bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biology and management of methicillin resistantStaphylococcus aureusin cystic fibrosis
Authors: Akil Nour , Muhlebach Marianne S. 
Published: August 2018

AbstractStaphylococcus aureusis one of the earliest bacteria isolated from the respiratory tract in people with cystic fibrosis (CF). Its methicillin resistant form, MRSA, has gained attention due to the rapid increase in the last decades and worse outcomes with chronic infection. In the United States, prevalence of MRSA in CF is around 27%, but is much lower (3‐18%) in most other countries. Methicillin is typically genetically encoded by themecA gene, which encodes for an alternative penicillin binding protein (PRBa). This PRBa has low affinity to β‐lactams, thereby enabling growth ofS. aureusin the presence of penicillinase resistant penicillins and most other β‐lactams. Non‐mecA positive strains of MRSA, so‐called borderline resistant (BORSA) have also been described. In addition to production of toxins, the virulence ofS. aureusis conferred by its adaptability allowing persistence in face of antibiotic therapies and host defense. These adaptive growth mechanisms include small colony variants, biofilms, and growth under anaerobic conditions. Several reports have described successful eradication of MRSA, yet only two randomized trials of eradication during early infection have been conducted. A list of MRSA specific antibiotics with dosing relevant to CF patients is presented here. Many of these require special dosing in people with CF. Novel antibiotics are in trials for skin and soft tissue infections and it is unclear if and when those might be available for lung infections. Thus the best strategies for MRSA would be primary prevention.
Testosterone regulates myosin II isoforms expression and functional activity in the rat prostate
Authors: Chen Ping , Xiao He , Huang Wei , Xu De‐Qiang , Guo Yu‐Ming , Wang Xiao , Wang Xing‐Huan , DiSanto Michael E. , Zhang Xin‐Hua 
Published: August 2018

BackgroundBenign prostatic hyperplasia (BPH) is mainly caused by increased prostatic smooth muscle (SM) tone and prostatic volume. At the molecular level, SM myosin II (SMM II) and non‐muscle myosin II (NMM II) mediate SM tone and cell proliferation while testosterone (T) plays a permissive role in the development of BPH.AimsThe novel objective of this study was to elucidate the effects of T on the proliferation and apoptosis of rat prostatic cells and SM contractility as well as related regulatory signaling pathways.Materials and MethodsBriefly, 36 male rats were divided into three groups (sham‐operated, surgically castrated, and castrated with T supplementation). In vitro organ bath studies, competitive RT‐PCR, Western‐blotting analysis, Masson's trichrome staining, and immunofluorescence staining were performed.ResultsOur data showed that castration dramatically increased prostatic SM contractility and SM MHC immunostaining revealed a relatively increased SM cell numbers in the stroma. T deprivation altered prostate SMM II isoform composition with upregulation of SM‐B and SM2 but downregulation of LC17a, favoring a faster more phasic‐type contraction. Moreover, protein expressions of MLCK, p‐MLCP, RhoB, ROCK1, and ROCK2 increased in castrated rats. Meanwhile NMM II heavy chain isoforms A, B, and C (NMMHC‐A, B, and C isoforms) were altered by castration which may be linked to decreased cell proliferation and increased apoptosis.ConclusionOur novel data demonstrated T regulates SMM II and NMM II and their functional activities in rat prostate and T ablation not only decreases prostate size (static component) but also changes the prostatic SM tone (dynamic component).
Omega‐3 fatty acids decrease prostate cancer progression associated with an anti‐tumor immune response in eugonadal and castrated mice
Authors: Gevariya Nikunj , Besançon Marjorie , Robitaille Karine , Picard Valérie , Diabaté Lamoussa , Alesawi Anwar , Julien Pierre , Fradet Yves , Bergeron Alain , Fradet Vincent 
Published: August 2018

