterized. The extent of CO activation varies slightly across the different group 13 ions, where the CO stretching frequency increases for M = Al < Ga < In.
Total Synthesis of (±)‐Englerin A and Its Tuncated Analogues
Authors: Reagan Colleen , Trevitt Graham , Tchabanenko Kirill
Published: January 2019

A convergent approach allowed total synthesis of (±)‐Englerin A, and its truncated analogues, employing a thermal 1,3‐dipolar cycloaddition of a highly substituted pyrylium ylide with vinyl acetate as the key step. The key intermediate, a 8‐oxabicyclo[3,2,1]octane oxygenated at the C6 position, was directly converted into a truncated Englerin A analogue. CuI catalyzed conjugate addition of vinyl Grignard to an enone, ozonolysis, and epimerisation of the resulting aldehyde allowed stereoselective introduction of the side‐chain leading to a total synthesis of the racemic natural product. The developed chemistry will allow synthesis of more complex analogues of the natural product based on the use of the key bicyclo[3,2,1]octane scaffold.
Ligand‐Free Palladium(II)‐Catalyzed ortho‐C–H Chalcogenations of N‐Arylsulfonamide via Weak Coordination
Authors: Gu Linghui , Fang Xinyue , Weng Zhengyun , Song Yupin , Ma Wenbo
Published: January 2019

The first palladium(II)‐catalyzed direct ortho‐C(sp2)–H chalcogenations of N‐arylsulfonamide via weak coordination have been achieved, affording the corresponding mono‐chalocgenated products in good to excellent yields. This strategy features ligand/additive‐free conditions, broad substrate scope with excellent functional group tolerance and a high position selectivity.
Boric Acid–Catalyzed Hard Carbon Microfiber Derived from Cotton as a High‐Performance Anode for Lithium‐Ion Batteries
Authors: Tan Muchu , Zhang Weihua , Fan Changling , Li Lingfang , Chen Han , Li Rong , Luo Ting , Han Shaochang
Published: January 2019

The catalysis role of boric acid at 800 °C is investigated in the synthesis of hard carbon from cotton. X‐ray diffraction analysis shows that d002 decreases and the size of the carbon crystal increases, which can only be realized at a higher temperature. Boron atoms are mainly combined on the surface layer of the particle. The specific capacity of the sample with B:C = 2.5 at 30, 1500 mA g−1 increases from 381.0 and 149.7 mAh g−1 (B:C = 0) to 526.8 and 196.6 mAh g−1, respectively. It is attributed not only to the plateau around 0.1 V, which results from the intercalation mechanism between graphite layers, but also to the storage mechanism of micropores. The capacity retention in the 200th cycle at 300 mA g−1 is improved from 88.5% to 94.1%. Therefore, the carbonization process of cotton is accelerated, and the catalysis function of boric acid proves to be workable. These improvements are partially resulting from the enlargement and regular stacking of carbon layers, which can accommodate more lithium ions. As boron atoms can occupy the defect vacancy points and order, large carbon layers are formed because of the electron deficiency property and fast transfer speed of boron atoms.
Electrochemical Behavior of Manganese Oxide Ores Using Coke Wastewater in Sulfuric Acid Solution
Authors: Kang Jinxing , Feng Yali , Li Haoran , Du Zhuwei , Deng Xiangyi , Wang Hongjun
Published: January 2019

The coke wastewater reductive leaching of pyrolusite ore in sulfuric acid solution was studied. This study was performed in two stages. First, the influence of tractable and refractory pollutants of coke wastewater on manganese leaching was determined. It was shown that the leaching efficiency of manganese is very sensitive to the decomposition of intractable pollutants. With the decrease of 1.85 g/L CODcr value of those contaminants, the extraction ratio of manganese increased more than 16% and exceeded 97.3%. Second, the corrosion behavior of pyrolusite ore in simulative wastewater solution was investigated using cyclic voltammograms, polarization curves, and Mott–Schottky curves. The reduction of manganese oxide ore by recalcitrant organic compounds involves two courses—the inducing conversion of manganese oxide to MnO·OH intermediate with hydrogen and free electron, which is from the oxidation of easily oxidized substances and the oxidation of persistent organic matter by this derivative. As a consequence, the latter process leads to the increment in manganese extraction efficiency. Coke wastewater is a promising reducing agent for MnO2. Likewise, it could be clarified and recycling. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13039, 2019
Removal of ammonia from a smelting wastewater by cyclic stripping and acid adsorption: Kinetics study
Authors: Jiang Ke , Zhou Kanggen , Yang Youcai
Published: January 2019

Air stripping is an effective method for the removal of ammonia from high‐concentration wastewater. The traditional open stripping process is expensive due to high consumptions of alkali reagent and energy. This study proposed a novel cyclic stripping‐acid adsorption system for ammonia removal. The stripped ammonia gas flowed into the stripping tower, and no fresh air was added during the cyclic stripping process. The kinetics model of ammonia removal from the smelting wastewater in a pilot‐scale cyclic stripping tower was investigated. The influences of stripping temperature (T), wastewater pH, air to liquid ratio (R), and acid spray flow (F) on the ammonia removal rate were discussed. The kinetics equation was determined as G = 4.14 × 10−3 × pH1.83 × T0.27 × F0.98 × R−0.49 when pH = 9.80–12.29, T = 19–35°C, F = 58–76 m3·h−1, and R = 1329–1725. The equation can be used to predict the removal rate of ammonia during operation. The ammonia concentration of the effluent decreased from 5951 mg·L−1 to 13 mg·L−1 within 15 h. Ammonia can be removed rapidly and economically from wastewater via the cyclic stripping process. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019
Joint relay selection and max‐min energy‐efficient power allocation in downlink multicell NOMA networks: A matching‐theoretic approach
Authors: Baidas Mohammed W. , Bahbahani Zainab , El‐Sharkawi Nancy , Shehada Halah , Alsusa Emad
Published: January 2019

In this paper, the problem of joint relay selection and max‐min energy‐efficient power allocation (J‐RS‐MMEE‐PA) in downlink multicell nonorthogonal multiple access (NOMA) networks is studied. In particular, the goal is to perform relay selection for each cellular user within each cell, so as to achieve max‐min energy efficiency while satisfying quality‐of‐service (QoS) constraints. However, the formulated J‐RS‐MMEE‐PA problem happens to be nonconvex (ie, computationally intensive). In turn, a solution procedure for max‐min energy‐efficient power allocation is devised to determine the energy efficiency of each user per potential relay while meeting the target minimum rate per user. After that, the relay selection problem is modeled as a student‐project allocation with preferences over projects matching problem. A polynomial‐time complexity stable matching (SM) algorithm is proposed, which takes into account the maximum number of users that can select a relay as well as the number of users that can be associated with a base station. However, the proposed SM algorithm can only guarantee an SM size that is at least half the size of the maximum “optimal” cardinality SM. Thus, the improved SM (I‐SM) algorithm with polynomial‐time complexity is devised, so as to guarantee an SM size that is at least two‐thirds of that of the optimal matching. Lastly, simulation results are presented to compare the proposed matching algorithms to the J‐RS‐MMEE‐PA scheme, where it has been shown that the I‐SM algorithm is superior to its SM counterpart and yields comparable energy efficiency per cellular user to the J‐RS‐MMEE‐PA scheme while satisfying QoS constraints.