BackgroundSeveral lines of evidence suggest effects of dietary fat on prostate cancer (PCa) development and progression. Targeting omega (ω)‐3:ω6 fatty acids (FA) ratio could be beneficial against PCa by favorably modulating inflammation. Here, we studied the effects of ω3‐ and ω6‐enriched diets on prostate tumor growth and inflammatory response in androgen‐deprived and non‐deprived conditions.MethodsImmune‐competent eugonadal and castrated C57BL/6 mice were injected with TRAMP‐C2 prostate tumor cells and daily fed with ω3‐ or ω6‐enriched diet. FA and cytokine profiles were measured in blood and tumors using gas chromatography and multiplex immunoassay, respectively. Immune cell infiltration in tumors was profiled by multicolor flow cytometry.Resultsω3‐enriched diet decreased prostate TRAMP‐C2 tumor growth in immune‐competent eugonadal and castrated mice. Cytokines associated with Th1 immune response (IL‐12 [p70], IFN‐γ, GM‐CSF) and eosinophil recruitment (eotaxin‐1, IL‐5, and IL‐13) were significantly elevated in tumors of ω3‐fed mice. Using in vitro experiments, we confirmed ω3 FA‐induced eotaxin‐1 secretion by tumor cells and that eotaxin‐1 secretion was regulated by androgens. Analysis of immune cell infiltrating tumors showed no major difference of immune cells’ abundance between ω3‐ and ω6‐enriched diets.Conclusionsω3‐enriched diet reduces prostate tumor growth independently of androgen levels. ω3 FA can inhibit tumor cell growth and induce a local anti‐tumor inflammatory response. These findings warrant further examination of dietary ω3's potential to slow down the progression of androgen‐sensitive and castrate‐resistant PCa by modulating immune cell function in tumors.
A new slow‐release formulation of methyl salicylate optimizes the alternative control of Sitobion avenae (Fabricius) (Hemiptera: Aphididae) in wheat fields
Authors: Wang Kang , Liu Jiahui , Zhan Yidi , Liu Yong 
Published: August 2018

AbstractBACKGROUNDSome defects, such as the short persistence and lower release stability of methyl salicylate (MeSA), must be resolved before efficient field application. To enhance the utilization efficacy of MeSA, a slow‐release MeSA alginate bead was designed and tested to measure its release rate in a laboratory environment and to obtain insights into its ecological effects in wheat fields.RESULTSIn laboratory tests, both the 2.5 and 10 mL formulations of MeSA alginate beads (hereafter referred to as MeSA 2.5 and MeSA 10) release stably and continuously for at least 15 days, whereas pure MeSA does so for only ∼ 7 days. In field experiments, both the MeSA 2.5 bead and the MeSA 10 bead reduce the abundance of Sitobion avenae significantly and attract Metasyrphus corollae compared with the control. In addition, the effect of MeSA 10 beads is significantly greater than that of MeSA 2.5.CONCLUSIONThe MeSA alginate bead we manufactured could be an efficient slow‐release formulation. The MeSA 10 bead had a significantly greater effect on S. avenae population suppression, partly by attracting M. corollae in fields. © 2018 Society of Chemical Industry
Tetrel bonds between PhSiF3/PhTH3(T = Si, Ge, Sn) and H3ZO (Z = N, P, As): A pentacoordinate silicon (IV) complex
Authors: Xu Hui‐Li , Cheng Jian‐Bo , Li Hai‐Bei , Yang Xin , Li Qing‐Zhong 
Published: August 2018

AbstractThe nature of the complexes PhTH3H3ZO and PhSiF3H3ZO (T = Si, Ge, and Sn; Z = N, P, and As) has been investigated at the MP2/aug’‐cc‐pVTZ(PP) level. These complexes are primarily stabilized by one T···O tetrel bond. Interaction energies of these complexes vary from 11 to 220 kJ/mol, and T···O separations from 1.89 to 3.09 Å. Charge transfer from the O lone pair into the CT and TH σ* antibonding orbitals leads to the stabilization of these complexes. The T···O tetrel bond between PhTH3/PhSiF3and H3NO exhibits a significant degree of covalence, characterized by the large interaction energy, negative energy density, and large charge transfer. Furthermore, a pentacoordinate silicon (IV) complex is formed in PhSiF3H3NO with the Si···O distance almost close to the length of SiO bond. This indicates that the oxygen atom in N‐oxides shows a strong affinity to the silicon atom in organosilicon compounds.
Quinone‐based switches for candidate building blocks of molecular junctions with QTAIM and the stress tensor
Authors: Xu Tianlv , Wang Lingling , Ping Yang , van Mourik Tanja , Früchtl Herbert , Kirk Steven R. , Jenkins Samantha 
Published: August 2018

AbstractThe current work investigates candidate building blocks based on molecular junctions from hydrogen transfer tautomerization in the benzoquinone‐like core of an azophenine molecule with QTAIM and the recently introduced stress tensor trajectory analysis. We find that in particular the stress tensor trajectories are well suited to describe the mechanism of the switching process. The effects of an Fe‐dopant atom coordinated to the quinone ring, as well as F and Cl substitution of different ring‐hydrogens, are investigated and the new QTAIM and stress tensor analysis is used to draw conclusions on the effectiveness of such molecules as molecular switches in nanosized electronic circuits. We find that the coordinated Fe‐dopant greatly improves the switching properties, both in terms of the tautomerization barrier that has to be crossed in the switching process and the expected conductance behavior, while the effects of hydrogen substitution are more subtle. The absence of the Fe‐dopant atom led to impaired functioning of the switch “OFF” mechanism as well as coinciding with the formation of closed‐shell H—H bond critical points that indicated a strained or electron deficient environment. Our analysis demonstrates promise for future use in design of molecular electronic devices.
Stable oxygen isotopes in water of concentrated liquid foodstuffs: Are the commonly determined values accurate?
Authors: Iacumin Paola , Di Matteo Antonietta , Selmo Enricomaria , Venturelli Giampiero 
Published: August 2018

RationaleOxygen isotope analysis of water molecules of liquid foodstuffs is commonly performed under isotopic equilibrium between water in the solution and the vapour water, assuming that the liquid water activity is equal to unity and that liquid water is an ideal mixture of H2O isotopologues. A priori this behaviour is not realistic for all foodstuffs, which frequently are very concentrated solutions. In this paper we mainly consider “balsamic vinegar” with the aim of defining an appropriate procedure of oxygen isotope ratio analysis of water molecules in these concentrated solutions.MethodsIsotope ratio mass spectrometry (IRMS) measurements of the oxygen isotope ratios (δ18O values) were carried out on CO2 equilibrated with water molecules at 22 ± 0.1°C. Three independently calibrated, very low salinity waters were used as standards.ResultsFor grape must and wine vinegar (density < 1.15 g/cm3) the δ18O values for water determined directly on these solutions are “true” values. On the contrary, for balsamic vinegar with density higher than 1.15–1.20 g/cm3, the δ18O values obtained directly on the solutions are systematically different from those obtained on water produced by distillation of the same samples at 70°C under vacuum.ConclusionsIn the case of balsamic vinegar with density higher than 1.15–1.20 g/cm3, to avoid severe systematic errors, the isotopic analyses must be carried out on water obtained by distillation under stirring.
A novel laser desorption/ionization method using through hole porous alumina membranes
Authors: Naito Yasuhide , Kotani Masahiro , Ohmura Takayuki 
Published: August 2018

RationaleA novel matrix‐free laser desorption/ionization method based on porous alumina membranes was developed. The porous alumina membranes have a two‐dimensional (2D) ordered structure consisting of closely aligned straight through holes of sub‐micron in diameter that are amenable to mass production by industrial fabrication processes.MethodsConsidering a balance between the ion generating efficiency and the mechanical strength of the membranes, the typical values for the hole diameter, open aperture ratio and membrane thickness were set to 200 nm, 50% and 5 μm, respectively. The membranes were coated with platinum on a single side that was exposed to the laser. Evaluation experiments were conducted on the feasibility of this membrane structure for an ionization method using a single peptide and mixed peptides and polyethylene glycol samples and a commercial matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight mass spectrometer in the positive ion mode.ResultsResults showed a softness of ionization and no sweet spot nature. The capillary action of the through holes with very high aspect ratio enables several loading protocols including sample impregnation from the surface opposite to the laser exposure side.ConclusionsThe feasibility study indicates that the through hole porous alumina membranes have several advantages in terms of usefulness over the conventional surface‐assisted laser desorption ionization (SALDI) methods. The proposed novel ionization method is termed Desorption Ionization Using Through Hole Alumina Membrane (DIUTHAME).
Cluster ion beam generation from a wetted needle emitter for organic secondary ion mass spectrometry (organic SIMS) using a protic ionic liquid, propylammonium nitrate
Authors: Fujiwara Yukio , Saito Naoaki 
Published: August 2018

RationalePropylammonium nitrate (PAN, [C3H7NH3][NO3]), a protic ionic liquid, has an active proton in its molecular structure, so that it can promote protonation. In addition, PAN has high aggregability, so that it tends to form large aggregated (or cluster) ions. These features will be desirable for cluster ion beams in secondary ion mass spectrometry (SIMS) of organic materials. The aggregability may enable us to generate a cluster ion beam from a needle tip wetted with PAN by electrospray in vacuum. For these reasons, cluster ion beam generation was investigated using an externally wetted needle emitter.MethodsA sharpened glass rod was used as a needle emitter. PAN was electrosprayed in vacuum using the needle emitter to generate a cluster ion beam. Beam characteristics were investigated with an apparatus for measuring transient responses of a beam current. SIMS experiments were also performed using the cluster ion beam as a primary ion beam; arginine and polyethylene glycol (PEG300) were analyzed.ResultsA stable cluster ion beam was generated from the needle emitter wetted with PAN. The ion beam consisted of mixed cluster ions whose m/z ranged from about 180 to 5000 or higher. The cluster ion beam successfully produced protonated molecules [M + H]+ (M denotes arginine and PEG molecules) with relatively little fragmentation. Adduct ions [M + C3H7NH3]+ formed by propylammonium‐attachment reaction were also detected for PEG.ConclusionsIt has been demonstrated that a needle emitter wetted with PAN can generate a cluster ion beam that includes massive cluster ions. The cluster ion beam proved to be helpful in producing molecular secondary ions and suitable for a primary ion beam in organic SIMS.
Mono(2‐ethylhexyl) phthalate (MEHP) and mono(2‐ethyl‐5‐oxohexyl) phthalate (MEOHP) but not di(2‐ethylhexyl) phthalate (DEHP) bind productively to the peroxisome proliferator‐activated receptor γ
Authors: Kratochvil Isabel , Hofmann Tommy , Rother Sandra , Schlichting Rita , Moretti Rocco , Scharnweber Dieter , Hintze Vera , Escher Beate I. , Meiler Jens , Kalkhof Stefan , von Bergen Martin 
Published: August 2018

RationaleThe most frequently occurring phthalate, di(2‐ethylhexyl) phthalate (DEHP), causes adverse effects on glucose homeostasis and insulin sensitivity in several cell models and epidemiological studies. However, thus far, there is no information available on the molecular interaction of phthalates and one of the key regulators of the metabolism, the peroxisome proliferator‐activated receptor gamma (PPARγ). Since the endogenous ligand of PPARγ, 15‐deoxy‐delta‐12,14‐prostaglandin J2 (15Δ‐PGJ2), features structural similarity to DEHP and its main metabolites produced in human hepatic metabolism, mono(2‐ethylhexyl) phthalate (MEHP) and mono(2‐ethyl‐5‐oxohexyl) phthalate (MEOHP), we tested the hypothesis of direct interactions between PPARγ and DEHP or its transformation products.MethodsHydrogen/deuterium exchange mass spectrometry (HDX‐MS) and docking were conducted to obtain structural insights into the interactions and surface plasmon resonance (SPR) analysis to reveal information about binding levels. To confirm the activation of PPARγ upon ligand binding on the cellular level, the GeneBLAzer® bioassay was performed.ResultsHDX‐MS and SPR analyses demonstrated that the metabolites MEHP and MEOHP, but not DEHP itself, bind to the ligand binding pocket of PPARγ. This binding leads to typical activation‐associated conformational changes, as observed with its endogenous ligand 15Δ‐PGJ2. Furthermore, the reporter gene assay confirmed productive interaction. DEHP was inactive up to a concentration of 14 μM, while the metabolites MEHP and MEOHP were active at low micromolar concentrations.ConclusionsIn summary, this study gives structural insights into the direct interaction of PPARγ with MEHP and MEOHP and shows that the DEHP transformation products may modulate the lipid metabolism through PPARγ pathways.
Fractionation of otolith nitrogen stable isotopes measured by peroxodisulfate oxidation‐bacterial conversion and isotope ratio mass spectrometry
Authors: Cheng Li‐Chi , Shiao Jen‐Chieh , Hsiao Silver Sung‐Yun , Wang Pei‐Ling 
Published: August 2018

RationaleOtoliths are usually used to estimate the age of fish and the chemical composition such as nitrogen stable isotope ratios (δ15N values) may record environmental information and ecological role of the fish. However, the isotopic fractionation of δ15N values between diets and otoliths has rarely been investigated and remains unclear.MethodsNitrogen isotopic fractionation between five different diets (δ15Ndiet values) and otoliths (δ15Noto values) were elucidated in tilapia Oreochromis mossambica reared in controlled feeding experiments. The otoliths were dissolved with hydrogen chloride and peroxodisulfate was used to oxidize the total organic materials to nitrate, which was further converted into N2O gas by denitrification bacteria before the measurement of δ15Noto values by isotope ratio mass spectrometry. The δ15N values of muscles, gills, scales and livers of the tilapias were also measured by isotope ratio mass spectrometry.ResultsThe peroxodisulfate oxidation‐bacterial conversion method reduced the minimum mass of the otoliths required for analysis to as low as 2 mg, unlike past methods, which have required masses of 8–155 mg. The δ15Noto values were not significantly different from the δ15Ndiet values of the five diets. Furthermore, the somatic growth rate had no effect on the δ15Noto values. Nevertheless, the δ15N values of metabolically active tissues were significantly different from each other and higher than the δ15Ndiet values, due to the deamination of these tissues.ConclusionsThese results suggest that diet was the main source of amino acids for the otolith organic matrix and there was no biochemical transamination during the assimilation of dietary amino acids to otoliths. The δ15Noto value can be used as a proxy of nitrogen sources of fishes and may have potential application in ecological studies such as the detection of diet shift, migration, trophic levels and environmental changes experienced by the fish population.
The funnel pre‐compensator
Authors: Berger Thomas , Reis Timo 
Published: August 2018

SummaryWe introduce the funnel pre‐compensator as a novel and simple adaptive pre‐compensator of “high‐gain type”. We show that this pre‐compensator is feasible for a large class of signal pairs, which satisfy a certain relationship. We show that the funnel pre‐compensator guarantees prescribed transient behavior of the compensator error, it is of low complexity and inherently robust since its design is model‐free. As an application in adaptive control of nonlinear systems, a cascade of funnel pre‐compensators is exploited to obtain an artificial output with explicitly known derivatives, which tracks the system output with prescribed transient behavior. In some important cases the interconnection of the system with the pre‐compensator cascade is shown to have input‐to‐state stable internal dynamics. This guarantees feasibility of a novel funnel controller that consists of a funnel pre‐compensator cascade in conjunction with a recently developed funnel controller for systems with arbitrary relative degree. We illustrate the application of this interconnection for some mechanical systems.
Quantization effects and convergence properties of rigid formation control systems with quantized distance measurements
Authors: Sun Zhiyong , Garcia de Marina Hector , Anderson Brian D. O. , Cao Ming 
Published: August 2018

SummaryIn this paper, we discuss quantization effects in rigid formation control systems when target formations are described by interagent distances. Because of practical sensing and measurement constraints, we consider in this paper distance measurements in their quantized forms. We show that under gradient‐based formation control, in the case of uniform quantization, the distance errors converge locally to a bounded set whose size depends on the quantization error, while in the case of logarithmic quantization, all distance errors converge locally to zero. A special quantizer involving the signum function is then considered with which all agents can only measure coarse distances in terms of binary information. In this case, the formation converges locally to a target formation within a finite time. Lastly, we discuss the effect of asymmetric uniform quantization on rigid formation control.
Fish assemblage change following the structural restoration of a degraded stream
Authors: Favata Carl A. , Maia Anabela , Pant Manisha , Nepal Vaskar , Colombo Robert E. 
Published: August 2018

AbstractDecades of anthropogenic pressure have harmed riverscapes throughout North America by degrading habitats and water quality and can result in the extirpation of sensitive aquatic taxa. Local stream restoration projects have increased in frequency, but monitoring is still infrequent. In 2010, Kickapoo Creek in East Central Illinois was subjected to a stream restoration project that included implementation of artificial riffles, riprap, scouring keys, and riparian vegetation. We monitored the restoration efforts for 6 years after the restoration through annual sampling efforts at restored and reference sites to determine changes in habitat and fish assemblage using standard habitat sampling and electrofishing techniques. We observed distinct temporal and spatial shifts in physico‐chemical parameters along with changes in fish community structure. Although biotic integrity remained moderately low in reference assemblages, restored reaches showed 3‐year delay in response to restoration, with biotic integrity positively linked to additional instream habitat and altered channel morphology. Larger substrate sizes, submerged terrestrial vegetation, and newly formed scour pools along with reduced siltation were found in the restored sites, in contrast to the reference sites. These changes resulted in increased species diversity, reduced number of opportunistic species and consequently an overall increase in health of fish communities. We also observed recruitment of habitat specialists and increase in species with reproductive strategies that rely on complex substrates. The results of this study highlight some of the complex dynamics driving reach‐scale restoration projects. We demonstrate the usefulness of structural restoration as a management tool to increase biotic integrity through long‐term alteration of critical habitat. The delay in the response of species to the restoration efforts emphasizes the need for long‐term continuous temporal and spatial monitoring.